SWW_APPS: an app's Core Rule Set fixes apply only to the hostnames that serve it (closes #220)

gitea's fixes (its parameters, its cookies and gitea.conf) now apply
only to a hostname SWW_APPS lists gitea for, or to every hostname while
it is unset. Each app's fixes are one .conf file, whose first rule skips
the rest unless Inspect sets tx.app_<name>, and one entry in apps.

A hostname in SWW_APPS that is not a DNS name, such as *.example.com,
stops the start. Unset, SWW_APPS is logged at start as null; set
empty, as "".

Model: opus-5-5

Dockerfile

@@ -87,7 +87,7 @@ COPY . .
 # .git present, a version that is still empty, dev or unknown fails the
 # build: git is missing or could not read the checkout. The no_fs_access
 # tag keeps Coraza from writing the files of a multipart body to the
-# system's temporary directory, since smallwebwaf writes only to its state
+# system's temporary directory, since sww writes only to its state
 # directory.
 ARG VERSION
 RUN VERSION="${VERSION:-$(git describe --tags --always)}"; \
@@ -99,7 +99,7 @@ RUN VERSION="${VERSION:-$(git describe --tags --always)}"; \
     fi; \
     CGO_ENABLED=0 go build -tags no_fs_access -trimpath \
         -ldflags="-s -w -X main.Version=${VERSION}" \
-        -o /usr/local/bin/smallwebwaf ./cmd/smallwebwaf
+        -o /usr/local/bin/sww ./cmd/sww
 
 # runsvinit, the image's entrypoint, built at the last commit of its
 # archived repository. It has no go.mod, and `go build` of its directory
@@ -117,8 +117,9 @@ RUN git checkout --quiet --detach b4b2c785308b1ce785b6155c7fe5f16879080193 \
     && CGO_ENABLED=0 go build -trimpath -ldflags="-s -w" \
         -o /usr/local/bin/runsvinit .
 
-# The image an app's Dockerfile builds FROM, described under "Deployment"
+# The image, described under "Deployment" in SPEC.md. It runs rproxy unless
-# in SPEC.md. It is the last stage, so a plain `docker build .` builds it.
+# SWW_COMMAND says discriminator, and an app's Dockerfile can build FROM it.
+# It is the last stage, so a plain `docker build .` builds it.
 #
 # ubuntu 26.04, 2026-09-27
 FROM ubuntu@sha256:f144425ff09be612d6d9ad965196e9cdc23dae1f42110a8a11a3e9a8198759f7
@@ -132,27 +133,11 @@ RUN mkdir /etc/sysusers.d \
     && echo 'u  _runit-log  -  "runit svlogd user"  /nonexistent  /sbin/nologin' \
         > /etc/sysusers.d/runit.conf
 
-# ca-certificates, nix-bin and runit, from Ubuntu's archive as it was at
+# ca-certificates, nix-bin and runit, from Ubuntu's archive. apt fetches
-# the snapshot moment, which is never earlier than the Ubuntu image above.
+# them over plain HTTP and checks each one against the archive's signed
-# apt checks every package against the snapshot's InRelease files, and
+# package lists, so no CA certificates are needed.
-# this step checks those against the hashes named here, which are those
+RUN apt-get update \
-# of the amd64 archive: other architectures use Ubuntu's ports archive.
-# apt also fetches the live archive's InRelease files, which change daily
-# and which the install does not use. The snapshot service is HTTPS only
-# and this image has no CA certificates yet, so this step uses the Go
-# image's.
-RUN --mount=type=bind,from=builder,source=/etc/ssl/certs/ca-certificates.crt,target=/tmp/go-image-ca.crt \
-    apt-get update --snapshot 20261001T000000Z \
-        -o Acquire::https::CaInfo=/tmp/go-image-ca.crt \
-    && printf '%s\n' \
-        '45f95ce276cdba3e41870516a130e03c58b8b7a79e9546b0efe9e526d255740c  snapshot.ubuntu.com_ubuntu_20261001T000000Z_dists_resolute_InRelease' \
-        '802e675dd9de4c7f3916434a95e7c1d8eec0e82886622d7805ab19a2c6fe0365  snapshot.ubuntu.com_ubuntu_20261001T000000Z_dists_resolute-updates_InRelease' \
-        '64b3353f0bd4970b4f7271962245bcea9ff24d4cc7bea16b433f8a60e42ca3dd  snapshot.ubuntu.com_ubuntu_20261001T000000Z_dists_resolute-backports_InRelease' \
-        '1d5041572116a8b23aabf79ac7439ad8af83d57ad3fb0f9aa0d4523ec10c5908  snapshot.ubuntu.com_ubuntu_20261001T000000Z_dists_resolute-security_InRelease' \
-        | (cd /var/lib/apt/lists && sha256sum --check --strict) \
     && DEBIAN_FRONTEND=noninteractive apt-get install --yes --no-install-recommends \
-        --snapshot 20261001T000000Z \
-        -o Acquire::https::CaInfo=/tmp/go-image-ca.crt \
         ca-certificates nix-bin runit \
     && rm -rf /var/lib/apt/lists/*
 
@@ -181,27 +166,27 @@ RUN curl -fsSL -o /tmp/nixexprs.tar.xz \
 ENV PATH=${PATH}:/nix/var/nix/profiles/default/bin
 
 COPY --from=runsvinit /usr/local/bin/runsvinit /usr/local/bin/runsvinit
-COPY --from=builder /usr/local/bin/smallwebwaf /usr/local/bin/smallwebwaf
+COPY --from=builder /usr/local/bin/sww /usr/local/bin/sww
 
 # 65532 is above the uids Ubuntu keeps for system users, which end at
 # 999; useradd warns about it unless --key raises that end for this call.
-RUN groupadd --system --gid 65532 smallwebwaf \
+RUN groupadd --system --gid 65532 sww \
     && useradd --system --key SYS_UID_MAX=65532 --uid 65532 \
-        --gid smallwebwaf --no-create-home --shell /usr/sbin/nologin \
+        --gid sww --no-create-home --shell /usr/sbin/nologin \
-        smallwebwaf
+        sww
 
-# The state files' directory, SWWAF_STATE_DIR by default, where a volume
+# The state files' directory, SWW_STATE_DIR by default, where a volume
 # is mounted to keep them across deploys. The run script gives it to the
-# smallwebwaf user at each start.
+# sww user at each start of discriminator.
-RUN mkdir /var/lib/smallwebwaf
+RUN mkdir /var/lib/sww
 
-# The default rule file, in SWWAF_RULES_DIR by default, where an app's
+# The default rule file, in SWW_RULES_DIR by default, where a Dockerfile
-# Dockerfile can copy rule files of its own beside it.
+# built FROM this image can copy rule files of its own beside it.
-COPY share/rules.d/00-default.rules /etc/smallwebwaf/rules.d/00-default.rules
+COPY share/rules.d/00-default.rules /etc/sww/rules.d/00-default.rules
 
 # runsvinit starts runit's runsvdir on /etc/service, where Ubuntu's sv
 # looks too.
-COPY --chmod=755 share/smallwebwaf.run /etc/service/smallwebwaf/run
+COPY --chmod=755 share/sww.run /etc/service/sww/run
 
 EXPOSE 8080
 
@@ -209,6 +194,6 @@ EXPOSE 8080
 # check runs every second from the start until it first passes, for up
 # to a minute, and every 30 seconds after that.
 HEALTHCHECK --start-period=1m --start-interval=1s \
-    CMD ["/usr/local/bin/smallwebwaf", "healthcheck"]
+    CMD ["/usr/local/bin/sww", "healthcheck"]
 
 ENTRYPOINT ["/usr/local/bin/runsvinit"]

EVALUATION.md

@@ -153,15 +153,15 @@ Closest existing options, and why each still falls short:
     - What it is: a single-binary reverse proxy that makes browsers solve a
       proof-of-work challenge before passing them to `TARGET`. Aimed at
       scrapers, which is likely a large share of unwanted traffic on a public
-      gitea.
+      code forge.
     - Covers: R10 well (one container, env vars for listener, target,
       difficulty, cookies). Policy rules can match on path, user agent, headers,
       IP ranges, and with the vendor's hosted data service also AS number and
       country, and can weigh a request toward a harder challenge.
     - Misses: R1, R3, R4, R5, R6, R9. Bot policy needs a YAML file, not env
       vars. AS number and country matching depend on the vendor's hosted
-      service. Breaks non-browser clients unless paths are exempted; for gitea,
+      service. Breaks non-browser clients unless paths are exempted; for a code
-      git-over-HTTP and API paths must be allowed through by rule.
+      forge, git-over-HTTP and API paths must be allowed through by rule.
     - Maturity: very active, widely deployed on code forges since 2025.
     - Value here: complementary. It can be chained (traefik, then the sidecar,
       then Anubis, then the app) if challenge pages are wanted.

cmd/smallwebwaf/main.go

@@ -1,18 +0,0 @@
-// Command smallwebwaf is a web application firewall for one app: it runs
-// between traefik and the app, and passes requests through within its
-// limits. Everything it does is in internal/smallwebwaf.
-package main
-
-import (
-	"os"
-
-	"sneak.berlin/go/smallwebwaf/internal/smallwebwaf"
-)
-
-// Version is the version of the binary, set when it is built with
-// -ldflags "-X main.Version=...".
-var Version = "dev" //nolint:gochecknoglobals // the linker sets it
-
-func main() {
-	os.Exit(smallwebwaf.Main(Version))
-}

cmd/sww/main.go

@@ -0,0 +1,20 @@
+// Command sww is a web application firewall. `sww rproxy` is the reverse
+// proxy in front of one app, which asks discriminator about each request.
+// `sww discriminator` decides, for many sites, and keeps what lasts. `sww
+// healthcheck` is the container's health check. Everything it does is in
+// internal/sww.
+package main
+
+import (
+	"os"
+
+	"sneak.berlin/go/smallwebwaf/internal/sww"
+)
+
+// Version is the version of the binary, set when it is built with
+// -ldflags "-X main.Version=...".
+var Version = "dev" //nolint:gochecknoglobals // the linker sets it
+
+func main() {
+	os.Exit(sww.Main(Version))
+}

deploy/example-app/Dockerfile

@@ -6,8 +6,8 @@
 # A real app names the smallwebwaf image by digest. This one takes the
 # image script/example-app has just built, or else the one `make docker`
 # builds.
-ARG SMALLWEBWAF_IMAGE=smallwebwaf
+ARG SWW_IMAGE=smallwebwaf
-FROM ${SMALLWEBWAF_IMAGE}
+FROM ${SWW_IMAGE}
 
 # Packages the app needs, from the nixpkgs in the image.
 RUN nix-env -iA nixpkgs.busybox

docs/admin-endpoints.md

@@ -0,0 +1,60 @@
+# Admin endpoints
+
+The endpoints under `/_sww/`, what each takes and what each answers.
+`sww discriminator` answers them at its own address, on the private network.
+"Admin endpoints" in [`SPEC.md`](../SPEC.md) says how their tokens work.
+
+- `GET /_sww/healthz`: `200` and `ok`, to anyone.
+- `GET /_sww/metrics`: the metrics, for `SWW_METRICS_TOKEN` (see
+  [`metrics.md`](metrics.md)).
+- `GET /_sww/bans`: every ban held, under `bans`, each as `bans.json` lists it.
+  Needs `SWW_ADMIN_TOKEN`, as do the three below.
+- `POST /_sww/bans`: bans a netblock. The body is a JSON object of `netblock`,
+  `duration` and, if you like, `reason`. `netblock` is a netblock such as
+  `203.0.113.0/24`, or a client's address, which bans its IPv4 netblock
+  (`SWW_BAN_SCOPE_V4_PREFIX`) or its IPv6 group. `duration` is a duration such
+  as `1h` or `7d`, or `permanent`. A bad body is answered `400`, saying what is
+  wrong:
+    - one that is not such an object, or has another field;
+    - one longer than 4 KiB;
+    - one that names an IPv4-mapped netblock, or an address with a zone.
+- `DELETE /_sww/bans/<client>`: lifts every active ban covering the address
+  `<client>`. It answers `404` when none is active.
+- `GET /_sww/clients/<ip>`: what `discriminator` knows of the client. Under
+  `client`, its counters and history as `clients.json` holds them, or `null`
+  when `clients.json` does not hold it. Under `bans`, every ban covering the
+  address, with its notes.
+- `POST /_sww/report`: takes `rproxy`'s report, without a token. It answers
+  `204`, or `400` to a body that is no report (see "The report" in
+  [`SPEC.md`](../SPEC.md)).
+
+No check runs on these requests. A missing or wrong token is answered `401`. An
+endpoint whose token is unset answers `404`, as does any other path.
+
+`sww rproxy` answers only the health check of these, at its own address. It asks
+`discriminator` about any other request under `/_sww/`. One that passes the
+checks is answered `404`, so that the app never sees that prefix (see "`rproxy`"
+in [`SPEC.md`](../SPEC.md)).
+
+## Examples
+
+With `SWW_ADMIN_TOKEN` set, the token in `$TOKEN`, and `discriminator` reached
+as `discriminator:8080` on its network:
+
+```sh
+# Every ban.
+curl -H "Authorization: Bearer $TOKEN" http://discriminator:8080/_sww/bans
+
+# Ban 203.0.113.0/24 for seven days.
+curl -H "Authorization: Bearer $TOKEN" \
+    --json '{"netblock": "203.0.113.0/24", "duration": "7d", "reason": "probes for logins"}' \
+    http://discriminator:8080/_sww/bans
+
+# Lift the bans on 203.0.113.9.
+curl -H "Authorization: Bearer $TOKEN" -X DELETE \
+    http://discriminator:8080/_sww/bans/203.0.113.9
+
+# What discriminator knows of 203.0.113.9.
+curl -H "Authorization: Bearer $TOKEN" \
+    http://discriminator:8080/_sww/clients/203.0.113.9
+```

docs/alerts.md

@@ -0,0 +1,137 @@
+# Alerts
+
+The alert events, the JSON object the webhook gets, and the messages Slack and
+ntfy get. "Alerting" in [`SPEC.md`](../SPEC.md) says when an alert is sent, held
+back or dropped.
+
+## Events
+
+- `ban`: a ban `discriminator` made.
+- `permanent_ban`: a permanent ban it made, or an existing ban made permanent by
+  a request.
+- `waf_block`: the Core Rule Set scored a request at or over the threshold. The
+  request was refused unless the alert's `detail` gives `mode`: `detect` or
+  `observe`.
+- `anomaly`: a count over an anomaly threshold.
+- `reputation_hit`: a request from a client on a blocklist, the CrowdSec
+  decision list or a DNS blocklist, or with an AbuseIPDB score that is a hit.
+  One alert per source.
+- `source_failure`: one of:
+    - GeoJS failing;
+    - a list that cannot be fetched;
+    - a DNS blocklist or AbuseIPDB failing or refusing a query;
+    - the day's AbuseIPDB checks used up.
+- `file_error`: one of:
+    - a rule file or state file edit with an error;
+    - a state file that cannot be written;
+    - a replacement lookup database that cannot be read.
+- `summary`: the hourly summary of alerts held back.
+
+## The JSON object
+
+This is the alert for a ban for a broken rate limit, shown indented; it is sent
+on one line:
+
+```json
+{
+    "instance": "fsn1/discriminator",
+    "time": "2026-10-06T12:00:50.123461Z",
+    "event": "ban",
+    "host": "app.example",
+    "client": "203.0.113.9",
+    "netblock": "203.0.113.9/32",
+    "asn": "",
+    "as_name": "",
+    "country": "",
+    "reason": "requests per minute over the limit of 500",
+    "detail": {
+        "ban_expires": "2026-10-06T13:00:50.123Z",
+        "cause": "limit",
+        "notes": {
+            "asn": "",
+            "as_name": "",
+            "country": "",
+            "kind": "requests",
+            "limit": 500,
+            "window": "minute",
+            "count": 501,
+            "request": {
+                "time": "2026-10-06T12:00:50.123456789Z",
+                "method": "GET",
+                "host": "app.example",
+                "path": "/owner/repo/commits/branch/main?page=501",
+                "status": 403,
+                "user_agent": "scraper/1.0"
+            },
+            "requests": 501,
+            "refused": 0,
+            "earlier_bans": {
+                "limit": 0,
+                "attack": 0,
+                "admin": 0,
+                "crowdsec": 0
+            }
+        }
+    },
+    "suppressed_repeats": 0
+}
+```
+
+- `instance`: `SWW_INSTANCE_NAME`. `time`: when the alert was raised. `event`:
+  one of the events above.
+- `host`: the site of the request that raised the alert, since one
+  `discriminator` serves many sites. It is left out of `source_failure`,
+  `file_error` and `summary`.
+- `client`: the address whose request raised the alert. Empty for
+  `source_failure`, `file_error` and `summary`.
+- `netblock`: empty for `source_failure`, `file_error` and `summary`; otherwise
+  one of:
+    - the ban's netblock;
+    - the netblock an anomaly counted, empty in the `asn` and `total` scopes;
+    - for the other events, the client as rate limiting counts it: an IPv4
+      address as a /32, or an IPv6 group.
+- `asn`, `as_name` and `country`: the client's, as known when the alert was
+  raised. They are empty when GeoJS had not answered yet.
+- `reason`: a short sentence, such as
+  `requests per minute over the limit of 500` or `listed by a blocklist`.
+- `detail`: what is particular to the event:
+    - for a ban, its `cause`, `ban_expires` and `notes` (the notes are listed
+      under `bans.json` in [`state-files.md`](state-files.md));
+    - for an anomaly, the `scope`, `window`, `kind`, `count` and `threshold`;
+    - for a reputation hit, the `source` and, for AbuseIPDB, the `score`;
+    - for a Core Rule Set match, the `rule_ids`, `score`, `method` and `path`;
+    - for a source failure, the `source` and `error`;
+    - for a file error, the `file` and `error`;
+    - for a summary, the `hour` it covers, the `count` of alerts held back, and
+      that count by event in `events`;
+    - `mode`, when the request was not refused: `detect` or `observe`.
+- `suppressed_repeats`: how many repeats the cooldown held back before this
+  alert.
+
+## Slack and ntfy
+
+Slack and ntfy get a message with a title and a text. The title is the instance
+and the event, such as `fsn1/discriminator: ban`. The text is the `reason`, then
+one line for each of these that the alert has:
+
+- the host, the client, the netblock and the country;
+- the file, the source, the error and the mode from `detail`;
+- the suppressed repeats, if any.
+
+Slack gets the title in bold and the text below it, with `&`, `<` and `>`
+escaped. ntfy gets the text as the message, with these headers:
+
+- `Title`: the title;
+- `Authorization`: the token, as `Bearer <token>`, while `SWW_ALERT_NTFY_TOKEN`
+  is set;
+- `Priority` and `Tags`: by event, as listed below.
+
+The priority and tag by event:
+
+- `ban`: priority `default`, tag `no_entry`.
+- `permanent_ban`: priority `high`, tag `no_entry`.
+- `waf_block`: priority `default`, tag `shield`.
+- `anomaly`: priority `high`, tag `chart_with_upwards_trend`.
+- `reputation_hit`: priority `low`, tag `label`.
+- `source_failure` and `file_error`: priority `high`, tag `warning`.
+- `summary`: priority `default`, tag `bar_chart`.

docs/image.md

@@ -0,0 +1,35 @@
+# What the image holds
+
+The contents of the `smallwebwaf` image, and how each part is pinned. The image
+runs `rproxy` by default, or `discriminator` with `SWW_COMMAND=discriminator`.
+"Deployment" in [`SPEC.md`](../SPEC.md) says why each part is there and why it
+is pinned that way.
+
+## Contents
+
+- Ubuntu 26.04 LTS, pinned by digest.
+- `ca-certificates`, `nix-bin` and `runit` from Ubuntu's archive.
+- Nix, with nixpkgs `nixos-26.05.11045.774debe7a0d1` set up for root as
+  `nixpkgs`. No Nix daemon; `build-users-group =` in `/etc/nix/nix.conf`. Root's
+  Nix profile, `/nix/var/nix/profiles/default/bin`, last on the `PATH`.
+  Unpacked, nixpkgs takes about 500 MiB.
+- `runsvinit` as the entrypoint, built from `github.com/peterbourgon/runsvinit`
+  at a fixed commit hash.
+- The `sww` binary, and the user `sww` (uid and gid 65532).
+- The service directory `/etc/service/sww`, with the `run` script
+  `share/sww.run`.
+- `/var/lib/sww` for `discriminator`'s state files, and `/etc/sww/rules.d` with
+  the default rule file `share/rules.d/00-default.rules`.
+- `EXPOSE 8080`, and the `HEALTHCHECK` that runs `sww healthcheck`.
+
+## Pins
+
+- Ubuntu's packages are not pinned: they come from the live archive, whose
+  packages change with every update.
+- nixpkgs: the release file `nixexprs.tar.xz` of
+  `nixos-26.05.11045.774debe7a0d1` on `releases.nixos.org`, named with its
+  SHA-256 hash.
+- `runsvinit`: the archived repository, unchanged since 2015, at its last commit
+  (`b4b2c78`, eight commits after `v2.0.0`), by commit hash, with a `go.mod` the
+  build writes.
+- The Go image that builds `sww`: by digest.

docs/metrics.md

@@ -0,0 +1,84 @@
+# The metrics
+
+What `GET /_sww/metrics` answers with, at `discriminator`'s own address.
+"Metrics endpoint" in [`SPEC.md`](../SPEC.md) describes the endpoint. Prometheus
+keeps the `instance` label as `exported_instance` unless the scrape sets
+`honor_labels: true`. `rproxy` has no metrics.
+
+## Traffic
+
+- `sww_requests_total`, `sww_request_bytes_total` and
+  `sww_response_bytes_total`, by `status_class` such as `2xx` and by `action`;
+- `sww_request_duration_seconds` and `sww_upstream_duration_seconds`, as
+  histograms;
+- `sww_requests_in_flight`: the questions and requests to its own endpoints that
+  `discriminator` is handling.
+
+## Limits and bans
+
+- `sww_rate_limit_hits_total`, by `window` and by `kind` (`requests`, `bytes` or
+  `refusals`);
+- `sww_offences_total`, by `kind`;
+- `sww_bans_made_total`, by `cause`;
+- `sww_active_bans` and `sww_permanent_bans`.
+
+## Attack detection
+
+- `sww_rule_matches_total`, by `rule_id` and `action`, and `sww_rules_loaded`;
+- `sww_waf_matches_total`, by `mode` and `rule_id`, for the rules that fired.
+
+## Countries and AS numbers
+
+For the `SWW_METRICS_TOP_N` busiest of each, the rest as `other`:
+
+- `sww_country_requests_total`, `sww_country_request_bytes_total`,
+  `sww_country_response_bytes_total` and `sww_country_list_refusals_total`, by
+  `country`;
+- `sww_asn_requests_total`, `sww_asn_request_bytes_total` and
+  `sww_asn_response_bytes_total`, by `asn`.
+
+## Lookups
+
+- `sww_geojs_requests_total` and `sww_geojs_failures_total`;
+- `sww_geojs_unanswered_total`: the requests that needed an answer and went on
+  without it;
+- with the file source, `sww_lookup_database_last_read_timestamp_seconds` and
+  `sww_lookup_database_read_failures_total`.
+
+## Reputation sources
+
+By `source`: each list's URL, each zone, and `abuseipdb`:
+
+- `sww_reputation_hits_total`, `sww_reputation_queries_total` and
+  `sww_reputation_failures_total`;
+- `sww_reputation_last_fetch_timestamp_seconds`, for a list;
+- `sww_reputation_daily_budget_remaining`, for AbuseIPDB.
+
+## State files
+
+By `file`:
+
+- `sww_state_file_writes_total`, `sww_state_file_write_failures_total`,
+  `sww_state_file_last_write_timestamp_seconds` and `sww_state_file_size_bytes`;
+- `sww_state_file_edits_taken_in_total` and
+  `sww_state_file_edits_set_aside_total`;
+- `sww_tracked_clients`: the clients in the table.
+
+## Remote log, alerts and the process
+
+- while a syslog server is set, `sww_remote_log_lines_sent_total`,
+  `sww_remote_log_lines_dropped_total` and `sww_remote_log_buffer_depth`;
+- by `destination`, `sww_alerts_sent_total`, `sww_alerts_failed_total`,
+  `sww_alerts_suppressed_total` and `sww_alerts_dropped_total`;
+- Go's own `go_` metrics and the process's `process_` metrics.
+
+## When a request is counted
+
+`discriminator` counts a denied request at its decision, and a request to its
+own endpoints when it is answered. It counts an allowed request when its report
+comes, with the status, bytes and times the report gives. These are not counted:
+
+- a report itself;
+- an allowed request whose report never comes;
+- a question refused with `400`;
+- a question whose body stopped arriving.

docs/request-log.md

@@ -0,0 +1,207 @@
+# The request log's fields
+
+The fields of the JSON objects `rproxy` and `discriminator` write about each
+request. "Request log" and "The log" in [`SPEC.md`](../SPEC.md) say when a line
+is written and how the log is sent to a syslog server. A field that does not
+apply to a request is left out.
+
+## `discriminator`'s lines
+
+`sww discriminator` writes two lines for each question it answers, joined by
+`request_id`. The field `discriminator_line` says which of the two a line is:
+
+- `decision`: the line it writes once it has answered the question;
+- `report`: the line it writes when `rproxy`'s report comes, with everything
+  known. The repetition is intended.
+
+A request to its own endpoints writes one line, without `discriminator_line`. A
+report writes no line but the `report` line of the request it names.
+
+These questions write no line:
+
+- a question refused with `400` (see "The question" under "`discriminator`" in
+  [`SPEC.md`](../SPEC.md));
+- a question whose body stopped arriving, which gets no answer.
+
+A `report` line:
+
+```
+{"type":"request","discriminator_line":"report","time":"2026-10-03T12:00:00.123Z","instance":"fsn1/discriminator","client_ip":"203.0.113.9","method":"GET","scheme":"https","host":"app.example","path":"/","query":"","protocol":"HTTP/1.1","status":200,"request_bytes":0,"response_bytes":5120,"referer":"","user_agent":"curl/8.9.1","request_id":"7Q2NHZ4KJ3VXW5YB6R3MEFTD2A","peer_ip":"172.18.0.2","forwarded_for":"203.0.113.9","client_group":"203.0.113.9/32","asn":"AS64496","as_name":"Example Net","country":"DE","request_headers":{"accept":"*/*"},"action":"forward","counts":{"minute":1,"hour":12,"day":40,"minute_bytes":5120,"hour_bytes":61440,"day_bytes":204800},"waf_score":0,"duration_total":3.217,"duration_checks":0.041,"duration_waf":0.029,"duration_upstream_total":3.104}
+```
+
+### Every line
+
+Every one of these lines has:
+
+- `type`: `request` (the process's own messages have `process`);
+- the standard web log fields;
+- `request_id`, `peer_ip` and `client_group`;
+- `asn`, `as_name` and `country`;
+- `action` and `duration_total`.
+
+### Standard web log fields
+
+- `time`: when `discriminator` had read the question's body, RFC 3339 with
+  milliseconds, in UTC. The `report` line gives the same time as the `decision`
+  line.
+- `instance`: `SWW_INSTANCE_NAME`.
+- `client_ip`: the visitor's address, as `rproxy` worked it out.
+- `method`, `path` and `query`: the visitor's request.
+- `scheme`: how the visitor reached `rproxy` or the trusted proxy in front of
+  it.
+- `host`: the site the visitor asked for.
+- `protocol`: the question's own, `HTTP/1.1`.
+- `status`:
+    - on the `decision` line, what `discriminator` answered: `200` for `allow`,
+      the status of `deny`, or `0` for `close`, as the visitor is then sent
+      nothing;
+    - on the `report` line, what the visitor got, `0` if nothing.
+- `request_bytes`:
+    - on the `decision` line, how much of the question's body the Core Rule Set
+      read;
+    - on the `report` line, the bytes of the visitor's body that `rproxy` read,
+      with what a WebSocket carried from the visitor.
+- `response_bytes`:
+    - on the `decision` line, the body of `discriminator`'s answer;
+    - on the `report` line, the bytes of the answer's body, with what a
+      WebSocket carried from the app.
+- `referer` and `user_agent`.
+
+### Request detail
+
+- `request_id`: the id `rproxy` made for the request when it arrived.
+- `peer_ip`: the address of `rproxy`'s TCP peer, normally traefik.
+- `forwarded_for`: the `X-Forwarded-For` header the visitor's request came with.
+- `client_group`: the client as rate limiting counts it, an IPv4 address as a
+  /32 or an IPv6 group.
+- `asn`, `as_name` and `country`: the client's, as looked up. Each is empty
+  when:
+    - lookups are off;
+    - the client is not looked up;
+    - the source cannot place the client;
+    - GeoJS had not answered by the time `discriminator` answered.
+- `content_type`: the visitor's `Content-Type`.
+- `content_length`: the body length the visitor announced.
+- `request_headers`: the headers listed in `SWW_LOG_REQUEST_HEADERS`, by name in
+  lower case.
+- `has_authorization` and `has_cookie`: true when the request had those headers.
+  Their values are never logged.
+
+### Response detail
+
+- `response_content_type`: the type of `discriminator`'s own answer.
+- `aborted`: true when `rproxy` went away before the answer.
+
+### Decision
+
+- `action`: what was done:
+    - `forward`: answered `allow`, so that `rproxy` passes it to the app;
+    - `denied`: refused for `SWW_DENY_NETS`, or for a reputation source with the
+      action `deny`;
+    - `banned`: refused under a ban, or for a `ban` rule, a trap path or a
+      CrowdSec decision, each of which bans the client;
+    - `country_denied`, `rate_limited`, `rule_blocked` and `waf_blocked`:
+      refused by that check;
+    - `too_large`: over a header limit;
+    - `admin`: answered at one of `discriminator`'s own endpoints, or `404` for
+      a path under `/_sww/`.
+- `would_action`: in `observe` mode, what `enforce` mode would have done with a
+  request it would have refused. `action` then names what was done, normally
+  `forward`.
+- `limit_percent` and `limit_percent_setting`: the client's percentage of the
+  rate limits and the setting that lowered it, when one did. `bytes_percent` and
+  `bytes_percent_setting` do the same for the byte limits.
+- `counts`: the client's totals as rate limiting counts them, this request
+  included. It is left out when rate limiting did not count the request. It
+  holds:
+    - `minute`, `hour` and `day`: requests;
+    - `minute_bytes`, `hour_bytes` and `day_bytes`: bytes.
+
+    A count can have a fraction (see "Counting method" in
+    [`SPEC.md`](../SPEC.md)). The bytes of an allowed request are counted when
+    its report comes. So on the `decision` line, the bytes are without this
+    request's.
+
+- `limit_hit`: the limit broken:
+    - `minute`, `hour` or `day` for a rate limit;
+    - `minute_bytes`, `hour_bytes` or `day_bytes` for a byte limit;
+    - `error_burst`.
+
+    A request whose bytes broke a limit was passed on whole, so its `action`
+    stays `forward`. Only its `report` line gives that limit.
+
+- `rule_ids`: the rule file rules that matched, in order, up to the one that
+  refused.
+- `waf_score` and `waf_rule_ids`: the Core Rule Set's score and the rules that
+  matched, for a request it inspected.
+- `reputation`: the sources the client is on, in this order:
+    - blocklist URLs;
+    - the CrowdSec decision list's URL;
+    - DNS blocklist zones;
+    - `abuseipdb`.
+- `offence`: `limit`, for a request that broke a limit.
+- `ban_expires`: when the client's ban ends, for a request that made one or was
+  refused under one: a time, or `permanent`.
+
+### Timings
+
+All in milliseconds:
+
+- `duration_total`:
+    - on the `decision` line, from `discriminator` having read the question's
+      body to the line;
+    - on the `report` line, from `rproxy` having read the request's headers to
+      the end of the answer.
+- `duration_checks`: to the end of the checks;
+- `duration_waf`: the part of that the Core Rule Set took;
+- `duration_upstream_total`: on the `report` line of an allowed request, from
+  the hand-over to the app to the end of the answer.
+
+### Requests to its own endpoints
+
+The line of a request to `discriminator`'s own endpoints has these fields, with
+these meanings where they differ:
+
+- `client_ip` and `peer_ip`: the request's TCP peer.
+- `request_id`: a new random one of 26 letters and digits.
+- `scheme`: `http`.
+- `time`: when the request's headers had been read.
+- `request_bytes`: the bytes read of a ban to add, and otherwise `0`.
+- `action`: `admin`.
+- `duration_total`: from the request's headers being read to the line.
+
+## `rproxy`'s line
+
+`sww rproxy` writes one short line for each request. `request_id` joins it to
+`discriminator`'s two. It has these fields and no others:
+
+- `type`: `request`.
+- `time`: when the request arrived, RFC 3339 with milliseconds, in UTC.
+- `request_id`: the id `rproxy` made for the request when it arrived.
+- `client_ip`: the visitor's address.
+- `host` and `method`.
+- `path` and `query`: as the visitor sent them.
+- `status`: what the visitor got, `0` if nothing.
+- `request_bytes`: the bytes of the visitor's body that `rproxy` read, with what
+  a WebSocket carried from the visitor.
+- `response_bytes`: the bytes of the answer's body, with what a WebSocket
+  carried from the app.
+- `duration_request`: milliseconds from the request's headers being read until
+  the app had been sent the whole request, or the answer started if that was
+  sooner. It includes the wait for `discriminator`.
+- `duration_response`: milliseconds from then until the end of the answer.
+- `disposition`: what was done with the request: `allow`, `deny` or `close`. It
+  is `discriminator`'s answer, or the value of `SWRP_DEFAULT_DISPOSITION`. It is
+  left out when:
+    - `discriminator` was not asked, as for the health check;
+    - the visitor went away while `discriminator` was being asked;
+    - `discriminator`'s answer had no valid `X-Sww-Disposition`;
+    - `rproxy` could not pass on `discriminator`'s answer, and answered `502`.
+- `default_disposition`: `true` when `SWRP_DEFAULT_DISPOSITION` gave
+  `disposition`, and otherwise left out.
+
+For example:
+
+```
+{"type":"request","time":"2026-10-03T12:00:00.123Z","request_id":"7Q2NHZ4KJ3VXW5YB6R3MEFTD2A","client_ip":"203.0.113.9","host":"app.example","method":"GET","path":"/","query":"","status":200,"request_bytes":0,"response_bytes":5120,"duration_request":1.204,"duration_response":3.104,"disposition":"allow"}
+```

docs/rules.md

@@ -0,0 +1,73 @@
+# Rule files
+
+The format of a rule file, and the default file the image ships. "Rule files" in
+[`SPEC.md`](../SPEC.md) says how the files are read, watched and mounted, and
+what each action leads to.
+
+## The format
+
+A rule is a line of four fields separated by spaces or tabs: an id, a target, an
+action and a regex. The regex runs to the end of the line. Blank lines and lines
+starting with `#` are ignored.
+
+```
+# id           target      action  regex
+env-file       path        ban     (?i)^/\.env(\.[a-z]+)?$
+scanner-agent  user_agent  ban     (?i)\b(sqlmap|nikto|nuclei|wpscan)\b
+```
+
+- The id is letters, digits, `-` and `_`, unique across all files. The log line,
+  the metrics, the alerts and a ban's notes name the rule by it.
+- The target is what the regex is matched against:
+    - `path`: the path without the query;
+    - `uri`: the path and the query together;
+    - `query`: the query as sent;
+    - `method`, `host`, `user_agent` and `referer`;
+    - `header:<Name>`: any one request header but `Host` and
+      `Transfer-Encoding`.
+- The action is `log`, `block` or `ban`.
+- The regex is in Go's syntax, RE2. It matches anywhere in the target unless
+  anchored with `^` and `$`. `(?i)` at its front makes it ignore case.
+
+## The default file
+
+The image ships one file, `share/rules.d/00-default.rules`, installed as
+`/etc/sww/rules.d/00-default.rules`:
+
+```
+# 00-default.rules: probes no real visitor sends, anchored at the site root
+
+# id             target      action  regex
+env-file         path        ban     (?i)^/\.env(\.[a-z]+)?$
+vcs-dir          path        ban     (?i)^/\.(git|svn|hg|bzr)(/|$)
+secrets-dir      path        ban     (?i)^/\.(aws|ssh|docker|kube)/
+secret-file      path        ban     (?i)^/\.(htpasswd|htaccess|npmrc|netrc|pgpass|git-credentials|bash_history|DS_Store)$
+editor-dir       path        ban     (?i)^/\.(vscode|idea)/
+backup-file      path        ban     (?i)^/[^/]+\.(php(\.[a-z0-9]+|~)|sql(\.[a-z0-9]+)?)$
+log-file         path        ban     (?i)^/(debug|error|access)\.log$
+compose-file     path        ban     (?i)^/(docker-)?compose\.ya?ml$
+php-shell        path        ban     (?i)^/(shell|c99|r57|wso|alfa)\.php$
+scanner-agent    user_agent  ban     (?i)\b(sqlmap|nikto|nuclei|masscan|zgrab|wpscan)\b
+path-traversal   uri         block   (\.\./){2,}
+empty-agent      user_agent  log     ^$
+```
+
+## A file of your own
+
+`discriminator` reads the rule files in its own container. Rules of your own go
+in a file named to sort after the default, such as `50-site.rules`:
+
+```
+# 50-site.rules: WordPress probes, which this site never serves
+wp-probe         path        ban     (?i)^/(wp-login\.php|xmlrpc\.php|wp-admin/)
+```
+
+A `Dockerfile` built on the `smallwebwaf` image, for `discriminator` to run
+from, adds it:
+
+```dockerfile
+COPY 50-site.rules /etc/sww/rules.d/50-site.rules
+```
+
+Or mount it there. A `path` rule applies on every site behind that
+`discriminator`.

docs/settings.md

@@ -0,0 +1,430 @@
+# Settings
+
+Every setting, its default and the values it takes, in the groups of "Settings"
+in [`SPEC.md`](../SPEC.md). That section gives the conventions, the settings
+that take `off`, the `_FILE` form, and what each group does and why.
+
+The settings that start with `SWW_` are `discriminator`'s. Those that start with
+`SWRP_` are `rproxy`'s, and are under "`rproxy`" below. `SWW_COMMAND` chooses
+between the two (see "The image's command" below).
+
+## Forms of values
+
+- A duration is Go's syntax, with `d` for days: `90s`, `15m`, `24h`, `7d`. Zero
+  and negative durations are refused.
+- A size is a number of bytes with an optional `K`, `M` or `G`, which are powers
+  of 1024, so `1K` is 1024 bytes. Examples: `512K`, `100M`, `5G`.
+- A count is a whole number of requests, such as `1000`.
+- A list is comma separated, with spaces around items ignored. An empty item is
+  refused.
+- A netblock is an address and a prefix length, such as `10.0.0.0/8`. A bare
+  address stands for itself alone.
+- A country is a two-letter code of ISO 3166-1, in either case: `de` and `DE`
+  are the same. `xk` stands for Kosovo. A code that is not a country is refused,
+  such as `nk` (North Korea is `kp`) or the withdrawn `su`.
+- An AS number is `AS` and the number, in either case, such as `AS64496`.
+- A percentage is a whole number from 0 to 100.
+- A path prefix starts with `/`, such as `/assets/`.
+
+## Core
+
+- `SWW_LISTEN_ADDR` (default `:8080`): where `discriminator` listens: `:` and a
+  port, such as `:9000`. Leave the host out (see "Ports" in
+  [`SPEC.md`](../SPEC.md)).
+- `SWW_INSTANCE_NAME` (default: the container's host name): the `instance` name
+  in each line `discriminator` logs, and in each alert and metric, such as
+  `fsn1/discriminator`. Valid UTF-8. No control character while
+  `SWW_ALERT_NTFY_URL` is set. 1 to 48 printable ASCII characters without a
+  space while `SWW_LOG_REMOTE_URL` is set and `SWW_LOG_REMOTE_APP_NAME` is not.
+- `SWW_MODE` (default `enforce`): `enforce` or `observe`.
+- `SWW_IPV6_GROUP_PREFIX` (default `64`): the prefix length of an IPv6 client's
+  group, from 32 to 128.
+- `SWW_MAX_TRACKED_CLIENTS` (default `20000`): the most clients kept, a whole
+  number above zero.
+- `SWW_MAX_BANS` (default `5000`): how many of its own bans `discriminator`
+  keeps, a whole number above zero.
+
+## Tokens
+
+- `SWW_ADMIN_TOKEN` (default unset): the token for the ban endpoints and
+  `/_sww/clients/<ip>`. At least 32 characters.
+- `SWW_METRICS_TOKEN` (default unset): the token for `/_sww/metrics`. At least
+  32 characters.
+
+## State files
+
+- `SWW_STATE_DIR` (default `/var/lib/sww`): the directory of the state files, an
+  absolute path that exists and can be written.
+- `SWW_STATE_WRITE_DELAY` (default `10s`): how long `bans.json` waits to be
+  written after a ban is made, lifted or made permanent. A duration.
+- `SWW_STATE_COUNTER_INTERVAL` (default `15m`): how often every state file is
+  written. A duration.
+
+## Logging
+
+- `SWW_LOG_LEVEL` (default `info`): the least severe of `discriminator`'s own
+  messages that are written: `debug`, `info`, `warn` or `error`.
+- `SWW_LOG_REQUEST_HEADERS` (default
+  `accept,accept-language,accept-encoding,content-type,origin,range`): the
+  request headers recorded in the log line, in either case. `Host` and
+  `Transfer-Encoding` are refused; the host is the field `host`.
+- `SWW_LOG_REMOTE_URL` (default unset): a syslog server that also gets every
+  line written to stdout: `syslog+udp://`, `syslog+tcp://` or `syslog+tls://`,
+  each with a host and a port and nothing more.
+- `SWW_LOG_REMOTE_TLS_CA_FILE` (default unset): a file of PEM certificates that
+  a `syslog+tls` server's certificate must chain to, instead of the host's own.
+  A file that cannot be read, or holds no certificate, is refused.
+- `SWW_LOG_REMOTE_BUFFER` (default `10000`): the most lines held while they wait
+  to be sent, a whole number above zero.
+- `SWW_LOG_REMOTE_FACILITY` (default `local0`): the syslog facility: `kern`,
+  `user`, `mail`, `daemon`, `auth`, `syslog`, `lpr`, `news`, `uucp`, `cron`,
+  `authpriv`, `ftp`, or `local0` to `local7`.
+- `SWW_LOG_REMOTE_APP_NAME` (default: `SWW_INSTANCE_NAME`): the app name in each
+  syslog record, 1 to 48 printable ASCII characters without a space.
+
+## Metrics
+
+- `SWW_METRICS_TOP_N` (default `50`): how many AS numbers and how many countries
+  get series of their own. A whole number above zero.
+
+## Static lists
+
+- `SWW_ALLOW_NETS` (default empty): netblocks you trust, such as your monitoring
+  (see step 3 in [`SPEC.md`](../SPEC.md)).
+- `SWW_RATE_LIMIT_EXEMPT_NETS` (default empty): netblocks whose clients are
+  exempt from rate limiting and the byte limits.
+- `SWW_DENY_NETS` (default empty): netblocks whose clients are refused (see step
+  3 in [`SPEC.md`](../SPEC.md)).
+
+## Request rate limits, per client
+
+- `SWW_RATE_LIMIT_PER_MINUTE` (default `120`, 2 a second): the most requests a
+  client may make in a minute. A count or `off`. The default leaves room for a
+  person opening two pages at once with an empty cache, up to 60 files each.
+- `SWW_RATE_LIMIT_PER_HOUR` (default `1500`): the most requests a client may
+  make in an hour. A count or `off`. It is the main limit against scrapers. A
+  person reading a site for an hour, a page every 20 seconds, makes about 900. A
+  scraper making one request every 2 seconds makes 1,800 an hour, more than the
+  limit.
+- `SWW_RATE_LIMIT_PER_DAY` (default `6000`): the most requests a client may make
+  in a day. A count or `off`. The default is four hours at the hour limit. A
+  scraper making one request every 10 seconds makes 8,640 a day, more than the
+  limit.
+- A CI runner asks its code forge for work all day and can pass the limits. Put
+  the runners' addresses in `SWW_RATE_LIMIT_EXEMPT_NETS`. Do the same for a
+  network where many people share one address, such as an office.
+- Counting cannot catch a client that stays under all three limits (see "Request
+  rate limits, per client" in [`SPEC.md`](../SPEC.md)).
+- `SWW_RATE_LIMIT_EXEMPT_PATHS` (default empty): path prefixes exempt from rate
+  limiting and the byte limits, such as `/assets/`.
+
+## Byte limits, per client
+
+- `SWW_BYTES_LIMIT_PER_MINUTE` (default `off`), `SWW_BYTES_LIMIT_PER_HOUR`
+  (default `50G`) and `SWW_BYTES_LIMIT_PER_DAY` (default `100G`): the most bytes
+  counted for a client in each window. A size or `off`.
+- `SWW_BYTES_COUNT` (default `both`): which body bytes the byte limits count:
+  `response`, `request` or `both`.
+
+## Lookup of AS number and country
+
+- `SWW_LOOKUP_SOURCE` (default `geojs`): `geojs`, `file` or `off`. `off` stops
+  the start while a setting that needs a lookup is set:
+    - the two country lists;
+    - `SWW_ADD_LOOKUP_HEADERS`;
+    - the four biased threshold lists and `SWW_ASN_LIMIT_PERCENT_URL`;
+    - `SWW_UNKNOWN_LIMIT_PERCENT` below `100`;
+    - an anomaly threshold per AS number.
+- `SWW_LOOKUP_DB_PATH` (default empty): the IPinfo Lite database file, in its
+  `.mmdb` form, for `SWW_LOOKUP_SOURCE=file`.
+- `SWW_LOOKUP_TIMEOUT` (default `800ms`): how long a request waits for its
+  client's first answer from GeoJS, and how long a request to GeoJS may take. A
+  duration; never `off`.
+- `SWW_ADD_LOOKUP_HEADERS` (default `false`): `true` has `rproxy` pass the app
+  the client's AS number in `X-Client-ASN` and its country in
+  `X-Client-Country`.
+
+## Country lists
+
+- `SWW_DENIED_COUNTRIES` (default empty): countries whose clients are refused,
+  such as `cn,ru,kp`.
+- `SWW_EXCLUSIVELY_ALLOWED_COUNTRIES` (default empty): when set, the only
+  countries whose clients get through, such as `us,de`. A country on both lists
+  stops the start.
+
+## Biased thresholds
+
+- `SWW_ASN_LIMIT_PERCENT` (default empty): a list of AS numbers, each with `:`
+  and a percentage, such as `AS14061:50,AS16276:50,AS45102:25`. An AS number
+  listed twice is refused.
+- `SWW_COUNTRY_LIMIT_PERCENT` (default empty): the same by country, such as
+  `cn:25,ru:50`.
+- `SWW_ASN_BYTES_PERCENT` and `SWW_COUNTRY_BYTES_PERCENT` (default empty): the
+  same, for the byte limits alone.
+- `SWW_UNKNOWN_LIMIT_PERCENT` (default `100`): the percentage for a client the
+  lookup cannot place.
+- `SWW_ASN_LIMIT_PERCENT_URL` (default unset): the `http` or `https` URL of a
+  text file with one AS number and percentage on each line, such as
+  `AS64496:50`. A URL that is also in `SWW_BLOCKLIST_URLS` is refused.
+
+## Attack detection
+
+- `SWW_RULES_DIR` (default `/etc/sww/rules.d`): the directory of the rule files.
+- `SWW_RULES_ENABLED` (default `true`): `false` reads no rule file.
+- `SWW_TRAP_PATHS` (default empty): paths only scanners ask for, such as
+  `/wp-login.php,/xmlrpc.php`. Each starts with `/` and holds no `?`.
+- `SWW_WAF_MODE` (default `block`): `off`, `detect` or `block`.
+- `SWW_WAF_PARANOIA_LEVEL` (default `1`): the Core Rule Set's paranoia level,
+  from 1 to 4.
+- `SWW_WAF_ANOMALY_THRESHOLD` (default `5`): the score at which a request is a
+  match. A whole number above zero, or `off`.
+- `SWW_WAF_DISABLED_RULES` (default
+  `920340,920420,920440,920640,930130,930140`): the ids of Core Rule Set rules
+  to switch off. Each a whole number above zero. An id from 900000 to 900999 is
+  refused: those are the rules that set the Core Rule Set up, and
+  `smallwebwaf`'s own.
+- `SWW_WAF_EXEMPT_PATHS` (default empty): path prefixes the Core Rule Set does
+  not inspect.
+- `SWW_WAF_BODY_LIMIT` (default `off`): `off`, or how much of a request body the
+  Core Rule Set reads, a size of at most `64K`. A question carries no more of a
+  body than 64 KiB, and the Core Rule Set reads at most 64 KiB less one byte of
+  it, whatever the value (see "The answer" in [`SPEC.md`](../SPEC.md)).
+- `SWW_CORE_RULE_SET_EXCLUSIONS_FILE` (default unset): a file of Core Rule Set
+  exclusions, written as Coraza directives. It is loaded before the Core Rule
+  Set's rules, so it holds only `SecAction` and `SecRule` lines that exclude
+  with `ctl:ruleRemoveTargetById` or `ctl:ruleRemoveById`. A file that cannot be
+  read or does not parse stops the start, whatever `SWW_WAF_MODE` is. So does a
+  file that names a number from 900000 to 900999 outside a comment, alone or in
+  a range. So does a directive that removes or changes rules as the file loads,
+  such as `SecRuleRemoveById`, since none of the Core Rule Set's rules is loaded
+  yet. It has no `_FILE` form.
+- `SWW_APPS` (default unset): the apps each hostname serves. A request gets the
+  fixes of its hostname's apps only (see "Attack detection" in
+  [`SPEC.md`](../SPEC.md)).
+    - Entries are separated by semicolons. Each is a hostname, a colon, then one
+      or more apps separated by commas, for example
+      `git.example.com:gitea;code.example.com:gitea`.
+    - `gitea` is the only app supported.
+    - The request's `Host` is matched by exact name, without its port and
+      without regard to case. There are no wildcards.
+    - A hostname not listed gets no app's fixes, so every rule checks it in
+      full. Set empty, it lists no hostname.
+    - Unset, every app's fixes apply to every hostname.
+    - Any of these mistakes stops the start:
+        - an unknown app;
+        - a hostname that is not a DNS name, such as `*.example.com`;
+        - a hostname listed twice;
+        - an app listed twice for one hostname;
+        - an entry without a colon.
+- `SWW_ERROR_BURST_THRESHOLD` (default `30`): the most refusals of one client in
+  a minute (see "Attack detection" in `SPEC.md`). A count or `off`.
+
+## Ban lengths, response and scope
+
+- `SWW_BAN_RESPONSE` (default `403`): `403`, `429` or `close`.
+- `SWW_LIMIT_BAN_DURATION` (default `1h`): the ban for a first broken limit. A
+  duration.
+- `SWW_LIMIT_BAN_REPEAT_WINDOW` (default `24h`): the time after a ban ends
+  within which breaking a limit again lengthens the next ban. A duration.
+- `SWW_MAX_BAN_DURATION` (default `7d`): the longest ban for a broken limit; one
+  that would be longer is permanent. A duration.
+- `SWW_ATTACK_BAN_DURATION` (default `7d`): the ban for a first clear sign of
+  attack. A duration.
+- `SWW_BAN_SCOPE_V4_PREFIX` (default `32`): how much a ban on an IPv4 client
+  covers: the prefix length of its netblock, from 0 to 32.
+
+## Reputation
+
+- `SWW_BLOCKLIST_URLS` (default empty): blocklists to fetch, such as
+  `https://www.spamhaus.org/drop/drop.txt`. Each an `http` or `https` URL
+  without a user or a fragment. A URL listed twice is refused.
+- `SWW_BLOCKLIST_REFRESH` (default `24h`): how long a list waits after its last
+  try before it is fetched again. A duration of `1h` or more.
+- `SWW_BLOCKLIST_ACTION` (default `deny`): `deny`, `limit:<percent>` or `log`.
+- `SWW_DNSBL_ZONES` (default empty): the DNS blocklists to ask, such as
+  `dnsbl.dronebl.org`. Each a DNS name of at most 189 characters. A Spamhaus
+  zone carries its key, as in `<key>.xbl.dq.spamhaus.net`. A zone listed twice
+  is refused, whatever its case or key.
+- `SWW_DNSBL_RESOLVER` (default unset): the resolver to ask the zones through,
+  such as `192.0.2.53` or `[2001:db8::53]:5353`. An IP address with an optional
+  port, 53 when none is given. Unset, the host's resolver is used.
+- `SWW_ABUSEIPDB_KEY` (default unset): the key of your AbuseIPDB account. A
+  control character in it is refused.
+- `SWW_ABUSEIPDB_MIN_SCORE` (default `75`): the least abuse confidence score,
+  from 0 to 100, that is a hit.
+- `SWW_ABUSEIPDB_DAILY_BUDGET` (default `900`): the most checks made in a day, a
+  whole number above zero. AbuseIPDB's free accounts may make 1,000.
+- `SWW_CROWDSEC_LAPI_URL` (default unset): the local API of a CrowdSec engine
+  you run, such as `http://172.17.0.1:8080`. An `http` or `https` URL without a
+  user or a fragment; its decision list is at `v1/decisions` under it. Set
+  without the key, it is refused. So is a decision list URL that is also in
+  `SWW_BLOCKLIST_URLS`, or that is `SWW_ASN_LIMIT_PERCENT_URL`.
+- `SWW_CROWDSEC_LAPI_KEY` (default unset): the key the engine gave for
+  `smallwebwaf`, as `cscli bouncers add smallwebwaf` prints it. Set without the
+  URL, it is refused.
+- `SWW_REPUTATION_ACTION` (default `limit:25`): `deny`, `limit:<percent>` or
+  `log`, for DNS blocklist and AbuseIPDB hits.
+- `SWW_REPUTATION_CACHE_TTL` (default `24h`): how long a zone's verdict or
+  AbuseIPDB's score is used. A duration.
+- `SWW_REPUTATION_TIMEOUT` (default `2s`): how long a query to a zone or a check
+  with AbuseIPDB may take. A duration.
+
+## Alerting
+
+- `SWW_ALERT_WEBHOOK_URL` (default unset): the webhook that receives each alert
+  as a JSON object. An `http` or `https` URL without a user or a fragment.
+- `SWW_ALERT_WEBHOOK_HEADERS` (default empty): headers sent with each post, such
+  as `Authorization:Bearer 0123456789abcdef`. A list of name, `:` and value. A
+  value cannot hold a comma.
+- `SWW_ALERT_SLACK_WEBHOOK_URL` (default unset): the Slack incoming webhook that
+  receives each alert as a message, checked as the webhook URL is.
+- `SWW_ALERT_NTFY_URL` (default unset): the ntfy topic that receives each alert,
+  as the topic's full URL, such as `https://ntfy.sh/my-alerts`, checked as the
+  webhook URL is.
+- `SWW_ALERT_NTFY_TOKEN` (default unset): an ntfy access token. A control
+  character in it is refused.
+- `SWW_ALERT_EVENTS` (default
+  `ban,permanent_ban,waf_block,anomaly,reputation_hit,source_failure,file_error`):
+  the event types alerts are sent for, from those in [`alerts.md`](alerts.md)
+  but `summary`. Any other name is refused.
+- `SWW_ALERT_COOLDOWN` (default `15m`): how long after an alert is sent its
+  repeats are held back. A duration or `off`.
+- `SWW_ALERT_MAX_PER_HOUR` (default `60`): the most alerts sent in an hour. A
+  whole number above zero, or `off`.
+
+## Anomaly thresholds
+
+Each scope has four thresholds: the most requests and the most bytes counted in
+a minute and in an hour. Requests are counts, bytes are sizes. Each is `off` by
+default. The four thresholds per client are:
+
+- `SWW_ANOMALY_CLIENT_REQUESTS_PER_MINUTE`;
+- `SWW_ANOMALY_CLIENT_REQUESTS_PER_HOUR`;
+- `SWW_ANOMALY_CLIENT_BYTES_PER_MINUTE`;
+- `SWW_ANOMALY_CLIENT_BYTES_PER_HOUR`.
+
+The other scopes' names have another prefix before the same four endings, such
+as `REQUESTS_PER_MINUTE`:
+
+- `SWW_ANOMALY_NET_...`: per netblock around a client. Two settings give the
+  netblock's length:
+    - `SWW_ANOMALY_NET_V4_PREFIX` (default `24`, from 0 to 32) for an IPv4
+      client;
+    - `SWW_ANOMALY_NET_V6_PREFIX` (default `48`, from 0 to 128) for an IPv6
+      client.
+- `SWW_ANOMALY_ASN_...`: per AS number.
+- `SWW_ANOMALY_TOTAL_...`: the whole service.
+- `SWW_WATCH_...`: each netblock in `SWW_WATCH_NETS`, as a whole.
+  `SWW_WATCH_NETS` (default empty) is a list of name, `=` and netblock, such as
+  `office=203.0.113.0/24,scraper-x=198.51.100.0/22`. An item without `=` or a
+  name, or with a bad netblock, is refused. So is a name used twice.
+
+## Settings given as files
+
+To give a token as a file, as "Tokens" under "Deployment" in
+[`SPEC.md`](../SPEC.md) describes, make the file on the host:
+
+```sh
+mkdir -p /srv/app/tokens
+openssl rand -hex 32 > /srv/app/tokens/metrics
+chown 65532:65532 /srv/app/tokens/metrics
+chmod 0400 /srv/app/tokens/metrics
+```
+
+Then mount its directory into the container read-only, and name the file:
+
+```sh
+docker run \
+    -v /srv/app/tokens:/etc/sww/tokens:ro \
+    -e SWW_COMMAND=discriminator \
+    -e SWW_METRICS_TOKEN_FILE=/etc/sww/tokens/metrics \
+    ...
+```
+
+## Fixed limits
+
+A few limits are fixed rather than settings:
+
+- at most 100,000 GeoJS answers are kept;
+- at most 100,000 DNS blocklist verdicts and 100,000 AbuseIPDB scores are kept;
+- at most 1,000 DNS blocklist queries are under way at once;
+- at most 20,000 anomaly counters are kept;
+- each alert destination's queue holds at most 1,000 alerts;
+- `discriminator` holds at most 10,000 answered requests awaiting their reports;
+- `discriminator` refuses a request with more than 50 cookies or more than 100
+  header fields (see "Answering in time" under "`discriminator`" in
+  [`SPEC.md`](../SPEC.md));
+- `rproxy` takes a request line and headers of at most 32 KiB, and closes a
+  kept-open connection idle for 120 seconds;
+- `rproxy` reads at most 1 MiB of the body of `discriminator`'s answer, and
+  answers `502` to a longer one.
+
+## `discriminator`'s answer and `rproxy`'s wait
+
+`SWW_LOOKUP_TIMEOUT` is the longest a question waits on an outside source. Keep
+it well under `rproxy`'s `SWRP_TIMEOUT_MS`, as the default is. No question waits
+for `SWW_REPUTATION_TIMEOUT`, since the DNS blocklists and AbuseIPDB are asked
+in the background (see "Answering in time" under "`discriminator`" in
+[`SPEC.md`](../SPEC.md)).
+
+## `rproxy`
+
+`sww rproxy` reads the settings below and no others. They are read once at
+start, and an invalid value stops the start. None can be given as a file, since
+`rproxy` never touches disk. "`rproxy`" in [`SPEC.md`](../SPEC.md) says what
+they do.
+
+A time here is a whole number of milliseconds above zero, such as `2000`.
+
+- `SWRP_WAF_BACKEND` (required, no default): `discriminator`'s URL. An `http` or
+  `https` URL with a host and an optional port, and nothing more. `rproxy`
+  speaks HTTP/1.1 to it.
+- `SWRP_TIMEOUT_MS` (default `2000`): how long `rproxy` waits for
+  `discriminator`'s answer, to a question and to a report. A time; never `off`.
+- `SWRP_DEFAULT_DISPOSITION` (default `allow`): what is done with a request when
+  `discriminator` cannot be connected to, does not answer at all, or does not
+  answer within `SWRP_TIMEOUT_MS`. `allow` passes it to the app, and `deny`
+  answers `503`. It does not apply to an answer `discriminator` gives, such as
+  an error.
+- `SWRP_MAX_REQUEST_SIZE` (default `100M`): the largest request body. A size or
+  `off`.
+- `SWRP_MAX_RESPONSE_SIZE` (default `1G`): the largest response body. A size or
+  `off`.
+- `SWRP_MAX_REQUEST_TIME_MS` (default `60000`): how long the visitor may take to
+  send its request line and headers. It then also bounds, from the end of the
+  headers, the time until the app has been sent the whole request. A time or
+  `off`.
+- `SWRP_MAX_RESPONSE_TIME_MS` (default `1800000`): how long the answer may take,
+  from the end of the request to its last byte reaching the visitor. A time or
+  `off`.
+- `SWRP_LISTEN_ADDR` (default `:8080`): where `rproxy` listens, such as `:9000`.
+- `SWRP_UPSTREAM_URL` (default `http://127.0.0.1:8081`): the app. An `http` or
+  `https` URL with a host and an optional port, and nothing more.
+- `SWRP_TRUSTED_PROXIES` (default `10.0.0.0/8,172.16.0.0/12,192.168.0.0/16`):
+  the netblocks whose `X-Forwarded-For` is believed. Set but empty, it trusts
+  nothing. A client outside these netblocks cannot claim another address. Where
+  other containers reach `rproxy` directly, or visitors on a private network
+  reach traefik, they can name another address in the header. Narrowing the
+  setting to traefik's own network closes that gap.
+
+## The image's command
+
+`SWW_COMMAND` (default `rproxy`) chooses what the image runs and what its health
+check checks: `rproxy` or `discriminator` (see "Deployment" in
+[`SPEC.md`](../SPEC.md)). It cannot be given as a file.
+
+## Where earlier settings went
+
+Nothing reads these names any more:
+
+- `SWW_UPSTREAM_URL` is `SWRP_UPSTREAM_URL`.
+- `SWW_TRUSTED_PROXIES` is `SWRP_TRUSTED_PROXIES`.
+- `SWW_REQUEST_MAX_BYTES` is `SWRP_MAX_REQUEST_SIZE`.
+- `SWW_RESPONSE_MAX_BYTES` is `SWRP_MAX_RESPONSE_SIZE`.
+- `SWW_CLIENT_REQUEST_TIMEOUT` and `SWW_UPSTREAM_REQUEST_TIMEOUT` are
+  `SWRP_MAX_REQUEST_TIME_MS`, in milliseconds.
+- `SWW_CLIENT_RESPONSE_TIMEOUT` and `SWW_UPSTREAM_RESPONSE_TIMEOUT` are
+  `SWRP_MAX_RESPONSE_TIME_MS`, in milliseconds.
+- `SWW_CLIENT_IDLE_TIMEOUT` and `SWW_CLIENT_REQUEST_HEADER_MAX_BYTES` have no
+  setting. `rproxy` closes a kept-open connection idle for 120 seconds, and
+  takes a request line and headers of at most 32 KiB.

docs/state-files.md

@@ -0,0 +1,104 @@
+# State files
+
+The five JSON files in `SWW_STATE_DIR`, and what each holds. "Persistent state"
+in [`SPEC.md`](../SPEC.md) says how they are written, read and edited. Each has
+a top-level `version` of 1.
+
+## `bans.json`
+
+Active and past bans: every ban an admin made, and up to `SWW_MAX_BANS` of those
+`discriminator` made. Per entry:
+
+- `netblock`, `start` and `expires` (`null` for a permanent ban);
+- `cause`: `attack`, `limit`, `admin` or `crowdsec`;
+- `reason`: a short reason;
+- `lifted`: when an admin lifted it, if one did;
+- `notes`: the notes below.
+
+An entry an admin adds needs `netblock`, `start` and `expires`; `reason`,
+`notes` and `cause` may be left out, and the cause is then `admin`:
+
+```json
+{
+    "version": 1,
+    "bans": [
+        {
+            "netblock": "203.0.113.0/24",
+            "start": "2026-10-06T12:00:00Z",
+            "expires": null,
+            "reason": "probes for logins"
+        }
+    ]
+}
+```
+
+"Bans" in [`SPEC.md`](../SPEC.md) says how an edit lifts, keeps or forgets a
+ban. The notes:
+
+- `asn`, `as_name` and `country`: the client's, added when the lookup answers
+  (empty when lookups are off);
+- for a broken limit, `kind` (`requests`, `bytes` or `refusals`), `limit`,
+  `window` and `count`: what the limit was on, the limit, its window and the
+  count reached;
+- `limit_percent` and `limit_percent_setting`: the client's percentage of that
+  limit and the setting that gave it, when a setting lowered it;
+- for a clear sign of attack, `rule_id` and `target`, or `trap_path`;
+- `reputation`: the sources the client was on, each with its `source` and, for
+  AbuseIPDB, its `score`;
+- `request`: the request that caused the ban, each text cut to 256 bytes:
+    - `time`, `method` and `host`;
+    - `path`, with its query string;
+    - `status` and `user_agent`;
+- `requests` and `refused`: the netblock's requests since it was first seen, and
+  how many this ban has refused so far, kept up to date while the ban lasts;
+- `earlier_bans`: how many earlier bans the netblock had, by cause.
+
+## `clients.json`
+
+Per client, one per line: its minute, hour and day counters, and its history
+since it was first seen:
+
+- the first and last time seen;
+- the AS number, AS name and country last looked up, and when;
+- total requests, and how many were forwarded and how many refused;
+- bytes in each direction;
+- responses by status class;
+- offences by kind: `limit`, `attack`, `rule_blocked` and `waf_blocked`. A file
+  may also hold `token_refused`, which is kept, and which nothing adds to.
+
+## `lookups.json`
+
+GeoJS answers, one per line:
+
+- `client`;
+- `asn`, `as_name` and `country`;
+- `answered`: when GeoJS answered;
+- `used`: when the answer was last used.
+
+## `reputation.json`
+
+- the last good copy of each list fetched from a URL, with when it was last
+  tried;
+- each DNS blocklist verdict still in use;
+- AbuseIPDB's scores, and the checks spent today.
+
+## `alerts.json`
+
+- the anomaly counters;
+- the alert cooldowns: for each event and netblock, source, file or anomaly
+  scope, when it was last sent and the count of repeats held back since;
+- the alerts sent and held back in the current hour;
+- the alerts waiting for each destination.
+
+## Sizes
+
+- `clients.json`: about 1 KiB per client, about 20 MiB at the default
+  `SWW_MAX_TRACKED_CLIENTS`. Written every 15 minutes, that is under 2 GiB of
+  disk writes a day.
+- `bans.json`: about 1.2 KiB per ban, at most about 2.5 KiB, so about 6 MiB at
+  the default `SWW_MAX_BANS`. Written every 15 minutes, a full file comes to
+  about 600 MiB of writes a day, and a hundred new bans a day add about 600 MiB
+  more.
+- `lookups.json`: about 150 bytes per answer, under 1.5 GiB of writes a day when
+  full.
+- `reputation.json` and `alerts.json`: usually a few MiB or less.

internal/alerts/alerts.go

@@ -1,12 +1,12 @@
 // Package alerts sends alerts on bans, on traffic over an anomaly
 // threshold, on a source that fails and on a file with an error to each
 // destination set: to the webhook
-// SWWAF_ALERT_WEBHOOK_URL names, each as one JSON object, as the "Alert
+// SWW_ALERT_WEBHOOK_URL names, each as one JSON object, as "The JSON
-// webhook schema" section of SPEC.md describes, to the Slack incoming
+// object" in docs/alerts.md describes, to the Slack incoming
-// webhook SWWAF_ALERT_SLACK_WEBHOOK_URL names, as a message, and to the
+// webhook SWW_ALERT_SLACK_WEBHOOK_URL names, as a message, and to the
-// ntfy topic SWWAF_ALERT_NTFY_URL names. A repeat within
+// ntfy topic SWW_ALERT_NTFY_URL names. A repeat within
-// SWWAF_ALERT_COOLDOWN is held back, and so is an alert past
+// SWW_ALERT_COOLDOWN is held back, and so is an alert past
-// SWWAF_ALERT_MAX_PER_HOUR, for the hour's summary. The others wait in a
+// SWW_ALERT_MAX_PER_HOUR, for the hour's summary. The others wait in a
 // bounded queue of each destination's own, so that a destination that is
 // slow or unreachable holds up neither the others nor any request. The
 // state is written to alerts.json and read from it by the state package.
@@ -34,41 +34,41 @@ import (
 	"time"
 )
 
-// The events an alert is for, as SWWAF_ALERT_EVENTS names them.
+// The events an alert is for, as SWW_ALERT_EVENTS names them.
 const (
-	// EventBan is a ban smallwebwaf made.
+	// EventBan is a ban sww made.
 	EventBan = "ban"
-	// EventPermanentBan is a permanent ban smallwebwaf made, or a ban it
+	// EventPermanentBan is a permanent ban sww made, or a ban it
 	// made permanent.
 	EventPermanentBan = "permanent_ban"
 	// EventAnomaly is a count of requests or bytes over an anomaly
 	// threshold.
 	EventAnomaly = "anomaly"
 	// EventWAFBlock is a request the Core Rule Set scored at or over
-	// SWWAF_WAF_ANOMALY_THRESHOLD, refused in block mode, let through in
+	// SWW_WAF_ANOMALY_THRESHOLD, refused in block mode, let through in
 	// detect mode.
 	EventWAFBlock = "waf_block"
 	// EventReputationHit is a request whose client a blocklist, the
 	// CrowdSec decision list or a DNSBL zone lists, or whose AbuseIPDB score
 	// is a hit.
 	EventReputationHit = "reputation_hit"
-	// EventSourceFailure is GeoJS failing or refusing smallwebwaf, a fetch
+	// EventSourceFailure is GeoJS failing or refusing sww, a fetch
 	// of a list failing, a query to a DNSBL zone or a check with AbuseIPDB
 	// failing or refused, or the day's AbuseIPDB checks used up.
 	EventSourceFailure = "source_failure"
-	// EventFileError is a rule file or state file edited while smallwebwaf
+	// EventFileError is a rule file or state file edited while sww
 	// runs that does not parse, a replacement of the lookup database that
 	// cannot be read, or a state file that cannot be written.
 	EventFileError = "file_error"
 	// EventSummary is the summary sent as an hour ends: of the alerts held
-	// back in it past SWWAF_ALERT_MAX_PER_HOUR, and of the repeats held
+	// back in it past SWW_ALERT_MAX_PER_HOUR, and of the repeats held
 	// back by the cooldowns dropped as it ends, which no alert let through
-	// has given. It is sent with SWWAF_ALERT_MAX_PER_HOUR off too, for
+	// has given. It is sent with SWW_ALERT_MAX_PER_HOUR off too, for
-	// those repeats. SWWAF_ALERT_EVENTS does not name it.
+	// those repeats. SWW_ALERT_EVENTS does not name it.
 	EventSummary = "summary"
 )
 
-// Events returns every event SWWAF_ALERT_EVENTS can name, which is its
+// Events returns every event SWW_ALERT_EVENTS can name, which is its
 // default.
 func Events() []string {
 	return []string{
@@ -80,12 +80,12 @@ func Events() []string {
 // The destinations alerts are sent to, as the metrics and alerts.json
 // name them.
 const (
-	// DestinationWebhook is the webhook SWWAF_ALERT_WEBHOOK_URL names.
+	// DestinationWebhook is the webhook SWW_ALERT_WEBHOOK_URL names.
 	DestinationWebhook = "webhook"
 	// DestinationSlack is the Slack incoming webhook
-	// SWWAF_ALERT_SLACK_WEBHOOK_URL names.
+	// SWW_ALERT_SLACK_WEBHOOK_URL names.
 	DestinationSlack = "slack"
-	// DestinationNtfy is the ntfy topic SWWAF_ALERT_NTFY_URL names.
+	// DestinationNtfy is the ntfy topic SWW_ALERT_NTFY_URL names.
 	DestinationNtfy = "ntfy"
 )
 
@@ -121,26 +121,26 @@ var (
 // NtfyURL set, no alert is sent.
 type Params struct {
 	// WebhookURL is where each alert is posted as JSON
-	// (SWWAF_ALERT_WEBHOOK_URL), nil while it is unset. WebhookHeaders
+	// (SWW_ALERT_WEBHOOK_URL), nil while it is unset. WebhookHeaders
-	// are sent with each (SWWAF_ALERT_WEBHOOK_HEADERS).
+	// are sent with each (SWW_ALERT_WEBHOOK_HEADERS).
 	WebhookURL     *url.URL
 	WebhookHeaders http.Header
 	// SlackURL is the Slack incoming webhook each alert is posted to as a
-	// message (SWWAF_ALERT_SLACK_WEBHOOK_URL), nil while it is unset.
+	// message (SWW_ALERT_SLACK_WEBHOOK_URL), nil while it is unset.
 	SlackURL *url.URL
 	// NtfyURL is the ntfy topic each alert is published to
-	// (SWWAF_ALERT_NTFY_URL), nil while it is unset. NtfyToken, unless
+	// (SWW_ALERT_NTFY_URL), nil while it is unset. NtfyToken, unless
-	// empty, is sent with each as a bearer token (SWWAF_ALERT_NTFY_TOKEN).
+	// empty, is sent with each as a bearer token (SWW_ALERT_NTFY_TOKEN).
 	NtfyURL   *url.URL
 	NtfyToken string
-	// Events are the events alerts are sent for (SWWAF_ALERT_EVENTS).
+	// Events are the events alerts are sent for (SWW_ALERT_EVENTS).
 	Events []string
 	// Cooldown is how long a repeat of an alert is held back
-	// (SWWAF_ALERT_COOLDOWN), 0 for no time. MaxPerHour is the most alerts
+	// (SWW_ALERT_COOLDOWN), 0 for no time. MaxPerHour is the most alerts
-	// sent in an hour (SWWAF_ALERT_MAX_PER_HOUR), 0 for no limit.
+	// sent in an hour (SWW_ALERT_MAX_PER_HOUR), 0 for no limit.
 	Cooldown   time.Duration
 	MaxPerHour int
-	// Instance is SWWAF_INSTANCE_NAME, which every alert gives.
+	// Instance is SWW_INSTANCE_NAME, which every alert gives.
 	Instance string
 	// Now tells the time of an alert, normally time.Now in UTC.
 	Now func() time.Time
@@ -149,15 +149,17 @@ type Params struct {
 }
 
 // Alert is one alert, as the webhook is sent it and alerts.json holds it,
-// with the fields of the "Alert webhook schema" section of SPEC.md. ASN,
+// with the fields of "The JSON object" in docs/alerts.md. ASN, ASName and
-// ASName and Country are, for a ban, the client's as the ban's notes give
+// Country are, for a ban, the client's as the ban's notes give them. Host is
-// them.
+// the site of the request that raised the alert, while one discriminator serves
+// many sites, and "" otherwise.
 //
-//nolint:tagliatelle // SPEC.md's alert webhook schema names its fields in snake_case
+//nolint:tagliatelle // docs/alerts.md names the alert's fields in snake_case
 type Alert struct {
 	Instance string       `json:"instance"`
 	Time     time.Time    `json:"time"`
 	Event    string       `json:"event"`
+	Host     string       `json:"host,omitempty"`
 	Client   netip.Addr   `json:"client"`
 	Netblock netip.Prefix `json:"netblock"`
 	ASN      string       `json:"asn"`
@@ -299,17 +301,17 @@ func New(params Params) *Queue {
 	}
 
 	if params.WebhookURL != nil {
-		q.addDestination(DestinationWebhook, "SWWAF_ALERT_WEBHOOK_URL",
+		q.addDestination(DestinationWebhook, "SWW_ALERT_WEBHOOK_URL",
 			params.WebhookURL, q.webhookMessage)
 	}
 
 	if params.SlackURL != nil {
-		q.addDestination(DestinationSlack, "SWWAF_ALERT_SLACK_WEBHOOK_URL",
+		q.addDestination(DestinationSlack, "SWW_ALERT_SLACK_WEBHOOK_URL",
 			params.SlackURL, slackMessage)
 	}
 
 	if params.NtfyURL != nil {
-		q.addDestination(DestinationNtfy, "SWWAF_ALERT_NTFY_URL",
+		q.addDestination(DestinationNtfy, "SWW_ALERT_NTFY_URL",
 			params.NtfyURL, q.ntfyMessage)
 	}
 
@@ -317,7 +319,7 @@ func New(params Params) *Queue {
 }
 
 // Raise sends alert, which names its event and what is particular to it,
-// unless no destination is set or SWWAF_ALERT_EVENTS leaves its event
+// unless no destination is set or SWW_ALERT_EVENTS leaves its event
 // out. It gives alert the instance and the time. An alert that repeats
 // the last one let through less than Cooldown before is held back and
 // counted. The next one let through gives that count, unless an hour of
@@ -361,7 +363,7 @@ func (q *Queue) Raise(alert Alert) {
 }
 
 // WouldSend reports whether Raise would let an alert for event on
-// netblock through now: a destination is set, SWWAF_ALERT_EVENTS chooses
+// netblock through now: a destination is set, SWW_ALERT_EVENTS chooses
 // event, no alert for event on netblock was let through less than
 // Cooldown before, and fewer than MaxPerHour alerts have been let through
 // in the hour under way. Unlike Raise, it counts nothing.
@@ -604,13 +606,13 @@ func (q *Queue) endHour(now time.Time) {
 
 	if heldBack > 0 {
 		reasons = append(reasons, fmt.Sprintf("%d alerts held back in the hour from %s, "+
-			"past the %d an hour SWWAF_ALERT_MAX_PER_HOUR allows", heldBack,
+			"past the %d an hour SWW_ALERT_MAX_PER_HOUR allows", heldBack,
 			q.hour.Start.Format(time.RFC3339), q.params.MaxPerHour))
 	}
 
 	if repeats > 0 {
 		reasons = append(reasons, fmt.Sprintf("%d repeats held back by "+
-			"SWWAF_ALERT_COOLDOWN that no later alert gives", repeats))
+			"SWW_ALERT_COOLDOWN that no later alert gives", repeats))
 	}
 
 	if len(reasons) > 0 {
@@ -681,7 +683,7 @@ func (d *destination) run(ctx context.Context) {
 
 				d.processLog.Warn("gave up an alert "+d.setting+" refused",
 					"event", alert.Event, "error", err.Error())
-			case ctx.Err() == nil: // not cut off as smallwebwaf stops
+			case ctx.Err() == nil: // not cut off as sww stops
 				d.failed.Add(1)
 
 				retryDelay = min(max(retryDelayFactor*retryDelay, firstRetryDelay),
@@ -900,12 +902,16 @@ func title(alert *Alert) string {
 }
 
 // text returns the text of alert in Slack and ntfy: its reason, then a
-// line for each of its client, netblock and country, the file, source,
+// line for each of its host, client, netblock and country, the file,
-// error and mode its detail gives, and its suppressed repeats, that it
+// source, error and mode its detail gives, and its suppressed repeats, that
-// has.
+// it has.
 func text(alert *Alert) string {
 	lines := []string{alert.Reason}
 
+	if alert.Host != "" {
+		lines = append(lines, "host: "+alert.Host)
+	}
+
 	if alert.Client.IsValid() {
 		lines = append(lines, "client: "+alert.Client.String())
 	}

internal/alerts/alerts_test.go

@@ -34,12 +34,12 @@ const (
 	// webhookURL is where the alerts are posted, slackURL the Slack
 	// incoming webhook, and ntfyURL the ntfy topic. ntfyToken is the ntfy
 	// token of the tests that set one.
-	webhookURL = "https://alerts.example/smallwebwaf?team=ops"
+	webhookURL = "https://alerts.example/sww?team=ops"
 	slackURL   = "https://hooks.slack.example/services/T0123/B4567/abcdef"
-	ntfyURL    = "https://ntfy.example/smallwebwaf-alerts"
+	ntfyURL    = "https://ntfy.example/sww-alerts"
 	ntfyToken  = "tk_0123456789abcdefghijklmnopq"
 	// instance is the instance name every alert gives.
-	instance = "fsn1app1/gitea"
+	instance = "fsn1app1/blog"
 	// started is when each test starts, as an alert gives it, and
 	// anHourOn an hour later.
 	started  = "2000-01-01T00:00:00Z"
@@ -132,7 +132,7 @@ func TestWouldSendOnlyForTheChosenEvents(t *testing.T) {
 
 	if q.WouldSend(alerts.EventBan, netblock(1)) ||
 		q.WouldSend(alerts.EventPermanentBan, netblock(1)) {
-		t.Error("a ban alert would be sent, though SWWAF_ALERT_EVENTS leaves it out")
+		t.Error("a ban alert would be sent, though SWW_ALERT_EVENTS leaves it out")
 	}
 
 	if !q.WouldSend(alerts.EventFileError, netip.Prefix{}) {
@@ -184,8 +184,8 @@ func TestWouldSendWithOnlySlackOrOnlyNtfySet(t *testing.T) {
 	onlyNtfy.NtfyURL = parseURL(ntfyURL)
 
 	for setting, params := range map[string]alerts.Params{
-		"SWWAF_ALERT_SLACK_WEBHOOK_URL": onlySlack,
+		"SWW_ALERT_SLACK_WEBHOOK_URL": onlySlack,
-		"SWWAF_ALERT_NTFY_URL":          onlyNtfy,
+		"SWW_ALERT_NTFY_URL":          onlyNtfy,
 	} {
 		if !alerts.New(params).WouldSend(alerts.EventBan, netblock(1)) {
 			t.Errorf("a ban alert would not be sent with only %s set", setting)
@@ -359,7 +359,7 @@ func TestAlertsPastTheHourlyLimitAreRolledIntoOneSummary(t *testing.T) {
 			"as_name":  "",
 			"country":  "",
 			"reason": "3 alerts held back in the hour from 2000-01-01T00:00:00Z, " +
-				"past the 2 an hour SWWAF_ALERT_MAX_PER_HOUR allows",
+				"past the 2 an hour SWW_ALERT_MAX_PER_HOUR allows",
 			"detail": map[string]any{
 				"hour":  started,
 				"count": float64(3),
@@ -525,7 +525,7 @@ func TestFailedRequestIsSentAgainWithBackoff(t *testing.T) {
 		wantCounts(t, q, 0, int64(len(want)), 0, 0)
 
 		if !strings.Contains(log.String(),
-			`"msg":"sending an alert to SWWAF_ALERT_WEBHOOK_URL failed"`) {
+			`"msg":"sending an alert to SWW_ALERT_WEBHOOK_URL failed"`) {
 			t.Errorf("process log %q names no failure", log.String())
 		}
 
@@ -595,7 +595,7 @@ func TestRefusedAlertIsGivenUpAndTheNextSent(t *testing.T) {
 		wantCounts(t, q, 1, 3, 0, 1)
 
 		if !strings.Contains(log.String(),
-			`"msg":"gave up an alert SWWAF_ALERT_WEBHOOK_URL refused"`) {
+			`"msg":"gave up an alert SWW_ALERT_WEBHOOK_URL refused"`) {
 			t.Errorf("process log %q names no alert given up", log.String())
 		}
 	})
@@ -619,7 +619,7 @@ func TestFailedRequestIsLoggedWithoutTheURL(t *testing.T) {
 
 		logged := log.String()
 		if !strings.Contains(logged,
-			`"msg":"sending an alert to SWWAF_ALERT_WEBHOOK_URL failed"`) ||
+			`"msg":"sending an alert to SWW_ALERT_WEBHOOK_URL failed"`) ||
 			strings.Contains(logged, "alerts.example") || strings.Contains(logged, "team=ops") {
 			t.Errorf("process log %q names no failure, or names the URL", logged)
 		}
@@ -782,8 +782,8 @@ func TestSlackAndNtfyAreSentTheSummaryAndTheRepeatsHeldBack(t *testing.T) {
 		}
 
 		const summary = "1 alerts held back in the hour from 2000-01-01T00:00:00Z, " +
-			"past the 1 an hour SWWAF_ALERT_MAX_PER_HOUR allows; 1 repeats held back " +
+			"past the 1 an hour SWW_ALERT_MAX_PER_HOUR allows; 1 repeats held back " +
-			"by SWWAF_ALERT_COOLDOWN that no later alert gives\nsuppressed repeats: 1"
+			"by SWW_ALERT_COOLDOWN that no later alert gives\nsuppressed repeats: 1"
 
 		wantSlackMessage(t, slack[1], "*"+instance+": summary*\n"+summary)
 		wantNtfyMessage(t, ntfy[1], instance+": summary", "default bar_chart", summary)
@@ -901,7 +901,7 @@ func TestDestinationThatDoesNotAnswerHoldsUpNeitherOther(t *testing.T) {
 
 		logged := log.String()
 		if !strings.Contains(logged,
-			`"msg":"sending an alert to SWWAF_ALERT_SLACK_WEBHOOK_URL failed"`) ||
+			`"msg":"sending an alert to SWW_ALERT_SLACK_WEBHOOK_URL failed"`) ||
 			strings.Contains(logged, "hooks.slack.example") ||
 			strings.Contains(logged, "T0123") {
 			t.Errorf("process log %q names no failure, or names the URL", logged)
@@ -965,8 +965,8 @@ func TestEachDestinationIsSentOnlyTheAlertsWaitingForIt(t *testing.T) {
 		synctest.Wait()
 
 		wantBodies(t, standIns[alerts.DestinationSlack],
-			`{"text":"*fsn1app1/gitea: file_error*\nsecond"}`,
+			`{"text":"*fsn1app1/blog: file_error*\nsecond"}`,
-			`{"text":"*fsn1app1/gitea: file_error*\nthird"}`)
+			`{"text":"*fsn1app1/blog: file_error*\nthird"}`)
 		wantBodies(t, standIns[alerts.DestinationNtfy], "fourth")
 
 		// alerts.json then lists Slack and ntfy alone, with no alert waiting.
@@ -1254,7 +1254,7 @@ type eventMessage struct {
 	title, priorityAndTag, text string
 }
 
-// anAlertForEachEvent returns an alert for each event SWWAF_ALERT_EVENTS
+// anAlertForEachEvent returns an alert for each event SWW_ALERT_EVENTS
 // names, the first in observe mode, each with its message.
 func anAlertForEachEvent() []eventMessage {
 	return []eventMessage{
@@ -1265,7 +1265,7 @@ func anAlertForEachEvent() []eventMessage {
 				Reason: "requests per hour over the limit of 10000",
 				Detail: map[string]any{"mode": "observe"},
 			},
-			"fsn1app1/gitea: ban", "default no_entry",
+			"fsn1app1/blog: ban", "default no_entry",
 			"requests per hour over the limit of 10000\nclient: 203.0.113.9\n" +
 				"netblock: 203.0.113.0/24\ncountry: DE\nmode: observe",
 		},
@@ -1275,7 +1275,7 @@ func anAlertForEachEvent() []eventMessage {
 				Netblock: netip.MustParsePrefix("198.51.100.7/32"), Country: "FR",
 				Reason: "matched the rule env-file",
 			},
-			"fsn1app1/gitea: permanent_ban", "high no_entry",
+			"fsn1app1/blog: permanent_ban", "high no_entry",
 			"matched the rule env-file\nclient: 198.51.100.7\n" +
 				"netblock: 198.51.100.7/32\ncountry: FR",
 		},
@@ -1284,16 +1284,18 @@ func anAlertForEachEvent() []eventMessage {
 				Event: alerts.EventWAFBlock, Client: netip.MustParseAddr("192.0.2.1"),
 				Netblock: netip.MustParsePrefix("192.0.2.1/32"),
 				Reason:   "refused by the Core Rule Set",
+				Host:     "app.example",
 			},
-			"fsn1app1/gitea: waf_block", "default shield",
+			"fsn1app1/blog: waf_block", "default shield",
-			"refused by the Core Rule Set\nclient: 192.0.2.1\nnetblock: 192.0.2.1/32",
+			"refused by the Core Rule Set\nhost: app.example\nclient: 192.0.2.1\n" +
+				"netblock: 192.0.2.1/32",
 		},
 		{
 			alerts.Alert{
 				Event: alerts.EventAnomaly, Netblock: netip.MustParsePrefix("192.0.2.0/24"),
 				Reason: "requests per minute over the threshold of 5000",
 			},
-			"fsn1app1/gitea: anomaly", "high chart_with_upwards_trend",
+			"fsn1app1/blog: anomaly", "high chart_with_upwards_trend",
 			"requests per minute over the threshold of 5000\nnetblock: 192.0.2.0/24",
 		},
 		{
@@ -1302,7 +1304,7 @@ func anAlertForEachEvent() []eventMessage {
 				Netblock: netip.MustParsePrefix("192.0.2.2/32"),
 				Reason:   "listed by a DNS blocklist",
 			},
-			"fsn1app1/gitea: reputation_hit", "low label",
+			"fsn1app1/blog: reputation_hit", "low label",
 			"listed by a DNS blocklist\nclient: 192.0.2.2\nnetblock: 192.0.2.2/32",
 		},
 		{
@@ -1310,7 +1312,7 @@ func anAlertForEachEvent() []eventMessage {
 				Event: alerts.EventSourceFailure, Reason: "asking GeoJS failed",
 				Detail: map[string]any{"source": "geojs"},
 			},
-			"fsn1app1/gitea: source_failure", "high warning",
+			"fsn1app1/blog: source_failure", "high warning",
 			"asking GeoJS failed\nsource: geojs",
 		},
 		{
@@ -1318,12 +1320,12 @@ func anAlertForEachEvent() []eventMessage {
 				Event:  alerts.EventFileError,
 				Reason: "a rule file has an error, and the rules stay as they were",
 				Detail: map[string]any{
-					"file": "/etc/smallwebwaf/rules.d/50-app.rules", "error": "line 2: no action",
+					"file": "/etc/sww/rules.d/50-app.rules", "error": "line 2: no action",
 				},
 			},
-			"fsn1app1/gitea: file_error", "high warning",
+			"fsn1app1/blog: file_error", "high warning",
 			"a rule file has an error, and the rules stay as they were\n" +
-				"file: /etc/smallwebwaf/rules.d/50-app.rules\nerror: line 2: no action",
+				"file: /etc/sww/rules.d/50-app.rules\nerror: line 2: no action",
 		},
 	}
 }

internal/anomaly/anomaly.go

@@ -1,8 +1,8 @@
 // Package anomaly counts requests and bytes over a minute and an hour, per
 // client, per surrounding netblock, per AS number, for the whole service
 // and per named netblock, and raises an anomaly alert for a count over its
-// threshold, as "Anomaly thresholds" under "Configuration surface" in
+// threshold, as "Anomaly thresholds" under "Settings" in SPEC.md
-// SPEC.md describes. It refuses and bans nothing. At most 20,000 counters
+// describes. It refuses and bans nothing. At most 20,000 counters
 // are kept, in memory, and written to alerts.json and read from it by the
 // state package.
 package anomaly
@@ -28,16 +28,16 @@ const maxCounters = 20000
 // alerts name them.
 const (
 	// ScopeClient is one client: an IPv4 address, or an IPv6 netblock of
-	// SWWAF_IPV6_GROUP_PREFIX.
+	// SWW_IPV6_GROUP_PREFIX.
 	ScopeClient = "client"
-	// ScopeNet is the netblock around a client, SWWAF_ANOMALY_NET_V4_PREFIX
+	// ScopeNet is the netblock around a client, SWW_ANOMALY_NET_V4_PREFIX
-	// or SWWAF_ANOMALY_NET_V6_PREFIX long.
+	// or SWW_ANOMALY_NET_V6_PREFIX long.
 	ScopeNet = "net"
 	// ScopeASN is an AS number.
 	ScopeASN = "asn"
 	// ScopeTotal is the whole service.
 	ScopeTotal = "total"
-	// ScopeWatch is a named netblock of SWWAF_WATCH_NETS.
+	// ScopeWatch is a named netblock of SWW_WATCH_NETS.
 	ScopeWatch = "watch"
 )
 
