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sneak/smallwebwaf:main sneak/smallwebwaf:issue-236-drupal-ordinary-requests sneak/smallwebwaf:issue-235-wordpress-ordinary-requests sneak/smallwebwaf:issue-220-apps-by-hostname sneak/smallwebwaf:issue-211-viper-config sneak/smallwebwaf:next sneak/smallwebwaf:issue-216-oci-labels sneak/smallwebwaf:readme-rewrite-155
sneak/smallwebwaf:v1.0.0-rc2 sneak/smallwebwaf:v1.0.0-rc1
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compare: sneak/smallwebwaf:7fcd79c1829b63c708c6c193600fcea214515798
sneak/smallwebwaf:issue-236-drupal-ordinary-requests sneak/smallwebwaf:issue-235-wordpress-ordinary-requests sneak/smallwebwaf:issue-220-apps-by-hostname sneak/smallwebwaf:issue-211-viper-config sneak/smallwebwaf:next sneak/smallwebwaf:issue-216-oci-labels sneak/smallwebwaf:main sneak/smallwebwaf:readme-rewrite-155
sneak/smallwebwaf:v1.0.0-rc2 sneak/smallwebwaf:v1.0.0-rc1
3 Commits
b5364bf282 .. 7fcd79c182
Author SHA1 Message Date
sneak 7fcd79c182 SWW_APPS: an app's Core Rule Set fixes apply only to the hostnames that serve it (closes #220)
check / check (push) Successful in 4m25s
Details 
gitea's fixes (its parameters, its cookies and gitea.conf) now apply
only to a hostname SWW_APPS lists gitea for, or to every hostname while
it is unset. Each app's fixes are one .conf file, whose first rule skips
the rest unless Inspect sets tx.app_<name>, and one entry in apps.

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

Model: opus-5-5
 2026-11-09 04:49:19 +00:00
clawbot 6850cb0e9f Add asn= and prefix= tags from a routewatch instance (closes #204)
check / check (push) Successful in 5m0s
Details 
With `SWW_ROUTEWATCH_URL` set, a new heuristic, `routewatch_tags`, adds `asn=<number>` and `prefix=<netblock>` to a request from what a routewatch instance answers about the client. New package `internal/routewatch` asks in the background, never on a request's path, and keeps answers 1 hour in memory. The request log gains `routewatch_tags_missing`, saying why a request has none. `prefix=` works in `SWW_TAG_DENY` and `SWW_TAG_LIMIT_PERCENT`.

Trips a reader: a client's first request has no routewatch tags, so `prefix=` refuses from its next request after the answer comes.
Judgement call: with `SWW_LOOKUP_SOURCE=off` and `SWW_ROUTEWATCH_URL` set, an `asn=` tag no longer stops the start.

Model: opus-5-5
 2026-11-09 05:47:34 +01:00
clawbot d7c62f2854 Say which bytes the byte limits count, and what passing one does (closes #203)
check / check (push) Failing after 3m48s
Details 
sneak asked for every document to be audited for sentences that do not say what they mean. The byte limits now say which bytes count (response bodies, request bodies or both, as `SWW_BYTES_COUNT` says, WebSocket traffic included) and what passing one does. Other unclear or false sentences in `README.md`, `SPEC.md`, `EVALUATION.md` and `docs/` are rewritten.

Documents only. `REPO_POLICIES.md` is shared policy text and stayed out.

Model: fable-5-1 (first audit); opus-5-5 (rework)
 2026-11-09 04:03:17 +01:00
17 changed files with 1197 additions and 126 deletions
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EVALUATION.md
+56 -44
View File
@@ -12,8 +12,8 @@ configured only by environment variables, that provides:
- R1: rate limits per minute, per hour and per day
- R2: netblocks that bypass rate limiting
- R3: alerts on attacks through webhook, Slack or ntfy
- R4: alerts on anomalies: requests or bytes per minute or hour, for given IPs
or netblocks, crossing a threshold
- R4: alerts on anomalies: requests made or bytes transferred per minute or
hour, for given IPs or netblocks, crossing a threshold
- R5: temporary blocks for abusers, permanent bans for repeat offenders
- R6: one or more RBLs or IP reputation APIs
- R7: AS number lookup
@@ -24,14 +24,19 @@ configured only by environment variables, that provides:
## Verdict
Nothing existing is suitable. No surveyed tool meets R8 (scaling limits by AS
number or country) or the bytes half of R4 at all, and the tools that come
closest on the rest fail R10: they need several containers, YAML or a web UI.
The recommendation is to build a small single-binary sidecar; `SPEC.md` in this
directory begins that spec. It reuses the mature parts of the surveyed field as
libraries and data sources (Coraza and the OWASP Core Rule Set for attack
detection, DNSBLs, AbuseIPDB, optionally a CrowdSec decision feed) instead of
reimplementing them.
Nothing existing is suitable. No surveyed tool meets R8, which asks for limits
scaled by AS number or country. None meets R4's alerts on bytes transferred. The
tools that come closest on the rest fail R10: they need several containers, YAML
or a web UI. The recommendation is to build a small single-binary sidecar;
`SPEC.md` in this directory begins that spec.
The sidecar reuses the mature parts of the surveyed field instead of
reimplementing them. It takes these as libraries and data sources:
- Coraza and the OWASP Core Rule Set, for attack detection
- DNSBLs
- AbuseIPDB
- optionally, a CrowdSec decision feed
Closest existing options, and why each still falls short:
@@ -45,13 +50,16 @@ Closest existing options, and why each still falls short:
external blacklist URLs, optional CrowdSec), R7 partly (AS number used for
blacklist and whitelist decisions), R9 (ModSecurity with the Core Rule
Set, or Coraza plugin), env-var settings.
- Fails: R8 (AS number and country can only allow or deny, never scale a
limit), R4 (no volume or byte threshold alerts in the free edition;
reporting is a paid feature), R5 escalation, and R10 in spirit: since 1.6
it needs a `bunkerweb` container plus a `bw-scheduler` container and a
database, or the all-in-one image that bundles nginx, scheduler, UI and
Redis in one container. It is designed to be the front door for many
sites, not a per-app sidecar. AGPL-3.0.
- Fails:
- R8: AS number and country can only allow or deny, never scale a limit.
- R4: no alerts on request-count or byte thresholds in the free edition;
reporting is a paid feature.
- R5: no escalation for repeat offenders.
- R10: since 1.6 it is not one plain sidecar. It needs a `bunkerweb`
container, a `bw-scheduler` container and a database, or the
all-in-one image that bundles nginx, the scheduler, the UI and Redis.
- It is designed as the proxy in front of many sites, not as a sidecar for
one app. AGPL-3.0.
- Unverified: whether several rates (minute, hour, day) can be stacked on
the same URL pattern; the documented design is one rate per URL pattern.
- CrowdSec is the strongest detection and ban engine, but it is not a proxy.
@@ -66,16 +74,20 @@ Closest existing options, and why each still falls short:
listed AS numbers is possible, but each is a hand-written YAML scenario,
it reacts after the fact by banning, and it is not an inline limiter that
answers 429.
- Fails: R10 (needs the security engine container with persistent state, log
acquisition from traefik, a bouncer such as the traefik plugin, and YAML
for acquisition, profiles, scenarios and notifications), bytes half of R4.
- Fails:
- R10, because it needs:
- the security engine container with persistent state
- log acquisition from traefik
- a bouncer such as the traefik plugin
- YAML for acquisition, profiles, scenarios and notifications
- R4's alerts on bytes.
- CrowdSec plus traefik's own `rateLimit` middleware is the best combination
with no new code. It gives inline limiting (one window per middleware, keyed
by IP, with `sourceCriterion` exclusions), bans with escalation, alerts and
reputation. It still fails R8, the bytes half of R4, R1's three stacked
windows only by chaining three middlewares per router, and R10 entirely: the
configuration lives in traefik labels and CrowdSec YAML on each host, not in
one sidecar's environment.
reputation lookups. It still fails R8, R4's alerts on bytes, and R10 entirely:
the configuration lives in traefik labels and CrowdSec YAML on each host, not
in one sidecar's environment. It meets R1's three windows only by chaining
three middlewares per router.
## Candidate by candidate
@@ -87,10 +99,10 @@ Closest existing options, and why each still falls short:
cached, streamed decision list (recommended), standalone against the
central API, or AppSec only. Supports captcha remediation.
- Covers: R5, R6, R9, R3 and R7 through the engine (see Verdict).
- Misses: the plugin itself does no rate limiting; R8; R4 bytes.
- Misses: the plugin itself does no rate limiting; R8; R4's alerts on bytes.
- Configuration: traefik static config to load the plugin, dynamic config or
labels for the middleware, CrowdSec YAML for everything else.
- Sidecar fit: no. It lives inside traefik, plus a separate engine
- Sidecar fit: no. It runs inside traefik and needs a separate engine
container.
- Maturity: widely used (about 900 stars, listed in the traefik plugin
catalog, documented by CrowdSec itself), actively maintained. Traefik
@@ -115,7 +127,7 @@ Closest existing options, and why each still falls short:
- What it is: nginx-derived (Tengine) reverse proxy with a proprietary
semantic detection engine and a web console. About 22,000 stars.
- Covers: R9 well, basic per-IP rate limiting with block duration, bot
challenge, authentication gate.
challenge, authentication in front of the app.
- Misses: R8, R7, R4; R1 has one window per rule. Country blocking, alert
messages, syslog forwarding and the better reputation database are paid
(Lite about 10 USD per month, Pro about 100 USD per month); the free
@@ -128,7 +140,7 @@ Closest existing options, and why each still falls short:
- Coraza (`corazawaf/coraza`) and Coraza-based proxies
- What it is: a Go library that implements the ModSecurity rule language and
runs the OWASP Core Rule Set. OWASP project, actively maintained, the
successor path now that ModSecurity is in maintenance only.
successor to ModSecurity, which is now in maintenance only.
- Packagings: `coraza-caddy` (Caddy module), `coraza-spoa` (HAProxy),
`coraza-proxy-wasm` (Envoy), a traefik WASM plugin, and
`coreruleset/coraza-crs-docker` (Caddy plus Coraza plus the Core Rule Set,
@@ -142,7 +154,7 @@ Closest existing options, and why each still falls short:
- ModSecurity Core Rule Set containers (`owasp/modsecurity-crs`)
- What it is: official images of Apache or nginx with ModSecurity and the
Core Rule Set, as a reverse proxy configured by env vars (`BACKEND`,
paranoia level, anomaly thresholds, many more). Current images carry
paranoia level, anomaly thresholds, many more). Current images contain
ModSecurity 2.9.x on Apache and Core Rule Set 4.x.
- Covers: R9, and R10 (single container, env vars, one backend).
- Misses: R1 to R8.
@@ -152,8 +164,8 @@ Closest existing options, and why each still falls short:
- Anubis (`TecharoHQ/anubis`), 1.27 current
- What it is: a single-binary reverse proxy that makes browsers solve a
proof-of-work challenge before passing them to `TARGET`. Aimed at
scrapers, which is likely a large share of unwanted traffic on a public
code forge.
scrapers, which are likely a large share of the unwanted traffic on a
public code forge.
