servewaf: each decision heuristic is its own module (closes #195)

Each check servewaf runs on a request is a type in its own file behind
one interface, heuristic, and is registered in one of four ordered lists
in heuristics.go. Order and behaviour are unchanged.

Every refusal now logs heuristic, the name of the heuristic that made
it, and heuristic_figures, the figures it acted on. A ban by
refusal_limit or byte_limits after the answer logs after_answer_heuristic
and after_answer_heuristic_figures instead, so a line can name both. All
four are in docs/request-log.md, and SPEC.md names each heuristic at its
step.

Model: opus-5-5

README.md

@@ -192,9 +192,9 @@ account, a key, a token or an alert destination stays off until you give one.
 - Any `SWWAF_` setting can be given as a file instead, for secrets and long
   lists: `SWWAF_ADMIN_TOKEN_FILE` names the file that holds `SWWAF_ADMIN_TOKEN`.
   The file's contents are the value, less one newline at the end. Setting both
-  forms stops the start. `SWWAF_LOG_REMOTE_TLS_CA_FILE` and
-  `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` already name a file, so they have no
-  `_FILE` form. No `SWRP_` setting has one, since `rproxy` never touches disk.
+  forms stops the start. `SWWAF_LOG_REMOTE_TLS_CA_FILE` already names a file, so
+  it has no `_FILE` form, and no `SWRP_` setting has one, since `rproxy` never
+  touches disk.
 - A duration is Go's syntax, with `d` for days: `90s`, `15m`, `24h`, `7d`.
 - A size is a number of bytes with an optional `K`, `M` or `G`, in powers of
   1024: `512K`, `100M`, `5G`.
@@ -272,7 +272,6 @@ Every setting the code reads, with its default:
 | `SWWAF_WAF_DISABLED_RULES`                 | `920340,920420,920440,920640,930130,930140`                                    | Core Rule Set rule ids switched off; a list you give replaces the default, so repeat these six to keep them off.                                                    |
 | `SWWAF_WAF_EXEMPT_PATHS`                   | empty                                                                          | Path prefixes the Core Rule Set does not inspect.                                                                                                                   |
 | `SWWAF_WAF_BODY_LIMIT`                     | `off`                                                                          | How much of a request body the Core Rule Set reads, a size up to `64K`; `off` reads none.                                                                           |
-| `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE`      | unset                                                                          | A file of Core Rule Set exclusions, as Coraza directives, that switch rules off for some fields or paths only; `deploy/gitea/crs-exclusions.conf` is gitea's.       |
 | `SWWAF_BLOCKLIST_URLS`                     | empty                                                                          | Blocklists to fetch, text files of addresses and netblocks one to a line, such as `https://www.spamhaus.org/drop/drop.txt`.                                         |
 | `SWWAF_BLOCKLIST_REFRESH`                  | `24h`                                                                          | How long after a list was last tried it is fetched again, `1h` or more.                                                                                             |
 | `SWWAF_BLOCKLIST_ACTION`                   | `deny`                                                                         | What a client on a blocklist gets: `deny`, `limit:<percent>` of every limit, or `log`.                                                                              |
@@ -637,14 +636,10 @@ and the status for a size or time limit, such as `413` for a body too large.
   headers of every request, and no body unless `SWWAF_WAF_BODY_LIMIT` is set. In
   front of a code forge, bodies carry what people write and publish, which the
   rules take for attacks.
-- `smallwebwaf` changes the Core Rule Set in seven ways so that it lets ordinary
+- `smallwebwaf` changes the Core Rule Set in six ways so that it lets ordinary
   requests to a code forge through, such as git over HTTP and sign-in through
   Git Credential Manager. No setting undoes them; "Attack detection" in
   [`SPEC.md`](SPEC.md) lists them.
-- `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` switches single rules off for an app's
-  own fields or paths. gitea's exclusions, in
-  `deploy/gitea/crs-exclusions.conf`, let its searches, file names and branch
-  names through.
 - Rule files are plain text, one rule to a line, edited by hand and read again
   while `servewaf` runs. The image ships one file of probes no real visitor
   sends (see [`docs/rules.md`](docs/rules.md)).

SPEC.md

@@ -36,8 +36,7 @@ to them.
     - the state files;
     - a lookup database;
     - a `SWWAF_` setting given as a file;
-    - the file `SWWAF_LOG_REMOTE_TLS_CA_FILE` names;
-    - the file `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` names.
+    - the file `SWWAF_LOG_REMOTE_TLS_CA_FILE` names.
 
 ## Non-goals
 
@@ -82,7 +81,7 @@ to them.
       of bans is full.
     - `internal/rules`: reads the rule files at start and again when they
       change, and tells which rules a request matches.
-    - `internal/waf`: the Core Rule Set, with the seven changes listed under
+    - `internal/waf`: the Core Rule Set, with the six changes listed under
       "Attack detection", as Coraza directives.
     - `internal/lookup`: looks clients up through GeoJS or in the lookup
       database.
@@ -124,7 +123,9 @@ runs steps 3 to 13, and does the counting of step 15. The first step that
 produces a final answer ends the checks. Step 15 runs for each request
 `servewaf` answers with `allow`, `deny` or `close`. `rproxy`'s size and time
 limits apply to the whole exchange. Each step names the section that holds its
-rules.
+rules. Each check is a heuristic. Its name, in parentheses below, is the value
+of the request log's `heuristic` field. `refusal_limit` and `byte_limits` give
+theirs in `after_answer_heuristic` instead.
 
 1. `GET /_smallwebwaf/healthz` is answered at once by `rproxy`, before any
    check, so a health checker never needs an exemption and is never refused.
@@ -142,9 +143,9 @@ rules.
       around its address, a /64 by default, since one abuser usually controls a
       whole /64. A client is therefore one IPv4 address or one IPv6 group.
 3. The static lists. A client in `SWWAF_ALLOW_NETS` skips steps 4 to 12, the
-   byte limits and the error burst. A client in `SWWAF_DENY_NETS` is refused; a
-   client in both lists is let through.
-4. Bans. A client under a ban is refused (see "Bans").
+   byte limits and the error burst. A client in `SWWAF_DENY_NETS` is refused
+   (`deny_nets`); a client in both lists is let through.
+4. Bans. A client under a ban is refused (`active_ban`; see "Bans").
 5. The lookup, unless `SWWAF_LOOKUP_SOURCE` is `off` (see "Lookup of AS number
    and country"). The request goes on at once. It waits for the first GeoJS
    answer, up to `SWWAF_LOOKUP_TIMEOUT`, only when one of these needs it:
@@ -154,22 +155,26 @@ rules.
 
     A request that ends before the answer comes is logged without it.
 
-6. The country lists (see "Country lists").
-7. The reputation sources (see "Reputation"). A client on a fetched blocklist
-   gets `SWWAF_BLOCKLIST_ACTION`. A client on the CrowdSec decision list is
-   banned. A client listed by a DNS blocklist, or scored at least
-   `SWWAF_ABUSEIPDB_MIN_SCORE` by AbuseIPDB, gets `SWWAF_REPUTATION_ACTION`.
+6. The country lists (`countries`; see "Country lists").
+7. The reputation sources (see "Reputation"), in this order:
+    - A client on a fetched blocklist gets `SWWAF_BLOCKLIST_ACTION`
+      (`blocklists`).
+    - A client on the CrowdSec decision list is banned (`crowdsec`).
+    - A client listed by a DNS blocklist gets `SWWAF_REPUTATION_ACTION`
+      (`dnsbl`).
+    - A client scored at least `SWWAF_ABUSEIPDB_MIN_SCORE` by AbuseIPDB gets
+      `SWWAF_REPUTATION_ACTION` (`abuseipdb`).
 8. The client's limit percentage (see "Biased thresholds").
-9. Rate limiting (see "Request rate limits, per client"). A request over a limit
-   times the percentage is refused and bans the client.
-10. The trap paths (see "Attack detection"). A request for one is refused and
-    bans the client.
-11. The rule files (see "Rule files"). Matching stops at the first rule that
-    refuses.
-12. The header limits (see "Answering in time"), and then the Core Rule Set (see
-    "Attack detection"). A Core Rule Set match is refused with `403` while
-    `SWWAF_WAF_MODE` is `block`, and only logged and alerted while it is
-    `detect`.
+9. Rate limiting (`rate_limits`; see "Request rate limits, per client"). A
+   request over a limit times the percentage is refused and bans the client.
+10. The trap paths (`trap_paths`; see "Attack detection"). A request for one is
+    refused and bans the client.
+11. The rule files (`rule_files`; see "Rule files"). Matching stops at the first
+    rule that refuses.
+12. The header limits (`header_limits`; see "Answering in time"), and then the
+    Core Rule Set (`core_rule_set`; see "Attack detection"). A Core Rule Set
+    match is refused with `403` while `SWWAF_WAF_MODE` is `block`, and only
+    logged and alerted while it is `detect`.
 13. A path under `/_smallwebwaf/` is answered `404`, so that the app never sees
     that prefix.
 14. `rproxy` passes the request to `SWRP_UPSTREAM_URL`, streaming (see "Passing
@@ -183,14 +188,14 @@ rules.
       are added to the byte counters, as `SWWAF_BYTES_COUNT` says. For a
       WebSocket, what it carried each way counts once it closes. A client whose
       total passes a byte limit times the percentage has broken that limit and
-      is banned. The response in progress is not cut off.
+      is banned (`byte_limits`). The response in progress is not cut off.
     - For a request it allowed, the client's history and the anomaly counters
       are updated, and the alert thresholds are evaluated.
 
     For a request it refused, `servewaf` adds nothing to the byte limits. It
     updates the history and the anomaly counters at its decision. It counts the
-    refusals the error burst counts at the decision too (see "Attack
-    detection").
+    refusals the error burst counts at the decision too (`refusal_limit`; see
+    "Attack detection").
 
 In `SWWAF_MODE=observe`, every refusal above is logged as what would have
 happened, nothing is refused, and `servewaf` makes no ban of its own. A path
@@ -326,10 +331,9 @@ Conventions:
   lists: `SWWAF_ADMIN_TOKEN_FILE` names the file that holds `SWWAF_ADMIN_TOKEN`.
   The file's contents are the value, less one newline at the end, and are
   checked as the value itself would be. Setting both forms stops the start, and
-  so does naming a file that cannot be read. `SWWAF_LOG_REMOTE_TLS_CA_FILE` and
-  `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` already hold a file name, so they have
-  no `_FILE` form. No `SWRP_` setting has one, since `rproxy` never touches
-  disk.
+  so does naming a file that cannot be read. `SWWAF_LOG_REMOTE_TLS_CA_FILE`
+  already holds a file name, so it has no `_FILE` form. No `SWRP_` setting has
+  one, since `rproxy` never touches disk.
 - Settings, files included, are read once at start. Changing one means
   restarting the container. The files `servewaf` watches while it runs are its
   state files, its rule files and the lookup database.
@@ -585,24 +589,6 @@ sends it.
     probes these rules caught (see "Rule files"). A list you give replaces the
     default, so name these six ids in it to keep them off.
 
-- `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` names a file of exclusions, written as
-  Coraza directives. An exclusion switches one rule off for some fields or paths
-  only, where `SWWAF_WAF_DISABLED_RULES` switches it off everywhere.
-  `deploy/gitea/crs-exclusions.conf` holds gitea's.
-    - `servewaf` loads the file after `smallwebwaf`'s own setup rules and before
-      the Core Rule Set's rules. The Core Rule Set puts its own file of
-      exclusions that run before the rules in the same place.
-    - So the file holds only `SecAction` and `SecRule` lines that exclude with
-      `ctl:ruleRemoveTargetById` or `ctl:ruleRemoveById`. These run with each
-      request, before the rules they exclude, those of phase 1 included.
-    - A rule that `SWWAF_WAF_DISABLED_RULES` switches off and the file names is
-      simply off.
-    - The start stops on a file that cannot be read or does not parse, whatever
-      `SWWAF_WAF_MODE` is.
-    - It stops too on a file that names a number from 900000 to 900999, the ids
-      of `smallwebwaf`'s own rules, alone or in a range. Comment lines are not
-      checked.
-
 - `SWWAF_WAF_BODY_LIMIT` switches body inspection on, up to that size. It takes
   at most `64K`, since `servewaf` gets no more of a body than that (see "The
   answer"). Form data and multipart bodies are read up to the size. JSON and XML
@@ -632,7 +618,7 @@ sends it.
     scanner from an ordinary client. In front of gitea, registry and git clients
     get `404` and `401` by design, hundreds of times a minute.
 
-`smallwebwaf` changes the Core Rule Set 4.25.0 in seven ways, since in front of
+`smallwebwaf` changes the Core Rule Set 4.25.0 in six ways, since in front of
 gitea it would otherwise refuse ordinary requests. The changes hold in front of
 every app, and no setting undoes them:
 
@@ -689,10 +675,6 @@ every app, and no setting undoes them:
       must check it itself.
 6. Responses are not inspected. A raw file from a repository, such as a shell
    script, looks to the response rules like source code leaking from the server.
-7. The `from` parameter of a container registry's upload path,
-   `/v2/<image>/blobs/uploads/`, is not checked for command names (932260). When
-   a push reuses a layer, `from` names the image the layer comes from. An image
-   such as `owner/python3-app` would have that push refused.
 
 The parameter and cookie names in these changes are matched without regard to
 case, as Coraza matches them.

deploy/gitea/compose.yaml

@@ -104,12 +104,11 @@ services:
             # address of an automation fleet on another host here too; without
             # that, it is counted like any client.
             SWWAF_ALLOW_NETS: 10.99.0.128/25,fd10:99:0:0:8000::/65
-            # The Core Rule Set's exclusions for Gitea's searches, file names
-            # and branch names.
-            SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE: /etc/smallwebwaf/crs-exclusions.conf
+            # In block mode the Core Rule Set refuses everyday Gitea searches
+            # and file names, and 31 refusals in a minute ban the address.
+            SWWAF_WAF_MODE: detect
         volumes:
             - servewaf-state:/var/lib/smallwebwaf
-            - ./crs-exclusions.conf:/etc/smallwebwaf/crs-exclusions.conf:ro
         networks:
             - shared
         logging: *logging