@@ -62,7 +62,7 @@ type Thresholds struct {
 	BytesPerHour      int64
 }
 
-// NamedNetblock is a netblock SWWAF_WATCH_NETS names.
+// NamedNetblock is a netblock SWW_WATCH_NETS names.
 type NamedNetblock struct {
 	Name     string
 	Netblock netip.Prefix
@@ -70,14 +70,14 @@ type NamedNetblock struct {
 
 // Params are what New needs.
 type Params struct {
-	// The thresholds of each scope: SWWAF_ANOMALY_CLIENT_*,
+	// The thresholds of each scope: SWW_ANOMALY_CLIENT_*,
-	// SWWAF_ANOMALY_NET_*, SWWAF_ANOMALY_ASN_*, SWWAF_ANOMALY_TOTAL_* and
+	// SWW_ANOMALY_NET_*, SWW_ANOMALY_ASN_*, SWW_ANOMALY_TOTAL_* and
-	// SWWAF_WATCH_*.
+	// SWW_WATCH_*.
 	Client, Net, ASN, Total, Watch Thresholds
 	// NetV4Prefix and NetV6Prefix are the lengths of the netblock around a
-	// client (SWWAF_ANOMALY_NET_V4_PREFIX and SWWAF_ANOMALY_NET_V6_PREFIX).
+	// client (SWW_ANOMALY_NET_V4_PREFIX and SWW_ANOMALY_NET_V6_PREFIX).
 	NetV4Prefix, NetV6Prefix int
-	// NamedNetblocks are SWWAF_WATCH_NETS.
+	// NamedNetblocks are SWW_WATCH_NETS.
 	NamedNetblocks []NamedNetblock
 	// Alerts receive the anomaly alerts.
 	Alerts *alerts.Queue
@@ -103,15 +103,17 @@ type Counter struct {
 
 // Request is a request that has ended, as the counters count it.
 type Request struct {
+	// Host is the site the alert names, "" for none.
+	Host string
 	// Client is the client's address, and ClientGroup the client it is
 	// counted as: its IPv4 address, or the IPv6 netblock of
-	// SWWAF_IPV6_GROUP_PREFIX its address is in.
+	// SWW_IPV6_GROUP_PREFIX its address is in.
 	Client      netip.Addr
 	ClientGroup netip.Prefix
 	// ASN, ASName and Country are the client's as looked up, each "" when
 	// unknown.
 	ASN, ASName, Country string
-	// Bytes are the request's bytes, as SWWAF_BYTES_COUNT counts them.
+	// Bytes are the request's bytes, as SWW_BYTES_COUNT counts them.
 	Bytes int64
 }
 
@@ -396,6 +398,7 @@ func alertFor(r Request, k key, o overThreshold) alerts.Alert {
 
 	return alerts.Alert{
 		Event:    alerts.EventAnomaly,
+		Host:     r.Host,
 		Client:   r.Client,
 		Netblock: k.netblock,
 		ASN:      r.ASN,

internal/bans/admin_test.go

@@ -33,7 +33,7 @@ func TestAdminsBansAreNeverDroppedAndDoNotCountTowardMaxBans(t *testing.T) {
 	third := netip.MustParsePrefix("203.0.113.3/32")
 
 	// Seen longest ago, a netblock with two of an admin's bans alone, and
-	// then one with an admin's ban before a ban smallwebwaf made: the one
+	// then one with an admin's ban before a ban sww made: the one
 	// ban counted toward MaxBans.
 	ledger.Load([]bans.Ban{
 		{Netblock: adminsOnly, Start: midnight().Add(-3 * time.Hour), Cause: bans.CauseAdmin},
@@ -48,7 +48,7 @@ func TestAdminsBansAreNeverDroppedAndDoNotCountTowardMaxBans(t *testing.T) {
 	})
 	wantBans(t, ledger, map[netip.Prefix]int{adminsOnly: 2, both: 2})
 
-	// A new ban drops the ban smallwebwaf made, and only that one.
+	// A new ban drops the ban sww made, and only that one.
 	ledger.BanForLimit(second, midnight(), bans.Notes{})
 	wantBans(t, ledger, map[netip.Prefix]int{adminsOnly: 2, both: 1, second: 1})
 
@@ -61,7 +61,60 @@ func TestAdminsBansAreNeverDroppedAndDoNotCountTowardMaxBans(t *testing.T) {
 	wantBans(t, ledger, map[netip.Prefix]int{adminsOnly: 2, both: 1, second: 0, third: 1})
 }
 
-func TestReasonOfTheBansSmallwebwafMakes(t *testing.T) {
+func TestEarlierBansCountABanDroppedAfterAnAdminsBan(t *testing.T) {
+	t.Parallel()
+
+	rules := defaultRules()
+	rules.MaxBans = 2
+	ledger := bans.New(rules)
+	netblock := netip.MustParsePrefix("203.0.113.1/32")
+	other := netip.MustParsePrefix("203.0.113.2/32")
+
+	// An admin bans the netblock for a minute, and it then breaks a limit
+	// twice, each time after its last ban has ended.
+	ledger.BanForAdmin(netblock, midnight(), midnight().Add(time.Minute),
+		"probes for logins")
+	first, _ := ledger.BanForLimit(netblock, midnight().Add(time.Minute), bans.Notes{})
+	second, _ := ledger.BanForLimit(netblock, first.Expires, bans.Notes{})
+
+	// A ban on another netblock fills the ledger, and the netblock's first
+	// ban for a limit, its earliest that is not an admin's, goes.
+	ledger.BanForLimit(other, second.Start, bans.Notes{})
+	wantBans(t, ledger, map[netip.Prefix]int{netblock: 2, other: 1})
+
+	// The netblock's next ban still counts it.
+	third, _ := ledger.BanForLimit(netblock, second.Expires, bans.Notes{})
+	if third.Notes.EarlierBans != (bans.EarlierBans{Limit: 2, Admin: 1}) {
+		t.Errorf("the third ban for a limit has earlier bans %+v, "+
+			"want 2 for a limit and 1 an admin's", third.Notes.EarlierBans)
+	}
+}
+
+func TestEarlierBansCountABanAnAdminKeepsOnce(t *testing.T) {
+	t.Parallel()
+
+	ledger := bans.New(defaultRules())
+	netblock := netip.MustParsePrefix("203.0.113.1/32")
+
+	// The netblock breaks a limit twice, the second time after its first
+	// ban has ended, and the second ban's notes count the first. An admin
+	// then keeps the first ban.
+	first, _ := ledger.BanForLimit(netblock, midnight(), bans.Notes{})
+	second, _ := ledger.BanForLimit(netblock, first.Expires, bans.Notes{})
+
+	kept := first
+	kept.Cause = bans.CauseAdmin
+	ledger.LoadEdit([]bans.Ban{kept, second})
+
+	// The netblock's next ban counts the kept ban once, as an admin's.
+	third, _ := ledger.BanForLimit(netblock, second.Expires, bans.Notes{})
+	if third.Notes.EarlierBans != (bans.EarlierBans{Limit: 1, Admin: 1}) {
+		t.Errorf("the third ban for a limit has earlier bans %+v, "+
+			"want 1 for a limit and 1 an admin's", third.Notes.EarlierBans)
+	}
+}
+
+func TestReasonOfTheBansSwwMakes(t *testing.T) {
 	t.Parallel()
 
 	ledger := bans.New(defaultRules())
@@ -173,7 +226,7 @@ func TestLoadEditCountsTheBansAnAdminMade(t *testing.T) {
 		t.Fatalf("%d bans made by an admin after the start's, want none", got)
 	}
 
-	// The admin keeps the ban smallwebwaf made, keeps the one read at the
+	// The admin keeps the ban sww made, keeps the one read at the
 	// start, and adds one without a cause: that one alone is made.
 	kept := made
 	kept.Cause = bans.CauseAdmin

internal/bans/bans.go

@@ -1,4 +1,4 @@
-// Package bans is the ban ledger: the bans smallwebwaf makes on the
+// Package bans is the ban ledger: the bans sww makes on the
 // netblocks of clients that break a rate limit, a byte limit or the error
 // burst, show a clear sign of attack or are listed by the CrowdSec
 // decision list, and
@@ -21,14 +21,14 @@ import (
 
 // The causes of bans.
 const (
-	// CauseLimit is a ban smallwebwaf made for a broken limit.
+	// CauseLimit is a ban sww made for a broken limit.
 	CauseLimit = "limit"
-	// CauseAttack is a ban smallwebwaf made for a clear sign of attack.
+	// CauseAttack is a ban sww made for a clear sign of attack.
 	CauseAttack = "attack"
-	// CauseAdmin is a ban an admin made, or one smallwebwaf made that an
+	// CauseAdmin is a ban an admin made, or one sww made that an
 	// admin keeps. It is never dropped.
 	CauseAdmin = "admin"
-	// CauseCrowdSec is a ban smallwebwaf made for a client the CrowdSec
+	// CauseCrowdSec is a ban sww made for a client the CrowdSec
 	// decision list lists. It ends when CrowdSec's decision does.
 	CauseCrowdSec = "crowdsec"
 )
@@ -70,7 +70,7 @@ type Ban struct {
 	Expires time.Time
 	// Cause is CauseLimit, CauseAttack, CauseAdmin or CauseCrowdSec.
 	Cause string
-	// Reason is a short text: for a ban smallwebwaf made, the limit broken,
+	// Reason is a short text: for a ban sww made, the limit broken,
 	// the rule that matched or the scenario of CrowdSec's decision; for an
 	// admin's, what the admin wrote.
 	Reason string
@@ -123,7 +123,7 @@ type Notes struct {
 	LimitPercentSetting string `json:"limit_percent_setting,omitempty"`
 	// RuleID and Target are, for a ban for a clear sign of attack, the id
 	// of the rule file rule that matched, and its target; TrapPath is, for
-	// one for a request for a path in SWWAF_TRAP_PATHS, that path as the
+	// one for a request for a path in SWW_TRAP_PATHS, that path as the
 	// client sent it.
 	RuleID   string `json:"rule_id,omitempty"`
 	Target   string `json:"target,omitempty"`
@@ -199,7 +199,7 @@ type Ledger struct {
 	// v4Lengths and v6Lengths are the lengths of the IPv4 and IPv6
 	// netblocks that have been banned. Check looks for a ban at each of
 	// them, so that a ban read from bans.json refuses every client in its
-	// netblock even when it was made with another SWWAF_BAN_SCOPE_V4_PREFIX,
+	// netblock even when it was made with another SWW_BAN_SCOPE_V4_PREFIX,
 	// or another length of an IPv6 client's netblock.
 	v4Lengths, v6Lengths []int
 }
@@ -581,7 +581,7 @@ func (l *Ledger) Load(bans []Ban) {
 }
 
 // LoadEdit is Load for an admin's edit of bans.json, taken in while
-// smallwebwaf runs. Each ban in it whose cause is CauseAdmin, and which
+// sww runs. Each ban in it whose cause is CauseAdmin, and which
 // the ledger did not hold, with the same netblock and start, is one the
 // admin made, and is counted among the bans made.
 func (l *Ledger) LoadEdit(bans []Ban) {
@@ -687,26 +687,51 @@ func (l *Ledger) ban(
 }
 
 // earlierBans returns how many bans a netblock with the bans held, oldest
-// first, has had, by cause: the first ban held counts the bans the
+// first, has had, by cause. Each ban held gives a count: the bans its
-// netblock had before that one, since dropped to make room, and each ban
+// notes count before it, and one for it and each ban held after it. A
-// held adds one.
+// ban's count misses a ban dropped after it to make room, and that of an
+// admin's ban added to bans.json without notes misses the bans before it,
+// so the count that names the most bans is taken, whole: a ban an admin
+// keeps by giving it CauseAdmin is still counted under its old cause in
+// later bans' notes, and taking each cause from another count would count
+// it twice.
 func earlierBans(held []Ban) EarlierBans {
-	earlier := held[0].Notes.EarlierBans
+	// fromHere counts ban and the bans held after it.
+	var most, fromHere EarlierBans
 
-	for _, ban := range held {
+	for _, ban := range slices.Backward(held) {
 		switch ban.Cause {
 		case CauseLimit:
-			earlier.Limit++
+			fromHere.Limit++
 		case CauseAttack:
-			earlier.Attack++
+			fromHere.Attack++
 		case CauseAdmin:
-			earlier.Admin++
+			fromHere.Admin++
 		case CauseCrowdSec:
-			earlier.CrowdSec++
+			fromHere.CrowdSec++
+		}
+
+		notes := ban.Notes.EarlierBans
+		count := EarlierBans{
+			Limit:    notes.Limit + fromHere.Limit,
+			Attack:   notes.Attack + fromHere.Attack,
+			Admin:    notes.Admin + fromHere.Admin,
+			CrowdSec: notes.CrowdSec + fromHere.CrowdSec,
+		}
+
+		// Of counts that name as many bans, the earlier ban's is taken: it
+		// counts more of the bans held by the cause they have now.
+		if count.total() >= most.total() {
+			most = count
 		}
 	}
 
-	return earlier
+	return most
+}
+
+// total returns how many bans e counts, of all causes.
+func (e EarlierBans) total() int {
+	return e.Limit + e.Attack + e.Admin + e.CrowdSec
 }
 
 // markChanged has Changed receive a value, unless one is waiting already.

internal/bans/snapshot_test.go

@@ -173,7 +173,7 @@ func TestPermanentBanStartedBeforeAnEndedOneRefuses(t *testing.T) {
 func TestNextBanWorkedOutFromTheBanThatEndedLast(t *testing.T) {
 	t.Parallel()
 
-	// A 9-hour ban smallwebwaf made, the third in a row, and an admin's
+	// A 9-hour ban sww made, the third in a row, and an admin's
 	// 1-hour ban added to bans.json over it, with no cause and no notes.
 	netblock := netip.MustParsePrefix("203.0.113.9/32")
 	nineHours := bans.Ban{

internal/config/config_test.go

@@ -23,108 +23,100 @@ import (
 
 // The settings, by name.
 const (
-	listenAddr              = "SWWAF_LISTEN_ADDR"
+	listenAddr           = "SWW_LISTEN_ADDR"
-	upstreamURL             = "SWWAF_UPSTREAM_URL"
+	mode                 = "SWW_MODE"
-	mode                    = "SWWAF_MODE"
+	ipv6GroupPrefix      = "SWW_IPV6_GROUP_PREFIX"
-	trustedProxies          = "SWWAF_TRUSTED_PROXIES"
+	maxTrackedClients    = "SWW_MAX_TRACKED_CLIENTS"
-	ipv6GroupPrefix         = "SWWAF_IPV6_GROUP_PREFIX"
+	allowNets            = "SWW_ALLOW_NETS"
-	maxTrackedClients       = "SWWAF_MAX_TRACKED_CLIENTS"
+	rateLimitExemptNets  = "SWW_RATE_LIMIT_EXEMPT_NETS"
-	clientRequestTimeout    = "SWWAF_CLIENT_REQUEST_TIMEOUT"
+	denyNets             = "SWW_DENY_NETS"
-	clientHeaderMaxBytes    = "SWWAF_CLIENT_REQUEST_HEADER_MAX_BYTES"
+	rateLimitPerMinute   = "SWW_RATE_LIMIT_PER_MINUTE"
-	clientIdleTimeout       = "SWWAF_CLIENT_IDLE_TIMEOUT"
+	rateLimitPerHour     = "SWW_RATE_LIMIT_PER_HOUR"
-	clientResponseTimeout   = "SWWAF_CLIENT_RESPONSE_TIMEOUT"
+	rateLimitPerDay      = "SWW_RATE_LIMIT_PER_DAY"
-	upstreamRequestTimeout  = "SWWAF_UPSTREAM_REQUEST_TIMEOUT"
+	rateLimitExemptPaths = "SWW_RATE_LIMIT_EXEMPT_PATHS"
-	upstreamResponseTimeout = "SWWAF_UPSTREAM_RESPONSE_TIMEOUT"
+	bytesLimitPerMinute  = "SWW_BYTES_LIMIT_PER_MINUTE"
-	requestMaxBytes         = "SWWAF_REQUEST_MAX_BYTES"
+	bytesLimitPerHour    = "SWW_BYTES_LIMIT_PER_HOUR"
-	responseMaxBytes        = "SWWAF_RESPONSE_MAX_BYTES"
+	bytesLimitPerDay     = "SWW_BYTES_LIMIT_PER_DAY"
-	allowNets               = "SWWAF_ALLOW_NETS"
+	bytesCount           = "SWW_BYTES_COUNT"
-	rateLimitExemptNets     = "SWWAF_RATE_LIMIT_EXEMPT_NETS"
+	lookupSource         = "SWW_LOOKUP_SOURCE"
-	denyNets                = "SWWAF_DENY_NETS"
+	lookupDBPath         = "SWW_LOOKUP_DB_PATH"
-	rateLimitPerMinute      = "SWWAF_RATE_LIMIT_PER_MINUTE"
+	lookupTimeout        = "SWW_LOOKUP_TIMEOUT"
-	rateLimitPerHour        = "SWWAF_RATE_LIMIT_PER_HOUR"
+	addLookupHeaders     = "SWW_ADD_LOOKUP_HEADERS"
-	rateLimitPerDay         = "SWWAF_RATE_LIMIT_PER_DAY"
+	deniedCountries      = "SWW_DENIED_COUNTRIES"
-	rateLimitExemptPaths    = "SWWAF_RATE_LIMIT_EXEMPT_PATHS"
+	allowedCountries     = "SWW_EXCLUSIVELY_ALLOWED_COUNTRIES"
-	bytesLimitPerMinute     = "SWWAF_BYTES_LIMIT_PER_MINUTE"
+	asnLimitPercent      = "SWW_ASN_LIMIT_PERCENT"
-	bytesLimitPerHour       = "SWWAF_BYTES_LIMIT_PER_HOUR"
+	countryLimitPercent  = "SWW_COUNTRY_LIMIT_PERCENT"
-	bytesLimitPerDay        = "SWWAF_BYTES_LIMIT_PER_DAY"
+	asnBytesPercent      = "SWW_ASN_BYTES_PERCENT"
-	bytesCount              = "SWWAF_BYTES_COUNT"
+	countryBytesPercent  = "SWW_COUNTRY_BYTES_PERCENT"
-	lookupSource            = "SWWAF_LOOKUP_SOURCE"
+	unknownLimitPercent  = "SWW_UNKNOWN_LIMIT_PERCENT"
-	lookupDBPath            = "SWWAF_LOOKUP_DB_PATH"
+	asnLimitPercentURL   = "SWW_ASN_LIMIT_PERCENT_URL"
-	lookupTimeout           = "SWWAF_LOOKUP_TIMEOUT"
+	blocklistURLs        = "SWW_BLOCKLIST_URLS"
-	addLookupHeaders        = "SWWAF_ADD_LOOKUP_HEADERS"
+	blocklistRefresh     = "SWW_BLOCKLIST_REFRESH"
-	deniedCountries         = "SWWAF_DENIED_COUNTRIES"
+	blocklistAction      = "SWW_BLOCKLIST_ACTION"
-	allowedCountries        = "SWWAF_EXCLUSIVELY_ALLOWED_COUNTRIES"
+	dnsblZones           = "SWW_DNSBL_ZONES"
-	asnLimitPercent         = "SWWAF_ASN_LIMIT_PERCENT"
+	dnsblResolver        = "SWW_DNSBL_RESOLVER"
-	countryLimitPercent     = "SWWAF_COUNTRY_LIMIT_PERCENT"
+	abuseIPDBKey         = "SWW_ABUSEIPDB_KEY"
-	asnBytesPercent         = "SWWAF_ASN_BYTES_PERCENT"
+	abuseIPDBMinScore    = "SWW_ABUSEIPDB_MIN_SCORE"
-	countryBytesPercent     = "SWWAF_COUNTRY_BYTES_PERCENT"
+	abuseIPDBDailyBudget = "SWW_ABUSEIPDB_DAILY_BUDGET"
-	unknownLimitPercent     = "SWWAF_UNKNOWN_LIMIT_PERCENT"
+	reputationAction     = "SWW_REPUTATION_ACTION"
-	asnLimitPercentURL      = "SWWAF_ASN_LIMIT_PERCENT_URL"
+	reputationCacheTTL   = "SWW_REPUTATION_CACHE_TTL"
-	blocklistURLs           = "SWWAF_BLOCKLIST_URLS"
+	reputationTimeout    = "SWW_REPUTATION_TIMEOUT"
-	blocklistRefresh        = "SWWAF_BLOCKLIST_REFRESH"
+	crowdSecURL          = "SWW_CROWDSEC_LAPI_URL"
-	blocklistAction         = "SWWAF_BLOCKLIST_ACTION"
+	crowdSecKey          = "SWW_CROWDSEC_LAPI_KEY"
-	dnsblZones              = "SWWAF_DNSBL_ZONES"
+	banResponse          = "SWW_BAN_RESPONSE"
-	dnsblResolver           = "SWWAF_DNSBL_RESOLVER"
+	limitBanDuration     = "SWW_LIMIT_BAN_DURATION"
-	abuseIPDBKey            = "SWWAF_ABUSEIPDB_KEY"
+	limitBanRepeatWindow = "SWW_LIMIT_BAN_REPEAT_WINDOW"
-	abuseIPDBMinScore       = "SWWAF_ABUSEIPDB_MIN_SCORE"
+	maxBanDuration       = "SWW_MAX_BAN_DURATION"
-	abuseIPDBDailyBudget    = "SWWAF_ABUSEIPDB_DAILY_BUDGET"
+	attackBanDuration    = "SWW_ATTACK_BAN_DURATION"
-	reputationAction        = "SWWAF_REPUTATION_ACTION"
+	maxBans              = "SWW_MAX_BANS"
-	reputationCacheTTL      = "SWWAF_REPUTATION_CACHE_TTL"
+	banScopeV4Prefix     = "SWW_BAN_SCOPE_V4_PREFIX"
-	reputationTimeout       = "SWWAF_REPUTATION_TIMEOUT"
+	stateDir             = "SWW_STATE_DIR"
-	crowdSecURL             = "SWWAF_CROWDSEC_LAPI_URL"
+	stateWriteDelay      = "SWW_STATE_WRITE_DELAY"
-	crowdSecKey             = "SWWAF_CROWDSEC_LAPI_KEY"
+	stateCounterInterval = "SWW_STATE_COUNTER_INTERVAL"
-	banResponse             = "SWWAF_BAN_RESPONSE"
+	adminToken           = "SWW_ADMIN_TOKEN"   //nolint:gosec // the setting's name
-	limitBanDuration        = "SWWAF_LIMIT_BAN_DURATION"
+	metricsToken         = "SWW_METRICS_TOKEN" //nolint:gosec // the setting's name
-	limitBanRepeatWindow    = "SWWAF_LIMIT_BAN_REPEAT_WINDOW"
+	metricsTopN          = "SWW_METRICS_TOP_N"
-	maxBanDuration          = "SWWAF_MAX_BAN_DURATION"
+	instanceName         = "SWW_INSTANCE_NAME"
-	attackBanDuration       = "SWWAF_ATTACK_BAN_DURATION"
+	logRequestHeaders    = "SWW_LOG_REQUEST_HEADERS"
-	maxBans                 = "SWWAF_MAX_BANS"
+	logLevel             = "SWW_LOG_LEVEL"
-	banScopeV4Prefix        = "SWWAF_BAN_SCOPE_V4_PREFIX"
+	rulesDir             = "SWW_RULES_DIR"
-	stateDir                = "SWWAF_STATE_DIR"
+	rulesEnabled         = "SWW_RULES_ENABLED"
-	stateWriteDelay         = "SWWAF_STATE_WRITE_DELAY"
+	wafMode              = "SWW_WAF_MODE"
-	stateCounterInterval    = "SWWAF_STATE_COUNTER_INTERVAL"
+	wafParanoiaLevel     = "SWW_WAF_PARANOIA_LEVEL"
-	adminToken              = "SWWAF_ADMIN_TOKEN"   //nolint:gosec // the setting's name
+	wafAnomalyThreshold  = "SWW_WAF_ANOMALY_THRESHOLD"
-	metricsToken            = "SWWAF_METRICS_TOKEN" //nolint:gosec // the setting's name
+	wafDisabledRules     = "SWW_WAF_DISABLED_RULES"
-	metricsTopN             = "SWWAF_METRICS_TOP_N"
+	wafExemptPaths       = "SWW_WAF_EXEMPT_PATHS"
-	instanceName            = "SWWAF_INSTANCE_NAME"
+	wafBodyLimit         = "SWW_WAF_BODY_LIMIT"
-	logRequestHeaders       = "SWWAF_LOG_REQUEST_HEADERS"
+	exclusionsFile       = "SWW_CORE_RULE_SET_EXCLUSIONS_FILE"
-	logLevel                = "SWWAF_LOG_LEVEL"
+	apps                 = "SWW_APPS"
-	rulesDir                = "SWWAF_RULES_DIR"
+	trapPaths            = "SWW_TRAP_PATHS"
-	rulesEnabled            = "SWWAF_RULES_ENABLED"
+	errorBurstThreshold  = "SWW_ERROR_BURST_THRESHOLD"
-	wafMode                 = "SWWAF_WAF_MODE"
+	logRemoteURL         = "SWW_LOG_REMOTE_URL"
-	wafParanoiaLevel        = "SWWAF_WAF_PARANOIA_LEVEL"
+	logRemoteTLSCAFile   = "SWW_LOG_REMOTE_TLS_CA_FILE"
-	wafAnomalyThreshold     = "SWWAF_WAF_ANOMALY_THRESHOLD"
+	logRemoteBuffer      = "SWW_LOG_REMOTE_BUFFER"
-	wafDisabledRules        = "SWWAF_WAF_DISABLED_RULES"
+	logRemoteFacility    = "SWW_LOG_REMOTE_FACILITY"
-	wafExemptPaths          = "SWWAF_WAF_EXEMPT_PATHS"
+	logRemoteAppName     = "SWW_LOG_REMOTE_APP_NAME"
-	wafBodyLimit            = "SWWAF_WAF_BODY_LIMIT"
+	alertWebhookURL      = "SWW_ALERT_WEBHOOK_URL"
-	trapPaths               = "SWWAF_TRAP_PATHS"
+	alertWebhookHeaders  = "SWW_ALERT_WEBHOOK_HEADERS"
-	errorBurstThreshold     = "SWWAF_ERROR_BURST_THRESHOLD"
+	alertSlackWebhookURL = "SWW_ALERT_SLACK_WEBHOOK_URL"
-	logRemoteURL            = "SWWAF_LOG_REMOTE_URL"
+	alertNtfyURL         = "SWW_ALERT_NTFY_URL"
-	logRemoteTLSCAFile      = "SWWAF_LOG_REMOTE_TLS_CA_FILE"
+	alertNtfyToken       = "SWW_ALERT_NTFY_TOKEN" //nolint:gosec // the setting's name
-	logRemoteBuffer         = "SWWAF_LOG_REMOTE_BUFFER"
+	alertEvents          = "SWW_ALERT_EVENTS"
-	logRemoteFacility       = "SWWAF_LOG_REMOTE_FACILITY"
+	alertCooldown        = "SWW_ALERT_COOLDOWN"
-	logRemoteAppName        = "SWWAF_LOG_REMOTE_APP_NAME"
+	alertMaxPerHour      = "SWW_ALERT_MAX_PER_HOUR"
-	alertWebhookURL         = "SWWAF_ALERT_WEBHOOK_URL"
+	anomalyNetV4Prefix   = "SWW_ANOMALY_NET_V4_PREFIX"
-	alertWebhookHeaders     = "SWWAF_ALERT_WEBHOOK_HEADERS"
+	anomalyNetV6Prefix   = "SWW_ANOMALY_NET_V6_PREFIX"
-	alertSlackWebhookURL    = "SWWAF_ALERT_SLACK_WEBHOOK_URL"
+	watchNets            = "SWW_WATCH_NETS"
-	alertNtfyURL            = "SWWAF_ALERT_NTFY_URL"
-	alertNtfyToken          = "SWWAF_ALERT_NTFY_TOKEN" //nolint:gosec // the setting's name
-	alertEvents             = "SWWAF_ALERT_EVENTS"
-	alertCooldown           = "SWWAF_ALERT_COOLDOWN"
-	alertMaxPerHour         = "SWWAF_ALERT_MAX_PER_HOUR"
-	anomalyNetV4Prefix      = "SWWAF_ANOMALY_NET_V4_PREFIX"
-	anomalyNetV6Prefix      = "SWWAF_ANOMALY_NET_V6_PREFIX"
-	watchNets               = "SWWAF_WATCH_NETS"
 )
 
 // The anomaly thresholds: each of the prefixes below, which name a scope,
 // followed by each of the four ends.
 const (
-	anomalyClient = "SWWAF_ANOMALY_CLIENT_"
+	anomalyClient = "SWW_ANOMALY_CLIENT_"
-	anomalyNet    = "SWWAF_ANOMALY_NET_"
+	anomalyNet    = "SWW_ANOMALY_NET_"
-	anomalyASN    = "SWWAF_ANOMALY_ASN_"
+	anomalyASN    = "SWW_ANOMALY_ASN_"
-	anomalyTotal  = "SWWAF_ANOMALY_TOTAL_"
+	anomalyTotal  = "SWW_ANOMALY_TOTAL_"
-	watch         = "SWWAF_WATCH_"
+	watch         = "SWW_WATCH_"
 
 	requestsPerMinute = "REQUESTS_PER_MINUTE"
 	requestsPerHour   = "REQUESTS_PER_HOUR"
@@ -165,21 +157,21 @@ func loggedAnomalyDefaults() map[string]string {
 	return logged
 }
 
-// defaultAlertEvents is the default of SWWAF_ALERT_EVENTS, and
+// defaultAlertEvents is the default of SWW_ALERT_EVENTS, and
-// defaultAlertCooldown that of SWWAF_ALERT_COOLDOWN.
+// defaultAlertCooldown that of SWW_ALERT_COOLDOWN.
 const (
 	defaultAlertEvents = "ban,permanent_ban,waf_block,anomaly,reputation_hit," +
 		"source_failure,file_error"
 	defaultAlertCooldown = "15m"
 )
 
-// defaultReputationCacheTTL is the default of SWWAF_REPUTATION_CACHE_TTL.
+// defaultReputationCacheTTL is the default of SWW_REPUTATION_CACHE_TTL.
 const defaultReputationCacheTTL = "24h"
 
-// defaultWAFDisabledRules is the default of SWWAF_WAF_DISABLED_RULES.
+// defaultWAFDisabledRules is the default of SWW_WAF_DISABLED_RULES.
 const defaultWAFDisabledRules = "920340,920420,920440,920640,930130,930140"
 
-// defaultLogRequestHeaders is the default of SWWAF_LOG_REQUEST_HEADERS.
+// defaultLogRequestHeaders is the default of SWW_LOG_REQUEST_HEADERS.
 const defaultLogRequestHeaders = "accept,accept-language,accept-encoding," +
 	"content-type,origin,range"
 
@@ -204,10 +196,10 @@ const (
 	otherToken = "fedcba9876543210fedcba9876543210"
 )
 
-// instance is an SWWAF_INSTANCE_NAME that is a valid app name too, and
+// instance is an SWW_INSTANCE_NAME that is a valid app name too, and
-// remoteURL an SWWAF_LOG_REMOTE_URL, for the tests that send the lines.
+// remoteURL an SWW_LOG_REMOTE_URL, for the tests that send the lines.
 const (
-	instance  = "fsn1app1/gitea"
+	instance  = "fsn1app1/blog"
 	remoteURL = "syslog+udp://192.0.2.1:514"
 )
 
@@ -217,7 +209,7 @@ const off = "off"
 // enabled is true, as a setting's value.
 const enabled = "true"
 
-// defaultLookupSource is the default of SWWAF_LOOKUP_SOURCE, and
+// defaultLookupSource is the default of SWW_LOOKUP_SOURCE, and
 // fileSource the source that is the lookup database.
 const (
 	defaultLookupSource = "geojs"
@@ -254,17 +246,9 @@ func TestDefaults(t *testing.T) {
 	wantSettings(t, cfg, config.Config{
 		ListenAddr:           ":8080",
 		Observe:              false,
-		ClientRequestTimeout:        time.Minute,
+		RateLimitPerMinute:   120,
-		ClientRequestHeaderMaxBytes: 32 << 10,
+		RateLimitPerHour:     1500,
-		ClientIdleTimeout:           2 * time.Minute,
+		RateLimitPerDay:      6000,
-		ClientResponseTimeout:       30 * time.Minute,
-		UpstreamRequestTimeout:      time.Minute,
-		UpstreamResponseTimeout:     30 * time.Minute,
-		RequestMaxBytes:             100 << 20,
-		ResponseMaxBytes:            5 << 30,
-		RateLimitPerMinute:          1000,
-		RateLimitPerHour:            10000,
-		RateLimitPerDay:             50000,
 		BanResponse:          403,
 		LimitBanDuration:     time.Hour,
 		LimitBanRepeatWindow: 24 * time.Hour,
@@ -272,28 +256,22 @@ func TestDefaults(t *testing.T) {
 		AttackBanDuration:    7 * 24 * time.Hour,
 		MaxBans:              5000,
 		BanScopeV4Prefix:     32,
-		StateDir:                    "/var/lib/smallwebwaf",
+		StateDir:             "/var/lib/sww",
 		StateWriteDelay:      10 * time.Second,
 		StateCounterInterval: 15 * time.Minute,
 		MetricsToken:         "",
 		MetricsTopN:          50,
-		RulesDir:                    "/etc/smallwebwaf/rules.d",
+		RulesDir:             "/etc/sww/rules.d",
 		RulesEnabled:         true,
 	})
 	wantLookupSettings(t, cfg, config.Config{
-		LookupSource: defaultLookupSource, LookupTimeout: time.Second,
+		LookupSource: defaultLookupSource, LookupTimeout: 800 * time.Millisecond,
 	})
 	wantByteLimitSettings(t, cfg, config.Config{
-		BytesLimitPerMinute: 10 << 30, BytesLimitPerHour: 20 << 30,
+		BytesLimitPerMinute: 0, BytesLimitPerHour: 50 << 30,
-		BytesLimitPerDay: 50 << 30, BytesCount: "both",
+		BytesLimitPerDay: 100 << 30, BytesCount: "both",
 	})
 
-	if cfg.UpstreamURL.String() != "http://127.0.0.1:8081" {
-		t.Errorf("%s is %s", upstreamURL, cfg.UpstreamURL)
-	}
-
-	wantNetblocks(t, cfg.TrustedProxies,
-		"10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16")
 	wantNetblocks(t, cfg.AllowNets)
 	wantNetblocks(t, cfg.RateLimitExemptNets)
 	wantNetblocks(t, cfg.DenyNets)
@@ -322,12 +300,17 @@ func TestNoSingleRequestBreaksAByteLimitAtTheDefaults(t *testing.T) {
 
 	cfg := fromEnvironment(t, environment{})
 
+	rproxy, err := rproxyConfig(map[string]string{wafBackend: backendURL})
+	if err != nil {
+		t.Fatalf("settings: %v", err)
+	}
+
 	// The largest request body and the largest response, both counted.
-	largest := cfg.RequestMaxBytes + cfg.ResponseMaxBytes
+	largest := rproxy.MaxRequestSize + rproxy.MaxResponseSize
 	for _, limit := range []int64{
 		cfg.BytesLimitPerMinute, cfg.BytesLimitPerHour, cfg.BytesLimitPerDay,
 	} {
-		if largest > limit {
+		if limit != 0 && largest > limit { // 0 is off
 			t.Errorf("a request of %d bytes breaks the byte limit of %d", largest, limit)
 		}
 	}
@@ -338,17 +321,7 @@ func TestValuesAsSet(t *testing.T) {
 
 	cfg := fromEnvironment(t, environment{
 		listenAddr:           "127.0.0.1:9000",
-		upstreamURL:             "https://app.internal:8443/",
 		mode:                 "observe",
-		trustedProxies:          " 192.0.2.1, 10.1.2.3/8 ,2001:db8::/32",
-		clientRequestTimeout:    "90s",
-		clientHeaderMaxBytes:    "8K",
-		clientIdleTimeout:       "5m",
-		clientResponseTimeout:   "7d",
-		upstreamRequestTimeout:  "1h30m",
-		upstreamResponseTimeout: off,
-		requestMaxBytes:         "512K",
-		responseMaxBytes:        "1234",
 		allowNets:            "192.0.2.7",
 		rateLimitExemptNets:  "2001:db8::/48, 10.9.8.7",
 		denyNets:             "198.51.100.0/24",
@@ -376,14 +349,6 @@ func TestValuesAsSet(t *testing.T) {
 	wantSettings(t, cfg, config.Config{
 		ListenAddr:           "127.0.0.1:9000",
 		Observe:              true,
-		ClientRequestTimeout:        90 * time.Second,
-		ClientRequestHeaderMaxBytes: 8 << 10,
-		ClientIdleTimeout:           5 * time.Minute,
-		ClientResponseTimeout:       7 * 24 * time.Hour,
-		UpstreamRequestTimeout:      90 * time.Minute,
-		UpstreamResponseTimeout:     0,
-		RequestMaxBytes:             512 << 10,
-		ResponseMaxBytes:            1234,
 		RateLimitPerMinute:   60,
 		RateLimitPerHour:     600,
 		RateLimitPerDay:      6000,
@@ -403,11 +368,6 @@ func TestValuesAsSet(t *testing.T) {
 		RulesEnabled:         false,
 	})
 
-	if cfg.UpstreamURL.String() != "https://app.internal:8443/" {
-		t.Errorf("%s is %s", upstreamURL, cfg.UpstreamURL)
-	}
-
-	wantNetblocks(t, cfg.TrustedProxies, "192.0.2.1/32", "10.0.0.0/8", "2001:db8::/32")
 	wantNetblocks(t, cfg.AllowNets, "192.0.2.7/32")
 	wantNetblocks(t, cfg.RateLimitExemptNets, "2001:db8::/48", "10.9.8.7/32")
 	wantNetblocks(t, cfg.DenyNets, "198.51.100.0/24")
@@ -581,13 +541,14 @@ func TestCoreRuleSetSettings(t *testing.T) {
 			environment{
 				wafMode: config.WAFModeDetect, wafParanoiaLevel: "4", wafAnomalyThreshold: "10",
 				wafDisabledRules: "942100, 920350", wafExemptPaths: "/api/, /static/",
-				wafBodyLimit: "128K",
+				wafBodyLimit: "32K", exclusionsFile: "/etc/sww/crs-exclusions.conf",
 			},
 			config.Config{
 				WAFMode: config.WAFModeDetect, WAFParanoiaLevel: 4, WAFAnomalyThreshold: 10,
 				WAFDisabledRules:          []int{942100, 920350},
 				WAFExemptPaths:            []string{"/api/", "/static/"},
-				WAFBodyLimit:     128 << 10,
+				WAFBodyLimit:              32 << 10,
+				CoreRuleSetExclusionsFile: "/etc/sww/crs-exclusions.conf",
 			},
 		},
 		{
@@ -608,6 +569,7 @@ func TestCoreRuleSetSettings(t *testing.T) {
 			WAFAnomalyThreshold: cfg.WAFAnomalyThreshold,
 			WAFDisabledRules:    cfg.WAFDisabledRules, WAFExemptPaths: cfg.WAFExemptPaths,
 			WAFBodyLimit:              cfg.WAFBodyLimit,
+			CoreRuleSetExclusionsFile: cfg.CoreRuleSetExclusionsFile,
 		}
 		if !reflect.DeepEqual(got, tc.want) {
 			t.Errorf("%v gave\n%+v\nwant\n%+v", tc.env, got, tc.want)
@@ -615,12 +577,98 @@ func TestCoreRuleSetSettings(t *testing.T) {
 	}
 }
 
-func TestWAFBodyLimitOf1G(t *testing.T) {
+func TestApps(t *testing.T) {
 	t.Parallel()
 
-	cfg := fromEnvironment(t, environment{wafBodyLimit: "1G"})
+	for _, tc := range []struct {
-	if cfg.WAFBodyLimit != 1<<30 {
+		env  environment
-		t.Errorf("1G read as %d", cfg.WAFBodyLimit)
+		want map[string][]string
+	}{
+		{environment{}, nil},
+		{environment{apps: ""}, map[string][]string{}},
+		{
+			environment{apps: "Git.Example.com:gitea; cloud.example.com : gitea "},
+			map[string][]string{
+				"git.example.com": {"gitea"}, "cloud.example.com": {"gitea"},
+			},
+		},
+	} {
+		cfg := fromEnvironment(t, tc.env)
+		if !reflect.DeepEqual(cfg.Apps, tc.want) {
+			t.Errorf("%v gave %#v, want %#v", tc.env, cfg.Apps, tc.want)
+		}
+	}
+}
+
+// Unset and set empty, SWW_APPS has opposite effects, so it logs differently.
+func TestUnsetAndEmptyAppsAreLoggedDifferently(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		env  environment
+		want string
+	}{
+		{environment{}, `"` + apps + `":null`},
+		{environment{apps: ""}, `"` + apps + `":""`},
+	} {
+		var out bytes.Buffer
+
+		slog.New(slog.NewJSONHandler(&out, nil)).
+			Info("starting", "settings", fromEnvironment(t, tc.env))
+
+		if !strings.Contains(out.String(), tc.want) {
+			t.Errorf("%v logged %s, want %s in it", tc.env, out.String(), tc.want)
+		}
+	}
+}
+
+func TestInvalidAppsStopsTheStart(t *testing.T) {
+	t.Parallel()
+
+	const (
+		notEntry = " is not a hostname, : and a list of apps, " +
+			"such as git.example.com:gitea"
+		notHostname = " is not a DNS name such as git.example.com"
+	)
+
+	for _, tc := range []struct{ value, want string }{
+		{"git.example.com:gitea;blog.example.com", `"blog.example.com"` + notEntry},
+		{"git.example.com:gitea;", `""` + notEntry},
+		{":gitea", `":gitea"` + notEntry},
+		{"git.example.com:", `"git.example.com:"` + notEntry},
+		{"*.example.com:gitea", `"*.example.com"` + notHostname},
+		{"git.example.com/:gitea", `"git.example.com/"` + notHostname},
+		{"git example.com:gitea", `"git example.com"` + notHostname},
+		{
+			"git.example.com:gitea,nextcloud",
+			`"nextcloud" is not an app sww has fixes for; the apps are gitea`,
+		},
+		{
+			"git.example.com:gitea;GIT.example.com:gitea",
+			`"git.example.com" is listed twice`,
+		},
+		{"git.example.com:gitea,gitea", `"gitea" is listed twice`},
+		{"git.example.com:gitea,", `"gitea," has an empty item in its list`},
+	} {
+		t.Run(tc.value, func(t *testing.T) {
+			t.Parallel()
+
+			_, err := config.FromEnvironment(environment{apps: tc.value}.lookupEnv)
+
+			want := apps + ": " + tc.want
+			if err == nil || err.Error() != want {
+				t.Errorf("error %v, want %s", err, want)
+			}
+		})
+	}
+}
+
+func TestWAFBodyLimitOf64K(t *testing.T) {
+	t.Parallel()
+
+	cfg := fromEnvironment(t, environment{wafBodyLimit: "64K"})
+	if cfg.WAFBodyLimit != 64<<10 {
+		t.Errorf("64K read as %d", cfg.WAFBodyLimit)
 	}
 }
 
@@ -630,7 +678,7 @@ func TestInvalidCoreRuleSetSettingStopsTheStart(t *testing.T) {
 	const (
 		notParanoiaLevel = " is not a paranoia level, from 1 to 4"
 		setupRule        = " is from 900000 to 900999, the ids of the rules that set " +
-			"the Core Rule Set up and of smallwebwaf's own, which cannot be switched off"
+			"the Core Rule Set up and of sww's own, which cannot be switched off"
 	)
 
 	for _, tc := range []struct{ name, value, want string }{
@@ -669,10 +717,11 @@ func TestInvalidCoreRuleSetSettingStopsTheStart(t *testing.T) {
 			wafBodyLimit, "128KB",
 			`"128KB" is not a size such as 512K, 100M or 5G, or off`,
 		},
-		{wafBodyLimit, "2G", `"2G" is more than 1G, the most Coraza reads`},
+		{wafBodyLimit, "65K", `"65K" is more than 64K, the most discriminator ` +
+			`gets of a body`},
 		{
-			wafBodyLimit, "1073741825",
+			wafBodyLimit, "65537",
-			`"1073741825" is more than 1G, the most Coraza reads`,
+			`"65537" is more than 64K, the most discriminator gets of a body`,
 		},
 	} {
 		t.Run(tc.name+"="+tc.value, func(t *testing.T) {
@@ -692,11 +741,11 @@ func TestInstanceNameAndLoggedHeadersAsSet(t *testing.T) {
 	t.Parallel()
 
 	cfg := fromEnvironment(t, environment{
-		instanceName:      "fsn1app1/gitea",
+		instanceName:      "fsn1app1/blog",
 		logRequestHeaders: " Accept , X-Custom",
 	})
 
-	if cfg.InstanceName != "fsn1app1/gitea" ||
+	if cfg.InstanceName != "fsn1app1/blog" ||
 		!slices.Equal(cfg.LogRequestHeaders, []string{"accept", "x-custom"}) {
 		t.Errorf("%s is %q and %s gives %v", instanceName, cfg.InstanceName,
 			logRequestHeaders, cfg.LogRequestHeaders)
@@ -839,7 +888,7 @@ func TestInstanceNameNotAnAppNameStopsTheStartOnlyWhileSending(t *testing.T) {
 
 	want := logRemoteAppName + `: is unset, and ` + instanceName +
 		` "fsn1 app1", its default, is not 1 to 48 printable ASCII characters ` +
-		`without a space, such as gitea`
+		`without a space, such as blog`
 	if err == nil || err.Error() != want {
 		t.Errorf("error %v, want %s", err, want)
 	}
@@ -868,7 +917,7 @@ func TestAppNameSetStopsTheStartWhileSending(t *testing.T) {
 	}.lookupEnv)
 
 	want := logRemoteAppName + `: "my app" is not 1 to 48 printable ASCII ` +
-		`characters without a space, such as gitea`
+		`characters without a space, such as blog`
 	if err == nil || err.Error() != want {
 		t.Errorf("error %v, want %s", err, want)
 	}
@@ -898,7 +947,7 @@ func TestAlertSettingsAsSet(t *testing.T) {
 	const (
 		webhook = "https://alerts.example:8443/hooks/waf?team=ops"
 		slack   = "https://hooks.slack.example/services/T0123/B4567/abcdef"
-		ntfy    = "https://ntfy.example/smallwebwaf-alerts"
+		ntfy    = "https://ntfy.example/sww-alerts"
 		token   = "tk_0123456789abcdefghijklmnopq"
 	)
 
@@ -946,17 +995,17 @@ func TestInvalidAlertSettingStopsTheStart(t *testing.T) {
 	t.Parallel()
 
 	wantStartStopped(t, []struct{ name, value string }{
-		{alertWebhookURL, "alerts.example/smallwebwaf"},
+		{alertWebhookURL, "alerts.example/sww"},
 		{alertWebhookURL, "ftp://alerts.example/"},
-		{alertWebhookURL, "https:///smallwebwaf"},
+		{alertWebhookURL, "https:///sww"},
 		{alertWebhookURL, "https://user:password@alerts.example/"},
 		{alertWebhookURL, "https://alerts.example/#top"},
 		{alertWebhookURL, "https://alerts.example:0/"},
 		{alertWebhookURL, "https://alerts.example:65536/"},
 		{alertSlackWebhookURL, "hooks.slack.example/services/T0123"},
 		{alertSlackWebhookURL, "https://user:password@hooks.slack.example/"},
-		{alertNtfyURL, "ntfy://ntfy.example/smallwebwaf-alerts"},
+		{alertNtfyURL, "ntfy://ntfy.example/sww-alerts"},
-		{alertNtfyURL, "https://ntfy.example/smallwebwaf-alerts#top"},
+		{alertNtfyURL, "https://ntfy.example/sww-alerts#top"},
 		{alertWebhookHeaders, "Authorization"},
 		{alertWebhookHeaders, "X Team:ops"},
 		{alertWebhookHeaders, ":ops"},
@@ -1036,7 +1085,7 @@ func TestWebhookURLIsLoggedWithoutItsPathOrQueryAndNeverShown(t *testing.T) {
 		_, err := config.FromEnvironment(environment{alertWebhookURL: value}.lookupEnv)
 
 		want := alertWebhookURL + ": is not an http or https URL without a user or " +
-			"a fragment, such as https://alerts.example/smallwebwaf"
+			"a fragment, such as https://alerts.example/sww"
 		if err == nil || err.Error() != want {
 			t.Errorf("error %v, want %s", err, want)
 		}
@@ -1050,7 +1099,7 @@ func TestSlackAndNtfySettingsAreLoggedWithoutTheirSecrets(t *testing.T) {
 
 	cfg := fromEnvironment(t, environment{
 		alertSlackWebhookURL: "https://hooks.slack.example/services/T0123/B4567/abcdef",
-		alertNtfyURL:         "https://ntfy.example/smallwebwaf-alerts",
+		alertNtfyURL:         "https://ntfy.example/sww-alerts",
 		alertNtfyToken:       token,
 	})
 
@@ -1069,7 +1118,7 @@ func TestSlackAndNtfySettingsAreLoggedWithoutTheirSecrets(t *testing.T) {
 		}
 	}
 
-	for _, secret := range []string{"T0123", "smallwebwaf-alerts", token} {
+	for _, secret := range []string{"T0123", "sww-alerts", token} {
 		if strings.Contains(logged, secret) {
 			t.Errorf("%s in the settings logged: %s", secret, logged)
 		}
@@ -1100,7 +1149,7 @@ func TestInstanceNameWithAControlCharacterStopsTheStartOnlyWithNtfySet(t *testin
 	const name = "fsn1app1\r"
 
 	_, err := config.FromEnvironment(environment{
-		instanceName: name, alertNtfyURL: "https://ntfy.example/smallwebwaf-alerts",
+		instanceName: name, alertNtfyURL: "https://ntfy.example/sww-alerts",
 	}.lookupEnv)
 
 	want := instanceName + `: "fsn1app1\r" holds a control character, such as the ` +
@@ -1165,7 +1214,7 @@ func TestLookupSettingsAsSet(t *testing.T) {
 
 	cfg = fromEnvironment(t, environment{lookupSource: off})
 	wantLookupSettings(t, cfg, config.Config{
-		LookupSource: off, LookupTimeout: time.Second,
+		LookupSource: off, LookupTimeout: 800 * time.Millisecond,
 	})
 }
 
@@ -1242,7 +1291,7 @@ func TestSettingNeedingLookupsStopsTheStartWhileTheyAreOff(t *testing.T) {
 	}
 
 	// Set empty, the lists need nothing looked up, and nor does
-	// SWWAF_UNKNOWN_LIMIT_PERCENT at 100, which lowers no limit, an anomaly
+	// SWW_UNKNOWN_LIMIT_PERCENT at 100, which lowers no limit, an anomaly
 	// threshold per AS number that is off, any other anomaly threshold, or
 	// a blocklist.
 	env := environment{
@@ -1480,7 +1529,7 @@ const (
 	asnURL  = "https://lists.example/asn.txt"
 )
 
-// The actions of SWWAF_BLOCKLIST_ACTION, as Config gives them.
+// The actions of SWW_BLOCKLIST_ACTION, as Config gives them.
 const (
 	actionDeny  = "deny"
 	actionLimit = "limit"
@@ -1576,7 +1625,7 @@ func TestASNLimitPercentURLThatIsABlocklistStopsTheStart(t *testing.T) {
 		blocklistURLs: dropURL + "," + asnURL, asnLimitPercentURL: asnURL,
 	}.lookupEnv)
 
-	want := asnLimitPercentURL + `: "` + asnURL + `" is in SWWAF_BLOCKLIST_URLS too`
+	want := asnLimitPercentURL + `: "` + asnURL + `" is in SWW_BLOCKLIST_URLS too`
 	if err == nil || err.Error() != want {
 		t.Errorf("error %v, want %s", err, want)
 	}
@@ -1879,7 +1928,7 @@ func TestInvalidCrowdSecSettingStopsTheStartSayingWhatIsWrong(t *testing.T) {
 		notLAPIURL = " is not an http or https URL without a user or a fragment, " +
 			"such as http://172.17.0.1:8080"
 		anotherList = `gives the decision list "` + lapi + `/v1/decisions", which is in ` +
-			`SWWAF_BLOCKLIST_URLS or is SWWAF_ASN_LIMIT_PERCENT_URL too`
+			`SWW_BLOCKLIST_URLS or is SWW_ASN_LIMIT_PERCENT_URL too`
 	)
 
 	for _, tc := range []struct {
@@ -1967,45 +2016,15 @@ func TestSizesAndOff(t *testing.T) {
 	t.Parallel()
 
 	cfg := fromEnvironment(t, environment{
-		requestMaxBytes:      "3G",
+		bytesLimitPerMinute: "3G",
-		responseMaxBytes:     off,
+		bytesLimitPerHour:   off,
-		clientRequestTimeout: off,
+		alertCooldown:       off,
-		clientIdleTimeout:    off,
 	})
 
-	if cfg.RequestMaxBytes != 3<<30 || cfg.ResponseMaxBytes != 0 ||
+	if cfg.BytesLimitPerMinute != 3<<30 || cfg.BytesLimitPerHour != 0 ||
-		cfg.ClientRequestTimeout != 0 || cfg.ClientIdleTimeout != 0 {
+		cfg.AlertCooldown != 0 {
-		t.Errorf("3G, off, off and off read as %d, %d, %s and %s",
+		t.Errorf("3G, off and off read as %d, %d and %s",
-			cfg.RequestMaxBytes, cfg.ResponseMaxBytes, cfg.ClientRequestTimeout,
+			cfg.BytesLimitPerMinute, cfg.BytesLimitPerHour, cfg.AlertCooldown)
-			cfg.ClientIdleTimeout)
-	}
-}
-
-func TestRequestHeaderMaxBytesJustOver4K(t *testing.T) {
-	t.Parallel()
-
-	cfg := fromEnvironment(t, environment{clientHeaderMaxBytes: "4097"})
-	if cfg.ClientRequestHeaderMaxBytes != 4097 {
-		t.Errorf("4097 read as %d", cfg.ClientRequestHeaderMaxBytes)
-	}
-}
-
-func TestRequestHeaderMaxBytesRefusalNeverOffersOff(t *testing.T) {
-	t.Parallel()
-
-	for _, value := range []string{"32KB", "0", "4K", off} {
-		t.Run(value, func(t *testing.T) {
-			t.Parallel()
-
-			_, err := config.FromEnvironment(
-				environment{clientHeaderMaxBytes: value}.lookupEnv)
-
-			want := clientHeaderMaxBytes + `: "` + value +
-				`" is not a size of more than 4K, such as 32K`
-			if err == nil || err.Error() != want {
-				t.Errorf("error %v, want %s", err, want)
-			}
-		})
 	}
 }
 
@@ -2034,34 +2053,12 @@ func TestBanResponseCloseIsZero(t *testing.T) {
 	}
 }
 
-func TestTrustedProxiesSetButEmptyTrustNothing(t *testing.T) {
-	t.Parallel()
-
-	cfg := fromEnvironment(t, environment{trustedProxies: ""})
-	if len(cfg.TrustedProxies) != 0 {
-		t.Errorf("trusted proxies %v, want none", cfg.TrustedProxies)
-	}
-}
-
 func TestInvalidValueStopsTheStart(t *testing.T) {
 	t.Parallel()
 
 	wantStartStopped(t, []struct{ name, value string }{
 		{listenAddr, "8080"}, {listenAddr, ":http"}, {listenAddr, ":65536"},
-		{upstreamURL, "127.0.0.1:8081"},
-		{upstreamURL, "ftp://127.0.0.1:8081"},
-		{upstreamURL, "http://"},
-		{upstreamURL, "http://:8081"},
-		{upstreamURL, "http://127.0.0.1:0"},
-		{upstreamURL, "http://127.0.0.1:99999"},
-		{upstreamURL, "http://127.0.0.1:8081/app"},
-		{upstreamURL, "http://127.0.0.1:8081/?a=1"},
-		{upstreamURL, "http://user:secret@127.0.0.1:8081"},
 		{mode, "Observe"}, {mode, "block"}, {mode, ""},
-		{trustedProxies, "10.0.0.0/33"},
-		{trustedProxies, "traefik"},
-		{trustedProxies, "10.0.0.0/8,,192.168.0.0/16"},
-		{trustedProxies, "fe80::1%eth0"},
 		{ipv6GroupPrefix, "31"}, {ipv6GroupPrefix, "129"}, {ipv6GroupPrefix, "/64"},
 		{ipv6GroupPrefix, off}, {ipv6GroupPrefix, ""},
 		{maxTrackedClients, "0"}, {maxTrackedClients, "-1"}, {maxTrackedClients, off},
@@ -2069,19 +2066,18 @@ func TestInvalidValueStopsTheStart(t *testing.T) {
 		{allowNets, "192.0.2.0/24,monitoring"},
 		{rateLimitExemptNets, "2001:db8::/129"},
 		{denyNets, "198.51.100.0/24,"},
-		{clientRequestTimeout, "60"}, {clientRequestTimeout, ""},
+		{alertCooldown, "60"}, {alertCooldown, ""},
-		{clientIdleTimeout, "0s"},
+		{alertCooldown, "0s"},
-		{clientIdleTimeout, "2 minutes"},
+		{alertCooldown, "2 minutes"},
-		{clientResponseTimeout, "1y"},
+		{alertCooldown, "1y"},
-		{upstreamRequestTimeout, "-1s"},
+		{alertCooldown, "-1s"},
-		{upstreamResponseTimeout, "0s"},
+		{alertCooldown, "1.5d"},
-		{upstreamResponseTimeout, "1.5d"},
+		{bytesLimitPerMinute, "100MB"},
-		{requestMaxBytes, "100MB"},
+		{bytesLimitPerMinute, "100m"},
-		{requestMaxBytes, "100m"},
+		{bytesLimitPerMinute, "1.5M"},
-		{requestMaxBytes, "1.5M"},
+		{bytesLimitPerHour, "0"},
-		{responseMaxBytes, "0"},
+		{bytesLimitPerHour, "-5"},
-		{responseMaxBytes, "-5"},
+		{bytesLimitPerHour, "99999999999G"},
-		{responseMaxBytes, "99999999999G"},
 		{rateLimitPerMinute, ""},
 		{rateLimitPerMinute, "1K"},
 		{rateLimitPerHour, "0"},
@@ -2134,7 +2130,7 @@ func TestInvalidBanOrStateValueStopsTheStart(t *testing.T) {
 		{maxBanDuration, off}, {maxBanDuration, "1w"}, {attackBanDuration, off},
 		{maxBans, off}, {maxBans, "0"}, {maxBans, "5K"},
 		{banScopeV4Prefix, "33"}, {banScopeV4Prefix, "-1"}, {banScopeV4Prefix, "/24"},
-		{stateDir, ""}, {stateDir, "state"}, {stateDir, "./var/lib/smallwebwaf"},
+		{stateDir, ""}, {stateDir, "state"}, {stateDir, "./var/lib/sww"},
 		{stateWriteDelay, off}, {stateWriteDelay, "0s"},
 		{stateCounterInterval, off}, {stateCounterInterval, "15"},
 	})
@@ -2246,10 +2242,10 @@ func TestSettingFromFileIsCheckedAsTheSettingItself(t *testing.T) {
 	t.Parallel()
 
 	_, err := config.FromEnvironment(environment{
-		requestMaxBytes + "_FILE": writeFile(t, "lots\n"),
+		bytesLimitPerMinute + "_FILE": writeFile(t, "lots\n"),
 	}.lookupEnv)
 
-	want := requestMaxBytes + `: "lots" is not a size such as 512K, 100M or 5G, or off`
+	want := bytesLimitPerMinute + `: "lots" is not a size such as 512K, 100M or 5G, or off`
 	if err == nil || err.Error() != want {
 		t.Errorf("error %v, want %s", err, want)
 	}
@@ -2261,7 +2257,7 @@ func TestSettingFromFileIsCheckedAsTheSettingItself(t *testing.T) {
 	}.lookupEnv)
 
 	want = logRemoteAppName + `: "my app" is not 1 to 48 printable ASCII ` +
-		`characters without a space, such as gitea`
+		`characters without a space, such as blog`
 	if err == nil || err.Error() != want {
 		t.Errorf("error %v, want %s", err, want)
 	}
@@ -2354,38 +2350,28 @@ func writeFile(t *testing.T, contents string) string {
 func TestLogsEachSettingWithItsValue(t *testing.T) {
 	t.Parallel()
 
-	cfg := fromEnvironment(t, environment{clientRequestTimeout: "45s"})
+	cfg := fromEnvironment(t, environment{rateLimitPerMinute: "45"})
 	hostname, _ := os.Hostname()
 
 	want := map[string]string{
 		listenAddr:           ":8080",
-		upstreamURL:             "http://127.0.0.1:8081",
 		mode:                 "enforce",
-		trustedProxies:          "10.0.0.0/8,172.16.0.0/12,192.168.0.0/16",
 		ipv6GroupPrefix:      "64",
 		maxTrackedClients:    "20000",
-		clientRequestTimeout:    "45s",
-		clientHeaderMaxBytes:    "32K",
-		clientIdleTimeout:       "120s",
-		clientResponseTimeout:   "30m",
-		upstreamRequestTimeout:  "60s",
-		upstreamResponseTimeout: "30m",
-		requestMaxBytes:         "100M",
-		responseMaxBytes:        "5G",
 		allowNets:            "",
 		rateLimitExemptNets:  "",
 		denyNets:             "",
-		rateLimitPerMinute:      "1000",
+		rateLimitPerMinute:   "45",
-		rateLimitPerHour:        "10000",
+		rateLimitPerHour:     "1500",
-		rateLimitPerDay:         "50000",
+		rateLimitPerDay:      "6000",
 		rateLimitExemptPaths: "",
-		bytesLimitPerMinute:     "10G",
+		bytesLimitPerMinute:  "off",
-		bytesLimitPerHour:       "20G",
+		bytesLimitPerHour:    "50G",
-		bytesLimitPerDay:        "50G",
+		bytesLimitPerDay:     "100G",
 		bytesCount:           "both",
 		lookupSource:         defaultLookupSource,
 		lookupDBPath:         "",
-		lookupTimeout:           "1s",
+		lookupTimeout:        "800ms",
 		addLookupHeaders:     "false",
 		deniedCountries:      "",
 		allowedCountries:     "",
@@ -2415,7 +2401,7 @@ func TestLogsEachSettingWithItsValue(t *testing.T) {
 		attackBanDuration:    "7d",
 		maxBans:              "5000",
 		banScopeV4Prefix:     "32",
-		stateDir:                "/var/lib/smallwebwaf",
+		stateDir:             "/var/lib/sww",
 		stateWriteDelay:      "10s",
 		stateCounterInterval: "15m",
 		adminToken:           "",
@@ -2424,7 +2410,7 @@ func TestLogsEachSettingWithItsValue(t *testing.T) {
 		instanceName:         hostname,
 		logRequestHeaders:    defaultLogRequestHeaders,
 		logLevel:             "info",
-		rulesDir:                "/etc/smallwebwaf/rules.d",
+		rulesDir:             "/etc/sww/rules.d",
 		rulesEnabled:         "true",
 		wafMode:              config.WAFModeBlock,
 		wafParanoiaLevel:     "1",
@@ -2432,6 +2418,8 @@ func TestLogsEachSettingWithItsValue(t *testing.T) {
 		wafDisabledRules:     defaultWAFDisabledRules,
 		wafExemptPaths:       "",
 		wafBodyLimit:         off,
+		exclusionsFile:       "",
+		apps:                 "", // logged as null, which decodes as ""
 		trapPaths:            "",
 		errorBurstThreshold:  "30",
 		logRemoteURL:         "",
@@ -2481,14 +2469,6 @@ func wantSettings(t *testing.T, got *config.Config, want config.Config) {
 
 	if got.ListenAddr != want.ListenAddr ||
 		got.Observe != want.Observe ||
-		got.ClientRequestTimeout != want.ClientRequestTimeout ||
-		got.ClientRequestHeaderMaxBytes != want.ClientRequestHeaderMaxBytes ||
-		got.ClientIdleTimeout != want.ClientIdleTimeout ||
-		got.ClientResponseTimeout != want.ClientResponseTimeout ||
-		got.UpstreamRequestTimeout != want.UpstreamRequestTimeout ||
-		got.UpstreamResponseTimeout != want.UpstreamResponseTimeout ||
-		got.RequestMaxBytes != want.RequestMaxBytes ||
-		got.ResponseMaxBytes != want.ResponseMaxBytes ||
 		got.RateLimitPerMinute != want.RateLimitPerMinute ||
 		got.RateLimitPerHour != want.RateLimitPerHour ||
 		got.RateLimitPerDay != want.RateLimitPerDay {

internal/config/rproxy.go

@@ -0,0 +1,192 @@
+package config
+
+import (
+	"errors"
+	"fmt"
+	"log/slog"
+	"math"
+	"net/netip"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// RProxy is the settings of `sww rproxy`. A size or time limit of zero
+// is off.
+type RProxy struct {
+	// ListenAddr is where rproxy listens (SWRP_LISTEN_ADDR).
+	ListenAddr string
+	// UpstreamURL is the app (SWRP_UPSTREAM_URL).
+	UpstreamURL *url.URL
+	// TrustedProxies are the netblocks whose X-Forwarded-For is believed
+	// (SWRP_TRUSTED_PROXIES).
+	TrustedProxies []netip.Prefix
+	// WAFBackend is discriminator's URL (SWRP_WAF_BACKEND).
+	WAFBackend *url.URL
+	// Timeout is how long rproxy waits for discriminator's answer to a question,
+	// and to a report (SWRP_TIMEOUT_MS). It cannot be off.
+	Timeout time.Duration
+	// DefaultDisposition is what is done with a request when discriminator cannot be
+	// connected to, does not answer at all, or does not answer within Timeout:
+	// allow or deny (SWRP_DEFAULT_DISPOSITION).
+	DefaultDisposition string
+	// MaxRequestSize is the largest request body (SWRP_MAX_REQUEST_SIZE), and
+	// MaxResponseSize the largest response body (SWRP_MAX_RESPONSE_SIZE).
+	MaxRequestSize  int64
+	MaxResponseSize int64
+	// MaxRequestTime bounds sending the whole request: the visitor's request
+	// line and headers, and then, from their end, its body on its way to the
+	// app (SWRP_MAX_REQUEST_TIME_MS). MaxResponseTime bounds the answer, from
+	// the end of the request to its last byte reaching the visitor
+	// (SWRP_MAX_RESPONSE_TIME_MS).
+	MaxRequestTime  time.Duration
+	MaxResponseTime time.Duration
+
+	// settings are the values read, as given or by default, for the log line
+	// at start.
+	settings []slog.Attr
+}
+
+var (
+	errNeedsWAFBackend = errors.New(
+		"is required: it is discriminator's URL, such as http://discriminator:8080")
+	errNotDisposition  = errors.New("is not allow or deny")
+	errNotMilliseconds = errors.New(
+		"is not a whole number of milliseconds above zero, such as 2000")
+	errNotMillisecondsOrOff = errors.New(
+		"is not a whole number of milliseconds above zero, such as 60000, or off")
+)
+
+// RProxyFromEnvironment reads rproxy's settings with lookupEnv, normally
+// os.LookupEnv. A setting that is not set takes its default, and
+// SWRP_WAF_BACKEND, which has none, must be set. A setting that is set but
+// invalid is an error that names it. Since rproxy never touches disk, its
+// settings have no _FILE form.
+func RProxyFromEnvironment(lookupEnv func(string) (string, bool)) (*RProxy, error) {
+	env := &environment{lookupEnv: withoutFileForms(lookupEnv)}
+	cfg := &RProxy{
+		ListenAddr:         env.address("SWRP_LISTEN_ADDR"),
+		UpstreamURL:        env.appURL("SWRP_UPSTREAM_URL", defaultUpstreamURL),
+		TrustedProxies:     env.netblocks("SWRP_TRUSTED_PROXIES", privateRanges),
+		WAFBackend:         env.wafBackend("SWRP_WAF_BACKEND"),
+		Timeout:            env.milliseconds("SWRP_TIMEOUT_MS", "2000"),
+		DefaultDisposition: env.disposition("SWRP_DEFAULT_DISPOSITION", "allow"),
+		MaxRequestSize:     env.size("SWRP_MAX_REQUEST_SIZE", "100M"),
+		MaxResponseSize:    env.size("SWRP_MAX_RESPONSE_SIZE", "1G"),
+		MaxRequestTime:     env.millisecondsOrOff("SWRP_MAX_REQUEST_TIME_MS", "60000"),
+		MaxResponseTime:    env.millisecondsOrOff("SWRP_MAX_RESPONSE_TIME_MS", "1800000"),
+	}
+
+	if env.err != nil {
+		return nil, env.err
+	}
+
+	cfg.settings = env.settings
+
+	return cfg, nil
+}
+
+// RProxyListenAddrAndUpstreamURL reads only SWRP_LISTEN_ADDR and
+// SWRP_UPSTREAM_URL. The health check in rproxy's container needs no other
+// setting, so it reads no other.
+func RProxyListenAddrAndUpstreamURL(
+	lookupEnv func(string) (string, bool),
+) (string, *url.URL, error) {
+	env := &environment{lookupEnv: withoutFileForms(lookupEnv)}
+	listenAddr := env.address("SWRP_LISTEN_ADDR")
+	upstreamURL := env.appURL("SWRP_UPSTREAM_URL", defaultUpstreamURL)
+
+	if env.err != nil {
+		return "", nil, env.err
+	}
+
+	return listenAddr, upstreamURL, nil
+}
+
+// withoutFileForms returns lookupEnv finding no setting named with _FILE, since
+// rproxy never touches disk.
+func withoutFileForms(
+	lookupEnv func(string) (string, bool),
+) func(string) (string, bool) {
+	return func(name string) (string, bool) {
+		if strings.HasSuffix(name, "_FILE") {
+			return "", false
+		}
+
+		return lookupEnv(name)
+	}
+}
+
+// LogValue makes an RProxy log as each setting's name with the value it was
+// given, or its default.
+func (c *RProxy) LogValue() slog.Value {
+	return slog.GroupValue(c.settings...)
+}
+
+// wafBackend reads the setting that is discriminator's URL, which must be set.
+func (e *environment) wafBackend(name string) *url.URL {
+	value := e.value(name, "")
+	if value == "" {
+		e.check(name, errNeedsWAFBackend)
+
+		return nil
+	}
+
+	backend, err := parseUpstreamURL(value)
+	e.check(name, err)
+
+	return backend
+}
+
+// disposition reads the setting that is what is done with a request when discriminator
+// cannot be connected to, does not answer at all, or does not answer in time:
+// allow or deny.
+func (e *environment) disposition(name, defaultValue string) string {
+	value := e.value(name, defaultValue)
+	if value != "allow" && value != "deny" {
+		e.check(name, fmt.Errorf("%q %w", value, errNotDisposition))
+	}
+
+	return value
+}
+
+// milliseconds reads a setting that is a whole number of milliseconds above
+// zero.
+func (e *environment) milliseconds(name, defaultValue string) time.Duration {
+	value := e.value(name, defaultValue)
+
+	duration, valid := parseMilliseconds(value)
+	if !valid {
+		e.check(name, fmt.Errorf("%q %w", value, errNotMilliseconds))
+	}
+
+	return duration
+}
+
+// millisecondsOrOff reads a setting that is a whole number of milliseconds
+// above zero, or off, which is 0.
+func (e *environment) millisecondsOrOff(name, defaultValue string) time.Duration {
+	value := e.value(name, defaultValue)
+	if value == off {
+		return 0
+	}
+
+	duration, valid := parseMilliseconds(value)
+	if !valid {
+		e.check(name, fmt.Errorf("%q %w", value, errNotMillisecondsOrOff))
+	}
+
+	return duration
+}
+
+// parseMilliseconds reads a whole number of milliseconds above zero, and
+// reports whether it is one.
+func parseMilliseconds(value string) (time.Duration, bool) {
+	n, err := strconv.ParseInt(value, 10, 64)
+	if err != nil || n <= 0 || n > math.MaxInt64/int64(time.Millisecond) {
+		return 0, false
+	}
+
+	return time.Duration(n) * time.Millisecond, true
+}

internal/config/rproxy_test.go

@@ -0,0 +1,231 @@
+package config_test
+
+import (
+	"net/netip"
+	"os"
+	"path/filepath"
+	"slices"
+	"strings"
+	"testing"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/config"
+)
+
+// rproxy's settings, by name, and their values in these tests.
+const (
+	wafBackend        = "SWRP_WAF_BACKEND"
+	rproxyTimeout     = "SWRP_TIMEOUT_MS"
+	rproxyDefault     = "SWRP_DEFAULT_DISPOSITION"
+	rproxyListen      = "SWRP_LISTEN_ADDR"
+	rproxyUpstream    = "SWRP_UPSTREAM_URL"
+	rproxyTrusted     = "SWRP_TRUSTED_PROXIES"
+	rproxyMaxRequest  = "SWRP_MAX_REQUEST_SIZE"
+	rproxyMaxResponse = "SWRP_MAX_RESPONSE_SIZE"
+	rproxyRequestTime = "SWRP_MAX_REQUEST_TIME_MS"
+	rproxyAnswerTime  = "SWRP_MAX_RESPONSE_TIME_MS"
+	backendURL        = "http://discriminator:8080"
+	rproxyDefaultAddr = ":8080"
+	rproxyDefaultApp  = "http://127.0.0.1:8081"
+	notASize          = "a lot"
+)
+
+// rproxyConfig reads rproxy's settings from env.
+func rproxyConfig(env map[string]string) (*config.RProxy, error) {
+	return config.RProxyFromEnvironment(func(name string) (string, bool) {
+		value, ok := env[name]
+
+		return value, ok
+	})
+}
+
+func TestRProxyDefaults(t *testing.T) {
+	t.Parallel()
+
+	cfg, err := rproxyConfig(map[string]string{wafBackend: backendURL})
+	if err != nil {
+		t.Fatalf("settings: %v", err)
+	}
+
+	if cfg.ListenAddr != rproxyDefaultAddr ||
+		cfg.UpstreamURL.String() != rproxyDefaultApp ||
+		cfg.WAFBackend.String() != backendURL {
+		t.Errorf("addresses %q, %v, %v", cfg.ListenAddr, cfg.UpstreamURL, cfg.WAFBackend)
+	}
+
+	if cfg.Timeout != 2*time.Second || cfg.DefaultDisposition != "allow" {
+		t.Errorf("timeout %v, default disposition %q", cfg.Timeout, cfg.DefaultDisposition)
+	}
+
+	if cfg.MaxRequestSize != 100<<20 || cfg.MaxResponseSize != 1<<30 {
+		t.Errorf("sizes %d and %d", cfg.MaxRequestSize, cfg.MaxResponseSize)
+	}
+
+	if cfg.MaxRequestTime != time.Minute || cfg.MaxResponseTime != 30*time.Minute {
+		t.Errorf("times %v and %v", cfg.MaxRequestTime, cfg.MaxResponseTime)
+	}
+
+	want := []netip.Prefix{
+		netip.MustParsePrefix("10.0.0.0/8"),
+		netip.MustParsePrefix("172.16.0.0/12"),
+		netip.MustParsePrefix("192.168.0.0/16"),
+	}
+	if !slices.Equal(cfg.TrustedProxies, want) {
+		t.Errorf("trusted proxies %v, want %v", cfg.TrustedProxies, want)
+	}
+}
+
+func TestRProxySettingsAreRead(t *testing.T) {
+	t.Parallel()
+
+	cfg, err := rproxyConfig(map[string]string{
+		wafBackend:        "https://waf.example:8443",
+		rproxyListen:      ":9000",
+		rproxyUpstream:    "http://app:3000",
+		rproxyTrusted:     "192.0.2.0/24",
+		rproxyTimeout:     "150",
+		rproxyDefault:     "deny",
+		rproxyMaxRequest:  "1K",
+		rproxyMaxResponse: off,
+		rproxyRequestTime: off,
+		rproxyAnswerTime:  "250",
+	})
+	if err != nil {
+		t.Fatalf("settings: %v", err)
+	}
+
+	if cfg.ListenAddr != ":9000" || cfg.UpstreamURL.Host != "app:3000" ||
+		cfg.WAFBackend.Host != "waf.example:8443" ||
+		cfg.TrustedProxies[0] != netip.MustParsePrefix("192.0.2.0/24") {
+		t.Errorf("addresses %+v", cfg)
+	}
+
+	if cfg.Timeout != 150*time.Millisecond || cfg.DefaultDisposition != "deny" ||
+		cfg.MaxRequestSize != 1024 || cfg.MaxResponseSize != 0 ||
+		cfg.MaxRequestTime != 0 || cfg.MaxResponseTime != 250*time.Millisecond {
+		t.Errorf("limits %+v", cfg)
+	}
+}
+
+func TestRProxyInvalidSettingsAreRefused(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name, value string
+	}{
+		{wafBackend, ""},
+		{wafBackend, "discriminator:8080"},
+		{wafBackend, "http://discriminator:8080/path"},
+		{rproxyTimeout, "0"},
+		{rproxyTimeout, "-1"},
+		{rproxyTimeout, off},
+		{rproxyTimeout, "2s"},
+		{rproxyTimeout, "1.25"},
+		{rproxyTimeout, "99999999999999999"},
+		{rproxyDefault, "maybe"},
+		{rproxyListen, "8080"},
+		{rproxyUpstream, "app"},
+		{rproxyUpstream, "127.0.0.1:8081"},
+		{rproxyUpstream, "ftp://127.0.0.1:8081"},
+		{rproxyUpstream, "http://"},
+		{rproxyUpstream, "http://:8081"},
+		{rproxyUpstream, "http://127.0.0.1:0"},
+		{rproxyUpstream, "http://127.0.0.1:99999"},
+		{rproxyUpstream, "http://127.0.0.1:8081/app"},
+		{rproxyUpstream, "http://127.0.0.1:8081/?a=1"},
+		{rproxyUpstream, "http://user:secret@127.0.0.1:8081"},
+		{rproxyTrusted, "not a netblock"},
+		{rproxyTrusted, "10.0.0.0/33"},
+		{rproxyTrusted, "10.0.0.0/8,,192.168.0.0/16"},
+		{rproxyTrusted, "fe80::1%eth0"},
+		{rproxyMaxRequest, notASize},
+		{rproxyMaxResponse, notASize},
+		{rproxyRequestTime, "0"},
+		{rproxyRequestTime, "1m"},
+		{rproxyAnswerTime, "0"},
+	} {
+		t.Run(tc.name+"="+tc.value, func(t *testing.T) {
+			t.Parallel()
+
+			_, err := rproxyConfig(map[string]string{wafBackend: backendURL, tc.name: tc.value})
+			if err == nil || !strings.HasPrefix(err.Error(), tc.name+": ") {
+				t.Errorf("error %v, want one naming %s", err, tc.name)
+			}
+		})
+	}
+}
+
+func TestRProxyTrustedProxiesSetButEmptyTrustNothing(t *testing.T) {
+	t.Parallel()
+
+	cfg, err := rproxyConfig(map[string]string{wafBackend: backendURL, rproxyTrusted: ""})
+	if err != nil {
+		t.Fatalf("settings: %v", err)
+	}
+
+	if len(cfg.TrustedProxies) != 0 {
+		t.Errorf("trusted proxies %v, want none", cfg.TrustedProxies)
+	}
+}
+
+func TestRProxyNeedsItsBackend(t *testing.T) {
+	t.Parallel()
+
+	_, err := rproxyConfig(nil)
+	if err == nil || !strings.HasPrefix(err.Error(), wafBackend+": is required") {
+		t.Errorf("error %v, want one saying %s is required", err, wafBackend)
+	}
+}
+
+func TestRProxyReadsNoFile(t *testing.T) {
+	t.Parallel()
+
+	path := filepath.Join(t.TempDir(), "backend")
+
+	err := os.WriteFile(path, []byte("http://from-a-file:8080\n"), 0o600)
+	if err != nil {
+		t.Fatalf("write: %v", err)
+	}
+
+	_, err = rproxyConfig(map[string]string{wafBackend + "_FILE": path})
+	if err == nil || !strings.HasPrefix(err.Error(), wafBackend+": is required") {
+		t.Errorf("error %v, want %s still required", err, wafBackend)
+	}
+
+	cfg, err := rproxyConfig(map[string]string{
+		wafBackend:              backendURL,
+		rproxyTimeout + "_FILE": "/nonexistent/timeout",
+	})
+	if err != nil {
+		t.Fatalf("settings: %v, with the file left unread", err)
+	}
+
+	if cfg.Timeout != 2*time.Second {
+		t.Errorf("timeout %v, want the default", cfg.Timeout)
+	}
+}
+
+func TestRProxySettingsAreLoggedByName(t *testing.T) {
+	t.Parallel()
+
+	cfg, err := rproxyConfig(map[string]string{wafBackend: backendURL})
+	if err != nil {
+		t.Fatalf("settings: %v", err)
+	}
+
+	group := cfg.LogValue().Group()
+
+	names := make([]string, 0, len(group))
+	for _, attr := range group {
+		names = append(names, attr.Key)
+	}
+
+	for _, name := range []string{
+		rproxyListen, rproxyUpstream, rproxyTrusted, wafBackend, rproxyTimeout, rproxyDefault,
+		rproxyMaxRequest, rproxyMaxResponse, rproxyRequestTime, rproxyAnswerTime,
+	} {
+		if !slices.Contains(names, name) {
+			t.Errorf("%s is not logged, only %v", name, names)
+		}
+	}
+}

internal/discriminator/admin.go

@@ -1,4 +1,4 @@
-package proxy
+package discriminator
 
 import (
 	"bytes"
@@ -9,7 +9,6 @@ import (
 	"io"
 	"net/http"
 	"net/netip"
-	"os"
 	"strings"
 	"time"
 
@@ -41,16 +40,22 @@ var (
 	errNotAddress = errors.New("is not an address, such as 203.0.113.9")
 )
 
-// answerAdmin answers a request for smallwebwaf itself, under
+// answerHealth answers a request for the health endpoint.
-// /_smallwebwaf/, once it has passed the checks. Each endpoint needs a
+func (rq *request) answerHealth() {
-// token, sent as Authorization: Bearer <token>: the metrics
+	rq.line.Action = requestlog.ActionAdmin
-// SWWAF_METRICS_TOKEN, the others SWWAF_ADMIN_TOKEN. A request without
+	// Set here rather than left to Go's server, which would set it only
-// it is refused with 401, which counts toward the error burst. An
+	// after the log line has taken the response's headers.
-// endpoint whose token is unset answers 404, as any other request under
+	rq.out.Header().Set("Content-Type", "text/plain; charset=utf-8")
-// /_smallwebwaf/ does.
+	_, _ = io.WriteString(rq.out, "ok\n")
+}
+
+// answerAdmin answers a request for one of discriminator's own endpoints. Each
+// needs a token, sent as Authorization: Bearer <token>: the metrics
+// SWW_METRICS_TOKEN, the others SWW_ADMIN_TOKEN. A request without it is
+// refused with 401. An endpoint whose token is unset answers 404, as any other
+// path does.
 func (rq *request) answerAdmin() {
 	rq.line.Action = requestlog.ActionAdmin
-	rq.startClientResponseTimeout()
 
 	token, answer := rq.endpoint()
 
@@ -58,12 +63,8 @@ func (rq *request) answerAdmin() {
 	case token == "":
 		http.Error(rq.out, http.StatusText(http.StatusNotFound), http.StatusNotFound)
 	case !hasToken(rq.in, token):
-		rq.tokenRefused = true
 		rq.out.Header().Set("WWW-Authenticate", "Bearer")
-		rq.answer(refusal{
+		http.Error(rq.out, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
-			status: http.StatusUnauthorized,
-			action: requestlog.ActionAdmin,
-		})
 	default:
 		answer()
 	}
@@ -120,26 +121,7 @@ type banToAdd struct {
 // an admin, from now for the duration the body gives, with its reason,
 // and answers with that ban.
 func (rq *request) addBan() {
-	// The body must arrive within SWWAF_CLIENT_REQUEST_TIMEOUT, as any
-	// other request's must.
-	rq.stopReadingBody(rq.clientRequestDeadline())
-
 	toAdd, err := rq.readBanToAdd()
-	if refused := rq.refused.Load(); refused != nil {
-		rq.answer(*refused) // the body is over SWWAF_REQUEST_MAX_BYTES
-
-		return
-	}
-
-	if errors.Is(err, os.ErrDeadlineExceeded) {
-		rq.answer(refusal{
-			status: http.StatusRequestTimeout,
-			action: requestlog.ActionTimedOut,
-			limit:  "SWWAF_CLIENT_REQUEST_TIMEOUT",
-		})
-
-		return
-	}
 
 	var (
 		netblock netip.Prefix
@@ -168,12 +150,9 @@ func (rq *request) addBan() {
 // readBanToAdd reads the body of POST BansPath: a JSON object with
 // nothing but whitespace after it, in at most banBodyMaxBytes.
 func (rq *request) readBanToAdd() (banToAdd, error) {
-	var body io.ReadCloser = http.NoBody
+	data, err := io.ReadAll(http.MaxBytesReader(nil, rq.in.Body, banBodyMaxBytes))
-	if rq.body != nil {
+	rq.requestBytes = int64(len(data))
-		body = rq.body
-	}
 
-	data, err := io.ReadAll(http.MaxBytesReader(nil, body, banBodyMaxBytes))
 	if err != nil {
 		return banToAdd{}, fmt.Errorf("%w: %w", errNotBanToAdd, err)
 	}
@@ -271,9 +250,9 @@ type clientAnswer struct {
 	Bans   []state.BanEntry  `json:"bans"`
 }
 
-// showClient answers GET ClientsPath<ip> with what smallwebwaf knows of
+// showClient answers GET ClientsPath<ip> with what discriminator knows of the client:
-// the client: its counters, its history, which holds its country as last
+// its counters, its history, which holds its country as last looked up and its
-// looked up and its offences, and its bans with their notes.
+// offences, and its bans with their notes.
 func (rq *request) showClient() {
 	addr, err := pathAddress(rq.in.URL.Path, ClientsPath)
 	if err != nil {

internal/discriminator/admin_test.go

@@ -1,30 +1,27 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"encoding/json"
 	"net/http"
 	"net/netip"
 	"reflect"
-	"strconv"
 	"strings"
 	"testing"
 	"time"
 
