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Author SHA1 Message Date
clawbot 82e20e0cb5 Anomaly thresholds: alerts for unusual traffic, nothing refused (closes #101)
check / check (push) Waiting to run
Details 
SWWAF_ANOMALY_CLIENT_*, _NET_*, _ASN_*, _TOTAL_* and SWWAF_WATCH_* with
SWWAF_WATCH_NETS: requests and bytes per minute and per hour, each off by
default; with all off, nothing is counted. Otherwise every request but the
health check is counted, allow-listed and exempt ones included; a count
over its threshold raises an anomaly alert, with a cooldown per scope. At
most 20,000 counters, kept in alerts.json. A per-AS-number threshold with
lookups off, or a malformed SWWAF_WATCH_NETS, stops the start. A cooldown
that has run out is dropped as the hour ends, whatever it held back; the
hour's summary gives its repeats.

Judgement call: refused requests are counted too.
Judgement call: per-client counters are kept in alerts.json, which SPEC.md does not list.
Judgement call: a request counts for an AS number only if the lookup answered before it ended.

Model: opus-5-5
 2026-10-07 16:12:19 +02:00
clawbot 2421cdc273 Lower limits for listed AS numbers and countries (closes #21)
check / check (push) Waiting to run
Details 
SWWAF_ASN_LIMIT_PERCENT and SWWAF_COUNTRY_LIMIT_PERCENT give the clients
of the AS numbers and countries they list that percentage of every rate
and byte limit, rounded down; SWWAF_ASN_BYTES_PERCENT and
SWWAF_COUNTRY_BYTES_PERCENT take its place for the byte limits of those
they list; SWWAF_UNKNOWN_LIMIT_PERCENT (100) covers clients without a
country. The lowest applies. While one lowers a limit, a request waits
for its client's lookup, and SWWAF_LOOKUP_SOURCE=off stops the start. Log
lines give limit_percent and bytes_percent with their settings; ban
notes, and so alerts, give the broken limit's.

Judgement call: a client without a country is unknown, whatever its AS number.
Judgement call: bytes_percent and its setting are log fields SPEC does not name.
Rule suppressed: funlen on FromEnvironment, one line per setting.

Model: opus-5-5
 2026-10-07 14:22:01 +02:00
clawbot f35e3ddfe8 Byte limits per client over a minute, an hour and a day (closes #20)
check / check (push) Waiting to run
Details 
SWWAF_BYTES_LIMIT_PER_MINUTE, _PER_HOUR and _PER_DAY (10G, 20G, 50G)
and SWWAF_BYTES_COUNT (both). A request's bytes are counted once its
answer has ended, for a request passed to the app that the rate limits
count; what a WebSocket carries each way, once it closes. Bytes over a
limit ban the client as a broken rate limit does, and cut nothing
short. clients.json keeps the byte buckets, the log line's counts carry
the byte totals, ban notes say what the limit is on, and the limit hits
metric is labelled by kind.

Judgement call: limit_hit names a byte window minute_bytes, hour_bytes
or day_bytes, as counts names the byte totals.
Judgement call: in observe mode, the bytes of a request enforce mode
would have refused are not counted.

Model: opus-5-5
 2026-10-07 13:13:06 +02:00
clawbot 0dc26041dc make tidy, and make check failing on an untidy go.mod or go.sum (closes #99)
check / check (push) Waiting to run
Details 
script/tidy runs `go mod tidy` in a new tidy stage of the Dockerfile,
on the test phase's Go image, and writes go.mod and go.sum back into the
working tree with `docker build --output`. The test phase now runs
`go mod tidy -diff` before the tests and fails naming `make tidy`; it
comes first because a missing go.sum line otherwise fails the tests with
Go's own message.

Judgement call: script/tidy's build has no tag, unlike the other builds
in script/: it makes no image.

Model: opus-5-5
 2026-10-07 10:30:46 +02:00
clawbot c80753c56e Look clients up in the IPinfo Lite file with SWWAF_LOOKUP_SOURCE=file (closes #22)
check / check (push) Waiting to run
Details 
SWWAF_LOOKUP_SOURCE=file looks every client up in the file
SWWAF_LOOKUP_DB_PATH names, without GeoJS. file without the path, the
path with another source, or a file that cannot be read stops the start.
The file is read whole into memory, so overwriting it in place cannot
disturb a lookup, and read again 2 seconds after its last change; a
replacement that cannot be read is logged, counted and sent as a
file_error alert, and the old one stays in use. Metrics give when it
was read and the failed reads. Tests write their databases through
internal/lookup/lookuptest.

Deviation: go.mod and go.sum written by hand; go runs only through make.
Judgement call: the 2-second wait, as the rule files have.

Model: opus-5-5
 2026-10-07 10:04:10 +02:00
clawbot 26f4abef7f AS number and country looked up for every client (closes #95)
check / check (push) Waiting to run
Details 
GeoJS's geo.json is asked about every new visitor unless
SWWAF_LOOKUP_SOURCE is off. A request waits for its client's first
answer only while a country list or SWWAF_ADD_LOOKUP_HEADERS needs it;
otherwise the answer reaches the client's history and ban notes when it
comes. The AS number and name go beside the country in the request log,
history, ban notes, alerts and lookups.json, with metrics by AS number;
64512 counts as unknown. A client's own X-Client-ASN and
X-Client-Country never reach the app, whatever the setting says, and
make example-app sends no address to GeoJS.

Judgement call: AS numbers are written AS64496, as SPEC's settings write them.
Judgement call: SWWAF_LOOKUP_TIMEOUT is added, default 1s, and cannot be off.

Model: opus-5-5
 2026-10-07 08:46:01 +02:00
clawbot f35cbd01cf Instance name on process log lines and every metric (closes #91)
check / check (push) Waiting to run
Details 
Process log lines carry instance, as request lines do; the instance name
is read before the other settings, so the line saying a setting is
invalid carries it too. Every metric, Go's and the process's included,
carries the label instance, set once on the registry. README.md says so,
and that Prometheus keeps it as exported_instance unless the scrape sets
honor_labels. An instance name that is not valid UTF-8 stops the start,
as the metrics library panics on such a label.

Tests that read metrics expect the label; one helper replaces the alert
tests' loops that wait for them.

Judgement call: the label is named instance, as in the log lines and
alerts, although Prometheus gives each target a label of that name.

Model: opus-5-5
 2026-10-07 06:48:09 +02:00
clawbot 70a8ea1b92 Alerts to Slack and ntfy, each destination with its own queue (closes #90)
check / check (push) Waiting to run
Details 
Each alert is posted as a message to the Slack incoming webhook
SWWAF_ALERT_SLACK_WEBHOOK_URL names, and published to the ntfy topic
SWWAF_ALERT_NTFY_URL names, with SWWAF_ALERT_NTFY_TOKEN as a bearer
token and a priority and tag by event. The cooldown and the hourly
limit stay shared; past them, each destination has its own bounded
queue and backoff, and its own sent, failed and dropped counts.
alerts.json keeps the alerts waiting by destination; one whose waiting
is still a list stops the start, saying what to change. A control
character in the ntfy token, or in the instance name ntfy is sent,
stops the start.

Judgement call: messages also give the detail's file, source, error and mode.
Judgement call: alerts_suppressed_total is the same for every destination.

Model: opus-5-5
 2026-10-07 05:54:34 +02:00
clawbot 432097ee3f Alerts to a JSON webhook, with a cooldown and an hourly summary (closes #26)
check / check (push) Waiting to run
Details 
SWWAF_ALERT_WEBHOOK_URL gets one JSON POST per alert, in SPEC.md's
schema, with SWWAF_ALERT_WEBHOOK_HEADERS: ban and permanent_ban, with
the ban's notes, in observe mode too, marked mode observe and worked
out only when the alert would be sent; source_failure for GeoJS;
file_error for a rule or state file with an error. SWWAF_ALERT_EVENTS
chooses; SWWAF_ALERT_COOLDOWN holds back repeats by netblock, file or
source; past SWWAF_ALERT_MAX_PER_HOUR the hour ends in one summary. A
bounded queue, retried with backoff, holds up no request; a 4xx other
than 408 and 429 gives the alert up. alerts.json keeps the queue, the
cooldowns and the hour. Nothing shows the URL's path or query.

Judgement call: the summary's event is summary, which SPEC.md omits.
Judgement call: an admin's ban raises no alert.

Model: opus-5-5
 2026-10-07 04:21:24 +02:00
clawbot 5d6f6ffaf9 Admin endpoints for bans and clients on the single listener (closes #27)
check / check (push) Successful in 4m26s
Details 
SWWAF_ADMIN_TOKEN, or its _FILE form, opens GET and POST
/_smallwebwaf/bans, DELETE /_smallwebwaf/bans/<client> and GET
/_smallwebwaf/clients/<ip>. Unset, they answer 404; a missing or wrong
token gets 401, in observe mode too. They go through every check, as
the metrics do. POST takes a netblock, not IPv4-mapped and without a
zone, or a client's address, a duration or permanent, and a reason, and
makes an admin ban even while another lasts. DELETE lifts every active
ban covering the address, kept and marked lifted. Bans come back as
bans.json entries; a client as clients.json holds it, with its bans.

Judgement call: answers leave out bans.json's version field.
Judgement call: DELETE takes an address, not a netblock.
Rule suppressed: gosec G304 on a test reading bans.json.

Model: opus-5-5
 2026-10-07 01:13:16 +02:00
clawbot bff65f4e2f Settings given as files: the _FILE form of every setting (closes #87)
check / check (push) Successful in 4m53s
Details 
Every setting X may instead be given as a file that X_FILE names, read
once at start: its contents, less one trailing newline, are the value,
checked as X would be. X and X_FILE both set, or a file that cannot be
read, stops the start with a message naming the variable. The logged
settings name the file, and mask a token read from one.
SWWAF_LOG_REMOTE_TLS_CA_FILE, whose value is a file already, has no
_FILE form. The health check reads only SWWAF_LISTEN_ADDR and
SWWAF_UPSTREAM_URL, so no other setting or file can fail it.

Judgement call: an invalid value read from a file is named as X, not X_FILE.
Rule suppressed: gosec G304 on reading the named file, as for the CA file.

Model: opus-5-5
 2026-10-07 00:01:19 +02:00
clawbot ee9ba08a8a Bans an admin makes or lifts: the admin cause, a reason, lifted bans kept (closes #86)
check / check (push) Successful in 3m27s
Details 
A bans.json entry without a cause gets the cause admin, written back so.
Bans whose cause is admin are never dropped and do not count toward
SWWAF_MAX_BANS, so setting a ban's cause to admin keeps it. Bans
smallwebwaf makes get a reason: the limit broken or the rule matched. A
lifted ban refuses nothing, is kept, and makes no later ban longer.
smallwebwaf_bans_made_total counts admin bans an edit adds while running;
earlier_bans counts admin in place of without_cause.

Judgement call: lifted lifts at once, whatever time it gives.
Judgement call: a lifted ban still counts in earlier_bans.
Known gap: a ban dropped from behind an admin's ban on its netblock leaves that netblock's later earlier_bans.

Model: opus-5-5
 2026-10-06 23:09:52 +02:00
clawbot 0797e5def2 Send every log line to a syslog server as well (closes #28)
check / check (push) Successful in 3m3s
Details 
With SWWAF_LOG_REMOTE_URL set (syslog+udp, syslog+tcp or syslog+tls),
every line on stdout is also sent as the message of an RFC 5424 record,
octet-counted over TCP and TLS, from a bounded buffer that drops its
oldest line when full, so a slow or unreachable server holds up nothing.
Failed connections are retried with backoff; lines sent, dropped and
waiting are metrics. At a stop the lines still waiting get at most two
seconds. SWWAF_LOG_REMOTE_APP_NAME defaults to SWWAF_INSTANCE_NAME; while
sending, an app name RFC 5424 does not allow stops the start. Standard
library only: log/syslog writes only the older format.

Model: opus-5-5
 2026-10-06 22:02:36 +02:00
clawbot e77dfb6891 Rule files, and bans for a clear sign of attack (closes #24)
check / check (push) Successful in 3m29s
Details 
Every *.rules file in SWWAF_RULES_DIR not named with a leading dot is
read at start, and again 2 seconds after the directory's last change.
Each request is checked against the rules after the rate limits: log
notes a match, block refuses with 403, ban refuses and bans the netblock
for SWWAF_ATTACK_BAN_DURATION, made permanent by its next request or
attack. path, query and uri are matched as the request line sent them;
header:Host and header:Transfer-Encoding are refused. Bans gain a cause.
The image ships 00-default.rules.

Judgement call: a header sent twice is matched with its values joined
by ", ".
Judgement call: SWWAF_MAX_BAN_DURATION does not cap a ban for an attack.
Not in this unit: offences for rule matches, with the error burst.

Model: opus-5-5
 2026-10-06 20:38:35 +02:00
clawbot 74bdc6a449 Leave SWWAF_RATE_LIMIT_EXEMPT_PATHS out of the request rate limits (closes #77)
check / check (push) Successful in 3m2s
Details 
A request is neither counted nor refused by the request rate limits
when its path as sent, the path the app receives, not percent-decoded,
starts with one of the comma-separated prefixes in
SWWAF_RATE_LIMIT_EXEMPT_PATHS, so /%61ssets/x is not under /assets/. A
request whose decoded path contains .. or a backslash, or whose path as
sent holds an encoded slash, is never exempt, since an app may act on
it as a path outside every prefix, such as /assets/..%2Flogin as
/login. The static lists, bans and the country lists still apply, and
its log line has no counts. The setting is empty by default, and a
prefix that does not start with / stops the start. README.md documents
it.

Model: opus-5-5
 2026-10-06 18:47:13 +02:00
clawbot 808e69f442 Log the rest of the request log's fields (closes #79)
check / check (push) Successful in 3m23s
Details 
Each request log line now has the fields "Request log" in SPEC.md lists
whose features are built: instance (SWWAF_INSTANCE_NAME), scheme,
request_id (a trusted proxy's X-Request-ID or a new one, sent on to the
app), forwarded_for, client_group, content_type, content_length, the
headers SWWAF_LOG_REQUEST_HEADERS names, has_authorization, has_cookie,
websocket, response_content_type, cache_control, location, counts and
the timings. Authorization, Cookie and Set-Cookie values are never
logged. An entry of SWWAF_LOG_REQUEST_HEADERS that is not a header name,
or is Host or Transfer-Encoding, stops the start.

Deviation: counts has request totals only.
Deviation: SWWAF_INSTANCE_NAME is on request lines only.

Model: opus-5-5
 2026-10-06 17:26:21 +02:00
clawbot 6ec52e5b87 Take in an admin's edits of the state files while running (closes #68)
check / check (push) Successful in 4m1s
Details 
smallwebwaf watches SWWAF_STATE_DIR with fsnotify and takes in a saved
edit of a state file in place of what it held. It knows its own writes
by the SHA-256 of what it last read or wrote; each write first takes in
an edit made since. An edit that does not parse is renamed to
<name>.bad at the next write. Each edit taken in or set aside is logged
and counted. Every ban on a netblock is checked, and the next ban is
worked out from the one that ended last. README.md says how to add and
lift a ban.

Judgement call: a broken edit is set aside at the next write, since an
editor's file can be read half written.