- Covers: R10 well (one container, env vars for listener, target,
difficulty, cookies). Policy rules can match on path, user agent, headers,
IP ranges, and with the vendor's hosted data service also AS number and
@@ -180,13 +192,13 @@ Closest existing options, and why each still falls short:
temporary ban, no escalation, state lost on traefik restart) and R2
(allowlist). Nothing else.
- `juitde/traefik-plugin-fail2ban`, fail2ban connector plugins, GeoBlock
plugins (country allow or deny through an external lookup API): same
shape, each one small feature, configured in traefik, state in memory.
plugins (country allow or deny through an external lookup API): each adds
one small feature, is configured in traefik and keeps its state in memory.
- Sidecar fit: no; they live inside traefik.
- Traefik built-in middlewares
- `rateLimit` (one average-and-burst window per middleware, optional Redis
in traefik 3.x), `inFlightReq`, `ipAllowList`. No bans, alerts, reputation
or AS number awareness.
lookups or AS number lookups.
- caddy-waf (`fabriziosalmi/caddy-waf`), 0.4.x
- What it is: a Caddy module with regex rules and anomaly scoring, per-IP
and per-path rate limiting with one configurable window, IP and DNS
@@ -198,12 +210,12 @@ Closest existing options, and why each still falls short:
- open-appsec (Check Point)
- Machine-learning WAF agent attached to nginx, Kong, Envoy or similar, with
a declarative policy file or the vendor's cloud console. Covers R9 only;
rate limiting and richer features are in paid tiers. Not a sidecar in the
required sense.
rate limiting and richer features are in paid tiers. It attaches to an
existing proxy, so it is not the sidecar R10 asks for.
- iocaine
- Serves generated garbage pages to clients the fronting proxy classifies as
scrapers. Not a limiter, WAF or ban tool; out of scope except as a
curiosity for scraper traffic.
scrapers. Not a limiter, WAF or ban tool; out of scope, and only of
passing interest for scraper traffic.
- Pangolin
- A tunnelled access platform that bundles traefik and optionally CrowdSec.
Replaces the ingress rather than adding a sidecar; out of scope.
@@ -214,17 +226,17 @@ Closest existing options, and why each still falls short:
Everyone else offers one window per rule or none.
- R2 bypass netblocks: BunkerWeb, CrowdSec, traefik, fail2ban plugins.
- R3 alerts: CrowdSec (best), BunkerWeb (denied requests only), SafeLine (paid).
- R4 volume and byte anomalies: none. CrowdSec can approximate request-count
anomalies with a custom scenario; nothing handles bytes.
- R5 temporary then permanent: CrowdSec only. BunkerWeb has fixed or permanent,
not both by history.
- R4 alerts on request counts and bytes: none. CrowdSec can approximate alerts
on request counts with a custom scenario; no surveyed tool alerts on bytes.
- R5 temporary then permanent: CrowdSec only. BunkerWeb's ban is either one
fixed length or permanent, and does not change with a client's history.
- R6 reputation: CrowdSec, BunkerWeb, go-away, caddy-waf (static lists).
- R7 AS number lookup: CrowdSec (enrichment), BunkerWeb and caddy-waf (allow or
deny), Anubis (hosted service).
- R8 biased thresholds: none.
- R9 attack detection: Coraza or ModSecurity with the Core Rule Set (open,
standard), CrowdSec AppSec, SafeLine (closed engine), BunkerWeb (wraps the
first).
standard), CrowdSec AppSec, SafeLine (closed engine), BunkerWeb (wraps Coraza
or ModSecurity).
- R10 env-var sidecar: `owasp/modsecurity-crs`, `coraza-crs-docker`, Anubis.
None of these covers anything beyond its one job.
README.md
+43 -35
View File
@@ -25,11 +25,11 @@ without an answer in time, `rproxy` passes the request to the app.
It protects against:
- Scrapers that fetch every page of a site, all day. Each client gets a limit on
requests and on bytes per minute, per hour and per day. The defaults leave
room for a person reading a site for hours. They catch a scraper that keeps up
one request every 2 seconds. A client over a limit is refused and banned: for
a while at first, for three times as long at each repeat, and permanently when
it keeps at it.
requests and on body bytes per minute, per hour and per day. The defaults
leave room for a person reading a site for hours. They catch a scraper that
keeps up one request every 2 seconds. A client that breaks a limit is banned:
for a while at first, for three times as long at each repeat, and permanently
when it keeps at it.
- Scanners that probe for secrets, such as `/.env` or `/.git/config`. The
default rule file bans such a client at its first probe, and its next request
during the ban makes the ban permanent. Your own rules, or a list of trap
@@ -210,6 +210,10 @@ account, a key, a token or an alert destination stays off until you give one.
percentage is a whole number from 0 to 100. A path prefix starts with `/`.
- `off` switches a limit, a threshold or a timeout off where the table says a
setting takes it.
- The byte limits and the byte anomaly thresholds count only body bytes: the
app's response bodies, the visitors' request bodies, or both, as
`SWW_BYTES_COUNT` says. Headers are never counted. What the visitor sent over
a WebSocket counts as request bytes, and what the app sent as response bytes.
- An invalid setting stops the process at start with one log line naming the
variable and what is wrong with the value. The settings in effect are logged
on one line at start, with tokens, keys and webhook paths shown as `********`.
@@ -217,7 +221,7 @@ account, a key, a token or an alert destination stays off until you give one.
Every setting the code reads, with its default:
| Variable | Default | What it does |
| ---------------------------------------- | ------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| ---------------------------------------- | ------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `SWW_COMMAND` | `rproxy` | Which command the image runs, and its health check checks: `rproxy` or `discriminator`. |
| `SWRP_WAF_BACKEND` | required | `discriminator`'s URL, such as `http://discriminator:8080`. |
| `SWRP_UPSTREAM_URL` | `http://127.0.0.1:8081` | The app's URL: a scheme, a host and an optional port, nothing more. |
@@ -226,8 +230,8 @@ Every setting the code reads, with its default:
| `SWRP_TIMEOUT_MS` | `2000` | How long `rproxy` waits for `discriminator`'s answer to a question and to a report, in milliseconds. |
| `SWRP_DEFAULT_DISPOSITION` | `allow` | What `rproxy` does with a request when `discriminator` cannot be reached or does not answer in time: `allow` passes it to the app, `deny` answers `503`. |
| `SWRP_MAX_REQUEST_SIZE` | `100M` | The largest request body, a size or `off`; a larger one is answered `413`. |
| `SWRP_MAX_RESPONSE_SIZE` | `1G` | The largest response body, a size or `off`; a larger one is answered `502`, or cut off once it has started. |
| `SWRP_MAX_REQUEST_TIME_MS` | `60000` | How long the visitor may take to send its request line and headers, and then the whole request to reach the app, in milliseconds or `off`. |
| `SWRP_MAX_RESPONSE_SIZE` | `1G` | The largest response body, a size or `off`. The visitor gets `502` in place of a larger one, or it is cut off if it has already started. |
| `SWRP_MAX_REQUEST_TIME_MS` | `60000` | Two time limits, each this long, in milliseconds or `off`: one for the visitor to send its request line and headers, then one for the whole request to reach the app. |
| `SWRP_MAX_RESPONSE_TIME_MS` | `1800000` | How long the answer may take, from the end of the request to its last byte reaching the visitor, in milliseconds or `off`. |
| `SWW_LISTEN_ADDR` | `:8080` | Where `discriminator` listens; leave the host part empty. |
| `SWW_INSTANCE_NAME` | the container's host name | The name in every line `discriminator` logs, and in every alert and metric, such as `fsn1/discriminator`. |
@@ -236,24 +240,24 @@ Every setting the code reads, with its default:
| `SWW_MAX_TRACKED_CLIENTS` | `20000` | The most clients kept, in memory and in `clients.json`; the least recently seen is dropped first. |
| `SWW_MAX_BANS` | `5000` | The most bans `discriminator` keeps of its own; bans an admin made do not count. |
| `SWW_ALLOW_NETS` | empty | Netblocks whose clients skip every check, such as your monitoring. |
| `SWW_RATE_LIMIT_EXEMPT_NETS` | empty | Netblocks whose clients the request and byte limits neither count nor refuse. |
| `SWW_RATE_LIMIT_EXEMPT_NETS` | empty | Netblocks whose clients are exempt from rate limiting and the byte limits. |
| `SWW_DENY_NETS` | empty | Netblocks whose clients are refused. |
| `SWW_RATE_LIMIT_PER_MINUTE` | `120` | The most requests a client may make in a minute, a count or `off`; one more bans it. |
| `SWW_RATE_LIMIT_PER_HOUR` | `1500` | The most requests a client may make in an hour, a count or `off`; one more bans it. |
| `SWW_RATE_LIMIT_PER_DAY` | `6000` | The most requests a client may make in a day, a count or `off`; one more bans it. |
| `SWW_RATE_LIMIT_EXEMPT_PATHS` | empty | Path prefixes whose requests the request and byte limits neither count nor refuse, such as `/assets/`. |
| `SWW_BYTES_LIMIT_PER_MINUTE` | `off` | The most bytes a client's requests may carry in a minute, a size or `off`; the request that takes a client past any byte limit bans it. |
| `SWW_BYTES_LIMIT_PER_HOUR` | `50G` | The most bytes a client's requests may carry in an hour, a size or `off`. |
| `SWW_BYTES_LIMIT_PER_DAY` | `100G` | The most bytes a client's requests may carry in a day, a size or `off`. |
| `SWW_BYTES_COUNT` | `both` | Which body bytes the byte limits count: `response`, `request` or `both`. |
| `SWW_ERROR_BURST_THRESHOLD` | `30` | The most refusals by a rule file, a trap path or the Core Rule Set a client may get in a minute, a count or `off`; one more bans it. |
| `SWW_RATE_LIMIT_PER_MINUTE` | `120` | The most requests a client may make in a minute, a count or `off`; the next request is refused and bans the client. |
| `SWW_RATE_LIMIT_PER_HOUR` | `1500` | The most requests a client may make in an hour, a count or `off`; the next request is refused and bans the client. |
| `SWW_RATE_LIMIT_PER_DAY` | `6000` | The most requests a client may make in a day, a count or `off`; the next request is refused and bans the client. |
| `SWW_RATE_LIMIT_EXEMPT_PATHS` | empty | Path prefixes exempt from rate limiting and the byte limits, such as `/assets/`. |