deploy/gitea/crs-exclusions.conf

@@ -1,150 +0,0 @@
-# The Core Rule Set's exclusions for Gitea, which servewaf loads from
-# SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE. servewaf loads this file before the Core
-# Rule Set's rules, so it holds only exclusions made while a request is checked:
-# SecAction and SecRule lines with ctl:ruleRemoveTargetById or
-# ctl:ruleRemoveById. Each switches one rule off for the Gitea fields or paths
-# where it refused ordinary Gitea requests. A SecAction applies on every path, a
-# SecRule on the paths it matches. Gitea sends these in the query string:
-#   - q: the text of every search;
-#   - file, path, template, body and redirect_to: a file name, alone or in
-#     JSON or a link;
-#   - name, tag, rule_name and refSubUrl: a branch or tag name.
-# docs/gitea.md says how to add an exclusion.
-
-# Searches.
-# 930110: a search for ../
-SecAction "id:10001,phase:1,pass,nolog,ctl:ruleRemoveTargetById=930110;ARGS:q"
-# 931100: a search for http://127.0.0.1:8080
-SecAction "id:10002,phase:1,pass,nolog,ctl:ruleRemoveTargetById=931100;ARGS:q"
-# 932140: a search for if (a == b) {
-SecAction "id:10003,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932140;ARGS:q"
-# 932235: a search for `make check`
-SecAction "id:10004,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932235;ARGS:q"
-# 932250: a search for ls -la
-SecAction "id:10005,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932250;ARGS:q"
-# 932380: a search for `whoami`
-SecAction "id:10006,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932380;ARGS:q"
-# 933100: a search for <?php echo
-SecAction "id:10007,phase:1,pass,nolog,ctl:ruleRemoveTargetById=933100;ARGS:q"
-# 933130: a search for $_GET[
-SecAction "id:10008,phase:1,pass,nolog,ctl:ruleRemoveTargetById=933130;ARGS:q"
-# 933135: a search for ${VAR}
-SecAction "id:10009,phase:1,pass,nolog,ctl:ruleRemoveTargetById=933135;ARGS:q"
-# 934110: a search for http://127.0.0.1:8080
-SecAction "id:10010,phase:1,pass,nolog,ctl:ruleRemoveTargetById=934110;ARGS:q"
-# 941100: a search for <script>
-SecAction "id:10011,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941100;ARGS:q"
-# 941110: a search for <script>, or a page opened from its results
-SecAction "id:10012,phase:1,pass,nolog,\
-    ctl:ruleRemoveTargetById=941110;ARGS:q,\
-    ctl:ruleRemoveTargetById=941110;REQUEST_HEADERS:Referer"
-# 941120: a page opened from the results of a search for onClick={
-SecAction "id:10013,phase:1,pass,nolog,\
-    ctl:ruleRemoveTargetById=941120;REQUEST_HEADERS:Referer"
-# 941160: a search for <img src=, or a page opened from its results
-SecAction "id:10014,phase:1,pass,nolog,\
-    ctl:ruleRemoveTargetById=941160;ARGS:q,\
-    ctl:ruleRemoveTargetById=941160;REQUEST_HEADERS:Referer"
-# 941390: a search for fetch(
-SecAction "id:10015,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941390;ARGS:q"
-# 942100: a search for SELECT * FROM users WHERE, or a page opened from the
-# results of a search for LIKE '%foo%'
-SecAction "id:10016,phase:1,pass,nolog,\
-    ctl:ruleRemoveTargetById=942100;ARGS:q,\
-    ctl:ruleRemoveTargetById=942100;REQUEST_HEADERS:Referer"
-# 942190: a search for union select
-SecAction "id:10017,phase:1,pass,nolog,ctl:ruleRemoveTargetById=942190;ARGS:q"
-# 942230: a search for if (a == b) {
-SecAction "id:10018,phase:1,pass,nolog,ctl:ruleRemoveTargetById=942230;ARGS:q"
-# 944100: a search for java.lang.Runtime, or a page opened from its results
-SecAction "id:10019,phase:1,pass,nolog,\
-    ctl:ruleRemoveTargetById=944100;ARGS:q,\
-    ctl:ruleRemoveTargetById=944100;REQUEST_HEADERS:Referer"
-
-# Searches, and file, branch and tag names.
-# 930120: a search for package.json, or the commit graph of .gitignore
-SecAction "id:10020,phase:1,pass,nolog,ctl:ruleRemoveTargetById=930120;\
-    ARGS:/^(?:q|file|template|body|refsuburl|name|tag|rule_name)$/"
-# 932160: a search for /bin/sh, or the API's contents of bin/docker-entrypoint
-SecAction "id:10021,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932160;\
-    ARGS:/^(?:q|file|template|body|refsuburl|name|tag|rule_name)$/"
-# 932260: a search for python3, or deleting the branch docker-build
-SecAction "id:10022,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932260;\
-    ARGS:/^(?:q|file|template|body|refsuburl|name|tag|rule_name)$/"
-
-# Searches, and file names in the query string.
-# 932120: a search for Invoke-WebRequest, or the commits of install-script.sh
-SecAction "id:10023,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932120;\
-    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
-# 932130: a search for $(pwd), or an issue opened from the template [draft].md
-SecAction "id:10024,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932130;\
-    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
-# 934100: a search for process.env, or the commits of process.env.d.ts
-SecAction "id:10025,phase:1,pass,nolog,ctl:ruleRemoveTargetById=934100;\
-    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
-# 934130: a search for __proto__, or the commits of __proto__.json
-SecAction "id:10026,phase:1,pass,nolog,ctl:ruleRemoveTargetById=934130;\
-    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
-# 941130: the commits of index.xhtml
-SecAction "id:10027,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941130;\
-    ARGS:/^(?:file|path|template|body|redirect_to)$/"
-# 941180: a search for document.cookie, or the commits of document.write.js
-SecAction "id:10028,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941180;\
-    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
-# 942140: a search for information_schema, or the commits of
-# information_schema.sql
-SecAction "id:10029,phase:1,pass,nolog,ctl:ruleRemoveTargetById=942140;\
-    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
-# 944110: a search for java.lang.Runtime, or the commits of Runtime.java
-SecAction "id:10030,phase:1,pass,nolog,ctl:ruleRemoveTargetById=944110;\
-    ARGS:/^(?:q|file|path|template|body|redirect_to)$/"
-# 944130: a search for java.lang.Runtime, the commits of java.lang.String.md,
-# or any page opened from that file's page, which names it in the Referer
-SecAction "id:10031,phase:1,pass,nolog,\
-    ctl:ruleRemoveTargetById=944130;\
-    ARGS:/^(?:q|file|path|template|body|redirect_to)$/,\
-    ctl:ruleRemoveTargetById=944130;REQUEST_HEADERS:Referer"
-
-# File names in the path of a file's page, raw file, blame, history and edit
-# page, and of the API's calls for its contents.
-# 920500: the page of notes.txt~
-SecRule REQUEST_FILENAME "@rx ^/(?:api/v1/repos/)?[^/]+/[^/]+/(?:src|raw|media|blame|commits|_edit|_delete|contents)/" \
-    "id:10032,phase:1,pass,nolog,ctl:ruleRemoveTargetById=920500;REQUEST_FILENAME"
-# 934100: the page of process.env.d.ts
-SecRule REQUEST_FILENAME "@rx ^/(?:api/v1/repos/)?[^/]+/[^/]+/(?:src|raw|media|blame|commits|_edit|_delete|contents)/" \
-    "id:10033,phase:1,pass,nolog,ctl:ruleRemoveTargetById=934100;REQUEST_FILENAME"
-# 941130: the page of docs/a b.xhtml
-SecRule REQUEST_FILENAME "@rx ^/(?:api/v1/repos/)?[^/]+/[^/]+/(?:src|raw|media|blame|commits|_edit|_delete|contents)/" \
-    "id:10034,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941130;REQUEST_FILENAME"
-# 944130: the page of java.lang.String.md
-SecRule REQUEST_FILENAME "@rx ^/(?:api/v1/repos/)?[^/]+/[^/]+/(?:src|raw|media|blame|commits|_edit|_delete|contents)/" \
-    "id:10035,phase:1,pass,nolog,ctl:ruleRemoveTargetById=944130;REQUEST_FILENAME"
-
-# The file name, in name, of an attachment uploaded through the API to a
-# release, an issue or a comment.
-# 932120: the attachment install-script.sh
-SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
-    "id:10036,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932120;ARGS:name"
-# 934100: the attachment process.env.d.ts
-SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
-    "id:10037,phase:1,pass,nolog,ctl:ruleRemoveTargetById=934100;ARGS:name"
-# 934130: the attachment __proto__.json
-SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
-    "id:10038,phase:1,pass,nolog,ctl:ruleRemoveTargetById=934130;ARGS:name"
-# 941130: the attachment index.xhtml
-SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
-    "id:10039,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941130;ARGS:name"
-# 941180: the attachment document.write.js
-SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
-    "id:10040,phase:1,pass,nolog,ctl:ruleRemoveTargetById=941180;ARGS:name"
-# 942140: the attachment information_schema.sql
-SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
-    "id:10041,phase:1,pass,nolog,ctl:ruleRemoveTargetById=942140;ARGS:name"
-# 944130: the attachment java.lang.String.md
-SecRule REQUEST_FILENAME "@rx ^/api/v1/repos/[^/]+/[^/]+/(?:releases|issues|issues/comments)/[0-9]+/assets$" \
-    "id:10042,phase:1,pass,nolog,ctl:ruleRemoveTargetById=944130;ARGS:name"
-
-# The header Content-Range of an artifact upload.
-# 920450: an artifact upload from actions/upload-artifact@v3
-SecRule REQUEST_FILENAME "@rx ^/api/actions_pipeline/_apis/pipelines/workflows/[0-9]+/artifacts/[^/]+/upload$" \
-    "id:10043,phase:1,pass,nolog,ctl:ruleRemoveTargetById=920450;REQUEST_HEADERS_NAMES:Content-Range"

docs/gitea.md

@@ -13,8 +13,7 @@ Four containers share one Docker network, the shared network:
   plain HTTP to HTTPS;
 - `rproxy`, in front of gitea;
 - gitea 1.27.3, as its image comes;
-- `servewaf`, with a volume for its state files, and with
-  `deploy/gitea/crs-exclusions.conf` mounted read-only.
+- `servewaf`, with a volume for its state files.
 
 To start it:
 
@@ -31,8 +30,7 @@ To start it:
    `docker run --rm <gitea's image> gitea generate secret SECRET_KEY`, with
    gitea's image as `deploy/gitea/compose.yaml` names it. Do this once per
    install, and keep the key.
-5. Run `docker compose up --detach` in `deploy/gitea`, with
-   `crs-exclusions.conf` beside `compose.yaml`.
+5. Run `docker compose up --detach` in `deploy/gitea`.
 6. Make gitea's first user with `gitea admin user create`, in gitea's container,
    as the user `git`.
 
@@ -48,12 +46,6 @@ under a name of its own, and checks:
   `rproxy`, and that `servewaf` checks them;
 - that gitea logs the visitor's address, not `rproxy`'s;
 - that a request from a container on the shared network skips the checks;
-- that the Core Rule Set refuses none of the ordinary gitea requests in
-  `internal/waf/testdata/gitea-requests.txt`, sent by a signed-in user;
-- that it refuses none of the API calls with JSON bodies;
-- that it refuses no fetch;
-- that it refuses SQL injection, path traversal and script injection in a query
-  string;
 - that with `servewaf` stopped, gitea still answers through `rproxy`.
 
 ## Uploads and downloads
@@ -87,8 +79,11 @@ GiB a day.
 
 ## The checks
 
-The Core Rule Set runs in `block` mode, the default, with gitea's exclusions
-(see "The Core Rule Set's exclusions" below).
+`SWWAF_WAF_MODE` is `detect`. The Core Rule Set then logs a match, with its rule
+ids, and refuses nothing. In `block` mode, the default, it refuses everyday
+gitea searches and file names. The section "What the Core Rule Set refuses in
+`block` mode" below lists them. Each such refusal counts toward the error burst,
+so 31 in one minute ban the address.
 
 Every other check stays at its default. A client may make 120 requests a minute,
 1,500 an hour and 6,000 a day. Archive downloads and blame and history pages are
@@ -158,49 +153,188 @@ within two minutes. Its address is then banned, its running jobs fail, and each
 repeat within a day makes the ban longer. Newer runners ask for work less often.
 Put the runners' addresses in `SWWAF_RATE_LIMIT_EXEMPT_NETS`.
 
-## The Core Rule Set's exclusions
+## What the Core Rule Set refuses in `block` mode
 
-`deploy/gitea/crs-exclusions.conf` switches single Core Rule Set rules off where
-they refused ordinary gitea requests. `servewaf` loads it from
-`SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE`, before the Core Rule Set's rules. Each
-exclusion covers one rule, in these places only:
+These notes record what the Core Rule Set does in front of gitea in `block`
+mode, at the other defaults. They are observations, not requirements.
+`script/gitea-requests` runs gitea behind `rproxy` and `servewaf` at the
+defaults. It sends through them a sample of gitea's ordinary use and the
+requests named below. It reports each request the Core Rule Set refuses, so that
+these notes can be checked again when gitea or the Core Rule Set changes
+version. In `detect` mode, as the setup runs it, the same requests are logged
+with their rule ids, and pass.
 
-- `q`, the text of every search;
-- the query parameters that hold a file name: `file`, `path`, `template`, `body`
-  and `redirect_to`;
-- the query parameters that hold a branch or tag name: `name`, `tag`,
-  `rule_name` and `refSubUrl`;
-- `Referer`, on a page opened from search results or from a file's page;
-- the path of a file's page, raw file, blame, history and edit page, and of the
-  API's call for its contents;
-- `name`, the file name of an attachment uploaded through the API;
-- the header `Content-Range` of an Actions artifact upload.
+Each refusal answers only that request ("Bans" in `SPEC.md` says what it counts
+toward). The request log names the rule in `waf_rule_ids`, which
+`SWWAF_WAF_DISABLED_RULES` can switch off.
 
-gitea reads these as text to search for, as names in a repository, or, for
-`Content-Range`, as the part of a file an upload carries. It never runs them as
-SQL, a command or a page's script. So an attack that only the excluded rules
-would catch there reaches gitea and does nothing. Every other field and path
-keeps every rule.
+### What it lets through
 
-To add an exclusion for a request the Core Rule Set refuses:
+The Core Rule Set lets gitea's ordinary use through, apart from the refusals in
+the sections after this one:
 
-1. Find the request in `servewaf`'s log. Its line gives the path and query, and
-   names the rules in `waf_rule_ids`.
-2. For each rule, add a line with `ctl:ruleRemoveTargetById` for the field it
-   matched. For a field on every path, copy one of the file's `SecAction` lines.
-   For some paths only, copy one of its `SecRule REQUEST_FILENAME` lines. Give
-   it a new id. An id from 900000 to 900999 stops the start.
-3. Above it, write a one-line comment naming the request it refused.
-4. Add the request to `internal/waf/testdata/gitea-requests.txt`, and run
-   `make check`.
-5. Restart `servewaf`.
+- browsing and views of files in a repository, with their history, blame and the
+  file tree;
+- diffs, including their hidden lines and large files, and pull request review;
+- git's clone, fetch and push over HTTP;
+- signing in, including the return to the page a visitor came from, and sign-in
+  with Git Credential Manager, git-credential-oauth or tea;
+- the API's calls for a file and its commits;
+- pushing and pulling container images and packages;
+- Actions runners, and artifacts uploaded with `actions/upload-artifact@v4`;
+- posting issues, pull requests, comments, wiki pages and files saved in the web
+  editor, code included, since no body is read;
+- the page gitea shows after a change, with its message naming what was done.
 
-The Core Rule Set still refuses the page of a file in a directory named `...`,
-which reads as path traversal.
+### A query string that reads as an attack
 
-With `SWWAF_WAF_BODY_LIMIT` set, it also refuses issue text, comments, wiki
-pages and files saved in the web editor that hold shell commands or code.
+Most often this is a search. A search term is a query parameter, which the Core
+Rule Set checks against its lists of system files and commands (see the fourth
+change under "Attack detection" in `SPEC.md`). A release attachment uploaded
+through the API as `docker-compose.yml` is refused the same way. Examples:
 
-`make gitea-requests` runs gitea behind `rproxy` and `servewaf` at the defaults,
-without these exclusions. It reports each request the Core Rule Set refuses
-there.
+- a name on those lists, such as `package.json`, `.gitignore` or
+  `docker-compose.yml`;
+- text that starts with a command name, such as `python3` or `ssh key`, or has
+  one right after a `/` in its first word, such as `feat/docker-support`;
+- a shell command with its options or a system path (`ls -la`, `sed -i`,
+  `/bin/sh`), or a command in backticks;
+- script code (`fetch(`, `${VAR}`, `process.env`), HTML (`<img src=`) or an SQL
+  statement (`SELECT * FROM users WHERE`);
+- a URL naming an IP address or `localhost`.
+
+### A branch, tag or file name that starts with a command name
+
+The Core Rule Set's list of commands (932260) holds names such as `docker-`,
+`python3`, `ansible`, `base64` and `whoami`. A query parameter holding a branch,
+tag or file name that starts with one is refused. So is one that has such a name
+right after a `/`, such as `feat/docker-support`, `fix/docker-build` or
+`renovate/docker-build-push-action-6.x`. gitea's own pages send the name in a
+query parameter that 930120, 932160 and 932260 still check:
+
+- `refSubUrl`, the branch or tag of a directory listing. A listing sends it when
+  it asks for its entries' last commits in a second request. It does so whenever
+  gitea takes more than a second to work them out;
+- `name`, when a branch is deleted or restored on the branches page;
+- `tag`, when a release is started from a tag;
+- `template`, the file of an issue template, when an issue is opened from it;
+- `rule_name`, when a branch protection rule is opened for editing in the
+  repository's settings or has just been saved.
+
+What a visitor sees, for a branch named `docker-build`:
+
+- A directory listing that makes that second request leaves those last commits
+  out and shows an error.
+- The branches page shows an error instead of deleting or restoring the branch.
+- A release started from such a tag gets the `403` answer of `smallwebwaf` in
+  place of its form. So does an issue opened from such a template, and such a
+  rule opened for editing.
+- Saving such a rule stores it. gitea then returns to the branch settings page,
+  which gets the `403` answer, so the save looks as if it failed.
+
+### A file name in a query parameter that trips the code rules
+
+The Core Rule Set's rules for Java, script, PowerShell and SQL find what they
+look for in some file names. This holds too in the ten query parameters that
+930120, 932160 and 932260 do not check (see the fourth change under "Attack
+detection" in `SPEC.md`). Examples:
+
+- `runtime` in OpenJDK's `src/java.base/share/classes/java/lang/Runtime.java`
+  (944110);
+- a Java class, as in `java.lang.String.md` (944130);
+- `document.write.js` (941180);
+- `process.env.d.ts` (934100);
+- `__proto__` (934130);
+- the PowerShell command `Install-Script`, as in `install-script.sh` (932120);
+- a database's name, as in PostgreSQL's `information_schema.sql` (942140).
+
+For such a file, these requests are refused:
+
+- the API's list of its commits (`path`);
+- the API's call for the contents of files that names it in its query (`body`);
+- the commit graph of that file alone (`file`);
+- the hidden lines of its diff (`path`), which stay hidden;
+- the sign-in page, for a visitor who opens a page of the file that needs
+  signing in, such as its edit page (`redirect_to`). The visitor can still sign
+  in by opening the sign-in page itself.
+
+### A path
+
+- A file name ending in `~`, or an `.xhtml` file whose path holds a space.
+- A path that holds what the Core Rule Set takes for a Java class (944130), as
+  `java.lang.String.md` and
+  `META-INF/services/org.apache.commons.logging.LogFactory` do.
+- A path that holds what it takes for Node.js code (934100), as
+  `process.env.d.ts` does.
+- A path with a directory named `...` (930100, 930110), such as `.../notes.txt`.
+
+For such a file, these are refused:
+
+- the page of the file;
+- its raw file;
+- its history and its blame;
+- its edit page.
+
+The directory that holds it lists it, and a clone carries it.
+
+### A container image push that reuses a layer
+
+A push can reuse a layer of an image docker has pushed to that gitea before.
+docker then asks gitea to take the layer from that image, naming it in the query
+parameter `from`, which 932260 checks. The request is refused when the image's
+owner starts with an entry on the list of commands. It is refused too when the
+image's name after the owner starts with one. Examples are `owner/python3-app`,
+`owner/docker-base`, and any image of an owner named `ansible` or `docker-team`.
+
+What happens next depends on docker's image store. A docker that keeps its
+images in containerd's image store fails the push, and fails each new try the
+same way. A new install of Docker Engine 29 does this. A docker that keeps them
+in its own older image store uploads the layer instead. The push then succeeds
+after one refusal for each layer it reuses, and each of those refusals counts
+toward the error burst ("Attack detection" in `SPEC.md`).
+
+### Artifact uploads from `actions/upload-artifact@v3`
+
+This action sends the header `Content-Range`, which the Core Rule Set refuses
+(920450). The action sends two files at a time, does not retry a `403`, and
+sends no further file once one is refused. So an upload is refused once or
+twice, however many files it holds, and the step fails. One upload does not ban
+the runner. The error burst ("Attack detection" in `SPEC.md`) bans it after more
+than 30 such refusals from its address in a minute, as when many jobs upload at
+once. `actions/upload-artifact@v4` does not send the header.
+
+### What body inspection refuses
+
+With `SWWAF_WAF_BODY_LIMIT` set, the Core Rule Set reads request bodies too. In
+front of gitea it then refuses these, until their rule ids, named in the request
+log, are added to `SWWAF_WAF_DISABLED_RULES`:
+
+- issue and comment text, wiki pages and files saved in the web editor that hold
+  shell commands or code (932125, 932235, 932250 and others);
+- package descriptions that show code;
+- PyPI uploads (922130);
+- attachments named like `debug.log` or `config.yml` (932180).
+
+### What `script/gitea-requests` sends
+
+Of the requests above, the script sends:
+
+- for each file named under "A file name in a query parameter that trips the
+  code rules", the API's list of its commits;
+- for `Runtime.java` alone, the commit graph of that file, the hidden lines of
+  its diff, and the API's call for the contents of files that names it;
+- the sign-in page for a visitor who opens the edit page of `document.write.js`;
+- the pages of `java.lang.String.md`,
+  `META-INF/services/org.apache.commons.logging.LogFactory`, `process.env.d.ts`
+  and `.../notes.txt`;
+- one container image push that reuses a layer, which it does not try again.
+
+It does not send the raw file, history, blame or edit page of those four files,
+or the pages of the directories `META-INF/services` and `...`. It also sends a
+short sample of gitea's ordinary use:
+
+- signing in;
+- pages of files and commits, and a diff;
+- the API;
+- a push, and clone and fetch over HTTP;
+- two container image pushes.