Model: opus-5-5
 2026-10-06 14:18:13 +02:00
79 changed files with 20090 additions and 1371 deletions
Expand all files Collapse all files
.golangci.yml
+4
View File
@@ -61,6 +61,10 @@ linters:
desc: >-
Test-support code belongs in test files and in packages whose
directory name ends in test, not in the shipped binary.
- pkg: sneak.berlin/go/smallwebwaf/internal/lookup/lookuptest
desc: >-
Test-support code belongs in test files and in packages whose
directory name ends in test, not in the shipped binary.
# Only decisions already recorded in the Go package defaults are
# listed here. Every entry matches the module path exactly.
gomodguard_v2:
Dockerfile
+29 -1
View File
@@ -29,6 +29,12 @@ RUN go mod download
COPY . .
# go.mod and go.sum must be as `go mod tidy` writes them, which is what
# `make tidy` does. Checked before the tests, which a missing go.sum line
# fails with a message that does not name `make tidy`.
RUN go mod tidy -diff || \
{ echo "go.mod or go.sum is not tidy: run make tidy" >&2; exit 1; }
# Go's build cache is kept on a tmpfs, out of the image: nothing uses it
# after this step, and writing it into the image takes seconds.
RUN --mount=type=tmpfs,target=/root/.cache/go-build \
@@ -36,7 +42,25 @@ RUN --mount=type=tmpfs,target=/root/.cache/go-build \
{ echo "--- Rerunning with -v for details ---"; \
go test -timeout 90s -race -v ./...; exit 1; }
# Build stage. Nothing is wanted from the two phases above; the copies
# Tidy stage: `go mod tidy` in the test phase's Go, so that the files it
# writes pass the test phase's check. Nothing else depends on it, so only
# script/tidy, which names the stage after it, builds it.
#
# golang 1.27.1-trixie, 2026-09-19
FROM golang@sha256:3b77fc618ec235a1ab412de7737f120dd507c57e8d87de4cbb7994fb94275ed5 AS tidy
WORKDIR /src
COPY . .
RUN go mod tidy
# go.mod and go.sum alone, which script/tidy writes into the working tree.
FROM scratch AS tidy-files
COPY --from=tidy /src/go.mod /src/go.sum /
# Build stage. Nothing is wanted from the lint and test phases; the copies
# are what make BuildKit build them first, so the image, which needs this
# stage, cannot be produced unless lint and test passed.
#
@@ -167,6 +191,10 @@ RUN groupadd --system --gid 65532 smallwebwaf \
# smallwebwaf user at each start.
RUN mkdir /var/lib/smallwebwaf
# The default rule file, in SWWAF_RULES_DIR by default, where an app's
# Dockerfile can copy rule files of its own beside it.
COPY share/rules.d/00-default.rules /etc/smallwebwaf/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
Makefile
+7 -3
View File
@@ -1,9 +1,10 @@
.PHONY: bootstrap setup test lint fmt fmt-check check docker hooks build run \
example-app
.PHONY: bootstrap setup test lint fmt fmt-check tidy check docker hooks build \
run example-app
# Makefile targets are thin shims; the implementations live in script/
# per the scripts-to-rule-them-all pattern (see the Entrypoints section
# of README.md). build and run are for working on the code by hand;
# of README.md). tidy writes go.mod and go.sum as `go mod tidy` does,
# which test checks. build and run are for working on the code by hand;
# example-app checks the image with an app built on it.
bootstrap:
@@ -24,6 +25,9 @@ fmt:
fmt-check:
@script/fmt-check
tidy:
@script/tidy
check:
@script/check
README.md
+1164 -251
View File
File diff suppressed because it is too large Load Diff
SPEC.md
+3 -2
View File
@@ -32,7 +32,7 @@ from a directory of hand-editable text files.
- Defence against traffic floods that saturate the host's network link. That
needs help upstream of the host.
- A web UI or a configuration file. Settings are environment variables. Apart
from settings given as files (the `_FILE` form of any setting, such as
from settings given as files (the `_FILE` form of a setting, such as
`SWWAF_ADMIN_TOKEN_FILE`, and `SWWAF_LOG_REMOTE_TLS_CA_FILE`), its own state
files and the lookup database, the only files read are the rule files, which
hold one regex per line and nothing more elaborate.
@@ -298,7 +298,8 @@ it.
- A list set to an empty value is an empty list, and replaces the default.
- Every setting may instead be given as a file holding the value, named by the
setting's name with `_FILE` added, such as `SWWAF_ADMIN_TOKEN_FILE`, for
secrets and long lists.
secrets and long lists. `SWWAF_LOG_REMOTE_TLS_CA_FILE`, whose value names a
file already, has no `_FILE` form.
- Settings, including those given as files, are read once at start; changing one
means restarting the container. The files `smallwebwaf` watches while it runs
are its state files, its rule files and the lookup database.
go.mod
+5 -1
View File
@@ -3,7 +3,10 @@ module sneak.berlin/go/smallwebwaf
go 1.26.0
require (
github.com/fsnotify/fsnotify v1.10.1
github.com/hashicorp/golang-lru/v2 v2.0.7
github.com/maxmind/mmdbwriter v1.2.0
github.com/oschwald/maxminddb-golang/v2 v2.7.0
github.com/prometheus/client_golang v1.24.1
)
@@ -15,6 +18,7 @@ require (
github.com/prometheus/client_model v0.6.2 // indirect
github.com/prometheus/common v0.70.1 // indirect
github.com/prometheus/procfs v0.21.1 // indirect
golang.org/x/sys v0.47.0 // indirect
go4.org/netipx v0.0.0-20231129151722-fdeea329fbba // indirect
golang.org/x/sys v0.48.0 // indirect
google.golang.org/protobuf v1.36.11 // indirect
)
go.sum
+14 -10
View File
@@ -2,8 +2,8 @@ github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/fsnotify/fsnotify v1.10.1 h1:b0/UzAf9yR5rhf3RPm9gf3ehBPpf0oZKIjtpKrx59Ho=
github.com/fsnotify/fsnotify v1.10.1/go.mod h1:TLheqan6HD6GBK6PrDWyDPBaEV8LspOxvPSjC+bVfgo=
github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
github.com/hashicorp/golang-lru/v2 v2.0.7 h1:a+bsQ5rvGLjzHuww6tVxozPZFVghXaHOwFs4luLUK2k=
@@ -12,10 +12,12 @@ github.com/klauspost/compress v1.19.1 h1:VsB4HPswih7mmZ8WleSFQ75c/Ui1M4trX5oAsJn
github.com/klauspost/compress v1.19.1/go.mod h1:cwPg85FWrGar70rWktvGQj8/hthj3wpl0PGDogxkrSQ=
github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
github.com/maxmind/mmdbwriter v1.2.0 h1:hyvDopImmgvle3aR8AaddxXnT0iQH2KWJX3vNfkwzYM=
github.com/maxmind/mmdbwriter v1.2.0/go.mod h1:EQmKHhk2y9DRVvyNxwCLKC5FrkXZLx4snc5OlLY5XLE=
github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/oschwald/maxminddb-golang/v2 v2.7.0 h1:ZcAr3GYc2LYC8aec2mCMX9+QOF0EolH3jDFKRV/Z1+U=
github.com/oschwald/maxminddb-golang/v2 v2.7.0/go.mod h1:DuKJLbbug6TXC0yJXgs1MWifvXHmudRWzMobMIUu04g=
github.com/prometheus/client_golang v1.24.1 h1:JnJkREXzWxUdCuPFpIWZiPispT9xVV59uiuyR2bPlnU=
github.com/prometheus/client_golang v1.24.1/go.mod h1:F+oSRECHg4sse5ucfYpYDeIv/hu68Zo0uoHKetWnzcE=
github.com/prometheus/client_model v0.6.2 h1:oBsgwpGs7iVziMvrGhE53c/GrLUsZdHnqNwqPLxwZyk=
@@ -24,15 +26,17 @@ github.com/prometheus/common v0.70.1 h1:1HvjP4D5oL3t8RsPlwxA9onvvStjtIHYE5XuuwOi
github.com/prometheus/common v0.70.1/go.mod h1:VdFUQDMZK3VLkurFUVhia6uys/0suUp86TJz5qbJRhc=
github.com/prometheus/procfs v0.21.1 h1:GljZCt+zSTS+NZq88cyQ1LjZ+RCHp3uVuabBWA5+OJI=
github.com/prometheus/procfs v0.21.1/go.mod h1:aB55Cww9pdSJVHk0hUf0inxWyyjPogFIjmHKYgMKmtY=
github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
github.com/stretchr/testify v1.12.1 h1:EuwCh5fleGS7H32xRwO3wRGT7DxrDhLAT6FF8MpWDWE=
github.com/stretchr/testify v1.12.1/go.mod h1:MDEgiDPPsNp5cuIrHPPCyornHKgEVbtFUmoNlxoYthg=
go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
go.yaml.in/yaml/v2 v2.4.4 h1:tuyd0P+2Ont/d6e2rl3be67goVK4R6deVxCUX5vyPaQ=
go.yaml.in/yaml/v2 v2.4.4/go.mod h1:gMZqIpDtDqOfM0uNfy0SkpRhvUryYH0Z6wdMYcacYXQ=
golang.org/x/sys v0.47.0 h1:o7XGOvZQCADBQQ4Y7VNq2dRWQR7JmOUW8Kxx4ZsNgWs=
golang.org/x/sys v0.47.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
go.yaml.in/yaml/v3 v3.0.5 h1:N6y/pJk8buWs9NY5ERU2HSMfm+IuD/OtfdAnq6kESPw=
go.yaml.in/yaml/v3 v3.0.5/go.mod h1:HVTZu1O7/Vkt2N+BFy8Zza+lnLsABggaTM2ZpNIGuKg=
go4.org/netipx v0.0.0-20231129151722-fdeea329fbba h1:0b9z3AuHCjxk0x/opv64kcgZLBseWJUpBw5I82+2U4M=
go4.org/netipx v0.0.0-20231129151722-fdeea329fbba/go.mod h1:PLyyIXexvUFg3Owu6p/WfdlivPbZJsZdgWZlrGope/Y=
golang.org/x/sys v0.48.0 h1:bbX/i/6MgT9BVLM9RT1thmxL04yeTAhbEz4SyadbXoo=
golang.org/x/sys v0.48.0/go.mod h1:hNLxWAXmnKAxqDtdwIYC4bM9oQPEecfsnNMuSxOs3og=
google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
internal/alerts/alerts.go
+927
View File
@@ -0,0 +1,927 @@
// 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
// webhook schema" section of SPEC.md describes, to the Slack incoming
// webhook SWWAF_ALERT_SLACK_WEBHOOK_URL names, as a message, and to the
// ntfy topic SWWAF_ALERT_NTFY_URL names. A repeat within
// SWWAF_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
// 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.
// Nothing logged names a destination's URL, whose path or query can carry
// a secret.
package alerts
import (
"bytes"
"cmp"
"context"
"encoding/json"
"errors"
"fmt"
"io"
"log/slog"
"maps"
"net/http"
"net/netip"
"net/url"
"slices"
"strings"
"sync"
"sync/atomic"
"time"
)
// The events an alert is for, as SWWAF_ALERT_EVENTS names them.
const (
// EventBan is a ban smallwebwaf made.
EventBan = "ban"
// EventPermanentBan is a permanent ban smallwebwaf 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 and EventReputationHit come with the Core Rule Set and
// the reputation sources; nothing raises them yet.
EventWAFBlock = "waf_block"
EventReputationHit = "reputation_hit"
// EventSourceFailure is GeoJS failing or refusing smallwebwaf.
EventSourceFailure = "source_failure"
// EventFileError is a rule file or state file edited while smallwebwaf
// 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 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
// those repeats. SWWAF_ALERT_EVENTS does not name it.
EventSummary = "summary"
)
// Events returns every event SWWAF_ALERT_EVENTS can name, which is its
// default.
func Events() []string {
return []string{
EventBan, EventPermanentBan, EventWAFBlock, EventAnomaly,
EventReputationHit, EventSourceFailure, EventFileError,
}
}
// 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 = "webhook"
// DestinationSlack is the Slack incoming webhook
// SWWAF_ALERT_SLACK_WEBHOOK_URL names.
DestinationSlack = "slack"
// DestinationNtfy is the ntfy topic SWWAF_ALERT_NTFY_URL names.
DestinationNtfy = "ntfy"
)
// Destinations returns every destination alerts can be sent to.
func Destinations() []string {
return []string{DestinationWebhook, DestinationSlack, DestinationNtfy}
}
const (
// queueSize is the most alerts that wait to be sent to a destination.
// Past it, the oldest is dropped.
queueSize = 1000
// sendTimeout bounds one request to a destination.
sendTimeout = 10 * time.Second
// After a request to a destination fails, the alert is sent again a
// second later, and retryDelayFactor times as long after each further
// failure in a row, up to a minute.
firstRetryDelay = time.Second
retryDelayFactor = 2
maxRetryDelay = time.Minute
// maxAnswerBytes is the most of a destination's answer that is read.
maxAnswerBytes = 64 << 10
)
var (
errStatus = errors.New("the destination answered")
// errRefused is a 4xx answer other than 408 and 429: the destination
// refuses the alert itself, and would refuse it again.
errRefused = errors.New("the destination refused the alert, answering")
)
// Params are what New needs. With none of WebhookURL, SlackURL and
// 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
// are sent with each (SWWAF_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.
SlackURL *url.URL
// NtfyURL is the ntfy topic each alert is published to
// (SWWAF_ALERT_NTFY_URL), nil while it is unset. NtfyToken, unless
// empty, is sent with each as a bearer token (SWWAF_ALERT_NTFY_TOKEN).
NtfyURL *url.URL
NtfyToken string
// Events are the events alerts are sent for (SWWAF_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
// sent in an hour (SWWAF_ALERT_MAX_PER_HOUR), 0 for no limit.
Cooldown time.Duration
MaxPerHour int
// Instance is SWWAF_INSTANCE_NAME, which every alert gives.
Instance string
// Now tells the time of an alert, normally time.Now in UTC.
Now func() time.Time
// ProcessLog receives the requests to a destination that fail.
ProcessLog *slog.Logger
}
// 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,
// ASName and Country are, for a ban, the client's as the ban's notes give
// them.
//
//nolint:tagliatelle // SPEC.md's alert webhook schema names its fields in snake_case
type Alert struct {
Instance string `json:"instance"`
Time time.Time `json:"time"`
Event string `json:"event"`
Client netip.Addr `json:"client"`
Netblock netip.Prefix `json:"netblock"`
ASN string `json:"asn"`
ASName string `json:"as_name"`
Country string `json:"country"`
// Reason is a short sentence, and Detail what is particular to the
// event: for a file_error, its "file", for a source_failure, its
// "source", and for an anomaly, its "scope", with the "asn" or the
// "name" of some scopes, which the cooldown tells repeats by.
Reason string `json:"reason"`
Detail map[string]any `json:"detail"`
// SuppressedRepeats is how many repeats of the alert the cooldown
// held back since the last one let through. For a summary, it is how
// many the cooldowns dropped as the hour ended had held back that no
// alert let through gave.
SuppressedRepeats int `json:"suppressed_repeats"`
}
// Cooldown is, for an event on a netblock, about a file or a source, or
// for an anomaly in a scope, when the last alert let through was raised,
// and how many repeats the cooldown has held back since, as alerts.json
// holds it.
//
//nolint:tagliatelle // the state files use snake_case, as the request log does
type Cooldown struct {
Event string `json:"event"`
Netblock netip.Prefix `json:"netblock"`
File string `json:"file,omitempty"`
Source string `json:"source,omitempty"`
Scope string `json:"scope,omitempty"`
ASN string `json:"asn,omitempty"`
Name string `json:"name,omitempty"`
Sent time.Time `json:"sent"`
SuppressedRepeats int `json:"suppressed_repeats"`
}
// Hour is the hour under way, by the clock, as alerts.json holds it: when
// it started, how many alerts were let through in it, and how many were
// held back in it past MaxPerHour, by event, for its summary.
//
//nolint:tagliatelle // the state files use snake_case, as the request log does
type Hour struct {
Start time.Time `json:"start"`
Sent int `json:"sent"`
HeldBack map[string]int `json:"held_back"`
}
// State is what alerts.json holds: the cooldowns, the hour under way, and
// for each destination set, the alerts waiting to be sent to it, oldest
// first.
type State struct {
Cooldowns []Cooldown `json:"cooldowns"`
Hour Hour `json:"hour"`
Waiting map[string][]Alert `json:"waiting"`
}
// Counts are, for a destination, how many alerts it took, how many
// requests to it failed, and how many alerts were dropped from its full
// queue or given up as it refused them.
type Counts struct {
Sent, Failed, Dropped int64
}
// Queue takes the alerts raised, holds back those it must, and sends the
// others to each destination set, from a queue of the destination's own.
// It is safe for concurrent use.
type Queue struct {
params Params
// destinations are the destinations set, in the order of
// Destinations.
destinations []*destination
mu sync.Mutex
// cooldowns are the alerts last let through, by event and netblock,
// file, source or scope.
cooldowns map[cooldownKey]*Cooldown
hour Hour
suppressed atomic.Int64
}
// destination is a destination set, with the alerts waiting to be sent
// to it. Its mu is taken after the Queue's, never before.
type destination struct {
// name is how the metrics and alerts.json name the destination, and
// setting the setting that is its URL, which the log names in place
// of the URL.
name string
setting string
url *url.URL
// message returns the body an alert is posted with, and the headers
// sent with it.
message func(alert *Alert) ([]byte, http.Header, error)
// httpClient follows no redirect: a redirect is a failure.
httpClient *http.Client
processLog *slog.Logger
// queued receives a value when an alert joins the queue, unless one
// waits already, so that run looks at the queue again.
queued chan struct{}
mu sync.Mutex
// waiting are the alerts waiting to be sent, oldest first.
waiting []*Alert
sent, failed, dropped atomic.Int64
}
// cooldownKey is what makes an alert a repeat of another: the same event
// on the same netblock, and about the same file or source, or in the same
// scope with the same AS number or name, as its detail names them. Each
// is empty for an alert without one.
type cooldownKey struct {
event string
netblock netip.Prefix
file string
source string
scope string
asn string
name string
}
// cooldownKeyOf returns what makes another alert a repeat of alert.
func cooldownKeyOf(alert *Alert) cooldownKey {
file, _ := alert.Detail["file"].(string)
source, _ := alert.Detail["source"].(string)
scope, _ := alert.Detail["scope"].(string)
asn, _ := alert.Detail["asn"].(string)
name, _ := alert.Detail["name"].(string)
return cooldownKey{alert.Event, alert.Netblock, file, source, scope, asn, name}
}
// New returns a Queue with no alert yet.
func New(params Params) *Queue {
q := &Queue{
params: params,
cooldowns: map[cooldownKey]*Cooldown{},
hour: Hour{HeldBack: map[string]int{}},
}
if params.WebhookURL != nil {
q.addDestination(DestinationWebhook, "SWWAF_ALERT_WEBHOOK_URL",
params.WebhookURL, q.webhookMessage)
}
if params.SlackURL != nil {
q.addDestination(DestinationSlack, "SWWAF_ALERT_SLACK_WEBHOOK_URL",
params.SlackURL, slackMessage)
}
if params.NtfyURL != nil {
q.addDestination(DestinationNtfy, "SWWAF_ALERT_NTFY_URL",
params.NtfyURL, q.ntfyMessage)
}
return q
}
// 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
// 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
// the clock ends first after the cooldown has run out: the cooldown is
// then dropped, and that hour's summary gives the count. Past MaxPerHour
// alerts let through in the hour under way, an alert is held back for
// that hour's summary instead, which is sent once the hour has ended; it
// starts no cooldown. Raise never waits: an alert let through joins the
// queue of each destination, from which Run sends it, and with queueSize
// alerts waiting for a destination, the oldest is dropped.
func (q *Queue) Raise(alert Alert) {
if len(q.destinations) == 0 || !slices.Contains(q.params.Events, alert.Event) {
return
}
q.mu.Lock()
defer q.mu.Unlock()
now := q.params.Now()
alert.Instance = q.params.Instance
alert.Time = now
if q.repeat(&alert, now) {
q.suppressed.Add(1)
return
}
q.endHour(now)
if q.params.MaxPerHour > 0 && q.hour.Sent >= q.params.MaxPerHour {
q.hour.HeldBack[alert.Event]++
q.suppressed.Add(1)
return
}
q.startCooldown(&alert, now)
q.hour.Sent++
q.queue(&alert)
}
// WouldSend reports whether Raise would let an alert for event on
// netblock through now: a destination is set, SWWAF_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.
func (q *Queue) WouldSend(event string, netblock netip.Prefix) bool {
if len(q.destinations) == 0 || !slices.Contains(q.params.Events, event) {
return false
}
q.mu.Lock()
defer q.mu.Unlock()
now := q.params.Now()
last, found := q.cooldowns[cooldownKey{event: event, netblock: netblock}]
if q.params.Cooldown > 0 && found && now.Sub(last.Sent) < q.params.Cooldown {
return false
}
q.endHour(now)
return q.params.MaxPerHour == 0 || q.hour.Sent < q.params.MaxPerHour
}
// Run sends the alerts waiting to each destination, from its own queue,
// as destination.run does, until ctx is done. It also ends each hour as
// Raise does, so that the hour's summary is sent as it ends. With no
// destination set, it returns at once.
func (q *Queue) Run(ctx context.Context) {
if len(q.destinations) == 0 {
return
}
var sending sync.WaitGroup
for _, d := range q.destinations {
sending.Go(func() { d.run(ctx) })
}
for {
q.mu.Lock()
untilHourEnds := q.hour.Start.Add(time.Hour).Sub(q.params.Now())
q.mu.Unlock()
select {
case <-ctx.Done():
sending.Wait()
return
case <-time.After(untilHourEnds):
q.mu.Lock()
q.endHour(q.params.Now())
q.mu.Unlock()
}
}
}
// Counts returns the counts of the destination name, all 0 for one not
// set.
func (q *Queue) Counts(name string) Counts {
for _, d := range q.destinations {
if d.name == name {
return Counts{
Sent: d.sent.Load(), Failed: d.failed.Load(), Dropped: d.dropped.Load(),
}
}
}
return Counts{}
}
// DestinationsSet returns the destinations set, in the order of
// Destinations.
func (q *Queue) DestinationsSet() []string {
names := make([]string, 0, len(q.destinations))
for _, d := range q.destinations {
names = append(names, d.name)
}
return names
}
// Suppressed is how many alerts were held back: by the cooldown, and past
// MaxPerHour. No destination is sent such an alert.
func (q *Queue) Suppressed() int64 {
return q.suppressed.Load()
}
// Snapshot returns the queue's state, as alerts.json holds it, with the
// cooldowns sorted by netblock, then by event, file, source, scope, AS
// number and name.
func (q *Queue) Snapshot() State {
q.mu.Lock()
defer q.mu.Unlock()
state := State{
Cooldowns: make([]Cooldown, 0, len(q.cooldowns)),
Hour: q.hour,
Waiting: map[string][]Alert{},
}
state.Hour.HeldBack = maps.Clone(q.hour.HeldBack)
for _, cooldown := range q.cooldowns {
state.Cooldowns = append(state.Cooldowns, *cooldown)
}
slices.SortFunc(state.Cooldowns, func(a, b Cooldown) int {
return cmp.Or(a.Netblock.Compare(b.Netblock), cmp.Compare(a.Event, b.Event),
cmp.Compare(a.File, b.File), cmp.Compare(a.Source, b.Source),
cmp.Compare(a.Scope, b.Scope), cmp.Compare(a.ASN, b.ASN),
cmp.Compare(a.Name, b.Name))
})
for _, d := range q.destinations {
state.Waiting[d.name] = d.snapshot()
}
return state
}
// Load puts state, read from alerts.json, in place of the queue's state.
// Each cooldown's netblock is masked to its length, so that
// 203.0.113.9/24 is 203.0.113.0/24. The alerts waiting for a destination
// that is not set are dropped, and so are the oldest past queueSize
// alerts waiting for one that is.
func (q *Queue) Load(state State) {
q.mu.Lock()
defer q.mu.Unlock()
q.cooldowns = map[cooldownKey]*Cooldown{}
for _, cooldown := range state.Cooldowns {
cooldown.Netblock = cooldown.Netblock.Masked()
key := cooldownKey{
cooldown.Event, cooldown.Netblock, cooldown.File, cooldown.Source,
cooldown.Scope, cooldown.ASN, cooldown.Name,
}
q.cooldowns[key] = &cooldown
}
q.hour = state.Hour
q.hour.HeldBack = maps.Clone(state.Hour.HeldBack)
if q.hour.HeldBack == nil {
q.hour.HeldBack = map[string]int{}
}
for _, d := range q.destinations {
d.load(state.Waiting[d.name])
}
}
// addDestination adds a destination: its name, the setting that gives
// its URL, that URL, target, and message, which makes the messages sent
// to it.
func (q *Queue) addDestination(
name, setting string, target *url.URL,
message func(alert *Alert) ([]byte, http.Header, error),
) {
q.destinations = append(q.destinations, &destination{
name: name,
setting: setting,
url: target,
message: message,
httpClient: &http.Client{
CheckRedirect: func(*http.Request, []*http.Request) error {
return http.ErrUseLastResponse
},
},
processLog: q.params.ProcessLog,
queued: make(chan struct{}, 1),
})
}
// repeat reports whether alert, raised at now, repeats the last one let
// through less than Cooldown before, and counts it if it does.
func (q *Queue) repeat(alert *Alert, now time.Time) bool {
if q.params.Cooldown == 0 {
return false
}
last, found := q.cooldowns[cooldownKeyOf(alert)]
if !found || now.Sub(last.Sent) >= q.params.Cooldown {
return false
}
last.SuppressedRepeats++
return true
}
// startCooldown gives alert, let through at now, the count of the repeats
// held back since the last one let through, and notes alert as the last
// one let through.
func (q *Queue) startCooldown(alert *Alert, now time.Time) {
if q.params.Cooldown == 0 {
return
}
key := cooldownKeyOf(alert)
last, found := q.cooldowns[key]
if found {
alert.SuppressedRepeats = last.SuppressedRepeats
}
q.cooldowns[key] = &Cooldown{
Event: alert.Event, Netblock: alert.Netblock, File: key.file, Source: key.source,
Scope: key.scope, ASN: key.asn, Name: key.name, Sent: now,
}
}
// endHour ends the hour under way, if now is past it. It drops the
// cooldowns that have run out, whatever repeats they held back, so that
// they do not pile up, and queues that hour's summary when alerts were
// held back in it past MaxPerHour, or when a cooldown dropped had held
// back repeats, which no alert let through has given: the summary gives
// them.
func (q *Queue) endHour(now time.Time) {
start := now.Truncate(time.Hour)
if !start.After(q.hour.Start) {
return
}
repeats := 0
for key, cooldown := range q.cooldowns {
if now.Sub(cooldown.Sent) >= q.params.Cooldown {
repeats += cooldown.SuppressedRepeats
delete(q.cooldowns, key)
}
}
heldBack := 0
for _, count := range q.hour.HeldBack {
heldBack += count
}
var reasons []string
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,
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))
}
if len(reasons) > 0 {
q.queue(&Alert{
Instance: q.params.Instance,
Time: now,
Event: EventSummary,
Reason: strings.Join(reasons, "; "),
Detail: map[string]any{
"hour": q.hour.Start, "count": heldBack, "events": q.hour.HeldBack,
},
SuppressedRepeats: repeats,
})
}
q.hour = Hour{Start: start, HeldBack: map[string]int{}}
}
// queue adds alert to the alerts waiting for each destination.
func (q *Queue) queue(alert *Alert) {
for _, d := range q.destinations {
d.add(alert)
}
}
// run sends the alerts waiting, oldest first, until ctx is done. An alert
// stays in the queue until the destination answers it with a 2xx status,
// or refuses it with a 4xx status other than 408 and 429: a refused alert
// is logged, counted as dropped, and given up, so that the next is sent.
// Any other request that fails is logged, and the alert sent again
// firstRetryDelay later, retryDelayFactor times as long after each
// further failure in a row, up to maxRetryDelay.
func (d *destination) run(ctx context.Context) {
var (
retryDelay time.Duration
retryAt time.Time
)
for {
alert := d.oldest()
var due <-chan time.Time // nil while no alert waits
if alert != nil {
due = time.After(time.Until(retryAt))
}
select {
case <-ctx.Done():
return
case <-d.queued:
case <-due:
err := d.send(ctx, alert)
switch {
case err == nil:
d.remove(alert)
d.sent.Add(1)
retryDelay = 0
retryAt = time.Time{}
case errors.Is(err, errRefused):
d.remove(alert)
d.failed.Add(1)
d.dropped.Add(1)
retryDelay = 0
retryAt = time.Time{}
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
d.failed.Add(1)
retryDelay = min(max(retryDelayFactor*retryDelay, firstRetryDelay),
maxRetryDelay)
retryAt = time.Now().Add(retryDelay)
d.processLog.Warn("sending an alert to "+d.setting+" failed",
"error", err.Error(), "sending_again_in", retryDelay.String())
}
}
}
}
// add adds alert to the alerts waiting, first dropping the oldest while
// queueSize wait, and has run look at the queue again.
func (d *destination) add(alert *Alert) {
d.mu.Lock()
defer d.mu.Unlock()
if len(d.waiting) == queueSize {
d.waiting = slices.Delete(d.waiting, 0, 1)
d.dropped.Add(1)
}
d.waiting = append(d.waiting, alert)
select {
case d.queued <- struct{}{}:
default: // a value waits already
}
}
// load puts waiting, read from alerts.json, in place of the alerts
// waiting, as add adds them.
func (d *destination) load(waiting []Alert) {
d.mu.Lock()
d.waiting = nil
d.mu.Unlock()
for _, alert := range waiting {
d.add(&alert)
}
}
// snapshot returns the alerts waiting, oldest first.
func (d *destination) snapshot() []Alert {
d.mu.Lock()
defer d.mu.Unlock()
waiting := make([]Alert, 0, len(d.waiting))
for _, alert := range d.waiting {
waiting = append(waiting, *alert)
}
return waiting
}
// oldest returns the oldest alert waiting, nil when none waits.
func (d *destination) oldest() *Alert {
d.mu.Lock()
defer d.mu.Unlock()
if len(d.waiting) == 0 {
return nil
}
return d.waiting[0]
}
// remove takes alert, which run has sent or given up, out of the queue,
// unless it has been dropped from it, or load has replaced the queue,
// since run took it. Only the oldest alert is ever dropped, so alert is
// the oldest if it is there at all.
func (d *destination) remove(alert *Alert) {
d.mu.Lock()
defer d.mu.Unlock()
if len(d.waiting) > 0 && d.waiting[0] == alert {
d.waiting = slices.Delete(d.waiting, 0, 1)
}
}
// send posts alert to the destination, as message makes it, and returns
// an error unless the destination answers with a 2xx status: one that
// wraps errRefused for a 4xx status other than 408 and 429. No error
// names the destination's URL, whose path or query can carry a secret.
func (d *destination) send(ctx context.Context, alert *Alert) error {
body, header, err := d.message(alert)
if err != nil {
return err
}
ctx, cancel := context.WithTimeout(ctx, sendTimeout)
defer cancel()
req, err := http.NewRequestWithContext(ctx, http.MethodPost, d.url.String(),
bytes.NewReader(body))
if err != nil {
return fmt.Errorf("make the request: %w", err)
}
maps.Copy(req.Header, header)
res, err := d.httpClient.Do(req)
if err != nil {
// The client's error names the URL: only what went wrong is kept.
if urlErr, ok := errors.AsType[*url.Error](err); ok {
return urlErr.Err
}
return err
}
defer func() {
_ = res.Body.Close()
}()
// Read, so that the connection can be used again.
_, _ = io.Copy(io.Discard, io.LimitReader(res.Body, maxAnswerBytes))
switch status := res.StatusCode; {
case status >= http.StatusOK && status < http.StatusMultipleChoices:
return nil
case status >= http.StatusBadRequest && status < http.StatusInternalServerError &&
status != http.StatusRequestTimeout && status != http.StatusTooManyRequests:
return fmt.Errorf("%w %s", errRefused, res.Status)
default:
return fmt.Errorf("%w %s", errStatus, res.Status)
}
}
// webhookMessage returns alert as JSON, for the webhook, and the headers
// sent with it: WebhookHeaders, and its Content-Type.
func (q *Queue) webhookMessage(alert *Alert) ([]byte, http.Header, error) {
body, err := json.Marshal(alert)
if err != nil {
return nil, nil, fmt.Errorf("encode the alert: %w", err)
}
header := http.Header{}
maps.Copy(header, q.params.WebhookHeaders)
header.Set("Content-Type", "application/json")
return body, header, nil
}
// slackMessage returns alert as a message for a Slack incoming webhook,
// in JSON: its title in bold, then its text, with &, < and > escaped, as
// Slack asks, so that nothing in them is read as a link or a mention.
func slackMessage(alert *Alert) ([]byte, http.Header, error) {
escape := strings.NewReplacer("&", "&amp;", "<", "&lt;", ">", "&gt;").Replace
body, err := json.Marshal(map[string]string{
"text": "*" + escape(title(alert)) + "*\n" + escape(text(alert)),
})
if err != nil {
return nil, nil, fmt.Errorf("encode the message: %w", err)
}
return body, http.Header{"Content-Type": {"application/json"}}, nil
}
// ntfyMessage returns alert's text, as the message published to ntfy,
// and the headers sent with it: its title, the priority and the tag of
// its event, and NtfyToken, unless it is empty, as a bearer token.
func (q *Queue) ntfyMessage(alert *Alert) ([]byte, http.Header, error) {
header := http.Header{
"Title": {title(alert)},
"Priority": {ntfyPriority(alert.Event)},
"Tags": {ntfyTag(alert.Event)},
}
if q.params.NtfyToken != "" {
header.Set("Authorization", "Bearer "+q.params.NtfyToken)
}
return []byte(text(alert)), header, nil
}
// ntfyPriority returns the priority an alert for event is published to
// ntfy with: high for an event the admin needs to look at.
func ntfyPriority(event string) string {
switch event {
case EventPermanentBan, EventAnomaly, EventSourceFailure, EventFileError:
return "high"
case EventReputationHit:
return "low"
default: // ban, waf_block and summary
return "default"
}
}
// ntfyTag returns the tag an alert for event is published to ntfy with,
// which ntfy shows as an emoji.
func ntfyTag(event string) string {
switch event {
case EventBan, EventPermanentBan:
return "no_entry"
case EventWAFBlock:
return "shield"
case EventAnomaly:
return "chart_with_upwards_trend"
case EventReputationHit:
return "label"
case EventSourceFailure, EventFileError:
return "warning"
default: // summary
return "bar_chart"
}
}
// title returns the title of alert in Slack and ntfy: the instance and
// the event.
func title(alert *Alert) string {
return alert.Instance + ": " + alert.Event
}
// 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,
// error and mode its detail gives, and its suppressed repeats, that it
// has.
func text(alert *Alert) string {
lines := []string{alert.Reason}
if alert.Client.IsValid() {
lines = append(lines, "client: "+alert.Client.String())
}
if alert.Netblock.IsValid() {
lines = append(lines, "netblock: "+alert.Netblock.String())
}
if alert.Country != "" {
lines = append(lines, "country: "+alert.Country)
}
for _, name := range []string{"file", "source", "error", "mode"} {
value, _ := alert.Detail[name].(string)
if value != "" {
lines = append(lines, name+": "+value)
}
}
if alert.SuppressedRepeats > 0 {
lines = append(lines, fmt.Sprintf("suppressed repeats: %d", alert.SuppressedRepeats))
}
return strings.Join(lines, "\n")
}
internal/alerts/alerts_test.go
+1376
View File
File diff suppressed because it is too large Load Diff
internal/alerts/export_test.go
+16
View File
@@ -0,0 +1,16 @@
package alerts
import "net/http"
// QueueSize is the most alerts that wait to be sent to a destination.
const QueueSize = queueSize
// SetTransport has q's requests to the destination name go through
// transport instead of the network.
func (q *Queue) SetTransport(name string, transport http.RoundTripper) {
for _, d := range q.destinations {
if d.name == name {
d.httpClient.Transport = transport
}
}
}
internal/anomaly/anomaly.go
+406
View File
@@ -0,0 +1,406 @@
// 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
// SPEC.md 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
import (
"cmp"
"fmt"
"net/netip"
"slices"
"sync"
"time"
"github.com/hashicorp/golang-lru/v2/simplelru"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
)
// maxCounters is how many counters are kept. Past it, the counter counted
// least recently is dropped, and starts afresh if it is counted again.
const maxCounters = 20000
// The scopes, what a counter counts, as the settings, alerts.json and the
// alerts name them.
const (
// ScopeClient is one client: an IPv4 address, or an IPv6 /64.
ScopeClient = "client"
// ScopeNet is the netblock around a client, SWWAF_ANOMALY_NET_V4_PREFIX
// or SWWAF_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 = "watch"
)
// Scopes returns every scope.
func Scopes() []string {
return []string{ScopeClient, ScopeNet, ScopeASN, ScopeTotal, ScopeWatch}
}
// The windows a counter counts in, as the alerts name them.
const (
minute = "minute"
hour = "hour"
)
// Thresholds are the most requests and the most bytes a scope may have
// counted in a minute and in an hour before an alert is raised. Zero is
// off.
type Thresholds struct {
RequestsPerMinute int64
RequestsPerHour int64
BytesPerMinute int64
BytesPerHour int64
}
// NamedNetblock is a netblock SWWAF_WATCH_NETS names.
type NamedNetblock struct {
Name string
Netblock netip.Prefix
}
// Params are what New needs.
type Params struct {
// The thresholds of each scope: SWWAF_ANOMALY_CLIENT_*,
// SWWAF_ANOMALY_NET_*, SWWAF_ANOMALY_ASN_*, SWWAF_ANOMALY_TOTAL_* and
// SWWAF_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).
NetV4Prefix, NetV6Prefix int
// NamedNetblocks are SWWAF_WATCH_NETS.
NamedNetblocks []NamedNetblock
// Alerts receive the anomaly alerts.
Alerts *alerts.Queue
}
// Counter is one scope's counts, as alerts.json holds them: the scope,
// with the netblock, the AS number or the name that tells it from the
// others in that scope, and its two buckets of requests and of bytes in
// the minute and in the hour. A bucket whose threshold is off counts
// nothing, and is left out.
//
//nolint:tagliatelle // the state files use snake_case, as the request log does
type Counter struct {
Scope string `json:"scope"`
Netblock netip.Prefix `json:"netblock,omitzero"`
ASN string `json:"asn,omitempty"`
Name string `json:"name,omitempty"`
Minute ratelimit.Buckets `json:"minute,omitzero"`
Hour ratelimit.Buckets `json:"hour,omitzero"`
MinuteBytes ratelimit.Buckets `json:"minute_bytes,omitzero"`
HourBytes ratelimit.Buckets `json:"hour_bytes,omitzero"`
}
// Request is a request that has ended, as the counters count it.
type Request struct {
// Client is the client's address, and ClientGroup the client it is
// counted as: its IPv4 address, or its IPv6 /64.
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 int64
}
// Counters counts each request in the scopes it is in. It is safe for
// concurrent use.
type Counters struct {
params Params
mu sync.Mutex
counters *simplelru.LRU[key, *Counter]
}
// key is what tells a counter from the others: its scope, with its
// netblock, AS number or name.
type key struct {
scope string
netblock netip.Prefix
asn string
name string
}
// New returns Counters for params, with nothing counted yet.
func New(params Params) *Counters {
counters, err := simplelru.NewLRU[key, *Counter](maxCounters, nil)
if err != nil {
panic(err) // NewLRU fails only for a size below one
}
return &Counters{params: params, counters: counters}
}
// Count counts r, a request that has ended, at now, in each scope it is
// in whose thresholds are not all off: its client, the netblock around
// it, its AS number once known, the whole service, and each named
// netblock it is in. Only the counts whose threshold is set are counted.
// For each scope whose count is over a threshold, it raises an anomaly
// alert, for the first such count in the order requests and bytes in the
// minute, then in the hour; the alert queue's cooldown holds back the
// repeats. Nothing is refused or banned.
func (c *Counters) Count(now time.Time, r Request) {
var raised []alerts.Alert
c.mu.Lock()
for _, scope := range c.scopesOf(r) {
counter, found := c.counters.Get(scope.key)
if !found {
counter = scope.key.counter()
c.counters.Add(scope.key, counter)
}
over, passed := counter.add(now, r.Bytes, scope.thresholds)
if passed {
raised = append(raised, alertFor(r, scope.key, over))
}
}
c.mu.Unlock()
for _, alert := range raised {
c.params.Alerts.Raise(alert)
}
}
// Snapshot returns every counter, sorted by scope, then by netblock, AS
// number and name, as alerts.json lists them.
func (c *Counters) Snapshot() []Counter {
c.mu.Lock()
counters := make([]Counter, 0, c.counters.Len())
for _, counter := range c.counters.Values() {
counters = append(counters, *counter)
}
c.mu.Unlock()
slices.SortFunc(counters, func(a, b Counter) int {
return cmp.Or(cmp.Compare(a.Scope, b.Scope), a.Netblock.Compare(b.Netblock),
cmp.Compare(a.ASN, b.ASN), cmp.Compare(a.Name, b.Name))
})
return counters
}
// Load puts counters, read from alerts.json, in place of those held, in
// the order they were last counted, as the starts of their buckets tell,
// so that the one counted least recently is dropped first. Each netblock
// is masked to its length, so that 203.0.113.9/24 is 203.0.113.0/24.
// Buckets whose time has passed at now are emptied, and a counter left
// with every bucket empty is dropped.
func (c *Counters) Load(counters []Counter, now time.Time) {
counters = slices.Clone(counters)
slices.SortStableFunc(counters, func(a, b Counter) int {
return a.lastStart().Compare(b.lastStart())
})
c.mu.Lock()
defer c.mu.Unlock()
c.counters.Purge()
for _, counter := range counters {
counter.Netblock = counter.Netblock.Masked()
empty := true
for _, count := range counter.counts() {
if count.buckets.Passed(now, count.length) {
*count.buckets = ratelimit.Buckets{}
}
empty = empty && *count.buckets == ratelimit.Buckets{}
}
if !empty {
c.counters.Add(counter.key(), &counter)
}
}
}
// scope is a scope a request is counted in, and its thresholds.
type scope struct {
key key
thresholds Thresholds
}
// scopesOf returns the scopes r is in whose thresholds are not all off.
func (c *Counters) scopesOf(r Request) []scope {
p := c.params
client := r.Client.Unmap()
all := []scope{
{key{scope: ScopeClient, netblock: r.ClientGroup}, p.Client},
{key{scope: ScopeNet, netblock: c.netAround(client)}, p.Net},
{key{scope: ScopeTotal}, p.Total},
}
if r.ASN != "" {
all = append(all, scope{key{scope: ScopeASN, asn: r.ASN}, p.ASN})
}
for _, named := range p.NamedNetblocks {
if named.Netblock.Contains(client) {
all = append(all, scope{
key{scope: ScopeWatch, netblock: named.Netblock, name: named.Name}, p.Watch,
})
}
}
return slices.DeleteFunc(all, func(s scope) bool {
return s.thresholds == Thresholds{}
})
}
// netAround returns the netblock around client that ScopeNet counts it
// in: NetV4Prefix or NetV6Prefix long.
func (c *Counters) netAround(client netip.Addr) netip.Prefix {
length := c.params.NetV6Prefix
if client.Is4() {
length = c.params.NetV4Prefix
}
return netip.PrefixFrom(client, length).Masked()
}
// overThreshold is a count over its threshold: what it counts, requests or
// bytes, its window, the count and the threshold.
type overThreshold struct {
kind, window string
count float64
threshold int64
}
// add counts a request of bytes at now in each of c's counts whose
// threshold, in thresholds, is set, and returns the first count over its
// threshold, and whether there is one.
func (c *Counter) add(
now time.Time, bytes int64, thresholds Thresholds,
) (overThreshold, bool) {
// In the order of counts.
inOrder := [4]int64{
thresholds.RequestsPerMinute, thresholds.BytesPerMinute,
thresholds.RequestsPerHour, thresholds.BytesPerHour,
}
var (
first overThreshold
passed bool
)
for i, count := range c.counts() {
threshold := inOrder[i]
if threshold == 0 {
continue
}
n := int64(1)
if count.kind == ratelimit.KindBytes {
n = bytes
}
counted := count.buckets.Add(now, count.length, n)
if !passed && counted > float64(threshold) {
first = overThreshold{count.kind, count.window, counted, threshold}
passed = true
}
}
return first, passed
}
// bucketCount is one of a counter's four counts: requests or bytes, in a
// window of length, and the buckets they are counted in.
type bucketCount struct {
kind, window string
length time.Duration
buckets *ratelimit.Buckets
}
// counts returns c's counts: requests and bytes in the minute, then in
// the hour.
func (c *Counter) counts() [4]bucketCount {
return [4]bucketCount{
{ratelimit.KindRequests, minute, time.Minute, &c.Minute},
{ratelimit.KindBytes, minute, time.Minute, &c.MinuteBytes},
{ratelimit.KindRequests, hour, time.Hour, &c.Hour},
{ratelimit.KindBytes, hour, time.Hour, &c.HourBytes},
}
}
// lastStart returns the start of c's latest bucket, which tells, to the
// minute or to the hour, when c was last counted.
func (c *Counter) lastStart() time.Time {
var latest time.Time
for _, count := range c.counts() {
if count.buckets.Start.After(latest) {
latest = count.buckets.Start
}
}
return latest
}
// key returns what tells c from the other counters.
func (c *Counter) key() key {
return key{scope: c.Scope, netblock: c.Netblock, asn: c.ASN, name: c.Name}
}
// counter returns a counter for k, with nothing counted yet.
func (k key) counter() *Counter {
return &Counter{Scope: k.scope, Netblock: k.netblock, ASN: k.asn, Name: k.name}
}
// alertFor returns the anomaly alert for o, a count over its threshold in
// the scope k, which r took over it. It gives r's client, with its AS
// number, AS name and country, and the netblock counted, of a client, the
// netblock around it or a named netblock. Its detail gives the scope, the
// AS number or the name of a scope that has one, the window, what is
// counted, the count and the threshold.
func alertFor(r Request, k key, o overThreshold) alerts.Alert {
detail := map[string]any{
"scope": k.scope, "window": o.window, "kind": o.kind, "count": o.count,
"threshold": o.threshold,
}
var counted string
switch k.scope {
case ScopeClient:
counted = "the client " + k.netblock.String()
case ScopeNet:
counted = "the netblock " + k.netblock.String()
case ScopeASN:
counted = k.asn
detail["asn"] = k.asn
case ScopeTotal:
counted = "the whole service"
default: // watch
counted = "the named netblock " + k.name + ", " + k.netblock.String()
detail["name"] = k.name
}
return alerts.Alert{
Event: alerts.EventAnomaly,
Client: r.Client,
Netblock: k.netblock,
ASN: r.ASN,
ASName: r.ASName,
Country: r.Country,
Reason: fmt.Sprintf("%s per %s of %s over the threshold of %d", o.kind, o.window,
counted, o.threshold),
Detail: detail,
}
}
internal/anomaly/anomaly_test.go
+238
View File
@@ -0,0 +1,238 @@
package anomaly_test
import (
"encoding/json"
"fmt"
"net/netip"
"net/url"
"reflect"
"slices"
"testing"
"time"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/anomaly"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
)
// maxCounters is how many counters are kept.
const maxCounters = 20000
func TestEachScopeHasACooldownOfItsOwn(t *testing.T) {
t.Parallel()
queue := newQueue()
office := netip.MustParsePrefix("203.0.113.0/24")
overAtTheSecond := anomaly.Thresholds{RequestsPerMinute: 1}
counters := anomaly.New(anomaly.Params{
Client: overAtTheSecond, Net: overAtTheSecond, ASN: overAtTheSecond,
Total: overAtTheSecond, Watch: overAtTheSecond,
// The netblock around a client is the client's own, and two names
// name one netblock.
NetV4Prefix: 32,
NamedNetblocks: []anomaly.NamedNetblock{
{Name: "office", Netblock: office}, {Name: "hq", Netblock: office},
},
Alerts: queue,
})
// The first client's second request is over the threshold in the six
// scopes it is in. The other client's two are both over it in the whole
// service and in each named netblock, three repeats each, and its
// second is over it in the scopes of its own, its client, its netblock
// and its AS number, which are no repeats.
for _, r := range []anomaly.Request{
{Client: netip.MustParseAddr("203.0.113.9"), ASN: "AS64496"},
{Client: netip.MustParseAddr("203.0.113.10"), ASN: "AS64511"},
} {
r.ClientGroup = netip.PrefixFrom(r.Client, 32)
for range 2 {
counters.Count(midnight(), r)
}
}
waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
if len(waiting) != 9 || queue.Suppressed() != 6 {
t.Fatalf("%d alerts wait and %d are held back, want 9 and 6: %+v",
len(waiting), queue.Suppressed(), waiting)
}
// alerts.json keeps each scope's cooldown: each alert raised again
// after a restart is a repeat.
data, err := json.Marshal(queue.Snapshot())
if err != nil {
t.Fatalf("encode: %v", err)
}
var read alerts.State
err = json.Unmarshal(data, &read)
if err != nil {
t.Fatalf("decode: %v", err)
}
after := newQueue()
after.Load(read)
for _, alert := range read.Waiting[alerts.DestinationWebhook] {
after.Raise(alert)
}
if after.Suppressed() != 9 {
t.Errorf("after loading, %d alerts are held back, want 9", after.Suppressed())
}
}
func TestKeepsAtMost20000CountersDroppingTheLeastRecentlyCounted(t *testing.T) {
t.Parallel()
counters := newCounters(anomaly.Params{
Client: anomaly.Thresholds{RequestsPerMinute: 1000},
})
for i := range maxCounters {
counters.Count(midnight(), request(i))
}
// Counted again, the first client is the most recently counted, and
// the second is dropped for a new one.
counters.Count(midnight(), request(0))
counters.Count(midnight(), request(maxCounters))
got := counters.Snapshot()
if len(got) != maxCounters || !holds(got, 0) || holds(got, 1) ||
!holds(got, maxCounters) {
t.Errorf("%d counters, holding the first client %v, the second %v and the "+
"new one %v, want %d, the first and the new one", len(got), holds(got, 0),
holds(got, 1), holds(got, maxCounters), maxCounters)
}
}
func TestLoadEmptiesBucketsWhoseTimeHasPassedAndDropsEmptyCounters(t *testing.T) {
t.Parallel()
counters := newCounters(anomaly.Params{
Net: anomaly.Thresholds{RequestsPerMinute: 1000, RequestsPerHour: 1000},
Total: anomaly.Thresholds{RequestsPerMinute: 1000},
NetV4Prefix: 24,
})
halfAnHourOn := midnight().Add(30 * time.Minute)
// Half an hour on, the hour's buckets count still, and the minute's
// do not.
counters.Load([]anomaly.Counter{
{
Scope: anomaly.ScopeNet,
Netblock: netip.MustParsePrefix("203.0.113.9/24"),
Minute: ratelimit.Buckets{Start: midnight(), Current: 5},
Hour: ratelimit.Buckets{Start: midnight(), Current: 7},
},
{
Scope: anomaly.ScopeTotal,
Minute: ratelimit.Buckets{Start: midnight(), Current: 1},
},
}, halfAnHourOn)
// The whole service's counter, left empty, is dropped, and the
// netblock read is masked to its length.
netblock := anomaly.Counter{
Scope: anomaly.ScopeNet,
Netblock: netip.MustParsePrefix("203.0.113.0/24"),
Hour: ratelimit.Buckets{Start: midnight(), Current: 7},
}
if got, want := counters.Snapshot(), []anomaly.Counter{netblock}; !reflect.DeepEqual(
got, want) {
t.Errorf("counters read\n%+v\nwant\n%+v", got, want)
}
// A request from the netblock is counted with the requests read.
counters.Count(halfAnHourOn, anomaly.Request{
Client: netip.MustParseAddr("203.0.113.9"),
ClientGroup: netip.MustParsePrefix("203.0.113.9/32"),
})
netblock.Minute = ratelimit.Buckets{Start: halfAnHourOn, Current: 1}
netblock.Hour.Current = 8
want := []anomaly.Counter{netblock, {
Scope: anomaly.ScopeTotal,
Minute: ratelimit.Buckets{Start: halfAnHourOn, Current: 1},
}}
if got := counters.Snapshot(); !reflect.DeepEqual(got, want) {
t.Errorf("counters after a request\n%+v\nwant\n%+v", got, want)
}
}
func TestLoadDropsTheLeastRecentlyCountedFirst(t *testing.T) {
t.Parallel()
counters := newCounters(anomaly.Params{
Client: anomaly.Thresholds{RequestsPerMinute: 1000},
})
now := midnight().Add(time.Minute)
// The second half of the file was counted in the minute before the
// first half.
read := make([]anomaly.Counter, 0, maxCounters)
for i := range maxCounters {
start := now
if i >= maxCounters/2 {
start = midnight()
}
read = append(read, anomaly.Counter{
Scope: anomaly.ScopeClient, Netblock: request(i).ClientGroup,
Minute: ratelimit.Buckets{Start: start, Current: 1},
})
}
counters.Load(read, now)
counters.Count(now, request(maxCounters))
got := counters.Snapshot()
if !holds(got, 0) || holds(got, maxCounters/2) {
t.Errorf("holding the first client of the file %v, and the first counted in "+
"the minute before %v, want only the first", holds(got, 0),
holds(got, maxCounters/2))
}
}
// midnight is the time of the tests' requests.
func midnight() time.Time {
return time.Date(2026, 10, 6, 0, 0, 0, 0, time.UTC)
}
// newCounters returns Counters for params, whose alerts go nowhere.
func newCounters(params anomaly.Params) *anomaly.Counters {
params.Alerts = alerts.New(alerts.Params{})
return anomaly.New(params)
}
// newQueue returns a queue of alerts to a webhook, with the default
// cooldown, which keeps them waiting, since it is never run.
func newQueue() *alerts.Queue {
return alerts.New(alerts.Params{
WebhookURL: &url.URL{Scheme: "https", Host: "alerts.example"},
Events: alerts.Events(),
Cooldown: 15 * time.Minute,
MaxPerHour: 60,
Now: midnight,
})
}
// request returns a request from client number i, an address in
// 10.0.0.0/8.
func request(i int) anomaly.Request {
client := netip.MustParseAddr(fmt.Sprintf("10.%d.%d.%d", i>>16, i>>8&255, i&255))
return anomaly.Request{Client: client, ClientGroup: netip.PrefixFrom(client, 32)}
}
// holds reports whether counters hold the counter of client number i.
func holds(counters []anomaly.Counter, i int) bool {
return slices.ContainsFunc(counters, func(counter anomaly.Counter) bool {
return counter.Netblock == request(i).ClientGroup
})
}
internal/bans/admin_test.go
+289
View File
@@ -0,0 +1,289 @@
package bans_test
import (
"net/netip"
"testing"
"time"
"sneak.berlin/go/smallwebwaf/internal/bans"
)
func TestBanWithoutACauseIsAnAdmins(t *testing.T) {
t.Parallel()
netblock := netip.MustParsePrefix("203.0.113.0/24")
ledger := bans.New(defaultRules())
ledger.Load([]bans.Ban{{Netblock: netblock, Start: midnight()}})
if got := ledger.Bans(netblock)[0].Cause; got != bans.CauseAdmin {
t.Errorf("the ban's cause is %q, want admin", got)
}
}
func TestAdminsBansAreNeverDroppedAndDoNotCountTowardMaxBans(t *testing.T) {
t.Parallel()
rules := defaultRules()
rules.MaxBans = 1
ledger := bans.New(rules)
adminsOnly := netip.MustParsePrefix("198.51.100.0/24")
both := netip.MustParsePrefix("203.0.113.1/32")
second := netip.MustParsePrefix("203.0.113.2/32")
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
// ban counted toward MaxBans.
ledger.Load([]bans.Ban{
{Netblock: adminsOnly, Start: midnight().Add(-3 * time.Hour), Cause: bans.CauseAdmin},
{Netblock: adminsOnly, Start: midnight().Add(-2 * time.Hour), Cause: bans.CauseAdmin},
{Netblock: both, Start: midnight().Add(-time.Hour), Cause: bans.CauseAdmin},
{
Netblock: both,
Start: midnight(),
Expires: midnight().Add(time.Hour),
Cause: bans.CauseLimit,
},
})
wantBans(t, ledger, map[netip.Prefix]int{adminsOnly: 2, both: 2})
// A new ban drops the ban smallwebwaf made, and only that one.
ledger.BanForLimit(second, midnight(), bans.Notes{})
wantBans(t, ledger, map[netip.Prefix]int{adminsOnly: 2, both: 1, second: 1})
if ledger.Bans(both)[0].Cause != bans.CauseAdmin {
t.Errorf("%s kept %+v, want the admin's ban", both, ledger.Bans(both))
}
// And the next drops that one.
ledger.BanForLimit(third, midnight(), bans.Notes{})
wantBans(t, ledger, map[netip.Prefix]int{adminsOnly: 2, both: 1, second: 0, third: 1})
}
func TestReasonOfTheBansSmallwebwafMakes(t *testing.T) {
t.Parallel()
ledger := bans.New(defaultRules())
limit, _ := ledger.BanForLimit(netip.MustParsePrefix("203.0.113.1/32"), midnight(),
bans.Notes{Kind: "requests", Limit: 1000, Window: "minute"})
byteLimit, _ := ledger.BanForLimit(netip.MustParsePrefix("203.0.113.3/32"),
midnight(), bans.Notes{Kind: "bytes", Limit: 10 << 30, Window: "hour"})
attack, _ := ledger.BanForAttack(netip.MustParsePrefix("203.0.113.2/32"), midnight(),
bans.Notes{RuleID: "git-dir", Target: "path"})
for _, tc := range []struct{ got, want string }{
{limit.Reason, "requests per minute over the limit of 1000"},
{byteLimit.Reason, "bytes per hour over the limit of 10737418240"},
{attack.Reason, "matched the rule git-dir"},
} {
if tc.got != tc.want {
t.Errorf("the reason is %q, want %q", tc.got, tc.want)
}
}
}
func TestLiftedBanForALimitRefusesNothingAndMakesNoBanLonger(t *testing.T) {
t.Parallel()
// An hour's ban lifted ten minutes after it started.
netblock := netip.MustParsePrefix("203.0.113.9/32")
lifted := bans.Ban{
Netblock: netblock,
Start: midnight(),
Expires: midnight().Add(time.Hour),
Cause: bans.CauseLimit,
Lifted: midnight().Add(10 * time.Minute),
}
ledger := bans.New(defaultRules())
ledger.Load([]bans.Ban{lifted})
// While it would still last, it refuses nothing, and a limit broken
// bans for an hour, as a first broken limit does; the lifted ban is
// kept, and counted among the earlier bans.
now := midnight().Add(30 * time.Minute)
_, banned, _ := ledger.Check(netblock.Addr(), now)
if banned {
t.Error("the lifted ban refuses")
}
ban, _ := ledger.BanForLimit(netblock, now, bans.Notes{})
if ban.Expires.Sub(ban.Start) != time.Hour ||
ban.Notes.EarlierBans != (bans.EarlierBans{Limit: 1}) {
t.Errorf("the next ban lasts %s with earlier bans %+v, want 1h and 1 for a limit",
ban.Expires.Sub(ban.Start), ban.Notes.EarlierBans)
}
held := ledger.Bans(netblock)
if len(held) != 2 || held[0] != lifted {
t.Errorf("the ledger holds %+v, want the lifted ban and the new one", held)
}
}
func TestLiftedBanForAnAttackRefusesNothingAndMakesNoBanLonger(t *testing.T) {
t.Parallel()
// A permanent ban for a clear sign of attack, lifted.
netblock := netip.MustParsePrefix("203.0.113.9/32")
ledger := bans.New(defaultRules())
ledger.Load([]bans.Ban{{
Netblock: netblock,
Start: midnight(),
Cause: bans.CauseAttack,
Lifted: midnight().Add(time.Hour),
}})
now := midnight().Add(2 * time.Hour)
_, banned, _ := ledger.Find(netblock.Addr(), now)
if banned {
t.Error("the lifted ban refuses")
}
active, permanent := ledger.Count(now)
if active != 0 || permanent != 0 {
t.Errorf("%d bans are active and %d permanent, want none", active, permanent)
}
// The next clear sign of attack bans for seven days, as a first does.
ban, _ := ledger.BanForAttack(netblock, now, bans.Notes{})
if ban.Expires.Sub(ban.Start) != 7*day {
t.Errorf("the next ban for an attack ends at %s, want seven days on", ban.Expires)
}
}
func TestLoadEditCountsTheBansAnAdminMade(t *testing.T) {
t.Parallel()
ledger := bans.New(defaultRules())
made, _ := ledger.BanForLimit(netip.MustParsePrefix("203.0.113.1/32"), midnight(),
bans.Notes{})
atStart := bans.Ban{
Netblock: netip.MustParsePrefix("203.0.113.2/32"),
Start: midnight(),
}
// The bans read at the start were made before it.
ledger.Load([]bans.Ban{made, atStart})
if got := ledger.Made(bans.CauseAdmin); got != 0 {
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
// start, and adds one without a cause: that one alone is made.
kept := made
kept.Cause = bans.CauseAdmin
added := bans.Ban{
Netblock: netip.MustParsePrefix("203.0.113.3/32"),
Start: midnight(),
}
ledger.LoadEdit([]bans.Ban{kept, atStart, added})
if ledger.Made(bans.CauseAdmin) != 1 || ledger.Made(bans.CauseLimit) != 1 {
t.Errorf("%d bans made by an admin and %d for a limit, want 1 of each",
ledger.Made(bans.CauseAdmin), ledger.Made(bans.CauseLimit))
}
}
func TestAdminsBanIsMadeWhileAnotherLasts(t *testing.T) {
t.Parallel()
netblock := netip.MustParsePrefix("203.0.113.0/24")
ledger := bans.New(defaultRules())
// An hour's ban for a broken limit.
ledger.BanForLimit(netblock, midnight(), bans.Notes{})
wantChanged(t, ledger, true)
// A minute later an admin bans the netblock for good, named by an
// address in it: that ban is made, and counts the other among the
// earlier bans.
now := midnight().Add(time.Minute)
want := bans.Ban{
Netblock: netblock,
Start: now,
Cause: bans.CauseAdmin,
Reason: "probes for logins",
Notes: bans.Notes{EarlierBans: bans.EarlierBans{Limit: 1}},
}
got := ledger.BanForAdmin(netip.MustParsePrefix("203.0.113.9/24"), now, time.Time{},
"probes for logins")
if got != want {
t.Errorf("the admin's ban is\n%+v\nwant\n%+v", got, want)
}
wantChanged(t, ledger, true)
if made := ledger.Made(bans.CauseAdmin); made != 1 {
t.Errorf("%d bans made by an admin, want 1", made)
}
// It refuses once the ban for the limit has ended.
ban, banned, _ := ledger.Find(netblock.Addr(), midnight().Add(2*time.Hour))
if !banned || ban != want {
t.Errorf("after the limit's ban the netblock is under %+v (%t), want %+v",
ban, banned, want)
}
}
func TestLiftLiftsEveryActiveBanCoveringTheClient(t *testing.T) {
t.Parallel()
client := netip.MustParseAddr("203.0.113.9")
own := netip.MustParsePrefix("203.0.113.9/32")
wide := netip.MustParsePrefix("203.0.113.0/24")
other := netip.MustParsePrefix("203.0.113.10/32")
ledger := bans.New(defaultRules())
ledger.Load([]bans.Ban{
// Ended an hour ago.
{
Netblock: own, Start: midnight().Add(-2 * time.Hour),
Expires: midnight().Add(-time.Hour), Cause: bans.CauseLimit,
},
// Active, on the client's address and on its /24.
{
Netblock: own, Start: midnight(), Expires: midnight().Add(time.Hour),
Cause: bans.CauseLimit,
},
{Netblock: wide, Start: midnight(), Cause: bans.CauseAdmin},
// Another client's.
{Netblock: other, Start: midnight(), Cause: bans.CauseAdmin},
})
now := midnight().Add(time.Minute)
lifted := ledger.Lift(client, now)
if len(lifted) != 2 || lifted[0].Lifted != now || lifted[1].Lifted != now {
t.Errorf("lifted %+v, want the two active bans covering the client", lifted)
}
wantChanged(t, ledger, true)
if _, banned, _ := ledger.Check(client, now); banned {
t.Error("the client is still banned")
}
if _, banned, _ := ledger.Check(other.Addr(), now); !banned {
t.Error("the other client's ban was lifted")
}
// The lifted bans are kept, and the one that had ended is not lifted.
covering := ledger.Covering(client)
if len(covering) != 3 || covering[0].Netblock != wide ||
!covering[1].Lifted.IsZero() || covering[2].Lifted != now {
t.Errorf("the bans covering the client are %+v, want the /24's and both "+
"of its own, the earlier not lifted", covering)
}
// With none active, nothing is lifted or changed.
if lifted = ledger.Lift(client, now); len(lifted) != 0 {
t.Errorf("lifted %+v again", lifted)
}
wantChanged(t, ledger, false)
}
internal/bans/bans.go
+511 -98
View File
@@ -1,10 +1,13 @@
// Package bans is the ban ledger: the bans smallwebwaf makes on the
// netblocks of clients that break a rate limit, with their notes, as the
// "Bans" section of SPEC.md describes. The bans are kept in memory, and
// written to bans.json and read from it by the state package.
// netblocks of clients that break a rate limit or a byte limit or show a
// clear sign of attack, and those an admin makes, with their notes, as
// the "Bans" section of SPEC.md describes. The bans are kept in memory,
// and written to bans.json and read from it by the state package.
package bans
import (
"fmt"
"math"
"net/netip"
"slices"
"strings"
@@ -14,6 +17,17 @@ import (
"github.com/hashicorp/golang-lru/v2/simplelru"
)
// The causes of bans.
const (
// CauseLimit is a ban smallwebwaf made for a broken limit.
CauseLimit = "limit"
// CauseAttack is a ban smallwebwaf made for a clear sign of attack.
CauseAttack = "attack"
// CauseAdmin is a ban an admin made, or one smallwebwaf made that an
// admin keeps. It is never dropped.
CauseAdmin = "admin"
)
// repeatFactor is how many times as long as the netblock's last ban a ban
// for a limit broken again within the repeat window lasts.
const repeatFactor = 3
@@ -21,31 +35,43 @@ const repeatFactor = 3
// maxTextBytes is how much of each text in a ban's notes is kept.
const maxTextBytes = 256
// Rules are how long a ban for a broken limit lasts, and how many bans
// are held.
// Rules are how long a ban lasts, and how many bans are held.
type Rules struct {
// LimitBanDuration is how long a first ban lasts.
// LimitBanDuration is how long a first ban for a broken limit lasts.
LimitBanDuration time.Duration
// LimitBanRepeatWindow is how soon after the netblock's last ban
// ended a broken limit counts as a repeat, which bans for
// repeatFactor times as long as that ban.
// LimitBanRepeatWindow is how soon after the end of the netblock's
// ban that ended last, other than one for a clear sign of attack, a
// broken limit counts as a repeat, which bans for repeatFactor times as
// long as that ban.
LimitBanRepeatWindow time.Duration
// MaxBanDuration is the longest ban; a ban that would be longer is
// permanent instead.
// MaxBanDuration is the longest ban for a broken limit; one that would
// be longer is permanent instead.
MaxBanDuration time.Duration
// MaxBans is the most bans held, at least one. Past it, the earliest
// ban of the netblock that has gone longest without a request is
// dropped.
// AttackBanDuration is how long a first ban for a clear sign of attack
// lasts.
AttackBanDuration time.Duration
// MaxBans is the most bans held whose cause is not CauseAdmin, at
// least one. Past it, the earliest such ban of the netblock that has
// gone longest without a request is dropped. Bans whose cause is
// CauseAdmin are held besides, and never dropped.
MaxBans int
}
// Ban is a ban on a netblock for a broken limit, the only kind of ban
// smallwebwaf makes so far.
// Ban is a ban on a netblock.
type Ban struct {
Netblock netip.Prefix
Start time.Time
// Expires is when the ban ends, zero for a permanent ban.
Expires time.Time
// Cause is CauseLimit, CauseAttack or CauseAdmin.
Cause string
// Reason is a short text: for a ban smallwebwaf made, the limit broken
// or the rule that matched; for an admin's, what the admin wrote.
Reason string
// Lifted is when an admin lifted the ban, zero while no admin has. A
// lifted ban refuses nothing, and does not make the netblock's next
// ban longer.
Lifted time.Time
Notes Notes
}
@@ -54,9 +80,10 @@ func (b Ban) Permanent() bool {
return b.Expires.IsZero()
}
// ActiveAt reports whether the ban refuses requests at now.
// ActiveAt reports whether the ban refuses requests at now: it has not
// been lifted, and has not run out.
func (b Ban) ActiveAt(now time.Time) bool {
return b.Permanent() || now.Before(b.Expires)
return b.Lifted.IsZero() && (b.Permanent() || now.Before(b.Expires))
}
// Notes are what an admin needs to decide whether to lift a ban. The
@@ -64,25 +91,51 @@ func (b Ban) ActiveAt(now time.Time) bool {
//
//nolint:tagliatelle // the state files use snake_case, as the request log does
type Notes struct {
// Country is the client's country, when it was looked up.
// ASN, ASName and Country are the client's AS number, AS name and
// country, when they were looked up: when the request that caused the
// ban was made, or when GeoJS answered about the client afterwards.
ASN string `json:"asn"`
ASName string `json:"as_name"`
Country string `json:"country"`
// Limit, Window and Count are the limit that was broken, its window,
// "minute", "hour" or "day", and the count reached: the client's
// requests in the window, the one that broke the limit included.
// These are the requests that counted toward the ban, and the window
// is the time over which they came.
Limit int64 `json:"limit"`
Window string `json:"window"`
Count float64 `json:"count"`
// Request is the request that broke the limit.
// Kind, Limit, Window and Count are, for a ban for a broken limit,
// what the limit was on, "requests" for a rate limit or "bytes" for a
// byte limit, the limit that was broken, its window, "minute", "hour"
// or "day", and the count reached: the client's requests, or bytes, in
// the window, those of the request that broke the limit included.
// These are what counted toward the ban, and the window is the time
// over which they came.
