Rename the program to sww and its deciding daemon to discriminator (closes #218)
check / check (push) Failing after 2m47s

The program is now sww, built from cmd/sww, with two modes: sww rproxy and
sww discriminator. servewaf becomes discriminator everywhere it names that
daemon: the package (internal/discriminator), its types, functions, files, the
discriminator_line log field, and its docs and tests.

smallwebwaf is left only where sneak's directive allows it: the documents'
product name, the git.eeqj.de/sneak/smallwebwaf URLs, and the Go module path
sneak.berlin/go/smallwebwaf. Everywhere else a name containing it takes the sww
form: the package (internal/sww), metric names (sww_*), the X-Sww-* headers,
the /_sww/ admin endpoints, the OS user, and the state and rules directories.
The SWWAF_ environment variables take the SWW_ form.

No logic changes. make check passes.

Model: deepseek-v4-pro
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sneak committed 2026-11-07 05:27:58 +00:00
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@@ -7,20 +7,20 @@ requests of scrapers, scanners and other abusers before they reach an app.
## What it does
A web application firewall reads each request on its way to a web app and
refuses the ones that look like abuse. `smallwebwaf` is one binary, shipped in
one image, with two commands that do this together:
refuses the ones that look like abuse. `smallwebwaf` is one program, `sww`,
shipped in one image, with two commands that do this together:
- `smallwebwaf rproxy` is a small reverse proxy in front of one app. traefik
routes to it. It asks `servewaf` about each request, passes the allowed ones
to the app, and passes the app's answers back. It keeps nothing and never
touches disk.
- `smallwebwaf servewaf` decides. It runs the checks and keeps the bans, the
counters and each client's history. One `servewaf` serves many sites: a client
banned through one site is refused on all of them, and its requests on all of
them count toward one set of limits.
- `sww rproxy` is a small reverse proxy in front of one app. traefik routes to
it. It asks `discriminator` about each request, passes the allowed ones to the
app, and passes the app's answers back. It keeps nothing and never touches
disk.
- `sww discriminator` decides. It runs the checks and keeps the bans, the
counters and each client's history. One `discriminator` serves many sites: a
client banned through one site is refused on all of them, and its requests on
all of them count toward one set of limits.
The site keeps answering while `servewaf` is down, slow or restarting: without
an answer in time, `rproxy` passes the request to the app.
The site keeps answering while `discriminator` is down, slow or restarting:
without an answer in time, `rproxy` passes the request to the app.
It protects against:
@@ -79,11 +79,11 @@ make docker
Push the image to a registry your hosts pull from, and name it there by digest.
The image runs `rproxy` by default. To run `servewaf` from the same image, set
the container's `SMALLWEBWAF_COMMAND` to `servewaf`. The image's health check
The image runs `rproxy` by default. To run `discriminator` from the same image,
set the container's `SWW_COMMAND` to `discriminator`. The image's health check
follows the command: in `rproxy`'s container it passes once `rproxy` answers and
the app accepts connections, whether or not `servewaf` answers; in `servewaf`'s
container, once `servewaf` answers.
the app accepts connections, whether or not `discriminator` answers; in
`discriminator`'s container, once `discriminator` answers.
### The usual setup: three containers
@@ -91,24 +91,24 @@ The usual setup is three containers on one private network:
- the app;
- `rproxy`, in front of the app, which traefik routes to: `SWRP_WAF_BACKEND`
names `servewaf` and `SWRP_UPSTREAM_URL` names the app;
- `servewaf`, with `SMALLWEBWAF_COMMAND=servewaf` and a volume at
`/var/lib/smallwebwaf` for its state files.
names `discriminator` and `SWRP_UPSTREAM_URL` names the app;
- `discriminator`, with `SWW_COMMAND=discriminator` and a volume at
`/var/lib/sww` for its state files.