docs/request-log.md

@@ -107,6 +107,35 @@ Every one of these lines has:
 - `would_action`: in `observe` mode, what `enforce` mode would have done with a
   request it would have refused. `action` then names what was done, normally
   `forward`.
+- `heuristic`: the heuristic that refused the request, in `observe` mode too. It
+  is left out when none did.
+- `heuristic_figures`: an object of the figures that heuristic acted on. Each
+  heuristic and its figures:
+    - `deny_nets`: `netblock`, the entry of `SWWAF_DENY_NETS` the client is in;
+    - `active_ban`: `netblock`, the ban's netblock, and `ban_expires`;
+    - `countries`: `country`, and `setting`, the country list that refused it;
+    - `blocklists`: `lists`, the blocklist URLs that list the client;
+    - `crowdsec`: `scenario`, the decision's scenario, and `expires`, when the
+      decision ends;
+    - `dnsbl`: `zones`, the DNS blocklist zones that list the client, their keys
+      masked;
+    - `abuseipdb`: `score`, and `min_score`, `SWWAF_ABUSEIPDB_MIN_SCORE`;
+    - `rate_limits`: `window`, `count` and `limit`;
+    - `trap_paths`: `path`, the trap path asked for;
+    - `rule_files`: `rule_id` and `rule_action`, of the rule that refused it;
+    - `header_limits`: `fields`, `fields_limit`, `cookies` and `cookies_limit`;
+    - `core_rule_set`: `score`, and `threshold`, `SWWAF_WAF_ANOMALY_THRESHOLD`;
+    - `refusal_limit`: `window`, `count` and `limit`, of the error burst;
+    - `byte_limits`: `window`, `count` and `limit`, the count in bytes.
+- `after_answer_heuristic`: the heuristic that banned the client after
+  `servewaf` answered the request, in `observe` mode too: `refusal_limit` or
+  `byte_limits`.
+- `after_answer_heuristic_figures`: an object of the figures that heuristic
+  acted on, as listed above.
+
+    `byte_limits` bans when the report comes, so only the `report` line names
+    it.
+
 - `limit_percent` and `limit_percent_setting`: the client's percentage of the
   rate limits and the setting that lowered it, when one did. `bytes_percent` and
   `bytes_percent_setting` do the same for the byte limits.

docs/settings.md

@@ -192,13 +192,6 @@ chooses between the two (see "The image's command" below).
   the Core Rule Set reads, a size of at most `64K`. A question carries no more
   of a body than 64 KiB, and the Core Rule Set reads at most 64 KiB less one
   byte of it, whatever the value (see "The answer" in [`SPEC.md`](../SPEC.md)).
-- `SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE` (default unset): a file of Core Rule Set
-  exclusions, written as Coraza directives. It is loaded before the Core Rule
-  Set's rules, so it holds only `SecAction` and `SecRule` lines that exclude
-  with `ctl:ruleRemoveTargetById` or `ctl:ruleRemoveById`. A file that cannot be
-  read or does not parse stops the start, whatever `SWWAF_WAF_MODE` is. So does
-  a file that names a number from 900000 to 900999 outside a comment, alone or
-  in a range. It has no `_FILE` form.
 - `SWWAF_ERROR_BURST_THRESHOLD` (default `30`): the most refusals of one client
   in a minute (see "Attack detection" in `SPEC.md`). A count or `off`.
 

internal/config/config.go

@@ -221,15 +221,12 @@ type Config struct {
 	// WAFExemptPaths the path prefixes it does not inspect
 	// (SWWAF_WAF_EXEMPT_PATHS), and WAFBodyLimit the most of a request body
 	// it reads (SWWAF_WAF_BODY_LIMIT), 0 while it is off and it reads none.
-	// CoreRuleSetExclusionsFile is the path of the file of its exclusions
-	// (SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE), "" while there is none.
 	WAFMode             string
 	WAFParanoiaLevel    int
 	WAFAnomalyThreshold int
 	WAFDisabledRules    []int
 	WAFExemptPaths      []string
 	WAFBodyLimit        int64
-	CoreRuleSetExclusionsFile string
 	// TrapPaths are the paths a request for which is a clear sign of
 	// attack (SWWAF_TRAP_PATHS), each starting with / and without a ?.
 	TrapPaths []string
@@ -528,8 +525,6 @@ func FromEnvironment(lookupEnv func(string) (string, bool)) (*Config, error) {
 			"920340,920420,920440,920640,930130,930140"),
 		WAFExemptPaths:       env.pathPrefixes("SWWAF_WAF_EXEMPT_PATHS", ""),
 		WAFBodyLimit:         env.wafBodyLimit("SWWAF_WAF_BODY_LIMIT", off),
-		CoreRuleSetExclusionsFile: env.filePath(
-			"SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE"),
 		TrapPaths:            env.trapPaths("SWWAF_TRAP_PATHS"),
 		ErrorBurstThreshold:  env.count("SWWAF_ERROR_BURST_THRESHOLD", "30"),
 		LogRemoteURL:         env.logRemoteURL("SWWAF_LOG_REMOTE_URL"),
@@ -1194,16 +1189,6 @@ func (e *environment) logRemoteURL(name string) *url.URL {
 	return remote
 }
 
-// filePath reads a setting that is the path of a file, "" while it is
-// unset. Its value names a file already, so, unlike the other settings,
-// it has no _FILE form. Whoever uses the file reads it.
-func (e *environment) filePath(name string) string {
-	path, _ := e.lookupEnv(name)
-	e.settings = append(e.settings, slog.String(name, path))
-
-	return path
-}
-
 // certificates reads a setting that is the path of a file of PEM
 // certificates. Unset or empty, it is nil. Its value names a file
 // already, so, unlike the other settings, it has no _FILE form.

internal/config/config_test.go

@@ -87,7 +87,6 @@ const (
 	wafDisabledRules     = "SWWAF_WAF_DISABLED_RULES"
 	wafExemptPaths       = "SWWAF_WAF_EXEMPT_PATHS"
 	wafBodyLimit         = "SWWAF_WAF_BODY_LIMIT"
-	exclusionsFile       = "SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE"
 	trapPaths            = "SWWAF_TRAP_PATHS"
 	errorBurstThreshold  = "SWWAF_ERROR_BURST_THRESHOLD"
 	logRemoteURL         = "SWWAF_LOG_REMOTE_URL"
@@ -540,14 +539,13 @@ func TestCoreRuleSetSettings(t *testing.T) {
 			environment{
 				wafMode: config.WAFModeDetect, wafParanoiaLevel: "4", wafAnomalyThreshold: "10",
 				wafDisabledRules: "942100, 920350", wafExemptPaths: "/api/, /static/",
-				wafBodyLimit: "32K", exclusionsFile: "/etc/smallwebwaf/crs-exclusions.conf",
+				wafBodyLimit: "32K",
 			},
 			config.Config{
 				WAFMode: config.WAFModeDetect, WAFParanoiaLevel: 4, WAFAnomalyThreshold: 10,
 				WAFDisabledRules: []int{942100, 920350},
 				WAFExemptPaths:   []string{"/api/", "/static/"},
 				WAFBodyLimit:     32 << 10,
-				CoreRuleSetExclusionsFile: "/etc/smallwebwaf/crs-exclusions.conf",
 			},
 		},
 		{
@@ -568,7 +566,6 @@ func TestCoreRuleSetSettings(t *testing.T) {
 			WAFAnomalyThreshold: cfg.WAFAnomalyThreshold,
 			WAFDisabledRules:    cfg.WAFDisabledRules, WAFExemptPaths: cfg.WAFExemptPaths,
 			WAFBodyLimit: cfg.WAFBodyLimit,
-			CoreRuleSetExclusionsFile: cfg.CoreRuleSetExclusionsFile,
 		}
 		if !reflect.DeepEqual(got, tc.want) {
 			t.Errorf("%v gave\n%+v\nwant\n%+v", tc.env, got, tc.want)
@@ -2330,7 +2327,6 @@ func TestLogsEachSettingWithItsValue(t *testing.T) {
 		wafDisabledRules:     defaultWAFDisabledRules,
 		wafExemptPaths:       "",
 		wafBodyLimit:         off,
-		exclusionsFile:       "",
 		trapPaths:            "",
 		errorBurstThreshold:  "30",
 		logRemoteURL:         "",

internal/requestlog/requestlog.go

@@ -131,6 +131,16 @@ type Line struct {
 	// ActionRuleBlocked, ActionWAFBlocked, or, in servewaf, ActionTooLarge
 	// for the header limits.
 	WouldAction string `json:"would_action,omitempty"`
+	// Heuristic is the name of the heuristic that refused the request, in
+	// observe mode too, and HeuristicFigures are the figures it acted on, by
+	// name.
+	Heuristic        string         `json:"heuristic,omitempty"`
+	HeuristicFigures map[string]any `json:"heuristic_figures,omitempty"`
+	// AfterAnswerHeuristic and AfterAnswerHeuristicFigures are the same for
+	// the heuristic that banned the client after servewaf answered the
+	// request.
+	AfterAnswerHeuristic        string         `json:"after_answer_heuristic,omitempty"`
+	AfterAnswerHeuristicFigures map[string]any `json:"after_answer_heuristic_figures,omitempty"` //nolint:lll // a struct tag cannot be split
 	// 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

internal/servewaf/abuseipdb.go

@@ -0,0 +1,55 @@
+package servewaf
+
+// The heuristic abuseipdb. It reads SWWAF_ABUSEIPDB_KEY,
+// SWWAF_ABUSEIPDB_MIN_SCORE and SWWAF_REPUTATION_ACTION.
+
+import (
+	"context"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/bans"
+	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
+	"sneak.berlin/go/smallwebwaf/internal/reputation"
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+// abuseIPDB notes AbuseIPDB, as noteHit does, with the score, when its score
+// of the client is a hit, and refuses the request when SWWAF_REPUTATION_ACTION
+// is deny, as dnsbl does for a zone. While SWWAF_ABUSEIPDB_KEY is unset it does
+// nothing. A client without a score is checked in the background, by the
+// request's address, if its history counts an offence, and the request does
+// not wait for the answer. The score is then used for each address of the
+// client. Its figures are the score and SWWAF_ABUSEIPDB_MIN_SCORE.
+type abuseIPDB struct{}
+
+func (abuseIPDB) name() string { return "abuseipdb" }
+
+func (abuseIPDB) check(ctx context.Context, rq *request, _ time.Time) *verdict {
+	if rq.h.config.AbuseIPDBKey == "" {
+		return nil
+	}
+
+	client := rq.h.clientGroup(rq.client)
+	held, _ := rq.h.limiter.Client(client)
+	offender := held.History.Offences != ratelimit.Offences{}
+
+	score, hit := rq.h.abuseIPDB.Hit(ctx, client, rq.client, offender)
+	if !hit {
+		return nil
+	}
+
+	rq.abuseIPDBHit = true
+	rq.noteHit(bans.ReputationHit{Source: reputation.AbuseIPDBSource, Score: &score},
+		"scored by AbuseIPDB at or over SWWAF_ABUSEIPDB_MIN_SCORE")
+
+	if rq.h.config.ReputationAction != deny {
+		return nil
+	}
+
+	return &verdict{
+		action: requestlog.ActionDenied,
+		figures: map[string]any{
+			figureScore: score, "min_score": rq.h.config.AbuseIPDBMinScore,
+		},
+	}
+}

internal/servewaf/answertime_test.go

@@ -91,6 +91,18 @@ func TestSixteenThousandCookiesAreRefusedWellWithinTheTimeLimit(t *testing.T) {
 	}
 }
 
+func TestHeaderLimitRefusalNamesItsHeuristicCountsAndLimits(t *testing.T) {
+	t.Parallel()
+
+	s := startServeWAF(t, "", nil)
+	req := s.question(siteA, client, "/")
+	fillHeaders(req, headerFieldLimit+1)
+	do(t, req)
+
+	wantHeuristic(t, s.out.requestLine(t), "header_limits",
+		`{"fields": 101, "fields_limit": 100, "cookies": 0, "cookies_limit": 50}`)
+}
+
 func TestEachHeaderLimitRefusesARequestOverIt(t *testing.T) {
 	t.Parallel()
 

internal/servewaf/bans.go

@@ -1,7 +1,10 @@
 package servewaf
 
+// The heuristic active_ban, and the code that makes bans, which several
+// heuristics share. active_ban reads SWWAF_MODE; the bans are the ban ledger's.
+
 import (
-	"net/http"
+	"context"
 	"net/netip"
 	"time"
 
@@ -18,11 +21,15 @@ func (rq *request) banResponse(action string) *refusal {
 	return &refusal{status: rq.h.config.BanResponse, action: action}
 }
 
-// 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. 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 {
+// activeBan refuses a client a ban covers: a ban on a netblock the client is
+// in, in force at now. It 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. Its figures are the ban's netblock and when it ends.
+type activeBan struct{}
+
+func (activeBan) name() string { return "active_ban" }
+
+func (activeBan) check(_ context.Context, rq *request, now time.Time) *verdict {
 	check := rq.h.ledger.Check
 	if rq.h.config.Observe {
 		check = rq.h.ledger.Find // the ban refuses nothing, and stays as it is
@@ -38,85 +45,24 @@ func (rq *request) banned(now time.Time) bool {
 		rq.alertBan(ban)
 	}
 
-	return banned
+	if !banned {
+		return nil
 	}
 
-// 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 {
-	counts, hit, over := rq.h.limiter.Count(rq.h.clientGroup(rq.client), now,
-		rq.limitPercent.percent)
-	rq.line.Counts = counts
-
-	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 report has come, and notes the client's byte totals
-// for the log line; its requests stay there as the rate limits counted them.
-// Only an allowed request 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(rq.h.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)
+	return &verdict{
+		action: requestlog.ActionBanned,
+		figures: map[string]any{
+			figureNetblock: ban.Netblock.String(), "ban_expires": rq.line.BanExpires,
+		},
 	}
 }
 
-// countRefusal counts the request for the error burst once it has been
-// answered, if servewaf refused it after a rule file match, a trap path or a
-// Core Rule Set match, and in observe mode if enforce mode would have: more than
-// SWWAF_ERROR_BURST_THRESHOLD such refusals of the client within a minute
-// break a limit. A client in SWWAF_ALLOW_NETS, which the checks skip, is
-// not counted, and nothing is while the threshold is off.
-func (rq *request) countRefusal() {
-	cfg := rq.h.config
-	if cfg.ErrorBurstThreshold == 0 {
-		return
+// limitFigures are the figures of a heuristic that broke hit, a limit: its
+// window, the count and the limit.
+func limitFigures(hit ratelimit.Hit) map[string]any {
+	return map[string]any{
+		figureWindow: hit.Window, figureCount: hit.Count, figureLimit: hit.Limit,
 	}
-
-	if !rq.attack && !rq.ruleBlocked && !rq.wafBlocked {
-		return
-	}
-
-	now := rq.h.now()
-
-	hit, over := rq.h.limiter.CountRefusal(rq.h.clientGroup(rq.client), now,
-		cfg.ErrorBurstThreshold)
-	if !over {
-		return
-	}
-
-	// What the client was sent, or in observe mode would have been.
-	status := rq.out.status
-
-	switch rq.line.WouldAction {
-	case requestlog.ActionRuleBlocked, requestlog.ActionWAFBlocked:
-		status = http.StatusForbidden
-	case requestlog.ActionBanned:
-		status = cfg.BanResponse
-	}
-
-	rq.banForLimit(now, hit, status)
 }
 
 // countedBytes returns the request's bytes, once it has ended, as the

internal/servewaf/bans_test.go

@@ -228,6 +228,22 @@ func TestBannedClientIsRefusedBeforeItsCountryIsLookedUp(t *testing.T) {
 	}
 }
 
+func TestRefusalUnderABanNamesItsHeuristicNetblockAndEnd(t *testing.T) {
+	t.Parallel()
+
+	s, clk, _ := startWithClock(t, "", map[string]string{
+		rateLimitPerMinute: "1", banScopeV4Prefix: "24",
+	})
+	expires := requestlog.FormatTime(clk.Now().Add(time.Hour))
+
+	s.get(client, http.StatusOK, requestlog.ActionForward)
+	s.get(client, http.StatusForbidden, requestlog.ActionRateLimited)
+
+	line := s.get(otherClient, http.StatusForbidden, requestlog.ActionBanned)
+	wantHeuristic(t, line, "active_ban",
+		`{"netblock": "`+clientsNet+`", "ban_expires": "`+expires+`"}`)
+}
+
 func TestBanResponseAnswersEveryRefusalButTheSizeLimits(t *testing.T) {
 	t.Parallel()
 

internal/servewaf/blocklists.go

@@ -0,0 +1,41 @@
+package servewaf
+
+// The heuristic blocklists. It reads SWWAF_BLOCKLIST_ACTION, and the blocklists
+// through the reputation lists.
+
+import (
+	"context"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+// blocklists notes the blocklists that list the client, as noteListed does,
+// and refuses the request when SWWAF_BLOCKLIST_ACTION is deny. Being limit, it
+// lowers the client's limits instead (see limitPercentages), and being log, it
+// does nothing more. Its figure is the blocklists that list the client.
+type blocklists struct{}
+
+func (blocklists) name() string { return "blocklists" }
+
+func (blocklists) check(_ context.Context, rq *request, _ time.Time) *verdict {
+	listedBy := rq.h.lists.ListedBy(rq.client)
+	rq.blocklisted = len(listedBy) > 0
+	rq.noteListed(listedBy, "listed by a blocklist")
+
+	if !rq.refusedByBlocklists(listedBy) {
+		return nil
+	}
+
+	return &verdict{
+		action:  requestlog.ActionDenied,
+		figures: map[string]any{"lists": listedBy},
+	}
+}
+
+// refusedByBlocklists reports whether the heuristic blocklists refuses a
+// client, given listedBy, the blocklists that list it: it does when one lists
+// it and SWWAF_BLOCKLIST_ACTION is deny.
+func (rq *request) refusedByBlocklists(listedBy []string) bool {
+	return len(listedBy) > 0 && rq.h.config.BlocklistAction == deny
+}

internal/servewaf/bytelimits.go

@@ -0,0 +1,43 @@
+package servewaf
+
+// The heuristic byte_limits. It reads SWWAF_BYTES_COUNT, and the byte limits
+// and biased thresholds through the limiter and limitPercentages.
+
+import (
+	"context"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+// byteLimits counts the request's bytes, as countedBytes gives them, for the
+// byte limits, once its report has come, and notes the client's byte totals for
+// the log line; its requests stay there as the rate limits counted them. Only
+// an allowed request 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, which bans the client; the response was passed on whole.
+// Its figures are the window, the count and the limit.
+type byteLimits struct{}
+
+func (byteLimits) name() string { return "byte_limits" }
+
+func (byteLimits) check(_ context.Context, rq *request, now time.Time) *verdict {
+	if !rq.counted || rq.line.WouldAction != "" {
+		return nil
+	}
+
+	counts, hit, over := rq.h.limiter.CountBytes(rq.h.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 {
+		return nil
+	}
+
+	rq.banForLimit(now, hit, rq.out.status)
+
+	return &verdict{action: requestlog.ActionBanned, figures: limitFigures(hit)}
+}

internal/servewaf/bytelimits_test.go

@@ -98,6 +98,21 @@ func TestEachByteLimitBansOnceTheResponseHasEnded(t *testing.T) {
 	}
 }
 