Kind string `json:"kind,omitempty"`
Limit int64 `json:"limit,omitempty"`
Window string `json:"window,omitempty"`
Count float64 `json:"count,omitempty"`
// LimitPercent and LimitPercentSetting are, for a ban for a limit a
// biased threshold lowered, the client's percentage of that kind of
// limit, of which Limit is the result, and the setting that gave it.
// Both are left out for a limit that was not lowered.
LimitPercent *int64 `json:"limit_percent,omitempty"`
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.
RuleID string `json:"rule_id,omitempty"`
Target string `json:"target,omitempty"`
// Request is the request that broke the limit, or whose bytes broke
// it, or that was the clear sign of attack.
Request Request `json:"request"`
// Requests is how many requests the netblock has sent since it was
// first seen, and Refused how many of them the ban has refused so
// far. Both go up with each request the ban refuses.
Requests int64 `json:"requests"`
Refused int64 `json:"refused"`
// EarlierBans is how many bans the netblock had before this one.
EarlierBans int `json:"earlier_bans"`
// EarlierBans is how many bans the netblock had before this one, by
// cause.
EarlierBans EarlierBans `json:"earlier_bans"`
}
// EarlierBans counts a netblock's bans before a ban, by cause.
type EarlierBans struct {
Limit int `json:"limit"`
Attack int `json:"attack"`
Admin int `json:"admin"`
}
// Request is a request in a ban's notes. Each text is cut to 256 bytes.
@@ -110,10 +163,13 @@ type Ledger struct {
// netblocks holds each banned netblock's bans, oldest first. Check and
// Find make each netblock they find the most recently seen.
netblocks *simplelru.LRU[netip.Prefix, *[]Ban]
// held is how many bans netblocks holds, at most rules.MaxBans.
// held is how many bans netblocks holds whose cause is not CauseAdmin,
// at most rules.MaxBans.
held int
// made is how many bans BanForLimit has made since the start.
made int
// made is how many bans have been made since the start, by cause: by
// the ledger, and by an admin, through BanForAdmin or in an edit of
// bans.json.
made map[string]int
// 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
@@ -124,9 +180,10 @@ type Ledger struct {
// New returns a Ledger with no ban yet.
func New(rules Rules) *Ledger {
// Every netblock held has a ban, so there are never more netblocks
// than rules.MaxBans, and the LRU never drops one itself.
netblocks, err := simplelru.NewLRU[netip.Prefix, *[]Ban](rules.MaxBans, nil)
// The ledger drops bans itself, and never those whose cause is
// CauseAdmin, however many there are, so the LRU has no limit of its
// own: it keeps the netblocks in the order they were last seen.
netblocks, err := simplelru.NewLRU[netip.Prefix, *[]Ban](math.MaxInt, nil)
if err != nil {
panic(err) // NewLRU fails only for a size below one
}
@@ -135,89 +192,226 @@ func New(rules Rules) *Ledger {
rules: rules,
changed: make(chan struct{}, 1),
netblocks: netblocks,
made: map[string]int{},
}
}
// Changed receives a value after a ban is made, so that bans.json can be
// written. Several bans made before it is read leave one value.
// Changed receives a value after a ban is made, lifted or made permanent,
// so that bans.json can be written. Several changes before it is read
// leave one value.
func (l *Ledger) Changed() <-chan struct{} {
return l.changed
}
// Check is called for a request from client, at now. It reports whether
// a ban on a netblock client is in is active, and returns that ban, with
// the request counted among those it refused.
func (l *Ledger) Check(client netip.Addr, now time.Time) (Ban, bool) {
// the request counted among those it refused. A ban for a clear sign of
// attack is made permanent by the request: the netblock is malicious.
// The last result reports whether the request made the ban permanent.
func (l *Ledger) Check(client netip.Addr, now time.Time) (Ban, bool, bool) {
l.mu.Lock()
defer l.mu.Unlock()
ban := l.active(client, now)
if ban == nil {
return Ban{}, false
return Ban{}, false, false
}
ban.Notes.Requests++
ban.Notes.Refused++
return *ban, true
madePermanent := ban.Cause == CauseAttack && !ban.Permanent()
if madePermanent {
ban.Expires = time.Time{}
l.markChanged()
}
return *ban, true, madePermanent
}
// Find is Check without counting the request among those the ban
// refused: in observe mode a ban refuses nothing.
func (l *Ledger) Find(client netip.Addr, now time.Time) (Ban, bool) {
// refused, and without making the ban permanent: in observe mode a ban
// refuses nothing. The last result reports whether Check would have made
// the ban permanent.
func (l *Ledger) Find(client netip.Addr, now time.Time) (Ban, bool, bool) {
l.mu.Lock()
defer l.mu.Unlock()
ban := l.active(client, now)
if ban == nil {
return Ban{}, false
return Ban{}, false, false
}
return *ban, true
return *ban, true, ban.Cause == CauseAttack && !ban.Permanent()
}
// activeBan returns the ban in bans, a netblock's bans oldest first, that
// is active at now, or nil when none is. If several are, it returns the
// one that started last. Every ban is looked at, since a ban an admin adds
// to bans.json can start before the netblock's others and outlast them.
func activeBan(bans []Ban, now time.Time) *Ban {
for i := len(bans) - 1; i >= 0; i-- {
if bans[i].ActiveAt(now) {
return &bans[i]
}
}
return nil
}
// BanForLimit bans netblock at now for a broken limit, with notes, and
// returns the ban. A first ban lasts LimitBanDuration. A ban made within
// LimitBanRepeatWindow after the netblock's last ban ended lasts
// returns the ban, and true. A first ban lasts LimitBanDuration. A ban
// made within LimitBanRepeatWindow after the netblock's ban that ended
// last, other than one for a clear sign of attack or a lifted one, lasts
// repeatFactor times as long as that one. A ban that would be longer
// than MaxBanDuration is permanent instead. If a ban on netblock is still
// active, as when two of its requests break a limit at once, that ban is
// returned and no other is made. The ledger fills in the notes' Refused
// and EarlierBans itself.
func (l *Ledger) BanForLimit(netblock netip.Prefix, now time.Time, notes Notes) Ban {
// returned with false, and no other is made. The ledger fills in the
// notes' Refused and EarlierBans itself, and gives the ban the reason
// "<Kind> per <Window> over the limit of <Limit>", from the notes, such
// as "requests per minute over the limit of 1000".
func (l *Ledger) BanForLimit(
netblock netip.Prefix, now time.Time, notes Notes,
) (Ban, bool) {
return l.ban(netblock, now, CauseLimit, limitReason(notes), notes, true)
}
// WouldBanForLimit returns what BanForLimit would, without making the ban:
// what observe mode would have done.
func (l *Ledger) WouldBanForLimit(
netblock netip.Prefix, now time.Time, notes Notes,
) (Ban, bool) {
return l.ban(netblock, now, CauseLimit, limitReason(notes), notes, false)
}
// BanForAttack bans netblock at now for a clear sign of attack, with
// notes, and returns the ban, and whether it made it, as BanForLimit
// does. A first ban lasts AttackBanDuration; once the netblock has had
// one that was not lifted, the next is permanent. Its reason is "matched
// the rule <RuleID>".
func (l *Ledger) BanForAttack(
netblock netip.Prefix, now time.Time, notes Notes,
) (Ban, bool) {
return l.ban(netblock, now, CauseAttack, attackReason(notes), notes, true)
}
// WouldBanForAttack returns what BanForAttack would, without making the
// ban: what observe mode would have done.
func (l *Ledger) WouldBanForAttack(
netblock netip.Prefix, now time.Time, notes Notes,
) (Ban, bool) {
return l.ban(netblock, now, CauseAttack, attackReason(notes), notes, false)
}
// WouldBePermanent reports whether a ban on netblock for cause, CauseLimit
// or CauseAttack, made at now would be permanent, as BanForLimit or
// BanForAttack would make it. It works out nothing else of the ban.
func (l *Ledger) WouldBePermanent(
netblock netip.Prefix, now time.Time, cause string,
) bool {
l.mu.Lock()
defer l.mu.Unlock()
var last *Ban
bans, found := l.netblocks.Get(netblock)
if found {
last = &(*bans)[len(*bans)-1]
if last.ActiveAt(now) {
return *last
var held []Ban
if bans, found := l.netblocks.Peek(netblock); found {
held = *bans
}
notes.EarlierBans = last.Notes.EarlierBans + 1
if cause == CauseAttack {
return l.attackExpiry(held, now).IsZero()
}
notes.Request = notes.Request.cut()
return l.limitExpiry(held, now).IsZero()
}
// limitReason is the reason of a ban for a broken limit, with notes.
func limitReason(notes Notes) string {
return fmt.Sprintf("%s per %s over the limit of %d",
notes.Kind, notes.Window, notes.Limit)
}
// attackReason is the reason of a ban for a clear sign of attack, with
// notes.
func attackReason(notes Notes) string {
return "matched the rule " + notes.RuleID
}
// BanForAdmin bans netblock at now for an admin, with reason, until
// expires, or for good when expires is zero, and returns the ban, whose
// cause is CauseAdmin. Unlike BanForLimit and BanForAttack, it makes the
// ban even while another on netblock is active, since the admin asked
// for this one. The ledger fills in the notes' EarlierBans, and counts
// the ban among those made.
func (l *Ledger) BanForAdmin(
netblock netip.Prefix, now, expires time.Time, reason string,
) Ban {
l.mu.Lock()
defer l.mu.Unlock()
ban := Ban{
Netblock: netblock,
Start: now,
Expires: l.expiry(last, now),
Notes: notes,
Netblock: netblock.Masked(), Start: now, Expires: expires, Cause: CauseAdmin,
Reason: reason,
}
l.add(ban)
l.made++
select {
case l.changed <- struct{}{}:
default: // a value is waiting already
held, found := l.netblocks.Get(ban.Netblock)
if found {
ban.Notes.EarlierBans = earlierBans(*held)
}
l.add(ban)
l.made[CauseAdmin]++
l.markChanged()
return ban
}
// Lift lifts, at now, every ban active then on a netblock client is in,
// as an admin does, and returns those bans. A lifted ban is kept, refuses
// nothing, and does not make the netblock's next ban longer.
func (l *Ledger) Lift(client netip.Addr, now time.Time) []Ban {
l.mu.Lock()
defer l.mu.Unlock()
var lifted []Ban
for _, bans := range l.covering(client) {
for i := range *bans {
ban := &(*bans)[i]
if ban.ActiveAt(now) {
ban.Lifted = now
lifted = append(lifted, *ban)
}
}
}
if len(lifted) > 0 {
l.markChanged()
}
return lifted
}
// Covering returns every ban held on a netblock client is in, active or
// not, sorted by netblock, and each netblock's bans oldest first. It is
// not a request from client, and leaves when the netblocks were last seen
// unchanged.
func (l *Ledger) Covering(client netip.Addr) []Ban {
l.mu.Lock()
defer l.mu.Unlock()
var held []Ban
for _, bans := range l.covering(client) {
held = append(held, *bans...)
}
slices.SortStableFunc(held, func(a, b Ban) int {
return a.Netblock.Compare(b.Netblock)
})
return held
}
// Bans returns the bans held on netblock, oldest first. It is not a
// request from netblock, and leaves when it was last seen unchanged.
func (l *Ledger) Bans(netblock netip.Prefix) []Ban {
@@ -232,17 +426,41 @@ func (l *Ledger) Bans(netblock netip.Prefix) []Ban {
return slices.Clone(*bans)
}
// Made returns how many bans the ledger has made since the start; bans
// read from bans.json are not among them.
func (l *Ledger) Made() int {
// AddLookup gives the notes of netblock's bans that have no AS number, AS
// name or country yet those of a client in it, as the lookup answered
// about it. It is not a request from netblock, and leaves when it was last
// seen unchanged. It does not have bans.json written at once: the notes
// are written with its next write, as the counts in them are.
func (l *Ledger) AddLookup(netblock netip.Prefix, asn, asName, country string) {
l.mu.Lock()
defer l.mu.Unlock()
return l.made
bans, found := l.netblocks.Peek(netblock)
if !found {
return
}
for i := range *bans {
notes := &(*bans)[i].Notes
if notes.ASN == "" && notes.ASName == "" && notes.Country == "" {
notes.ASN, notes.ASName, notes.Country = asn, asName, country
}
}
}
// Made returns how many bans for cause have been made since the start:
// for CauseLimit and CauseAttack, by the ledger; for CauseAdmin, by an
// admin, with BanForAdmin or in an edit of bans.json, as LoadEdit counts
// them. The bans read from bans.json at the start are not among them.
func (l *Ledger) Made(cause string) int {
l.mu.Lock()
defer l.mu.Unlock()
return l.made[cause]
}
// Count returns how many of the bans held are active at now, and how many
// are permanent.
// of those are permanent. A lifted ban is neither.
func (l *Ledger) Count(now time.Time) (int, int) {
l.mu.Lock()
defer l.mu.Unlock()
@@ -251,10 +469,12 @@ func (l *Ledger) Count(now time.Time) (int, int) {
for _, bans := range l.netblocks.Values() {
for _, ban := range *bans {
if ban.ActiveAt(now) {
active++
if !ban.ActiveAt(now) {
continue
}
active++
if ban.Permanent() {
permanent++
}
@@ -282,26 +502,148 @@ func (l *Ledger) Snapshot() []Ban {
return held
}
// Load puts bans read from bans.json into a ledger that holds none yet,
// in the order they started, so that a netblock whose last ban started
// latest counts as the most recently seen. Each netblock is masked to its
// length, so that 203.0.113.9/24 is 203.0.113.0/24, and each text in the
// notes is cut to 256 bytes. Past MaxBans the earliest bans are dropped,
// as when they are made.
// Load puts bans read from bans.json at the start into the ledger, in
// place of the bans it holds, in the order they started, so that a
// netblock whose last ban started latest counts as the most recently
// seen. A ban without a cause is an admin's, and gets CauseAdmin. Each
// netblock is masked to its length, so that 203.0.113.9/24 is
// 203.0.113.0/24, and each text in the notes is cut to 256 bytes. Past
// MaxBans the earliest bans whose cause is not CauseAdmin are dropped, as
// when they are made.
func (l *Ledger) Load(bans []Ban) {
l.mu.Lock()
defer l.mu.Unlock()
l.load(bans)
}
// 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
// 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) {
l.mu.Lock()
defer l.mu.Unlock()
l.made[CauseAdmin] += l.load(bans)
}
// load does what Load describes, and returns how many of bans are bans
// whose cause is CauseAdmin that the ledger did not hold before.
func (l *Ledger) load(bans []Ban) int {
bans = slices.Clone(bans)
added := 0
for i := range bans {
ban := &bans[i]
ban.Netblock = ban.Netblock.Masked()
ban.Notes.Request = ban.Notes.Request.cut()
if ban.Cause == "" {
ban.Cause = CauseAdmin
}
if ban.Cause == CauseAdmin && !l.holds(ban.Netblock, ban.Start) {
added++
}
}
slices.SortStableFunc(bans, func(a, b Ban) int {
return a.Start.Compare(b.Start)
})
l.netblocks.Purge()
l.held = 0
l.v4Lengths, l.v6Lengths = nil, nil
for _, ban := range bans {
ban.Netblock = ban.Netblock.Masked()
ban.Notes.Request = ban.Notes.Request.cut()
l.add(ban)
}
return added
}
// holds reports whether the ledger holds a ban on netblock that started
// at start.
func (l *Ledger) holds(netblock netip.Prefix, start time.Time) bool {
bans, found := l.netblocks.Peek(netblock)
return found && slices.ContainsFunc(*bans, func(ban Ban) bool {
return ban.Start.Equal(start)
})
}
// ban bans netblock at now for cause, with reason and notes, as
// BanForLimit and BanForAttack describe, and returns the ban, and whether
// it made it. Unless keep is true, the ban is not made, only returned: it
// is the ban that would have been made.
func (l *Ledger) ban(
netblock netip.Prefix, now time.Time, cause, reason string, notes Notes, keep bool,
) (Ban, bool) {
l.mu.Lock()
defer l.mu.Unlock()
// held are the netblock's bans, none of them active.
var held []Ban
bans, found := l.netblocks.Get(netblock)
if found {
active := activeBan(*bans, now)
if active != nil {
return *active, false
}
held = *bans
notes.EarlierBans = earlierBans(held)
}
notes.Request = notes.Request.cut()
ban := Ban{Netblock: netblock, Start: now, Cause: cause, Reason: reason, Notes: notes}
if cause == CauseAttack {
ban.Expires = l.attackExpiry(held, now)
} else {
ban.Expires = l.limitExpiry(held, now)
}
if !keep {
return ban, true
}
l.add(ban)
l.made[cause]++
l.markChanged()
return ban, true
}
// 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
// netblock had before that one, since dropped to make room, and each ban
// held adds one.
func earlierBans(held []Ban) EarlierBans {
earlier := held[0].Notes.EarlierBans
for _, ban := range held {
switch ban.Cause {
case CauseLimit:
earlier.Limit++
case CauseAttack:
earlier.Attack++
case CauseAdmin:
earlier.Admin++
}
}
return earlier
}
// markChanged has Changed receive a value, unless one is waiting already.
func (l *Ledger) markChanged() {
select {
case l.changed <- struct{}{}:
default: // a value is waiting already
}
}
// active returns the ban active at now on a netblock client is in, or
@@ -318,21 +660,41 @@ func (l *Ledger) active(client netip.Addr, now time.Time) *Ban {
continue
}
// A ban is made only once the one before has ended, so only the
// last can be active.
last := &(*bans)[len(*bans)-1]
if last.ActiveAt(now) {
return last
ban := activeBan(*bans, now)
if ban != nil {
return ban
}
}
return nil
}
// covering returns the bans of each netblock held that client is in,
// leaving when the netblocks were last seen unchanged.
func (l *Ledger) covering(client netip.Addr) []*[]Ban {
lengths := l.v6Lengths
if client.Is4() {
lengths = l.v4Lengths
}
var found []*[]Ban
for _, length := range lengths {
bans, ok := l.netblocks.Peek(netip.PrefixFrom(client, length).Masked())
if ok {
found = append(found, bans)
}
}
return found
}
// add adds ban to its netblock's bans, after the last, and makes its
// netblock the most recently seen. With MaxBans held, it drops one first.
// netblock the most recently seen. With MaxBans held, it drops one first,
// unless ban's cause is CauseAdmin, which does not count toward MaxBans.
func (l *Ledger) add(ban Ban) {
if l.held == l.rules.MaxBans {
counted := ban.Cause != CauseAdmin
if counted && l.held == l.rules.MaxBans {
l.dropOne()
}
@@ -345,7 +707,10 @@ func (l *Ledger) add(ban Ban) {
}
*bans = append(*bans, ban)
if counted {
l.held++
}
lengths := &l.v6Lengths
if ban.Netblock.Addr().Is4() {
@@ -357,12 +722,24 @@ func (l *Ledger) add(ban Ban) {
}
}
// expiry returns when a ban for a broken limit made at now ends, or zero
// when it is permanent. last is the netblock's last ban, which has ended,
// or nil when it has none.
func (l *Ledger) expiry(last *Ban, now time.Time) time.Time {
// limitExpiry returns when a ban for a broken limit made at now ends, or
// zero when it is permanent. held are the netblock's bans, none of them
// active, of which the one that ended last, other than a ban for a clear
// sign of attack or a lifted one, can make the new ban longer. A ban an
// admin adds to bans.json can start after another and end before it, so
// that one is looked for among them all.
func (l *Ledger) limitExpiry(held []Ban, now time.Time) time.Time {
length := l.rules.LimitBanDuration
var last *Ban
for i, ban := range held {
if ban.Cause != CauseAttack && ban.Lifted.IsZero() &&
(last == nil || ban.Expires.After(last.Expires)) {
last = &held[i]
}
}
if last != nil && now.Sub(last.Expires) <= l.rules.LimitBanRepeatWindow {
lastLength := last.Expires.Sub(last.Start)
// This is repeatFactor * lastLength > MaxBanDuration, written so
@@ -381,17 +758,53 @@ func (l *Ledger) expiry(last *Ban, now time.Time) time.Time {
return now.Add(length)
}
// dropOne drops the earliest ban of the netblock that has gone longest
// without a request, and the netblock with it if that was its only ban.
// attackExpiry returns when a ban for a clear sign of attack made at now
// ends. held are the netblock's bans, none of them active: if one of them
// is for a clear sign of attack too, and was not lifted, the new ban is
// permanent, and its end zero; otherwise it ends AttackBanDuration later.
func (l *Ledger) attackExpiry(held []Ban, now time.Time) time.Time {
for _, ban := range held {
if ban.Cause == CauseAttack && ban.Lifted.IsZero() {
return time.Time{}
}
}
return now.Add(l.rules.AttackBanDuration)
}
// dropOne drops the earliest ban whose cause is not CauseAdmin of the
// netblock that has gone longest without a request, of those that hold
// such a ban, and the netblock with it if that was its only ban. It is
// called with at least one such ban held. It looks at each netblock once
// at most, and drops nothing when none holds such a ban.
func (l *Ledger) dropOne() {
for range l.netblocks.Len() {
netblock, bans, _ := l.netblocks.GetOldest()
i := slices.IndexFunc(*bans, func(ban Ban) bool {
return ban.Cause != CauseAdmin
})
if i < 0 {
// Its bans are all an admin's, and never dropped. Get makes
// it the most recently seen, so that the next netblock is
// looked at; when it was seen matters only for dropping a
// ban, and a ban added to it makes it the most recently seen
// anyway.
l.netblocks.Get(netblock)
continue
}
if len(*bans) == 1 {
l.netblocks.Remove(netblock)
} else {
*bans = slices.Delete(*bans, 0, 1)
*bans = slices.Delete(*bans, i, i+1)
}
l.held--
return
}
}
// cut returns r with each text cut to maxTextBytes and copied, so that
internal/bans/bans_test.go
+262 -31
View File
@@ -21,11 +21,12 @@ func TestRepeatsTripleUntilPermanent(t *testing.T) {
// Each ban is followed by another as soon as it ends: 1, 3, 9, 27 and
// 81 hours.
for i, hours := range []int{1, 3, 9, 27, 81} {
ban := ledger.BanForLimit(netblock, now, bans.Notes{})
ban, _ := ledger.BanForLimit(netblock, now, bans.Notes{})
length := time.Duration(hours) * time.Hour
if !ban.Expires.Equal(now.Add(length)) || ban.Notes.EarlierBans != i {
t.Fatalf("ban %d lasts %s with %d earlier bans, want %d hours and %d",
if !ban.Expires.Equal(now.Add(length)) ||
ban.Notes.EarlierBans != (bans.EarlierBans{Limit: i}) {
t.Fatalf("ban %d lasts %s with earlier bans %+v, want %d hours and %d for a limit",
i+1, ban.Expires.Sub(now), ban.Notes.EarlierBans, hours, i)
}
@@ -34,12 +35,12 @@ func TestRepeatsTripleUntilPermanent(t *testing.T) {
// The sixth would last 243 hours, more than seven days: it is
// permanent, and never ends.
ban := ledger.BanForLimit(netblock, now, bans.Notes{})
ban, _ := ledger.BanForLimit(netblock, now, bans.Notes{})
if !ban.Permanent() {
t.Fatalf("sixth ban ends at %s, want a permanent one", ban.Expires)
}
_, banned := ledger.Check(netblock.Addr(), now.Add(100*365*day))
_, banned, _ := ledger.Check(netblock.Addr(), now.Add(100*365*day))
if !banned {
t.Error("a permanent ban ended")
}
@@ -63,11 +64,12 @@ func TestRepeatWindowRunsOut(t *testing.T) {
ledger := bans.New(defaultRules())
netblock := netip.MustParsePrefix("203.0.113.9/32")
first := ledger.BanForLimit(netblock, midnight(), bans.Notes{})
second := ledger.BanForLimit(netblock, first.Expires.Add(tc.gap), bans.Notes{})
first, _ := ledger.BanForLimit(netblock, midnight(), bans.Notes{})
second, _ := ledger.BanForLimit(netblock, first.Expires.Add(tc.gap), bans.Notes{})
if second.Expires.Sub(second.Start) != tc.want || second.Notes.EarlierBans != 1 {
t.Errorf("second ban lasts %s with %d earlier bans, want %s and 1",
if second.Expires.Sub(second.Start) != tc.want ||
second.Notes.EarlierBans != (bans.EarlierBans{Limit: 1}) {
t.Errorf("second ban lasts %s with earlier bans %+v, want %s and 1 for a limit",
second.Expires.Sub(second.Start), second.Notes.EarlierBans, tc.want)
}
})
@@ -81,7 +83,7 @@ func TestFirstBanLongerThanTheMaximumIsPermanent(t *testing.T) {
rules.LimitBanDuration = rules.MaxBanDuration + time.Hour
ledger := bans.New(rules)
ban := ledger.BanForLimit(netip.MustParsePrefix("203.0.113.9/32"), midnight(),
ban, _ := ledger.BanForLimit(netip.MustParsePrefix("203.0.113.9/32"), midnight(),
bans.Notes{})
if !ban.Permanent() {
t.Errorf("first ban ends at %s, want a permanent one", ban.Expires)
@@ -101,7 +103,7 @@ func TestLongestBanSetFarOffDoesNotOverflow(t *testing.T) {
now := midnight()
for i := range 14 {
ban := ledger.BanForLimit(netblock, now, bans.Notes{})
ban, _ := ledger.BanForLimit(netblock, now, bans.Notes{})
if !ban.Expires.After(ban.Start) {
t.Fatalf("ban %d starts at %s and ends at %s", i+1, ban.Start, ban.Expires)
}
@@ -109,7 +111,7 @@ func TestLongestBanSetFarOffDoesNotOverflow(t *testing.T) {
now = ban.Expires
}
ban := ledger.BanForLimit(netblock, now, bans.Notes{})
ban, _ := ledger.BanForLimit(netblock, now, bans.Notes{})
if !ban.Permanent() {
t.Errorf("15th ban ends at %s, want a permanent one", ban.Expires)
}
@@ -121,12 +123,22 @@ func TestBrokenLimitDuringABanMakesNoOther(t *testing.T) {
ledger := bans.New(defaultRules())
netblock := netip.MustParsePrefix("203.0.113.9/32")
first := ledger.BanForLimit(netblock, midnight(), bans.Notes{})
again := ledger.BanForLimit(netblock, midnight().Add(time.Minute), bans.Notes{})
first, made := ledger.BanForLimit(netblock, midnight(), bans.Notes{})
if !made {
t.Error("the first ban was not made")
}
if again != first || len(ledger.Bans(netblock)) != 1 {
t.Errorf("a limit broken during a ban gave %+v and %d bans, want %+v and 1",
again, len(ledger.Bans(netblock)), first)
again, made := ledger.BanForLimit(netblock, midnight().Add(time.Minute), bans.Notes{})
if made || again != first || len(ledger.Bans(netblock)) != 1 {
t.Errorf("a limit broken during a ban gave %+v, made %t, and %d bans, "+
"want %+v, not made, and 1", again, made, len(ledger.Bans(netblock)), first)
}
again, made = ledger.BanForAttack(netblock, midnight().Add(time.Minute), bans.Notes{})
if made || again != first {
t.Errorf("an attack during a ban gave %+v, made %t, want %+v, not made",
again, made, first)
}
}
@@ -135,21 +147,21 @@ func TestCheckRefusesWhileTheBanLastsAndCountsTheRefusals(t *testing.T) {
ledger := bans.New(defaultRules())
netblock := netip.MustParsePrefix("203.0.113.9/32")
ban := ledger.BanForLimit(netblock, midnight(), bans.Notes{Requests: 5})
ban, _ := ledger.BanForLimit(netblock, midnight(), bans.Notes{Requests: 5})
for range 3 {
got, banned := ledger.Check(netblock.Addr(), ban.Expires.Add(-time.Nanosecond))
got, banned, _ := ledger.Check(netblock.Addr(), ban.Expires.Add(-time.Nanosecond))
if !banned || got.Start != ban.Start {
t.Fatalf("check during the ban gives %+v and %t", got, banned)
}
}
_, banned := ledger.Check(netip.MustParseAddr("203.0.113.10"), midnight())
_, banned, _ := ledger.Check(netip.MustParseAddr("203.0.113.10"), midnight())
if banned {
t.Error("another netblock is banned")
}
_, banned = ledger.Check(netblock.Addr(), ban.Expires)
_, banned, _ = ledger.Check(netblock.Addr(), ban.Expires)
if banned {
t.Error("the ban did not end")
}
@@ -167,14 +179,14 @@ func TestFindCountsNothing(t *testing.T) {
ledger := bans.New(defaultRules())
netblock := netip.MustParsePrefix("203.0.113.9/32")
ban := ledger.BanForLimit(netblock, midnight(), bans.Notes{Requests: 5})
ban, _ := ledger.BanForLimit(netblock, midnight(), bans.Notes{Requests: 5})
got, banned := ledger.Find(netblock.Addr(), ban.Expires.Add(-time.Nanosecond))
got, banned, _ := ledger.Find(netblock.Addr(), ban.Expires.Add(-time.Nanosecond))
if !banned || got != ban {
t.Errorf("find during the ban gives %+v and %t, want %+v", got, banned, ban)
}
_, banned = ledger.Find(netblock.Addr(), ban.Expires)
_, banned, _ = ledger.Find(netblock.Addr(), ban.Expires)
if banned {
t.Error("the ban did not end")
}
@@ -196,7 +208,7 @@ func TestMaxBansDropsTheEarliestBanOfTheNetblockSeenLongestAgo(t *testing.T) {
d := netip.MustParsePrefix("2001:db8::/64")
now := midnight()
first := ledger.BanForLimit(a, now, bans.Notes{})
first, _ := ledger.BanForLimit(a, now, bans.Notes{})
ledger.BanForLimit(b, now, bans.Notes{})
ledger.BanForLimit(c, now, bans.Notes{})
@@ -231,13 +243,192 @@ func TestFullLedgerDropsTheEarlierBanOfTheNetblockBannedAgain(t *testing.T) {
ledger := bans.New(rules)
netblock := netip.MustParsePrefix("203.0.113.9/32")
first := ledger.BanForLimit(netblock, midnight(), bans.Notes{})
second := ledger.BanForLimit(netblock, first.Expires, bans.Notes{})
first, _ := ledger.BanForLimit(netblock, midnight(), bans.Notes{})
second, _ := ledger.BanForLimit(netblock, first.Expires, bans.Notes{})
held := ledger.Bans(netblock)
if len(held) != 1 || held[0] != second || held[0].Notes.EarlierBans != 1 {
t.Errorf("the ledger holds %+v, want only the second ban, with 1 earlier ban",
held)
if len(held) != 1 || held[0] != second ||
held[0].Notes.EarlierBans != (bans.EarlierBans{Limit: 1}) {
t.Errorf("the ledger holds %+v, want only the second ban, "+
"with 1 earlier ban for a limit", held)
}
}
func TestRequestDuringAnAttackBanMakesItPermanent(t *testing.T) {
t.Parallel()
ledger := bans.New(defaultRules())
netblock := netip.MustParsePrefix("203.0.113.9/32")
notes := bans.Notes{RuleID: "env-file", Target: "path"}
ban, _ := ledger.BanForAttack(netblock, midnight(), notes)
if !ban.Expires.Equal(midnight().Add(7*day)) || ban.Cause != bans.CauseAttack ||
ban.Notes.RuleID != "env-file" || ledger.Made(bans.CauseAttack) != 1 ||
ledger.Made(bans.CauseLimit) != 0 {
t.Fatalf("the ban is %+v, with %d made for an attack and %d for a limit, "+
"want one for an attack, of seven days", ban,
ledger.Made(bans.CauseAttack), ledger.Made(bans.CauseLimit))
}
wantChanged(t, ledger, true)
// In observe mode the ban refuses nothing, and stays as it is, while
// Find tells that the request would have made it permanent.
got, _, wouldMakePermanent := ledger.Find(netblock.Addr(), midnight().Add(time.Hour))
if got.Permanent() || ledger.Bans(netblock)[0].Permanent() || !wouldMakePermanent {
t.Fatalf("a request found under the ban left it %+v, would have made it "+
"permanent %t, want it as it was, and true", got, wouldMakePermanent)
}
wantChanged(t, ledger, false)
// A request it refuses makes it permanent, says so, and makes
// bans.json due.
got, _, madePermanent := ledger.Check(netblock.Addr(), midnight().Add(time.Hour))
if !madePermanent || !got.Permanent() || !ledger.Bans(netblock)[0].Permanent() {
t.Fatalf("after a request during the ban, it is %+v, made permanent %t, "+
"want it made permanent", got, madePermanent)
}
wantChanged(t, ledger, true)
// The next request finds it permanent already.
_, banned, madePermanent := ledger.Check(netblock.Addr(), midnight().Add(100*365*day))
if !banned || madePermanent {
t.Errorf("a later request is banned %t, and made the ban permanent %t, "+
"want banned by the permanent ban", banned, madePermanent)
}
}
func TestAttackAfterAnAttackBanHasEndedBansPermanently(t *testing.T) {
t.Parallel()
ledger := bans.New(defaultRules())
netblock := netip.MustParsePrefix("203.0.113.9/32")
// A ban for a broken limit before does not count.
first, _ := ledger.BanForLimit(netblock, midnight(), bans.Notes{})
second, _ := ledger.BanForAttack(netblock, first.Expires, bans.Notes{})
if second.Expires.Sub(second.Start) != 7*day {
t.Fatalf("the first ban for an attack lasts %s, want 7 days",
second.Expires.Sub(second.Start))
}
// Once that has run out without a request, the netblock is served, and
// its next clear sign of attack bans it for good.
_, banned, _ := ledger.Check(netblock.Addr(), second.Expires)
if banned {
t.Fatal("the ban did not end")
}
// Its notes show the earlier ban for an attack that makes it permanent,
// beside the one for a limit.
third, _ := ledger.BanForAttack(netblock, second.Expires.Add(30*day), bans.Notes{})
if !third.Permanent() ||
third.Notes.EarlierBans != (bans.EarlierBans{Limit: 1, Attack: 1}) {
t.Errorf("the next ban for an attack is %+v, want a permanent one, "+
"with 1 earlier ban for a limit and 1 for an attack", third)
}
}
func TestWouldBanGivesTheBanWithoutMakingIt(t *testing.T) {
t.Parallel()
ledger := bans.New(defaultRules())
netblock := netip.MustParsePrefix("203.0.113.9/32")
first, _ := ledger.BanForLimit(netblock, midnight(), bans.Notes{})
wantChanged(t, ledger, true)
// While the first ban lasts, none would be made.
during, would := ledger.WouldBanForAttack(netblock, midnight(), bans.Notes{})
if would || during != first {
t.Errorf("during the first ban, would ban %t with %+v, want false with %+v",
would, during, first)
}
// As it ends, a clear sign of attack would ban for seven days, and a
// limit broken again for three hours, but neither is made.
limitNotes := bans.Notes{Kind: "requests", Limit: 1, Window: "minute"}
attack, wouldAttack := ledger.WouldBanForAttack(netblock, first.Expires,
bans.Notes{RuleID: "git-dir"})
limit, wouldLimit := ledger.WouldBanForLimit(netblock, first.Expires, limitNotes)
if !wouldAttack || !attack.Expires.Equal(first.Expires.Add(7*day)) ||
attack.Reason != "matched the rule git-dir" || !wouldLimit ||
!limit.Expires.Equal(first.Expires.Add(3*time.Hour)) ||
limit.Reason != "requests per minute over the limit of 1" {
t.Errorf("would ban with %+v and %+v, want seven days for the attack and "+
"three hours for the limit", attack, limit)
}
if len(ledger.Bans(netblock)) != 1 || ledger.Made(bans.CauseLimit) != 1 ||
ledger.Made(bans.CauseAttack) != 0 {
t.Errorf("the ledger holds %+v, want the first ban alone", ledger.Bans(netblock))
}
wantChanged(t, ledger, false)
// The ban made is the one that would have been.
made, _ := ledger.BanForLimit(netblock, first.Expires, limitNotes)
if made != limit {
t.Errorf("the ban made is %+v, want %+v", made, limit)
}
}
func TestWouldBePermanentAnswersAsTheBanWouldBeMade(t *testing.T) {
t.Parallel()
ledger := bans.New(defaultRules())
netblock := netip.MustParsePrefix("203.0.113.9/32")
now := midnight()
// Five bans for a limit in a row, of 1, 3, 9, 27 and 81 hours, are not
// permanent. The sixth, of 243 hours, would be, while a first ban for
// an attack would not.
for i := range 5 {
if ledger.WouldBePermanent(netblock, now, bans.CauseLimit) {
t.Fatalf("ban %d for a limit would be permanent", i+1)
}
ban, _ := ledger.BanForLimit(netblock, now, bans.Notes{})
now = ban.Expires
}
if !ledger.WouldBePermanent(netblock, now, bans.CauseLimit) {
t.Error("the sixth ban for a limit would not be permanent")
}
if ledger.WouldBePermanent(netblock, now, bans.CauseAttack) {
t.Error("a first ban for an attack would be permanent")
}
// Once a first ban for an attack has ended, the next would be permanent.
attack, _ := ledger.BanForAttack(netblock, now, bans.Notes{})
if !ledger.WouldBePermanent(netblock, attack.Expires, bans.CauseAttack) {
t.Error("a second ban for an attack would not be permanent")
}
}
func TestAttackBanDoesNotLengthenTheNextBanForALimit(t *testing.T) {
t.Parallel()
ledger := bans.New(defaultRules())
netblock := netip.MustParsePrefix("203.0.113.9/32")
// Three times the seven days would be permanent; a limit broken as the
// ban for an attack ends bans for an hour, as a first broken limit does.
attack, _ := ledger.BanForAttack(netblock, midnight(), bans.Notes{})
limit, _ := ledger.BanForLimit(netblock, attack.Expires, bans.Notes{})
if limit.Expires.Sub(limit.Start) != time.Hour || limit.Cause != bans.CauseLimit {
t.Errorf("the ban for a limit is %+v, want one of an hour", limit)
}
// And a request during the ban for a limit leaves it as it is.
got, _, madePermanent := ledger.Check(netblock.Addr(), limit.Start)
if got.Permanent() || madePermanent {
t.Error("a request during a ban for a limit made it permanent")
}
}
@@ -251,7 +442,7 @@ func TestRequestTextsAreCutTo256Bytes(t *testing.T) {
Time: midnight(), Method: long, Host: long, Path: long, Status: 403, UserAgent: long,
}
ban := ledger.BanForLimit(netblock, midnight(), bans.Notes{Request: request})
ban, _ := ledger.BanForLimit(netblock, midnight(), bans.Notes{Request: request})
cut := long[:256]
want := bans.Request{
@@ -263,12 +454,52 @@ func TestRequestTextsAreCutTo256Bytes(t *testing.T) {
}
}
func TestLookupFillsTheNotesOfTheNetblocksBansWithoutOne(t *testing.T) {
t.Parallel()
ledger := bans.New(defaultRules())
netblock := netip.MustParsePrefix("203.0.113.9/32")
other := netip.MustParsePrefix("198.51.100.7/32")
// A ban made with the client's lookup, one made before it came, after
// the first ended, and one on another netblock.
ledger.BanForLimit(netblock, midnight(), bans.Notes{
ASN: "AS64497", ASName: "Other Net", Country: "FR",
})
ledger.BanForLimit(netblock, midnight().Add(time.Hour), bans.Notes{})
ledger.BanForLimit(other, midnight(), bans.Notes{})
ledger.AddLookup(netblock, "AS64496", "Example Net", "DE")
held := ledger.Bans(netblock)
if len(held) != 2 {
t.Fatalf("%s has %d bans, want 2", netblock, len(held))
}
for i, want := range []bans.Notes{
{ASN: "AS64497", ASName: "Other Net", Country: "FR"},
{ASN: "AS64496", ASName: "Example Net", Country: "DE"},
} {
got := held[i].Notes
if got.ASN != want.ASN || got.ASName != want.ASName || got.Country != want.Country {
t.Errorf("ban %d's notes give %q, %q and %q, want %q, %q and %q", i+1,
got.ASN, got.ASName, got.Country, want.ASN, want.ASName, want.Country)
}
}
if notes := ledger.Bans(other)[0].Notes; notes.ASN != "" || notes.Country != "" {
t.Errorf("the ban on %s has %q and %q, want neither",
other, notes.ASN, notes.Country)
}
}
// defaultRules are the rules at the settings' defaults.
func defaultRules() bans.Rules {
return bans.Rules{
LimitBanDuration: time.Hour,
LimitBanRepeatWindow: day,
MaxBanDuration: 7 * day,
AttackBanDuration: 7 * day,
MaxBans: 5000,
}
}
internal/bans/snapshot_test.go
+129 -8
View File
@@ -42,7 +42,7 @@ func TestSnapshotListsEveryBanByNetblock(t *testing.T) {
high := netip.MustParsePrefix("203.0.113.10/32")
low := netip.MustParsePrefix("203.0.113.9/32")
first := ledger.BanForLimit(v6, midnight(), bans.Notes{})
first, _ := ledger.BanForLimit(v6, midnight(), bans.Notes{})
ledger.BanForLimit(high, midnight(), bans.Notes{})
ledger.BanForLimit(low, midnight(), bans.Notes{})
ledger.BanForLimit(v6, first.Expires, bans.Notes{})
@@ -68,7 +68,7 @@ func TestLoadedBansCarryOn(t *testing.T) {
before := bans.New(defaultRules())
netblock := netip.MustParsePrefix("203.0.113.9/32")
ban := before.BanForLimit(netblock, midnight(), bans.Notes{Limit: 1})
ban, _ := before.BanForLimit(netblock, midnight(), bans.Notes{Limit: 1})
// Loaded into a new ledger, as across a restart, the ban still refuses
// while it lasts, and once it has ended a broken limit bans for three
@@ -76,14 +76,15 @@ func TestLoadedBansCarryOn(t *testing.T) {
after := bans.New(defaultRules())
after.Load(before.Snapshot())
_, banned := after.Check(netblock.Addr(), ban.Expires.Add(-time.Second))
_, banned, _ := after.Check(netblock.Addr(), ban.Expires.Add(-time.Second))
if !banned {
t.Error("the loaded ban does not refuse")
}
again := after.BanForLimit(netblock, ban.Expires, bans.Notes{})
if again.Expires.Sub(again.Start) != 3*time.Hour || again.Notes.EarlierBans != 1 {
t.Errorf("the next ban lasts %s with %d earlier bans, want 3h and 1",
again, _ := after.BanForLimit(netblock, ban.Expires, bans.Notes{})
if again.Expires.Sub(again.Start) != 3*time.Hour ||
again.Notes.EarlierBans != (bans.EarlierBans{Limit: 1}) {
t.Errorf("the next ban lasts %s with earlier bans %+v, want 3h and 1 for a limit",
again.Expires.Sub(again.Start), again.Notes.EarlierBans)
}
}
@@ -110,7 +111,7 @@ func TestLoadedBanRefusesEveryClientInItsNetblock(t *testing.T) {
"198.51.100.7": true,
"198.51.100.8": false,
} {
_, banned := ledger.Check(netip.MustParseAddr(client), midnight())
_, banned, _ := ledger.Check(netip.MustParseAddr(client), midnight())
if banned != want {
t.Errorf("%s is refused: %t, want %t", client, banned, want)
}
@@ -130,14 +131,91 @@ func TestLoadedBanRefusesEveryClientInItsNetblock(t *testing.T) {
}
}
func TestPermanentBanStartedBeforeAnEndedOneRefuses(t *testing.T) {
t.Parallel()
// As when an admin adds a permanent ban to bans.json with a start
// before that of the netblock's ban that has ended.
netblock := netip.MustParsePrefix("203.0.113.0/24")
permanent := bans.Ban{Netblock: netblock, Start: midnight().Add(-time.Hour)}
ended := bans.Ban{
Netblock: netblock,
Start: midnight(),
Expires: midnight().Add(time.Hour),
}
ledger := bans.New(defaultRules())
ledger.Load([]bans.Ban{permanent, ended})
now := midnight().Add(2 * time.Hour)
client := netip.MustParseAddr("203.0.113.9")
ban, banned, _ := ledger.Find(client, now)
if !banned || !ban.Permanent() {
t.Errorf("find gives %+v and %t, want the permanent ban", ban, banned)
}
ban, banned, _ = ledger.Check(client, now)
if !banned || !ban.Permanent() {
t.Errorf("the client is refused: %t, under %+v, want under the permanent ban",
banned, ban)
}
// A limit broken now makes no shorter ban over the permanent one.
ban, _ = ledger.BanForLimit(netblock, now, bans.Notes{})
if !ban.Permanent() || len(ledger.Bans(netblock)) != 2 {
t.Errorf("a broken limit returned %+v and left the netblock %d bans, "+
"want the permanent ban and 2", ban, len(ledger.Bans(netblock)))
}
}
func TestNextBanWorkedOutFromTheBanThatEndedLast(t *testing.T) {
t.Parallel()
// A 9-hour ban smallwebwaf 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{
Netblock: netblock,
Start: midnight(),
Expires: midnight().Add(9 * time.Hour),
Cause: bans.CauseLimit,
Notes: bans.Notes{EarlierBans: bans.EarlierBans{Limit: 2}},
}
admins := bans.Ban{
Netblock: netblock,
Start: midnight().Add(time.Hour),
Expires: midnight().Add(2 * time.Hour),
}
ledger := bans.New(defaultRules())
ledger.Load([]bans.Ban{nineHours, admins})
// Once both have ended, a limit broken within the repeat window bans
// for three times the 9 hours, and the notes count the two bans
// before the 9-hour one and it, for a limit, and the admin's.
ban, _ := ledger.BanForLimit(netblock, nineHours.Expires.Add(time.Hour), bans.Notes{})
if ban.Expires.Sub(ban.Start) != 27*time.Hour ||
ban.Notes.EarlierBans != (bans.EarlierBans{Limit: 3, Admin: 1}) {
t.Errorf("the next ban lasts %s with earlier bans %+v, "+
"want 27h, 3 for a limit and 1 an admin's",
ban.Expires.Sub(ban.Start), ban.Notes.EarlierBans)
}
}
func TestLoadKeepsAtMostMaxBansDroppingTheEarliest(t *testing.T) {
t.Parallel()
// bans.json lists the bans by netblock, not in the order they began.
later := bans.Ban{Netblock: netip.MustParsePrefix("203.0.113.1/32"), Start: midnight()}
later := bans.Ban{
Netblock: netip.MustParsePrefix("203.0.113.1/32"),
Start: midnight(),
Cause: bans.CauseLimit,
}
earlier := bans.Ban{
Netblock: netip.MustParsePrefix("203.0.113.2/32"),
Start: midnight().Add(-time.Hour),
Cause: bans.CauseLimit,
}
rules := defaultRules()
@@ -151,6 +229,49 @@ func TestLoadKeepsAtMostMaxBansDroppingTheEarliest(t *testing.T) {
}
}
func TestLoadReplacesTheBansHeld(t *testing.T) {
t.Parallel()
// Room for three bans, so that the second load, were it added to the
// two bans held, would drop none of them to make room.
rules := defaultRules()
rules.MaxBans = 3
ledger := bans.New(rules)
kept := bans.Ban{
Netblock: netip.MustParsePrefix("2001:db8::/64"),
Start: midnight(),
Cause: bans.CauseLimit,
}
ledger.Load([]bans.Ban{
{
Netblock: netip.MustParsePrefix("203.0.113.0/24"),
Start: midnight(),
Cause: bans.CauseLimit,
},
kept,
})
// Loaded again without the first ban, as when an admin's edit of
// bans.json is taken in, that ban is lifted.
ledger.Load([]bans.Ban{kept})
_, banned, _ := ledger.Check(netip.MustParseAddr("203.0.113.9"), midnight())
if banned {
t.Error("a ban left out of the second load still refuses")
}
// The ledger holds one ban, so it makes two more without dropping any.
first, _ := ledger.BanForLimit(netip.MustParsePrefix("198.51.100.7/32"), midnight(),
bans.Notes{})
second, _ := ledger.BanForLimit(netip.MustParsePrefix("198.51.100.8/32"), midnight(),
bans.Notes{})
want := []bans.Ban{first, second, kept}
if got := ledger.Snapshot(); !slices.Equal(got, want) {
t.Errorf("the ledger holds %+v, want %+v", got, want)
}
}
func TestLoadCutsTheTextsTo256Bytes(t *testing.T) {
t.Parallel()
internal/config/config.go
+968 -31
View File
File diff suppressed because it is too large Load Diff
internal/config/config_test.go
+1285 -32
View File
File diff suppressed because it is too large Load Diff
internal/lookup/file.go
+233
View File
@@ -0,0 +1,233 @@
package lookup
import (
"context"
"fmt"
"log/slog"
"net/netip"
"os"
"path/filepath"
"sync"
"time"
"github.com/fsnotify/fsnotify"
"github.com/oschwald/maxminddb-golang/v2"
"sneak.berlin/go/smallwebwaf/internal/alerts"
)
// quietTime is how long the lookup database must go without a change
// before it is read again, so that a file still being copied in is read
// only once whole.
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).
Path string
// Now tells the time, normally time.Now.
Now func() time.Time
// ProcessLog receives each reading of the file, and why a replacement
// of it cannot be read.
ProcessLog *slog.Logger
// Alerts receive a file_error alert for each replacement that cannot
// be read.
Alerts *alerts.Queue
}
// File looks up clients' AS numbers and countries in the lookup database,
// held in memory, and reads it again when it is replaced. It is safe for
// concurrent use.
type File struct {
params FileParams
mu sync.Mutex
// reader is the database in use, and lastRead when it was read.
// readFailures are the replacements that could not be read.
reader *maxminddb.Reader
lastRead time.Time
readFailures int
}
// record is what the lookup database holds about a network, of the fields
// smallwebwaf reads.
type record struct {
ASN string `maxminddb:"asn"`
ASName string `maxminddb:"as_name"`
CountryCode string `maxminddb:"country_code"`
}
// OpenFile reads the lookup database. A file that cannot be read, or that
// is not a .mmdb file, is an error.
func OpenFile(params FileParams) (*File, error) {
reader, err := read(params.Path)
if err != nil {
return nil, err
}
f := &File{params: params}
f.use(reader)
return f, nil
}
// LookUp returns what the lookup database says about client: its AS
// number, such as AS64496, the AS's name, and its country, such as DE,
// each "" when the database does not give it, as for an address missing
// from it. The database is asked about the client's first address, as
// GeoJS is.
func (f *File) LookUp(client netip.Prefix) Answer {
f.mu.Lock()
reader := f.reader
f.mu.Unlock()
var found record
// A record that cannot be decoded places the client nowhere, as a
// missing one does.
err := reader.Lookup(client.Addr()).Decode(&found)
if err != nil {
found = record{}
}
return Answer{
Client: client,
ASN: found.ASN,
ASName: found.ASName,
Country: found.CountryCode,
Answered: f.params.Now(),
}
}
// LastRead returns when the lookup database in use was read.
func (f *File) LastRead() time.Time {
f.mu.Lock()
defer f.mu.Unlock()
return f.lastRead
}
// ReadFailures returns how many replacements of the lookup database could
// not be read.
func (f *File) ReadFailures() int {
f.mu.Lock()
defer f.mu.Unlock()
return f.readFailures
}
// Watch watches the directory of the lookup database until ctx is done,
// and reads the file again once it has gone without a change for
// quietTime, after it is replaced, written or removed, and after Watch
// starts watching. If the directory cannot be watched, that is logged, and
// the database read at start stays in use.
func (f *File) Watch(ctx context.Context) {
watcher, err := fsnotify.NewWatcher()
if err == nil {
defer func() {
_ = watcher.Close()
}()
err = watcher.Add(filepath.Dir(f.params.Path))
}
if err != nil {
f.params.ProcessLog.Error("cannot watch the lookup database for replacements",
"error", err.Error())
return
}
f.params.ProcessLog.Info("watching the lookup database for replacements",
"file", f.params.Path)
f.readAfterChanges(ctx, watcher.Events, watcher.Errors)
}
// readAfterChanges reads the lookup database again once quietTime has
// passed without a change to it from events, until ctx is done, and logs
// the errors from errs. A change to another file in its directory does not
// count. The wait starts at once, as if for a change, so that a file
// replaced after OpenFile read it, and before its directory was watched,
// is read too.
func (f *File) readAfterChanges(
ctx context.Context, events <-chan fsnotify.Event, errs <-chan error,
) {
path := filepath.Clean(f.params.Path)
quiet := time.NewTimer(quietTime)
defer quiet.Stop()
for {
select {
case <-ctx.Done():
return
case event := <-events:
if filepath.Clean(event.Name) == path {
quiet.Reset(quietTime)
}
case <-quiet.C:
f.readAgain()
case err := <-errs:
f.params.ProcessLog.Warn("watching the lookup database failed",
"error", err.Error())
}
}
}
// readAgain reads the lookup database again, in place of the one in use,
// or, if it cannot be read, counts that, raises a file_error alert for it
// and logs it, and the one in use stays in use.
func (f *File) readAgain() {
reader, err := read(f.params.Path)
if err != nil {
const kept = "the lookup database cannot be read, " +
"and the one read before stays in use"
f.mu.Lock()
f.readFailures++
f.mu.Unlock()
// Raised before it is logged, so that the alert is there once the
// log line is.
f.params.Alerts.Raise(alerts.Alert{
Event: alerts.EventFileError,
Reason: kept,
Detail: map[string]any{"file": f.params.Path, "error": err.Error()},
})
f.params.ProcessLog.Error(kept, "error", err.Error())
return
}
f.use(reader)
}
// use puts reader in use, in place of the database read before, and logs
// that the file was read.
func (f *File) use(reader *maxminddb.Reader) {
f.mu.Lock()
f.reader = reader
f.lastRead = f.params.Now()
f.mu.Unlock()
f.params.ProcessLog.Info("read the lookup database", "file", f.params.Path)
}
// read reads the lookup database at path. The whole file is read into
// memory, rather than mapped into it as the reader can, so that a file
// overwritten in place cannot change, or end, under a lookup.
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)
}
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 reader, nil
}
internal/lookup/file_internal_test.go
+379
View File
@@ -0,0 +1,379 @@
package lookup
import (
"context"
"log/slog"
"net/netip"
"net/url"
"os"
"path/filepath"
"reflect"
"testing"
"testing/synctest"
"time"
"github.com/fsnotify/fsnotify"
"github.com/maxmind/mmdbwriter/mmdbtype"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/lookup/lookuptest"
)
// testNetblock is the netblock the tests' lookup databases place, and
// testClient a client in it.
const (
testNetblock = "203.0.113.0/24"
testClient = "203.0.113.9/32"
)
func TestFilePlacesClientsAndCountsAnAddressMissingFromItAsUnknown(t *testing.T) {
t.Parallel()
germany := lookuptest.Network{ASN: "AS64496", ASName: "Example Net", Country: "DE"}
northKorea := lookuptest.Network{ASN: "AS64511", ASName: "Other Net", Country: "KP"}
path := filepath.Join(t.TempDir(), "ipinfo_lite.mmdb")
lookuptest.Write(t, path, map[string]lookuptest.Network{
testNetblock: germany,
"2001:db8::/32": northKorea,
})
now := time.Date(2026, 10, 7, 0, 0, 0, 0, time.UTC)
f, err := OpenFile(FileParams{
Path: path,
Now: func() time.Time { return now },
ProcessLog: slog.New(slog.DiscardHandler),
Alerts: newQueue(),
})
if err != nil {
t.Fatalf("open %s: %v", path, err)
}
for client, want := range map[string]lookuptest.Network{
testClient: germany,
// An IPv6 client is its /64.
"2001:db8:1:2::/64": northKorea,
"198.51.100.7/32": {},
} {
prefix := netip.MustParsePrefix(client)
got := f.LookUp(prefix)
if got != (Answer{
Client: prefix, ASN: want.ASN, ASName: want.ASName, Country: want.Country,
Answered: now,
}) {
t.Errorf("%s has the answer %+v, want %+v, answered %s", client, got, want, now)
}
}
}
func TestRecordThatCannotBeReadPlacesTheClientNowhere(t *testing.T) {
t.Parallel()
// The AS number is a number, where a string belongs. The writer writes
// a record's fields in the order of their names, so as_name is read
// before the AS number fails.
path := filepath.Join(t.TempDir(), "ipinfo_lite.mmdb")
lookuptest.WriteRecords(t, path, map[string]mmdbtype.Map{
testNetblock: {
"asn": mmdbtype.Uint32(64496),
"as_name": mmdbtype.String("Example Net"),
"country_code": mmdbtype.String("DE"),
},
})
f := openFile(t, path, newQueue())
answer := f.LookUp(netip.MustParsePrefix(testClient))
if answer.ASN != "" || answer.ASName != "" || answer.Country != "" {
t.Errorf("%s is placed %+v, want nowhere", testClient, answer)
}
}
func TestFileThatCannotBeReadIsAnError(t *testing.T) {
t.Parallel()
dir := t.TempDir()
missing := filepath.Join(dir, "missing.mmdb")
notDatabase := filepath.Join(dir, "not.mmdb")
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 +
": no such file or directory",
notDatabase: "SWWAF_LOOKUP_DB_PATH " + notDatabase +
" is not a .mmdb file: error opening database: invalid MaxMind DB file",
} {
_, err := OpenFile(FileParams{
Path: path,
Now: time.Now,
ProcessLog: slog.New(slog.DiscardHandler),
Alerts: newQueue(),
})
if err == nil || err.Error() != want {
t.Errorf("opening %s failed with %v, want %s", path, err, want)
}
}
}
// The tests below run readAfterChanges in a synctest bubble, where time is
// a clock of the test's own: time.Sleep moves it on at once, and
// synctest.Wait returns once readAfterChanges waits again, so that every
// reading due by then is done. The test sends the changes itself, as the
// watch of a directory cannot run in a bubble.
func TestReplacementCopiedOverTheFileInTwoPartsIsReadOnlyWhole(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
dir := t.TempDir()
path := filepath.Join(dir, "ipinfo_lite.mmdb")
writeDatabase(t, path, "DE")
queue := newQueue()
f := openFile(t, path, queue)
changes := watch(t, f)
other := filepath.Join(dir, "replacement.mmdb")
writeDatabase(t, other, "KP")
replacement, err := os.ReadFile(other) //nolint:gosec // a file the test wrote
if err != nil {
t.Fatalf("read %s: %v", other, err)
}
// The file in use is overwritten in place, and keeps giving what
// it gave. Its first part alone is not a .mmdb file.
file, err := os.Create(path) //nolint:gosec // a file the test wrote
if err != nil {
t.Fatalf("create %s: %v", path, err)
}
defer func() {
_ = file.Close()
}()
half := len(replacement) / 2
write(t, file, replacement[:half])
changes <- fsnotify.Event{Name: path, Op: fsnotify.Write}
time.Sleep(quietTime - time.Nanosecond)
synctest.Wait()
wantCountry(t, f, "DE")
// The second part starts the wait again.
write(t, file, replacement[half:])
changes <- fsnotify.Event{Name: path, Op: fsnotify.Write}
time.Sleep(quietTime - time.Nanosecond)
synctest.Wait()
wantCountry(t, f, "DE")
time.Sleep(time.Nanosecond)
synctest.Wait()
wantCountry(t, f, "KP")
if !f.LastRead().Equal(time.Now()) || f.ReadFailures() != 0 {
t.Errorf("read at %s, with %d failures; want read now, with none",
f.LastRead(), f.ReadFailures())
}
wantAlerts(t, queue)
})
}
func TestReplacementThatCannotBeReadLeavesTheFileInUseWithOneAlert(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
path := filepath.Join(t.TempDir(), "ipinfo_lite.mmdb")
writeDatabase(t, path, "DE")
queue := newQueue()
f := openFile(t, path, queue)
read := f.LastRead()
changes := watch(t, f)
writeFile(t, path, "not a lookup database\n")
changes <- fsnotify.Event{Name: path, Op: fsnotify.Write}
// Long after, the replacement has been read once.
time.Sleep(time.Hour)
synctest.Wait()
wantCountry(t, f, "DE")
if !f.LastRead().Equal(read) || f.ReadFailures() != 1 {
t.Errorf("read at %s, with %d failures; want read at %s, with one",
f.LastRead(), f.ReadFailures(), read)
}
wantAlerts(t, queue, alerts.Alert{
Time: read.Add(quietTime),
Event: alerts.EventFileError,
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 opening database: invalid MaxMind DB file",
},
})
})
}
func TestChangeOfAnotherFileInTheDirectoryIsNoReplacement(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
dir := t.TempDir()
path := filepath.Join(dir, "ipinfo_lite.mmdb")
writeDatabase(t, path, "DE")
f := openFile(t, path, newQueue())
changes := watch(t, f)
// The wait that starts with the watch ends with a reading.
time.Sleep(quietTime)
synctest.Wait()
writeDatabase(t, path, "KP")
changes <- fsnotify.Event{Name: filepath.Join(dir, "other.mmdb"), Op: fsnotify.Create}
time.Sleep(quietTime)
synctest.Wait()
wantCountry(t, f, "DE")
changes <- fsnotify.Event{Name: path, Op: fsnotify.Write}
time.Sleep(quietTime)
synctest.Wait()
wantCountry(t, f, "KP")
})
}
func TestReplacementSavedBeforeTheWatchStartsIsRead(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
path := filepath.Join(t.TempDir(), "ipinfo_lite.mmdb")
writeDatabase(t, path, "DE")
f := openFile(t, path, newQueue())
// Saved after OpenFile read the file, and before its directory was
// watched, so that no change is seen for it.
writeDatabase(t, path, "KP")
watch(t, f)
time.Sleep(quietTime)
synctest.Wait()
wantCountry(t, f, "KP")
})
}
// newQueue returns a queue of alerts for a webhook that is never sent
// them, so that they wait in it for the test to look at.
func newQueue() *alerts.Queue {
return alerts.New(alerts.Params{
WebhookURL: &url.URL{Scheme: "https", Host: "alerts.example"},
Events: alerts.Events(),
Cooldown: 15 * time.Minute,
Now: time.Now,
})
}
// writeDatabase writes a lookup database at path that places testNetblock
// in country, and no other address.
func writeDatabase(t *testing.T, path, country string) {
t.Helper()
lookuptest.Write(t, path, map[string]lookuptest.Network{
testNetblock: {ASN: "AS64496", ASName: "Example Net", Country: country},
})
}
// openFile opens the lookup database at path, which raises its alerts to
// queue.
func openFile(t *testing.T, path string, queue *alerts.Queue) *File {
t.Helper()
f, err := OpenFile(FileParams{
Path: path,
Now: time.Now,
ProcessLog: slog.New(slog.DiscardHandler),
Alerts: queue,
})
if err != nil {
t.Fatalf("open %s: %v", path, err)
}
return f
}
// watch runs f's readAfterChanges until the test ends, and returns the
// channel that sends it changes.
func watch(t *testing.T, f *File) chan<- fsnotify.Event {
t.Helper()
changes := make(chan fsnotify.Event)
ctx, stop := context.WithCancel(t.Context())
stopped := make(chan struct{})
go func() {
f.readAfterChanges(ctx, changes, nil)
close(stopped)
}()
t.Cleanup(func() {
stop()
<-stopped
})
return changes
}
// wantCountry checks the country f gives testClient.
func wantCountry(t *testing.T, f *File, want string) {
t.Helper()
got := f.LookUp(netip.MustParsePrefix(testClient)).Country
if got != want {
t.Errorf("%s is in %q, want %q", testClient, got, want)
}
}
// wantAlerts checks the alerts waiting in queue, and that it held none
// back.
func wantAlerts(t *testing.T, queue *alerts.Queue, want ...alerts.Alert) {
t.Helper()
waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
if len(waiting) != len(want) || (len(want) > 0 && !reflect.DeepEqual(waiting, want)) {
t.Errorf("alerts waiting %+v, want %+v", waiting, want)
}
if queue.Suppressed() != 0 {
t.Errorf("%d alerts held back, want none", queue.Suppressed())
}
}
// writeFile writes content to the file at path.
func writeFile(t *testing.T, path, content string) {
t.Helper()
err := os.WriteFile(path, []byte(content), 0o600)
if err != nil {
t.Fatalf("write %s: %v", path, err)
}
}
// write writes data to the end of file.
func write(t *testing.T, file *os.File, data []byte) {
t.Helper()
_, err := file.Write(data)
if err != nil {
t.Fatalf("write: %v", err)
}
}
internal/lookup/lookup.go
+147 -70
View File
@@ -1,7 +1,8 @@
// Package lookup looks up each client's country through the GeoJS web
// service, and keeps the answers in memory, for at most 100,000 clients
// and for 7 days each. The answers are written to lookups.json and read
// from it by the state package.
// 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
// 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
import (
@@ -14,17 +15,20 @@ import (
"net/http"
"net/netip"
"slices"
"strconv"
"strings"
"sync"
"time"
"github.com/hashicorp/golang-lru/v2/simplelru"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/metrics"
)
// URL is GeoJS's country endpoint. Asked about several addresses at once,
// comma separated in its ip parameter, it answers with a list.
const URL = "https://get.geojs.io/v1/ip/country.json"
// URL is GeoJS's endpoint for an address's place and network. Asked about
// several addresses at once, comma separated in its ip parameter, it
// answers with a list.
const URL = "https://get.geojs.io/v1/ip/geo.json"
const (
// keepFor is how long an answer is used instead of asking GeoJS again.
@@ -39,9 +43,8 @@ const (
maxWaiting = 10000
// maxPerRequest is how many addresses one request to GeoJS asks about.
maxPerRequest = 200
// timeout is how long a new client waits for its answer, and how long
// a request to GeoJS may take before it is abandoned.
timeout = time.Second
// unknownASN is the AS number GeoJS gives when it knows none.
unknownASN = 64512
// After a failure GeoJS is not asked again for a second, and for
// retryDelayFactor times as long after each further failure in a row,
// up to five minutes.
@@ -61,6 +64,16 @@ var (
type Params struct {
// URL is where GeoJS is asked, normally URL.
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).
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.
Wait bool
// Answered, unless nil, is given each answer GeoJS gives, once it is
// kept.
Answered func(Answer)
// Now tells the time, normally time.Now.
Now func() time.Time
// ProcessLog receives GeoJS's failures.
@@ -68,16 +81,22 @@ type Params struct {
// Metrics count the requests to GeoJS, those that failed, and the
// clients that go without an answer.
Metrics *metrics.Metrics
// Alerts receive a source_failure alert each time GeoJS fails.
Alerts *alerts.Queue
}
// GeoJS looks up clients' countries through GeoJS. At most one request
// to GeoJS is under way at a time, and it asks about every client waiting,
// up to maxPerRequest. It is safe for concurrent use.
// GeoJS looks up clients' AS numbers and countries through GeoJS. At most
// one request to GeoJS is under way at a time, and it asks about every
// client waiting, up to maxPerRequest. It is safe for concurrent use.
type GeoJS struct {
url string
timeout time.Duration
wait bool
answered func(Answer)
now func() time.Time
processLog *slog.Logger
metrics *metrics.Metrics
alerts *alerts.Queue
// httpClient follows no redirect, so that visitors' addresses go to
// GeoJS alone: a redirect is a failure.
httpClient *http.Client
@@ -95,11 +114,18 @@ type GeoJS struct {
retryAt time.Time
}
// Answer is what GeoJS said about a client, as lookups.json holds it: its
// country, "" when GeoJS cannot place it, when GeoJS said so, and when
// the answer was last used.
// Answer is what GeoJS or the lookup database said about a client: its AS
// number, such as AS64496, and the AS's name, both "" when the source knows
// no AS number for it; its country, "" when the source cannot place it;
// when the source said so; and, for GeoJS's answers, which lookups.json
// holds, when the answer was last used. The zero Answer is that of a
// client with no answer.
//
//nolint:tagliatelle // the state files use snake_case, as the request log does
type Answer struct {
Client netip.Prefix `json:"client"`
ASN string `json:"asn"`
ASName string `json:"as_name"`
Country string `json:"country"`
Answered time.Time `json:"answered"`
Used time.Time `json:"used"`
@@ -124,9 +150,13 @@ func New(params Params) *GeoJS {
return &GeoJS{
url: params.URL,
timeout: params.Timeout,
wait: params.Wait,
answered: params.Answered,
now: params.Now,
processLog: params.ProcessLog,
metrics: params.Metrics,
alerts: params.Alerts,
httpClient: &http.Client{
CheckRedirect: func(*http.Request, []*http.Request) error {
return http.ErrUseLastResponse
@@ -137,23 +167,23 @@ func New(params Params) *GeoJS {
}
}
// Country returns the country GeoJS places client in, as a two-letter
// code in capitals, or "" when the country cannot be found: GeoJS cannot
// place the client, or has not answered in time. An answer is kept for 7
// days. Without one, a client waits up to timeout for it, unless it has
// gone without one before; until GeoJS answers, the client is asked about
// again in the background. ctx is the context of the client's request,
// and ends the wait when it ends.
// LookUp returns the answer GeoJS gave about client, with its country as
// a two-letter code in capitals, or the zero Answer when there is none
// yet. An answer is kept for 7 days. Without one, the client is asked
// about in the background, and, while Wait is set, the request waits up
// to Timeout for the answer, unless the client has gone without one
// before. ctx is the context of the client's request, and ends the wait
// when it ends.
//
// GeoJS is asked about the client's first address, which is the client's
// own address for IPv4, and an address in the same place for an IPv6 /64.
func (g *GeoJS) Country(ctx context.Context, client netip.Prefix) string {
country, asked := g.answerOrWait(ctx, client)
func (g *GeoJS) LookUp(ctx context.Context, client netip.Prefix) Answer {
answer, asked := g.answerOrWait(ctx, client)
if asked == nil {
return country
return answer
}
timer := time.NewTimer(timeout)
timer := time.NewTimer(g.timeout)
defer timer.Stop()
select {
@@ -165,7 +195,7 @@ func (g *GeoJS) Country(ctx context.Context, client netip.Prefix) string {
g.mu.Lock()
defer g.mu.Unlock()
country, found := g.kept(client)
answer, found := g.kept(client)
if !found {
g.metrics.GeoJSUnanswered.Inc()
}
@@ -175,7 +205,15 @@ func (g *GeoJS) Country(ctx context.Context, client netip.Prefix) string {
w.late = true
}
return country
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()
defer g.mu.Unlock()
return g.kept(client)
}
// Snapshot returns every answer kept, sorted by client, as lookups.json
@@ -197,19 +235,21 @@ func (g *GeoJS) Snapshot() []Answer {
return answers
}
// Load keeps answers read from lookups.json, in a GeoJS that keeps none
// yet, in the order they were last used, so that the one used longest