Point traefik's labels at port 8080 of `rproxy`
(`traefik.http.services.<name>.loadbalancer.server.port=8080`). Publish no port
of the app or of `servewaf`. Anything on that network can reach the app around
`rproxy`, and can ask `servewaf` questions, so the network holds only what you
trust. Each further app adds its own container and its own `rproxy`, whose
`SWRP_WAF_BACKEND` names the same `servewaf`. The "Smallest setup" example below
shows this shape.
of the app or of `discriminator`. Anything on that network can reach the app
around `rproxy`, and can ask `discriminator` questions, so the network holds
only what you trust. Each further app adds its own container and its own
`rproxy`, whose `SWRP_WAF_BACKEND` names the same `discriminator`. The "Smallest
setup" example below shows this shape.
### `rproxy` in the app's container
An app's image can instead be built on the `smallwebwaf` image, so that `rproxy`
runs beside the app in one container. `servewaf` still runs in a container of
its own. The app's `Dockerfile` starts `FROM` the `smallwebwaf` image, named by
digest, and adds:
runs beside the app in one container. `discriminator` still runs in a container
of its own. The app's `Dockerfile` starts `FROM` the `smallwebwaf` image, named
by digest, and adds:
- the app's binary;
- the packages the app needs, from the nixpkgs in the image;
@@ -168,16 +168,16 @@ does.
- A log line with `"msg":"starting"` gives the version, the address and every
setting in effect, with secrets masked.
- A request to the site through traefik gets the app's answer.
`https://<site>/_smallwebwaf/healthz` answers `ok`. `servewaf`'s log lines
about the request have `"action":"forward"`.
- To see a refusal without banning yourself, run `servewaf` with
`SWWAF_MODE=observe` and ask for `/.env`. The request reaches the app.
`servewaf`'s log lines have `"would_action":"banned"` and
`https://<site>/_sww/healthz` answers `ok`. `discriminator`'s log lines about
the request have `"action":"forward"`.
- To see a refusal without banning yourself, run `discriminator` with
`SWW_MODE=observe` and ask for `/.env`. The request reaches the app.
`discriminator`'s log lines have `"would_action":"banned"` and
`"rule_ids":["env-file"]`. A ban you get in `enforce` mode is lifted as
"Clients and bans" below describes.
- With `SWWAF_METRICS_TOKEN` set, this answers with the metrics, from a host on
`servewaf`'s network:
`curl -H "Authorization: Bearer $TOKEN" http://servewaf:8080/_smallwebwaf/metrics`.
- With `SWW_METRICS_TOKEN` set, this answers with the metrics, from a host on
`discriminator`'s network:
`curl -H "Authorization: Bearer $TOKEN" http://discriminator:8080/_sww/metrics`.
- `make example-app` builds the image and an app on it, runs them, and checks
the whole exchange (see "Entrypoints").
@@ -185,16 +185,17 @@ does.
Every setting is an environment variable, read once at start; changing one means
restarting the container. `rproxy` reads only the `SWRP_` settings, and
`servewaf` only the `SWWAF_` ones. Every setting but `SWRP_WAF_BACKEND` has a
`discriminator` only the `SWW_` ones. Every setting but `SWRP_WAF_BACKEND` has a
default, chosen for a service on the open internet. A setting that needs an
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.
- Any `SWW_` setting can be given as a file instead, for secrets and long lists:
`SWW_ADMIN_TOKEN_FILE` names the file that holds `SWW_ADMIN_TOKEN`. The file's
contents are the value, less one newline at the end. Setting both forms stops
the start. `SWW_LOG_REMOTE_TLS_CA_FILE` and
`SWW_CORE_RULE_SET_EXCLUSIONS_FILE` already name a file, so they have no
`_FILE` form. `SWW_COMMAND` cannot be given as a file. 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`.