 	"sneak.berlin/go/smallwebwaf/internal/bans"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
 	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 	"sneak.berlin/go/smallwebwaf/internal/state"
 )
 
 const (
-	adminToken = "SWWAF_ADMIN_TOKEN" //nolint:gosec // the setting's name
+	adminToken = "SWW_ADMIN_TOKEN" //nolint:gosec // the setting's name
-	// adminSecret is the SWWAF_ADMIN_TOKEN the tests set, and adminBearer
+	// adminSecret is the SWW_ADMIN_TOKEN the tests set, and adminBearer
 	// how a request carries it.
 	adminSecret = "fedcba9876543210fedcba9876543210"
 	adminBearer = "Bearer " + adminSecret
-	// adminClient is the client the tests' admin sends its requests from.
-	adminClient = "192.0.2.10"
 	// banOtherClient is the body of a request to ban otherClient for an
 	// hour.
 	banOtherClient = `{"netblock": "` + otherClient + `", "duration": "1h", ` +
@@ -43,8 +40,7 @@ func TestAdminEndpointsAreOffWhileTheTokenIsUnset(t *testing.T) {
 	// An empty token does not match the unset one either.
 	for _, authorization := range []string{adminBearer, bearer, "Bearer ", ""} {
 		for _, e := range adminEndpoints() {
-			s.adminRequest(adminClient, authorization, e.method, e.path, e.body,
+			s.adminRequest(authorization, e.method, e.path, e.body, http.StatusNotFound)
-				http.StatusNotFound, requestlog.ActionAdmin)
 		}
 	}
 
@@ -71,8 +67,8 @@ func TestAdminEndpointsNeedTheAdminToken(t *testing.T) {
 		for _, authorization := range []string{
 			"", bearer, "Bearer " + strings.ToUpper(adminSecret), "Basic " + adminSecret,
 		} {
-			got := s.adminRequest(adminClient, authorization, e.method, e.path, e.body,
+			got := s.adminRequest(authorization, e.method, e.path, e.body,
-				http.StatusUnauthorized, requestlog.ActionAdmin)
+				http.StatusUnauthorized)
 			if got.header.Get("WWW-Authenticate") != "Bearer" {
 				t.Errorf("%s %s with %q was answered without WWW-Authenticate: Bearer",
 					e.method, e.path, authorization)
@@ -90,13 +86,13 @@ func TestAdminEndpointsNeedTheAdminToken(t *testing.T) {
 		}
 	}
 
-	// Any other request under /_smallwebwaf/ is not found.
+	// Any other request under /_sww/ is not found.
 	for _, e := range []adminEndpoint{
-		{http.MethodPut, proxy.BansPath, banOtherClient},
+		{http.MethodPut, discriminator.BansPath, banOtherClient},
-		{http.MethodDelete, proxy.BansPath, ""},
+		{http.MethodDelete, discriminator.BansPath, ""},
-		{http.MethodGet, proxy.BansPath + "/" + otherClient, ""},
+		{http.MethodGet, discriminator.BansPath + "/" + otherClient, ""},
-		{http.MethodPost, proxy.ClientsPath + otherClient, ""},
+		{http.MethodPost, discriminator.ClientsPath + otherClient, ""},
-		{http.MethodGet, strings.TrimSuffix(proxy.ClientsPath, "/"), ""},
+		{http.MethodGet, strings.TrimSuffix(discriminator.ClientsPath, "/"), ""},
 	} {
 		s.admin(e.method, e.path, e.body, http.StatusNotFound)
 	}
@@ -122,8 +118,8 @@ func TestBanAddedListedAndLiftedThroughTheEndpoints(t *testing.T) {
 		Reason:   "probes for logins",
 	}
 
-	wantBans(t, s.admin(http.MethodPost, proxy.BansPath, banOtherClient, http.StatusOK),
+	wantBans(t, s.admin(http.MethodPost, discriminator.BansPath, banOtherClient,
-		want)
+		http.StatusOK), want)
 
 	line := s.get(client, http.StatusForbidden, requestlog.ActionBanned)
 	if line.BanExpires != requestlog.FormatTime(expires) {
@@ -133,7 +129,7 @@ func TestBanAddedListedAndLiftedThroughTheEndpoints(t *testing.T) {
 	// Its notes count the request it refused.
 	want.Notes.Requests, want.Notes.Refused = 1, 1
 
-	wantBans(t, s.admin(http.MethodGet, proxy.BansPath, "", http.StatusOK), want)
+	wantBans(t, s.admin(http.MethodGet, discriminator.BansPath, "", http.StatusOK), want)
 
 	// Ten minutes on, lifting the bans on client lifts that one, which is
 	// kept, marked lifted.
@@ -142,13 +138,13 @@ func TestBanAddedListedAndLiftedThroughTheEndpoints(t *testing.T) {
 	lifted := clk.Now()
 	want.Lifted = &lifted
 
-	wantBans(t, s.admin(http.MethodDelete, proxy.BansPath+"/"+client, "",
+	wantBans(t, s.admin(http.MethodDelete, discriminator.BansPath+"/"+client, "",
 		http.StatusOK), want)
 	s.get(client, http.StatusOK, requestlog.ActionForward)
-	wantBans(t, s.admin(http.MethodGet, proxy.BansPath, "", http.StatusOK), want)
+	wantBans(t, s.admin(http.MethodGet, discriminator.BansPath, "", http.StatusOK), want)
 
 	// No ban on it is active any more.
-	s.admin(http.MethodDelete, proxy.BansPath+"/"+client, "", http.StatusNotFound)
+	s.admin(http.MethodDelete, discriminator.BansPath+"/"+client, "", http.StatusNotFound)
 }
 
 func TestBanToAddGivesItsNetblockAndDuration(t *testing.T) {
@@ -185,7 +181,8 @@ func TestBanToAddGivesItsNetblockAndDuration(t *testing.T) {
 			want.Expires = &expires
 		}
 
-		wantBans(t, s.admin(http.MethodPost, proxy.BansPath, body, http.StatusOK), want)
+		wantBans(t, s.admin(http.MethodPost, discriminator.BansPath, body, http.StatusOK),
+			want)
 	}
 }
 
@@ -254,7 +251,8 @@ func TestBanToAddThatCannotBeReadIsRefused(t *testing.T) {
 			"request body too large",
 		},
 	} {
-		got := s.admin(http.MethodPost, proxy.BansPath, tc.body, http.StatusBadRequest)
+		got := s.admin(http.MethodPost, discriminator.BansPath, tc.body,
+			http.StatusBadRequest)
 		if !strings.Contains(string(got.body), tc.want) {
 			t.Errorf("%.80s was answered %q, want it to say %q", tc.body, got.body, tc.want)
 		}
@@ -265,64 +263,12 @@ func TestBanToAddThatCannotBeReadIsRefused(t *testing.T) {
 	}
 }
 
-func TestBanToAddOverTheRequestSizeLimitIsRefused(t *testing.T) {
-	t.Parallel()
-
-	s, _, server := startWithClock(t, "", map[string]string{
-		adminToken:      adminSecret,
-		requestMaxBytes: "16",
-	})
-
-	// Sent in a chunk, its length is not announced, so that it is found
-	// over SWWAF_REQUEST_MAX_BYTES only as it is read.
-	chunk := `{"netblock": "203.0.113.9", "duration": "1h"}`
-	s.adminRequest(adminClient, adminBearer+"\r\nTransfer-Encoding: chunked",
-		http.MethodPost, proxy.BansPath,
-		strconv.FormatInt(int64(len(chunk)), 16)+"\r\n"+chunk+"\r\n0\r\n\r\n",
-		http.StatusRequestEntityTooLarge, requestlog.ActionTooLarge)
-
-	if held := server.Ledger.Snapshot(); len(held) != 0 {
-		t.Errorf("the ledger holds %+v, want no ban", held)
-	}
-}
-
-func TestBanToAddSlowerThanTheClientRequestTimeoutIsRefused(t *testing.T) {
-	t.Parallel()
-
-	s, _, server := startWithClock(t, "", map[string]string{
-		adminToken:           adminSecret,
-		metricsToken:         token,
-		clientRequestTimeout: shortTimeoutSetting,
-	})
-
-	// The chunk announces 256 bytes and the rest of it never comes, so only
-	// the timeout ends the wait. A hold-up of the test process can only
-	// make the answer later, so the time is checked only for not being
-	// shorter than the timeout.
-	start := time.Now()
-
-	s.adminRequest(adminClient, adminBearer+"\r\nTransfer-Encoding: chunked",
-		http.MethodPost, proxy.BansPath, "100\r\n"+`{"netblock": "203.0.113.9", `,
-		http.StatusRequestTimeout, requestlog.ActionTimedOut)
-
-	if took := time.Since(start); took < shortTimeout {
-		t.Errorf("answered after %s, before the timeout of %s ran out", took, shortTimeout)
-	}
-
-	wantLimitHits(t, s.addr, clientRequestTimeout, 1)
-
-	if held := server.Ledger.Snapshot(); len(held) != 0 {
-		t.Errorf("the ledger holds %+v, want no ban", held)
-	}
-}
-
 func TestClientEndpointShowsTheClientAndItsBans(t *testing.T) {
 	t.Parallel()
 
 	s, clk, _ := startWithClock(t, "", map[string]string{
 		adminToken:         adminSecret,
 		rateLimitPerMinute: "2",
-		rateLimitExemptNets: adminClient,
 	})
 	start := clk.Now()
 
@@ -339,7 +285,8 @@ func TestClientEndpointShowsTheClientAndItsBans(t *testing.T) {
 			Bans   []state.BanEntry  `json:"bans"`
 		}
 
-		decode(t, s.admin(http.MethodGet, proxy.ClientsPath+addr, "", http.StatusOK), &got)
+		decode(t, s.admin(http.MethodGet, discriminator.ClientsPath+addr, "",
+			http.StatusOK), &got)
 
 		if got.Client == nil {
 			t.Fatalf("%s: no client", addr)
@@ -361,69 +308,16 @@ func TestClientEndpointShowsTheClientAndItsBans(t *testing.T) {
 
 	// Of an address no request came from and no ban covers, nothing is
 	// known.
-	got := s.admin(http.MethodGet, proxy.ClientsPath+"198.51.100.99", "", http.StatusOK)
+	got := s.admin(http.MethodGet, discriminator.ClientsPath+"198.51.100.99", "",
+		http.StatusOK)
 	if string(got.body) != "{\n    \"client\": null,\n    \"bans\": []\n}\n" {
 		t.Errorf("an unknown client is answered\n%s", got.body)
 	}
 
-	s.admin(http.MethodGet, proxy.ClientsPath+"203.0.113", "", http.StatusBadRequest)
+	s.admin(http.MethodGet, discriminator.ClientsPath+"203.0.113", "",
-	s.admin(http.MethodDelete, proxy.BansPath+"/203.0.113.0/24", "",
+		http.StatusBadRequest)
+	s.admin(http.MethodDelete, discriminator.BansPath+"/203.0.113.0/24", "",
 		http.StatusBadRequest)
-}
-
-func TestBannedClientIsRefusedAtTheEndpointsEvenWithTheToken(t *testing.T) {
-	t.Parallel()
-
-	s, _, _ := startWithClock(t, "", map[string]string{adminToken: adminSecret})
-
-	s.admin(http.MethodPost, proxy.BansPath, banOtherClient, http.StatusOK)
-
-	// otherClient cannot lift its own ban either.
-	for _, e := range adminEndpoints() {
-		s.adminRequest(otherClient, adminBearer, e.method, e.path, e.body,
-			http.StatusForbidden, requestlog.ActionBanned)
-	}
-}
-
-func TestAdminRequestsCountTowardTheLimits(t *testing.T) {
-	t.Parallel()
-
-	s, _, _ := startWithClock(t, "", map[string]string{
-		adminToken:         adminSecret,
-		rateLimitPerMinute: "2",
-	})
-
-	// A request refused for a missing token and one answered count toward
-	// the limit of two a minute, so the next breaks it.
-	s.adminRequest(client, "", http.MethodGet, proxy.BansPath, "",
-		http.StatusUnauthorized, requestlog.ActionAdmin)
-	s.adminRequest(client, adminBearer, http.MethodGet, proxy.BansPath, "",
-		http.StatusOK, requestlog.ActionAdmin)
-	s.adminRequest(client, adminBearer, http.MethodGet, proxy.BansPath, "",
-		http.StatusForbidden, requestlog.ActionRateLimited)
-}
-
-func TestClientInAllowNetsSkipsTheChecksButNeedsTheToken(t *testing.T) {
-	t.Parallel()
-
-	const allowed = "192.0.2.60" // in SWWAF_ALLOW_NETS
-
-	s, clk, server := startWithClock(t, "", map[string]string{
-		adminToken:         adminSecret,
-		allowNets:          allowed,
-		rateLimitPerMinute: "1",
-	})
-
-	// A ban on it refuses nothing, and its requests are not counted.
-	server.Ledger.BanForAdmin(netip.MustParsePrefix(allowed+"/32"), clk.Now(),
-		time.Time{}, "")
-
-	for range 2 {
-		s.adminRequest(allowed, "", http.MethodGet, proxy.BansPath, "",
-			http.StatusUnauthorized, requestlog.ActionAdmin)
-		s.adminRequest(allowed, adminBearer, http.MethodGet, proxy.BansPath, "",
-			http.StatusOK, requestlog.ActionAdmin)
-	}
 }
 
 func TestAdminEndpointsNeedTheTokenInObserveMode(t *testing.T) {
@@ -435,8 +329,7 @@ func TestAdminEndpointsNeedTheTokenInObserveMode(t *testing.T) {
 	})
 
 	for _, e := range adminEndpoints() {
-		s.adminRequest(adminClient, "", e.method, e.path, e.body,
+		s.adminRequest("", e.method, e.path, e.body, http.StatusUnauthorized)
-			http.StatusUnauthorized, requestlog.ActionAdmin)
 	}
 
 	if held := server.Ledger.Snapshot(); len(held) != 0 {
@@ -444,56 +337,50 @@ func TestAdminEndpointsNeedTheTokenInObserveMode(t *testing.T) {
 	}
 }
 
-// adminEndpoint is a request to an endpoint SWWAF_ADMIN_TOKEN opens.
+// adminEndpoint is a request to an endpoint SWW_ADMIN_TOKEN opens.
 type adminEndpoint struct {
 	method, path, body string
 }
 
-// adminEndpoints returns a request to each endpoint SWWAF_ADMIN_TOKEN
+// adminEndpoints returns a request to each endpoint SWW_ADMIN_TOKEN
 // opens: listing the bans, banning otherClient for an hour, lifting the
 // bans on otherClient, and asking about otherClient.
 func adminEndpoints() []adminEndpoint {
 	return []adminEndpoint{
-		{http.MethodGet, proxy.BansPath, ""},
+		{http.MethodGet, discriminator.BansPath, ""},
-		{http.MethodPost, proxy.BansPath, banOtherClient},
+		{http.MethodPost, discriminator.BansPath, banOtherClient},
-		{http.MethodDelete, proxy.BansPath + "/" + otherClient, ""},
+		{http.MethodDelete, discriminator.BansPath + "/" + otherClient, ""},
-		{http.MethodGet, proxy.ClientsPath + otherClient, ""},
+		{http.MethodGet, discriminator.ClientsPath + otherClient, ""},
 	}
 }
 
-// admin sends a request with method for path, with body, from
+// admin sends a request with method for path, with body, to discriminator's own
-// adminClient, with the admin token, and checks that it is answered with
+// address, with the admin token, and checks that it is answered with status, its
-// status, its log line's action admin. It returns the answer.
+// log line's action admin. It returns the answer.
 func (s *sender) admin(method, path, body string, status int) answer {
 	s.t.Helper()
 
-	return s.adminRequest(adminClient, adminBearer, method, path, body, status,
+	return s.adminRequest(adminBearer, method, path, body, status)
-		requestlog.ActionAdmin)
 }
 
-// adminRequest sends a request with method for path, with body, from the
+// adminRequest is admin with authorization as the request's Authorization header
-// client at from, with authorization as its Authorization header unless
+// unless it is "".
-// it is "", and checks its answer's status and its log line's action, as
-// request does. authorization may end in more header lines. A body that
-// is not "" has its length announced, unless authorization names
-// Transfer-Encoding. It returns the answer.
 func (s *sender) adminRequest(
-	from, authorization, method, path, body string, status int, action string,
+	authorization, method, path, body string, status int,
 ) answer {
 	s.t.Helper()
 
-	var header []string
+	req := newRequest(s.t, method, s.discriminatorAddr, path, strings.NewReader(body))
-
 	if authorization != "" {
-		header = append(header, "Authorization: "+authorization)
+		req.Header.Set("Authorization", authorization)
 	}
 
-	if body != "" && !strings.Contains(authorization, "Transfer-Encoding") {
+	got := do(s.t, req)
-		header = append(header, "Content-Length: "+strconv.Itoa(len(body)))
+	wantStatus(s.t, got, status)
-	}
 
-	_, got := s.requestWithBody(method, from, path, strings.Join(header, "\r\n"),
+	line := s.out.endedLines(s.t, s.sent+1)[s.sent]
-		body, status, action)
+	s.sent++
+	wantLine(s.t, line, status, requestlog.ActionAdmin)
 
 	return got
 }

internal/discriminator/alerts_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"maps"
@@ -10,15 +10,15 @@ import (
 
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 	"sneak.berlin/go/smallwebwaf/internal/bans"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
 
 const (
-	alertWebhookURL = "SWWAF_ALERT_WEBHOOK_URL"
+	alertWebhookURL = "SWW_ALERT_WEBHOOK_URL"
-	alertMaxPerHour = "SWWAF_ALERT_MAX_PER_HOUR"
+	alertMaxPerHour = "SWW_ALERT_MAX_PER_HOUR"
 	// alertInstance is the instance every alert of these tests gives.
-	alertInstance = "fsn1app1/gitea"
+	alertInstance = "fsn1app1/blog"
 )
 
 func TestBanForABrokenLimitRaisesABanAlertWithItsNotes(t *testing.T) {
@@ -201,7 +201,7 @@ func TestObserveModeWorksOutABanOnlyWhenItsAlertWouldBeSent(t *testing.T) {
 // never sent them, and returns the queue they wait in as well.
 func startWithAlerts(
 	t *testing.T, env map[string]string,
-) (*sender, *clock, *proxy.Server, *alerts.Queue) {
+) (*sender, *clock, *discriminator.Server, *alerts.Queue) {
 	t.Helper()
 
 	return startAppWithAlerts(t, func(http.ResponseWriter, *http.Request) {}, env)
@@ -210,21 +210,23 @@ func startWithAlerts(
 // startAppWithAlerts is startWithAlerts in front of the app handler.
 func startAppWithAlerts(
 	t *testing.T, handler http.HandlerFunc, env map[string]string,
-) (*sender, *clock, *proxy.Server, *alerts.Queue) {
+) (*sender, *clock, *discriminator.Server, *alerts.Queue) {
 	t.Helper()
 
 	app := startApp(t, handler)
 	clk := &clock{now: time.Date(2026, 10, 6, 0, 0, 0, 0, time.UTC)}
 	settings := map[string]string{
 		trustedProxies:  trustLocalhost,
-		alertWebhookURL: "https://alerts.example/smallwebwaf",
+		alertWebhookURL: "https://alerts.example/sww",
 		instanceName:    alertInstance,
 	}
 	maps.Copy(settings, env)
 
 	addr, out, server, queue := startProxyWithAlerts(t, app.URL, "", clk.Now, settings)
 
-	return &sender{t: t, addr: addr, out: out}, clk, server, queue
+	s := &sender{t: t, addr: addr, discriminatorAddr: server.Addr, out: out}
+
+	return s, clk, server, queue
 }
 
 // banAlert returns the alert for event, raised by a request from client at
@@ -237,6 +239,7 @@ func banAlert(
 		Instance: alertInstance,
 		Time:     raised,
 		Event:    event,
+		Host:     appHost,
 		Client:   netip.MustParseAddr(client),
 		Netblock: ban.Netblock,
 		Reason:   ban.Reason,

internal/discriminator/anomaly_internal_test.go

@@ -1,4 +1,4 @@
-package proxy
+package discriminator
 
 import (
 	"net/netip"
@@ -15,9 +15,11 @@ func TestWithEveryAnomalyThresholdOffARequestIsNotCounted(t *testing.T) {
 	// anomaly counters, nor a clock, and the request no response: reading
 	// any of them to count the request panics.
 	rq := &request{
-		h:        &handler{config: &config.Config{LookupSource: "geojs"}},
+		decision: decision{
 			client:   netip.MustParseAddr("203.0.113.9"),
 			lookedUp: true,
+		},
+		h: &handler{config: &config.Config{LookupSource: "geojs"}},
 	}
 
 	defer func() {

internal/discriminator/anomaly_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"maps"
@@ -13,7 +13,7 @@ import (
 
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 	"sneak.berlin/go/smallwebwaf/internal/anomaly"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
 	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
@@ -21,11 +21,11 @@ import (
 // The anomaly thresholds: the prefix of a scope followed by the end of a
 // count.
 const (
-	anomalyClient = "SWWAF_ANOMALY_CLIENT_"
+	anomalyClient = "SWW_ANOMALY_CLIENT_"
-	anomalyNet    = "SWWAF_ANOMALY_NET_"
+	anomalyNet    = "SWW_ANOMALY_NET_"
-	anomalyASN    = "SWWAF_ANOMALY_ASN_"
+	anomalyASN    = "SWW_ANOMALY_ASN_"
-	anomalyTotal  = "SWWAF_ANOMALY_TOTAL_"
+	anomalyTotal  = "SWW_ANOMALY_TOTAL_"
-	anomalyWatch  = "SWWAF_WATCH_"
+	anomalyWatch  = "SWW_WATCH_"
 
 	requestsPerMinute = "REQUESTS_PER_MINUTE"
 	requestsPerHour   = "REQUESTS_PER_HOUR"
@@ -35,9 +35,9 @@ const (
 
 // The other anomaly settings.
 const (
-	anomalyNetV4Prefix = "SWWAF_ANOMALY_NET_V4_PREFIX"
+	anomalyNetV4Prefix = "SWW_ANOMALY_NET_V4_PREFIX"
-	anomalyNetV6Prefix = "SWWAF_ANOMALY_NET_V6_PREFIX"
+	anomalyNetV6Prefix = "SWW_ANOMALY_NET_V6_PREFIX"
-	watchNets          = "SWWAF_WATCH_NETS"
+	watchNets          = "SWW_WATCH_NETS"
 )
 
 const (
@@ -117,6 +117,7 @@ func TestEachScopeAndWindowOverItsThresholdAlertsOncePerCooldown(t *testing.T) {
 					Instance: alertInstance,
 					Time:     start,
 					Event:    alerts.EventAnomaly,
+					Host:     appHost,
 					Client:   netip.MustParseAddr(client),
 					Netblock: scope.netblock,
 					ASN:      asnDE,
@@ -163,9 +164,9 @@ func TestEveryRequestIsCountedWhateverIsDoneWithIt(t *testing.T) {
 	t.Parallel()
 
 	const (
-		allowed = "192.0.2.7"  // in SWWAF_ALLOW_NETS
+		allowed = "192.0.2.7"  // in SWW_ALLOW_NETS
-		exempt  = "192.0.2.10" // in SWWAF_RATE_LIMIT_EXEMPT_NETS
+		exempt  = "192.0.2.10" // in SWW_RATE_LIMIT_EXEMPT_NETS
-		denied  = "192.0.2.20" // in SWWAF_DENY_NETS
+		denied  = "192.0.2.20" // in SWW_DENY_NETS
 	)
 
 	s, _, _, queue := startAppWithAlerts(t, readAndAnswer, map[string]string{
@@ -318,7 +319,7 @@ func TestRequestCountsForTheASNumberGeoJSGivesBeforeItEnds(t *testing.T) {
 	// kept.
 	geojsURL, _, release := startHeldGeoJS(t)
 
-	var server atomic.Pointer[proxy.Server]
+	var server atomic.Pointer[discriminator.Server]
 
 	app := startApp(t, func(http.ResponseWriter, *http.Request) {
 		release()

internal/discriminator/answertime_test.go

@@ -0,0 +1,570 @@
+package discriminator_test
+
+import (
+	"fmt"
+	"maps"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"net/netip"
+	"slices"
+	"strconv"
+	"strings"
+	"testing"
+	"testing/synctest"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/bans"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
+	"sneak.berlin/go/smallwebwaf/internal/lookup"
+	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
+	"sneak.berlin/go/smallwebwaf/internal/reputation"
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+const (
+	// answerTimeLimit is the default of rproxy's SWRP_TIMEOUT_MS, the time
+	// discriminator has to answer.
+	answerTimeLimit = 2 * time.Second
+	// defaultLookupWait is the default of SWW_LOOKUP_TIMEOUT.
+	defaultLookupWait = 800 * time.Millisecond
+	// The header limits SPEC.md gives.
+	cookieLimit      = 50
+	headerFieldLimit = 100
+	// cookieHeader is the header the cookie limit counts.
+	cookieHeader = "Cookie"
+	// tooLarge is how discriminator refuses a request over the header limits.
+	tooLarge = http.StatusRequestHeaderFieldsTooLarge
+	// silentAbuseIPDBURL is where AbuseIPDB never answers: at the stand-in
+	// that unansweredGeoJSURL names too.
+	silentAbuseIPDBURL = "unanswered://abuseipdb/api/v2/check"
+	// wholeLimit is the percentage of a rate limit that lowers it not at all.
+	wholeLimit = 100
+	// clientsDecision is the CrowdSec decision list holding client alone.
+	clientsDecision = `[{"duration": "4h0m0s", "scenario": "crowdsecurity/ssh-bf", ` +
+		`"scope": "Ip", "type": "ban", "value": "` + client + `"}]`
+)
+
+// cookies returns a Cookie header's value with count cookies.
+func cookies(count int) string {
+	parts := make([]string, 0, count)
+	for i := range count {
+		parts = append(parts, "c"+strconv.Itoa(i)+"=1")
+	}
+
+	return strings.Join(parts, "; ")
+}
+
+// fillHeaders adds headers to a question until the checks see total header
+// fields: all but ClientHeader and PeerHeader, which discriminator removes. Go's
+// client sends nothing else but Host, which the limit does not count, once
+// User-Agent is set.
+func fillHeaders(req *http.Request, total int) {
+	req.Header.Set("User-Agent", "test")
+
+	for i := len(req.Header) - 2; i < total; i++ {
+		req.Header.Set("X-Filler-"+strconv.Itoa(i), "1")
+	}
+}
+
+func TestSixteenThousandCookiesAreRefusedWellWithinTheTimeLimit(t *testing.T) {
+	t.Parallel()
+
+	s := startDiscriminator(t, "", map[string]string{wafMode: block})
+	req := s.question(siteA, client, "/")
+	req.Header.Set(cookieHeader, strings.Repeat("a;", 16000))
+
+	began := time.Now()
+	got := do(t, req)
+
+	if took := time.Since(began); took >= answerTimeLimit/2 {
+		t.Errorf("answered after %s, want well within %s", took, answerTimeLimit)
+	}
+
+	wantDisposition(t, got, tooLarge, discriminator.DispositionDeny)
+
+	line := s.out.requestLine(t)
+	wantLine(t, line, tooLarge, requestlog.ActionTooLarge)
+
+	if line.DurationWAF != nil {
+		t.Errorf("the Core Rule Set read the request, for %f ms", *line.DurationWAF)
+	}
+}
+
+func TestEachHeaderLimitRefusesARequestOverIt(t *testing.T) {
+	t.Parallel()
+
+	repeated := make([]string, headerFieldLimit)
+	for i := range repeated {
+		repeated[i] = "1"
+	}
+
+	for _, tc := range []struct {
+		name string
+		make func(*http.Request)
+		// refused is true for a request over a limit, and false for one at it.
+		refused bool
+	}{
+		{"cookies at the limit", func(req *http.Request) {
+			req.Header.Set(cookieHeader, cookies(cookieLimit))
+		}, false},
+		{"cookies over the limit", func(req *http.Request) {
+			req.Header.Set(cookieHeader, cookies(cookieLimit+1))
+		}, true},
+		{"parts empty or only spaces and tabs are no cookies", func(req *http.Request) {
+			req.Header.Set(cookieHeader, cookies(cookieLimit)+"; \t;;")
+		}, false},
+		{"parts of no-break spaces count", func(req *http.Request) {
+			req.Header.Set(cookieHeader, strings.Repeat(" ;", cookieLimit+1))
+		}, true},
+		{"cookies over the limit across two headers", func(req *http.Request) {
+			req.Header[cookieHeader] = []string{cookies(cookieLimit), "last=1"}
+		}, true},
+		{"cookies without a value count", func(req *http.Request) {
+			req.Header.Set(cookieHeader, strings.Repeat("a;", cookieLimit+1))
+		}, true},
+		{"header fields at the limit", func(req *http.Request) {
+			fillHeaders(req, headerFieldLimit)
+		}, false},
+		{"header fields over the limit", func(req *http.Request) {
+			fillHeaders(req, headerFieldLimit+1)
+		}, true},
+		{"a header sent many times counts each time", func(req *http.Request) {
+			req.Header["X-Filler"] = repeated
+		}, true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			s := startDiscriminator(t, "", map[string]string{wafMode: block})
+			req := s.question(siteA, client, "/")
+			tc.make(req)
+
+			got := do(t, req)
+			line := s.out.requestLine(t)
+
+			if tc.refused {
+				wantDisposition(t, got, tooLarge, discriminator.DispositionDeny)
+				wantLine(t, line, tooLarge, requestlog.ActionTooLarge)
+
+				return
+			}
+
+			wantDisposition(t, got, http.StatusOK, discriminator.DispositionAllow)
+			wantLine(t, line, http.StatusOK, requestlog.ActionForward)
+
+			if line.DurationWAF == nil {
+				t.Error("the Core Rule Set did not read a request within the limits")
+			}
+		})
+	}
+}
+
+func TestHeaderLimitsHoldWhateverTheCoreRuleSetSettingsSay(t *testing.T) {
+	t.Parallel()
+
+	for _, env := range []map[string]string{
+		{wafMode: off},
+		{wafMode: "detect"},
+		{wafMode: block, "SWW_WAF_EXEMPT_PATHS": "/"},
+	} {
+		t.Run(fmt.Sprint(env), func(t *testing.T) {
+			t.Parallel()
+
+			s := startDiscriminator(t, "", env)
+			req := s.question(siteA, client, "/")
+			req.Header.Set(cookieHeader, cookies(cookieLimit+1))
+
+			wantDisposition(t, do(t, req), tooLarge, discriminator.DispositionDeny)
+		})
+	}
+}
+
+func TestClientInTheAllowNetsSkipsTheHeaderLimits(t *testing.T) {
+	t.Parallel()
+
+	s := startDiscriminator(t, "", map[string]string{wafMode: block, allowNets: client})
+	req := s.question(siteA, client, "/")
+	req.Header.Set(cookieHeader, cookies(cookieLimit+1))
+
+	wantDisposition(t, do(t, req), http.StatusOK, discriminator.DispositionAllow)
+}
+
+func TestObserveModeAllowsARequestOverTheHeaderLimitsUnread(t *testing.T) {
+	t.Parallel()
+
+	s := startDiscriminator(t, "", map[string]string{mode: observe, wafMode: block})
+	req := s.question(siteA, client, "/")
+	req.Header.Set(cookieHeader, strings.Repeat("a;", 16000))
+
+	began := time.Now()
+	got := do(t, req)
+
+	if took := time.Since(began); took >= answerTimeLimit/2 {
+		t.Errorf("answered after %s, want well within %s", took, answerTimeLimit)
+	}
+
+	wantDisposition(t, got, http.StatusOK, discriminator.DispositionAllow)
+
+	line := s.out.requestLine(t)
+	if line.WouldAction != requestlog.ActionTooLarge || line.DurationWAF != nil {
+		t.Errorf("would_action %q and duration_waf %v, want %q and none",
+			line.WouldAction, line.DurationWAF, requestlog.ActionTooLarge)
+	}
+}
+
+func TestRequestsOverTheHeaderLimitsCountTowardTheRateLimits(t *testing.T) {
+	t.Parallel()
+
+	s := startDiscriminator(t, "", map[string]string{rateLimitPerMinute: "1"})
+	ask := func() answer {
+		req := s.question(siteA, client, "/")
+		req.Header.Set(cookieHeader, cookies(cookieLimit+1))
+
+		return do(t, req)
+	}
+
+	wantDisposition(t, ask(), tooLarge, discriminator.DispositionDeny)
+	wantDisposition(t, ask(), http.StatusForbidden, discriminator.DispositionDeny)
+
+	lines := s.out.requestLines(t, 2)
+	wantLine(t, lines[1], http.StatusForbidden, requestlog.ActionRateLimited)
+}
+
+func TestTheHeaderLimitsComeAfterTheTrapPathsAndTheRuleFiles(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name, path, action string
+	}{
+		{"a trap path", "/wp-login.php", requestlog.ActionBanned},
+		{"a block rule", "/blocked", requestlog.ActionRuleBlocked},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			s := startDiscriminator(t, "", map[string]string{
+				trapPaths: trapPathList, rulesDir: writeRules(t, testRules),
+			})
+			req := s.question(siteA, client, tc.path)
+			req.Header.Set(cookieHeader, cookies(cookieLimit+1))
+
+			wantDisposition(t, do(t, req), http.StatusForbidden, discriminator.DispositionDeny)
+			wantLine(t, s.out.requestLine(t), http.StatusForbidden, tc.action)
+		})
+	}
+}
+
+func TestNotWaitingForGeoJSNeverLowersAClientsLimit(t *testing.T) {
+	t.Parallel()
+
+	geojsURL, _ := startGeoJS(t)
+	s := startDiscriminator(t, geojsURL, map[string]string{
+		unknownLimitPercent: "0", lookupTimeout: "1h",
+	})
+	req := s.question(siteA, fromDE, "/")
+	req.Header.Set(cookieHeader, cookies(cookieLimit+1))
+
+	wantDisposition(t, do(t, req), tooLarge, discriminator.DispositionDeny)
+
+	line := s.out.requestLine(t)
+	wantLine(t, line, tooLarge, requestlog.ActionTooLarge)
+
+	if line.LimitPercent != nil {
+		t.Errorf("limit percentage %d, want none", *line.LimitPercent)
+	}
+
+	// The client is under no ban, and GeoJS places it in a country.
+	wantDisposition(t, s.ask(fromDE, "/"), http.StatusOK, discriminator.DispositionAllow)
+}
+
+func TestAClientGeoJSPlacedInNoCountryCountsAsUnknownWithoutWaiting(t *testing.T) {
+	t.Parallel()
+
+	geojsURL, _ := startGeoJS(t)
+	s := startDiscriminator(t, geojsURL, map[string]string{unknownLimitPercent: "0"})
+	s.server.GeoJS.Load([]lookup.Answer{{
+		Client: netip.MustParsePrefix(client + "/32"), ASN: "AS64512",
+		Answered: s.clock.Now(), Used: s.clock.Now(),
+	}})
+
+	req := s.question(siteA, client, "/")
+	req.Header.Set(cookieHeader, cookies(cookieLimit+1))
+
+	wantDisposition(t, do(t, req), http.StatusForbidden, discriminator.DispositionDeny)
+	wantLine(t, s.out.requestLine(t), http.StatusForbidden, requestlog.ActionRateLimited)
+}
+
+func TestObserveModeWaitsForGeoJSForARequestOverTheHeaderLimits(t *testing.T) {
+	t.Parallel()
+
+	geojsURL, _ := startGeoJS(t)
+	s := startDiscriminator(t, geojsURL, map[string]string{
+		mode: observe, addLookupHeaders: on, lookupTimeout: "1h",
+	})
+	req := s.question(siteA, fromDE, "/")
+	req.Header.Set(cookieHeader, cookies(cookieLimit+1))
+
+	got := do(t, req)
+	wantDisposition(t, got, http.StatusOK, discriminator.DispositionAllow)
+
+	asn, country := got.header.Get("X-Client-Asn"), got.header.Get("X-Client-Country")
+	if asn != asnDE || country != "DE" {
+		t.Errorf("answered with the AS number %q and the country %q, want %q and DE",
+			asn, country, asnDE)
+	}
+}
+
+// newDiscriminatorInBubble makes a discriminator for a synctest bubble: GeoJS never
+// answers, a setting needs its answer, and everything is at its default but
+// for env. No request to it may use the network.
+func newDiscriminatorInBubble(
+	t *testing.T, env map[string]string,
+) (*discriminator.Server, *output) {
+	t.Helper()
+
+	settings := map[string]string{deniedCountries: "KP"}
+	maps.Copy(settings, env)
+
+	server, out, _ := newDiscriminator(t, unansweredGeoJSURL, time.Now, settings)
+
+	return server, out
+}
+
+// askDirectly hands a question about a request from client straight to server,
+// as change leaves it, and returns the answer's status and how long it took.
+func askDirectly(
+	t *testing.T, server *discriminator.Server, change func(*http.Request),
+) (int, time.Duration) {
+	t.Helper()
+
+	req := httptest.NewRequestWithContext(t.Context(), http.MethodGet, "/", http.NoBody)
+	req.RemoteAddr = net.JoinHostPort(rproxyPeer, "1234")
+	req.Header.Set(discriminator.ClientHeader, client)
+	req.Header.Set(requestIDHeader, "the-id")
+	change(req)
+
+	recorder := httptest.NewRecorder()
+	began := time.Now()
+
+	server.Handler.ServeHTTP(recorder, req)
+
+	return recorder.Code, time.Since(began)
+}
+
+// banClient bans client at now.
+func banClient(_ *testing.T, server *discriminator.Server, now time.Time) {
+	server.Ledger.BanForLimit(netip.MustParsePrefix(client+"/32"), now, bans.Notes{})
+}
+
+// countClient counts one request from client at now for the rate limits.
+func countClient(_ *testing.T, server *discriminator.Server, now time.Time) {
+	server.Limiter.Count(netip.MustParsePrefix(client+"/32"), now, wholeLimit)
+}
+
+// listClient puts client on the blocklist at dropURL.
+func listClient(t *testing.T, server *discriminator.Server, now time.Time) {
+	t.Helper()
+
+	err := server.Lists.Load([]reputation.List{{
+		URL: dropURL, Tried: now, Fetched: now, Lines: []string{client},
+	}})
+	if err != nil {
+		t.Fatalf("load the blocklist: %v", err)
+	}
+}
+
+// decideOnClient puts client on the CrowdSec decision list.
+func decideOnClient(t *testing.T, server *discriminator.Server, now time.Time) {
+	t.Helper()
+	loadDecisions(t, server, now, clientsDecision)
+}
+
+// leaveAsItIs prepares nothing.
+func leaveAsItIs(*testing.T, *discriminator.Server, time.Time) {}
+
+func TestARefusedRequestDoesNotWaitForASlowGeoJS(t *testing.T) {
+	t.Parallel()
+
+	const forbidden = http.StatusForbidden
+
+	for _, tc := range []struct {
+		name string
+		env  map[string]string
+		// prepare gets the server ready, at now, before the question.
+		prepare func(t *testing.T, server *discriminator.Server, now time.Time)
+		// cookie is the request's Cookie header.
+		cookie string
+		status int
+		action string
+	}{
+		{
+			name: "SWW_DENY_NETS", env: map[string]string{denyNets: client},
+			prepare: leaveAsItIs, status: forbidden, action: requestlog.ActionDenied,
+		},
+		{
+			name:    "a ban",
+			prepare: banClient, status: forbidden, action: requestlog.ActionBanned,
+		},
+		{
+			name: "the rate limits", env: map[string]string{rateLimitPerMinute: "1"},
+			prepare: countClient, status: forbidden, action: requestlog.ActionRateLimited,
+		},
+		{
+			name:    "the rate limits, with a biased threshold",
+			env:     map[string]string{rateLimitPerMinute: "1", unknownLimitPercent: "50"},
+			prepare: countClient, status: forbidden, action: requestlog.ActionRateLimited,
+		},
+		{
+			name: "a blocklist", env: map[string]string{blocklistURLs: dropURL},
+			prepare: listClient, status: forbidden, action: requestlog.ActionDenied,
+		},
+		{
+			name:    "the CrowdSec decision list",
+			env:     map[string]string{crowdSecURL: lapi, crowdSecKey: bouncerKey},
+			prepare: decideOnClient, status: forbidden, action: requestlog.ActionBanned,
+		},
+		{
+			name: "the header limits", cookie: cookies(cookieLimit + 1),
+			prepare: leaveAsItIs, status: tooLarge, action: requestlog.ActionTooLarge,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			// In a synctest bubble, as TestRequestWaitsAsLongAsTheLookupTimeoutSays
+			// says, so that a request that does not wait takes no time at all.
+			synctest.Test(t, func(t *testing.T) {
+				server, out := newDiscriminatorInBubble(t, tc.env)
+				tc.prepare(t, server, time.Now())
+
+				status, took := askDirectly(t, server, func(req *http.Request) {
+					req.Header.Set(cookieHeader, tc.cookie)
+				})
+
+				if status != tc.status || took != 0 {
+					t.Errorf("answered %d after %s, want %d at once; output:\n%s",
+						status, took, tc.status, out.text())
+				}
+
+				wantLine(t, out.requestLine(t), tc.status, tc.action)
+
+				// GeoJS's request is abandoned before the bubble ends.
+				time.Sleep(defaultLookupWait)
+			})
+		})
+	}
+}
+
+func TestAQuestionWaitsForASlowGeoJSOnlyAsLongAsTheDefaultSays(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name string
+		env  map[string]string
+		// prepare gets the server ready, at now, before the question.
+		prepare func(t *testing.T, server *discriminator.Server, now time.Time)
+		status  int
+		action  string
+	}{
+		{"nothing refuses it", nil, leaveAsItIs, http.StatusOK, requestlog.ActionForward},
+		{
+			"a country list needs the answer", map[string]string{allowedCountries: "DE"},
+			leaveAsItIs, http.StatusForbidden, requestlog.ActionCountryDenied,
+		},
+		{
+			"a blocklist that only logs",
+			map[string]string{blocklistURLs: dropURL, blocklistAction: actionLog},
+			listClient, http.StatusOK, requestlog.ActionForward,
+		},
+		{
+			"a blocklist that only limits",
+			map[string]string{blocklistURLs: dropURL, blocklistAction: limitQuarter},
+			listClient, http.StatusOK, requestlog.ActionForward,
+		},
+		{
+			"over a rate limit on an exempt path",
+			map[string]string{rateLimitPerMinute: "1", rateLimitExemptPaths: "/"},
+			countClient, http.StatusOK, requestlog.ActionForward,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			synctest.Test(t, func(t *testing.T) {
+				server, out := newDiscriminatorInBubble(t, tc.env)
+				tc.prepare(t, server, time.Now())
+
+				status, took := askDirectly(t, server, func(*http.Request) {})
+
+				if status != tc.status || took != defaultLookupWait {
+					t.Errorf("answered %d after %s, want %d after %s; output:\n%s",
+						status, took, tc.status, defaultLookupWait, out.text())
+				}
+
+				wantLine(t, out.requestLine(t), tc.status, tc.action)
+			})
+		})
+	}
+}
+
+func TestDiscriminatorAnswersWithinTheTimeLimitWhileEveryOutsideSourceHangs(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	held, askedGeoJS, _ := startHeldGeoJS(t)
+
+	// A resolver that takes every query and answers none.
+	resolver, err := (&net.ListenConfig{}).ListenPacket(t.Context(), "udp", localhost+":0")
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+
+	t.Cleanup(func() { _ = resolver.Close() })
+
+	server, out, _ := newDiscriminatorWith(t, func(
+		params discriminator.Params,
+	) *discriminator.Server {
+		params.AbuseIPDBURL = silentAbuseIPDBURL
+
+		return discriminator.New(params)
+	}, held, time.Now, map[string]string{
+		deniedCountries: "KP", wafMode: block,
+		dnsblZones: dnsblZone, dnsblResolver: resolver.LocalAddr().String(),
+		abuseIPDBKey:  accountKey,
+		blocklistURLs: held + "/drop.txt", asnLimitPercentURL: held + "/asn.txt",
+		crowdSecURL: held, crowdSecKey: bouncerKey,
+	})
+
+	// AbuseIPDB is asked only about a client with an offence.
+	group := netip.MustParsePrefix(client + "/32")
+	server.Limiter.AddToHistory(group, time.Now(), ratelimit.Request{Attack: true})
+
+	go server.Lists.Run(t.Context())
+
+	status, took := askDirectly(t, server, func(req *http.Request) {
+		req.Header.Set("User-Agent", "test")
+		req.Header.Set("Accept", "*/*")
+		req.Host = siteA
+	})
+
+	if status != http.StatusOK || took >= answerTimeLimit {
+		t.Errorf("answered %d after %s, want %d within %s; output:\n%s",
+			status, took, http.StatusOK, answerTimeLimit, out.text())
+	}
+
+	// Each outside source was asked, and none has answered. The stand-in for
+	// GeoJS is the lists' too, which name no address.
+	if !slices.Contains(askedGeoJS(), client) {
+		t.Errorf("GeoJS was asked about %q, not %s", askedGeoJS(), client)
+	}
+
+	if queries := server.DNSBL.Queries(dnsblZone); queries != 1 {
+		t.Errorf("%d queries to the DNS blocklist, want 1", queries)
+	}
+
+	if checked := server.AbuseIPDB.Checked(); checked != 1 {
+		t.Errorf("%d checks with AbuseIPDB, want 1", checked)
+	}
+}

internal/discriminator/bans.go

@@ -1,4 +1,4 @@
-package proxy
+package discriminator
 
 import (
 	"net/http"
@@ -12,7 +12,7 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
 
-// banResponse is a refusal answered with SWWAF_BAN_RESPONSE, and logged
+// banResponse is a refusal answered with SWW_BAN_RESPONSE, and logged
 // with action.
 func (rq *request) banResponse(action string) *refusal {
 	return &refusal{status: rq.h.config.BanResponse, action: action}
@@ -58,13 +58,12 @@ func (rq *request) limitBroken(now time.Time) bool {
 }
 
 // countBytes counts the request's bytes, as countedBytes gives them, for
-// the byte limits, once its response has ended, and notes the client's
+// the byte limits, once its report has come, and notes the client's byte totals
-// byte totals for the log line; its requests stay there as the rate limits
+// for the log line; its requests stay there as the rate limits counted them.
-// counted them. Only a request passed to the app has them counted, and
+// Only an allowed request has them counted, and only one the rate limits
-// only one the rate limits counted; in observe mode, not one that enforce
+// counted; in observe mode, not one that enforce mode would have refused. Bytes
-// mode would have refused. Bytes that take the client over a byte limit,
+// that take the client over a byte limit, as its limit percentage for the byte
-// as its limit percentage for the byte limits lowers it, break it; the
+// limits lowers it, break it; the response was passed on whole.
-// response was passed on whole.
 func (rq *request) countBytes() {
 	if !rq.counted || rq.line.WouldAction != "" {
 		return
@@ -84,11 +83,10 @@ func (rq *request) countBytes() {
 }
 
 // countRefusal counts the request for the error burst once it has been
-// answered, if smallwebwaf refused it after a rule file match, a trap path
+// answered, if discriminator refused it after a rule file match, a trap path or a
-// or a Core Rule Set match, or for a missing or wrong token, and in
+// Core Rule Set match, and in observe mode if enforce mode would have: more than
-// observe mode if enforce mode would have: more than
+// SWW_ERROR_BURST_THRESHOLD such refusals of the client within a minute
-// SWWAF_ERROR_BURST_THRESHOLD such refusals of the client within a minute
+// break a limit. A client in SWW_ALLOW_NETS, which the checks skip, is
-// break a limit. A client in SWWAF_ALLOW_NETS, which the checks skip, is
 // not counted, and nothing is while the threshold is off.
 func (rq *request) countRefusal() {
 	cfg := rq.h.config
@@ -96,11 +94,7 @@ func (rq *request) countRefusal() {
 		return
 	}
 
-	// In observe mode, a request that enforce mode would have refused
+	if !rq.attack && !rq.ruleBlocked && !rq.wafBlocked {
-	// before it reached the endpoint has had no token refused there.
-	tokenRefused := rq.tokenRefused && rq.line.WouldAction == "" &&
-		!isInside(rq.client, cfg.AllowNets)
-	if !rq.attack && !rq.ruleBlocked && !rq.wafBlocked && !tokenRefused {
 		return
 	}
 
@@ -127,16 +121,9 @@ func (rq *request) countRefusal() {
 
 // countedBytes returns the request's bytes, once it has ended, as the
 // byte limits and the anomaly thresholds count them: the response's body
-// bytes, the request's, or both, as SWWAF_BYTES_COUNT says. For an
+// bytes, the request's, or both, as SWW_BYTES_COUNT says.
-// upgraded connection, such as a WebSocket, which has closed by then, what
-// it carried from the app counts with the response's and what it carried
-// from the client with the request's.
 func (rq *request) countedBytes() int64 {
-	response, request := rq.out.bytes, rq.requestBytes()
+	response, request := rq.out.bytes, rq.requestBytes
-	if rq.upgraded != nil {
-		response += rq.upgraded.fromApp.Load()
-		request += rq.upgraded.toApp.Load()
-	}
 
 	switch rq.h.config.BytesCount {
 	case "response":
@@ -151,7 +138,7 @@ func (rq *request) countedBytes() int64 {
 // banForLimit bans the client's netblock at now for a broken limit, the
 // one hit names, notes the offence for the log line and counts the hit in
 // the metrics. status is what the client was sent, or is sent:
-// SWWAF_BAN_RESPONSE for a request over a rate limit, the app's answer for
+// SWW_BAN_RESPONSE for a request over a rate limit, what the report says for
 // one whose bytes broke a byte limit, the refusal for one that broke the
 // error burst. The ban's notes give the client's limit percentage for a
 // rate limit or a byte limit; the error burst is not lowered. The ban sets
@@ -290,7 +277,7 @@ func (rq *request) banForCrowdSec(now time.Time, decision reputation.Decision) {
 // wouldAlertBan reports whether the alert for a ban on netblock for cause
 // made at now would be sent. In observe mode the ban the request would
 // have made is worked out only then, at most once per
-// SWWAF_ALERT_COOLDOWN and never with no webhook set: its notes count the
+// SWW_ALERT_COOLDOWN and never with no webhook set: its notes count the
 // netblock's requests, which can mean going through every client.
 func (rq *request) wouldAlertBan(
 	netblock netip.Prefix, now time.Time, cause string,
@@ -323,6 +310,7 @@ func (rq *request) alertBan(ban bans.Ban) {
 
 	rq.h.alerts.Raise(alerts.Alert{
 		Event:    event,
+		Host:     rq.site,
 		Client:   rq.client,
 		Netblock: ban.Netblock,
 		ASN:      ban.Notes.ASN,
@@ -339,11 +327,11 @@ func (rq *request) alertBan(ban bans.Ban) {
 func (rq *request) noted(now time.Time, status int) bans.Request {
 	return bans.Request{
 		Time:      now,
-		Method:    rq.in.Method,
+		Method:    rq.line.Method,
-		Host:      rq.in.Host,
+		Host:      rq.line.Host,
-		Path:      rq.in.URL.RequestURI(),
+		Path:      rq.requestURI,
 		Status:    status,
-		UserAgent: rq.in.UserAgent(),
+		UserAgent: rq.line.UserAgent,
 	}
 }
 
@@ -355,7 +343,7 @@ func (rq *request) netblockRequests(netblock netip.Prefix) int64 {
 }
 
 // netblock is the netblock a ban on client covers: its IPv4 address,
-// widened to SWWAF_BAN_SCOPE_V4_PREFIX, or the IPv6 group clientGroup
+// widened to SWW_BAN_SCOPE_V4_PREFIX, or the IPv6 group clientGroup
 // counts it in.
 func (h *handler) netblock(client netip.Addr) netip.Prefix {
 	addr := client.Unmap()

internal/discriminator/bans_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"bufio"
@@ -9,12 +9,13 @@ import (
 	"net/netip"
 	"reflect"
 	"slices"
+	"strings"
 	"sync"
 	"testing"
 	"time"
 
 	"sneak.berlin/go/smallwebwaf/internal/bans"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
 
@@ -25,6 +26,8 @@ const (
 	userAgent = "ban-test/1.0"
 	// permanent is the log line's ban_expires for a permanent ban.
 	permanent = "permanent"
+	// banResponseClose is the SWW_BAN_RESPONSE that closes the connection.
+	banResponseClose = "close"
 )
 
 func TestBrokenLimitBansTheClient(t *testing.T) {
@@ -86,19 +89,19 @@ func TestBanLengthsFollowTheSettings(t *testing.T) {
 		}
 	}
 
-	// A first ban lasts SWWAF_LIMIT_BAN_DURATION; one within
+	// A first ban lasts SWW_LIMIT_BAN_DURATION; one within
-	// SWWAF_LIMIT_BAN_REPEAT_WINDOW after it ended, three times as long.
+	// SWW_LIMIT_BAN_REPEAT_WINDOW after it ended, three times as long.
 	wantExpires(breakLimit(), 10*time.Minute)
 	clk.advance(10*time.Minute + time.Hour)
 	wantExpires(breakLimit(), 30*time.Minute)
 
-	// Later than that, SWWAF_LIMIT_BAN_DURATION again.
+	// Later than that, SWW_LIMIT_BAN_DURATION again.
 	clk.advance(30*time.Minute + time.Hour + time.Second)
 	wantExpires(breakLimit(), 10*time.Minute)
 	clk.advance(10 * time.Minute)
 	wantExpires(breakLimit(), 30*time.Minute)
 
-	// 90 minutes would be longer than SWWAF_MAX_BAN_DURATION: the ban is
+	// 90 minutes would be longer than SWW_MAX_BAN_DURATION: the ban is
 	// permanent.
 	clk.advance(30 * time.Minute)
 
@@ -145,8 +148,8 @@ func TestBanCoversTheClientsNetblock(t *testing.T) {
 
 	// In the IPv4 cases, client breaks the limit; these two are next to it.
 	const (
-		allowed = "203.0.113.60" // in SWWAF_ALLOW_NETS
+		allowed = "203.0.113.60" // in SWW_ALLOW_NETS
-		exempt  = "203.0.113.50" // in SWWAF_RATE_LIMIT_EXEMPT_NETS
+		exempt  = "203.0.113.50" // in SWW_RATE_LIMIT_EXEMPT_NETS
 	)
 
 	for _, tc := range []struct {
@@ -161,7 +164,7 @@ func TestBanCoversTheClientsNetblock(t *testing.T) {
 			nil, []string{otherClient, exempt},
 		},
 		{
-			"the IPv4 netblock SWWAF_BAN_SCOPE_V4_PREFIX sets",
+			"the IPv4 netblock SWW_BAN_SCOPE_V4_PREFIX sets",
 			map[string]string{banScopeV4Prefix: "24"}, client,
 			[]string{otherClient, exempt}, []string{"203.0.112.9", allowed},
 		},
@@ -170,7 +173,7 @@ func TestBanCoversTheClientsNetblock(t *testing.T) {
 			[]string{"2001:db8:5::ffff:1"}, []string{"2001:db8:5:1::1"},
 		},
 		{
-			"the IPv6 netblock SWWAF_IPV6_GROUP_PREFIX sets",
+			"the IPv6 netblock SWW_IPV6_GROUP_PREFIX sets",
 			map[string]string{ipv6GroupPrefix: "48"}, "2001:db8:7::1",
 			[]string{"2001:db8:7:ffff::1"}, []string{"2001:db8:8::1"},
 		},
@@ -228,16 +231,16 @@ func TestBannedClientIsRefusedBeforeItsCountryIsLookedUp(t *testing.T) {
 func TestBanResponseAnswersEveryRefusalButTheSizeLimits(t *testing.T) {
 	t.Parallel()
 
-	const denied = "192.0.2.50" // in SWWAF_DENY_NETS
+	const denied = "192.0.2.50" // in SWW_DENY_NETS
 
 	for _, tc := range []struct {
-		setting string // "" leaves SWWAF_BAN_RESPONSE at its default
+		setting string // "" leaves SWW_BAN_RESPONSE at its default
 		status  int    // 0 is the connection closed without an answer
 	}{
 		{"", http.StatusForbidden},
 		{"403", http.StatusForbidden},
 		{"429", http.StatusTooManyRequests},
-		{"close", 0},
+		{banResponseClose, 0},
 	} {
 		t.Run(banResponse+"="+tc.setting, func(t *testing.T) {
 			t.Parallel()
@@ -349,7 +352,7 @@ func TestMaxBansDropsTheBanOfTheNetblockSeenLongestAgo(t *testing.T) {
 	s.get(otherClient, http.StatusForbidden, requestlog.ActionBanned)
 }
 
-// clock is the time a test sets, by which smallwebwaf counts requests and
+// clock is the time a test sets, by which sww counts requests and
 // makes bans.
 type clock struct {
 	mu  sync.Mutex
@@ -372,14 +375,14 @@ func (c *clock) advance(d time.Duration) {
 	c.now = c.now.Add(d)
 }
 
-// startWithClock starts smallwebwaf in front of an app that answers 200,
+// startWithClock starts discriminator, and rproxy in front of an app that answers 200,
 // with the settings in env on top of trusting localhost's
 // X-Forwarded-For, clients' AS numbers and countries looked up at
 // geojsURL, and a clock set to midnight, the start of a bucket in every
 // window.
 func startWithClock(
 	t *testing.T, geojsURL string, env map[string]string,
-) (*sender, *clock, *proxy.Server) {
+) (*sender, *clock, *discriminator.Server) {
 	t.Helper()
 
 	app := startApp(t, func(http.ResponseWriter, *http.Request) {})
@@ -389,16 +392,18 @@ func startWithClock(
 
 	addr, out, server := startProxyWithClock(t, app.URL, geojsURL, clk.Now, settings)
 
-	return &sender{t: t, addr: addr, out: out}, clk, server
+	return &sender{t: t, addr: addr, discriminatorAddr: server.Addr, out: out}, clk, server
 }
 
-// sender sends requests to smallwebwaf one after another, each on a
+// sender sends requests to rproxy one after another, each on a connection of its
-// connection of its own, and checks each one's answer and log line. They
+// own, and checks each one's answer and log line. discriminatorAddr is where
-// must be the only requests smallwebwaf is sent, since the log lines are
+// discriminator's own endpoints are, which adminRequest asks. Every request
+// discriminator gets must come through the sender, since the log lines are
 // matched to them in order.
 type sender struct {
 	t                 *testing.T
 	addr              string
+	discriminatorAddr string
 	out               *output
 	sent              int
 }
@@ -417,22 +422,19 @@ func (s *sender) get(from string, status int, action string) logLine {
 func (s *sender) request(from, path string, status int, action string) logLine {
 	s.t.Helper()
 
-	line, _ := s.requestWithHeader(from, path, "", status, action)
+	return s.requestWithHeader(from, path, "", status, action)
-
-	return line
 }
 
 // requestWithHeader is request with header, such as "Authorization:
-// Bearer x", added to the request unless it is "". It returns the body of
+// Bearer x", added to the request unless it is "".
-// the answer too.
 func (s *sender) requestWithHeader(
 	from, path, header string, status int, action string,
-) (logLine, string) {
+) logLine {
 	s.t.Helper()
 
-	line, got := s.requestWithBody(http.MethodGet, from, path, header, "", status, action)
+	line, _ := s.requestWithBody(http.MethodGet, from, path, header, "", status, action)
 
-	return line, string(got.body)
+	return line
 }
 
 // requestWithBody is requestWithHeader for a request with method, whose
@@ -448,10 +450,14 @@ func (s *sender) requestWithBody(
 		header += "\r\n"
 	}
 
+	// rproxy refuses a request with more than one.
+	if !strings.Contains(header, "User-Agent:") {
+		header += "User-Agent: " + userAgent + "\r\n"
+	}
+
 	conn := dial(s.t, s.addr)
-	send(s.t, conn, method+" "+path+" HTTP/1.1\r\nHost: "+appHost+
+	send(s.t, conn, method+" "+path+" HTTP/1.1\r\nHost: "+appHost+"\r\n"+
-		"\r\nUser-Agent: "+userAgent+"\r\n"+forwardedFor+": "+from+"\r\n"+
+		forwardedFor+": "+from+"\r\n"+header+"\r\n"+body)
-		header+"\r\n"+body)
 
 	err := conn.SetReadDeadline(time.Now().Add(waitLimit))
 	if err != nil {
@@ -476,7 +482,7 @@ func (s *sender) requestWithBody(
 			got.status, status)
 	}
 
-	line := s.out.requestLines(s.t, s.sent+1)[s.sent]
+	line := s.out.endedLines(s.t, s.sent+1)[s.sent]
 	s.sent++
 	wantLine(s.t, line, status, action)
 

internal/discriminator/biased.go

@@ -1,4 +1,4 @@
-package proxy
+package discriminator
 
 import (
 	"sneak.berlin/go/smallwebwaf/internal/config"
@@ -18,7 +18,7 @@ type percentage struct {
 
 // biasedThresholdsSet reports whether a biased threshold can lower a
 // client's limits: one of its lists is not empty,
-// SWWAF_UNKNOWN_LIMIT_PERCENT is below 100, or SWWAF_ASN_LIMIT_PERCENT_URL
+// SWW_UNKNOWN_LIMIT_PERCENT is below 100, or SWW_ASN_LIMIT_PERCENT_URL
 // is set. The client's lookup is then needed before its request goes on.
 func biasedThresholdsSet(cfg *config.Config) bool {
 	return len(cfg.ASNLimitPercent) > 0 || len(cfg.CountryLimitPercent) > 0 ||
@@ -31,52 +31,52 @@ func biasedThresholdsSet(cfg *config.Config) bool {
 // up, each "" when unknown, and the blocklists, DNSBL zones and AbuseIPDB
 // that list it. Each is the lowest of those the settings give it, the
 // first of them in the order below when several are lowest: the
-// percentage SWWAF_ASN_LIMIT_PERCENT gives its AS number, the one the file
+// percentage SWW_ASN_LIMIT_PERCENT gives its AS number, the one the file
-// SWWAF_ASN_LIMIT_PERCENT_URL names gives it, the one
+// SWW_ASN_LIMIT_PERCENT_URL names gives it, the one
-// SWWAF_COUNTRY_LIMIT_PERCENT gives its country, for a client without a
+// SWW_COUNTRY_LIMIT_PERCENT gives its country, for a client without a
-// country, SWWAF_UNKNOWN_LIMIT_PERCENT, for a client a blocklist lists,
+// country, unless its request skipped the wait for GeoJS,
-// the percentage of SWWAF_BLOCKLIST_ACTION while it is limit, and for a
+// SWW_UNKNOWN_LIMIT_PERCENT, for a client a blocklist lists, the
-// client a DNSBL zone's verdict lists, or whose AbuseIPDB score is a hit,
+// percentage of SWW_BLOCKLIST_ACTION while it is limit, and for a client
-// the percentage of SWWAF_REPUTATION_ACTION while it is limit. For the
+// a DNSBL zone's verdict lists, or whose AbuseIPDB score is a hit, the
-// byte limits, SWWAF_ASN_BYTES_PERCENT and SWWAF_COUNTRY_BYTES_PERCENT
+// percentage of SWW_REPUTATION_ACTION while it is limit. For the byte
-// take the place of the first three for an AS number or a country they
+// limits, SWW_ASN_BYTES_PERCENT and SWW_COUNTRY_BYTES_PERCENT take the
-// list.
+// place of the first three for an AS number or a country they list.
 func (rq *request) limitPercentages() (percentage, percentage) {
 	cfg := rq.h.config
 	asn, country := rq.line.ASN, rq.line.Country
 
 	unknown := percentage{percent: whole}
-	if country == "" {
+	if country == "" && !rq.skippedLookupWait {
-		unknown = percentage{cfg.UnknownLimitPercent, "SWWAF_UNKNOWN_LIMIT_PERCENT"}
+		unknown = percentage{cfg.UnknownLimitPercent, "SWW_UNKNOWN_LIMIT_PERCENT"}
 	}
 
 	fetched := percentage{percent: whole}
 	if percent, listed := rq.h.lists.ASNLimitPercent(asn); listed {
-		fetched = percentage{percent, "SWWAF_ASN_LIMIT_PERCENT_URL"}
+		fetched = percentage{percent, "SWW_ASN_LIMIT_PERCENT_URL"}
 	}
 
 	blocklisted := percentage{percent: whole}
 	if rq.blocklisted && cfg.BlocklistAction == "limit" {
-		blocklisted = percentage{cfg.BlocklistLimitPercent, "SWWAF_BLOCKLIST_ACTION"}
+		blocklisted = percentage{cfg.BlocklistLimitPercent, "SWW_BLOCKLIST_ACTION"}
 	}
 
 	reputationListed := percentage{percent: whole}
 	if (rq.dnsblListed || rq.abuseIPDBHit) && cfg.ReputationAction == "limit" {
-		reputationListed = percentage{cfg.ReputationLimitPercent, "SWWAF_REPUTATION_ACTION"}
+		reputationListed = percentage{cfg.ReputationLimitPercent, "SWW_REPUTATION_ACTION"}
 	}
 
-	asnRequests := lowest(given(cfg.ASNLimitPercent, asn, "SWWAF_ASN_LIMIT_PERCENT"),
+	asnRequests := lowest(given(cfg.ASNLimitPercent, asn, "SWW_ASN_LIMIT_PERCENT"),
 		fetched)
 	countryRequests := given(cfg.CountryLimitPercent, country,
-		"SWWAF_COUNTRY_LIMIT_PERCENT")
+		"SWW_COUNTRY_LIMIT_PERCENT")
 
 	asnBytes, countryBytes := asnRequests, countryRequests
 	if _, listed := cfg.ASNBytesPercent[asn]; listed {
-		asnBytes = given(cfg.ASNBytesPercent, asn, "SWWAF_ASN_BYTES_PERCENT")
+		asnBytes = given(cfg.ASNBytesPercent, asn, "SWW_ASN_BYTES_PERCENT")
 	}
 
 	if _, listed := cfg.CountryBytesPercent[country]; listed {
-		countryBytes = given(cfg.CountryBytesPercent, country, "SWWAF_COUNTRY_BYTES_PERCENT")
+		countryBytes = given(cfg.CountryBytesPercent, country, "SWW_COUNTRY_BYTES_PERCENT")
 	}
 
 	return lowest(asnRequests, countryRequests, unknown, blocklisted, reputationListed),

internal/discriminator/biased_test.go

@@ -1,10 +1,9 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"fmt"
 	"io"
 	"maps"
-	"net"
 	"net/http"
 	"net/http/httptest"
 	"net/netip"
@@ -16,18 +15,18 @@ import (
 
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 	"sneak.berlin/go/smallwebwaf/internal/bans"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
 	"sneak.berlin/go/smallwebwaf/internal/lookup/lookuptest"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
 
 // The biased thresholds.
 const (
-	asnLimitPercent     = "SWWAF_ASN_LIMIT_PERCENT"
+	asnLimitPercent     = "SWW_ASN_LIMIT_PERCENT"
-	countryLimitPercent = "SWWAF_COUNTRY_LIMIT_PERCENT"
+	countryLimitPercent = "SWW_COUNTRY_LIMIT_PERCENT"
-	asnBytesPercent     = "SWWAF_ASN_BYTES_PERCENT"
+	asnBytesPercent     = "SWW_ASN_BYTES_PERCENT"
-	countryBytesPercent = "SWWAF_COUNTRY_BYTES_PERCENT"
+	countryBytesPercent = "SWW_COUNTRY_BYTES_PERCENT"
-	unknownLimitPercent = "SWWAF_UNKNOWN_LIMIT_PERCENT"
+	unknownLimitPercent = "SWW_UNKNOWN_LIMIT_PERCENT"
 )
 
 const (
@@ -231,7 +230,7 @@ func TestLowestPercentageApplies(t *testing.T) {
 			noCountry, "25 from " + unknownLimitPercent,
 		},
 		{
-			// SWWAF_UNKNOWN_LIMIT_PERCENT is left at its default, 100.
+			// SWW_UNKNOWN_LIMIT_PERCENT is left at its default, 100.
 			"the AS number's, for a client without a country",
 			map[string]string{asnLimitPercent: "AS64500:25"},
 			noCountry, "25 from " + asnLimitPercent,
@@ -281,12 +280,12 @@ func TestClientWithoutAnAnswerInTimeHasTheUnknownLimitPercent(t *testing.T) {
 	// In a synctest bubble, as TestRequestWaitsAsLongAsTheLookupTimeoutSays
 	// says, with a GeoJS that never answers.
 	synctest.Test(t, func(t *testing.T) {
-		server, out, _ := newProxy(t, "http://app.invalid", unansweredGeoJSURL,
+		server, out, _ := newDiscriminator(t, unansweredGeoJSURL, time.Now,
-			time.Now, map[string]string{unknownLimitPercent: "0"})
+			map[string]string{unknownLimitPercent: "0"})
 
-		// Once the second the request waits for its answer is up, the client
+		// Once the time the request waits for its answer is up, the client
 		// counts as without a country, and its zero allowance refuses the
-		// request before it reaches the app.
+		// request.
 		serveFromDE(t, server, http.MethodGet, http.NoBody)
 
 		line := out.requestLine(t)
@@ -320,13 +319,8 @@ func TestRequestWaitsForItsLookupWhileABiasedThresholdIsSet(t *testing.T) {
 			// In a synctest bubble, as TestRequestWaitsAsLongAsTheLookupTimeoutSays
 			// says, with a GeoJS that never answers.
 			synctest.Test(t, func(t *testing.T) {
-				// The request's body is over SWWAF_REQUEST_MAX_BYTES, so that it
+				server, out, _ := newDiscriminator(t, unansweredGeoJSURL, time.Now,
-				// is refused after the checks, and never reaches the app.
+					map[string]string{lookupTimeout: timeout.String(), tc.setting: tc.value})
-				server, out, _ := newProxy(t, "http://app.invalid", unansweredGeoJSURL,
-					time.Now, map[string]string{
-						lookupTimeout: timeout.String(), requestMaxBytes: "1",
-						tc.setting: tc.value,
-					})
 				began := time.Now()
 
 				serveFromDE(t, server, http.MethodPost, strings.NewReader("ab"))
@@ -340,8 +334,7 @@ func TestRequestWaitsForItsLookupWhileABiasedThresholdIsSet(t *testing.T) {
 					t.Errorf("the request waited %s for its answer, want %s", waited, want)
 				}
 
-				wantLine(t, out.requestLine(t), http.StatusRequestEntityTooLarge,
+				wantLine(t, out.requestLine(t), http.StatusOK, requestlog.ActionForward)
-					requestlog.ActionTooLarge)
 
 				// The bubble's clock stops once this function returns, so the
 				// request to GeoJS, which a request that did not wait leaves
@@ -426,7 +419,7 @@ func TestBanForALoweredLimitGivesThePercentageInItsNotesAndItsAlert(t *testing.T
 // clock.
 func startWithLookups(
 	t *testing.T, env map[string]string,
-) (*sender, *proxy.Server, *alerts.Queue) {
+) (*sender, *discriminator.Server, *alerts.Queue) {
 	t.Helper()
 
 	s, _, server, queue := startWithLookupsAndClock(t, env)
@@ -441,7 +434,7 @@ func startWithLookups(
 // country, and no other address.
 func startWithLookupsAndClock(
 	t *testing.T, env map[string]string,
-) (*sender, *clock, *proxy.Server, *alerts.Queue) {
+) (*sender, *clock, *discriminator.Server, *alerts.Queue) {
 	t.Helper()
 
 	path := filepath.Join(t.TempDir(), "ipinfo_lite.mmdb")
@@ -467,13 +460,17 @@ func (s *sender) uploadFrom(from string) logLine {
 	return line
 }
 
-// serveFromDE hands a request from fromDE with method and body straight to
+// serveFromDE hands a question about a request from fromDE with method and body
-// server's handler, without the network, and returns once it is answered.
+// straight to server's handler, without the network, and returns once it is
-func serveFromDE(t *testing.T, server *proxy.Server, method string, body io.Reader) {
+// answered.
+func serveFromDE(
+	t *testing.T, server *discriminator.Server, method string, body io.Reader,
+) {
 	t.Helper()
 
 	req := httptest.NewRequestWithContext(t.Context(), method, "/", body)
-	req.RemoteAddr = net.JoinHostPort(fromDE, "1234")
+	req.Header.Set(discriminator.ClientHeader, fromDE)
+	req.Header.Set(requestIDHeader, "the-id")
 
 	server.Handler.ServeHTTP(httptest.NewRecorder(), req)
 }
@@ -490,7 +487,7 @@ func wantPercent(t *testing.T, what string, percent *int64, setting, want string
 }
 
 // percentText gives a limit percentage and the setting that gave it as
-// text, such as "50 from SWWAF_ASN_LIMIT_PERCENT", or none when both are
+// text, such as "50 from SWW_ASN_LIMIT_PERCENT", or none when both are
 // left out.
 func percentText(percent *int64, setting string) string {
 	switch {

internal/discriminator/bytelimits_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"bufio"
@@ -19,13 +19,13 @@ import (
 
 // The byte limit settings.
 const (
-	bytesLimitPerMinute = "SWWAF_BYTES_LIMIT_PER_MINUTE"
+	bytesLimitPerMinute = "SWW_BYTES_LIMIT_PER_MINUTE"
-	bytesLimitPerHour   = "SWWAF_BYTES_LIMIT_PER_HOUR"
+	bytesLimitPerHour   = "SWW_BYTES_LIMIT_PER_HOUR"
-	bytesLimitPerDay    = "SWWAF_BYTES_LIMIT_PER_DAY"
+	bytesLimitPerDay    = "SWW_BYTES_LIMIT_PER_DAY"
-	bytesCount          = "SWWAF_BYTES_COUNT"
+	bytesCount          = "SWW_BYTES_COUNT"
 )
 
-// The values of SWWAF_BYTES_COUNT.
+// The values of SWW_BYTES_COUNT.
 const (
 	countResponse = "response"
 	countRequest  = "request"
@@ -40,15 +40,13 @@ const (
 	// byteLimit is the byte limit these tests set, as a setting: a request
 	// with a body and its answer, 100 bytes, go over it.
 	byteLimit = "99"
-	// minuteBytes is limit_hit for SWWAF_BYTES_LIMIT_PER_MINUTE.
+	// minuteBytes is limit_hit for SWW_BYTES_LIMIT_PER_MINUTE.
 	minuteBytes = "minute_bytes"
 )
 
 func TestEachByteLimitBansOnceTheResponseHasEnded(t *testing.T) {
 	t.Parallel()
 
-	const scraper = "192.0.2.200"
-
 	for _, tc := range []struct {
 		setting, window string
 		// apart is the time between the two requests, which the window
@@ -94,7 +92,7 @@ func TestEachByteLimitBansOnceTheResponseHasEnded(t *testing.T) {
 
 			s.get(client, http.StatusForbidden, requestlog.ActionBanned)
 
-			wantMetric(t, s.scrape(scraper), `smallwebwaf_rate_limit_hits_total{`+
+			wantMetric(t, s.scrape(), `sww_rate_limit_hits_total{`+
 				`instance="`+alertInstance+`",kind="bytes",window="`+tc.window+`"}`, 1)
 		})
 	}
@@ -126,7 +124,7 @@ func TestBytesOfAnAnswerThatBreaksOffAreCounted(t *testing.T) {
 	// The 70 bytes passed on before the app broke off are over the limit of
 	// 50, and ban the client for an hour.
 	line, got := s.requestWithBody(http.MethodGet, client, "/", "", "", http.StatusOK,
-		requestlog.ActionUpstreamError)
+		requestlog.ActionForward)
 	if len(got.body) != answerBytes || line.LimitHit != minuteBytes ||
 		line.BanExpires != expires {
 		t.Errorf("got %d bytes, and the log line has limit_hit %q and ban_expires %q, "+
@@ -168,39 +166,6 @@ func TestWebSocketBytesAreCountedOnceItCloses(t *testing.T) {
 	}
 }
 
-func TestWebSocketPassesTheAnswerAfterTheClientStopsSending(t *testing.T) {
-	t.Parallel()
-
-	app := startApp(t, echoOnceTheClientStops)
-	addr, out := startProxy(t, app.URL,
-		map[string]string{trustedProxies: trustLocalhost})
-	s := &sender{t: t, addr: addr, out: out}
-
-	conn, reader := s.openWebSocket()
-	send(t, conn, uploadBody)
-
-	// The client closes its sending side and waits for the answer, which the
-	// app sends only once it has seen the client stop. smallwebwaf passes the
-	// close on to the app through CloseWrite on upgradedConn; without that,
-	// it closes both connections, and the answer is lost.
-	tcp, ok := conn.(*net.TCPConn)
-	if !ok {
-		t.Fatalf("connection is a %T, want a *net.TCPConn", conn)
-	}
-
-	err := tcp.CloseWrite()
-	if err != nil {
-		t.Fatalf("close the sending side: %v", err)
-	}
-
-	got, err := io.ReadAll(reader)
-	if err != nil || string(got) != uploadBody {
-		t.Errorf("got %q (%v), want %q", got, err, uploadBody)
-	}
-
-	s.closeWebSocket(conn)
-}
-
 func TestBytesCountSaysWhichBytesCount(t *testing.T) {
 	t.Parallel()
 
@@ -247,8 +212,8 @@ func TestByteLimitsLeaveOutWhatTheRateLimitsLeaveOut(t *testing.T) {
 	t.Parallel()
 
 	const (
-		allowed = "192.0.2.7"  // in SWWAF_ALLOW_NETS
+		allowed = "192.0.2.7"  // in SWW_ALLOW_NETS
-		exempt  = "192.0.2.10" // in SWWAF_RATE_LIMIT_EXEMPT_NETS
+		exempt  = "192.0.2.10" // in SWW_RATE_LIMIT_EXEMPT_NETS
 	)
 
 	s, _ := startWithAnswers(t, map[string]string{
@@ -465,28 +430,6 @@ func answerAfterUpgrade(w http.ResponseWriter, _ *http.Request) {
 	}
 }
 
-// echoOnceTheClientStops is an app that switches protocols, as for a
-// WebSocket, reads what the client sends until the client stops sending,
-// and then sends it all back.
-func echoOnceTheClientStops(w http.ResponseWriter, _ *http.Request) {
-	conn, buffered, err := http.NewResponseController(w).Hijack()
-	if err != nil {
-		return
-	}
-
-	defer func() {
-		_ = conn.Close()
-	}()
-
-	_, _ = buffered.WriteString("HTTP/1.1 101 Switching Protocols\r\n" +
-		"Connection: Upgrade\r\nUpgrade: websocket\r\n\r\n")
-	_ = buffered.Flush()
-
-	received, _ := io.ReadAll(buffered)
-	_, _ = buffered.Write(received)
-	_ = buffered.Flush()
-}
-
 // webSocket opens a WebSocket from client to answerAfterUpgrade, sends a
 // line of bodyBytes on it, reads the answer, and closes it. It checks the
 // answer, and the log line as request does, and returns the log line.
@@ -543,7 +486,7 @@ func (s *sender) closeWebSocket(conn net.Conn) logLine {
 
 	_ = conn.Close()
 
-	line := s.out.requestLines(s.t, s.sent+1)[s.sent]
+	line := s.out.endedLines(s.t, s.sent+1)[s.sent]
 	s.sent++
 	wantLine(s.t, line, http.StatusSwitchingProtocols, requestlog.ActionForward)
 

internal/discriminator/client.go

@@ -0,0 +1,62 @@
+package discriminator
+
+import (
+	"crypto/rand"
+	"net/http"
+	"net/netip"
+	"slices"
+)
+
+// peerAddress is the address of the request's TCP peer.
+func peerAddress(r *http.Request) netip.Addr {
+	addrPort, err := netip.ParseAddrPort(r.RemoteAddr)
+	if err != nil {
+		return netip.Addr{}
+	}
+
+	return addrPort.Addr().Unmap()
+}
+
+// requestIDHeader carries the request's id, from rproxy.
+const requestIDHeader = "X-Request-ID"
+
+// requestID is the request's id: the one a question gives, or for any other
+// request a new random one.
+func requestID(r *http.Request, isQuestion bool) string {
+	if isQuestion {
+		return r.Header.Get(requestIDHeader)
+	}
+
+	return rand.Text()
+}
+
+// scheme is how the visitor reached rproxy, or the trusted proxy in front of
+// it, as a question says in X-Forwarded-Proto, or otherwise http.
+func scheme(r *http.Request, isQuestion bool) string {
+	proto := r.Header.Get("X-Forwarded-Proto")
+	if !isQuestion || proto == "" {
+		return "http"
+	}
+
+	return proto
+}
+
+// clientGroup is the client a request is counted toward: its IPv4
+// address, or its IPv6 group, the netblock its IPv6 address is in of the
+// length SWW_IPV6_GROUP_PREFIX sets, a /64 by default, since one abuser
+// usually holds a whole /64. An IPv4 address in IPv6 form counts as IPv4.
+func (h *handler) clientGroup(addr netip.Addr) netip.Prefix {
+	addr = addr.Unmap()
+	if addr.Is6() {
+		return netip.PrefixFrom(addr, h.config.IPv6GroupPrefix).Masked()
+	}
+
+	return netip.PrefixFrom(addr, addr.BitLen())
+}
+
+// isInside reports whether addr is in one of the netblocks.
+func isInside(addr netip.Addr, netblocks []netip.Prefix) bool {
+	return slices.ContainsFunc(netblocks, func(netblock netip.Prefix) bool {
+		return netblock.Contains(addr)
+	})
+}

internal/discriminator/coreruleset.go

@@ -1,9 +1,6 @@
-package proxy
+package discriminator
 
 import (
-	"errors"
-	"net/http"
-	"os"
 	"time"
 
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
@@ -13,26 +10,25 @@ import (
 )
 
 // checkCoreRuleSet inspects the request with the Core Rule Set, unless
-// SWWAF_WAF_MODE is off or SWWAF_WAF_EXEMPT_PATHS exempts its path, as
+// SWW_WAF_MODE is off or SWW_WAF_EXEMPT_PATHS exempts its path, as
 // pathExempt decides, and notes the rules it matched and its score in the
 // log line, and the rules in the metrics. A score at or over
-// SWWAF_WAF_ANOMALY_THRESHOLD is a match: it raises the waf_block alert,
+// SWW_WAF_ANOMALY_THRESHOLD is a match: it raises the waf_block alert,
 // and in block mode refuses the request, which is an offence its client's
 // history counts, and so returns ActionWAFBlocked. It returns "" for a
-// request it does not refuse, and for one whose body meets a size or time
+// request it does not refuse.
-// limit while the Core Rule Set reads it, which it notes nothing of.
 func (rq *request) checkCoreRuleSet() string {
 	cfg := rq.h.config
-	if cfg.WAFMode == config.WAFModeOff || pathExempt(rq.in.URL, cfg.WAFExemptPaths) {
+	if cfg.WAFMode == config.WAFModeOff || pathExempt(rq.in, cfg.WAFExemptPaths) {
 		return ""
 	}
 
 	start := time.Now()
 
-	result := rq.inspect()
+	// A question's body has been read into memory, so that reading it here
-	if rq.refused.Load() != nil {
+	// cannot fail.
-		return "" // the refusal for that limit, which check returns
+	result, read, _ := rq.h.coreRuleSet.Inspect(rq.in, rq.client, rq.in.Body)
-	}
+	rq.requestBytes = int64(len(read))
 
 	rq.line.DurationWAF = new(requestlog.Milliseconds(time.Since(start)))
 	rq.line.WAFRuleIDs = result.RuleIDs
@@ -58,41 +54,8 @@ func (rq *request) checkCoreRuleSet() string {
 	return requestlog.ActionWAFBlocked
 }
 
-// inspect runs the Core Rule Set on the request, which reads the part of
-// its body it inspects within SWWAF_CLIENT_REQUEST_TIMEOUT, and keeps that
-// part for the app. A client that runs out of time is refused with 408
-// here, and a body over SWWAF_REQUEST_MAX_BYTES with 413 as it is read;
-// check returns the refusal. A body that breaks off for any other reason
-// is passed on as far as it came, and the request to the app fails there,
-// as it would have without the Core Rule Set.
-func (rq *request) inspect() waf.Result {
-	if rq.body == nil {
-		// Nothing is read of no body, so nothing can go wrong reading it.
-		result, _, _ := rq.h.coreRuleSet.Inspect(rq.in, rq.client, http.NoBody)
-
-		return result
-	}
-
-	_ = rq.rc.SetReadDeadline(rq.clientRequestDeadline())
-	result, read, err := rq.h.coreRuleSet.Inspect(rq.in, rq.client, rq.body)
-	// The timeouts that run while the request goes to the app take over.
-	_ = rq.rc.SetReadDeadline(time.Time{})
-
-	rq.body.readByCoreRuleSet = read
-
-	if errors.Is(err, os.ErrDeadlineExceeded) {
-		rq.refuse(refusal{
-			status: http.StatusRequestTimeout,
-			action: requestlog.ActionTimedOut,
-			limit:  "SWWAF_CLIENT_REQUEST_TIMEOUT",
-		})
-	}
-
-	return result
-}
-
 // alertWAFBlock raises the waf_block alert for the request, which the Core
-// Rule Set scored at result, at or over SWWAF_WAF_ANOMALY_THRESHOLD. Its
+// Rule Set scored at result, at or over SWW_WAF_ANOMALY_THRESHOLD. Its
 // detail gives the rule ids, the score, the method and the path with the
 // query, and, for a request that is not refused for it, the mode: detect,
 // or observe in observe mode.
@@ -113,12 +76,13 @@ func (rq *request) alertWAFBlock(result waf.Result) {
 
 	rq.h.alerts.Raise(alerts.Alert{
 		Event:    alerts.EventWAFBlock,
+		Host:     rq.site,
 		Client:   rq.client,
 		Netblock: rq.h.clientGroup(rq.client),
 		ASN:      rq.line.ASN,
 		ASName:   rq.line.ASName,
 		Country:  rq.line.Country,
-		Reason:   "scored by the Core Rule Set at or over SWWAF_WAF_ANOMALY_THRESHOLD",
+		Reason:   "scored by the Core Rule Set at or over SWW_WAF_ANOMALY_THRESHOLD",
 		Detail:   detail,
 	})
 }

internal/discriminator/coreruleset_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"io"
@@ -8,20 +8,21 @@ import (
 	"strconv"
 	"strings"
 	"testing"
-	"time"
 
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
 	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
 
-// The Core Rule Set's settings the tests set, besides SWWAF_WAF_MODE, and
+// The Core Rule Set's settings the tests set, besides SWW_WAF_MODE, and
 // its two modes that inspect requests.
 const (
-	wafAnomalyThreshold = "SWWAF_WAF_ANOMALY_THRESHOLD"
+	wafAnomalyThreshold = "SWW_WAF_ANOMALY_THRESHOLD"
-	wafDisabledRules    = "SWWAF_WAF_DISABLED_RULES"
+	wafDisabledRules    = "SWW_WAF_DISABLED_RULES"
-	wafExemptPaths      = "SWWAF_WAF_EXEMPT_PATHS"
+	wafExemptPaths      = "SWW_WAF_EXEMPT_PATHS"
-	wafBodyLimit        = "SWWAF_WAF_BODY_LIMIT"
+	wafBodyLimit        = "SWW_WAF_BODY_LIMIT"
+	apps                = "SWW_APPS"
 	block               = "block"
 	detect              = "detect"
 )
@@ -29,9 +30,16 @@ const (
 // formData is the type of a form's body.
 const formData = "application/x-www-form-urlencoded"
 
+// sizeLimit is SWW_WAF_BODY_LIMIT in the tests that read bodies, 1K as a
+// setting.
+const (
+	sizeLimit        = 1 << 10
+	sizeLimitSetting = "1K"
+)
+
 // sqlInjection asks for / with an SQL injection in its query, which only
 // the Core Rule Set's rule 942100 matches, with a score of 5, the default
-// SWWAF_WAF_ANOMALY_THRESHOLD.
+// SWW_WAF_ANOMALY_THRESHOLD.
 const sqlInjection = "/?id=1'%20OR%20'1'='1"
 
 // wantWAF checks the request log line's waf_rule_ids and waf_score, and
@@ -96,7 +104,7 @@ func TestCoreRuleSetRefusesAttacksInBlockModeAndOnlyLogsThemInDetectMode(t *test
 			} {
 				s, _, _ := startWithClock(t, "", map[string]string{wafMode: tc.mode})
 
-				line, _ := s.requestWithHeader(client, attack.path, attack.header,
+				line := s.requestWithHeader(client, attack.path, attack.header,
 					tc.status, tc.action)
 				wantWAF(t, line, &attack.score, attack.ruleIDs...)
 			}
@@ -119,7 +127,7 @@ func TestCoreRuleSetIsNotRunWhenOffOrForAnExemptClientPathOrRuleFileRefusal(
 ) {
 	t.Parallel()
 