+func TestByteLimitBanNamesItsHeuristicWindowCountAndLimit(t *testing.T) {
+	t.Parallel()
+
+	s, _ := startWithAnswers(t, map[string]string{bytesLimitPerMinute: byteLimit})
+
+	line, _ := s.download()
+	wantAfterAnswerHeuristic(t, line, "", "null")
+
+	// Two answers of 70 bytes are over the limit of 99.
+	line, _ = s.download()
+	wantHeuristic(t, line, "", "null")
+	wantAfterAnswerHeuristic(t, line, "byte_limits",
+		`{"window": "minute", "count": 140, "limit": 99}`)
+}
+
 func TestResponseOverAByteLimitByItselfIsPassedOnWhole(t *testing.T) {
 	t.Parallel()
 

internal/servewaf/coreruleset.go

@@ -1,6 +1,10 @@
 package servewaf
 
+// The heuristic core_rule_set. It reads SWWAF_WAF_MODE, SWWAF_WAF_EXEMPT_PATHS
+// and SWWAF_WAF_ANOMALY_THRESHOLD.
+
 import (
+	"context"
 	"time"
 
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
@@ -9,18 +13,21 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/waf"
 )
 
-// checkCoreRuleSet inspects the request with the Core Rule Set, unless
+// coreRuleSet inspects the request with the Core Rule Set, unless
 // SWWAF_WAF_MODE is off or SWWAF_WAF_EXEMPT_PATHS exempts its path, as
 // pathExempt decides, and notes the rules it matched and its score in the
 // log line, and the rules in the metrics. A score at or over
 // SWWAF_WAF_ANOMALY_THRESHOLD is a match: it raises the waf_block alert,
-// and in block mode refuses the request, which is an offence its client's
-// history counts, and so returns ActionWAFBlocked. It returns "" for a
-// request it does not refuse.
-func (rq *request) checkCoreRuleSet() string {
+// and in block mode refuses the request with 403, which is an offence its
+// client's history counts. Its figures are the score and the threshold.
+type coreRuleSet struct{}
+
+func (coreRuleSet) name() string { return "core_rule_set" }
+
+func (coreRuleSet) check(_ context.Context, rq *request, _ time.Time) *verdict {
 	cfg := rq.h.config
 	if cfg.WAFMode == config.WAFModeOff || pathExempt(rq.in, cfg.WAFExemptPaths) {
-		return ""
+		return nil
 	}
 
 	start := time.Now()
@@ -40,18 +47,21 @@ func (rq *request) checkCoreRuleSet() string {
 
 	threshold := cfg.WAFAnomalyThreshold
 	if threshold == 0 || result.Score < threshold {
-		return ""
+		return nil
 	}
 
 	rq.alertWAFBlock(result)
 
 	if cfg.WAFMode == config.WAFModeDetect {
-		return ""
+		return nil
 	}
 
 	rq.wafBlocked = true
 
-	return requestlog.ActionWAFBlocked
+	return &verdict{
+		action:  requestlog.ActionWAFBlocked,
+		figures: map[string]any{figureScore: result.Score, "threshold": threshold},
+	}
 }
 
 // alertWAFBlock raises the waf_block alert for the request, which the Core

internal/servewaf/coreruleset_test.go

@@ -110,6 +110,16 @@ func TestCoreRuleSetRefusesAttacksInBlockModeAndOnlyLogsThemInDetectMode(t *test
 	}
 }
 
+func TestCoreRuleSetRefusalNamesItsHeuristicScoreAndThreshold(t *testing.T) {
+	t.Parallel()
+
+	s, _, _ := startWithClock(t, "", map[string]string{wafMode: block})
+
+	line := s.request(client, sqlInjection, http.StatusForbidden,
+		requestlog.ActionWAFBlocked)
+	wantHeuristic(t, line, "core_rule_set", `{"score": 5, "threshold": 5}`)
+}
+
 func TestOrdinaryRequestIsInspectedAndPassed(t *testing.T) {
 	t.Parallel()
 

internal/servewaf/countries.go

@@ -1,21 +1,42 @@
 package servewaf
 
+// The heuristic countries. It reads SWWAF_DENIED_COUNTRIES and
+// SWWAF_EXCLUSIVELY_ALLOWED_COUNTRIES.
+
 import (
+	"context"
 	"slices"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
 
-// 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 {
+// countries refuses a 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. Its figures are the country and the
+// setting that refused it.
+type countries struct{}
+
+func (countries) name() string { return "countries" }
+
+func (countries) check(_ context.Context, rq *request, _ time.Time) *verdict {
 	denied := rq.h.config.DeniedCountries
 	allowed := rq.h.config.ExclusivelyAllowedCountries
 	country := rq.line.Country
 
-	if slices.Contains(denied, country) {
-		return true
+	var setting string
+
+	switch {
+	case slices.Contains(denied, country):
+		setting = "SWWAF_DENIED_COUNTRIES"
+	case len(allowed) > 0 && !slices.Contains(allowed, country):
+		setting = "SWWAF_EXCLUSIVELY_ALLOWED_COUNTRIES"
+	default:
+		return nil
 	}
 
-	return len(allowed) > 0 && !slices.Contains(allowed, country)
+	return &verdict{
+		action:  requestlog.ActionCountryDenied,
+		figures: map[string]any{"country": country, "setting": setting},
+	}
 }

internal/servewaf/countries_test.go

@@ -90,6 +90,23 @@ func TestCountryLists(t *testing.T) {
 	}
 }
 
+func TestCountryRefusalNamesItsHeuristicCountryAndSetting(t *testing.T) {
+	t.Parallel()
+
+	geojsURL, _ := startGeoJS(t)
+	s, _, _ := startWithClock(t, geojsURL, map[string]string{
+		lookupTimeout: "1h", deniedCountries: "kp", allowedCountries: "de",
+	})
+
+	line := s.get(fromKP, http.StatusForbidden, requestlog.ActionCountryDenied)
+	wantHeuristic(t, line, "countries",
+		`{"country": "KP", "setting": "SWWAF_DENIED_COUNTRIES"}`)
+
+	line = s.get(unplaced, http.StatusForbidden, requestlog.ActionCountryDenied)
+	wantHeuristic(t, line, "countries",
+		`{"country": "", "setting": "SWWAF_EXCLUSIVELY_ALLOWED_COUNTRIES"}`)
+}
+
 func TestCountryRefusalKeepsARequestFromTheApp(t *testing.T) {
 	t.Parallel()
 

internal/servewaf/crowdsec.go

@@ -0,0 +1,49 @@
+package servewaf
+
+// The heuristic crowdsec. It reads SWWAF_CROWDSEC_LAPI_URL, and the decisions
+// through the reputation lists.
+
+import (
+	"context"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/bans"
+	"sneak.berlin/go/smallwebwaf/internal/reputation"
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+// crowdSec refuses a request when a decision of the CrowdSec decision list on
+// the client is in force at now. It then notes the list, as noteHit does, and
+// bans the client until that decision ends. Its figures are the decision's
+// scenario and when it ends.
+type crowdSec struct{}
+
+func (crowdSec) name() string { return "crowdsec" }
+
+func (crowdSec) check(_ context.Context, rq *request, now time.Time) *verdict {
+	decision, listed := rq.crowdSecDecisionInForce(now)
+	if !listed {
+		return nil
+	}
+
+	rq.noteHit(bans.ReputationHit{Source: rq.h.config.CrowdSecDecisionsURL},
+		"listed by the CrowdSec decision list")
+	rq.banForCrowdSec(now, decision)
+
+	return &verdict{
+		action: requestlog.ActionBanned,
+		figures: map[string]any{
+			"scenario": decision.Scenario,
+			"expires":  requestlog.FormatTime(decision.Expires),
+		},
+	}
+}
+
+// crowdSecDecisionInForce returns the decision of the CrowdSec decision list on
+// the client that is in force at now, and reports whether there is one, which
+// the heuristic crowdsec refuses the request for.
+func (rq *request) crowdSecDecisionInForce(
+	now time.Time,
+) (reputation.Decision, bool) {
+	return rq.h.lists.CrowdSecDecision(rq.client, now)
+}

internal/servewaf/crowdsec_test.go

@@ -95,6 +95,21 @@ func TestClientTheCrowdSecDecisionListListsIsBannedUntilTheDecisionEnds(t *testi
 		float64(fetched.Unix()))
 }
 
+func TestCrowdSecBanNamesItsHeuristicScenarioAndEnd(t *testing.T) {
+	t.Parallel()
+
+	s, clk, server, _ := startWithAlerts(t, map[string]string{
+		crowdSecURL: lapi, crowdSecKey: bouncerKey,
+	})
+	loadDecisions(t, server, clk.Now(), `[{"duration": "4h0m0s", `+
+		`"scenario": "crowdsecurity/ssh-bf", "scope": "Ip", "type": "ban", `+
+		`"value": "`+client+`"}]`)
+
+	line := s.get(client, http.StatusForbidden, requestlog.ActionBanned)
+	wantHeuristic(t, line, "crowdsec", `{"scenario": "crowdsecurity/ssh-bf", `+
+		`"expires": "`+requestlog.FormatTime(clk.Now().Add(4*time.Hour))+`"}`)
+}
+
 func TestEndedCrowdSecDecisionNoLongerBansThoughTheCopyStillHoldsIt(t *testing.T) {
 	t.Parallel()
 

internal/servewaf/denynets.go

@@ -0,0 +1,29 @@
+package servewaf
+
+// The heuristic deny_nets. It reads SWWAF_DENY_NETS.
+
+import (
+	"context"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+// denyNets refuses a client in SWWAF_DENY_NETS. Its figure is the netblock of
+// the setting the client is in.
+type denyNets struct{}
+
+func (denyNets) name() string { return "deny_nets" }
+
+func (denyNets) check(_ context.Context, rq *request, _ time.Time) *verdict {
+	for _, netblock := range rq.h.config.DenyNets {
+		if netblock.Contains(rq.client) {
+			return &verdict{
+				action:  requestlog.ActionDenied,
+				figures: map[string]any{figureNetblock: netblock.String()},
+			}
+		}
+	}
+
+	return nil
+}

internal/servewaf/dnsbl.go

@@ -0,0 +1,36 @@
+package servewaf
+
+// The heuristic dnsbl. It reads SWWAF_REPUTATION_ACTION, and the DNSBL zones'
+// verdicts through the DNSBL checker.
+
+import (
+	"context"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+// dnsbl notes the DNSBL zones whose verdict lists the client, as noteListed
+// does, and refuses the request when SWWAF_REPUTATION_ACTION is deny. Being
+// limit, it lowers the client's limits instead (see limitPercentages), and
+// being log, it does nothing more. A zone without a verdict on the client is
+// asked about it in the background, and the request does not wait for the
+// answer. Its figure is the zones that list the client, their keys masked.
+type dnsbl struct{}
+
+func (dnsbl) name() string { return "dnsbl" }
+
+func (dnsbl) check(ctx context.Context, rq *request, _ time.Time) *verdict {
+	listedBy := rq.h.dnsbl.ListedBy(ctx, rq.client)
+	rq.dnsblListed = len(listedBy) > 0
+	rq.noteListed(listedBy, "listed by a DNSBL zone")
+
+	if !rq.dnsblListed || rq.h.config.ReputationAction != deny {
+		return nil
+	}
+
+	return &verdict{
+		action:  requestlog.ActionDenied,
+		figures: map[string]any{"zones": listedBy},
+	}
+}

internal/servewaf/headerlimits.go

@@ -0,0 +1,71 @@
+package servewaf
+
+// The heuristic header_limits. It reads no setting: its limits are fixed.
+
+import (
+	"context"
+	"strings"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+// The header limits: the most cookies and header fields a request may have
+// when the checks reach the Core Rule Set. Real clients never reach them.
+const (
+	maxCookies      = 50
+	maxHeaderFields = 100
+)
+
+// headerLimits refuses a request over the header limits, with 431. Its figures
+// are the request's header fields and cookies, and the limit of each.
+type headerLimits struct{}
+
+func (headerLimits) name() string { return "header_limits" }
+
+func (headerLimits) check(_ context.Context, rq *request, _ time.Time) *verdict {
+	fields, cookies := rq.headerCounts()
+	if !overHeaderLimits(fields, cookies) {
+		return nil
+	}
+
+	return &verdict{
+		action: requestlog.ActionTooLarge,
+		figures: map[string]any{
+			"fields": fields, "fields_limit": maxHeaderFields,
+			"cookies": cookies, "cookies_limit": maxCookies,
+		},
+	}
+}
+
+// overHeaderLimits reports whether a request with these counts of header fields
+// and cookies, as headerCounts counts them, is over the header limits: it has
+// more than maxHeaderFields fields or more than maxCookies cookies.
+func overHeaderLimits(fields, cookies int) bool {
+	return fields > maxHeaderFields || cookies > maxCookies
+}
+
+// headerCounts returns the request's header fields, each value of a header sent
+// twice being one, and its cookies, each part of a Cookie header between
+// semicolons being one unless it is empty or only spaces and tabs. The Core
+// Rule Set runs each of its rules on each cookie, so that thousands of small
+// cookies keep it busy for over a second. It trims only spaces and control
+// characters, of which a header value can hold only tabs, so a part of Unicode
+// spaces is a cookie to it.
+func (rq *request) headerCounts() (int, int) {
+	fields, cookies := 0, 0
+
+	for _, values := range rq.in.Header {
+		fields += len(values)
+	}
+
+	for _, value := range rq.in.Header.Values("Cookie") {
+		for part := range strings.SplitSeq(value, ";") {
+			if strings.Trim(part, " \t") != "" {
+				cookies++
+			}
+		}
+	}
+
+	return fields, cookies
+}

internal/servewaf/heuristics.go

@@ -0,0 +1,133 @@
+package servewaf
+
+import (
+	"context"
+	"time"
+)
+
+// To add a heuristic, write one file with a type that implements heuristic,
+// and add one line for it to one of the lists below. Its settings go in
+// config.Config, and the comment at the top of its file names them.
+
+// heuristic is one of the checks that decide what servewaf does with a request.
+type heuristic interface {
+	// name is the heuristic's name, which the log line gives.
+	name() string
+	// check looks at the request at now, and returns nil to let it through.
+	// ctx is the request's own context.
+	check(ctx context.Context, rq *request, now time.Time) *verdict
+}
+
+// verdict is a heuristic refusing a request, or banning its client: the action
+// the log line names, one of requestlog's Action constants, and the figures the
+// heuristic acted on, by name, such as the count and the limit.
+type verdict struct {
+	action  string
+	figures map[string]any
+}
+
+// The names of the figures that more than one heuristic gives.
+const (
+	figureWindow   = "window"
+	figureCount    = "count"
+	figureLimit    = "limit"
+	figureScore    = "score"
+	figureNetblock = "netblock"
+)
+
+// The lists of heuristics, each in the order its heuristics run. A client in
+// SWWAF_ALLOW_NETS skips them all.
+
+// beforeLookup are the heuristics that run before the client's AS number and
+// country are looked up, so that a client they refuse is not looked up.
+func beforeLookup() []heuristic {
+	return []heuristic{
+		denyNets{},
+		activeBan{},
+	}
+}
+
+// afterLookup are the heuristics that run once the lookup has been made.
+func afterLookup() []heuristic {
+	return []heuristic{
+		countries{},
+		blocklists{},
+		crowdSec{},
+		dnsbl{},
+		abuseIPDB{},
+		rateLimits{},
+		trapPaths{},
+		ruleFiles{},
+		headerLimits{},
+		coreRuleSet{},
+	}
+}
+
+// afterAnswer are the heuristics that run on a request once servewaf has
+// answered it, before its decision line is written. They ban the client, and do
+// not change what the request got: their verdict's action is not used.
+func afterAnswer() []heuristic {
+	return []heuristic{
+		refusalLimit{},
+	}
+}
+
+// onReport are the heuristics that run on an allowed request when rproxy's
+// report of it comes, before its report line is written. Like afterAnswer, they
+// only ban.
+func onReport() []heuristic {
+	return []heuristic{
+		byteLimits{},
+	}
+}
+
+// runAfterAnswer runs the heuristics of afterAnswer on the request, at the time
+// it is called.
+func (rq *request) runAfterAnswer(ctx context.Context) {
+	rq.runBanningHeuristics(ctx, afterAnswer())
+}
+
+// runHeuristics runs list, beforeLookup or afterLookup, on the request at now,
+// and returns the first verdict, or nil when none gives one. The log line's
+// heuristic and heuristic_figures name the heuristic that gave it, and give its
+// figures. ctx is the request's own context.
+func (rq *request) runHeuristics(
+	ctx context.Context, list []heuristic, now time.Time,
+) *verdict {
+	name, v := rq.firstVerdict(ctx, list, now)
+	if v != nil {
+		rq.line.Heuristic = name
+		rq.line.HeuristicFigures = v.figures
+	}
+
+	return v
+}
+
+// runBanningHeuristics runs list, afterAnswer or onReport, on the request at
+// the time it is called. The log line's after_answer_heuristic and
+// after_answer_heuristic_figures name the heuristic that gave a verdict, and
+// give its figures, so that heuristic and heuristic_figures still name the one
+// that refused the request. ctx is the request's own context.
+func (rq *request) runBanningHeuristics(ctx context.Context, list []heuristic) {
+	name, v := rq.firstVerdict(ctx, list, rq.h.now())
+	if v != nil {
+		rq.line.AfterAnswerHeuristic = name
+		rq.line.AfterAnswerHeuristicFigures = v.figures
+	}
+}
+
+// firstVerdict runs list on the request at now, in order, until a heuristic
+// gives a verdict, and returns that heuristic's name and its verdict, or "" and
+// nil when none gives one. ctx is the request's own context.
+func (rq *request) firstVerdict(
+	ctx context.Context, list []heuristic, now time.Time,
+) (string, *verdict) {
+	for _, each := range list {
+		v := each.check(ctx, rq, now)
+		if v != nil {
+			return each.name(), v
+		}
+	}
+
+	return "", nil
+}

internal/servewaf/observe_test.go

@@ -14,6 +14,18 @@ import (
 // observe is the value of SWWAF_MODE for observe mode.
 const observe = "observe"
 
+func TestObserveModeNamesTheHeuristicThatWouldHaveRefused(t *testing.T) {
+	t.Parallel()
+
+	s, _, _ := startWithClock(t, "", map[string]string{
+		mode: observe, denyNets: client,
+	})
+
+	line := s.get(client, http.StatusOK, requestlog.ActionForward)
+	wantWouldAction(t, line, requestlog.ActionDenied)
+	wantHeuristic(t, line, "deny_nets", `{"netblock": "`+client+`/32"}`)
+}
+
 func TestObserveModeForwardsWhatEnforceModeRefuses(t *testing.T) {
 	t.Parallel()
 

internal/servewaf/proxy.go

@@ -4,7 +4,6 @@
 package servewaf
 
 import (
-	"fmt"
 	"io"
 	"log/slog"
 	"net/http"
@@ -61,9 +60,6 @@ type Params struct {
 	// LookupFile is the lookup database they are looked up in while
 	// SWWAF_LOOKUP_SOURCE is file, and nil otherwise.
 	LookupFile *lookup.File
-	// CoreRuleSet is what NewCoreRuleSet returns: what inspects requests
-	// while SWWAF_WAF_MODE is not off, and nil while it is.
-	CoreRuleSet *waf.CoreRuleSet
 	// Now tells the time by which requests are counted for the rate
 	// limits, bans are made and run out, and GeoJS's answers are kept,
 	// normally time.Now in UTC, the time the state files give.
@@ -148,7 +144,7 @@ func newHandler(params Params) *handler {
 		dnsbl:       dnsbl,
 		abuseIPDB:   abuseIPDB,
 		rules:       params.Rules,
-		coreRuleSet: params.CoreRuleSet,
+		coreRuleSet: newCoreRuleSet(params.Config),
 		alerts:      params.Alerts,
 	}
 	h.geojs = lookup.New(lookup.Params{
@@ -206,35 +202,29 @@ func newReputation(
 	return lists, dnsbl, abuseIPDB
 }
 