@@ -214,122 +215,122 @@ 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 |
| ------------------------------------------ | ------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `SMALLWEBWAF_COMMAND` | `rproxy` | Which command the image runs, and its health check checks: `rproxy` or `servewaf`. |
| `SWRP_WAF_BACKEND` | required | `servewaf`'s URL, such as `http://servewaf:8080`. |
| `SWRP_UPSTREAM_URL` | `http://127.0.0.1:8081` | The app's URL: a scheme, a host and an optional port, nothing more. |
| `SWRP_LISTEN_ADDR` | `:8080` | Where `rproxy` listens; leave the host part empty. |
| `SWRP_TRUSTED_PROXIES` | `10.0.0.0/8,172.16.0.0/12,192.168.0.0/16` | The netblocks whose `X-Forwarded-For` `rproxy` believes; set but empty, it believes none. |
| `SWRP_TIMEOUT_MS` | `2000` | How long `rproxy` waits for `servewaf`'s answer to a question and to a report, in milliseconds. |
| `SWRP_DEFAULT_DISPOSITION` | `allow` | What `rproxy` does with a request when `servewaf` 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_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`. |
| `SWWAF_LISTEN_ADDR` | `:8080` | Where `servewaf` listens; leave the host part empty. |
| `SWWAF_INSTANCE_NAME` | the container's host name | The name in every line `servewaf` logs, and in every alert and metric, such as `fsn1/servewaf`. |
| `SWWAF_MODE` | `enforce` | `observe` refuses nothing and makes no ban; each log line says what `enforce` would have done. |
| `SWWAF_IPV6_GROUP_PREFIX` | `64` | The prefix length of the IPv6 netblock that counts as one client, from 32 to 128. |
| `SWWAF_MAX_TRACKED_CLIENTS` | `20000` | The most clients kept, in memory and in `clients.json`; the least recently seen is dropped first. |
| `SWWAF_MAX_BANS` | `5000` | The most bans `servewaf` keeps of its own; bans an admin made do not count. |
| `SWWAF_ALLOW_NETS` | empty | Netblocks whose clients skip every check, such as your monitoring. |
| `SWWAF_RATE_LIMIT_EXEMPT_NETS` | empty | Netblocks whose clients the request and byte limits neither count nor refuse. |
| `SWWAF_DENY_NETS` | empty | Netblocks whose clients are refused. |
| `SWWAF_RATE_LIMIT_PER_MINUTE` | `120` | The most requests a client may make in a minute, a count or `off`; one more bans it. |
| `SWWAF_RATE_LIMIT_PER_HOUR` | `1500` | The most requests a client may make in an hour, a count or `off`; one more bans it. |
| `SWWAF_RATE_LIMIT_PER_DAY` | `6000` | The most requests a client may make in a day, a count or `off`; one more bans it. |
| `SWWAF_RATE_LIMIT_EXEMPT_PATHS` | empty | Path prefixes whose requests the request and byte limits neither count nor refuse, such as `/assets/`. |
| `SWWAF_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. |
| `SWWAF_BYTES_LIMIT_PER_HOUR` | `50G` | The most bytes a client's requests may carry in an hour, a size or `off`. |
| `SWWAF_BYTES_LIMIT_PER_DAY` | `100G` | The most bytes a client's requests may carry in a day, a size or `off`. |
| `SWWAF_BYTES_COUNT` | `both` | Which body bytes the byte limits count: `response`, `request` or `both`. |
| `SWWAF_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. |
| `SWWAF_BAN_RESPONSE` | `403` | How a refused client is answered: `403`, `429` or `close`, which drops the connection. |
| `SWWAF_LIMIT_BAN_DURATION` | `1h` | The ban for a first broken limit. |
| `SWWAF_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. |
| `SWWAF_MAX_BAN_DURATION` | `7d` | A ban for a broken limit that would be longer than this is permanent instead. |