// Load keeps answers read from lookups.json, in place of the answers it
// keeps, in the order they were last used, so that the one used longest
// ago is dropped first. Answers GeoJS gave keepFor ago or more are
// dropped.
func (g *GeoJS) Load(answers []Answer) {
g.mu.Lock()
defer g.mu.Unlock()
answers = slices.Clone(answers)
slices.SortStableFunc(answers, func(a, b Answer) int {
return a.Used.Compare(b.Used)
})
g.mu.Lock()
defer g.mu.Unlock()
g.answers.Purge()
now := g.now()
for _, answer := range answers {
@@ -225,13 +265,13 @@ func (g *GeoJS) Load(answers []Answer) {
// nil when there is nothing to wait for.
func (g *GeoJS) answerOrWait(
ctx context.Context, client netip.Prefix,
) (string, <-chan struct{}) {
) (Answer, <-chan struct{}) {
g.mu.Lock()
defer g.mu.Unlock()
country, found := g.kept(client)
answer, found := g.kept(client)
if found {
return country, nil
return answer, nil
}
w, waiting := g.waiting[client]
@@ -242,10 +282,14 @@ func (g *GeoJS) answerOrWait(
g.ask(ctx)
if !g.wait {
return Answer{}, nil // the answer is not needed before the request goes on
}
if w == nil {
g.metrics.GeoJSUnanswered.Inc()
return "", nil // too many clients wait already
return Answer{}, nil // too many clients wait already
}
if !g.asking {
@@ -256,25 +300,25 @@ func (g *GeoJS) answerOrWait(
if w.late {
g.metrics.GeoJSUnanswered.Inc()
return "", nil
return Answer{}, nil
}
return "", w.asked
return Answer{}, w.asked
}
// kept returns client's answer, if GeoJS gave it less than keepFor ago,
// and notes that it was used.
func (g *GeoJS) kept(client netip.Prefix) (string, bool) {
func (g *GeoJS) kept(client netip.Prefix) (Answer, bool) {
now := g.now()
kept, found := g.answers.Get(client)
if !found || now.Sub(kept.Answered) >= keepFor {
return "", false
return Answer{}, false
}
kept.Used = now
return kept.Country, true
return *kept, true
}
// ask starts asking GeoJS about the waiting clients, unless a request to
@@ -292,7 +336,8 @@ func (g *GeoJS) ask(ctx context.Context) {
}
// askAboutWaiting asks GeoJS about the waiting clients, one request at a
// time, until none is left or GeoJS fails.
// time, until none is left or GeoJS fails. Each answer kept is given to
// Answered, outside the lock, since Answered takes locks of its own.
func (g *GeoJS) askAboutWaiting(ctx context.Context) {
for {
clients := g.nextClients()
@@ -300,8 +345,16 @@ func (g *GeoJS) askAboutWaiting(ctx context.Context) {
return
}
countries, err := g.request(ctx, clients)
if !g.keep(clients, countries, err) {
given, err := g.request(ctx, clients)
kept, answered := g.keep(clients, given, err)
if g.answered != nil {
for _, answer := range kept {
g.answered(answer)
}
}
if !answered {
return
}
}
@@ -333,32 +386,35 @@ func (g *GeoJS) nextClients() []netip.Prefix {
return clients
}
// keep notes how a request to GeoJS about clients ended, and reports
// whether GeoJS answered about all of them. Each client whose address
// GeoJS's answer names gets its answer, with no country when GeoJS gave
// none. An answer that leaves an address out is a failure. After a
// failure GeoJS is left alone for a while, and every client still waiting
// stops waiting and is asked about once GeoJS is asked again.
// keep notes how a request to GeoJS about clients ended, given being the
// answer for each address GeoJS's answer names. It returns the answers it
// kept, and reports whether GeoJS answered about all of the clients. Each
// client whose address GeoJS's answer names gets its answer. An answer
// that leaves an address out is a failure. After a failure GeoJS is left
// alone for a while, and every client still waiting stops waiting and is
// asked about once GeoJS is asked again.
func (g *GeoJS) keep(
clients []netip.Prefix, countries map[netip.Addr]string, err error,
) bool {
clients []netip.Prefix, given map[netip.Addr]Answer, err error,
) ([]Answer, bool) {
g.mu.Lock()
defer g.mu.Unlock()
now := g.now()
kept := make([]Answer, 0, len(clients))
leftOut := 0
for _, client := range clients {
country, named := countries[client.Addr()]
answer, named := given[client.Addr()]
if !named {
leftOut++
continue
}
g.answers.Add(client, &Answer{
Client: client, Country: country, Answered: now, Used: now,
})
answer.Client, answer.Answered, answer.Used = client, now, now
g.answers.Add(client, &answer)
kept = append(kept, answer)
close(g.waiting[client].asked)
delete(g.waiting, client)
}
@@ -384,27 +440,37 @@ func (g *GeoJS) keep(
g.processLog.Warn("asking GeoJS failed",
"error", err.Error(), "asking_again_in", g.retryDelay.String())
g.alerts.Raise(alerts.Alert{
Event: alerts.EventSourceFailure,
Reason: "asking GeoJS failed",
Detail: map[string]any{
"source": "geojs", "error": err.Error(),
"asking_again_in": g.retryDelay.String(),
},
})
return false
return kept, false
}
g.retryDelay = 0
return true
return kept, true
}
// request asks GeoJS about clients in one request, and returns the
// country it gave, in capitals, for each address its answer names.
// request asks GeoJS about clients in one request, and returns the answer
// for each address GeoJS's answer names: its AS number and the AS's name,
// both "" for the AS number 64512, which GeoJS gives when it knows none,
// and its country, in capitals.
func (g *GeoJS) request(
ctx context.Context, clients []netip.Prefix,
) (map[netip.Addr]string, error) {
) (map[netip.Addr]Answer, error) {
addrs := make([]string, 0, len(clients))
for _, client := range clients {
addrs = append(addrs, client.Addr().String())
}
ctx, cancel := context.WithTimeout(ctx, timeout)
ctx, cancel := context.WithTimeout(ctx, g.timeout)
defer cancel()
req, err := http.NewRequestWithContext(ctx, http.MethodGet, g.url, http.NoBody)
@@ -431,9 +497,12 @@ func (g *GeoJS) request(
return nil, fmt.Errorf("%w %s", errStatus, res.Status)
}
//nolint:tagliatelle // GeoJS's own names
var answers []struct {
IP string `json:"ip"`
Country string `json:"country"`
ASN int64 `json:"asn"`
ASName string `json:"organization_name"`
CountryCode string `json:"country_code"`
}
err = json.NewDecoder(io.LimitReader(res.Body, maxResponseBytes)).Decode(&answers)
@@ -441,14 +510,22 @@ func (g *GeoJS) request(
return nil, fmt.Errorf("read GeoJS's answer: %w", err)
}
countries := make(map[netip.Addr]string, len(answers))
given := make(map[netip.Addr]Answer, len(answers))
for _, item := range answers {
addr, err := netip.ParseAddr(item.IP)
if err == nil {
countries[addr] = strings.ToUpper(item.Country)
}
if err != nil {
continue
}
return countries, nil
answer := Answer{Country: strings.ToUpper(item.CountryCode)}
if item.ASN != 0 && item.ASN != unknownASN {
answer.ASN = "AS" + strconv.FormatInt(item.ASN, 10)
answer.ASName = item.ASName
}
given[addr] = answer
}
return given, nil
}
internal/lookup/lookup_test.go
+246 -15
View File
@@ -6,6 +6,8 @@ import (
"net/http"
"net/http/httptest"
"net/netip"
"net/url"
"reflect"
"slices"
"strings"
"sync"
@@ -14,15 +16,20 @@ import (
"time"
"github.com/prometheus/client_golang/prometheus/testutil"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/lookup"
"sneak.berlin/go/smallwebwaf/internal/metrics"
)
const (
// germany is where the stand-in for GeoJS places every address but
// unplaced.
// unplaced, and asNumber, kept as asn, and asName the AS it gives them.
germany = "DE"
// unplaced is the address it cannot place.
asNumber = 64496
asn = "AS64496"
asName = "Example Net"
// unplaced is the address it cannot place, for which it gives the AS
// number 64512 and the AS name Unknown, as GeoJS does.
unplaced = "192.0.2.1"
// leftOut is the address it leaves out of its answer when
// answeringWithoutLeftOut.
@@ -80,7 +87,7 @@ func TestNewClientWaitsAtMostOneSecondThenCountsAsNotFound(t *testing.T) {
var earlier sync.WaitGroup
earlier.Go(func() { g.Country(t.Context(), netip.MustParsePrefix("203.0.113.1/32")) })
earlier.Go(func() { g.LookUp(t.Context(), netip.MustParsePrefix("203.0.113.1/32")) })
defer earlier.Wait()
waitForRequests(t, geojs, 1)
@@ -112,6 +119,58 @@ func TestNewClientWaitsAtMostOneSecondThenCountsAsNotFound(t *testing.T) {
})
}
func TestRequestWaitsAsLongAsTheTimeoutSaysAndGeoJSIsAbandonedAfterIt(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
// A timeout longer than the default second, and a GeoJS that does
// not answer.
const longerTimeout = 3 * time.Second
m := metrics.New(1, "app")
g := lookup.New(lookup.Params{
URL: lookup.URL,
Timeout: longerTimeout,
Wait: true,
Now: time.Now,
ProcessLog: slog.New(slog.DiscardHandler),
Metrics: m,
Alerts: alerts.New(alerts.Params{}),
})
g.SetTransport(&standIn{answers: hanging})
var (
request sync.WaitGroup
waited time.Duration
)
request.Go(func() {
began := time.Now()
wantCountry(t, g, netip.MustParsePrefix("203.0.113.9/32"), "")
waited = time.Since(began)
})
// A moment before the timeout runs out, GeoJS is still being asked:
// the request to it has not failed.
time.Sleep(longerTimeout - time.Millisecond)
synctest.Wait()
wantFailures(t, m, 0)
// As it runs out, the client's request goes on, and the request to
// GeoJS is abandoned, which counts as a failure.
request.Wait()
synctest.Wait()
if waited != longerTimeout {
t.Errorf("waited %s for the answer, want %s", waited, longerTimeout)
}
wantFailures(t, m, 1)
})
}
func TestAddressLeftOutOfAnAnswerIsAskedAboutAgain(t *testing.T) {
t.Parallel()
@@ -184,6 +243,96 @@ func TestCountryIsKeptInCapitals(t *testing.T) {
})
}
func TestAnswerHoldsTheASNumberTheASNameAndTheCountry(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
_, clock, g := start()
placed := netip.MustParsePrefix("203.0.113.9/32")
notPlaced := netip.MustParsePrefix(unplaced + "/32")
now := clock.Now()
// For the client it cannot place, GeoJS gives the AS number 64512
// and the AS name Unknown, which count as unknown.
for client, want := range map[netip.Prefix]lookup.Answer{
placed: {
Client: placed, ASN: asn, ASName: asName, Country: germany,
Answered: now, Used: now,
},
notPlaced: {Client: notPlaced, Answered: now, Used: now},
} {
got := g.LookUp(t.Context(), client)
if got != want {
t.Errorf("answer for %s\n%+v\nwant\n%+v", client, got, want)
}
}
})
}
func TestWithoutWaitTheRequestGoesOnAtOnceAndTheAnswerIsGivenWhenItComes(
t *testing.T,
) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
var (
mu sync.Mutex
given []lookup.Answer
)
geojs := &standIn{answers: answeringSlowly}
clock := newClock()
m := metrics.New(1, "app")
g := lookup.New(lookup.Params{
URL: lookup.URL,
Timeout: timeout,
Answered: func(answer lookup.Answer) {
mu.Lock()
defer mu.Unlock()
given = append(given, answer)
},
Now: clock.Now,
ProcessLog: slog.New(slog.DiscardHandler),
Metrics: m,
Alerts: alerts.New(alerts.Params{}),
})
g.SetTransport(geojs)
client := netip.MustParsePrefix("203.0.113.9/32")
// The request goes on at once, without an answer, and GeoJS is asked
// about the client, which it answers most of a second later.
began := time.Now()
got := g.LookUp(t.Context(), client)
if took := time.Since(began); took != 0 || got != (lookup.Answer{}) {
t.Errorf("waited %s for %+v, want no wait and no answer", took, got)
}
waitForRequests(t, geojs, 1)
wantAsked(t, geojs, 0, "203.0.113.9")
time.Sleep(timeout)
synctest.Wait()
now := clock.Now()
want := lookup.Answer{
Client: client, ASN: asn, ASName: asName, Country: germany,
Answered: now, Used: now,
}
mu.Lock()
if !slices.Equal(given, []lookup.Answer{want}) {
t.Errorf("answers given %+v, want only %+v", given, want)
}
mu.Unlock()
wantCountry(t, g, client, germany)
wantUnanswered(t, m, 0)
})
}
func TestFailureIsLoggedWithoutTheAddressesAskedAbout(t *testing.T) {
t.Parallel()
@@ -194,9 +343,12 @@ func TestFailureIsLoggedWithoutTheAddressesAskedAbout(t *testing.T) {
geojs := &standIn{answers: hanging}
g := lookup.New(lookup.Params{
URL: lookup.URL,
Timeout: timeout,
Wait: true,
Now: time.Now,
ProcessLog: slog.New(slog.NewTextHandler(&log, nil)),
Metrics: metrics.New(1),
Metrics: metrics.New(1, "app"),
Alerts: alerts.New(alerts.Params{}),
})
g.SetTransport(geojs)
@@ -211,6 +363,45 @@ func TestFailureIsLoggedWithoutTheAddressesAskedAbout(t *testing.T) {
})
}
func TestFailureRaisesASourceFailureAlertOncePerCooldown(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
geojs, clock, g, queue := startWithAlerts()
clients := newClients()
geojs.set(failing)
wantCountry(t, g, clients(), "")
want := alerts.Alert{
Time: clock.Now(),
Event: alerts.EventSourceFailure,
Reason: "asking GeoJS failed",
Detail: map[string]any{
"source": "geojs",
"error": "GeoJS answered 503 Service Unavailable",
"asking_again_in": "1s",
},
}
// The next failure, a second later, is a repeat within the
// cooldown.
clock.advance(time.Second)
wantCountry(t, g, clients(), "")
wantRequests(t, geojs, 2)
waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
if len(waiting) != 1 || !reflect.DeepEqual(waiting[0], want) {
t.Errorf("alerts waiting %+v, want only %+v", waiting, want)
}
if queue.Suppressed() != 1 {
t.Errorf("%d alerts held back, want the repeat", queue.Suppressed())
}
})
}
func TestWaitingClientsAreAskedAboutInOneRequest(t *testing.T) {
t.Parallel()
@@ -355,12 +546,15 @@ func TestClientsWithoutAnAnswerAreCounted(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
m := metrics.New(1)
m := metrics.New(1, "app")
g := lookup.New(lookup.Params{
URL: lookup.URL,
Timeout: timeout,
Wait: true,
Now: time.Now,
ProcessLog: slog.New(slog.DiscardHandler),
Metrics: m,
Alerts: alerts.New(alerts.Params{}),
})
g.SetTransport(&standIn{answers: failing})
@@ -450,21 +644,24 @@ func (s *standIn) ServeHTTP(w http.ResponseWriter, r *http.Request) {
}
}
list := make([]map[string]string, 0, len(addrs))
list := make([]map[string]any, 0, len(addrs))
for _, addr := range addrs {
country := germany
item := map[string]any{
"ip": addr, "asn": asNumber, "organization_name": asName,
"country_code": germany,
}
switch {
case addr == unplaced:
country = ""
item = map[string]any{"ip": addr, "asn": 64512, "organization_name": "Unknown"}
case addr == leftOut && answers == answeringWithoutLeftOut:
continue
case answers == answeringInLowerCase:
country = strings.ToLower(germany)
item["country_code"] = strings.ToLower(germany)
}
list = append(list, map[string]string{"ip": addr, "country": country})
list = append(list, item)
}
var answer any = list
@@ -522,19 +719,43 @@ func (c *testClock) advance(d time.Duration) {
}
// start returns a stand-in for GeoJS that answers, a clock, and a GeoJS
// asking the stand-in by that clock.
// asking the stand-in by that clock, for which a request waits for its
// client's first answer.
func start() (*standIn, *testClock, *lookup.GeoJS) {
geojs, clock, g, _ := startWithAlerts()
return geojs, clock, g
}
// startWithAlerts is start, and returns the queue of the alerts GeoJS
// raises as well, for a webhook that is never sent them, with the default
// cooldown, by the same clock.
func startWithAlerts() (*standIn, *testClock, *lookup.GeoJS, *alerts.Queue) {
geojs := &standIn{}
clock := &testClock{now: time.Date(2026, 10, 4, 0, 0, 0, 0, time.UTC)}
clock := newClock()
queue := alerts.New(alerts.Params{
WebhookURL: &url.URL{Scheme: "https", Host: "alerts.example"},
Events: alerts.Events(),
Cooldown: 15 * time.Minute,
Now: clock.Now,
})
g := lookup.New(lookup.Params{
URL: lookup.URL,
Timeout: timeout,
Wait: true,
Now: clock.Now,
ProcessLog: slog.New(slog.DiscardHandler),
Metrics: metrics.New(1),
Metrics: metrics.New(1, "app"),
Alerts: queue,
})
g.SetTransport(geojs)
return geojs, clock, g
return geojs, clock, g, queue
}
// newClock returns a clock set to the start of a day.
func newClock() *testClock {
return &testClock{now: time.Date(2026, 10, 4, 0, 0, 0, 0, time.UTC)}
}
// newClients returns what returns a new IPv4 client each time it is
@@ -553,7 +774,7 @@ func newClients() func() netip.Prefix {
func wantCountry(t *testing.T, g *lookup.GeoJS, client netip.Prefix, want string) {
t.Helper()
got := g.Country(t.Context(), client)
got := g.LookUp(t.Context(), client).Country
if got != want {
t.Errorf("%s is in %q, want %q", client, got, want)
}
@@ -598,6 +819,16 @@ func wantUnanswered(t *testing.T, m *metrics.Metrics, want float64) {
}
}
// wantFailures checks how many requests to GeoJS m counts as failed.
func wantFailures(t *testing.T, m *metrics.Metrics, want float64) {
t.Helper()
got := testutil.ToFloat64(m.GeoJSFailures)
if got != want {
t.Errorf("%v requests to GeoJS failed, want %v", got, want)
}
}
// waitForRequests waits until g has done all it can before time passes,
// checks that GeoJS has had count requests, and returns the addresses each
// asked about.
internal/lookup/lookuptest/lookuptest.go
+83
View File
@@ -0,0 +1,83 @@
// Package lookuptest writes lookup databases, IPinfo Lite files in their
// .mmdb form, for the tests of the packages that read them.
package lookuptest
import (
"bytes"
"net"
"os"
"testing"
"github.com/maxmind/mmdbwriter"
"github.com/maxmind/mmdbwriter/mmdbtype"
)
// fileMode is the mode of the files written: read and written by their
// owner alone.
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
// its country, such as DE.
type Network struct {
ASN string
ASName string
Country string
}
// Write writes a lookup database at path that places each netblock in
// networks, such as 203.0.113.0/24, as its Network says, and no other
// address.
func Write(tb testing.TB, path string, networks map[string]Network) {
tb.Helper()
records := make(map[string]mmdbtype.Map, len(networks))
for netblock, network := range networks {
records[netblock] = mmdbtype.Map{
"asn": mmdbtype.String(network.ASN),
"as_name": mmdbtype.String(network.ASName),
"country_code": mmdbtype.String(network.Country),
}
}
WriteRecords(tb, path, records)
}
// WriteRecords writes a lookup database at path that holds each record in
// records for its netblock, and nothing for any other address.
func WriteRecords(tb testing.TB, path string, records map[string]mmdbtype.Map) {
tb.Helper()
tree, err := mmdbwriter.New(mmdbwriter.Options{
DatabaseType: "ipinfo_lite",
// The tests' clients are in the netblocks kept for documentation.
IncludeReservedNetworks: true,
})
if err != nil {
tb.Fatalf("new lookup database: %v", err)
}
for netblock, record := range records {
_, network, err := net.ParseCIDR(netblock)
if err != nil {
tb.Fatalf("netblock %q: %v", netblock, err)
}
err = tree.Insert(network, record)
if err != nil {
tb.Fatalf("insert %s: %v", netblock, err)
}
}
var database bytes.Buffer
_, err = tree.WriteTo(&database)
if err != nil {
tb.Fatalf("write the lookup database: %v", err)
}
err = os.WriteFile(path, database.Bytes(), fileMode)
if err != nil {
tb.Fatalf("write %s: %v", path, err)
}
}
internal/lookup/snapshot_test.go
+5 -2
View File
@@ -26,8 +26,11 @@ func TestSnapshotHoldsEachAnswerAndWhenItWasLastUsed(t *testing.T) {
wantCountry(t, g, placed, germany)
want := []lookup.Answer{
{Client: notPlaced, Country: "", Answered: asked, Used: asked},
{Client: placed, Country: germany, Answered: asked, Used: asked.Add(time.Hour)},
{Client: notPlaced, Answered: asked, Used: asked},
{
Client: placed, ASN: asn, ASName: asName, Country: germany,
Answered: asked, Used: asked.Add(time.Hour),
},
}
if got := g.Snapshot(); !slices.Equal(got, want) {
t.Errorf("snapshot\n%+v\nwant\n%+v", got, want)
internal/metrics/busiest.go
+155
View File
@@ -0,0 +1,155 @@
package metrics
import (
"sync"
"github.com/prometheus/client_golang/prometheus"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
// other is the label value under which the countries or AS numbers
// outside the busiest are counted.
const other = "other"
// busiest are the metrics by one thing the lookup finds of the client,
// its country or its AS number, for requests whose client's is known.
// The topN busiest countries or AS numbers, by their requests since the
// start, have series of their own, and the others are counted under
// other, so that there are never more than topN + 1 series. One that
// drops out of the busiest loses its series, and its next requests are
// counted under other; one that becomes one of them gets a series that
// counts from then on. Each series therefore only ever goes up.
type busiest struct {
topN int
requests *prometheus.CounterVec
requestBytes *prometheus.CounterVec
responseBytes *prometheus.CounterVec
// refused are, by country, the requests the country lists refused; nil
// by AS number.
refused *prometheus.CounterVec
mu sync.Mutex
// seen is each country's or AS number's requests since the start, by
// which they are ranked.
seen map[string]int64
// top are those with series of their own.
top map[string]bool
}
// newCountries returns the metrics by country, with series of their own
// 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",
"Requests the country lists refused, by the client's country.",
[]string{"country"})
return countries
}
// newASNs returns the metrics by AS number, with series of their own for
// the topN busiest AS numbers.
func newASNs(topN int) *busiest {
return newBusiest(topN, "asn", "the client's AS number")
}
// newBusiest returns the metrics by label, which is described as
// description, with series of their own for the topN busiest values.
func newBusiest(topN int, label, description string) *busiest {
by := []string{label}
return &busiest{
topN: topN,
requests: counterVec("smallwebwaf_"+label+"_requests_total",
"Requests, by "+description+".", by),
requestBytes: counterVec("smallwebwaf_"+label+"_request_bytes_total",
"Request body bytes, by "+description+".", by),
responseBytes: counterVec("smallwebwaf_"+label+"_response_bytes_total",
"Response body bytes, by "+description+".", by),
seen: map[string]int64{},
top: map[string]bool{},
}
}
// Describe and Collect make the metrics a prometheus.Collector, so that
// they are registered together.
func (b *busiest) Describe(ch chan<- *prometheus.Desc) {
for _, vec := range b.vecs() {
vec.Describe(ch)
}
}
// Collect is the other half of prometheus.Collector, with Describe.
func (b *busiest) Collect(ch chan<- prometheus.Metric) {
for _, vec := range b.vecs() {
vec.Collect(ch)
}
}
// vecs returns the metrics: by AS number, those of requests and bytes; by
// country, the refusals by the country lists as well.
func (b *busiest) vecs() []*prometheus.CounterVec {
vecs := []*prometheus.CounterVec{b.requests, b.requestBytes, b.responseBytes}
if b.refused != nil {
vecs = append(vecs, b.refused)
}
return vecs
}
// add counts a request from its log line, whose client's country or AS
// number, value, is known.
func (b *busiest) add(value string, line *requestlog.Line) {
b.mu.Lock()
defer b.mu.Unlock()
b.seen[value]++
label := b.label(value)
b.requests.WithLabelValues(label).Inc()
b.requestBytes.WithLabelValues(label).Add(float64(line.RequestBytes))
b.responseBytes.WithLabelValues(label).Add(float64(line.ResponseBytes))
if b.refused != nil && line.Action == requestlog.ActionCountryDenied {
b.refused.WithLabelValues(label).Inc()
}
}
// label returns the label a request from value is counted under: value
// while it is one of the busiest, other while it is not. A value busier
// than the least busy of them takes its place, and that one's series are
// dropped.
func (b *busiest) label(value string) string {
if b.top[value] {
return value
}
if len(b.top) < b.topN {
b.top[value] = true
return value
}
least := ""
for top := range b.top {
if least == "" || b.seen[top] < b.seen[least] {
least = top
}
}
if b.seen[value] <= b.seen[least] {
return other
}
delete(b.top, least)
for _, vec := range b.vecs() {
vec.DeleteLabelValues(least)
}
b.top[value] = true
return value
}
internal/metrics/countries.go
-116
View File
@@ -1,116 +0,0 @@
package metrics
import (
"sync"
"github.com/prometheus/client_golang/prometheus"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
// other is the label under which the countries outside the busiest are
// counted.
const other = "other"
// countries are the metrics by the client's country, for requests whose
// client's country is known. The topN busiest countries, by their requests
// since the start, have series of their own, and the others are counted
// under other, so that there are never more than topN + 1 series. A
// country that drops out of the busiest loses its series, and its next
// requests are counted under other; one that becomes one of them gets a
// series that counts from then on. Each series therefore only ever goes
// up.
type countries struct {
topN int
requests *prometheus.CounterVec
requestBytes *prometheus.CounterVec
responseBytes *prometheus.CounterVec
// refused are the requests the country lists refused.
refused *prometheus.CounterVec
mu sync.Mutex
// seen is each country's requests since the start, by which the
// countries are ranked. GeoJS gives two-letter codes, so it holds at
// most a few hundred.
seen map[string]int64
// top are the countries with series of their own.
top map[string]bool
}
// newCountries returns the metrics by country, with series of their own
// for the topN busiest countries.
func newCountries(topN int) *countries {
byCountry := []string{"country"}
return &countries{
topN: topN,
requests: counterVec("smallwebwaf_country_requests_total",
"Requests, by the client's country.", byCountry),
requestBytes: counterVec("smallwebwaf_country_request_bytes_total",
"Request body bytes, by the client's country.", byCountry),
responseBytes: counterVec("smallwebwaf_country_response_bytes_total",
"Response body bytes, by the client's country.", byCountry),
refused: counterVec("smallwebwaf_country_list_refusals_total",
"Requests the country lists refused, by the client's country.",
byCountry),
seen: map[string]int64{},
top: map[string]bool{},
}
}
// add counts a request from its log line, whose country is known.
func (c *countries) add(line *requestlog.Line) {
c.mu.Lock()
defer c.mu.Unlock()
c.seen[line.Country]++
label := c.label(line.Country)
c.requests.WithLabelValues(label).Inc()
c.requestBytes.WithLabelValues(label).Add(float64(line.RequestBytes))
c.responseBytes.WithLabelValues(label).Add(float64(line.ResponseBytes))
if line.Action == requestlog.ActionCountryDenied {
c.refused.WithLabelValues(label).Inc()
}
}
// label returns the label a request from country is counted under: the
// country while it is one of the busiest, other while it is not. A
// country busier than the least busy of them takes its place, and that
// country's series are dropped.
func (c *countries) label(country string) string {
if c.top[country] {
return country
}
if len(c.top) < c.topN {
c.top[country] = true
return country
}
least := ""
for top := range c.top {
if least == "" || c.seen[top] < c.seen[least] {
least = top
}
}
if c.seen[country] <= c.seen[least] {
return other
}
delete(c.top, least)
for _, vec := range []*prometheus.CounterVec{
c.requests, c.requestBytes, c.responseBytes, c.refused,
} {
vec.DeleteLabelValues(least)
}
c.top[country] = true
return country
}
internal/metrics/metrics.go
+190 -28
View File
@@ -6,19 +6,24 @@ package metrics
import (
"net/http"
"strconv"
"strings"
"time"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/collectors"
"github.com/prometheus/client_golang/prometheus/promhttp"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/bans"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
"sneak.berlin/go/smallwebwaf/internal/remotelog"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
"sneak.berlin/go/smallwebwaf/internal/rules"
)
// Metrics are smallwebwaf's metrics. They are safe for concurrent use.
type Metrics struct {
registry *prometheus.Registry
// registry gives every metric registered with it the label instance.
registry prometheus.Registerer
handler http.Handler
inFlight prometheus.Gauge
@@ -30,12 +35,15 @@ type Metrics struct {
rateLimitHits *prometheus.CounterVec
sizeAndTimeLimitHits *prometheus.CounterVec
offences *prometheus.CounterVec
countries *countries
// ruleMatches are made by AddRules.
ruleMatches *prometheus.CounterVec
countries *busiest
asns *busiest
// GeoJSRequests are the requests to GeoJS, and GeoJSFailures those
// that failed. GeoJSUnanswered are the requests whose client counted
// as coming from an unknown country because GeoJS had not answered
// about it in time.
// that failed. GeoJSUnanswered are the requests that needed their
// client's answer, for a setting that acts on it, and went on without
// it because GeoJS had not given it in time.
GeoJSRequests prometheus.Counter
GeoJSFailures prometheus.Counter
GeoJSUnanswered prometheus.Counter
@@ -44,17 +52,23 @@ type Metrics struct {
stateFileWriteFailures *prometheus.CounterVec
stateFileLastWrite *prometheus.GaugeVec
stateFileSize *prometheus.GaugeVec
stateFileEditsTakenIn *prometheus.CounterVec
stateFileEditsSetAside *prometheus.CounterVec
}
// New returns the metrics, with the Go runtime's and the process's own.
// topN is how many countries get series of their own
// (SWWAF_METRICS_TOP_N).
func New(topN int) *Metrics {
// topN is how many countries and how many AS numbers get series of their
// own (SWWAF_METRICS_TOP_N). Every metric carries instanceName
// (SWWAF_INSTANCE_NAME) as its label instance.
func New(topN int, instanceName string) *Metrics {
byStatus := []string{"status_class", "action"}
byFile := []string{"file"}
registry := prometheus.NewRegistry()
m := &Metrics{
registry: prometheus.NewRegistry(),
registry: prometheus.WrapRegistererWith(
prometheus.Labels{"instance": instanceName}, registry),
handler: promhttp.HandlerFor(registry, promhttp.HandlerOpts{}),
inFlight: prometheus.NewGauge(prometheus.GaugeOpts{
Name: "smallwebwaf_requests_in_flight",
Help: "Requests under way.",
@@ -76,14 +90,16 @@ func New(topN int) *Metrics {
Help: "How long requests passed to the app took, from then to their end.",
}),
rateLimitHits: counterVec("smallwebwaf_rate_limit_hits_total",
"Requests that broke a rate limit, by its window.",
[]string{"window"}),
"Requests that broke a rate limit or a byte limit, by its window and "+
"its kind, requests or bytes.",
[]string{"window", "kind"}),
sizeAndTimeLimitHits: counterVec("smallwebwaf_size_and_time_limit_hits_total",
"Requests that passed a size or time limit, by its setting.",
[]string{"limit"}),
offences: counterVec("smallwebwaf_offences_total",
"Offences, by kind.", []string{"kind"}),
countries: newCountries(topN),
asns: newASNs(topN),
GeoJSRequests: prometheus.NewCounter(prometheus.CounterOpts{
Name: "smallwebwaf_geojs_requests_total",
Help: "Requests to GeoJS.",
@@ -94,8 +110,8 @@ func New(topN int) *Metrics {
}),
GeoJSUnanswered: prometheus.NewCounter(prometheus.CounterOpts{
Name: "smallwebwaf_geojs_unanswered_total",
Help: "Requests whose client counted as coming from an unknown " +
"country because GeoJS had not answered about it in time.",
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",
"Writes of each state file.", byFile),
@@ -105,21 +121,23 @@ func New(topN int) *Metrics {
"When each state file was last written, in seconds since 1970.", byFile),
stateFileSize: gaugeVec("smallwebwaf_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",
"Edits of each state file taken in while running.", byFile),
stateFileEditsSetAside: counterVec("smallwebwaf_state_file_edits_set_aside_total",
"Edits of each state file renamed to <name>.bad because they did not parse.",
byFile),
}
m.handler = promhttp.HandlerFor(m.registry, promhttp.HandlerOpts{})
m.registry.MustRegister(
collectors.NewGoCollector(),
collectors.NewProcessCollector(collectors.ProcessCollectorOpts{}),
m.inFlight, m.requests, m.requestBytes, m.responseBytes,
m.requestDuration, m.upstreamDuration,
m.rateLimitHits, m.sizeAndTimeLimitHits, m.offences,
m.countries.requests, m.countries.requestBytes, m.countries.responseBytes,
m.countries.refused,
m.rateLimitHits, m.sizeAndTimeLimitHits, m.offences, m.countries, m.asns,
m.GeoJSRequests, m.GeoJSFailures, m.GeoJSUnanswered,
m.stateFileWrites, m.stateFileWriteFailures,
m.stateFileLastWrite, m.stateFileSize,
m.stateFileEditsTakenIn, m.stateFileEditsSetAside,
)
return m
@@ -127,19 +145,22 @@ func New(topN int) *Metrics {
// AddBansAndClients adds the metrics read from the ledger and the table
// of clients as the metrics are asked for: the bans made since the start,
// the bans active and permanent at now, and the clients in the table.
// by cause, the bans active and permanent at now, and the clients in the
// table.
func (m *Metrics) AddBansAndClients(
ledger *bans.Ledger, limiter *ratelimit.Limiter, now func() time.Time,
) {
m.registry.MustRegister(
// Every ban smallwebwaf makes so far is for a broken limit.
prometheus.NewCounterFunc(prometheus.CounterOpts{
for _, cause := range []string{bans.CauseLimit, bans.CauseAttack, bans.CauseAdmin} {
m.registry.MustRegister(prometheus.NewCounterFunc(prometheus.CounterOpts{
Name: "smallwebwaf_bans_made_total",
Help: "Bans made, by cause.",
ConstLabels: prometheus.Labels{"cause": "limit"},
ConstLabels: prometheus.Labels{"cause": cause},
}, func() float64 {
return float64(ledger.Made())
}),
return float64(ledger.Made(cause))
}))
}
m.registry.MustRegister(
prometheus.NewGaugeFunc(prometheus.GaugeOpts{
Name: "smallwebwaf_active_bans",
Help: "Bans active now, the permanent ones included.",
@@ -150,7 +171,7 @@ func (m *Metrics) AddBansAndClients(
}),
prometheus.NewGaugeFunc(prometheus.GaugeOpts{
Name: "smallwebwaf_permanent_bans",
Help: "Permanent bans.",
Help: "Permanent bans not lifted.",
}, func() float64 {
_, permanent := ledger.Count(now())
@@ -165,6 +186,117 @@ func (m *Metrics) AddBansAndClients(
)
}
// AddRules adds the metrics of the rule files: the requests that matched
// each rule, which RuleMatched counts, and the rules loaded from
// 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",
"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",
Help: "Rules loaded from the rule files.",
}, func() float64 {
return float64(ruleFiles.Len())
}))
}
// AddRemoteLog adds the metrics of sending the log lines to
// SWWAF_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",
Help: "Log lines sent to SWWAF_LOG_REMOTE_URL.",
}, func() float64 {
return float64(remote.Sent())
}),
prometheus.NewCounterFunc(prometheus.CounterOpts{
Name: "smallwebwaf_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",
Help: "Log lines in the buffer, waiting to be sent.",
}, func() float64 {
return float64(remote.Depth())
}),
)
}
// AddLookupFile adds the metrics of the lookup database, read as the
// metrics are asked for: when the file in use was read, which lastRead
// returns, and the replacements of it that could not be read, which
// readFailures returns. The lookup package's File, which has both, cannot
// be named here: that package counts GeoJS's requests in these metrics.
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",
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",
Help: "Replacements of the lookup database that could not be read.",
}, func() float64 {
return float64(readFailures())
}),
)
}
// AddAlerts adds the metrics of the alerts sent to each destination set,
// read from queue as the metrics are asked for, by destination: the
// alerts sent, the requests to the destination that failed, the alerts
// held back, which are the same for every destination, and those
// dropped. With no destination set, it adds none.
func (m *Metrics) AddAlerts(queue *alerts.Queue) {
for _, name := range queue.DestinationsSet() {
destination := prometheus.Labels{"destination": name}
m.registry.MustRegister(
prometheus.NewCounterFunc(prometheus.CounterOpts{
Name: "smallwebwaf_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",
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",
Help: "Alerts held back: repeats within SWWAF_ALERT_COOLDOWN, and " +
"alerts past SWWAF_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",
Help: "Alerts dropped, the oldest first, from a full queue, and " +
"alerts given up as the destination refused them.",
ConstLabels: destination,
}, func() float64 {
return float64(queue.Counts(name).Dropped)
}),
)
}
}
// ServeHTTP answers with the metrics in the Prometheus text format.
func (m *Metrics) ServeHTTP(w http.ResponseWriter, r *http.Request) {
m.handler.ServeHTTP(w, r)
@@ -195,7 +327,15 @@ func (m *Metrics) RequestEnded(
}
if line.LimitHit != "" {
m.rateLimitHits.WithLabelValues(line.LimitHit).Inc()
// The log line names a byte limit's window with _bytes after it.
window, isBytes := strings.CutSuffix(line.LimitHit, "_bytes")
kind := ratelimit.KindRequests
if isBytes {
kind = ratelimit.KindBytes
}
m.rateLimitHits.WithLabelValues(window, kind).Inc()
}
if limit != "" {
@@ -207,8 +347,18 @@ func (m *Metrics) RequestEnded(
}
if line.Country != "" {
m.countries.add(line)
m.countries.add(line.Country, line)
}
if line.ASN != "" {
m.asns.add(line.ASN, line)
}
}
// RuleMatched counts a request that matched the rule id, whose action is
// action.
func (m *Metrics) RuleMatched(id, action string) {
m.ruleMatches.WithLabelValues(id, action).Inc()
}
// StateFileWritten counts a write of the state file name, of size bytes,
@@ -230,6 +380,18 @@ func (m *Metrics) StateFileWritten(name string, size int, err error) {
m.stateFileSize.WithLabelValues(name).Set(float64(size))
}
// StateFileEditTakenIn counts an admin's edit of the state file name
// taken in while smallwebwaf runs.
func (m *Metrics) StateFileEditTakenIn(name string) {
m.stateFileEditsTakenIn.WithLabelValues(name).Inc()
}
// StateFileEditSetAside counts an admin's edit of the state file name
// renamed to name.bad because it did not parse.
func (m *Metrics) StateFileEditSetAside(name string) {
m.stateFileEditsSetAside.WithLabelValues(name).Inc()
}
// statusClass returns the class of status, such as 2xx, or none when no
// status was sent.
func statusClass(status int) string {
internal/proxy/admin.go
+289 -7
View File
@@ -1,26 +1,60 @@
package proxy
import (
"bytes"
"crypto/subtle"
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"net/netip"
"os"
"strings"
"time"
"sneak.berlin/go/smallwebwaf/internal/bans"
"sneak.berlin/go/smallwebwaf/internal/config"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
"sneak.berlin/go/smallwebwaf/internal/state"
)
// banBodyMaxBytes is the most of the body of a request to add a ban that
// is read; its three fields need far less.
const banBodyMaxBytes = 4 << 10
// permanent is how the log line and the ban endpoint name a ban that
// never ends.
const permanent = "permanent"
var (
errNotBanToAdd = errors.New(
"the body is not a JSON object of netblock, duration and reason")
errNotNetblock = errors.New(
"is not an address or a netblock, such as 203.0.113.9 or 203.0.113.0/24")
errMappedNetblock = errors.New(
"is IPv4-mapped: give the IPv4 netblock, such as 203.0.113.0/24")
errZone = errors.New("has a zone, which a netblock cannot have")
errNotDuration = errors.New(
"is not a duration above zero, such as 1h or 7d, or permanent")
errNotAddress = errors.New("is not an address, such as 203.0.113.9")
)
// answerAdmin answers a request for smallwebwaf itself, under
// /_smallwebwaf/, once it has passed the checks: GET MetricsPath with
// SWWAF_METRICS_TOKEN gets the metrics, and without it is refused with
// 401. Any other request gets 404, as the metrics do while
// SWWAF_METRICS_TOKEN is unset.
// /_smallwebwaf/, once it has passed the checks. Each endpoint needs a
// token, sent as Authorization: Bearer <token>: the metrics
// SWWAF_METRICS_TOKEN, the others SWWAF_ADMIN_TOKEN. A request without
// it is refused with 401. An endpoint whose token is unset answers 404,
// as any other request under /_smallwebwaf/ does.
func (rq *request) answerAdmin() {
rq.line.Action = requestlog.ActionAdmin
rq.startClientResponseTimeout()
token := rq.h.config.MetricsToken
token, answer := rq.endpoint()
switch {
case token == "" || rq.in.Method != http.MethodGet || rq.in.URL.Path != MetricsPath:
case token == "":
http.Error(rq.out, http.StatusText(http.StatusNotFound), http.StatusNotFound)
case !hasToken(rq.in, token):
rq.out.Header().Set("WWW-Authenticate", "Bearer")
@@ -29,7 +63,29 @@ func (rq *request) answerAdmin() {
action: requestlog.ActionAdmin,
})
default:
rq.h.metrics.ServeHTTP(rq.out, rq.in)
answer()
}
}
// endpoint returns the token the request's endpoint needs, and what
// answers the request there; "" when there is no such endpoint.
func (rq *request) endpoint() (string, func()) {
cfg := rq.h.config
method, path := rq.in.Method, rq.in.URL.Path
switch {
case method == http.MethodGet && path == MetricsPath:
return cfg.MetricsToken, func() { rq.h.metrics.ServeHTTP(rq.out, rq.in) }
case method == http.MethodGet && path == BansPath:
return cfg.AdminToken, rq.listBans
case method == http.MethodPost && path == BansPath:
return cfg.AdminToken, rq.addBan
case method == http.MethodDelete && strings.HasPrefix(path, BansPath+"/"):
return cfg.AdminToken, rq.liftBans
case method == http.MethodGet && strings.HasPrefix(path, ClientsPath):
return cfg.AdminToken, rq.showClient
default:
return "", nil
}
}
@@ -41,3 +97,229 @@ func hasToken(r *http.Request, token string) bool {
return strings.EqualFold(scheme, "Bearer") &&
subtle.ConstantTimeCompare([]byte(sent), []byte(token)) == 1
}
// listBans answers GET BansPath with every ban held.
func (rq *request) listBans() {
rq.answerBans(rq.h.ledger.Snapshot())
}
// banToAdd is the body of POST BansPath.
type banToAdd struct {
// Netblock is a netblock, or a client's address, which stands for the
// netblock a ban on that client covers.
Netblock string `json:"netblock"`
// Duration is how long the ban lasts, as a setting gives a duration,
// or permanent.
Duration string `json:"duration"`
Reason string `json:"reason"`
}
// addBan answers POST BansPath: it bans the netblock the body names, as
// 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
expires time.Time
now = rq.h.now()
)
if err == nil {
netblock, err = rq.h.banNetblock(toAdd.Netblock)
}
if err == nil {
expires, err = expiry(toAdd.Duration, now)
}
if err != nil {
http.Error(rq.out, err.Error(), http.StatusBadRequest)
return
}
ban := rq.h.ledger.BanForAdmin(netblock, now, expires, toAdd.Reason)
rq.answerBans([]bans.Ban{ban})
}
// 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
if rq.body != nil {
body = rq.body
}
data, err := io.ReadAll(http.MaxBytesReader(nil, body, banBodyMaxBytes))
if err != nil {
return banToAdd{}, fmt.Errorf("%w: %w", errNotBanToAdd, err)
}
var toAdd banToAdd
decoder := json.NewDecoder(bytes.NewReader(data))
decoder.DisallowUnknownFields()
err = decoder.Decode(&toAdd)
if err != nil {
return banToAdd{}, fmt.Errorf("%w: %w", errNotBanToAdd, err)
}
// Token returns io.EOF only when nothing but whitespace is left.
_, err = decoder.Token()
if !errors.Is(err, io.EOF) {
return banToAdd{}, fmt.Errorf("%w: more follows the object", errNotBanToAdd)
}
return toAdd, nil
}
// banNetblock reads value, a netblock such as 203.0.113.0/24, or a
// client's address, which stands for the netblock a ban on that client
// covers. An IPv4-mapped netblock, such as ::ffff:203.0.113.0/120, is
// refused, since a client's address is looked up as IPv4 and a ban on it
// would refuse nothing, and so is a value with a zone.
func (h *handler) banNetblock(value string) (netip.Prefix, error) {
netblock, err := netip.ParsePrefix(value)
if err == nil {
if netblock.Addr().Is4In6() {
return netip.Prefix{}, fmt.Errorf("netblock %q %w", value, errMappedNetblock)
}
return netblock, nil
}
// ParsePrefix refuses a zone, but ParseAddr reads the /48 of
// 2001:db8::1%x/48 as part of the zone.
addr, err := netip.ParseAddr(value)
if err != nil {
return netip.Prefix{}, fmt.Errorf("netblock %q %w", value, errNotNetblock)
}
if addr.Zone() != "" {
return netip.Prefix{}, fmt.Errorf("netblock %q %w", value, errZone)
}
return h.netblock(addr), nil
}
// expiry returns when a ban made at now for duration ends: duration
// later, for a duration as a setting gives one, or zero for permanent.
func expiry(duration string, now time.Time) (time.Time, error) {
if duration == permanent {
return time.Time{}, nil
}
length, err := config.ParseDurationNotOff(duration)
if err != nil {
return time.Time{}, fmt.Errorf("duration %q %w", duration, errNotDuration)
}
return now.Add(length), nil
}
// liftBans answers DELETE BansPath/<client>: it lifts every ban active on
// a netblock the client's address is in, and answers with those bans, or
// with 404 when none is active.
func (rq *request) liftBans() {
client, err := pathAddress(rq.in.URL.Path, BansPath+"/")
if err != nil {
http.Error(rq.out, err.Error(), http.StatusBadRequest)
return
}
lifted := rq.h.ledger.Lift(client, rq.h.now())
if len(lifted) == 0 {
http.Error(rq.out, "no ban is active on "+client.String(), http.StatusNotFound)
return
}
rq.answerBans(lifted)
}
// clientAnswer is the answer to GET ClientsPath<ip>: the client the
// address is, as clients.json holds it, or null when the table of
// clients does not hold it, and the bans on each netblock the address is
// in, as bans.json lists them.
type clientAnswer struct {
Client *ratelimit.Client `json:"client"`
Bans []state.BanEntry `json:"bans"`
}
// showClient answers GET ClientsPath<ip> with what smallwebwaf knows of
// the client: its counters, its history, which holds its country as last
// looked up and its offences, and its bans with their notes.
func (rq *request) showClient() {
addr, err := pathAddress(rq.in.URL.Path, ClientsPath)
if err != nil {
http.Error(rq.out, err.Error(), http.StatusBadRequest)
return
}
answer := clientAnswer{Bans: state.BanEntries(rq.h.ledger.Covering(addr))}
client, seen := rq.h.limiter.Client(clientGroup(addr))
if seen {
answer.Client = &client
}
rq.answerJSON(answer)
}
// pathAddress reads the client's address that follows prefix in path.
func pathAddress(path, prefix string) (netip.Addr, error) {
value := strings.TrimPrefix(path, prefix)
addr, err := netip.ParseAddr(value)
if err != nil {
return netip.Addr{}, fmt.Errorf("%q %w", value, errNotAddress)
}
return addr.Unmap(), nil
}
// answerBans answers with held under bans, as bans.json lists them.
func (rq *request) answerBans(held []bans.Ban) {
rq.answerJSON(struct {
Bans []state.BanEntry `json:"bans"`
}{state.BanEntries(held)})
}
// answerJSON answers with value as indented JSON.
func (rq *request) answerJSON(value any) {
body, err := json.MarshalIndent(value, "", " ")
if err != nil {
rq.h.processLog.Error("encoding an answer failed", "error", err.Error())
http.Error(rq.out, http.StatusText(http.StatusInternalServerError),
http.StatusInternalServerError)
return
}
rq.out.Header().Set("Content-Type", "application/json")
_, _ = rq.out.Write(append(body, '\n'))
}
internal/proxy/admin_test.go
+535
View File
@@ -0,0 +1,535 @@
package proxy_test
import (
"encoding/json"
"net/http"
"net/netip"
"slices"
"strconv"
"strings"
"testing"
"time"
"sneak.berlin/go/smallwebwaf/internal/bans"
"sneak.berlin/go/smallwebwaf/internal/proxy"
"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
// adminSecret is the SWWAF_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", ` +
`"reason": "probes for logins"}`
)
func TestAdminEndpointsAreOffWhileTheTokenIsUnset(t *testing.T) {
t.Parallel()
// The metrics token is set, and opens none of them.
s, clk, server := startWithClock(t, "", map[string]string{metricsToken: token})
server.Ledger.BanForLimit(netip.MustParsePrefix(otherClient+"/32"), clk.Now(),
bans.Notes{})
before := server.Ledger.Snapshot()
// 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,
http.StatusNotFound, requestlog.ActionAdmin)
}
}
if after := server.Ledger.Snapshot(); !slices.Equal(after, before) {
t.Errorf("the bans are now\n%+v\nwant them unchanged\n%+v", after, before)
}
}
func TestAdminEndpointsNeedTheAdminToken(t *testing.T) {
t.Parallel()
s, _, server := startWithClock(t, "", map[string]string{
adminToken: adminSecret,
metricsToken: token,
})
// Listing the bans, banning otherClient, lifting that ban, and asking
// about otherClient, in that order. Without the admin token, with the
// metrics token, or with one that differs, each is refused, and
// changes nothing; with the admin token, it is answered.
for _, e := range adminEndpoints() {
before := server.Ledger.Snapshot()
for _, authorization := range []string{
"", bearer, "Bearer " + strings.ToUpper(adminSecret), "Basic " + adminSecret,
} {
got := s.adminRequest(adminClient, authorization, e.method, e.path, e.body,
http.StatusUnauthorized, requestlog.ActionAdmin)
if got.header.Get("WWW-Authenticate") != "Bearer" {
t.Errorf("%s %s with %q was answered without WWW-Authenticate: Bearer",
e.method, e.path, authorization)
}
}
if after := server.Ledger.Snapshot(); !slices.Equal(after, before) {
t.Errorf("%s %s without the token changed the bans to\n%+v\nfrom\n%+v",
e.method, e.path, after, before)
}
got := s.admin(e.method, e.path, e.body, http.StatusOK)
if got.header.Get("Content-Type") != "application/json" {
t.Errorf("%s %s answered %q", e.method, e.path, got.header.Get("Content-Type"))
}
}
// Any other request under /_smallwebwaf/ is not found.
for _, e := range []adminEndpoint{
{http.MethodPut, proxy.BansPath, banOtherClient},
{http.MethodDelete, proxy.BansPath, ""},
{http.MethodGet, proxy.BansPath + "/" + otherClient, ""},
{http.MethodPost, proxy.ClientsPath + otherClient, ""},
{http.MethodGet, strings.TrimSuffix(proxy.ClientsPath, "/"), ""},
} {
s.admin(e.method, e.path, e.body, http.StatusNotFound)
}
}
func TestBanAddedListedAndLiftedThroughTheEndpoints(t *testing.T) {
t.Parallel()
s, clk, _ := startWithClock(t, "", map[string]string{
adminToken: adminSecret,
banScopeV4Prefix: "24",
})
// A ban on otherClient bans the /24 a ban on that client covers, so it
// refuses client too, for an hour.
start := clk.Now()
expires := start.Add(time.Hour)
want := state.BanEntry{
Netblock: netip.MustParsePrefix("203.0.113.0/24"),
Start: start,
Expires: &expires,
Cause: bans.CauseAdmin,
Reason: "probes for logins",
}
wantBans(t, s.admin(http.MethodPost, proxy.BansPath, banOtherClient, http.StatusOK),
want)
line := s.get(client, http.StatusForbidden, requestlog.ActionBanned)
if line.BanExpires != requestlog.FormatTime(expires) {
t.Errorf("the ban ends at %s, want %s", line.BanExpires, expires)
}
// 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)
// Ten minutes on, lifting the bans on client lifts that one, which is
// kept, marked lifted.
clk.advance(10 * time.Minute)
lifted := clk.Now()
want.Lifted = &lifted
wantBans(t, s.admin(http.MethodDelete, proxy.BansPath+"/"+client, "",
http.StatusOK), want)
s.get(client, http.StatusOK, requestlog.ActionForward)
wantBans(t, s.admin(http.MethodGet, proxy.BansPath, "", http.StatusOK), want)
// No ban on it is active any more.
s.admin(http.MethodDelete, proxy.BansPath+"/"+client, "", http.StatusNotFound)
}
func TestBanToAddGivesItsNetblockAndDuration(t *testing.T) {
t.Parallel()
s, clk, _ := startWithClock(t, "", map[string]string{
adminToken: adminSecret,
banScopeV4Prefix: "24",
})
start := clk.Now()
for _, tc := range []struct {
netblock, duration string
want string
length time.Duration // 0 for a permanent ban
}{
// An address stands for the netblock a ban on that client covers.
{client, "7d", "203.0.113.0/24", 7 * 24 * time.Hour},
{"::ffff:198.51.100.7", "90m", "198.51.100.0/24", 90 * time.Minute},
{"2001:db8:5::1", "permanent", "2001:db8:5::/64", 0},
// A netblock stands for itself, its bits past its length cleared.
{"198.51.100.7/16", "1h", "198.51.0.0/16", time.Hour},
{"2001:db8:6::/48", "1h", "2001:db8:6::/48", time.Hour},
} {
// Whitespace may follow the object.
body := `{"netblock": "` + tc.netblock + `", "duration": "` + tc.duration + `"}` +
"\r\n"
want := state.BanEntry{
Netblock: netip.MustParsePrefix(tc.want), Start: start, Cause: bans.CauseAdmin,
}
if tc.length != 0 {
expires := start.Add(tc.length)
want.Expires = &expires
}
wantBans(t, s.admin(http.MethodPost, proxy.BansPath, body, http.StatusOK), want)
}
}
func TestBanToAddThatCannotBeReadIsRefused(t *testing.T) {
t.Parallel()
s, _, server := startWithClock(t, "", map[string]string{adminToken: adminSecret})
for _, tc := range []struct{ body, want string }{
{"", "the body is not a JSON object of netblock, duration and reason: EOF"},
{"netblock=203.0.113.9", "the body is not a JSON object"},
{
`{"netblock": "203.0.113.9", "duration": "1h", "until": "2027"}`,
`unknown field "until"`,
},
{
`{"netblock": "203.0.113", "duration": "1h"}`,
`netblock "203.0.113" is not an address or a netblock`,
},
// A client's address is looked up as IPv4, so a ban on an
// IPv4-mapped netblock would refuse nothing.
{
`{"netblock": "::ffff:203.0.113.0/120", "duration": "1h"}`,
`netblock "::ffff:203.0.113.0/120" is IPv4-mapped`,
},
// Read as an address, its zone would be "x/48", and its ban on the
// /64 around it.
{
`{"netblock": "2001:db8::1%x/48", "duration": "1h"}`,
`netblock "2001:db8::1%x/48" has a zone`,
},
{
`{"netblock": "fe80::1%eth0", "duration": "1h"}`,
`netblock "fe80::1%eth0" has a zone`,
},
// Anything but whitespace after the object.
{
`{"netblock": "203.0.113.9", "duration": "1h"}` +
`{"netblock": "198.51.100.0/24", "duration": "1h"}`,
"more follows the object",
},
{`{"netblock": "203.0.113.9", "duration": "1h"} x`, "more follows the object"},
{`{"duration": "1h"}`, `netblock "" is not an address or a netblock`},
{`{"netblock": "203.0.113.9"}`, `duration "" is not a duration above zero`},
{
`{"netblock": "203.0.113.9", "duration": "off"}`,
`duration "off" is not a duration above zero`,
},
{
`{"netblock": "203.0.113.9", "duration": "0s"}`,
`duration "0s" is not a duration above zero`,
},
{
`{"netblock": "203.0.113.9", "duration": "forever"}`,
`duration "forever" is not a duration above zero, such as 1h or 7d, ` +
`or permanent`,
},
// Over the 4 KiB read of a body, even when the object comes first.
{
`{"netblock": "203.0.113.9", "duration": "1h", "reason": "` +
strings.Repeat("x", 4<<10) + `"}`,
"request body too large",
},
{
`{"netblock": "203.0.113.9", "duration": "1h"}` + strings.Repeat(" ", 4<<10),
"request body too large",
},
} {
got := s.admin(http.MethodPost, proxy.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)
}
}
if held := server.Ledger.Snapshot(); len(held) != 0 {
t.Errorf("the ledger holds %+v, want no ban", held)
}
}
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()
// Two of otherClient's requests are let through; the third breaks the
// limit of two a minute, and bans it.
s.get(otherClient, http.StatusOK, requestlog.ActionForward)
s.get(otherClient, http.StatusOK, requestlog.ActionForward)
s.get(otherClient, http.StatusForbidden, requestlog.ActionRateLimited)
// Asked about by its address in IPv6 form too.
for _, addr := range []string{otherClient, "::ffff:" + otherClient} {
var got struct {
Client *ratelimit.Client `json:"client"`
Bans []state.BanEntry `json:"bans"`
}
decode(t, s.admin(http.MethodGet, proxy.ClientsPath+addr, "", http.StatusOK), &got)
if got.Client == nil {
t.Fatalf("%s: no client", addr)
}
history := got.Client.History
if got.Client.Client != netip.MustParsePrefix(otherClient+"/32") ||
history.Requests != 3 || history.Forwarded != 2 || history.Refused != 1 ||
history.Offences.Limit != 1 || !history.FirstSeen.Equal(start) {
t.Errorf("%s: client %+v", addr, got.Client)
}
if len(got.Bans) != 1 || got.Bans[0].Cause != bans.CauseLimit ||
got.Bans[0].Reason != "requests per minute over the limit of 2" ||
got.Bans[0].Notes.Count != 3 {
t.Errorf("%s: bans %+v, want the one for the broken limit", addr, got.Bans)
}
}
// 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)
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.MethodDelete, proxy.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) {
t.Parallel()
s, _, server := startWithClock(t, "", map[string]string{
adminToken: adminSecret,
mode: observe,
})
for _, e := range adminEndpoints() {
s.adminRequest(adminClient, "", e.method, e.path, e.body,
http.StatusUnauthorized, requestlog.ActionAdmin)
}
if held := server.Ledger.Snapshot(); len(held) != 0 {
t.Errorf("the ledger holds %+v, want no ban", held)
}
}
// adminEndpoint is a request to an endpoint SWWAF_ADMIN_TOKEN opens.
type adminEndpoint struct {
method, path, body string
}
// adminEndpoints returns a request to each endpoint SWWAF_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.MethodPost, proxy.BansPath, banOtherClient},
{http.MethodDelete, proxy.BansPath + "/" + otherClient, ""},
{http.MethodGet, proxy.ClientsPath + otherClient, ""},
}
}
// admin sends a request with method for path, with body, from
// adminClient, with the admin token, and checks that it is answered with
// status, its 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,
requestlog.ActionAdmin)
}
// adminRequest sends a request with method for path, with body, from the
// client at from, with authorization as its Authorization header unless
// 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,
) answer {
s.t.Helper()
var header []string
if authorization != "" {
header = append(header, "Authorization: "+authorization)
}
if body != "" && !strings.Contains(authorization, "Transfer-Encoding") {
header = append(header, "Content-Length: "+strconv.Itoa(len(body)))
}
_, got := s.requestWithBody(method, from, path, strings.Join(header, "\r\n"),
body, status, action)
return got
}
// wantBans checks that a ban endpoint answered with want, and no other
// ban.
func wantBans(t *testing.T, got answer, want ...state.BanEntry) {
t.Helper()
var decoded struct {
Bans []state.BanEntry `json:"bans"`
}
decode(t, got, &decoded)
gotJSON, err := json.Marshal(decoded.Bans)
if err != nil {
t.Fatalf("encode %+v: %v", decoded.Bans, err)
}
wantJSON, err := json.Marshal(want)
if err != nil {
t.Fatalf("encode %+v: %v", want, err)
}
if string(gotJSON) != string(wantJSON) {
t.Errorf("bans\n%s\nwant\n%s", gotJSON, wantJSON)
}
}
// decode reads the JSON answer of an endpoint into value.
func decode(t *testing.T, got answer, value any) {
t.Helper()
err := json.Unmarshal(got.body, value)
if err != nil {
t.Fatalf("decode %s: %v", got.body, err)
}
}
internal/proxy/alerts_test.go
+273
View File
@@ -0,0 +1,273 @@
package proxy_test
import (
"maps"
"net/http"
"net/netip"
"reflect"
"testing"
"time"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/bans"
"sneak.berlin/go/smallwebwaf/internal/proxy"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
const (
alertWebhookURL = "SWWAF_ALERT_WEBHOOK_URL"
alertMaxPerHour = "SWWAF_ALERT_MAX_PER_HOUR"
// alertInstance is the instance every alert of these tests gives.
alertInstance = "fsn1app1/gitea"
)
func TestBanForABrokenLimitRaisesABanAlertWithItsNotes(t *testing.T) {
t.Parallel()
s, clk, server, queue := startWithAlerts(t, map[string]string{
rateLimitPerMinute: "1",
banScopeV4Prefix: "24",
})
start := clk.Now()
s.get(client, http.StatusOK, requestlog.ActionForward)
s.get(client, http.StatusForbidden, requestlog.ActionRateLimited)
netblock := netip.MustParsePrefix("203.0.113.0/24")
ban := server.Ledger.Bans(netblock)[0]
// A request refused under the ban raises no other alert.
clk.advance(time.Minute)
s.get(client, http.StatusForbidden, requestlog.ActionBanned)
wantAlerts(t, queue, banAlert(alerts.EventBan, start, client, bans.Ban{
Netblock: netblock, Cause: bans.CauseLimit,
Reason: "requests per minute over the limit of 1", Notes: ban.Notes,
}, requestlog.FormatTime(start.Add(time.Hour))))
if ban.Notes.Limit != 1 || ban.Notes.Request.Path != "/" {
t.Errorf("the alert's notes are %+v, want those of the broken limit", ban.Notes)
}
}
func TestAttackBanRaisesABanAlertThenAPermanentBanAlert(t *testing.T) {
t.Parallel()
s, clk, server, queue := startWithAlerts(t, map[string]string{
rulesDir: writeRules(t, testRules),
})
start := clk.Now()
netblock := netip.MustParsePrefix(client + "/32")
other := netip.MustParsePrefix(otherClient + "/32")
// The probe bans the client for seven days, and its next request makes
// the ban permanent. The request after that changes nothing.
s.request(client, "/.env", http.StatusForbidden, requestlog.ActionBanned)
attackBan := server.Ledger.Bans(netblock)[0]
clk.advance(time.Minute)
s.get(client, http.StatusForbidden, requestlog.ActionBanned)
permanentBan := server.Ledger.Bans(netblock)[0]
s.get(client, http.StatusForbidden, requestlog.ActionBanned)
// Another client's probe after its first ban has run out without a
// request makes a permanent ban at once.
s.request(otherClient, "/.env", http.StatusForbidden, requestlog.ActionBanned)
clk.advance(7 * 24 * time.Hour)
s.request(otherClient, "/.env", http.StatusForbidden, requestlog.ActionBanned)
otherBans := server.Ledger.Bans(other)
wantAlerts(t, queue,
attackAlert(alerts.EventBan, start, client, attackBan,
requestlog.FormatTime(start.Add(7*24*time.Hour))),
attackAlert(alerts.EventPermanentBan, start.Add(time.Minute), client,
permanentBan, "permanent"),
attackAlert(alerts.EventBan, start.Add(time.Minute), otherClient, otherBans[0],
requestlog.FormatTime(start.Add(time.Minute+7*24*time.Hour))),
attackAlert(alerts.EventPermanentBan, start.Add(time.Minute+7*24*time.Hour),
otherClient, otherBans[1], "permanent"),
)
}
func TestObserveModeRaisesTheBanAlertsItWouldHave(t *testing.T) {
t.Parallel()
s, clk, server, queue := startWithAlerts(t, map[string]string{
mode: observe,
rateLimitPerMinute: "2",
rulesDir: writeRules(t, testRules),
})
start := clk.Now()
// A ban for a clear sign of attack, which a request under it would make
// permanent.
group := netip.MustParsePrefix(ipv6Group)
attackBan, _ := server.Ledger.BanForAttack(group, start, bans.Notes{RuleID: "probe"})
// The third request breaks the limit, and so does the fourth, within the
// cooldown, which raises nothing. The probe is a clear sign of attack.
for range 4 {
s.get(client, http.StatusOK, requestlog.ActionForward)
}
s.request(otherClient, "/.env", http.StatusOK, requestlog.ActionForward)
line := s.get(ipv6Client, http.StatusOK, requestlog.ActionForward)
// No ban is made, and none made permanent.
if held := server.Ledger.Snapshot(); len(held) != 1 || held[0] != attackBan ||
line.BanExpires != requestlog.FormatTime(attackBan.Expires) {
t.Errorf("the ledger holds %+v, and the log line gives %s, want the ban "+
"for the attack alone, as it was", held, line.BanExpires)
}
waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
if len(waiting) != 3 || queue.Suppressed() != 0 {
t.Fatalf("%d alerts wait and %d are held back, want 3 and 0: %+v",
len(waiting), queue.Suppressed(), waiting)
}
limitNotes, _ := waiting[0].Detail["notes"].(bans.Notes)
attackNotes, _ := waiting[1].Detail["notes"].(bans.Notes)
if limitNotes.Limit != 2 || limitNotes.Request.Path != "/" ||
attackNotes.Request.Path != "/.env" {
t.Errorf("the notes are %+v and %+v, want those of the broken limit and "+
"of the probe", limitNotes, attackNotes)
}
// Each alert is the one enforce mode would have raised, with mode
// observe in its detail.
want := []alerts.Alert{
banAlert(alerts.EventBan, start, client, bans.Ban{
Netblock: netip.MustParsePrefix(client + "/32"), Cause: bans.CauseLimit,
Reason: "requests per minute over the limit of 2", Notes: limitNotes,
}, requestlog.FormatTime(start.Add(time.Hour))),
attackAlert(alerts.EventBan, start, otherClient, bans.Ban{
Netblock: netip.MustParsePrefix(otherClient + "/32"), Notes: attackNotes,
}, requestlog.FormatTime(start.Add(7*24*time.Hour))),
attackAlert(alerts.EventPermanentBan, start, ipv6Client, attackBan, permanent),
}
for _, alert := range want {
alert.Detail["mode"] = observe
}
wantAlerts(t, queue, want...)
}
func TestObserveModeWorksOutABanOnlyWhenItsAlertWouldBeSent(t *testing.T) {
t.Parallel()
s, _, _, queue := startWithAlerts(t, map[string]string{
mode: observe,
rateLimitPerMinute: "2",
rulesDir: writeRules(t, testRules),
alertMaxPerHour: "2",
})
// The client's third request breaks the limit, and raises the first
// alert of the hour. Its fourth is within the cooldown.
for range 4 {
s.get(client, http.StatusOK, requestlog.ActionForward)
}
// The other client's first probe raises the second. Its second probe is
// within the cooldown.
for range 2 {
s.request(otherClient, "/.env", http.StatusOK, requestlog.ActionForward)
}
// The IPv6 client's third request breaks the limit past the two alerts
// an hour.
for range 3 {
s.get(ipv6Client, http.StatusOK, requestlog.ActionForward)
}
// Had the ban been worked out for any of the requests within the
// cooldown or past the two an hour, its alert would have been raised,
// held back and counted.
waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
if len(waiting) != 2 || queue.Suppressed() != 0 {
t.Errorf("%d alerts wait and %d are held back, want 2 and 0: %+v",
len(waiting), queue.Suppressed(), waiting)
}
}
// startWithAlerts is startWithClock with alerts to a webhook, which is
// 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) {
t.Helper()
return startAppWithAlerts(t, func(http.ResponseWriter, *http.Request) {}, env)
}
// 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) {
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",
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
}
// banAlert returns the alert for event, raised by a request from client at
// the time raised, for ban, with its netblock, cause, reason and notes,
// which ends at expires, as the log line gives it.
func banAlert(
event string, raised time.Time, client string, ban bans.Ban, expires string,
) alerts.Alert {
return alerts.Alert{
Instance: alertInstance,
Time: raised,
Event: event,
Client: netip.MustParseAddr(client),
Netblock: ban.Netblock,
Reason: ban.Reason,
Detail: map[string]any{
"cause": ban.Cause, "ban_expires": expires, "notes": ban.Notes,
},
}
}
// attackAlert is banAlert for a ban for the probe rule of testRules, with
// the netblock and the notes of ban.
func attackAlert(
event string, raised time.Time, client string, ban bans.Ban, expires string,