-	const allowed = "192.0.2.60" // in SWWAF_ALLOW_NETS
+	const allowed = "192.0.2.60" // in SWW_ALLOW_NETS
 
 	s, _, _ := startWithClock(t, "", map[string]string{
 		wafMode:        block,
@@ -128,7 +136,7 @@ func TestCoreRuleSetIsNotRunWhenOffOrForAnExemptClientPathOrRuleFileRefusal(
 		rulesDir:       writeRules(t, testRules),
 	})
 
-	// A client in SWWAF_ALLOW_NETS, and a path SWWAF_WAF_EXEMPT_PATHS
+	// A client in SWW_ALLOW_NETS, and a path SWW_WAF_EXEMPT_PATHS
 	// exempts, are not inspected.
 	line := s.request(allowed, sqlInjection, http.StatusOK, requestlog.ActionForward)
 	wantWAF(t, line, nil)
@@ -147,7 +155,7 @@ func TestCoreRuleSetIsNotRunWhenOffOrForAnExemptClientPathOrRuleFileRefusal(
 		requestlog.ActionRuleBlocked)
 	wantWAF(t, line, nil)
 
-	// With SWWAF_WAF_MODE off, no request is.
+	// With SWW_WAF_MODE off, no request is.
 	s, _, _ = startWithClock(t, "", map[string]string{wafMode: off})
 	line = s.request(client, sqlInjection, http.StatusOK, requestlog.ActionForward)
 	wantWAF(t, line, nil)
@@ -231,6 +239,27 @@ func TestDisabledRulesSwitchOffWhatGiteaWouldBeRefused(t *testing.T) {
 	}
 }
 
+func TestGiteasFixesApplyOnlyToAHostnameThatServesGitea(t *testing.T) {
+	t.Parallel()
+
+	// Only gitea's fixes let a file name through in path, a parameter
+	// gitea sends file names in.
+	const fileName = "/?path=.gitignore"
+
+	s := startDiscriminator(t, "", map[string]string{
+		wafMode: block, apps: siteA + ":gitea",
+	})
+
+	wantDisposition(t, do(t, s.question(siteA, client, fileName)),
+		http.StatusOK, discriminator.DispositionAllow)
+	wantDisposition(t, do(t, s.question(siteB, client, fileName)),
+		http.StatusForbidden, discriminator.DispositionDeny)
+
+	lines := s.out.requestLines(t, 2)
+	wantLine(t, lines[0], http.StatusOK, requestlog.ActionForward)
+	wantLine(t, lines[1], http.StatusForbidden, requestlog.ActionWAFBlocked)
+}
+
 func TestAttackInAFormBodyIsRefusedOnlyWhileBodiesAreRead(t *testing.T) {
 	t.Parallel()
 
@@ -299,7 +328,7 @@ func TestBodiesReachTheAppAsSentWhileBodiesAreRead(t *testing.T) {
 				tc.name, len(got.body), got.status, len(tc.body))
 		}
 
-		line := out.requestLines(t, i+1)[i]
+		line := out.endedLines(t, i+1)[i]
 		wantLine(t, line, http.StatusOK, requestlog.ActionForward)
 
 		if line.RequestBytes != int64(len(tc.body)) {
@@ -309,119 +338,6 @@ func TestBodiesReachTheAppAsSentWhileBodiesAreRead(t *testing.T) {
 	}
 }
 
-func TestFormBodyLongerThanTheLimitStreamsOnToTheApp(t *testing.T) {
-	t.Parallel()
-
-	const (
-		first = "a=" // and twice the limit of b's, then the rest
-		rest  = 64 * sizeLimit
-	)
-
-	// past is closed once the app has received twice what the Core Rule
-	// Set reads, and got is the length of the whole body it received.
-	past := make(chan struct{})
-	got := make(chan int64, 1)
-	app := startApp(t, func(_ http.ResponseWriter, r *http.Request) {
-		n, _ := io.CopyN(io.Discard, r.Body, 2*sizeLimit)
-
-		close(past)
-
-		m, _ := io.Copy(io.Discard, r.Body)
-		got <- n + m
-	})
-	addr, out := startProxy(t, app.URL, map[string]string{
-		wafMode: block, wafBodyLimit: sizeLimitSetting,
-	})
-
-	// The client sends the rest only once the app has received the first
-	// part: were smallwebwaf to hold the body until the end, it would
-	// never come.
-	body, sender := io.Pipe()
-
-	go func() {
-		_, _ = io.WriteString(sender, first+strings.Repeat("b", 2*sizeLimit))
-
-		select {
-		case <-past:
-		case <-time.After(waitLimit):
-			t.Error("the app got no more than the Core Rule Set reads " +
-				"before the whole body was sent")
-
-			_ = sender.CloseWithError(io.ErrUnexpectedEOF)
-
-			return
-		}
-
-		_, _ = io.WriteString(sender, strings.Repeat("b", rest))
-		_ = sender.Close()
-	}()
-
-	req := newRequest(t, http.MethodPost, addr, "/", body)
-	req.Header.Set("Content-Type", formData)
-	wantStatus(t, do(t, req), http.StatusOK)
-
-	want := int64(len(first) + 2*sizeLimit + rest)
-	if n := <-got; n != want {
-		t.Errorf("the app got %d bytes, want %d", n, want)
-	}
-
-	wantLine(t, out.requestLine(t), http.StatusOK, requestlog.ActionForward)
-}
-
-func TestClientTooSlowToSendWhatTheCoreRuleSetReads(t *testing.T) {
-	t.Parallel()
-
-	app := startApp(t, func(http.ResponseWriter, *http.Request) {})
-	addr, out := startProxy(t, app.URL, map[string]string{
-		wafMode: block, wafBodyLimit: sizeLimitSetting,
-		clientRequestTimeout: shortTimeoutSetting, metricsToken: token,
-	})
-
-	conn := dial(t, addr)
-	send(t, conn, "POST /comment HTTP/1.1\r\nHost: app\r\nContent-Type: "+formData+
-		"\r\nContent-Length: 100\r\n\r\ncontent=the first bytes")
-
-	wantStatus(t, readResponse(t, conn), http.StatusRequestTimeout)
-
-	line := out.requestLine(t)
-	wantLine(t, line, http.StatusRequestTimeout, requestlog.ActionTimedOut)
-	wantNotSentToTheApp(t, line)
-	wantLimitHits(t, addr, clientRequestTimeout, 1)
-}
-
-func TestBodyOverTheSizeLimitWhileTheCoreRuleSetReadsIt(t *testing.T) {
-	t.Parallel()
-
-	app := startApp(t, func(http.ResponseWriter, *http.Request) {})
-	addr, out := startProxy(t, app.URL, map[string]string{
-		wafMode: block, wafBodyLimit: "4K",
-		requestMaxBytes: sizeLimitSetting, metricsToken: token,
-	})
-
-	// Sent in chunks, its length is not announced, and is found to be over
-	// the limit as the Core Rule Set reads it.
-	body := io.MultiReader(strings.NewReader("a=" + strings.Repeat("b", 2*sizeLimit)))
-	req := newRequest(t, http.MethodPost, addr, "/", body)
-	req.Header.Set("Content-Type", formData)
-	wantStatus(t, do(t, req), http.StatusRequestEntityTooLarge)
-
-	line := out.requestLine(t)
-	wantLine(t, line, http.StatusRequestEntityTooLarge, requestlog.ActionTooLarge)
-	wantNotSentToTheApp(t, line)
-	wantLimitHits(t, addr, requestMaxBytes, 1)
-}
-
-// wantNotSentToTheApp checks that the request of line was not sent to the
-// app at all.
-func wantNotSentToTheApp(t *testing.T, line logLine) {
-	t.Helper()
-
-	_, sent := line.fields["duration_upstream_total"]
-	if sent {
-		t.Error("log line has duration_upstream_total, for a request sent to the app")
-	}
-}
-
 func TestResponsesAreNotInspected(t *testing.T) {
 	t.Parallel()
 
@@ -441,14 +357,12 @@ func TestResponsesAreNotInspected(t *testing.T) {
 		t.Errorf("answered %d with %q, want 200 with the app's page", got.status, got.body)
 	}
 
-	wantLine(t, out.requestLine(t), http.StatusOK, requestlog.ActionForward)
+	wantLine(t, out.endedLine(t), http.StatusOK, requestlog.ActionForward)
 }
 
 func TestCoreRuleSetRefusalIsAnOffenceAndCountsTowardTheErrorBurst(t *testing.T) {
 	t.Parallel()
 
-	const scraper = "192.0.2.200"
-
 	s, _, server := startWithClock(t, "", map[string]string{
 		wafMode: block, errorBurstThreshold: "2", metricsToken: token,
 	})
@@ -474,20 +388,18 @@ func TestCoreRuleSetRefusalIsAnOffenceAndCountsTowardTheErrorBurst(t *testing.T)
 		t.Errorf("history counts the offences %+v, want %+v", offences, want)
 	}
 
-	metrics := s.scrape(scraper)
+	metrics := s.scrape()
 	wantMetric(t, metrics,
-		`smallwebwaf_waf_matches_total{instance="app",mode="block",rule_id="942100"}`, 3)
+		`sww_waf_matches_total{instance="app",mode="block",rule_id="942100"}`, 3)
 	wantMetric(t, metrics,
-		`smallwebwaf_offences_total{instance="app",kind="waf_blocked"}`, 3)
+		`sww_offences_total{instance="app",kind="waf_blocked"}`, 3)
-	wantMetric(t, metrics, `smallwebwaf_requests_total{action="waf_blocked",`+
+	wantMetric(t, metrics, `sww_requests_total{action="waf_blocked",`+
 		`instance="app",status_class="4xx"}`, 3)
 }
 
 func TestDetectModeMatchIsNoOffenceAndNotCountedTowardTheErrorBurst(t *testing.T) {
 	t.Parallel()
 
-	const scraper = "192.0.2.200"
-
 	s, _, server := startWithClock(t, "", map[string]string{
 		wafMode: detect, errorBurstThreshold: "2", metricsToken: token,
 	})
@@ -503,11 +415,11 @@ func TestDetectModeMatchIsNoOffenceAndNotCountedTowardTheErrorBurst(t *testing.T
 		t.Errorf("history counts the offences %+v, want none", offences)
 	}
 
-	metrics := s.scrape(scraper)
+	metrics := s.scrape()
 	wantMetric(t, metrics,
-		`smallwebwaf_waf_matches_total{instance="app",mode="detect",rule_id="942100"}`, 3)
+		`sww_waf_matches_total{instance="app",mode="detect",rule_id="942100"}`, 3)
 	wantNoSeries(t, metrics,
-		`smallwebwaf_offences_total{instance="app",kind="waf_blocked"}`)
+		`sww_offences_total{instance="app",kind="waf_blocked"}`)
 }
 
 func TestObserveModeLogsWhatTheCoreRuleSetWouldDo(t *testing.T) {
@@ -576,9 +488,10 @@ func TestCoreRuleSetMatchRaisesTheWAFBlockAlert(t *testing.T) {
 				Instance: alertInstance,
 				Time:     clk.Now(),
 				Event:    alerts.EventWAFBlock,
+				Host:     appHost,
 				Client:   netip.MustParseAddr(client),
 				Netblock: netip.MustParsePrefix(client + "/32"),
-				Reason:   "scored by the Core Rule Set at or over SWWAF_WAF_ANOMALY_THRESHOLD",
+				Reason:   "scored by the Core Rule Set at or over SWW_WAF_ANOMALY_THRESHOLD",
 				Detail:   detail,
 			})
 

internal/discriminator/countries.go

@@ -1,4 +1,4 @@
-package proxy
+package discriminator
 
 import (
 	"slices"
@@ -7,7 +7,7 @@ import (
 // countryDenied reports whether the country lists refuse the request, by
 // the client's country as it was looked up. A client without a country,
 // or whose country cannot be found, is refused only by
-// SWWAF_EXCLUSIVELY_ALLOWED_COUNTRIES.
+// SWW_EXCLUSIVELY_ALLOWED_COUNTRIES.
 func (rq *request) countryDenied() bool {
 	denied := rq.h.config.DeniedCountries
 	allowed := rq.h.config.ExclusivelyAllowedCountries

internal/discriminator/countries_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"encoding/json"
@@ -65,7 +65,7 @@ func TestCountryLists(t *testing.T) {
 				req.Header.Set(forwardedFor, sent.client)
 				got := do(t, req)
 
-				line := out.requestLines(t, i+1)[i]
+				line := out.endedLines(t, i+1)[i]
 				if line.ASN != sent.asn || line.ASName != sent.asName ||
 					line.Country != sent.country {
 					t.Errorf("log line has %q, %q and %q, want %q, %q and %q",
@@ -90,7 +90,7 @@ func TestCountryLists(t *testing.T) {
 	}
 }
 
-func TestCountryRefusalComesBeforeTheBody(t *testing.T) {
+func TestCountryRefusalKeepsARequestFromTheApp(t *testing.T) {
 	t.Parallel()
 
 	var calls atomic.Int32
@@ -109,13 +109,9 @@ func TestCountryRefusalComesBeforeTheBody(t *testing.T) {
 	req.Header.Set(forwardedFor, fromKP)
 	wantStatus(t, do(t, req), http.StatusForbidden)
 
-	line := out.requestLine(t)
+	line := out.endedLine(t)
 	wantLine(t, line, http.StatusForbidden, requestlog.ActionCountryDenied)
 
-	if line.RequestBytes != 0 {
-		t.Errorf("log line has request_bytes %d, want 0", line.RequestBytes)
-	}
-
 	if calls.Load() != 0 {
 		t.Errorf("the app was called %d times, want none", calls.Load())
 	}
@@ -211,7 +207,7 @@ func TestPrivateAddressIsNeverLookedUp(t *testing.T) {
 
 				wantStatus(t, do(t, req), http.StatusOK)
 
-				line := out.requestLines(t, i+1)[i]
+				line := out.endedLines(t, i+1)[i]
 				wantLine(t, line, http.StatusOK, requestlog.ActionForward)
 
 				for _, field := range []string{"asn", "as_name", "country"} {
@@ -249,11 +245,11 @@ func TestExclusiveListRefusesAPrivateAddressUnlessAllowed(t *testing.T) {
 		action    string
 	}{
 		{
-			"not in SWWAF_ALLOW_NETS", "",
+			"not in SWW_ALLOW_NETS", "",
 			http.StatusForbidden, requestlog.ActionCountryDenied,
 		},
 		{
-			"in SWWAF_ALLOW_NETS", "10.0.0.7,fd00::/8",
+			"in SWW_ALLOW_NETS", "10.0.0.7,fd00::/8",
 			http.StatusOK, requestlog.ActionForward,
 		},
 	} {
@@ -283,10 +279,10 @@ func TestExclusiveListRefusesAPrivateAddressUnlessAllowed(t *testing.T) {
 // startGeoJS starts a stand-in for GeoJS, which places fromDE and fromKP,
 // each in an AS of its own, and no other address. It returns its URL, and
 // what returns the addresses it has been asked about. A test that needs
-// the stand-in to be asked or to answer sets SWWAF_LOOKUP_TIMEOUT to an
+// the stand-in to be asked or to answer sets SWW_LOOKUP_TIMEOUT to an
-// hour, whether or not a request waits for the answer: on the default
+// hour, whether or not a request waits for the answer: on the default, a
-// second, a hold-up of the test process can abandon the request to the
+// hold-up of the test process can abandon the request to the stand-in, and
-// stand-in, and leave the client unknown.
+// leave the client unknown.
 func startGeoJS(t *testing.T) (string, func() []string) {
 	t.Helper()
 
@@ -354,7 +350,7 @@ const (
 )
 
 // geojsAnswer is an answer of GeoJS about one address, with the fields
-// smallwebwaf reads.
+// sww reads.
 //
 //nolint:tagliatelle // GeoJS's own names
 type geojsAnswer struct {

internal/discriminator/crowdsec_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"net/http"
@@ -9,7 +9,7 @@ import (
 
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 	"sneak.berlin/go/smallwebwaf/internal/bans"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
 	"sneak.berlin/go/smallwebwaf/internal/reputation"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
@@ -18,8 +18,8 @@ import (
 // test puts in the copy of its decision list, at decisionsURL, that it
 // needs, as reputation.json would at start.
 const (
-	crowdSecURL  = "SWWAF_CROWDSEC_LAPI_URL"
+	crowdSecURL  = "SWW_CROWDSEC_LAPI_URL"
-	crowdSecKey  = "SWWAF_CROWDSEC_LAPI_KEY"
+	crowdSecKey  = "SWW_CROWDSEC_LAPI_KEY"
 	lapi         = "http://crowdsec.example:8080"
 	decisionsURL = lapi + "/v1/decisions"
 	bouncerKey   = "crowdsec-key-0123456789abcdef"
@@ -84,14 +84,14 @@ func TestClientTheCrowdSecDecisionListListsIsBannedUntilTheDecisionEnds(t *testi
 
 	// The ban and the hit are counted, and the list has the metrics of any
 	// list fetched from a URL.
-	metrics := s.scrape(unplaced)
+	metrics := s.scrape()
 	labels := `{instance="` + alertInstance + `",source="` + decisionsURL + `"}`
 
-	wantMetric(t, metrics, `smallwebwaf_bans_made_total{cause="crowdsec",`+
+	wantMetric(t, metrics, `sww_bans_made_total{cause="crowdsec",`+
 		`instance="`+alertInstance+`"}`, 1)
-	wantMetric(t, metrics, "smallwebwaf_reputation_hits_total"+labels, 1)
+	wantMetric(t, metrics, "sww_reputation_hits_total"+labels, 1)
-	wantMetric(t, metrics, "smallwebwaf_reputation_failures_total"+labels, 0)
+	wantMetric(t, metrics, "sww_reputation_failures_total"+labels, 0)
-	wantMetric(t, metrics, "smallwebwaf_reputation_last_fetch_timestamp_seconds"+labels,
+	wantMetric(t, metrics, "sww_reputation_last_fetch_timestamp_seconds"+labels,
 		float64(fetched.Unix()))
 }
 
@@ -168,7 +168,7 @@ func TestObserveModeForwardsAClientTheCrowdSecDecisionListListsAndAlertsTheBan(
 // decisionsURL, answer, the engine's answer, fetched at fetched, as
 // reputation.json would at start.
 func loadDecisions(
-	t *testing.T, server *proxy.Server, fetched time.Time, answer string,
+	t *testing.T, server *discriminator.Server, fetched time.Time, answer string,
 ) {
 	t.Helper()
 

internal/discriminator/discriminator.go

@@ -0,0 +1,510 @@
+package discriminator
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"net/http"
+	"net/netip"
+	"strconv"
+	"strings"
+	"time"
+	"unicode/utf8"
+
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+// The headers of rproxy's question and of discriminator's answer, as
+// "discriminator" in SPEC.md gives them.
+const (
+	// ClientHeader marks a request as rproxy's question, and gives the
+	// visitor's address.
+	ClientHeader = "X-Sww-Client"
+	// PeerHeader gives the address of rproxy's own TCP peer.
+	PeerHeader = "X-Sww-Peer"
+	// ContentLengthHeader gives the body length the visitor announced.
+	ContentLengthHeader = "X-Sww-Content-Length"
+	// DispositionHeader gives discriminator's answer.
+	DispositionHeader = "X-Sww-Disposition"
+)
+
+// The values of DispositionHeader.
+const (
+	// DispositionAllow tells rproxy to pass the request to the app.
+	DispositionAllow = "allow"
+	// DispositionDeny tells rproxy to give the visitor the answer's status,
+	// headers and body.
+	DispositionDeny = "deny"
+	// DispositionClose tells rproxy to close the visitor's connection
+	// without an answer, which SWW_BAN_RESPONSE asks for when it is close.
+	// discriminator closing the question's connection instead would read as
+	// discriminator being down, and rproxy would then let the request through.
+	DispositionClose = "close"
+)
+
+// ReportPath is where rproxy sends the report of each request discriminator
+// answered.
+const ReportPath = "/_sww/report"
+
+// QuestionBodyMaxBytes is the most of a visitor's body a question carries.
+const QuestionBodyMaxBytes = 64 << 10
+
+// The header limits: the most cookies and header fields a request may have
+// when the checks reach the Core Rule Set. Real clients never reach them.
+const (
+	maxCookies      = 50
+	maxHeaderFields = 100
+)
+
+const (
+	// maxAwaitingReport is the most answered requests held until their
+	// reports come. Past it, the request answered longest ago is dropped.
+	maxAwaitingReport = 10000
+	// maxRequestIDBytes is the longest id a question may give.
+	maxRequestIDBytes = 128
+	// reportBodyMaxBytes is the most of a report's body that is read. It is
+	// far above any report's.
+	reportBodyMaxBytes = 1 << 20
+	// maxHTTPStatus is the highest status a report may give.
+	maxHTTPStatus = 599
+	// maxReportedBytes is the most bytes a report may give for each way, 1
+	// PiB, so that adding them up cannot overflow.
+	maxReportedBytes = 1 << 50
+	// maxReportedMilliseconds is the longest duration a report may give,
+	// about 31 years, so that it fits a time.Duration.
+	maxReportedMilliseconds = 1e12
+	// discriminatorTimeout bounds how long a request to discriminator takes to
+	// arrive, and its answer to leave, and discriminatorIdleTimeout how long a
+	// kept-open connection waits for its next request.
+	discriminatorTimeout     = 60 * time.Second
+	discriminatorIdleTimeout = 120 * time.Second
+)
+
+var (
+	errReportFieldMissing = errors.New("a field is missing")
+	errReportValue        = errors.New("a value is out of range")
+)
+
+// Report is the JSON object rproxy posts to ReportPath once the visitor's
+// answer has ended, its fields named as the request log's of the same
+// meaning. RequestID is the question's id. Status is what the visitor got, 0
+// if nothing. The durations are in milliseconds.
+//
+//nolint:tagliatelle // docs/request-log.md names the fields in snake_case
+type Report struct {
+	RequestID             string  `json:"request_id"`
+	Status                int     `json:"status"`
+	RequestBytes          int64   `json:"request_bytes"`
+	ResponseBytes         int64   `json:"response_bytes"`
+	DurationTotal         float64 `json:"duration_total"`
+	DurationUpstreamTotal float64 `json:"duration_upstream_total"`
+}
+
+// New returns the server `sww discriminator` runs. It answers
+// rproxy's questions, takes rproxy's reports and answers its own endpoints. It
+// passes nothing to an app. rproxy applies the size and time limits to the
+// visitor. Go's default limit on a request's line and headers, 1 MiB, stays: it
+// is far above rproxy's, and a question refused for its size would have rproxy
+// let the request through.
+func New(params Params) *Server {
+	h := newHandler(params)
+
+	return &Server{
+		Server: &http.Server{
+			Addr:         params.Config.ListenAddr,
+			Handler:      h,
+			ErrorLog:     slog.NewLogLogger(params.ProcessLog.Handler(), slog.LevelWarn),
+			ReadTimeout:  discriminatorTimeout,
+			WriteTimeout: discriminatorTimeout,
+			IdleTimeout:  discriminatorIdleTimeout,
+		},
+		Ledger:     h.ledger,
+		Limiter:    h.limiter,
+		GeoJS:      h.geojs,
+		Anomalies:  h.anomalies,
+		LookupFile: h.lookupFile,
+		Lists:      h.lists,
+		DNSBL:      h.dnsbl,
+		AbuseIPDB:  h.abuseIPDB,
+		Metrics:    h.metrics,
+	}
+}
+
+// ServeHTTP handles one request to discriminator: a request carrying
+// ClientHeader is rproxy's question, and any other is for discriminator
+// itself.
+func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if len(r.Header.Values(ClientHeader)) > 0 {
+		h.answerQuestion(w, r)
+
+		return
+	}
+
+	h.answerOwnEndpoint(w, r)
+}
+
+// refusedWhateverTheAnswer reports whether the request is one that does not wait
+// for GeoJS, since the checks will refuse it at now whatever GeoJS answers about
+// its client: it is over the header limits, a blocklist lists its client while
+// SWW_BLOCKLIST_ACTION is deny, the CrowdSec decision list lists it, or it is
+// over a whole rate limit. In observe mode, which refuses nothing, none is.
+// rproxy lets a request through when discriminator answers too late.
+func (rq *request) refusedWhateverTheAnswer(now time.Time) bool {
+	if rq.h.config.Observe {
+		return false
+	}
+
+	lists := rq.h.lists
+	_, decided := lists.CrowdSecDecision(rq.client, now)
+
+	return decided || rq.overHeaderLimits() ||
+		(rq.h.config.BlocklistAction == deny && len(lists.ListedBy(rq.client)) > 0) ||
+		(rq.countedByRateLimits() &&
+			rq.h.limiter.OverARateLimit(rq.h.clientGroup(rq.client), now))
+}
+
+// overHeaderLimits reports whether discriminator refuses the request for its
+// headers: it has more than maxHeaderFields fields, each value of a header sent
+// twice being one, or more than maxCookies cookies, each part of a Cookie header
+// between semicolons being one unless it is empty or only spaces and tabs. The
+// Core Rule Set runs each of its rules on each cookie, so that thousands of small
+// cookies keep it busy for over a second. It trims only spaces and control
+// characters, of which a header value can hold only tabs, so a part of Unicode
+// spaces is a cookie to it.
+func (rq *request) overHeaderLimits() bool {
+	fields, cookies := 0, 0
+
+	for _, values := range rq.in.Header {
+		fields += len(values)
+	}
+
+	for _, value := range rq.in.Header.Values("Cookie") {
+		for part := range strings.SplitSeq(value, ";") {
+			if strings.Trim(part, " \t") != "" {
+				cookies++
+			}
+		}
+	}
+
+	return fields > maxHeaderFields || cookies > maxCookies
+}
+
+// answerQuestion runs the checks on the visitor's request a question
+// carries, and answers rproxy what to do with it. A denied request's counting
+// is finished here, and an allowed one's by its report.
+func (h *handler) answerQuestion(w http.ResponseWriter, r *http.Request) {
+	client, body, ok := h.readQuestion(w, r)
+	if !ok {
+		return
+	}
+
+	// One that cannot be read leaves the log line's peer_ip invalid.
+	peer, _ := netip.ParseAddr(r.Header.Get(PeerHeader))
+
+	rq := h.startRequest(w, asTheVisitorSentIt(r, body), client.Unmap(), peer.Unmap(),
+		true)
+	// The last deferred runs first, so that what is held has the finished log
+	// line. Go's server sends the answer only once this function has
+	// returned, so the report cannot come before it is held.
+	defer rq.holdForReport()
+	defer rq.finish()
+
+	rq.site = r.Host
+	rq.line.DiscriminatorLine = requestlog.DiscriminatorLineDecision
+	refused := rq.check(r.Context())
+	rq.checked = time.Now()
+	underOwnPrefix := strings.HasPrefix(r.URL.Path, adminPrefix)
+
+	if refused == nil && !underOwnPrefix {
+		// In observe mode, what enforce mode would have refused counts here.
+		defer rq.countRefusal()
+
+		rq.allow()
+
+		return
+	}
+
+	// The last deferred runs first: countRefusal before addToHistory, so that a
+	// broken error burst is in the client's history.
+	defer rq.addToHistory()
+	defer rq.countAnomalies()
+	defer rq.countRefusal()
+
+	if refused != nil {
+		rq.deny(*refused)
+
+		return
+	}
+
+	// The app never sees this prefix. discriminator's own endpoints are at its
+	// own address, so this answers as a path with no endpoint does.
+	rq.line.Action = requestlog.ActionAdmin
+	rq.out.Header().Set(DispositionHeader, DispositionDeny)
+	http.Error(rq.out, http.StatusText(http.StatusNotFound), http.StatusNotFound)
+}
+
+// readQuestion returns the visitor's address and the body a question carries,
+// and whether discriminator takes the question. It answers a question it does not
+// take with 400 and no disposition, which rproxy treats as it treats no
+// answer. The id of a question it takes is held from here on, without a
+// decision yet, so that another question with that id is refused while this
+// one is being handled.
+//
+// The body is read before any check, since Go's server does not send an answer
+// until it has read the body. A question whose body stops arriving gets no
+// answer, and is not looked at.
+func (h *handler) readQuestion(
+	w http.ResponseWriter, r *http.Request,
+) (netip.Addr, []byte, bool) {
+	client, err := netip.ParseAddr(r.Header.Get(ClientHeader))
+	if err != nil || client.Zone() != "" {
+		h.refuseQuestion(w, ClientHeader+" is not an address without a zone")
+
+		return netip.Addr{}, nil, false
+	}
+
+	id := r.Header.Get(requestIDHeader)
+	if id == "" || len(id) > maxRequestIDBytes || !utf8.ValidString(id) {
+		h.refuseQuestion(w, requestIDHeader+" is not a valid id")
+
+		return netip.Addr{}, nil, false
+	}
+
+	body, err := io.ReadAll(http.MaxBytesReader(w, r.Body, QuestionBodyMaxBytes))
+
+	if _, tooLarge := errors.AsType[*http.MaxBytesError](err); tooLarge {
+		h.refuseQuestion(w, "the body is over 64 KiB")
+
+		return netip.Addr{}, nil, false
+	}
+
+	if err != nil {
+		h.processLog.Warn("a question's body stopped arriving", "error", err.Error())
+		// This panic has Go's server close the connection without an answer,
+		// and log nothing.
+		panic(http.ErrAbortHandler)
+	}
+
+	held, _ := h.awaitingReport.ContainsOrAdd(id, nil)
+	if held {
+		h.refuseQuestion(w, requestIDHeader+" is the id of a request discriminator holds")
+
+		return netip.Addr{}, nil, false
+	}
+
+	return client, body, true
+}
+
+// refuseQuestion answers a question discriminator does not take, for reason.
+func (h *handler) refuseQuestion(w http.ResponseWriter, reason string) {
+	h.processLog.Warn("a question is refused", "reason", reason)
+	http.Error(w, reason, http.StatusBadRequest)
+}
+
+// asTheVisitorSentIt returns a copy of r, a question, as the checks and the
+// log line are to see it: without the headers rproxy adds for discriminator,
+// with body, which has been read of r, and with the length the visitor
+// announced, as -1 when it announced none. The question's own length covers
+// only the part of the body it carries.
+func asTheVisitorSentIt(r *http.Request, body []byte) *http.Request {
+	sent := r.Clone(r.Context())
+	announced := sent.Header.Get(ContentLengthHeader)
+
+	sent.Header.Del(ClientHeader)
+	sent.Header.Del(PeerHeader)
+	sent.Header.Del(ContentLengthHeader)
+	sent.Header.Del("Content-Length")
+
+	sent.ContentLength = -1
+
+	length, err := strconv.ParseInt(announced, 10, 64)
+	if err == nil && length >= 0 {
+		sent.ContentLength = length
+		sent.Header.Set("Content-Length", announced)
+	}
+
+	sent.Body = http.NoBody
+	if len(body) > 0 {
+		sent.Body = io.NopCloser(bytes.NewReader(body))
+	}
+
+	return sent
+}
+
+// allow answers a question with DispositionAllow and, while
+// SWW_ADD_LOOKUP_HEADERS is set, the client's AS number and country.
+func (rq *request) allow() {
+	rq.allowed = true
+
+	header := rq.out.Header()
+	header.Set(DispositionHeader, DispositionAllow)
+
+	if rq.h.config.AddLookupHeaders {
+		setLookupHeaders(header, rq.line.ASN, rq.line.Country)
+	}
+
+	rq.out.WriteHeader(http.StatusOK)
+}
+
+// holdForReport holds a copy of what the report's steps need, by the request's
+// id. A report only ever reaches that copy, never the request being handled.
+func (rq *request) holdForReport() {
+	held := rq.decision
+	rq.h.awaitingReport.Add(rq.line.RequestID, &held)
+}
+
+// deny answers a question with what the visitor is to get for r.
+func (rq *request) deny(r refusal) {
+	rq.refused = &r
+
+	if r.status == 0 {
+		// SWW_BAN_RESPONSE is close. Written past rq.out, since the log line's
+		// status stays 0: the visitor is sent nothing.
+		rq.out.Header().Set(DispositionHeader, DispositionClose)
+		rq.out.ResponseWriter.WriteHeader(http.StatusOK)
+
+		return
+	}
+
+	rq.out.Header().Set(DispositionHeader, DispositionDeny)
+	http.Error(rq.out, http.StatusText(r.status), r.status)
+}
+
+// answerOwnEndpoint answers a request to discriminator's own address. No check
+// runs on it: the address is on the private network, where the peers are
+// rproxy and the admin's tools, not visitors.
+func (h *handler) answerOwnEndpoint(w http.ResponseWriter, r *http.Request) {
+	if r.Method == http.MethodPost && r.URL.Path == ReportPath {
+		h.takeReport(w, r)
+
+		return
+	}
+
+	peer := peerAddress(r)
+
+	rq := h.startRequest(w, r, peer, peer, false)
+	defer rq.finish()
+
+	if r.Method == http.MethodGet && r.URL.Path == HealthPath {
+		rq.answerHealth()
+
+		return
+	}
+
+	rq.answerAdmin()
+}
+
+// takeReport answers POST ReportPath: it finishes the request the report
+// names, if it holds that request's decision, and ignores the report
+// otherwise.
+func (h *handler) takeReport(w http.ResponseWriter, r *http.Request) {
+	report, err := readReport(w, r)
+	if err != nil {
+		h.processLog.Warn("a report is refused", "error", err.Error())
+		http.Error(w, "the body is not a report", http.StatusBadRequest)
+
+		return
+	}
+
+	held, found := h.awaitingReport.Peek(report.RequestID)
+	// Remove reports true to one report only, of several that name the id. A
+	// question still being handled is held as nil.
+	if found && held != nil && h.awaitingReport.Remove(report.RequestID) {
+		h.finishWith(held, report)
+	}
+
+	w.WriteHeader(http.StatusNoContent)
+}
+
+// readReport reads a report from r's body, which must be one JSON object with
+// all of Report's fields, in the ranges SPEC.md gives.
+func readReport(w http.ResponseWriter, r *http.Request) (Report, error) {
+	var report Report
+
+	body, err := io.ReadAll(http.MaxBytesReader(w, r.Body, reportBodyMaxBytes))
+	if err != nil {
+		return report, fmt.Errorf("read the body: %w", err)
+	}
+
+	var fields map[string]json.RawMessage
+
+	err = json.Unmarshal(body, &fields)
+	if err != nil {
+		return report, fmt.Errorf("decode the body: %w", err)
+	}
+
+	for _, name := range []string{
+		"request_id", "status", "request_bytes", "response_bytes",
+		"duration_total", "duration_upstream_total",
+	} {
+		value, there := fields[name]
+		if !there || string(value) == "null" {
+			return report, fmt.Errorf("%w: %s", errReportFieldMissing, name)
+		}
+	}
+
+	err = json.Unmarshal(body, &report)
+	if err != nil {
+		return report, fmt.Errorf("decode the body: %w", err)
+	}
+
+	return report, report.checkRanges()
+}
+
+// checkRanges returns an error for a value of the report that cannot be true.
+func (report *Report) checkRanges() error {
+	switch {
+	case report.Status != 0 &&
+		(report.Status < http.StatusContinue || report.Status > maxHTTPStatus):
+		return fmt.Errorf("%w: status", errReportValue)
+	case report.RequestBytes < 0 || report.RequestBytes > maxReportedBytes:
+		return fmt.Errorf("%w: request_bytes", errReportValue)
+	case report.ResponseBytes < 0 || report.ResponseBytes > maxReportedBytes:
+		return fmt.Errorf("%w: response_bytes", errReportValue)
+	case report.DurationTotal < 0 || report.DurationTotal > maxReportedMilliseconds:
+		return fmt.Errorf("%w: duration_total", errReportValue)
+	case report.DurationUpstreamTotal < 0 ||
+		report.DurationUpstreamTotal > maxReportedMilliseconds:
+		return fmt.Errorf("%w: duration_upstream_total", errReportValue)
+	}
+
+	return nil
+}
+
+// finishWith finishes a request with what its report says, and writes the
+// request's last log line, which holds its decision's fields and the report's.
+// For an allowed request it first counts the request's bytes, and adds it to its
+// client's history, the anomaly counters and the metrics, with the status and
+// bytes the report gives. A denied request's counting was finished at its
+// decision.
+func (h *handler) finishWith(held *decision, report Report) {
+	rq := &request{
+		decision:     *held,
+		h:            h,
+		out:          &responseWriter{status: report.Status, bytes: report.ResponseBytes},
+		requestBytes: report.RequestBytes,
+	}
+
+	rq.line.DiscriminatorLine = requestlog.DiscriminatorLineReport
+	rq.line.Status = report.Status
+	rq.line.RequestBytes = report.RequestBytes
+	rq.line.ResponseBytes = report.ResponseBytes
+	rq.line.DurationTotal = report.DurationTotal
+
+	if rq.allowed {
+		rq.line.DurationUpstreamTotal = &report.DurationUpstreamTotal
+
+		rq.countBytes()
+		rq.countAnomalies()
+		rq.addToHistory()
+
+		rq.h.metrics.RequestReported(&rq.line,
+			time.Duration(report.DurationTotal*float64(time.Millisecond)),
+			time.Duration(report.DurationUpstreamTotal*float64(time.Millisecond)))
+	}
+
+	rq.writeLine()
+}

internal/discriminator/errorburst_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"maps"
@@ -10,15 +10,15 @@ import (
 
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 	"sneak.berlin/go/smallwebwaf/internal/bans"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
 	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
 
-const errorBurstThreshold = "SWWAF_ERROR_BURST_THRESHOLD"
+const errorBurstThreshold = "SWW_ERROR_BURST_THRESHOLD"
 
-// refused is a request the tests here send, which smallwebwaf refuses
+// refused is a request the tests here send, which discriminator refuses after a rule
-// after a rule file match, or for a missing or wrong token.
+// file match.
 type refused int
 
 const (
@@ -27,11 +27,6 @@ const (
 	// banRule is one its ban rule refuses with 403, and bans the client
 	// for.
 	banRule
-	// noMetricsToken is one for the metrics without a token, and
-	// wrongAdminToken one for the bans with the metrics token, each
-	// refused with 401.
-	noMetricsToken
-	wrongAdminToken
 )
 
 // send sends r from the client at from, checks its answer and log line as
@@ -45,14 +40,6 @@ func (r refused) send(s *sender, from string) logLine {
 			requestlog.ActionRuleBlocked)
 	case banRule:
 		return s.request(from, probePath, http.StatusForbidden, requestlog.ActionBanned)
-	case noMetricsToken:
-		return s.request(from, proxy.MetricsPath, http.StatusUnauthorized,
-			requestlog.ActionAdmin)
-	case wrongAdminToken:
-		line, _ := s.requestWithHeader(from, proxy.BansPath, "Authorization: "+bearer,
-			http.StatusUnauthorized, requestlog.ActionAdmin)
-
-		return line
 	}
 
 	s.t.Fatalf("no request for the refusal %d", r)
@@ -60,17 +47,16 @@ func (r refused) send(s *sender, from string) logLine {
 	return logLine{}
 }
 
-// startForErrorBurst is startWithClock with testRules, both tokens and
+// startForErrorBurst is startWithClock with testRules, the metrics token and
-// SWWAF_ERROR_BURST_THRESHOLD at threshold, and the settings in env.
+// SWW_ERROR_BURST_THRESHOLD at threshold, and the settings in env.
 func startForErrorBurst(
 	t *testing.T, threshold string, env map[string]string,
-) (*sender, *clock, *proxy.Server) {
+) (*sender, *clock, *discriminator.Server) {
 	t.Helper()
 
 	settings := map[string]string{
 		errorBurstThreshold: threshold,
 		rulesDir:            writeRules(t, testRules),
-		adminToken:          adminSecret,
 		metricsToken:        token,
 	}
 	maps.Copy(settings, env)
@@ -87,14 +73,7 @@ func TestErrorBurstBreaksAtOneOverTheThreshold(t *testing.T) {
 		refusals []refused
 	}{
 		{"block rule", []refused{blockRule, blockRule, blockRule, blockRule}},
-		{
+		{"a ban rule last", []refused{blockRule, blockRule, blockRule, banRule}},
-			"missing or wrong token",
-			[]refused{noMetricsToken, wrongAdminToken, noMetricsToken, wrongAdminToken},
-		},
-		{
-			"a mix ending in a ban rule",
-			[]refused{blockRule, noMetricsToken, blockRule, banRule},
-		},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
 			t.Parallel()
@@ -130,13 +109,11 @@ func TestErrorBurstBreaksAtOneOverTheThreshold(t *testing.T) {
 func TestErrorBurstBanNotesHistoryAndMetrics(t *testing.T) {
 	t.Parallel()
 
-	const scraper = "192.0.2.200"
-
 	s, clk, server := startForErrorBurst(t, "2", nil)
 	start := clk.Now()
 
 	blockRule.send(s, client)
-	wrongAdminToken.send(s, client)
+	blockRule.send(s, client)
 	line := blockRule.send(s, client)
 
 	expires := start.Add(time.Hour)
@@ -173,20 +150,18 @@ func TestErrorBurstBanNotesHistoryAndMetrics(t *testing.T) {
 		t.Fatalf("bans\n%+v\nwant\n%+v", got, want)
 	}
 
-	wantOffences := ratelimit.Offences{Limit: 1, RuleBlocked: 2, TokenRefused: 1}
+	wantOffences := ratelimit.Offences{Limit: 1, RuleBlocked: 3}
 	if offences := historyOf(t, server, client).Offences; offences != wantOffences {
 		t.Errorf("history counts the offences %+v, want %+v", offences, wantOffences)
 	}
 
-	metrics := s.scrape(scraper)
+	metrics := s.scrape()
-	wantMetric(t, metrics, `smallwebwaf_rate_limit_hits_total{instance="app",`+
+	wantMetric(t, metrics, `sww_rate_limit_hits_total{instance="app",`+
 		`kind="refusals",window="minute"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_offences_total{instance="app",kind="limit"}`, 1)
+	wantMetric(t, metrics, `sww_offences_total{instance="app",kind="limit"}`, 1)
 	wantMetric(t, metrics,
-		`smallwebwaf_offences_total{instance="app",kind="rule_blocked"}`, 2)
+		`sww_offences_total{instance="app",kind="rule_blocked"}`, 3)
-	wantMetric(t, metrics,
+	wantMetric(t, metrics, `sww_bans_made_total{cause="limit",instance="app"}`, 1)
-		`smallwebwaf_offences_total{instance="app",kind="token_refused"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_bans_made_total{cause="limit",instance="app"}`, 1)
 }
 
 func TestErrorBurstIsNotLoweredForAClientWithLowerLimits(t *testing.T) {
@@ -283,27 +258,23 @@ func TestErrorBurstCountsEachClientTheChecksApplyTo(t *testing.T) {
 	t.Parallel()
 
 	const (
-		allowed = "192.0.2.60" // in SWWAF_ALLOW_NETS
+		allowed = "192.0.2.60" // in SWW_ALLOW_NETS
-		exempt  = "192.0.2.50" // in SWWAF_RATE_LIMIT_EXEMPT_NETS
+		exempt  = "192.0.2.50" // in SWW_RATE_LIMIT_EXEMPT_NETS
 	)
 
 	s, _, _ := startForErrorBurst(t, "1", map[string]string{
 		allowNets: allowed, rateLimitExemptNets: exempt,
 	})
 
-	// A client in SWWAF_ALLOW_NETS still needs the token, but is not
+	// A client in SWW_ALLOW_NETS is not refused, and so not counted.
-	// counted.
 	for range 3 {
-		line := noMetricsToken.send(s, allowed)
+		s.request(allowed, blockedPath, http.StatusOK, requestlog.ActionForward)
-		if line.LimitHit != "" {
-			t.Errorf("log line has limit_hit %q, want none", line.LimitHit)
-		}
 	}
 
 	// One the rate limits do not apply to is.
-	noMetricsToken.send(s, exempt)
+	blockRule.send(s, exempt)
 
-	line := wrongAdminToken.send(s, exempt)
+	line := blockRule.send(s, exempt)
 	if line.LimitHit != requestlog.LimitHitErrorBurst {
 		t.Errorf("log line has limit_hit %q, want error_burst", line.LimitHit)
 	}
@@ -336,7 +307,6 @@ func TestObserveModeLogsAndAlertsTheErrorBurst(t *testing.T) {
 		mode:                observe,
 		errorBurstThreshold: "1",
 		rulesDir:            writeRules(t, testRules),
-		adminToken:          adminSecret,
 	})
 	start := clk.Now()
 	held := bans.Ban{
@@ -347,10 +317,11 @@ func TestObserveModeLogsAndAlertsTheErrorBurst(t *testing.T) {
 	}
 	server.Ledger.Load([]bans.Ban{held})
 
-	// Under a ban, enforce mode would have refused these before the
+	// Under a ban, enforce mode would have refused these before the rule, so
-	// endpoint, so their tokens are not counted.
+	// they are not counted.
 	for range 2 {
-		line := wrongAdminToken.send(s, otherClient)
+		line := s.request(otherClient, blockedPath, http.StatusOK,
+			requestlog.ActionForward)
 		wantWouldAction(t, line, requestlog.ActionBanned)
 
 		if line.LimitHit != "" {
@@ -360,7 +331,7 @@ func TestObserveModeLogsAndAlertsTheErrorBurst(t *testing.T) {
 
 	// The block rule's refusal, which enforce mode would have answered 403,
 	// is the second of the client's, and would have banned it.
-	wrongAdminToken.send(s, client)
+	s.request(client, blockedPath, http.StatusOK, requestlog.ActionForward)
 
 	line := s.request(client, blockedPath, http.StatusOK, requestlog.ActionForward)
 	wantWouldAction(t, line, requestlog.ActionRuleBlocked)

internal/discriminator/health_test.go

@@ -0,0 +1,40 @@
+package discriminator_test
+
+import (
+	"net/http"
+	"testing"
+
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+func TestHealthEndpointCountsTowardNoLimit(t *testing.T) {
+	t.Parallel()
+
+	// With a limit of one request a minute, any request counted before
+	// the last one would have it refused.
+	s, _, _ := startWithClock(t, "", map[string]string{rateLimitPerMinute: "1"})
+
+	const (
+		healthChecks = 3
+		contentType  = "text/plain; charset=utf-8"
+	)
+
+	for range healthChecks {
+		got := s.adminRequest("", http.MethodGet, discriminator.HealthPath, "", http.StatusOK)
+
+		if string(got.body) != "ok\n" || got.header.Get("Content-Type") != contentType {
+			t.Errorf("health endpoint answered %q with Content-Type %q, want ok "+
+				"with %q", got.body, got.header.Get("Content-Type"), contentType)
+		}
+	}
+
+	s.get(client, http.StatusOK, requestlog.ActionForward)
+
+	for _, line := range s.out.endedLines(t, healthChecks)[:healthChecks] {
+		if line.ResponseContentType != contentType {
+			t.Errorf("health check's log line has response_content_type %q, "+
+				"want %q", line.ResponseContentType, contentType)
+		}
+	}
+}

internal/discriminator/history_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"io"
@@ -8,7 +8,7 @@ import (
 	"testing"
 	"time"
 
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
 	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
@@ -45,7 +45,7 @@ func TestHistoryKeepsEachRequestOfTheClient(t *testing.T) {
 		Requests:  4,
 		Forwarded: 2,
 		Refused:   2,
-		// The app answers with no body, smallwebwaf with its status text.
+		// The app answers with no body, sww with its status text.
 		ResponseBytes: 2 * int64(len("Forbidden\n")),
 		Responses:     ratelimit.Responses{Status2xx: 2, Status4xx: 2},
 		Offences:      ratelimit.Offences{Limit: 1},
@@ -86,7 +86,7 @@ func TestHistoryCountsTheBodiesEachWay(t *testing.T) {
 
 	got := do(t, newRequest(t, http.MethodPost, addr, "/", strings.NewReader("abc")))
 	wantStatus(t, got, http.StatusOK)
-	out.requestLine(t)
+	out.endedLine(t)
 
 	history := historyOf(t, server, localhost)
 	if history.RequestBytes != 3 || history.ResponseBytes != 5 {
@@ -95,43 +95,41 @@ func TestHistoryCountsTheBodiesEachWay(t *testing.T) {
 	}
 }
 
-func TestHealthEndpointIsNotInTheHistory(t *testing.T) {
+func TestOwnEndpointsAreNotInTheHistory(t *testing.T) {
 	t.Parallel()
 
-	app := startApp(t, func(http.ResponseWriter, *http.Request) {})
+	s, _, server := startWithClock(t, "", map[string]string{metricsToken: token})
-	addr, out, server := startProxyWithClock(t, app.URL, "", time.Now, nil)
 
-	wantStatus(t, get(t, addr, proxy.HealthPath), http.StatusOK)
+	s.adminRequest("", http.MethodGet, discriminator.HealthPath, "", http.StatusOK)
-	out.requestLine(t)
+	s.adminRequest("", http.MethodGet, discriminator.MetricsPath, "",
+		http.StatusUnauthorized)
+	s.scrape()
 
 	if clients := server.Limiter.Snapshot(); len(clients) != 0 {
 		t.Errorf("the table holds %+v, want no client", clients)
 	}
 }
 
-func TestRequestForSmallwebwafIsRefusedOnlyWithoutTheToken(t *testing.T) {
+func TestPathUnderTheOwnPrefixIsNeitherForwardedNorRefused(t *testing.T) {
 	t.Parallel()
 
 	app := startApp(t, func(http.ResponseWriter, *http.Request) {})
-	addr, out, server := startProxyWithClock(t, app.URL, "", time.Now,
+	addr, out, server := startProxyWithClock(t, app.URL, "", time.Now, nil)
-		map[string]string{metricsToken: token})
 
-	// The metrics and the 404 are neither forwarded nor refused; the 401
+	wantStatus(t, get(t, addr, "/_sww/nothing"), http.StatusNotFound)
-	// is refused.
+	out.endedLine(t)
-	scrape(t, addr)
-	wantStatus(t, get(t, addr, "/_smallwebwaf/nothing"), http.StatusNotFound)
-	wantStatus(t, get(t, addr, proxy.MetricsPath), http.StatusUnauthorized)
-	out.requestLines(t, 3)
 
 	history := historyOf(t, server, localhost)
-	if history.Requests != 3 || history.Forwarded != 0 || history.Refused != 1 {
+	if history.Requests != 1 || history.Forwarded != 0 || history.Refused != 0 {
 		t.Errorf("history counts %d requests, %d forwarded and %d refused, "+
-			"want 3, 0 and 1", history.Requests, history.Forwarded, history.Refused)
+			"want 1, 0 and 0", history.Requests, history.Forwarded, history.Refused)
 	}
 }
 
 // historyOf returns the history of the client at addr.
-func historyOf(t *testing.T, server *proxy.Server, addr string) ratelimit.History {
+func historyOf(
+	t *testing.T, server *discriminator.Server, addr string,
+) ratelimit.History {
 	t.Helper()
 
 	client := netip.MustParsePrefix(addr + "/32")

internal/discriminator/lookup.go

@@ -1,18 +1,18 @@
-package proxy
+package discriminator
 
 import (
 	"context"
 	"net/http"
 	"net/netip"
+	"time"
 
 	"sneak.berlin/go/smallwebwaf/internal/lookup"
 )
 
-// The headers in which the app is passed the client's AS number and
+// The headers in which an answer of allow gives rproxy the client's AS number
-// country while SWWAF_ADD_LOOKUP_HEADERS is set. Go writes every header
+// and country, for the app, while SWW_ADD_LOOKUP_HEADERS is set. Go writes
-// name in this form, as it sends it and as it receives it, so X-Client-ASN
+// every header name in this form, as it sends it and as it receives it, so
-// arrives as X-Client-Asn, and Del removes a client's own whatever their
+// X-Client-ASN arrives as X-Client-Asn; header names are not case-sensitive.
-// case; header names are not case-sensitive.
 const (
 	asnHeader     = "X-Client-Asn"
 	countryHeader = "X-Client-Country"
@@ -20,20 +20,27 @@ const (
 
 // lookUp looks up the client's AS number and country, in the lookup
 // database or through GeoJS, and notes them for the log line, unless
-// SWWAF_LOOKUP_SOURCE is off or the client is on a private, loopback or
+// SWW_LOOKUP_SOURCE is off or the client is on a private, loopback or
 // link-local address, which no lookup can place. The lookup database
 // answers at once. With GeoJS, while a setting needs the answer, such as a
-// country list or a biased threshold, a new client's request waits for it.
+// country list or a biased threshold, a new client's request waits for it,
-// ctx is the request's own context.
+// unless refusedWhateverTheAnswer reports true. ctx is the request's own
-func (rq *request) lookUp(ctx context.Context) {
+// context.
+func (rq *request) lookUp(ctx context.Context, now time.Time) {
 	if rq.h.config.LookupSource == "off" || !canBePlaced(rq.client) {
 		return
 	}
 
-	if rq.h.config.LookupSource == "file" {
+	client := rq.h.clientGroup(rq.client)
-		rq.lookupAnswer = rq.h.lookupFile.LookUp(rq.h.clientGroup(rq.client))
+
-	} else {
+	switch {
-		rq.lookupAnswer = rq.h.geojs.LookUp(ctx, rq.h.clientGroup(rq.client))
+	case rq.h.config.LookupSource == "file":
+		rq.lookupAnswer = rq.h.lookupFile.LookUp(client)
+	case rq.refusedWhateverTheAnswer(now):
+		rq.lookupAnswer = rq.h.geojs.LookUpWithoutWaiting(ctx, client)
+		rq.skippedLookupWait = rq.lookupAnswer.Answered.IsZero()
+	default:
+		rq.lookupAnswer = rq.h.geojs.LookUp(ctx, client)
 	}
 
 	rq.lookedUp = true
@@ -52,8 +59,8 @@ func (h *handler) addLookup(answer lookup.Answer) {
 		answer.ASN, answer.ASName, answer.Country)
 }
 
-// setLookupHeaders sets the headers in which the app is passed the
+// setLookupHeaders sets the headers that give the client's AS number and
-// client's AS number and country, leaving out one that is unknown.
+// country, leaving out one that is unknown.
 func setLookupHeaders(header http.Header, asn, country string) {
 	if asn != "" {
 		header.Set(asnHeader, asn)

internal/discriminator/lookup_test.go

@@ -1,9 +1,7 @@
-package proxy_test
+package discriminator_test
 
 import (
-	"net"
 	"net/http"
-	"net/http/httptest"
 	"net/netip"
 	"path/filepath"
 	"slices"
@@ -22,7 +20,7 @@ import (
 // and country.
 type asnAndCountry struct{ asn, asName, country string }
 
-// fileSource is the SWWAF_LOOKUP_SOURCE that looks clients up in the
+// fileSource is the SWW_LOOKUP_SOURCE that looks clients up in the
 // lookup database.
 const fileSource = "file"
 
@@ -142,7 +140,7 @@ func TestRequestThatWaitedForItsLookupIsCountedWhenItGoesOn(t *testing.T) {
 		t.Fatalf("first request: %v", err)
 	}
 
-	wantLine(t, out.requestLines(t, 2)[1], http.StatusOK, requestlog.ActionForward)
+	wantLine(t, out.endedLines(t, 2)[1], http.StatusOK, requestlog.ActionForward)
 
 	// The third request's count holds all three: the first was counted
 	// when it went on, in the minute under way, and the second's count
@@ -150,7 +148,7 @@ func TestRequestThatWaitedForItsLookupIsCountedWhenItGoesOn(t *testing.T) {
 	clk.advance(500 * time.Millisecond)
 	wantStatus(t, do(t, requestFromDE()), http.StatusOK)
 
-	if got := out.requestLines(t, 3)[2].Counts.Minute; got != 3 {
+	if got := out.endedLines(t, 3)[2].Counts.Minute; got != 3 {
 		t.Errorf("the third request's count in the minute is %v, want 3", got)
 	}
 }
@@ -164,7 +162,7 @@ func TestASNumberAndNameInTheLogLineTheHistoryTheBanNotesAndTheAlert(t *testing.
 	addr, out, server, queue := startProxyWithAlerts(t, app.URL, geojsURL, clk.Now,
 		map[string]string{
 			trustedProxies:     trustLocalhost,
-			alertWebhookURL:    "https://alerts.example/smallwebwaf",
+			alertWebhookURL:    "https://alerts.example/sww",
 			rateLimitPerMinute: "1",
 		})
 	s := &sender{t: t, addr: addr, out: out}
@@ -319,7 +317,7 @@ func TestLookupHeadersArePassedToTheAppAndTheClientsOwnRemoved(t *testing.T) {
 	addr, out, _ := startProxyWithClock(t, app.URL, geojsURL, time.Now, map[string]string{
 		trustedProxies:   trustLocalhost,
 		lookupTimeout:    "1h",
-		addLookupHeaders: "true",
+		addLookupHeaders: on,
 	})
 	s := &sender{t: t, addr: addr, out: out}
 
@@ -381,24 +379,21 @@ func TestRequestWaitsAsLongAsTheLookupTimeoutSays(t *testing.T) {
 	// clock of the test's own: the wait lasts exactly as long as it should,
 	// however slowly the test process runs. Nothing in it may wait on the
 	// network, which would keep that clock from moving on: the request is
-	// handed to the proxy's handler, and GeoJS is one that never answers.
+	// handed to discriminator's handler, and GeoJS is one that never answers.
 	synctest.Test(t, func(t *testing.T) {
-		// Not the default second. The exclusive list needs the answer, and
+		// Not the default. The exclusive list needs the answer, and the app
-		// the app is never reached.
+		// is never reached.
 		const timeout = 3 * time.Second
 
-		server, out, _ := newProxy(t, "http://app.invalid", unansweredGeoJSURL,
+		server, out, _ := newDiscriminator(t, unansweredGeoJSURL, time.Now,
-			time.Now, map[string]string{
+			map[string]string{
 				lookupTimeout:    timeout.String(),
 				allowedCountries: "DE",
 			})
 
-		req := httptest.NewRequestWithContext(t.Context(), http.MethodGet, "/",
-			http.NoBody)
-		req.RemoteAddr = net.JoinHostPort(fromDE, "1234")
 		began := time.Now()
 
-		server.Handler.ServeHTTP(httptest.NewRecorder(), req)
+		serveFromDE(t, server, http.MethodGet, http.NoBody)
 
 		if waited := time.Since(began); waited != timeout {
 			t.Errorf("the request waited %s for its answer, want %s", waited, timeout)

internal/discriminator/metrics_test.go

@@ -0,0 +1,432 @@
+package discriminator_test
+
+import (
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"net/netip"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/bans"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
+	"sneak.berlin/go/smallwebwaf/internal/lookup"
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+const (
+	metricsToken = "SWW_METRICS_TOKEN" //nolint:gosec // the setting's name
+	metricsTopN  = "SWW_METRICS_TOP_N"
+	// token is the SWW_METRICS_TOKEN the tests set, and bearer how a
+	// request carries it.
+	token  = "0123456789abcdef0123456789abcdef"
+	bearer = "Bearer " + token
+)
+
+func TestMetricsAreOffWhileTheTokenIsUnset(t *testing.T) {
+	t.Parallel()
+
+	s, _, _ := startWithClock(t, "", nil)
+
+	// An empty token does not match the unset one either.
+	for _, authorization := range []string{bearer, "Bearer ", ""} {
+		s.adminRequest(authorization, http.MethodGet, discriminator.MetricsPath, "",
+			http.StatusNotFound)
+	}
+}
+
+func TestMetricsNeedTheTokenAndOtherPathsAreNotFound(t *testing.T) {
+	t.Parallel()
+
+	s, _, _ := startWithClock(t, "", map[string]string{metricsToken: token})
+
+	for _, tc := range []struct {
+		method, path, authorization string
+		status                      int
+	}{
+		{http.MethodGet, discriminator.MetricsPath, "", http.StatusUnauthorized},
+		{
+			http.MethodGet, discriminator.MetricsPath, "Bearer " + strings.ToUpper(token),
+			http.StatusUnauthorized,
+		},
+		{http.MethodGet, discriminator.MetricsPath, "Basic " + token,
+			http.StatusUnauthorized},
+		{http.MethodGet, discriminator.MetricsPath, bearer, http.StatusOK},
+		{http.MethodGet, discriminator.MetricsPath, "bearer " + token, http.StatusOK},
+		{http.MethodPost, discriminator.MetricsPath, bearer, http.StatusNotFound},
+		{http.MethodGet, discriminator.MetricsPath + "/", bearer, http.StatusNotFound},
+		{http.MethodGet, "/_sww/bans", bearer, http.StatusNotFound},
+		{http.MethodPost, discriminator.HealthPath, "", http.StatusNotFound},
+	} {
+		got := s.adminRequest(tc.authorization, tc.method, tc.path, "", tc.status)
+
+		if tc.status == http.StatusUnauthorized &&
+			got.header.Get("WWW-Authenticate") != "Bearer" {
+			t.Errorf("%q was answered without WWW-Authenticate: Bearer",
+				tc.authorization)
+		}
+
+		if tc.status == http.StatusOK &&
+			!strings.Contains(string(got.body), "# TYPE sww_requests_total counter") {
+			t.Errorf("the metrics are\n%s", got.body)
+		}
+	}
+}
+
+func TestMetricsCountTheTraffic(t *testing.T) {
+	t.Parallel()
+
+	app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.Copy(io.Discard, r.Body)
+		_, _ = io.WriteString(w, "hello")
+	})
+	addr, out, server := startProxyWithClock(t, app.URL, "", time.Now,
+		map[string]string{metricsToken: token})
+
+	got := do(t, newRequest(t, http.MethodPost, addr, "/", strings.NewReader("abc")))
+	wantStatus(t, got, http.StatusOK)
+	wantStatus(t, get(t, addr, "/_sww/nothing"), http.StatusNotFound)
+	out.endedLines(t, 2)
+
+	forward := `{action="forward",instance="app",status_class="2xx"}`
+	notFound := `{action="admin",instance="app",status_class="4xx"}`
+
+	// The request for the metrics is itself under way.
+	metrics := scrape(t, server.Addr)
+	wantMetric(t, metrics, "sww_requests_total"+forward, 1)
+	wantMetric(t, metrics, "sww_requests_total"+notFound, 1)
+	wantMetric(t, metrics, "sww_request_bytes_total"+forward, 3)
+	wantMetric(t, metrics, "sww_response_bytes_total"+forward, 5)
+	wantMetric(t, metrics, "sww_response_bytes_total"+notFound,
+		float64(len("Not Found\n")))
+	wantMetric(t, metrics,
+		`sww_request_duration_seconds_count{instance="app"}`, 2)
+	wantMetric(t, metrics,
+		`sww_upstream_duration_seconds_count{instance="app"}`, 1)
+	wantMetric(t, metrics, `sww_requests_in_flight{instance="app"}`, 1)
+	metric(t, metrics, `go_goroutines{instance="app"}`)
+	metric(t, metrics, `process_start_time_seconds{instance="app"}`)
+}
+
+func TestMetricsCountLimitsAndBans(t *testing.T) {
+	t.Parallel()
+
+	const denied = "192.0.2.50" // in SWW_DENY_NETS
+
+	s, clk, _ := startWithClock(t, "", map[string]string{
+		metricsToken:       token,
+		rateLimitPerMinute: "1",
+		denyNets:           denied,
+		banResponse:        banResponseClose,
+		limitBanDuration:   "1h",
+		maxBanDuration:     "2h",
+	})
+
+	// SWW_BAN_RESPONSE=close sends no status at all.
+	s.get(denied, 0, requestlog.ActionDenied)
+
+	// A first broken limit bans for an hour.
+	s.get(client, http.StatusOK, requestlog.ActionForward)
+	s.get(client, 0, requestlog.ActionRateLimited)
+
+	metrics := s.scrape()
+	wantMetric(t, metrics,
+		`sww_requests_total{action="denied",instance="app",status_class="none"}`, 1)
+	wantMetric(t, metrics, `sww_rate_limit_hits_total{instance="app",`+
+		`kind="requests",window="minute"}`, 1)
+	wantMetric(t, metrics, `sww_offences_total{instance="app",kind="limit"}`, 1)
+	wantMetric(t, metrics, `sww_bans_made_total{cause="limit",instance="app"}`, 1)
+	wantMetric(t, metrics, `sww_active_bans{instance="app"}`, 1)
+	wantMetric(t, metrics, `sww_permanent_bans{instance="app"}`, 0)
+
+	clk.advance(time.Hour)
+	wantMetric(t, s.scrape(), `sww_active_bans{instance="app"}`, 0)
+
+	// A limit broken again right after would ban for three hours, longer
+	// than SWW_MAX_BAN_DURATION, so the ban is permanent.
+	s.get(client, http.StatusOK, requestlog.ActionForward)
+	s.get(client, 0, requestlog.ActionRateLimited)
+
+	metrics = s.scrape()
+	wantMetric(t, metrics, `sww_rate_limit_hits_total{instance="app",`+
+		`kind="requests",window="minute"}`, 2)
+	wantMetric(t, metrics, `sww_offences_total{instance="app",kind="limit"}`, 2)
+	wantMetric(t, metrics, `sww_bans_made_total{cause="limit",instance="app"}`, 2)
+	wantMetric(t, metrics, `sww_active_bans{instance="app"}`, 1)
+	wantMetric(t, metrics, `sww_permanent_bans{instance="app"}`, 1)
+	// denied and client.
+	wantMetric(t, metrics, `sww_tracked_clients{instance="app"}`, 2)
+}
+
+func TestMetricsCountTheBansAnAdminMakes(t *testing.T) {
+	t.Parallel()
+
+	s, clk, server := startWithClock(t, "", map[string]string{
+		metricsToken: token,
+		adminToken:   adminSecret,
+	})
+
+	const admins = `sww_bans_made_total{cause="admin",instance="app"}`
+
+	wantMetric(t, s.scrape(), admins, 0)
+
+	// As an admin's edit of bans.json that adds a ban is taken in.
+	server.Ledger.LoadEdit([]bans.Ban{{
+		Netblock: netip.MustParsePrefix(client + "/32"),
+		Start:    clk.Now(),
+	}})
+
+	wantMetric(t, s.scrape(), admins, 1)
+
+	// And a ban made through the endpoint.
+	s.admin(http.MethodPost, discriminator.BansPath, banOtherClient, http.StatusOK)
+	wantMetric(t, s.scrape(), admins, 2)
+}
+
+func TestMetricsByCountryKeepTheBusiestAndCountTheRestAsOther(t *testing.T) {
+	t.Parallel()
+
+	const fromFR = "198.51.100.20"
+
+	app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.Copy(io.Discard, r.Body)
+		_, _ = io.WriteString(w, "hello")
+	})
+	env := map[string]string{
+		trustedProxies:  trustLocalhost,
+		metricsToken:    token,
+		metricsTopN:     "2",
+		deniedCountries: "kp",
+	}
+	geojsURL, _ := startGeoJS(t)
+	addr, out, server := startProxyWithClock(t, app.URL, geojsURL, time.Now, env)
+
+	// The answers are kept before the requests, so that none waits for
+	// GeoJS.
+	server.GeoJS.Load([]lookup.Answer{
+		keptAnswer(fromKP, "KP"), keptAnswer(fromDE, "DE"), keptAnswer(fromFR, "FR"),
+	})
+
+	lines := 0
+	send := func(from string, times, status int) {
+		t.Helper()
+
+		for range times {
+			req := newRequest(t, http.MethodPost, addr, "/", strings.NewReader("abc"))
+			req.Header.Set(forwardedFor, from)
+			wantStatus(t, do(t, req), status)
+
+			// Each is counted before the next is sent, so that the
+			// countries are ranked in the order sent.
+			lines++
+			out.endedLines(t, lines)
+		}
+	}
+
+	// With two countries of their own, the third is counted as other.
+	send(fromKP, 3, http.StatusForbidden)
+	send(fromDE, 2, http.StatusOK)
+	send(fromFR, 1, http.StatusOK)
+
+	metrics := scrape(t, server.Addr)
+	lines++
+
+	wantMetric(t, metrics,
+		`sww_country_requests_total{country="KP",instance="app"}`, 3)
+	wantMetric(t, metrics,
+		`sww_country_requests_total{country="DE",instance="app"}`, 2)
+	wantMetric(t, metrics,
+		`sww_country_requests_total{country="other",instance="app"}`, 1)
+	wantMetric(t, metrics,
+		`sww_country_list_refusals_total{country="KP",instance="app"}`, 3)
+	wantMetric(t, metrics,
+		`sww_country_request_bytes_total{country="KP",instance="app"}`, 0)
+	wantMetric(t, metrics,
+		`sww_country_request_bytes_total{country="DE",instance="app"}`, 6)
+	wantMetric(t, metrics,
+		`sww_country_response_bytes_total{country="KP",instance="app"}`,
+		float64(3*len("Forbidden\n")))
+	wantMetric(t, metrics,
+		`sww_country_response_bytes_total{country="other",instance="app"}`,
+		float64(len("hello")))
+	wantNoSeries(t, metrics,
+		`sww_country_requests_total{country="FR",instance="app"}`)
+
+	// Once FR is busier than DE, it takes DE's place: its series counts
+	// from then on, and DE's is gone.
+	send(fromFR, 3, http.StatusOK)
+
+	metrics = scrape(t, server.Addr)
+	wantMetric(t, metrics,
+		`sww_country_requests_total{country="KP",instance="app"}`, 3)
+	wantMetric(t, metrics,
+		`sww_country_requests_total{country="FR",instance="app"}`, 2)
+	wantMetric(t, metrics,
+		`sww_country_requests_total{country="other",instance="app"}`, 2)
+	wantNoSeries(t, metrics,
+		`sww_country_requests_total{country="DE",instance="app"}`)
+	wantNoSeries(t, metrics,
+		`sww_country_request_bytes_total{country="DE",instance="app"}`)
+}
+
+func TestMetricsByASNumberKeepTheBusiestAndCountTheRestAsOther(t *testing.T) {
+	t.Parallel()
+
+	geojsURL, _ := startGeoJS(t)
+	s, clk, server := startWithClock(t, geojsURL, map[string]string{
+		metricsToken: token,
+		metricsTopN:  "1",
+	})
+
+	// The answers are kept before the requests, so that GeoJS gives none
+	// of its own. Each client is in an AS of its own.
+	answer := func(addr, asn string) lookup.Answer {
+		return lookup.Answer{
+			Client: netip.MustParsePrefix(addr + "/32"), ASN: asn,
+			Answered: clk.Now(), Used: clk.Now(),
+		}
+	}
+	server.GeoJS.Load([]lookup.Answer{
+		answer(fromDE, "AS64501"), answer(fromKP, "AS64502"),
+	})
+
+	// With one AS number of its own, the other is counted as other.
+	s.get(fromDE, http.StatusOK, requestlog.ActionForward)
+	s.get(fromDE, http.StatusOK, requestlog.ActionForward)
+	s.get(fromKP, http.StatusOK, requestlog.ActionForward)
+
+	metrics := s.scrape()
+	wantMetric(t, metrics,
+		`sww_asn_requests_total{asn="AS64501",instance="app"}`, 2)
+	wantMetric(t, metrics,
+		`sww_asn_requests_total{asn="other",instance="app"}`, 1)
+	wantMetric(t, metrics,
+		`sww_asn_request_bytes_total{asn="AS64501",instance="app"}`, 0)
+	wantMetric(t, metrics,
+		`sww_asn_response_bytes_total{asn="other",instance="app"}`, 0)
+	wantNoSeries(t, metrics,
+		`sww_asn_requests_total{asn="AS64502",instance="app"}`)
+}
+
+func TestMetricsCountGeoJSRequestsAndFailures(t *testing.T) {
+	t.Parallel()
+
+	geojs := httptest.NewServer(http.HandlerFunc(
+		func(w http.ResponseWriter, _ *http.Request) {
+			w.WriteHeader(http.StatusServiceUnavailable)
+		}))
+	t.Cleanup(geojs.Close)
+
+	app := startApp(t, func(http.ResponseWriter, *http.Request) {})
+	addr, _, server := startProxyWithClock(t, app.URL, geojs.URL, time.Now,
+		map[string]string{
+			trustedProxies:  trustLocalhost,
+			metricsToken:    token,
+			deniedCountries: "kp",
+		})
+
+	// GeoJS fails, so the client counts as coming from an unknown country,
+	// which SWW_DENIED_COUNTRIES does not refuse.
+	req := newRequest(t, http.MethodGet, addr, "/", http.NoBody)
+	req.Header.Set(forwardedFor, fromDE)
+	wantStatus(t, do(t, req), http.StatusOK)
+
+	// The client stops waiting for GeoJS once SWW_LOOKUP_TIMEOUT is up, so
+	// GeoJS's failure can come after its request has ended.
+	deadline := time.Now().Add(waitLimit)
+	metrics := scrape(t, server.Addr)
+
+	for metric(t, metrics, `sww_geojs_failures_total{instance="app"}`) == 0 &&
+		time.Now().Before(deadline) {
+		time.Sleep(pollInterval)
+
+		metrics = scrape(t, server.Addr)
+	}
+
+	wantMetric(t, metrics, `sww_geojs_requests_total{instance="app"}`, 1)
+	wantMetric(t, metrics, `sww_geojs_failures_total{instance="app"}`, 1)
+	wantMetric(t, metrics, `sww_geojs_unanswered_total{instance="app"}`, 1)
+}
+
+// keptAnswer returns GeoJS's answer that the client at addr is in
+// country, given now.
+func keptAnswer(addr, country string) lookup.Answer {
+	now := time.Now()
+
+	return lookup.Answer{
+		Client: netip.MustParsePrefix(addr + "/32"), Country: country,
+		Answered: now, Used: now,
+	}
+}
+
+// scrape asks discriminator at addr for the metrics, with the token, and returns
+// them.
+func scrape(t *testing.T, addr string) string {
+	t.Helper()
+
+	req := newRequest(t, http.MethodGet, addr, discriminator.MetricsPath, http.NoBody)
+	req.Header.Set("Authorization", bearer)
+
+	got := do(t, req)
+	if got.status != http.StatusOK {
+		t.Fatalf("the metrics were answered %d", got.status)
+	}
+
+	return string(got.body)
+}
+
+// scrape asks for the metrics, with the token, and returns them.
+func (s *sender) scrape() string {
+	s.t.Helper()
+
+	return string(s.adminRequest(bearer, http.MethodGet, discriminator.MetricsPath, "",
+		http.StatusOK).body)
+}
+
+// metric returns the value of series in metrics, which are in the
+// Prometheus text format. series is a name and its labels in the order of
+// their names, such as
+// sww_offences_total{instance="app",kind="limit"}. It fails the
+// test if there is no such series.
+func metric(t *testing.T, metrics, series string) float64 {
+	t.Helper()
+
+	for line := range strings.Lines(metrics) {
+		value, found := strings.CutPrefix(strings.TrimSuffix(line, "\n"), series+" ")
+		if !found {
+			continue
+		}
+
+		number, err := strconv.ParseFloat(value, 64)
+		if err != nil {
+			t.Fatalf("%s has the value %q", series, value)
+		}
+
+		return number
+	}
+
+	t.Fatalf("no series %s in the metrics:\n%s", series, metrics)
+
+	return 0
+}
+
+// wantMetric checks the value of series in metrics, as metric reads it.
+func wantMetric(t *testing.T, metrics, series string, want float64) {
+	t.Helper()
+
+	got := metric(t, metrics, series)
+	if got != want {
+		t.Errorf("%s is %v, want %v", series, got, want)
+	}
+}
+
+// wantNoSeries checks that metrics have no series series.
+func wantNoSeries(t *testing.T, metrics, series string) {
+	t.Helper()
+
+	if strings.Contains(metrics, "\n"+series+" ") {
+		t.Errorf("there is a series %s", series)
+	}
+}

internal/discriminator/observe_test.go

@@ -1,33 +1,29 @@
-package proxy_test
+package discriminator_test
 
 import (
-	"bytes"
-	"io"
 	"net/http"
 	"net/netip"
 	"reflect"
-	"sync/atomic"
 	"testing"
 	"time"
 
 	"sneak.berlin/go/smallwebwaf/internal/bans"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
 
-// observe is the value of SWWAF_MODE for observe mode.
+// observe is the value of SWW_MODE for observe mode.
 const observe = "observe"
 
 func TestObserveModeForwardsWhatEnforceModeRefuses(t *testing.T) {
 	t.Parallel()
 
 	const (
-		denied = "192.0.2.50" // in SWWAF_DENY_NETS
+		denied = "192.0.2.50" // in SWW_DENY_NETS
 		banned = otherClient  // under a ban read from bans.json
 	)
 
 	for _, tc := range []struct {
-		setting string // "" leaves SWWAF_MODE at its default
+		setting string // "" leaves SWW_MODE at its default
 		observe bool
 	}{
 		{"", false},
@@ -76,11 +72,6 @@ func TestObserveModeForwardsWhatEnforceModeRefuses(t *testing.T) {
 				// Passed to the app, which answered it.
 				line := s.get(sent.from, http.StatusOK, requestlog.ActionForward)
 				wantWouldAction(t, line, sent.refusal)
-
-				if line.UpstreamStatus != http.StatusOK {
-					t.Errorf("log line has upstream_status %d, want 200",
-						line.UpstreamStatus)
-				}
 			}
 		})
 	}
@@ -133,62 +124,6 @@ func TestObserveModeMakesNoBanAndKeepsTheBansItHas(t *testing.T) {
 	}
 }
 
-func TestObserveModeKeepsTheSizeLimitsAndTheToken(t *testing.T) {
-	t.Parallel()
-
-	const denied = "192.0.2.50" // in SWWAF_DENY_NETS
-
-	var calls atomic.Int32
-
-	app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
-		calls.Add(1)
-		answerWithSize(w, 2*sizeLimit, true)
-	})
-	addr, out := startProxy(t, app.URL, map[string]string{
-		mode:             observe,
-		trustedProxies:   trustLocalhost,
-		denyNets:         denied,
-		requestMaxBytes:  sizeLimitSetting,
-		responseMaxBytes: sizeLimitSetting,
-		metricsToken:     token,
-	})
-
-	// SWWAF_DENY_NETS would refuse each request; instead a size limit or
-	// the missing token does.
-	for i, tc := range []struct {
-		method, path string
-		body         io.Reader
-		status       int
-		action       string
-	}{
-		{
-			http.MethodPost, "/upload", bytes.NewReader(make([]byte, 2*sizeLimit)),
-			http.StatusRequestEntityTooLarge, requestlog.ActionTooLarge,
-		},
-		{
-			http.MethodGet, "/download", http.NoBody,
-			http.StatusBadGateway, requestlog.ActionTooLarge,
-		},
-		{
-			http.MethodGet, proxy.MetricsPath, http.NoBody,
-			http.StatusUnauthorized, requestlog.ActionAdmin,
-		},
-	} {
-		req := newRequest(t, tc.method, addr, tc.path, tc.body)
-		req.Header.Set(forwardedFor, denied)
-		wantStatus(t, do(t, req), tc.status)
-
-		line := out.requestLines(t, i+1)[i]
-		wantLine(t, line, tc.status, tc.action)
-		wantWouldAction(t, line, requestlog.ActionDenied)
-	}
-
-	// The upload was refused before it reached the app.
-	if calls.Load() != 1 {
-		t.Errorf("the app was called %d times, want once", calls.Load())
-	}
-}
-
 // wantWouldAction checks the request log line's would_action, and that a
 // line that should have none has no such field.
 func wantWouldAction(t *testing.T, line logLine, want string) {

internal/discriminator/proxy.go

@@ -1,16 +1,17 @@
-// Package proxy passes each request to the app and the app's answer back,
+// Package discriminator is the server the discriminator command runs. It answers
-// unchanged, within the size and time limits, and writes one request log
+// rproxy's questions, takes rproxy's reports and answers its own endpoints, and
-// line for each request.
+// writes a log line for each.
-package proxy
+package discriminator
 
 import (
+	"fmt"
 	"io"
-	"log"
 	"log/slog"
 	"net/http"
-	"strings"
 	"time"
 
+	lru "github.com/hashicorp/golang-lru/v2"
+
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 	"sneak.berlin/go/smallwebwaf/internal/anomaly"
 	"sneak.berlin/go/smallwebwaf/internal/bans"
@@ -19,53 +20,51 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/metrics"
 	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
 	"sneak.berlin/go/smallwebwaf/internal/reputation"
-	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 	"sneak.berlin/go/smallwebwaf/internal/rules"
 	"sneak.berlin/go/smallwebwaf/internal/waf"
 )
 
-// How smallwebwaf keeps connections to the app open between requests.
+// adminPrefix starts the path of each of discriminator's own endpoints. The app never
-const (
+// sees a path under it.
-	appIdleConns       = 100
+const adminPrefix = "/_sww/"
-	appIdleConnTimeout = 90 * time.Second
-)
 
-// adminPrefix starts the path of every request for smallwebwaf itself,
+// HealthPath is the health endpoint of discriminator and of rproxy, which the
-// which never reaches the app.
+// container's health check asks.
-const adminPrefix = "/_smallwebwaf/"
+const HealthPath = "/_sww/healthz"
-
-// HealthPath is smallwebwaf's health endpoint, which the container's
-// health check asks.
-const HealthPath = "/_smallwebwaf/healthz"
 
 // MetricsPath is where the metrics are, for a request that carries
-// SWWAF_METRICS_TOKEN.
+// SWW_METRICS_TOKEN.
-const MetricsPath = "/_smallwebwaf/metrics"
+const MetricsPath = "/_sww/metrics"
 
 // BansPath is where an admin lists and adds bans, and, followed by / and
-// a client's address, lifts them, with SWWAF_ADMIN_TOKEN.
+// a client's address, lifts them, with SWW_ADMIN_TOKEN.
-const BansPath = "/_smallwebwaf/bans"
+const BansPath = "/_sww/bans"
 
-// ClientsPath is where an admin asks what smallwebwaf knows of a client,
+// ClientsPath is where an admin asks what discriminator knows of a client, by
-// by the client's address after it, with SWWAF_ADMIN_TOKEN.
+// the client's address after it, with SWW_ADMIN_TOKEN.
-const ClientsPath = "/_smallwebwaf/clients/"
+const ClientsPath = "/_sww/clients/"
 
 // Params are what New needs.
 type Params struct {
 	Config *config.Config
-	// RequestLog receives one JSON line per request.
+	// RequestLog receives two JSON lines per question, one at its decision and
+	// one when its report comes, and one per request to discriminator's own
+	// endpoints.
 	RequestLog io.Writer
 	// ProcessLog receives the process's own messages.
 	ProcessLog *slog.Logger
 	// GeoJSURL is where clients' AS numbers and countries are looked up
-	// while SWWAF_LOOKUP_SOURCE is geojs, normally lookup.URL.
+	// while SWW_LOOKUP_SOURCE is geojs, normally lookup.URL.
 	GeoJSURL string
 	// AbuseIPDBURL is where clients are checked with AbuseIPDB while
-	// SWWAF_ABUSEIPDB_KEY is set, normally reputation.AbuseIPDBURL.
+	// SWW_ABUSEIPDB_KEY is set, normally reputation.AbuseIPDBURL.
 	AbuseIPDBURL string
 	// LookupFile is the lookup database they are looked up in while
-	// SWWAF_LOOKUP_SOURCE is file, and nil otherwise.
+	// SWW_LOOKUP_SOURCE is file, and nil otherwise.
 	LookupFile *lookup.File
+	// CoreRuleSet is what NewCoreRuleSet returns: what inspects requests
+	// while SWW_WAF_MODE is not off, and nil while it is.
+	CoreRuleSet *waf.CoreRuleSet
 	// Now tells the time by which requests are counted for the rate
 	// limits, bans are made and run out, and GeoJS's answers are kept,
 	// normally time.Now in UTC, the time the state files give.
@@ -73,21 +72,20 @@ type Params struct {
 	// Rules are the rule files' rules, which each request is checked
 	// against.
 	Rules *rules.Files
-	// Alerts receive the alert for each ban the proxy makes or makes
+	// Alerts receive the alert for each ban discriminator makes or makes
 	// permanent, for each count over an anomaly threshold, for each request
 	// whose client a blocklist, the CrowdSec decision list, a DNSBL zone or
 	// AbuseIPDB lists, for each request the Core Rule Set scores at or over
-	// SWWAF_WAF_ANOMALY_THRESHOLD, and for GeoJS failing, a fetch of a list
+	// SWW_WAF_ANOMALY_THRESHOLD, and for GeoJS failing, a fetch of a list
 	// failing, a query to a DNSBL zone or a check with AbuseIPDB failing,
 	// or the day's AbuseIPDB checks used up.
 	Alerts *alerts.Queue
 }
 
-// Server is the server smallwebwaf runs, with the parts of the proxy
+// Server is the server discriminator runs, with the parts whose state the state
-// whose state the state files keep, the lookup database, nil unless
+// files keep, the lookup database, nil unless SWW_LOOKUP_SOURCE is file, the
-// SWWAF_LOOKUP_SOURCE is file, the lists fetched from URLs, which its Run
+// lists fetched from URLs, which its Run fetches, the DNSBL zones' verdicts,
-// fetches, the DNSBL zones' verdicts, AbuseIPDB's scores and checks
+// AbuseIPDB's scores and checks spent, and the metrics.
-// spent, and the metrics.
 type Server struct {
 	*http.Server
 
@@ -102,24 +100,24 @@ type Server struct {
 	Metrics    *metrics.Metrics
 }
 
-// New returns the server smallwebwaf runs: each request it reads passes
+// newHandler returns the handler with what every request shares, as the
-// through the proxy. Go's server itself refuses a request line and
+// settings in params make it.
-// headers over SWWAF_CLIENT_REQUEST_HEADER_MAX_BYTES, with 431, closes a
+func newHandler(params Params) *handler {
-// connection idle for SWWAF_CLIENT_IDLE_TIMEOUT, and applies
-// SWWAF_CLIENT_REQUEST_TIMEOUT while the headers arrive; the proxy
-// applies the timeouts and size limits from then on.
-func New(params Params) *Server {
-	errorLog := slog.NewLogLogger(params.ProcessLog.Handler(), slog.LevelWarn)
 	m := metrics.New(params.Config.MetricsTopN, params.Config.InstanceName)
 	lists, dnsbl, abuseIPDB := newReputation(params, m)
+
+	awaitingReport, err := lru.New[string, *decision](maxAwaitingReport)
+	if err != nil {
+		panic(err) // New fails only for a size below one
+	}
+
 	h := &handler{
 		config:         params.Config,
 		requestLog:     params.RequestLog,
 		processLog:     params.ProcessLog,
-		errorLog:   errorLog,
-		transport:  newTransport(),
 		now:            params.Now,
 		metrics:        m,
+		awaitingReport: awaitingReport,
 		limiter: ratelimit.New(ratelimit.Limits{
 			PerMinute:      params.Config.RateLimitPerMinute,
 			PerHour:        params.Config.RateLimitPerHour,
@@ -151,7 +149,7 @@ func New(params Params) *Server {
 		dnsbl:       dnsbl,
 		abuseIPDB:   abuseIPDB,
 		rules:       params.Rules,
-		coreRuleSet: newCoreRuleSet(params.Config),
+		coreRuleSet: params.CoreRuleSet,
 		alerts:      params.Alerts,
 	}
 	h.geojs = lookup.New(lookup.Params{
@@ -171,35 +169,13 @@ func New(params Params) *Server {
 	m.AddBansAndClients(h.ledger, h.limiter, params.Now)
 	m.AddRules(params.Rules)
 
-	return &Server{
+	return h
-		Server: &http.Server{
-			Addr:              params.Config.ListenAddr,
-			Handler:           h,
-			ReadHeaderTimeout: params.Config.ClientRequestTimeout,
-			// Off is an IdleTimeout of 0, which Go's server replaces with
-			// ReadTimeout: no limit, as long as ReadTimeout stays unset.
-			IdleTimeout: params.Config.ClientIdleTimeout,
-			// Go's server reads 4 KiB past MaxHeaderBytes before it
-			// refuses, so the limit a client meets is the setting.
-			MaxHeaderBytes: int(params.Config.ClientRequestHeaderMaxBytes - 4<<10),
-			ErrorLog:       errorLog,
-		},
-		Ledger:     h.ledger,
-		Limiter:    h.limiter,
-		GeoJS:      h.geojs,
-		Anomalies:  h.anomalies,
-		LookupFile: h.lookupFile,
-		Lists:      h.lists,
-		DNSBL:      h.dnsbl,
-		AbuseIPDB:  h.abuseIPDB,
-		Metrics:    m,
-	}
 }
 
 // newReputation returns the lists fetched from URLs, the DNSBL zones'
 // verdicts and AbuseIPDB's scores, as the settings in params name them,
 // with none fetched, asked for or checked yet, and adds their metrics to
-// m, AbuseIPDB's while SWWAF_ABUSEIPDB_KEY is set.
+// m, AbuseIPDB's while SWW_ABUSEIPDB_KEY is set.
 func newReputation(
 	params Params, m *metrics.Metrics,
 ) (*reputation.Lists, *reputation.DNSBL, *reputation.AbuseIPDB) {
@@ -231,36 +207,44 @@ func newReputation(
 	return lists, dnsbl, abuseIPDB
 }
 