| `SWWAF_ATTACK_BAN_DURATION` | `7d` | The ban for a first clear sign of attack: a `ban` rule or a trap path. |
| `SWWAF_BAN_SCOPE_V4_PREFIX` | `32` | The prefix length of the netblock a ban on an IPv4 client covers, from 0 to 32. |
| `SWWAF_LOOKUP_SOURCE` | `geojs` | Where each client's AS number and country come from: `geojs`, a web service, `file`, or `off`. |
| `SWWAF_LOOKUP_DB_PATH` | empty | The IPinfo Lite database file, in its `.mmdb` form, read while the source is `file`. |
| `SWWAF_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. |
| `SWWAF_ADD_LOOKUP_HEADERS` | `false` | `true` passes the app the client's AS number and country in `X-Client-ASN` and `X-Client-Country`. |
| `SWWAF_DENIED_COUNTRIES` | empty | Countries whose clients are refused, such as `cn,ru`. |
| `SWWAF_EXCLUSIVELY_ALLOWED_COUNTRIES` | empty | When set, the only countries whose clients get through; a client the lookup cannot place is refused too. |
| `SWWAF_ASN_LIMIT_PERCENT` | empty | AS numbers whose clients get a percentage of every request and byte limit, such as `AS14061:50,AS16276:25`. |
| `SWWAF_COUNTRY_LIMIT_PERCENT` | empty | The same by country, such as `cn:25`. |
| `SWWAF_ASN_BYTES_PERCENT` | empty | A percentage of the byte limits alone for the AS numbers listed, in place of their `SWWAF_ASN_LIMIT_PERCENT`. |
| `SWWAF_COUNTRY_BYTES_PERCENT` | empty | A percentage of the byte limits alone for the countries listed, in place of their `SWWAF_COUNTRY_LIMIT_PERCENT`. |
| `SWWAF_UNKNOWN_LIMIT_PERCENT` | `100` | The percentage of every limit a client without a country gets. |
| `SWWAF_ASN_LIMIT_PERCENT_URL` | unset | The URL of a text file of `AS<number>:<percent>` lines, fetched like a blocklist; where it and `SWWAF_ASN_LIMIT_PERCENT` both give a percentage, the lower applies. |
| `SWWAF_RULES_DIR` | `/etc/smallwebwaf/rules.d` | The directory of the rule files, read at start and again when a file there changes. |
| `SWWAF_RULES_ENABLED` | `true` | `false` reads no rule file. |
| `SWWAF_TRAP_PATHS` | empty | Paths only scanners ask for, such as `/wp-login.php,/xmlrpc.php`; a request for one bans the client. |
| `SWWAF_WAF_MODE` | `block` | What the Core Rule Set does with a match: `block` refuses it with `403`, `detect` only logs and alerts it, `off` runs no rule. |
| `SWWAF_WAF_PARANOIA_LEVEL` | `1` | The Core Rule Set's paranoia level, from 1 to 4; each level up finds more attacks and takes more ordinary requests for attacks. |
| `SWWAF_WAF_ANOMALY_THRESHOLD` | `5` | The Core Rule Set score at which a request is a match, a whole number or `off`; one critical rule scores 5. |
| `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. |
| `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`. |
| `SWWAF_DNSBL_ZONES` | empty | DNS blocklists asked about each new client in the background, such as `dnsbl.dronebl.org`. |
| `SWWAF_DNSBL_RESOLVER` | unset | The resolver the zones are asked through, an IP address with an optional port; unset, the host's resolver is used. |
| `SWWAF_ABUSEIPDB_KEY` | unset | The key of your AbuseIPDB account; set, a client that has committed an offence is checked in the background. |
| `SWWAF_ABUSEIPDB_MIN_SCORE` | `75` | The least AbuseIPDB abuse confidence score, from 0 to 100, that is a hit. |
| `SWWAF_ABUSEIPDB_DAILY_BUDGET` | `900` | The most AbuseIPDB checks made in a day. |