) alerts.Alert {
return banAlert(event, raised, client, bans.Ban{
Netblock: ban.Netblock, Cause: bans.CauseAttack, Reason: "matched the rule probe",
Notes: ban.Notes,
}, expires)
}
// wantAlerts checks the alerts waiting in queue, in order.
func wantAlerts(t *testing.T, queue *alerts.Queue, want ...alerts.Alert) {
t.Helper()
got := queue.Snapshot().Waiting[alerts.DestinationWebhook]
if len(got) != len(want) {
t.Fatalf("%d alerts wait, want %d: %+v", len(got), len(want), got)
}
for i := range want {
if !reflect.DeepEqual(got[i], want[i]) {
t.Errorf("alert %d is\n%+v\nwant\n%+v", i, got[i], want[i])
}
}
}
internal/proxy/anomaly_internal_test.go
+30
View File
@@ -0,0 +1,30 @@
package proxy
import (
"net/netip"
"testing"
"sneak.berlin/go/smallwebwaf/internal/config"
)
func TestWithEveryAnomalyThresholdOffARequestIsNotCounted(t *testing.T) {
t.Parallel()
// A request from a client looked up through GeoJS, with every anomaly
// threshold off. Its handler has neither GeoJS's answers nor the
// 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"}},
client: netip.MustParseAddr("203.0.113.9"),
lookedUp: true,
}
defer func() {
if r := recover(); r != nil {
t.Errorf("counting the request did work, with every threshold off: %v", r)
}
}()
rq.countAnomalies()
}
internal/proxy/anomaly_test.go
+377
View File
@@ -0,0 +1,377 @@
package proxy_test
import (
"maps"
"net/http"
"net/netip"
"reflect"
"slices"
"strconv"
"sync/atomic"
"testing"
"time"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/anomaly"
"sneak.berlin/go/smallwebwaf/internal/proxy"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
// The anomaly thresholds: the prefix of a scope followed by the end of a
// count.
const (
anomalyClient = "SWWAF_ANOMALY_CLIENT_"
anomalyNet = "SWWAF_ANOMALY_NET_"
anomalyASN = "SWWAF_ANOMALY_ASN_"
anomalyTotal = "SWWAF_ANOMALY_TOTAL_"
anomalyWatch = "SWWAF_WATCH_"
requestsPerMinute = "REQUESTS_PER_MINUTE"
requestsPerHour = "REQUESTS_PER_HOUR"
bytesPerMinute = "BYTES_PER_MINUTE"
bytesPerHour = "BYTES_PER_HOUR"
)
// The other anomaly settings.
const (
anomalyNetV4Prefix = "SWWAF_ANOMALY_NET_V4_PREFIX"
anomalyNetV6Prefix = "SWWAF_ANOMALY_NET_V6_PREFIX"
watchNets = "SWWAF_WATCH_NETS"
)
const (
// clientsNet is the netblock around client at the default length, and
// office a named netblock of the same.
clientsNet = "203.0.113.0/24"
office = "office=" + clientsNet
// aLot is a threshold no test reaches.
aLot = "1000"
// hour is the window an alert names for a threshold per hour.
hour = "hour"
)
func TestEachScopeAndWindowOverItsThresholdAlertsOncePerCooldown(t *testing.T) {
t.Parallel()
for _, scope := range []struct {
prefix, scope string
// netblock is the alert's, and counted what its reason names. extra
// is what its detail gives besides what every anomaly alert's does.
netblock netip.Prefix
counted string
extra map[string]any
}{
{
anomalyClient, anomaly.ScopeClient, netip.MustParsePrefix(client + "/32"),
"the client " + client + "/32", nil,
},
{
anomalyNet, anomaly.ScopeNet, netip.MustParsePrefix(clientsNet),
"the netblock " + clientsNet, nil,
},
{anomalyASN, anomaly.ScopeASN, netip.Prefix{}, asnDE, map[string]any{"asn": asnDE}},
{anomalyTotal, anomaly.ScopeTotal, netip.Prefix{}, "the whole service", nil},
{
anomalyWatch, anomaly.ScopeWatch, netip.MustParsePrefix(clientsNet),
"the named netblock office, " + clientsNet, map[string]any{"name": "office"},
},
} {
for _, threshold := range []struct {
end, kind, window string
// value is the threshold, which the third upload of 100 bytes
// takes the count over, to count.
value int64
count float64
}{
{requestsPerMinute, ratelimit.KindRequests, minute, 2, 3},
{requestsPerHour, ratelimit.KindRequests, hour, 2, 3},
{bytesPerMinute, ratelimit.KindBytes, minute, 250, 300},
{bytesPerHour, ratelimit.KindBytes, hour, 250, 300},
} {
setting := scope.prefix + threshold.end
value := strconv.FormatInt(threshold.value, 10)
t.Run(setting, func(t *testing.T) {
t.Parallel()
s, clk, server, queue := startWithLookupsAndClock(t, map[string]string{
setting: value, watchNets: office,
})
start := clk.Now()
// The third upload takes the count over the threshold, and the
// fourth, within the cooldown, is held back. Each is passed to
// the app.
for range 4 {
s.uploadFrom(client)
}
detail := map[string]any{
"scope": scope.scope, "window": threshold.window, "kind": threshold.kind,
"count": threshold.count, "threshold": threshold.value,
}
maps.Copy(detail, scope.extra)
wantAlerts(t, queue, alerts.Alert{
Instance: alertInstance,
Time: start,
Event: alerts.EventAnomaly,
Client: netip.MustParseAddr(client),
Netblock: scope.netblock,
ASN: asnDE,
ASName: asNameDE,
Country: "DE",
Reason: threshold.kind + " per " + threshold.window + " of " +
scope.counted + " over the threshold of " + value,
Detail: detail,
})
wantAlertedAgainOnceTheCooldownHasRunOut(t, s, clk, queue)
if held := server.Ledger.Snapshot(); len(held) != 0 {
t.Errorf("the ledger holds %+v, want no ban", held)
}
})
}
}
}
// wantAlertedAgainOnceTheCooldownHasRunOut checks that, once the cooldown
// has run out after a first alert, which held back one repeat, the next
// count over the threshold, at the latest three uploads from client on,
// raises another alert, giving that repeat.
func wantAlertedAgainOnceTheCooldownHasRunOut(
t *testing.T, s *sender, clk *clock, queue *alerts.Queue,
) {
t.Helper()
clk.advance(15 * time.Minute)
for range 3 {
s.uploadFrom(client)
}
waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
if len(waiting) != 2 || !waiting[1].Time.Equal(clk.Now()) ||
waiting[1].SuppressedRepeats != 1 {
t.Errorf("alerts wait %+v, want the first and another, with 1 repeat", waiting)
}
}
func TestEveryRequestIsCountedWhateverIsDoneWithIt(t *testing.T) {
t.Parallel()
const (
allowed = "192.0.2.7" // in SWWAF_ALLOW_NETS
exempt = "192.0.2.10" // in SWWAF_RATE_LIMIT_EXEMPT_NETS
denied = "192.0.2.20" // in SWWAF_DENY_NETS
)
s, _, _, queue := startAppWithAlerts(t, readAndAnswer, map[string]string{
anomalyClient + requestsPerMinute: "2",
allowNets: allowed,
rateLimitExemptNets: exempt,
rateLimitExemptPaths: "/static/",
denyNets: denied,
})
// The third request of each takes its client's count over the threshold
// of 2.
for _, sent := range []struct {
from, path string
status int
action string
}{
{allowed, "/", http.StatusOK, requestlog.ActionForward},
{exempt, "/", http.StatusOK, requestlog.ActionForward},
{client, "/static/app.js", http.StatusOK, requestlog.ActionForward},
{denied, "/", http.StatusForbidden, requestlog.ActionDenied},
} {
for range 3 {
s.request(sent.from, sent.path, sent.status, sent.action)
}
}
waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
got := make([]string, 0, len(waiting))
for _, alert := range waiting {
got = append(got, alert.Client.String())
}
if want := []string{allowed, exempt, client, denied}; !slices.Equal(got, want) {
t.Errorf("alerts for the clients %v, want %v", got, want)
}
}
func TestThresholdsOffCountNothingAndAlertNothing(t *testing.T) {
t.Parallel()
// With every threshold off, nothing is counted.
s, server, queue := startWithLookups(t, map[string]string{watchNets: office})
for range 5 {
s.uploadFrom(client)
}
if counters := server.Anomalies.Snapshot(); len(counters) != 0 {
t.Errorf("counters %+v, want none", counters)
}
wantAlerts(t, queue)
// With one set, its count alone is counted, in its scope alone.
s, clk, server, queue := startWithLookupsAndClock(t, map[string]string{
anomalyNet + requestsPerMinute: aLot, watchNets: office,
})
for range 5 {
s.uploadFrom(client)
}
want := []anomaly.Counter{{
Scope: anomaly.ScopeNet,
Netblock: netip.MustParsePrefix(clientsNet),
Minute: ratelimit.Buckets{Start: clk.Now(), Current: 5},
}}
if got := server.Anomalies.Snapshot(); !reflect.DeepEqual(got, want) {
t.Errorf("counters\n%+v\nwant\n%+v", got, want)
}
wantAlerts(t, queue)
}
func TestNetblockAroundAClientIsAsLongAsTheSettingsSay(t *testing.T) {
t.Parallel()
for _, tc := range []struct {
name string
env map[string]string
// Each client of sent sends one request, and want gives the
// netblocks they are counted in, each with its requests.
sent []string
want map[string]int64
}{
{
"by default", nil,
[]string{client, "203.0.113.200", "192.0.2.7", ipv6Client, "2001:db8:0:ffff::1"},
map[string]int64{clientsNet: 2, "192.0.2.0/24": 1, "2001:db8::/48": 2},
},
{
"as set", map[string]string{anomalyNetV4Prefix: "16", anomalyNetV6Prefix: "32"},
[]string{client, "203.0.200.1", ipv6Client, "2001:db8:ffff::1"},
map[string]int64{"203.0.0.0/16": 2, "2001:db8::/32": 2},
},
} {
t.Run(tc.name, func(t *testing.T) {
t.Parallel()
env := map[string]string{anomalyNet + requestsPerMinute: aLot}
maps.Copy(env, tc.env)
s, _, server, _ := startAppWithAlerts(t, readAndAnswer, env)
for _, from := range tc.sent {
s.get(from, http.StatusOK, requestlog.ActionForward)
}
got := map[string]int64{}
for _, counter := range server.Anomalies.Snapshot() {
got[counter.Netblock.String()] = counter.Minute.Current
}
if !maps.Equal(got, tc.want) {
t.Errorf("requests by netblock %v, want %v", got, tc.want)
}
})
}
}
func TestClientIsCountedForItsASNumberOnceTheLookupGivesOne(t *testing.T) {
t.Parallel()
s, server, _ := startWithLookups(t, map[string]string{
anomalyASN + requestsPerMinute: aLot,
})
// The lookup database does not hold unplaced.
for _, from := range []string{fromDE, fromDE, fromKP, noCountry, unplaced} {
s.uploadFrom(from)
}
got := map[string]int64{}
for _, counter := range server.Anomalies.Snapshot() {
got[counter.ASN] = counter.Minute.Current
}
if want := map[string]int64{asnDE: 2, asnKP: 1, "AS64500": 1}; !maps.Equal(got, want) {
t.Errorf("requests by AS number %v, want %v", got, want)
}
}
func TestRequestCountsForTheASNumberGeoJSGivesBeforeItEnds(t *testing.T) {
t.Parallel()
// The stand-in for GeoJS answers only once released, which the app
// does as it answers the request, and then waits until the answer is
// kept.
geojsURL, _, release := startHeldGeoJS(t)
var server atomic.Pointer[proxy.Server]
app := startApp(t, func(http.ResponseWriter, *http.Request) {
release()
waitUntil(func() bool {
_, kept := server.Load().GeoJS.Kept(netip.MustParsePrefix(fromDE + "/32"))
return kept
})
})
clk := &clock{now: time.Date(2026, 10, 6, 0, 0, 0, 0, time.UTC)}
addr, out, started := startProxyWithClock(t, app.URL, geojsURL, clk.Now,
map[string]string{
trustedProxies: trustLocalhost,
lookupTimeout: "1h",
anomalyASN + requestsPerMinute: aLot,
})
server.Store(started)
// The request went on without the answer, and is counted for the AS
// number it gives.
s := &sender{t: t, addr: addr, out: out}
if line := s.get(fromDE, http.StatusOK, requestlog.ActionForward); line.ASN != "" {
t.Errorf("log line has AS number %q, want none: the request waited", line.ASN)
}
want := []anomaly.Counter{{
Scope: anomaly.ScopeASN, ASN: asnDE,
Minute: ratelimit.Buckets{Start: clk.Now(), Current: 1},
}}
if got := started.Anomalies.Snapshot(); !reflect.DeepEqual(got, want) {
t.Errorf("counters\n%+v\nwant\n%+v", got, want)
}
}
func TestEachNamedNetblockCountsTheClientsInIt(t *testing.T) {
t.Parallel()
s, _, server, _ := startAppWithAlerts(t, readAndAnswer, map[string]string{
anomalyWatch + requestsPerMinute: aLot,
watchNets: office + ",wide=203.0.0.0/16,other=198.51.100.0/25",
})
// client is in office and in wide.
for _, from := range []string{client, "203.0.200.1", "192.0.2.7"} {
s.get(from, http.StatusOK, requestlog.ActionForward)
}
got := map[string]int64{}
for _, counter := range server.Anomalies.Snapshot() {
got[counter.Name] = counter.Minute.Current
}
if want := map[string]int64{"office": 1, "wide": 2}; !maps.Equal(got, want) {
t.Errorf("requests by named netblock %v, want %v", got, want)
}
}
internal/proxy/bans.go
+226 -31
View File
@@ -4,8 +4,11 @@ import (
"net/netip"
"time"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/bans"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
"sneak.berlin/go/smallwebwaf/internal/rules"
)
// banResponse is a refusal answered with SWWAF_BAN_RESPONSE, and logged
@@ -15,70 +18,262 @@ func (rq *request) banResponse(action string) *refusal {
}
// banned reports whether a ban on a netblock the client is in covers the
// request at now, and notes for the log line when that ban ends.
// request at now, and notes for the log line when that ban ends. A
// request that makes the ban permanent, or in observe mode would have,
// raises the alert for it.
func (rq *request) banned(now time.Time) bool {
check := rq.h.ledger.Check
if rq.h.config.Observe {
check = rq.h.ledger.Find // in observe mode the ban refuses nothing
check = rq.h.ledger.Find // the ban refuses nothing, and stays as it is
}
ban, banned := check(rq.client, now)
ban, banned, madePermanent := check(rq.client, now)
if banned {
rq.line.BanExpires = banExpires(ban)
}
if madePermanent {
ban.Expires = time.Time{} // the ban made permanent, which Find leaves as it is
rq.alertBan(ban)
}
return banned
}
// limitBroken counts the request for the rate limits at now, and reports
// whether it takes the client over one. In enforce mode such a request
// bans the client's netblock, and sets the client's counters back to
// zero; in observe mode it does neither.
// limitBroken counts the request for the rate limits at now, notes the
// client's counts for the log line, and reports whether the request takes
// the client over a rate limit, as its limit percentage lowers it, which
// breaks it.
func (rq *request) limitBroken(now time.Time) bool {
group := clientGroup(rq.client)
counts, hit, over := rq.h.limiter.Count(clientGroup(rq.client), now,
rq.limitPercent.percent)
rq.line.Counts = counts
hit, over := rq.h.limiter.Count(group, now)
if !over {
return false
if over {
rq.banForLimit(now, hit, rq.h.config.BanResponse)
}
return over
}
// countBytes counts the request's bytes, as countedBytes gives them, for
// the byte limits, once its response has ended, and notes the client's
// byte totals for the log line; its requests stay there as the rate limits
// counted them. Only a request passed to the app has them counted, and
// only one the rate limits counted; in observe mode, not one that enforce
// mode would have refused. Bytes that take the client over a byte limit,
// as its limit percentage for the byte limits lowers it, break it; the
// response was passed on whole.
func (rq *request) countBytes() {
if !rq.counted || rq.line.WouldAction != "" {
return
}
now := rq.h.now()
counts, hit, over := rq.h.limiter.CountBytes(clientGroup(rq.client), now,
rq.countedBytes(), rq.bytesPercent.percent)
rq.line.Counts.MinuteBytes = counts.MinuteBytes
rq.line.Counts.HourBytes = counts.HourBytes
rq.line.Counts.DayBytes = counts.DayBytes
if over {
rq.banForLimit(now, hit, rq.out.status)
}
}
// 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
// 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()
if rq.upgraded != nil {
response += rq.upgraded.fromApp.Load()
request += rq.upgraded.toApp.Load()
}
switch rq.h.config.BytesCount {
case "response":
return response
case "request":
return request
default: // both
return response + request
}
}
// banForLimit bans the client's netblock at now for a broken limit, the
// one hit names, and notes the offence for the log line. 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 one whose bytes broke a byte limit.
// The ban's notes give the client's limit percentage for that kind of
// limit. The ban sets the client's counters back to zero. In observe mode
// it makes no ban and sets nothing back, and raises the alert for the ban
// it would have made, if that alert would be sent.
func (rq *request) banForLimit(now time.Time, hit ratelimit.Hit, status int) {
rq.line.LimitHit = hit.Window
if hit.Kind == ratelimit.KindBytes {
rq.line.LimitHit += "_bytes" // as counts names the byte totals
}
rq.line.Offence = requestlog.OffenceLimit
if rq.h.config.Observe {
return true
netblock := rq.h.netblock(rq.client)
if rq.h.config.Observe && !rq.wouldAlertBan(netblock, now, bans.CauseLimit) {
return
}
netblock := rq.netblock()
ban := rq.h.ledger.BanForLimit(netblock, now, bans.Notes{
notes := bans.Notes{
ASN: rq.line.ASN,
ASName: rq.line.ASName,
Country: rq.line.Country,
Kind: hit.Kind,
Limit: hit.Limit,
Window: hit.Window,
Count: hit.Requests,
Request: bans.Request{
Count: hit.Count,
Request: rq.noted(now, status),
Requests: rq.netblockRequests(netblock),
}
percent := rq.limitPercent
if hit.Kind == ratelimit.KindBytes {
percent = rq.bytesPercent
}
notes.LimitPercent, notes.LimitPercentSetting = percent.logged()
if rq.h.config.Observe {
ban, wouldBan := rq.h.ledger.WouldBanForLimit(netblock, now, notes)
if wouldBan {
rq.alertBan(ban)
}
return
}
ban, made := rq.h.ledger.BanForLimit(netblock, now, notes)
rq.h.limiter.Reset(clientGroup(rq.client))
rq.line.BanExpires = banExpires(ban)
if made {
rq.alertBan(ban)
}
}
// banForAttack bans the client's netblock at now for a clear sign of
// attack, the match of rule, a ban rule. In observe mode it makes no ban,
// and raises the alert for the ban it would have made, if that alert
// would be sent.
func (rq *request) banForAttack(now time.Time, rule rules.Rule) {
netblock := rq.h.netblock(rq.client)
if rq.h.config.Observe && !rq.wouldAlertBan(netblock, now, bans.CauseAttack) {
return
}
notes := bans.Notes{
ASN: rq.line.ASN,
ASName: rq.line.ASName,
Country: rq.line.Country,
RuleID: rule.ID,
Target: rule.Target,
Request: rq.noted(now, rq.h.config.BanResponse),
Requests: rq.netblockRequests(netblock),
}
if rq.h.config.Observe {
ban, wouldBan := rq.h.ledger.WouldBanForAttack(netblock, now, notes)
if wouldBan {
rq.alertBan(ban)
}
return
}
ban, made := rq.h.ledger.BanForAttack(netblock, now, notes)
rq.line.BanExpires = banExpires(ban)
if made {
rq.alertBan(ban)
}
}
// 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
// netblock's requests, which can mean going through every client.
func (rq *request) wouldAlertBan(
netblock netip.Prefix, now time.Time, cause string,
) bool {
event := alerts.EventBan
if rq.h.ledger.WouldBePermanent(netblock, now, cause) {
event = alerts.EventPermanentBan
}
return rq.h.alerts.WouldSend(event, netblock)
}
// alertBan raises the alert for ban, which the request made, or made
// permanent: permanent_ban for a permanent ban, ban for another. Its
// detail gives the ban's cause, when it ends, and its notes, and in
// observe mode, where ban is the ban that would have been made, or made
// permanent, mode, observe.
func (rq *request) alertBan(ban bans.Ban) {
event := alerts.EventBan
if ban.Permanent() {
event = alerts.EventPermanentBan
}
detail := map[string]any{
"cause": ban.Cause, "ban_expires": banExpires(ban), "notes": ban.Notes,
}
if rq.h.config.Observe {
detail["mode"] = "observe"
}
rq.h.alerts.Raise(alerts.Alert{
Event: event,
Client: rq.client,
Netblock: ban.Netblock,
ASN: ban.Notes.ASN,
ASName: ban.Notes.ASName,
Country: ban.Notes.Country,
Reason: ban.Reason,
Detail: detail,
})
}
// noted is the request, at now, with status, what the client was sent, or
// in observe mode would have been, as the notes of the ban it makes keep
// it.
func (rq *request) noted(now time.Time, status int) bans.Request {
return bans.Request{
Time: now,
Method: rq.in.Method,
Host: rq.in.Host,
Path: rq.in.URL.RequestURI(),
Status: rq.h.config.BanResponse,
Status: status,
UserAgent: rq.in.UserAgent(),
},
// The histories count this request only once it has ended.
Requests: rq.h.limiter.Requests(netblock) + 1,
})
rq.h.limiter.Reset(group)
rq.line.BanExpires = banExpires(ban)
return true
}
}
// netblock is the netblock a ban on the client covers: its IPv4 address,
// netblockRequests is how many requests netblock has sent since it was
// first seen, this one included: the histories count it only once it has
// ended.
func (rq *request) netblockRequests(netblock netip.Prefix) int64 {
return rq.h.limiter.Requests(netblock) + 1
}
// netblock is the netblock a ban on client covers: its IPv4 address,
// widened to SWWAF_BAN_SCOPE_V4_PREFIX, or the IPv6 group clientGroup
// counts it in.
func (rq *request) netblock() netip.Prefix {
addr := rq.client.Unmap()
func (h *handler) netblock(client netip.Addr) netip.Prefix {
addr := client.Unmap()
if addr.Is4() {
return netip.PrefixFrom(addr, rq.h.config.BanScopeV4Prefix).Masked()
return netip.PrefixFrom(addr, h.config.BanScopeV4Prefix).Masked()
}
return clientGroup(addr)
@@ -88,7 +283,7 @@ func (rq *request) netblock() netip.Prefix {
// permanent.
func banExpires(ban bans.Ban) string {
if ban.Permanent() {
return "permanent"
return permanent
}
return requestlog.FormatTime(ban.Expires)
internal/proxy/bans_test.go
+28 -8
View File
@@ -278,8 +278,13 @@ func TestBanNotes(t *testing.T) {
Netblock: netblock,
Start: start,
Expires: start.Add(time.Hour),
Cause: bans.CauseLimit,
Reason: "requests per minute over the limit of 1",
Notes: bans.Notes{
ASN: asnDE,
ASName: asNameDE,
Country: "DE",
Kind: "requests",
Limit: 1,
Window: minute,
Count: 2,
@@ -295,7 +300,7 @@ func TestBanNotes(t *testing.T) {
// refused under the ban.
Requests: 4,
Refused: 2,
EarlierBans: 0,
EarlierBans: bans.EarlierBans{},
},
}
@@ -312,8 +317,8 @@ func TestBanNotes(t *testing.T) {
s.get(fromDE, http.StatusForbidden, requestlog.ActionRateLimited)
got = ledger.Bans(netblock)
if len(got) != 2 || got[1].Notes.EarlierBans != 1 {
t.Errorf("bans %+v, want two, the second with one earlier ban", got)
if len(got) != 2 || got[1].Notes.EarlierBans != (bans.EarlierBans{Limit: 1}) {
t.Errorf("bans %+v, want two, the second with one earlier ban for a limit", got)
}
}
@@ -360,8 +365,9 @@ func (c *clock) advance(d time.Duration) {
// startWithClock starts smallwebwaf in front of an app that answers 200,
// with the settings in env on top of trusting localhost's
// X-Forwarded-For, clients' countries looked up at geojsURL, and a clock
// set to midnight, the start of a bucket in every window.
// 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) {
@@ -415,14 +421,28 @@ func (s *sender) requestWithHeader(
) (logLine, string) {
s.t.Helper()
line, got := s.requestWithBody(http.MethodGet, from, path, header, "", status, action)
return line, string(got.body)
}
// requestWithBody is requestWithHeader for a request with method, whose
// body is sent as it is after the headers, header holding its
// Content-Length or Transfer-Encoding. header may hold several lines,
// separated by "\r\n". It returns the whole answer.
func (s *sender) requestWithBody(
method, from, path, header, body string, status int, action string,
) (logLine, answer) {
s.t.Helper()
if header != "" {
header += "\r\n"
}
conn := dial(s.t, s.addr)
send(s.t, conn, "GET "+path+" HTTP/1.1\r\nHost: "+appHost+
send(s.t, conn, method+" "+path+" HTTP/1.1\r\nHost: "+appHost+
"\r\nUser-Agent: "+userAgent+"\r\n"+forwardedFor+": "+from+"\r\n"+
header+"\r\n")
header+"\r\n"+body)
err := conn.SetReadDeadline(time.Now().Add(waitLimit))
if err != nil {
@@ -451,5 +471,5 @@ func (s *sender) requestWithHeader(
s.sent++
wantLine(s.t, line, status, action)
return line, string(got.body)
return line, got
}
internal/proxy/biased.go
+96
View File
@@ -0,0 +1,96 @@
package proxy
import (
"sneak.berlin/go/smallwebwaf/internal/config"
)
// whole is the percentage of each limit a client gets when no biased
// threshold lowers its limits.
const whole = 100
// percentage is a client's limit percentage for the rate limits or for
// the byte limits, as the biased thresholds give it, and the setting that
// gave it: "" with whole when none lowers that kind of limit.
type percentage struct {
percent int64
setting string
}
// biasedThresholdsSet reports whether a biased threshold can lower a
// client's limits: one of its lists is not empty, or
// SWWAF_UNKNOWN_LIMIT_PERCENT is below 100. 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 ||
len(cfg.ASNBytesPercent) > 0 || len(cfg.CountryBytesPercent) > 0 ||
cfg.UnknownLimitPercent < whole
}
// limitPercentages returns a client's limit percentages, for the rate
// limits and for the byte limits, by its AS number and country as looked
// up, each "" when unknown. 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
// SWWAF_COUNTRY_LIMIT_PERCENT gives its country, and, for a client
// without a country, SWWAF_UNKNOWN_LIMIT_PERCENT. For the byte limits,
// SWWAF_ASN_BYTES_PERCENT and SWWAF_COUNTRY_BYTES_PERCENT take the place
// of the first two for an AS number or a country they list.
func limitPercentages(
cfg *config.Config, asn, country string,
) (percentage, percentage) {
unknown := percentage{percent: whole}
if country == "" {
unknown = percentage{cfg.UnknownLimitPercent, "SWWAF_UNKNOWN_LIMIT_PERCENT"}
}
asnRequests := given(cfg.ASNLimitPercent, asn, "SWWAF_ASN_LIMIT_PERCENT")
countryRequests := given(cfg.CountryLimitPercent, country,
"SWWAF_COUNTRY_LIMIT_PERCENT")
asnBytes, countryBytes := asnRequests, countryRequests
if _, listed := cfg.ASNBytesPercent[asn]; listed {
asnBytes = given(cfg.ASNBytesPercent, asn, "SWWAF_ASN_BYTES_PERCENT")
}
if _, listed := cfg.CountryBytesPercent[country]; listed {
countryBytes = given(cfg.CountryBytesPercent, country, "SWWAF_COUNTRY_BYTES_PERCENT")
}
return lowest(asnRequests, countryRequests, unknown),
lowest(asnBytes, countryBytes, unknown)
}
// given returns the percentage percents, the setting named setting, gives
// code, an AS number or a country, or whole when it does not list code.
func given(percents map[string]int64, code, setting string) percentage {
percent, listed := percents[code]
if !listed {
return percentage{percent: whole}
}
return percentage{percent, setting}
}
// lowest returns the lowest of percentages below whole, the first of them
// when several are lowest, or whole when none is below it.
func lowest(percentages ...percentage) percentage {
low := percentage{percent: whole}
for _, p := range percentages {
if p.percent < low.percent {
low = p
}
}
return low
}
// logged returns p as the log line and the notes of a ban give it: its
// percent and setting, or nil and "" for whole, which they leave out.
func (p percentage) logged() (*int64, string) {
if p.percent == whole {
return nil, ""
}
return &p.percent, p.setting
}
internal/proxy/biased_test.go
+503
View File
@@ -0,0 +1,503 @@
package proxy_test
import (
"fmt"
"io"
"maps"
"net"
"net/http"
"net/http/httptest"
"net/netip"
"path/filepath"
"strings"
"testing"
"testing/synctest"
"time"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/bans"
"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"
countryLimitPercent = "SWWAF_COUNTRY_LIMIT_PERCENT"
asnBytesPercent = "SWWAF_ASN_BYTES_PERCENT"
countryBytesPercent = "SWWAF_COUNTRY_BYTES_PERCENT"
unknownLimitPercent = "SWWAF_UNKNOWN_LIMIT_PERCENT"
)
const (
// asnDEHalf and countryDEHalf give fromDE's AS number and its country
// half of every limit, and asnDEQuarter gives its AS number a quarter.
asnDEHalf = asnDE + ":50"
asnDEQuarter = asnDE + ":25"
countryDEHalf = "de:50"
// noCountry is in an AS of its own, AS64500, and in no country.
noCountry = "192.0.2.80"
// fourAMinute is the rate limit these tests set: half of it is 2
// requests a minute, a quarter of it 1.
fourAMinute = "4"
// twoUploads is the byte limit these tests set: 199 bytes, which an
// upload, a request with a body and its answer, 100 bytes, is within,
// and half of which, 99 bytes, it is over.
twoUploads = "199"
// none is how percentText gives a percentage left out.
none = "none"
)
func TestEachBiasedThresholdLowersTheRateLimits(t *testing.T) {
t.Parallel()
for _, tc := range []struct {
setting, value, from string
}{
{asnLimitPercent, asnDEHalf, fromDE},
{countryLimitPercent, countryDEHalf, fromDE},
{unknownLimitPercent, "50", unplaced},
} {
t.Run(tc.setting, func(t *testing.T) {
t.Parallel()
s, _, _ := startWithLookups(t, map[string]string{
rateLimitPerMinute: fourAMinute, tc.setting: tc.value,
})
// Half of 4 requests a minute: the third breaks the limit.
for _, sent := range []struct {
status int
action string
}{
{http.StatusOK, requestlog.ActionForward},
{http.StatusOK, requestlog.ActionForward},
{http.StatusForbidden, requestlog.ActionRateLimited},
} {
line := s.get(tc.from, sent.status, sent.action)
wantPercent(t, "limit_percent", line.LimitPercent, line.LimitPercentSetting,
"50 from "+tc.setting)
}
// fromKP, which no setting lists, has the whole limit.
for range 3 {
line := s.get(fromKP, http.StatusOK, requestlog.ActionForward)
wantPercent(t, "limit_percent", line.LimitPercent, line.LimitPercentSetting,
none)
}
})
}
}
func TestEachBiasedThresholdLowersTheByteLimits(t *testing.T) {
t.Parallel()
// The AS numbers and countries are given in either case.
for _, tc := range []struct {
setting, value, from string
}{
{asnLimitPercent, asnDEHalf, fromDE},
{countryLimitPercent, "DE:50", fromDE},
{unknownLimitPercent, "50", unplaced},
{asnBytesPercent, "as64496:50", fromDE},
{countryBytesPercent, countryDEHalf, fromDE},
} {
t.Run(tc.setting, func(t *testing.T) {
t.Parallel()
s, _, _ := startWithLookups(t, map[string]string{
bytesLimitPerMinute: twoUploads, tc.setting: tc.value,
})
// The upload's 100 bytes are over half of 199, 99.
line := s.uploadFrom(tc.from)
if line.LimitHit != minuteBytes {
t.Errorf("log line has limit_hit %q, want %s", line.LimitHit, minuteBytes)
}
wantPercent(t, "bytes_percent", line.BytesPercent, line.BytesPercentSetting,
"50 from "+tc.setting)
// fromKP, which no setting lists, has the whole limit.
line = s.uploadFrom(fromKP)
if line.LimitHit != "" {
t.Errorf("log line for %s has limit_hit %q, want none", fromKP, line.LimitHit)
}
wantPercent(t, "bytes_percent", line.BytesPercent, line.BytesPercentSetting, none)
})
}
}
func TestBytesPercentSettingsTakeThePlaceOfTheOthersForByteLimits(t *testing.T) {
t.Parallel()
for _, tc := range []struct {
name string
env map[string]string
// limitPercent and bytesPercent are the log line's, as percentText
// gives them, and limitHit is its limit_hit.
limitPercent, bytesPercent, limitHit string
}{
{
"lowering the byte limits alone",
map[string]string{asnBytesPercent: asnDEHalf},
none, "50 from " + asnBytesPercent, minuteBytes,
},
{
"lowering the byte limits alone, by country",
map[string]string{countryBytesPercent: countryDEHalf},
none, "50 from " + countryBytesPercent, minuteBytes,
},
{
"raising the byte limits back",
map[string]string{asnLimitPercent: asnDEHalf, asnBytesPercent: asnDE + ":100"},
"50 from " + asnLimitPercent, none, "",
},
{
"raising the byte limits back, by country",
map[string]string{countryLimitPercent: countryDEHalf, countryBytesPercent: "de:100"},
"50 from " + countryLimitPercent, none, "",
},
} {
t.Run(tc.name, func(t *testing.T) {
t.Parallel()
env := map[string]string{bytesLimitPerMinute: twoUploads}
maps.Copy(env, tc.env)
s, _, _ := startWithLookups(t, env)
// The upload's 100 bytes are over 99, half of 199, and within 199.
line := s.uploadFrom(fromDE)
if line.LimitHit != tc.limitHit {
t.Errorf("log line has limit_hit %q, want %q", line.LimitHit, tc.limitHit)
}
wantPercent(t, "limit_percent", line.LimitPercent, line.LimitPercentSetting,
tc.limitPercent)
wantPercent(t, "bytes_percent", line.BytesPercent, line.BytesPercentSetting,
tc.bytesPercent)
})
}
}
func TestZeroPercentIsAZeroAllowance(t *testing.T) {
t.Parallel()
s, _, _ := startWithLookups(t, map[string]string{asnLimitPercent: asnDE + ":0"})
// The first request breaks the limit, and bans the client; the log line
// gives the 0.
line := s.get(fromDE, http.StatusForbidden, requestlog.ActionRateLimited)
if line.fields["limit_percent"] != float64(0) ||
line.fields["limit_percent_setting"] != asnLimitPercent {
t.Errorf("log line has limit_percent %v from %v, want 0 from %s",
line.fields["limit_percent"], line.fields["limit_percent_setting"],
asnLimitPercent)
}
s.get(fromDE, http.StatusForbidden, requestlog.ActionBanned)
}
func TestLowestPercentageApplies(t *testing.T) {
t.Parallel()
for _, tc := range []struct {
name string
env map[string]string
from string
// want is the log line's limit_percent, as percentText gives it.
want string
}{
{
"the country's",
map[string]string{asnLimitPercent: asnDEHalf, countryLimitPercent: "de:25"},
fromDE, "25 from " + countryLimitPercent,
},
{
"the AS number's",
map[string]string{asnLimitPercent: asnDEQuarter, countryLimitPercent: countryDEHalf},
fromDE, "25 from " + asnLimitPercent,
},
{
"the AS number's, the first of two alike",
map[string]string{asnLimitPercent: asnDEQuarter, countryLimitPercent: "de:25"},
fromDE, "25 from " + asnLimitPercent,
},
{
"that for a client without a country",
map[string]string{asnLimitPercent: "AS64500:50", unknownLimitPercent: "25"},
noCountry, "25 from " + unknownLimitPercent,
},
{
// SWWAF_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,
},
} {
t.Run(tc.name, func(t *testing.T) {
t.Parallel()
env := map[string]string{rateLimitPerMinute: fourAMinute}
maps.Copy(env, tc.env)
s, _, _ := startWithLookups(t, env)
// A quarter of 4 requests a minute: the second breaks the limit.
s.get(tc.from, http.StatusOK, requestlog.ActionForward)
line := s.get(tc.from, http.StatusForbidden, requestlog.ActionRateLimited)
wantPercent(t, "limit_percent", line.LimitPercent, line.LimitPercentSetting,
tc.want)
})
}
}
func TestUnknownLimitPercentGivesEveryClientWithoutACountryItsPercentage(t *testing.T) {
t.Parallel()
s, _, _ := startWithLookups(t, map[string]string{
rateLimitPerMinute: fourAMinute, unknownLimitPercent: "50",
})
// One the lookup database does not hold, and one on a private address,
// which is never looked up: the third request of each breaks half of 4.
for _, from := range []string{unplaced, "10.0.0.8"} {
s.get(from, http.StatusOK, requestlog.ActionForward)
s.get(from, http.StatusOK, requestlog.ActionForward)
s.get(from, http.StatusForbidden, requestlog.ActionRateLimited)
}
// One in a country has the whole limit.
for range 3 {
s.get(fromDE, http.StatusOK, requestlog.ActionForward)
}
}
func TestClientWithoutAnAnswerInTimeHasTheUnknownLimitPercent(t *testing.T) {
t.Parallel()
// 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,
time.Now, map[string]string{unknownLimitPercent: "0"})
// Once the second 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.
serveFromDE(t, server, http.MethodGet, http.NoBody)
line := out.requestLine(t)
wantLine(t, line, http.StatusForbidden, requestlog.ActionRateLimited)
wantPercent(t, "limit_percent", line.LimitPercent, line.LimitPercentSetting,
"0 from "+unknownLimitPercent)
})
}
func TestRequestWaitsForItsLookupWhileABiasedThresholdIsSet(t *testing.T) {
t.Parallel()
const timeout = 3 * time.Second
for _, tc := range []struct {
setting, value string
waits bool
}{
{asnLimitPercent, asnDEHalf, true},
{countryLimitPercent, countryDEHalf, true},
{asnBytesPercent, asnDEHalf, true},
{countryBytesPercent, countryDEHalf, true},
{unknownLimitPercent, "99", true},
// At 100, its default, it lowers no limit.
{unknownLimitPercent, "100", false},
} {
t.Run(tc.setting+"="+tc.value, func(t *testing.T) {
t.Parallel()
// 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
// is refused after the checks, and never reaches the app.
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"))
want := time.Duration(0)
if tc.waits {
want = timeout
}
if waited := time.Since(began); waited != want {
t.Errorf("the request waited %s for its answer, want %s", waited, want)
}
wantLine(t, out.requestLine(t), http.StatusRequestEntityTooLarge,
requestlog.ActionTooLarge)
// The bubble's clock stops once this function returns, so the
// request to GeoJS, which a request that did not wait leaves
// under way, has to be abandoned before then.
time.Sleep(timeout)
})
})
}
}
func TestBanForALoweredLimitGivesThePercentageInItsNotesAndItsAlert(t *testing.T) {
t.Parallel()
for _, tc := range []struct {
name string
env map[string]string
// before is how many uploads come before the one that breaks a
// limit, which is answered with status and logged with action.
before int
status int
action string
// reason and want are the ban's reason, and its notes' limit
// percentage, as percentText gives it.
reason, want string
}{
{
// A quarter of 12 requests a minute is 3: the fourth breaks it.
"a rate limit",
map[string]string{rateLimitPerMinute: "12", asnLimitPercent: asnDEQuarter},
3, http.StatusForbidden, requestlog.ActionRateLimited,
"requests per minute over the limit of 3", "25 from " + asnLimitPercent,
},
{
// The byte limits' percentage, not the rate limits'.
"a byte limit",
map[string]string{
bytesLimitPerMinute: twoUploads, asnLimitPercent: asnDEQuarter,
asnBytesPercent: asnDEHalf,
},
0, http.StatusOK, requestlog.ActionForward,
"bytes per minute over the limit of 99", "50 from " + asnBytesPercent,
},
} {
t.Run(tc.name, func(t *testing.T) {
t.Parallel()
s, server, queue := startWithLookups(t, tc.env)
for range tc.before {
s.uploadFrom(fromDE)
}
s.requestWithBody(http.MethodPost, fromDE, "/", uploadHeader, uploadBody,
tc.status, tc.action)
held := server.Ledger.Bans(netip.MustParsePrefix(fromDE + "/32"))
if len(held) != 1 {
t.Fatalf("bans %+v, want one", held)
}
notes := held[0].Notes
if held[0].Reason != tc.reason {
t.Errorf("the ban's reason is %q, want %q", held[0].Reason, tc.reason)
}
wantPercent(t, "the notes' limit_percent", notes.LimitPercent,
notes.LimitPercentSetting, tc.want)
waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
if len(waiting) != 1 {
t.Fatalf("%d alerts wait, want the ban's alone: %+v", len(waiting), waiting)
}
alerted, _ := waiting[0].Detail["notes"].(bans.Notes)
wantPercent(t, "the alert's notes' limit_percent", alerted.LimitPercent,
alerted.LimitPercentSetting, tc.want)
})
}
}
// startWithLookups is startWithLookupsAndClock for a test that needs no
// clock.
func startWithLookups(
t *testing.T, env map[string]string,
) (*sender, *proxy.Server, *alerts.Queue) {
t.Helper()
s, _, server, queue := startWithLookupsAndClock(t, env)
return s, server, queue
}
// startWithLookupsAndClock is startAppWithAlerts in front of
// readAndAnswer, with the settings in env on top of clients looked up in a
// lookup database, which places fromDE and fromKP in the AS numbers and
// countries the stand-in for GeoJS gives them, noCountry in AS64500 and no
// country, and no other address.
func startWithLookupsAndClock(
t *testing.T, env map[string]string,
) (*sender, *clock, *proxy.Server, *alerts.Queue) {
t.Helper()
path := filepath.Join(t.TempDir(), "ipinfo_lite.mmdb")
lookuptest.Write(t, path, map[string]lookuptest.Network{
fromDE + "/32": {ASN: asnDE, ASName: asNameDE, Country: "DE"},
fromKP + "/32": {ASN: asnKP, ASName: asNameKP, Country: "KP"},
noCountry + "/32": {ASN: "AS64500", ASName: "Nowhere Net"},
})
settings := map[string]string{lookupSource: fileSource, lookupDBPath: path}
maps.Copy(settings, env)
return startAppWithAlerts(t, readAndAnswer, settings)
}
// uploadFrom is upload from the client at from.
func (s *sender) uploadFrom(from string) logLine {
s.t.Helper()
line, _ := s.requestWithBody(http.MethodPost, from, "/", uploadHeader, uploadBody,
http.StatusOK, requestlog.ActionForward)
return line
}
// serveFromDE hands a request from fromDE with method and body straight to
// server's handler, without the network, and returns once it is answered.
func serveFromDE(t *testing.T, server *proxy.Server, method string, body io.Reader) {
t.Helper()
req := httptest.NewRequestWithContext(t.Context(), method, "/", body)
req.RemoteAddr = net.JoinHostPort(fromDE, "1234")
server.Handler.ServeHTTP(httptest.NewRecorder(), req)
}
// wantPercent checks a limit percentage that a log line or a ban's notes
// give, what, and the setting that gave it, against want, as percentText
// gives them.
func wantPercent(t *testing.T, what string, percent *int64, setting, want string) {
t.Helper()
if got := percentText(percent, setting); got != want {
t.Errorf("%s is %s, want %s", what, got, want)
}
}
// 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
// left out.
func percentText(percent *int64, setting string) string {
switch {
case percent == nil && setting == "":
return none
case percent == nil:
return "none from " + setting
default:
return fmt.Sprintf("%d from %s", *percent, setting)
}
}
internal/proxy/bodies.go
+42
View File
@@ -103,6 +103,48 @@ func (b *responseBody) Close() error {
return b.body.Close()
}
// upgradedConn is the connection to the app once the app has switched
// protocols, as for a WebSocket. ReverseProxy writes to it what the client
// sends and reads from it what the app sends, on goroutines of its own,
// until the connection closes; it counts the bytes each way, for the byte
// limits.
type upgradedConn struct {
io.ReadWriteCloser
// fromApp is how many bytes the app has sent, and toApp how many the
// client has.
fromApp atomic.Int64
toApp atomic.Int64
}
// Read reads what the app sends.
func (c *upgradedConn) Read(p []byte) (int, error) {
n, err := c.ReadWriteCloser.Read(p)
c.fromApp.Add(int64(n))
return n, err
}
// Write sends the app what the client sent.
func (c *upgradedConn) Write(p []byte) (int, error) {
n, err := c.ReadWriteCloser.Write(p)
c.toApp.Add(int64(n))
return n, err
}
// CloseWrite tells the app that the client sends no more, while what the
// app sends still passes. ReverseProxy calls it once the client has
// stopped 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 {
return http.ErrNotSupported
}
return conn.CloseWrite()
}
// limitBody returns body, cut off with an *http.MaxBytesError after
// maxBytes, or unchanged if maxBytes is zero, which is off.
func limitBody(body io.ReadCloser, maxBytes int64) io.ReadCloser {
internal/proxy/bytelimits_test.go
+583
View File
@@ -0,0 +1,583 @@
package proxy_test
import (
"bufio"
"io"
"net"
"net/http"
"net/netip"
"strconv"
"strings"
"testing"
"time"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/bans"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
// The byte limit settings.
const (
bytesLimitPerMinute = "SWWAF_BYTES_LIMIT_PER_MINUTE"
bytesLimitPerHour = "SWWAF_BYTES_LIMIT_PER_HOUR"
bytesLimitPerDay = "SWWAF_BYTES_LIMIT_PER_DAY"
bytesCount = "SWWAF_BYTES_COUNT"
)
// The values of SWWAF_BYTES_COUNT.
const (
countResponse = "response"
countRequest = "request"
countBoth = "both"
)
const (
// bodyBytes is the size of the body of each request these tests send
// with one, and answerBytes that of each answer of the app.
bodyBytes = 30
answerBytes = 70
// 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 = "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
// still covers.
apart time.Duration
}{
{bytesLimitPerMinute, minute, 0},
{bytesLimitPerHour, "hour", 2 * time.Minute},
{bytesLimitPerDay, "day", 2 * time.Hour},
} {
t.Run(tc.setting, func(t *testing.T) {
t.Parallel()
s, clk := startWithAnswers(t, map[string]string{
tc.setting: byteLimit, metricsToken: token,
})
// 70 bytes are within the limit of 99.
line, _ := s.download()
if line.LimitHit != "" || line.Offence != "" {
t.Errorf("log line has limit_hit %q and offence %q, want neither",
line.LimitHit, line.Offence)
}
// 140 bytes are over it. The response is passed on whole, and
// then bans the client for an hour.
clk.advance(tc.apart)
expires := requestlog.FormatTime(clk.Now().Add(time.Hour))
line, got := s.download()
if got.err != nil || len(got.body) != answerBytes ||
line.ResponseBytes != answerBytes {
t.Errorf("got %d bytes (%v), and the log line has response_bytes %d, "+
"want %d", len(got.body), got.err, line.ResponseBytes, answerBytes)
}
if line.LimitHit != tc.window+"_bytes" || line.Offence != requestlog.OffenceLimit ||
line.BanExpires != expires {
t.Errorf("log line has limit_hit %q, offence %q and ban_expires %q, "+
"want %s_bytes, limit and %s", line.LimitHit, line.Offence,
line.BanExpires, tc.window, expires)
}
s.get(client, http.StatusForbidden, requestlog.ActionBanned)
wantMetric(t, s.scrape(scraper), `smallwebwaf_rate_limit_hits_total{`+
`instance="`+alertInstance+`",kind="bytes",window="`+tc.window+`"}`, 1)
})
}
}
func TestResponseOverAByteLimitByItselfIsPassedOnWhole(t *testing.T) {
t.Parallel()
s, _ := startWithAnswers(t, map[string]string{bytesLimitPerMinute: "50"})
// The answer's 70 bytes are over the limit of 50 on their own.
line, got := s.download()
if got.err != nil || len(got.body) != answerBytes || line.LimitHit != minuteBytes {
t.Errorf("got %d bytes (%v), and the log line has limit_hit %q, want %d and %s",
len(got.body), got.err, line.LimitHit, answerBytes, minuteBytes)
}
s.get(client, http.StatusForbidden, requestlog.ActionBanned)
}
func TestBytesOfAnAnswerThatBreaksOffAreCounted(t *testing.T) {
t.Parallel()
s, clk, _, _ := startAppWithAlerts(t, breakOff, map[string]string{
bytesLimitPerMinute: "50",
})
expires := requestlog.FormatTime(clk.Now().Add(time.Hour))
// 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)
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, "+
"want %d, %s and %s", len(got.body), line.LimitHit, line.BanExpires,
answerBytes, minuteBytes, expires)
}
s.get(client, http.StatusForbidden, requestlog.ActionBanned)
}
func TestWebSocketBytesAreCountedOnceItCloses(t *testing.T) {
t.Parallel()
for _, tc := range []struct {
setting string
counted float64
}{
{countResponse, answerBytes},
{countRequest, bodyBytes},
{countBoth, bodyBytes + answerBytes},
} {
t.Run(tc.setting, func(t *testing.T) {
t.Parallel()
s, _, _, _ := startAppWithAlerts(t, answerAfterUpgrade, map[string]string{
bytesLimitPerMinute: "29", bytesCount: tc.setting,
})
// The client sends 30 bytes and the app 70, each over the limit
// of 29, which bans the client once the WebSocket has closed.
line := s.webSocket()
if line.LimitHit != minuteBytes || line.Counts.MinuteBytes != tc.counted {
t.Errorf("log line has limit_hit %q and minute_bytes %v, want %s and %v",
line.LimitHit, line.Counts.MinuteBytes, minuteBytes, tc.counted)
}
s.get(client, http.StatusForbidden, requestlog.ActionBanned)
})
}
}
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()
for _, tc := range []struct {
setting string
// each is the bytes each request counts, and breaking the request
// that goes over the limit of 99.
each float64
breaking int
}{
{countResponse, answerBytes, 2},
{countRequest, bodyBytes, 4},
{countBoth, bodyBytes + answerBytes, 1},
} {
t.Run(tc.setting, func(t *testing.T) {
t.Parallel()
s, _ := startWithAnswers(t, map[string]string{
bytesLimitPerMinute: byteLimit, bytesCount: tc.setting,
})
for i := 1; i <= tc.breaking; i++ {
line := s.upload()
want := ""
if i == tc.breaking {
want = minuteBytes
}
counted := float64(i) * tc.each
if line.LimitHit != want || line.Counts.MinuteBytes != counted {
t.Errorf("request %d: log line has limit_hit %q and minute_bytes %v, "+
"want %q and %v", i, line.LimitHit, line.Counts.MinuteBytes,
want, counted)
}
}
s.get(client, http.StatusForbidden, requestlog.ActionBanned)
})
}
}
func TestByteLimitsLeaveOutWhatTheRateLimitsLeaveOut(t *testing.T) {
t.Parallel()
const (
allowed = "192.0.2.7" // in SWWAF_ALLOW_NETS
exempt = "192.0.2.10" // in SWWAF_RATE_LIMIT_EXEMPT_NETS
)
s, _ := startWithAnswers(t, map[string]string{
bytesLimitPerMinute: byteLimit,
allowNets: allowed,
rateLimitExemptNets: exempt,
rateLimitExemptPaths: "/assets/",
})
// Each sends 200 bytes, none of which is counted.
for _, sent := range []struct{ from, path string }{
{allowed, "/"}, {exempt, "/"}, {client, "/assets/app.js"},
} {
for range 2 {
line, _ := s.requestWithBody(http.MethodPost, sent.from, sent.path,
uploadHeader, uploadBody, http.StatusOK, requestlog.ActionForward)
if _, counted := line.fields["counts"]; counted || line.LimitHit != "" {
t.Errorf("%s %s: log line has counts %v and limit_hit %q, want neither",
sent.from, sent.path, line.fields["counts"], line.LimitHit)
}
}
}
// A path that is not exempt is counted, and breaks the limit.
line := s.upload()
if line.LimitHit != minuteBytes {
t.Errorf("log line has limit_hit %q, want %s", line.LimitHit, minuteBytes)
}
}
func TestByteLimitsOffCountTheBytesAndBanNoOne(t *testing.T) {
t.Parallel()
const off = "off"
s, _ := startWithAnswers(t, map[string]string{
bytesLimitPerMinute: off, bytesLimitPerHour: off, bytesLimitPerDay: off,
})
for i := 1; i <= 3; i++ {
line := s.upload()
counted := float64(i * (bodyBytes + answerBytes))
if line.LimitHit != "" || line.Counts.MinuteBytes != counted ||
line.Counts.HourBytes != counted || line.Counts.DayBytes != counted {
t.Errorf("request %d: log line has limit_hit %q and counts %+v, "+
"want none and %v bytes in each window", i, line.LimitHit,
line.Counts, counted)
}
}
}
func TestBanForABrokenByteLimitHasItsNotesAndItsAlert(t *testing.T) {
t.Parallel()
s, clk, server, queue := startAppWithAlerts(t, readAndAnswer, map[string]string{
bytesLimitPerMinute: byteLimit,
})
start := clk.Now()
s.requestWithBody(http.MethodPost, client, "/upload?part=1", uploadHeader,
uploadBody, http.StatusOK, requestlog.ActionForward)
netblock := netip.MustParsePrefix(client + "/32")
want := bans.Ban{
Netblock: netblock,
Start: start,
Expires: start.Add(time.Hour),
Cause: bans.CauseLimit,
Reason: "bytes per minute over the limit of " + byteLimit,
Notes: bans.Notes{
Kind: "bytes",
Limit: 99,
Window: minute,
Count: bodyBytes + answerBytes,
// The request as it was answered, by the app.
Request: bans.Request{
Time: start,
Method: http.MethodPost,
Host: appHost,
Path: "/upload?part=1",
Status: http.StatusOK,
UserAgent: userAgent,
},
Requests: 1,
},
}
got := server.Ledger.Bans(netblock)
if len(got) != 1 || got[0] != want {
t.Fatalf("bans\n%+v\nwant\n%+v", got, want)
}
wantAlerts(t, queue, banAlert(alerts.EventBan, start, client, want,
requestlog.FormatTime(want.Expires)))
if offences := historyOf(t, server, client).Offences.Limit; offences != 1 {
t.Errorf("history counts %d offences for a limit, want 1", offences)
}
}
func TestObserveModeLogsAndAlertsAByteLimitAndBansNoOne(t *testing.T) {
t.Parallel()
s, clk, server, queue := startAppWithAlerts(t, readAndAnswer, map[string]string{
mode: observe,
bytesLimitPerMinute: byteLimit,
})
start := clk.Now()
// No ban sets the client's counters back to zero, so each request
// breaks the limit again. The answer is the app's either way, and the
// alert for the ban is not sent twice within the cooldown.
for range 2 {
line := s.upload()
wantWouldAction(t, line, "")
if line.LimitHit != minuteBytes || line.Offence != requestlog.OffenceLimit ||
line.BanExpires != "" {
t.Errorf("log line has limit_hit %q, offence %q and ban_expires %q, "+
"want %s, limit and none", line.LimitHit, line.Offence, line.BanExpires,
minuteBytes)
}
}
if held := server.Ledger.Snapshot(); len(held) != 0 {
t.Errorf("the ledger holds %+v, want no ban", held)
}
waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
if len(waiting) != 1 {
t.Fatalf("%d alerts wait, want 1: %+v", len(waiting), waiting)
}
notes, _ := waiting[0].Detail["notes"].(bans.Notes)
alert := banAlert(alerts.EventBan, start, client, bans.Ban{
Netblock: netip.MustParsePrefix(client + "/32"), Cause: bans.CauseLimit,
Reason: "bytes per minute over the limit of " + byteLimit, Notes: notes,
}, requestlog.FormatTime(start.Add(time.Hour)))
alert.Detail["mode"] = observe
wantAlerts(t, queue, alert)
}
func TestObserveModeLeavesOutTheBytesOfARequestEnforceModeRefuses(t *testing.T) {
t.Parallel()
s, _ := startWithAnswers(t, map[string]string{
mode: observe,
rateLimitPerMinute: "1",
bytesLimitPerMinute: "150",
})
s.upload()
// The second request breaks the rate limit, which in enforce mode would
// refuse it before the app sent anything, so its 100 bytes are not
// counted, and the byte limit is not broken. Its line gives the bytes
// counted before it.
line := s.upload()
wantWouldAction(t, line, requestlog.ActionRateLimited)
if line.LimitHit != minute || line.Counts.MinuteBytes != bodyBytes+answerBytes {
t.Errorf("log line has limit_hit %q and minute_bytes %v, want minute and %d",
line.LimitHit, line.Counts.MinuteBytes, bodyBytes+answerBytes)
}
}
// uploadHeader and uploadBody are the header and the body of a request
// with a body of bodyBytes.
//
//nolint:gochecknoglobals // a constant cannot call strings.Repeat
var (
uploadHeader = "Content-Length: " + strconv.Itoa(bodyBytes)
uploadBody = strings.Repeat("u", bodyBytes)
)
// readAndAnswer is the app of these tests: it reads each request's whole
// body and answers with answerBytes bytes.
func readAndAnswer(w http.ResponseWriter, r *http.Request) {
_, _ = io.Copy(io.Discard, r.Body)
_, _ = io.WriteString(w, strings.Repeat("a", answerBytes))
}
// breakOff is an app that announces an answer of twice answerBytes, and
// breaks off after answerBytes.
func breakOff(w http.ResponseWriter, _ *http.Request) {
w.Header().Set("Content-Length", strconv.Itoa(2*answerBytes))
_, _ = io.WriteString(w, strings.Repeat("a", answerBytes))
}
// answerAfterUpgrade is an app that switches protocols, as for a
// WebSocket, and then answers each line it receives with a line of
// answerBytes.
func answerAfterUpgrade(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()
for {
_, err := buffered.ReadString('\n')
if err != nil {
return
}
_, _ = buffered.WriteString(strings.Repeat("a", answerBytes-1) + "\n")
_ = buffered.Flush()
}
}
// 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.
func (s *sender) webSocket() logLine {
s.t.Helper()
conn, reader := s.openWebSocket()
send(s.t, conn, strings.Repeat("u", bodyBytes-1)+"\n")
got, err := reader.ReadString('\n')
if err != nil || len(got) != answerBytes {
s.t.Errorf("got %d bytes (%v), want %d", len(got), err, answerBytes)
}
return s.closeWebSocket(conn)
}
// openWebSocket sends a request from client to switch protocols, as for a
// WebSocket, and checks that the app switches. It returns the connection,
// on which reading fails once waitLimit has passed, and a reader of what
// the app sends on it.
func (s *sender) openWebSocket() (net.Conn, *bufio.Reader) {
s.t.Helper()
conn := dial(s.t, s.addr)
send(s.t, conn, "GET /socket HTTP/1.1\r\nHost: "+appHost+"\r\n"+forwardedFor+
": "+client+"\r\nConnection: Upgrade\r\nUpgrade: websocket\r\n\r\n")
err := conn.SetReadDeadline(time.Now().Add(waitLimit))
if err != nil {
s.t.Fatalf("set read deadline: %v", err)
}
reader := bufio.NewReader(conn)
res, err := http.ReadResponse(reader, nil)
if err != nil {
s.t.Fatalf("read the answer to the upgrade: %v", err)
}
_ = res.Body.Close()
if res.StatusCode != http.StatusSwitchingProtocols {
s.t.Fatalf("status %d, want %d", res.StatusCode, http.StatusSwitchingProtocols)
}
return conn, reader
}
// closeWebSocket closes conn, a WebSocket openWebSocket opened, checks its
// log line as request does, and returns it.
func (s *sender) closeWebSocket(conn net.Conn) logLine {
s.t.Helper()
_ = conn.Close()
line := s.out.requestLines(s.t, s.sent+1)[s.sent]
s.sent++
wantLine(s.t, line, http.StatusSwitchingProtocols, requestlog.ActionForward)
return line
}
// startWithAnswers is startAppWithAlerts in front of readAndAnswer, for a
// test that looks at neither the server nor the alerts.
func startWithAnswers(t *testing.T, env map[string]string) (*sender, *clock) {
t.Helper()
s, clk, _, _ := startAppWithAlerts(t, readAndAnswer, env)
return s, clk
}
// download sends a GET request for / from client, and checks that the
// app's answer is passed on, as request does. It returns the log line and
// the answer.
func (s *sender) download() (logLine, answer) {
s.t.Helper()
return s.requestWithBody(http.MethodGet, client, "/", "", "", http.StatusOK,
requestlog.ActionForward)
}
// upload is download for a POST request with a body of bodyBytes, and
// returns the log line.
func (s *sender) upload() logLine {
s.t.Helper()
line, _ := s.requestWithBody(http.MethodPost, client, "/", uploadHeader,
uploadBody, http.StatusOK, requestlog.ActionForward)
return line
}
internal/proxy/client.go
+28
View File
@@ -1,6 +1,7 @@
package proxy
import (
"crypto/rand"
"net/http"
"net/netip"
"slices"
@@ -48,6 +49,33 @@ func clientAddress(
return client
}
// requestIDHeader carries the request's id, from traefik and to the app.
const requestIDHeader = "X-Request-ID"
// 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 == "" {
return "http"
}
return proto
}
// ipv6GroupPrefix is the length of the IPv6 netblock that is one client.
const ipv6GroupPrefix = 64
internal/proxy/client_test.go
+10 -6
View File
@@ -14,10 +14,14 @@ const (
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.
// 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"
// secure is the scheme a client reached traefik with.
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.
@@ -67,11 +71,11 @@ func clientAddressCases() []clientAddressCase {
forged := http.Header{
forwardedFor: {client},
"X-Forwarded-Host": {"forged.example"},
"X-Forwarded-Proto": {secure},
forwardedProto: {secure},
"X-Real-Ip": {client},
}
replaced := appHeaders{
ForwardedFor: localhost, ForwardedHost: appHost, ForwardedProto: "http",
ForwardedFor: localhost, ForwardedHost: appHost, ForwardedProto: plain,
}
return []clientAddressCase{{
@@ -89,7 +93,7 @@ func clientAddressCases() []clientAddressCase {
header: http.Header{
forwardedFor: {"198.51.100.7, " + client + ", 10.0.0.2"},
"X-Forwarded-Host": {appHost},
"X-Forwarded-Proto": {secure},
forwardedProto: {secure},
"X-Real-Ip": {client},
},
wantClient: client,
@@ -138,7 +142,7 @@ func requestWithHeaders(
Host: r.Host,
ForwardedFor: r.Header.Get(forwardedFor),
ForwardedHost: r.Header.Get("X-Forwarded-Host"),
ForwardedProto: r.Header.Get("X-Forwarded-Proto"),
ForwardedProto: r.Header.Get(forwardedProto),
RealIP: r.Header.Get("X-Real-IP"),
})
})
internal/proxy/countries.go
+6 -26
View File
@@ -1,31 +1,17 @@
package proxy
import (
"context"
"net/netip"
"slices"
)
// countryDenied reports whether the country lists refuse the request.
// The client's country is looked up only while a list is set, and never
// for a client on a private, loopback or link-local address, which has
// no country. A client without a country, or whose country cannot be
// found, is refused only by SWWAF_EXCLUSIVELY_ALLOWED_COUNTRIES. ctx is
// the request's own context.
func (rq *request) countryDenied(ctx context.Context) bool {
// 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.
func (rq *request) countryDenied() bool {
denied := rq.h.config.DeniedCountries
allowed := rq.h.config.ExclusivelyAllowedCountries
if len(denied) == 0 && len(allowed) == 0 {
return false
}
var country string
if hasCountry(rq.client) {
country = rq.h.geojs.Country(ctx, clientGroup(rq.client))
}
rq.line.Country = country
country := rq.line.Country
if slices.Contains(denied, country) {
return true
@@ -33,9 +19,3 @@ func (rq *request) countryDenied(ctx context.Context) bool {
return len(allowed) > 0 && !slices.Contains(allowed, country)
}
// hasCountry reports whether addr can be placed in a country: private,
// loopback and link-local addresses cannot.
func hasCountry(addr netip.Addr) bool {
return !addr.IsPrivate() && !addr.IsLoopback() && !addr.IsLinkLocalUnicast()
}
internal/proxy/countries_test.go
+94 -29
View File
@@ -56,16 +56,21 @@ func TestCountryLists(t *testing.T) {
maps.Copy(env, tc.env)
addr, out := startProxyWithGeoJS(t, app.URL, geojsURL, env)
for i, sent := range []struct{ client, country string }{
{fromDE, "DE"}, {fromKP, "KP"}, {unplaced, ""},
// The AS number GeoJS gives unplaced, 64512, counts as unknown.
for i, sent := range []struct{ client, asn, asName, country string }{
{fromDE, asnDE, asNameDE, "DE"}, {fromKP, asnKP, asNameKP, "KP"},
{unplaced, "", "", ""},
} {
req := newRequest(t, http.MethodGet, addr, "/", http.NoBody)
req.Header.Set(forwardedFor, sent.client)
got := do(t, req)
line := out.requestLines(t, i+1)[i]
if line.Country != sent.country {
t.Errorf("log line has country %q, want %q", line.Country, sent.country)
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",
line.ASN, line.ASName, line.Country,
sent.asn, sent.asName, sent.country)
}
if slices.Contains(tc.refused, sent.client) {
@@ -130,7 +135,7 @@ func TestRequestRefusedByCountryIsNotCounted(t *testing.T) {
return
}
answer := []map[string]string{{"ip": r.URL.Query().Get("ip"), "country": "DE"}}
answer := []geojsAnswer{{IP: r.URL.Query().Get("ip"), CountryCode: "DE"}}
err := json.NewEncoder(w).Encode(answer)
if err != nil {
@@ -174,20 +179,15 @@ func TestRequestRefusedByCountryIsNotCounted(t *testing.T) {
wantStatus(t, got, http.StatusOK)
}
func TestCountryNotLookedUpWithoutAListOrForAPrivateAddress(t *testing.T) {
func TestPrivateAddressIsNeverLookedUp(t *testing.T) {
t.Parallel()
for _, tc := range []struct {
name string
env map[string]string
clients []string // "" sends no X-Forwarded-For: the client is 127.0.0.1
}{
{"no country list is set", nil, []string{fromKP, fromDE}},
{
"private, loopback and link-local addresses",
map[string]string{deniedCountries: "kp"},
[]string{"10.0.0.5", "192.168.1.9", "fd00::5", "", "169.254.0.9", "fe80::9"},
},
{"no setting needs the lookup", nil},
{"a country list is set", map[string]string{deniedCountries: "kp"}},
} {
t.Run(tc.name, func(t *testing.T) {
t.Parallel()
@@ -198,7 +198,10 @@ func TestCountryNotLookedUpWithoutAListOrForAPrivateAddress(t *testing.T) {
maps.Copy(env, tc.env)
addr, out := startProxyWithGeoJS(t, app.URL, geojsURL, env)
for i, sent := range tc.clients {
// "" sends no X-Forwarded-For: the client is 127.0.0.1.
for i, sent := range []string{
"10.0.0.5", "192.168.1.9", "fd00::5", "", "169.254.0.9", "fe80::9",
} {
req := newRequest(t, http.MethodGet, addr, "/", http.NoBody)
if sent != "" {
req.Header.Set(forwardedFor, sent)
@@ -209,15 +212,26 @@ func TestCountryNotLookedUpWithoutAListOrForAPrivateAddress(t *testing.T) {
line := out.requestLines(t, i+1)[i]
wantLine(t, line, http.StatusOK, requestlog.ActionForward)
country, present := line.fields["country"]
if !present || country != "" {
t.Errorf("log line for %q has country %v, want an empty one",
line.ClientIP, country)
for _, field := range []string{"asn", "as_name", "country"} {
value, present := line.fields[field]
if !present || value != "" {
t.Errorf("log line for %q has %s %v, want an empty one",
line.ClientIP, field, value)
}
}
}
if len(asked()) != 0 {
t.Errorf("GeoJS was asked about %v, want nothing", asked())
// GeoJS is asked about up to 200 waiting clients at once, so once it
// has been asked about fromDE, which comes last, it has been asked
// about every client before it that waited for an answer.
req := newRequest(t, http.MethodGet, addr, "/", http.NoBody)
req.Header.Set(forwardedFor, fromDE)
wantStatus(t, do(t, req), http.StatusOK)
waitUntil(func() bool { return slices.Contains(asked(), fromDE) })
if got := asked(); !slices.Equal(got, []string{fromDE}) {
t.Errorf("GeoJS was asked about %v, want %s alone", got, fromDE)
}
})
}
@@ -264,18 +278,31 @@ func TestExclusiveListRefusesAPrivateAddressUnlessAllowed(t *testing.T) {
}
}
// startGeoJS starts a stand-in for GeoJS, which places fromDE and fromKP
// and no other address. It returns its URL, and what returns the
// addresses it has been asked about.
// 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.
func startGeoJS(t *testing.T) (string, func() []string) {
t.Helper()
places := map[string]string{fromDE: "DE", fromKP: "KP"}
geojsURL, asked, release := startHeldGeoJS(t)
release()
var asked struct {
return geojsURL, asked
}
// startHeldGeoJS is startGeoJS for a stand-in that answers nothing until
// release is called. Each request to it waits until then.
func startHeldGeoJS(t *testing.T) (string, func() []string, func()) {
t.Helper()
var (
asked struct {
mu sync.Mutex
addrs []string
}
released = make(chan struct{})
once sync.Once
)
geojs := httptest.NewServer(http.HandlerFunc(
func(w http.ResponseWriter, r *http.Request) {
@@ -285,11 +312,11 @@ func startGeoJS(t *testing.T) (string, func() []string) {
asked.addrs = append(asked.addrs, addrs...)
asked.mu.Unlock()
answers := make([]map[string]string, 0, len(addrs))
<-released
answers := make([]geojsAnswer, 0, len(addrs))
for _, addr := range addrs {
answers = append(answers, map[string]string{
"ip": addr, "country": places[addr],
})
answers = append(answers, answerAbout(addr))
}
err := json.NewEncoder(w).Encode(answers)
@@ -299,10 +326,48 @@ func startGeoJS(t *testing.T) (string, func() []string) {
}))
t.Cleanup(geojs.Close)
release := func() { once.Do(func() { close(released) }) }
// Run before geojs.Close, which waits for every request to be answered.
t.Cleanup(release)
return geojs.URL, func() []string {
asked.mu.Lock()
defer asked.mu.Unlock()
return slices.Clone(asked.addrs)
}, release
}
// The AS numbers and names the stand-in for GeoJS gives fromDE and
// fromKP, as they are logged.
const (
asnDE = "AS64496"
asNameDE = "Example Net"
asnKP = "AS64511"
asNameKP = "Other Net"
)
// geojsAnswer is an answer of GeoJS about one address, with the fields
// smallwebwaf reads.
//
//nolint:tagliatelle // GeoJS's own names
type geojsAnswer struct {
IP string `json:"ip"`
ASN int `json:"asn"`
ASName string `json:"organization_name"`
CountryCode string `json:"country_code,omitempty"`
}
// answerAbout is what the stand-in for GeoJS answers about addr: for an
// address it cannot place, the AS number 64512 and the AS name Unknown
// with no country, as GeoJS does.
func answerAbout(addr string) geojsAnswer {
switch addr {
case fromDE:
return geojsAnswer{IP: addr, ASN: 64496, ASName: asNameDE, CountryCode: "DE"}
case fromKP:
return geojsAnswer{IP: addr, ASN: 64511, ASName: asNameKP, CountryCode: "KP"}
}
return geojsAnswer{IP: addr, ASN: 64512, ASName: "Unknown"}
}
internal/proxy/health_test.go
+12 -3
View File
@@ -21,14 +21,18 @@ func TestHealthEndpointIsAnsweredBeforeAnyCheck(t *testing.T) {
// the last one would have it refused.
addr, out := startProxy(t, app.URL, map[string]string{rateLimitPerMinute: "1"})
const healthChecks = 3
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" {