| `SWW_BYTES_LIMIT_PER_MINUTE` | `off` | The most bytes counted for a client in a minute, a size or `off`. `SWW_BYTES_COUNT` says which bytes count: response bodies, request bodies or both. The request that passes the limit is not cut off, and the client is banned when its response ends. |
| `SWW_BYTES_LIMIT_PER_HOUR` | `50G` | The most bytes counted for a client in an hour, a size or `off`. `SWW_BYTES_COUNT` says which bytes count: response bodies, request bodies or both. The request that passes the limit is not cut off, and the client is banned when its response ends. |
| `SWW_BYTES_LIMIT_PER_DAY` | `100G` | The most bytes counted for a client in a day, a size or `off`. `SWW_BYTES_COUNT` says which bytes count: response bodies, request bodies or both. The request that passes the limit is not cut off, and the client is banned when its response ends. |
| `SWW_BYTES_COUNT` | `both` | What the byte limits and the byte anomaly thresholds count: `response`, the app's response bodies; `request`, the visitors' request bodies; or `both`. What the visitor sent over a WebSocket counts as request bytes, and what the app sent as response bytes. |
| `SWW_ERROR_BURST_THRESHOLD` | `30` | The most refusals a client may get in a minute from a rule file, a trap path or the Core Rule Set, a count or `off`. The next one bans the client. |
| `SWW_BAN_RESPONSE` | `403` | How a refused client is answered: `403`, `429` or `close`, which drops the connection. |
| `SWW_LIMIT_BAN_DURATION` | `1h` | The ban for a first broken limit. |
| `SWW_LIMIT_BAN_REPEAT_WINDOW` | `24h` | A limit broken again within this time after the last such ban ended gets a ban three times as long. |
| `SWW_LIMIT_BAN_REPEAT_WINDOW` | `24h` | A client that breaks a limit again within this time after its last such ban ended gets a ban three times as long. |
| `SWW_MAX_BAN_DURATION` | `7d` | A ban for a broken limit that would be longer than this is permanent instead. |
| `SWW_ATTACK_BAN_DURATION` | `7d` | The ban for a first clear sign of attack: a `ban` rule or a trap path. |
| `SWW_BAN_SCOPE_V4_PREFIX` | `32` | The prefix length of the netblock a ban on an IPv4 client covers, from 0 to 32. |
| `SWW_LOOKUP_SOURCE` | `geojs` | Where each client's AS number and country come from: `geojs`, a web service, `file`, or `off`. |
| `SWW_LOOKUP_SOURCE` | `geojs` | Where each client's AS number and country come from: `geojs` (a web service), `file` (a local database) or `off`. |
| `SWW_LOOKUP_DB_PATH` | empty | The IPinfo Lite database file, in its `.mmdb` form, read while the source is `file`. |
| `SWW_LOOKUP_TIMEOUT` | `800ms` | How long a request waits for its client's first GeoJS answer when a setting needs it, and how long a request to GeoJS may take. |
| `SWW_ADD_LOOKUP_HEADERS` | `false` | `true` passes the app the client's AS number and country in `X-Client-ASN` and `X-Client-Country`. |
@@ -261,6 +265,7 @@ Every setting the code reads, with its default:
| `SWW_TAG_LISTS` | empty | Address lists that each add a tag to their clients' requests, as `name=URL` pairs, such as `torexit=https://example.com/tor.txt`. |
| `SWW_TAG_DENY` | empty | Tags whose requests are refused, such as `torexit,country=CN`. |
| `SWW_TAG_LIMIT_PERCENT` | empty | Tags whose clients get a percentage, from 1 to 99, of every request and byte limit, such as `vpn:50,asn=14061:25`; the lowest applies. |
| `SWW_ROUTEWATCH_URL` | unset | The URL of a routewatch instance, which gives each client's `asn=` and `prefix=` tags. Unset, nothing asks routewatch. |
| `SWW_ASN_BYTES_PERCENT` | empty | A percentage of the byte limits alone for the AS numbers listed, in place of their `asn=` tag's percentage. |
| `SWW_COUNTRY_BYTES_PERCENT` | empty | A percentage of the byte limits alone for the countries listed, in place of their `country=` tag's percentage. |
| `SWW_UNKNOWN_LIMIT_PERCENT` | `100` | The percentage of every limit a client without a country gets. |
@@ -312,27 +317,27 @@ Every setting the code reads, with its default:
| `SWW_ALERT_MAX_PER_HOUR` | `60` | The most alerts sent in an hour, a number or `off`; the rest are counted in the hour's `summary`. |
| `SWW_ANOMALY_CLIENT_REQUESTS_PER_MINUTE` | `off` | Alert when one client makes more requests than this in a minute, a count. |
| `SWW_ANOMALY_CLIENT_REQUESTS_PER_HOUR` | `off` | Alert when one client makes more requests than this in an hour, a count. |
| `SWW_ANOMALY_CLIENT_BYTES_PER_MINUTE` | `off` | Alert when one client's requests carry more bytes than this in a minute, a size. |
| `SWW_ANOMALY_CLIENT_BYTES_PER_HOUR` | `off` | Alert when one client's requests carry more bytes than this in an hour, a size. |
| `SWW_ANOMALY_CLIENT_BYTES_PER_MINUTE` | `off` | Alert when more than this many bytes, as `SWW_BYTES_COUNT` counts them, are counted for one client in a minute, a size. |
| `SWW_ANOMALY_CLIENT_BYTES_PER_HOUR` | `off` | Alert when more than this many bytes, as `SWW_BYTES_COUNT` counts them, are counted for one client in an hour, a size. |
| `SWW_ANOMALY_NET_REQUESTS_PER_MINUTE` | `off` | Alert when the netblock around a client makes more requests than this in a minute, a count. |
| `SWW_ANOMALY_NET_REQUESTS_PER_HOUR` | `off` | Alert when the netblock around a client makes more requests than this in an hour, a count. |
| `SWW_ANOMALY_NET_BYTES_PER_MINUTE` | `off` | Alert when the netblock around a client carries more bytes than this in a minute, a size. |
| `SWW_ANOMALY_NET_BYTES_PER_HOUR` | `off` | Alert when the netblock around a client carries more bytes than this in an hour, a size. |
| `SWW_ANOMALY_NET_BYTES_PER_MINUTE` | `off` | Alert when more than this many bytes, as `SWW_BYTES_COUNT` counts them, are counted for the netblock around a client in a minute, a size. |
| `SWW_ANOMALY_NET_BYTES_PER_HOUR` | `off` | Alert when more than this many bytes, as `SWW_BYTES_COUNT` counts them, are counted for the netblock around a client in an hour, a size. |
| `SWW_ANOMALY_NET_V4_PREFIX` | `24` | The prefix length of the netblock around an IPv4 client that the `SWW_ANOMALY_NET_` thresholds count, from 0 to 32. |
| `SWW_ANOMALY_NET_V6_PREFIX` | `48` | The prefix length of the netblock around an IPv6 client that the `SWW_ANOMALY_NET_` thresholds count, from 0 to 128. |
| `SWW_ANOMALY_ASN_REQUESTS_PER_MINUTE` | `off` | Alert when one AS number makes more requests than this in a minute, a count. |
| `SWW_ANOMALY_ASN_REQUESTS_PER_HOUR` | `off` | Alert when one AS number makes more requests than this in an hour, a count. |
| `SWW_ANOMALY_ASN_BYTES_PER_MINUTE` | `off` | Alert when one AS number carries more bytes than this in a minute, a size. |
| `SWW_ANOMALY_ASN_BYTES_PER_HOUR` | `off` | Alert when one AS number carries more bytes than this in an hour, a size. |
| `SWW_ANOMALY_ASN_BYTES_PER_MINUTE` | `off` | Alert when more than this many bytes, as `SWW_BYTES_COUNT` counts them, are counted for one AS number in a minute, a size. |
| `SWW_ANOMALY_ASN_BYTES_PER_HOUR` | `off` | Alert when more than this many bytes, as `SWW_BYTES_COUNT` counts them, are counted for one AS number in an hour, a size. |
| `SWW_ANOMALY_TOTAL_REQUESTS_PER_MINUTE` | `off` | Alert when the whole service gets more requests than this in a minute, a count. |
| `SWW_ANOMALY_TOTAL_REQUESTS_PER_HOUR` | `off` | Alert when the whole service gets more requests than this in an hour, a count. |
| `SWW_ANOMALY_TOTAL_BYTES_PER_MINUTE` | `off` | Alert when the whole service carries more bytes than this in a minute, a size. |
| `SWW_ANOMALY_TOTAL_BYTES_PER_HOUR` | `off` | Alert when the whole service carries more bytes than this in an hour, a size. |
| `SWW_ANOMALY_TOTAL_BYTES_PER_MINUTE` | `off` | Alert when more than this many bytes, as `SWW_BYTES_COUNT` counts them, are counted for the whole service in a minute, a size. |
| `SWW_ANOMALY_TOTAL_BYTES_PER_HOUR` | `off` | Alert when more than this many bytes, as `SWW_BYTES_COUNT` counts them, are counted for the whole service in an hour, a size. |
| `SWW_WATCH_NETS` | empty | Named netblocks the `SWW_WATCH_` thresholds count each as a whole, such as `office=203.0.113.0/24,scraper-x=198.51.100.0/22`. |
| `SWW_WATCH_REQUESTS_PER_MINUTE` | `off` | Alert when a watched netblock makes more requests than this in a minute, a count. |
| `SWW_WATCH_REQUESTS_PER_HOUR` | `off` | Alert when a watched netblock makes more requests than this in an hour, a count. |
| `SWW_WATCH_BYTES_PER_MINUTE` | `off` | Alert when a watched netblock carries more bytes than this in a minute, a size. |
| `SWW_WATCH_BYTES_PER_HOUR` | `off` | Alert when a watched netblock carries more bytes than this in an hour, a size. |
| `SWW_WATCH_BYTES_PER_MINUTE` | `off` | Alert when more than this many bytes, as `SWW_BYTES_COUNT` counts them, are counted for a watched netblock in a minute, a size. |
| `SWW_WATCH_BYTES_PER_HOUR` | `off` | Alert when more than this many bytes, as `SWW_BYTES_COUNT` counts them, are counted for a watched netblock in an hour, a size. |
[`docs/settings.md`](docs/settings.md) gives the values each setting takes in
full, and the limits that are fixed rather than settings.
@@ -528,8 +533,9 @@ of the request reaches the app.
17. The request is passed to the app, streaming.
18. After the answer, `rproxy` sends `discriminator` a report with the status
and the bytes each way. For an allowed request, `discriminator` counts the
bytes toward the byte limits and adds the request to the client's history.
and the body bytes each way. For an allowed request, `discriminator` counts
the bytes `SWW_BYTES_COUNT` names toward the byte limits, bans the client if
they take it past one, and adds the request to the client's history.
A refused visitor is answered with `SWW_BAN_RESPONSE`. A `block` rule or a Core
Rule Set match answers `403` and bans nobody, since the Core Rule Set has false
@@ -563,7 +569,9 @@ the `tags` field of its log line:
or `vpn=mullvad`;
- `crowdsec`, `dnsbl=<zone>` and `abuseipdb`, when that reputation source lists
the client;
- `exploitsignature`, when a rule file or the Core Rule Set matched the request.
- `exploitsignature`, when a rule file or the Core Rule Set matched the request;
- `asn=<number>` and `prefix=<netblock>`, from a routewatch instance, while
`SWW_ROUTEWATCH_URL` is set.
`SWW_TAG_DENY` refuses requests by tag, and `SWW_TAG_LIMIT_PERCENT` lowers a
client's limits by tag. See "Request tags" in [`SPEC.md`](SPEC.md).
@@ -630,8 +638,8 @@ is set aside as `<name>.bad`, and never stops the running process (see
- `internal/discriminator`: `discriminator`'s server, which runs the checks and
answers its own endpoints.