| `SWWAF_CROWDSEC_LAPI_URL` | unset | The local API of a CrowdSec engine you run, such as `http://172.17.0.1:8080`; its decision list is fetched every minute, and a listed client is banned. |
| `SWWAF_CROWDSEC_LAPI_KEY` | unset | The key the engine gave for `smallwebwaf`, as `cscli bouncers add smallwebwaf` prints it; set with the URL, never alone. |
| `SWWAF_REPUTATION_ACTION` | `limit:25` | What a client listed by a DNS blocklist, or scored a hit by AbuseIPDB, gets: `deny`, `limit:<percent>` or `log`. |
| `SWWAF_REPUTATION_CACHE_TTL` | `24h` | How long a DNS blocklist verdict or an AbuseIPDB score is used. |
| `SWWAF_REPUTATION_TIMEOUT` | `2s` | How long a DNS blocklist query or an AbuseIPDB check may take. |
| `SWWAF_STATE_DIR` | `/var/lib/smallwebwaf` | The directory of the state files, an absolute path. |
| `SWWAF_STATE_WRITE_DELAY` | `10s` | How long `bans.json` waits to be written after a ban is made, lifted or made permanent. |
| `SWWAF_STATE_COUNTER_INTERVAL` | `15m` | How often every state file is written. |
| `SWWAF_LOG_LEVEL` | `info` | The least severe of `servewaf`'s own messages that are written: `debug`, `info`, `warn` or `error`; request lines are always written. |
| `SWWAF_LOG_REQUEST_HEADERS` | `accept,accept-language,accept-encoding,content-type,origin,range` | The request headers whose values the request log records; `Authorization` and `Cookie` are never recorded. |
| `SWWAF_LOG_REMOTE_URL` | unset | A syslog server that also gets every line `servewaf` writes: `syslog+udp://`, `syslog+tcp://` or `syslog+tls://` with a host and a port. |
| `SWWAF_LOG_REMOTE_TLS_CA_FILE` | unset | A file of PEM certificates a `syslog+tls` server's certificate must chain to, instead of the host's own. |
| `SWWAF_LOG_REMOTE_BUFFER` | `10000` | The most lines held while they wait to be sent; past it, the oldest is dropped. |
| `SWWAF_LOG_REMOTE_FACILITY` | `local0` | The syslog facility of each record sent. |
| `SWWAF_LOG_REMOTE_APP_NAME` | `SWWAF_INSTANCE_NAME` | The app name in each syslog record, 1 to 48 printable ASCII characters without a space. |
| `SWWAF_ADMIN_TOKEN` | unset | The bearer token for the ban and client endpoints, at least 32 characters; unset, they answer `404`. |
| `SWWAF_METRICS_TOKEN` | unset | The bearer token for `/_smallwebwaf/metrics`, at least 32 characters; unset, the metrics are off. |
| `SWWAF_METRICS_TOP_N` | `50` | How many AS numbers and how many countries get metric series of their own; the rest are summed as `other`. |
| `SWWAF_ALERT_WEBHOOK_URL` | unset | A webhook each alert is posted to as a JSON object. |
| `SWWAF_ALERT_WEBHOOK_HEADERS` | empty | Headers sent with each post, a list of `Name:value`, such as `Authorization:Bearer <token>`. |
| `SWWAF_ALERT_SLACK_WEBHOOK_URL` | unset | A Slack incoming webhook each alert is posted to as a message. |
| `SWWAF_ALERT_NTFY_URL` | unset | An ntfy topic each alert is published to, as its full URL, such as `https://ntfy.sh/my-alerts`. |
| `SWWAF_ALERT_NTFY_TOKEN` | unset | An ntfy access token sent with each alert. |
| `SWWAF_ALERT_EVENTS` | `ban,permanent_ban,waf_block,anomaly,reputation_hit,source_failure,file_error` | The events alerts are sent for; the hourly `summary` is sent whatever it says. |
| `SWWAF_ALERT_COOLDOWN` | `15m` | How long after an alert its repeats are held back and counted, a duration or `off`. |
| `SWWAF_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`. |
| `SWWAF_ANOMALY_CLIENT_REQUESTS_PER_MINUTE` | `off` | Alert when one client makes more requests than this in a minute, a count. |