-// NewCoreRuleSet returns the Core Rule Set at SWWAF_WAF_PARANOIA_LEVEL,
+// newCoreRuleSet returns the Core Rule Set at SWWAF_WAF_PARANOIA_LEVEL,
 // without the rules SWWAF_WAF_DISABLED_RULES switches off, reading bodies
-// up to SWWAF_WAF_BODY_LIMIT, with the exclusions in
-// SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE, or nil while SWWAF_WAF_MODE is off. It
-// reads at most QuestionBodyMaxBytes less one byte: a question's body of
+// up to SWWAF_WAF_BODY_LIMIT, or nil while SWWAF_WAF_MODE is off. It reads at
+// most QuestionBodyMaxBytes less one byte: a question's body of
 // QuestionBodyMaxBytes may be cut short, and the Core Rule Set does not read a
-// JSON or XML body over its limit. An exclusions file that cannot be read, does
-// not parse or names an id of smallwebwaf's own rules is an error in every
-// mode. While the mode is off, a set file is loaded with the Core Rule Set only
-// to check it.
-func NewCoreRuleSet(cfg *config.Config) (*waf.CoreRuleSet, error) {
-	if cfg.WAFMode == config.WAFModeOff && cfg.CoreRuleSetExclusionsFile == "" {
-		return nil, nil //nolint:nilnil // off is no Core Rule Set, and no error
+// JSON or XML body over its limit.
+func newCoreRuleSet(cfg *config.Config) *waf.CoreRuleSet {
+	if cfg.WAFMode == config.WAFModeOff {
+		return nil
 	}
 
 	coreRuleSet, err := waf.New(waf.Params{
 		ParanoiaLevel: cfg.WAFParanoiaLevel, DisabledRules: cfg.WAFDisabledRules,
 		BodyLimit: min(cfg.WAFBodyLimit, QuestionBodyMaxBytes-1),
-		ExclusionsFile: cfg.CoreRuleSetExclusionsFile,
 	})
 	if err != nil {
-		return nil, fmt.Errorf("SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE: %w", err)
+		// The Core Rule Set is built in, and the settings cannot break it:
+		// the paranoia level is from 1 to 4, and the id of no rule switches
+		// nothing off.
+		panic(err)
 	}
 
-	if cfg.WAFMode == config.WAFModeOff {
-		return nil, nil //nolint:nilnil // off is no Core Rule Set, and no error
-	}
-
-	return coreRuleSet, nil
+	return coreRuleSet
 }
 
 // handler is servewaf's handler. It holds what every request shares; what

internal/servewaf/proxy_test.go

@@ -463,11 +463,6 @@ func newServeWAFWith(
 		}
 	}
 
-	coreRuleSet, err := servewaf.NewCoreRuleSet(cfg)
-	if err != nil {
-		t.Fatalf("Core Rule Set: %v", err)
-	}
-
 	server := build(servewaf.Params{
 		Config:       cfg,
 		RequestLog:   out,
@@ -475,7 +470,6 @@ func newServeWAFWith(
 		GeoJSURL:     geojsURL,
 		AbuseIPDBURL: abuseIPDBURL,
 		LookupFile:   lookupFile,
-		CoreRuleSet:  coreRuleSet,
 		Now:          now,
 		Rules:        ruleFiles,
 		Alerts:       alertQueue,

internal/servewaf/ratelimits.go

@@ -0,0 +1,65 @@
+package servewaf
+
+// The heuristic rate_limits. It reads SWWAF_RATE_LIMIT_EXEMPT_NETS,
+// SWWAF_RATE_LIMIT_EXEMPT_PATHS and SWWAF_BAN_RESPONSE, and the rate limits and
+// biased thresholds through the limiter and limitPercentages.
+
+import (
+	"context"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+// rateLimits counts the request for the rate limits, unless
+// countedByRateLimits exempts it, by the client's limit percentages, which it
+// notes for the log line with the client's counts. A request that takes the
+// client over a rate limit, as its limit percentage lowers it, breaks it: it is
+// refused, and bans the client. A request exempt from the rate limits is exempt
+// from the byte limits too. Its figures are the window, the count and the
+// limit.
+type rateLimits struct{}
+
+func (rateLimits) name() string { return "rate_limits" }
+
+func (rateLimits) check(_ context.Context, rq *request, now time.Time) *verdict {
+	rq.counted = rq.countedByRateLimits()
+	if !rq.counted {
+		return nil
+	}
+
+	rq.limitPercent, rq.bytesPercent = rq.limitPercentages()
+	rq.line.LimitPercent, rq.line.LimitPercentSetting = rq.limitPercent.logged()
+	rq.line.BytesPercent, rq.line.BytesPercentSetting = rq.bytesPercent.logged()
+
+	counts, hit, over := rq.h.limiter.Count(rq.h.clientGroup(rq.client), now,
+		rq.limitPercent.percent)
+	rq.line.Counts = counts
+
+	if !over {
+		return nil
+	}
+
+	rq.banForLimit(now, hit, rq.h.config.BanResponse)
+
+	return &verdict{action: requestlog.ActionRateLimited, figures: limitFigures(hit)}
+}
+
+// overAWholeRateLimit reports whether the heuristic rate_limits will refuse the
+// request at now, whatever its client's limit percentages: the rate limits
+// count it, and one more request from its client takes it over a whole rate
+// limit. It counts nothing.
+func (rq *request) overAWholeRateLimit(now time.Time) bool {
+	return rq.countedByRateLimits() &&
+		rq.h.limiter.OverARateLimit(rq.h.clientGroup(rq.client), now)
+}
+
+// countedByRateLimits reports whether the rate limits count the request: its
+// client is not in SWWAF_RATE_LIMIT_EXEMPT_NETS, and its path is not exempt
+// under SWWAF_RATE_LIMIT_EXEMPT_PATHS.
+func (rq *request) countedByRateLimits() bool {
+	cfg := rq.h.config
+
+	return !isInside(rq.client, cfg.RateLimitExemptNets) &&
+		!pathExempt(rq.in, cfg.RateLimitExemptPaths)
+}

internal/servewaf/ratelimits_test.go

@@ -72,6 +72,17 @@ func TestRateLimitRefusesBeforeTheApp(t *testing.T) {
 	}
 }
 
+func TestRateLimitRefusalNamesItsHeuristicWindowCountAndLimit(t *testing.T) {
+	t.Parallel()
+
+	s, _, _ := startWithClock(t, "", map[string]string{rateLimitPerMinute: "1"})
+
+	s.get(client, http.StatusOK, requestlog.ActionForward)
+
+	line := s.get(client, http.StatusForbidden, requestlog.ActionRateLimited)
+	wantHeuristic(t, line, "rate_limits", `{"window": "minute", "count": 2, "limit": 1}`)
+}
+
 func TestIPv6GroupPrefixSetsTheClientTheLimitsCount(t *testing.T) {
 	t.Parallel()
 

internal/servewaf/refusallimit.go

@@ -0,0 +1,54 @@
+package servewaf
+
+// The heuristic refusal_limit. It reads SWWAF_ERROR_BURST_THRESHOLD and
+// SWWAF_BAN_RESPONSE.
+
+import (
+	"context"
+	"net/http"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+// refusalLimit counts the request once it has been answered, if servewaf
+// refused it after a rule file match, a trap path or a Core Rule Set match, and
+// in observe mode if enforce mode would have: more than
+// SWWAF_ERROR_BURST_THRESHOLD such refusals of the client within a minute break
+// a limit, which bans the client. A client in SWWAF_ALLOW_NETS, which the
+// heuristics skip, is not counted, and nothing is while the threshold is off.
+// Its figures are the window, the count and the limit.
+type refusalLimit struct{}
+
+func (refusalLimit) name() string { return "refusal_limit" }
+
+func (refusalLimit) check(_ context.Context, rq *request, now time.Time) *verdict {
+	cfg := rq.h.config
+	if cfg.ErrorBurstThreshold == 0 {
+		return nil
+	}
+
+	if !rq.attack && !rq.ruleBlocked && !rq.wafBlocked {
+		return nil
+	}
+
+	hit, over := rq.h.limiter.CountRefusal(rq.h.clientGroup(rq.client), now,
+		cfg.ErrorBurstThreshold)
+	if !over {
+		return nil
+	}
+
+	// What the client was sent, or in observe mode would have been.
+	status := rq.out.status
+
+	switch rq.line.WouldAction {
+	case requestlog.ActionRuleBlocked, requestlog.ActionWAFBlocked:
+		status = http.StatusForbidden
+	case requestlog.ActionBanned:
+		status = cfg.BanResponse
+	}
+
+	rq.banForLimit(now, hit, status)
+
+	return &verdict{action: requestlog.ActionBanned, figures: limitFigures(hit)}
+}

internal/servewaf/refusallimit_test.go

@@ -106,6 +106,25 @@ func TestErrorBurstBreaksAtOneOverTheThreshold(t *testing.T) {
 	}
 }
 
+func TestRefusalLimitBanNamesItsHeuristicWindowCountAndLimit(t *testing.T) {
+	t.Parallel()
+
+	s, _, _ := startForErrorBurst(t, "1", nil)
+
+	const ruleFigures = `{"rule_id": "blocked", "rule_action": "block"}`
+
+	line := blockRule.send(s, client)
+	wantHeuristic(t, line, "rule_files", ruleFigures)
+	wantAfterAnswerHeuristic(t, line, "", "null")
+
+	// The second refusal is the request refusal_limit bans for, and the line
+	// names both.
+	line = blockRule.send(s, client)
+	wantHeuristic(t, line, "rule_files", ruleFigures)
+	wantAfterAnswerHeuristic(t, line, "refusal_limit",
+		`{"window": "minute", "count": 2, "limit": 1}`)
+}
+
 func TestErrorBurstBanNotesHistoryAndMetrics(t *testing.T) {
 	t.Parallel()
 

internal/servewaf/reputation.go

@@ -1,91 +1,17 @@
 package servewaf
 
-import (
-	"context"
-	"time"
+// What the reputation heuristics share: blocklists, crowdsec, dnsbl and
+// abuseipdb.
 
+import (
 	"sneak.berlin/go/smallwebwaf/internal/alerts"
 	"sneak.berlin/go/smallwebwaf/internal/bans"
-	"sneak.berlin/go/smallwebwaf/internal/ratelimit"
-	"sneak.berlin/go/smallwebwaf/internal/reputation"
 )
 
 // deny is the SWWAF_BLOCKLIST_ACTION and the SWWAF_REPUTATION_ACTION that
 // refuses the requests of a client a source lists.
 const deny = "deny"
 
-// blocklistDenied notes the blocklists that list the client, as
-// noteListed does, and reports whether SWWAF_BLOCKLIST_ACTION, being deny,
-// refuses the request. Being limit, it lowers the client's limits instead
-// (see limitPercentages), and being log, it does nothing more.
-func (rq *request) blocklistDenied() bool {
-	listedBy := rq.h.lists.ListedBy(rq.client)
-	rq.blocklisted = len(listedBy) > 0
-	rq.noteListed(listedBy, "listed by a blocklist")
-
-	return rq.blocklisted && rq.h.config.BlocklistAction == deny
-}
-
-// crowdSecBanned reports whether a decision of the CrowdSec decision list
-// on the client is in force at now. If one is, it notes the list, as
-// noteHit does, and bans the client until that decision ends.
-func (rq *request) crowdSecBanned(now time.Time) bool {
-	decision, listed := rq.h.lists.CrowdSecDecision(rq.client, now)
-	if !listed {
-		return false
-	}
-
-	rq.noteHit(bans.ReputationHit{Source: rq.h.config.CrowdSecDecisionsURL},
-		"listed by the CrowdSec decision list")
-	rq.banForCrowdSec(now, decision)
-
-	return true
-}
-
-// dnsblDenied notes the DNSBL zones whose verdict lists the client, as
-// noteListed does, and reports whether SWWAF_REPUTATION_ACTION, being
-// deny, refuses the request. Being limit, it lowers the client's limits
-// instead (see limitPercentages), and being log, it does nothing more. A
-// zone without a verdict on the client is asked about it in the
-// background, and the request does not wait for the answer. ctx is the
-// request's own context.
-func (rq *request) dnsblDenied(ctx context.Context) bool {
-	listedBy := rq.h.dnsbl.ListedBy(ctx, rq.client)
-	rq.dnsblListed = len(listedBy) > 0
-	rq.noteListed(listedBy, "listed by a DNSBL zone")
-
-	return rq.dnsblListed && rq.h.config.ReputationAction == deny
-}
-
-// abuseIPDBDenied notes AbuseIPDB, as noteHit does, with the score, when
-// its score of the client is a hit, and reports whether
-// SWWAF_REPUTATION_ACTION, being deny, refuses the request, as dnsblDenied
-// does for a zone. While SWWAF_ABUSEIPDB_KEY is unset it does nothing. A
-// client without a score is checked in the background, by the request's
-// address, if its history counts an offence, and the request does not
-// wait for the answer. The score is then used for each address of the
-// client. ctx is the request's own context.
-func (rq *request) abuseIPDBDenied(ctx context.Context) bool {
-	if rq.h.config.AbuseIPDBKey == "" {
-		return false
-	}
-
-	client := rq.h.clientGroup(rq.client)
-	held, _ := rq.h.limiter.Client(client)
-	offender := held.History.Offences != ratelimit.Offences{}
-
-	score, hit := rq.h.abuseIPDB.Hit(ctx, client, rq.client, offender)
-	if !hit {
-		return false
-	}
-
-	rq.abuseIPDBHit = true
-	rq.noteHit(bans.ReputationHit{Source: reputation.AbuseIPDBSource, Score: &score},
-		"scored by AbuseIPDB at or over SWWAF_ABUSEIPDB_MIN_SCORE")
-
-	return rq.h.config.ReputationAction == deny
-}
-
 // noteListed notes each of sources, the URLs of the blocklists or the
 // DNSBL zones, their keys masked, that list the client, as noteHit does,
 // with reason.

internal/servewaf/reputation_test.go

@@ -118,6 +118,56 @@ func TestEachBlocklistActionForAListedAddressAndAListedNetblock(t *testing.T) {
 	}
 }
 
+func TestReputationRefusalNamesItsHeuristicAndWhatListedTheClient(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		heuristic string
+		env       map[string]string
+		load      func(*testing.T, *servewaf.Server)
+		figures   string
+	}{
+		{
+			"blocklists",
+			map[string]string{blocklistURLs: dropURL, blocklistAction: actionDeny},
+			func(t *testing.T, server *servewaf.Server) {
+				t.Helper()
+				loadLists(t, server, map[string][]string{dropURL: {client}})
+			},
+			`{"lists": ["` + dropURL + `"]}`,
+		},
+		{
+			"dnsbl",
+			map[string]string{
+				dnsblZones: dnsblZone, dnsblResolver: noResolver,
+				reputationAction: actionDeny,
+			},
+			func(_ *testing.T, server *servewaf.Server) {
+				loadVerdicts(server, map[string][]string{client: {dnsblZone}})
+			},
+			`{"zones": ["` + dnsblZone + `"]}`,
+		},
+		{
+			"abuseipdb",
+			map[string]string{abuseIPDBKey: accountKey, reputationAction: actionDeny},
+			func(_ *testing.T, server *servewaf.Server) {
+				loadScores(server, map[string]int64{client: 80})
+			},
+			`{"score": 80, "min_score": 75}`,
+		},
+	} {
+		t.Run(tc.heuristic, func(t *testing.T) {
+			t.Parallel()
+
+			s, server, _ := startWithLookups(t, tc.env)
+			tc.load(t, server)
+
+			line := s.get(client, http.StatusForbidden, requestlog.ActionDenied)
+			wantHeuristic(t, line, tc.heuristic, tc.figures)
+		})
+	}
+}
+
 func TestBlocklistsComeAfterTheCountryListsAndSkipAllowNets(t *testing.T) {
 	t.Parallel()
 

internal/servewaf/request.go

@@ -160,16 +160,20 @@ func requestHeaders(r *http.Request, names []string) map[string]string {
 }
 
 // check is the one place where a request can be refused. It returns nil to let
-// the request through. The checks of checkClient decide: a request they refuse
-// is answered with SWWAF_BAN_RESPONSE, 403 for a block rule or the Core Rule Set,
-// or 431 for the header limits. In observe mode nothing is refused, and the log
-// line names what enforce mode would have done. ctx is the request's own context.
+// the request through. The heuristics of checkClient decide: a request they
+// refuse is answered with SWWAF_BAN_RESPONSE, 403 for a block rule or the Core
+// Rule Set, or 431 for the header limits. In observe mode nothing is refused,
+// and the log line names what enforce mode would have done. ctx is the
+// request's own context.
 func (rq *request) check(ctx context.Context) *refusal {
-	action := rq.checkClient(ctx)
+	v := rq.checkClient(ctx)
+	if v == nil {
+		return nil
+	}
+
+	action := v.action
 
 	switch {
-	case action == "":
-		return nil
 	case rq.h.config.Observe:
 		rq.line.WouldAction = action
 
@@ -183,35 +187,21 @@ 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, and is not looked up. For any
-// other client, SWWAF_DENY_NETS comes first, then a ban on its netblock,
-// so that a client either refuses is not looked up, then the lookup of
-// its AS number and country, then the country lists, then the blocklists,
-// then the CrowdSec decision list, which bans the client it lists, then
-// the DNSBL zones' verdicts, and then AbuseIPDB's score; a request any of
-// them refuses is not counted for the rate limits. Then come the
-// rate limits, unless the client is in SWWAF_RATE_LIMIT_EXEMPT_NETS or the
-// request's path is exempt under SWWAF_RATE_LIMIT_EXEMPT_PATHS, so that
-// every other request is counted, each of them by the client's limit
-// percentages, then SWWAF_TRAP_PATHS, then the rule files, then the header
-// limits, and last the Core Rule Set. A request exempt from the rate limits
-// is exempt from the byte limits too. ctx is the request's own context.
-func (rq *request) checkClient(ctx context.Context) string {
-	cfg := rq.h.config
-	if isInside(rq.client, cfg.AllowNets) {
-		return ""
+// checkClient runs the heuristics of beforeLookup on the request, then looks
+// up the client's AS number and country, then runs those of afterLookup. It
+// returns the first verdict, or nil when none gives one. A client in
+// SWWAF_ALLOW_NETS skips them all, and is not looked up. ctx is the request's
+// own context.
+func (rq *request) checkClient(ctx context.Context) *verdict {
+	if isInside(rq.client, rq.h.config.AllowNets) {
+		return nil
 	}
 
 	now := rq.h.now()
 