- `internal/ratelimit`, `internal/bans`, `internal/rules`, `internal/waf`,
`internal/lookup`, `internal/reputation`, `internal/anomaly` and
`internal/alerts`: one check or source each.
`internal/lookup`, `internal/reputation`, `internal/routewatch`,
`internal/anomaly` and `internal/alerts`: one check or source each.
- `internal/state`, `internal/requestlog`, `internal/remotelog` and
`internal/metrics`: the state files, the log lines, the syslog sender and the
metrics.
SPEC.md
+50 -21
View File
@@ -22,8 +22,8 @@ to them.
key or a token stays off until the operator supplies it.
- It keeps a site answering while the part that decides is down, slow or
restarting (see "Without an answer from `discriminator`").
- It limits each client's requests and bytes per minute, hour and day. It bounds
the size and duration of every request and answer. It detects attacks.
- It limits each client's requests and body bytes per minute, hour and day. It
bounds the size and duration of every request and answer. It detects attacks.
- It bans abusers: briefly at first, for seven days on a clear sign of attack,
and permanently when they keep at it.
- It looks up each client's AS number and country. It can refuse whole countries
@@ -87,6 +87,8 @@ to them.
database.
- `internal/reputation`: fetches the lists, asks the DNS blocklists and
AbuseIPDB in the background, and keeps their answers.
- `internal/routewatch`: asks a routewatch instance about clients in the
background, and keeps its answers.
- `internal/anomaly`: the anomaly counters and their alerts.
- `internal/alerts`: holds back repeats and alerts past the hourly limit,
and sends the rest to the webhook, Slack and ntfy, each from a queue of
@@ -144,7 +146,9 @@ request log's `heuristic` field gives that name. `refusal_limit` and
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 tag lists (`tag_lists`; see "Request tags"). Each list that holds the
client adds its tag. A client in `SWW_ALLOW_NETS` gets no tag.
client adds its tag. Next, `routewatch_tags` adds the client's `asn=` and
`prefix=` tags while `SWW_ROUTEWATCH_URL` is set. A client in
`SWW_ALLOW_NETS` gets no tag.
4. The static lists. A client in `SWW_ALLOW_NETS` skips steps 5 to 15, the byte
limits and the error burst. A client in `SWW_DENY_NETS` is refused
(`deny_nets`); a client in both lists is let through.
@@ -192,11 +196,12 @@ request log's `heuristic` field gives that name. `refusal_limit` and
sent is removed.
18. After the visitor's answer has ended, `rproxy` sends the report (see "The
report"). `discriminator` then counts:
- For a request it allowed, the response bytes, the request bytes or both
are added to the byte counters, as `SWW_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 (`byte_limits`). The response in progress is not cut off.
- For a request it allowed, the body bytes of the response, of the request
or of both are added to the byte counters, as `SWW_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 (`byte_limits`). The request that broke it has already been
passed on whole; nothing is cut off.
- For a request it allowed, the client's history and the anomaly counters
are updated, and the alert thresholds are evaluated.
@@ -259,7 +264,8 @@ to a ban, each by its own rule:
clear sign of attack bans it permanently at once.
- A broken limit, one of:
- a request over a rate limit;
- a response that takes the client's byte total past a byte limit;
- the bytes counted for a request and its response taking the client's total
past a byte limit;
- more than `SWW_ERROR_BURST_THRESHOLD` refusals within a minute.
The bans for a broken limit:
@@ -448,10 +454,15 @@ the same way.
### Byte limits, per client
By default there is no minute limit, so a client can download in a burst at full
speed. The hour limit defaults to 50 GiB and the day limit to 100 GiB. They
allow several downloads of a few GiB each. A response's bytes are counted when
it ends (see step 18).
The byte limits count body bytes: the app's response bodies, the visitors'
request bodies, or both, as `SWW_BYTES_COUNT` says. Headers are never counted.
What the visitor sent over a WebSocket counts as request bytes, and what the app
sent as response bytes. The bytes counted for a request and its response are
added to the client's total once the response has ended (see step 18). So the
request that takes a client past a limit is passed on whole, and the ban refuses
the client's requests from then on. By default there is no minute limit, so a
client can download in a burst at full speed. The hour limit defaults to 50 GiB
and the day limit to 100 GiB. They allow several downloads of a few GiB each.
### Lookup of AS number and country
@@ -547,6 +558,21 @@ Each tag and where it comes from:
- `exploitsignature`, when a rule file or the Core Rule Set matched the request.
For the Core Rule Set a match is a score at or over
`SWW_WAF_ANOMALY_THRESHOLD`.
- `asn=<number>` and `prefix=<netblock>` from a routewatch instance
(`routewatch_tags`), while `SWW_ROUTEWATCH_URL` is set:
- The tag `prefix=` holds the netblock the client's address is announced in,
such as `prefix=192.0.2.0/24`.
- An `asn=` tag has the same spelling as the lookup's. When routewatch and
the lookup give the same AS number, a request has one `asn=` tag. When
they differ, it has both.
- They are added before `deny_nets`, so the log line of a request it refused
has them.
- `discriminator` asks routewatch in the background and never waits for it.
An answer is kept for 1 hour, in memory only.
- After a query fails, routewatch is not asked for 1 minute.
- A request without these tags gives the reason in the log field
`routewatch_tags_missing` (see
[`docs/request-log.md`](docs/request-log.md)).
A client in `SWW_ALLOW_NETS` skips the checks and gets no tag. Every tag is in
lower case, except a country code, which is in capitals. `SWW_TAG_DENY` and
@@ -564,7 +590,9 @@ Two settings act on tags:
The tag settings are empty by default, for the same reason as the country list.
The lookup waits for GeoJS when either names an `asn=` or `country=` tag. A
setting that names one stops the start while `SWW_LOOKUP_SOURCE` is `off`.
setting that names one stops the start while `SWW_LOOKUP_SOURCE` is `off`. The
exception is an `asn=` tag while `SWW_ROUTEWATCH_URL` is set, since routewatch
gives that tag.
### Biased thresholds
@@ -976,7 +1004,8 @@ which the metrics show. They reveal a widely distributed scraper, thousands of
addresses at low rates each, which the per-client limits do not see. A low
percentage for its `asn=` tag in `SWW_TAG_LIMIT_PERCENT` is the response.
- Requests and bytes are counted per minute and per hour, for each of:
- Requests and body bytes, as `SWW_BYTES_COUNT` counts them, are counted per
minute and per hour, for each of:
- a client;
- the surrounding netblock;
- an AS number;
@@ -1286,9 +1315,9 @@ short.
### Answering in time
`rproxy` stops waiting for `discriminator` after `SWRP_TIMEOUT_MS`, by default 2
seconds, and `SWRP_DEFAULT_DISPOSITION` then decides. So at the defaults,
`discriminator` answers a request well within that time, whatever the request
and whatever its outside sources do.
seconds, and `SWRP_DEFAULT_DISPOSITION` then decides. The longest a question
waits on an outside source is `SWW_LOOKUP_TIMEOUT`, by default 800 milliseconds,
well within that time.
GeoJS is the only outside source a question can wait on. A question waits only
when step 6 says so, and for at most `SWW_LOOKUP_TIMEOUT`, by default 800
@@ -1384,9 +1413,9 @@ answer.
For a request it holds, `discriminator` writes the request's last log line (see
"The log"). For a request it allowed, it first:
- counts the bytes as `SWW_BYTES_COUNT` says, toward the client's byte limits at
the percentages it gave that request;
- bans a client that passes a byte limit;
- counts the body bytes `SWW_BYTES_COUNT` names, toward the client's byte limits
at the percentages it gave that request;
- bans a client whose total passes a byte limit;
- adds the request with its status to the client's history, the anomaly counters
and the metrics.
docs/metrics.md
+3
View File
@@ -5,6 +5,9 @@ What `GET /_sww/metrics` answers with, at `discriminator`'s own address.
keeps the `instance` label as `exported_instance` unless the scrape sets
`honor_labels: true`. `rproxy` has no metrics.
Every `sww_*request_bytes_total` and `sww_*response_bytes_total` series counts
body bytes, never headers, whatever `SWW_BYTES_COUNT` says.
## Traffic
- `sww_requests_total`, `sww_request_bytes_total` and
docs/request-log.md
+14 -6
View File
@@ -145,20 +145,22 @@ Every one of these lines has:
included. It is left out when rate limiting did not count the request. It
holds:
- `minute`, `hour` and `day`: requests;
- `minute_bytes`, `hour_bytes` and `day_bytes`: bytes.
- `minute_bytes`, `hour_bytes` and `day_bytes`: the body bytes
`SWW_BYTES_COUNT` names, in that window.
A count can have a fraction (see "Counting method" in
[`SPEC.md`](../SPEC.md)). The bytes of an allowed request are counted when
its report comes. So on the `decision` line, the bytes are without this
request's.
[`SPEC.md`](../SPEC.md)). The bytes counted for an allowed request and its
response are added when its report comes. So on the `decision` line, the
three byte totals leave them out.
- `limit_hit`: the limit broken:
- `minute`, `hour` or `day` for a rate limit;
- `minute_bytes`, `hour_bytes` or `day_bytes` for a byte limit;
- `error_burst`.
A request whose bytes broke a limit was passed on whole, so its `action`
stays `forward`. Only its `report` line gives that limit.
When the bytes counted for a request and its response break a limit, the
request has been passed on whole, so its `action` stays `forward`. Only its
`report` line gives that limit.
- `rule_ids`: the rule file rules that matched, in order, up to the one that
refused.
@@ -171,6 +173,12 @@ Every one of these lines has:
- `abuseipdb`.
- `tags`: the request's tags, sorted, left out when it has none. Each tag and
where it comes from is under "Request tags" in [`SPEC.md`](../SPEC.md).
- `routewatch_tags_missing`: why the request got no tags from routewatch,
present only while `SWW_ROUTEWATCH_URL` is set:
- `no_answer_yet`: routewatch has not answered about this client yet;
- `request_failed`: a query to routewatch failed within the last minute, and
the process log says why;
- `no_route`: routewatch knows no live route for the address.
- `offence`: `limit`, for a request that broke a limit.
- `ban_expires`: when the client's ban ends, for a request that made one or was
refused under one: a time, or `permanent`.
docs/settings.md
+34 -10
View File
@@ -98,6 +98,8 @@ between the two (see "The image's command" below).
## Request rate limits, per client
The request past one of these limits is refused, and the client is banned.
- `SWW_RATE_LIMIT_PER_MINUTE` (default `120`, 2 a second): the most requests a
client may make in a minute. A count or `off`. The default leaves room for a
person opening two pages at once with an empty cache, up to 60 files each.
@@ -120,11 +122,22 @@ between the two (see "The image's command" below).
## Byte limits, per client
These count body bytes, never headers. What the visitor sent over a WebSocket
counts as request bytes, and what the app sent as response bytes. The bytes
counted for a request and its response are added to the client's total once the
response has ended. The request that takes a client's total past a limit is not
cut off; the client is banned.
- `SWW_BYTES_LIMIT_PER_MINUTE` (default `off`), `SWW_BYTES_LIMIT_PER_HOUR`
(default `50G`) and `SWW_BYTES_LIMIT_PER_DAY` (default `100G`): the most bytes
counted for a client in each window. A size or `off`.