| `SWWAF_ANOMALY_CLIENT_REQUESTS_PER_HOUR` | `off` | Alert when one client makes more requests than this in an hour, a count. |
| `SWWAF_ANOMALY_CLIENT_BYTES_PER_MINUTE` | `off` | Alert when one client's requests carry more bytes than this in a minute, a size. |
| `SWWAF_ANOMALY_CLIENT_BYTES_PER_HOUR` | `off` | Alert when one client's requests carry more bytes than this in an hour, a size. |
| `SWWAF_ANOMALY_NET_REQUESTS_PER_MINUTE` | `off` | Alert when the netblock around a client makes more requests than this in a minute, a count. |
| `SWWAF_ANOMALY_NET_REQUESTS_PER_HOUR` | `off` | Alert when the netblock around a client makes more requests than this in an hour, a count. |
| `SWWAF_ANOMALY_NET_BYTES_PER_MINUTE` | `off` | Alert when the netblock around a client carries more bytes than this in a minute, a size. |
| `SWWAF_ANOMALY_NET_BYTES_PER_HOUR` | `off` | Alert when the netblock around a client carries more bytes than this in an hour, a size. |
| `SWWAF_ANOMALY_NET_V4_PREFIX` | `24` | The prefix length of the netblock around an IPv4 client that the `SWWAF_ANOMALY_NET_` thresholds count, from 0 to 32. |
| `SWWAF_ANOMALY_NET_V6_PREFIX` | `48` | The prefix length of the netblock around an IPv6 client that the `SWWAF_ANOMALY_NET_` thresholds count, from 0 to 128. |
| `SWWAF_ANOMALY_ASN_REQUESTS_PER_MINUTE` | `off` | Alert when one AS number makes more requests than this in a minute, a count. |
| `SWWAF_ANOMALY_ASN_REQUESTS_PER_HOUR` | `off` | Alert when one AS number makes more requests than this in an hour, a count. |
| `SWWAF_ANOMALY_ASN_BYTES_PER_MINUTE` | `off` | Alert when one AS number carries more bytes than this in a minute, a size. |
| `SWWAF_ANOMALY_ASN_BYTES_PER_HOUR` | `off` | Alert when one AS number carries more bytes than this in an hour, a size. |
| `SWWAF_ANOMALY_TOTAL_REQUESTS_PER_MINUTE` | `off` | Alert when the whole service gets more requests than this in a minute, a count. |
| `SWWAF_ANOMALY_TOTAL_REQUESTS_PER_HOUR` | `off` | Alert when the whole service gets more requests than this in an hour, a count. |
| `SWWAF_ANOMALY_TOTAL_BYTES_PER_MINUTE` | `off` | Alert when the whole service carries more bytes than this in a minute, a size. |
| `SWWAF_ANOMALY_TOTAL_BYTES_PER_HOUR` | `off` | Alert when the whole service carries more bytes than this in an hour, a size. |
| `SWWAF_WATCH_NETS` | empty | Named netblocks the `SWWAF_WATCH_` thresholds count each as a whole, such as `office=203.0.113.0/24,scraper-x=198.51.100.0/22`. |
| `SWWAF_WATCH_REQUESTS_PER_MINUTE` | `off` | Alert when a watched netblock makes more requests than this in a minute, a count. |
| `SWWAF_WATCH_REQUESTS_PER_HOUR` | `off` | Alert when a watched netblock makes more requests than this in an hour, a count. |
| `SWWAF_WATCH_BYTES_PER_MINUTE` | `off` | Alert when a watched netblock carries more bytes than this in a minute, a size. |
| `SWWAF_WATCH_BYTES_PER_HOUR` | `off` | Alert when a watched netblock carries more bytes than this in an hour, a size. |
| 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. |
| `SWRP_LISTEN_ADDR` | `:8080` | Where `rproxy` listens; leave the host part empty. |
| `SWRP_TRUSTED_PROXIES` | `10.0.0.0/8,172.16.0.0/12,192.168.0.0/16` | The netblocks whose `X-Forwarded-For` `rproxy` believes; set but empty, it believes none. |
| `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_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`. |