t.Errorf("health endpoint answered %q, want ok", got.body)
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)
}
}
@@ -37,6 +41,11 @@ func TestHealthEndpointIsAnsweredBeforeAnyCheck(t *testing.T) {
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)
internal/proxy/history_test.go
+6 -2
View File
@@ -24,7 +24,9 @@ func TestHistoryKeepsEachRequestOfTheClient(t *testing.T) {
start := clk.Now()
// Two let through, one over the limit, which bans the client, and one
// refused under that ban, for which the country is not looked up.
// refused under that ban, for which the client is not looked up. GeoJS
// answers about the client at its first request, and its later ones
// use that answer.
s.get(fromDE, http.StatusOK, requestlog.ActionForward)
clk.advance(time.Second)
s.get(fromDE, http.StatusOK, requestlog.ActionForward)
@@ -35,8 +37,10 @@ func TestHistoryKeepsEachRequestOfTheClient(t *testing.T) {
want := ratelimit.History{
FirstSeen: start,
LastSeen: start.Add(2 * time.Second),
ASN: asnDE,
ASName: asNameDE,
Country: "DE",
LookedUp: start.Add(time.Second),
LookedUp: start,
Requests: 4,
Forwarded: 2,
Refused: 2,
internal/proxy/lookup.go
+71
View File
@@ -0,0 +1,71 @@
package proxy
import (
"context"
"net/http"
"net/netip"
"sneak.berlin/go/smallwebwaf/internal/lookup"
)
// The headers in which the app is passed the client's AS number and
// country while SWWAF_ADD_LOOKUP_HEADERS is set. 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 client's own whatever their
// case; header names are not case-sensitive.
const (
asnHeader = "X-Client-Asn"
countryHeader = "X-Client-Country"
)
// 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
// 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.
// ctx is the request's own context.
func (rq *request) lookUp(ctx context.Context) {
if rq.h.config.LookupSource == "off" || !canBePlaced(rq.client) {
return
}
if rq.h.config.LookupSource == "file" {
rq.lookupAnswer = rq.h.lookupFile.LookUp(clientGroup(rq.client))
} else {
rq.lookupAnswer = rq.h.geojs.LookUp(ctx, clientGroup(rq.client))
}
rq.lookedUp = true
rq.line.ASN = rq.lookupAnswer.ASN
rq.line.ASName = rq.lookupAnswer.ASName
rq.line.Country = rq.lookupAnswer.Country
}
// addLookup adds answer, an answer about a client from the lookup
// database or GeoJS, to the client's history, and to the notes of the bans
// on its netblock that have no AS number, AS name or country yet.
func (h *handler) addLookup(answer lookup.Answer) {
h.limiter.AddLookup(answer.Client, answer.Answered,
answer.ASN, answer.ASName, answer.Country)
h.ledger.AddLookup(h.netblock(answer.Client.Addr()),
answer.ASN, answer.ASName, answer.Country)
}
// setLookupHeaders sets the headers in which the app is passed the
// client's AS number and country, leaving out one that is unknown.
func setLookupHeaders(header http.Header, asn, country string) {
if asn != "" {
header.Set(asnHeader, asn)
}
if country != "" {
header.Set(countryHeader, country)
}
}
// canBePlaced reports whether a lookup can place addr: private, loopback
// and link-local addresses have no AS number or country.
func canBePlaced(addr netip.Addr) bool {
return !addr.IsPrivate() && !addr.IsLoopback() && !addr.IsLinkLocalUnicast()
}
internal/proxy/lookup_test.go
+377
View File
@@ -0,0 +1,377 @@
package proxy_test
import (
"net"
"net/http"
"net/http/httptest"
"net/netip"
"path/filepath"
"slices"
"sync"
"testing"
"testing/synctest"
"time"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/lookup"
"sneak.berlin/go/smallwebwaf/internal/lookup/lookuptest"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
// asnAndCountry is what a lookup gives a client: its AS number, AS name
// and country.
type asnAndCountry struct{ asn, asName, country string }
// fileSource is the SWWAF_LOOKUP_SOURCE that looks clients up in the
// lookup database.
const fileSource = "file"
func TestEveryClientIsLookedUpWithoutWaitingWhileNoSettingNeedsIt(t *testing.T) {
t.Parallel()
// The stand-in for GeoJS answers only once released. A request that
// waited for it would wait an hour, and get no answer within
// waitLimit.
geojsURL, asked, release := startHeldGeoJS(t)
s, _, server := startWithClock(t, geojsURL, map[string]string{
lookupTimeout: "1h",
rateLimitPerMinute: "1",
})
// fromDE's second request breaks the limit and bans it, and fromKP
// comes too. None waits for GeoJS.
for _, line := range []logLine{
s.get(fromDE, http.StatusOK, requestlog.ActionForward),
s.get(fromDE, http.StatusForbidden, requestlog.ActionRateLimited),
s.get(fromKP, http.StatusOK, requestlog.ActionForward),
} {
got := asnAndCountry{line.ASN, line.ASName, line.Country}
if got != (asnAndCountry{}) {
t.Errorf("log line has %+v before GeoJS answered, want nothing", got)
}
}
// Once GeoJS answers, each answer reaches the client's history, and
// fromDE's reaches the notes of its ban.
release()
netblock := netip.MustParsePrefix(fromDE + "/32")
waitUntil(func() bool {
return historyOf(t, server, fromDE).ASN != "" &&
historyOf(t, server, fromKP).ASN != "" &&
server.Ledger.Bans(netblock)[0].Notes.ASN != ""
})
de := asnAndCountry{asnDE, asNameDE, "DE"}
for addr, want := range map[string]asnAndCountry{
fromDE: de, fromKP: {asnKP, asNameKP, "KP"},
} {
h := historyOf(t, server, addr)
if got := (asnAndCountry{h.ASN, h.ASName, h.Country}); got != want {
t.Errorf("%s's history has %+v, want %+v", addr, got, want)
}
}
notes := server.Ledger.Bans(netblock)[0].Notes
if got := (asnAndCountry{notes.ASN, notes.ASName, notes.Country}); got != de {
t.Errorf("the ban's notes have %+v, want %+v", got, de)
}
// GeoJS was asked about each client once, fromKP after fromDE, whose
// request was under way when fromKP came.
if got := asked(); !slices.Equal(got, []string{fromDE, fromKP}) {
t.Errorf("GeoJS was asked about %v, want %s and %s", got, fromDE, fromKP)
}
}
func TestASNumberAndNameInTheLogLineTheHistoryTheBanNotesAndTheAlert(t *testing.T) {
t.Parallel()
geojsURL, _ := startGeoJS(t)
app := startApp(t, func(http.ResponseWriter, *http.Request) {})
clk := &clock{now: time.Date(2026, 10, 6, 0, 0, 0, 0, time.UTC)}
addr, out, server, queue := startProxyWithAlerts(t, app.URL, geojsURL, clk.Now,
map[string]string{
trustedProxies: trustLocalhost,
alertWebhookURL: "https://alerts.example/smallwebwaf",
rateLimitPerMinute: "1",
})
s := &sender{t: t, addr: addr, out: out}
// The answer is kept before the requests, so GeoJS is not asked, and
// gives no answer of its own.
netblock := netip.MustParsePrefix(fromDE + "/32")
server.GeoJS.Load([]lookup.Answer{{
Client: netblock, ASN: asnDE, ASName: asNameDE, Country: "DE",
Answered: clk.Now(), Used: clk.Now(),
}})
want := asnAndCountry{asnDE, asNameDE, "DE"}
for _, line := range []logLine{
s.get(fromDE, http.StatusOK, requestlog.ActionForward),
s.get(fromDE, http.StatusForbidden, requestlog.ActionRateLimited),
} {
if got := (asnAndCountry{line.ASN, line.ASName, line.Country}); got != want {
t.Errorf("log line has %+v, want %+v", got, want)
}
}
h := historyOf(t, server, fromDE)
if got := (asnAndCountry{h.ASN, h.ASName, h.Country}); got != want ||
!h.LookedUp.Equal(clk.Now()) {
t.Errorf("history has %+v, looked up at %s; want %+v, at %s",
got, h.LookedUp, want, clk.Now())
}
notes := server.Ledger.Bans(netblock)[0].Notes
if got := (asnAndCountry{notes.ASN, notes.ASName, notes.Country}); got != want {
t.Errorf("the ban's notes have %+v, want %+v", got, want)
}
waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
if len(waiting) != 1 {
t.Fatalf("alerts waiting %+v, want the ban's alone", waiting)
}
alert := waiting[0]
if got := (asnAndCountry{alert.ASN, alert.ASName, alert.Country}); got != want {
t.Errorf("the ban's alert has %+v, want %+v", got, want)
}
}
func TestLookupSourceOffLooksNoClientUp(t *testing.T) {
t.Parallel()
geojsURL, asked := startGeoJS(t)
s, clk, server := startWithClock(t, geojsURL, map[string]string{lookupSource: "off"})
// Even an answer kept from before is not used.
server.GeoJS.Load([]lookup.Answer{{
Client: netip.MustParsePrefix(fromDE + "/32"), ASN: asnDE, ASName: asNameDE,
Country: "DE", Answered: clk.Now(), Used: clk.Now(),
}})
for _, from := range []string{fromDE, fromKP} {
line := s.get(from, http.StatusOK, requestlog.ActionForward)
got := asnAndCountry{line.ASN, line.ASName, line.Country}
if got != (asnAndCountry{}) {
t.Errorf("log line has %+v, want nothing", got)
}
}
if h := historyOf(t, server, fromDE); h.ASN != "" || !h.LookedUp.IsZero() {
t.Errorf("history has %q, looked up at %s, want no lookup", h.ASN, h.LookedUp)
}
if len(asked()) != 0 {
t.Errorf("GeoJS was asked about %v, want nothing", asked())
}
}
func TestClientsAreLookedUpInTheLookupDatabaseAndGeoJSIsNotAsked(t *testing.T) {
t.Parallel()
geojsURL, asked := startGeoJS(t)
path := filepath.Join(t.TempDir(), "ipinfo_lite.mmdb")
lookuptest.Write(t, path, map[string]lookuptest.Network{
fromDE + "/32": {ASN: asnDE, ASName: asNameDE, Country: "DE"},
fromKP + "/32": {ASN: asnKP, ASName: asNameKP, Country: "KP"},
})
s, clk, server := startWithClock(t, geojsURL, map[string]string{
lookupSource: fileSource,
lookupDBPath: path,
allowedCountries: "DE",
rateLimitPerMinute: "1",
})
// fromDE's second request breaks the limit and bans it. The list
// refuses fromKP, and unplaced, which the file does not hold.
de := asnAndCountry{asnDE, asNameDE, "DE"}
for _, tc := range []struct {
line logLine
want asnAndCountry
}{
{s.get(fromDE, http.StatusOK, requestlog.ActionForward), de},
{s.get(fromDE, http.StatusForbidden, requestlog.ActionRateLimited), de},
{
s.get(fromKP, http.StatusForbidden, requestlog.ActionCountryDenied),
asnAndCountry{asnKP, asNameKP, "KP"},
},
{
s.get(unplaced, http.StatusForbidden, requestlog.ActionCountryDenied),
asnAndCountry{},
},
} {
got := asnAndCountry{tc.line.ASN, tc.line.ASName, tc.line.Country}
if got != tc.want {
t.Errorf("log line has %+v, want %+v", got, tc.want)
}
}
h := historyOf(t, server, fromDE)
if got := (asnAndCountry{h.ASN, h.ASName, h.Country}); got != de ||
!h.LookedUp.Equal(clk.Now()) {
t.Errorf("history has %+v, looked up at %s; want %+v, at %s",
got, h.LookedUp, de, clk.Now())
}
notes := server.Ledger.Bans(netip.MustParsePrefix(fromDE + "/32"))[0].Notes
if got := (asnAndCountry{notes.ASN, notes.ASName, notes.Country}); got != de {
t.Errorf("the ban's notes have %+v, want %+v", got, de)
}
if len(asked()) != 0 {
t.Errorf("GeoJS was asked about %v, want nothing", asked())
}
}
func TestLookupHeadersArePassedToTheAppAndTheClientsOwnRemoved(t *testing.T) {
t.Parallel()
var (
mu sync.Mutex
got [][2][]string // each request's X-Client-ASN and X-Client-Country
)
app := startApp(t, func(_ http.ResponseWriter, r *http.Request) {
mu.Lock()
defer mu.Unlock()
got = append(got, [2][]string{
r.Header.Values("X-Client-Asn"), r.Header.Values("X-Client-Country"),
})
})
geojsURL, _ := startGeoJS(t)
addr, out, _ := startProxyWithClock(t, app.URL, geojsURL, time.Now, map[string]string{
trustedProxies: trustLocalhost,
addLookupHeaders: "true",
})
s := &sender{t: t, addr: addr, out: out}
// Each client sends headers of its own. fromDE's first request waits
// for its answer, which the app is passed; unplaced has none to pass,
// and a client on a private address is not looked up.
for _, from := range []string{fromDE, unplaced, "10.0.0.8"} {
s.requestWithHeader(from, "/", clientsOwnLookupHeaders,
http.StatusOK, requestlog.ActionForward)
}
mu.Lock()
defer mu.Unlock()
want := [][2][]string{{{asnDE}, {"DE"}}, {nil, nil}, {nil, nil}}
if !slices.EqualFunc(got, want, func(a, b [2][]string) bool {
return slices.Equal(a[0], b[0]) && slices.Equal(a[1], b[1])
}) {
t.Errorf("the app was passed %v, want %v", got, want)
}
}
func TestClientsOwnLookupHeadersAreRemovedWhileTheSettingIsOff(t *testing.T) {
t.Parallel()
var (
mu sync.Mutex
asn, country []string
)
app := startApp(t, func(_ http.ResponseWriter, r *http.Request) {
mu.Lock()
defer mu.Unlock()
asn, country = r.Header.Values("X-Client-Asn"), r.Header.Values("X-Client-Country")
})
geojsURL, _ := startGeoJS(t)
addr, out, _ := startProxyWithClock(t, app.URL, geojsURL, time.Now, map[string]string{
trustedProxies: trustLocalhost,
})
s := &sender{t: t, addr: addr, out: out}
s.requestWithHeader(fromDE, "/", clientsOwnLookupHeaders,
http.StatusOK, requestlog.ActionForward)
mu.Lock()
defer mu.Unlock()
if asn != nil || country != nil {
t.Errorf("the app was passed X-Client-ASN %v and X-Client-Country %v, want neither",
asn, country)
}
}
func TestRequestWaitsAsLongAsTheLookupTimeoutSays(t *testing.T) {
t.Parallel()
// The test runs in a synctest bubble, where the time package runs on a
// 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.
synctest.Test(t, func(t *testing.T) {
// Not the default second. The exclusive list needs the answer, and
// the app is never reached.
const timeout = 3 * time.Second
server, out, _ := newProxy(t, "http://app.invalid", unansweredGeoJSURL,
time.Now, 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)
if waited := time.Since(began); waited != timeout {
t.Errorf("the request waited %s for its answer, want %s", waited, timeout)
}
// Without an answer, the client is in no country the list allows.
wantLine(t, out.requestLine(t), http.StatusForbidden,
requestlog.ActionCountryDenied)
})
}
// unansweredGeoJSURL is where a GeoJS that never answers is asked: a
// request to it waits, without the network, until it is abandoned.
// TestMain registers it with Go's default transport, through which GeoJS
// is asked.
const unansweredGeoJSURL = "unanswered://geojs/v1/ip/geo.json"
func TestMain(m *testing.M) {
transport, _ := http.DefaultTransport.(*http.Transport)
transport.RegisterProtocol("unanswered", unansweredGeoJS{})
m.Run()
}
// unansweredGeoJS is the GeoJS at unansweredGeoJSURL.
type unansweredGeoJS struct{}
// RoundTrip waits until req is abandoned.
func (unansweredGeoJS) RoundTrip(req *http.Request) (*http.Response, error) {
<-req.Context().Done()
return nil, req.Context().Err()
}
// clientsOwnLookupHeaders are the X-Client-ASN and X-Client-Country a
// client sends of its own, each twice, in two cases.
const clientsOwnLookupHeaders = "X-Client-ASN: AS1\r\nx-client-asn: AS2\r\n" +
"X-CLIENT-COUNTRY: KP\r\nx-client-country: CN"
// waitUntil waits until done reports true, for at most waitLimit.
func waitUntil(done func() bool) {
deadline := time.Now().Add(waitLimit)
for !done() && time.Now().Before(deadline) {
time.Sleep(pollInterval)
}
}
internal/proxy/metrics_test.go
+134 -44
View File
@@ -12,6 +12,7 @@ import (
"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"
@@ -147,8 +148,8 @@ func TestMetricsCountTheTraffic(t *testing.T) {
wantStatus(t, get(t, addr, "/_smallwebwaf/nothing"), http.StatusNotFound)
out.requestLines(t, 2)
forward := `{action="forward",status_class="2xx"}`
notFound := `{action="admin",status_class="4xx"}`
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)
@@ -158,11 +159,13 @@ func TestMetricsCountTheTraffic(t *testing.T) {
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", 2)
wantMetric(t, metrics, "smallwebwaf_upstream_duration_seconds_count", 1)
wantMetric(t, metrics, "smallwebwaf_requests_in_flight", 1)
metric(t, metrics, "go_goroutines")
metric(t, metrics, "process_start_time_seconds")
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)
@@ -179,7 +182,7 @@ func TestMetricsCountTheTraffic(t *testing.T) {
}()
<-arrived
wantMetric(t, scrape(t, addr), "smallwebwaf_requests_in_flight", 2)
wantMetric(t, scrape(t, addr), `smallwebwaf_requests_in_flight{instance="app"}`, 2)
releaseApp()
err := <-ended
@@ -188,7 +191,7 @@ func TestMetricsCountTheTraffic(t *testing.T) {
}
out.requestLines(t, 5)
wantMetric(t, scrape(t, addr), "smallwebwaf_requests_in_flight", 1)
wantMetric(t, scrape(t, addr), `smallwebwaf_requests_in_flight{instance="app"}`, 1)
}
func TestMetricsCountLimitsAndBans(t *testing.T) {
@@ -218,15 +221,16 @@ func TestMetricsCountLimitsAndBans(t *testing.T) {
metrics := s.scrape(scraper)
wantMetric(t, metrics,
`smallwebwaf_requests_total{action="denied",status_class="none"}`, 1)
wantMetric(t, metrics, `smallwebwaf_rate_limit_hits_total{window="minute"}`, 1)
wantMetric(t, metrics, `smallwebwaf_offences_total{kind="limit"}`, 1)
wantMetric(t, metrics, `smallwebwaf_bans_made_total{cause="limit"}`, 1)
wantMetric(t, metrics, "smallwebwaf_active_bans", 1)
wantMetric(t, metrics, "smallwebwaf_permanent_bans", 0)
`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", 0)
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.
@@ -234,13 +238,42 @@ func TestMetricsCountLimitsAndBans(t *testing.T) {
s.get(client, 0, requestlog.ActionRateLimited)
metrics = s.scrape(scraper)
wantMetric(t, metrics, `smallwebwaf_rate_limit_hits_total{window="minute"}`, 2)
wantMetric(t, metrics, `smallwebwaf_offences_total{kind="limit"}`, 2)
wantMetric(t, metrics, `smallwebwaf_bans_made_total{cause="limit"}`, 2)
wantMetric(t, metrics, "smallwebwaf_active_bans", 1)
wantMetric(t, metrics, "smallwebwaf_permanent_bans", 1)
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", 3)
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) {
@@ -258,7 +291,8 @@ func TestMetricsByCountryKeepTheBusiestAndCountTheRestAsOther(t *testing.T) {
metricsTopN: "2",
deniedCountries: "kp",
}
addr, out, server := startProxyWithClock(t, app.URL, "", time.Now, env)
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.
@@ -290,28 +324,82 @@ func TestMetricsByCountryKeepTheBusiestAndCountTheRestAsOther(t *testing.T) {
metrics := scrape(t, addr)
lines++
wantMetric(t, metrics, `smallwebwaf_country_requests_total{country="KP"}`, 3)
wantMetric(t, metrics, `smallwebwaf_country_requests_total{country="DE"}`, 2)
wantMetric(t, metrics, `smallwebwaf_country_requests_total{country="other"}`, 1)
wantMetric(t, metrics, `smallwebwaf_country_list_refusals_total{country="KP"}`, 3)
wantMetric(t, metrics, `smallwebwaf_country_request_bytes_total{country="KP"}`, 0)
wantMetric(t, metrics, `smallwebwaf_country_request_bytes_total{country="DE"}`, 6)
wantMetric(t, metrics, `smallwebwaf_country_response_bytes_total{country="KP"}`,
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"}`,
wantMetric(t, metrics,
`smallwebwaf_country_response_bytes_total{country="other",instance="app"}`,
float64(len("hello")))
wantNoSeries(t, metrics, `smallwebwaf_country_requests_total{country="FR"}`)
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"}`, 3)
wantMetric(t, metrics, `smallwebwaf_country_requests_total{country="FR"}`, 2)
wantMetric(t, metrics, `smallwebwaf_country_requests_total{country="other"}`, 2)
wantNoSeries(t, metrics, `smallwebwaf_country_requests_total{country="DE"}`)
wantNoSeries(t, metrics, `smallwebwaf_country_request_bytes_total{country="DE"}`)
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) {
@@ -341,16 +429,16 @@ func TestMetricsCountGeoJSRequestsAndFailures(t *testing.T) {
deadline := time.Now().Add(waitLimit)
metrics := scrape(t, addr)
for metric(t, metrics, "smallwebwaf_geojs_failures_total") == 0 &&
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", 1)
wantMetric(t, metrics, "smallwebwaf_geojs_failures_total", 1)
wantMetric(t, metrics, "smallwebwaf_geojs_unanswered_total", 1)
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
@@ -393,8 +481,9 @@ func (s *sender) scrape(from string) string {
// 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{kind="limit"}. It fails
// the test if there is no such series.
// 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()
@@ -442,7 +531,8 @@ func wantNoSeries(t *testing.T, metrics, series string) {
func wantLimitHits(t *testing.T, addr, limit string, hits int) {
t.Helper()
series := `smallwebwaf_size_and_time_limit_hits_total{limit="` + limit + `"}`
series := `smallwebwaf_size_and_time_limit_hits_total{instance="app",limit="` +
limit + `"}`
metrics := scrape(t, addr)
if hits == 0 {
internal/proxy/observe_test.go
+1
View File
@@ -95,6 +95,7 @@ func TestObserveModeMakesNoBanAndKeepsTheBansItHas(t *testing.T) {
Netblock: netip.MustParsePrefix(otherClient + "/32"),
Start: clk.Now(),
Expires: clk.Now().Add(time.Hour),
Cause: bans.CauseAdmin,
}
server.Ledger.Load([]bans.Ban{kept})
internal/proxy/passthrough_test.go
+33 -16
View File
@@ -6,6 +6,7 @@ import (
"errors"
"io"
"net/http"
"reflect"
"slices"
"strings"
"sync/atomic"
@@ -14,6 +15,7 @@ import (
"sneak.berlin/go/smallwebwaf/internal/config"
"sneak.berlin/go/smallwebwaf/internal/proxy"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
@@ -115,27 +117,37 @@ func wantAnswer(t *testing.T, got answer, body []byte) {
}
}
// wantRequestFields checks the log line's fields about the request.
// 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()
want := requestlog.Line{
Type: "request", Time: line.Time, ClientIP: localhost, PeerIP: localhost,
Method: http.MethodPatch, Host: host, Path: rawPath, Query: rawQuery,
Protocol: "HTTP/1.1", Status: http.StatusTeapot,
UpstreamStatus: http.StatusTeapot, RequestBytes: int64(sent),
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",
Action: requestlog.ActionForward, DurationTotal: line.DurationTotal,
DurationUpstreamTotal: line.DurationUpstreamTotal,
}
if line.Line != want {
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.DurationTotal <= 0 || line.DurationUpstreamTotal <= 0 {
t.Errorf("log line has time %q and durations %v and %v",
line.Time, line.DurationTotal, line.DurationUpstreamTotal)
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"])
}
}
@@ -308,7 +320,7 @@ func TestServerHasTheDefaultLimits(t *testing.T) {
server := proxy.New(proxy.Params{
Config: cfg,
RequestLog: io.Discard,
ProcessLog: requestlog.NewProcessLogger(io.Discard),
ProcessLog: requestlog.NewProcessLogger(io.Discard, cfg.InstanceName),
})
if server.Addr != ":8080" || server.MaxHeaderBytes != 28<<10 ||
@@ -371,8 +383,13 @@ func TestAnswers502WhenTheAppCannotBeReached(t *testing.T) {
addr, out := startProxy(t, "http://"+localhost+":1", nil)
wantStatus(t, get(t, addr, "/"), http.StatusBadGateway)
wantLine(t, out.requestLine(t), http.StatusBadGateway,
requestlog.ActionUpstreamError)
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"
internal/proxy/proxy.go
+75 -7
View File
@@ -11,12 +11,15 @@ import (
"strings"
"time"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"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/metrics"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
"sneak.berlin/go/smallwebwaf/internal/rules"
)
// How smallwebwaf keeps connections to the app open between requests.
@@ -37,6 +40,14 @@ const HealthPath = "/_smallwebwaf/healthz"
// SWWAF_METRICS_TOKEN.
const MetricsPath = "/_smallwebwaf/metrics"
// BansPath is where an admin lists and adds bans, and, followed by / and
// a client's address, lifts them, with SWWAF_ADMIN_TOKEN.
const BansPath = "/_smallwebwaf/bans"
// ClientsPath is where an admin asks what smallwebwaf knows of a client,
// by the client's address after it, with SWWAF_ADMIN_TOKEN.
const ClientsPath = "/_smallwebwaf/clients/"
// Params are what New needs.
type Params struct {
Config *config.Config
@@ -44,23 +55,36 @@ type Params struct {
RequestLog io.Writer
// ProcessLog receives the process's own messages.
ProcessLog *slog.Logger
// GeoJSURL is where clients' countries are looked up, normally
// lookup.URL. GeoJS is asked only while a country list is set.
// GeoJSURL is where clients' AS numbers and countries are looked up
// while SWWAF_LOOKUP_SOURCE is geojs, normally lookup.URL.
GeoJSURL string
// LookupFile is the lookup database they are looked up in while
// SWWAF_LOOKUP_SOURCE is file, and nil otherwise.
LookupFile *lookup.File
// 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.
Now func() time.Time
// 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
// permanent, for each count over an anomaly threshold, and for GeoJS
// failing.
Alerts *alerts.Queue
}
// Server is the server smallwebwaf runs, with the parts of the proxy
// whose state the state files keep, and the metrics.
// whose state the state files keep, the lookup database, nil unless
// SWWAF_LOOKUP_SOURCE is file, and the metrics.
type Server struct {
*http.Server
Ledger *bans.Ledger
Limiter *ratelimit.Limiter
GeoJS *lookup.GeoJS
Anomalies *anomaly.Counters
LookupFile *lookup.File
Metrics *metrics.Metrics
}
@@ -72,7 +96,7 @@ type Server struct {
// 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)
m := metrics.New(params.Config.MetricsTopN, params.Config.InstanceName)
h := &handler{
config: params.Config,
requestLog: params.RequestLog,
@@ -85,21 +109,48 @@ func New(params Params) *Server {
PerMinute: params.Config.RateLimitPerMinute,
PerHour: params.Config.RateLimitPerHour,
PerDay: params.Config.RateLimitPerDay,
BytesPerMinute: params.Config.BytesLimitPerMinute,
BytesPerHour: params.Config.BytesLimitPerHour,
BytesPerDay: params.Config.BytesLimitPerDay,
}),
ledger: bans.New(bans.Rules{
LimitBanDuration: params.Config.LimitBanDuration,
LimitBanRepeatWindow: params.Config.LimitBanRepeatWindow,
MaxBanDuration: params.Config.MaxBanDuration,
AttackBanDuration: params.Config.AttackBanDuration,
MaxBans: params.Config.MaxBans,
}),
geojs: lookup.New(lookup.Params{
anomalies: anomaly.New(anomaly.Params{
Client: params.Config.AnomalyClient,
Net: params.Config.AnomalyNet,
ASN: params.Config.AnomalyASN,
Total: params.Config.AnomalyTotal,
Watch: params.Config.AnomalyWatch,
NetV4Prefix: params.Config.AnomalyNetV4Prefix,
NetV6Prefix: params.Config.AnomalyNetV6Prefix,
NamedNetblocks: params.Config.WatchNets,
Alerts: params.Alerts,
}),
lookupFile: params.LookupFile,
rules: params.Rules,
alerts: params.Alerts,
}
h.geojs = lookup.New(lookup.Params{
URL: params.GeoJSURL,
Timeout: params.Config.LookupTimeout,
// The country lists, the headers and the biased thresholds act on
// the answer before the request goes on.
Wait: len(params.Config.DeniedCountries) > 0 ||
len(params.Config.ExclusivelyAllowedCountries) > 0 ||
params.Config.AddLookupHeaders || biasedThresholdsSet(params.Config),
Answered: h.addLookup,
Now: params.Now,
ProcessLog: params.ProcessLog,
Metrics: m,
}),
}
Alerts: params.Alerts,
})
m.AddBansAndClients(h.ledger, h.limiter, params.Now)
m.AddRules(params.Rules)
return &Server{
Server: &http.Server{
@@ -117,6 +168,8 @@ func New(params Params) *Server {
Ledger: h.ledger,
Limiter: h.limiter,
GeoJS: h.geojs,
Anomalies: h.anomalies,
LookupFile: h.lookupFile,
Metrics: m,
}
}
@@ -134,6 +187,10 @@ type handler struct {
limiter *ratelimit.Limiter
ledger *bans.Ledger
geojs *lookup.GeoJS
anomalies *anomaly.Counters
lookupFile *lookup.File
rules *rules.Files
alerts *alerts.Queue
}
// newTransport returns what carries requests to the app. It never goes
@@ -160,6 +217,9 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
// 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
@@ -167,8 +227,11 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
// Once the request has ended, before its log line is written.
defer rq.addToHistory()
defer rq.countAnomalies()
refused := rq.check(r.Context())
rq.checked = time.Now()
if refused != nil {
rq.answer(*refused)
@@ -183,5 +246,10 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
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/proxy/proxy_test.go
+119 -22
View File
@@ -14,9 +14,12 @@ import (
"testing"
"time"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/config"
"sneak.berlin/go/smallwebwaf/internal/lookup"
"sneak.berlin/go/smallwebwaf/internal/proxy"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
"sneak.berlin/go/smallwebwaf/internal/rules"
)
const (
@@ -35,6 +38,10 @@ const (
// localhost is where every test server listens, and so the address
// smallwebwaf 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 = "HTTP/1.1"
)
// shortTimeoutSetting is shortTimeout as a setting's value.
@@ -59,6 +66,11 @@ const (
denyNets = "SWWAF_DENY_NETS"
rateLimitPerMinute = "SWWAF_RATE_LIMIT_PER_MINUTE"
rateLimitPerDay = "SWWAF_RATE_LIMIT_PER_DAY"
rateLimitExemptPaths = "SWWAF_RATE_LIMIT_EXEMPT_PATHS"
lookupSource = "SWWAF_LOOKUP_SOURCE"
lookupDBPath = "SWWAF_LOOKUP_DB_PATH"
lookupTimeout = "SWWAF_LOOKUP_TIMEOUT"
addLookupHeaders = "SWWAF_ADD_LOOKUP_HEADERS"
deniedCountries = "SWWAF_DENIED_COUNTRIES"
allowedCountries = "SWWAF_EXCLUSIVELY_ALLOWED_COUNTRIES"
banResponse = "SWWAF_BAN_RESPONSE"
@@ -67,6 +79,10 @@ const (
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"
)
// output collects what smallwebwaf writes on stdout.
@@ -83,6 +99,14 @@ func (o *output) Write(p []byte) (int, error) {
return o.buf.Write(p)
}
// text returns everything written so far.
func (o *output) text() string {
o.mu.Lock()
defer o.mu.Unlock()
return o.buf.String()
}
// lines returns every line written so far, decoded.
func (o *output) lines(t *testing.T) []map[string]any {
t.Helper()
@@ -122,7 +146,7 @@ func (o *output) requestLines(t *testing.T, count int) []logLine {
var found []logLine
for _, fields := range o.lines(t) {
if fields["type"] == "request" {
if fields["type"] == requestType {
found = append(found, decodeLine(t, fields))
}
}
@@ -184,8 +208,8 @@ func startProxy(t *testing.T, appURL string, env map[string]string) (string, *ou
return startProxyWithGeoJS(t, appURL, "", env)
}
// startProxyWithGeoJS is startProxy with clients' countries looked up at
// geojsURL.
// startProxyWithGeoJS is startProxy with clients' AS numbers and
// countries looked up at geojsURL.
func startProxyWithGeoJS(
t *testing.T, appURL, geojsURL string, env map[string]string,
) (string, *output) {
@@ -197,33 +221,30 @@ func startProxyWithGeoJS(
}
// startProxyWithClock is startProxyWithGeoJS with requests counted and
// bans made by the time now tells, and returns the server as well.
// bans made by the time now tells, and returns the server as well. Unless
// env sets SWWAF_RULES_DIR, it is an empty directory, of no rules, and
// unless it sets SWWAF_INSTANCE_NAME, that is app, 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) {
t.Helper()
settings := map[string]string{"SWWAF_UPSTREAM_URL": appURL}
maps.Copy(settings, env)
addr, out, server, _ := startProxyWithAlerts(t, appURL, geojsURL, now, env)
cfg, err := config.FromEnvironment(func(name string) (string, bool) {
value, ok := settings[name]
return addr, out, server
}
return value, ok
})
if err != nil {
t.Fatalf("settings %v: %v", settings, err)
}
// startProxyWithAlerts is startProxyWithClock, and returns the queue of
// the alerts the proxy raises as well, as newProxy makes them.
func startProxyWithAlerts(
t *testing.T, appURL, geojsURL string, now func() time.Time,
env map[string]string,
) (string, *output, *proxy.Server, *alerts.Queue) {
t.Helper()
out := &output{}
server := proxy.New(proxy.Params{
Config: cfg,
RequestLog: out,
ProcessLog: requestlog.NewProcessLogger(out),
GeoJSURL: geojsURL,
Now: now,
})
server, out, alertQueue := newProxy(t, appURL, geojsURL, now, env)
listener, err := (&net.ListenConfig{}).Listen(t.Context(), "tcp", localhost+":0")
if err != nil {
@@ -238,7 +259,83 @@ func startProxyWithClock(
_ = server.Close()
})
return listener.Addr().String(), out, server
return listener.Addr().String(), out, server, alertQueue
}
// newProxy makes the server startProxyWithClock starts, without starting
// it, and returns it, what it writes, and the queue of the alerts the
// proxy raises, as the settings in env make it. No alert is sent from the
// queue: they wait in it, for the test to look at. With no geojsURL, there
// is no stand-in for GeoJS to look clients up at, and SWWAF_LOOKUP_SOURCE
// is off unless env sets it. While it is file, the lookup database
// SWWAF_LOOKUP_DB_PATH names is read.
func newProxy(
t *testing.T, appURL, geojsURL string, now func() time.Time,
env map[string]string,
) (*proxy.Server, *output, *alerts.Queue) {
t.Helper()
settings := map[string]string{
"SWWAF_UPSTREAM_URL": appURL, rulesDir: t.TempDir(), instanceName: "app",
}
if geojsURL == "" {
settings[lookupSource] = "off"
}
maps.Copy(settings, env)
cfg, err := config.FromEnvironment(func(name string) (string, bool) {
value, ok := settings[name]
return value, ok
})
if err != nil {
t.Fatalf("settings %v: %v", settings, err)
}
out := &output{}
processLog := requestlog.NewProcessLogger(out, cfg.InstanceName)
ruleFiles, err := rules.Load(rules.Params{
Dir: cfg.RulesDir, Enabled: cfg.RulesEnabled, ProcessLog: processLog,
})
if err != nil {
t.Fatalf("rule files: %v", err)
}
alertQueue := alerts.New(alerts.Params{
WebhookURL: cfg.AlertWebhookURL,
Events: cfg.AlertEvents,
Cooldown: cfg.AlertCooldown,
MaxPerHour: cfg.AlertMaxPerHour,
Instance: cfg.InstanceName,
Now: now,
ProcessLog: processLog,
})
var lookupFile *lookup.File
if cfg.LookupSource == fileSource {
lookupFile, err = lookup.OpenFile(lookup.FileParams{
Path: cfg.LookupDBPath, Now: now, ProcessLog: processLog, Alerts: alertQueue,
})
if err != nil {
t.Fatalf("lookup database: %v", err)
}
}
server := proxy.New(proxy.Params{
Config: cfg,
RequestLog: out,
ProcessLog: processLog,
GeoJSURL: geojsURL,
LookupFile: lookupFile,
Now: now,
Rules: ruleFiles,
Alerts: alertQueue,
})
return server, out, alertQueue
}
// newClient returns an HTTP client that sends requests as they are made,
internal/proxy/ratelimits_test.go
+89
View File
@@ -5,6 +5,8 @@ import (
"sync/atomic"
"testing"
"sneak.berlin/go/smallwebwaf/internal/lookup"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
@@ -69,3 +71,90 @@ func TestRateLimitRefusesBeforeTheApp(t *testing.T) {
t.Errorf("the app was called %d times, want 4", calls.Load())
}
}
func TestRateLimitExemptPathsAreNeitherCountedNorRefused(t *testing.T) {
t.Parallel()
const denied = "192.0.2.50" // in SWWAF_DENY_NETS
geojsURL, _ := startGeoJS(t)
s, _, server := startWithClock(t, geojsURL, map[string]string{
rateLimitPerMinute: "1",
rateLimitExemptPaths: "/assets/,/favicon.ico",
denyNets: denied,
deniedCountries: "kp",
})
// The answers are kept before the requests, so that none waits for
// GeoJS.
server.GeoJS.Load([]lookup.Answer{
keptAnswer(client, "DE"), keptAnswer(fromKP, "KP"),
})
// With a limit of one request a minute, the requests for paths under a
// prefix are not counted, so client's first request for / is within
// the limit; and once client has reached it, they are not refused.
s.request(client, "/assets/app.js", http.StatusOK, requestlog.ActionForward)
s.request(client, "/favicon.ico?v=2", http.StatusOK, requestlog.ActionForward)
s.get(client, http.StatusOK, requestlog.ActionForward)
line := s.request(client, "/assets/app.js", http.StatusOK, requestlog.ActionForward)
if line.LimitHit != "" || line.Counts != (ratelimit.Counts{}) {
t.Errorf("log line has limit_hit %q and counts %+v, want neither",
line.LimitHit, line.Counts)
}
// A path outside every prefix is counted: /assets is not under
// /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
// under a prefix.
s.request(client, "/assets/app.js", http.StatusForbidden, requestlog.ActionBanned)
s.request(denied, "/assets/app.js", http.StatusForbidden, requestlog.ActionDenied)
s.request(fromKP, "/assets/app.js",
http.StatusForbidden, requestlog.ActionCountryDenied)
}
func TestRateLimitCountsPathsThatAreNotExempt(t *testing.T) {
t.Parallel()
for _, sent := range []string{
// A prefix matches only at the start of the path.
"/static/assets/app.js",
// A prefix matches the path as sent: a router that matches the
// path as received does not take /%61ssets/x for a path under
// /assets/.
"/%61ssets/x",
// .. once percent-decoded: an app may act on these as /login, the
// last as a path under /sneak/app/ or as /assets/x.
"/assets/../login",
"/assets/%2e%2e/login",
"/assets/..%2Flogin",
"/assets/..;/login",
"/sneak/app/src/branch/main/..%2F..%2F..%2F..%2F..%2F..%2Fassets/x",
// Not under /assets/ as sent: Go's router takes /assets%2Fx for one
// path segment, not a path under /assets/.
"/assets%2Fx",
"/assets%2fx",
// Under /assets/ as sent, but holding an encoded slash, in either
// case, or a backslash: never exempt, whatever the prefix.
"/assets/x%2Fy",
"/assets/x%2fy",
`/assets/x\y`,
} {
t.Run(sent, func(t *testing.T) {
t.Parallel()
s, _, _ := startWithClock(t, "", map[string]string{
rateLimitPerMinute: "1",
rateLimitExemptPaths: "/assets/",
})
// Counted, the second request breaks the limit of one request
// a minute.
s.request(client, sent, http.StatusOK, requestlog.ActionForward)
s.request(client, sent, http.StatusForbidden, requestlog.ActionRateLimited)
})
}
}
internal/proxy/request.go
+270 -43
View File
@@ -3,15 +3,22 @@ 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/config"
"sneak.berlin/go/smallwebwaf/internal/lookup"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
@@ -45,8 +52,21 @@ type request struct {
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
start time.Time
// upstreamStart is when the request was handed to the app.
// 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
@@ -54,28 +74,39 @@ type request struct {
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 from its own; once
// timersStopped is set, none of them acts any more.
// 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
// requestSent is when the app had been sent the whole request.
// 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, and works out the client.
// 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
client := clientAddress(peer, r.Header.Values("X-Forwarded-For"), trusted)
peerTrusted := isInside(peer, trusted)
forwardedFor := r.Header.Values("X-Forwarded-For")
client := clientAddress(peer, forwardedFor, trusted)
rq := &request{
h: h,
@@ -84,22 +115,37 @@ func (h *handler) newRequest(w http.ResponseWriter, r *http.Request) *request {
out: &responseWriter{ResponseWriter: w},
client: client,
peer: peer,
peerTrusted: isInside(peer, trusted),
peerTrusted: peerTrusted,
start: start,
line: requestlog.Line{
Time: requestlog.FormatTime(start),
Instance: h.config.InstanceName,
ClientIP: client.String(),
PeerIP: peer.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: 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}
}
@@ -107,23 +153,47 @@ func (h *handler) newRequest(w http.ResponseWriter, r *http.Request) *request {
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 its body is read or anything reaches the app. It
// returns nil to let the request through. The checks of checkClient come
// first, answered with SWWAF_BAN_RESPONSE, 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. ctx is the request's own
// context.
// first, answered with SWWAF_BAN_RESPONSE, or 403 for a block rule, 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. ctx is
// the request's own context.
func (rq *request) check(ctx context.Context) *refusal {
action := rq.checkClient(ctx)
if action != "" {
if !rq.h.config.Observe {
return rq.banResponse(action)
}
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:
return &refusal{status: http.StatusForbidden, action: action}
default:
return rq.banResponse(action)
}
maxBytes := rq.h.config.RequestMaxBytes
@@ -140,13 +210,17 @@ func (rq *request) check(ctx context.Context) *refusal {
// 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. 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, and then the country lists; 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, so that every other request is counted.
// ctx is the request's own context.
// 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, and then the country lists; 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, and last the rule files. 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) {
@@ -163,15 +237,49 @@ func (rq *request) checkClient(ctx context.Context) string {
return requestlog.ActionBanned
}
if rq.countryDenied(ctx) {
rq.lookUp(ctx)
if rq.countryDenied() {
return requestlog.ActionCountryDenied
}
if !isInside(rq.client, cfg.RateLimitExemptNets) && rq.limitBroken(now) {
rq.counted = !isInside(rq.client, cfg.RateLimitExemptNets) &&
!pathExempt(rq.in.URL, cfg.RateLimitExemptPaths)
if rq.counted {
rq.limitPercent, rq.bytesPercent = limitPercentages(cfg, rq.line.ASN, rq.line.Country)
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
}
return ""
return rq.checkRules(now)
}
// pathExempt reports whether the rate limits leave out a request for u
// because of SWWAF_RATE_LIMIT_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
@@ -182,7 +290,9 @@ func (rq *request) forward(ctx context.Context) {
rq.cancel = cancel
ctx = httptrace.WithClientTrace(ctx, &httptrace.ClientTrace{
GotConn: rq.gotConn,
WroteRequest: rq.wroteRequest,
GotFirstResponseByte: rq.gotFirstResponseByte,
})
out := rq.in.WithContext(ctx)
@@ -205,7 +315,10 @@ func (rq *request) forward(ctx context.Context) {
}
// rewrite makes the request the app receives: the client's request,
// unchanged, sent to SWWAF_UPSTREAM_URL, with the forwarded headers set.
// 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
@@ -214,6 +327,13 @@ func (rq *request) rewrite(pr *httputil.ProxyRequest) {
// 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
@@ -224,9 +344,17 @@ 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
// timeouts. ReverseProxy writes this answer straight to the
// connection it takes over, not through rq.out.
// 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
}
@@ -303,10 +431,14 @@ func (rq *request) answer(r refusal) {
}
// refuse records r, unless an earlier refusal was, and ends the request
// to the app.
// 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
@@ -322,10 +454,11 @@ func (rq *request) finish() {
line := &rq.line
line.Status = rq.out.status
line.ResponseBytes = rq.out.bytes
if rq.body != nil {
line.RequestBytes = rq.body.bytes.Load()
}
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
@@ -346,12 +479,18 @@ func (rq *request) finish() {
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 = requestlog.Milliseconds(upstreamDuration)
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
@@ -364,25 +503,95 @@ func (rq *request) finish() {
}
}
// addToHistory adds the request, which has ended, to its client's
// history.
func (rq *request) addToHistory() {
var requestBytes int64
if rq.body != nil {
requestBytes = rq.body.bytes.Load()
// 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 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()
rq.h.limiter.AddToHistory(clientGroup(rq.client), rq.h.now(), ratelimit.Request{
Country: rq.line.Country,
Forwarded: forwarded,
Refused: !forwarded && rq.refused.Load() != nil,
Status: rq.out.status,
RequestBytes: requestBytes,
RequestBytes: rq.requestBytes(),
ResponseBytes: rq.out.bytes,
BrokeLimit: rq.line.Offence == requestlog.OffenceLimit,
})
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: 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(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
@@ -473,6 +682,24 @@ func (rq *request) bodyReceived() {
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) {
internal/proxy/requestlog_test.go
+371
View File
@@ -0,0 +1,371 @@
package proxy_test
import (
"io"
"maps"
"math"
"net/http"
"reflect"
"slices"
"strings"
"testing"
"time"
"sneak.berlin/go/smallwebwaf/internal/proxy"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
const (
// requestIDHeader carries the request's id.
requestIDHeader = "X-Request-ID"
// instance is the SWWAF_INSTANCE_NAME a test sets.
instance = "fsn1app1/gitea"
// ipv6Client is a client on IPv6, and ipv6Group the netblock the rate
// limits count it as.
ipv6Client = "2001:db8::7"
ipv6Group = "2001:db8::/64"
)
func TestLogLineHasEachFieldWhereItApplies(t *testing.T) {
t.Parallel()
received := make(chan string, 2) // the request ids the app received
app := startApp(t, func(w http.ResponseWriter, r *http.Request) {
received <- r.Header.Get(requestIDHeader)
_, _ = io.Copy(io.Discard, r.Body)
if r.URL.Path != "/full" {
w.WriteHeader(http.StatusNoContent)
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")
})
addr, out := startProxy(t, app.URL, map[string]string{
trustedProxies: trustLocalhost,
rateLimitExemptNets: localhost,
instanceName: instance,
logRequestHeaders: "Accept,x-custom,Authorization,cookie,SET-COOKIE",
})
// This request comes from ipv6Client through a trusted proxy, with a
// body and each header the log line looks at, and is answered with a
// redirect.
conn := dial(t, addr)
send(t, conn, "POST /full HTTP/1.1\r\nHost: "+appHost+"\r\n"+
forwardedFor+": 198.51.100.7, "+ipv6Client+"\r\n"+
forwardedProto+": "+secure+"\r\n"+requestIDHeader+": from-traefik\r\n"+
"Content-Type: application/x-www-form-urlencoded\r\nContent-Length: 3\r\n"+
"Accept: text/html\r\nX-Custom: one\r\nX-Custom: two\r\n"+
"Authorization: Bearer secret-token\r\nCookie: session=secret-cookie\r\n"+
"Set-Cookie: secret-set-cookie\r\n\r\na=b")
wantStatus(t, readResponse(t, conn), http.StatusFound)
// 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]
// 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
// request_bytes is not its content_length, and no header the log line
// looks at, and is answered with 204 and no header.
conn = dial(t, addr)
send(t, conn, "POST /bare HTTP/1.1\r\nHost: "+appHost+"\r\n"+
"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]
wantFullLine(t, full)
wantBareLine(t, bare)
for _, line := range []logLine{full, bare} {
got := <-received
if got != line.RequestID {
t.Errorf("the app received request id %q, the log line has %q",
got, line.RequestID)
}
}
if strings.Contains(out.text(), "secret") {
t.Errorf("a value of Authorization, Cookie or Set-Cookie is logged:\n%s",
out.text())
}
}
// wantFullLine checks the log line of the request with every header the
// line looks at. Its timings are checked by TestTimingsAreInOrder.
func wantFullLine(t *testing.T, line logLine) {
t.Helper()
headers := map[string]string{"accept": "text/html", "x-custom": "one, two"}
want := withTimings(line, requestlog.Line{
Type: requestType, 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,
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) {
t.Errorf("log line\n%+v\nwant\n%+v", line.Line, want)
}
}
// wantBareLine checks the log line of the request with none of them, and
// that the fields that do not apply to it are left out.
func wantBareLine(t *testing.T, line logLine) {
t.Helper()
want := withTimings(line, requestlog.Line{
Type: requestType, 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,
})
if !reflect.DeepEqual(line.Line, want) || line.RequestID == "" {
t.Errorf("log line\n%+v\nwant\n%+v, with a request id", line.Line, want)
}
for _, name := range []string{
"forwarded_for", "content_type", "content_length", "request_headers",
"has_authorization", "has_cookie", "websocket", "response_content_type",
"cache_control", "location", "counts",
} {
_, present := line.fields[name]
if present {
t.Errorf("log line has %s, which does not apply", name)
}
}
}
// withTimings returns want with the timings of line.
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
}
func TestHasAuthorizationAndHasCookieEachComeFromTheirOwnHeader(t *testing.T) {
t.Parallel()
const hasAuthorization, hasCookie = "has_authorization", "has_cookie"
for _, tc := range []struct{ header, field, other string }{
{"Authorization", hasAuthorization, hasCookie},
{"Cookie", hasCookie, hasAuthorization},
} {
t.Run("only "+tc.header, func(t *testing.T) {
t.Parallel()
app := startApp(t, func(http.ResponseWriter, *http.Request) {})
addr, out := startProxy(t, app.URL, nil)
req := newRequest(t, http.MethodGet, addr, "/", http.NoBody)
req.Header.Set(tc.header, "secret")
wantStatus(t, do(t, req), http.StatusOK)
line := out.requestLine(t)
_, otherPresent := line.fields[tc.other]
if line.fields[tc.field] != true || otherPresent {
t.Errorf("log line has %s %v and %s %v, want true and none",
tc.field, line.fields[tc.field], tc.other, line.fields[tc.other])
}
})
}
}
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
app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
// The pauses set the times apart; a hold-up of the test only
// lengthens them.
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{
trustedProxies: trustLocalhost,
denyNets: denied,
})
// 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]
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]
wantStatus(t, get(t, addr, proxy.HealthPath), http.StatusOK)
health := out.requestLines(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")
if t.Failed() {
return
}
// In whole microseconds, as they are logged, so that the sum below is
// 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
// connection comes before the answer, which the app ends after a
// pause.
if checks+upstream > total || connect >= firstByte || firstByte >= 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 {
t.Errorf("refused request's checks took %v of %v milliseconds",
*refused.DurationChecks, refused.DurationTotal)
}
}
// wantTimings checks that the timings named are the only ones line has.
func wantTimings(t *testing.T, line logLine, want ...string) {
t.Helper()
var got []string
for name := range line.fields {
if strings.HasPrefix(name, "duration_") {
got = append(got, name)
}
}
slices.Sort(got)
slices.Sort(want)
if !slices.Equal(got, want) {
t.Errorf("log line of %s has timings %v, want %v", line.Path, got, want)
}
}
// microseconds is a timing in whole microseconds.
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/proxy/rulefiles_test.go
+233
View File
@@ -0,0 +1,233 @@
package proxy_test
import (
"net/http"
"net/netip"
"os"
"path/filepath"
"slices"
"testing"
"time"
"sneak.berlin/go/smallwebwaf/internal/bans"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
// testRules are the rules most tests here load: a block rule for
// /blocked and a ban rule for /.env.
const testRules = `
blocked path block ^/blocked$
probe path ban ^/\.env$
`
func TestEachRuleAction(t *testing.T) {
t.Parallel()
s, clk, server := startWithClock(t, "", map[string]string{
rulesDir: writeRules(t, "noted path log ^/\n"+testRules),
banResponse: "429",
})
start := clk.Now()
// A log rule notes its match, and lets the request through.
line := s.get(client, http.StatusOK, requestlog.ActionForward)
wantRuleIDs(t, line, "noted")
// A block rule refuses with 403, whatever SWWAF_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
// seven days, the default.
line = s.request(client, "/.env", http.StatusTooManyRequests, requestlog.ActionBanned)
wantRuleIDs(t, line, "noted", "probe")
if line.BanExpires != requestlog.FormatTime(start.Add(7*24*time.Hour)) {
t.Errorf("log line has ban_expires %q, want seven days on", line.BanExpires)
}
netblock := netip.MustParsePrefix(client + "/32")
want := bans.Ban{
Netblock: netblock,
Start: start,
Expires: start.Add(7 * 24 * time.Hour),
Cause: bans.CauseAttack,
Reason: "matched the rule probe",
Notes: bans.Notes{
RuleID: "probe",
Target: "path",
Request: bans.Request{
Time: start,
Method: http.MethodGet,
Host: appHost,
Path: "/.env",
Status: http.StatusTooManyRequests,
UserAgent: userAgent,
},
// The four requests up to and including the probe.
Requests: 4,
},
}
got := server.Ledger.Bans(netblock)
if len(got) != 1 || got[0] != want {
t.Fatalf("bans\n%+v\nwant\n%+v", got, want)
}
// The next request is refused under the ban, without being checked
// against the rules, and makes the ban permanent.
clk.advance(time.Hour)
line = s.get(client, http.StatusTooManyRequests, requestlog.ActionBanned)
wantRuleIDs(t, line)
if line.BanExpires != permanent {
t.Errorf("log line has ban_expires %q, want permanent", line.BanExpires)
}
clk.advance(365 * 24 * time.Hour)
s.get(client, http.StatusTooManyRequests, requestlog.ActionBanned)
}
func TestNextClearSignOfAttackAfterABanBansPermanently(t *testing.T) {
t.Parallel()
s, clk, _ := startWithClock(t, "", map[string]string{
rulesDir: writeRules(t, testRules),
attackBanDuration: "1h",
})
// The first probe bans for SWWAF_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)
}
// Once that ban has run out without a request, the client is served,
// and its next probe bans it for good.
clk.advance(time.Hour)
s.get(client, http.StatusOK, requestlog.ActionForward)
line = s.request(client, "/.env", http.StatusForbidden, requestlog.ActionBanned)
if line.BanExpires != permanent {
t.Errorf("log line has ban_expires %q, want permanent", line.BanExpires)
}
}
func TestRulesComeAfterTheOtherChecks(t *testing.T) {
t.Parallel()
const (
allowed = "192.0.2.60" // in SWWAF_ALLOW_NETS
exempt = "192.0.2.50" // in SWWAF_RATE_LIMIT_EXEMPT_NETS
)
s, _, server := startWithClock(t, "", map[string]string{
rulesDir: writeRules(t, testRules),
allowNets: allowed,
rateLimitExemptNets: exempt,
rateLimitPerMinute: "1",
})
// A client in SWWAF_ALLOW_NETS is not checked.
line := s.request(allowed, "/.env", http.StatusOK, requestlog.ActionForward)
wantRuleIDs(t, line)
// A probe over the rate limit breaks the limit before any rule sees
// it.
s.get(client, http.StatusOK, requestlog.ActionForward)
line = s.request(client, "/.env", http.StatusForbidden, requestlog.ActionRateLimited)
wantRuleIDs(t, line)
limitBan := server.Ledger.Bans(netip.MustParsePrefix(client + "/32"))
if len(limitBan) != 1 || limitBan[0].Cause != bans.CauseLimit {
t.Errorf("bans %+v, want one for a broken limit", limitBan)
}
// A client the rate limits do not apply to is still checked.
s.get(exempt, http.StatusOK, requestlog.ActionForward)
s.request(exempt, "/.env", http.StatusForbidden, requestlog.ActionBanned)
}
func TestObserveModeLogsWhatTheRulesWouldDo(t *testing.T) {
t.Parallel()
s, _, server := startWithClock(t, "", map[string]string{
rulesDir: writeRules(t, testRules),
mode: observe,
})
line := s.request(client, "/blocked", http.StatusOK, requestlog.ActionForward)
wantWouldAction(t, line, requestlog.ActionRuleBlocked)
wantRuleIDs(t, line, "blocked")
line = s.request(client, "/.env", http.StatusOK, requestlog.ActionForward)
wantWouldAction(t, line, requestlog.ActionBanned)
wantRuleIDs(t, line, "probe")
if line.BanExpires != "" {
t.Errorf("log line has ban_expires %q, want none", line.BanExpires)
}
// No ban was made.
line = s.get(client, http.StatusOK, requestlog.ActionForward)
wantWouldAction(t, line, "")
if got := server.Ledger.Snapshot(); len(got) != 0 {
t.Errorf("bans %+v, want none", got)
}
}
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,
})
s.request(client, "/blocked", http.StatusForbidden, requestlog.ActionRuleBlocked)
s.request(client, "/.env", http.StatusForbidden, requestlog.ActionBanned)
s.get(client, http.StatusForbidden, requestlog.ActionBanned)
metrics := s.scrape(scraper)
wantMetric(t, metrics,
`smallwebwaf_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)
wantMetric(t, metrics, `smallwebwaf_rules_loaded{instance="app"}`, 2)
wantMetric(t, metrics, `smallwebwaf_requests_total{action="rule_blocked",`+
`instance="app",status_class="4xx"}`, 1)
wantMetric(t, metrics, `smallwebwaf_bans_made_total{cause="attack",instance="app"}`, 1)
wantMetric(t, metrics, `smallwebwaf_bans_made_total{cause="limit",instance="app"}`, 0)
wantMetric(t, metrics, `smallwebwaf_permanent_bans{instance="app"}`, 1)
}
// writeRules writes content as a rule file into a new directory, and
// returns the directory.
func writeRules(t *testing.T, content string) string {
t.Helper()
dir := t.TempDir()
err := os.WriteFile(filepath.Join(dir, "test.rules"), []byte(content), 0o600)
if err != nil {
t.Fatalf("write the rule file: %v", err)
}
return dir
}
// wantRuleIDs checks the request log line's rule_ids.
func wantRuleIDs(t *testing.T, line logLine, want ...string) {
t.Helper()
if !slices.Equal(line.RuleIDs, want) {
t.Errorf("log line has rule_ids %v, want %v", line.RuleIDs, want)
}
}
internal/proxy/rules.go
+39
View File
@@ -0,0 +1,39 @@
package proxy
import (
"time"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
"sneak.berlin/go/smallwebwaf/internal/rules"
)
// checkRules checks the request against the rules of the rule files at
// now, notes the ids of those it matches in the log line, and returns the
// action of the rule that refuses it, ActionRuleBlocked for a block rule
// and ActionBanned for a ban rule, or "" when none does. A ban rule bans
// the client's netblock for a clear sign of attack, or in observe mode
// raises the alert for the ban it would have made.
func (rq *request) checkRules(now time.Time) string {
matched := rq.h.rules.Match(rq.in)
for _, rule := range matched {
rq.line.RuleIDs = append(rq.line.RuleIDs, rule.ID)
rq.h.metrics.RuleMatched(rule.ID, rule.Action)
}
if len(matched) == 0 {
return ""
}
// Only the last rule matched can refuse the request.
switch last := matched[len(matched)-1]; last.Action {
case rules.ActionBlock:
return requestlog.ActionRuleBlocked
case rules.ActionBan:
rq.banForAttack(now, last)
return requestlog.ActionBanned
default:
return ""
}
}
internal/ratelimit/history_test.go
+39 -4
View File
@@ -16,10 +16,10 @@ func TestHistoryKeepsEveryRequest(t *testing.T) {
start := midnight()
for i, r := range []ratelimit.Request{
{Country: "DE", Forwarded: true, Status: 200, RequestBytes: 10, ResponseBytes: 100},
{Forwarded: true, Status: 200, RequestBytes: 10, ResponseBytes: 100},
{Forwarded: true, Status: 101},
{Forwarded: true, Status: 304, RequestBytes: 5},
{Country: "FR", Refused: true, Status: 403, ResponseBytes: 10, BrokeLimit: true},
{Refused: true, Status: 403, ResponseBytes: 10, BrokeLimit: true},
{Forwarded: true, Status: 502, ResponseBytes: 12},
// Closed without an answer: refused, and no response.
{Refused: true, Status: 0},
@@ -33,8 +33,6 @@ func TestHistoryKeepsEveryRequest(t *testing.T) {
want := ratelimit.History{
FirstSeen: start,
LastSeen: start.Add(6 * time.Minute),
Country: "FR",
LookedUp: start.Add(3 * time.Minute),
Requests: 7,
Forwarded: 4,
Refused: 2,
@@ -52,6 +50,43 @@ func TestHistoryKeepsEveryRequest(t *testing.T) {
}
}
func TestLookupReachesTheHistoryOfAClientInTheTable(t *testing.T) {
t.Parallel()
limiter := ratelimit.New(ratelimit.Limits{})
client := netip.MustParsePrefix("203.0.113.9/32")
other := netip.MustParsePrefix("198.51.100.7/32")
start := midnight()
limiter.AddToHistory(client, start, ratelimit.Request{Forwarded: true})
limiter.AddLookup(client, start, "AS64496", "Example Net", "DE")
// A later answer replaces it, and one for a client the table does not
// hold adds no client.
limiter.AddLookup(client, start.Add(time.Hour), "AS64497", "Other Net", "FR")
limiter.AddLookup(other, start, "AS64496", "Example Net", "DE")
want := ratelimit.History{
FirstSeen: start,
LastSeen: start,
ASN: "AS64497",
ASName: "Other Net",
Country: "FR",
LookedUp: start.Add(time.Hour),
Requests: 1,
Forwarded: 1,
}
got := historyOf(t, limiter, client)
if got != want {
t.Errorf("history\n%+v\nwant\n%+v", got, want)
}
if clients := limiter.Snapshot(); len(clients) != 1 {
t.Errorf("the table holds %+v, want %s alone", clients, client)
}
}
func TestResetKeepsTheHistory(t *testing.T) {
t.Parallel()
internal/ratelimit/ratelimit.go
+219 -72
View File
@@ -1,9 +1,9 @@
// Package ratelimit keeps the table of clients: each client's requests
// 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, and each client's history since it was first seen.
// At most 20,000 clients are kept, in memory, and written to clients.json
// and read from it by the state package.
// 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 20,000 clients are kept, in memory, and
// written to clients.json and read from it by the state package.
package ratelimit
import (
@@ -23,19 +23,30 @@ const maxClients = 20000
const day = 24 * time.Hour
// The kinds of limits, as the metrics name them.
const (
// KindRequests is a rate limit, on a client's requests.
KindRequests = "requests"
// KindBytes is a byte limit, on a client's bytes.
KindBytes = "bytes"
)
// Limits are the most requests a client may make in a minute, an hour and
// a day. Zero is no limit.
// a day, and the most bytes. Zero is no limit.
type Limits struct {
PerMinute int64
PerHour int64
PerDay int64
BytesPerMinute int64
BytesPerHour int64
BytesPerDay int64
}
// Limiter counts each client's requests against the limits, and keeps
// its history. It is safe for concurrent use.
// Limiter counts each client's requests and bytes against the limits, and
// keeps its history. It is safe for concurrent use.
type Limiter struct {
// windows are the minute, the hour and the day, in the order of
// Client.buckets.
// Client.buckets and Client.byteBuckets.
windows [3]window
mu sync.Mutex
@@ -43,17 +54,23 @@ type Limiter struct {
}
// Client is a client in the table, as clients.json holds it: its buckets
// in each window, and its history.
// of requests and of bytes in each window, and its history.
//
//nolint:tagliatelle // the state files use snake_case, as the request log does
type Client struct {
Client netip.Prefix `json:"client"`
Minute Buckets `json:"minute"`
Hour Buckets `json:"hour"`
Day Buckets `json:"day"`
MinuteBytes Buckets `json:"minute_bytes"`
HourBytes Buckets `json:"hour_bytes"`
DayBytes Buckets `json:"day_bytes"`
History History `json:"history"`
}
// Buckets are a client's two buckets in one window: the requests in the
// bucket under way, which began at Start, and in the bucket before it.
// Buckets are a client's two buckets in one window: the requests, or the
// bytes, in the bucket under way, which began at Start, and in the bucket
// before it.
type Buckets struct {
Start time.Time `json:"start"`
Current int64 `json:"current"`
@@ -66,8 +83,12 @@ type Buckets struct {
type History struct {
FirstSeen time.Time `json:"first_seen"`
LastSeen time.Time `json:"last_seen"`
// Country is the client's country as it was last looked up, and
// LookedUp when that was; both are empty while it never was.
// ASN, ASName and Country are the client's AS number, AS name and
// country as last looked up, each empty when the lookup could not
// find it, and LookedUp is when the lookup gave that answer; all are
// empty while the client never was looked up.
ASN string `json:"asn,omitempty"`
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
@@ -97,14 +118,12 @@ type Responses struct {
// Offences are a client's offences, by kind.
type Offences struct {
// Limit is its requests that broke a rate limit.
// Limit is its requests that broke a rate limit or a byte limit.
Limit int64 `json:"limit"`
}
// Request is what a client's history keeps of one of its requests.
type Request struct {
// Country is the client's country, when the request looked it up.
Country string
// Forwarded is true for a request passed to the app, Refused for one
// refused before anything reached it, a 401 at smallwebwaf's own
// endpoints included. Both are false for any other request smallwebwaf
@@ -117,7 +136,8 @@ type Request struct {
// and of its response.
RequestBytes int64
ResponseBytes int64
// BrokeLimit is true for a request that broke a rate limit.
// BrokeLimit is true for a request that broke a rate limit or a byte
// limit.
BrokeLimit bool
}
@@ -130,49 +150,74 @@ func New(limits Limits) *Limiter {
return &Limiter{
windows: [3]window{
{name: "minute", length: time.Minute, limit: limits.PerMinute},
{name: "hour", length: time.Hour, limit: limits.PerHour},
{name: "day", length: day, limit: limits.PerDay},
{
name: "minute", length: time.Minute,
limit: limits.PerMinute, byteLimit: limits.BytesPerMinute,
},
{
name: "hour", length: time.Hour,
limit: limits.PerHour, byteLimit: limits.BytesPerHour,
},
{
name: "day", length: day,
limit: limits.PerDay, byteLimit: limits.BytesPerDay,
},
},
clients: clients,
}
}
// Hit is a request that takes a client over a rate limit.
// Hit is a request that takes a client over a rate limit, or whose bytes
// take it over a byte limit.
type Hit struct {
// Kind is KindRequests for a rate limit, KindBytes for a byte limit.
Kind string
// Window is "minute", "hour" or "day".
Window string
// Limit is the window's limit.
// Limit is the window's limit, as the client's percentage of it.
Limit int64
// Requests is the client's requests counted in the window, this one
// included.
Requests float64
// Count is the client's requests, or bytes, counted in the window,
// this request's included.
Count float64
}
// 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
type Counts struct {
Minute float64 `json:"minute"`
Hour float64 `json:"hour"`
Day float64 `json:"day"`
MinuteBytes float64 `json:"minute_bytes"`
HourBytes float64 `json:"hour_bytes"`
DayBytes float64 `json:"day_bytes"`
}
// Count counts a request from client at now, in every window, whether or
// not it is refused. It reports whether the request takes the client over
// a limit, and the window whose limit it goes over, the shortest if it is
// over several.
func (l *Limiter) Count(client netip.Prefix, now time.Time) (Hit, bool) {
l.mu.Lock()
defer l.mu.Unlock()
var hit Hit
for i, b := range l.get(client).buckets() {
w := l.windows[i]
requests := b.add(now, w.length)
if hit.Window == "" && w.limit > 0 && requests > float64(w.limit) {
hit = Hit{Window: w.name, Limit: w.limit, Requests: requests}
}
}
return hit, hit.Window != ""
// not it is refused, and returns the client's counts in each window. It
// reports whether the request takes the client over a rate limit, of
// which the client gets the percentage percent, rounded down, and the hit:
// the window whose limit it goes over, the shortest if it is over
// several. A limit that is off stays off.
func (l *Limiter) Count(
client netip.Prefix, now time.Time, percent int64,
) (Counts, Hit, bool) {
return l.count(client, now, 1, 0, percent)
}
// Reset sets client's counts in every window back to zero. Its history
// keeps its totals.
// 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
// the client gets the percentage percent, and the hit, as Count does.
func (l *Limiter) CountBytes(