- `SWW_BYTES_COUNT` (default `both`): which body bytes the byte limits count:
`response`, `request` or `both`.
counted for a client in each window, a size or `off`. `SWW_BYTES_COUNT` says
which bytes count: response bodies, request bodies or both. The request that
passes the limit is not cut off, and the client is banned when its response
ends.
- `SWW_BYTES_COUNT` (default `both`): what the byte limits and the byte anomaly
thresholds count: `response`, the app's response bodies; `request`, the
visitors' request bodies; or `both`. What the visitor sent over a WebSocket
counts as request bytes, and what the app sent as response bytes.
## Lookup of AS number and country
@@ -132,8 +145,8 @@ between the two (see "The image's command" below).
the start while a setting that needs a lookup is set:
- `SWW_EXCLUSIVELY_ALLOWED_COUNTRIES`;
- `SWW_ADD_LOOKUP_HEADERS`;
- `SWW_TAG_DENY` or `SWW_TAG_LIMIT_PERCENT` naming an `asn=` or `country=`
tag;
- `SWW_TAG_DENY` or `SWW_TAG_LIMIT_PERCENT` naming a `country=` tag, or an
`asn=` tag while `SWW_ROUTEWATCH_URL` is unset;
- the two byte percentage lists and `SWW_ASN_LIMIT_PERCENT_URL`;
- `SWW_UNKNOWN_LIMIT_PERCENT` below `100`;
- an anomaly threshold per AS number.
@@ -173,11 +186,20 @@ Every request gets tags from what `discriminator` knows of its client. See
`exploitsignature`: a request gets that tag after the rate limits have counted
it.
- `SWW_ROUTEWATCH_URL` (default unset): the `http` or `https` URL of a
routewatch instance. [routewatch](https://git.eeqj.de/sneak/routewatch) is a
service that gives an address's announced netblock and origin AS.
`discriminator` asks it about each client, in the background, and adds the
tags `asn=<number>` and `prefix=<netblock>` from its answer. While it is
unset, nothing asks routewatch and no request gets a `prefix=` tag.
`SWW_TAG_DENY` and `SWW_TAG_LIMIT_PERCENT` accept tags in either case. A tag
that no request can get stops the start. A request can get only these:
- a name in `SWW_TAG_LISTS`;
- an `asn=` or `country=` tag;
- a `prefix=` tag with a netblock, while `SWW_ROUTEWATCH_URL` is set. It matches
only that exact announced netblock, such as `prefix=192.0.2.0/24`;
- a `dnsbl=` tag of a zone in `SWW_DNSBL_ZONES`, in lower case, with a key
masked as the `reputation` field shows it;
- `abuseipdb`, while `SWW_ABUSEIPDB_KEY` is set;
@@ -251,8 +273,9 @@ the request first.
- a hostname listed twice;
- an app listed twice for one hostname;
- an entry without a colon.
- `SWW_ERROR_BURST_THRESHOLD` (default `30`): the most refusals of one client in
a minute (see "Attack detection" in `SPEC.md`). A count or `off`.
- `SWW_ERROR_BURST_THRESHOLD` (default `30`): the most refusals a client may get
in a minute from a rule file, a trap path or the Core Rule Set, a count or
`off`. The next one bans the client (see "Attack detection" in `SPEC.md`).
## Ban lengths, response and scope
@@ -329,9 +352,10 @@ the request first.
## Anomaly thresholds
Each scope has four thresholds: the most requests and the most bytes counted in
a minute and in an hour. Requests are counts, bytes are sizes. Each is `off` by
default. The four thresholds per client are:
Each scope has four thresholds: the most requests and the most body bytes
counted in a minute and in an hour. The bytes are those `SWW_BYTES_COUNT` names.
Requests are counts, bytes are sizes. Each is `off` by default. The four
thresholds per client are:
- `SWW_ANOMALY_CLIENT_REQUESTS_PER_MINUTE`;
- `SWW_ANOMALY_CLIENT_REQUESTS_PER_HOUR`;
docs/state-files.md
+1 -1
View File
@@ -61,7 +61,7 @@ since it was first seen:
- the first and last time seen;
- the AS number, AS name and country last looked up, and when;
- total requests, and how many were forwarded and how many refused;
- bytes in each direction;
- body bytes of its requests, and of the responses it was sent;
- responses by status class;
- offences by kind: `limit`, `attack`, `rule_blocked` and `waf_blocked`. A file
may also hold `token_refused`, which is kept, and which nothing adds to.
internal/config/config.go
+57 -8
View File
@@ -12,6 +12,7 @@ import (
"errors"
"fmt"
"log/slog"
"maps"
"math"
"net"
"net/http"
@@ -107,6 +108,9 @@ type Config struct {
TagLists []TagList
TagDeny []string
TagLimitPercent map[string]int64
// RouteWatchURL is where the routewatch instance is that adds the asn=
// and prefix= tags, "" for none (SWW_ROUTEWATCH_URL).
RouteWatchURL string
// The biased thresholds. ASNBytesPercent and CountryBytesPercent give
// those they list a percentage of the byte limits in place of the one
// TagLimitPercent gives their asn= or country= tag
@@ -473,6 +477,9 @@ var (
errNotLAPIURL = errors.New(
"is not an http or https URL without a user or a fragment, " +
"such as http://172.17.0.1:8080")
errNotRouteWatchURL = errors.New(
"is not an http or https URL without a user or a fragment, " +
"such as https://routewatch.example")
errNeedsLAPIKey = errors.New("the engine answers no request without it")
errLAPIKeyUnused = errors.New("it is sent only to the engine at that URL")
errAnotherList = errors.New(
@@ -486,6 +493,8 @@ var (
"is not a tag, : and a percentage, such as vpn:50 or asn=14061:25")
errNotTagPercent = errors.New("is not a percentage from 1 to 99")
errNotASNTag = errors.New("is not asn= and a number, such as asn=14061")
errNotPrefixTag = errors.New(
"is not prefix= and a netblock, such as prefix=192.0.2.0/24")
errExploitTag = errors.New(
"cannot lower limits: the rate limits count a request before its " +
"rules are matched")
@@ -494,8 +503,9 @@ var (
errNoRequestGetsTag = errors.New(
"is a tag no request can get: it is not a name in SWW_TAG_LISTS, an " +
"asn= or country= tag, a dnsbl= tag of a zone in SWW_DNSBL_ZONES, " +
"abuseipdb with SWW_ABUSEIPDB_KEY set, or exploitsignature with " +
"rule files or the Core Rule Set on")
"a prefix= tag with SWW_ROUTEWATCH_URL set, abuseipdb with " +
"SWW_ABUSEIPDB_KEY set, or exploitsignature with rule files or the " +
"Core Rule Set on")
)
// FromEnvironment reads the settings with lookupEnv, normally
@@ -535,6 +545,7 @@ func FromEnvironment(
TagLists: env.tagLists("SWW_TAG_LISTS"),
TagDeny: env.tags("SWW_TAG_DENY"),
TagLimitPercent: env.tagPercents("SWW_TAG_LIMIT_PERCENT"),
RouteWatchURL: env.routeWatchURL("SWW_ROUTEWATCH_URL"),
ASNBytesPercent: env.percents("SWW_ASN_BYTES_PERCENT", ParseASN),
CountryBytesPercent: env.percents("SWW_COUNTRY_BYTES_PERCENT", parseCountry),
UnknownLimitPercent: env.percent("SWW_UNKNOWN_LIMIT_PERCENT", "100"),
@@ -1050,6 +1061,22 @@ func (e *environment) crowdSecDecisionsURL(name string) string {
return lapi.JoinPath("v1", "decisions").String()
}
// routeWatchURL reads the setting that is the URL of a routewatch instance,
// "" while it is unset or empty.
func (e *environment) routeWatchURL(name string) string {
value := e.value(name, "")
if value == "" {
return ""
}
instance, err := url.Parse(value)
if err != nil || !isHTTPURL(instance) {
e.check(name, fmt.Errorf("%q %w", value, errNotRouteWatchURL))
}
return value
}
// lookupSource reads the setting that is where clients are looked up:
// geojs, file, or off.
func (e *environment) lookupSource(name, defaultValue string) string {
@@ -1095,14 +1122,21 @@ func (e *environment) checkCountriesAndLookups(cfg *Config) {
return
}
// routewatch gives asn= tags too.
onlyLookupGives := func(tag string) bool {
return isLookupTag(tag) &&
(cfg.RouteWatchURL == "" || !strings.HasPrefix(tag, ASNTagPrefix))
}
for _, setting := range []struct {
name string
set bool
}{
{"SWW_EXCLUSIVELY_ALLOWED_COUNTRIES", len(cfg.ExclusivelyAllowedCountries) > 0},
{"SWW_ADD_LOOKUP_HEADERS", cfg.AddLookupHeaders},
{"SWW_TAG_DENY", slices.ContainsFunc(cfg.TagDeny, isLookupTag)},
{"SWW_TAG_LIMIT_PERCENT", tagLimitNeedsLookups(cfg)},
{"SWW_TAG_DENY", slices.ContainsFunc(cfg.TagDeny, onlyLookupGives)},
{"SWW_TAG_LIMIT_PERCENT", slices.ContainsFunc(
slices.Collect(maps.Keys(cfg.TagLimitPercent)), onlyLookupGives)},
{"SWW_ASN_BYTES_PERCENT", len(cfg.ASNBytesPercent) > 0},
{"SWW_COUNTRY_BYTES_PERCENT", len(cfg.CountryBytesPercent) > 0},
{"SWW_UNKNOWN_LIMIT_PERCENT", cfg.UnknownLimitPercent < 100},
@@ -1202,6 +1236,10 @@ func requestCanGetTag(cfg *Config, tag string) bool {
return cfg.AbuseIPDBKey != ""
}
if strings.HasPrefix(tag, PrefixTagPrefix) {
return cfg.RouteWatchURL != ""
}
zone, isZoneTag := strings.CutPrefix(tag, DNSBLTagPrefix)
return isZoneTag && slices.ContainsFunc(cfg.DNSBLZones, func(each string) bool {
@@ -1210,7 +1248,7 @@ func requestCanGetTag(cfg *Config, tag string) bool {
}
// TagsNeedLookup reports whether SWW_TAG_DENY or SWW_TAG_LIMIT_PERCENT
// names an asn= or country= tag, which only the lookup can give a request.
// names an asn= or country= tag.
func (c *Config) TagsNeedLookup() bool {
return slices.ContainsFunc(c.TagDeny, isLookupTag) || tagLimitNeedsLookups(c)
}
@@ -2013,6 +2051,7 @@ const (
ASNTagPrefix = "asn="
CountryTagPrefix = "country="
DNSBLTagPrefix = "dnsbl="
PrefixTagPrefix = "prefix="
AbuseIPDBTag = "abuseipdb"
CrowdSecTag = "crowdsec"
// ExploitSignatureTag is the tag of a request a rule file or the Core
@@ -2089,9 +2128,10 @@ func parseTags(value string) ([]string, error) {
// parseTag reads a tag in either case, with spaces around it, and returns it
// as a request carries it: in lower case, but for a country code, which is in
// capitals, and an asn= tag's number without leading zeros. An asn= or
// country= tag must name a number or a country, so that a mistyped one stops
// the start instead of never matching.