| `SWW_MODE` | `enforce` | `observe` refuses nothing and makes no ban; each log line says what `enforce` would have done. |
| `SWW_IPV6_GROUP_PREFIX` | `64` | The prefix length of the IPv6 netblock that counts as one client, from 32 to 128. |
| `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_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_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_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_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`. |
| `SWW_DENIED_COUNTRIES` | empty | Countries whose clients are refused, such as `cn,ru`. |
| `SWW_EXCLUSIVELY_ALLOWED_COUNTRIES` | empty | When set, the only countries whose clients get through; a client the lookup cannot place is refused too. |
| `SWW_ASN_LIMIT_PERCENT` | empty | AS numbers whose clients get a percentage of every request and byte limit, such as `AS14061:50,AS16276:25`. |
| `SWW_COUNTRY_LIMIT_PERCENT` | empty | The same by country, such as `cn:25`. |
| `SWW_ASN_BYTES_PERCENT` | empty | A percentage of the byte limits alone for the AS numbers listed, in place of their `SWW_ASN_LIMIT_PERCENT`. |
| `SWW_COUNTRY_BYTES_PERCENT` | empty | A percentage of the byte limits alone for the countries listed, in place of their `SWW_COUNTRY_LIMIT_PERCENT`. |
| `SWW_UNKNOWN_LIMIT_PERCENT` | `100` | The percentage of every limit a client without a country gets. |
| `SWW_ASN_LIMIT_PERCENT_URL` | unset | The URL of a text file of `AS<number>:<percent>` lines, fetched like a blocklist; where it and `SWW_ASN_LIMIT_PERCENT` both give a percentage, the lower applies. |
| `SWW_RULES_DIR` | `/etc/sww/rules.d` | The directory of the rule files, read at start and again when a file there changes. |
| `SWW_RULES_ENABLED` | `true` | `false` reads no rule file. |
| `SWW_TRAP_PATHS` | empty | Paths only scanners ask for, such as `/wp-login.php,/xmlrpc.php`; a request for one bans the client. |
| `SWW_WAF_MODE` | `block` | What the Core Rule Set does with a match: `block` refuses it with `403`, `detect` only logs and alerts it, `off` runs no rule. |
| `SWW_WAF_PARANOIA_LEVEL` | `1` | The Core Rule Set's paranoia level, from 1 to 4; each level up finds more attacks and takes more ordinary requests for attacks. |
| `SWW_WAF_ANOMALY_THRESHOLD` | `5` | The Core Rule Set score at which a request is a match, a whole number or `off`; one critical rule scores 5. |
| `SWW_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. |
| `SWW_WAF_EXEMPT_PATHS` | empty | Path prefixes the Core Rule Set does not inspect. |
| `SWW_WAF_BODY_LIMIT` | `off` | How much of a request body the Core Rule Set reads, a size up to `64K`; `off` reads none. |
| `SWW_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. |
| `SWW_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`. |
| `SWW_BLOCKLIST_REFRESH` | `24h` | How long after a list was last tried it is fetched again, `1h` or more. |
| `SWW_BLOCKLIST_ACTION` | `deny` | What a client on a blocklist gets: `deny`, `limit:<percent>` of every limit, or `log`. |
| `SWW_DNSBL_ZONES` | empty | DNS blocklists asked about each new client in the background, such as `dnsbl.dronebl.org`. |
| `SWW_DNSBL_RESOLVER` | unset | The resolver the zones are asked through, an IP address with an optional port; unset, the host's resolver is used. |
| `SWW_ABUSEIPDB_KEY` | unset | The key of your AbuseIPDB account; set, a client that has committed an offence is checked in the background. |