-// newCoreRuleSet returns the Core Rule Set at SWWAF_WAF_PARANOIA_LEVEL,
+// NewCoreRuleSet returns the Core Rule Set at SWW_WAF_PARANOIA_LEVEL,
-// without the rules SWWAF_WAF_DISABLED_RULES switches off, reading bodies
+// without the rules SWW_WAF_DISABLED_RULES switches off, reading bodies
-// up to SWWAF_WAF_BODY_LIMIT, or nil while SWWAF_WAF_MODE is off.
+// up to SWW_WAF_BODY_LIMIT, with the exclusions in
-func newCoreRuleSet(cfg *config.Config) *waf.CoreRuleSet {
+// SWW_CORE_RULE_SET_EXCLUSIONS_FILE and the fixes of the apps in SWW_APPS,
-	if cfg.WAFMode == config.WAFModeOff {
+// or nil while SWW_WAF_MODE is off. It
-		return nil
+// reads at most QuestionBodyMaxBytes less one byte: a question's body of
+// QuestionBodyMaxBytes may be cut short, and the Core Rule Set does not read a
+// JSON or XML body over its limit. An exclusions file that waf.New refuses is
+// an error in every mode. While the mode is off, a set file is loaded with the
+// Core Rule Set only to check it.
+func NewCoreRuleSet(cfg *config.Config) (*waf.CoreRuleSet, error) {
+	if cfg.WAFMode == config.WAFModeOff && cfg.CoreRuleSetExclusionsFile == "" {
+		return nil, nil //nolint:nilnil // off is no Core Rule Set, and no error
 	}
 
 	coreRuleSet, err := waf.New(waf.Params{
 		ParanoiaLevel: cfg.WAFParanoiaLevel, DisabledRules: cfg.WAFDisabledRules,
-		BodyLimit: cfg.WAFBodyLimit,
+		BodyLimit:      min(cfg.WAFBodyLimit, QuestionBodyMaxBytes-1),
+		ExclusionsFile: cfg.CoreRuleSetExclusionsFile,
+		Apps:           cfg.Apps,
 	})
 	if err != nil {
-		// The Core Rule Set is built in, and the settings cannot break it:
+		return nil, fmt.Errorf("SWW_CORE_RULE_SET_EXCLUSIONS_FILE: %w", err)
-		// the paranoia level is from 1 to 4, the body limit at most 1G, and
-		// the id of no rule switches nothing off.
-		panic(err)
 	}
 
-	return coreRuleSet
+	if cfg.WAFMode == config.WAFModeOff {
+		return nil, nil //nolint:nilnil // off is no Core Rule Set, and no error
+	}
+
+	return coreRuleSet, nil
 }
 
-// handler is the proxy. It holds what every request shares; what belongs
+// handler is discriminator's handler. It holds what every request shares; what
-// to one request is in a request.
+// belongs to one request is in a request.
 type handler struct {
 	config      *config.Config
 	requestLog  io.Writer
 	processLog  *slog.Logger
-	errorLog    *log.Logger
-	transport   http.RoundTripper
 	now         func() time.Time
 	metrics     *metrics.Metrics
 	limiter     *ratelimit.Limiter
@@ -274,68 +258,7 @@ type handler struct {
 	rules       *rules.Files
 	coreRuleSet *waf.CoreRuleSet
 	alerts      *alerts.Queue
-}
+	// awaitingReport holds the decision on each answered question by its id
-
+	// until its report comes, and nil for a question still being handled.
-// newTransport returns what carries requests to the app. It never goes
+	awaitingReport *lru.Cache[string, *decision]
-// through a proxy named in the environment, and leaves the app's answers
-// compressed or not as the app sent them.
-func newTransport() *http.Transport {
-	return &http.Transport{
-		MaxIdleConns:        appIdleConns,
-		MaxIdleConnsPerHost: appIdleConns,
-		IdleConnTimeout:     appIdleConnTimeout,
-		DisableCompression:  true,
-	}
-}
-
-// ServeHTTP handles one request: it works out the client, runs the
-// checks, passes the request to the app and the answer back within the
-// limits, or answers it itself if it is for smallwebwaf, and writes the
-// request's log line.
-func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	rq := h.newRequest(w, r)
-	defer rq.finish()
-
-	// The health endpoint is answered at once, before any check, so that
-	// a health checker is never refused. It does not ask the app.
-	if r.Method == http.MethodGet && r.URL.Path == HealthPath {
-		rq.line.Action = requestlog.ActionAdmin
-		// Set here rather than left to Go's server, which would set it only
-		// after the log line has taken the response's headers.
-		rq.out.Header().Set("Content-Type", "text/plain; charset=utf-8")
-		_, _ = io.WriteString(rq.out, "ok\n")
-
-		return
-	}
-
-	// Once the request has ended, before its log line is written. The
-	// last deferred runs first: countRefusal before addToHistory, so that
-	// a broken error burst is in the client's history.
-	defer rq.addToHistory()
-	defer rq.countAnomalies()
-	defer rq.countRefusal()
-
-	refused := rq.check(r.Context())
-	rq.checked = time.Now()
-
-	if refused != nil {
-		rq.answer(*refused)
-
-		return
-	}
-
-	// A request for smallwebwaf itself is answered where another would be
-	// passed to the app, so that it goes through every check first.
-	if strings.HasPrefix(r.URL.Path, adminPrefix) {
-		rq.answerAdmin()
-
-		return
-	}
-
-	// Once the response has ended, before the request is added to its
-	// client's history. Deferred, since ReverseProxy panics to end a
-	// response it cannot finish.
-	defer rq.countBytes()
-
-	rq.forward(r.Context())
 }

internal/discriminator/proxy_test.go

@@ -1,10 +1,11 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"bufio"
 	"bytes"
 	"encoding/json"
 	"io"
+	"log/slog"
 	"maps"
 	"net"
 	"net/http"
@@ -16,88 +17,86 @@ import (
 
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 	"sneak.berlin/go/smallwebwaf/internal/config"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
 	"sneak.berlin/go/smallwebwaf/internal/lookup"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+	"sneak.berlin/go/smallwebwaf/internal/rproxy"
 	"sneak.berlin/go/smallwebwaf/internal/rules"
 )
 
 const (
-	// shortTimeout is what a test sets a timeout to, to see it run out.
-	// It starts before the test has set up its case, such as an upgrade
-	// or the app's buffers filling, so it is as long as the hold-up of the
-	// test process that wantTimedOut allows: a shorter one can run out
-	// first on a busy host.
-	shortTimeout = waitLimit / 2
-	// longTimeoutSetting is a timeout that does not run out in a test.
-	longTimeoutSetting = "1m"
 	// waitLimit bounds how long a test waits for what should happen.
 	waitLimit = 10 * time.Second
 	// pollInterval is how often a test looks for a log line.
 	pollInterval = 10 * time.Millisecond
-	// localhost is where every test server listens, and so the address
+	// localhost is where every test server listens, and so the address rproxy
-	// smallwebwaf sees each test's requests come from.
+	// sees each test's requests come from.
 	localhost = "127.0.0.1"
 	// requestType is the type that marks a request log line.
 	requestType = "request"
-	// protocol is the protocol of every test's requests.
+	// protocol is the protocol of every question.
 	protocol = "HTTP/1.1"
+	// trustLocalhost trusts the address every test connects from, and a
+	// network for proxies in front of it.
+	trustLocalhost = localhost + "/32,10.0.0.0/8"
+	// appHost is the host every test asks for.
+	appHost = "app.example"
+	// client is the client's address, as a proxy names it.
+	client = "203.0.113.9"
+	// forwardedFor is the header that lists the client and its proxies,
+	// and forwardedProto the one that gives the scheme the client used.
+	forwardedFor   = "X-Forwarded-For"
+	forwardedProto = "X-Forwarded-Proto"
+	// secure is the scheme a client reached traefik with, and plain the one
+	// rproxy serves.
+	secure = "https"
+	plain  = "http"
 )
 
-// shortTimeoutSetting is shortTimeout as a setting's value.
-//
-//nolint:gochecknoglobals // a constant cannot call String
-var shortTimeoutSetting = shortTimeout.String()
-
 // The settings the tests set.
 const (
-	clientRequestTimeout    = "SWWAF_CLIENT_REQUEST_TIMEOUT"
+	mode                 = "SWW_MODE"
-	clientHeaderMaxBytes    = "SWWAF_CLIENT_REQUEST_HEADER_MAX_BYTES"
+	trustedProxies       = "SWRP_TRUSTED_PROXIES"
-	clientIdleTimeout       = "SWWAF_CLIENT_IDLE_TIMEOUT"
+	ipv6GroupPrefix      = "SWW_IPV6_GROUP_PREFIX"
-	clientResponseTimeout   = "SWWAF_CLIENT_RESPONSE_TIMEOUT"
+	maxTrackedClients    = "SWW_MAX_TRACKED_CLIENTS"
-	upstreamRequestTimeout  = "SWWAF_UPSTREAM_REQUEST_TIMEOUT"
+	allowNets            = "SWW_ALLOW_NETS"
-	upstreamResponseTimeout = "SWWAF_UPSTREAM_RESPONSE_TIMEOUT"
+	rateLimitExemptNets  = "SWW_RATE_LIMIT_EXEMPT_NETS"
-	mode                    = "SWWAF_MODE"
+	denyNets             = "SWW_DENY_NETS"
-	requestMaxBytes         = "SWWAF_REQUEST_MAX_BYTES"
+	rateLimitPerMinute   = "SWW_RATE_LIMIT_PER_MINUTE"
-	responseMaxBytes        = "SWWAF_RESPONSE_MAX_BYTES"
+	rateLimitPerDay      = "SWW_RATE_LIMIT_PER_DAY"
-	trustedProxies          = "SWWAF_TRUSTED_PROXIES"
+	rateLimitExemptPaths = "SWW_RATE_LIMIT_EXEMPT_PATHS"
-	ipv6GroupPrefix         = "SWWAF_IPV6_GROUP_PREFIX"
+	lookupSource         = "SWW_LOOKUP_SOURCE"
-	maxTrackedClients       = "SWWAF_MAX_TRACKED_CLIENTS"
+	lookupDBPath         = "SWW_LOOKUP_DB_PATH"
-	allowNets               = "SWWAF_ALLOW_NETS"
+	lookupTimeout        = "SWW_LOOKUP_TIMEOUT"
-	rateLimitExemptNets     = "SWWAF_RATE_LIMIT_EXEMPT_NETS"
+	addLookupHeaders     = "SWW_ADD_LOOKUP_HEADERS"
-	denyNets                = "SWWAF_DENY_NETS"
+	deniedCountries      = "SWW_DENIED_COUNTRIES"
-	rateLimitPerMinute      = "SWWAF_RATE_LIMIT_PER_MINUTE"
+	allowedCountries     = "SWW_EXCLUSIVELY_ALLOWED_COUNTRIES"
-	rateLimitPerDay         = "SWWAF_RATE_LIMIT_PER_DAY"
+	banResponse          = "SWW_BAN_RESPONSE"
-	rateLimitExemptPaths    = "SWWAF_RATE_LIMIT_EXEMPT_PATHS"
+	limitBanDuration     = "SWW_LIMIT_BAN_DURATION"
-	lookupSource            = "SWWAF_LOOKUP_SOURCE"
+	limitBanRepeatWindow = "SWW_LIMIT_BAN_REPEAT_WINDOW"
-	lookupDBPath            = "SWWAF_LOOKUP_DB_PATH"
+	maxBanDuration       = "SWW_MAX_BAN_DURATION"
-	lookupTimeout           = "SWWAF_LOOKUP_TIMEOUT"
+	maxBans              = "SWW_MAX_BANS"
-	addLookupHeaders        = "SWWAF_ADD_LOOKUP_HEADERS"
+	banScopeV4Prefix     = "SWW_BAN_SCOPE_V4_PREFIX"
-	deniedCountries         = "SWWAF_DENIED_COUNTRIES"
+	instanceName         = "SWW_INSTANCE_NAME"
-	allowedCountries        = "SWWAF_EXCLUSIVELY_ALLOWED_COUNTRIES"
+	logRequestHeaders    = "SWW_LOG_REQUEST_HEADERS"
-	banResponse             = "SWWAF_BAN_RESPONSE"
+	attackBanDuration    = "SWW_ATTACK_BAN_DURATION"
-	limitBanDuration        = "SWWAF_LIMIT_BAN_DURATION"
+	rulesDir             = "SWW_RULES_DIR"
-	limitBanRepeatWindow    = "SWWAF_LIMIT_BAN_REPEAT_WINDOW"
+	wafMode              = "SWW_WAF_MODE"
-	maxBanDuration          = "SWWAF_MAX_BAN_DURATION"
-	maxBans                 = "SWWAF_MAX_BANS"
-	banScopeV4Prefix        = "SWWAF_BAN_SCOPE_V4_PREFIX"
-	instanceName            = "SWWAF_INSTANCE_NAME"
-	logRequestHeaders       = "SWWAF_LOG_REQUEST_HEADERS"
-	attackBanDuration       = "SWWAF_ATTACK_BAN_DURATION"
-	rulesDir                = "SWWAF_RULES_DIR"
-	wafMode                 = "SWWAF_WAF_MODE"
 )
 
 // off is the value that switches a setting off.
 const off = "off"
 
-// output collects what smallwebwaf writes on stdout.
+// on is the value that switches a setting that takes true or false on.
+const on = "true"
+
+// output collects what sww writes on stdout.
 type output struct {
 	mu  sync.Mutex
 	buf bytes.Buffer
 }
 
-// Write adds lines smallwebwaf writes.
+// Write adds lines sww writes.
 func (o *output) Write(p []byte) (int, error) {
 	o.mu.Lock()
 	defer o.mu.Unlock()
@@ -176,6 +175,73 @@ func (o *output) requestLine(t *testing.T) logLine {
 	return o.requestLines(t, 1)[0]
 }
 
+// endedLines waits for count requests that went through rproxy, or to discriminator's
+// own endpoints, to have ended, and returns the last log line of each, in the
+// order discriminator took them. A question's last line is the one its report writes.
+func (o *output) endedLines(t *testing.T, count int) []logLine {
+	t.Helper()
+
+	deadline := time.Now().Add(waitLimit)
+	for time.Now().Before(deadline) {
+		found := o.lastLines(t)
+
+		ended := len(found) >= count
+		for _, line := range found[:min(count, len(found))] {
+			if line.DiscriminatorLine == requestlog.DiscriminatorLineDecision {
+				ended = false
+			}
+		}
+
+		if ended {
+			return found
+		}
+
+		time.Sleep(pollInterval)
+	}
+
+	t.Fatalf("fewer than %d requests have ended after %s", count, waitLimit)
+
+	return nil
+}
+
+// lastLines returns the last request log line written so far of each request,
+// in the order discriminator took them.
+func (o *output) lastLines(t *testing.T) []logLine {
+	t.Helper()
+
+	var found []logLine
+
+	places := map[string]int{}
+
+	for _, fields := range o.lines(t) {
+		if fields["type"] != requestType {
+			continue
+		}
+
+		line := decodeLine(t, fields)
+
+		place, seen := places[line.RequestID]
+		if seen {
+			found[place] = line
+
+			continue
+		}
+
+		places[line.RequestID] = len(found)
+		found = append(found, line)
+	}
+
+	return found
+}
+
+// endedLine waits for a test's one request to have ended, and returns its last
+// log line.
+func (o *output) endedLine(t *testing.T) logLine {
+	t.Helper()
+
+	return o.endedLines(t, 1)[0]
+}
+
 // decodeLine reads a request log line's fields into a logLine.
 func decodeLine(t *testing.T, fields map[string]any) logLine {
 	t.Helper()
@@ -195,7 +261,7 @@ func decodeLine(t *testing.T, fields map[string]any) logLine {
 	return line
 }
 
-// startApp starts app as the app smallwebwaf passes requests to.
+// startApp starts app as the app rproxy passes requests to.
 func startApp(t *testing.T, app http.HandlerFunc) *httptest.Server {
 	t.Helper()
 
@@ -205,9 +271,9 @@ func startApp(t *testing.T, app http.HandlerFunc) *httptest.Server {
 	return server
 }
 
-// startProxy starts smallwebwaf in front of the app at appURL, with the
+// startProxy starts discriminator, and rproxy in front of the app at appURL, each with
-// settings in env on top of the defaults, and returns where it listens and
+// the settings in env on top of the defaults, and returns where rproxy listens
-// what it writes.
+// and what discriminator writes.
 func startProxy(t *testing.T, appURL string, env map[string]string) (string, *output) {
 	t.Helper()
 
@@ -227,14 +293,14 @@ func startProxyWithGeoJS(
 }
 
 // startProxyWithClock is startProxyWithGeoJS with requests counted and
-// bans made by the time now tells, and returns the server as well. Unless
+// bans made by the time now tells, and returns discriminator's server as well, whose
-// env sets SWWAF_RULES_DIR, it is an empty directory, of no rules, and
+// Addr is where discriminator listens. Unless env sets SWW_RULES_DIR, it is an empty
-// unless it sets SWWAF_INSTANCE_NAME, that is app, the label instance of
+// directory, of no rules, and unless it sets SWW_INSTANCE_NAME, that is app,
-// every metric.
+// the label instance of every metric.
 func startProxyWithClock(
 	t *testing.T, appURL, geojsURL string, now func() time.Time,
 	env map[string]string,
-) (string, *output, *proxy.Server) {
+) (string, *output, *discriminator.Server) {
 	t.Helper()
 
 	addr, out, server, _ := startProxyWithAlerts(t, appURL, geojsURL, now, env)
@@ -243,14 +309,70 @@ func startProxyWithClock(
 }
 
 // startProxyWithAlerts is startProxyWithClock, and returns the queue of
-// the alerts the proxy raises as well, as newProxy makes them.
+// the alerts discriminator raises as well, as newDiscriminator makes them.
 func startProxyWithAlerts(
 	t *testing.T, appURL, geojsURL string, now func() time.Time,
 	env map[string]string,
-) (string, *output, *proxy.Server, *alerts.Queue) {
+) (string, *output, *discriminator.Server, *alerts.Queue) {
 	t.Helper()
 
-	server, out, alertQueue := newProxy(t, appURL, geojsURL, now, env)
+	server, out, alertQueue := newDiscriminator(t, geojsURL, now, env)
+	serve(t, server)
+
+	return startRProxy(t, server.Addr, appURL, env), out, server, alertQueue
+}
+
+// serve serves server on a port of its own until the test ends, and sets its
+// Addr to where it listens.
+func serve(t *testing.T, server *discriminator.Server) {
+	t.Helper()
+
+	listener, err := (&net.ListenConfig{}).Listen(t.Context(), "tcp", localhost+":0")
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+
+	server.Addr = listener.Addr().String()
+
+	go func() {
+		_ = server.Serve(listener)
+	}()
+
+	t.Cleanup(func() {
+		_ = server.Close()
+	})
+}
+
+// startRProxy starts rproxy in front of the app at appURL, asking the discriminator
+// at discriminatorAddr, with the settings in env on top of the defaults, and returns
+// where it listens. What it writes is dropped. SWRP_TIMEOUT_MS is a minute unless
+// env sets it, so that on a busy host SWRP_DEFAULT_DISPOSITION does not decide.
+func startRProxy(
+	t *testing.T, discriminatorAddr, appURL string, env map[string]string,
+) string {
+	t.Helper()
+
+	settings := map[string]string{
+		"SWRP_WAF_BACKEND":  "http://" + discriminatorAddr,
+		"SWRP_UPSTREAM_URL": appURL,
+		"SWRP_TIMEOUT_MS":   "60000",
+	}
+	maps.Copy(settings, env)
+
+	cfg, err := config.RProxyFromEnvironment(func(name string) (string, bool) {
+		value, ok := settings[name]
+
+		return value, ok
+	})
+	if err != nil {
+		t.Fatalf("settings %v: %v", settings, err)
+	}
+
+	server := rproxy.New(rproxy.Params{
+		Config:     cfg,
+		RequestLog: io.Discard,
+		ProcessLog: requestlog.NewProcessLogger(io.Discard, "rproxy", slog.LevelInfo),
+	})
 
 	listener, err := (&net.ListenConfig{}).Listen(t.Context(), "tcp", localhost+":0")
 	if err != nil {
@@ -265,28 +387,36 @@ func startProxyWithAlerts(
 		_ = server.Close()
 	})
 
-	return listener.Addr().String(), out, server, alertQueue
+	return listener.Addr().String()
 }
 
-// newProxy makes the server startProxyWithClock starts, without starting
+// newDiscriminator makes discriminator's server, without starting it, and
-// it, and returns it, what it writes, and the queue of the alerts the
+// returns it, what it writes, and the queue of the alerts it raises, as the
-// proxy raises, as the settings in env make it. No alert is sent from the
+// settings in env make it. No alert is sent from the queue: they wait in it,
-// queue: they wait in it, for the test to look at. With no geojsURL, there
+// for the test to look at.
-// is no stand-in for GeoJS to look clients up at, and SWWAF_LOOKUP_SOURCE
+// With no geojsURL, there is no stand-in for GeoJS to look clients up at, and
-// is off unless env sets it. While it is file, the lookup database
+// SWW_LOOKUP_SOURCE is off unless env sets it. While it is file, the lookup
-// SWWAF_LOOKUP_DB_PATH names is read. Clients are checked with AbuseIPDB
+// database SWW_LOOKUP_DB_PATH names is read. Clients are checked with AbuseIPDB
-// at abuseIPDBURL while env sets SWWAF_ABUSEIPDB_KEY. SWWAF_WAF_MODE is off
+// at abuseIPDBURL while env sets SWW_ABUSEIPDB_KEY. SWW_WAF_MODE is off unless
-// unless env sets it, so that only the tests of the Core Rule Set have
+// env sets it, so that only the tests of the Core Rule Set have their requests
-// their requests inspected by it.
+// inspected by it.
-func newProxy(
+func newDiscriminator(
-	t *testing.T, appURL, geojsURL string, now func() time.Time,
+	t *testing.T, geojsURL string, now func() time.Time, env map[string]string,
-	env map[string]string,
+) (*discriminator.Server, *output, *alerts.Queue) {
-) (*proxy.Server, *output, *alerts.Queue) {
+	t.Helper()
+
+	return newDiscriminatorWith(t, discriminator.New, geojsURL, now, env)
+}
+
+// newDiscriminatorWith is newDiscriminator for the server build makes.
+func newDiscriminatorWith(
+	t *testing.T, build func(discriminator.Params) *discriminator.Server,
+	geojsURL string, now func() time.Time, env map[string]string,
+) (*discriminator.Server, *output, *alerts.Queue) {
 	t.Helper()
 
 	settings := map[string]string{
-		"SWWAF_UPSTREAM_URL": appURL, rulesDir: t.TempDir(), instanceName: "app",
+		rulesDir: t.TempDir(), instanceName: "app", wafMode: off,
-		wafMode: off,
 	}
 	if geojsURL == "" {
 		settings[lookupSource] = off
@@ -334,13 +464,19 @@ func newProxy(
 		}
 	}
 
-	server := proxy.New(proxy.Params{
+	coreRuleSet, err := discriminator.NewCoreRuleSet(cfg)
+	if err != nil {
+		t.Fatalf("Core Rule Set: %v", err)
+	}
+
+	server := build(discriminator.Params{
 		Config:       cfg,
 		RequestLog:   out,
 		ProcessLog:   processLog,
 		GeoJSURL:     geojsURL,
 		AbuseIPDBURL: abuseIPDBURL,
 		LookupFile:   lookupFile,
+		CoreRuleSet:  coreRuleSet,
 		Now:          now,
 		Rules:        ruleFiles,
 		Alerts:       alertQueue,
@@ -378,7 +514,7 @@ func readAnswer(res *http.Response) answer {
 	return answer{status: res.StatusCode, header: res.Header, body: body, err: err}
 }
 
-// newRequest makes a request for path to smallwebwaf at addr.
+// newRequest makes a request for path to addr, where rproxy or discriminator listens.
 func newRequest(t *testing.T, method, addr, path string, body io.Reader) *http.Request {
 	t.Helper()
 
@@ -402,15 +538,15 @@ func do(t *testing.T, req *http.Request) answer {
 	return readAnswer(res)
 }
 
-// get sends a GET request for path to smallwebwaf at addr.
+// get sends a GET request for path to addr.
 func get(t *testing.T, addr, path string) answer {
 	t.Helper()
 
 	return do(t, newRequest(t, http.MethodGet, addr, path, http.NoBody))
 }
 
-// dial opens a connection to smallwebwaf at addr, for requests the HTTP
+// dial opens a connection to addr, for requests the HTTP client cannot make,
-// client cannot make, such as one that stops sending halfway.
+// such as one that stops sending halfway.
 func dial(t *testing.T, addr string) net.Conn {
 	t.Helper()
 
@@ -471,14 +607,3 @@ func wantStatus(t *testing.T, got answer, status int) {
 		t.Errorf("status %d, want %d", got.status, status)
 	}
 }
-
-// wantTimedOut checks that what began at start ended once shortTimeout
-// had run out, and not much later.
-func wantTimedOut(t *testing.T, start time.Time) {
-	t.Helper()
-
-	took := time.Since(start)
-	if took < shortTimeout || took > shortTimeout+waitLimit/2 {
-		t.Errorf("took %s, want %s", took, shortTimeout)
-	}
-}

internal/discriminator/ratelimits_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"net/http"
@@ -10,7 +10,7 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
 
-// minute is the window of SWWAF_RATE_LIMIT_PER_MINUTE, as a log line's
+// minute is the window of SWW_RATE_LIMIT_PER_MINUTE, as a log line's
 // limit_hit names it.
 const minute = "minute"
 
@@ -51,7 +51,7 @@ func TestRateLimitRefusesBeforeTheApp(t *testing.T) {
 		req.Header.Set(forwardedFor, sent.client)
 		wantStatus(t, do(t, req), sent.want)
 
-		line := out.requestLines(t, i+1)[i]
+		line := out.endedLines(t, i+1)[i]
 		if line.ClientIP != sent.logged {
 			t.Errorf("log line has client_ip %q, want %q", line.ClientIP, sent.logged)
 		}
@@ -75,7 +75,7 @@ func TestRateLimitRefusesBeforeTheApp(t *testing.T) {
 func TestIPv6GroupPrefixSetsTheClientTheLimitsCount(t *testing.T) {
 	t.Parallel()
 
-	// With SWWAF_IPV6_GROUP_PREFIX at 48, the first two addresses, in two
+	// With SWW_IPV6_GROUP_PREFIX at 48, the first two addresses, in two
 	// /64s of one /48, are one client, and the second's request breaks the
 	// limit; the third, in the next /48, is another client.
 	const (
@@ -118,7 +118,7 @@ func TestIPv6GroupPrefixSetsTheClientTheLimitsCount(t *testing.T) {
 func TestRateLimitExemptPathsAreNeitherCountedNorRefused(t *testing.T) {
 	t.Parallel()
 
-	const denied = "192.0.2.50" // in SWWAF_DENY_NETS
+	const denied = "192.0.2.50" // in SWW_DENY_NETS
 
 	geojsURL, _ := startGeoJS(t)
 	s, _, server := startWithClock(t, geojsURL, map[string]string{
@@ -151,7 +151,7 @@ func TestRateLimitExemptPathsAreNeitherCountedNorRefused(t *testing.T) {
 	// /assets/, and breaks the limit.
 	s.request(client, "/assets", http.StatusForbidden, requestlog.ActionRateLimited)
 
-	// A ban, SWWAF_DENY_NETS and the country lists still refuse a path
+	// A ban, SWW_DENY_NETS and the country lists still refuse a path
 	// under a prefix.
 	s.request(client, "/assets/app.js", http.StatusForbidden, requestlog.ActionBanned)
 	s.request(denied, "/assets/app.js", http.StatusForbidden, requestlog.ActionDenied)
@@ -185,6 +185,9 @@ func TestRateLimitCountsPathsThatAreNotExempt(t *testing.T) {
 		"/assets/x%2Fy",
 		"/assets/x%2fy",
 		`/assets/x\y`,
+		// The same with a character Go escapes, |, for which Go's
+		// URL.EscapedPath gives /assets/x/y%7Cz, with no encoded slash.
+		"/assets/x%2Fy|z",
 	} {
 		t.Run(sent, func(t *testing.T) {
 			t.Parallel()

internal/discriminator/reputation.go

@@ -1,4 +1,4 @@
-package proxy
+package discriminator
 
 import (
 	"context"
@@ -10,12 +10,12 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/reputation"
 )
 
-// deny is the SWWAF_BLOCKLIST_ACTION and the SWWAF_REPUTATION_ACTION that
+// deny is the SWW_BLOCKLIST_ACTION and the SWW_REPUTATION_ACTION that
 // refuses the requests of a client a source lists.
 const deny = "deny"
 
 // blocklistDenied notes the blocklists that list the client, as
-// noteListed does, and reports whether SWWAF_BLOCKLIST_ACTION, being deny,
+// noteListed does, and reports whether SWW_BLOCKLIST_ACTION, being deny,
 // refuses the request. Being limit, it lowers the client's limits instead
 // (see limitPercentages), and being log, it does nothing more.
 func (rq *request) blocklistDenied() bool {
@@ -43,7 +43,7 @@ func (rq *request) crowdSecBanned(now time.Time) bool {
 }
 
 // dnsblDenied notes the DNSBL zones whose verdict lists the client, as
-// noteListed does, and reports whether SWWAF_REPUTATION_ACTION, being
+// noteListed does, and reports whether SWW_REPUTATION_ACTION, being
 // deny, refuses the request. Being limit, it lowers the client's limits
 // instead (see limitPercentages), and being log, it does nothing more. A
 // zone without a verdict on the client is asked about it in the
@@ -59,8 +59,8 @@ func (rq *request) dnsblDenied(ctx context.Context) bool {
 
 // abuseIPDBDenied notes AbuseIPDB, as noteHit does, with the score, when
 // its score of the client is a hit, and reports whether
-// SWWAF_REPUTATION_ACTION, being deny, refuses the request, as dnsblDenied
+// SWW_REPUTATION_ACTION, being deny, refuses the request, as dnsblDenied
-// does for a zone. While SWWAF_ABUSEIPDB_KEY is unset it does nothing. A
+// does for a zone. While SWW_ABUSEIPDB_KEY is unset it does nothing. A
 // client without a score is checked in the background, by the request's
 // address, if its history counts an offence, and the request does not
 // wait for the answer. The score is then used for each address of the
@@ -81,7 +81,7 @@ func (rq *request) abuseIPDBDenied(ctx context.Context) bool {
 
 	rq.abuseIPDBHit = true
 	rq.noteHit(bans.ReputationHit{Source: reputation.AbuseIPDBSource, Score: &score},
-		"scored by AbuseIPDB at or over SWWAF_ABUSEIPDB_MIN_SCORE")
+		"scored by AbuseIPDB at or over SWW_ABUSEIPDB_MIN_SCORE")
 
 	return rq.h.config.ReputationAction == deny
 }
@@ -110,6 +110,7 @@ func (rq *request) noteHit(hit bans.ReputationHit, reason string) {
 	rq.h.metrics.ReputationHit(hit.Source)
 	rq.h.alerts.Raise(alerts.Alert{
 		Event:    alerts.EventReputationHit,
+		Host:     rq.site,
 		Client:   rq.client,
 		Netblock: rq.h.clientGroup(rq.client),
 		ASN:      rq.line.ASN,

internal/discriminator/reputation_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"fmt"
@@ -15,7 +15,7 @@ import (
 
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 	"sneak.berlin/go/smallwebwaf/internal/bans"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
 	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
 	"sneak.berlin/go/smallwebwaf/internal/reputation"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
@@ -23,12 +23,12 @@ import (
 
 // The reputation settings.
 const (
-	blocklistURLs      = "SWWAF_BLOCKLIST_URLS"
+	blocklistURLs      = "SWW_BLOCKLIST_URLS"
-	blocklistAction    = "SWWAF_BLOCKLIST_ACTION"
+	blocklistAction    = "SWW_BLOCKLIST_ACTION"
-	asnLimitPercentURL = "SWWAF_ASN_LIMIT_PERCENT_URL"
+	asnLimitPercentURL = "SWW_ASN_LIMIT_PERCENT_URL"
 )
 
-// The actions of SWWAF_BLOCKLIST_ACTION and SWWAF_REPUTATION_ACTION:
+// The actions of SWW_BLOCKLIST_ACTION and SWW_REPUTATION_ACTION:
 // limitHalf gives a listed client half of every limit, and limitQuarter a
 // quarter.
 const (
@@ -127,7 +127,7 @@ func TestBlocklistsComeAfterTheCountryListsAndSkipAllowNets(t *testing.T) {
 	loadLists(t, server, map[string][]string{dropURL: {fromDE, fromKP}})
 
 	// fromKP's country refuses it before the list is looked at, and fromDE,
-	// in SWWAF_ALLOW_NETS, is not checked at all: neither is noted, nor
+	// in SWW_ALLOW_NETS, is not checked at all: neither is noted, nor
 	// alerted.
 	wantReputation(t, s.get(fromKP, http.StatusForbidden, requestlog.ActionCountryDenied))
 	wantReputation(t, s.get(fromDE, http.StatusOK, requestlog.ActionForward))
@@ -224,7 +224,7 @@ func TestASNLimitPercentFileCountsAsTheSettingDoesTheLowerWinning(t *testing.T)
 		},
 		{"none, for an AS number the file does not list", nil, asnKP + ":25", none, none},
 		{
-			"SWWAF_ASN_BYTES_PERCENT's in place of the file's for the byte limits",
+			"SWW_ASN_BYTES_PERCENT's in place of the file's for the byte limits",
 			map[string]string{asnBytesPercent: asnDE + ":100"}, asnDEQuarter, fromURL, none,
 		},
 	} {
@@ -272,6 +272,7 @@ func TestEachBlocklistThatListsAClientRaisesAnAlertOncePerCooldownAndIsCounted(
 			Instance: alertInstance,
 			Time:     clk.Now(),
 			Event:    alerts.EventReputationHit,
+			Host:     appHost,
 			Client:   netip.MustParseAddr(fromDE),
 			Netblock: netip.MustParsePrefix(fromDE + "/32"),
 			ASN:      asnDE,
@@ -289,7 +290,7 @@ func TestEachBlocklistThatListsAClientRaisesAnAlertOncePerCooldownAndIsCounted(
 
 	// Each list's hits, none of its fetches failed, and when its copy was
 	// fetched, 0 for the one without.
-	metrics := s.scrape(unplaced)
+	metrics := s.scrape()
 	fetched := float64(listsFetched().Unix())
 
 	for listURL, want := range map[string]struct{ hits, fetched float64 }{
@@ -298,22 +299,22 @@ func TestEachBlocklistThatListsAClientRaisesAnAlertOncePerCooldownAndIsCounted(
 		labels := `{instance="` + alertInstance + `",source="` + listURL + `"}`
 
 		if want.hits == 0 {
-			wantNoSeries(t, metrics, "smallwebwaf_reputation_hits_total"+labels)
+			wantNoSeries(t, metrics, "sww_reputation_hits_total"+labels)
 		} else {
-			wantMetric(t, metrics, "smallwebwaf_reputation_hits_total"+labels, want.hits)
+			wantMetric(t, metrics, "sww_reputation_hits_total"+labels, want.hits)
 		}
 
-		wantMetric(t, metrics, "smallwebwaf_reputation_failures_total"+labels, 0)
+		wantMetric(t, metrics, "sww_reputation_failures_total"+labels, 0)
-		wantMetric(t, metrics, "smallwebwaf_reputation_last_fetch_timestamp_seconds"+labels,
+		wantMetric(t, metrics, "sww_reputation_last_fetch_timestamp_seconds"+labels,
 			want.fetched)
 	}
 }
 
 // The DNSBL settings.
 const (
-	dnsblZones       = "SWWAF_DNSBL_ZONES"
+	dnsblZones       = "SWW_DNSBL_ZONES"
-	dnsblResolver    = "SWWAF_DNSBL_RESOLVER"
+	dnsblResolver    = "SWW_DNSBL_RESOLVER"
-	reputationAction = "SWWAF_REPUTATION_ACTION"
+	reputationAction = "SWW_REPUTATION_ACTION"
 )
 
 // The DNSBL zones these tests name, which are never asked about the
@@ -369,7 +370,7 @@ func TestEachReputationActionForAClientADNSBLZoneLists(t *testing.T) {
 			for _, from := range []string{fromDE, fromKP} {
 				for i := range 3 {
 					line := s.get(from, tc.statuses[i], tc.actions[i])
-					// In the order SWWAF_DNSBL_ZONES names them.
+					// In the order SWW_DNSBL_ZONES names them.
 					wantReputation(t, line, listedBy[from]...)
 					wantPercent(t, "limit_percent", line.LimitPercent,
 						line.LimitPercentSetting, tc.percent)
@@ -415,7 +416,7 @@ func TestDNSBLZonesComeAfterTheBlocklistsAndSkipAllowNets(t *testing.T) {
 	loadVerdicts(server, map[string][]string{fromKP: {dnsblZone}, fromDE: {dnsblZone}})
 
 	// The blocklist refuses fromKP before its verdict is looked at, and
-	// fromDE, in SWWAF_ALLOW_NETS, is not checked at all: neither is noted
+	// fromDE, in SWW_ALLOW_NETS, is not checked at all: neither is noted
 	// for the zone, nor alerted, nor asked about.
 	wantReputation(t, s.get(fromKP, http.StatusForbidden, requestlog.ActionDenied),
 		dropURL)
@@ -513,6 +514,7 @@ func TestEachZoneThatListsAClientRaisesAnAlertOncePerCooldownAndIsCounted(
 			Instance: alertInstance,
 			Time:     clk.Now(),
 			Event:    alerts.EventReputationHit,
+			Host:     appHost,
 			Client:   netip.MustParseAddr(fromDE),
 			Netblock: netip.MustParsePrefix(fromDE + "/32"),
 			ASN:      asnDE,
@@ -530,14 +532,14 @@ func TestEachZoneThatListsAClientRaisesAnAlertOncePerCooldownAndIsCounted(
 
 	// Each zone's hits, and its queries and their failures, none, since
 	// every client had its verdicts.
-	metrics := s.scrape(unplaced)
+	metrics := s.scrape()
 
 	for _, zone := range []string{dnsblZone, otherZone} {
 		labels := `{instance="` + alertInstance + `",source="` + zone + `"}`
 
-		wantMetric(t, metrics, "smallwebwaf_reputation_hits_total"+labels, 2)
+		wantMetric(t, metrics, "sww_reputation_hits_total"+labels, 2)
-		wantMetric(t, metrics, "smallwebwaf_reputation_queries_total"+labels, 0)
+		wantMetric(t, metrics, "sww_reputation_queries_total"+labels, 0)
-		wantMetric(t, metrics, "smallwebwaf_reputation_failures_total"+labels, 0)
+		wantMetric(t, metrics, "sww_reputation_failures_total"+labels, 0)
 	}
 }
 
@@ -564,8 +566,8 @@ func TestZoneKeyIsMaskedInTheLogTheAlertAndTheMetrics(t *testing.T) {
 			masked)
 	}
 
-	metrics := s.scrape(unplaced)
+	metrics := s.scrape()
-	wantMetric(t, metrics, `smallwebwaf_reputation_hits_total{instance="`+
+	wantMetric(t, metrics, `sww_reputation_hits_total{instance="`+
 		alertInstance+`",source="`+masked+`"}`, 1)
 
 	for name, shown := range map[string]string{
@@ -607,7 +609,7 @@ func TestRequestFromAClientWithoutAVerdictHasTheZoneAskedAboutIt(t *testing.T) {
 
 // The AbuseIPDB settings, and accountKey, the key the tests set.
 const (
-	abuseIPDBKey = "SWWAF_ABUSEIPDB_KEY"
+	abuseIPDBKey = "SWW_ABUSEIPDB_KEY"
 	accountKey   = "abuseipdb-key-0123456789abcdef"
 )
 
@@ -615,7 +617,7 @@ const (
 // AbuseIPDB.
 const abuseipdb = reputation.AbuseIPDBSource
 
-// abuseIPDBURL is where newProxy has clients checked with AbuseIPDB: at
+// abuseIPDBURL is where newDiscriminator has clients checked with AbuseIPDB: at
 // abuseIPDBStandIn, which TestMain registers with Go's default transport,
 // through which AbuseIPDB is asked.
 const abuseIPDBURL = "abuseipdb://stand-in/api/v2/check"
@@ -737,10 +739,6 @@ func TestClientRefusedForAnOffenceIsCheckedWithAbuseIPDBAtItsNextRequest(t *test
 			"a trap path", "/xmlrpc.php", http.StatusForbidden, requestlog.ActionBanned,
 			ratelimit.Offences{Attack: 1},
 		},
-		{
-			"a missing token", proxy.MetricsPath, http.StatusUnauthorized,
-			requestlog.ActionAdmin, ratelimit.Offences{TokenRefused: 1},
-		},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
 			t.Parallel()
@@ -748,7 +746,7 @@ func TestClientRefusedForAnOffenceIsCheckedWithAbuseIPDBAtItsNextRequest(t *test
 			s, clk, server := startWithClock(t, "", map[string]string{
 				abuseIPDBKey: accountKey, reputationAction: actionLog,
 				rulesDir: writeRules(t, testRules), attackBanDuration: "1h",
-				trapPaths: trapPathList, metricsToken: token, wafMode: block,
+				trapPaths: trapPathList, wafMode: block,
 			})
 
 			s.request(client, tc.path, tc.status, tc.action)
@@ -802,7 +800,7 @@ func TestEachReputationActionForAClientAbuseIPDBScoresAtOrOverTheMinimum(t *test
 				rateLimitPerMinute: fourAMinute, abuseIPDBKey: accountKey,
 				reputationAction: tc.action,
 			})
-			// At SWWAF_ABUSEIPDB_MIN_SCORE, 75 by default, and just under it.
+			// At SWW_ABUSEIPDB_MIN_SCORE, 75 by default, and just under it.
 			loadScores(server, map[string]int64{fromDE: 75, fromKP: 74})
 
 			for i := range 3 {
@@ -853,7 +851,7 @@ func TestAbuseIPDBHitRaisesAnAlertWithTheScoreOncePerCooldownAndIsCounted(
 	// The alert is made as a DNSBL zone's is, with the score besides.
 	waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
 	if len(waiting) != 1 || waiting[0].Event != alerts.EventReputationHit ||
-		waiting[0].Reason != "scored by AbuseIPDB at or over SWWAF_ABUSEIPDB_MIN_SCORE" ||
+		waiting[0].Reason != "scored by AbuseIPDB at or over SWW_ABUSEIPDB_MIN_SCORE" ||
 		waiting[0].Detail["source"] != abuseipdb || waiting[0].Detail["score"] != int64(90) ||
 		queue.Suppressed() != 1 {
 		t.Errorf("alerts waiting %+v, %d held back, want AbuseIPDB's reputation_hit "+
@@ -862,13 +860,13 @@ func TestAbuseIPDBHitRaisesAnAlertWithTheScoreOncePerCooldownAndIsCounted(
 
 	// The hits, and the checks, none, since no client committed an
 	// offence, so that the whole budget is left.
-	metrics := s.scrape(unplaced)
+	metrics := s.scrape()
 	labels := `{instance="` + alertInstance + `",source="` + abuseipdb + `"}`
 
-	wantMetric(t, metrics, "smallwebwaf_reputation_hits_total"+labels, 2)
+	wantMetric(t, metrics, "sww_reputation_hits_total"+labels, 2)
-	wantMetric(t, metrics, "smallwebwaf_reputation_queries_total"+labels, 0)
+	wantMetric(t, metrics, "sww_reputation_queries_total"+labels, 0)
-	wantMetric(t, metrics, "smallwebwaf_reputation_failures_total"+labels, 0)
+	wantMetric(t, metrics, "sww_reputation_failures_total"+labels, 0)
-	wantMetric(t, metrics, "smallwebwaf_reputation_daily_budget_remaining"+labels, 900)
+	wantMetric(t, metrics, "sww_reputation_daily_budget_remaining"+labels, 900)
 }
 
 func TestWithoutAnAbuseIPDBKeyNoClientIsCheckedNorAScoreUsed(t *testing.T) {
@@ -889,7 +887,7 @@ func TestWithoutAnAbuseIPDBKeyNoClientIsCheckedNorAScoreUsed(t *testing.T) {
 	wantReputation(t, s.get(fromDE, http.StatusOK, forward))
 	wantAbuseIPDBChecks(t, server, 0)
 
-	wantNoSeries(t, s.scrape(unplaced), `smallwebwaf_reputation_daily_budget_remaining{`+
+	wantNoSeries(t, s.scrape(), `sww_reputation_daily_budget_remaining{`+
 		`instance="`+alertInstance+`",source="`+abuseipdb+`"}`)
 }
 
@@ -924,7 +922,7 @@ func TestBanNotesNameEachReputationSourceThatListedTheClient(t *testing.T) {
 				abuseIPDBKey: accountKey, reputationAction: actionLog,
 			})
 			// Every source lists client, and none otherClient, whose score is
-			// under SWWAF_ABUSEIPDB_MIN_SCORE, 75 by default.
+			// under SWW_ABUSEIPDB_MIN_SCORE, 75 by default.
 			loadLists(t, server, map[string][]string{dropURL: {client}})
 			loadVerdicts(server, map[string][]string{client: {dnsblZone}, otherClient: nil})
 			loadScores(server, map[string]int64{client: score, otherClient: 74})
@@ -973,11 +971,11 @@ func verdictsFetched() time.Time {
 }
 
 // loadVerdicts puts into server's DNSBL, for each client listedBy names,
-// a verdict of each zone SWWAF_DNSBL_ZONES names, fetched at
+// a verdict of each zone SWW_DNSBL_ZONES names, fetched at
 // verdictsFetched, as reputation.json would at start: one that lists the
 // client from each zone listedBy gives for it, and one that does not from
 // each other zone.
-func loadVerdicts(server *proxy.Server, listedBy map[string][]string) {
+func loadVerdicts(server *discriminator.Server, listedBy map[string][]string) {
 	verdicts := make([]reputation.Verdict, 0, len(listedBy)*len(server.DNSBL.Zones()))
 
 	for client, zones := range listedBy {
@@ -995,7 +993,7 @@ func loadVerdicts(server *proxy.Server, listedBy map[string][]string) {
 // loadScores puts into server's AbuseIPDB the score scores gives each
 // client, an IPv4 address, fetched at verdictsFetched, as reputation.json
 // would at start.
-func loadScores(server *proxy.Server, scores map[string]int64) {
+func loadScores(server *discriminator.Server, scores map[string]int64) {
 	kept := make([]reputation.Score, 0, len(scores))
 	for client, score := range scores {
 		kept = append(kept, reputation.Score{
@@ -1009,7 +1007,7 @@ func loadScores(server *proxy.Server, scores map[string]int64) {
 
 // wantAbuseIPDBChecks checks how many clients server has checked with
 // AbuseIPDB.
-func wantAbuseIPDBChecks(t *testing.T, server *proxy.Server, want int) {
+func wantAbuseIPDBChecks(t *testing.T, server *discriminator.Server, want int) {
 	t.Helper()
 
 	if got := server.AbuseIPDB.Checked(); got != want {
@@ -1019,7 +1017,7 @@ func wantAbuseIPDBChecks(t *testing.T, server *proxy.Server, want int) {
 
 // loadLists puts copies of lists into server's lists, by URL, each with
 // its lines, fetched at listsFetched, as reputation.json would at start.
-func loadLists(t *testing.T, server *proxy.Server, copies map[string][]string) {
+func loadLists(t *testing.T, server *discriminator.Server, copies map[string][]string) {
 	t.Helper()
 
 	lists := make([]reputation.List, 0, len(copies))

internal/discriminator/request.go

@@ -0,0 +1,462 @@
+package discriminator
+
+import (
+	"context"
+	"net/http"
+	"net/netip"
+	"slices"
+	"strings"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/anomaly"
+	"sneak.berlin/go/smallwebwaf/internal/bans"
+	"sneak.berlin/go/smallwebwaf/internal/config"
+	"sneak.berlin/go/smallwebwaf/internal/lookup"
+	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+	"sneak.berlin/go/smallwebwaf/internal/rules"
+)
+
+// refusal is discriminator refusing a request: the status the visitor is to get, 0
+// to close its connection without an answer, and the action the log line names.
+type refusal struct {
+	status int
+	action string
+}
+
+// decision is what the checks note of a request: its log line, and what
+// counting the request needs once it has ended. discriminator keeps a copy of it
+// until the request's report comes. It holds no credentials, since the log line
+// never does, and neither the request's objects nor their bodies.
+type decision struct {
+	line   requestlog.Line
+	client netip.Addr
+	// requestURI is the path with the query, as a ban's notes keep it.
+	requestURI string
+	// site is, for a question, the host the visitor asked for, which the
+	// alerts name, since one discriminator serves many sites.
+	site string
+	// allowed is true for a question answered with DispositionAllow.
+	allowed bool
+	// lookedUp is true once the client's AS number and country have been
+	// looked up, whether or not an answer was there, and lookupAnswer is
+	// what the lookup gave then, the zero Answer while GeoJS had given none.
+	lookedUp     bool
+	lookupAnswer lookup.Answer
+	// skippedLookupWait is true for a request that did not wait for GeoJS and
+	// found no answer kept. SWW_UNKNOWN_LIMIT_PERCENT does not apply to it,
+	// so that not waiting never lowers its client's limits.
+	skippedLookupWait bool
+	// counted is true for a request the rate limits counted, whose bytes
+	// the byte limits count once it has ended. limitPercent and
+	// bytesPercent are then its client's limit percentages for the rate
+	// limits and for the byte limits.
+	counted                    bool
+	limitPercent, bytesPercent percentage
+	// attack is true for a request that matched a ban rule or asked for a
+	// trap path, ruleBlocked for one a block rule refused, and wafBlocked for
+	// one the Core Rule Set refused, each an offence its client's history
+	// counts.
+	attack, ruleBlocked, wafBlocked bool
+	// reputation is the reputation sources that list the client, for the
+	// notes of a ban the request makes.
+	reputation []bans.ReputationHit
+}
+
+// request is one request to discriminator, from the moment its headers have been
+// read to its log line.
+type request struct {
+	decision
+
+	h   *handler
+	in  *http.Request
+	out *responseWriter
+
+	// blocklisted is true once a blocklist is found to list the client,
+	// dnsblListed once a DNSBL zone's verdict is, and abuseIPDBHit once
+	// AbuseIPDB's score of it is a hit.
+	blocklisted, dnsblListed, abuseIPDBHit bool
+	start                                  time.Time
+	// checked is when the checks were done.
+	checked time.Time
+	// refused is what the request was refused with, nil if it was not.
+	refused *refusal
+	// requestBytes is how many bytes of the request's body have been read.
+	requestBytes int64
+}
+
+// startRequest starts handling r from client, which came through peer: it
+// notes the time, counts the request as under way, and starts the log line
+// with what is known of the request. isQuestion says whether r is a question,
+// whose headers give the request's id and scheme.
+func (h *handler) startRequest(
+	w http.ResponseWriter, r *http.Request, client, peer netip.Addr, isQuestion bool,
+) *request {
+	h.metrics.RequestStarted()
+
+	start := time.Now()
+	forwardedFor := r.Header.Values("X-Forwarded-For")
+
+	rq := &request{
+		decision: decision{
+			client:     client,
+			requestURI: r.URL.RequestURI(),
+			line: requestlog.Line{
+				Time:             requestlog.FormatTime(start),
+				Instance:         h.config.InstanceName,
+				ClientIP:         client.String(),
+				Method:           r.Method,
+				Scheme:           scheme(r, isQuestion),
+				Host:             r.Host,
+				Path:             rules.Path(r),
+				Query:            r.URL.RawQuery,
+				Protocol:         r.Proto,
+				Referer:          r.Referer(),
+				UserAgent:        r.UserAgent(),
+				RequestID:        requestID(r, isQuestion),
+				PeerIP:           peer.String(),
+				ForwardedFor:     strings.Join(forwardedFor, ", "),
+				ClientGroup:      h.clientGroup(client).String(),
+				ContentType:      r.Header.Get("Content-Type"),
+				RequestHeaders:   requestHeaders(r, h.config.LogRequestHeaders),
+				HasAuthorization: len(r.Header.Values("Authorization")) > 0,
+				HasCookie:        len(r.Header.Values("Cookie")) > 0,
+				Action:           requestlog.ActionForward,
+			},
+		},
+		h:     h,
+		in:    r,
+		out:   &responseWriter{ResponseWriter: w},
+		start: start,
+	}
+
+	// A length of -1 is a body whose length was not announced.
+	if r.ContentLength > 0 {
+		rq.line.ContentLength = r.ContentLength
+	}
+
+	return rq
+}
+
+// requestHeaders returns the headers of r that names lists, by name in
+// lower case, each with its values joined by ", ". Authorization, Cookie
+// and Set-Cookie are never among them, whatever names says.
+func requestHeaders(r *http.Request, names []string) map[string]string {
+	headers := map[string]string{}
+
+	for _, name := range names {
+		switch name {
+		case "authorization", "cookie", "set-cookie":
+			continue
+		}
+
+		values := r.Header.Values(name)
+		if len(values) > 0 {
+			headers[name] = strings.Join(values, ", ")
+		}
+	}
+
+	return headers
+}
+
+// check is the one place where a request can be refused. It returns nil to let
+// the request through. The checks of checkClient decide: a request they refuse
+// is answered with SWW_BAN_RESPONSE, 403 for a block rule or the Core Rule Set,
+// or 431 for the header limits. In observe mode nothing is refused, and the log
+// line names what enforce mode would have done. ctx is the request's own context.
+func (rq *request) check(ctx context.Context) *refusal {
+	action := rq.checkClient(ctx)
+
+	switch {
+	case action == "":
+		return nil
+	case rq.h.config.Observe:
+		rq.line.WouldAction = action
+
+		return nil
+	case action == requestlog.ActionRuleBlocked || action == requestlog.ActionWAFBlocked:
+		return &refusal{status: http.StatusForbidden, action: action}
+	case action == requestlog.ActionTooLarge:
+		return &refusal{status: http.StatusRequestHeaderFieldsTooLarge, action: action}
+	default:
+		return rq.banResponse(action)
+	}
+}
+
+// checkClient runs the checks on the request's client, and returns the
+// action of the first that refuses the request, or "" when none does. A
+// client in SWW_ALLOW_NETS skips them, and is not looked up. For any
+// other client, SWW_DENY_NETS comes first, then a ban on its netblock,
+// so that a client either refuses is not looked up, then the lookup of
+// its AS number and country, then the country lists, then the blocklists,
+// then the CrowdSec decision list, which bans the client it lists, then
+// the DNSBL zones' verdicts, and then AbuseIPDB's score; a request any of
+// them refuses is not counted for the rate limits. Then come the
+// rate limits, unless the client is in SWW_RATE_LIMIT_EXEMPT_NETS or the
+// request's path is exempt under SWW_RATE_LIMIT_EXEMPT_PATHS, so that
+// every other request is counted, each of them by the client's limit
+// percentages, then SWW_TRAP_PATHS, then the rule files, then the header
+// limits, and last the Core Rule Set. A request exempt from the rate limits
+// is exempt from the byte limits too. ctx is the request's own context.
+func (rq *request) checkClient(ctx context.Context) string {
+	cfg := rq.h.config
+	if isInside(rq.client, cfg.AllowNets) {
+		return ""
+	}
+
+	now := rq.h.now()
+
+	if isInside(rq.client, cfg.DenyNets) {
+		return requestlog.ActionDenied
+	}
+
+	if rq.banned(now) {
+		return requestlog.ActionBanned
+	}
+
+	rq.lookUp(ctx, now)
+
+	// The lookup can wait for GeoJS, so the checks after it read the time
+	// again: a request counted at the time it arrived could be counted
+	// after a later one of its client's, which the rate limits would take
+	// for the clock set back.
+	now = rq.h.now()
+
+	if rq.countryDenied() {
+		return requestlog.ActionCountryDenied
+	}
+
+	if rq.blocklistDenied() {
+		return requestlog.ActionDenied
+	}
+
+	if rq.crowdSecBanned(now) {
+		return requestlog.ActionBanned
+	}
+
+	if rq.dnsblDenied(ctx) || rq.abuseIPDBDenied(ctx) {
+		return requestlog.ActionDenied
+	}
+
+	rq.counted = rq.countedByRateLimits()
+	if rq.counted {
+		rq.limitPercent, rq.bytesPercent = rq.limitPercentages()
+		rq.line.LimitPercent, rq.line.LimitPercentSetting = rq.limitPercent.logged()
+		rq.line.BytesPercent, rq.line.BytesPercentSetting = rq.bytesPercent.logged()
+	}
+
+	if rq.counted && rq.limitBroken(now) {
+		return requestlog.ActionRateLimited
+	}
+
+	if rq.trapPath(now) {
+		return requestlog.ActionBanned
+	}
+
+	action := rq.checkRules(now)
+	if action != "" {
+		return action
+	}
+
+	if rq.overHeaderLimits() {
+		return requestlog.ActionTooLarge
+	}
+
+	return rq.checkCoreRuleSet()
+}
+
+// countedByRateLimits reports whether the rate limits count the request: its
+// client is not in SWW_RATE_LIMIT_EXEMPT_NETS, and its path is not exempt
+// under SWW_RATE_LIMIT_EXEMPT_PATHS.
+func (rq *request) countedByRateLimits() bool {
+	cfg := rq.h.config
+
+	return !isInside(rq.client, cfg.RateLimitExemptNets) &&
+		!pathExempt(rq.in, cfg.RateLimitExemptPaths)
+}
+
+// pathExempt reports whether r is exempt under prefixes,
+// SWW_RATE_LIMIT_EXEMPT_PATHS or SWW_WAF_EXEMPT_PATHS: whether its
+// path as sent, the path the app receives, not percent-decoded, starts
+// with one of prefixes, so that /%61ssets/x is not under /assets/ for an
+// app whose router matches the path as received. A request whose decoded
+// path contains .. anywhere or a backslash, or whose path as sent holds an
+// encoded slash (%2F or %2f), never is, since an app may act on it as a
+// path outside every prefix: /assets/..%2Flogin as /login, or /assets%2Fx
+// as one path segment, as Go's router does.
+func pathExempt(r *http.Request, prefixes []string) bool {
+	decoded := r.URL.Path
+	sent := rules.Path(r)
+
+	if strings.Contains(decoded, "..") || strings.Contains(decoded, `\`) ||
+		strings.Contains(strings.ToLower(sent), "%2f") {
+		return false
+	}
+
+	return slices.ContainsFunc(prefixes, func(prefix string) bool {
+		return strings.HasPrefix(sent, prefix)
+	})
+}
+
+// finish counts the request in the metrics and writes its log line.
+func (rq *request) finish() {
+	line := &rq.line
+	line.Status = rq.out.status
+	line.ResponseBytes = rq.out.bytes
+	line.ResponseContentType = rq.out.Header().Get("Content-Type")
+	line.RequestBytes = rq.requestBytes
+
+	switch {
+	case rq.refused != nil:
+		line.Action = rq.refused.action
+	case rq.out.err != nil || rq.in.Context().Err() != nil:
+		line.Aborted = true
+	}
+
+	duration := time.Since(rq.start)
+	line.DurationTotal = requestlog.Milliseconds(duration)
+	line.DurationChecks = timing(rq.start, rq.checked)
+
+	// Counted before the log line is written, so that the metrics count
+	// every request whose line is out. An allowed request is the exception:
+	// its report gives the status, bytes and times the metrics count.
+	if rq.allowed {
+		rq.h.metrics.RequestAllowed()
+	} else {
+		rq.h.metrics.RequestEnded(line, duration)
+	}
+
+	rq.writeLine()
+}
+
+// writeLine writes the request's log line.
+func (rq *request) writeLine() {
+	err := requestlog.Write(rq.h.requestLog, &rq.line)
+	if err != nil {
+		rq.h.processLog.Error("writing the request log failed", "error", err.Error())
+	}
+}
+
+// timing is the time from start to end in milliseconds, for one of the
+// log line's timings, or nil when end is zero: what it times never
+// happened.
+func timing(start, end time.Time) *float64 {
+	if end.IsZero() {
+		return nil
+	}
+
+	return new(requestlog.Milliseconds(end.Sub(start)))
+}
+
+// addToHistory adds the request, which has ended, to its client's
+// history, and counts its offences in the metrics, and then the lookup's
+// answer about the client, as answerAtTheEnd gives it, to that history and
+// to the notes of the bans on its netblock: an answer may have come
+// before either was there, and one from GeoJS that comes later is added
+// when it comes.
+func (rq *request) addToHistory() {
+	request := ratelimit.Request{
+		Forwarded:     rq.allowed,
+		Refused:       rq.refused != nil,
+		Status:        rq.out.status,
+		RequestBytes:  rq.requestBytes,
+		ResponseBytes: rq.out.bytes,
+		BrokeLimit:    rq.line.Offence == requestlog.OffenceLimit,
+		Attack:        rq.attack,
+		RuleBlocked:   rq.ruleBlocked,
+		WAFBlocked:    rq.wafBlocked,
+	}
+
+	rq.h.limiter.AddToHistory(rq.h.clientGroup(rq.client), rq.h.now(), request)
+	rq.h.metrics.Offences(request)
+
+	answer, found := rq.answerAtTheEnd()
+	if found {
+		rq.h.addLookup(answer)
+	}
+}
+
+// countAnomalies counts the request, which has ended, and its bytes, as
+// countedBytes gives them, for the anomaly thresholds, whatever was done
+// with it: a request refused, one from a client in SWW_ALLOW_NETS or
+// SWW_RATE_LIMIT_EXEMPT_NETS, and one for a path in
+// SWW_RATE_LIMIT_EXEMPT_PATHS are counted too. It is counted for its
+// client's AS number when answerAtTheEnd gives one. With every anomaly
+// threshold off, the default, it does nothing.
+func (rq *request) countAnomalies() {
+	if !anomalyThresholdsSet(rq.h.config) {
+		return
+	}
+
+	answer, _ := rq.answerAtTheEnd()
+
+	rq.h.anomalies.Count(rq.h.now(), anomaly.Request{
+		Host:        rq.site,
+		Client:      rq.client,
+		ClientGroup: rq.h.clientGroup(rq.client),
+		ASN:         answer.ASN,
+		ASName:      answer.ASName,
+		Country:     answer.Country,
+		Bytes:       rq.countedBytes(),
+	})
+}
+
+// anomalyThresholdsSet reports whether any anomaly threshold is set.
+func anomalyThresholdsSet(cfg *config.Config) bool {
+	off := anomaly.Thresholds{}
+
+	return cfg.AnomalyClient != off || cfg.AnomalyNet != off || cfg.AnomalyASN != off ||
+		cfg.AnomalyTotal != off || cfg.AnomalyWatch != off
+}
+
+// answerAtTheEnd returns, for a client that was looked up, the lookup's
+// answer about it as the request ends, and whether there is one: the
+// lookup database's, which was there at once, or the one GeoJS has given
+// by then, which a request does not wait for unless a setting needs it.
+func (rq *request) answerAtTheEnd() (lookup.Answer, bool) {
+	if !rq.lookedUp {
+		return lookup.Answer{}, false
+	}
+
+	if rq.h.config.LookupSource == "file" {
+		return rq.lookupAnswer, true
+	}
+
+	return rq.h.geojs.Kept(rq.h.clientGroup(rq.client))
+}
+
+// responseWriter is discriminator's answer to a request. It notes the status and
+// size for the log line, and the first error writing the answer.
+type responseWriter struct {
+	http.ResponseWriter
+
+	// status is the status sent, or zero before one is.
+	status int
+	bytes  int64
+	err    error
+}
+
+// WriteHeader sends the status and headers.
+func (w *responseWriter) WriteHeader(status int) {
+	if w.status == 0 {
+		w.status = status
+	}
+
+	w.ResponseWriter.WriteHeader(status)
+}
+
+// Write sends part of the body.
+func (w *responseWriter) Write(p []byte) (int, error) {
+	if w.status == 0 {
+		w.status = http.StatusOK
+	}
+
+	n, err := w.ResponseWriter.Write(p)
+	w.bytes += int64(n)
+
+	if w.err == nil {
+		w.err = err
+	}
+
+	return n, err
+}

internal/discriminator/requestlog_test.go

@@ -1,8 +1,7 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"io"
-	"maps"
 	"math"
 	"net/http"
 	"reflect"
@@ -11,7 +10,7 @@ import (
 	"testing"
 	"time"
 
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
 	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
@@ -19,8 +18,8 @@ import (
 const (
 	// requestIDHeader carries the request's id.
 	requestIDHeader = "X-Request-ID"
-	// instance is the SWWAF_INSTANCE_NAME a test sets.
+	// instance is the SWW_INSTANCE_NAME a test sets.
-	instance = "fsn1app1/gitea"
+	instance = "fsn1app1/blog"
 	// ipv6Client is a client on IPv6, and ipv6Group the netblock the rate
 	// limits count it as.
 	ipv6Client = "2001:db8::7"
@@ -42,9 +41,6 @@ func TestLogLineHasEachFieldWhereItApplies(t *testing.T) {
 			return
 		}
 
-		w.Header().Set("Content-Type", "text/html")
-		w.Header().Set("Cache-Control", "no-store")
-		w.Header().Set("Location", "/elsewhere")
 		w.WriteHeader(http.StatusFound)
 		_, _ = io.WriteString(w, "moved")
 	})
@@ -70,7 +66,7 @@ func TestLogLineHasEachFieldWhereItApplies(t *testing.T) {
 
 	// A request's log line can come after its answer: each is waited for
 	// before the next request, so that the lines are in order.
-	full := out.requestLines(t, 1)[0]
+	full := out.endedLines(t, 1)[0]
 
 	// This one comes from 127.0.0.1, which the rate limits do not count,
 	// with a body of 4 bytes whose length it does not announce, so that its
@@ -81,7 +77,7 @@ func TestLogLineHasEachFieldWhereItApplies(t *testing.T) {
 		"Transfer-Encoding: chunked\r\n\r\n4\r\nbody\r\n0\r\n\r\n")
 	wantStatus(t, readResponse(t, conn), http.StatusNoContent)
 
-	bare := out.requestLines(t, 2)[1]
+	bare := out.endedLines(t, 2)[1]
 
 	wantFullLine(t, full)
 	wantBareLine(t, bare)
@@ -108,24 +104,23 @@ func wantFullLine(t *testing.T, line logLine) {
 	headers := map[string]string{"accept": "text/html", "x-custom": "one, two"}
 
 	want := withTimings(line, requestlog.Line{
-		Type: requestType, Time: line.Time, Instance: instance,
+		Type: requestType, DiscriminatorLine: requestlog.DiscriminatorLineReport,
+		Time: line.Time, Instance: instance,
 		ClientIP: ipv6Client, Method: http.MethodPost, Scheme: secure,
 		Host: appHost, Path: "/full", Protocol: protocol,
 		Status: http.StatusFound, RequestBytes: 3, ResponseBytes: 5,
-		RequestID: "from-traefik", PeerIP: localhost,
+		RequestID: line.RequestID, PeerIP: localhost,
 		ForwardedFor: "198.51.100.7, " + ipv6Client, ClientGroup: ipv6Group,
 		ContentType: "application/x-www-form-urlencoded", ContentLength: 3,
 		RequestHeaders: headers, HasAuthorization: true, HasCookie: true,
-		ResponseContentType: "text/html", UpstreamStatus: http.StatusFound,
-		CacheControl: "no-store", Location: "/elsewhere",
 		Action: requestlog.ActionForward,
 		// Its 3 bytes in and 5 out, each way counted by default.
 		Counts: ratelimit.Counts{
 			Minute: 1, Hour: 1, Day: 1, MinuteBytes: 8, HourBytes: 8, DayBytes: 8,
 		},
 	})
-	if !reflect.DeepEqual(line.Line, want) {
+	if !reflect.DeepEqual(line.Line, want) || line.RequestID == "from-traefik" {
-		t.Errorf("log line\n%+v\nwant\n%+v", line.Line, want)
+		t.Errorf("log line\n%+v\nwant\n%+v, with a new request id", line.Line, want)
 	}
 }
 
@@ -135,12 +130,13 @@ func wantBareLine(t *testing.T, line logLine) {
 	t.Helper()
 
 	want := withTimings(line, requestlog.Line{
-		Type: requestType, Time: line.Time, Instance: instance,
+		Type: requestType, DiscriminatorLine: requestlog.DiscriminatorLineReport,
+		Time: line.Time, Instance: instance,
 		ClientIP: localhost, Method: http.MethodPost, Scheme: plain,
 		Host: appHost, Path: "/bare", Protocol: protocol,
 		Status: http.StatusNoContent, RequestBytes: 4, RequestID: line.RequestID,
 		PeerIP: localhost, ClientGroup: localhost + "/32",
-		UpstreamStatus: http.StatusNoContent, Action: requestlog.ActionForward,
+		Action: requestlog.ActionForward,
 	})
 	if !reflect.DeepEqual(line.Line, want) || line.RequestID == "" {
 		t.Errorf("log line\n%+v\nwant\n%+v, with a request id", line.Line, want)
@@ -148,8 +144,7 @@ func wantBareLine(t *testing.T, line logLine) {
 
 	for _, name := range []string{
 		"forwarded_for", "content_type", "content_length", "request_headers",
-		"has_authorization", "has_cookie", "websocket", "response_content_type",
+		"has_authorization", "has_cookie", "response_content_type", "counts",
-		"cache_control", "location", "counts",
 	} {
 		_, present := line.fields[name]
 		if present {
@@ -162,8 +157,6 @@ func wantBareLine(t *testing.T, line logLine) {
 func withTimings(line logLine, want requestlog.Line) requestlog.Line {
 	want.DurationTotal = line.DurationTotal
 	want.DurationChecks = line.DurationChecks
-	want.DurationUpstreamConnect = line.DurationUpstreamConnect
-	want.DurationUpstreamFirstByte = line.DurationUpstreamFirstByte
 	want.DurationUpstreamTotal = line.DurationUpstreamTotal
 
 	return want
@@ -188,7 +181,7 @@ func TestHasAuthorizationAndHasCookieEachComeFromTheirOwnHeader(t *testing.T) {
 			req.Header.Set(tc.header, "secret")
 			wantStatus(t, do(t, req), http.StatusOK)
 
-			line := out.requestLine(t)
+			line := out.endedLine(t)
 
 			_, otherPresent := line.fields[tc.other]
 			if line.fields[tc.field] != true || otherPresent {
@@ -199,81 +192,20 @@ func TestHasAuthorizationAndHasCookieEachComeFromTheirOwnHeader(t *testing.T) {
 	}
 }
 
-func TestRequestIDAndSchemeComeOnlyFromATrustedProxy(t *testing.T) {
-	t.Parallel()
-
-	const sentID = "from-traefik"
-
-	sent := http.Header{requestIDHeader: {sentID}, forwardedProto: {secure}}
-	trusted := map[string]string{trustedProxies: trustLocalhost}
-
-	for _, tc := range []struct {
-		name   string
-		env    map[string]string
-		header http.Header
-		// wantID is the request id logged, "" for a new one.
-		wantID, wantScheme string
-	}{
-		{"a trusted proxy's are kept", trusted, sent, sentID, secure},
-		{"without them, the id is new and the scheme http", trusted, nil, "", plain},
-		{"another peer's are replaced", nil, sent, "", plain},
-	} {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			received := make(chan string, 2)
-			app := startApp(t, func(_ http.ResponseWriter, r *http.Request) {
-				received <- r.Header.Get(requestIDHeader)
-			})
-			addr, out := startProxy(t, app.URL, tc.env)
-
-			// Two requests, so that two new ids can be told apart.
-			ids := make([]string, 0, 2)
-
-			for i := range 2 {
-				req := newRequest(t, http.MethodGet, addr, "/", http.NoBody)
-				maps.Copy(req.Header, tc.header)
-				wantStatus(t, do(t, req), http.StatusOK)
-
-				line := out.requestLines(t, i+1)[i]
-				ids = append(ids, line.RequestID)
-
-				got := <-received
-				if line.RequestID != got || line.Scheme != tc.wantScheme {
-					t.Errorf("log line has request_id %q and scheme %q, and the "+
-						"app received id %q; want the same id and scheme %q",
-						line.RequestID, line.Scheme, got, tc.wantScheme)
-				}
-			}
-
-			switch {
-			case tc.wantID != "" && (ids[0] != tc.wantID || ids[1] != tc.wantID):
-				t.Errorf("request ids %q, want %q", ids, tc.wantID)
-			case tc.wantID == "" && (slices.Contains(ids, sentID) ||
-				slices.Contains(ids, "") || ids[0] == ids[1]):
-				t.Errorf("request ids %q, want two new ones", ids)
-			}
-		})
-	}
-}
-
 func TestTimingsAreInOrder(t *testing.T) {
 	t.Parallel()
 
-	const denied = "192.0.2.50" // in SWWAF_DENY_NETS
+	const denied = "192.0.2.50" // in SWW_DENY_NETS
 
 	app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
-		// The pauses set the times apart; a hold-up of the test only
+		// The pause sets the times apart; a hold-up of the test only lengthens
-		// lengthens them.
+		// it.
-		time.Sleep(time.Millisecond)
-		w.WriteHeader(http.StatusOK)
-		_ = http.NewResponseController(w).Flush()
-
 		time.Sleep(time.Millisecond)
 
 		_, _ = io.WriteString(w, "done")
 	})
-	addr, out := startProxy(t, app.URL, map[string]string{
+
+	addr, out, server := startProxyWithClock(t, app.URL, "", time.Now, map[string]string{
 		trustedProxies: trustLocalhost,
 		denyNets:       denied,
 	})
@@ -281,20 +213,19 @@ func TestTimingsAreInOrder(t *testing.T) {
 	// Each log line is waited for before the next request, so that the
 	// lines are in order.
 	wantStatus(t, get(t, addr, "/"), http.StatusOK)
-	forwarded := out.requestLines(t, 1)[0]
+	forwarded := out.endedLines(t, 1)[0]
 
 	req := newRequest(t, http.MethodGet, addr, "/", http.NoBody)
 	req.Header.Set(forwardedFor, denied)
 	wantStatus(t, do(t, req), http.StatusForbidden)
-	refused := out.requestLines(t, 2)[1]
+	refused := out.endedLines(t, 2)[1]
 
-	wantStatus(t, get(t, addr, proxy.HealthPath), http.StatusOK)
+	wantStatus(t, get(t, server.Addr, discriminator.HealthPath), http.StatusOK)
-	health := out.requestLines(t, 3)[2]
+	health := out.endedLines(t, 3)[2]
 
 	// A request passed to the app has every timing; one refused, none of
 	// the app's; the health check, which runs no check, only the total.
 	wantTimings(t, forwarded, "duration_total", "duration_checks",
-		"duration_upstream_connect", "duration_upstream_first_byte",
 		"duration_upstream_total")
 	wantTimings(t, refused, "duration_total", "duration_checks")
 	wantTimings(t, health, "duration_total")
@@ -307,17 +238,12 @@ func TestTimingsAreInOrder(t *testing.T) {
 	// exact.
 	total := microseconds(forwarded.DurationTotal)
 	checks := microseconds(*forwarded.DurationChecks)
-	connect := microseconds(*forwarded.DurationUpstreamConnect)
-	firstByte := microseconds(*forwarded.DurationUpstreamFirstByte)
 	upstream := microseconds(*forwarded.DurationUpstreamTotal)
 
-	// The checks end before the request is handed to the app, and the
+	// The checks end before the request is handed to the app.
-	// connection comes before the answer, which the app ends after a
+	if checks+upstream > total {
-	// pause.
+		t.Errorf("timings in microseconds: total %d, checks %d, upstream total %d",
-	if checks+upstream > total || connect >= firstByte || firstByte >= upstream {
+			total, checks, upstream)
-		t.Errorf("timings in microseconds: total %d, checks %d, connect %d, "+
-			"first byte %d, upstream total %d", total, checks, connect, firstByte,
-			upstream)
 	}
 
 	if *refused.DurationChecks > refused.DurationTotal {
@@ -350,22 +276,3 @@ func wantTimings(t *testing.T, line logLine, want ...string) {
 func microseconds(milliseconds float64) int64 {
 	return int64(math.Round(milliseconds * 1000))
 }
-
-func TestLogsAnUpgradedConnection(t *testing.T) {
-	t.Parallel()
-
-	app := startApp(t, echoAfterUpgrade)
-	addr, out := startProxy(t, app.URL, nil)
-
-	conn := dial(t, addr)
-	send(t, conn, "GET /socket HTTP/1.1\r\nHost: app\r\n"+
-		"Connection: Upgrade\r\nUpgrade: websocket\r\n\r\n")
-	wantStatus(t, readResponse(t, conn), http.StatusSwitchingProtocols)
-
-	_ = conn.Close()
-
-	line := out.requestLine(t)
-	if line.fields["websocket"] != true {
-		t.Errorf("log line has websocket %v, want true", line.fields["websocket"])
-	}
-}

internal/discriminator/rulefiles_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"net/http"
@@ -34,14 +34,14 @@ func TestEachRuleAction(t *testing.T) {
 	line := s.get(client, http.StatusOK, requestlog.ActionForward)
 	wantRuleIDs(t, line, "noted")
 
-	// A block rule refuses with 403, whatever SWWAF_BAN_RESPONSE is, and
+	// A block rule refuses with 403, whatever SWW_BAN_RESPONSE is, and
 	// bans no one.
 	line = s.request(client, "/blocked", http.StatusForbidden,
 		requestlog.ActionRuleBlocked)
 	wantRuleIDs(t, line, "noted", "blocked")
 	s.get(client, http.StatusOK, requestlog.ActionForward)
 
-	// A ban rule refuses with SWWAF_BAN_RESPONSE, and bans the client for
+	// A ban rule refuses with SWW_BAN_RESPONSE, and bans the client for
 	// seven days, the default.
 	line = s.request(client, "/.env", http.StatusTooManyRequests, requestlog.ActionBanned)
 	wantRuleIDs(t, line, "noted", "probe")
@@ -101,7 +101,7 @@ func TestNextClearSignOfAttackAfterABanBansPermanently(t *testing.T) {
 		attackBanDuration: "1h",
 	})
 
-	// The first probe bans for SWWAF_ATTACK_BAN_DURATION.
+	// The first probe bans for SWW_ATTACK_BAN_DURATION.
 	line := s.request(client, "/.env", http.StatusForbidden, requestlog.ActionBanned)
 	if line.BanExpires != requestlog.FormatTime(clk.Now().Add(time.Hour)) {
 		t.Errorf("log line has ban_expires %q, want an hour on", line.BanExpires)
@@ -122,8 +122,8 @@ func TestRulesComeAfterTheOtherChecks(t *testing.T) {
 	t.Parallel()
 
 	const (
-		allowed = "192.0.2.60" // in SWWAF_ALLOW_NETS
+		allowed = "192.0.2.60" // in SWW_ALLOW_NETS
-		exempt  = "192.0.2.50" // in SWWAF_RATE_LIMIT_EXEMPT_NETS
+		exempt  = "192.0.2.50" // in SWW_RATE_LIMIT_EXEMPT_NETS
 	)
 
 	s, _, server := startWithClock(t, "", map[string]string{
@@ -133,7 +133,7 @@ func TestRulesComeAfterTheOtherChecks(t *testing.T) {
 		rateLimitPerMinute:  "1",
 	})
 
-	// A client in SWWAF_ALLOW_NETS is not checked.
+	// A client in SWW_ALLOW_NETS is not checked.
 	line := s.request(allowed, "/.env", http.StatusOK, requestlog.ActionForward)
 	wantRuleIDs(t, line)
 
@@ -185,8 +185,6 @@ func TestObserveModeLogsWhatTheRulesWouldDo(t *testing.T) {
 func TestMetricsCountRuleMatchesAndBansForAnAttack(t *testing.T) {
 	t.Parallel()
 
-	const scraper = "192.0.2.200"
-
 	s, _, _ := startWithClock(t, "", map[string]string{
 		rulesDir:     writeRules(t, testRules),
 		metricsToken: token,
@@ -196,20 +194,20 @@ func TestMetricsCountRuleMatchesAndBansForAnAttack(t *testing.T) {
 	s.request(client, "/.env", http.StatusForbidden, requestlog.ActionBanned)
 	s.get(client, http.StatusForbidden, requestlog.ActionBanned)
 
-	metrics := s.scrape(scraper)
+	metrics := s.scrape()
 	wantMetric(t, metrics,
-		`smallwebwaf_rule_matches_total{action="block",instance="app",rule_id="blocked"}`, 1)
+		`sww_rule_matches_total{action="block",instance="app",rule_id="blocked"}`, 1)
 	wantMetric(t, metrics,
-		`smallwebwaf_rule_matches_total{action="ban",instance="app",rule_id="probe"}`, 1)
+		`sww_rule_matches_total{action="ban",instance="app",rule_id="probe"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_rules_loaded{instance="app"}`, 2)
+	wantMetric(t, metrics, `sww_rules_loaded{instance="app"}`, 2)
-	wantMetric(t, metrics, `smallwebwaf_requests_total{action="rule_blocked",`+
+	wantMetric(t, metrics, `sww_requests_total{action="rule_blocked",`+
 		`instance="app",status_class="4xx"}`, 1)
 	wantMetric(t, metrics,
-		`smallwebwaf_offences_total{instance="app",kind="rule_blocked"}`, 1)
+		`sww_offences_total{instance="app",kind="rule_blocked"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_offences_total{instance="app",kind="attack"}`, 1)
+	wantMetric(t, metrics, `sww_offences_total{instance="app",kind="attack"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_bans_made_total{cause="attack",instance="app"}`, 1)
+	wantMetric(t, metrics, `sww_bans_made_total{cause="attack",instance="app"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_bans_made_total{cause="limit",instance="app"}`, 0)
+	wantMetric(t, metrics, `sww_bans_made_total{cause="limit",instance="app"}`, 0)
-	wantMetric(t, metrics, `smallwebwaf_permanent_bans{instance="app"}`, 1)
+	wantMetric(t, metrics, `sww_permanent_bans{instance="app"}`, 1)
 }
 
 // writeRules writes content as a rule file into a new directory, and

internal/discriminator/rules.go

@@ -1,4 +1,4 @@
-package proxy
+package discriminator
 
 import (
 	"slices"
@@ -10,7 +10,7 @@ import (
 )
 
 // trapPath reports whether the request asks for a path in
-// SWWAF_TRAP_PATHS: its path as a path rule sees it, without the query,
+// SWW_TRAP_PATHS: its path as a path rule sees it, without the query,
 // as sent or once percent-decoded, is one of them. Such a request is a
 // clear sign of attack, as a ban rule's match is: it bans the client's
 // netblock, or in observe mode raises the alert for the ban it would have

internal/discriminator/staticlists_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"net/http"
@@ -17,7 +17,7 @@ const (
 	unlistedAddr = "2001:db8::2"
 )
 
-func TestAllowNetsSkipEveryCheckButTheSizeLimit(t *testing.T) {
+func TestAllowNetsSkipEveryCheck(t *testing.T) {
 	t.Parallel()
 
 	var calls atomic.Int32
@@ -26,7 +26,7 @@ func TestAllowNetsSkipEveryCheckButTheSizeLimit(t *testing.T) {
 		calls.Add(1)
 	})
 	geojsURL, asked := startGeoJS(t)
-	// fromKP is in SWWAF_ALLOW_NETS, and in SWWAF_DENY_NETS too, which
+	// fromKP is in SWW_ALLOW_NETS, and in SWW_DENY_NETS too, which
 	// comes after it.
 	addr, out := startProxyWithGeoJS(t, app.URL, geojsURL, map[string]string{
 		trustedProxies:     trustLocalhost,
@@ -34,10 +34,9 @@ func TestAllowNetsSkipEveryCheckButTheSizeLimit(t *testing.T) {
 		denyNets:           fromKP,
 		deniedCountries:    "kp",
 		rateLimitPerMinute: "1",
-		requestMaxBytes:    "1K",
 	})
 
-	// Neither SWWAF_DENY_NETS, the country lists nor the limit of one
+	// Neither SWW_DENY_NETS, the country lists nor the limit of one
 	// request a minute refuses the client, and its country is not looked
 	// up.
 	wantAnswers(t, addr, out, []sentRequest{
@@ -49,14 +48,6 @@ func TestAllowNetsSkipEveryCheckButTheSizeLimit(t *testing.T) {
 		t.Errorf("GeoJS was asked about %v, want nothing", asked())
 	}
 
-	// The size limit still applies.
-	body := strings.NewReader(strings.Repeat("a", 2<<10))
-	req := newRequest(t, http.MethodPost, addr, "/", body)
-	req.Header.Set(forwardedFor, fromKP)
-	wantStatus(t, do(t, req), http.StatusRequestEntityTooLarge)
-	wantLine(t, out.requestLines(t, 3)[2],
-		http.StatusRequestEntityTooLarge, requestlog.ActionTooLarge)
-
 	if calls.Load() != 2 {
 		t.Errorf("the app was called %d times, want 2", calls.Load())
 	}
@@ -82,7 +73,7 @@ func TestRequestFromAllowNetsIsNotCounted(t *testing.T) {
 	})
 }
 
-func TestDenyNetsRefuseBeforeTheLookupAndTheBody(t *testing.T) {
+func TestDenyNetsRefuseBeforeTheLookup(t *testing.T) {
 	t.Parallel()
 
 	var calls atomic.Int32
@@ -101,13 +92,9 @@ func TestDenyNetsRefuseBeforeTheLookupAndTheBody(t *testing.T) {
 	req.Header.Set(forwardedFor, fromDE)
 	wantStatus(t, do(t, req), http.StatusForbidden)
 
-	line := out.requestLine(t)
+	line := out.endedLine(t)
 	wantLine(t, line, http.StatusForbidden, requestlog.ActionDenied)
 
-	if line.RequestBytes != 0 {
-		t.Errorf("log line has request_bytes %d, want 0", line.RequestBytes)
-	}
-
 	if len(asked()) != 0 {
 		t.Errorf("GeoJS was asked about %v, want nothing", asked())
 	}
@@ -170,9 +157,9 @@ type sentRequest struct {
 	action string
 }
 
-// wantAnswers sends requests to smallwebwaf at addr one after another and
+// wantAnswers sends requests to sww at addr one after another and
 // checks each one's answer and log line. They must be the first requests
-// smallwebwaf is sent, since the log lines are matched to them in order.
+// sww is sent, since the log lines are matched to them in order.
 func wantAnswers(t *testing.T, addr string, out *output, requests []sentRequest) {
 	t.Helper()
 
@@ -180,6 +167,6 @@ func wantAnswers(t *testing.T, addr string, out *output, requests []sentRequest)
 		req := newRequest(t, http.MethodGet, addr, "/", http.NoBody)
 		req.Header.Set(forwardedFor, sent.client)
 		wantStatus(t, do(t, req), sent.status)
-		wantLine(t, out.requestLines(t, i+1)[i], sent.status, sent.action)
+		wantLine(t, out.endedLines(t, i+1)[i], sent.status, sent.action)
 	}
 }

internal/discriminator/trappaths_test.go

@@ -1,4 +1,4 @@
-package proxy_test
+package discriminator_test
 
 import (
 	"net/http"
@@ -14,14 +14,14 @@ import (
 // trapPaths is the setting's name, and trapPathList what the tests set it
 // to.
 const (
-	trapPaths    = "SWWAF_TRAP_PATHS"
+	trapPaths    = "SWW_TRAP_PATHS"
 	trapPathList = "/wp-login.php,/xmlrpc.php"
 )
 
 func TestTrapPathBansAsABanRuleDoes(t *testing.T) {
 	t.Parallel()
 
-	const allowed = "192.0.2.60" // in SWWAF_ALLOW_NETS
+	const allowed = "192.0.2.60" // in SWW_ALLOW_NETS
 
 	// A block rule for the same path: the trap path comes first.
 	s, clk, server := startWithClock(t, "", map[string]string{
@@ -38,7 +38,7 @@ func TestTrapPathBansAsABanRuleDoes(t *testing.T) {
 		s.request(otherClient, path, http.StatusOK, requestlog.ActionForward)
 	}
 
-	// A client in SWWAF_ALLOW_NETS is not checked.
+	// A client in SWW_ALLOW_NETS is not checked.
 	s.request(allowed, "/xmlrpc.php", http.StatusOK, requestlog.ActionForward)
 
 	// The query is not part of the path.
@@ -104,7 +104,7 @@ func TestTrapPathsNeedNoRuleFiles(t *testing.T) {
 
 	s, _, _ := startWithClock(t, "", map[string]string{
 		trapPaths:           trapPathList,
-		"SWWAF_RULES_ENABLED": "false",
+		"SWW_RULES_ENABLED": "false",
 	})
 
 	s.request(client, "/xmlrpc.php", http.StatusForbidden, requestlog.ActionBanned)

internal/lookup/file.go

@@ -24,7 +24,7 @@ const quietTime = 2 * time.Second
 // FileParams are what OpenFile needs.
 type FileParams struct {
 	// Path is the lookup database, the IPinfo Lite file in its .mmdb form
-	// (SWWAF_LOOKUP_DB_PATH).
+	// (SWW_LOOKUP_DB_PATH).
 	Path string
 	// Now tells the time, normally time.Now.
 	Now func() time.Time
@@ -51,7 +51,7 @@ type File struct {
 }
 