// capitals, an asn= tag's number without leading zeros, and a prefix= tag's
// netblock as routewatch writes it. An asn=, country= or prefix= tag must name
// a number, a country or a netblock, so that a mistyped one stops the start
// instead of never matching.
func parseTag(value string) (string, error) {
tag := strings.ToLower(strings.TrimSpace(value))
@@ -2113,6 +2153,15 @@ func parseTag(value string) (string, error) {
return CountryTagPrefix + country, nil
}
if text, isPrefix := strings.CutPrefix(tag, PrefixTagPrefix); isPrefix {
netblock, err := netip.ParsePrefix(text)
if err != nil || netblock != netblock.Masked() {
return "", fmt.Errorf("%q %w", value, errNotPrefixTag)
}
return PrefixTagPrefix + netblock.String(), nil
}
return tag, nil
}
internal/config/config_test.go
+59
View File
@@ -61,6 +61,7 @@ const (
reputationAction = "SWW_REPUTATION_ACTION"
reputationCacheTTL = "SWW_REPUTATION_CACHE_TTL"
reputationTimeout = "SWW_REPUTATION_TIMEOUT"
routeWatchURL = "SWW_ROUTEWATCH_URL"
crowdSecURL = "SWW_CROWDSEC_LAPI_URL"
crowdSecKey = "SWW_CROWDSEC_LAPI_KEY"
banResponse = "SWW_BAN_RESPONSE"
@@ -1490,6 +1491,63 @@ func TestTagSettingsAsSet(t *testing.T) {
}
}
func TestRouteWatchURLAndPrefixTags(t *testing.T) {
t.Parallel()
const rw = "https://routewatch.example"
if cfg := fromEnvironment(t, environment{}); cfg.RouteWatchURL != "" {
t.Errorf("default %s is %q, want unset", routeWatchURL, cfg.RouteWatchURL)
}
cfg := fromEnvironment(t, environment{
routeWatchURL: rw, tagDeny: "prefix=2001:DB8::/32",
tagLimitPercent: "prefix=192.0.2.0/24:50",
})
wantDeny := []string{"prefix=2001:db8::/32"}
if cfg.RouteWatchURL != rw || !slices.Equal(cfg.TagDeny, wantDeny) ||
cfg.TagLimitPercent["prefix=192.0.2.0/24"] != 50 {
t.Errorf("gave %q, %v, %v", cfg.RouteWatchURL, cfg.TagDeny, cfg.TagLimitPercent)
}
// routewatch gives asn= tags too, so an asn= tag needs no lookups while it is set.
fromEnvironment(t, environment{
lookupSource: off, routeWatchURL: rw, tagDeny: "asn=64496",
})
for _, stopped := range []struct {
env environment
name string
}{
{environment{routeWatchURL: "ftp://routewatch.example"}, routeWatchURL},
{environment{routeWatchURL: "routewatch.example"}, routeWatchURL},
{environment{tagDeny: "prefix=192.0.2.0/24"}, tagDeny},
{environment{routeWatchURL: rw, tagDeny: "prefix=nowhere"}, tagDeny},
{environment{routeWatchURL: rw, tagDeny: "prefix=192.0.2.5/24"}, tagDeny},
{
environment{routeWatchURL: rw, tagLimitPercent: "prefix=192.0.2.0/33:50"},
tagLimitPercent,
},
{environment{lookupSource: off, routeWatchURL: rw, tagDeny: "country=DE"}, tagDeny},
{environment{lookupSource: off, tagDeny: "asn=64496"}, tagDeny},
} {
_, err := config.FromEnvironment(stopped.env.lookupEnv)
if err == nil || !strings.HasPrefix(err.Error(), stopped.name+": ") {
t.Errorf("%v gave the error %v, want one naming %s", stopped.env, err, stopped.name)
}
}
badURL := environment{routeWatchURL: "ftp://routewatch.example"}
_, err := config.FromEnvironment(badURL.lookupEnv)
want := routeWatchURL + `: "ftp://routewatch.example" is not an http or https URL ` +
"without a user or a fragment, such as https://routewatch.example"
if err == nil || err.Error() != want {
t.Errorf("error %v, want %s", err, want)
}
}
func TestTagThatNoRequestCanGetIsToldApartFromOneItCan(t *testing.T) {
t.Parallel()
@@ -2590,6 +2648,7 @@ func TestLogsEachSettingWithItsValue(t *testing.T) {
reputationAction: "limit:25",
reputationCacheTTL: defaultReputationCacheTTL,
reputationTimeout: "2s",
routeWatchURL: "",
crowdSecURL: "",
crowdSecKey: "",
banResponse: "403",
internal/discriminator/discriminator.go
+1
View File
@@ -123,6 +123,7 @@ func New(params Params) *Server {
Lists: h.lists,
DNSBL: h.dnsbl,
AbuseIPDB: h.abuseIPDB,
RouteWatch: h.routeWatch,
Metrics: h.metrics,
}
}
internal/discriminator/heuristics.go
+1
View File
@@ -44,6 +44,7 @@ const (
func beforeLookup() []heuristic {
return []heuristic{
tagLists{},
routeWatchTags{},
denyNets{},
activeBan{},
}
internal/discriminator/proxy.go
+11 -1
View File
@@ -20,6 +20,7 @@ import (
"sneak.berlin/go/smallwebwaf/internal/metrics"
"sneak.berlin/go/smallwebwaf/internal/ratelimit"
"sneak.berlin/go/smallwebwaf/internal/reputation"
"sneak.berlin/go/smallwebwaf/internal/routewatch"
"sneak.berlin/go/smallwebwaf/internal/rules"
"sneak.berlin/go/smallwebwaf/internal/waf"
)
@@ -85,7 +86,8 @@ type Params struct {
// Server is the server discriminator runs, with the parts whose state the state
// files keep, the lookup database, nil unless SWW_LOOKUP_SOURCE is file, the
// lists fetched from URLs, which its Run fetches, the DNSBL zones' verdicts,
// AbuseIPDB's scores and checks spent, and the metrics.
// AbuseIPDB's scores and checks spent, and the metrics. RouteWatch, nil while
// SWW_ROUTEWATCH_URL is unset, keeps its answers in memory only.
type Server struct {
*http.Server
@@ -97,6 +99,7 @@ type Server struct {
Lists *reputation.Lists
DNSBL *reputation.DNSBL
AbuseIPDB *reputation.AbuseIPDB
RouteWatch *routewatch.Client
Metrics *metrics.Metrics
}
@@ -152,6 +155,12 @@ func newHandler(params Params) *handler {
coreRuleSet: params.CoreRuleSet,
alerts: params.Alerts,
}
if params.Config.RouteWatchURL != "" {
h.routeWatch = routewatch.New(routewatch.Params{
URL: params.Config.RouteWatchURL, Now: params.Now, ProcessLog: params.ProcessLog,
})
}
h.geojs = lookup.New(lookup.Params{
URL: params.GeoJSURL,
Timeout: params.Config.LookupTimeout,
@@ -257,6 +266,7 @@ type handler struct {
lists *reputation.Lists
dnsbl *reputation.DNSBL
abuseIPDB *reputation.AbuseIPDB
routeWatch *routewatch.Client
rules *rules.Files
coreRuleSet *waf.CoreRuleSet
alerts *alerts.Queue
internal/discriminator/routewatchtags.go
+42
View File
@@ -0,0 +1,42 @@
package discriminator
// The heuristic routewatch_tags. It reads SWW_ROUTEWATCH_URL.
import (
"context"
"strconv"
"time"
"sneak.berlin/go/smallwebwaf/internal/config"
)
// routeWatchTags adds to the request the tags asn=<number> and prefix=<netblock>
// from what routewatch answered about the client. It refuses nothing, and the
// request does not wait for routewatch. A request that gets no tags from it has
// the reason in the log line's routewatch_tags_missing. While SWW_ROUTEWATCH_URL
// is unset it does nothing. Answers are kept by client and asked for by the
// request's address, and a route without an origin AS gives only the prefix= tag.
type routeWatchTags struct{}
func (routeWatchTags) name() string { return "routewatch_tags" }
func (routeWatchTags) check(ctx context.Context, rq *request, _ time.Time) *verdict {
if rq.h.routeWatch == nil {
return nil
}
route, missing := rq.h.routeWatch.Route(ctx, rq.h.clientGroup(rq.client), rq.client)
if missing != "" {
rq.line.RouteWatchTagsMissing = string(missing)
return nil
}
rq.addTag(config.PrefixTagPrefix + route.Netblock.String())
if route.ASN != 0 {
rq.addTag(config.ASNTagPrefix + strconv.FormatUint(uint64(route.ASN), 10))
}
return nil
}
internal/discriminator/routewatchtags_test.go
+245
View File
@@ -0,0 +1,245 @@
package discriminator_test
import (
"context"
"encoding/json"
"net/http"
"net/http/httptest"
"net/netip"
"strings"
"testing"
"time"
"sneak.berlin/go/smallwebwaf/internal/discriminator"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
)
// routeWatchURL is SWW_ROUTEWATCH_URL, and tagsMissing the log line's field
// that says why a request got no tags from routewatch.
const (
routeWatchURL = "SWW_ROUTEWATCH_URL"
tagsMissing = "routewatch_tags_missing"
fromV6 = "2001:db8:1::5"
prefixV6 = "2001:db8::/32"
prefixDE = "203.0.113.0/24"
prefixKP = "198.51.100.0/24"
)
// standInRoute is what the stand-in for routewatch answers about an address.
type standInRoute struct {
Netblock string `json:"netblock"`
ASN int `json:"asn"`
}
// startRouteWatch starts a stand-in for routewatch's IP info API that knows the
// routes given by address, and returns its URL.
func startRouteWatch(t *testing.T, routes map[string]standInRoute) string {
t.Helper()
server := httptest.NewServer(http.HandlerFunc(
func(w http.ResponseWriter, r *http.Request) {
address := strings.TrimPrefix(r.URL.Path, "/api/v1/ip/")
result := map[string]any{"ip": address}
if route, known := routes[address]; known {
result["netblock"], result["asn"] = route.Netblock, route.ASN
}
_ = json.NewEncoder(w).Encode(map[string]any{
"status": "ok",
"data": map[string]any{"results": []any{result}},
})
}))
t.Cleanup(server.Close)
return server.URL
}
// waitForRouteWatch waits until routewatch's answer about from, in the client
// group of the given length, is kept, so that the next request gets its tags.