client netip.Prefix, now time.Time, bytes, percent int64,
) (Counts, Hit, bool) {
return l.count(client, now, 0, bytes, percent)
}
// Reset sets client's counts of requests and of bytes in every window
// back to zero. Its history keeps its totals.
func (l *Limiter) Reset(client netip.Prefix) {
l.mu.Lock()
defer l.mu.Unlock()
@@ -180,6 +225,7 @@ func (l *Limiter) Reset(client netip.Prefix) {
c, seen := l.clients.Peek(client)
if seen {
c.Minute, c.Hour, c.Day = Buckets{}, Buckets{}, Buckets{}
c.MinuteBytes, c.HourBytes, c.DayBytes = Buckets{}, Buckets{}, Buckets{}
}
}
@@ -196,11 +242,6 @@ func (l *Limiter) AddToHistory(client netip.Prefix, now time.Time, r Request) {
h.LastSeen = now
if r.Country != "" {
h.Country = r.Country
h.LookedUp = now
}
h.Requests++
if r.Forwarded {
h.Forwarded++
@@ -219,6 +260,25 @@ func (l *Limiter) AddToHistory(client netip.Prefix, now time.Time, r Request) {
}
}
// AddLookup gives client's history its AS number, AS name and country, as
// the lookup gave them at lookedUp, if the table of clients holds the
// client.
// It does not make the client the most recently seen.
func (l *Limiter) AddLookup(
client netip.Prefix, lookedUp time.Time, asn, asName, country string,
) {
l.mu.Lock()
defer l.mu.Unlock()
c, held := l.clients.Peek(client)
if !held {
return
}
h := &c.History
h.ASN, h.ASName, h.Country, h.LookedUp = asn, asName, country, lookedUp
}
// Requests returns how many requests the clients inside netblock have
// sent, as their histories count them.
func (l *Limiter) Requests(netblock netip.Prefix) int64 {
@@ -242,6 +302,20 @@ func (l *Limiter) Requests(netblock netip.Prefix) int64 {
return requests
}
// Client returns client as the table holds it, and whether it does. It is
// not a request from client, and leaves when it was last seen unchanged.
func (l *Limiter) Client(client netip.Prefix) (Client, bool) {
l.mu.Lock()
defer l.mu.Unlock()
c, seen := l.clients.Peek(client)
if !seen {
return Client{}, false
}
return *c, true
}
// Len returns how many clients are in the table.
func (l *Limiter) Len() int {
l.mu.Lock()
@@ -269,32 +343,79 @@ func (l *Limiter) Snapshot() []Client {
return clients
}
// Load puts clients read from clients.json into a table that holds none
// yet, in the order they were last seen, so that the least recently seen
// is dropped first. Buckets whose time has passed at now are emptied.
// Load puts clients read from clients.json into the table, in place of
// the clients it holds, in the order they were last seen, so that the
// least recently seen is dropped first. Buckets whose time has passed at
// now are emptied.
func (l *Limiter) Load(clients []Client, now time.Time) {
l.mu.Lock()
defer l.mu.Unlock()
clients = slices.Clone(clients)
slices.SortStableFunc(clients, func(a, b Client) int {
return a.History.LastSeen.Compare(b.History.LastSeen)
})
l.mu.Lock()
defer l.mu.Unlock()
l.clients.Purge()
for _, c := range clients {
for i, b := range c.buckets() {
// The window that ends at now covers neither bucket once it
// begins after the bucket under way has ended.
length := l.windows[i].length
if !now.Add(-length).Before(b.Start.Add(length)) {
for i, w := range l.windows {
for _, b := range []*Buckets{c.buckets()[i], c.byteBuckets()[i]} {
if b.Passed(now, w.length) {
*b = Buckets{}
}
}
}
l.clients.Add(c.Client, &c)
}
}
// count adds requests and bytes from client at now to its buckets in
// every window, and returns its counts. A limit is broken only by what is
// added to it, so that a request whose bytes are counted after another of
// the client's requests broke a rate limit does not break it too. The
// client gets the percentage percent of each limit.
func (l *Limiter) count(
client netip.Prefix, now time.Time, requests, bytes, percent int64,
) (Counts, Hit, bool) {
l.mu.Lock()
defer l.mu.Unlock()
c := l.get(client)
requestBuckets, byteBuckets := c.buckets(), c.byteBuckets()
var (
requestCounts, byteCounts [3]float64
hit Hit
)
for i, w := range l.windows {
requestCounts[i] = requestBuckets[i].Add(now, w.length, requests)
byteCounts[i] = byteBuckets[i].Add(now, w.length, bytes)
limit, byteLimit := percentOf(w.limit, percent), percentOf(w.byteLimit, percent)
switch {
case hit.Window != "":
case requests > 0 && w.limit > 0 && requestCounts[i] > float64(limit):
hit = Hit{
Kind: KindRequests, Window: w.name, Limit: limit, Count: requestCounts[i],
}
case bytes > 0 && w.byteLimit > 0 && byteCounts[i] > float64(byteLimit):
hit = Hit{
Kind: KindBytes, Window: w.name, Limit: byteLimit, Count: byteCounts[i],
}
}
}
counts := Counts{
Minute: requestCounts[0], Hour: requestCounts[1], Day: requestCounts[2],
MinuteBytes: byteCounts[0], HourBytes: byteCounts[1], DayBytes: byteCounts[2],
}
return counts, hit, hit.Window != ""
}
// get returns client's entry in the table, a new one if it has none, and
// makes it the most recently seen.
func (l *Limiter) get(client netip.Prefix) *Client {
@@ -307,30 +428,48 @@ func (l *Limiter) get(client netip.Prefix) *Client {
return c
}
// buckets returns c's buckets in the minute, the hour and the day.
// buckets returns c's buckets of requests in the minute, the hour and the
// day.
func (c *Client) buckets() [3]*Buckets {
return [3]*Buckets{&c.Minute, &c.Hour, &c.Day}
}
// window is a length of time over which requests are counted, and the
// most requests a client may make in it.
// byteBuckets returns c's buckets of bytes in the minute, the hour and the
// day.
func (c *Client) byteBuckets() [3]*Buckets {
return [3]*Buckets{&c.MinuteBytes, &c.HourBytes, &c.DayBytes}
}
// window is a length of time over which requests and bytes are counted,
// and the most requests and the most bytes a client may have in it.
type window struct {
name string
length time.Duration
limit int64
byteLimit int64
}
// add counts a request at now in a window of length, and returns the
// client's requests in the window that ends at now: those in the bucket
// under way, and those in the bucket before it weighted by how much of
// that bucket the window still covers.
// percentOf returns the percentage percent of limit, rounded down. It is
// written as limit's hundreds times percent, plus the rest's share, since
// limit*percent can overflow for a byte limit.
func percentOf(limit, percent int64) int64 {
const hundred = 100
return limit/hundred*percent + limit%hundred*percent/hundred
}
// Add counts n requests, or n bytes, at now in a window of length, and
// returns the count in the window that ends at now: what is in the bucket
// under way, and what is in the bucket before it weighted by how much of
// that bucket the window still covers. With n zero it counts nothing, and
// returns the count. The anomaly counters count in Buckets too.
//
// Concurrent requests can be counted out of order, so now can be a moment
// before the bucket under way began; such a request is counted in that
// bucket. A request dated more than a second before it means the clock
// was set back, and the buckets start afresh: otherwise the bucket before
// would keep its full weight until the clock caught up.
func (b *Buckets) add(now time.Time, length time.Duration) float64 {
func (b *Buckets) Add(now time.Time, length time.Duration, n int64) float64 {
if now.Before(b.Start.Add(-time.Second)) {
*b = Buckets{}
}
@@ -347,7 +486,7 @@ func (b *Buckets) add(now time.Time, length time.Duration) float64 {
b.Current = 0
}
b.Current++
b.Current += n
elapsed := max(now.Sub(b.Start), 0)
covered := 1 - float64(elapsed)/float64(length)
@@ -355,6 +494,14 @@ func (b *Buckets) add(now time.Time, length time.Duration) float64 {
return float64(b.Previous)*covered + float64(b.Current)
}
// Passed reports whether the window of length that ends at now covers
// neither of b's buckets: it begins after the bucket under way has ended.
// What they hold then counts no more, and a state file read at now drops
// it.
func (b *Buckets) Passed(now time.Time, length time.Duration) bool {
return !now.Add(-length).Before(b.Start.Add(length))
}
// add counts a response with status in its class. A status of 0, for
// nothing sent, is not a response.
func (r *Responses) add(status int) {
internal/ratelimit/ratelimit_test.go
+205 -4
View File
@@ -1,6 +1,7 @@
package ratelimit_test
import (
"math"
"net/netip"
"testing"
"time"
@@ -11,6 +12,10 @@ import (
// limit is the limit the tests set.
const limit = 3
// whole is the percentage of each limit a client gets when nothing lowers
// its limits.
const whole = 100
// The windows, as Count names them.
const (
minute = "minute"
@@ -62,22 +67,203 @@ func TestHitGivesTheLimitAndTheRequestsCounted(t *testing.T) {
start := midnight()
for range limit {
_, over := limiter.Count(client, start)
_, _, over := limiter.Count(client, start, whole)
if over {
t.Fatal("a request within the limit is over it")
}
}
// Over both limits; the minute's is named, with the four requests.
hit, over := limiter.Count(client, start)
_, hit, over := limiter.Count(client, start, whole)
want := ratelimit.Hit{Window: minute, Limit: limit, Requests: limit + 1}
want := ratelimit.Hit{
Kind: ratelimit.KindRequests, Window: minute, Limit: limit, Count: limit + 1,
}
if !over || hit != want {
t.Errorf("request over the limit gives %+v and %t, want %+v and true",
hit, over, want)
}
}
func TestClientGetsItsPercentageOfEachLimitRoundedDown(t *testing.T) {
t.Parallel()
limiter := ratelimit.New(ratelimit.Limits{PerMinute: 5, BytesPerDay: math.MaxInt64})
client := netip.MustParsePrefix("203.0.113.9/32")
start := midnight()
// Half of 5 requests is 2.5, rounded down to 2: the third is over.
for range 2 {
_, _, over := limiter.Count(client, start, 50)
if over {
t.Fatal("a request within half the limit is over it")
}
}
_, hit, over := limiter.Count(client, start, 50)
want := ratelimit.Hit{Kind: ratelimit.KindRequests, Window: minute, Limit: 2, Count: 3}
if !over || hit != want {
t.Errorf("the third request gives %+v and %t, want %+v and true", hit, over, want)
}
// Half of the largest byte limit is still far above a TiB: working it
// out does not overflow.
_, hit, over = limiter.CountBytes(client, start, 1<<40, 50)
if over {
t.Errorf("a TiB is over half the largest byte limit: %+v", hit)
}
}
func TestZeroPercentIsAZeroAllowanceAndALimitOffStaysOff(t *testing.T) {
t.Parallel()
// Only the hour has limits: the minute's and the day's are off.
limiter := ratelimit.New(ratelimit.Limits{PerHour: limit, BytesPerHour: 1000})
client := netip.MustParsePrefix("203.0.113.9/32")
start := midnight()
// At 0 percent, the first request and the first byte are over the
// hour's limits, which are 0; the minute's, which are off, stay off.
_, hit, _ := limiter.Count(client, start, 0)
want := ratelimit.Hit{Kind: ratelimit.KindRequests, Window: hour, Limit: 0, Count: 1}
if hit != want {
t.Errorf("the first request gives %+v, want %+v", hit, want)
}
_, hit, _ = limiter.CountBytes(client, start, 1, 0)
want = ratelimit.Hit{Kind: ratelimit.KindBytes, Window: hour, Limit: 0, Count: 1}
if hit != want {
t.Errorf("the first byte gives %+v, want %+v", hit, want)
}
}
func TestEachByteLimitIsBrokenByTheBytesCounted(t *testing.T) {
t.Parallel()
const byteLimit = 1000
for _, tc := range []struct {
window string
limits ratelimit.Limits
}{
{minute, ratelimit.Limits{BytesPerMinute: byteLimit}},
{hour, ratelimit.Limits{BytesPerHour: byteLimit}},
{"day", ratelimit.Limits{BytesPerDay: byteLimit}},
} {
t.Run(tc.window, func(t *testing.T) {
t.Parallel()
limiter := ratelimit.New(tc.limits)
client := netip.MustParsePrefix("203.0.113.9/32")
// 600 bytes are within the limit, 600 more over it.
_, _, over := limiter.CountBytes(client, midnight(), 600, whole)
if over {
t.Fatal("600 bytes are over the limit of 1000")
}
_, hit, over := limiter.CountBytes(client, midnight(), 600, whole)
want := ratelimit.Hit{
Kind: ratelimit.KindBytes, Window: tc.window, Limit: byteLimit, Count: 1200,
}
if !over || hit != want {
t.Errorf("1200 bytes give %+v and %t, want %+v and true", hit, over, want)
}
})
}
}
func TestALimitIsBrokenOnlyByWhatIsAddedToIt(t *testing.T) {
t.Parallel()
limiter := ratelimit.New(ratelimit.Limits{PerMinute: 2, BytesPerMinute: 1000})
client := netip.MustParsePrefix("203.0.113.9/32")
other := netip.MustParsePrefix("203.0.113.10/32")
start := midnight()
// The third request breaks the rate limit. The bytes of a request
// counted after it, within the byte limit, do not break it again.
for range 2 {
wantCount(t, limiter, client, start, "")
}
wantCount(t, limiter, client, start, minute)
wantBytesCount(t, limiter, client, start, 500, "")
wantBytesCount(t, limiter, client, start, 600, ratelimit.KindBytes)
// Bytes over the byte limit do not have the next request break it, nor
// the rate limit, which that request is within.
wantBytesCount(t, limiter, other, start, 1200, ratelimit.KindBytes)
wantCount(t, limiter, other, start, "")
}
func TestCountGivesTheBytesInEachWindow(t *testing.T) {
t.Parallel()
limiter := ratelimit.New(ratelimit.Limits{})
client := netip.MustParsePrefix("203.0.113.9/32")
start := midnight()
limiter.CountBytes(client, start, 300, whole)
// A quarter into the next hour, the minute has only these 100 bytes.
// The hour still covers three quarters of the bucket before, whose 300
// bytes count 225, and these: 325. The day covers all 400.
later := start.Add(time.Hour + time.Hour/4)
limiter.CountBytes(client, later, 100, whole)
// A request's counts give the bytes counted so far too.
counts, _, _ := limiter.Count(client, later, whole)
want := ratelimit.Counts{
Minute: 1, Hour: 1, Day: 1, MinuteBytes: 100, HourBytes: 325, DayBytes: 400,
}
if counts != want {
t.Errorf("counts %+v, want %+v", counts, want)
}
}
func TestResetSetsTheBytesBackToZero(t *testing.T) {
t.Parallel()
limiter := ratelimit.New(ratelimit.Limits{BytesPerDay: 1000})
client := netip.MustParsePrefix("203.0.113.9/32")
start := midnight()
wantBytesCount(t, limiter, client, start, 1200, ratelimit.KindBytes)
limiter.Reset(client)
// The client has its whole allowance of bytes again.
wantBytesCount(t, limiter, client, start, 1000, "")
}
func TestCountGivesTheRequestsInEachWindow(t *testing.T) {
t.Parallel()
limiter := ratelimit.New(ratelimit.Limits{})
client := netip.MustParsePrefix("203.0.113.9/32")
start := midnight()
for range 3 {
limiter.Count(client, start, whole)
}
// A quarter into the next hour, the minute has only this request. The
// hour still covers three quarters of the bucket before, with its three
// requests, which count 2.25, and this one: 3.25. The day covers all
// four.
counts, _, _ := limiter.Count(client, start.Add(time.Hour+time.Hour/4), whole)
want := ratelimit.Counts{Minute: 1, Hour: 3.25, Day: 4}
if counts != want {
t.Errorf("counts %+v, want %+v", counts, want)
}
}
func TestResetSetsTheCountsBackToZero(t *testing.T) {
t.Parallel()
@@ -238,9 +424,24 @@ func wantCount(
) {
t.Helper()
hit, _ := limiter.Count(client, now)
_, hit, _ := limiter.Count(client, now, whole)
if hit.Window != want {
t.Errorf("request from %s at %s is over %q, want %q",
client, now.Format(time.RFC3339), hit.Window, want)
}
}
// wantBytesCount counts bytes from client at now, and checks the kind of
// the limit they break, "" for none.
func wantBytesCount(
t *testing.T, limiter *ratelimit.Limiter, client netip.Prefix, now time.Time,
bytes int64, want string,
) {
t.Helper()
_, hit, _ := limiter.CountBytes(client, now, bytes, whole)
if hit.Kind != want {
t.Errorf("%d bytes from %s at %s break a limit on %q, want %q",
bytes, client, now.Format(time.RFC3339), hit.Kind, want)
}
}
internal/ratelimit/snapshot_test.go
+14 -7
View File
@@ -16,7 +16,7 @@ func TestSnapshotListsTheClientsByAddress(t *testing.T) {
limiter := ratelimit.New(ratelimit.Limits{})
for _, i := range []int{2, 3, 0, 1} {
limiter.Count(netip.MustParsePrefix(want[i]), midnight())
limiter.Count(netip.MustParsePrefix(want[i]), midnight(), whole)
}
snapshot := limiter.Snapshot()
@@ -63,7 +63,8 @@ func TestLoadEmptiesBucketsWhoseTimeHasPassed(t *testing.T) {
start := midnight()
limiter := ratelimit.New(ratelimit.Limits{})
limiter.Count(client, start)
limiter.Count(client, start, whole)
limiter.CountBytes(client, start, 5, whole)
limiter.AddToHistory(client, start, ratelimit.Request{Forwarded: true})
loaded := func(now time.Time) ratelimit.Client {
@@ -76,19 +77,25 @@ func TestLoadEmptiesBucketsWhoseTimeHasPassed(t *testing.T) {
}
// Two minutes on, the window that ends then covers neither of the
// minute's buckets, which are emptied; the hour's and the day's stay,
// and so does the history.
// minute's buckets, of requests and of bytes, which are emptied; the
// hour's and the day's stay, and so does the history.
got := loaded(start.Add(2 * time.Minute))
if got.Minute != (ratelimit.Buckets{}) || got.Hour.Current != 1 ||
got.Day.Current != 1 || got.History.Requests != 1 {
t.Errorf("loaded two minutes on as %+v", got)
}
if got.MinuteBytes != (ratelimit.Buckets{}) || got.HourBytes.Current != 5 ||
got.DayBytes.Current != 5 {
t.Errorf("loaded two minutes on with buckets of bytes %+v, %+v and %+v",
got.MinuteBytes, got.HourBytes, got.DayBytes)
}
// A moment before, the window still covers some of the earlier one.
got = loaded(start.Add(2*time.Minute - time.Nanosecond))
if got.Minute.Current != 1 {
t.Errorf("loaded just under two minutes on with minute buckets %+v",
got.Minute)
if got.Minute.Current != 1 || got.MinuteBytes.Current != 5 {
t.Errorf("loaded just under two minutes on with minute buckets %+v and %+v",
got.Minute, got.MinuteBytes)
}
}
internal/remotelog/remotelog.go
+310
View File
@@ -0,0 +1,310 @@
// Package remotelog sends the lines smallwebwaf writes on stdout to the
// remote log endpoint, SWWAF_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.
package remotelog
import (
"bytes"
"context"
"crypto/tls"
"crypto/x509"
"errors"
"fmt"
"log/slog"
"net"
"net/url"
"os"
"strconv"
"sync/atomic"
"syscall"
"time"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
// The forms of SWWAF_LOG_REMOTE_URL, by its scheme.
const (
SchemeUDP = "syslog+udp"
SchemeTCP = "syslog+tcp"
SchemeTLS = "syslog+tls"
)
// A record's priority is the number of its facility times the number of
// severities there are, plus the number of its severity. Every record's
// severity is informational.
const (
severities = 8
informational = 6
)
const (
// dialTimeout bounds connecting to the endpoint, the TLS handshake
// included.
dialTimeout = 10 * time.Second
// After a failed attempt to connect, or a connection on which a record
// fails, the next attempt to connect is made a second later, and
// retryDelayFactor times as long after each further failure in a row,
// up to a minute. A connection that fails after it has stayed up for
// resetRetryDelayAfter ends the row.
firstRetryDelay = time.Second
retryDelayFactor = 2
maxRetryDelay = time.Minute
resetRetryDelayAfter = time.Minute
)
// Params are what New needs.
type Params struct {
// URL is the endpoint (SWWAF_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.
RootCAs *x509.CertPool
// Buffer is the most lines held while they wait to be sent
// (SWWAF_LOG_REMOTE_BUFFER).
Buffer int
// Facility is the number of the records' syslog facility
// (SWWAF_LOG_REMOTE_FACILITY), and AppName their APP-NAME
// (SWWAF_LOG_REMOTE_APP_NAME).
Facility int
AppName string
}
// Sender sends lines to the endpoint. Write puts them in its buffer, and
// Run sends them from there.
type Sender struct {
url *url.URL
tlsConfig *tls.Config
// beforeTime and afterTime are the parts of every record's header
// before and after its time, as RFC 5424 lays the header out.
beforeTime string
afterTime string
// records is the buffer: each line's record, framed to be sent.
records chan []byte
sent atomic.Int64
dropped atomic.Int64
}
// New returns a Sender for the endpoint params.URL.
func New(params Params) *Sender {
hostname, err := os.Hostname()
if err != nil || hostname == "" {
hostname = "-" // RFC 5424's value for a field that has none
}
priority := params.Facility*severities + informational
return &Sender{
url: params.URL,
tlsConfig: &tls.Config{
RootCAs: params.RootCAs,
MinVersion: tls.VersionTLS12,
},
// The 1 is the version of the format. The process id, the message
// id and the structured data have no value.
beforeTime: "<" + strconv.Itoa(priority) + ">1 ",
afterTime: " " + hostname + " " + params.AppName + " - - - ",
records: make(chan []byte, params.Buffer),
}
}
// Write puts each line in p in the buffer, as the message of a record of
// its own, and never waits: when the buffer is full, the oldest record in
// it is dropped to make room. It is safe for concurrent use.
func (s *Sender) Write(p []byte) (int, error) {
at := requestlog.FormatTime(time.Now())
for line := range bytes.Lines(p) {
line = bytes.TrimSuffix(line, []byte("\n"))
if len(line) > 0 {
s.put(s.record(at, line))
}
}
return len(p), nil
}
// Sent is how many records have been sent.
func (s *Sender) Sent() int64 {
return s.sent.Load()
}
// Dropped is how many records were dropped: the oldest in a full buffer,
// and those whose sending failed.
func (s *Sender) Dropped() int64 {
return s.dropped.Load()
}
// Depth is how many records are in the buffer.
func (s *Sender) Depth() int {
return len(s.records)
}
// Run connects to the endpoint and sends each record as it comes into the
// buffer, until ctx is done. Then it sends the records still in the buffer,
// on the connection open at that time or, if there is none, on a new one,
// until none is left or one fails, and returns. How long it may take over
// that is for the caller to bound.
//
// A connection on which a record fails is closed and the record dropped.
// That failure, like a failed attempt to connect, is logged to processLog
// and followed by the next attempt after firstRetryDelay, retryDelayFactor
// times as long after each further failure in a row up to maxRetryDelay,
// and firstRetryDelay again after a connection that stayed up for
// resetRetryDelayAfter. Meanwhile the records wait in the buffer.
func (s *Sender) Run(ctx context.Context, processLog *slog.Logger) {
conn := s.send(ctx, processLog)
if conn == nil && len(s.records) > 0 {
conn, _ = s.dial(context.WithoutCancel(ctx))
}
if conn == nil {
return
}
defer func() {
_ = conn.Close()
}()
for {
select {
case record := <-s.records:
if s.write(conn, record) != nil {
return
}
default:
return
}
}
}
// record returns line as an RFC 5424 record made at the time at, framed
// for the endpoint: on its own over UDP, since each datagram holds one,
// and over TCP and TLS after its length in bytes and a space, the
// octet-counted framing of RFC 6587 and RFC 5425.
func (s *Sender) record(at string, line []byte) []byte {
record := make([]byte, 0, len(s.beforeTime)+len(at)+len(s.afterTime)+len(line))
record = append(record, s.beforeTime...)
record = append(record, at...)
record = append(record, s.afterTime...)
record = append(record, line...)
if s.url.Scheme == SchemeUDP {
return record
}
return append([]byte(strconv.Itoa(len(record))+" "), record...)
}
// put adds record to the buffer, first dropping the oldest record in it
// while it is full.
func (s *Sender) put(record []byte) {
for {
select {
case s.records <- record:
return
default:
}
select {
case <-s.records:
s.dropped.Add(1)
default:
}
}
}
// send connects to the endpoint and sends each record as it comes into
// the buffer, until ctx is done, and returns the connection then open, or
// nil.
func (s *Sender) send(ctx context.Context, processLog *slog.Logger) net.Conn {
delay := firstRetryDelay
for {
conn, err := s.dial(ctx)
if ctx.Err() != nil {
return conn
}
if err == nil {
connected := time.Now()
err = s.sendOn(ctx, conn)
if err == nil {
return conn
}
_ = conn.Close()
if time.Since(connected) >= resetRetryDelayAfter {
delay = firstRetryDelay
}
}
processLog.Warn("sending to SWWAF_LOG_REMOTE_URL failed",
"error", err.Error(), "connecting_again_in", delay.String())
select {
case <-time.After(delay):
case <-ctx.Done():
return nil
}
delay = min(retryDelayFactor*delay, maxRetryDelay)
}
}
// sendOn sends each record on conn as it comes into the buffer, until one
// fails, whose error it returns, or ctx is done.
func (s *Sender) sendOn(ctx context.Context, conn net.Conn) error {
for {
select {
case record := <-s.records:
err := s.write(conn, record)
if err != nil {
return err
}
case <-ctx.Done():
return nil
}
}
}
// write sends record on conn, and counts it as sent or, if that fails,
// as dropped. A record too long for one UDP datagram is dropped without
// an error, since the connection has not failed: a long request must not
// hold up the lines after it.
func (s *Sender) write(conn net.Conn, record []byte) error {
_, err := conn.Write(record)
if err != nil {
s.dropped.Add(1)
if errors.Is(err, syscall.EMSGSIZE) {
return nil
}
return fmt.Errorf("send a record: %w", err)
}
s.sent.Add(1)
return nil
}
// dial connects to the endpoint.
func (s *Sender) dial(ctx context.Context) (net.Conn, error) {
dialer := &net.Dialer{Timeout: dialTimeout}
switch s.url.Scheme {
case SchemeUDP:
return dialer.DialContext(ctx, "udp", s.url.Host)
case SchemeTLS:
tlsDialer := &tls.Dialer{NetDialer: dialer, Config: s.tlsConfig}
return tlsDialer.DialContext(ctx, "tcp", s.url.Host)
default:
return dialer.DialContext(ctx, "tcp", s.url.Host)
}
}
internal/remotelog/remotelog_test.go
+640
View File
@@ -0,0 +1,640 @@
package remotelog_test
import (
"bufio"
"bytes"
"context"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/tls"
"crypto/x509"
"crypto/x509/pkix"
"encoding/json"
"fmt"
"io"
"log/slog"
"math/big"
"net"
"net/url"
"os"
"slices"
"strconv"
"strings"
"sync"
"sync/atomic"
"testing"
"testing/synctest"
"time"
"sneak.berlin/go/smallwebwaf/internal/remotelog"
)
// The tests run in a synctest bubble, where the time package runs on a
// clock of the test's own, which starts at 2000-01-01T00:00:00Z: a wait
// lasts exactly as long as it should, however slowly the test process
// runs, and synctest.Wait returns once the sender has done all it can
// before time passes. The endpoint is a listener on the loopback address.
// A test reads from it only once the records are on their way, and checks
// the sender's counts first, since a goroutine of the bubble that waits on
// the network keeps that clock from moving on. For the same reason the
// endpoint that refuses connections, a tlsEndpoint, runs outside the
// bubble: a sender connecting over TLS waits on the endpoint's answer.
const (
// started is the time a record made as a test starts gives.
started = "2000-01-01T00:00:00.000Z"
appName = "fsn1app1/gitea"
// local0 is the number of the default facility, and local0Info the
// priority of its records.
local0 = 16
local0Info = "<134>"
// loopback is where the endpoints listen.
loopback = "127.0.0.1:0"
)
func TestRecordsOverUDPGoOnePerDatagram(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
endpoint, err := (&net.ListenConfig{}).ListenPacket(t.Context(), "udp", loopback)
if err != nil {
t.Fatalf("listen: %v", err)
}
t.Cleanup(func() { _ = endpoint.Close() })
sender, _, _ := run(t, params(remotelog.SchemeUDP, endpoint.LocalAddr()))
_, _ = sender.Write([]byte(`{"type":"request"}` + "\n" + `{"type":"process"}` + "\n"))
synctest.Wait()
wantCounts(t, sender, 2, 0, 0)
for _, line := range []string{`{"type":"request"}`, `{"type":"process"}`} {
datagram := make([]byte, 1024)
n, _, err := endpoint.ReadFrom(datagram)
if err != nil {
t.Fatalf("read: %v", err)
}
want := record(t, local0Info, appName, line)
if string(datagram[:n]) != want {
t.Errorf("datagram %q, want %q", datagram[:n], want)
}
}
})
}
func TestRecordsOverTCPAreOctetCountedWithTheirFacility(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
endpoint := listen(t)
endpointParams := params(remotelog.SchemeTCP, endpoint.Addr())
endpointParams.Facility = 19 // local3
endpointParams.AppName = "gitea"
sender, _, _ := run(t, endpointParams)
_, _ = sender.Write([]byte("first\nsecond\n"))
synctest.Wait()
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>", "gitea", "second"))
})
}
func TestStalledEndpointHoldsUpNoWriteAndOldestRecordsAreDropped(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
certificate, roots := testCertificate(t)
endpoint := listen(t)
endpointParams := params(remotelog.SchemeTLS, endpoint.Addr())
endpointParams.RootCAs = roots
endpointParams.Buffer = 3
sender, _, _ := run(t, endpointParams)
// The sender connects, and its TLS handshake waits for an answer
// the endpoint does not give yet.
conn := accept(t, endpoint)
var stdout bytes.Buffer
out := io.MultiWriter(&stdout, sender)
for i := range 5 {
_, _ = fmt.Fprintf(out, "line %d\n", i+1)
}
if stdout.String() != "line 1\nline 2\nline 3\nline 4\nline 5\n" {
t.Errorf("stdout has %q", stdout.String())
}
wantCounts(t, sender, 0, 2, 3)
// Once the endpoint answers, the three newest records are sent.
server := tls.Server(conn, &tls.Config{
Certificates: []tls.Certificate{certificate},
MinVersion: tls.VersionTLS12,
})
err := server.HandshakeContext(t.Context())
if err != nil {
t.Fatalf("handshake: %v", err)
}
synctest.Wait()
wantCounts(t, sender, 3, 2, 0)
frames := bufio.NewReader(server)
for _, line := range []string{"line 3", "line 4", "line 5"} {
wantFrame(t, frames, record(t, local0Info, appName, line))
}
})
}
func TestReconnectsWithBackoffAfterTheEndpointGoesAway(t *testing.T) {
t.Parallel()
certificate, roots := testCertificate(t)
endpoint := startTLSEndpoint(t, certificate)
synctest.Test(t, func(t *testing.T) {
endpointParams := params(remotelog.SchemeTLS, endpoint.addr)
endpointParams.RootCAs = roots
sender, logged, _ := run(t, endpointParams)
_, _ = sender.Write([]byte("one\n"))
synctest.Wait()
wantCounts(t, sender, 1, 0, 0)
conn := endpoint.next(t)
wantFrame(t, bufio.NewReader(conn), record(t, local0Info, appName, "one"))
// The endpoint goes away: it closes the connection, and refuses the
// next ones. The sender notices when a record fails, and tries to
// connect again a second later, then two seconds after that.
endpoint.refusing.Store(true)
_ = conn.Close()
writeUntilDropped(t, sender, 1)
sent := sender.Sent()
_, _ = sender.Write([]byte("two\n"))
time.Sleep(time.Second)
synctest.Wait()
endpoint.refusing.Store(false)
time.Sleep(2*time.Second - time.Nanosecond)
synctest.Wait()
wantCounts(t, sender, sent, 1, 1)
// The endpoint is back, and the record waiting is sent.
time.Sleep(time.Nanosecond)
synctest.Wait()
wantCounts(t, sender, sent+1, 1, 0)
conn = endpoint.next(t)
wantFrame(t, bufio.NewReader(conn), record(t, local0Info, appName, "two"))
wantRetries(t, logged, "1s", "2s")
})
}
func TestAConnectionClosedAtOnceIsMadeAgainAfterAGrowingDelay(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
endpoint := listen(t)
sender, logged, _ := run(t, params(remotelog.SchemeTCP, endpoint.Addr()))
// The endpoint closes each connection as soon as it takes it. The
// sender notices when a record fails, and connects again a second
// later, then two seconds after that, then four.
delays := []time.Duration{time.Second, 2 * time.Second, 4 * time.Second}
for i, delay := range delays {
_ = accept(t, endpoint).Close()
writeUntilDropped(t, sender, int64(i+1))
wantConnectedAgainAfter(t, sender, delay)
}
wantRetries(t, logged, "1s", "2s", "4s")
})
}
func TestTheDelayStartsAgainAfterAConnectionThatStayedUpAMinute(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
endpoint := listen(t)
sender, logged, _ := run(t, params(remotelog.SchemeTCP, endpoint.Addr()))
_ = accept(t, endpoint).Close()
writeUntilDropped(t, sender, 1)
wantConnectedAgainAfter(t, sender, time.Second)
// A connection that fails just short of a minute after it was made
// leaves the delay growing.
conn := accept(t, endpoint)
time.Sleep(time.Minute - time.Nanosecond)
_ = conn.Close()
writeUntilDropped(t, sender, 2)
wantConnectedAgainAfter(t, sender, 2*time.Second)
// One that fails a minute after it was made starts it again from a
// second.
conn = accept(t, endpoint)
time.Sleep(time.Minute)
_ = conn.Close()
writeUntilDropped(t, sender, 3)
wantConnectedAgainAfter(t, sender, time.Second)
wantRetries(t, logged, "1s", "2s", "1s")
})
}
func TestALineTooLongForADatagramIsDroppedAlone(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
endpoint, err := (&net.ListenConfig{}).ListenPacket(t.Context(), "udp", loopback)
if err != nil {
t.Fatalf("listen: %v", err)
}
t.Cleanup(func() { _ = endpoint.Close() })
sender, logged, _ := run(t, params(remotelog.SchemeUDP, endpoint.LocalAddr()))
// With its header, the first line's record is longer than the 65507
// bytes a UDP datagram over IPv4 holds. It is dropped, nothing is
// logged, and the next line is sent at once.
_, _ = sender.Write([]byte(strings.Repeat("x", 65507) + "\nnext\n"))
synctest.Wait()
wantCounts(t, sender, 1, 1, 0)
wantRetries(t, logged)
datagram := make([]byte, 1024)
n, _, err := endpoint.ReadFrom(datagram)
if err != nil {
t.Fatalf("read: %v", err)
}
want := record(t, local0Info, appName, "next")
if string(datagram[:n]) != want {
t.Errorf("datagram %q, want %q", datagram[:n], want)
}
})
}
func TestRecordsWaitingAtTheStopAreSent(t *testing.T) {
t.Parallel()
certificate, roots := testCertificate(t)
endpoint := startTLSEndpoint(t, certificate)
synctest.Test(t, func(t *testing.T) {
// The endpoint refuses the sender's first connection: it fails to
// connect, and waits a second to try again.
endpoint.refusing.Store(true)
endpointParams := params(remotelog.SchemeTLS, endpoint.addr)
endpointParams.RootCAs = roots
sender, logged, stop := run(t, endpointParams)
synctest.Wait()
wantRetries(t, logged, "1s")
_, _ = sender.Write([]byte("one\ntwo\n"))
endpoint.refusing.Store(false)
// Stopped before that second is over, it connects to send them.
stop()
wantCounts(t, sender, 2, 0, 0)
frames := bufio.NewReader(endpoint.next(t))
wantFrame(t, frames, record(t, local0Info, appName, "one"))
wantFrame(t, frames, record(t, local0Info, appName, "two"))
})
}
// output collects what the sender logs.
type output struct {
mu sync.Mutex
buf bytes.Buffer
}
// Write adds lines the sender logs.
func (o *output) Write(p []byte) (int, error) {
o.mu.Lock()
defer o.mu.Unlock()
return o.buf.Write(p)
}
// text returns everything logged so far.
func (o *output) text() string {
o.mu.Lock()
defer o.mu.Unlock()
return o.buf.String()
}
// params returns the settings of a Sender for the endpoint at addr, in
// the form scheme names: room for ten lines, the default facility, and
// appName.
func params(scheme string, addr net.Addr) remotelog.Params {
return remotelog.Params{
URL: &url.URL{Scheme: scheme, Host: addr.String()},
Buffer: 10,
Facility: local0,
AppName: appName,
}
}
// run runs a Sender with settings until the test ends or the function
// it returns is called, which waits for Run to return. It returns the
// Sender, and what it logs.
func run(t *testing.T, settings remotelog.Params) (*remotelog.Sender, *output, func()) {
t.Helper()
sender := remotelog.New(settings)
logged := &output{}
ctx, cancel := context.WithCancel(t.Context())
ran := make(chan struct{})
go func() {
sender.Run(ctx, slog.New(slog.NewJSONHandler(logged, nil)))
close(ran)
}()
stop := func() {
cancel()
<-ran
}
t.Cleanup(stop)
return sender, logged, stop
}
// listen returns a TCP listener on the loopback address, closed when the
// test ends.
func listen(t *testing.T) net.Listener {
t.Helper()
listener, err := (&net.ListenConfig{}).Listen(t.Context(), "tcp", loopback)
if err != nil {
t.Fatalf("listen: %v", err)
}
t.Cleanup(func() { _ = listener.Close() })
return listener
}
// accept returns the next connection to listener, closed when the test
// ends.
func accept(t *testing.T, listener net.Listener) net.Conn {
t.Helper()
conn, err := listener.Accept()
if err != nil {
t.Fatalf("accept: %v", err)
}
t.Cleanup(func() { _ = conn.Close() })
return conn
}
// tlsEndpoint is a syslog+tls endpoint on the loopback address, which a
// test starts outside its bubble. It keeps its listener until the test
// ends, and either takes each connection or refuses it.
type tlsEndpoint struct {
addr net.Addr
// refusing is set while the endpoint closes each connection before the
// TLS handshake, which fails the sender's attempt to connect.
refusing atomic.Bool
// conns are the connections it has taken, after the handshake.
conns chan net.Conn
}
// startTLSEndpoint starts a tlsEndpoint with certificate, which takes
// connections until it is told to refuse them.
func startTLSEndpoint(t *testing.T, certificate tls.Certificate) *tlsEndpoint {
t.Helper()
listener := listen(t)
endpoint := &tlsEndpoint{addr: listener.Addr(), conns: make(chan net.Conn, 10)}
config := &tls.Config{
Certificates: []tls.Certificate{certificate},
MinVersion: tls.VersionTLS12,
}
go func() {
for {
conn, err := listener.Accept()
if err != nil {
return
}
server := tls.Server(conn, config)
if endpoint.refusing.Load() || server.HandshakeContext(t.Context()) != nil {
_ = conn.Close()
continue
}
endpoint.conns <- server
}
}()
return endpoint
}
// next returns the next connection the endpoint has taken, closed when
// the test ends.
func (e *tlsEndpoint) next(t *testing.T) net.Conn {
t.Helper()
conn := <-e.conns
t.Cleanup(func() { _ = conn.Close() })
return conn
}
// record returns the record of line made as the test started, with the
// priority and the app name given.
func record(t *testing.T, priority, app, line string) string {
t.Helper()
hostname, err := os.Hostname()
if err != nil || hostname == "" {
hostname = "-"
}
return priority + "1 " + started + " " + hostname + " " + app + " - - - " + line
}
// wantFrame reads the next octet-counted frame from frames, and checks
// that it holds want.
func wantFrame(t *testing.T, frames *bufio.Reader, want string) {
t.Helper()
count, err := frames.ReadString(' ')
if err != nil {
t.Fatalf("read a frame's length: %v", err)
}
length, err := strconv.Atoi(strings.TrimSuffix(count, " "))
if err != nil {
t.Fatalf("frame starts %q, not with its length", count)
}
got := make([]byte, length)
_, err = io.ReadFull(frames, got)
if err != nil {
t.Fatalf("read a frame: %v", err)
}
if string(got) != want {
t.Errorf("frame %q, want %q", got, want)
}
}
// wantCounts checks the records sender has sent, dropped and holds in
// its buffer.
func wantCounts(
t *testing.T, sender *remotelog.Sender, sent, dropped int64, depth int,
) {
t.Helper()
if sender.Sent() != sent || sender.Dropped() != dropped || sender.Depth() != depth {
t.Fatalf("sent %d, dropped %d, %d in the buffer; want %d, %d and %d",
sender.Sent(), sender.Dropped(), sender.Depth(), sent, dropped, depth)
}
}
// writeUntilDropped writes a line at a time until the count of records
// sender has dropped reaches dropped. The records it sends on a
// connection the endpoint has closed are lost before one fails; how many
// depends on when the endpoint's host answers that the connection is
// gone.
func writeUntilDropped(t *testing.T, sender *remotelog.Sender, dropped int64) {
t.Helper()
for sender.Dropped() < dropped {
_, _ = sender.Write([]byte("lost\n"))
synctest.Wait()
}
}
// wantConnectedAgainAfter writes a line while the sender waits to connect
// again, and checks that it connects, and takes the line from the buffer,
// only once delay is over.
func wantConnectedAgainAfter(
t *testing.T, sender *remotelog.Sender, delay time.Duration,
) {
t.Helper()
_, _ = sender.Write([]byte("waiting\n"))
time.Sleep(delay - time.Nanosecond)
synctest.Wait()
if sender.Depth() != 1 {
t.Fatalf("connected again before %v", delay)
}
time.Sleep(time.Nanosecond)
synctest.Wait()
if sender.Depth() != 0 {
t.Fatalf("not connected again after %v", delay)
}
}
// wantRetries checks that the sender logged a failure, of an attempt to
// connect or of a connection, for each of delays, the time until the next
// attempt, in order, and logged nothing else.
func wantRetries(t *testing.T, logged *output, delays ...string) {
t.Helper()
var got []string
for line := range strings.Lines(logged.text()) {
var fields map[string]any
err := json.Unmarshal([]byte(line), &fields)
if err != nil || fields["msg"] != "sending to SWWAF_LOG_REMOTE_URL failed" {
t.Fatalf("logged %q", line)
}
delay, _ := fields["connecting_again_in"].(string)
got = append(got, delay)
}
if !slices.Equal(got, delays) {
t.Errorf("logged failures to connect again in %v, want %v", got, delays)
}
}
// testCertificate returns a certificate for 127.0.0.1 that is its own
// CA, and a pool that holds it. It is valid on the bubble's clock, which
// starts at 2000-01-01T00:00:00Z.
func testCertificate(t *testing.T) (tls.Certificate, *x509.CertPool) {
t.Helper()
key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
if err != nil {
t.Fatalf("generate a key: %v", err)
}
template := &x509.Certificate{
SerialNumber: big.NewInt(1),
Subject: pkix.Name{CommonName: "smallwebwaf 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,
BasicConstraintsValid: true,
KeyUsage: x509.KeyUsageCertSign | x509.KeyUsageDigitalSignature,
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
IPAddresses: []net.IP{net.IPv4(127, 0, 0, 1)},
}
der, err := x509.CreateCertificate(rand.Reader, template, template,
&key.PublicKey, key)
if err != nil {
t.Fatalf("create a certificate: %v", err)
}
certificate, err := x509.ParseCertificate(der)
if err != nil {
t.Fatalf("parse the certificate: %v", err)
}
roots := x509.NewCertPool()
roots.AddCert(certificate)
return tls.Certificate{Certificate: [][]byte{der}, PrivateKey: key}, roots
}
internal/requestlog/requestlog.go
+87 -17
View File
@@ -9,6 +9,8 @@ import (
"io"
"log/slog"
"time"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
)
// The action a request line names: what smallwebwaf did with the
@@ -26,8 +28,12 @@ const (
// ActionRateLimited is a request refused because it took its client
// over a rate limit, which bans the client.
ActionRateLimited = "rate_limited"
// ActionBanned is a request refused because a ban covers its client.
// ActionBanned is a request refused because a ban covers its client,
// or because it matched a ban rule, which bans the client.
ActionBanned = "banned"
// ActionRuleBlocked is a request refused because it matched a block
// rule.
ActionRuleBlocked = "rule_blocked"
// ActionDenied is a request refused because its client is in
// SWWAF_DENY_NETS.
ActionDenied = "denied"
@@ -39,51 +45,115 @@ const (
)
// OffenceLimit is the offence a request line names for a request that
// broke a rate limit.
// broke a rate limit, or whose bytes broke a byte limit.
const OffenceLimit = "limit"
// 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 are
// those of the "Request log" section of SPEC.md.
// 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
// that may not apply to a request is left out of its line when it does
// not.
//
//nolint:tagliatelle // SPEC.md's request log names its fields in snake_case
type Line struct {
Type string `json:"type"`
// The standard web log fields. Scheme is how the client reached
// smallwebwaf, or the trusted proxy in front of it.
Time string `json:"time"`
Instance string `json:"instance"`
ClientIP string `json:"client_ip"`
PeerIP string `json:"peer_ip"`
Country string `json:"country"`
Method string `json:"method"`
Scheme string `json:"scheme"`
Host string `json:"host"`
Path string `json:"path"`
Query string `json:"query"`
Protocol string `json:"protocol"`
Status int `json:"status"`
UpstreamStatus int `json:"upstream_status,omitempty"`
RequestBytes int64 `json:"request_bytes"`
ResponseBytes int64 `json:"response_bytes"`
Referer string `json:"referer"`
UserAgent string `json:"user_agent"`
// Request detail. RequestID is the X-Request-ID a trusted proxy sent,
// or a new one, and is sent on to the app. 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.
RequestID string `json:"request_id"`
PeerIP string `json:"peer_ip"`
ForwardedFor string `json:"forwarded_for,omitempty"`
ClientGroup string `json:"client_group"`
ASN string `json:"asn"`
ASName string `json:"as_name"`
Country string `json:"country"`
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
// 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
// passed on, or those of smallwebwaf's own. Aborted is true when the
// 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.
Action string `json:"action"`
// WouldAction is, in observe mode, the action enforce mode would have
// taken with a request it would have refused: ActionDenied,
// ActionBanned, ActionCountryDenied or ActionRateLimited.
// ActionBanned, ActionCountryDenied, ActionRateLimited or
// ActionRuleBlocked.
WouldAction string `json:"would_action,omitempty"`
// LimitHit is the window whose rate limit the request went over:
// minute, hour or day.
// LimitPercent and LimitPercentSetting are, for a request the rate
// limits counted whose client a biased threshold gives a percentage of
// the rate limits below 100, that percentage and the setting that gave
// it. BytesPercent and BytesPercentSetting are the same for the byte
// limits.
LimitPercent *int64 `json:"limit_percent,omitempty"`
LimitPercentSetting string `json:"limit_percent_setting,omitempty"`
BytesPercent *int64 `json:"bytes_percent,omitempty"`
BytesPercentSetting string `json:"bytes_percent_setting,omitempty"`
// Counts are, for a request the rate limits counted, the client's
// requests as they counted them with this one, and its bytes as the
// byte limits counted them, with this request's once it has ended if
// they count them.
Counts ratelimit.Counts `json:"counts,omitzero"`
// RuleIDs are the ids of the rule file rules the request matched.
RuleIDs []string `json:"rule_ids,omitempty"`
// LimitHit is the window whose limit the request went over, named as
// Counts names its count: minute, hour or day for a rate limit, and
// minute_bytes, hour_bytes or day_bytes for a byte limit.
LimitHit string `json:"limit_hit,omitempty"`
// Offence is the offence the request was held as, OffenceLimit.
Offence string `json:"offence,omitempty"`
// BanExpires is when the ban the request made, or was refused under,
// ends: a time, or "permanent".
BanExpires string `json:"ban_expires,omitempty"`
// Aborted is true when the client went away early.
Aborted bool `json:"aborted,omitempty"`
// DurationTotal and DurationUpstreamTotal are in milliseconds.
// The timings, in milliseconds. DurationChecks is the time until the
// checks were done. DurationUpstreamConnect, DurationUpstreamFirstByte
// and DurationUpstreamTotal run from when the request was handed to the
// app: until there was a connection to it, until the first byte of its
// 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"`
DurationUpstreamTotal float64 `json:"duration_upstream_total,omitempty"`
DurationChecks *float64 `json:"duration_checks,omitempty"`
DurationUpstreamConnect *float64 `json:"duration_upstream_connect,omitempty"`
DurationUpstreamFirstByte *float64 `json:"duration_upstream_first_byte,omitempty"`
DurationUpstreamTotal *float64 `json:"duration_upstream_total,omitempty"`
}
// Write writes line to w as one JSON line marked "type":"request".
@@ -116,8 +186,8 @@ 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.
func NewProcessLogger(w io.Writer) *slog.Logger {
// as a request line's, and instanceName, SWWAF_INSTANCE_NAME, as instance.
func NewProcessLogger(w io.Writer, instanceName string) *slog.Logger {
handler := slog.NewJSONHandler(w, &slog.HandlerOptions{
ReplaceAttr: func(groups []string, attr slog.Attr) slog.Attr {
if attr.Key == slog.TimeKey && len(groups) == 0 {
@@ -128,5 +198,5 @@ func NewProcessLogger(w io.Writer) *slog.Logger {
},
})
return slog.New(handler).With("type", "process")
return slog.New(handler).With("type", "process", "instance", instanceName)
}
internal/requestlog/requestlog_test.go
+10 -5
View File
@@ -50,7 +50,11 @@ func TestWriteWritesOneJSONLineMarkedRequest(t *testing.T) {
}
unset := []string{
"upstream_status", "limit_hit", "offence", "ban_expires", "aborted",
"forwarded_for", "content_type", "content_length", "request_headers",
"has_authorization", "has_cookie", "websocket", "response_content_type",
"upstream_status", "cache_control", "location", "aborted", "counts",
"limit_hit", "offence", "ban_expires", "duration_checks",
"duration_upstream_connect", "duration_upstream_first_byte",
"duration_upstream_total",
}
for _, name := range unset {
@@ -61,12 +65,12 @@ func TestWriteWritesOneJSONLineMarkedRequest(t *testing.T) {
}
}
func TestProcessLinesAreMarkedProcess(t *testing.T) {
func TestProcessLinesAreMarkedProcessAndGiveTheInstance(t *testing.T) {
t.Parallel()
var out bytes.Buffer
requestlog.NewProcessLogger(&out).Info("starting", "version", "v1")
requestlog.NewProcessLogger(&out, "fsn1app1/gitea").Info("starting", "version", "v1")
var fields map[string]any
@@ -75,8 +79,9 @@ func TestProcessLinesAreMarkedProcess(t *testing.T) {
t.Fatalf("decode %q: %v", out.String(), err)
}
if fields["type"] != "process" || fields["msg"] != "starting" ||
fields["level"] != "INFO" || fields["version"] != "v1" {
if fields["type"] != "process" || fields["instance"] != "fsn1app1/gitea" ||
fields["msg"] != "starting" || fields["level"] != "INFO" ||
fields["version"] != "v1" {
t.Errorf("process line %v", fields)
}
internal/rules/rules.go
+483
View File
@@ -0,0 +1,483 @@
// Package rules reads the rule files: the plain text files in
// SWWAF_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.
package rules
import (
"context"
"encoding/hex"
"errors"
"fmt"
"log/slog"
"net/http"
"os"
"path/filepath"
"regexp"
"slices"
"strings"
"sync/atomic"
"time"
"github.com/fsnotify/fsnotify"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/config"
)
// The actions a rule takes when it matches.
const (
// ActionLog notes the match in the request log, and does nothing else.
ActionLog = "log"
// ActionBlock refuses the request with 403.
ActionBlock = "block"
// ActionBan refuses the request and bans the client's netblock: the
// request is a clear sign of attack.
ActionBan = "ban"
)
// extension ends the name of every rule file.
const extension = ".rules"
// quietTime is how long SWWAF_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.
const quietTime = 2 * time.Second
// headerTarget starts the target that is one request header,
// header:<Name>.
const headerTarget = "header:"
// escapeLength is the length of a percent escape, such as %2e.
const escapeLength = 3
var (
// ruleLine is a rule: four fields separated by spaces or tabs, of
// which the fourth, the regex, runs to the end of the line.
ruleLine = regexp.MustCompile(`^([^ \t]+)[ \t]+([^ \t]+)[ \t]+([^ \t]+)[ \t]+(.+)$`)
// idChars are the characters of a rule's id.
idChars = regexp.MustCompile(`^[A-Za-z0-9_-]+$`)
)
var (
errNotRule = errors.New(
"is not a rule: an id, a target, an action and a regex, " +
"separated by spaces or tabs")
errNotID = errors.New("is not an id of letters, digits, - and _")
errNotTarget = errors.New(
"is not path, query, uri, method, host, user_agent, referer or header:<Name>")
errNotHeaderName = errors.New(
"has a character after header: that no header name can have")
errHeaderTakenOut = errors.New(
"names a header that Go's HTTP server takes out of every request, " +
"so a rule never sees it")
errNotAction = errors.New("is not log, block or ban")
errNotRegex = errors.New("does not compile")
errUsedTwice = errors.New("is already the id of the rule at")
)
// Rule is one rule of a rule file.
type Rule struct {
// ID names the rule in the request log, the metrics and ban notes.
ID string
// Target is what the regex is matched against, such as path or
// header:Accept.
Target string
// Action is ActionLog, ActionBlock or ActionBan.
Action string
regex *regexp.Regexp
}
// Params are what Load needs.
type Params struct {
// Dir is the directory of the rule files (SWWAF_RULES_DIR).
Dir string
// Enabled is SWWAF_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.
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
// from them. They are safe for concurrent use.
type Files struct {
params Params
// rules are the rules loaded, in the order of their files' names, and
// then of their lines.
rules atomic.Pointer[[]Rule]
}
// Load reads the rules of every *.rules file in Dir, in the order of the
// files' names, unless Enabled is false. A Dir that cannot be read is an
// error, and so is a line that is not a rule, a header name with a
// character no header name can have, a rule for the Host or the
// Transfer-Encoding header, which Go's HTTP server takes out of every
// request, a regex that does not compile and an id used twice, each named
// with its file and line.
func Load(params Params) (*Files, error) {
f := &Files{params: params}
f.rules.Store(&[]Rule{})
if !params.Enabled {
return f, nil
}
rules, _, err := read(params.Dir)
if err != nil {
return nil, err
}
f.rules.Store(&rules)
f.logRead(len(rules))
return f, nil
}
// Match checks r against the rules, in order, and returns those it
// matches, up to the first whose action refuses it, block or ban, which
// is then the last one returned.
func (f *Files) Match(r *http.Request) []Rule {
var matched []Rule
for _, rule := range *f.rules.Load() {
if !rule.matches(r) {
continue
}
matched = append(matched, rule)
if rule.Action != ActionLog {
break
}
}
return matched
}
// Len returns how many rules are loaded.
func (f *Files) Len() int {
return len(*f.rules.Load())
}
// Watch watches Dir until ctx is done, and reads the rule files again
// once Dir has had no change for quietTime, after one is edited, added or
// removed, and after Watch starts watching. If they then hold an error,
// the rules stay as they were, the error is logged with its file and
// line, and the files are read again after the next change. If Dir cannot
// be watched, that is logged, and the rules stay as they were loaded.
// While Enabled is false, Watch returns at once.
func (f *Files) Watch(ctx context.Context) {
if !f.params.Enabled {
return
}
watcher, err := fsnotify.NewWatcher()
if err == nil {
defer func() {
_ = watcher.Close()
}()
err = watcher.Add(f.params.Dir)
}
if err != nil {
f.params.ProcessLog.Error("cannot watch the rule files for edits",
"error", err.Error())
return
}
f.params.ProcessLog.Info("watching the rule files for edits",
"directory", f.params.Dir)
f.readAfterChanges(ctx, watcher.Events, watcher.Errors)
}
// readAfterChanges reads the rule files again once quietTime has passed
// without a change from events, until ctx is done, and logs the errors
// from errs. The wait starts at once, as if for a change, so that an edit
// saved after Load read the files, and before Dir was watched, is taken
// in too.
func (f *Files) readAfterChanges(
ctx context.Context, events <-chan fsnotify.Event, errs <-chan error,
) {
quiet := time.NewTimer(quietTime)
defer quiet.Stop()
for {
select {
case <-ctx.Done():
return
case <-events:
quiet.Reset(quietTime)
case <-quiet.C:
f.readAgain()
case err := <-errs:
f.params.ProcessLog.Warn("watching the rule files failed",
"error", err.Error())
}
}
}
// readAgain reads the rule files again, in place of the rules loaded, or
// logs the error that keeps the rules as they were, and raises a
// file_error alert for it, for the file it is in.
func (f *Files) readAgain() {
rules, path, err := read(f.params.Dir)
if err != nil {
const kept = "a rule file has an error, and the rules stay as they were"
// Raised before it is logged, so that the alert is there once the
// log line is.
f.params.Alerts.Raise(alerts.Alert{
Event: alerts.EventFileError,
Reason: kept,
Detail: map[string]any{"file": path, "error": err.Error()},
})
f.params.ProcessLog.Error(kept, "error", err.Error())
return
}
f.rules.Store(&rules)
f.logRead(len(rules))
}
// logRead logs that the rule files were read, and how many rules they
// hold, which can be none.
func (f *Files) logRead(count int) {
f.params.ProcessLog.Info("read the rule files",
"directory", f.params.Dir, "rules", count)
}
// read returns the rules of every rule file in dir, in the order of the
// files' names, and then of their lines, or an error, with the path of the
// rule file it is in, or dir. A file whose name starts with a dot, such as
// an editor's lock file .#50-app.rules, is not a rule file, as a shell's
// *.rules would not match it.
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)
}
var rules []Rule
// places are where each id is, as "<file>, line <n>".
places := map[string]string{}
for _, entry := range entries {
name := entry.Name()
if entry.IsDir() || strings.HasPrefix(name, ".") || filepath.Ext(name) != extension {
continue
}
path := filepath.Join(dir, name)
rules, err = readFile(path, rules, places)
if err != nil {
return nil, path, err
}
}
return rules, "", nil
}
// 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
if err != nil {
return nil, err
}
number := 0
for line := range strings.Lines(string(data)) {
number++
place := fmt.Sprintf("%s, line %d", path, number)
text := strings.TrimSuffix(strings.TrimSuffix(line, "\n"), "\r")
rule, isRule, err := parse(text)
if err != nil {
return nil, fmt.Errorf("%s: %w", place, err)
}
if !isRule {
continue
}
first, used := places[rule.ID]
if used {
return nil, fmt.Errorf("%s: the id %q %w %s", place, rule.ID, errUsedTwice, first)
}
places[rule.ID] = place
rules = append(rules, rule)
}
return rules, nil
}
// parse reads a line of a rule file. It returns false for a blank line
// and for a comment, a line that starts with #. Spaces and tabs at the
// end of the line are not part of its regex, so a line with only those
// after its action has no regex, and is not a rule.
func parse(line string) (Rule, bool, error) {
line = strings.Trim(line, " \t")
if line == "" || strings.HasPrefix(line, "#") {
return Rule{}, false, nil
}
fields := ruleLine.FindStringSubmatch(line)
if fields == nil {
return Rule{}, false, errNotRule
}
rule := Rule{ID: fields[1], Target: fields[2], Action: fields[3]}
headerName, isHeader := strings.CutPrefix(rule.Target, headerTarget)
switch {
case !idChars.MatchString(rule.ID):
return Rule{}, false, fmt.Errorf("the id %q %w", rule.ID, errNotID)
case !isTarget(rule.Target):
return Rule{}, false, fmt.Errorf("the target %q %w", rule.Target, errNotTarget)
case isHeader && !config.IsHeaderName(headerName):
return Rule{}, false, fmt.Errorf("the target %q %w", rule.Target, errNotHeaderName)
case strings.EqualFold(rule.Target, headerTarget+"Host"):
return Rule{}, false, fmt.Errorf(
"the target %q %w; the request's host is the target host",
rule.Target, errHeaderTakenOut)
case strings.EqualFold(rule.Target, headerTarget+"Transfer-Encoding"):
return Rule{}, false, fmt.Errorf("the target %q %w", rule.Target, errHeaderTakenOut)
case !slices.Contains([]string{ActionLog, ActionBlock, ActionBan}, rule.Action):
return Rule{}, false, fmt.Errorf("the action %q %w", rule.Action, errNotAction)
}
regex, err := regexp.Compile(fields[4])
if err != nil {
return Rule{}, false, fmt.Errorf("the regex %w: %w", errNotRegex, err)
}
rule.regex = regex
return rule, true, nil
}
// isTarget reports whether target is one a rule may have.
func isTarget(target string) bool {
switch target {
case "path", "query", "uri", "method", "host", "user_agent", "referer":
return true
}
name, isHeader := strings.CutPrefix(target, headerTarget)
return isHeader && name != ""
}
// matches reports whether the rule's regex matches its target in r. For
// uri it is matched against the path and query as received, and against
// them once percent-decoded, so that an encoded probe cannot slip past.
func (rule Rule) matches(r *http.Request) bool {
if rule.Target == "uri" {
uri := pathAndQuery(r)
return rule.regex.MatchString(uri) || rule.regex.MatchString(decodeOnce(uri))
}
return rule.regex.MatchString(value(rule.Target, r))
}
// value returns what a rule with target, other than uri, is matched
// against in r: the path and the query as the client sent them, before
// any decoding or re-encoding, split at the first ?, and a header's values
// joined by ", ", as HTTP joins those of a header sent more than once.
func value(target string, r *http.Request) string {
switch target {
case "path":
path, _, _ := strings.Cut(pathAndQuery(r), "?")
return path
case "query":
_, query, _ := strings.Cut(pathAndQuery(r), "?")
return query
case "method":
return r.Method
case "host":
return r.Host
case "user_agent":
return header(r, "User-Agent")
case "referer":
return header(r, "Referer")
default:
return header(r, strings.TrimPrefix(target, headerTarget))
}
}
// pathAndQuery returns the target of r's request line, r.RequestURI, as
// the client sent it, less any scheme and host: a target with a scheme
// gives what follows the scheme and its :, and the host when // follows.
// So http://host/path, as a client sends it to a proxy, gives /path, and
// so does http:/path, which Go reads as a target with a scheme and no
// host. r.URL is not used: when the path holds a character it escapes,
// such as \ or a non-ASCII byte, it decodes the whole path and escapes it
// again, so that \ becomes %5C and %2e a dot.
func pathAndQuery(r *http.Request) string {
if !r.URL.IsAbs() {
return r.RequestURI
}
_, afterScheme, _ := strings.Cut(r.RequestURI, ":")
hostAndRest, hasHost := strings.CutPrefix(afterScheme, "//")
if !hasHost {
return afterScheme
}
start := strings.IndexAny(hostAndRest, "/?")
if start < 0 {
return ""
}
return hostAndRest[start:]
}
// header returns the values of r's header name joined by ", ", or "" if
// r has no such header.
func header(r *http.Request, name string) string {
return strings.Join(r.Header.Values(name), ", ")
}
// decodeOnce returns s with each percent escape, such as %2e, replaced by
// the byte it stands for. A % that is not followed by two hex digits is
// left as it is, so that a malformed escape cannot keep the rest of s
// from being decoded.
func decodeOnce(s string) string {
var decoded strings.Builder
for i := 0; i < len(s); i++ {
if s[i] == '%' && i+escapeLength <= len(s) {
b, err := hex.DecodeString(s[i+1 : i+escapeLength])
if err == nil {
decoded.Write(b)
i += escapeLength - 1
continue
}
}
decoded.WriteByte(s[i])
}
return decoded.String()
}
internal/rules/rules_test.go
+687
View File
@@ -0,0 +1,687 @@
package rules_test
import (
"context"
"encoding/json"
"log/slog"
"maps"
"net/http"
"net/http/httptest"
"net/url"
"os"
"path/filepath"
"slices"
"strconv"
"testing"
"time"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/rules"
)
const (
// What the process log says once Watch watches the directory, after
// each reading of the rule files, and for one that has an error.
watching = "watching the rule files for edits"
read = "read the rule files"
hasError = "a rule file has an error, and the rules stay as they were"
// maxLogLines is how many lines of the process log wait for a test to
// read them.
maxLogLines = 64
// browser is the user agent of an ordinary visitor.
browser = "Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.0"
// testFile is the rule file of a test that needs only one, and
// firstFile the first of a test's rule files.
testFile = "test.rules"
firstFile = "00-a.rules"
// userAgent is the header that carries the user agent.
userAgent = "User-Agent"
)
func TestEachTargetMatchesWhatItNames(t *testing.T) {
t.Parallel()
for _, tc := range []struct {
name string
rule string // its target, action and regex
uri string // the request's path and query
header http.Header
want bool
}{
{"path as received", `path log ^/%2eenv$`, "/%2eenv", nil, true},
{"path not decoded", `path log ^/\.env$`, "/%2eenv", nil, false},
{"path without the query", `path log ^/a$`, "/a?b=c", nil, true},
{"query as received", `query log ^b=%2e$`, "/a?b=%2e", nil, true},
{"uri as received", `uri log ^/a\?b=%2e$`, "/a?b=%2e", nil, true},
{"uri decoded", `uri log (\.\./){2}`, "/a?f=%2e%2e%2f%2e%2e%2f", nil, true},
{
"uri decoded past malformed escapes", `uri log (\.\./){2}&h=%$`,
"/a?g=%zz&f=%2e%2e%2f%2e%2e%2f&h=%", nil, true,
},
{"uri decoded only once", `uri log ^/a\.b$`, "/a%252eb", nil, false},
{"method", `method log ^PUT$`, "/", nil, true},
{"host", `host log ^app\.example$`, "/", nil, true},
{
"user_agent", `user_agent log ^sqlmap/`, "/",
http.Header{userAgent: {"sqlmap/1.8"}}, true,
},
{
"user_agent sent twice", `user_agent log ^curl/8, sqlmap/`, "/",
http.Header{userAgent: {"curl/8", "sqlmap/1.8"}}, true,
},
{"user_agent missing", `user_agent log ^$`, "/", nil, true},
{
"referer", `referer log ^https://spam\.example/`, "/",
http.Header{"Referer": {"https://spam.example/buy"}}, true,
},
{
"a header sent twice", `header:x-api-version log ^2, 3$`, "/",
http.Header{"X-Api-Version": {"2", "3"}}, true,
},
{"a header missing", `header:X-Api-Version log ^$`, "/", nil, true},
} {
t.Run(tc.name, func(t *testing.T) {
t.Parallel()
files := load(t, ruleFiles{testFile: "a-rule " + tc.rule + "\n"})
// Every request is a PUT, which the method rule looks for.
r := httptest.NewRequestWithContext(t.Context(), http.MethodPut,
"http://app.example"+tc.uri, nil)
maps.Copy(r.Header, tc.header)
got := len(files.Match(r)) == 1
if got != tc.want {
t.Errorf("%s matches %s: %t, want %t", tc.rule, tc.uri, got, tc.want)
}
})
}
}
func TestPathMatchedAsTheClientSentIt(t *testing.T) {
t.Parallel()
// Each path holds a character Go's URL type would escape again, \ or
// a non-ASCII byte, and each rule is written for the path as sent.
for _, tc := range []struct {
rule string // its target, action and regex
sent string // the path and query the client sent
}{
{`path log ^/\.\.\\\.\.\\windows\\win\.ini$`, `/..\..\windows\win.ini`},
{`path log ^/%2e%2e\\%2e%2e\\windows\\win\.ini$`, `/%2e%2e\%2e%2e\windows\win.ini`},
{`path log ^/café$`, "/café?x=1"},
{`uri log ^/%2e%2e\\%2e%2e\\boot\.ini\?x=1$`, `/%2e%2e\%2e%2e\boot.ini?x=1`},