-	if isInside(rq.client, cfg.DenyNets) {
-		return requestlog.ActionDenied
-	}
-
-	if rq.banned(now) {
-		return requestlog.ActionBanned
+	v := rq.runHeuristics(ctx, beforeLookup(), now)
+	if v != nil {
+		return v
 	}
 
 	rq.lookUp(ctx, now)
@@ -220,59 +210,7 @@ func (rq *request) checkClient(ctx context.Context) string {
 	// again: a request counted at the time it arrived could be counted
 	// after a later one of its client's, which the rate limits would take
 	// for the clock set back.
-	now = rq.h.now()
-
-	if rq.countryDenied() {
-		return requestlog.ActionCountryDenied
-	}
-
-	if rq.blocklistDenied() {
-		return requestlog.ActionDenied
-	}
-
-	if rq.crowdSecBanned(now) {
-		return requestlog.ActionBanned
-	}
-
-	if rq.dnsblDenied(ctx) || rq.abuseIPDBDenied(ctx) {
-		return requestlog.ActionDenied
-	}
-
-	rq.counted = rq.countedByRateLimits()
-	if rq.counted {
-		rq.limitPercent, rq.bytesPercent = rq.limitPercentages()
-		rq.line.LimitPercent, rq.line.LimitPercentSetting = rq.limitPercent.logged()
-		rq.line.BytesPercent, rq.line.BytesPercentSetting = rq.bytesPercent.logged()
-	}
-
-	if rq.counted && rq.limitBroken(now) {
-		return requestlog.ActionRateLimited
-	}
-
-	if rq.trapPath(now) {
-		return requestlog.ActionBanned
-	}
-
-	action := rq.checkRules(now)
-	if action != "" {
-		return action
-	}
-
-	if rq.overHeaderLimits() {
-		return requestlog.ActionTooLarge
-	}
-
-	return rq.checkCoreRuleSet()
-}
-
-// countedByRateLimits reports whether the rate limits count the request: its
-// client is not in SWWAF_RATE_LIMIT_EXEMPT_NETS, and its path is not exempt
-// under SWWAF_RATE_LIMIT_EXEMPT_PATHS.
-func (rq *request) countedByRateLimits() bool {
-	cfg := rq.h.config
-
-	return !isInside(rq.client, cfg.RateLimitExemptNets) &&
-		!pathExempt(rq.in, cfg.RateLimitExemptPaths)
+	return rq.runHeuristics(ctx, afterLookup(), rq.h.now())
 }
 
 // pathExempt reports whether r is exempt under prefixes,

internal/servewaf/requestlog_test.go

@@ -1,6 +1,7 @@
 package servewaf_test
 
 import (
+	"encoding/json"
 	"io"
 	"math"
 	"net/http"
@@ -272,6 +273,48 @@ func wantTimings(t *testing.T, line logLine, want ...string) {
 	}
 }
 
+// wantHeuristic checks that line names heuristic as the one that refused the
+// request, with figures, a JSON object. A heuristic of "" with figures "null" is
+// a line that names none.
+func wantHeuristic(t *testing.T, line logLine, heuristic, figures string) {
+	t.Helper()
+
+	if line.Heuristic != heuristic ||
+		!reflect.DeepEqual(line.HeuristicFigures, decodeFigures(t, figures)) {
+		t.Errorf("log line has heuristic %q with heuristic_figures %v, want %q with %s",
+			line.Heuristic, line.HeuristicFigures, heuristic, figures)
+	}
+}
+
+// wantAfterAnswerHeuristic checks after_answer_heuristic and
+// after_answer_heuristic_figures as wantHeuristic checks heuristic and
+// heuristic_figures.
+func wantAfterAnswerHeuristic(t *testing.T, line logLine, heuristic, figures string) {
+	t.Helper()
+
+	if line.AfterAnswerHeuristic != heuristic ||
+		!reflect.DeepEqual(line.AfterAnswerHeuristicFigures, decodeFigures(t, figures)) {
+		t.Errorf("log line has after_answer_heuristic %q with "+
+			"after_answer_heuristic_figures %v, want %q with %s",
+			line.AfterAnswerHeuristic, line.AfterAnswerHeuristicFigures, heuristic, figures)
+	}
+}
+
+// decodeFigures decodes figures, a JSON object of a heuristic's figures, as
+// the log line's figures are decoded.
+func decodeFigures(t *testing.T, figures string) map[string]any {
+	t.Helper()
+
+	var decoded map[string]any
+
+	err := json.Unmarshal([]byte(figures), &decoded)
+	if err != nil {
+		t.Fatalf("decode %s: %v", figures, err)
+	}
+
+	return decoded
+}
+
 // microseconds is a timing in whole microseconds.
 func microseconds(milliseconds float64) int64 {
 	return int64(math.Round(milliseconds * 1000))

internal/servewaf/rulefiles.go

@@ -0,0 +1,55 @@
+package servewaf
+
+// The heuristic rule_files. It reads the rules of the rule files, which
+// SWWAF_RULES_DIR and SWWAF_RULES_ENABLED name.
+
+import (
+	"context"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/bans"
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+	"sneak.berlin/go/smallwebwaf/internal/rules"
+)
+
+// ruleFiles checks the request against the rules of the rule files at now,
+// notes the ids of those it matches in the log line, and refuses the request
+// when the last rule it matches refuses it: with ActionRuleBlocked for a block
+// rule, and ActionBanned for a ban rule. 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. Either rule's match is noted as an offence, for the
+// client's history. Its figures are the rule's id and action.
+type ruleFiles struct{}
+
+func (ruleFiles) name() string { return "rule_files" }
+
+func (ruleFiles) check(_ context.Context, rq *request, now time.Time) *verdict {
+	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 nil
+	}
+
+	// Only the last rule matched can refuse the request.
+	last := matched[len(matched)-1]
+	figures := map[string]any{"rule_id": last.ID, "rule_action": last.Action}
+
+	switch last.Action {
+	case rules.ActionBlock:
+		rq.ruleBlocked = true
+
+		return &verdict{action: requestlog.ActionRuleBlocked, figures: figures}
+	case rules.ActionBan:
+		rq.attack = true
+		rq.banForAttack(now, bans.Notes{RuleID: last.ID, Target: last.Target})
+
+		return &verdict{action: requestlog.ActionBanned, figures: figures}
+	default:
+		return nil
+	}
+}

internal/servewaf/rulefiles_test.go

@@ -93,6 +93,21 @@ func TestEachRuleAction(t *testing.T) {
 	s.get(client, http.StatusTooManyRequests, requestlog.ActionBanned)
 }
 
+func TestRuleRefusalNamesItsHeuristicAndTheRule(t *testing.T) {
+	t.Parallel()
+
+	s, _, _ := startWithClock(t, "", map[string]string{
+		rulesDir: writeRules(t, "noted path log ^/\n"+testRules),
+	})
+
+	line := s.request(client, "/blocked", http.StatusForbidden,
+		requestlog.ActionRuleBlocked)
+	wantHeuristic(t, line, "rule_files", `{"rule_id": "blocked", "rule_action": "block"}`)
+
+	line = s.request(client, "/.env", http.StatusForbidden, requestlog.ActionBanned)
+	wantHeuristic(t, line, "rule_files", `{"rule_id": "probe", "rule_action": "ban"}`)
+}
+
 func TestNextClearSignOfAttackAfterABanBansPermanently(t *testing.T) {
 	t.Parallel()
 

internal/servewaf/rules.go

@@ -1,64 +0,0 @@
-package servewaf
-
-import (
-	"slices"
-	"time"
-
-	"sneak.berlin/go/smallwebwaf/internal/bans"
-	"sneak.berlin/go/smallwebwaf/internal/requestlog"
-	"sneak.berlin/go/smallwebwaf/internal/rules"
-)
-
-// trapPath reports whether the request asks for a path in
-// SWWAF_TRAP_PATHS: its path as a path rule sees it, without the query,
-// as sent or once percent-decoded, is one of them. Such a request is a
-// clear sign of attack, as a ban rule's match is: it bans the client's
-// netblock, or in observe mode raises the alert for the ban it would have
-// made. The ban's notes give the path as sent.
-func (rq *request) trapPath(now time.Time) bool {
-	path := rules.Path(rq.in)
-	if !slices.Contains(rq.h.config.TrapPaths, path) &&
-		!slices.Contains(rq.h.config.TrapPaths, rules.DecodeOnce(path)) {
-		return false
-	}
-
-	rq.attack = true
-	rq.banForAttack(now, bans.Notes{TrapPath: path})
-
-	return true
-}
-
-// 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. Either rule's match
-// is noted as an offence, for the client's history.
-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:
-		rq.ruleBlocked = true
-
-		return requestlog.ActionRuleBlocked
-	case rules.ActionBan:
-		rq.attack = true
-		rq.banForAttack(now, bans.Notes{RuleID: last.ID, Target: last.Target})
-
-		return requestlog.ActionBanned
-	default:
-		return ""
-	}
-}

internal/servewaf/servewaf.go

@@ -2,6 +2,7 @@ package servewaf
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -52,13 +53,6 @@ const ReportPath = "/_smallwebwaf/report"
 // QuestionBodyMaxBytes is the most of a visitor's body a question carries.
 const QuestionBodyMaxBytes = 64 << 10
 
-// The header limits: the most cookies and header fields a request may have
-// when the checks reach the Core Rule Set. Real clients never reach them.
-const (
-	maxCookies      = 50
-	maxHeaderFields = 100
-)
-
 const (
 	// maxAwaitingReport is the most answered requests held until their
 	// reports come. Past it, the request answered longest ago is dropped.
@@ -147,48 +141,20 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 // refusedWhateverTheAnswer reports whether the request is one that does not wait
 // for GeoJS, since the checks will refuse it at now whatever GeoJS answers about
-// its client: it is over the header limits, a blocklist lists its client while
-// SWWAF_BLOCKLIST_ACTION is deny, the CrowdSec decision list lists it, or it is
-// over a whole rate limit. In observe mode, which refuses nothing, none is.
-// rproxy lets a request through when servewaf answers too late.
+// its client: the heuristic crowdsec, header_limits, blocklists or rate_limits
+// will refuse it, as a function in that heuristic's file says. In observe mode,
+// which refuses nothing, none is. rproxy lets a request through when servewaf
+// answers too late.
 func (rq *request) refusedWhateverTheAnswer(now time.Time) bool {
 	if rq.h.config.Observe {
 		return false
 	}
 
-	lists := rq.h.lists
-	_, decided := lists.CrowdSecDecision(rq.client, now)
+	_, decided := rq.crowdSecDecisionInForce(now)
 
-	return decided || rq.overHeaderLimits() ||
-		(rq.h.config.BlocklistAction == deny && len(lists.ListedBy(rq.client)) > 0) ||
-		(rq.countedByRateLimits() &&
-			rq.h.limiter.OverARateLimit(rq.h.clientGroup(rq.client), now))
-}
-
-// overHeaderLimits reports whether servewaf refuses the request for its
-// headers: it has more than maxHeaderFields fields, each value of a header sent
-// twice being one, or more than maxCookies cookies, each part of a Cookie header
-// between semicolons being one unless it is empty or only spaces and tabs. The
-// Core Rule Set runs each of its rules on each cookie, so that thousands of small
-// cookies keep it busy for over a second. It trims only spaces and control
-// characters, of which a header value can hold only tabs, so a part of Unicode
-// spaces is a cookie to it.
-func (rq *request) overHeaderLimits() bool {
-	fields, cookies := 0, 0
-
-	for _, values := range rq.in.Header {
-		fields += len(values)
-	}
-
-	for _, value := range rq.in.Header.Values("Cookie") {
-		for part := range strings.SplitSeq(value, ";") {
-			if strings.Trim(part, " \t") != "" {
-				cookies++
-			}
-		}
-	}
-
-	return fields > maxHeaderFields || cookies > maxCookies
+	return decided || overHeaderLimits(rq.headerCounts()) ||
+		rq.refusedByBlocklists(rq.h.lists.ListedBy(rq.client)) ||
+		rq.overAWholeRateLimit(now)
 }
 
 // answerQuestion runs the checks on the visitor's request a question
@@ -219,18 +185,18 @@ func (h *handler) answerQuestion(w http.ResponseWriter, r *http.Request) {
 
 	if refused == nil && !underOwnPrefix {
 		// In observe mode, what enforce mode would have refused counts here.
-		defer rq.countRefusal()
+		defer rq.runAfterAnswer(r.Context())
 
 		rq.allow()
 
 		return
 	}
 
-	// The last deferred runs first: countRefusal before addToHistory, so that a
-	// broken error burst is in the client's history.
+	// The last deferred runs first: runAfterAnswer before addToHistory, so that
+	// a broken refusal limit is in the client's history.
 	defer rq.addToHistory()
 	defer rq.countAnomalies()
-	defer rq.countRefusal()
+	defer rq.runAfterAnswer(r.Context())
 
 	if refused != nil {
 		rq.deny(*refused)
@@ -412,7 +378,7 @@ func (h *handler) takeReport(w http.ResponseWriter, r *http.Request) {
 	// Remove reports true to one report only, of several that name the id. A
 	// question still being handled is held as nil.
 	if found && held != nil && h.awaitingReport.Remove(report.RequestID) {
-		h.finishWith(held, report)
+		h.finishWith(r.Context(), held, report)
 	}
 
 	w.WriteHeader(http.StatusNoContent)
@@ -475,11 +441,11 @@ func (report *Report) checkRanges() error {
 
 // finishWith finishes a request with what its report says, and writes the
 // request's last log line, which holds its decision's fields and the report's.
-// For an allowed request it first counts the request's bytes, and adds it to its
-// client's history, the anomaly counters and the metrics, with the status and
-// bytes the report gives. A denied request's counting was finished at its
-// decision.
-func (h *handler) finishWith(held *decision, report Report) {
+// For an allowed request it first runs the heuristics of onReport, and adds the
+// request to its client's history, the anomaly counters and the metrics, with
+// the status and bytes the report gives. A denied request's counting was
+// finished at its decision. ctx is the report's own context.
+func (h *handler) finishWith(ctx context.Context, held *decision, report Report) {
 	rq := &request{
 		decision:     *held,
 		h:            h,
@@ -496,7 +462,7 @@ func (h *handler) finishWith(held *decision, report Report) {
 	if rq.allowed {
 		rq.line.DurationUpstreamTotal = &report.DurationUpstreamTotal
 
-		rq.countBytes()
+		rq.runBanningHeuristics(ctx, onReport())
 		rq.countAnomalies()
 		rq.addToHistory()
 

internal/servewaf/staticlists_test.go

@@ -104,6 +104,15 @@ func TestDenyNetsRefuseBeforeTheLookup(t *testing.T) {
 	}
 }
 
+func TestDenyNetsRefusalNamesItsHeuristicAndNetblock(t *testing.T) {
+	t.Parallel()
+
+	s, _, _ := startWithClock(t, "", map[string]string{denyNets: clientsNet})
+
+	line := s.get(client, http.StatusForbidden, requestlog.ActionDenied)
+	wantHeuristic(t, line, "deny_nets", `{"netblock": "`+clientsNet+`"}`)
+}
+
 func TestRequestRefusedByDenyNetsIsNotCounted(t *testing.T) {
 	t.Parallel()
 

internal/servewaf/trappaths.go

@@ -0,0 +1,39 @@
+package servewaf
+
+// The heuristic trap_paths. It reads SWWAF_TRAP_PATHS.
+
+import (
+	"context"
+	"slices"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/bans"
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+	"sneak.berlin/go/smallwebwaf/internal/rules"
+)
+
+// trapPaths refuses a request for a path in SWWAF_TRAP_PATHS: its path as a
+// path rule sees it, without the query, as sent or once percent-decoded, is one
+// of them. Such a request is a clear sign of attack, as a ban rule's match is:
+// it bans the client's netblock, or in observe mode raises the alert for the
+// ban it would have made. The ban's notes give the path as sent, and so does
+// its figure.
+type trapPaths struct{}
+
+func (trapPaths) name() string { return "trap_paths" }
+
+func (trapPaths) check(_ context.Context, rq *request, now time.Time) *verdict {
+	path := rules.Path(rq.in)
+	if !slices.Contains(rq.h.config.TrapPaths, path) &&
+		!slices.Contains(rq.h.config.TrapPaths, rules.DecodeOnce(path)) {
+		return nil
+	}
+
+	rq.attack = true
+	rq.banForAttack(now, bans.Notes{TrapPath: path})
+
+	return &verdict{
+		action:  requestlog.ActionBanned,
+		figures: map[string]any{"path": path},
+	}
+}

internal/servewaf/trappaths_test.go

@@ -83,6 +83,16 @@ func TestTrapPathBansAsABanRuleDoes(t *testing.T) {
 	}
 }
 
+func TestTrapPathRefusalNamesItsHeuristicAndPath(t *testing.T) {
+	t.Parallel()
+
+	s, _, _ := startWithClock(t, "", map[string]string{trapPaths: trapPathList})
+
+	line := s.request(client, "/wp-login.php?redirect_to=x", http.StatusForbidden,
+		requestlog.ActionBanned)
+	wantHeuristic(t, line, "trap_paths", `{"path": "/wp-login.php"}`)
+}
+
 func TestTrapPathMatchesThePathDecodedOnce(t *testing.T) {
 	t.Parallel()
 

internal/smallwebwaf/smallwebwaf.go

@@ -29,7 +29,6 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/rules"
 	"sneak.berlin/go/smallwebwaf/internal/servewaf"
 	"sneak.berlin/go/smallwebwaf/internal/state"
-	"sneak.berlin/go/smallwebwaf/internal/waf"
 )
 
 // shutdownTimeout is how long requests in progress may take to finish
@@ -151,14 +150,7 @@ func RunServeWAF(ctx context.Context, params Params) int {
 		return 1
 	}
 
-	crs, err := servewaf.NewCoreRuleSet(cfg)
-	if err != nil {
-		processLog.Error("cannot use the Core Rule Set", "error", err.Error())
-
-		return 1
-	}
-
-	server, err := newServer(cfg, stdout, processLog, now, ruleFiles, alertQueue, crs)
+	server, err := newServer(cfg, stdout, processLog, now, ruleFiles, alertQueue)
 	if err != nil {
 		processLog.Error("cannot use the lookup database", "error", err.Error())
 