func waitForRouteWatch(
t *testing.T, server *discriminator.Server, from string, bits int,
) {
t.Helper()
addr := netip.MustParseAddr(from)
client := netip.PrefixFrom(addr, bits).Masked()
deadline := time.Now().Add(5 * time.Second)
for {
_, missing := server.RouteWatch.Route(context.Background(), client, addr)
if missing == "" {
return
}
if time.Now().After(deadline) {
t.Fatalf("routewatch's answer about %s not kept: %q", from, missing)
}
time.Sleep(time.Millisecond)
}
}
func wantTagsMissing(t *testing.T, line logLine, want string) {
t.Helper()
got, _ := line.fields[tagsMissing].(string)
if got != want {
t.Errorf("log line has %s %q, want %q", tagsMissing, got, want)
}
}
func TestRouteWatchTagsAreOnTheLogLineWithTheLookupsTags(t *testing.T) {
t.Parallel()
url := startRouteWatch(t, map[string]standInRoute{fromDE: {prefixDE, 64496}})
s, server, _ := startWithLookups(t, map[string]string{routeWatchURL: url})
waitForRouteWatch(t, server, fromDE, 32)
line := s.get(fromDE, http.StatusOK, requestlog.ActionForward)
wantTags(t, line, "asn=64496", "country=DE", "prefix="+prefixDE)
wantTagsMissing(t, line, "")
}
func TestRouteWatchTagsAreOnALineDenyNetsRefused(t *testing.T) {
t.Parallel()
url := startRouteWatch(t, map[string]standInRoute{fromKP: {prefixKP, 64511}})
s, _, server := startWithClock(t, "", map[string]string{
lookupSource: off, routeWatchURL: url, denyNets: fromKP,
})
waitForRouteWatch(t, server, fromKP, 32)
line := s.get(fromKP, http.StatusForbidden, requestlog.ActionDenied)
wantHeuristic(t, line, "deny_nets", `{"netblock": "`+fromKP+`/32"}`)
wantTags(t, line, "asn=64511", "prefix="+prefixKP)
}
func TestRouteWithoutAnOriginASGivesOnlyThePrefixTag(t *testing.T) {
t.Parallel()
url := startRouteWatch(t, map[string]standInRoute{fromDE: {prefixDE, 0}})
s, _, server := startWithClock(t, "", map[string]string{
lookupSource: off, routeWatchURL: url,
})
waitForRouteWatch(t, server, fromDE, 32)
wantTags(t, s.get(fromDE, http.StatusOK, requestlog.ActionForward),
"prefix="+prefixDE)
}
func TestUnsetRouteWatchChangesNothing(t *testing.T) {
t.Parallel()
s, _, server := startWithClock(t, "", map[string]string{lookupSource: off})
if server.RouteWatch != nil {
t.Error("RouteWatch is set while SWW_ROUTEWATCH_URL is unset")
}
line := s.get(fromDE, http.StatusOK, requestlog.ActionForward)
if _, present := line.fields[tagsMissing]; present {
t.Errorf("log line has %s", tagsMissing)
}
if _, present := line.fields["tags"]; present {
t.Errorf("log line has tags %v", line.fields["tags"])
}
}
func TestUnreachableRouteWatchLetsTheRequestThroughAndSaysWhy(t *testing.T) {
t.Parallel()
// A stand-in that is closed at once, so that the port refuses connections.
dead := httptest.NewServer(http.NotFoundHandler())
url := dead.URL
dead.Close()
s, _, _ := startWithClock(t, "", map[string]string{
lookupSource: off, routeWatchURL: url,
})
wantTagsMissing(t, s.get(fromDE, http.StatusOK, requestlog.ActionForward),
"no_answer_yet")
deadline := time.Now().Add(5 * time.Second)
for {
line := s.get(fromDE, http.StatusOK, requestlog.ActionForward)
missing, _ := line.fields[tagsMissing].(string)
if missing == "request_failed" {
return
}
if time.Now().After(deadline) {
t.Fatalf("still %q, want request_failed", missing)
}
time.Sleep(time.Millisecond)
}
}
func TestAddressWithoutARouteHasNoTagsAndTheLineSaysSo(t *testing.T) {
t.Parallel()
s, _, _ := startWithClock(t, "", map[string]string{
lookupSource: off, routeWatchURL: startRouteWatch(t, nil),
})
deadline := time.Now().Add(5 * time.Second)
for {
line := s.get(fromDE, http.StatusOK, requestlog.ActionForward)
missing, _ := line.fields[tagsMissing].(string)
if missing == "no_route" {
return
}
if time.Now().After(deadline) {
t.Fatalf("still %q, want no_route", missing)
}
time.Sleep(time.Millisecond)
}
}
func TestTagDenyRefusesOnARouteWatchPrefix(t *testing.T) {
t.Parallel()
url := startRouteWatch(t, map[string]standInRoute{
fromDE: {prefixDE, 64496}, fromKP: {prefixKP, 64511},
})
s, _, server := startWithClock(t, "", map[string]string{
lookupSource: off, routeWatchURL: url, tagDeny: "prefix=" + prefixKP,
})
waitForRouteWatch(t, server, fromKP, 32)
waitForRouteWatch(t, server, fromDE, 32)
wantHeuristic(t, s.get(fromKP, http.StatusForbidden, requestlog.ActionDenied),
"tag_deny", `{"tag": "prefix=`+prefixKP+`"}`)
s.get(fromDE, http.StatusOK, requestlog.ActionForward)
}
func TestTagLimitPercentWorksWithAnIPv6Prefix(t *testing.T) {
t.Parallel()
url := startRouteWatch(t, map[string]standInRoute{fromV6: {prefixV6, 64496}})
s, _, server := startWithClock(t, "", map[string]string{
lookupSource: off, routeWatchURL: url, rateLimitPerMinute: "2",
tagLimitPercent: "prefix=" + prefixV6 + ":50",
})
waitForRouteWatch(t, server, fromV6, 64)
// Half of two is one: the second request breaks the limit.
line := s.get(fromV6, http.StatusOK, requestlog.ActionForward)
wantTags(t, line, "asn=64496", "prefix="+prefixV6)
s.get(fromV6, http.StatusForbidden, requestlog.ActionRateLimited)
}
internal/requestlog/requestlog.go
+4
View File
@@ -182,6 +182,10 @@ type Line struct {
Reputation []string `json:"reputation,omitempty"`
// Tags are the request's tags, sorted.
Tags []string `json:"tags,omitempty"`
// RouteWatchTagsMissing, while SWW_ROUTEWATCH_URL is set, says why the
// request got no tags from routewatch: no_answer_yet, request_failed or
// no_route.
RouteWatchTagsMissing string `json:"routewatch_tags_missing,omitempty"`
// Offence is the offence the request was held as, OffenceLimit.
Offence string `json:"offence,omitempty"`
// BanExpires is when the ban the request made, or was refused under,
internal/routewatch/routewatch.go
+243
View File
@@ -0,0 +1,243 @@
// Package routewatch asks a routewatch instance about client addresses, in the
// background, and keeps its answers in memory. A routewatch instance knows, for
// an address, the netblock it is announced in and the AS that originates it.
package routewatch
import (
"context"
"encoding/json"
"errors"
"fmt"
"io"
"log/slog"
"net/http"
"net/netip"
"net/url"
"sync"
"time"
"github.com/hashicorp/golang-lru/v2/simplelru"
)
const (
// answerKept is how long an answer is used after it came.
answerKept = time.Hour
// failureKept is how long routewatch is not asked again after a query
// fails, so that a dead routewatch is not asked on every request.
failureKept = time.Minute
// queryTimeout is how long one query may take. routewatch answers only
// after a reverse DNS lookup it allows 2 seconds, so this is longer.
queryTimeout = 5 * time.Second
// maxAnswers is how many answers are kept. Past it, the one that came
// longest ago is dropped.
maxAnswers = 100000
// maxQueries is how many queries may be under way at once. Past it, a
// client is not asked about until its next request, so that a swarm of
// new addresses cannot fill the memory.
maxQueries = 100
// maxAnswerBytes is the most of an answer that is read.
maxAnswerBytes = 64 << 10
)
// Missing is why Route gives no route. The request log's field
// routewatch_tags_missing gives these values.
type Missing string
const (
// NoAnswerYet is a client routewatch has not answered about yet.
NoAnswerYet Missing = "no_answer_yet"
// RequestFailed is no answer because a recent query failed.
RequestFailed Missing = "request_failed"
// NoRoute is routewatch knowing no live route for the address.
NoRoute Missing = "no_route"
)
var (
errStatus = errors.New("routewatch answered")
errNoResult = errors.New("the answer holds no result")
errNotNetblock = errors.New("the answer's netblock is not a netblock")
)
// Route is what routewatch knows of an address: the netblock it is announced
// in, and the AS that originates it.
type Route struct {
Netblock netip.Prefix
ASN uint32
}
// Params are what New needs.
type Params struct {
// URL is where routewatch is (SWW_ROUTEWATCH_URL).
URL string
// Now tells the time, normally time.Now in UTC.
Now func() time.Time
// ProcessLog receives the query that fails, and why.
ProcessLog *slog.Logger
}
// Client asks a routewatch instance about clients, in the background, and keeps
// its answers. It is safe for concurrent use.
type Client struct {
params Params
httpClient *http.Client
mu sync.Mutex
// answers are by client. Each is added as it comes and never moved up,
// so that the one that came longest ago is the first dropped.
answers *simplelru.LRU[netip.Prefix, answer]
// asking are the clients whose query is under way.
asking map[netip.Prefix]bool
// retryAt is when routewatch may be asked again after a query failed.
retryAt time.Time
}
// answer is one kept answer: the route, or why there is none, and when it came.
type answer struct {
route Route
missing Missing
came time.Time
}
// New returns a Client with no answer yet.
func New(params Params) *Client {
answers, err := simplelru.NewLRU[netip.Prefix, answer](maxAnswers, nil)
if err != nil {
panic(err) // NewLRU fails only for a size below one
}
return &Client{
params: params,
httpClient: &http.Client{},
answers: answers,
asking: map[netip.Prefix]bool{},
}
}
// Route returns what routewatch answered about client, an IPv4 address or an
// IPv6 group, or why it has no route. It never waits for a query. A client
// without an answer is asked about in the background, by addr, the address its
// request came from, unless its query is under way, a query failed less than
// failureKept ago, or maxQueries are under way. ctx is the context of the
// client's request, and a query goes on after the request ends.
func (c *Client) Route(
ctx context.Context, client netip.Prefix, addr netip.Addr,
) (Route, Missing) {
c.mu.Lock()
defer c.mu.Unlock()
now := c.params.Now()
kept, found := c.answers.Peek(client)
if found && now.Sub(kept.came) < answerKept {
return kept.route, kept.missing
}
if now.Before(c.retryAt) {
return Route{}, RequestFailed
}
if !c.asking[client] && len(c.asking) < maxQueries {
c.asking[client] = true
go c.ask(context.WithoutCancel(ctx), client, addr)
}
return Route{}, NoAnswerYet
}
// ask asks routewatch about addr, keeps the answer as client's, and notes the
// query as no longer under way. A query that fails gives no answer, and
// routewatch is not asked again for failureKept. Only the first failure of
// those under way is logged.
func (c *Client) ask(ctx context.Context, client netip.Prefix, addr netip.Addr) {
route, missing, err := c.query(ctx, addr)
now := c.params.Now()
c.mu.Lock()
delete(c.asking, client)
firstFailure := err != nil && !now.Before(c.retryAt)
if err == nil {
c.answers.Add(client, answer{route: route, missing: missing, came: now})
} else {
c.retryAt = now.Add(failureKept)
}
c.mu.Unlock()
if firstFailure {
c.params.ProcessLog.Warn("asking routewatch failed", "error", err.Error())
}
}
// query asks routewatch's IP info API about addr. An answer other than 200, one
// that cannot be read, and none within queryTimeout, fail. A result with no
// netblock is an address without a live route.