} {
files := load(t, ruleFiles{testFile: "as-sent " + tc.rule + "\n"})
// The target in origin form, as traefik sends it, in absolute form,
// as a client sends it to a proxy, and with a scheme but no host,
// which Go reads as absolute form with no host, sending the app
// the path.
for _, target := range []string{
tc.sent, "http://app.example" + tc.sent, "http:" + tc.sent, "foo:" + tc.sent,
} {
r := httptest.NewRequestWithContext(t.Context(), http.MethodGet, target, nil)
wantMatched(t, files, r, "as-sent")
}
}
}
func TestMatchingStopsAtTheFirstRuleThatRefuses(t *testing.T) {
t.Parallel()
files := load(t, ruleFiles{testFile: `
every-path path log ^/
no-path path log ^$
first-refusal path block ^/probe
later-ban path ban ^/probe
after path log ^/
`})
// Every log rule that matches is noted, and the block rule ends the
// matching.
wantMatched(t, files, get(t, "/probe"), "every-path", "first-refusal")
wantMatched(t, files, get(t, "/page"), "every-path", "after")
// A ban rule ends it too.
files = load(t, ruleFiles{testFile: "ban path ban ^/\nlater path block ^/\n"})
wantMatched(t, files, get(t, "/"), "ban")
}
func TestSpacesAndTabsEndingALineAreNotPartOfItsRegex(t *testing.T) {
t.Parallel()
files := load(t, ruleFiles{testFile: "env-file path block ^/\\.env$ \t \n"})
wantMatched(t, files, get(t, "/.env"), "env-file")
}
func TestFilesReadInNameOrderThenLineOrder(t *testing.T) {
t.Parallel()
files := load(t, ruleFiles{
"50-b.rules": "b1 path log ^/\n\n# a comment\n # an indented one\nb2 path log ^/\n",
firstFile: "a1 path log ^/\r\n",
// None is a rule file.
"notes.txt": "notes, not rules\n",
"10-c.rules.bak": "an old copy\n",
"20-d.rules/keep": "a file in a directory\n",
})
wantMatched(t, files, get(t, "/"), "a1", "b1", "b2")
if files.Len() != 3 {
t.Errorf("%d rules loaded, want 3", files.Len())
}
}
func TestFileWhoseNameStartsWithADotIsNotARuleFile(t *testing.T) {
t.Parallel()
dir := writeFiles(t, ruleFiles{firstFile: "probe path block ^/probe\n"})
// The lock file Emacs makes beside a file while it is edited: a link to
// nothing, which cannot be read.
err := os.Symlink("user@host.1234:1700000000", filepath.Join(dir, ".#"+firstFile))
if err != nil {
t.Fatalf("symlink: %v", err)
}
params, _ := newParams(dir)
files, err := rules.Load(params)
if err != nil {
t.Fatalf("load: %v", err)
}
wantMatched(t, files, get(t, "/probe"), "probe")
}
func TestFaultStopsTheStartNamingTheFileAndLine(t *testing.T) {
t.Parallel()
for _, tc := range []struct {
name string
content string
line int
want string
}{
{
"too few fields", "env-file path ban\n", 1,
"is not a rule: an id, a target, an action and a regex, " +
"separated by spaces or tabs",
},
{
// Else its regex would be a space, found in nearly every user agent.
"a regex of only spaces and tabs", "scanner user_agent ban\t \n", 1,
"is not a rule: an id, a target, an action and a regex, " +
"separated by spaces or tabs",
},
{
"an id of other characters", "# ids\n\nenv.file path ban ^/\n", 3,
`the id "env.file" is not an id of letters, digits, - and _`,
},
{
"an unknown target", "env-file paths ban ^/\n", 1,
`the target "paths" is not path, query, uri, method, host, ` +
"user_agent, referer or header:<Name>",
},
{
"a header without a name", "env-file header: ban ^/\n", 1,
`the target "header:" is not path, query, uri, method, host, ` +
"user_agent, referer or header:<Name>",
},
{
"a header name written with its colon", "sqlmap header:User-Agent: ban sqlmap\n", 1,
`the target "header:User-Agent:" has a character after header: ` +
"that no header name can have",
},
{
"a header name with a semicolon", "accept header:Accept;q log ^$\n", 1,
`the target "header:Accept;q" has a character after header: ` +
"that no header name can have",
},
{
"a header name with brackets", "x-header header:X(y) log ^$\n", 1,
`the target "header:X(y)" has a character after header: ` +
"that no header name can have",
},
{
"the Host header", "host-header header:host block ^$\n", 1,
`the target "header:host" names a header that Go's HTTP server ` +
"takes out of every request, so a rule never sees it; " +
"the request's host is the target host",
},
{
"the Transfer-Encoding header",
"# bodies sent in chunks\nchunked header:Transfer-Encoding block ^chunked$\n", 2,
`the target "header:Transfer-Encoding" names a header that Go's ` +
"HTTP server takes out of every request, so a rule never sees it",
},
{
"an unknown action", "env-file path deny ^/\n", 1,
`the action "deny" is not log, block or ban`,
},
{
"a regex that does not compile", "env-file path ban ^/(\n", 1,
"the regex does not compile: error parsing regexp: " +
"missing closing ): `^/(`",
},
} {
t.Run(tc.name, func(t *testing.T) {
t.Parallel()
dir := writeFiles(t, ruleFiles{"00-default.rules": tc.content})
path := filepath.Join(dir, "00-default.rules")
wantRefused(t, dir, path+", line "+strconv.Itoa(tc.line)+": "+tc.want)
})
}
}
func TestIDUsedTwiceStopsTheStartNamingBothPlaces(t *testing.T) {
t.Parallel()
dir := writeFiles(t, ruleFiles{
"00-a.rules": "probe path log ^/a\n",
"50-b.rules": "other path log ^/b\nprobe path ban ^/c\n",
})
wantRefused(t, dir, filepath.Join(dir, "50-b.rules")+`, line 2: the id "probe" `+
"is already the id of the rule at "+filepath.Join(dir, "00-a.rules")+", line 1")
}
func TestDirectoryThatDoesNotExistStopsTheStart(t *testing.T) {
t.Parallel()
dir := filepath.Join(t.TempDir(), "rules.d")
wantRefused(t, dir, "SWWAF_RULES_DIR cannot be read: open "+dir+
": no such file or directory")
}
func TestEmptyDirectoryLoadsNoRulesAndSaysSo(t *testing.T) {
t.Parallel()
params, lines := newParams(writeFiles(t, ruleFiles{"00-default.rules": "# none\n"}))
files, err := rules.Load(params)
if err != nil {
t.Fatalf("load: %v", err)
}
line := lines.waitFor(t, read)
if files.Len() != 0 || line["rules"] != 0.0 {
t.Errorf("%d rules loaded, and the log says %v, want none", files.Len(), line)
}
}
func TestRuleFilesOffReadNothing(t *testing.T) {
t.Parallel()
// SWWAF_RULES_DIR does not exist, which would stop the start.
params, _ := newParams(filepath.Join(t.TempDir(), "rules.d"))
params.Enabled = false
files, err := rules.Load(params)
if err != nil {
t.Fatalf("load: %v", err)
}
if files.Len() != 0 || files.Match(get(t, "/")) != nil {
t.Errorf("%d rules loaded with the rule files off", files.Len())
}
// It would watch until the test ends.
files.Watch(t.Context())
}
func TestEditsTakenInWhileRunning(t *testing.T) {
t.Parallel()
dir := writeFiles(t, ruleFiles{firstFile: "first path block ^/first\n"})
files, lines, _ := watch(t, dir)
// matches reports whether path matches a rule.
matches := func(path string) bool { return len(files.Match(get(t, path))) == 1 }
// A file added.
save(t, dir, "50-b.rules", "second path block ^/second\n")
lines.waitUntil(t, func() bool { return matches("/second") })
wantMatched(t, files, get(t, "/first"), "first")
// A file edited.
save(t, dir, firstFile, "first path block ^/edited\n")
lines.waitUntil(t, func() bool { return !matches("/first") })
wantMatched(t, files, get(t, "/edited"), "first")
// A file removed.
err := os.Remove(filepath.Join(dir, "50-b.rules"))
if err != nil {
t.Fatalf("remove: %v", err)
}
lines.waitUntil(t, func() bool { return !matches("/second") })
wantMatched(t, files, get(t, "/edited"), "first")
}
func TestBrokenEditKeepsTheRulesAsTheyWere(t *testing.T) {
t.Parallel()
dir := writeFiles(t, ruleFiles{firstFile: "first path block ^/first\n"})
files, lines, queue := watch(t, dir)
// The edit's second line has an unknown action, so the rules stay as
// they were, the first line's earlier version included.
save(t, dir, firstFile, "first path block ^/edited\nsecond path bann ^/second\n")
line := lines.waitFor(t, hasError)
want := filepath.Join(dir, firstFile) +
`, line 2: the action "bann" is not log, block or ban`
if line["error"] != want || line["level"] != "ERROR" {
t.Errorf("logged %v, want an error %q", line, want)
}
// The error is raised as a file_error alert too, for the file.
wantFileError := func() {
t.Helper()
waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
if len(waiting) != 1 || waiting[0].Event != alerts.EventFileError ||
waiting[0].Reason != hasError || waiting[0].Detail["error"] != want ||
waiting[0].Detail["file"] != filepath.Join(dir, firstFile) {
t.Errorf("alerts waiting %+v, want one file_error alert for %q", waiting, want)
}
}
wantFileError()
wantMatched(t, files, get(t, "/first"), "first")
wantMatched(t, files, get(t, "/second"))
// Once mended, the file is read again, and raises no alert.
save(t, dir, firstFile, "first path block ^/edited\nsecond path ban ^/second\n")
lines.waitUntil(t, func() bool { return len(files.Match(get(t, "/second"))) == 1 })
wantMatched(t, files, get(t, "/edited"), "first")
wantFileError()
}
func TestDefaultFileBansProbesAtTheSiteRootAlone(t *testing.T) {
t.Parallel()
params, _ := newParams(filepath.Join("..", "..", "share", "rules.d"))
files, err := rules.Load(params)
if err != nil {
t.Fatalf("load the default file: %v", err)
}
// Probes sent by a browser, by the rule that refuses them.
for rule, targets := range map[string][]string{
"env-file": {"/.env", "/.env.production", "/.ENV"},
"vcs-dir": {"/.git/config", "/.git", "/.svn/entries"},
"secrets-dir": {"/.aws/credentials", "/.ssh/id_rsa"},
"secret-file": {"/.htpasswd", "/.DS_Store", "/.git-credentials"},
"editor-dir": {"/.vscode/sftp.json"},
"backup-file": {
"/wp-config.php.bak", "/index.php~", "/dump.sql", "/backup.sql.gz",
},
"log-file": {"/debug.log"},
"compose-file": {"/docker-compose.yml", "/compose.yaml"},
"php-shell": {"/shell.php"},
"path-traversal": {
"/static/../../etc/passwd", "/f?f=%2e%2e%2f%2e%2e%2fetc%2fpasswd",
},
} {
for _, target := range targets {
wantRefusedBy(t, files, target, browser, rule)
}
}
// Scanners, by their user agents.
for _, scanner := range []string{
"sqlmap/1.8.4#stable (https://sqlmap.org)",
"Mozilla/5.0 (compatible; Nuclei - Open-source project)",
} {
wantRefusedBy(t, files, "/", scanner, "scanner-agent")
}
// Ordinary requests to a code forge for files of those names deeper
// in its paths, and for other files at its root.
for _, target := range []string{
"/owner/repo/src/branch/main/.env.example",
"/owner/repo/src/branch/main/.env",
"/owner/repo/src/branch/main/.github/workflows/ci.yml",
"/owner/repo/src/branch/main/.vscode/settings.json",
"/owner/repo/src/branch/main/.htaccess",
"/owner/repo/src/branch/main/docker-compose.yml",
"/owner/repo/src/branch/main/db/schema.sql",
"/owner/repo/raw/branch/main/debug.log",
"/owner/repo.git/info/refs?service=git-upload-pack",
"/owner/repo/src/branch/main/docs/../README.md",
"/user/login?redirect_to=%2fowner%2frepo",
"/index.php",
"/.well-known/security.txt",
} {
r := get(t, target)
r.Header.Set(userAgent, browser)
matched := files.Match(r)
if len(matched) != 0 {
t.Errorf("%s matched %v, want no rule", target, ids(matched))
}
}
// A request without a user agent is only noted.
wantMatched(t, files, get(t, "/"), "empty-agent")
}
// ruleFiles are files to write into a directory of rule files, by name.
type ruleFiles map[string]string
// writeFiles writes files into a new directory, and returns it.
func writeFiles(t *testing.T, files ruleFiles) string {
t.Helper()
dir := t.TempDir()
for name, content := range files {
path := filepath.Join(dir, name)
err := os.MkdirAll(filepath.Dir(path), 0o700)
if err != nil {
t.Fatalf("mkdir: %v", err)
}
err = os.WriteFile(path, []byte(content), 0o600)
if err != nil {
t.Fatalf("write %s: %v", name, err)
}
}
return dir
}
// save writes content to the rule file name in dir as an editor that
// saves by renaming does, so that the file is never seen half written.
func save(t *testing.T, dir, name, content string) {
t.Helper()
path := filepath.Join(dir, name)
err := os.WriteFile(path+".tmp", []byte(content), 0o600)
if err != nil {
t.Fatalf("write %s: %v", name, err)
}
err = os.Rename(path+".tmp", path)
if err != nil {
t.Fatalf("rename: %v", err)
}
}
// newParams returns Params for the rule files in dir, switched on, with
// the process log in the processLog returned, and the alerts waiting in a
// queue for a webhook that is never sent them.
func newParams(dir string) (rules.Params, processLog) {
lines := make(processLog, maxLogLines)
return rules.Params{
Dir: dir,
Enabled: true,
ProcessLog: slog.New(slog.NewJSONHandler(lines, nil)),
Alerts: alerts.New(alerts.Params{
WebhookURL: &url.URL{Scheme: "https", Host: "alerts.example"},
Events: alerts.Events(),
Cooldown: 15 * time.Minute,
Now: time.Now,
}),
}, lines
}
// load writes files into a new directory and loads the rules in it.
func load(t *testing.T, files ruleFiles) *rules.Files {
t.Helper()
params, _ := newParams(writeFiles(t, files))
params.ProcessLog = slog.New(slog.DiscardHandler)
loaded, err := rules.Load(params)
if err != nil {
t.Fatalf("load: %v", err)
}
return loaded
}
// watch loads the rules in dir, runs their Watch until the test ends, and
// waits until it watches the directory. It returns the alerts' queue as
// well.
func watch(t *testing.T, dir string) (*rules.Files, processLog, *alerts.Queue) {
t.Helper()
params, lines := newParams(dir)
files, err := rules.Load(params)
if err != nil {
t.Fatalf("load: %v", err)
}
ctx, stop := context.WithCancel(t.Context())
stopped := make(chan struct{})
go func() {
files.Watch(ctx)
close(stopped)
}()
t.Cleanup(func() {
stop()
<-stopped
})
lines.waitFor(t, watching)
return files, lines, params.Alerts
}
// wantRefused checks that loading the rule files in dir fails with the
// error want.
func wantRefused(t *testing.T, dir, want string) {
t.Helper()
params, _ := newParams(dir)
_, err := rules.Load(params)
if err == nil || err.Error() != want {
t.Errorf("error %v, want %s", err, want)
}
}
// get returns a GET request for target, a path and an optional query, as
// smallwebwaf's server reads it, without a user agent.
func get(t *testing.T, target string) *http.Request {
t.Helper()
return httptest.NewRequestWithContext(t.Context(), http.MethodGet,
"http://app.example"+target, nil)
}
// wantRefusedBy checks that a GET request for target with the user agent
// sent matches rule alone, and that rule refuses it.
func wantRefusedBy(t *testing.T, files *rules.Files, target, sent, rule string) {
t.Helper()
r := get(t, target)
r.Header.Set(userAgent, sent)
matched := files.Match(r)
if len(matched) != 1 || matched[0].ID != rule || matched[0].Action == rules.ActionLog {
t.Errorf("%s from %q matched %v, want %s alone, refusing it", target,
sent, ids(matched), rule)
}
}
// wantMatched checks the ids of the rules r matches, in order.
func wantMatched(t *testing.T, files *rules.Files, r *http.Request, want ...string) {
t.Helper()
got := ids(files.Match(r))
if !slices.Equal(got, want) {
t.Errorf("%s matched %v, want %v", r.URL, got, want)
}
}
// ids returns the ids of matched.
func ids(matched []rules.Rule) []string {
got := make([]string, 0, len(matched))
for _, rule := range matched {
got = append(got, rule.ID)
}
return got
}
// processLog receives the lines of a process log, each a JSON object, for
// a test to wait for.
type processLog chan string
// Write receives a line of the process log.
func (l processLog) Write(line []byte) (int, error) {
l <- string(line)
return len(line), nil
}
// waitFor returns the next line of the process log whose message is msg,
// passing over the lines before it. It waits as long as that takes, so
// that a slow test process cannot fail the test.
func (l processLog) waitFor(t *testing.T, msg string) map[string]any {
t.Helper()
for line := range l {
var fields map[string]any
err := json.Unmarshal([]byte(line), &fields)
if err != nil {
t.Fatalf("process log line %q is not JSON: %v", line, err)
}
if fields["msg"] == msg {
return fields
}
}
return nil
}
// waitUntil waits for the rule files to be read until done reports true,
// as it does once they have been read after the test's last change. They
// can be read before then too, as they are once Watch starts watching.
func (l processLog) waitUntil(t *testing.T, done func() bool) {
t.Helper()
for !done() {
l.waitFor(t, read)
}
}
internal/rules/watch_internal_test.go
+165
View File
@@ -0,0 +1,165 @@
package rules
import (
"context"
"log/slog"
"net/http"
"net/http/httptest"
"os"
"path/filepath"
"slices"
"testing"
"testing/synctest"
"time"
"github.com/fsnotify/fsnotify"
"sneak.berlin/go/smallwebwaf/internal/alerts"
)
// The tests below run readAfterChanges in a synctest bubble, where time is
// a clock of the test's own: time.Sleep moves it on at once, and
// synctest.Wait returns once readAfterChanges waits again, so that every
// reading due by then is done. The test sends the changes itself, as the
// watch of a directory cannot run in a bubble.
func TestFileWrittenInTwoPartsTakenInOnlyWhole(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
dir := t.TempDir()
path := filepath.Join(dir, "50-app.rules")
writeFile(t, path, "first path block ^/first\n")
files := load(t, dir)
changes := run(t, files)
file, err := os.Create(path) //nolint:gosec // a file the test wrote
if err != nil {
t.Fatalf("create: %v", err)
}
defer func() {
_ = file.Close()
}()
// The first part ends in the middle of a ban rule's regex, which,
// read then, would ban every request.
write(t, file, "first path block ^/first\nprobe path ban ^/")
changes <- fsnotify.Event{Name: path, Op: fsnotify.Write}
time.Sleep(quietTime - time.Nanosecond)
synctest.Wait()
wantMatched(t, files, "/anything")
// The second part starts the wait again.
write(t, file, `\.env$`+"\n")
changes <- fsnotify.Event{Name: path, Op: fsnotify.Write}
time.Sleep(quietTime - time.Nanosecond)
synctest.Wait()
wantMatched(t, files, "/.env")
time.Sleep(time.Nanosecond)
synctest.Wait()
wantMatched(t, files, "/.env", "probe")
wantMatched(t, files, "/anything")
})
}
func TestEditSavedBeforeTheWatchStartsTakenIn(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
dir := t.TempDir()
path := filepath.Join(dir, "50-app.rules")
writeFile(t, path, "first path block ^/first\n")
files := load(t, dir)
// Saved after Load read the files, and before the directory was
// watched, so that no change is seen for it.
writeFile(t, path, "first path block ^/edited\n")
run(t, files)
time.Sleep(quietTime)
synctest.Wait()
wantMatched(t, files, "/edited", "first")
})
}
// load loads the rules in dir.
func load(t *testing.T, dir string) *Files {
t.Helper()
files, err := Load(Params{
Dir: dir, Enabled: true, ProcessLog: slog.New(slog.DiscardHandler),
Alerts: alerts.New(alerts.Params{}),
})
if err != nil {
t.Fatalf("load: %v", err)
}
return files
}
// run runs files' readAfterChanges until the test ends, and returns the
// channel that sends it changes.
func run(t *testing.T, files *Files) chan<- fsnotify.Event {
t.Helper()
changes := make(chan fsnotify.Event)
ctx, stop := context.WithCancel(t.Context())
stopped := make(chan struct{})
go func() {
files.readAfterChanges(ctx, changes, nil)
close(stopped)
}()
t.Cleanup(func() {
stop()
<-stopped
})
return changes
}
// writeFile writes content to the file at path.
func writeFile(t *testing.T, path, content string) {
t.Helper()
err := os.WriteFile(path, []byte(content), 0o600)
if err != nil {
t.Fatalf("write %s: %v", path, err)
}
}
// write writes text to the end of file.
func write(t *testing.T, file *os.File, text string) {
t.Helper()
_, err := file.WriteString(text)
if err != nil {
t.Fatalf("write: %v", err)
}
}
// wantMatched checks the ids of the rules that a GET request for path
// matches, in order.
func wantMatched(t *testing.T, files *Files, path string, want ...string) {
t.Helper()
r := httptest.NewRequestWithContext(t.Context(), http.MethodGet,
"http://app.example"+path, nil)
matched := files.Match(r)
got := make([]string, 0, len(matched))
for _, rule := range matched {
got = append(got, rule.ID)
}
if !slices.Equal(got, want) {
t.Errorf("%s matched %v, want %v", path, got, want)
}
}
internal/smallwebwaf/healthcheck.go
+5 -3
View File
@@ -23,6 +23,8 @@ var errHealthEndpoint = errors.New("smallwebwaf's health endpoint answered")
// 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(
@@ -50,13 +52,13 @@ func healthCheck(ctx context.Context, lookupEnv func(string) (string, bool)) err
ctx, cancel := context.WithTimeout(ctx, healthCheckTimeout)
defer cancel()
cfg, err := config.FromEnvironment(lookupEnv)
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(cfg.ListenAddr)
_, 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)
@@ -75,7 +77,7 @@ func healthCheck(ctx context.Context, lookupEnv func(string) (string, bool)) err
return fmt.Errorf("%w %s", errHealthEndpoint, res.Status)
}
conn, err := (&net.Dialer{}).DialContext(ctx, "tcp", appAddress(cfg.UpstreamURL))
conn, err := (&net.Dialer{}).DialContext(ctx, "tcp", appAddress(upstreamURL))
if err != nil {
return fmt.Errorf("connect to the app: %w", err)
}
internal/smallwebwaf/healthcheck_test.go
+33
View File
@@ -6,6 +6,8 @@ import (
"net"
"net/http"
"net/http/httptest"
"os"
"path/filepath"
"strings"
"testing"
"time"
@@ -28,6 +30,7 @@ func TestHealthCheck(t *testing.T) {
listenAddr: localhost + ":0",
upstreamURL: app.URL,
stateDir: t.TempDir(),
rulesDir: t.TempDir(),
}
go func() {
@@ -42,6 +45,21 @@ func TestHealthCheck(t *testing.T) {
wantHealthCheck(t, env, 0, "")
// The health check reads those two settings alone, here given as
// files: a removed or invalid token file, or an invalid value of
// another setting, does not fail it.
for _, other := range []struct{ name, value string }{
{"SWWAF_METRICS_TOKEN_FILE", filepath.Join(t.TempDir(), "removed")},
{"SWWAF_METRICS_TOKEN_FILE", writeFile(t, "too short\n")},
{"SWWAF_MODE", "neither"},
} {
wantHealthCheck(t, map[string]string{
listenAddr + "_FILE": writeFile(t, ":"+port+"\n"),
upstreamURL + "_FILE": writeFile(t, app.URL+"\n"),
other.name: other.value,
}, 0, "")
}
app.Close()
wantHealthCheck(t, env, 1, "unhealthy: connect to the app: ")
@@ -97,3 +115,18 @@ func wantHealthCheck(t *testing.T, env map[string]string, status int, message st
got, wrote, status, message)
}
}
// writeFile writes contents to a file in a directory of its own, removed
// when the test ends, and returns the file's path.
func writeFile(t *testing.T, contents string) string {
t.Helper()
path := filepath.Join(t.TempDir(), "setting")
err := os.WriteFile(path, []byte(contents), 0o600)
if err != nil {
t.Fatalf("write %s: %v", path, err)
}
return path
}
internal/smallwebwaf/smallwebwaf.go
+220 -42
View File
@@ -1,6 +1,7 @@
// Package smallwebwaf runs the smallwebwaf process: it reads the settings
// and the state files, serves requests until it is told to stop, and then
// stops in an orderly way, writing the state files.
// Package smallwebwaf runs the smallwebwaf process: it reads the settings,
// the rule files, the lookup database and the state files, serves requests
// until it is told to stop, and then stops in an orderly way, writing the
// state files.
package smallwebwaf
import (
@@ -15,10 +16,13 @@ import (
"syscall"
"time"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/config"
"sneak.berlin/go/smallwebwaf/internal/lookup"
"sneak.berlin/go/smallwebwaf/internal/proxy"
"sneak.berlin/go/smallwebwaf/internal/remotelog"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
"sneak.berlin/go/smallwebwaf/internal/rules"
"sneak.berlin/go/smallwebwaf/internal/state"
)
@@ -27,6 +31,11 @@ import (
// runit and docker wait a little longer before they kill the process.
const shutdownTimeout = 5 * time.Second
// remoteLogStopTimeout is how long, as smallwebwaf stops, the log lines
// still waiting are sent to SWWAF_LOG_REMOTE_URL before they are given
// up. stdout has carried them.
const remoteLogStopTimeout = 2 * time.Second
// Params are what Run needs from the process.
type Params struct {
// Version is the version of the binary, set when it is built.
@@ -56,11 +65,12 @@ func Main(version string) int {
})
}
// Run reads the settings and the state files, then serves requests until
// ctx is done. It returns the process's exit status, 1 when smallwebwaf
// cannot start.
// Run reads the settings, the rule files, the lookup database and the
// state files, then serves requests until ctx is done. It returns the
// process's exit status, 1 when smallwebwaf cannot start.
func Run(ctx context.Context, params Params) int {
processLog := requestlog.NewProcessLogger(params.Stdout)
processLog := requestlog.NewProcessLogger(params.Stdout,
config.InstanceName(params.LookupEnv))
cfg, err := config.FromEnvironment(params.LookupEnv)
if err != nil {
@@ -69,28 +79,50 @@ func Run(ctx context.Context, params Params) int {
return 1
}
// The state files give times in UTC.
// While SWWAF_LOG_REMOTE_URL is set, every line on stdout from here on
// is sent there too.
stdout := params.Stdout
var remote *remotelog.Sender
if cfg.LogRemoteURL != nil {
remote = newRemoteLogSender(cfg)
stdout = io.MultiWriter(params.Stdout, remote)
processLog = requestlog.NewProcessLogger(stdout, cfg.InstanceName)
stopSending := startSending(ctx, remote, processLog)
defer stopSending()
}
// The state files and the alerts give times in UTC.
now := func() time.Time { return time.Now().UTC() }
server := proxy.New(proxy.Params{
Config: cfg,
RequestLog: params.Stdout,
ProcessLog: processLog,
GeoJSURL: lookup.URL,
Now: now,
})
alertQueue := newAlertQueue(cfg, now, processLog)
files, err := state.Load(state.Params{
Dir: cfg.StateDir,
WriteDelay: cfg.StateWriteDelay,
CounterInterval: cfg.StateCounterInterval,
Ledger: server.Ledger,
Limiter: server.Limiter,
GeoJS: server.GeoJS,
Now: now,
ruleFiles, err := rules.Load(rules.Params{
Dir: cfg.RulesDir,
Enabled: cfg.RulesEnabled,
ProcessLog: processLog,
Metrics: server.Metrics,
Alerts: alertQueue,
})
if err != nil {
processLog.Error("cannot use the rule files", "error", err.Error())
return 1
}
server, err := newServer(cfg, stdout, processLog, now, ruleFiles, alertQueue)
if err != nil {
processLog.Error("cannot use the lookup database", "error", err.Error())
return 1
}
if remote != nil {
server.Metrics.AddRemoteLog(remote)
}
files, err := loadStateFiles(cfg, server, alertQueue, now, processLog)
if err != nil {
processLog.Error("cannot use the state files", "error", err.Error())
@@ -110,15 +142,139 @@ func Run(ctx context.Context, params Params) int {
"address", listener.Addr().String(),
"settings", cfg)
return serve(ctx, server.Server, listener, files, processLog)
return serve(ctx, server, listener, files, ruleFiles, alertQueue, processLog)
}
// serve serves requests on listener, and writes the state files as they
// are due, until ctx is done. Then it gives the requests in progress
// shutdownTimeout to finish, and writes every state file.
// newServer returns the server smallwebwaf runs, with the metrics of the
// alerts, after reading the lookup database while SWWAF_LOOKUP_SOURCE is
// file. A lookup database that cannot be read is an error.
func newServer(
cfg *config.Config, stdout io.Writer, processLog *slog.Logger,
now func() time.Time, ruleFiles *rules.Files, alertQueue *alerts.Queue,
) (*proxy.Server, error) {
var lookupFile *lookup.File
if cfg.LookupSource == "file" {
var err error
lookupFile, err = lookup.OpenFile(lookup.FileParams{
Path: cfg.LookupDBPath,
Now: now,
ProcessLog: processLog,
Alerts: alertQueue,
})
if err != nil {
return nil, err
}
}
server := proxy.New(proxy.Params{
Config: cfg,
RequestLog: stdout,
ProcessLog: processLog,
GeoJSURL: lookup.URL,
LookupFile: lookupFile,
Now: now,
Rules: ruleFiles,
Alerts: alertQueue,
})
server.Metrics.AddAlerts(alertQueue)
if lookupFile != nil {
server.Metrics.AddLookupFile(lookupFile.LastRead, lookupFile.ReadFailures)
}
return server, nil
}
// loadStateFiles reads the state files into the parts of server and into
// alertQueue, as state.Load does.
func loadStateFiles(
cfg *config.Config, server *proxy.Server, alertQueue *alerts.Queue,
now func() time.Time, processLog *slog.Logger,
) (*state.Files, error) {
return state.Load(state.Params{
Dir: cfg.StateDir,
WriteDelay: cfg.StateWriteDelay,
CounterInterval: cfg.StateCounterInterval,
Ledger: server.Ledger,
Limiter: server.Limiter,
GeoJS: server.GeoJS,
Alerts: alertQueue,
Anomalies: server.Anomalies,
Now: now,
ProcessLog: processLog,
Metrics: server.Metrics,
})
}
// newAlertQueue returns the queue of the alerts to the webhook, Slack and
// ntfy, with the settings for them.
func newAlertQueue(
cfg *config.Config, now func() time.Time, processLog *slog.Logger,
) *alerts.Queue {
return alerts.New(alerts.Params{
WebhookURL: cfg.AlertWebhookURL,
WebhookHeaders: cfg.AlertWebhookHeaders,
SlackURL: cfg.AlertSlackWebhookURL,
NtfyURL: cfg.AlertNtfyURL,
NtfyToken: cfg.AlertNtfyToken,
Events: cfg.AlertEvents,
Cooldown: cfg.AlertCooldown,
MaxPerHour: cfg.AlertMaxPerHour,
Instance: cfg.InstanceName,
Now: now,
ProcessLog: processLog,
})
}
// newRemoteLogSender returns a sender of the log lines to
// SWWAF_LOG_REMOTE_URL, with the settings for it.
func newRemoteLogSender(cfg *config.Config) *remotelog.Sender {
return remotelog.New(remotelog.Params{
URL: cfg.LogRemoteURL,
RootCAs: cfg.LogRemoteTLSCAs,
Buffer: cfg.LogRemoteBuffer,
Facility: cfg.LogRemoteFacility,
AppName: cfg.LogRemoteAppName,
})
}
// startSending runs remote until the function it returns is called, which
// then waits at most remoteLogStopTimeout for the lines still waiting to
// be sent. Sending goes on after ctx is done, so that the lines written
// while smallwebwaf stops are sent too.
func startSending(
ctx context.Context, remote *remotelog.Sender, processLog *slog.Logger,
) func() {
sending, stop := context.WithCancel(context.WithoutCancel(ctx))
sent := make(chan struct{})
go func() {
remote.Run(sending, processLog)
close(sent)
}()
return func() {
stop()
select {
case <-sent:
case <-time.After(remoteLogStopTimeout):
}
}
}
// serve serves requests on listener, writes the state files as they are
// due, takes in an admin's edits of them, reads the rule files again as
// they change, and the lookup database when it is replaced, and sends the
// alerts, until ctx is done. Then it gives the requests in progress
// shutdownTimeout to finish, and writes every state file, alerts.json with
// the alerts still waiting.
func serve(
ctx context.Context, server *http.Server, listener net.Listener,
files *state.Files, processLog *slog.Logger,
ctx context.Context, server *proxy.Server, listener net.Listener,
files *state.Files, ruleFiles *rules.Files, alertQueue *alerts.Queue,
processLog *slog.Logger,
) int {
served := make(chan error, 1)
@@ -129,12 +285,15 @@ func serve(
writing, stopWriting := context.WithCancel(ctx)
defer stopWriting()
written := make(chan struct{})
go func() {
files.Run(writing)
close(written)
}()
written := inBackground(func() { files.Run(writing) })
watched := inBackground(func() { files.Watch(writing) })
rulesWatched := inBackground(func() { ruleFiles.Watch(writing) })
lookupFileWatched := inBackground(func() {
if server.LookupFile != nil {
server.LookupFile.Watch(writing)
}
})
alertsSent := inBackground(func() { alertQueue.Run(writing) })
select {
case err := <-served:
@@ -165,13 +324,19 @@ func serve(
return 1
}
// Run's last write has ended, so nothing else writes the files. Every
// request has ended too, but for two kinds that Go's server does not
// wait for: one cut off because Shutdown timed out, and one whose
// connection switched protocols, such as a WebSocket. Such a request
// adds to its client's history only as it ends, which can be after
// this write, and then that request is missing from clients.json.
// Run and Watch have ended, so nothing else reads or writes the
// files, and no alert is being sent, so that alerts.json keeps every
// alert not yet sent. Every request has ended too, but for two kinds
// that Go's server does not wait for: one cut off because Shutdown
// timed out, and one whose connection switched protocols, such as a
// WebSocket. Such a request adds to its client's history only as it
// ends, which can be after this write, and then that request is
// missing from clients.json.
<-written
<-watched
<-rulesWatched
<-lookupFileWatched
<-alertsSent
err = files.WriteAll()
if err != nil {
@@ -184,3 +349,16 @@ func serve(
return 0
}
// inBackground runs task on a goroutine of its own, and returns a channel
// that is closed once task has returned.
func inBackground(task func()) <-chan struct{} {
done := make(chan struct{})
go func() {
task()
close(done)
}()
return done
}
internal/smallwebwaf/smallwebwaf_internal_test.go
+82
View File
@@ -0,0 +1,82 @@
package smallwebwaf
import (
"log/slog"
"net/url"
"testing"
"testing/synctest"
"time"
"sneak.berlin/go/smallwebwaf/internal/remotelog"
)
// The stop's tests run in a synctest bubble, where the time package runs
// on a clock of the test's own, so that how long the stop takes can be
// told exactly. The sender is held up by its process log, not by the
// network: a goroutine of the bubble that waits on the network keeps that
// clock from moving on.
func TestStopWaitsForTheSenderToFinish(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
took := stopHeldSender(t, time.Second)
if took != time.Second {
t.Errorf("the stop took %s, want the second the sender took", took)
}
})
}
func TestStopWaitsForTheSenderAtMostTwoSeconds(t *testing.T) {
t.Parallel()
synctest.Test(t, func(t *testing.T) {
took := stopHeldSender(t, time.Minute)
if took != 2*time.Second {
t.Errorf("the stop took %s, want 2s", took)
}
})
}
// heldLog holds each line written to it until it is closed.
type heldLog chan struct{}
// Write waits until the log is closed.
func (l heldLog) Write(p []byte) (int, error) {
<-l
return len(p), nil
}
// stopHeldSender starts sending to an endpoint the sender cannot connect
// to, holds the sender as it logs that failure until release has passed,
// stops the sending, and returns how long the stop took. It returns once
// the sender has ended, as a bubble must.
func stopHeldSender(t *testing.T, release time.Duration) time.Duration {
t.Helper()
log := make(heldLog)
sender := remotelog.New(remotelog.Params{
// No port is 65536, so each attempt to connect fails at once,
// before it reaches the network.
URL: &url.URL{Scheme: remotelog.SchemeTCP, Host: "127.0.0.1:65536"},
Buffer: 1,
})
stopSending := startSending(t.Context(), sender,
slog.New(slog.NewJSONHandler(log, nil)))
synctest.Wait()
time.AfterFunc(release, func() { close(log) })
stopped := time.Now()
stopSending()
took := time.Since(stopped)
time.Sleep(release)
synctest.Wait()
return took
}
internal/smallwebwaf/smallwebwaf_test.go
+981 -16
View File
File diff suppressed because it is too large Load Diff
internal/state/state.go
+506 -95
View File
@@ -1,24 +1,36 @@
// Package state keeps smallwebwaf's state in JSON files in
// SWWAF_STATE_DIR, as the "Persistent state" section of SPEC.md describes:
// bans.json holds the bans, clients.json each client's counters and
// history, and lookups.json GeoJS's answers. Load reads them at start, and
// Run and WriteAll write them, each from a snapshot its part takes under
// its own lock, so that no request waits on the disk.
// history, lookups.json GeoJS's answers, and alerts.json the cooldowns,
// the hour under way, the alerts waiting for each destination and the
// anomaly counters. Load
// reads them at start, Watch takes in an admin's edit of one while
// smallwebwaf runs, and Run and WriteAll write them. The disk is read and
// written outside the parts' locks, which are held only to take a
// snapshot or to put in what a file holds, so that no request waits on
// the disk.
package state
import (
"bytes"
"context"
"crypto/sha256"
"encoding/json"
"errors"
"fmt"
"io/fs"
"log/slog"
"maps"
"net/netip"
"os"
"path/filepath"
"slices"
"sync"
"time"
"github.com/fsnotify/fsnotify"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/anomaly"
"sneak.berlin/go/smallwebwaf/internal/bans"
"sneak.berlin/go/smallwebwaf/internal/lookup"
"sneak.berlin/go/smallwebwaf/internal/metrics"
@@ -37,12 +49,19 @@ const (
bansJSON = "bans.json"
clientsJSON = "clients.json"
lookupsJSON = "lookups.json"
alertsJSON = "alerts.json"
)
var (
errVersion = errors.New("unknown version")
// errMissing is for an entry without a field it needs.
errMissing = errors.New("has no")
errCause = errors.New("is not limit, attack or admin")
errDestination = errors.New("is not webhook, slack or ntfy")
errScope = errors.New("is not client, net, asn, total or watch")
errWaitingList = errors.New(`waiting is a list, but now lists the alerts by ` +
`destination: put the list under "webhook", as "waiting": {"webhook": [...]}, ` +
`or remove the file`)
)
// Params are what Load needs.
@@ -54,36 +73,56 @@ type Params struct {
// is (SWWAF_STATE_COUNTER_INTERVAL).
WriteDelay time.Duration
CounterInterval time.Duration
// Ledger, Limiter and GeoJS hold the state.
// Ledger, Limiter, GeoJS, Alerts and Anomalies hold the state. Alerts
// also receive a file_error alert for an edit set aside, and for a
// write that fails while smallwebwaf runs.
Ledger *bans.Ledger
Limiter *ratelimit.Limiter
GeoJS *lookup.GeoJS
Alerts *alerts.Queue
Anomalies *anomaly.Counters
// Now tells the time by which the counters' buckets run out, normally
// time.Now in UTC.
Now func() time.Time
// ProcessLog receives what was read, and the writes that fail.
// ProcessLog receives what was read and taken in, the edits set aside,
// and the writes that fail.
ProcessLog *slog.Logger
// Metrics count each file's writes.
// Metrics count each file's writes, and the edits taken in and set
// aside.
Metrics *metrics.Metrics
}
// Files are the state files of a running smallwebwaf.
type Files struct {
params Params
// mu is held while a file is read for an edit, and while it is
// written, so that Watch and the writes take turns. No request takes
// it.
mu sync.Mutex
// sums are the SHA-256 sums of what each file held, by name, when
// smallwebwaf last read or wrote it. A file that holds anything else
// has been edited since.
sums map[string][sha256.Size]byte
}
// bansFile is bans.json, indented for an admin to read and edit.
type bansFile struct {
Version int `json:"version"`
Bans []banEntry `json:"bans"`
Bans []BanEntry `json:"bans"`
}
// banEntry is a ban as bans.json holds it: a permanent ban's expires is
// null.
type banEntry struct {
// BanEntry is a ban as bans.json holds it: a permanent ban's expires is
// null, a ban an admin added may have no cause, which makes it an
// admin's, and lifted is left out until an admin lifts the ban. The ban
// endpoints answer with bans in this form too.
type BanEntry struct {
Netblock netip.Prefix `json:"netblock"`
Start time.Time `json:"start"`
Expires *time.Time `json:"expires"`
Cause string `json:"cause"`
Reason string `json:"reason,omitempty"`
Lifted *time.Time `json:"lifted,omitempty"`
Notes bans.Notes `json:"notes"`
}
@@ -99,6 +138,17 @@ type lookupsFile struct {
Lookups []lookup.Answer `json:"lookups"`
}
// alertsFile is alerts.json, indented for an admin to read and edit.
//
//nolint:tagliatelle // the state files use snake_case, as the request log does
type alertsFile struct {
Version int `json:"version"`
Cooldowns []alerts.Cooldown `json:"cooldowns"`
Hour alerts.Hour `json:"hour"`
Waiting map[string][]alerts.Alert `json:"waiting"`
AnomalyCounters []anomaly.Counter `json:"anomaly_counters"`
}
// stateFile is the struct of a state file. Once the file is decoded, its
// check refuses the first entry without a field it needs, which would
// otherwise be read as something the entry does not say. data is the
@@ -120,41 +170,30 @@ func Load(params Params) (*Files, error) {
return nil, fmt.Errorf("SWWAF_STATE_DIR cannot be written: %w", err)
}
var (
bansIn bansFile
clientsIn clientsFile
lookupsIn lookupsFile
)
f := &Files{params: params, sums: map[string][sha256.Size]byte{}}
err = errors.Join(
read(params.Dir, bansJSON, &bansIn),
read(params.Dir, clientsJSON, &clientsIn),
read(params.Dir, lookupsJSON, &lookupsIn),
)
bansRead, bansErr := f.read(bansJSON)
clientsRead, clientsErr := f.read(clientsJSON)
lookupsRead, lookupsErr := f.read(lookupsJSON)
alertsRead, alertsErr := f.read(alertsJSON)
err = errors.Join(bansErr, clientsErr, lookupsErr, alertsErr)
if err != nil {
return nil, err
}
held := make([]bans.Ban, 0, len(bansIn.Bans))
for _, entry := range bansIn.Bans {
held = append(held, entry.ban())
}
params.Ledger.Load(held)
params.Limiter.Load(clientsIn.Clients, params.Now())
params.GeoJS.Load(lookupsIn.Lookups)
params.ProcessLog.Info("read the state files", "directory", params.Dir,
"bans", len(bansIn.Bans), "clients", len(clientsIn.Clients),
"lookups", len(lookupsIn.Lookups))
"bans", bansRead, "clients", clientsRead, "lookups", lookupsRead,
"alerts_waiting", alertsRead)
return &Files{params: params}, nil
return f, nil
}
// Run writes bans.json WriteDelay after a ban is made, with every ban
// made in between, and every file every CounterInterval, until ctx is
// done. A write that fails is logged, and the file is written again at
// its next write.
// done. A write that fails is logged, raised as a file_error alert, and
// the file is written again at its next write. Each write takes in an
// admin's edit of its file first, as writeFile describes.
func (f *Files) Run(ctx context.Context) {
interval := time.NewTicker(f.params.CounterInterval)
defer interval.Stop()
@@ -172,9 +211,11 @@ func (f *Files) Run(ctx context.Context) {
case <-bansDue:
bansDue = nil
f.logFailure(f.writeBans())
f.logFailure(bansJSON, f.writeFile(bansJSON))
case <-interval.C:
f.logFailure(f.WriteAll())
for _, name := range []string{bansJSON, clientsJSON, lookupsJSON, alertsJSON} {
f.logFailure(name, f.writeFile(name))
}
}
}
}
@@ -182,80 +223,367 @@ func (f *Files) Run(ctx context.Context) {
// WriteAll writes every state file, as smallwebwaf stops. A file that
// fails does not keep the others from being written.
func (f *Files) WriteAll() error {
return errors.Join(f.writeBans(), f.writeClients(), f.writeLookups())
return errors.Join(f.writeFile(bansJSON), f.writeFile(clientsJSON),
f.writeFile(lookupsJSON), f.writeFile(alertsJSON))
}
// logFailure logs a write that failed.
func (f *Files) logFailure(err error) {
// Watch watches Dir until ctx is done, and takes in an admin's edit of a
// state file as soon as it is saved: what the file holds replaces what
// smallwebwaf held for it. An edit that does not parse is left for the
// file's next write, which sets it aside, since a file can be read while
// an editor is still writing it. If Dir cannot be watched, that is
// logged, and an edit is taken in only before its file is written.
func (f *Files) Watch(ctx context.Context) {
watcher, err := fsnotify.NewWatcher()
if err == nil {
defer func() {
_ = watcher.Close()
}()
err = watcher.Add(f.params.Dir)
}
if err != nil {
f.params.ProcessLog.Error("writing the state files failed",
f.params.ProcessLog.Error("cannot watch the state files for edits",
"error", err.Error())
return
}
f.params.ProcessLog.Info("watching the state files for edits",
"directory", f.params.Dir)
for {
select {
case <-ctx.Done():
return
case event := <-watcher.Events:
switch name := filepath.Base(event.Name); name {
case bansJSON, clientsJSON, lookupsJSON, alertsJSON:
f.fileChanged(name)
}
case err = <-watcher.Errors:
f.params.ProcessLog.Warn("watching the state files failed",
"error", err.Error())
}
}
}
// writeBans writes bans.json.
func (f *Files) writeBans() error {
held := f.params.Ledger.Snapshot()
file := bansFile{Version: version, Bans: make([]banEntry, 0, len(held))}
for _, ban := range held {
file.Bans = append(file.Bans, newBanEntry(ban))
}
data, err := json.MarshalIndent(file, "", " ")
// logFailure logs a write of the state file name that failed, and raises
// a file_error alert for it.
func (f *Files) logFailure(name string, err error) {
if err != nil {
return fmt.Errorf("encode %s: %w", bansJSON, err)
}
const failed = "writing the state files failed"
return f.writeCounted(bansJSON, append(data, '\n'))
// Raised before it is logged, so that the alert is there once the
// log line is.
f.params.Alerts.Raise(alerts.Alert{
Event: alerts.EventFileError,
Reason: failed,
Detail: map[string]any{
"file": filepath.Join(f.params.Dir, name), "error": err.Error(),
},
})
f.params.ProcessLog.Error(failed, "error", err.Error())
}
}
// writeClients writes clients.json.
func (f *Files) writeClients() error {
data, err := encodeOnePerLine("clients", f.params.Limiter.Snapshot())
// fileChanged takes in what the state file name holds, as Watch sees it
// change, if that is an edit made since smallwebwaf last read or wrote
// the file. A file that cannot be read or does not parse is left for its
// next write.
func (f *Files) fileChanged(name string) {
f.mu.Lock()
defer f.mu.Unlock()
data, changed, err := f.readChanged(name)
if err != nil || !changed {
return
}
_ = f.takeInEdit(name, data)
}
// takeInEdit takes in data, an edit of the state file name, as takeIn
// does, and counts and logs it. Every edit taken in while smallwebwaf
// runs, by Watch or by a write, is taken in here. An edit that does not
// parse is neither counted nor logged, and takeIn's error returned.
func (f *Files) takeInEdit(name string, data []byte) error {
_, err := f.takeIn(name, data, true)
if err != nil {
return fmt.Errorf("encode %s: %w", clientsJSON, err)
return err
}
return f.writeCounted(clientsJSON, data)
// Counted before it is logged, so that the count is there once the
// log line is.
f.params.Metrics.StateFileEditTakenIn(name)
f.params.ProcessLog.Info("took in an edit of a state file",
"file", filepath.Join(f.params.Dir, name))
return nil
}
// writeLookups writes lookups.json.
func (f *Files) writeLookups() error {
data, err := encodeOnePerLine("lookups", f.params.GeoJS.Snapshot())
// read takes in the state file name at start, and returns how many
// entries it holds. A missing file holds none.
func (f *Files) read(name string) (int, error) {
data, changed, err := f.readChanged(name)
if err != nil || !changed {
return 0, err
}
return f.takeIn(name, data, false)
}
// readChanged returns what the state file name holds, and whether that
// has changed since smallwebwaf last read or wrote the file, as it has
// for a file smallwebwaf never read or wrote. A missing file has not
// changed: it is written again at its next write.
func (f *Files) readChanged(name string) ([]byte, bool, error) {
path := filepath.Join(f.params.Dir, name)
data, err := os.ReadFile(path) //nolint:gosec // a state file, in SWWAF_STATE_DIR
if errors.Is(err, fs.ErrNotExist) {
return nil, false, nil
}
if err != nil {
return fmt.Errorf("encode %s: %w", lookupsJSON, err)
return nil, false, err
}
return f.writeCounted(lookupsJSON, data)
return data, sha256.Sum256(data) != f.sums[name], nil
}
// writeCounted writes data to the state file name, as write does, and
// counts the write in the metrics.
func (f *Files) writeCounted(name string, data []byte) error {
err := write(f.params.Dir, name, data)
// takeIn parses data, what the state file name holds, puts it into the
// part that keeps that state, in place of what the part held, and returns
// how many entries the file holds. edit is whether data is an admin's
// edit taken in while smallwebwaf runs, rather than the file read at the
// start. An error names the file and, where the JSON decoder tells it,
// the line and column, or else the entry.
func (f *Files) takeIn(name string, data []byte, edit bool) (int, error) {
path := filepath.Join(f.params.Dir, name)
var entries int
switch name {
case bansJSON:
var file bansFile
err := parse(path, data, &file)
if err != nil {
return 0, err
}
held := make([]bans.Ban, 0, len(file.Bans))
for _, entry := range file.Bans {
held = append(held, entry.ban())
}
if edit {
f.params.Ledger.LoadEdit(held)
} else {
f.params.Ledger.Load(held)
}
entries = len(held)
case clientsJSON:
var file clientsFile
err := parse(path, data, &file)
if err != nil {
return 0, err
}
f.params.Limiter.Load(file.Clients, f.params.Now())
entries = len(file.Clients)
case lookupsJSON:
var file lookupsFile
err := parse(path, data, &file)
if err != nil {
return 0, err
}
f.params.GeoJS.Load(file.Lookups)
entries = len(file.Lookups)
case alertsJSON:
// waiting was a list, of the alerts waiting for the webhook, before
// alerts went to Slack and ntfy too.
var written struct {
Waiting json.RawMessage `json:"waiting"`
}
if json.Unmarshal(data, &written) == nil &&
bytes.HasPrefix(written.Waiting, []byte("[")) {
return 0, fmt.Errorf("%s: %w", path, errWaitingList)
}
var file alertsFile
err := parse(path, data, &file)
if err != nil {
return 0, err
}
f.params.Alerts.Load(alerts.State{
Cooldowns: file.Cooldowns, Hour: file.Hour, Waiting: file.Waiting,
})
f.params.Anomalies.Load(file.AnomalyCounters, f.params.Now())
for _, waiting := range file.Waiting {
entries += len(waiting)
}
}
f.sums[name] = sha256.Sum256(data)
return entries, nil
}
// writeFile writes the state file name from what smallwebwaf holds. An
// edit made since smallwebwaf last read or wrote the file is taken in
// first, so that it is not overwritten, or set aside if it does not
// parse. A file that cannot be read, or an edit that cannot be set
// aside, is left as it is, and the write given up. Every write is counted
// in the metrics, and one that fails or is given up as a failure.
func (f *Files) writeFile(name string) error {
f.mu.Lock()
defer f.mu.Unlock()
data, changed, err := f.readChanged(name)
if err == nil && changed {
err = f.takeInEdit(name, data)
if err != nil {
err = f.setAside(name, err)
}
}
if err == nil {
data, err = f.encode(name)
if err != nil {
err = fmt.Errorf("encode %s: %w", name, err)
}
}
if err == nil {
err = write(f.params.Dir, name, data)
}
if err == nil {
// The file holds data from here on, even if the directory sync
// fails, so that its next read does not take it for an admin's
// edit.
f.sums[name] = sha256.Sum256(data)
err = syncDirectory(f.params.Dir)
}
f.params.Metrics.StateFileWritten(name, len(data), err)
return err
}
// setAside renames the state file name, an edit that does not parse with
// parseErr, to name.bad, for the admin to mend, and logs it with where in
// the file the error is, and raises a file_error alert for it. If the
// rename fails, the edit is left as it is, and the error returned is
// parseErr joined with the rename's.
func (f *Files) setAside(name string, parseErr error) error {
path := filepath.Join(f.params.Dir, name)
err := os.Rename(path, path+".bad")
if err != nil {
return errors.Join(parseErr, err)
}
const setAside = "set aside an edit of a state file that does not parse"
// Raised before it is logged, so that the alert is there once the log
// line is.
f.params.Alerts.Raise(alerts.Alert{
Event: alerts.EventFileError,
Reason: setAside,
Detail: map[string]any{"file": path + ".bad", "error": parseErr.Error()},
})
f.params.ProcessLog.Error(setAside, "file", path+".bad", "error", parseErr.Error())
f.params.Metrics.StateFileEditSetAside(name)
return nil
}
// encode returns the state file name as smallwebwaf writes it, from a
// snapshot of the part that keeps that state.
func (f *Files) encode(name string) ([]byte, error) {
switch name {
case bansJSON:
file := bansFile{Version: version, Bans: BanEntries(f.params.Ledger.Snapshot())}
data, err := json.MarshalIndent(file, "", " ")
if err != nil {
return nil, err
}
return append(data, '\n'), nil
case clientsJSON:
return encodeOnePerLine("clients", f.params.Limiter.Snapshot())
case lookupsJSON:
return encodeOnePerLine("lookups", f.params.GeoJS.Snapshot())
default: // alerts.json
held := f.params.Alerts.Snapshot()
file := alertsFile{
Version: version, Cooldowns: held.Cooldowns, Hour: held.Hour,
Waiting: held.Waiting, AnomalyCounters: f.params.Anomalies.Snapshot(),
}
data, err := json.MarshalIndent(file, "", " ")
if err != nil {
return nil, err
}
return append(data, '\n'), nil
}
}
// BanEntries returns held as bans.json lists them, an empty list for
// none.
func BanEntries(held []bans.Ban) []BanEntry {
entries := make([]BanEntry, 0, len(held))
for _, ban := range held {
entries = append(entries, newBanEntry(ban))
}
return entries
}
// newBanEntry returns ban as bans.json holds it.
func newBanEntry(ban bans.Ban) banEntry {
entry := banEntry{Netblock: ban.Netblock, Start: ban.Start, Notes: ban.Notes}
func newBanEntry(ban bans.Ban) BanEntry {
entry := BanEntry{
Netblock: ban.Netblock, Start: ban.Start, Cause: ban.Cause, Reason: ban.Reason,
Notes: ban.Notes,
}
if !ban.Permanent() {
entry.Expires = &ban.Expires
}
if !ban.Lifted.IsZero() {
entry.Lifted = &ban.Lifted
}
return entry
}
// ban returns the ban an entry of bans.json holds.
func (e banEntry) ban() bans.Ban {
ban := bans.Ban{Netblock: e.Netblock, Start: e.Start, Notes: e.Notes}
func (e BanEntry) ban() bans.Ban {
ban := bans.Ban{
Netblock: e.Netblock, Start: e.Start, Cause: e.Cause, Reason: e.Reason,
Notes: e.Notes,
}
if e.Expires != nil {
ban.Expires = *e.Expires
}
if e.Lifted != nil {
ban.Lifted = *e.Lifted
}
return ban
}
@@ -263,7 +591,8 @@ func (e banEntry) ban() bans.Ban {
// client, a start, from which the length of the netblock's next ban is
// worked out, or an expires, which would make it permanent. A permanent
// ban's expires is null, which Bans cannot tell from a missing one, so
// each expires is read again as written.
// each expires is read again as written. A cause other than limit,
// attack or admin, most likely misspelt, is refused too.
func (f *bansFile) check(data []byte) error {
var written struct {
Bans []struct {
@@ -284,6 +613,9 @@ func (f *bansFile) check(data []byte) error {
return missing(i, "start")
case written.Bans[i].Expires == nil:
return missing(i, "expires")
case entry.Cause != "" && entry.Cause != bans.CauseLimit &&
entry.Cause != bans.CauseAttack && entry.Cause != bans.CauseAdmin:
return fmt.Errorf("entry %d's cause %q %w", i+1, entry.Cause, errCause)
}
}
@@ -291,8 +623,8 @@ func (f *bansFile) check(data []byte) error {
}
// check refuses a client without its address, which would count nobody's
// requests, or with requests in a window but no start, which would drop
// them and give the client a fresh allowance.
// requests, or with requests or bytes in a window but no start, which
// would drop them and give the client a fresh allowance.
func (f *clientsFile) check([]byte) error {
for i, client := range f.Clients {
switch {
@@ -304,6 +636,12 @@ func (f *clientsFile) check([]byte) error {
return missing(i, "hour.start")
case countsWithoutStart(client.Day):
return missing(i, "day.start")
case countsWithoutStart(client.MinuteBytes):
return missing(i, "minute_bytes.start")
case countsWithoutStart(client.HourBytes):
return missing(i, "hour_bytes.start")
case countsWithoutStart(client.DayBytes):
return missing(i, "day_bytes.start")
}
}
@@ -341,8 +679,90 @@ func (f *lookupsFile) check(data []byte) error {
return nil
}
// countsWithoutStart reports whether b holds requests but no start, which
// places them in time.
// check refuses a cooldown without its event or when its alert was sent,
// which would hold back no repeat, alerts waiting for a destination with
// another name than webhook, slack or ntfy, most likely misspelt, an
// alert waiting without its event or its time, and an anomaly counter as
// checkAnomalyCounters does.
func (f *alertsFile) check([]byte) error {
for i, cooldown := range f.Cooldowns {
switch {
case cooldown.Event == "":
return fmt.Errorf("cooldowns %w", missing(i, "event"))
case cooldown.Sent.IsZero():
return fmt.Errorf("cooldowns %w", missing(i, "sent"))
}
}
for _, destination := range slices.Sorted(maps.Keys(f.Waiting)) {
if !slices.Contains(alerts.Destinations(), destination) {
return fmt.Errorf("waiting %q %w", destination, errDestination)
}
for i, alert := range f.Waiting[destination] {
switch {
case alert.Event == "":
return fmt.Errorf("waiting %s %w", destination, missing(i, "event"))
case alert.Time.IsZero():
return fmt.Errorf("waiting %s %w", destination, missing(i, "time"))
}
}
}
return checkAnomalyCounters(f.AnomalyCounters)
}
// checkAnomalyCounters refuses an anomaly counter whose scope is not
// client, net, asn, total or watch, most likely misspelt, and one without
// a field it needs, as missingFromCounter tells.
func checkAnomalyCounters(counters []anomaly.Counter) error {
for i, counter := range counters {
if !slices.Contains(anomaly.Scopes(), counter.Scope) {
return fmt.Errorf("anomaly_counters entry %d's scope %q %w", i+1,
counter.Scope, errScope)
}
field := missingFromCounter(counter)
if field != "" {
return fmt.Errorf("anomaly_counters %w", missing(i, field))
}
}
return nil
}
// missingFromCounter returns the first field counter, an anomaly counter,
// needs and has not, or "" when it has them all: what tells it from the
// others in its scope, without which it would never be counted again, the
// netblock of a client, net or watch counter, the AS number of an asn one
// and the name of a watch one; and the start of a window in which it has
// requests or bytes, without which they would be dropped.
func missingFromCounter(counter anomaly.Counter) string {
scope := counter.Scope
switch {
case scope != anomaly.ScopeASN && scope != anomaly.ScopeTotal &&
!counter.Netblock.IsValid():
return "netblock"
case scope == anomaly.ScopeASN && counter.ASN == "":
return "asn"
case scope == anomaly.ScopeWatch && counter.Name == "":
return "name"
case countsWithoutStart(counter.Minute):
return "minute.start"
case countsWithoutStart(counter.Hour):
return "hour.start"
case countsWithoutStart(counter.MinuteBytes):
return "minute_bytes.start"
case countsWithoutStart(counter.HourBytes):
return "hour_bytes.start"
default:
return ""
}
}
// countsWithoutStart reports whether b holds requests, or bytes, but no
// start, which places them in time.
func countsWithoutStart(b ratelimit.Buckets) bool {
return b.Start.IsZero() && (b.Current != 0 || b.Previous != 0)
}
@@ -389,28 +809,16 @@ func checkWritable(dir string) error {
return errors.Join(file.Close(), os.Remove(file.Name()))
}
// read reads the state file name in dir into file, a pointer to that
// file's struct, and checks its entries. A missing file leaves file as it
// is.
func read(dir, name string, file stateFile) error {
path := filepath.Join(dir, name)
data, err := os.ReadFile(path) //nolint:gosec // a state file, in SWWAF_STATE_DIR
if errors.Is(err, fs.ErrNotExist) {
return nil
}
if err != nil {
return err
}
// parse reads data, what the state file at path holds, into file, a
// pointer to that file's struct, and checks its entries.
func parse(path string, data []byte, file stateFile) error {
// The version is read first, so that a file of another version is
// refused for that, and not for an entry this version cannot read.
var header struct {
Version int `json:"version"`
}
err = json.Unmarshal(data, &header)
err := json.Unmarshal(data, &header)
if err == nil && header.Version != version {
err = fmt.Errorf("%w %d, where this smallwebwaf reads version %d",
errVersion, header.Version, version)
@@ -463,7 +871,7 @@ func position(data []byte, err error) string {
// write writes data to the file name in dir so that a crash at any
// moment leaves either the old file or the new one, whole: data goes to a
// temporary file in the same directory, which is synced and renamed over
// name, and then the directory is synced, so that the rename lasts.
// name. syncDirectory must follow, so that the rename lasts.
func write(dir, name string, data []byte) error {
path := filepath.Join(dir, name)
temporary := path + ".tmp"
@@ -475,10 +883,13 @@ func write(dir, name string, data []byte) error {
if err != nil {
_ = os.Remove(temporary)
return err
}
return err
}
// syncDirectory syncs dir to the disk, so that a rename in it lasts.
func syncDirectory(dir string) error {
directory, err := os.Open(dir) //nolint:gosec // SWWAF_STATE_DIR itself
if err != nil {
return err
internal/state/state_test.go
+1156 -35
View File
File diff suppressed because it is too large Load Diff
internal/state/write_internal_test.go
+35
View File
@@ -0,0 +1,35 @@
package state
import (
"os"
"path/filepath"
"testing"
)
// The test is on write itself: a state file is read before it is
// written, and a directory in its place fails that read first.
func TestFailedRenameLeavesNoTemporaryFile(t *testing.T) {
t.Parallel()
dir := t.TempDir()
// A directory named bans.json cannot be renamed over.
err := os.Mkdir(filepath.Join(dir, bansJSON), 0o700)
if err != nil {
t.Fatalf("mkdir: %v", err)
}
err = write(dir, bansJSON, []byte("{}\n"))
if err == nil {
t.Error("writing over a directory did not fail")
}
entries, err := os.ReadDir(dir)
if err != nil {
t.Fatalf("read %s: %v", dir, err)
}
if len(entries) != 1 || entries[0].Name() != bansJSON {
t.Errorf("%s holds %v, want only bans.json", dir, entries)
}
}
script/example-app
+34 -10
View File
@@ -3,12 +3,14 @@
# deploy/example-app, then run the app's container with a volume for the
# state files and check that the health check passes, that a request is
# served through smallwebwaf, that a second one in a minute bans the
# client, that `sv stop` stops smallwebwaf in order, that `docker stop`
# stops the container without having to kill it, and that a new
# container on the same volume still refuses the banned client. The
# containers, the volume and both images are removed however the script
# ends. Building the app needs network access, for nixpkgs' binary cache.
# script/check does not run this.
# client, that a probe for /.env bans another client, which its next
# request bans for good, that `sv stop` stops smallwebwaf in order, that
# `docker stop` stops the container without having to kill it, and that
# a new container on the same volume still refuses the banned client. The
# containers run with SWWAF_LOOKUP_SOURCE=off, so that no address is sent
# to GeoJS. The containers, the volume and both images are removed however
# the script ends. Building the app needs network access, for nixpkgs'
# binary cache. script/check does not run this.
set -eu
SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -52,18 +54,23 @@ healthy() {
[ "$status" = healthy ]
}
# logged <text>: the container's output holds text.
# logged <text>...: a line of the container's output holds every text,
# in any order.
logged() {
docker logs "$CONTAINER" 2>&1 | grep -qF "$1"
lines="$(docker logs "$CONTAINER" 2>&1)"
for text in "$@"; do
lines="$(printf '%s\n' "$lines" | grep -F "$text")" || return 1
done
}
# start_container: run the app's container, with the state files on the
# volume and a rate limit of one request a minute, and wait until it is
# healthy.
# volume, a rate limit of one request a minute and no client looked up,
# and wait until it is healthy.
start_container() {
docker run --detach --name "$CONTAINER" --publish 127.0.0.1::8080 \
--volume "$VOLUME:/var/lib/smallwebwaf" \
--env SWWAF_RATE_LIMIT_PER_MINUTE=1 \
--env SWWAF_LOOKUP_SOURCE=off \
"$APP_IMAGE" >/dev/null
wait_for "the health check did not pass" healthy
address="$(docker port "$CONTAINER" 8080/tcp)"
@@ -77,6 +84,15 @@ refused() {
[ "$code" = 403 ]
}
# refused_from <client> <path>: a request for path from client, as
# X-Forwarded-For names it, gets 403. smallwebwaf believes the header
# from docker's gateway, a private address.
refused_from() {
code="$(curl --silent --output /dev/null --write-out '%{http_code}' \
--max-time 10 --header "X-Forwarded-For: $1" "http://$address$2")" || true
[ "$code" = 403 ]
}
main() {
cd "$ROOT"
trap cleanup EXIT
@@ -100,6 +116,14 @@ main() {
wait_for "smallwebwaf logged no ban" logged '"action":"rate_limited"'
echo "example-app: a second request in a minute bans the client"
refused_from 203.0.113.9 /.env || fail "a probe for /.env was not refused"
wait_for "smallwebwaf logged no ban for the probe" \
logged '"action":"banned"' '"rule_ids":["env-file"]'
refused_from 203.0.113.9 / || fail "the client of the probe was let through"
wait_for "the client's next request did not make its ban permanent" \
logged '"ban_expires":"permanent"'
echo "example-app: a probe for /.env bans the client, its next request for good"
docker exec "$CONTAINER" sv stop smallwebwaf >/dev/null ||
fail "sv stop smallwebwaf failed"
wait_for "smallwebwaf did not stop in order" logged '"msg":"stopped"'
script/run
+7 -1
View File
@@ -1,7 +1,9 @@
#!/bin/sh
# script/run: build bin/smallwebwaf with script/build and run it, with
# the settings in the environment. Unless SWWAF_STATE_DIR is set, the
# state files go in bin/state, beside the binary.
# state files go in bin/state, beside the binary, and unless
# SWWAF_RULES_DIR is set, the rule files are those of share/rules.d,
# which the image ships.
set -eu
SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -14,6 +16,10 @@ main() {
export SWWAF_STATE_DIR
mkdir -p "$SWWAF_STATE_DIR"
fi
if [ -z "${SWWAF_RULES_DIR+set}" ]; then
SWWAF_RULES_DIR="$ROOT/share/rules.d"
export SWWAF_RULES_DIR
fi
exec "$ROOT/bin/smallwebwaf"
}
script/tidy
Executable
+19
View File
@@ -0,0 +1,19 @@
#!/bin/sh
# script/tidy: write go.mod and go.sum as `go mod tidy` writes them, which
# the test phase of the Dockerfile checks. This builds the Dockerfile's
# tidy-files stage, which holds the two files alone, and --output writes
# them into the working tree. The build makes no image, so it has no tag.
# --no-cache because `go mod tidy` asks the module proxy, whose answers a
# cached layer would repeat.
set -eu
ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
main() {
cd "$ROOT"
docker build --no-cache \
--target tidy-files \
--output "type=local,dest=$ROOT" .
}
main "$@"
share/rules.d/00-default.rules
+15
View File
@@ -0,0 +1,15 @@
# 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 ^$