@@ -178,7 +170,8 @@ func RunServeWAF(ctx context.Context, params Params) int {
 
 	listener, err := (&net.ListenConfig{}).Listen(ctx, "tcp", cfg.ListenAddr)
 	if err != nil {
-		processLog.Error("cannot listen on SWWAF_LISTEN_ADDR", "error", err.Error())
+		processLog.Error("cannot listen on SWWAF_LISTEN_ADDR",
+			"error", err.Error())
 
 		return 1
 	}
@@ -197,7 +190,6 @@ func RunServeWAF(ctx context.Context, params Params) int {
 func newServer(
 	cfg *config.Config, stdout io.Writer, processLog *slog.Logger,
 	now func() time.Time, ruleFiles *rules.Files, alertQueue *alerts.Queue,
-	crs *waf.CoreRuleSet,
 ) (*servewaf.Server, error) {
 	var lookupFile *lookup.File
 
@@ -222,7 +214,6 @@ func newServer(
 		GeoJSURL:     lookup.URL,
 		AbuseIPDBURL: reputation.AbuseIPDBURL,
 		LookupFile:   lookupFile,
-		CoreRuleSet:  crs,
 		Now:          now,
 		Rules:        ruleFiles,
 		Alerts:       alertQueue,

internal/smallwebwaf/smallwebwaf_test.go

@@ -19,7 +19,6 @@ import (
 	"testing"
 	"time"
 
-	"sneak.berlin/go/smallwebwaf/internal/config"
 	"sneak.berlin/go/smallwebwaf/internal/lookup/lookuptest"
 	"sneak.berlin/go/smallwebwaf/internal/servewaf"
 	"sneak.berlin/go/smallwebwaf/internal/smallwebwaf"
@@ -552,56 +551,6 @@ func TestRulesDirThatDoesNotExistStopsTheStart(t *testing.T) {
 		": no such file or directory")
 }
 
-func TestCoreRuleSetExclusionsFileThatCannotBeReadStopsTheStart(t *testing.T) {
-	t.Parallel()
-
-	path := filepath.Join(t.TempDir(), "crs-exclusions.conf")
-	out := &output{}
-
-	status := run(t.Context(), map[string]string{
-		listenAddr: localhost + ":0", stateDir: t.TempDir(), rulesDir: t.TempDir(),
-		"SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE": path,
-	}, out)
-	if status != 1 {
-		t.Fatalf("exit status %d, want 1", status)
-	}
-
-	line := out.line(t, "msg", "cannot use the Core Rule Set")
-	want := "SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE: read the exclusions file: open " +
-		path + ": no such file or directory"
-
-	if line["error"] != want {
-		t.Errorf("start refused with %v, want the error %q", line, want)
-	}
-}
-
-func TestCoreRuleSetExclusionsFileThatCannotBeUsedStopsTheStartWhileTheCoreRuleSetIsOff(
-	t *testing.T,
-) {
-	t.Parallel()
-
-	broken := filepath.Join(t.TempDir(), "broken.conf")
-
-	err := os.WriteFile(broken, []byte("SecNoSuchDirective On\n"), 0o600)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	for _, path := range []string{filepath.Join(t.TempDir(), "missing.conf"), broken} {
-		out := &output{}
-
-		status := run(t.Context(), map[string]string{
-			listenAddr: localhost + ":0", stateDir: t.TempDir(), rulesDir: t.TempDir(),
-			"SWWAF_WAF_MODE": config.WAFModeOff, "SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE": path,
-		}, out)
-		if status != 1 {
-			t.Fatalf("%s: exit status %d, want 1", path, status)
-		}
-
-		out.line(t, "msg", "cannot use the Core Rule Set")
-	}
-}
-
 func TestLookupDatabaseReplacedWhileRunningTakesEffect(t *testing.T) {
 	t.Parallel()
 

internal/waf/testdata/gitea-requests.txt

@@ -1,337 +0,0 @@
-# Ordinary gitea requests that the Core Rule Set must let through with
-# deploy/gitea/crs-exclusions.conf. Each line is a path and query, and may end
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-# and script/gitea-setup sends each to gitea through the setup as a GET. The Core
-# Rule Set reads the query and the headers the same way for any method.
-
-# Searches with ordinary words and symbols.
-/owner/repo/search?q=package.json
-/owner/repo/search?q=.gitignore
-/owner/repo/search?q=docker-compose.yml
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-/owner/repo/search?q=%24_GET%5B
-/owner/repo/search?q=%24_POST
-/owner/repo/search?q=%24_SERVER%5B%27REQUEST_URI%27%5D
-/owner/repo/search?q=%3C%3Fphp%20echo
-/owner/repo/search?q=information_schema
-/owner/repo/search?q=LIKE%20%27%25foo%25%27
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-/explore/code?q=SELECT%20%2A%20FROM%20users%20WHERE
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-/owner/repo/pulls?q=SELECT%20%2A%20FROM%20users%20WHERE
-/owner/repo/pulls?q=%3Cimg%20src%3D
-/issues?type=your_repositories&q=SELECT%20%2A%20FROM%20users%20WHERE
-/issues?type=your_repositories&q=%3Cimg%20src%3D
-/owner/repo/commits/branch/main/search?q=SELECT%20%2A%20FROM%20users%20WHERE
-/owner/repo/commits/branch/main/search?q=%3Cimg%20src%3D
-/owner/repo/wiki/search?q=SELECT%20%2A%20FROM%20users%20WHERE
-/owner/repo/wiki/search?q=%3Cimg%20src%3D
-/owner/repo/branches?q=SELECT%20%2A%20FROM%20users%20WHERE
-/owner/repo/branches?q=%3Cimg%20src%3D
-/owner/repo/releases?q=SELECT%20%2A%20FROM%20users%20WHERE
-/owner/repo/releases?q=%3Cimg%20src%3D
-/owner/-/packages?q=SELECT%20%2A%20FROM%20users%20WHERE
-/owner/-/packages?q=%3Cimg%20src%3D
-/user/search?q=SELECT%20%2A%20FROM%20users%20WHERE
-/user/search?q=%3Cimg%20src%3D
-/api/v1/repos/search?q=SELECT%20%2A%20FROM%20users%20WHERE
-/api/v1/repos/search?q=%3Cimg%20src%3D
-/api/v1/repos/issues/search?q=SELECT%20%2A%20FROM%20users%20WHERE
-/api/v1/repos/issues/search?q=%3Cimg%20src%3D
-/api/v1/repos/owner/repo/issues?q=SELECT%20%2A%20FROM%20users%20WHERE
-/api/v1/repos/owner/repo/issues?q=%3Cimg%20src%3D
-
-# Pages, raw files and edit pages of files, and the API's call for their
-# contents.
-/owner/repo/src/branch/main/package.json
-/owner/repo/raw/branch/main/package.json
-/owner/repo/_edit/main/package.json
-/api/v1/repos/owner/repo/contents/package.json
-/owner/repo/src/branch/main/.gitignore
-/owner/repo/raw/branch/main/.gitignore
-/owner/repo/_edit/main/.gitignore
-/api/v1/repos/owner/repo/contents/.gitignore
-/owner/repo/src/branch/main/docker-compose.yml
-/owner/repo/raw/branch/main/docker-compose.yml
-/owner/repo/_edit/main/docker-compose.yml
-/api/v1/repos/owner/repo/contents/docker-compose.yml
-/owner/repo/src/branch/main/Dockerfile
-/owner/repo/raw/branch/main/Dockerfile
-/owner/repo/_edit/main/Dockerfile
-/api/v1/repos/owner/repo/contents/Dockerfile
-/owner/repo/src/branch/main/.htaccess
-/owner/repo/raw/branch/main/.htaccess
-/owner/repo/_edit/main/.htaccess
-/api/v1/repos/owner/repo/contents/.htaccess
-/owner/repo/src/branch/main/rootfs/etc/passwd
-/owner/repo/raw/branch/main/rootfs/etc/passwd
-/owner/repo/_edit/main/rootfs/etc/passwd
-/api/v1/repos/owner/repo/contents/rootfs/etc/passwd
-/owner/repo/src/branch/main/bin/docker-entrypoint
-/owner/repo/raw/branch/main/bin/docker-entrypoint
-/owner/repo/_edit/main/bin/docker-entrypoint
-/api/v1/repos/owner/repo/contents/bin/docker-entrypoint
-/owner/repo/src/branch/main/scripts/python3-setup.sh
-/owner/repo/raw/branch/main/scripts/python3-setup.sh
-/owner/repo/_edit/main/scripts/python3-setup.sh
-/api/v1/repos/owner/repo/contents/scripts/python3-setup.sh
-/owner/repo/src/branch/main/src/java.base/share/classes/java/lang/Runtime.java
-/owner/repo/raw/branch/main/src/java.base/share/classes/java/lang/Runtime.java
-/owner/repo/_edit/main/src/java.base/share/classes/java/lang/Runtime.java
-/api/v1/repos/owner/repo/contents/src/java.base/share/classes/java/lang/Runtime.java
-/owner/repo/src/branch/main/java.lang.String.md
-/owner/repo/raw/branch/main/java.lang.String.md
-/owner/repo/_edit/main/java.lang.String.md
-/api/v1/repos/owner/repo/contents/java.lang.String.md
-/owner/repo/src/branch/main/META-INF/services/org.apache.commons.logging.LogFactory
-/owner/repo/raw/branch/main/META-INF/services/org.apache.commons.logging.LogFactory
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-/api/v1/repos/owner/repo/contents/META-INF/services/org.apache.commons.logging.LogFactory
-/owner/repo/src/branch/main/process.env.d.ts
-/owner/repo/raw/branch/main/process.env.d.ts
-/owner/repo/_edit/main/process.env.d.ts
-/api/v1/repos/owner/repo/contents/process.env.d.ts
-/owner/repo/src/branch/main/document.write.js
-/owner/repo/raw/branch/main/document.write.js
-/owner/repo/_edit/main/document.write.js
-/api/v1/repos/owner/repo/contents/document.write.js
-/owner/repo/src/branch/main/test/fixtures/__proto__.json
-/owner/repo/raw/branch/main/test/fixtures/__proto__.json
-/owner/repo/_edit/main/test/fixtures/__proto__.json
-/api/v1/repos/owner/repo/contents/test/fixtures/__proto__.json
-/owner/repo/src/branch/main/install-script.sh
-/owner/repo/raw/branch/main/install-script.sh
-/owner/repo/_edit/main/install-script.sh
-/api/v1/repos/owner/repo/contents/install-script.sh
-/owner/repo/src/branch/main/src/backend/catalog/information_schema.sql
-/owner/repo/raw/branch/main/src/backend/catalog/information_schema.sql
-/owner/repo/_edit/main/src/backend/catalog/information_schema.sql
-/api/v1/repos/owner/repo/contents/src/backend/catalog/information_schema.sql
-/owner/repo/src/branch/main/docs/a%20b.xhtml
-/owner/repo/raw/branch/main/docs/a%20b.xhtml
-/owner/repo/_edit/main/docs/a%20b.xhtml
-/api/v1/repos/owner/repo/contents/docs/a%20b.xhtml
-/owner/repo/src/branch/main/%5Bdraft%5D.md
-/owner/repo/raw/branch/main/%5Bdraft%5D.md
-/owner/repo/_edit/main/%5Bdraft%5D.md
-/api/v1/repos/owner/repo/contents/%5Bdraft%5D.md
-/owner/repo/src/branch/main/notes.txt~
-/owner/repo/raw/branch/main/notes.txt~
-/owner/repo/_edit/main/notes.txt~
-/api/v1/repos/owner/repo/contents/notes.txt~
-
-# File names in the query string: the commit graph of a file, the API's lists
-# of its commits and of its contents, an issue opened from a template, and the
-# sign-in page on the way to its edit page.
-/owner/repo/graph?file=package.json
-/api/v1/repos/owner/repo/commits?path=package.json
-/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22package.json%22%5D%7D
-/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fpackage.json
-/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fpackage.json
-/owner/repo/graph?file=.gitignore
-/api/v1/repos/owner/repo/commits?path=.gitignore
-/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22.gitignore%22%5D%7D
-/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2F.gitignore
-/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2F.gitignore
-/owner/repo/graph?file=docker-compose.yml
-/api/v1/repos/owner/repo/commits?path=docker-compose.yml
-/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22docker-compose.yml%22%5D%7D
-/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fdocker-compose.yml
-/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fdocker-compose.yml
-/owner/repo/graph?file=.htaccess
-/api/v1/repos/owner/repo/commits?path=.htaccess
-/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22.htaccess%22%5D%7D
-/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2F.htaccess
-/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2F.htaccess
-/owner/repo/graph?file=rootfs%2Fetc%2Fpasswd
-/api/v1/repos/owner/repo/commits?path=rootfs%2Fetc%2Fpasswd
-/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22rootfs%2Fetc%2Fpasswd%22%5D%7D
-/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Frootfs%2Fetc%2Fpasswd
-/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Frootfs%2Fetc%2Fpasswd
-/owner/repo/graph?file=bin%2Fdocker-entrypoint
-/api/v1/repos/owner/repo/commits?path=bin%2Fdocker-entrypoint
-/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22bin%2Fdocker-entrypoint%22%5D%7D
-/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fbin%2Fdocker-entrypoint
-/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fbin%2Fdocker-entrypoint
-/owner/repo/graph?file=scripts%2Fpython3-setup.sh
-/api/v1/repos/owner/repo/commits?path=scripts%2Fpython3-setup.sh
-/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22scripts%2Fpython3-setup.sh%22%5D%7D
-/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Fscripts%2Fpython3-setup.sh
-/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fscripts%2Fpython3-setup.sh
-/owner/repo/graph?file=src%2Fjava.base%2Fshare%2Fclasses%2Fjava%2Flang%2FRuntime.java
-/api/v1/repos/owner/repo/commits?path=src%2Fjava.base%2Fshare%2Fclasses%2Fjava%2Flang%2FRuntime.java
-/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22src%2Fjava.base%2Fshare%2Fclasses%2Fjava%2Flang%2FRuntime.java%22%5D%7D
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-/owner/repo/graph?file=install-script.sh
-/api/v1/repos/owner/repo/commits?path=install-script.sh
-/api/v1/repos/owner/repo/file-contents?body=%7B%22files%22%3A%5B%22install-script.sh%22%5D%7D
-/owner/repo/issues/new?template=.gitea%2FISSUE_TEMPLATE%2Finstall-script.sh
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-/owner/repo/graph?file=src%2Fbackend%2Fcatalog%2Finformation_schema.sql
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-/owner/repo/graph?file=docs%2Fa%20b.xhtml
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-/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2Fdocs%2Fa%20b.xhtml
-/owner/repo/graph?file=%5Bdraft%5D.md
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-/user/login?redirect_to=%2Fowner%2Frepo%2F_edit%2Fmain%2F%5Bdraft%5D.md
-
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-/api/v1/repos/owner/repo/releases/1/assets?name=package.json
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-
-# An artifact upload from actions/upload-artifact@v3, which sends Content-Range.
-/api/actions_pipeline/_apis/pipelines/workflows/1/artifacts/9b7c1f3a/upload?itemPath=artifact%2Freport.txt Content-Range: bytes 0-9/10
-
-# Branch and tag names in the query string: deleting a branch, starting a
-# release from a tag, a branch protection rule, a directory listing's last
-# commits, and a container image push that reuses a layer.
-/owner/repo/branches?name=docker-build
-/owner/repo/releases/new?tag=docker-build
-/owner/repo/settings/branches/edit?rule_name=docker-build
-/owner/repo/lastcommit/main/src?refSubUrl=branch%2Fdocker-build
-/v2/owner/app/blobs/uploads/?mount=sha256%3A0000&from=owner%2Fdocker-build
-/owner/repo/branches?name=feat%2Fdocker-support
-/owner/repo/releases/new?tag=feat%2Fdocker-support
-/owner/repo/settings/branches/edit?rule_name=feat%2Fdocker-support
-/owner/repo/lastcommit/main/src?refSubUrl=branch%2Ffeat%2Fdocker-support
-/v2/owner/app/blobs/uploads/?mount=sha256%3A0000&from=owner%2Ffeat%2Fdocker-support
-/owner/repo/branches?name=renovate%2Fdocker-build-push-action-6.x
-/owner/repo/releases/new?tag=renovate%2Fdocker-build-push-action-6.x
-/owner/repo/settings/branches/edit?rule_name=renovate%2Fdocker-build-push-action-6.x
-/owner/repo/lastcommit/main/src?refSubUrl=branch%2Frenovate%2Fdocker-build-push-action-6.x
-/v2/owner/app/blobs/uploads/?mount=sha256%3A0000&from=owner%2Frenovate%2Fdocker-build-push-action-6.x
-/owner/repo/branches?name=python3-migration
-/owner/repo/releases/new?tag=python3-migration
-/owner/repo/settings/branches/edit?rule_name=python3-migration
-/owner/repo/lastcommit/main/src?refSubUrl=branch%2Fpython3-migration
-/v2/owner/app/blobs/uploads/?mount=sha256%3A0000&from=owner%2Fpython3-migration
-/owner/repo/branches?name=ansible-roles
-/owner/repo/releases/new?tag=ansible-roles
-/owner/repo/settings/branches/edit?rule_name=ansible-roles
-/owner/repo/lastcommit/main/src?refSubUrl=branch%2Fansible-roles
-/v2/owner/app/blobs/uploads/?mount=sha256%3A0000&from=owner%2Fansible-roles
-/owner/repo/branches?name=whoami
-/owner/repo/releases/new?tag=whoami
-/owner/repo/settings/branches/edit?rule_name=whoami
-/owner/repo/lastcommit/main/src?refSubUrl=branch%2Fwhoami
-/v2/owner/app/blobs/uploads/?mount=sha256%3A0000&from=owner%2Fwhoami
-
-# Pages a signed-in user opens.
-/
-/owner/repo
-/owner/repo/issues
-/owner/repo/pulls
-/owner/repo/releases
-/owner/repo/wiki
-/owner/repo/activity
-/owner/repo/branches
-/owner/repo/tags
-/owner/repo/settings
-/owner/repo/actions
-/owner/repo/compare/main...main
-/owner/repo/commits/branch/main
-/owner/repo/archive/main.zip
-/notifications
-/user/settings
-/user/settings/applications
-/explore/repos
-/-/admin

internal/waf/waf.go

@@ -1,9 +1,8 @@
 // Package waf runs the OWASP Core Rule Set 4.25.0, through Coraza, on the
 // method, the URL with its query and the headers of a request, and on its
-// body while SWWAF_WAF_BODY_LIMIT is set, with the seven changes smallwebwaf
-// makes to it and the exclusions in SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE, as
-// "Attack detection" under "Settings" in SPEC.md describes them. It reads no
-// response.
+// body while SWWAF_WAF_BODY_LIMIT is set, with the six changes smallwebwaf
+// makes to it, as "Attack detection" under "Settings" in SPEC.md describes
+// them. It reads no response.
 //
 // smallwebwaf writes only to its state directory, so Coraza is built with
 // its no_fs_access tag, as the Dockerfile and script/build build it: of a
@@ -12,13 +11,10 @@
 package waf
 
 import (
-	"errors"
 	"fmt"
 	"io"
 	"net/http"
 	"net/netip"
-	"os"
-	"regexp"
 	"slices"
 	"strconv"
 	"strings"
@@ -30,13 +26,12 @@ import (
 )
 