func (c *Client) query(ctx context.Context, addr netip.Addr) (Route, Missing, error) {
ctx, cancel := context.WithTimeout(ctx, queryTimeout)
defer cancel()
endpoint, err := url.JoinPath(c.params.URL, "api/v1/ip", addr.String())
if err != nil {
return Route{}, "", fmt.Errorf("make the URL: %w", err)
}
req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, http.NoBody)
if err != nil {
return Route{}, "", fmt.Errorf("make the request: %w", err)
}
req.Header.Set("Accept", "application/json")
res, err := c.httpClient.Do(req)
if err != nil {
// Do's error names the URL, which holds the client's address, which
// is not to be logged: only what went wrong is kept.
return Route{}, "", fmt.Errorf("ask routewatch: %w", errors.Unwrap(err))
}
defer func() {
_ = res.Body.Close()
}()
if res.StatusCode != http.StatusOK {
return Route{}, "", fmt.Errorf("%w %s", errStatus, res.Status)
}
return readAnswer(io.LimitReader(res.Body, maxAnswerBytes))
}
// readAnswer reads routewatch's answer about one address.
func readAnswer(body io.Reader) (Route, Missing, error) {
var decoded struct {
Data struct {
Results []struct {
Netblock string `json:"netblock"`
ASN uint32 `json:"asn"`
} `json:"results"`
} `json:"data"`
}
err := json.NewDecoder(body).Decode(&decoded)
if err != nil {
return Route{}, "", fmt.Errorf("read the answer: %w", err)
}
if len(decoded.Data.Results) == 0 {
return Route{}, "", errNoResult
}
result := decoded.Data.Results[0]
if result.Netblock == "" {
return Route{}, NoRoute, nil
}
netblock, err := netip.ParsePrefix(result.Netblock)
if err != nil {
return Route{}, "", fmt.Errorf("%w: %q", errNotNetblock, result.Netblock)
}
return Route{Netblock: netblock.Masked(), ASN: result.ASN}, "", nil
}
internal/routewatch/routewatch_test.go
+333
View File
@@ -0,0 +1,333 @@
package routewatch_test
import (
"bytes"
"context"
"log/slog"
"net/http"
"net/http/httptest"
"net/netip"
"strings"
"sync"
"sync/atomic"
"testing"
"time"
"sneak.berlin/go/smallwebwaf/internal/routewatch"
)
const (
clientAddr = "192.0.2.1"
routedAnswer = `{"status":"ok","data":{"results":[` +
`{"ip":"192.0.2.1","netblock":"192.0.2.0/24","asn":64496}]}}`
noRouteAnswer = `{"status":"ok","data":{"results":[{"ip":"192.0.2.1"}]}}`
// slowAnswer is longer than routewatch allows a reverse DNS lookup.
slowAnswer = 2500 * time.Millisecond
// waitLimit is longer than the Client allows a query.
waitLimit = 10 * time.Second
)
// clock is a time the tests move by hand.
type clock struct {
mu sync.Mutex
now time.Time
}
func (c *clock) Now() time.Time {
c.mu.Lock()
defer c.mu.Unlock()
return c.now
}
func (c *clock) advance(by time.Duration) {
c.mu.Lock()
defer c.mu.Unlock()
c.now = c.now.Add(by)
}
// fixture is a Client asking a stand-in for routewatch. queries counts what the
// stand-in was asked, paths holds the last path it was asked for, and log holds
// the process log.
type fixture struct {
t *testing.T
server *httptest.Server
client *routewatch.Client
clk *clock
queries *atomic.Int32
path *atomic.Value
log *syncBuffer
}
// syncBuffer is a buffer the background queries can log to while a test reads it.
type syncBuffer struct {
mu sync.Mutex
buf bytes.Buffer
}
func (b *syncBuffer) Write(p []byte) (int, error) {
b.mu.Lock()
defer b.mu.Unlock()
return b.buf.Write(p)
}
func (b *syncBuffer) String() string {
b.mu.Lock()
defer b.mu.Unlock()
return b.buf.String()
}
func newFixture(t *testing.T, standIn http.HandlerFunc) *fixture {
t.Helper()
f := &fixture{
t: t,
clk: &clock{now: time.Date(2026, 11, 9, 0, 0, 0, 0, time.UTC)},
queries: &atomic.Int32{},
path: &atomic.Value{},
log: &syncBuffer{},
}
f.server = httptest.NewServer(http.HandlerFunc(
func(w http.ResponseWriter, r *http.Request) {
f.queries.Add(1)
f.path.Store(r.URL.Path)
standIn(w, r)
}))
t.Cleanup(f.server.Close)
f.client = routewatch.New(routewatch.Params{
URL: f.server.URL + "/", Now: f.clk.Now,
ProcessLog: slog.New(slog.NewTextHandler(f.log, nil)),
})
return f
}
func answering(body string) http.HandlerFunc {
return func(w http.ResponseWriter, _ *http.Request) {
_, _ = w.Write([]byte(body))
}
}
func (f *fixture) route() (routewatch.Route, routewatch.Missing) {
addr := netip.MustParseAddr(clientAddr)
client := netip.PrefixFrom(addr, addr.BitLen())
return f.client.Route(context.Background(), client, addr)
}
// waitFor asks until the answer is why, or, while why is "", until there is a
// route, and returns the route.
func (f *fixture) waitFor(why routewatch.Missing) routewatch.Route {
f.t.Helper()
deadline := time.Now().Add(waitLimit)
for {
route, missing := f.route()
if missing == why {
return route
}
if time.Now().After(deadline) {
f.t.Fatalf("still %q after %s, want %q", missing, waitLimit, why)
}
time.Sleep(time.Millisecond)
}
}
// wantFailureLoggedWithoutTheClient waits for the process log to name a failed
// query, and checks that it does not name the client.
func (f *fixture) wantFailureLoggedWithoutTheClient() {
f.t.Helper()
// The failure is noted before it is logged.
deadline := time.Now().Add(waitLimit)
for !strings.Contains(f.log.String(), "asking routewatch failed") {
if time.Now().After(deadline) {
f.t.Fatalf("process log %q names no failure", f.log.String())
}
time.Sleep(time.Millisecond)
}
if strings.Contains(f.log.String(), clientAddr) {
f.t.Errorf("process log %q names the client", f.log.String())
}
}
func TestRouteGivesRoutewatchsAnswerAndAsksByAddress(t *testing.T) {
t.Parallel()
f := newFixture(t, answering(routedAnswer))
if _, missing := f.route(); missing != routewatch.NoAnswerYet {
t.Errorf("before the answer: %q, want %q", missing, routewatch.NoAnswerYet)
}
route := f.waitFor("")
want := routewatch.Route{Netblock: netip.MustParsePrefix("192.0.2.0/24"), ASN: 64496}
if route != want {
t.Errorf("route %+v, want %+v", route, want)
}
if got := f.path.Load(); got != "/api/v1/ip/"+clientAddr {
t.Errorf("asked for path %v", got)
}
}
func TestAnswerAfterASlowReverseDNSLookupIsKept(t *testing.T) {
t.Parallel()
f := newFixture(t, func(w http.ResponseWriter, _ *http.Request) {
time.Sleep(slowAnswer)
_, _ = w.Write([]byte(routedAnswer))
})
f.route()
route := f.waitFor("")
want := routewatch.Route{Netblock: netip.MustParsePrefix("192.0.2.0/24"), ASN: 64496}
if route != want {
t.Errorf("route %+v, want %+v", route, want)
}
}
func TestAddressWithoutARouteIsKeptAsNoRoute(t *testing.T) {
t.Parallel()
f := newFixture(t, answering(noRouteAnswer))
f.route()
f.waitFor(routewatch.NoRoute)
if got := f.queries.Load(); got != 1 {
t.Errorf("%d queries, want 1", got)
}
}
func TestAnswerRoutewatchCannotBeTakenFromFails(t *testing.T) {
t.Parallel()
tests := map[string]http.HandlerFunc{
"500": func(w http.ResponseWriter, _ *http.Request) {
w.WriteHeader(http.StatusInternalServerError)
},
"not JSON": answering("no"),
"no results": answering(`{"status":"ok","data":{"results":[]}}`),
"bad netblock": answering(
`{"status":"ok","data":{"results":[{"netblock":"nowhere","asn":1}]}}`),
}
for name, standIn := range tests {
t.Run(name, func(t *testing.T) {
t.Parallel()
f := newFixture(t, standIn)
f.route()
f.waitFor(routewatch.RequestFailed)
f.wantFailureLoggedWithoutTheClient()
})
}
}
func TestRefusedConnectionFailsTheQueryAndTheLogOmitsTheClient(t *testing.T) {
t.Parallel()
f := newFixture(t, answering(routedAnswer))
f.server.Close()
f.route()
f.waitFor(routewatch.RequestFailed)
f.wantFailureLoggedWithoutTheClient()
}
func TestFailureIsKeptForAMinuteSoRoutewatchIsNotAskedPerRequest(t *testing.T) {
t.Parallel()
f := newFixture(t, func(w http.ResponseWriter, _ *http.Request) {
w.WriteHeader(http.StatusInternalServerError)
})
f.route()
f.waitFor(routewatch.RequestFailed)
f.route()
if got := f.queries.Load(); got != 1 {
t.Errorf("%d queries while the failure is kept, want 1", got)
}
f.clk.advance(time.Minute)
f.route()
deadline := time.Now().Add(waitLimit)
for f.queries.Load() != 2 {
if time.Now().After(deadline) {
t.Fatalf("%d queries after the failure expired, want 2", f.queries.Load())
}
time.Sleep(time.Millisecond)
}
}
func TestHangingRoutewatchNeverDelaysAndFailsTheQuery(t *testing.T) {
t.Parallel()
f := newFixture(t, func(_ http.ResponseWriter, r *http.Request) {
<-r.Context().Done()
})
start := time.Now()
f.route()
if elapsed := time.Since(start); elapsed > time.Second {
t.Errorf("Route took %s while routewatch hangs", elapsed)
}
f.waitFor(routewatch.RequestFailed)
f.wantFailureLoggedWithoutTheClient()
}
func TestRepeatedRequestsMakeOneQueryAndTheAnswerExpires(t *testing.T) {
t.Parallel()
release := make(chan struct{})
f := newFixture(t, func(w http.ResponseWriter, _ *http.Request) {
<-release
_, _ = w.Write([]byte(routedAnswer))
})
for range 50 {
f.route()
}
close(release)
f.waitFor("")
for range 50 {
f.route()
}
if got := f.queries.Load(); got != 1 {
t.Errorf("%d queries for repeated requests, want 1", got)
}
f.clk.advance(time.Hour)
f.waitFor(routewatch.NoAnswerYet)
f.waitFor("")
if got := f.queries.Load(); got != 2 {
t.Errorf("%d queries after the answer expired, want 2", got)
}
}