 // record is what the lookup database holds about a network, of the fields
-// smallwebwaf reads.
+// sww reads.
 type record struct {
 	ASN         string `maxminddb:"asn"`
 	ASName      string `maxminddb:"as_name"`
@@ -221,12 +221,12 @@ func (f *File) use(reader *maxminddb.Reader) {
 func read(path string) (*maxminddb.Reader, error) {
 	data, err := os.ReadFile(path) //nolint:gosec // the file the admin names
 	if err != nil {
-		return nil, fmt.Errorf("SWWAF_LOOKUP_DB_PATH cannot be read: %w", err)
+		return nil, fmt.Errorf("SWW_LOOKUP_DB_PATH cannot be read: %w", err)
 	}
 
 	reader, err := maxminddb.OpenBytes(data)
 	if err != nil {
-		return nil, fmt.Errorf("SWWAF_LOOKUP_DB_PATH %s is not a .mmdb file: %w", path, err)
+		return nil, fmt.Errorf("SWW_LOOKUP_DB_PATH %s is not a .mmdb file: %w", path, err)
 	}
 
 	return reader, nil

internal/lookup/file_internal_test.go

@@ -99,9 +99,9 @@ func TestFileThatCannotBeReadIsAnError(t *testing.T) {
 	writeFile(t, notDatabase, "not a lookup database\n")
 
 	for path, want := range map[string]string{
-		missing: "SWWAF_LOOKUP_DB_PATH cannot be read: open " + missing +
+		missing: "SWW_LOOKUP_DB_PATH cannot be read: open " + missing +
 			": no such file or directory",
-		notDatabase: "SWWAF_LOOKUP_DB_PATH " + notDatabase +
+		notDatabase: "SWW_LOOKUP_DB_PATH " + notDatabase +
 			" is not a .mmdb file: error opening database: invalid MaxMind DB file",
 	} {
 		_, err := OpenFile(FileParams{
@@ -216,7 +216,7 @@ func TestReplacementThatCannotBeReadLeavesTheFileInUseWithOneAlert(t *testing.T)
 			Reason: "the lookup database cannot be read, and the one read before stays in use",
 			Detail: map[string]any{
 				"file": path,
-				"error": "SWWAF_LOOKUP_DB_PATH " + path + " is not a .mmdb file: " +
+				"error": "SWW_LOOKUP_DB_PATH " + path + " is not a .mmdb file: " +
 					"error opening database: invalid MaxMind DB file",
 			},
 		})

internal/lookup/lookup.go

@@ -1,6 +1,6 @@
 // Package lookup looks up each client's AS number and country, through
 // the GeoJS web service or in the lookup database, the IPinfo Lite file
-// SWWAF_LOOKUP_DB_PATH names. GeoJS's answers are kept in memory, for at
+// SWW_LOOKUP_DB_PATH names. GeoJS's answers are kept in memory, for at
 // most 100,000 clients and for 7 days each, and are written to
 // lookups.json and read from it by the state package.
 package lookup
@@ -66,7 +66,7 @@ type Params struct {
 	URL string
 	// Timeout is how long a request waits for its client's first answer,
 	// and how long a request to GeoJS may take before it is abandoned
-	// (SWWAF_LOOKUP_TIMEOUT).
+	// (SWW_LOOKUP_TIMEOUT).
 	Timeout time.Duration
 	// Wait is true when a setting needs each request's answer before the
 	// request goes on. Otherwise no request waits for one.
@@ -179,7 +179,7 @@ func New(params Params) *GeoJS {
 // own address for IPv4, and an address in the same place for an IPv6
 // netblock.
 func (g *GeoJS) LookUp(ctx context.Context, client netip.Prefix) Answer {
-	answer, asked := g.answerOrWait(ctx, client)
+	answer, asked := g.answerOrWait(ctx, client, g.wait)
 	if asked == nil {
 		return answer
 	}
@@ -209,6 +209,14 @@ func (g *GeoJS) LookUp(ctx context.Context, client netip.Prefix) Answer {
 	return answer
 }
 
+// LookUpWithoutWaiting is LookUp for a request that does not need the answer,
+// whatever Wait says: it returns the zero Answer at once when none is kept.
+func (g *GeoJS) LookUpWithoutWaiting(ctx context.Context, client netip.Prefix) Answer {
+	answer, _ := g.answerOrWait(ctx, client, false)
+
+	return answer
+}
+
 // Kept returns client's answer, if one is kept, without asking GeoJS.
 func (g *GeoJS) Kept(client netip.Prefix) (Answer, bool) {
 	g.mu.Lock()
@@ -263,9 +271,9 @@ func (g *GeoJS) Load(answers []Answer) {
 // answerOrWait returns client's kept answer if it has one. Otherwise it
 // puts the client among those waiting if there is room, has GeoJS asked
 // about them if it can be, and returns what to wait on for the answer, or
-// nil when there is nothing to wait for.
+// nil when there is nothing to wait for or mustWait is false.
 func (g *GeoJS) answerOrWait(
-	ctx context.Context, client netip.Prefix,
+	ctx context.Context, client netip.Prefix, mustWait bool,
 ) (Answer, <-chan struct{}) {
 	g.mu.Lock()
 	defer g.mu.Unlock()
@@ -283,7 +291,7 @@ func (g *GeoJS) answerOrWait(
 
 	g.ask(ctx)
 
-	if !g.wait {
+	if !mustWait {
 		return Answer{}, nil // the answer is not needed before the request goes on
 	}
 

internal/lookup/lookup_test.go

@@ -72,6 +72,39 @@ func TestKeptAnswerIsUsedFor7DaysThenAskedAgain(t *testing.T) {
 	})
 }
 
+func TestLookUpWithoutWaitingAsksGeoJSAndGoesOnAtOnce(t *testing.T) {
+	t.Parallel()
+
+	synctest.Test(t, func(t *testing.T) {
+		geojs, clock, g := start()
+		client := netip.MustParsePrefix("203.0.113.9/32")
+
+		// Wait is set, and GeoJS does not answer.
+		geojs.set(hanging)
+
+		began := time.Now()
+		answer := g.LookUpWithoutWaiting(t.Context(), client)
+
+		if waited := time.Since(began); waited != 0 || answer != (lookup.Answer{}) {
+			t.Errorf("got %+v after %s, want no answer at once", answer, waited)
+		}
+
+		waitForRequests(t, geojs, 1)
+		wantAsked(t, geojs, 0, "203.0.113.9")
+
+		// That request is abandoned, and has failed once this returns. GeoJS
+		// answers when it is asked again, and the answer is kept.
+		time.Sleep(timeout)
+		synctest.Wait()
+		geojs.set(answering)
+		waitForCountry(t, g, clock, client, germany)
+
+		if got := g.LookUpWithoutWaiting(t.Context(), client).Country; got != germany {
+			t.Errorf("the kept answer gives the country %q, want %q", got, germany)
+		}
+	})
+}
+
 func TestNewClientWaitsAtMostOneSecondThenCountsAsNotFound(t *testing.T) {
 	t.Parallel()
 
@@ -123,8 +156,8 @@ func TestRequestWaitsAsLongAsTheTimeoutSaysAndGeoJSIsAbandonedAfterIt(t *testing
 	t.Parallel()
 
 	synctest.Test(t, func(t *testing.T) {
-		// A timeout longer than the default second, and a GeoJS that does
+		// A timeout longer than the default, and a GeoJS that does not
-		// not answer.
+		// answer.
 		const longerTimeout = 3 * time.Second
 
 		m := metrics.New(1, "app")

internal/lookup/lookuptest/lookuptest.go

@@ -17,7 +17,7 @@ import (
 const fileMode = 0o600
 
 // Network is what a lookup database holds about a netblock, of the fields
-// smallwebwaf reads: its AS number, such as AS64496, the AS's name, and
+// sww reads: its AS number, such as AS64496, the AS's name, and
 // its country, such as DE.
 type Network struct {
 	ASN     string

internal/metrics/busiest.go

@@ -41,7 +41,7 @@ type busiest struct {
 // for the topN busiest countries.
 func newCountries(topN int) *busiest {
 	countries := newBusiest(topN, "country", "the client's country")
-	countries.refused = counterVec("smallwebwaf_country_list_refusals_total",
+	countries.refused = counterVec("sww_country_list_refusals_total",
 		"Requests the country lists refused, by the client's country.",
 		[]string{"country"})
 
@@ -61,11 +61,11 @@ func newBusiest(topN int, label, description string) *busiest {
 
 	return &busiest{
 		topN: topN,
-		requests: counterVec("smallwebwaf_"+label+"_requests_total",
+		requests: counterVec("sww_"+label+"_requests_total",
 			"Requests, by "+description+".", by),
-		requestBytes: counterVec("smallwebwaf_"+label+"_request_bytes_total",
+		requestBytes: counterVec("sww_"+label+"_request_bytes_total",
 			"Request body bytes, by "+description+".", by),
-		responseBytes: counterVec("smallwebwaf_"+label+"_response_bytes_total",
+		responseBytes: counterVec("sww_"+label+"_response_bytes_total",
 			"Response body bytes, by "+description+".", by),
 		seen: map[string]int64{},
 		top:  map[string]bool{},

internal/metrics/metrics.go

@@ -1,6 +1,7 @@
-// Package metrics keeps smallwebwaf's Prometheus metrics, as the "Metrics
+// Package metrics keeps sww's Prometheus metrics, as
-// endpoint" section of SPEC.md lists them, and serves them in the
+// docs/metrics.md lists them, and serves them in the Prometheus text
-// Prometheus text format. No metric carries a client's address.
+// format, as the "Metrics endpoint" section of SPEC.md requires. No
+// metric carries a client's address.
 package metrics
 
 import (
@@ -21,7 +22,7 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/rules"
 )
 
-// Metrics are smallwebwaf's metrics. They are safe for concurrent use.
+// Metrics are sww's metrics. They are safe for concurrent use.
 type Metrics struct {
 	// registry gives every metric registered with it the label instance.
 	registry prometheus.Registerer
@@ -34,7 +35,6 @@ type Metrics struct {
 	requestDuration  prometheus.Histogram
 	upstreamDuration prometheus.Histogram
 	rateLimitHits    *prometheus.CounterVec
-	sizeAndTimeLimitHits *prometheus.CounterVec
 	offences         *prometheus.CounterVec
 	wafMatches       *prometheus.CounterVec
 	// ruleMatches are made by AddRules, and reputationHits by
@@ -62,8 +62,8 @@ type Metrics struct {
 
 // New returns the metrics, with the Go runtime's and the process's own.
 // topN is how many countries and how many AS numbers get series of their
-// own (SWWAF_METRICS_TOP_N). Every metric carries instanceName
+// own (SWW_METRICS_TOP_N). Every metric carries instanceName
-// (SWWAF_INSTANCE_NAME) as its label instance.
+// (SWW_INSTANCE_NAME) as its label instance.
 //
 //nolint:funlen // a few lines for each metric, a list that grows with them
 func New(topN int, instanceName string) *Metrics {
@@ -76,63 +76,60 @@ func New(topN int, instanceName string) *Metrics {
 			prometheus.Labels{"instance": instanceName}, registry),
 		handler: promhttp.HandlerFor(registry, promhttp.HandlerOpts{}),
 		inFlight: prometheus.NewGauge(prometheus.GaugeOpts{
-			Name: "smallwebwaf_requests_in_flight",
+			Name: "sww_requests_in_flight",
 			Help: "Requests under way.",
 		}),
-		requests: counterVec("smallwebwaf_requests_total",
+		requests: counterVec("sww_requests_total",
 			"Requests, by the class of their status and their action.", byStatus),
-		requestBytes: counterVec("smallwebwaf_request_bytes_total",
+		requestBytes: counterVec("sww_request_bytes_total",
 			"Request body bytes, by the class of the status and the action.",
 			byStatus),
-		responseBytes: counterVec("smallwebwaf_response_bytes_total",
+		responseBytes: counterVec("sww_response_bytes_total",
 			"Response body bytes, by the class of the status and the action.",
 			byStatus),
 		requestDuration: prometheus.NewHistogram(prometheus.HistogramOpts{
-			Name: "smallwebwaf_request_duration_seconds",
+			Name: "sww_request_duration_seconds",
 			Help: "How long requests took, from their arrival to their end.",
 		}),
 		upstreamDuration: prometheus.NewHistogram(prometheus.HistogramOpts{
-			Name: "smallwebwaf_upstream_duration_seconds",
+			Name: "sww_upstream_duration_seconds",
 			Help: "How long requests passed to the app took, from then to their end.",
 		}),
-		rateLimitHits: counterVec("smallwebwaf_rate_limit_hits_total",
+		rateLimitHits: counterVec("sww_rate_limit_hits_total",
 			"Requests that broke a rate limit, a byte limit or the error burst, by "+
 				"its window and its kind, requests, bytes or refusals.",
 			[]string{"window", "kind"}),
-		sizeAndTimeLimitHits: counterVec("smallwebwaf_size_and_time_limit_hits_total",
+		offences: counterVec("sww_offences_total",
-			"Requests that passed a size or time limit, by its setting.",
-			[]string{"limit"}),
-		offences: counterVec("smallwebwaf_offences_total",
 			"Offences, by kind.", []string{"kind"}),
-		wafMatches: counterVec("smallwebwaf_waf_matches_total",
+		wafMatches: counterVec("sww_waf_matches_total",
-			"Requests that matched a rule of the Core Rule Set, by SWWAF_WAF_MODE "+
+			"Requests that matched a rule of the Core Rule Set, by SWW_WAF_MODE "+
 				"and the rule's id.", []string{"mode", "rule_id"}),
 		countries: newCountries(topN),
 		asns:      newASNs(topN),
 		GeoJSRequests: prometheus.NewCounter(prometheus.CounterOpts{
-			Name: "smallwebwaf_geojs_requests_total",
+			Name: "sww_geojs_requests_total",
 			Help: "Requests to GeoJS.",
 		}),
 		GeoJSFailures: prometheus.NewCounter(prometheus.CounterOpts{
-			Name: "smallwebwaf_geojs_failures_total",
+			Name: "sww_geojs_failures_total",
 			Help: "Requests to GeoJS that failed.",
 		}),
 		GeoJSUnanswered: prometheus.NewCounter(prometheus.CounterOpts{
-			Name: "smallwebwaf_geojs_unanswered_total",
+			Name: "sww_geojs_unanswered_total",
 			Help: "Requests that needed their client's answer from GeoJS and " +
 				"went on without it, because GeoJS had not given it in time.",
 		}),
-		stateFileWrites: counterVec("smallwebwaf_state_file_writes_total",
+		stateFileWrites: counterVec("sww_state_file_writes_total",
 			"Writes of each state file.", byFile),
-		stateFileWriteFailures: counterVec("smallwebwaf_state_file_write_failures_total",
+		stateFileWriteFailures: counterVec("sww_state_file_write_failures_total",
 			"Writes of each state file that failed.", byFile),
-		stateFileLastWrite: gaugeVec("smallwebwaf_state_file_last_write_timestamp_seconds",
+		stateFileLastWrite: gaugeVec("sww_state_file_last_write_timestamp_seconds",
 			"When each state file was last written, in seconds since 1970.", byFile),
-		stateFileSize: gaugeVec("smallwebwaf_state_file_size_bytes",
+		stateFileSize: gaugeVec("sww_state_file_size_bytes",
 			"The size of each state file, as it was last written.", byFile),
-		stateFileEditsTakenIn: counterVec("smallwebwaf_state_file_edits_taken_in_total",
+		stateFileEditsTakenIn: counterVec("sww_state_file_edits_taken_in_total",
 			"Edits of each state file taken in while running.", byFile),
-		stateFileEditsSetAside: counterVec("smallwebwaf_state_file_edits_set_aside_total",
+		stateFileEditsSetAside: counterVec("sww_state_file_edits_set_aside_total",
 			"Edits of each state file renamed to <name>.bad because they did not parse.",
 			byFile),
 	}
@@ -142,7 +139,7 @@ func New(topN int, instanceName string) *Metrics {
 		collectors.NewProcessCollector(collectors.ProcessCollectorOpts{}),
 		m.inFlight, m.requests, m.requestBytes, m.responseBytes,
 		m.requestDuration, m.upstreamDuration,
-		m.rateLimitHits, m.sizeAndTimeLimitHits, m.offences, m.wafMatches,
+		m.rateLimitHits, m.offences, m.wafMatches,
 		m.countries, m.asns,
 		m.GeoJSRequests, m.GeoJSFailures, m.GeoJSUnanswered,
 		m.stateFileWrites, m.stateFileWriteFailures,
@@ -164,7 +161,7 @@ func (m *Metrics) AddBansAndClients(
 		bans.CauseLimit, bans.CauseAttack, bans.CauseAdmin, bans.CauseCrowdSec,
 	} {
 		m.registry.MustRegister(prometheus.NewCounterFunc(prometheus.CounterOpts{
-			Name:        "smallwebwaf_bans_made_total",
+			Name:        "sww_bans_made_total",
 			Help:        "Bans made, by cause.",
 			ConstLabels: prometheus.Labels{"cause": cause},
 		}, func() float64 {
@@ -174,7 +171,7 @@ func (m *Metrics) AddBansAndClients(
 
 	m.registry.MustRegister(
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name: "smallwebwaf_active_bans",
+			Name: "sww_active_bans",
 			Help: "Bans active now, the permanent ones included.",
 		}, func() float64 {
 			active, _ := ledger.Count(now())
@@ -182,7 +179,7 @@ func (m *Metrics) AddBansAndClients(
 			return float64(active)
 		}),
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name: "smallwebwaf_permanent_bans",
+			Name: "sww_permanent_bans",
 			Help: "Permanent bans not lifted.",
 		}, func() float64 {
 			_, permanent := ledger.Count(now())
@@ -190,7 +187,7 @@ func (m *Metrics) AddBansAndClients(
 			return float64(permanent)
 		}),
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name: "smallwebwaf_tracked_clients",
+			Name: "sww_tracked_clients",
 			Help: "Clients in the table of clients.",
 		}, func() float64 {
 			return float64(limiter.Len())
@@ -203,13 +200,13 @@ func (m *Metrics) AddBansAndClients(
 // ruleFiles, read as the metrics are asked for. It is called once, before
 // RuleMatched.
 func (m *Metrics) AddRules(ruleFiles *rules.Files) {
-	m.ruleMatches = counterVec("smallwebwaf_rule_matches_total",
+	m.ruleMatches = counterVec("sww_rule_matches_total",
 		"Requests that matched a rule of the rule files, by its id and action.",
 		[]string{"rule_id", "action"})
 
 	m.registry.MustRegister(m.ruleMatches,
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name: "smallwebwaf_rules_loaded",
+			Name: "sww_rules_loaded",
 			Help: "Rules loaded from the rule files.",
 		}, func() float64 {
 			return float64(ruleFiles.Len())
@@ -217,25 +214,25 @@ func (m *Metrics) AddRules(ruleFiles *rules.Files) {
 }
 
 // AddRemoteLog adds the metrics of sending the log lines to
-// SWWAF_LOG_REMOTE_URL, read from remote as the metrics are asked for: the
+// SWW_LOG_REMOTE_URL, read from remote as the metrics are asked for: the
 // lines sent, those dropped, and those waiting in the buffer.
 func (m *Metrics) AddRemoteLog(remote *remotelog.Sender) {
 	m.registry.MustRegister(
 		prometheus.NewCounterFunc(prometheus.CounterOpts{
-			Name: "smallwebwaf_remote_log_lines_sent_total",
+			Name: "sww_remote_log_lines_sent_total",
-			Help: "Log lines sent to SWWAF_LOG_REMOTE_URL.",
+			Help: "Log lines sent to SWW_LOG_REMOTE_URL.",
 		}, func() float64 {
 			return float64(remote.Sent())
 		}),
 		prometheus.NewCounterFunc(prometheus.CounterOpts{
-			Name: "smallwebwaf_remote_log_lines_dropped_total",
+			Name: "sww_remote_log_lines_dropped_total",
 			Help: "Log lines dropped: the oldest in a full buffer, and those " +
 				"whose sending failed.",
 		}, func() float64 {
 			return float64(remote.Dropped())
 		}),
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name: "smallwebwaf_remote_log_buffer_depth",
+			Name: "sww_remote_log_buffer_depth",
 			Help: "Log lines in the buffer, waiting to be sent.",
 		}, func() float64 {
 			return float64(remote.Depth())
@@ -251,13 +248,13 @@ func (m *Metrics) AddRemoteLog(remote *remotelog.Sender) {
 func (m *Metrics) AddLookupFile(lastRead func() time.Time, readFailures func() int) {
 	m.registry.MustRegister(
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name: "smallwebwaf_lookup_database_last_read_timestamp_seconds",
+			Name: "sww_lookup_database_last_read_timestamp_seconds",
 			Help: "When the lookup database in use was read, in seconds since 1970.",
 		}, func() float64 {
 			return float64(lastRead().Unix())
 		}),
 		prometheus.NewCounterFunc(prometheus.CounterOpts{
-			Name: "smallwebwaf_lookup_database_read_failures_total",
+			Name: "sww_lookup_database_read_failures_total",
 			Help: "Replacements of the lookup database that could not be read.",
 		}, func() float64 {
 			return float64(readFailures())
@@ -278,7 +275,7 @@ const sourceLabel = "source"
 // copy in use was fetched, and for a zone, the queries made and those that
 // failed. It is called once, before ReputationHit.
 func (m *Metrics) AddReputation(lists *reputation.Lists, dnsbl *reputation.DNSBL) {
-	m.reputationHits = counterVec("smallwebwaf_reputation_hits_total",
+	m.reputationHits = counterVec("sww_reputation_hits_total",
 		"Requests whose client a blocklist, the CrowdSec decision list, a DNSBL "+
 			"zone or AbuseIPDB lists, by the list's URL, the zone, or abuseipdb.",
 		[]string{sourceLabel})
@@ -297,7 +294,7 @@ func (m *Metrics) AddReputation(lists *reputation.Lists, dnsbl *reputation.DNSBL
 		m.addReputationFailures(source, func() int { return lists.Failures(listURL) })
 		m.registry.MustRegister(
 			prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-				Name: "smallwebwaf_reputation_last_fetch_timestamp_seconds",
+				Name: "sww_reputation_last_fetch_timestamp_seconds",
 				Help: "When the copy of the list in use was fetched, in seconds since " +
 					"1970, or 0 while there is none.",
 				ConstLabels: source,
@@ -316,7 +313,7 @@ func (m *Metrics) AddReputation(lists *reputation.Lists, dnsbl *reputation.DNSBL
 // AddAbuseIPDB adds the metrics of AbuseIPDB, with the source abuseipdb,
 // read from abuseIPDB as the metrics are asked for: the checks made, those
 // that failed, and how many checks the day's budget has left. It is
-// called once, after AddReputation, while SWWAF_ABUSEIPDB_KEY is set.
+// called once, after AddReputation, while SWW_ABUSEIPDB_KEY is set.
 func (m *Metrics) AddAbuseIPDB(abuseIPDB *reputation.AbuseIPDB) {
 	source := prometheus.Labels{sourceLabel: reputation.AbuseIPDBSource}
 
@@ -324,8 +321,8 @@ func (m *Metrics) AddAbuseIPDB(abuseIPDB *reputation.AbuseIPDB) {
 	m.addReputationFailures(source, abuseIPDB.Failures)
 	m.registry.MustRegister(
 		prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-			Name:        "smallwebwaf_reputation_daily_budget_remaining",
+			Name:        "sww_reputation_daily_budget_remaining",
-			Help:        "Checks of the day's SWWAF_ABUSEIPDB_DAILY_BUDGET not yet spent.",
+			Help:        "Checks of the day's SWW_ABUSEIPDB_DAILY_BUDGET not yet spent.",
 			ConstLabels: source,
 		}, func() float64 {
 			return float64(abuseIPDB.BudgetLeft())
@@ -351,29 +348,29 @@ func (m *Metrics) AddAlerts(queue *alerts.Queue) {
 
 		m.registry.MustRegister(
 			prometheus.NewCounterFunc(prometheus.CounterOpts{
-				Name:        "smallwebwaf_alerts_sent_total",
+				Name:        "sww_alerts_sent_total",
 				Help:        "Alerts the destination took.",
 				ConstLabels: destination,
 			}, func() float64 {
 				return float64(queue.Counts(name).Sent)
 			}),
 			prometheus.NewCounterFunc(prometheus.CounterOpts{
-				Name:        "smallwebwaf_alerts_failed_total",
+				Name:        "sww_alerts_failed_total",
 				Help:        "Requests to the destination that failed.",
 				ConstLabels: destination,
 			}, func() float64 {
 				return float64(queue.Counts(name).Failed)
 			}),
 			prometheus.NewCounterFunc(prometheus.CounterOpts{
-				Name: "smallwebwaf_alerts_suppressed_total",
+				Name: "sww_alerts_suppressed_total",
-				Help: "Alerts held back: repeats within SWWAF_ALERT_COOLDOWN, and " +
+				Help: "Alerts held back: repeats within SWW_ALERT_COOLDOWN, and " +
-					"alerts past SWWAF_ALERT_MAX_PER_HOUR, for the hour's summary.",
+					"alerts past SWW_ALERT_MAX_PER_HOUR, for the hour's summary.",
 				ConstLabels: destination,
 			}, func() float64 {
 				return float64(queue.Suppressed())
 			}),
 			prometheus.NewCounterFunc(prometheus.CounterOpts{
-				Name: "smallwebwaf_alerts_dropped_total",
+				Name: "sww_alerts_dropped_total",
 				Help: "Alerts dropped, the oldest first, from a full queue, and " +
 					"alerts given up as the destination refused them.",
 				ConstLabels: destination,
@@ -394,36 +391,26 @@ func (m *Metrics) RequestStarted() {
 	m.inFlight.Inc()
 }
 
-// RequestEnded counts a request that has ended, from its log line. limit
+// RequestEnded counts a request that has ended without being passed to the app,
-// is the setting whose size or time limit the request passed, "" if none.
+// from its log line. duration is how long the request took.
-// duration is how long the request took, and upstreamDuration how long it
+func (m *Metrics) RequestEnded(line *requestlog.Line, duration time.Duration) {
-// took from when it was passed to the app, zero if it was not.
-func (m *Metrics) RequestEnded(
-	line *requestlog.Line, limit string, duration, upstreamDuration time.Duration,
-) {
 	m.inFlight.Dec()
+	m.count(line, duration, 0)
+}
 
-	class := statusClass(line.Status)
+// RequestAllowed counts a question of rproxy's, answered allow, as no longer
-	m.requests.WithLabelValues(class, line.Action).Inc()
+// under way. RequestReported counts the request it was about.
-	m.requestBytes.WithLabelValues(class, line.Action).Add(float64(line.RequestBytes))
+func (m *Metrics) RequestAllowed() {
-	m.responseBytes.WithLabelValues(class, line.Action).Add(float64(line.ResponseBytes))
+	m.inFlight.Dec()
-	m.requestDuration.Observe(duration.Seconds())
+}
 
-	if upstreamDuration > 0 {
+// RequestReported counts a request rproxy passed to the app, from what its
-		m.upstreamDuration.Observe(upstreamDuration.Seconds())
+// report says, which line holds: duration is how long the request took, and
-	}
+// upstreamDuration how long it took from when it was passed to the app.
-
+func (m *Metrics) RequestReported(
-	if limit != "" {
+	line *requestlog.Line, duration, upstreamDuration time.Duration,
-		m.sizeAndTimeLimitHits.WithLabelValues(limit).Inc()
+) {
-	}
+	m.count(line, duration, upstreamDuration)
-
-	if line.Country != "" {
-		m.countries.add(line.Country, line)
-	}
-
-	if line.ASN != "" {
-		m.asns.add(line.ASN, line)
-	}
 }
 
 // LimitHit counts a request that broke a rate limit, a byte limit or the
@@ -441,7 +428,6 @@ func (m *Metrics) Offences(r ratelimit.Request) {
 		"attack":       r.Attack,
 		"rule_blocked": r.RuleBlocked,
 		"waf_blocked":  r.WAFBlocked,
-		"token_refused": r.TokenRefused,
 	} {
 		if committed {
 			m.offences.WithLabelValues(kind).Inc()
@@ -456,7 +442,7 @@ func (m *Metrics) RuleMatched(id, action string) {
 }
 
 // WAFMatched counts a request that matched the Core Rule Set's rule id,
-// with SWWAF_WAF_MODE at mode.
+// with SWW_WAF_MODE at mode.
 func (m *Metrics) WAFMatched(mode string, id int) {
 	m.wafMatches.WithLabelValues(mode, strconv.Itoa(id)).Inc()
 }
@@ -481,7 +467,7 @@ func (m *Metrics) StateFileWritten(name string, size int, err error) {
 }
 
 // StateFileEditTakenIn counts an admin's edit of the state file name
-// taken in while smallwebwaf runs.
+// taken in while sww runs.
 func (m *Metrics) StateFileEditTakenIn(name string) {
 	m.stateFileEditsTakenIn.WithLabelValues(name).Inc()
 }
@@ -492,11 +478,35 @@ func (m *Metrics) StateFileEditSetAside(name string) {
 	m.stateFileEditsSetAside.WithLabelValues(name).Inc()
 }
 
+// count counts a request that has ended, as RequestEnded and RequestReported
+// describe.
+func (m *Metrics) count(
+	line *requestlog.Line, duration, upstreamDuration time.Duration,
+) {
+	class := statusClass(line.Status)
+	m.requests.WithLabelValues(class, line.Action).Inc()
+	m.requestBytes.WithLabelValues(class, line.Action).Add(float64(line.RequestBytes))
+	m.responseBytes.WithLabelValues(class, line.Action).Add(float64(line.ResponseBytes))
+	m.requestDuration.Observe(duration.Seconds())
+
+	if upstreamDuration > 0 {
+		m.upstreamDuration.Observe(upstreamDuration.Seconds())
+	}
+
+	if line.Country != "" {
+		m.countries.add(line.Country, line)
+	}
+
+	if line.ASN != "" {
+		m.asns.add(line.ASN, line)
+	}
+}
+
 // addReputationQueries adds the counter of the queries to source, a DNSBL
 // zone, or of the checks of clients with AbuseIPDB, which count tells.
 func (m *Metrics) addReputationQueries(source prometheus.Labels, count func() int) {
 	m.registry.MustRegister(prometheus.NewCounterFunc(prometheus.CounterOpts{
-		Name:        "smallwebwaf_reputation_queries_total",
+		Name:        "sww_reputation_queries_total",
 		Help:        "Queries to the DNSBL zone, or checks of clients with AbuseIPDB.",
 		ConstLabels: source,
 	}, func() float64 {
@@ -509,7 +519,7 @@ func (m *Metrics) addReputationQueries(source prometheus.Labels, count func() in
 // that failed, which count tells.
 func (m *Metrics) addReputationFailures(source prometheus.Labels, count func() int) {
 	m.registry.MustRegister(prometheus.NewCounterFunc(prometheus.CounterOpts{
-		Name: "smallwebwaf_reputation_failures_total",
+		Name: "sww_reputation_failures_total",
 		Help: "Fetches of the list, queries to the DNSBL zone, or checks with " +
 			"AbuseIPDB, that failed.",
 		ConstLabels: source,

internal/proxy/client_test.go

@@ -1,165 +0,0 @@
-package proxy_test
-
-import (
-	"encoding/json"
-	"net/http"
-	"testing"
-)
-
-const (
-	// trustLocalhost trusts the address every test connects from, and a
-	// network for proxies in front of it.
-	trustLocalhost = localhost + "/32,10.0.0.0/8"
-	// appHost is the host every test asks for.
-	appHost = "app.example"
-	// client is the client's address, as a proxy names it.
-	client = "203.0.113.9"
-	// forwardedFor is the header that lists the client and its proxies,
-	// and forwardedProto the one that gives the scheme the client used.
-	forwardedFor   = "X-Forwarded-For"
-	forwardedProto = "X-Forwarded-Proto"
-	// secure is the scheme a client reached traefik with, and plain the
-	// one smallwebwaf serves.
-	secure = "https"
-	plain  = "http"
-)
-
-// appHeaders is what the app tells about the headers it received.
-type appHeaders struct {
-	Host           string `json:"host"`
-	ForwardedFor   string `json:"forwardedFor"`
-	ForwardedHost  string `json:"forwardedHost"`
-	ForwardedProto string `json:"forwardedProto"`
-	RealIP         string `json:"realIp"`
-}
-
-// clientAddressCase is a request and what smallwebwaf makes of it.
-type clientAddressCase struct {
-	name       string
-	env        map[string]string
-	header     http.Header
-	wantClient string
-	wantApp    appHeaders
-}
-
-func TestClientAddressAndForwardedHeaders(t *testing.T) {
-	t.Parallel()
-
-	for _, tc := range clientAddressCases() {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			got, line := requestWithHeaders(t, tc.env, tc.header)
-
-			tc.wantApp.Host = appHost
-			if got != tc.wantApp {
-				t.Errorf("app received %+v, want %+v", got, tc.wantApp)
-			}
-
-			if line.ClientIP != tc.wantClient || line.PeerIP != localhost {
-				t.Errorf("log line has client_ip %q and peer_ip %q, want %q and %q",
-					line.ClientIP, line.PeerIP, tc.wantClient, localhost)
-			}
-		})
-	}
-}
-
-// clientAddressCases are the requests TestClientAddressAndForwardedHeaders
-// sends, from 127.0.0.1, which the default trusted proxies leave out.
-func clientAddressCases() []clientAddressCase {
-	trusted := map[string]string{trustedProxies: trustLocalhost}
-	forged := http.Header{
-		forwardedFor:       {client},
-		"X-Forwarded-Host": {"forged.example"},
-		forwardedProto:     {secure},
-		"X-Real-Ip":        {client},
-	}
-	replaced := appHeaders{
-		ForwardedFor: localhost, ForwardedHost: appHost, ForwardedProto: plain,
-	}
-
-	return []clientAddressCase{{
-		name: "a peer outside the trusted proxies is the client, " +
-			"and its forwarded headers are replaced",
-		header: forged, wantClient: localhost, wantApp: replaced,
-	}, {
-		name:   "set but empty, the trusted proxies trust nothing",
-		env:    map[string]string{trustedProxies: ""},
-		header: forged, wantClient: localhost, wantApp: replaced,
-	}, {
-		name: "behind a trusted peer, the client is the first address " +
-			"outside the trusted proxies from the right",
-		env: trusted,
-		header: http.Header{
-			forwardedFor:       {"198.51.100.7, " + client + ", 10.0.0.2"},
-			"X-Forwarded-Host": {appHost},
-			forwardedProto:     {secure},
-			"X-Real-Ip":        {client},
-		},
-		wantClient: client,
-		wantApp: appHeaders{
-			ForwardedFor:  "198.51.100.7, " + client + ", 10.0.0.2, " + localhost,
-			ForwardedHost: appHost, ForwardedProto: secure, RealIP: client,
-		},
-	}, {
-		name:       "when every address is a trusted proxy, the leftmost is the client",
-		env:        trusted,
-		header:     http.Header{forwardedFor: {"10.0.0.5, 10.0.0.2"}},
-		wantClient: "10.0.0.5",
-		wantApp:    appHeaders{ForwardedFor: "10.0.0.5, 10.0.0.2, " + localhost},
-	}, {
-		name:       "with no header, a trusted peer is the client",
-		env:        trusted,
-		wantClient: localhost,
-		wantApp:    appHeaders{ForwardedFor: localhost},
-	}, {
-		name:       "an entry that is not an address ends the reading",
-		env:        trusted,
-		header:     http.Header{forwardedFor: {client + ", unknown, 10.0.0.2"}},
-		wantClient: "10.0.0.2",
-		wantApp: appHeaders{
-			ForwardedFor: client + ", unknown, 10.0.0.2, " + localhost,
-		},
-	}, {
-		name:       "several header lines are read as one list",
-		env:        trusted,
-		header:     http.Header{forwardedFor: {"2001:db8::7", "10.0.0.2"}},
-		wantClient: "2001:db8::7",
-		wantApp:    appHeaders{ForwardedFor: "2001:db8::7, 10.0.0.2, " + localhost},
-	}}
-}
-
-// requestWithHeaders sends a request for appHost with header through
-// smallwebwaf, with the settings in env, and returns the headers the app
-// received and the request's log line.
-func requestWithHeaders(
-	t *testing.T, env map[string]string, header http.Header,
-) (appHeaders, logLine) {
-	t.Helper()
-
-	app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
-		_ = json.NewEncoder(w).Encode(appHeaders{
-			Host:           r.Host,
-			ForwardedFor:   r.Header.Get(forwardedFor),
-			ForwardedHost:  r.Header.Get("X-Forwarded-Host"),
-			ForwardedProto: r.Header.Get(forwardedProto),
-			RealIP:         r.Header.Get("X-Real-IP"),
-		})
-	})
-	addr, out := startProxy(t, app.URL, env)
-
-	req := newRequest(t, http.MethodGet, addr, "/", http.NoBody)
-	req.Host = appHost
-	req.Header = header.Clone()
-
-	answered := do(t, req)
-
-	var got appHeaders
-
-	err := json.Unmarshal(answered.body, &got)
-	if err != nil {
-		t.Fatalf("decode the app's answer %q: %v", answered.body, err)
-	}
-
-	return got, out.requestLine(t)
-}

internal/proxy/health_test.go

@@ -1,56 +0,0 @@
-package proxy_test
-
-import (
-	"net/http"
-	"sync/atomic"
-	"testing"
-
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
-	"sneak.berlin/go/smallwebwaf/internal/requestlog"
-)
-
-func TestHealthEndpointIsAnsweredBeforeAnyCheck(t *testing.T) {
-	t.Parallel()
-
-	var calls atomic.Int32
-
-	app := startApp(t, func(http.ResponseWriter, *http.Request) {
-		calls.Add(1)
-	})
-	// With a limit of one request a minute, any request counted before
-	// the last one would have it refused.
-	addr, out := startProxy(t, app.URL, map[string]string{rateLimitPerMinute: "1"})
-
-	const (
-		healthChecks = 3
-		contentType  = "text/plain; charset=utf-8"
-	)
-
-	for range healthChecks {
-		got := get(t, addr, proxy.HealthPath)
-		wantStatus(t, got, http.StatusOK)
-
-		if string(got.body) != "ok\n" || got.header.Get("Content-Type") != contentType {
-			t.Errorf("health endpoint answered %q with Content-Type %q, want ok "+
-				"with %q", got.body, got.header.Get("Content-Type"), contentType)
-		}
-	}
-
-	wantStatus(t, get(t, addr, "/"), http.StatusOK)
-
-	lines := out.requestLines(t, healthChecks+1)
-	for _, line := range lines[:healthChecks] {
-		wantLine(t, line, http.StatusOK, requestlog.ActionAdmin)
-
-		if line.ResponseContentType != contentType {
-			t.Errorf("health check's log line has response_content_type %q, "+
-				"want %q", line.ResponseContentType, contentType)
-		}
-	}
-
-	wantLine(t, lines[healthChecks], http.StatusOK, requestlog.ActionForward)
-
-	if calls.Load() != 1 {
-		t.Errorf("the app was called %d times, want once", calls.Load())
-	}
-}

internal/proxy/limits_test.go

@@ -1,162 +0,0 @@
-package proxy_test
-
-import (
-	"bytes"
-	"errors"
-	"io"
-	"net/http"
-	"strconv"
-	"sync/atomic"
-	"testing"
-
-	"sneak.berlin/go/smallwebwaf/internal/requestlog"
-)
-
-// sizeLimit is the size limit the tests set, 1K as a setting.
-const (
-	sizeLimit        = 1 << 10
-	sizeLimitSetting = "1K"
-)
-
-func TestRequestBodyLimit(t *testing.T) {
-	t.Parallel()
-
-	for _, tc := range []struct {
-		name string
-		size int
-		// announced sends the size in Content-Length; otherwise the body
-		// is sent in chunks with no length given.
-		announced bool
-		want      int
-		action    string
-		// refusedBeforeApp is a refusal before anything reaches the app.
-		// A body over the limit with no length given has already partly
-		// reached the app when it is refused.
-		refusedBeforeApp bool
-	}{
-		{"announced, over the limit", 2 * sizeLimit, true,
-			http.StatusRequestEntityTooLarge, requestlog.ActionTooLarge, true},
-		{"announced, at the limit", sizeLimit, true,
-			http.StatusOK, requestlog.ActionForward, false},
-		{"not announced, over the limit", 4 * sizeLimit, false,
-			http.StatusRequestEntityTooLarge, requestlog.ActionTooLarge, false},
-		{"not announced, at the limit", sizeLimit, false,
-			http.StatusOK, requestlog.ActionForward, false},
-	} {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			var calls atomic.Int32
-
-			app := startApp(t, func(_ http.ResponseWriter, r *http.Request) {
-				calls.Add(1)
-
-				_, _ = io.Copy(io.Discard, r.Body)
-			})
-			addr, out := startProxy(t, app.URL, map[string]string{
-				requestMaxBytes: sizeLimitSetting,
-				metricsToken:    token,
-			})
-
-			var body io.Reader = bytes.NewReader(make([]byte, tc.size))
-			if !tc.announced {
-				body = io.MultiReader(body) // hides the length
-			}
-
-			wantStatus(t, do(t, newRequest(t, http.MethodPost, addr, "/upload", body)),
-				tc.want)
-			wantLine(t, out.requestLine(t), tc.want, tc.action)
-
-			hits := 0
-			if tc.action == requestlog.ActionTooLarge {
-				hits = 1
-			}
-
-			wantLimitHits(t, addr, requestMaxBytes, hits)
-
-			if tc.refusedBeforeApp && calls.Load() != 0 {
-				t.Errorf("the app was called %d times, want never", calls.Load())
-			}
-		})
-	}
-}
-
-func TestResponseBodyLimit(t *testing.T) {
-	t.Parallel()
-
-	for _, tc := range []struct {
-		name string
-		size int
-		// announced sends the size in Content-Length; otherwise the body
-		// is sent in chunks with no length given.
-		announced bool
-		want      int
-		action    string
-		// received is how much of a body the client gets, and cutOff
-		// whether the connection is then cut.
-		received int
-		cutOff   bool
-	}{
-		{"announced, over the limit", 2 * sizeLimit, true, http.StatusBadGateway,
-			requestlog.ActionTooLarge, len("Bad Gateway\n"), false},
-		{"announced, at the limit", sizeLimit, true, http.StatusOK,
-			requestlog.ActionForward, sizeLimit, false},
-		{"not announced, over the limit", 4 * sizeLimit, false, http.StatusOK,
-			requestlog.ActionTooLarge, sizeLimit, true},
-		{"not announced, at the limit", sizeLimit, false, http.StatusOK,
-			requestlog.ActionForward, sizeLimit, false},
-	} {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
-				answerWithSize(w, tc.size, tc.announced)
-			})
-			addr, out := startProxy(t, app.URL, map[string]string{
-				responseMaxBytes: sizeLimitSetting,
-				metricsToken:     token,
-			})
-
-			got := get(t, addr, "/download")
-			wantStatus(t, got, tc.want)
-
-			if len(got.body) != tc.received ||
-				errors.Is(got.err, io.ErrUnexpectedEOF) != tc.cutOff {
-				t.Errorf("client got %d bytes (%v), want %d",
-					len(got.body), got.err, tc.received)
-			}
-
-			line := out.requestLine(t)
-			wantLine(t, line, tc.want, tc.action)
-
-			if line.UpstreamStatus != http.StatusOK {
-				t.Errorf("log line has upstream_status %d", line.UpstreamStatus)
-			}
-
-			hits := 0
-			if tc.action == requestlog.ActionTooLarge {
-				hits = 1
-			}
-
-			wantLimitHits(t, addr, responseMaxBytes, hits)
-		})
-	}
-}
-
-// answerWithSize answers with a body of size bytes, announced in
-// Content-Length or sent in chunks with no length given.
-func answerWithSize(w http.ResponseWriter, size int, announced bool) {
-	body := make([]byte, size)
-	if announced {
-		w.Header().Set("Content-Length", strconv.Itoa(size))
-		_, _ = w.Write(body)
-
-		return
-	}
-
-	// Sending part of it before the end keeps Go's server from working
-	// out the length.
-	_, _ = w.Write(body[:size/2])
-	_ = http.NewResponseController(w).Flush()
-	_, _ = w.Write(body[size/2:])
-}

internal/proxy/metrics_test.go

@@ -1,545 +0,0 @@
-package proxy_test
-
-import (
-	"io"
-	"net/http"
-	"net/http/httptest"
-	"net/netip"
-	"strconv"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"testing"
-	"time"
-
-	"sneak.berlin/go/smallwebwaf/internal/bans"
-	"sneak.berlin/go/smallwebwaf/internal/lookup"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
-	"sneak.berlin/go/smallwebwaf/internal/requestlog"
-)
-
-const (
-	metricsToken = "SWWAF_METRICS_TOKEN" //nolint:gosec // the setting's name
-	metricsTopN  = "SWWAF_METRICS_TOP_N"
-	// token is the SWWAF_METRICS_TOKEN the tests set, and bearer how a
-	// request carries it.
-	token  = "0123456789abcdef0123456789abcdef"
-	bearer = "Bearer " + token
-)
-
-func TestMetricsAreOffWhileTheTokenIsUnset(t *testing.T) {
-	t.Parallel()
-
-	var calls atomic.Int32
-
-	app := startApp(t, func(http.ResponseWriter, *http.Request) {
-		calls.Add(1)
-	})
-	addr, out := startProxy(t, app.URL, nil)
-
-	// An empty token does not match the unset one either.
-	for i, authorization := range []string{bearer, "Bearer ", ""} {
-		req := newRequest(t, http.MethodGet, addr, proxy.MetricsPath, http.NoBody)
-		if authorization != "" {
-			req.Header.Set("Authorization", authorization)
-		}
-
-		wantStatus(t, do(t, req), http.StatusNotFound)
-		wantLine(t, out.requestLines(t, i+1)[i], http.StatusNotFound,
-			requestlog.ActionAdmin)
-	}
-
-	if calls.Load() != 0 {
-		t.Errorf("the app was called %d times, want never", calls.Load())
-	}
-}
-
-func TestMetricsNeedTheTokenAndOtherPathsAreNotFound(t *testing.T) {
-	t.Parallel()
-
-	var calls atomic.Int32
-
-	app := startApp(t, func(http.ResponseWriter, *http.Request) {
-		calls.Add(1)
-	})
-	addr, out := startProxy(t, app.URL, map[string]string{metricsToken: token})
-
-	for i, tc := range []struct {
-		method, path, authorization string
-		status                      int
-	}{
-		{http.MethodGet, proxy.MetricsPath, "", http.StatusUnauthorized},
-		{
-			http.MethodGet, proxy.MetricsPath, "Bearer " + strings.ToUpper(token),
-			http.StatusUnauthorized,
-		},
-		{http.MethodGet, proxy.MetricsPath, "Basic " + token, http.StatusUnauthorized},
-		{http.MethodGet, proxy.MetricsPath, bearer, http.StatusOK},
-		{http.MethodGet, proxy.MetricsPath, "bearer " + token, http.StatusOK},
-		{http.MethodPost, proxy.MetricsPath, bearer, http.StatusNotFound},
-		{http.MethodGet, proxy.MetricsPath + "/", bearer, http.StatusNotFound},
-		{http.MethodGet, "/_smallwebwaf/bans", bearer, http.StatusNotFound},
-		{http.MethodPost, proxy.HealthPath, "", http.StatusNotFound},
-	} {
-		req := newRequest(t, tc.method, addr, tc.path, http.NoBody)
-		if tc.authorization != "" {
-			req.Header.Set("Authorization", tc.authorization)
-		}
-
-		got := do(t, req)
-		wantStatus(t, got, tc.status)
-		wantLine(t, out.requestLines(t, i+1)[i], tc.status, requestlog.ActionAdmin)
-
-		if tc.status == http.StatusUnauthorized &&
-			got.header.Get("WWW-Authenticate") != "Bearer" {
-			t.Errorf("%q was answered without WWW-Authenticate: Bearer",
-				tc.authorization)
-		}
-
-		if tc.status == http.StatusOK &&
-			!strings.Contains(string(got.body), "# TYPE smallwebwaf_requests_total counter") {
-			t.Errorf("the metrics are\n%s", got.body)
-		}
-	}
-
-	if calls.Load() != 0 {
-		t.Errorf("the app was called %d times, want never", calls.Load())
-	}
-}
-
-func TestMetricsAreAskedForThroughTheChecks(t *testing.T) {
-	t.Parallel()
-
-	s, _, _ := startWithClock(t, "", map[string]string{
-		metricsToken:       token,
-		rateLimitPerMinute: "1",
-	})
-
-	// Asking for the metrics counts toward the client's limit of one
-	// request a minute, so its next request breaks it, and bans it. A
-	// banned client is refused the metrics too.
-	s.scrape(client)
-	s.get(client, http.StatusForbidden, requestlog.ActionRateLimited)
-	s.requestWithHeader(client, proxy.MetricsPath, "Authorization: "+bearer,
-		http.StatusForbidden, requestlog.ActionBanned)
-}
-
-func TestMetricsCountTheTraffic(t *testing.T) {
-	t.Parallel()
-
-	arrived, release := make(chan struct{}), make(chan struct{})
-	app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
-		_, _ = io.Copy(io.Discard, r.Body)
-
-		if r.URL.Path == "/held" {
-			close(arrived)
-			<-release
-		}
-
-		_, _ = io.WriteString(w, "hello")
-	})
-	releaseApp := sync.OnceFunc(func() { close(release) })
-	t.Cleanup(releaseApp)
-
-	addr, out := startProxy(t, app.URL, map[string]string{metricsToken: token})
-
-	got := do(t, newRequest(t, http.MethodPost, addr, "/", strings.NewReader("abc")))
-	wantStatus(t, got, http.StatusOK)
-	wantStatus(t, get(t, addr, "/_smallwebwaf/nothing"), http.StatusNotFound)
-	out.requestLines(t, 2)
-
-	forward := `{action="forward",instance="app",status_class="2xx"}`
-	notFound := `{action="admin",instance="app",status_class="4xx"}`
-
-	// The request for the metrics is itself under way.
-	metrics := scrape(t, addr)
-	wantMetric(t, metrics, "smallwebwaf_requests_total"+forward, 1)
-	wantMetric(t, metrics, "smallwebwaf_requests_total"+notFound, 1)
-	wantMetric(t, metrics, "smallwebwaf_request_bytes_total"+forward, 3)
-	wantMetric(t, metrics, "smallwebwaf_response_bytes_total"+forward, 5)
-	wantMetric(t, metrics, "smallwebwaf_response_bytes_total"+notFound,
-		float64(len("Not Found\n")))
-	wantMetric(t, metrics,
-		`smallwebwaf_request_duration_seconds_count{instance="app"}`, 2)
-	wantMetric(t, metrics,
-		`smallwebwaf_upstream_duration_seconds_count{instance="app"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_requests_in_flight{instance="app"}`, 1)
-	metric(t, metrics, `go_goroutines{instance="app"}`)
-	metric(t, metrics, `process_start_time_seconds{instance="app"}`)
-
-	// A request the app holds is under way until it ends.
-	httpClient := newClient(t)
-	held := newRequest(t, http.MethodGet, addr, "/held", http.NoBody)
-	ended := make(chan error, 1)
-
-	go func() {
-		res, err := httpClient.Do(held)
-		if err == nil {
-			err = readAnswer(res).err
-		}
-
-		ended <- err
-	}()
-
-	<-arrived
-	wantMetric(t, scrape(t, addr), `smallwebwaf_requests_in_flight{instance="app"}`, 2)
-	releaseApp()
-
-	err := <-ended
-	if err != nil {
-		t.Fatalf("held request: %v", err)
-	}
-
-	out.requestLines(t, 5)
-	wantMetric(t, scrape(t, addr), `smallwebwaf_requests_in_flight{instance="app"}`, 1)
-}
-
-func TestMetricsCountLimitsAndBans(t *testing.T) {
-	t.Parallel()
-
-	const (
-		scraper = "192.0.2.200" // in SWWAF_RATE_LIMIT_EXEMPT_NETS
-		denied  = "192.0.2.50"  // in SWWAF_DENY_NETS
-	)
-
-	s, clk, _ := startWithClock(t, "", map[string]string{
-		metricsToken:        token,
-		rateLimitPerMinute:  "1",
-		rateLimitExemptNets: scraper,
-		denyNets:            denied,
-		banResponse:         "close",
-		limitBanDuration:    "1h",
-		maxBanDuration:      "2h",
-	})
-
-	// SWWAF_BAN_RESPONSE=close sends no status at all.
-	s.get(denied, 0, requestlog.ActionDenied)
-
-	// A first broken limit bans for an hour.
-	s.get(client, http.StatusOK, requestlog.ActionForward)
-	s.get(client, 0, requestlog.ActionRateLimited)
-
-	metrics := s.scrape(scraper)
-	wantMetric(t, metrics,
-		`smallwebwaf_requests_total{action="denied",instance="app",status_class="none"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_rate_limit_hits_total{instance="app",`+
-		`kind="requests",window="minute"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_offences_total{instance="app",kind="limit"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_bans_made_total{cause="limit",instance="app"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_active_bans{instance="app"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_permanent_bans{instance="app"}`, 0)
-
-	clk.advance(time.Hour)
-	wantMetric(t, s.scrape(scraper), `smallwebwaf_active_bans{instance="app"}`, 0)
-
-	// A limit broken again right after would ban for three hours, longer
-	// than SWWAF_MAX_BAN_DURATION, so the ban is permanent.
-	s.get(client, http.StatusOK, requestlog.ActionForward)
-	s.get(client, 0, requestlog.ActionRateLimited)
-
-	metrics = s.scrape(scraper)
-	wantMetric(t, metrics, `smallwebwaf_rate_limit_hits_total{instance="app",`+
-		`kind="requests",window="minute"}`, 2)
-	wantMetric(t, metrics, `smallwebwaf_offences_total{instance="app",kind="limit"}`, 2)
-	wantMetric(t, metrics, `smallwebwaf_bans_made_total{cause="limit",instance="app"}`, 2)
-	wantMetric(t, metrics, `smallwebwaf_active_bans{instance="app"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_permanent_bans{instance="app"}`, 1)
-	// denied, client, and the scraper as of its earlier requests.
-	wantMetric(t, metrics, `smallwebwaf_tracked_clients{instance="app"}`, 3)
-}
-
-func TestMetricsCountTheBansAnAdminMakes(t *testing.T) {
-	t.Parallel()
-
-	const scraper = "192.0.2.200" // in SWWAF_RATE_LIMIT_EXEMPT_NETS
-
-	s, clk, server := startWithClock(t, "", map[string]string{
-		metricsToken:        token,
-		adminToken:          adminSecret,
-		rateLimitExemptNets: scraper,
-	})
-
-	const admins = `smallwebwaf_bans_made_total{cause="admin",instance="app"}`
-
-	wantMetric(t, s.scrape(scraper), admins, 0)
-
-	// As an admin's edit of bans.json that adds a ban is taken in.
-	server.Ledger.LoadEdit([]bans.Ban{{
-		Netblock: netip.MustParsePrefix(client + "/32"),
-		Start:    clk.Now(),
-	}})
-
-	wantMetric(t, s.scrape(scraper), admins, 1)
-
-	// And a ban made through the endpoint.
-	s.admin(http.MethodPost, proxy.BansPath, banOtherClient, http.StatusOK)
-	wantMetric(t, s.scrape(scraper), admins, 2)
-}
-
-func TestMetricsByCountryKeepTheBusiestAndCountTheRestAsOther(t *testing.T) {
-	t.Parallel()
-
-	const fromFR = "198.51.100.20"
-
-	app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
-		_, _ = io.Copy(io.Discard, r.Body)
-		_, _ = io.WriteString(w, "hello")
-	})
-	env := map[string]string{
-		trustedProxies:  trustLocalhost,
-		metricsToken:    token,
-		metricsTopN:     "2",
-		deniedCountries: "kp",
-	}
-	geojsURL, _ := startGeoJS(t)
-	addr, out, server := startProxyWithClock(t, app.URL, geojsURL, time.Now, env)
-
-	// The answers are kept before the requests, so that none waits for
-	// GeoJS.
-	server.GeoJS.Load([]lookup.Answer{
-		keptAnswer(fromKP, "KP"), keptAnswer(fromDE, "DE"), keptAnswer(fromFR, "FR"),
-	})
-
-	lines := 0
-	send := func(from string, times, status int) {
-		t.Helper()
-
-		for range times {
-			req := newRequest(t, http.MethodPost, addr, "/", strings.NewReader("abc"))
-			req.Header.Set(forwardedFor, from)
-			wantStatus(t, do(t, req), status)
-
-			// Each is counted before the next is sent, so that the
-			// countries are ranked in the order sent.
-			lines++
-			out.requestLines(t, lines)
-		}
-	}
-
-	// With two countries of their own, the third is counted as other.
-	send(fromKP, 3, http.StatusForbidden)
-	send(fromDE, 2, http.StatusOK)
-	send(fromFR, 1, http.StatusOK)
-
-	metrics := scrape(t, addr)
-	lines++
-
-	wantMetric(t, metrics,
-		`smallwebwaf_country_requests_total{country="KP",instance="app"}`, 3)
-	wantMetric(t, metrics,
-		`smallwebwaf_country_requests_total{country="DE",instance="app"}`, 2)
-	wantMetric(t, metrics,
-		`smallwebwaf_country_requests_total{country="other",instance="app"}`, 1)
-	wantMetric(t, metrics,
-		`smallwebwaf_country_list_refusals_total{country="KP",instance="app"}`, 3)
-	wantMetric(t, metrics,
-		`smallwebwaf_country_request_bytes_total{country="KP",instance="app"}`, 0)
-	wantMetric(t, metrics,
-		`smallwebwaf_country_request_bytes_total{country="DE",instance="app"}`, 6)
-	wantMetric(t, metrics,
-		`smallwebwaf_country_response_bytes_total{country="KP",instance="app"}`,
-		float64(3*len("Forbidden\n")))
-	wantMetric(t, metrics,
-		`smallwebwaf_country_response_bytes_total{country="other",instance="app"}`,
-		float64(len("hello")))
-	wantNoSeries(t, metrics,
-		`smallwebwaf_country_requests_total{country="FR",instance="app"}`)
-
-	// Once FR is busier than DE, it takes DE's place: its series counts
-	// from then on, and DE's is gone.
-	send(fromFR, 3, http.StatusOK)
-
-	metrics = scrape(t, addr)
-	wantMetric(t, metrics,
-		`smallwebwaf_country_requests_total{country="KP",instance="app"}`, 3)
-	wantMetric(t, metrics,
-		`smallwebwaf_country_requests_total{country="FR",instance="app"}`, 2)
-	wantMetric(t, metrics,
-		`smallwebwaf_country_requests_total{country="other",instance="app"}`, 2)
-	wantNoSeries(t, metrics,
-		`smallwebwaf_country_requests_total{country="DE",instance="app"}`)
-	wantNoSeries(t, metrics,
-		`smallwebwaf_country_request_bytes_total{country="DE",instance="app"}`)
-}
-
-func TestMetricsByASNumberKeepTheBusiestAndCountTheRestAsOther(t *testing.T) {
-	t.Parallel()
-
-	geojsURL, _ := startGeoJS(t)
-	s, clk, server := startWithClock(t, geojsURL, map[string]string{
-		metricsToken: token,
-		metricsTopN:  "1",
-	})
-
-	// The answers are kept before the requests, so that GeoJS gives none
-	// of its own. Each client is in an AS of its own.
-	answer := func(addr, asn string) lookup.Answer {
-		return lookup.Answer{
-			Client: netip.MustParsePrefix(addr + "/32"), ASN: asn,
-			Answered: clk.Now(), Used: clk.Now(),
-		}
-	}
-	server.GeoJS.Load([]lookup.Answer{
-		answer(fromDE, "AS64501"), answer(fromKP, "AS64502"),
-	})
-
-	// With one AS number of its own, the other is counted as other. The
-	// metrics are asked for from a private address, which has no AS number.
-	s.get(fromDE, http.StatusOK, requestlog.ActionForward)
-	s.get(fromDE, http.StatusOK, requestlog.ActionForward)
-	s.get(fromKP, http.StatusOK, requestlog.ActionForward)
-
-	metrics := s.scrape("10.0.0.9")
-	wantMetric(t, metrics,
-		`smallwebwaf_asn_requests_total{asn="AS64501",instance="app"}`, 2)
-	wantMetric(t, metrics,
-		`smallwebwaf_asn_requests_total{asn="other",instance="app"}`, 1)
-	wantMetric(t, metrics,
-		`smallwebwaf_asn_request_bytes_total{asn="AS64501",instance="app"}`, 0)
-	wantMetric(t, metrics,
-		`smallwebwaf_asn_response_bytes_total{asn="other",instance="app"}`, 0)
-	wantNoSeries(t, metrics,
-		`smallwebwaf_asn_requests_total{asn="AS64502",instance="app"}`)
-}
-
-func TestMetricsCountGeoJSRequestsAndFailures(t *testing.T) {
-	t.Parallel()
-
-	geojs := httptest.NewServer(http.HandlerFunc(
-		func(w http.ResponseWriter, _ *http.Request) {
-			w.WriteHeader(http.StatusServiceUnavailable)
-		}))
-	t.Cleanup(geojs.Close)
-
-	app := startApp(t, func(http.ResponseWriter, *http.Request) {})
-	addr, _ := startProxyWithGeoJS(t, app.URL, geojs.URL, map[string]string{
-		trustedProxies:  trustLocalhost,
-		metricsToken:    token,
-		deniedCountries: "kp",
-	})
-
-	// GeoJS fails, so the client counts as coming from an unknown country,
-	// which SWWAF_DENIED_COUNTRIES does not refuse.
-	req := newRequest(t, http.MethodGet, addr, "/", http.NoBody)
-	req.Header.Set(forwardedFor, fromDE)
-	wantStatus(t, do(t, req), http.StatusOK)
-
-	// The client stops waiting for GeoJS after a second, so GeoJS's
-	// failure can come after its request has ended.
-	deadline := time.Now().Add(waitLimit)
-	metrics := scrape(t, addr)
-
-	for metric(t, metrics, `smallwebwaf_geojs_failures_total{instance="app"}`) == 0 &&
-		time.Now().Before(deadline) {
-		time.Sleep(pollInterval)
-
-		metrics = scrape(t, addr)
-	}
-
-	wantMetric(t, metrics, `smallwebwaf_geojs_requests_total{instance="app"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_geojs_failures_total{instance="app"}`, 1)
-	wantMetric(t, metrics, `smallwebwaf_geojs_unanswered_total{instance="app"}`, 1)
-}
-
-// keptAnswer returns GeoJS's answer that the client at addr is in
-// country, given now.
-func keptAnswer(addr, country string) lookup.Answer {
-	now := time.Now()
-
-	return lookup.Answer{
-		Client: netip.MustParsePrefix(addr + "/32"), Country: country,
-		Answered: now, Used: now,
-	}
-}
-
-// scrape asks smallwebwaf at addr for the metrics, with the token, and
-// returns them.
-func scrape(t *testing.T, addr string) string {
-	t.Helper()
-
-	req := newRequest(t, http.MethodGet, addr, proxy.MetricsPath, http.NoBody)
-	req.Header.Set("Authorization", bearer)
-
-	got := do(t, req)
-	if got.status != http.StatusOK {
-		t.Fatalf("the metrics were answered %d", got.status)
-	}
-
-	return string(got.body)
-}
-
-// scrape asks for the metrics, with the token, from the client at from,
-// and returns them.
-func (s *sender) scrape(from string) string {
-	s.t.Helper()
-
-	_, metrics := s.requestWithHeader(from, proxy.MetricsPath, "Authorization: "+bearer,
-		http.StatusOK, requestlog.ActionAdmin)
-
-	return metrics
-}
-
-// metric returns the value of series in metrics, which are in the
-// Prometheus text format. series is a name and its labels in the order of
-// their names, such as
-// smallwebwaf_offences_total{instance="app",kind="limit"}. It fails the
-// test if there is no such series.
-func metric(t *testing.T, metrics, series string) float64 {
-	t.Helper()
-
-	for line := range strings.Lines(metrics) {
-		value, found := strings.CutPrefix(strings.TrimSuffix(line, "\n"), series+" ")
-		if !found {
-			continue
-		}
-
-		number, err := strconv.ParseFloat(value, 64)
-		if err != nil {
-			t.Fatalf("%s has the value %q", series, value)
-		}
-
-		return number
-	}
-
-	t.Fatalf("no series %s in the metrics:\n%s", series, metrics)
-
-	return 0
-}
-
-// wantMetric checks the value of series in metrics, as metric reads it.
-func wantMetric(t *testing.T, metrics, series string, want float64) {
-	t.Helper()
-
-	got := metric(t, metrics, series)
-	if got != want {
-		t.Errorf("%s is %v, want %v", series, got, want)
-	}
-}
-
-// wantNoSeries checks that metrics have no series series.
-func wantNoSeries(t *testing.T, metrics, series string) {
-	t.Helper()
-
-	if strings.Contains(metrics, "\n"+series+" ") {
-		t.Errorf("there is a series %s", series)
-	}
-}
-
-// wantLimitHits checks that the metrics of smallwebwaf at addr count hits
-// requests that passed the size or time limit of the setting limit, with
-// no series for it when hits is 0.
-func wantLimitHits(t *testing.T, addr, limit string, hits int) {
-	t.Helper()
-
-	series := `smallwebwaf_size_and_time_limit_hits_total{instance="app",limit="` +
-		limit + `"}`
-	metrics := scrape(t, addr)
-
-	if hits == 0 {
-		wantNoSeries(t, metrics, series)
-
-		return
-	}
-
-	wantMetric(t, metrics, series, float64(hits))
-}

internal/proxy/passthrough_test.go

@@ -1,468 +0,0 @@
-package proxy_test
-
-import (
-	"bufio"
-	"bytes"
-	"errors"
-	"io"
-	"net/http"
-	"reflect"
-	"slices"
-	"strings"
-	"sync/atomic"
-	"testing"
-	"time"
-
-	"sneak.berlin/go/smallwebwaf/internal/config"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
-	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
-	"sneak.berlin/go/smallwebwaf/internal/requestlog"
-)
-
-// A request target with an escaped slash and space in its path, and a
-// query with a parameter ReverseProxy cannot parse.
-const (
-	rawPath  = "/some%2Fpath/with%20space"
-	rawQuery = "b=2&a=1&bad=%zz;x"
-)
-
-// chunkSize is the size of each part of a body a test sends in parts.
-const chunkSize = 1 << 10
-
-var errNotStreamed = errors.New("the first part never reached the app")
-
-// appSaw is what the app received.
-type appSaw struct {
-	method string
-	target string
-	header http.Header
-	body   []byte
-}
-
-func TestPassesRequestAndAnswerUnchanged(t *testing.T) {
-	t.Parallel()
-
-	requestBody := bytes.Repeat([]byte("request body "), 8000)
-	answerBody := bytes.Repeat([]byte("answer body "), 8000)
-	saw := make(chan appSaw, 1)
-
-	app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
-		body, _ := io.ReadAll(r.Body)
-		saw <- appSaw{r.Method, r.RequestURI, r.Header.Clone(), body}
-
-		w.Header().Set("X-App", "yes")
-		w.Header().Add("Set-Cookie", "a=1")
-		w.Header().Add("Set-Cookie", "b=2")
-		w.WriteHeader(http.StatusTeapot)
-		_, _ = w.Write(answerBody)
-	})
-	addr, out := startProxy(t, app.URL, nil)
-
-	req := newRequest(t, http.MethodPatch, addr, rawPath+"?"+rawQuery,
-		bytes.NewReader(requestBody))
-	req.Header.Add("X-Test", "one")
-	req.Header.Add("X-Test", "two")
-	req.Header.Set("User-Agent", "test-agent")
-
-	got := do(t, req)
-
-	wantAppSaw(t, <-saw, requestBody)
-	wantAnswer(t, got, answerBody)
-
-	line := out.requestLine(t)
-	wantLine(t, line, http.StatusTeapot, requestlog.ActionForward)
-	wantRequestFields(t, line, addr, len(requestBody), len(answerBody))
-}
-
-// wantAppSaw checks that the app received the test's request unchanged.
-func wantAppSaw(t *testing.T, saw appSaw, body []byte) {
-	t.Helper()
-
-	if saw.method != http.MethodPatch || saw.target != rawPath+"?"+rawQuery {
-		t.Errorf("app saw %s %s, want %s %s", saw.method, saw.target,
-			http.MethodPatch, rawPath+"?"+rawQuery)
-	}
-
-	if !slices.Equal(saw.header.Values("X-Test"), []string{"one", "two"}) {
-		t.Errorf("app saw X-Test %q", saw.header.Values("X-Test"))
-	}
-
-	if saw.header.Get("User-Agent") != "test-agent" {
-		t.Errorf("app saw User-Agent %q", saw.header.Get("User-Agent"))
-	}
-
-	if !bytes.Equal(saw.body, body) {
-		t.Errorf("app saw a body of %d bytes, want the %d sent",
-			len(saw.body), len(body))
-	}
-}
-
-// wantAnswer checks that the client received the app's answer unchanged.
-func wantAnswer(t *testing.T, got answer, body []byte) {
-	t.Helper()
-
-	wantStatus(t, got, http.StatusTeapot)
-
-	if got.header.Get("X-App") != "yes" {
-		t.Errorf("client got X-App %q", got.header.Get("X-App"))
-	}
-
-	if !slices.Equal(got.header.Values("Set-Cookie"), []string{"a=1", "b=2"}) {
-		t.Errorf("client got Set-Cookie %q", got.header.Values("Set-Cookie"))
-	}
-
-	if got.err != nil || !bytes.Equal(got.body, body) {
-		t.Errorf("client got %d bytes (%v), want the %d the app sent",
-			len(got.body), got.err, len(body))
-	}
-}
-
-// wantRequestFields checks the log line's fields about the request. Its
-// time, its id and its timings are checked only for being there.
-func wantRequestFields(t *testing.T, line logLine, host string, sent, received int) {
-	t.Helper()
-
-	bytes := float64(sent + received)
-
-	want := withTimings(line, requestlog.Line{
-		Type: requestType, Time: line.Time, Instance: "app",
-		ClientIP: localhost, Method: http.MethodPatch, Scheme: plain, Host: host,
-		Path: rawPath, Query: rawQuery, Protocol: protocol,
-		Status: http.StatusTeapot, RequestBytes: int64(sent),
-		ResponseBytes: int64(received), UserAgent: "test-agent",
-		RequestID: line.RequestID, PeerIP: localhost, ClientGroup: localhost + "/32",
-		ContentLength: int64(sent), ResponseContentType: "text/plain; charset=utf-8",
-		UpstreamStatus: http.StatusTeapot, Action: requestlog.ActionForward,
-		Counts: ratelimit.Counts{
-			Minute: 1, Hour: 1, Day: 1,
-			MinuteBytes: bytes, HourBytes: bytes, DayBytes: bytes,
-		},
-	})
-	if !reflect.DeepEqual(line.Line, want) {
-		t.Errorf("log line\n%+v\nwant\n%+v", line.Line, want)
-	}
-
-	_, err := time.Parse(time.RFC3339, line.Time)
-	if err != nil || line.RequestID == "" || line.DurationTotal <= 0 ||
-		line.DurationUpstreamTotal == nil || *line.DurationUpstreamTotal <= 0 {
-		t.Errorf("log line has time %q, request_id %q and durations %v and %v",
-			line.Time, line.RequestID, line.DurationTotal,
-			line.fields["duration_upstream_total"])
-	}
-}
-
-func TestStreamsTheRequestBody(t *testing.T) {
-	t.Parallel()
-
-	chunk := bytes.Repeat([]byte("x"), chunkSize)
-	firstArrived := make(chan struct{})
-
-	app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
-		first := make([]byte, len(chunk))
-
-		_, err := io.ReadFull(r.Body, first)
-		if err != nil {
-			return
-		}
-
-		close(firstArrived)
-
-		rest, _ := io.ReadAll(r.Body)
-		_, _ = w.Write(rest)
-	})
-	addr, _ := startProxy(t, app.URL, nil)
-
-	body, writer := io.Pipe()
-
-	go func() {
-		_, _ = writer.Write(chunk)
-
-		select {
-		case <-firstArrived:
-			_, _ = writer.Write(chunk)
-			_ = writer.Close()
-		case <-time.After(waitLimit):
-			_ = writer.CloseWithError(errNotStreamed)
-		}
-	}()
-
-	got := do(t, newRequest(t, http.MethodPost, addr, "/upload", body))
-	if got.err != nil || !bytes.Equal(got.body, chunk) {
-		t.Errorf("app read %d bytes after the first part (%v), want %d",
-			len(got.body), got.err, len(chunk))
-	}
-}
-
-func TestStreamsTheAnswerBody(t *testing.T) {
-	t.Parallel()
-
-	chunk := bytes.Repeat([]byte("y"), chunkSize)
-	firstArrived := make(chan struct{})
-
-	app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
-		_, _ = w.Write(chunk)
-		_ = http.NewResponseController(w).Flush()
-
-		select {
-		case <-firstArrived:
-			_, _ = w.Write(chunk)
-		case <-time.After(waitLimit):
-		}
-	})
-	addr, _ := startProxy(t, app.URL, nil)
-
-	req := newRequest(t, http.MethodGet, addr, "/download", http.NoBody)
-
-	res, err := newClient(t).Do(req)
-	if err != nil {
-		t.Fatalf("request: %v", err)
-	}
-
-	first := make([]byte, len(chunk))
-	_, err = io.ReadFull(res.Body, first)
-
-	close(firstArrived)
-
-	got := readAnswer(res)
-	if err != nil || got.err != nil || !bytes.Equal(got.body, chunk) {
-		t.Errorf("client read %d bytes after the first part (%v, %v), want %d",
-			len(got.body), err, got.err, len(chunk))
-	}
-}
-
-func TestUpgradedConnectionOutlastsTheTimeouts(t *testing.T) {
-	t.Parallel()
-
-	app := startApp(t, echoAfterUpgrade)
-	addr, out := startProxy(t, app.URL, map[string]string{
-		clientRequestTimeout:    shortTimeoutSetting,
-		clientResponseTimeout:   shortTimeoutSetting,
-		upstreamRequestTimeout:  shortTimeoutSetting,
-		upstreamResponseTimeout: shortTimeoutSetting,
-	})
-
-	conn := dial(t, addr)
-	send(t, conn, "GET /socket HTTP/1.1\r\nHost: app\r\n"+
-		"Connection: Upgrade\r\nUpgrade: websocket\r\n\r\n")
-
-	reader := bufio.NewReader(conn)
-
-	res, err := http.ReadResponse(reader, nil)
-	if err != nil {
-		t.Fatalf("read the answer to the upgrade: %v", err)
-	}
-
-	answered := time.Now()
-	_ = res.Body.Close()
-
-	if res.StatusCode != http.StatusSwitchingProtocols {
-		t.Fatalf("status %d, want %d", res.StatusCode, http.StatusSwitchingProtocols)
-	}
-
-	// Every timeout started before the upgrade was answered, the response
-	// timeouts last, at the end of the request: wait until just past
-	// shortTimeout after the answer was read, then use the connection.
-	time.Sleep(time.Until(answered.Add(shortTimeout + 100*time.Millisecond)))
-	send(t, conn, "still here\n")
-
-	echoed, err := reader.ReadString('\n')
-	if err != nil || echoed != "still here\n" {
-		t.Errorf("echo %q (%v), want %q", echoed, err, "still here\n")
-	}
-
-	_ = conn.Close()
-
-	wantLine(t, out.requestLine(t), http.StatusSwitchingProtocols,
-		requestlog.ActionForward)
-}
-
-// echoAfterUpgrade is an app that switches protocols on request, and then
-// sends back each line it receives.
-func echoAfterUpgrade(w http.ResponseWriter, r *http.Request) {
-	if r.Header.Get("Upgrade") != "websocket" {
-		http.Error(w, "not an upgrade", http.StatusBadRequest)
-
-		return
-	}
-
-	conn, buffered, err := http.NewResponseController(w).Hijack()
-	if err != nil {
-		return
-	}
-
-	defer func() {
-		_ = conn.Close()
-	}()
-
-	_, _ = buffered.WriteString("HTTP/1.1 101 Switching Protocols\r\n" +
-		"Connection: Upgrade\r\nUpgrade: websocket\r\n\r\n")
-	_ = buffered.Flush()
-
-	for {
-		line, err := buffered.ReadString('\n')
-		if err != nil {
-			return
-		}
-
-		_, _ = buffered.WriteString(line)
-		_ = buffered.Flush()
-	}
-}
-
-func TestServerHasTheDefaultLimits(t *testing.T) {
-	t.Parallel()
-
-	cfg, err := config.FromEnvironment(func(string) (string, bool) { return "", false })
-	if err != nil {
-		t.Fatalf("default settings: %v", err)
-	}
-
-	server := proxy.New(proxy.Params{
-		Config:     cfg,
-		RequestLog: io.Discard,
-		ProcessLog: requestlog.NewProcessLogger(io.Discard, cfg.InstanceName, cfg.LogLevel),
-	})
-
-	if server.Addr != ":8080" || server.MaxHeaderBytes != 28<<10 ||
-		server.IdleTimeout != 2*time.Minute || server.ReadHeaderTimeout != time.Minute {
-		t.Errorf("server listens on %q with header limit %d, idle time %s and "+
-			"header timeout %s", server.Addr, server.MaxHeaderBytes,
-			server.IdleTimeout, server.ReadHeaderTimeout)
-	}
-}
-
-func TestRefusesHeadersOverTheLimit(t *testing.T) {
-	t.Parallel()
-
-	for _, tc := range []struct {
-		name  string
-		env   map[string]string
-		limit int
-	}{
-		{"by default", nil, 32 << 10},
-		{"as set", map[string]string{clientHeaderMaxBytes: "8K"}, 8 << 10},
-	} {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			var calls atomic.Int32
-
-			app := startApp(t, func(http.ResponseWriter, *http.Request) {
-				calls.Add(1)
-			})
-			addr, _ := startProxy(t, app.URL, tc.env)
-
-			// size counts every byte of the request: the request line,
-			// the headers and the blank line that ends them.
-			const (
-				start = "GET / HTTP/1.1\r\nHost: app\r\nX-Large: "
-				end   = "\r\n\r\n"
-			)
-
-			for _, sent := range []struct{ size, want int }{
-				{tc.limit, http.StatusOK},
-				{tc.limit + 1, http.StatusRequestHeaderFieldsTooLarge},
-			} {
-				conn := dial(t, addr)
-				send(t, conn,
-					start+strings.Repeat("a", sent.size-len(start)-len(end))+end)
-				wantStatus(t, readResponse(t, conn), sent.want)
-			}
-
-			if calls.Load() != 1 {
-				t.Errorf("the app was called %d times, want once", calls.Load())
-			}
-		})
-	}
-}
-
-func TestAnswers502WhenTheAppCannotBeReached(t *testing.T) {
-	t.Parallel()
-
-	// No test can listen on port 1: listening on port 0 gets one from 32768 up.
-	addr, out := startProxy(t, "http://"+localhost+":1", nil)
-
-	wantStatus(t, get(t, addr, "/"), http.StatusBadGateway)
-
-	line := out.requestLine(t)
-	wantLine(t, line, http.StatusBadGateway, requestlog.ActionUpstreamError)
-
-	// There never was a connection to the app, nor an answer from it.
-	wantTimings(t, line, "duration_total", "duration_checks",
-		"duration_upstream_total")
-
-	logged := slices.ContainsFunc(out.lines(t), func(line map[string]any) bool {
-		return line["type"] == "process" && line["msg"] == "request to the app failed"
-	})
-	if !logged {
-		t.Errorf("no process line says the request to the app failed")
-	}
-}
-
-func TestLogLevelHoldsBackNoRequestLine(t *testing.T) {
-	t.Parallel()
-
-	// At error the warning that the request to the app failed is held back,
-	// and is written before the answer is.
-	addr, out := startProxy(t, "http://"+localhost+":1", map[string]string{
-		"SWWAF_LOG_LEVEL": "error",
-	})
-
-	wantStatus(t, get(t, addr, "/"), http.StatusBadGateway)
-	wantLine(t, out.requestLine(t), http.StatusBadGateway, requestlog.ActionUpstreamError)
-
-	for _, line := range out.lines(t) {
-		if line["type"] == "process" {
-			t.Errorf("process line %v, want none at error", line)
-		}
-	}
-}
-
-func TestLogsAnAnswerThatBrokeOff(t *testing.T) {
-	t.Parallel()
-
-	app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
-		_, _ = io.WriteString(w, "the first part")
-		_ = http.NewResponseController(w).Flush()
-
-		panic(http.ErrAbortHandler) // drops the connection mid-answer
-	})
-	addr, out := startProxy(t, app.URL, nil)
-
-	got := get(t, addr, "/")
-	if string(got.body) != "the first part" || !errors.Is(got.err, io.ErrUnexpectedEOF) {
-		t.Errorf("client read %q (%v), want the first part cut off", got.body, got.err)
-	}
-
-	wantLine(t, out.requestLine(t), http.StatusOK, requestlog.ActionUpstreamError)
-}
-
-func TestLogsAClientThatWentAway(t *testing.T) {
-	t.Parallel()
-
-	arrived := make(chan struct{})
-
-	app := startApp(t, func(_ http.ResponseWriter, r *http.Request) {
-		close(arrived)
-		<-r.Context().Done()
-	})
-	addr, out := startProxy(t, app.URL, nil)
-
-	conn := dial(t, addr)
-	send(t, conn, "GET /slow HTTP/1.1\r\nHost: app\r\n\r\n")
-
-	select {
-	case <-arrived:
-	case <-time.After(waitLimit):
-		t.Fatal("the request never reached the app")
-	}
-
-	_ = conn.Close()
-
-	line := out.requestLine(t)
-	if !line.Aborted || line.Status != 0 || line.Action != requestlog.ActionForward {
-		t.Errorf("log line has aborted %v, status %d and action %q, "+
-			"want true, 0 and %q",
-			line.Aborted, line.Status, line.Action, requestlog.ActionForward)
-	}
-}