 // directives are the Core Rule Set as smallwebwaf runs it, with the
-// paranoia level for %d, bodyDirectives for the first %s while
-// SWWAF_WAF_BODY_LIMIT is set, and the exclusions file for the second.
-// Each rule smallwebwaf adds has an id from 900000 to 900999, the ids the
-// Core Rule Set keeps for the rules that set it up, which
-// SWWAF_WAF_DISABLED_RULES and the exclusions file refuse, so that no
-// setting switches one off. Coraza joins a line ending in \ to the next,
-// without the spaces at the start of the next.
+// paranoia level for %d, and bodyDirectives for %s while
+// SWWAF_WAF_BODY_LIMIT is set. Each rule smallwebwaf adds has an id from
+// 900000 to 900999, the ids the Core Rule Set keeps for the rules that set
+// it up, which SWWAF_WAF_DISABLED_RULES refuses, so that no setting
+// switches one off. Coraza joins a line ending in \ to the next, without
+// the spaces at the start of the next.
 const directives = `
 # The engine only detects. smallwebwaf compares the request's anomaly
 # score with SWWAF_WAF_ANOMALY_THRESHOLD itself, in block and detect mode
@@ -74,11 +69,6 @@ SecArgumentsLimit 1000
 SecRule ARGUMENTS_LIMIT_REACHED "@eq 1" "id:900300,phase:2,pass,\
     severity:'CRITICAL',setvar:'tx.inbound_anomaly_score_pl1=+5'"
 
-# The exclusions file comes before the rules, where the Core Rule Set puts
-# its own file of exclusions that run before the rules, so that they run
-# before the rules of phase 1 too.
-%s
-
 # The sixth: only the rules for requests are loaded, and no response is
 # inspected.
 Include @owasp_crs/REQUEST-*.conf
@@ -110,13 +100,6 @@ SecRuleUpdateTargetById 932260 "!ARGS:path|!ARGS:files|!ARGS:skip-to|\
 # Inspect.
 SecRuleUpdateTargetById 932340 "!REQUEST_HEADERS:Referer"
 SecRuleUpdateTargetById 944110 "!REQUEST_HEADERS:Referer"
-
-# The seventh: a container image push that reuses a layer names the image
-# it takes the layer from in the query parameter from, which is not
-# checked for command names. 932260 refused the push of a layer from
-# owner/python3-app.
-SecRule REQUEST_FILENAME "@rx ^/v2/.+/blobs/uploads/$" \
-    "id:900500,phase:1,pass,nolog,ctl:ruleRemoveTargetById=932260;ARGS:from"
 `
 
 // bodyDirectives have the Core Rule Set read the part of a request body
@@ -177,51 +160,6 @@ type Params struct {
 	// BodyLimit is the most of a request body the Core Rule Set reads
 	// (SWWAF_WAF_BODY_LIMIT), 0 while it is off and it reads none.
 	BodyLimit int64
-	// ExclusionsFile is the path of a file of exclusions loaded before the
-	// Core Rule Set's rules (SWWAF_CORE_RULE_SET_EXCLUSIONS_FILE), "" while
-	// there is none.
-	ExclusionsFile string
-}
-
-// The ids of smallwebwaf's own rules, which an exclusions file may not
-// name.
-const (
-	firstOwnRuleID = 900000
-	lastOwnRuleID  = 900999
-)
-
-// numberOrRange matches a number, or a range of numbers such as
-// 900000-900999.
-var numberOrRange = regexp.MustCompile(`(\d+)(?:-(\d+))?`)
-
-// errSmallwebwafRuleID is the error of an exclusions file that names an
-// id of smallwebwaf's own rules.
-var errSmallwebwafRuleID = errors.New("an id of smallwebwaf's own rules")
-
-// ownRuleNamed returns the first number or range in exclusions, the text
-// of an exclusions file, that takes in an id of smallwebwaf's own rules,
-// or "" if none does. Comment lines are skipped, as Coraza skips them.
-func ownRuleNamed(exclusions string) string {
-	for line := range strings.Lines(exclusions) {
-		if strings.HasPrefix(strings.TrimSpace(line), "#") {
-			continue
-		}
-
-		for _, match := range numberOrRange.FindAllStringSubmatch(line, -1) {
-			first, _ := strconv.Atoi(match[1])
-
-			last := first
-			if match[2] != "" {
-				last, _ = strconv.Atoi(match[2])
-			}
-
-			if first <= lastOwnRuleID && last >= firstOwnRuleID {
-				return match[0]
-			}
-		}
-	}
-
-	return ""
 }
 
 // CoreRuleSet is the Core Rule Set, ready to inspect requests. It is safe
@@ -231,35 +169,16 @@ type CoreRuleSet struct {
 	bodyLimit int64
 }
 
-// New returns the Core Rule Set with the seven changes, at params'
-// paranoia level, without the rules it switches off, reading request
-// bodies up to params' limit, and with params' exclusions file loaded
-// before the Core Rule Set's rules. An exclusions file that cannot be
-// read, does not parse or names an id of smallwebwaf's own rules is an
-// error.
+// New returns the Core Rule Set with the six changes, at params'
+// paranoia level, without the rules it switches off, and reading request
+// bodies up to params' limit.
 func New(params Params) (*CoreRuleSet, error) {
 	body := ""
 	if params.BodyLimit > 0 {
 		body = fmt.Sprintf(bodyDirectives, params.BodyLimit)
 	}
 
-	exclusions := ""
-
-	if params.ExclusionsFile != "" {
-		file, err := os.ReadFile(params.ExclusionsFile)
-		if err != nil {
-			return nil, fmt.Errorf("read the exclusions file: %w", err)
-		}
-
-		exclusions = string(file)
-
-		if named := ownRuleNamed(exclusions); named != "" {
-			return nil, fmt.Errorf("the exclusions file names %s: %w", named,
-				errSmallwebwafRuleID)
-		}
-	}
-
-	text := fmt.Sprintf(directives, params.ParanoiaLevel, body, exclusions)
+	text := fmt.Sprintf(directives, params.ParanoiaLevel, body)
 
 	if len(params.DisabledRules) > 0 {
 		ids := make([]string, len(params.DisabledRules))

internal/waf/waf_test.go

@@ -5,7 +5,6 @@ import (
 	"net/http/httptest"
 	"net/netip"
 	"net/url"
-	"os"
 	"path/filepath"
 	"reflect"
 	"strconv"
@@ -120,7 +119,7 @@ func atDefaults(t *testing.T) *waf.CoreRuleSet {
 }
 
 // wantChange checks that crs lets through passes, a gitea request one of
-// the seven changes is for, and still finds result in refused, a request
+// the six changes is for, and still finds result in refused, a request
 // like it that the change is not for.
 func wantChange(
 	t *testing.T, crs *waf.CoreRuleSet, passes, refused request, result waf.Result,
@@ -363,167 +362,6 @@ func TestEachDisabledRuleIsSwitchedOff(t *testing.T) {
 	wantResult(t, newCoreRuleSet(t, 1, 920350, 911100), r, waf.Result{})
 }
 
-func TestImagePushThatReusesALayerIsNotCheckedForCommandNames(t *testing.T) {
-	t.Parallel()
-
-	crs := atDefaults(t)
-	reuse := "?mount=sha256:0000&from=owner/python3-app"
-
-	wantChange(t, crs, get("/v2/owner/app/blobs/uploads/"+reuse), get("/upload/"+reuse),
-		matched(932260))
-
-	// A command after the image's name is still refused.
-	wantResult(t, crs,
-		get("/v2/owner/app/blobs/uploads/?from=owner/app;cat%20/etc/passwd"),
-		matched(930120, 932160))
-}
-
-// withExclusions returns the Core Rule Set at the defaults, with the
-// exclusions file at path.
-func withExclusions(path string) (*waf.CoreRuleSet, error) {
-	return waf.New(waf.Params{
-		ParanoiaLevel: 1, DisabledRules: defaultDisabledRules, ExclusionsFile: path,
-	})
-}
-
-// exclusionsFile writes text to a file of exclusions and returns its path.
-func exclusionsFile(t *testing.T, text string) string {
-	t.Helper()
-
-	path := filepath.Join(t.TempDir(), "exclusions.conf")
-
-	err := os.WriteFile(path, []byte(text), 0o600)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	return path
-}
-
-// backupFileExclusion is an exclusions file that switches 920500, a rule
-// of phase 1, off for the path of a backup file under /files/.
-const backupFileExclusion = `SecRule REQUEST_FILENAME "@beginsWith /files/" ` +
-	`"id:1,phase:1,pass,nolog,ctl:ruleRemoveTargetById=920500;REQUEST_FILENAME"` + "\n"
-
-func TestExclusionsFileIsLoadedBeforeTheRules(t *testing.T) {
-	t.Parallel()
-
-	crs, err := withExclusions(exclusionsFile(t, backupFileExclusion))
-	if err != nil {
-		t.Fatalf("load the exclusions: %v", err)
-	}
-
-	wantChange(t, crs, get("/files/notes.txt~"), get("/notes.txt~"), matched(920500))
-}
-
-func TestRuleSwitchedOffAndNamedInTheExclusionsFileIsOff(t *testing.T) {
-	t.Parallel()
-
-	crs, err := waf.New(waf.Params{
-		ParanoiaLevel: 1, DisabledRules: []int{920500},
-		ExclusionsFile: exclusionsFile(t, backupFileExclusion),
-	})
-	if err != nil {
-		t.Fatalf("load the exclusions: %v", err)
-	}
-
-	wantResult(t, crs, get("/notes.txt~"), waf.Result{})
-}
-
-func TestExclusionsFileMayNameAnyNumberInAComment(t *testing.T) {
-	t.Parallel()
-
-	_, err := withExclusions(exclusionsFile(t,
-		"# 942100: GET /issues/900123\n"+backupFileExclusion))
-	if err != nil {
-		t.Errorf("the exclusions did not load: %v", err)
-	}
-}
-
-func TestExclusionsFileThatCannotBeUsedIsAnError(t *testing.T) {
-	t.Parallel()
-
-	for _, path := range []string{
-		filepath.Join(t.TempDir(), "missing.conf"),
-		exclusionsFile(t, "SecNoSuchDirective On\n"),
-		// The Core Rule Set's rules are not loaded yet.
-		exclusionsFile(t, "SecRuleUpdateTargetById 942100 \"!ARGS:id\"\n"),
-		// smallwebwaf's own rules may not be switched off or changed, by
-		// id or in a range.
-		exclusionsFile(t, "SecRuleRemoveById 900300\n"),
-		exclusionsFile(t, "SecRuleRemoveById 899999-901000\n"),
-		exclusionsFile(t, "SecAction \"id:1,phase:1,pass,nolog,"+
-			"ctl:ruleRemoveById=899999-901000\"\n"),
-		exclusionsFile(t, "SecAction \"id:1,phase:1,pass,nolog,"+
-			"ctl:ruleRemoveTargetById=900500;ARGS:from\"\n"),
-	} {
-		_, err := withExclusions(path)
-		if err == nil {
-			t.Errorf("%s loaded", path)
-		}
-	}
-}
-
-// giteaRequests returns the recorded ordinary gitea requests in testdata,
-// which script/gitea-setup sends too. Each has the Referer of a page that
-// names the same, as a page opened from it has.
-func giteaRequests(t *testing.T) []request {
-	t.Helper()
-
-	text, err := os.ReadFile(filepath.Join("testdata", "gitea-requests.txt"))
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	var requests []request
-
-	for line := range strings.Lines(string(text)) {
-		line = strings.TrimSpace(line)
-		if line == "" || strings.HasPrefix(line, "#") {
-			continue
-		}
-
-		target, header, _ := strings.Cut(line, " ")
-
-		headers := []string{"Referer: http://git.example" + target}
-		if header != "" {
-			headers = append(headers, header)
-		}
-
-		requests = append(requests, get(target, headers...))
-	}
-
-	return requests
-}
-
-func TestGiteaExclusionsLetOrdinaryGiteaRequestsThroughAndRefuseAttacks(t *testing.T) {
-	t.Parallel()
-
-	crs, err := withExclusions(filepath.Join("..", "..", "deploy", "gitea",
-		"crs-exclusions.conf"))
-	if err != nil {
-		t.Fatalf("load gitea's exclusions: %v", err)
-	}
-
-	const threshold = 5 // SWWAF_WAF_ANOMALY_THRESHOLD's default
-
-	for _, r := range giteaRequests(t) {
-		if got := inspect(t, crs, r); got.Score >= threshold {
-			t.Errorf("%s %q refused: %+v", r.target, r.headers[1:], got)
-		}
-	}
-
-	for _, attack := range []string{
-		"/owner/repo?id=1'%20OR%20'1'='1",
-		"/owner/repo?id=..%2Fcustom%2Fconf%2Fapp.ini",
-		"/owner/repo?id=%3Cscript%3Ealert(1)%3C%2Fscript%3E",
-	} {
-		if got := inspect(t, crs, get(attack)); got.Score < threshold {
-			t.Errorf("%s let through: %+v", attack, got)
-		}
-	}
-}
-
 // bodyLimit is SWWAF_WAF_BODY_LIMIT in the tests that read bodies.
 const bodyLimit = 8 << 10
 

script/gitea-requests

@@ -4,8 +4,7 @@
 # default but these: SWRP_UPSTREAM_URL names gitea's container, SWRP_WAF_BACKEND
 # names servewaf's, and SWWAF_LOG_REQUEST_HEADERS adds the header that labels a
 # request. Then send through rproxy the gitea requests that reading gitea's
-# source found the Core Rule Set refuses without the exclusions in
-# deploy/gitea/crs-exclusions.conf, and a
+# source found the Core Rule Set refuses, which docs/gitea.md records, and a
 # short sample of gitea's ordinary use: signing in, pages of files and commits,
 # a diff, the API, a push, clone and fetch over HTTP, and two container image
 # pushes. Last, print each request servewaf logged, with what it did with it and

script/gitea-setup

@@ -5,12 +5,6 @@
 #     rproxy, and that servewaf checks them;
 #   - that gitea logs the visitor's address, not rproxy's;
 #   - that a request from a container on the shared network skips the checks;
-#   - that the Core Rule Set refuses none of the ordinary gitea requests in
-#     internal/waf/testdata/gitea-requests.txt;
-#   - that it refuses none of the API calls with JSON bodies;
-#   - that it refuses no fetch;
-#   - that it refuses SQL injection, path traversal and script injection in a
-#     query string;
 #   - that with servewaf stopped, gitea still answers through rproxy.
 # It publishes no port of traefik's, since this host's ports 80 and 443 may be
 # taken. It reaches traefik at its address on the shared network instead, so
@@ -142,71 +136,6 @@ passed_through() {
         "\"client_ip\":\"$gateway\"" '"action":"forward"' '"counts":' '"waf_score":'
 }
 
-# refused: print each request servewaf logged as refused, for any reason.
-refused() {
-    compose logs --no-color --no-log-prefix servewaf 2>&1 |
-        grep -F '"servewaf_line":"report"' | grep -v -F '"action":"forward"' || true
-}
-
-# ordinary_requests: sign in as the owner, save a file and open an issue
-# through the API with JSON bodies, then send, signed in, each request in
-# internal/waf/testdata/gitea-requests.txt, with the header its line ends with,
-# if any, and that request's own address as its Referer, as a page opened from it
-# has. One a second keeps them under the default limit of 120 requests a minute,
-# since a request refused for a limit is never inspected. Fail if servewaf
-# refuses any of them.
-ordinary_requests() {
-    send /user/login --cookie-jar "$WORK/cookies" >/dev/null
-    status="$(send /user/login --cookie "$WORK/cookies" --cookie-jar "$WORK/cookies" \
-        --header "Origin: https://$SITE" --data-urlencode user_name=owner \
-        --data-urlencode "password=$PASSWORD")"
-    [ "$status" = 303 ] || fail "signing in was answered $status"
-
-    content="$(printf 'declare const env: Record<string, string>;\n' | base64)"
-    status="$(send /api/v1/repos/owner/repo/contents/process.env.d.ts \
-        --user "owner:$PASSWORD" --header "Content-Type: application/json" \
-        --data "{\"message\":\"Add process.env.d.ts\",\"content\":\"$content\"}")"
-    [ "$status" = 201 ] || fail "saving a file through the API was answered $status"
-    status="$(send /api/v1/repos/owner/repo/issues --user "owner:$PASSWORD" \
-        --header "Content-Type: application/json" \
-        --data '{"title":"ls -la fails","body":"SELECT * FROM users; <img src=x>"}')"
-    [ "$status" = 201 ] || fail "opening an issue through the API was answered $status"
-
-    grep -v -e '^#' -e '^$' "$ROOT/internal/waf/testdata/gitea-requests.txt" |
-        while read -r target header; do
-            if [ -n "$header" ]; then
-                send "$target" --globoff --cookie "$WORK/cookies" \
-                    --header "Referer: https://$SITE$target" --header "$header" >/dev/null
-            else
-                send "$target" --globoff --cookie "$WORK/cookies" \
-                    --header "Referer: https://$SITE$target" >/dev/null
-            fi
-            sleep 1
-        done
-
-    # The last request's report is logged once its answer has ended.
-    send /api/v1/settings/api >/dev/null
-    wait_for "servewaf logged no report of the last ordinary request" logged servewaf \
-        '"servewaf_line":"report"' '"path":"/api/v1/settings/api"'
-    refusals="$(refused)"
-    [ -z "$refusals" ] || fail "servewaf refused ordinary requests:
-$refusals"
-}
-
-# attacks: send SQL injection, path traversal and script injection in a query
-# string, and fail unless the Core Rule Set refuses each.
-attacks() {
-    # The traversal climbs one directory: the default rule file refuses two or
-    # more first, before the Core Rule Set runs.
-    for query in "id=1'%20OR%20'1'%3D'1" "id=..%2Fcustom%2Fconf%2Fapp.ini" \
-        "id=%3Cscript%3Ealert(1)%3C%2Fscript%3E"; do
-        status="$(send "/owner/repo?$query")"
-        [ "$status" = 403 ] || fail "the attack ?$query was answered $status"
-        wait_for "servewaf logged no refusal of ?$query" logged servewaf \
-            '"servewaf_line":"report"' '"action":"waf_blocked"' "\"query\":\"$query\""
-    done
-}
-
 main() {
     cd "$ROOT"
     trap cleanup EXIT
@@ -275,12 +204,6 @@ main() {
     esac
     echo "gitea-setup: a request from the shared network skips the checks"
 
-    site_git -C "$WORK/clone" fetch --quiet || fail "the fetch failed"
-    ordinary_requests
-    echo "gitea-setup: the Core Rule Set refuses no ordinary gitea request"
-    attacks
-    echo "gitea-setup: the Core Rule Set refuses the attacks"
-
     compose stop servewaf >/dev/null 2>&1 || fail "servewaf did not stop"
     status="$(send /owner/repo)"
     [ "$status" = 200 ] ||