internal/proxy/request.go

@@ -1,848 +0,0 @@
-package proxy
-
-import (
-	"context"
-	"errors"
-	"io"
-	"net/http"
-	"net/http/httptrace"
-	"net/http/httputil"
-	"net/netip"
-	"net/url"
-	"os"
-	"slices"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"time"
-
-	"sneak.berlin/go/smallwebwaf/internal/anomaly"
-	"sneak.berlin/go/smallwebwaf/internal/bans"
-	"sneak.berlin/go/smallwebwaf/internal/config"
-	"sneak.berlin/go/smallwebwaf/internal/lookup"
-	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
-	"sneak.berlin/go/smallwebwaf/internal/requestlog"
-)
-
-// flushAfterEachWrite has ReverseProxy pass on each part of the app's
-// answer as soon as it arrives.
-const flushAfterEachWrite time.Duration = -1
-
-// refusal is smallwebwaf refusing a request, or refusing to go on with it:
-// the status the client is answered if the response has not started yet,
-// 0 to close the connection without an answer, the action the log line
-// names, and the setting whose size or time limit the request passed, if
-// that is why.
-type refusal struct {
-	status int
-	action string
-	limit  string
-}
-
-// request is one request on its way through smallwebwaf, from the moment
-// its headers have been read to its log line.
-type request struct {
-	h  *handler
-	in *http.Request
-	// rc sets the deadlines of the connection to the client.
-	rc   *http.ResponseController
-	out  *responseWriter
-	body *requestBody // nil for a request without a body
-	line requestlog.Line
-
-	client      netip.Addr
-	peer        netip.Addr
-	peerTrusted bool
-	// lookedUp is true once the client's AS number and country have been
-	// looked up, whether or not an answer was there, and lookupAnswer is
-	// what the lookup gave then, the zero Answer while GeoJS had given none.
-	lookedUp     bool
-	lookupAnswer lookup.Answer
-	// counted is true for a request the rate limits counted, whose bytes
-	// the byte limits count once it has ended. limitPercent and
-	// bytesPercent are then its client's limit percentages for the rate
-	// limits and for the byte limits.
-	counted                    bool
-	limitPercent, bytesPercent percentage
-	// attack is true for a request that matched a ban rule or asked for a
-	// trap path, ruleBlocked for one a block rule refused, wafBlocked for
-	// one the Core Rule Set refused, and tokenRefused for one refused for a
-	// missing or wrong token, each an offence its client's history counts.
-	attack, ruleBlocked, wafBlocked, tokenRefused bool
-	// blocklisted is true once a blocklist is found to list the client,
-	// dnsblListed once a DNSBL zone's verdict is, and abuseIPDBHit once
-	// AbuseIPDB's score of it is a hit.
-	blocklisted, dnsblListed, abuseIPDBHit bool
-	// reputation is the reputation sources that list the client, for the
-	// notes of a ban the request makes.
-	reputation []bans.ReputationHit
-	start      time.Time
-	// checked is when the checks were done, and upstreamStart when the
-	// request was handed to the app.
-	checked       time.Time
-	upstreamStart time.Time
-	// cancel ends the request to the app.
-	cancel context.CancelFunc
-	// refused is the first refusal, from whichever goroutine meets it.
-	refused atomic.Pointer[refusal]
-	// complete is true once the app's whole answer has been passed on.
-	complete bool
-	// upgraded is the connection to the app once the app has switched
-	// protocols, as for a WebSocket, and nil otherwise.
-	upgraded *upgradedConn
-
-	// mu guards what follows. The timeouts run on goroutines of their
-	// own, and the transport starts and stops them, and notes the times
-	// below, from its own; once timersStopped is set, none of the timeouts
-	// acts any more.
-	mu                    sync.Mutex
-	timersStopped         bool
-	clientRequestTimer    *time.Timer
-	upstreamRequestTimer  *time.Timer
-	upstreamResponseTimer *time.Timer
-	// connected is when there was a connection to the app, requestSent
-	// when the app had been sent the whole request, and answerStarted
-	// when the first byte of its answer arrived.
-	connected     time.Time
-	requestSent   time.Time
-	answerStarted time.Time
-}
-
-// newRequest starts handling r: it notes the time, counts the request as
-// under way, works out the client, and starts the log line with what is
-// known of the request.
-func (h *handler) newRequest(w http.ResponseWriter, r *http.Request) *request {
-	h.metrics.RequestStarted()
-
-	start := time.Now()
-	peer := peerAddress(r)
-	trusted := h.config.TrustedProxies
-	peerTrusted := isInside(peer, trusted)
-	forwardedFor := r.Header.Values("X-Forwarded-For")
-	client := clientAddress(peer, forwardedFor, trusted)
-
-	rq := &request{
-		h:           h,
-		in:          r,
-		rc:          http.NewResponseController(w),
-		out:         &responseWriter{ResponseWriter: w},
-		client:      client,
-		peer:        peer,
-		peerTrusted: peerTrusted,
-		start:       start,
-		line: requestlog.Line{
-			Time:             requestlog.FormatTime(start),
-			Instance:         h.config.InstanceName,
-			ClientIP:         client.String(),
-			Method:           r.Method,
-			Scheme:           scheme(r, peerTrusted),
-			Host:             r.Host,
-			Path:             r.URL.EscapedPath(),
-			Query:            r.URL.RawQuery,
-			Protocol:         r.Proto,
-			Referer:          r.Referer(),
-			UserAgent:        r.UserAgent(),
-			RequestID:        requestID(r, peerTrusted),
-			PeerIP:           peer.String(),
-			ForwardedFor:     strings.Join(forwardedFor, ", "),
-			ClientGroup:      h.clientGroup(client).String(),
-			ContentType:      r.Header.Get("Content-Type"),
-			RequestHeaders:   requestHeaders(r, h.config.LogRequestHeaders),
-			HasAuthorization: len(r.Header.Values("Authorization")) > 0,
-			HasCookie:        len(r.Header.Values("Cookie")) > 0,
-			Action:           requestlog.ActionForward,
-		},
-	}
-
-	// A length of -1 is a body whose length was not announced.
-	if r.ContentLength > 0 {
-		rq.line.ContentLength = r.ContentLength
-	}
-
-	if r.Body != http.NoBody {
-		rq.body = &requestBody{body: limitBody(r.Body, h.config.RequestMaxBytes), rq: rq}
-	}
-
-	return rq
-}
-
-// requestHeaders returns the headers of r that names lists, by name in
-// lower case, each with its values joined by ", ". Authorization, Cookie
-// and Set-Cookie are never among them, whatever names says.
-func requestHeaders(r *http.Request, names []string) map[string]string {
-	headers := map[string]string{}
-
-	for _, name := range names {
-		switch name {
-		case "authorization", "cookie", "set-cookie":
-			continue
-		}
-
-		values := r.Header.Values(name)
-		if len(values) > 0 {
-			headers[name] = strings.Join(values, ", ")
-		}
-	}
-
-	return headers
-}
-
-// check is the one place where a request can be refused once its client
-// is known, before anything reaches the app, and before its body is read,
-// but for the part the Core Rule Set reads. It returns nil to let the
-// request through. The checks of checkClient come first, answered with
-// SWWAF_BAN_RESPONSE, or 403 for a block rule or the Core Rule Set, and
-// then the size limit, so that a request the rate limits count is counted
-// even when it is refused for its size. In observe mode a request
-// checkClient refuses goes on to the size limit like any other. A size or
-// time limit the Core Rule Set's reading of the body meets ends the
-// request in either mode. ctx is the request's own context.
-func (rq *request) check(ctx context.Context) *refusal {
-	action := rq.checkClient(ctx)
-
-	refused := rq.refused.Load()
-	if refused != nil {
-		return refused
-	}
-
-	switch {
-	case action == "":
-	case rq.h.config.Observe:
-		// The log line names what enforce mode would have done.
-		rq.line.WouldAction = action
-	case action == requestlog.ActionRuleBlocked || action == requestlog.ActionWAFBlocked:
-		return &refusal{status: http.StatusForbidden, action: action}
-	default:
-		return rq.banResponse(action)
-	}
-
-	maxBytes := rq.h.config.RequestMaxBytes
-	if maxBytes > 0 && rq.in.ContentLength > maxBytes {
-		return &refusal{
-			status: http.StatusRequestEntityTooLarge,
-			action: requestlog.ActionTooLarge,
-			limit:  "SWWAF_REQUEST_MAX_BYTES",
-		}
-	}
-
-	return nil
-}
-
-// checkClient runs the checks on the request's client, and returns the
-// action of the first that refuses the request, or "" when none does. A
-// client in SWWAF_ALLOW_NETS skips them, and is not looked up. For any
-// other client, SWWAF_DENY_NETS comes first, then a ban on its netblock,
-// so that a client either refuses is not looked up, then the lookup of
-// its AS number and country, then the country lists, then the blocklists,
-// then the CrowdSec decision list, which bans the client it lists, then
-// the DNSBL zones' verdicts, and then AbuseIPDB's score; a request any of
-// them refuses is not counted for the rate limits. Then come the
-// rate limits, unless the client is in SWWAF_RATE_LIMIT_EXEMPT_NETS or the
-// request's path is exempt under SWWAF_RATE_LIMIT_EXEMPT_PATHS, so that
-// every other request is counted, each of them by the client's limit
-// percentages, then SWWAF_TRAP_PATHS, then the rule files, and last the
-// Core Rule Set. A request exempt from the rate limits is exempt from the
-// byte limits too. ctx is the request's own context.
-func (rq *request) checkClient(ctx context.Context) string {
-	cfg := rq.h.config
-	if isInside(rq.client, cfg.AllowNets) {
-		return ""
-	}
-
-	now := rq.h.now()
-
-	if isInside(rq.client, cfg.DenyNets) {
-		return requestlog.ActionDenied
-	}
-
-	if rq.banned(now) {
-		return requestlog.ActionBanned
-	}
-
-	rq.lookUp(ctx)
-
-	// The lookup can wait for GeoJS, so the checks after it read the time
-	// again: a request counted at the time it arrived could be counted
-	// after a later one of its client's, which the rate limits would take
-	// for the clock set back.
-	now = rq.h.now()
-
-	if rq.countryDenied() {
-		return requestlog.ActionCountryDenied
-	}
-
-	if rq.blocklistDenied() {
-		return requestlog.ActionDenied
-	}
-
-	if rq.crowdSecBanned(now) {
-		return requestlog.ActionBanned
-	}
-
-	if rq.dnsblDenied(ctx) || rq.abuseIPDBDenied(ctx) {
-		return requestlog.ActionDenied
-	}
-
-	rq.counted = !isInside(rq.client, cfg.RateLimitExemptNets) &&
-		!pathExempt(rq.in.URL, cfg.RateLimitExemptPaths)
-	if rq.counted {
-		rq.limitPercent, rq.bytesPercent = rq.limitPercentages()
-		rq.line.LimitPercent, rq.line.LimitPercentSetting = rq.limitPercent.logged()
-		rq.line.BytesPercent, rq.line.BytesPercentSetting = rq.bytesPercent.logged()
-	}
-
-	if rq.counted && rq.limitBroken(now) {
-		return requestlog.ActionRateLimited
-	}
-
-	if rq.trapPath(now) {
-		return requestlog.ActionBanned
-	}
-
-	action := rq.checkRules(now)
-	if action != "" {
-		return action
-	}
-
-	return rq.checkCoreRuleSet()
-}
-
-// pathExempt reports whether a request for u is exempt under prefixes,
-// SWWAF_RATE_LIMIT_EXEMPT_PATHS or SWWAF_WAF_EXEMPT_PATHS: whether its
-// path as sent, the path the app receives, not percent-decoded, starts
-// with one of prefixes, so that /%61ssets/x is not under /assets/ for an
-// app whose router matches the path as received. A request whose decoded
-// path contains .. anywhere or a backslash, or whose path as sent holds an
-// encoded slash (%2F or %2f), never is, since an app may act on it as a
-// path outside every prefix: /assets/..%2Flogin as /login, or /assets%2Fx
-// as one path segment, as Go's router does.
-func pathExempt(u *url.URL, prefixes []string) bool {
-	decoded := u.Path
-	// EscapedPath is the path as the app receives it, not decoded.
-	sent := u.EscapedPath()
-
-	if strings.Contains(decoded, "..") || strings.Contains(decoded, `\`) ||
-		strings.Contains(strings.ToLower(sent), "%2f") {
-		return false
-	}
-
-	return slices.ContainsFunc(prefixes, func(prefix string) bool {
-		return strings.HasPrefix(sent, prefix)
-	})
-}
-
-// forward passes the request to the app and the app's answer back. ctx
-// is the request's own context.
-func (rq *request) forward(ctx context.Context) {
-	ctx, cancel := context.WithCancel(ctx)
-	defer cancel()
-
-	rq.cancel = cancel
-	ctx = httptrace.WithClientTrace(ctx, &httptrace.ClientTrace{
-		GotConn:              rq.gotConn,
-		WroteRequest:         rq.wroteRequest,
-		GotFirstResponseByte: rq.gotFirstResponseByte,
-	})
-
-	out := rq.in.WithContext(ctx)
-	if rq.body != nil {
-		out.Body = rq.body
-	}
-
-	reverseProxy := &httputil.ReverseProxy{
-		Rewrite:        rq.rewrite,
-		Transport:      rq.h.transport,
-		FlushInterval:  flushAfterEachWrite,
-		ErrorLog:       rq.h.errorLog,
-		ModifyResponse: rq.modifyResponse,
-		ErrorHandler:   rq.answerError,
-	}
-
-	rq.startRequestTimers()
-	rq.upstreamStart = time.Now()
-	reverseProxy.ServeHTTP(rq.out, out)
-}
-
-// rewrite makes the request the app receives: the client's request,
-// unchanged, sent to SWWAF_UPSTREAM_URL, with the forwarded headers and
-// the request's id set, without any X-Client-ASN or X-Client-Country the
-// client sent, whatever SWWAF_ADD_LOOKUP_HEADERS says, and, while it is
-// set, with the client's AS number and country in them.
-func (rq *request) rewrite(pr *httputil.ProxyRequest) {
-	upstream := rq.h.config.UpstreamURL
-	pr.Out.URL.Scheme = upstream.Scheme
-	pr.Out.URL.Host = upstream.Host
-	// ReverseProxy drops query parameters it cannot parse; the app gets
-	// the query as the client sent it.
-	pr.Out.URL.RawQuery = pr.In.URL.RawQuery
-	setForwardedHeaders(pr.In, pr.Out, rq.peer, rq.peerTrusted)
-	pr.Out.Header.Set(requestIDHeader, rq.line.RequestID)
-	pr.Out.Header.Del(asnHeader)
-	pr.Out.Header.Del(countryHeader)
-
-	if rq.h.config.AddLookupHeaders {
-		setLookupHeaders(pr.Out.Header, rq.line.ASN, rq.line.Country)
-	}
-}
-
-// modifyResponse looks at the app's answer before ReverseProxy passes it
-// on.
-func (rq *request) modifyResponse(res *http.Response) error {
-	rq.line.UpstreamStatus = res.StatusCode
-
-	if res.StatusCode == http.StatusSwitchingProtocols {
-		// An upgraded connection, such as a WebSocket, is not cut by the
-		// timeouts. ReverseProxy writes this answer straight to the
-		// connection it takes over, not through rq.out, and then copies
-		// what passes each way through res.Body, the connection to the app.
-		rq.stopTimers()
-		rq.out.status = res.StatusCode
-		rq.line.Websocket = true
-
-		conn, ok := res.Body.(io.ReadWriteCloser)
-		if ok {
-			rq.upgraded = &upgradedConn{ReadWriteCloser: conn}
-			res.Body = rq.upgraded
-		}
-
-		return nil
-	}
-
-	maxBytes := rq.h.config.ResponseMaxBytes
-	if maxBytes > 0 && res.Body != http.NoBody && res.ContentLength > maxBytes {
-		rq.refuse(refusal{
-			status: http.StatusBadGateway,
-			action: requestlog.ActionTooLarge,
-			limit:  "SWWAF_RESPONSE_MAX_BYTES",
-		})
-
-		return errResponseTooLarge
-	}
-
-	res.Body = &responseBody{body: limitBody(res.Body, maxBytes), rq: rq}
-	rq.startClientResponseTimeout()
-
-	return nil
-}
-
-// answerError is ReverseProxy's ErrorHandler: the request could not be
-// passed to the app, or the app's answer cannot be passed on.
-func (rq *request) answerError(_ http.ResponseWriter, _ *http.Request, err error) {
-	refused := rq.refused.Load()
-	if refused == nil {
-		if rq.in.Context().Err() != nil {
-			return // the client has gone, and there is no one to answer
-		}
-
-		rq.h.processLog.Warn("request to the app failed", "error", err.Error())
-
-		refused = &refusal{
-			status: http.StatusBadGateway,
-			action: requestlog.ActionUpstreamError,
-		}
-	}
-
-	rq.answer(*refused)
-}
-
-// answer sends smallwebwaf's own answer, unless the response has already
-// started, and records the refusal for the log line.
-func (rq *request) answer(r refusal) {
-	rq.refused.CompareAndSwap(nil, &r)
-
-	if rq.out.status != 0 {
-		return // too late to answer: the connection can only be cut
-	}
-
-	if r.status == 0 {
-		// SWWAF_BAN_RESPONSE is close. This panic has Go's server close
-		// the connection without an answer, and log nothing; the log line
-		// is still written as the handler returns.
-		panic(http.ErrAbortHandler)
-	}
-
-	// A client found too slow is read no more; any other may go on
-	// sending until its time is up, so that Go's server can read the
-	// rest of the body and end the request cleanly.
-	deadline := rq.clientRequestDeadline()
-	if r.status == http.StatusRequestTimeout {
-		deadline = time.Now()
-	}
-
-	rq.stopReadingBody(deadline)
-
-	timeout := rq.h.config.ClientResponseTimeout
-	if timeout > 0 {
-		_ = rq.rc.SetWriteDeadline(time.Now().Add(timeout))
-	}
-
-	http.Error(rq.out, http.StatusText(r.status), r.status)
-}
-
-// refuse records r, unless an earlier refusal was, and ends the request
-// to the app, if one was made: smallwebwaf reads the body of a request
-// it answers itself too.
-func (rq *request) refuse(r refusal) {
-	rq.refused.CompareAndSwap(nil, &r)
-
-	if rq.cancel != nil {
-		rq.cancel()
-	}
-}
-
-// finish ends the request's timeouts, counts it in the metrics and writes
-// its log line.
-func (rq *request) finish() {
-	rq.stopTimers()
-
-	refused := rq.refused.Load()
-	if refused == nil {
-		rq.stopReadingBody(rq.clientRequestDeadline())
-	}
-
-	line := &rq.line
-	line.Status = rq.out.status
-	line.ResponseBytes = rq.out.bytes
-	header := rq.out.Header()
-	line.ResponseContentType = header.Get("Content-Type")
-	line.CacheControl = header.Get("Cache-Control")
-	line.Location = header.Get("Location")
-	line.RequestBytes = rq.requestBytes()
-
-	// limit is the setting whose size or time limit the request passed.
-	var limit string
-
-	switch {
-	case refused != nil:
-		line.Action = refused.action
-		limit = refused.limit
-	case errors.Is(rq.out.err, os.ErrDeadlineExceeded):
-		// The client took longer than SWWAF_CLIENT_RESPONSE_TIMEOUT to
-		// take the response.
-		line.Action = requestlog.ActionTimedOut
-		limit = "SWWAF_CLIENT_RESPONSE_TIMEOUT"
-	case !rq.complete && (rq.out.err != nil || rq.in.Context().Err() != nil):
-		line.Aborted = true
-	}
-
-	now := time.Now()
-	duration := now.Sub(rq.start)
-	line.DurationTotal = requestlog.Milliseconds(duration)
-	line.DurationChecks = timing(rq.start, rq.checked)
-
-	var upstreamDuration time.Duration
-
-	if !rq.upstreamStart.IsZero() {
-		upstreamDuration = now.Sub(rq.upstreamStart)
-		line.DurationUpstreamTotal = new(requestlog.Milliseconds(upstreamDuration))
-
-		rq.mu.Lock()
-		line.DurationUpstreamConnect = timing(rq.upstreamStart, rq.connected)
-		line.DurationUpstreamFirstByte = timing(rq.upstreamStart, rq.answerStarted)
-		rq.mu.Unlock()
-	}
-
-	// Counted before the log line is written, so that the metrics count
-	// every request whose line is out.
-	rq.h.metrics.RequestEnded(line, limit, duration, upstreamDuration)
-
-	err := requestlog.Write(rq.h.requestLog, line)
-	if err != nil {
-		rq.h.processLog.Error("writing the request log failed", "error", err.Error())
-	}
-}
-
-// timing is the time from start to end in milliseconds, for one of the
-// log line's timings, or nil when end is zero: what it times never
-// happened.
-func timing(start, end time.Time) *float64 {
-	if end.IsZero() {
-		return nil
-	}
-
-	return new(requestlog.Milliseconds(end.Sub(start)))
-}
-
-// addToHistory adds the request, which has ended, to its client's
-// history, and counts its offences in the metrics, and then the lookup's
-// answer about the client, as answerAtTheEnd gives it, to that history and
-// to the notes of the bans on its netblock: an answer may have come
-// before either was there, and one from GeoJS that comes later is added
-// when it comes.
-func (rq *request) addToHistory() {
-	forwarded := !rq.upstreamStart.IsZero()
-	request := ratelimit.Request{
-		Forwarded:     forwarded,
-		Refused:       !forwarded && rq.refused.Load() != nil,
-		Status:        rq.out.status,
-		RequestBytes:  rq.requestBytes(),
-		ResponseBytes: rq.out.bytes,
-		BrokeLimit:    rq.line.Offence == requestlog.OffenceLimit,
-		Attack:        rq.attack,
-		RuleBlocked:   rq.ruleBlocked,
-		WAFBlocked:    rq.wafBlocked,
-		TokenRefused:  rq.tokenRefused,
-	}
-
-	rq.h.limiter.AddToHistory(rq.h.clientGroup(rq.client), rq.h.now(), request)
-	rq.h.metrics.Offences(request)
-
-	answer, found := rq.answerAtTheEnd()
-	if found {
-		rq.h.addLookup(answer)
-	}
-}
-
-// countAnomalies counts the request, which has ended, and its bytes, as
-// countedBytes gives them, for the anomaly thresholds, whatever was done
-// with it: a request refused, one from a client in SWWAF_ALLOW_NETS or
-// SWWAF_RATE_LIMIT_EXEMPT_NETS, and one for a path in
-// SWWAF_RATE_LIMIT_EXEMPT_PATHS are counted too. It is counted for its
-// client's AS number when answerAtTheEnd gives one. With every anomaly
-// threshold off, the default, it does nothing.
-func (rq *request) countAnomalies() {
-	if !anomalyThresholdsSet(rq.h.config) {
-		return
-	}
-
-	answer, _ := rq.answerAtTheEnd()
-
-	rq.h.anomalies.Count(rq.h.now(), anomaly.Request{
-		Client:      rq.client,
-		ClientGroup: rq.h.clientGroup(rq.client),
-		ASN:         answer.ASN,
-		ASName:      answer.ASName,
-		Country:     answer.Country,
-		Bytes:       rq.countedBytes(),
-	})
-}
-
-// anomalyThresholdsSet reports whether any anomaly threshold is set.
-func anomalyThresholdsSet(cfg *config.Config) bool {
-	off := anomaly.Thresholds{}
-
-	return cfg.AnomalyClient != off || cfg.AnomalyNet != off || cfg.AnomalyASN != off ||
-		cfg.AnomalyTotal != off || cfg.AnomalyWatch != off
-}
-
-// answerAtTheEnd returns, for a client that was looked up, the lookup's
-// answer about it as the request ends, and whether there is one: the
-// lookup database's, which was there at once, or the one GeoJS has given
-// by then, which a request does not wait for unless a setting needs it.
-func (rq *request) answerAtTheEnd() (lookup.Answer, bool) {
-	if !rq.lookedUp {
-		return lookup.Answer{}, false
-	}
-
-	if rq.h.config.LookupSource == "file" {
-		return rq.lookupAnswer, true
-	}
-
-	return rq.h.geojs.Kept(rq.h.clientGroup(rq.client))
-}
-
-// requestBytes is how many bytes of the request's body have been read.
-func (rq *request) requestBytes() int64 {
-	if rq.body == nil {
-		return 0
-	}
-
-	return rq.body.bytes.Load()
-}
-
-// clientRequestDeadline is when the client must have sent its whole
-// request, or zero when SWWAF_CLIENT_REQUEST_TIMEOUT is off.
-func (rq *request) clientRequestDeadline() time.Time {
-	timeout := rq.h.config.ClientRequestTimeout
-	if timeout == 0 {
-		return time.Time{}
-	}
-
-	return rq.start.Add(timeout)
-}
-
-// stopReadingBody ends, at deadline, the reading of a client body that has
-// not arrived whole: Go's server then reads no more of it, and closes the
-// connection after the answer.
-func (rq *request) stopReadingBody(deadline time.Time) {
-	if rq.body == nil || rq.body.received.Load() {
-		return
-	}
-
-	_ = rq.rc.SetReadDeadline(deadline)
-}
-
-// startRequestTimers starts the timeouts that run while the request goes
-// to the app: SWWAF_CLIENT_REQUEST_TIMEOUT until the client has sent its
-// whole body, and SWWAF_UPSTREAM_REQUEST_TIMEOUT until the app has been
-// sent the whole request.
-func (rq *request) startRequestTimers() {
-	rq.mu.Lock()
-	defer rq.mu.Unlock()
-
-	if rq.body != nil && rq.h.config.ClientRequestTimeout > 0 {
-		rq.clientRequestTimer = time.AfterFunc(
-			time.Until(rq.clientRequestDeadline()), func() {
-				rq.requestTimedOut("SWWAF_CLIENT_REQUEST_TIMEOUT")
-			})
-	}
-
-	timeout := rq.h.config.UpstreamRequestTimeout
-	if timeout > 0 {
-		rq.upstreamRequestTimer = time.AfterFunc(timeout, func() {
-			rq.requestTimedOut("SWWAF_UPSTREAM_REQUEST_TIMEOUT")
-		})
-	}
-}
-
-// requestTimedOut is called when limit, SWWAF_CLIENT_REQUEST_TIMEOUT or
-// SWWAF_UPSTREAM_REQUEST_TIMEOUT, runs out while the request is still on
-// its way to the app. The answer names the side smallwebwaf was waiting
-// on at that moment: 408 when it was waiting for the client to send more
-// of its body, 504 when it was waiting for the app to be reached or to
-// take what it had.
-func (rq *request) requestTimedOut(limit string) {
-	rq.mu.Lock()
-	defer rq.mu.Unlock()
-
-	if rq.timersStopped {
-		return
-	}
-
-	if rq.body == nil || !rq.body.waiting.Load() {
-		rq.refuse(refusal{
-			status: http.StatusGatewayTimeout,
-			action: requestlog.ActionTimedOut,
-			limit:  limit,
-		})
-
-		return
-	}
-
-	rq.refuse(refusal{
-		status: http.StatusRequestTimeout,
-		action: requestlog.ActionTimedOut,
-		limit:  limit,
-	})
-	// The transport gives up on the app only once its Read of the
-	// client's body returns, so that Read is ended now. The lock keeps
-	// this from reaching the connection after the request is handled.
-	_ = rq.rc.SetReadDeadline(time.Now())
-}
-
-// bodyReceived is called once the client has sent its whole body.
-func (rq *request) bodyReceived() {
-	rq.mu.Lock()
-	defer rq.mu.Unlock()
-
-	stopTimer(rq.clientRequestTimer)
-}
-
-// gotConn is called once there is a connection to the app, a new one or
-// one kept open from an earlier request.
-func (rq *request) gotConn(httptrace.GotConnInfo) {
-	rq.mu.Lock()
-	defer rq.mu.Unlock()
-
-	rq.connected = time.Now()
-}
-
-// gotFirstResponseByte is called once the first byte of the app's answer
-// has arrived.
-func (rq *request) gotFirstResponseByte() {
-	rq.mu.Lock()
-	defer rq.mu.Unlock()
-
-	rq.answerStarted = time.Now()
-}
-
-// wroteRequest is called once the app has been sent the whole request:
-// the request timeouts end and SWWAF_UPSTREAM_RESPONSE_TIMEOUT starts.
-func (rq *request) wroteRequest(info httptrace.WroteRequestInfo) {
-	if info.Err != nil {
-		return // the transport gives up, or tries again
-	}
-
-	rq.mu.Lock()
-	defer rq.mu.Unlock()
-
-	if rq.timersStopped {
-		return
-	}
-
-	stopTimer(rq.clientRequestTimer)
-	stopTimer(rq.upstreamRequestTimer)
-	rq.requestSent = time.Now()
-
-	timeout := rq.h.config.UpstreamResponseTimeout
-	if timeout > 0 {
-		rq.upstreamResponseTimer = time.AfterFunc(timeout, rq.responseTimedOut)
-	}
-}
-
-// responseTimedOut is called when SWWAF_UPSTREAM_RESPONSE_TIMEOUT runs out
-// before the app has sent its whole answer.
-func (rq *request) responseTimedOut() {
-	rq.mu.Lock()
-	defer rq.mu.Unlock()
-
-	if !rq.timersStopped {
-		rq.refuse(refusal{
-			status: http.StatusGatewayTimeout,
-			action: requestlog.ActionTimedOut,
-			limit:  "SWWAF_UPSTREAM_RESPONSE_TIMEOUT",
-		})
-	}
-}
-
-// responseReceived is called once the app has sent its whole answer.
-func (rq *request) responseReceived() {
-	rq.complete = true
-	rq.stopTimers()
-}
-
-// startClientResponseTimeout sets SWWAF_CLIENT_RESPONSE_TIMEOUT on the
-// connection to the client: the response must reach the client within it
-// of the end of the request, or of now if the app answers before it has
-// the whole request.
-func (rq *request) startClientResponseTimeout() {
-	timeout := rq.h.config.ClientResponseTimeout
-	if timeout == 0 {
-		return
-	}
-
-	from := rq.sentAt()
-	if from.IsZero() {
-		from = time.Now()
-	}
-
-	_ = rq.rc.SetWriteDeadline(from.Add(timeout))
-}
-
-// sentAt is when the app had been sent the whole request, or zero.
-func (rq *request) sentAt() time.Time {
-	rq.mu.Lock()
-	defer rq.mu.Unlock()
-
-	return rq.requestSent
-}
-
-// stopTimers stops the request's timeouts and keeps any from starting
-// later: the app's answer is complete, the connection upgraded, or the
-// request handled.
-func (rq *request) stopTimers() {
-	rq.mu.Lock()
-	defer rq.mu.Unlock()
-
-	rq.timersStopped = true
-	stopTimer(rq.clientRequestTimer)
-	stopTimer(rq.upstreamRequestTimer)
-	stopTimer(rq.upstreamResponseTimer)
-}
-
-// stopTimer stops t, which is nil when its timeout is off.
-func stopTimer(t *time.Timer) {
-	if t != nil {
-		t.Stop()
-	}
-}

internal/proxy/timeouts_test.go

@@ -1,307 +0,0 @@
-package proxy_test
-
-import (
-	"errors"
-	"io"
-	"net"
-	"net/http"
-	"net/http/httptest"
-	"strconv"
-	"sync"
-	"sync/atomic"
-	"testing"
-	"time"
-
-	"sneak.berlin/go/smallwebwaf/internal/requestlog"
-)
-
-// largeBodySize is more than the connections between the client,
-// smallwebwaf and the app can hold while nobody reads, so that a sender
-// soon waits.
-const largeBodySize = 64 << 20
-
-// writeSize is how much a test sender writes at a time.
-const writeSize = 32 << 10
-
-func TestRequestTimeouts(t *testing.T) {
-	t.Parallel()
-
-	for _, tc := range []struct {
-		name string
-		// limit is the setting set to shortTimeout, which runs out; long
-		// is one set to longTimeoutSetting, which does not, or "".
-		limit, long string
-		// appTakesNothing has the app never read, while the client sends
-		// as fast as it can; otherwise the app reads, and the client
-		// stops sending halfway.
-		appTakesNothing bool
-		want            int
-	}{
-		{
-			name:  "client request timeout, waiting on the client",
-			limit: clientRequestTimeout,
-			want:  http.StatusRequestTimeout,
-		},
-		{
-			name:  "upstream request timeout, waiting on the client",
-			limit: upstreamRequestTimeout,
-			long:  clientRequestTimeout,
-			want:  http.StatusRequestTimeout,
-		},
-		{
-			name:            "upstream request timeout, waiting on the app",
-			limit:           upstreamRequestTimeout,
-			appTakesNothing: true,
-			want:            http.StatusGatewayTimeout,
-		},
-		{
-			name:            "client request timeout, waiting on the app",
-			limit:           clientRequestTimeout,
-			long:            upstreamRequestTimeout,
-			appTakesNothing: true,
-			want:            http.StatusGatewayTimeout,
-		},
-	} {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			var (
-				app         *httptest.Server
-				appURL      string
-				sendRequest func(*testing.T, string) net.Conn
-				appGotBody  atomic.Bool
-			)
-
-			if tc.appTakesNothing {
-				appURL, sendRequest = startAppThatTakesNothing(t), sendLargeBody
-			} else {
-				app = startApp(t, func(_ http.ResponseWriter, r *http.Request) {
-					n, _ := io.Copy(io.Discard, r.Body)
-					appGotBody.Store(n > 0)
-				})
-				appURL, sendRequest = app.URL, sendPartOfBody
-			}
-
-			env := map[string]string{tc.limit: shortTimeoutSetting, metricsToken: token}
-			if tc.long != "" {
-				env[tc.long] = longTimeoutSetting
-			}
-
-			addr, out := startProxy(t, appURL, env)
-			start := time.Now()
-			got := readResponse(t, sendRequest(t, addr))
-			wantTimedOut(t, start)
-
-			want := tc.want
-
-			if app != nil {
-				// Close returns once the app has finished with the request.
-				app.Close()
-
-				// Until some of the body has reached the app, smallwebwaf
-				// waits on the app, and SPEC.md asks for 504; the timeout
-				// runs out then only if the test process is held up.
-				if !appGotBody.Load() {
-					want = http.StatusGatewayTimeout
-				}
-			}
-
-			wantStatus(t, got, want)
-			wantLine(t, out.requestLine(t), want, requestlog.ActionTimedOut)
-			wantLimitHits(t, addr, tc.limit, 1)
-		})
-	}
-}
-
-// startAppThatTakesNothing starts an app that accepts connections and
-// never reads from them, and returns its URL.
-func startAppThatTakesNothing(t *testing.T) string {
-	t.Helper()
-
-	listener, err := (&net.ListenConfig{}).Listen(t.Context(), "tcp", localhost+":0")
-	if err != nil {
-		t.Fatalf("listen: %v", err)
-	}
-
-	var (
-		mu   sync.Mutex
-		held []net.Conn
-	)
-
-	hold := func(conn net.Conn) {
-		mu.Lock()
-		defer mu.Unlock()
-
-		held = append(held, conn)
-	}
-
-	go func() {
-		for {
-			conn, err := listener.Accept()
-			if err != nil {
-				return
-			}
-
-			hold(conn)
-		}
-	}()
-
-	t.Cleanup(func() {
-		_ = listener.Close()
-
-		mu.Lock()
-		defer mu.Unlock()
-
-		for _, conn := range held {
-			_ = conn.Close()
-		}
-	})
-
-	return "http://" + listener.Addr().String()
-}
-
-// sendPartOfBody sends a request that announces a large body, and only
-// the first bytes of it.
-func sendPartOfBody(t *testing.T, addr string) net.Conn {
-	t.Helper()
-
-	conn := dial(t, addr)
-	send(t, conn, "POST /upload HTTP/1.1\r\nHost: app\r\nContent-Length: "+
-		strconv.Itoa(largeBodySize)+"\r\n\r\nthe first bytes")
-
-	return conn
-}
-
-// sendLargeBody sends a request with a large body, as fast as smallwebwaf
-// takes it, from a goroutine of its own.
-func sendLargeBody(t *testing.T, addr string) net.Conn {
-	t.Helper()
-
-	conn := dial(t, addr)
-	send(t, conn, "POST /upload HTTP/1.1\r\nHost: app\r\nContent-Length: "+
-		strconv.Itoa(largeBodySize)+"\r\n\r\n")
-
-	go func() {
-		chunk := make([]byte, writeSize)
-		for range largeBodySize / writeSize {
-			_, err := conn.Write(chunk)
-			if err != nil {
-				return
-			}
-		}
-	}()
-
-	return conn
-}
-
-func TestAppTooSlowToAnswer(t *testing.T) {
-	t.Parallel()
-
-	app := startApp(t, func(_ http.ResponseWriter, r *http.Request) {
-		<-r.Context().Done()
-	})
-	addr, out := startProxy(t, app.URL, map[string]string{
-		upstreamResponseTimeout: shortTimeoutSetting,
-		metricsToken:            token,
-	})
-
-	start := time.Now()
-
-	wantStatus(t, get(t, addr, "/slow"), http.StatusGatewayTimeout)
-	wantTimedOut(t, start)
-
-	line := out.requestLine(t)
-	wantLine(t, line, http.StatusGatewayTimeout, requestlog.ActionTimedOut)
-
-	_, answered := line.fields["upstream_status"]
-	if answered {
-		t.Errorf("log line has upstream_status %v for an app that never answered",
-			line.fields["upstream_status"])
-	}
-
-	wantLimitHits(t, addr, upstreamResponseTimeout, 1)
-}
-
-func TestAppTooSlowToFinishItsAnswer(t *testing.T) {
-	t.Parallel()
-
-	app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
-		_, _ = io.WriteString(w, "the first part")
-		_ = http.NewResponseController(w).Flush()
-
-		<-r.Context().Done()
-	})
-	addr, out := startProxy(t, app.URL, map[string]string{
-		upstreamResponseTimeout: shortTimeoutSetting,
-	})
-
-	start := time.Now()
-	got := get(t, addr, "/slow")
-	wantStatus(t, got, http.StatusOK)
-
-	if string(got.body) != "the first part" || !errors.Is(got.err, io.ErrUnexpectedEOF) {
-		t.Errorf("client read %q (%v), want the first part cut off", got.body, got.err)
-	}
-
-	wantTimedOut(t, start)
-
-	line := out.requestLine(t)
-	wantLine(t, line, http.StatusOK, requestlog.ActionTimedOut)
-
-	if line.UpstreamStatus != http.StatusOK {
-		t.Errorf("log line has upstream_status %d, want %d",
-			line.UpstreamStatus, http.StatusOK)
-	}
-}
-
-func TestClientTooSlowToTakeTheAnswer(t *testing.T) {
-	t.Parallel()
-
-	app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
-		chunk := make([]byte, writeSize)
-		for range largeBodySize / writeSize {
-			_, err := w.Write(chunk)
-			if err != nil {
-				return
-			}
-		}
-	})
-	addr, out := startProxy(t, app.URL, map[string]string{
-		clientResponseTimeout: shortTimeoutSetting,
-		metricsToken:          token,
-	})
-
-	start := time.Now()
-
-	// The client asks, and never reads the answer.
-	conn := dial(t, addr)
-	send(t, conn, "GET /large HTTP/1.1\r\nHost: app\r\n\r\n")
-
-	line := out.requestLine(t)
-	wantTimedOut(t, start)
-	wantLine(t, line, http.StatusOK, requestlog.ActionTimedOut)
-	wantLimitHits(t, addr, clientResponseTimeout, 1)
-}
-
-func TestClosesAnIdleConnection(t *testing.T) {
-	t.Parallel()
-
-	app := startApp(t, func(http.ResponseWriter, *http.Request) {})
-	addr, _ := startProxy(t, app.URL, map[string]string{
-		clientIdleTimeout: shortTimeoutSetting,
-	})
-
-	// The idle time starts once the answer is sent, so after start.
-	start := time.Now()
-	conn := dial(t, addr)
-	send(t, conn, "GET / HTTP/1.1\r\nHost: app\r\n\r\n")
-	wantStatus(t, readResponse(t, conn), http.StatusOK)
-
-	// The read deadline readResponse set still bounds this read.
-	_, err := conn.Read(make([]byte, 1))
-	if !errors.Is(err, io.EOF) {
-		t.Fatalf("read on the idle connection: %v, want it closed", err)
-	}
-
-	wantTimedOut(t, start)
-}

internal/ratelimit/history_test.go

@@ -23,8 +23,8 @@ func TestHistoryKeepsEveryRequest(t *testing.T) {
 		{Forwarded: true, Status: 502, ResponseBytes: 12},
 		// Closed without an answer: refused, and no response.
 		{Refused: true, Status: 0},
-		// Answered 404 at smallwebwaf's own endpoints: neither forwarded
+		// Answered 404 for a path under /_sww/: neither forwarded nor
-		// nor refused.
+		// refused.
 		{Status: 404},
 	} {
 		limiter.AddToHistory(client, start.Add(time.Duration(i)*time.Minute), r)

internal/ratelimit/ratelimit.go

@@ -2,7 +2,7 @@
 // and bytes counted over a minute, an hour and a day, as the "Counting
 // method" section of SPEC.md describes, which tell when a request takes
 // the client over a rate limit or a byte limit, and each client's history
-// since it was first seen. At most SWWAF_MAX_TRACKED_CLIENTS clients are
+// since it was first seen. At most SWW_MAX_TRACKED_CLIENTS clients are
 // kept, in memory, and written to clients.json and read from it by the
 // state package.
 package ratelimit
@@ -25,7 +25,7 @@ const (
 	KindRequests = "requests"
 	// KindBytes is a byte limit, on a client's bytes.
 	KindBytes = "bytes"
-	// KindRefusals is the error burst, on a client's requests smallwebwaf
+	// KindRefusals is the error burst, on a client's requests sww
 	// refused after a rule file match or for a missing or wrong token.
 	KindRefusals = "refusals"
 )
@@ -92,10 +92,9 @@ type History struct {
 	ASName   string    `json:"as_name,omitempty"`
 	Country  string    `json:"country,omitempty"`
 	LookedUp time.Time `json:"looked_up,omitzero"`
-	// Requests are all the client's requests: Forwarded those passed to
+	// Requests are all the client's requests: Forwarded those discriminator allowed,
-	// the app, Refused those refused before anything reached it, a 401 at
+	// Refused those it refused, and neither those for a path under
-	// smallwebwaf's own endpoints included, and neither the others
+	// /_sww/.
-	// smallwebwaf answered there.
 	Requests  int64 `json:"requests"`
 	Forwarded int64 `json:"forwarded"`
 	Refused   int64 `json:"refused"`
@@ -124,21 +123,20 @@ type Offences struct {
 	// Limit is its requests that broke a rate limit, a byte limit or the
 	// error burst, Attack those that were a clear sign of attack, a match
 	// of a ban rule or a request for a trap path, RuleBlocked those a block
-	// rule refused, WAFBlocked those the Core Rule Set refused, and
+	// rule refused, and WAFBlocked those the Core Rule Set refused.
-	// TokenRefused those refused for a missing or wrong token.
 	Limit       int64 `json:"limit"`
 	Attack      int64 `json:"attack"`
 	RuleBlocked int64 `json:"rule_blocked"`
 	WAFBlocked  int64 `json:"waf_blocked"`
-	TokenRefused int64 `json:"token_refused"`
+	// TokenRefused is what a clients.json written by an earlier version gives,
+	// which must still load. Nothing adds to it.
+	TokenRefused int64 `json:"token_refused,omitempty"`
 }
 
 // Request is what a client's history keeps of one of its requests.
 type Request struct {
-	// Forwarded is true for a request passed to the app, Refused for one
+	// Forwarded is true for a request discriminator allowed, and Refused for one it
-	// refused before anything reached it, a 401 at smallwebwaf's own
+	// refused. Both are false for a request for a path under /_sww/.
-	// endpoints included. Both are false for any other request smallwebwaf
-	// answered there.
 	Forwarded bool
 	Refused   bool
 	// Status is what the client was sent, 0 if nothing was.
@@ -149,18 +147,16 @@ type Request struct {
 	ResponseBytes int64
 	// BrokeLimit is true for a request that broke a rate limit, a byte
 	// limit or the error burst, Attack for one that matched a ban rule or
-	// asked for a trap path, RuleBlocked for one a block rule refused,
+	// asked for a trap path, RuleBlocked for one a block rule refused, and
-	// WAFBlocked for one the Core Rule Set refused, and TokenRefused for
+	// WAFBlocked for one the Core Rule Set refused.
-	// one refused for a missing or wrong token.
 	BrokeLimit  bool
 	Attack      bool
 	RuleBlocked bool
 	WAFBlocked  bool
-	TokenRefused bool
 }
 
 // New returns a Limiter for limits, with no client counted yet, whose
-// table holds at most maxClients clients (SWWAF_MAX_TRACKED_CLIENTS). Past
+// table holds at most maxClients clients (SWW_MAX_TRACKED_CLIENTS). Past
 // it, the least recently seen client is dropped, with its history, and
 // starts afresh if it comes back.
 func New(limits Limits, maxClients int) *Limiter {
@@ -206,7 +202,7 @@ type Hit struct {
 // Counts are a client's requests and bytes in the minute, the hour and
 // the day that end at a request, that request's included.
 //
-//nolint:tagliatelle // SPEC.md's request log names its fields in snake_case
+//nolint:tagliatelle // docs/request-log.md names the fields in snake_case
 type Counts struct {
 	Minute      float64 `json:"minute"`
 	Hour        float64 `json:"hour"`
@@ -228,6 +224,30 @@ func (l *Limiter) Count(
 	return l.count(client, now, 1, 0, percent)
 }
 
+// OverARateLimit reports whether one more request from client at now would
+// take it over a whole rate limit. A client's percentage can only lower a
+// limit, so that request is over the limit at any percentage. It counts
+// nothing, and does not make the client the most recently seen.
+func (l *Limiter) OverARateLimit(client netip.Prefix, now time.Time) bool {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	c, seen := l.clients.Peek(client)
+	if !seen {
+		return false
+	}
+
+	buckets := c.buckets()
+
+	for i, w := range l.windows {
+		if w.limit > 0 && buckets[i].Add(now, w.length, 0)+1 > float64(w.limit) {
+			return true
+		}
+	}
+
+	return false
+}
+
 // CountBytes counts bytes, those of a request from client that has ended,
 // at now, in every window, and returns the client's counts in each window.
 // It reports whether the bytes take the client over a byte limit, of which
@@ -238,7 +258,7 @@ func (l *Limiter) CountBytes(
 	return l.count(client, now, 0, bytes, percent)
 }
 
-// CountRefusal counts a request from client at now that smallwebwaf
+// CountRefusal counts a request from client at now that sww
 // refused after a rule file or Core Rule Set match or for a missing or
 // wrong token, and reports whether the client's refusals in the minute
 // that ends at now, this one included, are more than threshold, which
@@ -310,10 +330,6 @@ func (l *Limiter) AddToHistory(client netip.Prefix, now time.Time, r Request) {
 	if r.WAFBlocked {
 		h.Offences.WAFBlocked++
 	}
-
-	if r.TokenRefused {
-		h.Offences.TokenRefused++
-	}
 }
 
 // AddLookup gives client's history its AS number, AS name and country, as

internal/ratelimit/ratelimit_test.go

@@ -13,7 +13,7 @@ import (
 const limit = 3
 
 // tableSize is the most clients the tests' tables hold, the default of
-// SWWAF_MAX_TRACKED_CLIENTS.
+// SWW_MAX_TRACKED_CLIENTS.
 const tableSize = 20000
 
 // whole is the percentage of each limit a client gets when nothing lowers
@@ -26,6 +26,50 @@ const (
 	hour   = "hour"
 )
 
+func TestOverARateLimitSaysWhatTheNextRequestWouldDoAndCountsNothing(t *testing.T) {
+	t.Parallel()
+
+	client := netip.MustParsePrefix("203.0.113.9/32")
+	now := midnight()
+	limiter := ratelimit.New(ratelimit.Limits{PerMinute: limit, PerDay: limit + 1},
+		tableSize)
+
+	if limiter.OverARateLimit(client, now) {
+		t.Error("a client never seen is over a rate limit")
+	}
+
+	if limiter.Len() != 0 {
+		t.Error("asking about a client never seen added it to the table")
+	}
+
+	for range limit {
+		if limiter.OverARateLimit(client, now) {
+			t.Error("a client with room for another request is over a rate limit")
+		}
+
+		wantCount(t, limiter, client, now, "")
+	}
+
+	if !limiter.OverARateLimit(client, now) {
+		t.Error("a client at its limit is not over a rate limit")
+	}
+
+	held, _ := limiter.Client(client)
+	if held.Minute.Current != limit {
+		t.Errorf("the client's minute holds %d requests, want %d", held.Minute.Current, limit)
+	}
+
+	wantCount(t, limiter, client, now, minute)
+
+	// A limit that is off is never gone over.
+	off := ratelimit.New(ratelimit.Limits{}, tableSize)
+	off.Count(client, now, whole)
+
+	if off.OverARateLimit(client, now) {
+		t.Error("a client is over a rate limit that is off")
+	}
+}
+
 func TestEachWindowRefusesAtItsLimitAndLetsTheClientBack(t *testing.T) {
 	t.Parallel()
 

internal/remotelog/remotelog.go

@@ -1,5 +1,5 @@
-// Package remotelog sends the lines smallwebwaf writes on stdout to the
+// Package remotelog sends the lines sww writes on stdout to the
-// remote log endpoint, SWWAF_LOG_REMOTE_URL, as the "Request log" section
+// remote log endpoint, SWW_LOG_REMOTE_URL, as the "Request log" section
 // of SPEC.md describes: each line as the message of an RFC 5424 syslog
 // record, over UDP, TCP or TLS. Lines wait in a bounded buffer, so a slow
 // or unreachable endpoint never holds up a request or stdout.
@@ -24,7 +24,7 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
 
-// The forms of SWWAF_LOG_REMOTE_URL, by its scheme.
+// The forms of SWW_LOG_REMOTE_URL, by its scheme.
 const (
 	SchemeUDP = "syslog+udp"
 	SchemeTCP = "syslog+tcp"
@@ -56,18 +56,18 @@ const (
 
 // Params are what New needs.
 type Params struct {
-	// URL is the endpoint (SWWAF_LOG_REMOTE_URL): SchemeUDP, SchemeTCP or
+	// URL is the endpoint (SWW_LOG_REMOTE_URL): SchemeUDP, SchemeTCP or
 	// SchemeTLS, a host and a port.
 	URL *url.URL
 	// RootCAs are the certificates a SchemeTLS endpoint's certificate
-	// must chain to (SWWAF_LOG_REMOTE_TLS_CA_FILE), nil for the host's.
+	// must chain to (SWW_LOG_REMOTE_TLS_CA_FILE), nil for the host's.
 	RootCAs *x509.CertPool
 	// Buffer is the most lines held while they wait to be sent
-	// (SWWAF_LOG_REMOTE_BUFFER).
+	// (SWW_LOG_REMOTE_BUFFER).
 	Buffer int
 	// Facility is the number of the records' syslog facility
-	// (SWWAF_LOG_REMOTE_FACILITY), and AppName their APP-NAME
+	// (SWW_LOG_REMOTE_FACILITY), and AppName their APP-NAME
-	// (SWWAF_LOG_REMOTE_APP_NAME).
+	// (SWW_LOG_REMOTE_APP_NAME).
 	Facility int
 	AppName  string
 }
@@ -243,7 +243,7 @@ func (s *Sender) send(ctx context.Context, processLog *slog.Logger) net.Conn {
 			}
 		}
 
-		processLog.Warn("sending to SWWAF_LOG_REMOTE_URL failed",
+		processLog.Warn("sending to SWW_LOG_REMOTE_URL failed",
 			"error", err.Error(), "connecting_again_in", delay.String())
 
 		select {

internal/remotelog/remotelog_test.go

@@ -44,7 +44,7 @@ import (
 const (
 	// started is the time a record made as a test starts gives.
 	started = "2000-01-01T00:00:00.000Z"
-	appName = "fsn1app1/gitea"
+	appName = "fsn1app1/blog"
 	// local0 is the number of the default facility, and local0Info the
 	// priority of its records.
 	local0     = 16
@@ -94,7 +94,7 @@ func TestRecordsOverTCPAreOctetCountedWithTheirFacility(t *testing.T) {
 		endpoint := listen(t)
 		endpointParams := params(remotelog.SchemeTCP, endpoint.Addr())
 		endpointParams.Facility = 19 // local3
-		endpointParams.AppName = "gitea"
+		endpointParams.AppName = "blog"
 		sender, _, _ := run(t, endpointParams)
 
 		_, _ = sender.Write([]byte("first\nsecond\n"))
@@ -103,8 +103,8 @@ func TestRecordsOverTCPAreOctetCountedWithTheirFacility(t *testing.T) {
 		wantCounts(t, sender, 2, 0, 0)
 
 		frames := bufio.NewReader(accept(t, endpoint))
-		wantFrame(t, frames, record(t, "<158>", "gitea", "first"))
+		wantFrame(t, frames, record(t, "<158>", "blog", "first"))
-		wantFrame(t, frames, record(t, "<158>", "gitea", "second"))
+		wantFrame(t, frames, record(t, "<158>", "blog", "second"))
 	})
 }
 
@@ -586,7 +586,7 @@ func wantRetries(t *testing.T, logged *output, delays ...string) {
 		var fields map[string]any
 
 		err := json.Unmarshal([]byte(line), &fields)
-		if err != nil || fields["msg"] != "sending to SWWAF_LOG_REMOTE_URL failed" {
+		if err != nil || fields["msg"] != "sending to SWW_LOG_REMOTE_URL failed" {
 			t.Fatalf("logged %q", line)
 		}
 
@@ -612,7 +612,7 @@ func testCertificate(t *testing.T) (tls.Certificate, *x509.CertPool) {
 
 	template := &x509.Certificate{
 		SerialNumber:          big.NewInt(1),
-		Subject:               pkix.Name{CommonName: "smallwebwaf test CA"},
+		Subject:               pkix.Name{CommonName: "sww test CA"},
 		NotBefore:             time.Date(1999, 12, 31, 0, 0, 0, 0, time.UTC),
 		NotAfter:              time.Date(2000, 1, 2, 0, 0, 0, 0, time.UTC),
 		IsCA:                  true,

internal/reputation/abuseipdb.go

@@ -58,17 +58,17 @@ type Checks struct {
 // AbuseIPDBParams are what NewAbuseIPDB needs.
 type AbuseIPDBParams struct {
 	// URL is where clients are checked, normally AbuseIPDBURL, with Key,
-	// the account's key (SWWAF_ABUSEIPDB_KEY).
+	// the account's key (SWW_ABUSEIPDB_KEY).
 	URL string
 	Key string
-	// MinScore is the least score that is a hit (SWWAF_ABUSEIPDB_MIN_SCORE),
+	// MinScore is the least score that is a hit (SWW_ABUSEIPDB_MIN_SCORE),
 	// and DailyBudget the most checks made in a day, in UTC
-	// (SWWAF_ABUSEIPDB_DAILY_BUDGET).
+	// (SWW_ABUSEIPDB_DAILY_BUDGET).
 	MinScore    int64
 	DailyBudget int
 	// CacheTTL is how long a score is used after it was fetched
-	// (SWWAF_REPUTATION_CACHE_TTL), and Timeout how long a check may take
+	// (SWW_REPUTATION_CACHE_TTL), and Timeout how long a check may take
-	// (SWWAF_REPUTATION_TIMEOUT).
+	// (SWW_REPUTATION_TIMEOUT).
 	CacheTTL time.Duration
 	Timeout  time.Duration
 	// Now tells the time, normally time.Now in UTC.

internal/reputation/abuseipdb_test.go

@@ -397,7 +397,7 @@ func TestMetricsCountTheChecksTheFailuresAndTheBudgetLeft(t *testing.T) {
 			"failures_total":         "1",
 			"daily_budget_remaining": "3",
 		} {
-			line := "\nsmallwebwaf_reputation_" + series +
+			line := "\nsww_reputation_" + series +
 				`{instance="app",source="abuseipdb"} ` + want + "\n"
 			if !strings.Contains(scraped, line) {
 				t.Errorf("metrics\n%s\nwant%s", scraped, line)
@@ -581,7 +581,7 @@ func wantScore(
 
 // hitFrom is checker's Hit for a request from address, offender or not.
 // Its client is address for an IPv4 address, and its /64 for an IPv6 one,
-// as smallwebwaf counts clients.
+// as sww counts clients.
 func hitFrom(
 	t *testing.T, checker *reputation.AbuseIPDB, address string, offender bool,
 ) (int64, bool) {

internal/reputation/dnsbl.go

@@ -53,15 +53,15 @@ type Verdict struct {
 // DNSBLParams are what NewDNSBL needs.
 type DNSBLParams struct {
 	// Zones are the DNSBL zones clients are asked about in
-	// (SWWAF_DNSBL_ZONES).
+	// (SWW_DNSBL_ZONES).
 	Zones []string
 	// Resolver is the resolver they are asked through
-	// (SWWAF_DNSBL_RESOLVER), or, while it is the zero AddrPort, the
+	// (SWW_DNSBL_RESOLVER), or, while it is the zero AddrPort, the
 	// host's, as /etc/resolv.conf names it.
 	Resolver netip.AddrPort
 	// CacheTTL is how long a verdict is used after it was fetched
-	// (SWWAF_REPUTATION_CACHE_TTL), and Timeout how long a query may take
+	// (SWW_REPUTATION_CACHE_TTL), and Timeout how long a query may take
-	// (SWWAF_REPUTATION_TIMEOUT).
+	// (SWW_REPUTATION_TIMEOUT).
 	CacheTTL time.Duration
 	Timeout  time.Duration
 	// Now tells the time, normally time.Now in UTC.
@@ -127,13 +127,13 @@ func NewDNSBL(params DNSBLParams) *DNSBL {
 	}
 }
 
-// Zones returns the zones, in the order SWWAF_DNSBL_ZONES names them.
+// Zones returns the zones, in the order SWW_DNSBL_ZONES names them.
 func (d *DNSBL) Zones() []string {
 	return slices.Clone(d.params.Zones)
 }
 
 // ListedBy returns the zones whose verdict on addr, a client's address,
-// lists it, in the order SWWAF_DNSBL_ZONES names them, each with its key
+// lists it, in the order SWW_DNSBL_ZONES names them, each with its key
 // masked, as config.MaskZoneKey masks it, since they go to the request
 // log, the alerts and the metrics. A verdict is used until CacheTTL has
 // passed since it was fetched. Each zone without one is asked about addr
@@ -210,7 +210,7 @@ func (d *DNSBL) Snapshot() []Verdict {
 }
 
 // Load keeps verdicts, read from reputation.json, in place of those it
-// keeps, but for those of a zone SWWAF_DNSBL_ZONES does not name, and,
+// keeps, but for those of a zone SWW_DNSBL_ZONES does not name, and,
 // past maxVerdicts, those fetched longest ago. One fetched CacheTTL ago or
 // more is neither used nor written, as for any verdict.
 func (d *DNSBL) Load(verdicts []Verdict) {

internal/reputation/dnsbl_test.go

@@ -40,8 +40,8 @@ const (
 	// zone and otherZone are the DNSBL zones the tests name.
 	zone      = "dnsbl.example"
 	otherZone = "other.example"
-	// cacheTTL is the tests' SWWAF_REPUTATION_CACHE_TTL, and timeout their
+	// cacheTTL is the tests' SWW_REPUTATION_CACHE_TTL, and timeout their
-	// SWWAF_REPUTATION_TIMEOUT: a second, the least time /etc/resolv.conf
+	// SWW_REPUTATION_TIMEOUT: a second, the least time /etc/resolv.conf
 	// can have Go's resolver wait for one server, so that it is the
 	// DNSBL's own timeout that ends a query, whatever that file says.
 	cacheTTL = 24 * time.Hour
@@ -311,7 +311,7 @@ func TestMetricsCountEachZonesQueriesAndThoseThatFailed(t *testing.T) {
 			"queries_total" + `{instance="app",source="` + otherZone + `"}`:  "1",
 			"failures_total" + `{instance="app",source="` + otherZone + `"}`: "1",
 		} {
-			line := "\nsmallwebwaf_reputation_" + series + " " + want + "\n"
+			line := "\nsww_reputation_" + series + " " + want + "\n"
 			if !strings.Contains(scraped.Body.String(), line) {
 				t.Errorf("metrics\n%s\nwant%s", scraped.Body.String(), line)
 			}
@@ -419,7 +419,7 @@ func TestNeitherAVerdictOfAZoneNotNamedNorOnePastItsTTLIsKept(t *testing.T) {
 	dnsbl := reputation.NewDNSBL(p)
 
 	// The last verdict still in use, one fetched a TTL ago, and one of a
-	// zone SWWAF_DNSBL_ZONES does not name.
+	// zone SWW_DNSBL_ZONES does not name.
 	inUse := reputation.Verdict{
 		Zone: zone, Client: netip.MustParseAddr(listed), Listed: true,
 		Fetched: now.Add(-cacheTTL + time.Nanosecond),
@@ -471,7 +471,7 @@ func TestAtMost100000VerdictsKeptTheOneFetchedLongestAgoDroppedFirst(t *testing.
 }
 
 //nolint:paralleltest // one at a time, as the comment at the top of this file says
-func TestQueriesGoToTheResolverSWWAFDNSBLResolverNames(t *testing.T) {
+func TestQueriesGoToTheResolverSWWDNSBLResolverNames(t *testing.T) {
 	resolver := &resolverStandIn{answers: map[string]answer{
 		listedName: {addrs: []string{listing}},
 	}}

internal/reputation/reputation.go

@@ -1,10 +1,10 @@
 // Package reputation fetches the lists the settings name by URL: the
-// blocklists of SWWAF_BLOCKLIST_URLS, the file of AS:percent lines
+// blocklists of SWW_BLOCKLIST_URLS, the file of AS:percent lines
-// SWWAF_ASN_LIMIT_PERCENT_URL names, and the decision list of the CrowdSec
+// SWW_ASN_LIMIT_PERCENT_URL names, and the decision list of the CrowdSec
-// engine SWWAF_CROWDSEC_LAPI_URL names. It keeps the last good copy of
+// engine SWW_CROWDSEC_LAPI_URL names. It keeps the last good copy of
 // each, whole, comment lines included, which is used while a fetch fails,
 // and when each was last tried. It also asks the DNSBL zones of
-// SWWAF_DNSBL_ZONES about clients, and keeps their verdicts, and checks
+// SWW_DNSBL_ZONES about clients, and keeps their verdicts, and checks
 // clients with AbuseIPDB, and keeps their scores and the checks spent
 // today. The state package writes all of these to reputation.json and
 // reads them from it, so that a restart keeps them too.
@@ -66,18 +66,18 @@ type List struct {
 
 // Params are what New needs.
 type Params struct {
-	// BlocklistURLs are the blocklists (SWWAF_BLOCKLIST_URLS), and
+	// BlocklistURLs are the blocklists (SWW_BLOCKLIST_URLS), and
 	// ASNLimitPercentURL the file of AS:percent lines
-	// (SWWAF_ASN_LIMIT_PERCENT_URL), "" while it is unset.
+	// (SWW_ASN_LIMIT_PERCENT_URL), "" while it is unset.
 	BlocklistURLs      []string
 	ASNLimitPercentURL string
 	// CrowdSecDecisionsURL is the CrowdSec decision list, "" while
-	// SWWAF_CROWDSEC_LAPI_URL is unset, fetched with CrowdSecKey
+	// SWW_CROWDSEC_LAPI_URL is unset, fetched with CrowdSecKey
-	// (SWWAF_CROWDSEC_LAPI_KEY).
+	// (SWW_CROWDSEC_LAPI_KEY).
 	CrowdSecDecisionsURL string
 	CrowdSecKey          string
 	// Refresh is how long after a list was last fetched or tried it is
-	// fetched again (SWWAF_BLOCKLIST_REFRESH), but for the CrowdSec decision
+	// fetched again (SWW_BLOCKLIST_REFRESH), but for the CrowdSec decision
 	// list, which is fetched again crowdSecRefresh after.
 	Refresh time.Duration
 	// Now tells the time, normally time.Now in UTC.
@@ -152,7 +152,7 @@ func New(params Params) *Lists {
 }
 
 // URLs returns the URL of every list: the blocklists' in the order
-// SWWAF_BLOCKLIST_URLS names them, then SWWAF_ASN_LIMIT_PERCENT_URL, then
+// SWW_BLOCKLIST_URLS names them, then SWW_ASN_LIMIT_PERCENT_URL, then
 // the CrowdSec decision list's.
 func (l *Lists) URLs() []string {
 	urls := slices.Clone(l.params.BlocklistURLs)
@@ -168,7 +168,7 @@ func (l *Lists) URLs() []string {
 }
 
 // ListedBy returns the URLs of the blocklists whose copy lists addr, in
-// the order SWWAF_BLOCKLIST_URLS names them.
+// the order SWW_BLOCKLIST_URLS names them.
 func (l *Lists) ListedBy(addr netip.Addr) []string {
 	l.mu.Lock()
 	defer l.mu.Unlock()
@@ -371,7 +371,7 @@ func (l *Lists) due(listURL string) time.Time {
 // fetch fetches the list at listURL, and notes the try. A good copy takes
 // the place of the one held. A failure leaves that in use, and is counted,
 // logged and raised as a source_failure alert. A fetch cut off as ctx
-// ends, as smallwebwaf stops, is no failure, but is still noted as a try,
+// ends, as sww stops, is no failure, but is still noted as a try,
 // so that a restart waits for it: the server may have had its request.
 func (l *Lists) fetch(ctx context.Context, listURL string) {
 	lines, err := l.get(ctx, listURL)
@@ -551,7 +551,7 @@ func parseNetblock(text string) (netip.Prefix, bool) {
 }
 
 // parsePercents reads the lines of the file of AS:percent lines, each an
-// AS number, : and a percentage, as SWWAF_ASN_LIMIT_PERCENT takes them. An
+// AS number, : and a percentage, as SWW_ASN_LIMIT_PERCENT takes them. An
 // AS number listed more than once gets the lowest of its percentages.
 func parsePercents(lines []string) (entries, error) {
 	found := entries{percents: map[string]int64{}}

internal/reputation/reputation_test.go

@@ -34,8 +34,8 @@ const (
 	dropURL = "https://lists.example/drop.txt"
 	torURL  = "https://lists.example/tor.txt"
 	asnURL  = "https://lists.example/asn.txt"
-	// refresh is the tests' SWWAF_BLOCKLIST_REFRESH, and cooldown their
+	// refresh is the tests' SWW_BLOCKLIST_REFRESH, and cooldown their
-	// SWWAF_ALERT_COOLDOWN, longer than it.
+	// SWW_ALERT_COOLDOWN, longer than it.
 	refresh  = 24 * time.Hour
 	cooldown = 48 * time.Hour
 	// drop is a blocklist as the Spamhaus DROP list is written, with an
@@ -116,7 +116,7 @@ func TestClientIsListedByEachBlocklistThatListsIt(t *testing.T) {
 		}}
 		lists := start(t, servers, params(torURL, dropURL))
 
-		// In the order SWWAF_BLOCKLIST_URLS names them.
+		// In the order SWW_BLOCKLIST_URLS names them.
 		wantListedBy(t, lists, "203.0.113.9", torURL, dropURL)
 		wantListedBy(t, lists, "203.0.113.8", dropURL)
 	})

internal/requestlog/requestlog.go

@@ -1,6 +1,7 @@
-// Package requestlog writes the lines smallwebwaf prints on stdout: one
+// Package requestlog writes the lines sww prints on stdout: one
-// JSON object per request, marked "type":"request", and the process's own
+// JSON object per request, two from discriminator and a short one from rproxy,
-// messages as JSON lines marked "type":"process".
+// marked "type":"request", and the process's own messages as JSON lines marked
+// "type":"process".
 package requestlog
 
 import (
@@ -13,18 +14,13 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
 )
 
-// The action a request line names: what smallwebwaf did with the
+// The action a request line names: what discriminator did with the request.
-// request.
 const (
-	// ActionForward is a request passed to the app.
+	// ActionForward is a request discriminator allowed, which rproxy passes to
+	// the app.
 	ActionForward = "forward"
-	// ActionTooLarge is a request or response over its size limit.
+	// ActionTooLarge is a request over the header limits.
 	ActionTooLarge = "too_large"
-	// ActionTimedOut is a request or response that ran out of time.
-	ActionTimedOut = "timed_out"
-	// ActionUpstreamError is a request the app could not be reached
-	// for, or whose answer could not be passed on.
-	ActionUpstreamError = "upstream_error"
 	// ActionRateLimited is a request refused because it took its client
 	// over a rate limit, which bans the client.
 	ActionRateLimited = "rate_limited"
@@ -37,17 +33,17 @@ const (
 	// rule.
 	ActionRuleBlocked = "rule_blocked"
 	// ActionWAFBlocked is a request refused because the Core Rule Set
-	// scored it at or over SWWAF_WAF_ANOMALY_THRESHOLD.
+	// scored it at or over SWW_WAF_ANOMALY_THRESHOLD.
 	ActionWAFBlocked = "waf_blocked"
 	// ActionDenied is a request refused because its client is in
-	// SWWAF_DENY_NETS, in a blocklist while SWWAF_BLOCKLIST_ACTION is deny,
+	// SWW_DENY_NETS, in a blocklist while SWW_BLOCKLIST_ACTION is deny,
 	// or listed by a DNSBL zone, or scored a hit by AbuseIPDB, while
-	// SWWAF_REPUTATION_ACTION is deny.
+	// SWW_REPUTATION_ACTION is deny.
 	ActionDenied = "denied"
 	// ActionCountryDenied is a request refused for its client's country.
 	ActionCountryDenied = "country_denied"
-	// ActionAdmin is a request smallwebwaf answered at one of its own
+	// ActionAdmin is a request discriminator answered at one of its own
-	// endpoints, under /_smallwebwaf/.
+	// endpoints, or a question about a path under /_sww/.
 	ActionAdmin = "admin"
 )
 
@@ -60,20 +56,32 @@ const OffenceLimit = "limit"
 // that broke the error burst.
 const LimitHitErrorBurst = "error_burst"
 
+// The discriminator_line a request line names, which says which of
+// discriminator's two lines about a question it is.
+const (
+	// DiscriminatorLineDecision is discriminator's line at its decision.
+	DiscriminatorLineDecision = "decision"
+	// DiscriminatorLineReport is discriminator's line when rproxy's report
+	// comes, with the decision's fields and the report's together.
+	DiscriminatorLineReport = "report"
+)
+
 // timeLayout is RFC 3339 with milliseconds.
 const timeLayout = "2006-01-02T15:04:05.000Z07:00"
 
 // Line is one request's line in the request log. The field names, and
-// their order, are those of the "Request log" section of SPEC.md. A field
+// their order, are those of docs/request-log.md. A field that may not
-// that may not apply to a request is left out of its line when it does
+// apply to a request is left out of its line when it does not.
-// not.
 //
-//nolint:tagliatelle // SPEC.md's request log names its fields in snake_case
+//nolint:tagliatelle // docs/request-log.md names the fields in snake_case
 type Line struct {
 	Type string `json:"type"`
+	// DiscriminatorLine is DiscriminatorLineDecision or DiscriminatorLineReport
+	// on discriminator's two lines about a question.
+	DiscriminatorLine string `json:"discriminator_line,omitempty"`
 
-	// The standard web log fields. Scheme is how the client reached
+	// The standard web log fields. Scheme is how the client reached rproxy, or
-	// smallwebwaf, or the trusted proxy in front of it.
+	// the trusted proxy in front of it.
 	Time          string `json:"time"`
 	Instance      string `json:"instance"`
 	ClientIP      string `json:"client_ip"`
@@ -89,8 +97,8 @@ type Line struct {
 	Referer       string `json:"referer"`
 	UserAgent     string `json:"user_agent"`
 
-	// Request detail. RequestID is the X-Request-ID a trusted proxy sent,
+	// Request detail. RequestID is the id rproxy made for the request, or for a
-	// or a new one, and is sent on to the app. ForwardedFor is the
+	// request to discriminator's own endpoints a new one. ForwardedFor is the
 	// X-Forwarded-For header as received. ClientGroup is the netblock the
 	// client is counted as. ASN, ASName and Country are the client's AS
 	// number, AS name and country, as looked up.
@@ -104,22 +112,15 @@ type Line struct {
 	ContentType  string `json:"content_type,omitempty"`
 	// ContentLength is the length of its body the request announced.
 	ContentLength int64 `json:"content_length,omitempty"`
-	// RequestHeaders are the headers SWWAF_LOG_REQUEST_HEADERS names that
+	// RequestHeaders are the headers SWW_LOG_REQUEST_HEADERS names that
 	// the request carried, by name in lower case.
 	RequestHeaders   map[string]string `json:"request_headers,omitempty"`
 	HasAuthorization bool              `json:"has_authorization,omitempty"`
 	HasCookie        bool              `json:"has_cookie,omitempty"`
-	// Websocket is true when the connection was upgraded, as for a
-	// WebSocket.
-	Websocket bool `json:"websocket,omitempty"`
 
-	// Response detail, from the headers of the answer: the app's, as
+	// Response detail, of discriminator's own answer. Aborted is true when
-	// passed on, or those of smallwebwaf's own. Aborted is true when the
+	// rproxy, or the admin's tool, went away before the answer.
-	// client went away early.
 	ResponseContentType string `json:"response_content_type,omitempty"`
-	UpstreamStatus      int    `json:"upstream_status,omitempty"`
-	CacheControl        string `json:"cache_control,omitempty"`
-	Location            string `json:"location,omitempty"`
 	Aborted             bool   `json:"aborted,omitempty"`
 
 	// The decision.
@@ -127,7 +128,8 @@ type Line struct {
 	// WouldAction is, in observe mode, the action enforce mode would have
 	// taken with a request it would have refused: ActionDenied,
 	// ActionBanned, ActionCountryDenied, ActionRateLimited,
-	// ActionRuleBlocked or ActionWAFBlocked.
+	// ActionRuleBlocked, ActionWAFBlocked, or, in discriminator, ActionTooLarge
+	// for the header limits.
 	WouldAction string `json:"would_action,omitempty"`
 	// LimitPercent and LimitPercentSetting are, for a request the rate
 	// limits counted whose client a biased threshold gives a percentage of
@@ -168,23 +170,60 @@ type Line struct {
 
 	// The timings, in milliseconds. DurationChecks is the time until the
 	// checks were done, and DurationWAF the part of it the Core Rule Set
-	// took. DurationUpstreamConnect, DurationUpstreamFirstByte and
+	// took. DurationUpstreamTotal is what the report of an allowed request gives,
-	// DurationUpstreamTotal run from when the request was handed to the
+	// from the hand-over to the app until the end of its answer. Each but
-	// app: until there was a connection to it, until the first byte of its
+	// DurationTotal is nil for a request that did not get that far.
-	// answer arrived, and until the end. Each but DurationTotal is nil for
-	// a request that did not get that far.
 	DurationTotal         float64  `json:"duration_total"`
 	DurationChecks        *float64 `json:"duration_checks,omitempty"`
 	DurationWAF           *float64 `json:"duration_waf,omitempty"`
-	DurationUpstreamConnect   *float64 `json:"duration_upstream_connect,omitempty"`
-	DurationUpstreamFirstByte *float64 `json:"duration_upstream_first_byte,omitempty"`
 	DurationUpstreamTotal *float64 `json:"duration_upstream_total,omitempty"`
 }
 
+// RProxyLine is rproxy's short line in the request log about one request. The
+// field names, and their order, are those of docs/request-log.md. A field that
+// does not apply to a request is left out of its line.
+//
+//nolint:tagliatelle // docs/request-log.md names the fields in snake_case
+type RProxyLine struct {
+	Type          string `json:"type"`
+	Time          string `json:"time"`
+	RequestID     string `json:"request_id"`
+	ClientIP      string `json:"client_ip"`
+	Host          string `json:"host"`
+	Method        string `json:"method"`
+	Path          string `json:"path"`
+	Query         string `json:"query"`
+	Status        int    `json:"status"`
+	RequestBytes  int64  `json:"request_bytes"`
+	ResponseBytes int64  `json:"response_bytes"`
+	// DurationRequest runs in milliseconds from the request's headers being read
+	// until the app has been sent the whole request, or the answer has started
+	// if that is sooner. DurationResponse runs from then until the answer ends.
+	DurationRequest  float64 `json:"duration_request"`
+	DurationResponse float64 `json:"duration_response"`
+	// Disposition is the valid disposition discriminator answered or, while
+	// DefaultDisposition is true, the value of SWRP_DEFAULT_DISPOSITION. It is ""
+	// when neither gave one.
+	Disposition        string `json:"disposition,omitempty"`
+	DefaultDisposition bool   `json:"default_disposition,omitempty"`
+}
+
 // Write writes line to w as one JSON line marked "type":"request".
 func Write(w io.Writer, line *Line) error {
 	line.Type = "request"
 
+	return writeJSONLine(w, line)
+}
+
+// WriteRProxyLine writes line to w as one JSON line marked "type":"request".
+func WriteRProxyLine(w io.Writer, line *RProxyLine) error {
+	line.Type = "request"
+
+	return writeJSONLine(w, line)
+}
+
+// writeJSONLine writes line to w as one JSON line.
+func writeJSONLine(w io.Writer, line any) error {
 	encoded, err := json.Marshal(line)
 	if err != nil {
 		return fmt.Errorf("encode the request log line: %w", err)
@@ -211,8 +250,8 @@ func Milliseconds(d time.Duration) float64 {
 
 // NewProcessLogger returns the logger for the process's own messages:
 // JSON lines on w, marked "type":"process", with the time in the same form
-// as a request line's, and instanceName, SWWAF_INSTANCE_NAME, as instance.
+// as a request line's, and instanceName, SWW_INSTANCE_NAME, as instance.
-// It writes only the messages at level, SWWAF_LOG_LEVEL, or more severe;
+// It writes only the messages at level, SWW_LOG_LEVEL, or more severe;
 // the request lines Write writes are never held back.
 func NewProcessLogger(w io.Writer, instanceName string, level slog.Level) *slog.Logger {
 	handler := slog.NewJSONHandler(w, &slog.HandlerOptions{

internal/requestlog/requestlog_test.go

@@ -67,12 +67,34 @@ func TestWriteWritesOneJSONLineMarkedRequest(t *testing.T) {
 	}
 }
 
+func TestWriteRProxyLineWritesOneJSONLineWithOnlyItsFields(t *testing.T) {
+	t.Parallel()
+
+	var out bytes.Buffer
+
+	err := requestlog.WriteRProxyLine(&out, &requestlog.RProxyLine{
+		RequestID:   "an-id",
+		Disposition: "allow",
+	})
+	if err != nil {
+		t.Fatalf("write: %v", err)
+	}
+
+	const want = `{"type":"request","time":"","request_id":"an-id","client_ip":"",` +
+		`"host":"","method":"","path":"","query":"","status":0,"request_bytes":0,` +
+		`"response_bytes":0,"duration_request":0,"duration_response":0,` +
+		`"disposition":"allow"}` + "\n"
+	if out.String() != want {
+		t.Errorf("wrote %s, want %s", out.String(), want)
+	}
+}
+
 func TestProcessLinesAreMarkedProcessAndGiveTheInstance(t *testing.T) {
 	t.Parallel()
 
 	var out bytes.Buffer
 
-	requestlog.NewProcessLogger(&out, "fsn1app1/gitea", slog.LevelInfo).Info("starting",
+	requestlog.NewProcessLogger(&out, "fsn1app1/blog", slog.LevelInfo).Info("starting",
 		"version", "v1")
 
 	var fields map[string]any
@@ -82,7 +104,7 @@ func TestProcessLinesAreMarkedProcessAndGiveTheInstance(t *testing.T) {
 		t.Fatalf("decode %q: %v", out.String(), err)
 	}
 
-	if fields["type"] != "process" || fields["instance"] != "fsn1app1/gitea" ||
+	if fields["type"] != "process" || fields["instance"] != "fsn1app1/blog" ||
 		fields["msg"] != "starting" || fields["level"] != "INFO" ||
 		fields["version"] != "v1" {
 		t.Errorf("process line %v", fields)
@@ -111,7 +133,7 @@ func TestProcessLoggerWritesTheMessagesAtItsLevelOrMoreSevere(t *testing.T) {
 
 			var out bytes.Buffer
 
-			processLog := requestlog.NewProcessLogger(&out, "fsn1app1/gitea", level)
+			processLog := requestlog.NewProcessLogger(&out, "fsn1app1/blog", level)
 			for _, at := range levels {
 				processLog.Log(t.Context(), at, "message")
 			}

internal/rproxy/bodies.go

@@ -1,43 +1,44 @@
-package proxy
+package rproxy
 
 import (
+	"bufio"
 	"errors"
 	"io"
+	"net"
 	"net/http"
 	"sync/atomic"
-
-	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
 
 // errResponseTooLarge ends an app's response body that is longer than
-// SWWAF_RESPONSE_MAX_BYTES.
+// SWRP_MAX_RESPONSE_SIZE.
 var errResponseTooLarge = errors.New(
-	"the response body is over SWWAF_RESPONSE_MAX_BYTES")
+	"the response body is over SWRP_MAX_RESPONSE_SIZE")
 
-// requestBody is the client's request body on its way to the app. The
+// requestBody is the visitor's request body. rproxy first reads up to the first
-// transport reads it on a goroutine of its own.
+// 64 KiB of it into held, and then, on its way to the app, the transport reads
+// it on a goroutine of its own.
 type requestBody struct {
-	// body is the client's body, ending in an *http.MaxBytesError past
+	// body is the visitor's body, ending in an *http.MaxBytesError past
-	// SWWAF_REQUEST_MAX_BYTES.
+	// SWRP_MAX_REQUEST_SIZE.
 	body io.ReadCloser
 	rq   *request
-	// readByCoreRuleSet is what the Core Rule Set read of the body before
+	// held is the part read before the request goes to the app, which Read gives
-	// the request went to the app, and Read gives first.
+	// first.
-	readByCoreRuleSet []byte
+	held []byte
-	// waiting is true while a Read waits for the client to send more.
+	// waiting is true while a Read waits for the visitor to send more.
 	waiting atomic.Bool
-	// received is true once the client has sent the whole body.
+	// received is true once the visitor has sent the whole body.
 	received atomic.Bool
 	// bytes is how much of the body has been read.
 	bytes atomic.Int64
 }
 
-// Read reads from the client's body, after what the Core Rule Set read of
+// Read reads from the visitor's body, after the part held, which has been
-// it, which has been counted already.
+// counted already.
 func (b *requestBody) Read(p []byte) (int, error) {
-	if len(b.readByCoreRuleSet) > 0 {
+	if len(b.held) > 0 {
-		n := copy(p, b.readByCoreRuleSet)
+		n := copy(p, b.held)
-		b.readByCoreRuleSet = b.readByCoreRuleSet[n:]
+		b.held = b.held[n:]
 
 		return n, nil
 	}
@@ -52,27 +53,22 @@ func (b *requestBody) Read(p []byte) (int, error) {
 	switch {
 	case errors.Is(err, io.EOF):
 		b.received.Store(true)
-		b.rq.bodyReceived()
 	case errors.As(err, &tooLarge):
-		b.rq.refuse(refusal{
+		b.rq.refuse(http.StatusRequestEntityTooLarge)
-			status: http.StatusRequestEntityTooLarge,
-			action: requestlog.ActionTooLarge,
-			limit:  "SWWAF_REQUEST_MAX_BYTES",
-		})
 	}
 
 	return n, err
 }
 
-// Close closes the client's body.
+// Close closes the visitor's body.
 func (b *requestBody) Close() error {
 	return b.body.Close()
 }
 
-// responseBody is the app's response body on its way to the client.
+// responseBody is the app's response body on its way to the visitor.
 type responseBody struct {
 	// body is the app's body, ending in an *http.MaxBytesError past
-	// SWWAF_RESPONSE_MAX_BYTES.
+	// SWRP_MAX_RESPONSE_SIZE.
 	body io.ReadCloser
 	rq   *request
 }
@@ -90,20 +86,13 @@ func (b *responseBody) Read(p []byte) (int, error) {
 	case errors.Is(err, io.EOF):
 		b.rq.responseReceived()
 	case errors.As(err, &tooLarge):
-		b.rq.refuse(refusal{
+		b.rq.refuse(http.StatusBadGateway)
-			status: http.StatusBadGateway,
-			action: requestlog.ActionTooLarge,
-			limit:  "SWWAF_RESPONSE_MAX_BYTES",
-		})
 
 		return n, errResponseTooLarge
 	case b.rq.in.Context().Err() == nil:
-		// The answer broke off, not because the client went away. If a
+		// The answer broke off, not because the visitor went away. If a time
-		// timeout cut it, that refusal came first and is the one kept.
+		// limit cut it, that refusal came first and is the one kept.
-		b.rq.refuse(refusal{
+		b.rq.refuse(http.StatusBadGateway)
-			status: http.StatusBadGateway,
-			action: requestlog.ActionUpstreamError,
-		})
 	}
 
 	return n, err
@@ -115,15 +104,14 @@ func (b *responseBody) Close() error {
 }
 
 // upgradedConn is the connection to the app once the app has switched
-// protocols, as for a WebSocket. ReverseProxy writes to it what the client
+// protocols, as for a WebSocket. ReverseProxy writes to it what the visitor
-// sends and reads from it what the app sends, on goroutines of its own,
+// sends and reads from it what the app sends, on goroutines of its own, until
-// until the connection closes; it counts the bytes each way, for the byte
+// the connection closes; it counts the bytes each way, for the report.
-// limits.
 type upgradedConn struct {
 	io.ReadWriteCloser
 
 	// fromApp is how many bytes the app has sent, and toApp how many the
-	// client has.
+	// visitor has.
 	fromApp atomic.Int64
 	toApp   atomic.Int64
 }
@@ -136,7 +124,7 @@ func (c *upgradedConn) Read(p []byte) (int, error) {
 	return n, err
 }
 
-// Write sends the app what the client sent.
+// Write sends the app what the visitor sent.
 func (c *upgradedConn) Write(p []byte) (int, error) {
 	n, err := c.ReadWriteCloser.Write(p)
 	c.toApp.Add(int64(n))
@@ -144,9 +132,9 @@ func (c *upgradedConn) Write(p []byte) (int, error) {
 	return n, err
 }
 
-// CloseWrite tells the app that the client sends no more, while what the
+// CloseWrite tells the app that the visitor sends no more, while what the app
-// app sends still passes. ReverseProxy calls it once the client has
+// sends still passes. ReverseProxy calls it once the visitor has stopped
-// stopped sending, and closes the connection there if it is not supported.
+// sending, and closes the connection there if it is not supported.
 func (c *upgradedConn) CloseWrite() error {
 	conn, ok := c.ReadWriteCloser.(interface{ CloseWrite() error })
 	if !ok {
@@ -156,8 +144,8 @@ func (c *upgradedConn) CloseWrite() error {
 	return conn.CloseWrite()
 }
 
-// limitBody returns body, cut off with an *http.MaxBytesError after
+// limitBody returns body, cut off with an *http.MaxBytesError after maxBytes, or
-// maxBytes, or unchanged if maxBytes is zero, which is off.
+// unchanged if maxBytes is zero, which is off.
 func limitBody(body io.ReadCloser, maxBytes int64) io.ReadCloser {
 	if maxBytes == 0 {
 		return body
@@ -167,19 +155,18 @@ func limitBody(body io.ReadCloser, maxBytes int64) io.ReadCloser {
 	return http.MaxBytesReader(nil, body, maxBytes)
 }
 
-// responseWriter is the response to the client. It notes the status and
+// responseWriter is the response to the visitor. It notes the status and size
-// size for the log line, and the first error writing to the client.
+// for the log line and the report.
 type responseWriter struct {
 	http.ResponseWriter
 
 	// status is the final status sent, or zero before one is.
 	status int
 	bytes  int64
-	err    error
 }
 
-// WriteHeader sends the status and headers. An informational 1xx status
+// WriteHeader sends the status and headers. An informational 1xx status is
-// is passed on and the final status still comes later.
+// passed on and the final status still comes later.
 func (w *responseWriter) WriteHeader(status int) {
 	if status >= http.StatusOK && w.status == 0 {
 		w.status = status
@@ -194,33 +181,31 @@ func (w *responseWriter) Write(p []byte) (int, error) {
 		w.status = http.StatusOK
 	}
 
-	n, err := w.ResponseWriter.Write(p)
+	n, err := w.ResponseWriter.Write(p) //nolint:gosec // the answer, as it was given
 	w.bytes += int64(n)
-	w.noteError(err)
 
 	return n, err
 }
 
-// FlushError sends what has been written so far.
+// FlushError sends what has been written so far. http.ResponseController calls
-// http.ResponseController calls it, as ReverseProxy does after each
+// it, as ReverseProxy does after each write.
-// write.
 func (w *responseWriter) FlushError() error {
-	err := http.NewResponseController(w.ResponseWriter).Flush()
+	return http.NewResponseController(w.ResponseWriter).Flush()
-	w.noteError(err)
-
-	return err
 }
 
-// Unwrap lets http.ResponseController reach net/http's own
+// Hijack takes over the connection to the visitor, which ReverseProxy does only
-// ResponseWriter, which is how ReverseProxy takes over the connection of
+// to pass on the app's 101 Switching Protocols: that is then the status sent.
-// an upgraded request.
+func (w *responseWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	conn, buffered, err := http.NewResponseController(w.ResponseWriter).Hijack()
+	if err == nil {
+		w.status = http.StatusSwitchingProtocols
+	}
+
+	return conn, buffered, err
+}
+
+// Unwrap lets http.ResponseController reach net/http's own ResponseWriter for
+// what responseWriter does not do itself.
 func (w *responseWriter) Unwrap() http.ResponseWriter {
 	return w.ResponseWriter
 }
-
-// noteError keeps the first error writing to the client.
-func (w *responseWriter) noteError(err error) {
-	if w.err == nil {
-		w.err = err
-	}
-}

internal/rproxy/client.go

@@ -1,30 +1,40 @@
-package proxy
+package rproxy
 
 import (
-	"crypto/rand"
 	"net/http"
 	"net/netip"
 	"slices"
 	"strings"
 )
 
-// peerAddress is the address of the request's TCP peer, normally traefik.
+// The headers rproxy sets on the requests it passes to the app. Go writes every
+// header name in this form, as it sends it and as it receives it, so
+// X-Client-ASN arrives as X-Client-Asn, and Del removes a visitor's own whatever
+// their case; header names are not case-sensitive.
+const (
+	requestIDHeader = "X-Request-ID"
+	asnHeader       = "X-Client-Asn"
+	countryHeader   = "X-Client-Country"
+)
+
+// peerAddress is the address of the request's TCP peer, normally traefik, without
+// any IPv6 zone, which discriminator refuses.
 func peerAddress(r *http.Request) netip.Addr {
 	addrPort, err := netip.ParseAddrPort(r.RemoteAddr)
 	if err != nil {
 		return netip.Addr{}
 	}
 
-	return addrPort.Addr().Unmap()
+	return addrPort.Addr().Unmap().WithZone("")
 }
 
-// clientAddress works out who the client is. A peer outside the trusted
+// clientAddress works out who the visitor is. A peer outside the trusted
-// proxies is the client, and what it says in X-Forwarded-For is ignored.
+// proxies is the visitor, and what it says in X-Forwarded-For is ignored. For a
-// For a peer inside them, X-Forwarded-For is read from the right, and the
+// peer inside them, X-Forwarded-For is read from the right, and the first
-// first address outside them is the client; if every address in it is
+// address outside them is the visitor; if every address in it is inside, the
-// inside, the leftmost is, and with no header, the peer. An entry that is
+// leftmost is, and with no header, the peer. An entry that is not an address
-// not an address ends the reading, since nothing to its left can be
+// ends the reading, since nothing to its left can be believed. The visitor's
-// believed.
+// address never has an IPv6 zone, which discriminator refuses.
 func clientAddress(
 	peer netip.Addr, forwardedFor []string, trusted []netip.Prefix,
 ) netip.Addr {
@@ -40,7 +50,7 @@ func clientAddress(
 			break
 		}
 
-		client = addr.Unmap()
+		client = addr.Unmap().WithZone("")
 		if !isInside(client, trusted) {
 			break
 		}
@@ -49,24 +59,8 @@ func clientAddress(
 	return client
 }
 
-// requestIDHeader carries the request's id, from traefik and to the app.
+// scheme is how the visitor reached traefik, as a trusted proxy says in
-const requestIDHeader = "X-Request-ID"
+// X-Forwarded-Proto, or otherwise http, the only scheme rproxy serves.
-
-// requestID is the request's id: the one a trusted proxy sent, or a new
-// random one. A peer outside the trusted proxies did not come through
-// traefik, so the id it sends is its own claim, and is replaced.
-func requestID(r *http.Request, peerTrusted bool) string {
-	id := r.Header.Get(requestIDHeader)
-	if !peerTrusted || id == "" {
-		id = rand.Text()
-	}
-
-	return id
-}
-
-// scheme is how the client reached traefik, as a trusted proxy says in
-// X-Forwarded-Proto, or otherwise http, the only scheme smallwebwaf
-// serves.
 func scheme(r *http.Request, peerTrusted bool) string {
 	proto := r.Header.Get("X-Forwarded-Proto")
 	if !peerTrusted || proto == "" {
@@ -76,19 +70,6 @@ func scheme(r *http.Request, peerTrusted bool) string {
 	return proto
 }
 
-// clientGroup is the client a request is counted toward: its IPv4
-// address, or its IPv6 group, the netblock its IPv6 address is in of the
-// length SWWAF_IPV6_GROUP_PREFIX sets, a /64 by default, since one abuser
-// usually holds a whole /64. An IPv4 address in IPv6 form counts as IPv4.
-func (h *handler) clientGroup(addr netip.Addr) netip.Prefix {
-	addr = addr.Unmap()
-	if addr.Is6() {
-		return netip.PrefixFrom(addr, h.config.IPv6GroupPrefix).Masked()
-	}
-
-	return netip.PrefixFrom(addr, addr.BitLen())
-}
-
 // isInside reports whether addr is in one of the netblocks.
 func isInside(addr netip.Addr, netblocks []netip.Prefix) bool {
 	return slices.ContainsFunc(netblocks, func(netblock netip.Prefix) bool {
@@ -97,12 +78,11 @@ func isInside(addr netip.Addr, netblocks []netip.Prefix) bool {
 }
 
 // setForwardedHeaders sets the headers in which the app learns about the
-// client, so that it sees what it would see from traefik directly. A
+// visitor, so that it sees what it would see from traefik directly. A trusted
-// trusted proxy's forwarded headers pass on, with the proxy's own address
+// proxy's forwarded headers pass on, with the proxy's own address added to
-// added to X-Forwarded-For. Those of any other peer are its own claims and
+// X-Forwarded-For. Those of any other peer are its own claims and are replaced:
-// are replaced: X-Forwarded-For names the peer, X-Forwarded-Host the host
+// X-Forwarded-For names the peer, X-Forwarded-Host the host it asked for, and
-// it asked for, and X-Forwarded-Proto plain http, which is how it reached
+// X-Forwarded-Proto plain http, which is how it reached rproxy.
-// smallwebwaf.
 func setForwardedHeaders(in, out *http.Request, peer netip.Addr, trusted bool) {
 	forwardedFor := peer.String()
 
@@ -125,9 +105,9 @@ func setForwardedHeaders(in, out *http.Request, peer netip.Addr, trusted bool) {
 		return
 	}
 
-	// ReverseProxy has removed Forwarded and the three set below; these
+	// ReverseProxy has removed Forwarded and the three set below; these are the
-	// are the other headers in which traefik tells the app about the
+	// other headers in which traefik tells the app about the visitor and its
-	// client and its request.
+	// request.
 	for _, name := range []string{
 		"X-Forwarded-Port", "X-Forwarded-Server", "X-Forwarded-Uri",
 		"X-Forwarded-Method", "X-Forwarded-Prefix", "X-Forwarded-Tls-Client-Cert",

internal/rproxy/discriminator.go

@@ -0,0 +1,267 @@
+package rproxy
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"maps"
+	"net/http"
+	"strings"
+
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
+)
+
+// answerBodyMaxBytes is the most of the body of discriminator's answer that is read.
+// It is far above any answer's.
+const answerBodyMaxBytes = 1 << 20
+
+// reportAnswerMaxBytes is the most of the answer to a report that is read,
+// which has no body when discriminator takes the report.
+const reportAnswerMaxBytes = 4 << 10
+
+var (
+	errCannotPassOn  = errors.New("the answer cannot be passed to the visitor")
+	errReportRefused = errors.New("the report was answered")
+)
+
+// discriminatorAnswer is what discriminator answered to a question.
+type discriminatorAnswer struct {
+	status int
+	header http.Header
+	body   []byte
+}
+
+// noteAnswer notes what discriminator answered. An answer without a valid disposition
+// notes nothing, and no report is due for it: discriminator holds no decision to report
+// on.
+func (rq *request) noteAnswer(answer *discriminatorAnswer) {
+	disposition := answer.header.Get(discriminator.DispositionHeader)
+
+	switch disposition {
+	case discriminator.DispositionAllow, discriminator.DispositionDeny,
+		discriminator.DispositionClose:
+		rq.disposition = disposition
+		rq.answered = true
+		rq.asn = answer.header.Get(asnHeader)
+		rq.country = answer.header.Get(countryHeader)
+	}
+}
+
+// handleNoUsableAnswer deals with a request whose question ended in err, which
+// leaves no answer to act on. ctx is the request's own context.
+func (rq *request) handleNoUsableAnswer(ctx context.Context, err error) {
+	switch {
+	case ctx.Err() != nil:
+		// The visitor went away while discriminator was being asked. discriminator has not
+		// failed, and nothing is noted. This panic has Go's server close the
+		// connection without an answer, and log nothing; the deferred finish still
+		// runs.
+		panic(http.ErrAbortHandler)
+	case errors.Is(err, errCannotPassOn):
+		rq.h.processLog.Warn("discriminator's answer is dropped", "error", err.Error())
+		rq.answer(http.StatusBadGateway)
+	default:
+		// discriminator cannot be connected to, does not answer at all, or does not answer
+		// within SWRP_TIMEOUT_MS. A request that keeps discriminator busy past
+		// SWRP_TIMEOUT_MS, like any request while discriminator is overloaded, gets
+		// SWRP_DEFAULT_DISPOSITION here. deny closes this, at the cost of answering 503
+		// whenever discriminator is slow. Making such requests hard to send is
+		// https://git.eeqj.de/sneak/smallwebwaf/issues/182.
+		rq.h.processLog.Warn("discriminator gave no answer", "error", err.Error())
+
+		rq.disposition = rq.h.config.DefaultDisposition
+		rq.byDefault = true
+
+		if rq.disposition == discriminator.DispositionAllow {
+			rq.passToApp(ctx)
+		} else {
+			rq.answer(http.StatusServiceUnavailable)
+		}
+	}
+}
+
+// ask sends discriminator the question, and returns its answer, which must have come
+// whole within SWRP_TIMEOUT_MS. It ends when ctx does, as when the visitor goes
+// away.
+func (rq *request) ask(ctx context.Context) (*discriminatorAnswer, error) {
+	ctx, cancel := context.WithTimeout(ctx, rq.h.config.Timeout)
+	defer cancel()
+
+	question, err := rq.newQuestion(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	res, err := rq.h.discriminatorTransport.RoundTrip(question)
+	if err != nil {
+		return nil, fmt.Errorf("send the question: %w", err)
+	}
+
+	defer func() {
+		_ = res.Body.Close()
+	}()
+
+	// The body of a 101 is the connection itself, and the time limit does not end
+	// a read of that. Go's client also takes a status below 100, which Go's server
+	// panics when asked to send.
+	if res.StatusCode < http.StatusOK {
+		return nil, fmt.Errorf("%w: its status is %d", errCannotPassOn, res.StatusCode)
+	}
+
+	body, err := io.ReadAll(io.LimitReader(res.Body, answerBodyMaxBytes+1))
+	if err != nil {
+		return nil, fmt.Errorf("read the answer: %w", err)
+	}
+
+	if len(body) > answerBodyMaxBytes {
+		return nil, fmt.Errorf("%w: its body is over 1 MiB", errCannotPassOn)
+	}
+
+	return &discriminatorAnswer{res.StatusCode, res.Header, body}, nil
+}
+
+// canBeAsked reports whether Go's client can send discriminator r as the visitor sent
+// it. It cannot send these as they came:
+//   - a target that does not start with /, or that starts with //;
+//   - an empty Host, for which it sends discriminator's own address;
+//   - a Host holding an IPv6 zone, which it removes;
+//   - more than one User-Agent, of which it sends the first;
+//   - an empty User-Agent, which it leaves out, the one case that still goes to
+//     discriminator.
+func canBeAsked(r *http.Request) bool {
+	target, host := r.RequestURI, r.Host
+	hostHasZone := strings.HasPrefix(host, "[") && strings.Contains(host, "%")
+
+	return strings.HasPrefix(target, "/") && !strings.HasPrefix(target, "//") &&
+		host != "" && !hostHasZone && len(r.Header.Values("User-Agent")) <= 1
+}
+
+// newQuestion returns the question about the request, as "The question" in
+// SPEC.md gives it: the visitor's request as the visitor sent it, with the part
+// of the body it holds and rproxy's headers.
+func (rq *request) newQuestion(ctx context.Context) (*http.Request, error) {
+	in := rq.in
+
+	var held []byte
+	if rq.body != nil {
+		held = rq.body.held
+	}
+
+	question, err := http.NewRequestWithContext( //nolint:gosec // a setting's URL
+		ctx, in.Method, rq.h.config.WAFBackend.String(), bytes.NewReader(held))
+	if err != nil {
+		return nil, fmt.Errorf("make the question: %w", err)
+	}
+
+	backend := question.URL
+	target := *in.URL
+	target.Scheme = backend.Scheme
+	target.Host = backend.Host
+	setPathAsSent(&target, in)
+	question.URL = &target
+	question.Host = in.Host
+
+	// The length NewRequestWithContext set is that of what is held. This line makes
+	// a body whose length the visitor did not announce go chunked, as "The question"
+	// in SPEC.md requires.
+	question.TransferEncoding = in.TransferEncoding
+
+	question.Header = in.Header.Clone()
+	question.Header.Set(discriminator.ClientHeader, rq.client.String())
+	question.Header.Set(discriminator.PeerHeader, rq.peer.String())
+	question.Header.Del(discriminator.ContentLengthHeader)
+
+	announced := in.Header.Get("Content-Length")
+	if announced != "" {
+		question.Header.Set(discriminator.ContentLengthHeader, announced)
+	}
+
+	question.Header.Set(requestIDHeader, rq.id)
+	question.Header.Set("X-Forwarded-Proto", scheme(in, rq.peerTrusted))
+
+	// Go's client adds a User-Agent of its own to a request without the key.
+	_, sent := question.Header["User-Agent"]
+	if !sent {
+		question.Header["User-Agent"] = nil
+	}
+
+	return question, nil
+}
+
+// answerWith gives the visitor discriminator's answer, less its disposition.
+func (rq *request) answerWith(answer *discriminatorAnswer) {
+	rq.prepareOwnAnswer(rq.requestDeadline())
+
+	header := rq.out.Header()
+	maps.Copy(header, answer.header)
+	header.Del(discriminator.DispositionHeader)
+
+	// Go's server adds a Content-Type it guesses from the body to a response whose
+	// headers have no Content-Type key. The key with no value sends none.
+	if header.Get("Content-Type") == "" {
+		header["Content-Type"] = nil
+	}
+
+	rq.send(answer.status, answer.body)
+}
+
+// sendReport sends discriminator report on a goroutine of its own, so that the
+// visitor does not wait for it. The report goes on after ctx, the request's own
+// context, has ended.
+func (h *handler) sendReport(ctx context.Context, report *discriminator.Report) {
+	h.reportsMu.Lock()
+	defer h.reportsMu.Unlock()
+
+	if h.reportsStopped {
+		return
+	}
+
+	h.reports.Go(func() {
+		err := h.postReport(context.WithoutCancel(ctx), report)
+		if err != nil {
+			h.processLog.Warn("a report is dropped", "error", err.Error())
+		}
+	})
+}
+
+// postReport posts report to discriminator, and waits for its answer for up to
+// SWRP_TIMEOUT_MS.
+func (h *handler) postReport(ctx context.Context, report *discriminator.Report) error {
+	body, err := json.Marshal(report)
+	if err != nil {
+		return fmt.Errorf("encode the report: %w", err)
+	}
+
+	ctx, cancel := context.WithTimeout(ctx, h.config.Timeout)
+	defer cancel()
+
+	req, err := http.NewRequestWithContext( //nolint:gosec // a setting's URL
+		ctx, http.MethodPost, h.reportURL, bytes.NewReader(body))
+	if err != nil {
+		return fmt.Errorf("make the request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+
+	res, err := h.discriminatorTransport.RoundTrip(req)
+	if err != nil {
+		return fmt.Errorf("send the report: %w", err)
+	}
+
+	// The body of a 101 is the connection itself, and the time limit does not end
+	// a read of that.
+	if res.StatusCode >= http.StatusOK {
+		_, _ = io.Copy(io.Discard, io.LimitReader(res.Body, reportAnswerMaxBytes))
+	}
+
+	_ = res.Body.Close()
+
+	if res.StatusCode != http.StatusNoContent {
+		return fmt.Errorf("%w %s", errReportRefused, res.Status)
+	}
+
+	return nil
+}

internal/rproxy/limits_test.go

@@ -0,0 +1,831 @@
+package rproxy_test
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"io"
+	"log/slog"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"strings"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/config"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+	"sneak.berlin/go/smallwebwaf/internal/rproxy"
+)
+
+// post is the start of a POST whose headers end with what follows it.
+const post = "POST / HTTP/1.1\r\nHost: site.example\r\n"
+
+// announcedLength is the header that announces a body of size bytes, and the
+// end of the headers.
+func announcedLength(size int) string {
+	return "Content-Length: " + strconv.Itoa(size) + "\r\n\r\n"
+}
+
+func TestServerHasTheFixedLimits(t *testing.T) {
+	t.Parallel()
+
+	cfg, err := config.RProxyFromEnvironment(func(name string) (string, bool) {
+		if name == "SWRP_WAF_BACKEND" {
+			return nowhere, true
+		}
+
+		return "", false
+	})
+	if err != nil {
+		t.Fatalf("settings: %v", err)
+	}
+
+	server := rproxy.New(rproxy.Params{
+		Config:     cfg,
+		RequestLog: io.Discard,
+		ProcessLog: requestlog.NewProcessLogger(io.Discard, "test", slog.LevelInfo),
+	})
+
+	if server.Addr != ":8080" || server.MaxHeaderBytes != 28<<10 ||
+		server.IdleTimeout != 2*time.Minute || server.ReadHeaderTimeout != time.Minute {
+		t.Errorf("server listens on %q with header limit %d, idle time %s and "+
+			"header timeout %s", server.Addr, server.MaxHeaderBytes,
+			server.IdleTimeout, server.ReadHeaderTimeout)
+	}
+}
+
+func TestABodyAnnouncedOverItsLimitIsRefusedOnceDiscriminatorAllowsIt(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name, limit string
+		size, asked int
+	}{
+		{"with the limit within the first part", "1K", 1025, 1024},
+		{"with the limit past the first part", "128K", 129 << 10, questionBodyMaxBytes},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			standIn := startDiscriminator(t, allow)
+			app := startApp(t, func(http.ResponseWriter, *http.Request) {
+				t.Error("the app was asked")
+			})
+			addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+				maxRequestSize: tc.limit,
+			})
+
+			got := visit(t, newRequest(t, http.MethodPost, addr, "/",
+				bytes.NewReader(make([]byte, tc.size))))
+			if got.status != http.StatusRequestEntityTooLarge {
+				t.Errorf("answered %+v, want 413", got)
+			}
+
+			if asked := standIn.question(t); len(asked.body) != tc.asked {
+				t.Errorf("the question carries %d bytes, want %d", len(asked.body), tc.asked)
+			}
+
+			report := standIn.report(t)
+			if report.Status != http.StatusRequestEntityTooLarge {
+				t.Errorf("report %+v, want status 413", report)
+			}
+		})
+	}
+}
+
+func TestADenyOutranksTheBodySizeLimit(t *testing.T) {
+	t.Parallel()
+
+	standIn := startDiscriminator(t, deny)
+	app := startApp(t, greet)
+	addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+		maxRequestSize: "1K",
+	})
+
+	got := visit(t, newRequest(t, http.MethodPost, addr, "/",
+		bytes.NewReader(make([]byte, 1025))))
+	if got.status != http.StatusForbidden {
+		t.Errorf("answered %+v, want discriminator's 403", got)
+	}
+}
+
+func TestABodyNotAnnouncedOverItsLimitIsRefused(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name, limit string
+		size        int
+		// mayReachApp is true when the part of the body the limit lets through
+		// goes on to the app before the limit is met. The app may still not have
+		// started on the request when it is cut off.
+		mayReachApp bool
+	}{
+		{"within the first part", "1K", 2 << 10, false},
+		{"past the first part", "128K", 129 << 10, true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			var asked atomic.Bool
+
+			standIn := startDiscriminator(t, allow)
+			app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
+				asked.Store(true)
+				greet(w, r)
+			})
+			addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+				maxRequestSize: tc.limit,
+			})
+
+			conn := dial(t, addr)
+			send(t, conn, post+"Transfer-Encoding: chunked\r\n\r\n"+
+				strconv.FormatInt(int64(tc.size), 16)+"\r\n"+strings.Repeat("x", tc.size)+
+				"\r\n0\r\n\r\n")
+
+			if status := readStatus(t, conn); status != http.StatusRequestEntityTooLarge {
+				t.Errorf("status %d, want 413", status)
+			}
+
+			if asked.Load() && !tc.mayReachApp {
+				t.Error("the app was asked")
+			}
+		})
+	}
+}
+
+func TestAResponseOverItsLimit(t *testing.T) {
+	t.Parallel()
+
+	large := strings.Repeat("x", 2<<10)
+
+	t.Run("announced, is refused", func(t *testing.T) {
+		t.Parallel()
+
+		standIn := startDiscriminator(t, allow)
+		app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
+			w.Header().Set(contentLengthHeader, strconv.Itoa(len(large)))
+			_, _ = io.WriteString(w, large)
+		})
+		addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+			maxResponseSize: "1K",
+		})
+
+		got := get(t, addr, "/")
+		if got.status != http.StatusBadGateway {
+			t.Errorf("answered %d, want 502", got.status)
+		}
+
+		if report := standIn.report(t); report.Status != http.StatusBadGateway {
+			t.Errorf("report %+v, want status 502", report)
+		}
+	})
+
+	t.Run("not announced, is cut off", func(t *testing.T) {
+		t.Parallel()
+
+		standIn := startDiscriminator(t, allow)
+		app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
+			_, _ = io.WriteString(w, large[:1])
+			_ = http.NewResponseController(w).Flush()
+			_, _ = io.WriteString(w, large[1:])
+		})
+		addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+			maxResponseSize: "1K",
+		})
+
+		conn := dial(t, addr)
+		send(t, conn, "GET / HTTP/1.1\r\nHost: site.example\r\n\r\n")
+
+		text, err := io.ReadAll(conn)
+		if err != nil || bytes.Contains(text, []byte(large)) {
+			t.Errorf("read %d bytes (%v), want the answer cut off", len(text), err)
+		}
+
+		report := standIn.report(t)
+		if report.Status != http.StatusOK || report.ResponseBytes > 1<<10 {
+			t.Errorf("report %+v, want status 200 and at most 1K of the answer", report)
+		}
+	})
+}
+
+func TestAHeadWhoseAnswerAnnouncesMoreThanTheResponseLimitIsPassedOn(t *testing.T) {
+	t.Parallel()
+
+	const announced = "2048"
+
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
+		w.Header().Set(contentLengthHeader, announced)
+	})
+	addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+		maxResponseSize: "1K",
+	})
+
+	got := visit(t, newRequest(t, http.MethodHead, addr, "/", http.NoBody))
+	if got.status != http.StatusOK || got.header.Get(contentLengthHeader) != announced {
+		t.Errorf("answered %+v, want the app's 200 announcing %s bytes", got, announced)
+	}
+}
+
+func TestASettingOfOffSetsNoLimit(t *testing.T) {
+	t.Parallel()
+
+	for _, setting := range []string{
+		maxRequestSize, maxResponseSize, maxRequestTime, maxResponseTime,
+	} {
+		t.Run(setting, func(t *testing.T) {
+			t.Parallel()
+
+			standIn := startDiscriminator(t, allow)
+			app := startApp(t, greet)
+			addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+				setting: "off",
+			})
+
+			// A body and an answer that a limit of zero would cut off, as it would the
+			// next answer, which rproxy gives itself.
+			wantGreeting(t, visit(t, newRequest(t, http.MethodPost, addr, "/",
+				strings.NewReader("a body"))))
+
+			if got := get(t, addr, discriminator.HealthPath); got.status != http.StatusOK {
+				t.Errorf("answered %+v, want rproxy's own 200", got)
+			}
+		})
+	}
+}
+
+func TestAVisitorTooSlowToSendTheFirstPartIsAnswered408(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name, rest string
+	}{
+		{"with its length announced", announcedLength(100) + "some of it"},
+		{"with no length announced", "Transfer-Encoding: chunked\r\n\r\na\r\nsome of it\r\n"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			standIn := startDiscriminator(t, allow)
+			app := startApp(t, greet)
+			addr, out := startRProxy(t, standIn.URL, app.URL, map[string]string{
+				maxRequestTime: "500",
+			})
+
+			conn := dial(t, addr)
+			send(t, conn, post+tc.rest)
+
+			if status := readStatus(t, conn); status != http.StatusRequestTimeout {
+				t.Errorf("status %d, want 408", status)
+			}
+
+			line := out.requestLine(t)
+			if line["disposition"] != nil || line["request_bytes"] != 10.0 {
+				t.Errorf("line %v, want no disposition and 10 bytes", line)
+			}
+
+			if len(standIn.questions) != 0 {
+				t.Error("discriminator was asked")
+			}
+
+			standIn.wantNoReport(t)
+		})
+	}
+}
+
+func TestAVisitorThatGoesAwayBeforeTheFirstPartIsNotAsked(t *testing.T) {
+	t.Parallel()
+
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, greet)
+	addr, out := startRProxy(t, standIn.URL, app.URL, nil)
+
+	conn := dial(t, addr)
+	send(t, conn, post+announcedLength(100)+"some of it")
+	_ = conn.Close()
+
+	line := out.requestLine(t)
+	if line["status"] != 0.0 || line["disposition"] != nil {
+		t.Errorf("line %v, want no answer and no disposition", line)
+	}
+
+	if len(standIn.questions) != 0 {
+		t.Error("discriminator was asked")
+	}
+}
+
+func TestABodyThatCannotBeReadClosesTheConnectionWithoutAnAnswer(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name, request string
+		stopsSending  bool
+	}{
+		{
+			"a malformed chunk", post + "Transfer-Encoding: chunked\r\n\r\nnot a chunk\r\n",
+			false,
+		},
+		{"a visitor that stops sending", post + announcedLength(100) + "some of it", true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			standIn := startDiscriminator(t, allow)
+			app := startApp(t, greet)
+			addr, out := startRProxy(t, standIn.URL, app.URL, nil)
+
+			conn := dial(t, addr)
+			send(t, conn, tc.request)
+
+			if tc.stopsSending {
+				tcpConn, ok := conn.(*net.TCPConn)
+				if !ok {
+					t.Fatalf("the connection is a %T", conn)
+				}
+
+				err := tcpConn.CloseWrite()
+				if err != nil {
+					t.Fatalf("stop sending: %v", err)
+				}
+			}
+
+			text, err := io.ReadAll(conn)
+			if err != nil || len(text) != 0 {
+				t.Errorf("read %q (%v), want the connection closed without an answer",
+					text, err)
+			}
+
+			line := out.requestLine(t)
+			if line["status"] != 0.0 || line["disposition"] != nil {
+				t.Errorf("line %v, want no answer and no disposition", line)
+			}
+
+			if len(standIn.questions) != 0 {
+				t.Error("discriminator was asked")
+			}
+		})
+	}
+}
+
+// deadlineRecorder notes the time limits rproxy sets on reading the visitor's body
+// and on sending its answer.
+type deadlineRecorder struct {
+	*httptest.ResponseRecorder
+
+	readDeadline  time.Time
+	writeDeadline time.Time
+}
+
+// SetReadDeadline notes deadline.
+func (w *deadlineRecorder) SetReadDeadline(deadline time.Time) error {
+	w.readDeadline = deadline
+
+	return nil
+}
+
+// SetWriteDeadline notes deadline.
+func (w *deadlineRecorder) SetWriteDeadline(deadline time.Time) error {
+	w.writeDeadline = deadline
+
+	return nil
+}
+
+func TestABodyLeftUnreadIsReadOnlyUntilTheRequestTimeLimit(t *testing.T) {
+	t.Parallel()
+
+	const (
+		limit = 5 * time.Minute
+		// announced is over what Go's server reads of a body left unread, so that
+		// the app's own server answers without waiting for the rest.
+		announced = 100 * questionBodyMaxBytes
+	)
+
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusNoContent)
+	})
+	_, _, server := startServer(t, standIn.URL, app.URL, map[string]string{
+		maxRequestTime: strconv.FormatInt(limit.Milliseconds(), 10),
+	})
+
+	// The visitor sends the first part and a little more, and then nothing.
+	stalled, stop := io.Pipe()
+
+	t.Cleanup(func() { _ = stop.Close() })
+
+	req := httptest.NewRequestWithContext(t.Context(), http.MethodPost, "/",
+		io.MultiReader(bytes.NewReader(make([]byte, questionBodyMaxBytes+1)), stalled))
+	req.ContentLength = announced
+	req.Header.Set(contentLengthHeader, strconv.Itoa(announced))
+
+	w := &deadlineRecorder{ResponseRecorder: httptest.NewRecorder()}
+
+	before := time.Now()
+
+	server.Handler.ServeHTTP(w, req)
+
+	if w.Code != http.StatusNoContent {
+		t.Errorf("status %d, want the app's 204", w.Code)
+	}
+
+	if w.readDeadline.Before(before.Add(limit)) ||
+		w.readDeadline.After(time.Now().Add(limit)) {
+		t.Errorf("the reading of the body ends at %s, want %s from the request",
+			w.readDeadline, limit)
+	}
+}
+
+func TestAnAnswerRProxyGivesItselfHasTheResponseTimeToBeSent(t *testing.T) {
+	t.Parallel()
+
+	const limit = 5 * time.Minute
+
+	for _, tc := range []struct {
+		name, target string
+		status       int
+	}{
+		{"discriminator's deny", "/", http.StatusForbidden},
+		{"rproxy's own 400", "x:admin", http.StatusBadRequest},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			standIn := startDiscriminator(t, deny)
+			app := startApp(t, greet)
+			_, _, server := startServer(t, standIn.URL, app.URL, map[string]string{
+				maxResponseTime: strconv.FormatInt(limit.Milliseconds(), 10),
+			})
+
+			req := httptest.NewRequestWithContext(t.Context(), http.MethodGet, tc.target,
+				http.NoBody)
+			w := &deadlineRecorder{ResponseRecorder: httptest.NewRecorder()}
+
+			before := time.Now()
+
+			server.Handler.ServeHTTP(w, req)
+
+			if w.Code != tc.status {
+				t.Errorf("status %d, want %d", w.Code, tc.status)
+			}
+
+			if w.writeDeadline.Before(before.Add(limit)) ||
+				w.writeDeadline.After(time.Now().Add(limit)) {
+				t.Errorf("the time limit on sending ends at %s, want %s from the answer",
+					w.writeDeadline, limit)
+			}
+		})
+	}
+}
+
+func TestAVisitorTooSlowToSendTheRestIsAnswered408(t *testing.T) {
+	t.Parallel()
+
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, greet)
+	addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+		maxRequestTime: "3000",
+	})
+
+	conn := dial(t, addr)
+	send(t, conn, post+announcedLength(2*questionBodyMaxBytes)+
+		strings.Repeat("x", questionBodyMaxBytes+1))
+
+	if status := readStatus(t, conn); status != http.StatusRequestTimeout {
+		t.Errorf("status %d, want 408", status)
+	}
+
+	if asked := standIn.question(t); len(asked.body) != questionBodyMaxBytes {
+		t.Errorf("the question carries %d bytes", len(asked.body))
+	}
+
+	if report := standIn.report(t); report.Status != http.StatusRequestTimeout {
+		t.Errorf("report %+v, want status 408", report)
+	}
+}
+
+// startAppThatTakesNothing starts an app that accepts connections and never
+// reads from them, and returns its URL.
+func startAppThatTakesNothing(t *testing.T) string {
+	t.Helper()
+
+	listener, err := (&net.ListenConfig{}).Listen(t.Context(), "tcp", localhost+":0")
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+
+	stopped := make(chan struct{})
+
+	t.Cleanup(func() {
+		close(stopped)
+
+		_ = listener.Close()
+	})
+
+	go func() {
+		for {
+			conn, err := listener.Accept()
+			if err != nil {
+				return
+			}
+
+			go func() {
+				<-stopped
+
+				_ = conn.Close()
+			}()
+		}
+	}()
+
+	return "http://" + listener.Addr().String()
+}
+
+func TestAnAppTooSlowToTakeTheRequestIsAnswered504(t *testing.T) {
+	t.Parallel()
+
+	// More than the connections hold while nobody reads, written a little at a
+	// time, so that rproxy soon waits for the app.
+	const (
+		bodySize  = 64 << 20
+		writeSize = 32 << 10
+	)
+
+	standIn := startDiscriminator(t, allow)
+	addr, _ := startRProxy(t, standIn.URL, startAppThatTakesNothing(t),
+		map[string]string{maxRequestTime: "3000"})
+
+	conn := dial(t, addr)
+	send(t, conn, post+announcedLength(bodySize))
+
+	go func() {
+		part := make([]byte, writeSize)
+
+		for range bodySize / writeSize {
+			_, err := conn.Write(part)
+			if err != nil {
+				return
+			}
+		}
+	}()
+
+	if status := readStatus(t, conn); status != http.StatusGatewayTimeout {
+		t.Errorf("status %d, want 504", status)
+	}
+}
+
+func TestAnAppTooSlowToAnswerIsAnswered504(t *testing.T) {
+	t.Parallel()
+
+	release := make(chan struct{})
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, func(http.ResponseWriter, *http.Request) {
+		<-release
+	})
+
+	t.Cleanup(func() { close(release) })
+
+	addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+		maxResponseTime: "300",
+	})
+
+	got := get(t, addr, "/")
+	if got.status != http.StatusGatewayTimeout {
+		t.Errorf("answered %d, want 504", got.status)
+	}
+
+	if report := standIn.report(t); report.Status != http.StatusGatewayTimeout {
+		t.Errorf("report %+v, want status 504", report)
+	}
+}
+
+func TestAnAppTooSlowToFinishItsAnswerIsCutOff(t *testing.T) {
+	t.Parallel()
+
+	const start = "the start"
+
+	release := make(chan struct{})
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
+		_, _ = io.WriteString(w, start)
+		_ = http.NewResponseController(w).Flush()
+
+		<-release
+	})
+
+	t.Cleanup(func() { close(release) })
+
+	// The time limit is long enough for a loaded host to pass on the start of the
+	// answer before it runs out.
+	addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+		maxResponseTime: "3000",
+	})
+
+	conn := dial(t, addr)
+	send(t, conn, "GET / HTTP/1.1\r\nHost: site.example\r\n\r\n")
+
+	res, err := http.ReadResponse(bufio.NewReader(conn), nil)
+	if err != nil {
+		t.Fatalf("read the answer: %v", err)
+	}
+
+	// The body breaks off when rproxy closes the connection. If the connection
+	// stays open, dial's deadline ends this read with a timeout instead.
+	body, err := io.ReadAll(res.Body)
+	_ = res.Body.Close()
+
+	if res.StatusCode != http.StatusOK || string(body) != start ||
+		!errors.Is(err, io.ErrUnexpectedEOF) {
+		t.Errorf("answered %d %q (%v), want the app's 200 %q, then the connection closed",
+			res.StatusCode, body, err, start)
+	}
+
+	if report := standIn.report(t); report.Status != http.StatusOK {
+		t.Errorf("report %+v, want the status the visitor got", report)
+	}
+}
+
+func TestAVisitorTooSlowToTakeTheAnswerIsCutOff(t *testing.T) {
+	t.Parallel()
+
+	// More than the connections hold while nobody reads.
+	const (
+		bodySize  = 64 << 20
+		writeSize = 32 << 10
+	)
+
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
+		part := make([]byte, writeSize)
+
+		for range bodySize / writeSize {
+			_, err := w.Write(part)
+			if err != nil {
+				return
+			}
+		}
+	})
+	// The time limit is long enough for a loaded host to start passing on the
+	// answer before it runs out.
+	addr, out := startRProxy(t, standIn.URL, app.URL, map[string]string{
+		maxResponseTime: "3000",
+	})
+
+	// The visitor asks, and never reads the answer.
+	conn := dial(t, addr)
+	send(t, conn, "GET / HTTP/1.1\r\nHost: site.example\r\n\r\n")
+
+	line := out.requestLine(t)
+
+	responseBytes, _ := line["response_bytes"].(float64)
+	if line["status"] != float64(http.StatusOK) || responseBytes >= bodySize {
+		t.Errorf("line %v, want status 200 and the answer cut off", line)
+	}
+
+	report := standIn.report(t)
+	if report.Status != http.StatusOK || report.ResponseBytes >= bodySize {
+		t.Errorf("report %+v, want status 200 and the answer cut off", report)
+	}
+}
+
+func TestAnAppThatCannotBeReachedIsAnswered502WithAReport(t *testing.T) {
+	t.Parallel()
+
+	standIn := startDiscriminator(t, allow)
+	addr, _ := startRProxy(t, standIn.URL, nowhere, nil)
+
+	got := get(t, addr, "/")
+	if got.status != http.StatusBadGateway {
+		t.Errorf("answered %d, want 502", got.status)
+	}
+
+	if report := standIn.report(t); report.Status != http.StatusBadGateway {
+		t.Errorf("report %+v, want status 502", report)
+	}
+}
+
+func TestAVisitorThatStopsSendingAfterTheAppHasAnsweredGetsTheAnswer(t *testing.T) {
+	t.Parallel()
+
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
+		_, _ = io.WriteString(w, greeting)
+	})
+	addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+		maxRequestTime: "3000",
+	})
+
+	// Far more announced than sent, so that Go's server answers for the app
+	// without waiting for the rest.
+	conn := dial(t, addr)
+	send(t, conn, post+announcedLength(100*questionBodyMaxBytes)+
+		strings.Repeat("x", questionBodyMaxBytes))
+
+	if status := readStatus(t, conn); status != http.StatusOK {
+		t.Errorf("status %d, want the app's 200", status)
+	}
+}
+
+func TestAVisitorThatStopsSendingWhileTheAppWorksGetsNoAnswer(t *testing.T) {
+	t.Parallel()
+
+	working := make(chan struct{})
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, func(_ http.ResponseWriter, r *http.Request) {
+		close(working)
+		<-r.Context().Done()
+	})
+	addr, out := startRProxy(t, standIn.URL, app.URL, nil)
+
+	conn := dial(t, addr)
+	send(t, conn, "GET / HTTP/1.1\r\nHost: site.example\r\n\r\n")
+
+	select {
+	case <-working:
+	case <-time.After(waitLimit):
+		t.Fatal("the app was not asked")
+	}
+
+	tcpConn, ok := conn.(*net.TCPConn)
+	if !ok {
+		t.Fatalf("the connection is a %T", conn)
+	}
+
+	err := tcpConn.CloseWrite()
+	if err != nil {
+		t.Fatalf("stop sending: %v", err)
+	}
+
+	text, err := io.ReadAll(conn)
+	if err != nil || len(text) != 0 {
+		t.Errorf("read %q (%v), want the connection closed without an answer", text, err)
+	}
+
+	if line := out.requestLine(t); line["status"] != 0.0 {
+		t.Errorf("line %v, want status 0", line)
+	}
+}
+
+func TestTheRequestTimeLimitDoesNotCutAnAnswerOnceTheAppHasTheRequest(t *testing.T) {
+	t.Parallel()
+
+	const answer = "the end of a long answer"
+
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.Copy(io.Discard, r.Body)
+		_ = http.NewResponseController(w).Flush()
+
+		time.Sleep(2100 * time.Millisecond)
+
+		_, _ = io.WriteString(w, answer)
+	})
+	addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+		maxRequestTime: "2000",
+	})
+
+	got := visit(t, newRequest(t, http.MethodPost, addr, "/", strings.NewReader("a body")))
+	if got.status != http.StatusOK || got.body != answer {
+		t.Errorf("answered %d %q, want the app's whole answer", got.status, got.body)
+	}
+}
+
+func TestAVisitorThatStopsSendingGetsAnAnswerRProxyGivesByTheDeadline(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name, start string
+		status      int
+	}{
+		{"a deny", post, http.StatusForbidden},
+		{
+			"the health check",
+			"GET " + discriminator.HealthPath + " HTTP/1.1\r\nHost: site.example\r\n",
+			http.StatusOK,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			standIn := startDiscriminator(t, deny)
+			app := startApp(t, greet)
+			// The time limit is long enough for a loaded host to read the first part of
+			// the body before it runs out.
+			addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+				maxRequestTime: "3000",
+			})
+
+			// Go's server waits for a little of the body left before it sends an answer,
+			// and the time for sending the request ends that wait.
+			conn := dial(t, addr)
+			send(t, conn, tc.start+announcedLength(questionBodyMaxBytes+100)+
+				strings.Repeat("x", questionBodyMaxBytes))
+
+			if status := readStatus(t, conn); status != tc.status {
+				t.Errorf("status %d, want %d", status, tc.status)
+			}
+		})
+	}
+}

internal/rproxy/question_test.go

@@ -0,0 +1,524 @@
+package rproxy_test
+
+import (
+	"bytes"
+	"crypto/rand"
+	"io"
+	"maps"
+	"net/http"
+	"net/http/httptest"
+	"slices"
+	"strconv"
+	"strings"
+	"testing"
+
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
+)
+
+// questionBodyMaxBytes is the most of a body a question carries.
+const questionBodyMaxBytes = discriminator.QuestionBodyMaxBytes
+
+// chunked is the encoding of a body whose length the visitor did not announce.
+const chunked = "chunked"
+
+// pathGoReencodes is a path Go's client would decode and escape again, %2F turned
+// into / and | into %7C, unless told to send it as it is. A test sets it as the
+// visitor's URL.Opaque, so that the visitor sends it unchanged too.
+const pathGoReencodes = "/some%2Fpath/with%20space|pipe"
+
+func TestQuestionIsTheVisitorsRequestWithRProxysHeaders(t *testing.T) {
+	t.Parallel()
+
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, greet)
+	addr, _ := startRProxy(t, standIn.URL, app.URL, nil)
+
+	const target = pathGoReencodes + "?b=2&a=1&bad=%zz;x"
+
+	req := newRequest(t, http.MethodDelete, addr, target, http.NoBody)
+	req.URL.Opaque = pathGoReencodes
+	req.Host = site
+	req.Header.Set("X-Test", "from the visitor")
+	req.Header.Set(forwardedForHeader, "198.51.100.1")
+	req.Header.Set(forwardedProtoHeader, "gopher")
+	req.Header.Set(requestIDHeader, "the-visitor's")
+	req.Header.Set(discriminator.ClientHeader, "198.51.100.2")
+	req.Header.Set(discriminator.PeerHeader, "198.51.100.3")
+	req.Header.Set(discriminator.ContentLengthHeader, "12345")
+	// Go's client then sends no User-Agent, so that one in the question would be
+	// Go's own.
+	req.Header["User-Agent"] = nil
+
+	wantGreeting(t, visit(t, req))
+
+	asked := standIn.question(t)
+	if asked.method != http.MethodDelete || asked.target != target ||
+		asked.host != site {
+		t.Errorf("asked about %s %s at %s", asked.method, asked.target, asked.host)
+	}
+
+	if asked.header.Get(requestIDHeader) == "the-visitor's" {
+		t.Error("the question carries the visitor's id")
+	}
+
+	// Exactly these: visit's connection has the visitor send Connection: close.
+	want := http.Header{}
+	want.Set("Connection", "close")
+	want.Set("X-Test", "from the visitor")
+	want.Set(forwardedForHeader, "198.51.100.1")
+	want.Set(forwardedProtoHeader, "http")
+	want.Set(requestIDHeader, asked.header.Get(requestIDHeader))
+	want.Set(discriminator.ClientHeader, localhost)
+	want.Set(discriminator.PeerHeader, localhost)
+
+	if !maps.EqualFunc(asked.header, want, slices.Equal) {
+		t.Errorf("the question's headers are %v, want %v", asked.header, want)
+	}
+}
+
+func TestQuestionNamesTheVisitorATrustedProxySpeaksFor(t *testing.T) {
+	t.Parallel()
+
+	const visitor = "203.0.113.9"
+
+	for _, tc := range []struct {
+		name, trusted, client, proto, forwarded string
+	}{
+		{
+			"from a trusted proxy", localhost + "/32", visitor, "https",
+			visitor + ", " + localhost,
+		},
+		{"from a peer not trusted", "10.0.0.0/8", localhost, "http", localhost},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			standIn := startDiscriminator(t, allow)
+			forwarded := make(chan http.Header, 1)
+			app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
+				forwarded <- r.Header.Clone()
+
+				greet(w, r)
+			})
+			addr, out := startRProxy(t, standIn.URL, app.URL, map[string]string{
+				trustedProxies: tc.trusted,
+			})
+
+			req := newRequest(t, http.MethodGet, addr, "/", http.NoBody)
+			req.Header.Set(forwardedForHeader, visitor)
+			req.Header.Set(forwardedProtoHeader, "https")
+			wantGreeting(t, visit(t, req))
+
+			asked := standIn.question(t)
+			if asked.header.Get(discriminator.ClientHeader) != tc.client ||
+				asked.header.Get(discriminator.PeerHeader) != localhost ||
+				asked.header.Get(forwardedForHeader) != visitor ||
+				asked.header.Get(forwardedProtoHeader) != tc.proto {
+				t.Errorf("the question's headers are %v", asked.header)
+			}
+
+			if line := out.requestLine(t); line["client_ip"] != tc.client {
+				t.Errorf("line %v, want client_ip %s", line, tc.client)
+			}
+
+			if got := (<-forwarded).Get(forwardedForHeader); got != tc.forwarded {
+				t.Errorf("the app saw %s %q, want %q", forwardedForHeader, got, tc.forwarded)
+			}
+		})
+	}
+}
+
+func TestQuestionNamesTheClientAsTheForwardedAddressesSay(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name   string
+		header []string
+		client string
+	}{
+		{
+			"the first address outside the trusted proxies, from the right",
+			[]string{"198.51.100.7, 203.0.113.9, 10.0.0.2"}, "203.0.113.9",
+		},
+		{
+			"the leftmost, when every address is a trusted proxy",
+			[]string{"10.0.0.5, 10.0.0.2"}, "10.0.0.5",
+		},
+		{"the peer, with no header", nil, localhost},
+		{
+			"the last address read, before an entry that is not an address",
+			[]string{"203.0.113.9, unknown, 10.0.0.2"}, "10.0.0.2",
+		},
+		{
+			"read as one list, with several header lines",
+			[]string{"2001:db8::7", "10.0.0.2"}, "2001:db8::7",
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			standIn := startDiscriminator(t, allow)
+			app := startApp(t, greet)
+			addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+				trustedProxies: localhost + "/32,10.0.0.0/8",
+			})
+
+			req := newRequest(t, http.MethodGet, addr, "/", http.NoBody)
+			req.Header[forwardedForHeader] = tc.header
+			wantGreeting(t, visit(t, req))
+
+			if got := standIn.question(t).header.Get(discriminator.ClientHeader); got !=
+				tc.client {
+				t.Errorf("the question names %s, want %s", got, tc.client)
+			}
+		})
+	}
+}
+
+// randomBytes returns n random bytes.
+func randomBytes(n int) []byte {
+	body := make([]byte, n)
+	_, _ = rand.Read(body) // it never returns an error
+
+	return body
+}
+
+func TestFirst64KiBReachDiscriminatorAndTheWholeBodyTheApp(t *testing.T) {
+	t.Parallel()
+
+	for _, size := range []int{
+		1, questionBodyMaxBytes - 1, questionBodyMaxBytes, questionBodyMaxBytes + 1,
+		5 * questionBodyMaxBytes,
+	} {
+		for _, announced := range []bool{true, false} {
+			name := strconv.Itoa(size) + " bytes, length announced: " +
+				strconv.FormatBool(announced)
+
+			t.Run(name, func(t *testing.T) {
+				t.Parallel()
+
+				body := randomBytes(size)
+				standIn := startDiscriminator(t, allow)
+				received := make(chan []byte, 1)
+				app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
+					whole, _ := io.ReadAll(r.Body)
+					received <- whole
+
+					greet(w, r)
+				})
+				addr, _ := startRProxy(t, standIn.URL, app.URL, nil)
+
+				req := newRequest(t, http.MethodPost, addr, "/", bytes.NewReader(body))
+				if !announced {
+					// Go's client sends a body of unknown length in chunks.
+					req.ContentLength = -1
+				}
+
+				wantGreeting(t, visit(t, req))
+
+				asked := standIn.question(t)
+				want := body[:min(size, questionBodyMaxBytes)]
+				wantQuestionBody(t, asked, want, size, announced)
+
+				if !bytes.Equal(<-received, body) {
+					t.Error("the app did not get the whole body")
+				}
+
+				if report := standIn.report(t); report.RequestBytes != int64(size) {
+					t.Errorf("report %+v, of %d bytes", report, size)
+				}
+			})
+		}
+	}
+}
+
+// wantQuestionBody checks the body a question carries, want, and how it gives
+// the length of the visitor's body, of size bytes.
+func wantQuestionBody(
+	t *testing.T, asked question, want []byte, size int, announced bool,
+) {
+	t.Helper()
+
+	if !bytes.Equal(asked.body, want) {
+		t.Errorf("the question carries %d bytes, want the first %d", len(asked.body),
+			len(want))
+	}
+
+	values := asked.header.Values(discriminator.ContentLengthHeader)
+
+	if announced {
+		if !slices.Equal(values, []string{strconv.Itoa(size)}) ||
+			asked.contentLength != int64(len(want)) {
+			t.Errorf("announced %v and length %d, want %d and %d", values,
+				asked.contentLength, size, len(want))
+		}
+
+		return
+	}
+
+	if len(values) != 0 || !slices.Equal(asked.transferEncoding, []string{chunked}) {
+		t.Errorf("announced %v and encoded %v, want none and chunked", values,
+			asked.transferEncoding)
+	}
+}
+
+func TestDenyNeedsOnlyTheFirstPartOfALargeBody(t *testing.T) {
+	t.Parallel()
+
+	standIn := startDiscriminator(t, deny)
+	app := startApp(t, greet)
+	addr, _ := startRProxy(t, standIn.URL, app.URL, nil)
+
+	// Far more announced than sent. Go's server does not wait for that much, so
+	// the answer comes at once.
+	conn := dial(t, addr)
+	send(t, conn, post+announcedLength(100*questionBodyMaxBytes)+
+		strings.Repeat("x", questionBodyMaxBytes))
+
+	if status := readStatus(t, conn); status != http.StatusForbidden {
+		t.Errorf("status %d, want discriminator's 403", status)
+	}
+
+	if report := standIn.report(t); report.RequestBytes != questionBodyMaxBytes {
+		t.Errorf("report %+v, want the first part's bytes", report)
+	}
+}
+
+func TestAQuestionCarriesItsBodyWhateverTheMethod(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name, framing, body string
+		encoding            []string
+	}{
+		{
+			chunked, "Transfer-Encoding: chunked\r\n\r\n4\r\nbody\r\n0\r\n\r\n", "body",
+			[]string{chunked},
+		},
+		{
+			"chunked and empty", "Transfer-Encoding: chunked\r\n\r\n0\r\n\r\n", "",
+			[]string{chunked},
+		},
+		{"with its length", announcedLength(4) + "body", "body", nil},
+	} {
+		for _, method := range []string{
+			http.MethodGet, http.MethodDelete, http.MethodPost,
+		} {
+			t.Run(method+" "+tc.name, func(t *testing.T) {
+				t.Parallel()
+
+				standIn := startDiscriminator(t, deny)
+				addr, _ := startRProxy(t, standIn.URL, nowhere, nil)
+
+				conn := dial(t, addr)
+				send(t, conn, method+" /x HTTP/1.1\r\nHost: site.example\r\n"+tc.framing)
+
+				if status := readStatus(t, conn); status != http.StatusForbidden {
+					t.Errorf("status %d, want discriminator's 403", status)
+				}
+
+				asked := standIn.question(t)
+				if string(asked.body) != tc.body ||
+					!slices.Equal(asked.transferEncoding, tc.encoding) {
+					t.Errorf("the question carries %q, encoded %v, want %q, encoded %v",
+						asked.body, asked.transferEncoding, tc.body, tc.encoding)
+				}
+			})
+		}
+	}
+}
+
+func TestAMethodNotPassedOnIsAnswered405(t *testing.T) {
+	t.Parallel()
+
+	for _, method := range []string{http.MethodTrace, "PROPFIND", "LOCK", "BREW"} {
+		t.Run(method, func(t *testing.T) {
+			t.Parallel()
+
+			standIn := startDiscriminator(t, allow)
+			app := startApp(t, func(http.ResponseWriter, *http.Request) {
+				t.Error("the app was asked")
+			})
+			addr, out := startRProxy(t, standIn.URL, app.URL, nil)
+
+			got := visit(t, newRequest(t, method, addr, "/", http.NoBody))
+			if got.status != http.StatusMethodNotAllowed ||
+				got.header.Get("Allow") != "GET, HEAD, POST, OPTIONS, PUT, DELETE, PATCH, QUERY" {
+				t.Errorf("answered %+v, want 405 naming the methods passed on", got)
+			}
+
+			line := out.requestLine(t)
+			if line["status"] != float64(http.StatusMethodNotAllowed) ||
+				line["disposition"] != nil || line["default_disposition"] != nil {
+				t.Errorf("line %v, want status 405 and no disposition", line)
+			}
+
+			if len(standIn.questions) != 0 {
+				t.Error("discriminator was asked")
+			}
+
+			standIn.wantNoReport(t)
+		})
+	}
+}
+
+func TestEachMethodPassedOnReachesDiscriminatorAndTheApp(t *testing.T) {
+	t.Parallel()
+
+	for _, method := range []string{
+		http.MethodGet, http.MethodHead, http.MethodPost, http.MethodOptions,
+		http.MethodPut, http.MethodDelete, http.MethodPatch, "QUERY",
+	} {
+		t.Run(method, func(t *testing.T) {
+			t.Parallel()
+
+			reached := make(chan string, 1)
+			standIn := startDiscriminator(t, allow)
+			app := startApp(t, func(_ http.ResponseWriter, r *http.Request) {
+				reached <- r.Method
+			})
+			addr, _ := startRProxy(t, standIn.URL, app.URL, nil)
+
+			got := visit(t, newRequest(t, method, addr, "/", http.NoBody))
+			if got.status != http.StatusOK {
+				t.Errorf("answered %+v, want the app's 200", got)
+			}
+
+			if asked := standIn.question(t); asked.method != method {
+				t.Errorf("discriminator was asked about %s", asked.method)
+			}
+
+			if atApp := <-reached; atApp != method {
+				t.Errorf("the app was asked %s", atApp)
+			}
+		})
+	}
+}
+
+func TestARequestThatCannotGoToDiscriminatorAsSentIsRefused(t *testing.T) {
+	t.Parallel()
+
+	const host = "Host: site.example\r\n\r\n"
+
+	for name, request := range map[string]string{
+		"a target of a scheme":    "GET x:admin HTTP/1.1\r\n" + host,
+		"a target of a URL":       "GET http://site.example/ HTTP/1.1\r\n" + host,
+		"a host Go will not send": "GET http://a<b/ HTTP/1.1\r\n" + host,
+		"a target of a host":      "GET site.example:443 HTTP/1.1\r\n" + host,
+		"a target of *":           "GET * HTTP/1.1\r\n" + host,
+		"a target of //":          "GET //x/y HTTP/1.1\r\n" + host,
+		"a target of // escaped":  "GET //x%2Fadmin| HTTP/1.1\r\n" + host,
+		"an empty Host":           "GET / HTTP/1.1\r\nHost:\r\n\r\n",
+		"HTTP/1.0 with no Host":   "GET / HTTP/1.0\r\n\r\n",
+		"a Host with a zone":      "GET / HTTP/1.1\r\nHost: [fe80::1%25eth0]:80\r\n\r\n",
+		"two User-Agents": "GET / HTTP/1.1\r\nUser-Agent: a\r\nUser-Agent: b\r\n" +
+			host,
+	} {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			standIn := startDiscriminator(t, allow)
+			app := startApp(t, greet)
+			addr, out := startRProxy(t, standIn.URL, app.URL, nil)
+
+			conn := dial(t, addr)
+			send(t, conn, request)
+
+			if status := readStatus(t, conn); status != http.StatusBadRequest {
+				t.Errorf("status %d, want 400", status)
+			}
+
+			line := out.requestLine(t)
+			if line["status"] != float64(http.StatusBadRequest) ||
+				line["disposition"] != nil || line["default_disposition"] != nil {
+				t.Errorf("line %v, want status 400 and no disposition", line)
+			}
+
+			if len(standIn.questions) != 0 {
+				t.Error("discriminator was asked")
+			}
+
+			standIn.wantNoReport(t)
+		})
+	}
+}
+
+func TestAHostWithAPercentSignButNoBracketGoesToDiscriminator(t *testing.T) {
+	t.Parallel()
+
+	const host = "a%b"
+
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, greet)
+	addr, _ := startRProxy(t, standIn.URL, app.URL, nil)
+
+	conn := dial(t, addr)
+	send(t, conn, "GET / HTTP/1.1\r\nHost: "+host+"\r\n\r\n")
+
+	if status := readStatus(t, conn); status != http.StatusOK {
+		t.Errorf("status %d, want the app's 200", status)
+	}
+
+	if asked := standIn.question(t); asked.host != host {
+		t.Errorf("asked about the host %q, want %q", asked.host, host)
+	}
+}
+
+func TestATrustedPeerWithNoForwardedProtoIsAskedAboutAsHTTP(t *testing.T) {
+	t.Parallel()
+
+	const want = "http"
+
+	standIn := startDiscriminator(t, allow)
+	app := startApp(t, greet)
+	addr, _ := startRProxy(t, standIn.URL, app.URL, map[string]string{
+		trustedProxies: localhost + "/32",
+	})
+
+	wantGreeting(t, get(t, addr, "/"))
+
+	asked := standIn.question(t)
+	if got := asked.header.Get(forwardedProtoHeader); got != want {
+		t.Errorf("the question's %s is %q, want %s", forwardedProtoHeader, got, want)
+	}
+}
+
+func TestAQuestionNamesNoZone(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name, remoteAddr, forwardedFor, client, peer string
+	}{
+		{"from a link-local peer", "[fe80::1%eth0]:1234", "", "fe80::1", "fe80::1"},
+		{
+			"from X-Forwarded-For through a trusted peer", localhost + ":1234",
+			"2001:db8::1%eth0", "2001:db8::1", localhost,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			standIn := startDiscriminator(t, deny)
+			app := startApp(t, greet)
+			_, out, server := startServer(t, standIn.URL, app.URL, map[string]string{
+				trustedProxies: localhost + "/32",
+			})
+
+			req := httptest.NewRequestWithContext(t.Context(), http.MethodGet, "/", http.NoBody)
+			req.RemoteAddr = tc.remoteAddr
+			req.Header.Set(forwardedForHeader, tc.forwardedFor)
+
+			server.Handler.ServeHTTP(httptest.NewRecorder(), req)
+
+			asked := standIn.question(t)
+			if asked.header.Get(discriminator.ClientHeader) != tc.client ||
+				asked.header.Get(discriminator.PeerHeader) != tc.peer {
+				t.Errorf("the question's headers are %v", asked.header)
+			}
+
+			if line := out.requestLine(t); line["client_ip"] != tc.client {
+				t.Errorf("line %v, want client_ip %s", line, tc.client)
+			}
+		})
+	}
+}

internal/rproxy/request.go

@@ -0,0 +1,593 @@
+package rproxy
+
+import (
+	"context"
+	"crypto/rand"
+	"errors"
+	"io"
+	"net/http"
+	"net/http/httptrace"
+	"net/http/httputil"
+	"net/netip"
+	"net/url"
+	"os"
+	"strconv"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+	"sneak.berlin/go/smallwebwaf/internal/rules"
+)
+
+// flushAfterEachWrite has ReverseProxy pass on each part of the app's answer as
+// soon as it arrives.
+const flushAfterEachWrite time.Duration = -1
+
+// reportStatusMax is the highest status discriminator takes in a report. An app can
+// send a higher one, up to 999, and the visitor gets that as it is.
+const reportStatusMax = 599
+
+// plainText is the Content-Type of the answers rproxy gives itself.
+const plainText = "text/plain; charset=utf-8"
+
+// request is one request on its way through rproxy, from the moment its headers
+// have been read to its log line and report.
+type request struct {
+	h  *handler
+	in *http.Request
+	// rc sets the deadlines of the connection to the visitor.
+	rc   *http.ResponseController
+	out  *responseWriter
+	body *requestBody // nil for a request without a body
+
+	// id is the fresh id made for the request when it arrived.
+	id          string
+	client      netip.Addr
+	peer        netip.Addr
+	peerTrusted bool
+	start       time.Time
+
+	// disposition is what is done with the request: discriminator's valid disposition,
+	// or SWRP_DEFAULT_DISPOSITION. It is "" when neither gave one.
+	disposition string
+	// answered is true when discriminator gave disposition, which makes a report due,
+	// and byDefault when SWRP_DEFAULT_DISPOSITION did.
+	answered  bool
+	byDefault bool
+	// asn and country are discriminator's X-Client-ASN and X-Client-Country, for the
+	// app.
+	asn, country string
+
+	// upstreamStart is when the request was handed to the app.
+	upstreamStart time.Time
+	// cancel ends the request to the app.
+	cancel context.CancelFunc
+	// refused is the status of the first refusal, from whichever goroutine meets
+	// it: what the visitor is answered if the response has not started yet.
+	refused atomic.Int64
+	// upgraded is the connection to the app once the app has switched protocols,
+	// as for a WebSocket, and nil otherwise.
+	upgraded *upgradedConn
+
+	// mu guards what follows. The time limits run on goroutines of their own,
+	// and the transport starts and stops them, and notes the times below, from
+	// its own; once timersStopped is set, neither time limit acts any more.
+	mu            sync.Mutex
+	timersStopped bool
+	requestTimer  *time.Timer
+	responseTimer *time.Timer
+	// requestEnd is when the app had been sent the whole request, or the answer
+	// started, if that was sooner.
+	requestEnd time.Time
+	// answerStarted is when the first byte of the app's answer arrived.
+	answerStarted time.Time
+}
+
+// newRequest starts handling r: it notes the time, works out the visitor from
+// the TCP peer and X-Forwarded-For, and makes the request's id.
+func (h *handler) newRequest(w http.ResponseWriter, r *http.Request) *request {
+	peer := peerAddress(r)
+	trusted := h.config.TrustedProxies
+
+	rq := &request{
+		h:           h,
+		in:          r,
+		rc:          http.NewResponseController(w),
+		out:         &responseWriter{ResponseWriter: w},
+		id:          rand.Text(),
+		client:      clientAddress(peer, r.Header.Values("X-Forwarded-For"), trusted),
+		peer:        peer,
+		peerTrusted: isInside(peer, trusted),
+		start:       time.Now(),
+	}
+
+	if r.Body != http.NoBody {
+		rq.body = &requestBody{body: limitBody(r.Body, h.config.MaxRequestSize), rq: rq}
+	}
+
+	return rq
+}
+
+// answerHealth answers the health check.
+func (rq *request) answerHealth() {
+	rq.prepareOwnAnswer(rq.requestDeadline())
+	rq.out.Header().Set("Content-Type", plainText)
+	rq.send(http.StatusOK, []byte("ok\n"))
+}
+
+// readFirstPartOfBody reads up to the first 64 KiB of the body into memory,
+// within SWRP_MAX_REQUEST_TIME_MS, and reports whether the request goes on. A
+// visitor too slow to send it is answered 408. For a malformed chunk, or a
+// visitor that went away or stopped its sending side, the connection is closed
+// without an answer. A body over SWRP_MAX_REQUEST_SIZE goes on with the part
+// read, so that discriminator is asked first; passToApp then refuses it.
+func (rq *request) readFirstPartOfBody() bool {
+	if rq.body == nil {
+		return true
+	}
+
+	_ = rq.rc.SetReadDeadline(rq.requestDeadline())
+	held, err := io.ReadAll(io.LimitReader(rq.body, discriminator.QuestionBodyMaxBytes))
+	// From here on, the request timer ends a read of the rest of the body, so that
+	// the answer can name the side rproxy was waiting on.
+	_ = rq.rc.SetReadDeadline(time.Time{})
+
+	rq.body.held = held
+
+	switch {
+	case err == nil || rq.refused.Load() != 0:
+		return true
+	case errors.Is(err, os.ErrDeadlineExceeded):
+		rq.answer(http.StatusRequestTimeout)
+
+		return false
+	default:
+		// This panic has Go's server close the connection without an answer, and
+		// log nothing; the deferred finish still runs.
+		panic(http.ErrAbortHandler)
+	}
+}
+
+// setPathAsSent has out, the URL of a request made from in, send the path as the
+// visitor sent it. Go sends the path URL.EscapedPath gives, which, for a path
+// holding a character Go escapes, such as |, is the whole path decoded and
+// escaped again, %2F turned into /. Opaque is sent as it is.
+func setPathAsSent(out *url.URL, in *http.Request) {
+	out.Opaque = rules.Path(in)
+}
+
+// forward passes the request to the app, the part of the body held and then the
+// rest, and the app's answer back. ctx is the request's own context.
+func (rq *request) forward(ctx context.Context) {
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	rq.cancel = cancel
+	ctx = httptrace.WithClientTrace(ctx, &httptrace.ClientTrace{
+		WroteRequest:         rq.wroteRequest,
+		GotFirstResponseByte: rq.gotFirstResponseByte,
+	})
+
+	out := rq.in.WithContext(ctx)
+	if rq.body != nil {
+		out.Body = rq.body
+	}
+
+	reverseProxy := &httputil.ReverseProxy{
+		Rewrite:        rq.rewrite,
+		Transport:      rq.h.transport,
+		FlushInterval:  flushAfterEachWrite,
+		ErrorLog:       rq.h.errorLog,
+		ModifyResponse: rq.modifyResponse,
+		ErrorHandler:   rq.answerError,
+	}
+
+	rq.startRequestTimer()
+	rq.upstreamStart = time.Now()
+	reverseProxy.ServeHTTP(rq.out, out)
+}
+
+// rewrite makes the request the app receives: the visitor's request, unchanged,
+// sent to SWRP_UPSTREAM_URL, with the forwarded headers and the request's id set,
+// without any X-Client-ASN or X-Client-Country the visitor sent, and with
+// discriminator's.
+func (rq *request) rewrite(pr *httputil.ProxyRequest) {
+	upstream := rq.h.config.UpstreamURL
+	pr.Out.URL.Scheme = upstream.Scheme
+	pr.Out.URL.Host = upstream.Host
+	// ReverseProxy drops query parameters it cannot parse; the app gets the
+	// query as the visitor sent it.
+	pr.Out.URL.RawQuery = pr.In.URL.RawQuery
+	setPathAsSent(pr.Out.URL, pr.In)
+
+	setForwardedHeaders(pr.In, pr.Out, rq.peer, rq.peerTrusted)
+	pr.Out.Header.Set(requestIDHeader, rq.id)
+	pr.Out.Header.Del(asnHeader)
+	pr.Out.Header.Del(countryHeader)
+
+	if rq.asn != "" {
+		pr.Out.Header.Set(asnHeader, rq.asn)
+	}
+
+	if rq.country != "" {
+		pr.Out.Header.Set(countryHeader, rq.country)
+	}
+}
+
+// modifyResponse looks at the app's answer before ReverseProxy passes it on.
+func (rq *request) modifyResponse(res *http.Response) error {
+	if res.StatusCode == http.StatusSwitchingProtocols {
+		// An upgraded connection, such as a WebSocket, is not cut by the time
+		// limits. ReverseProxy writes this answer straight to the connection it
+		// takes over, not through rq.out, and then copies what passes each way
+		// through res.Body, the connection to the app. It may still refuse the
+		// switch, as when the app's Upgrade is not the visitor's, so the status
+		// is noted only once it has taken over the connection, by rq.out's
+		// Hijack.
+		rq.stopTimers()
+
+		conn, ok := res.Body.(io.ReadWriteCloser)
+		if ok {
+			rq.upgraded = &upgradedConn{ReadWriteCloser: conn}
+			res.Body = rq.upgraded
+		}
+
+		return nil
+	}
+
+	maxBytes := rq.h.config.MaxResponseSize
+	if maxBytes > 0 && res.Body != http.NoBody && res.ContentLength > maxBytes {
+		rq.refuse(http.StatusBadGateway)
+
+		return errResponseTooLarge
+	}
+
+	// Go's server adds a Content-Type it guesses from the body to a response
+	// whose headers have no Content-Type key. The key with no value sends none,
+	// as the app sent none.
+	if res.Header.Get("Content-Type") == "" {
+		rq.out.Header()["Content-Type"] = nil
+	}
+
+	res.Body = &responseBody{body: limitBody(res.Body, maxBytes), rq: rq}
+	rq.setResponseDeadline()
+
+	return nil
+}
+
+// answerError is ReverseProxy's ErrorHandler: the request could not be passed to
+// the app, or the app's answer cannot be passed on.
+func (rq *request) answerError(_ http.ResponseWriter, _ *http.Request, err error) {
+	if rq.upgraded != nil {
+		// The app switched protocols, but the switch was not passed on, and
+		// ReverseProxy leaves the app's connection open when it refuses it.
+		_ = rq.upgraded.Close()
+	}
+
+	status := int(rq.refused.Load())
+	if status == 0 {
+		if rq.in.Context().Err() != nil {
+			// The visitor went away or stopped its sending side. This panic has Go's
+			// server close the connection without an answer, and log nothing; the
+			// deferred finish still runs.
+			panic(http.ErrAbortHandler)
+		}
+
+		rq.h.processLog.Warn("request to the app failed", "error", err.Error())
+
+		status = http.StatusBadGateway
+	}
+
+	rq.answer(status)
+}
+
+// answer sends rproxy's own answer, unless the response has already started.
+func (rq *request) answer(status int) {
+	rq.refused.CompareAndSwap(0, int64(status))
+
+	if rq.out.status != 0 {
+		return // too late to answer: the connection can only be cut
+	}
+
+	// A visitor found too slow is read no more; any other may go on sending until
+	// its time is up, so that Go's server can read the rest of the body and end
+	// the request cleanly.
+	deadline := rq.requestDeadline()
+	if status == http.StatusRequestTimeout {
+		deadline = time.Now()
+	}
+
+	rq.prepareOwnAnswer(deadline)
+
+	header := rq.out.Header()
+	header.Set("Content-Type", plainText)
+	header.Set("X-Content-Type-Options", "nosniff")
+	rq.send(status, []byte(http.StatusText(status)+"\n"))
+}
+
+// send gives the visitor an answer rproxy holds whole: status, the headers set so
+// far and body. Go's server would otherwise send so short an answer only once the
+// handler has returned, after finish has written the log line and sent the report.
+// Without Content-Length, the flush would send the body in chunks, the last of
+// which would still wait for the handler. A HEAD's answer has no body, so any
+// Content-Length it has stays as discriminator gave it.
+func (rq *request) send(status int, body []byte) {
+	if rq.in.Method != http.MethodHead {
+		rq.out.Header().Set("Content-Length", strconv.Itoa(len(body)))
+	}
+
+	rq.out.WriteHeader(status)
+	_, _ = rq.out.Write(body)
+	_ = rq.rc.Flush()
+}
+
+// prepareOwnAnswer readies the connection for an answer rproxy gives itself: the
+// reading of a body that has not arrived whole ends at deadline, and the answer
+// has SWRP_MAX_RESPONSE_TIME_MS from now to reach the visitor, even when the app
+// used that time up first.
+func (rq *request) prepareOwnAnswer(deadline time.Time) {
+	rq.stopReadingBody(deadline)
+	rq.endRequest()
+
+	limit := rq.h.config.MaxResponseTime
+	if limit > 0 {
+		_ = rq.rc.SetWriteDeadline(time.Now().Add(limit))
+	}
+}
+
+// refuse records status, unless an earlier refusal was, and ends the request to
+// the app, if one was made.
+func (rq *request) refuse(status int) {
+	rq.refused.CompareAndSwap(0, int64(status))
+
+	if rq.cancel != nil {
+		rq.cancel()
+	}
+}
+
+// finish ends the request's time limits, writes its log line and, if discriminator
+// answered the question, sends the report. ctx is the request's own context.
+func (rq *request) finish(ctx context.Context) {
+	rq.stopTimers()
+
+	if rq.refused.Load() == 0 {
+		rq.stopReadingBody(rq.requestDeadline())
+	}
+
+	requestEnd := rq.endRequest()
+	end := time.Now()
+	requestBytes, responseBytes := rq.bytesEachWay()
+
+	err := requestlog.WriteRProxyLine(rq.h.requestLog, &requestlog.RProxyLine{
+		Time:               requestlog.FormatTime(rq.start),
+		RequestID:          rq.id,
+		ClientIP:           rq.client.String(),
+		Host:               rq.in.Host,
+		Method:             rq.in.Method,
+		Path:               rules.Path(rq.in),
+		Query:              rq.in.URL.RawQuery,
+		Status:             rq.out.status,
+		RequestBytes:       requestBytes,
+		ResponseBytes:      responseBytes,
+		DurationRequest:    requestlog.Milliseconds(requestEnd.Sub(rq.start)),
+		DurationResponse:   requestlog.Milliseconds(end.Sub(requestEnd)),
+		Disposition:        rq.disposition,
+		DefaultDisposition: rq.byDefault,
+	})
+	if err != nil {
+		rq.h.processLog.Error("writing the request log failed", "error", err.Error())
+	}
+
+	if !rq.answered {
+		return
+	}
+
+	report := &discriminator.Report{
+		RequestID:     rq.id,
+		Status:        min(rq.out.status, reportStatusMax),
+		RequestBytes:  requestBytes,
+		ResponseBytes: responseBytes,
+		DurationTotal: requestlog.Milliseconds(end.Sub(rq.start)),
+	}
+	if !rq.upstreamStart.IsZero() {
+		report.DurationUpstreamTotal = requestlog.Milliseconds(end.Sub(rq.upstreamStart))
+	}
+
+	rq.h.sendReport(ctx, report)
+}
+
+// bytesEachWay returns the body bytes of the request and of the answer. For an
+// upgraded connection, such as a WebSocket, which has closed by then, what it
+// carried from the visitor counts with the request's and what it carried from the
+// app with the answer's.
+func (rq *request) bytesEachWay() (int64, int64) {
+	var requestBytes int64
+	if rq.body != nil {
+		requestBytes = rq.body.bytes.Load()
+	}
+
+	responseBytes := rq.out.bytes
+
+	if rq.upgraded != nil {
+		requestBytes += rq.upgraded.toApp.Load()
+		responseBytes += rq.upgraded.fromApp.Load()
+	}
+
+	return requestBytes, responseBytes
+}
+
+// requestDeadline is when the visitor must have sent its whole request, or zero
+// when SWRP_MAX_REQUEST_TIME_MS is off.
+func (rq *request) requestDeadline() time.Time {
+	limit := rq.h.config.MaxRequestTime
+	if limit == 0 {
+		return time.Time{}
+	}
+
+	return rq.start.Add(limit)
+}
+
+// stopReadingBody ends, at deadline, the reading of a visitor's body that has not
+// arrived whole: Go's server then reads no more of it, and closes the connection
+// after the answer.
+func (rq *request) stopReadingBody(deadline time.Time) {
+	if rq.body == nil || rq.body.received.Load() {
+		return
+	}
+
+	_ = rq.rc.SetReadDeadline(deadline)
+}
+
+// startRequestTimer starts SWRP_MAX_REQUEST_TIME_MS, which runs from the
+// request's headers being read until the app has been sent the whole request.
+func (rq *request) startRequestTimer() {
+	deadline := rq.requestDeadline()
+	if deadline.IsZero() {
+		return
+	}
+
+	rq.mu.Lock()
+	defer rq.mu.Unlock()
+
+	rq.requestTimer = time.AfterFunc(time.Until(deadline), rq.requestTimedOut)
+}
+
+// requestTimedOut is called when SWRP_MAX_REQUEST_TIME_MS runs out while the
+// request is still on its way to the app. The answer names the side rproxy was
+// waiting on at that moment: 408 when it was waiting for the visitor to send more
+// of its body, 504 when it was waiting for the app to be reached or to take what
+// it had.
+func (rq *request) requestTimedOut() {
+	rq.mu.Lock()
+	defer rq.mu.Unlock()
+
+	if rq.timersStopped {
+		return
+	}
+
+	if rq.body == nil || !rq.body.waiting.Load() {
+		// Once the app has answered, the transport, ReverseProxy and Go's server
+		// each close the visitor's body, and closing it reads what is left of a
+		// body under 256 KiB without requestBody.Read, so waiting is false while
+		// that read waits for the visitor. That read ends now, before refuse:
+		// should rproxy still answer itself, answer then sets the deadline it
+		// gives its own answers.
+		if !rq.answerStarted.IsZero() {
+			rq.stopReadingBody(time.Now())
+		}
+
+		rq.refuse(http.StatusGatewayTimeout)
+
+		return
+	}
+
+	rq.refuse(http.StatusRequestTimeout)
+	// The transport gives up on the app only once its Read of the visitor's body
+	// returns, so that Read is ended now. The lock keeps this from reaching the
+	// connection after the request is handled.
+	_ = rq.rc.SetReadDeadline(time.Now())
+}
+
+// gotFirstResponseByte is called once the first byte of the app's answer has
+// arrived.
+func (rq *request) gotFirstResponseByte() {
+	rq.mu.Lock()
+	defer rq.mu.Unlock()
+
+	rq.answerStarted = time.Now()
+}
+
+// wroteRequest is called once the app has been sent the whole request:
+// SWRP_MAX_REQUEST_TIME_MS ends and SWRP_MAX_RESPONSE_TIME_MS starts.
+func (rq *request) wroteRequest(info httptrace.WroteRequestInfo) {
+	if info.Err != nil {
+		return // the transport gives up, or tries again
+	}
+
+	requestEnd := rq.endRequest()
+
+	rq.mu.Lock()
+	defer rq.mu.Unlock()
+
+	if rq.timersStopped {
+		return
+	}
+
+	stopTimer(rq.requestTimer)
+
+	limit := rq.h.config.MaxResponseTime
+	if limit > 0 {
+		rq.responseTimer = time.AfterFunc(time.Until(requestEnd.Add(limit)),
+			rq.responseTimedOut)
+	}
+}
+
+// responseTimedOut is called when SWRP_MAX_RESPONSE_TIME_MS runs out before the
+// app has sent its whole answer.
+func (rq *request) responseTimedOut() {
+	rq.mu.Lock()
+	defer rq.mu.Unlock()
+
+	if !rq.timersStopped {
+		rq.refuse(http.StatusGatewayTimeout)
+	}
+}
+
+// responseReceived is called once the app has sent its whole answer. An app may
+// answer before the visitor has sent its whole body, as with a 404 it sends
+// without reading it. The time limits then run on: until the transport's read of
+// the body returns, Go's server cannot send the answer, and
+// SWRP_MAX_REQUEST_TIME_MS is what ends that read for a visitor that stops
+// sending.
+func (rq *request) responseReceived() {
+	if rq.body != nil && !rq.body.received.Load() {
+		return
+	}
+
+	rq.stopTimers()
+}
+
+// setResponseDeadline sets SWRP_MAX_RESPONSE_TIME_MS on the connection to the
+// visitor: the app's answer must reach the visitor within it of the end of the
+// request.
+func (rq *request) setResponseDeadline() {
+	requestEnd := rq.endRequest()
+
+	limit := rq.h.config.MaxResponseTime
+	if limit > 0 {
+		_ = rq.rc.SetWriteDeadline(requestEnd.Add(limit))
+	}
+}
+
+// endRequest notes now as the end of the request, unless an end is noted, and
+// returns the end noted.
+func (rq *request) endRequest() time.Time {
+	rq.mu.Lock()
+	defer rq.mu.Unlock()
+
+	if rq.requestEnd.IsZero() {
+		rq.requestEnd = time.Now()
+	}
+
+	return rq.requestEnd
+}
+
+// stopTimers stops the request's time limits and keeps any from starting later:
+// the app's answer is complete, the connection upgraded, or the request handled.
+func (rq *request) stopTimers() {
+	rq.mu.Lock()
+	defer rq.mu.Unlock()
+
+	rq.timersStopped = true
+	stopTimer(rq.requestTimer)
+	stopTimer(rq.responseTimer)
+}
+
+// stopTimer stops t, which is nil when its time limit is off.
+func stopTimer(t *time.Timer) {
+	if t != nil {
+		t.Stop()
+	}
+}

internal/rproxy/rproxy.go

@@ -0,0 +1,228 @@
+// Package rproxy is the reverse proxy in front of one app that asks discriminator
+// about each request. It passes a request discriminator allows to the app and the
+// app's answer back, within the size and time limits. Any other answer from
+// discriminator goes to the visitor as discriminator gave it. SWRP_DEFAULT_DISPOSITION
+// decides only when discriminator cannot be connected to, does not answer at all, or
+// does not answer within SWRP_TIMEOUT_MS. rproxy itself refuses a request with a
+// method it does not pass on, or one it cannot put to discriminator as the visitor
+// sent it. It keeps nothing between requests and never touches disk. "rproxy" in
+// SPEC.md says what it does.
+package rproxy
+
+import (
+	"context"
+	"io"
+	"log"
+	"log/slog"
+	"net/http"
+	"net/url"
+	"slices"
+	"strings"
+	"sync"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/config"
+	"sneak.berlin/go/smallwebwaf/internal/discriminator"
+)
+
+// How rproxy keeps connections to the app and to discriminator open between
+// requests.
+const (
+	idleConns       = 100
+	idleConnTimeout = 90 * time.Second
+)
+
+// The limits on a connection from a visitor that have no setting.
+const (
+	// requestHeaderMaxBytes is the largest request line and headers a visitor
+	// may send.
+	requestHeaderMaxBytes = 32 << 10
+	// goServerExtraHeaderBytes is how far past MaxHeaderBytes Go's server reads
+	// before it refuses.
+	goServerExtraHeaderBytes = 4 << 10
+	// idleTimeout is how long a kept-open connection may wait for its next
+	// request.
+	idleTimeout = 120 * time.Second
+)
+
+// adminPrefix starts the path of every request for sww itself, which
+// never reaches the app.
+const adminPrefix = "/_sww/"
+
+// allowedMethods lists the methods rproxy passes on, as an Allow header gives
+// them. It answers any other method 405 itself.
+const allowedMethods = "GET, HEAD, POST, OPTIONS, PUT, DELETE, PATCH, QUERY"
+
+// Params are what New needs.
+type Params struct {
+	Config *config.RProxy
+	// RequestLog receives one short JSON line per request.
+	RequestLog io.Writer
+	// ProcessLog receives the process's own messages.
+	ProcessLog *slog.Logger
+}
+
+// Server is the server `sww rproxy` runs.
+type Server struct {
+	*http.Server
+
+	h *handler
+}
+
+// New returns the server `sww rproxy` runs. Go's server itself refuses
+// a request line and headers over requestHeaderMaxBytes, with 431, closes a
+// connection idle for idleTimeout, and applies SWRP_MAX_REQUEST_TIME_MS while
+// the headers arrive. The handler applies the time and size limits from then
+// on.
+func New(params Params) *Server {
+	backend := params.Config.WAFBackend
+	errorLog := slog.NewLogLogger(params.ProcessLog.Handler(), slog.LevelWarn)
+	h := &handler{
+		config:                 params.Config,
+		requestLog:             params.RequestLog,
+		processLog:             params.ProcessLog,
+		errorLog:               errorLog,
+		transport:              newTransport(),
+		discriminatorTransport: newDiscriminatorTransport(),
+		reportURL: (&url.URL{
+			Scheme: backend.Scheme, Host: backend.Host, Path: discriminator.ReportPath,
+		}).String(),
+	}
+
+	return &Server{
+		Server: &http.Server{
+			Addr:              params.Config.ListenAddr,
+			Handler:           h,
+			ErrorLog:          errorLog,
+			ReadHeaderTimeout: params.Config.MaxRequestTime,
+			IdleTimeout:       idleTimeout,
+			MaxHeaderBytes:    requestHeaderMaxBytes - goServerExtraHeaderBytes,
+		},
+		h: h,
+	}
+}
+
+// WaitForReports returns once the reports being sent have gone or failed,
+// which SWRP_TIMEOUT_MS bounds. Any report after this call is dropped: that of
+// a WebSocket that closes while rproxy stops, for one.
+func (s *Server) WaitForReports() {
+	s.h.reportsMu.Lock()
+	s.h.reportsStopped = true
+	s.h.reportsMu.Unlock()
+
+	s.h.reports.Wait()
+}
+
+// handler is the proxy. It holds what every request shares; what belongs to
+// one request is in a request.
+type handler struct {
+	config     *config.RProxy
+	requestLog io.Writer
+	processLog *slog.Logger
+	errorLog   *log.Logger
+	// transport carries requests to the app, and discriminatorTransport questions and
+	// reports to discriminator.
+	transport              http.RoundTripper
+	discriminatorTransport http.RoundTripper
+	// reportURL is where the reports go.
+	reportURL string
+	// reports waits for the reports being sent. reportsMu guards starting one
+	// against reportsStopped, which is set once nothing is to wait for another.
+	reports        sync.WaitGroup
+	reportsMu      sync.Mutex
+	reportsStopped bool
+}
+
+// newTransport returns what carries requests to the app. It never goes through
+// a proxy named in the environment, and leaves answers compressed or not as they
+// were sent.
+func newTransport() *http.Transport {
+	return &http.Transport{
+		MaxIdleConns:        idleConns,
+		MaxIdleConnsPerHost: idleConns,
+		IdleConnTimeout:     idleConnTimeout,
+		DisableCompression:  true,
+	}
+}
+
+// newDiscriminatorTransport returns what carries questions and reports to
+// discriminator. It speaks HTTP/1.1 only. Go's HTTP/2 client refuses to send
+// a visitor's Upgrade header, or a Connection header other than close or
+// keep-alive, and that would read as discriminator giving no answer.
+func newDiscriminatorTransport() *http.Transport {
+	transport := newTransport()
+	transport.Protocols = new(http.Protocols)
+	transport.Protocols.SetHTTP1(true)
+
+	return transport
+}
+
+// ServeHTTP handles one request: it answers the health check itself, refuses a
+// request with a method it does not pass on or one it cannot put to discriminator as
+// the visitor sent it, and for any other request reads the first part of the
+// body, asks discriminator, and does what the answer says. Once the answer has ended,
+// it writes the request's log line and sends its report.
+func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	rq := h.newRequest(w, r)
+	defer rq.finish(r.Context())
+
+	if r.Method == http.MethodGet && r.URL.Path == discriminator.HealthPath {
+		rq.answerHealth()
+
+		return
+	}
+
+	if !slices.Contains(strings.Split(allowedMethods, ", "), r.Method) {
+		rq.out.Header().Set("Allow", allowedMethods)
+		rq.answer(http.StatusMethodNotAllowed)
+
+		return
+	}
+
+	if !canBeAsked(r) {
+		rq.answer(http.StatusBadRequest)
+
+		return
+	}
+
+	if !rq.readFirstPartOfBody() {
+		return
+	}
+
+	answer, err := rq.ask(r.Context())
+	if err != nil {
+		rq.handleNoUsableAnswer(r.Context(), err)
+
+		return
+	}
+
+	rq.noteAnswer(answer)
+
+	switch rq.disposition {
+	case discriminator.DispositionAllow:
+		rq.passToApp(r.Context())
+	case discriminator.DispositionClose:
+		// This panic has Go's server close the connection without an answer,
+		// and log nothing; the deferred finish still runs.
+		panic(http.ErrAbortHandler)
+	default: // a deny, an error, or an answer without a valid disposition
+		rq.answerWith(answer)
+	}
+}
+
+// passToApp passes the request on to the app, unless a limit or its path keeps
+// it from the app. discriminator answers a path under adminPrefix itself, so such a
+// request gets here only when SWRP_DEFAULT_DISPOSITION allowed it. ctx is the
+// request's own context.
+func (rq *request) passToApp(ctx context.Context) {
+	maxBytes := rq.h.config.MaxRequestSize
+
+	switch {
+	case rq.refused.Load() != 0 || (maxBytes > 0 && rq.in.ContentLength > maxBytes):
+		rq.answer(http.StatusRequestEntityTooLarge)
+	case strings.HasPrefix(rq.in.URL.Path, adminPrefix):
+		rq.answer(http.StatusNotFound)
+	default:
+		rq.forward(ctx)
+	}
+}

internal/rules/rules.go

@@ -1,5 +1,5 @@
 // Package rules reads the rule files: the plain text files in
-// SWWAF_RULES_DIR, one rule to a line, that each request is checked
+// SWW_RULES_DIR, one rule to a line, that each request is checked
 // against, as the "Rule files" section of SPEC.md describes. They are read
 // at start, and again once the directory has had no change for a short
 // time after one is edited, added or removed.
@@ -40,7 +40,7 @@ const (
 // extension ends the name of every rule file.
 const extension = ".rules"
 
-// quietTime is how long SWWAF_RULES_DIR must go without a change before
+// quietTime is how long SWW_RULES_DIR must go without a change before
 // the rule files are read again, so that a file still being written, such
 // as one saved in place, appended to or copied in with scp, is read only
 // once whole.
@@ -100,19 +100,19 @@ type Rule struct {
 
 // Params are what Load needs.
 type Params struct {
-	// Dir is the directory of the rule files (SWWAF_RULES_DIR).
+	// Dir is the directory of the rule files (SWW_RULES_DIR).
 	Dir string
-	// Enabled is SWWAF_RULES_ENABLED: while it is false, no file is read
+	// Enabled is SWW_RULES_ENABLED: while it is false, no file is read
 	// and no rule loaded.
 	Enabled bool
 	// ProcessLog receives how many rules were read, and the error in a
-	// rule file edited while smallwebwaf runs.
+	// rule file edited while sww runs.
 	ProcessLog *slog.Logger
 	// Alerts receive a file_error alert for that error.
 	Alerts *alerts.Queue
 }
 
-// Files are the rule files of a running smallwebwaf, and the rules read
+// Files are the rule files of a running sww, and the rules read
 // from them. They are safe for concurrent use.
 type Files struct {
 	params Params
@@ -271,7 +271,7 @@ func (f *Files) logRead(count int) {
 func read(dir string) ([]Rule, string, error) {
 	entries, err := os.ReadDir(dir)
 	if err != nil {
-		return nil, dir, fmt.Errorf("SWWAF_RULES_DIR cannot be read: %w", err)
+		return nil, dir, fmt.Errorf("SWW_RULES_DIR cannot be read: %w", err)
 	}
 
 	var rules []Rule
@@ -299,7 +299,7 @@ func read(dir string) ([]Rule, string, error) {
 // readFile appends the rules of the rule file at path to rules. places
 // are where each id read so far is, and gain those of the file.
 func readFile(path string, rules []Rule, places map[string]string) ([]Rule, error) {
-	data, err := os.ReadFile(path) //nolint:gosec // a rule file, in SWWAF_RULES_DIR
+	data, err := os.ReadFile(path) //nolint:gosec // a rule file, in SWW_RULES_DIR
 	if err != nil {
 		return nil, err
 	}

internal/rules/rules_test.go

@@ -298,7 +298,7 @@ func TestDirectoryThatDoesNotExistStopsTheStart(t *testing.T) {
 
 	dir := filepath.Join(t.TempDir(), "rules.d")
 
-	wantRefused(t, dir, "SWWAF_RULES_DIR cannot be read: open "+dir+
+	wantRefused(t, dir, "SWW_RULES_DIR cannot be read: open "+dir+
 		": no such file or directory")
 }
 
@@ -321,7 +321,7 @@ func TestEmptyDirectoryLoadsNoRulesAndSaysSo(t *testing.T) {
 func TestRuleFilesOffReadNothing(t *testing.T) {
 	t.Parallel()
 
-	// SWWAF_RULES_DIR does not exist, which would stop the start.
+	// SWW_RULES_DIR does not exist, which would stop the start.
 	params, _ := newParams(filepath.Join(t.TempDir(), "rules.d"))
 	params.Enabled = false
 
@@ -601,7 +601,7 @@ func wantRefused(t *testing.T, dir, want string) {
 }
 
 // get returns a GET request for target, a path and an optional query, as
-// smallwebwaf's server reads it, without a user agent.
+// sww's server reads it, without a user agent.
 func get(t *testing.T, target string) *http.Request {
 	t.Helper()
 

internal/smallwebwaf/healthcheck.go

@@ -1,102 +0,0 @@
-package smallwebwaf
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"io"
-	"net"
-	"net/http"
-	"net/url"
-	"time"
-
-	"sneak.berlin/go/smallwebwaf/internal/config"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
-)
-
-// healthCheckTimeout bounds the whole health check.
-const healthCheckTimeout = 5 * time.Second
-
-var errHealthEndpoint = errors.New("smallwebwaf's health endpoint answered")
-
-// HealthCheck is the container's health check. It returns 0 while
-// smallwebwaf answers its health endpoint on 127.0.0.1, at the port in
-// SWWAF_LISTEN_ADDR, and the app accepts connections at the address in
-// SWWAF_UPSTREAM_URL. Otherwise it writes why to stderr and returns 1.
-// It reads no other setting, nor a file that another names, so neither
-// can fail it.
-// args are the arguments after `healthcheck`; it takes none, and given
-// one it names it on stderr and returns 1 without checking anything.
-func HealthCheck(
-	ctx context.Context, args []string, lookupEnv func(string) (string, bool),
-	stderr io.Writer,
-) int {
-	if len(args) > 0 {
-		_, _ = fmt.Fprintf(stderr,
-			"smallwebwaf healthcheck: unexpected argument %q\n", args[0])
-
-		return 1
-	}
-
-	err := healthCheck(ctx, lookupEnv)
-	if err != nil {
-		_, _ = fmt.Fprintln(stderr, "unhealthy:", err)
-
-		return 1
-	}
-
-	return 0
-}
-
-func healthCheck(ctx context.Context, lookupEnv func(string) (string, bool)) error {
-	ctx, cancel := context.WithTimeout(ctx, healthCheckTimeout)
-	defer cancel()
-
-	listenAddr, upstreamURL, err := config.ListenAddrAndUpstreamURL(lookupEnv)
-	if err != nil {
-		return fmt.Errorf("invalid setting: %w", err)
-	}
-
-	// The settings have checked that the address has a port.
-	_, port, _ := net.SplitHostPort(listenAddr)
-	health := "http://" + net.JoinHostPort("127.0.0.1", port) + proxy.HealthPath
-
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, health, http.NoBody)
-	if err != nil {
-		return fmt.Errorf("make the request: %w", err)
-	}
-
-	res, err := http.DefaultClient.Do(req)
-	if err != nil {
-		return fmt.Errorf("ask smallwebwaf: %w", err)
-	}
-
-	_ = res.Body.Close()
-
-	if res.StatusCode != http.StatusOK {
-		return fmt.Errorf("%w %s", errHealthEndpoint, res.Status)
-	}
-
-	conn, err := (&net.Dialer{}).DialContext(ctx, "tcp", appAddress(upstreamURL))
-	if err != nil {
-		return fmt.Errorf("connect to the app: %w", err)
-	}
-
-	_ = conn.Close()
-
-	return nil
-}
-
-// appAddress is the host and port of the app's URL, the port being the
-// scheme's own when the URL names none.
-func appAddress(app *url.URL) string {
-	port := app.Port()
-	if port == "" {
-		port = "80"
-		if app.Scheme == "https" {
-			port = "443"
-		}
-	}
-
-	return net.JoinHostPort(app.Hostname(), port)
-}