| `SWW_ABUSEIPDB_MIN_SCORE` | `75` | The least AbuseIPDB abuse confidence score, from 0 to 100, that is a hit. |
| `SWW_ABUSEIPDB_DAILY_BUDGET` | `900` | The most AbuseIPDB checks made in a day. |
| `SWW_CROWDSEC_LAPI_URL` | unset | The local API of a CrowdSec engine you run, such as `http://172.17.0.1:8080`; its decision list is fetched every minute, and a listed client is banned. |
| `SWW_CROWDSEC_LAPI_KEY` | unset | The key the engine gave for `smallwebwaf`, as `cscli bouncers add smallwebwaf` prints it; set with the URL, never alone. |
| `SWW_REPUTATION_ACTION` | `limit:25` | What a client listed by a DNS blocklist, or scored a hit by AbuseIPDB, gets: `deny`, `limit:<percent>` or `log`. |
| `SWW_REPUTATION_CACHE_TTL` | `24h` | How long a DNS blocklist verdict or an AbuseIPDB score is used. |
| `SWW_REPUTATION_TIMEOUT` | `2s` | How long a DNS blocklist query or an AbuseIPDB check may take. |
| `SWW_STATE_DIR` | `/var/lib/sww` | The directory of the state files, an absolute path. |
| `SWW_STATE_WRITE_DELAY` | `10s` | How long `bans.json` waits to be written after a ban is made, lifted or made permanent. |
| `SWW_STATE_COUNTER_INTERVAL` | `15m` | How often every state file is written. |
| `SWW_LOG_LEVEL` | `info` | The least severe of `discriminator`'s own messages that are written: `debug`, `info`, `warn` or `error`; request lines are always written. |
| `SWW_LOG_REQUEST_HEADERS` | `accept,accept-language,accept-encoding,content-type,origin,range` | The request headers whose values the request log records; `Authorization` and `Cookie` are never recorded. |
| `SWW_LOG_REMOTE_URL` | unset | A syslog server that also gets every line `discriminator` writes: `syslog+udp://`, `syslog+tcp://` or `syslog+tls://` with a host and a port. |
| `SWW_LOG_REMOTE_TLS_CA_FILE` | unset | A file of PEM certificates a `syslog+tls` server's certificate must chain to, instead of the host's own. |
| `SWW_LOG_REMOTE_BUFFER` | `10000` | The most lines held while they wait to be sent; past it, the oldest is dropped. |
| `SWW_LOG_REMOTE_FACILITY` | `local0` | The syslog facility of each record sent. |
| `SWW_LOG_REMOTE_APP_NAME` | `SWW_INSTANCE_NAME` | The app name in each syslog record, 1 to 48 printable ASCII characters without a space. |
| `SWW_ADMIN_TOKEN` | unset | The bearer token for the ban and client endpoints, at least 32 characters; unset, they answer `404`. |
| `SWW_METRICS_TOKEN` | unset | The bearer token for `/_sww/metrics`, at least 32 characters; unset, the metrics are off. |
| `SWW_METRICS_TOP_N` | `50` | How many AS numbers and how many countries get metric series of their own; the rest are summed as `other`. |
| `SWW_ALERT_WEBHOOK_URL` | unset | A webhook each alert is posted to as a JSON object. |
| `SWW_ALERT_WEBHOOK_HEADERS` | empty | Headers sent with each post, a list of `Name:value`, such as `Authorization:Bearer <token>`. |
| `SWW_ALERT_SLACK_WEBHOOK_URL` | unset | A Slack incoming webhook each alert is posted to as a message. |
| `SWW_ALERT_NTFY_URL` | unset | An ntfy topic each alert is published to, as its full URL, such as `https://ntfy.sh/my-alerts`. |
| `SWW_ALERT_NTFY_TOKEN` | unset | An ntfy access token sent with each alert. |
| `SWW_ALERT_EVENTS` | `ban,permanent_ban,waf_block,anomaly,reputation_hit,source_failure,file_error` | The events alerts are sent for; the hourly `summary` is sent whatever it says. |
| `SWW_ALERT_COOLDOWN` | `15m` | How long after an alert its repeats are held back and counted, a duration or `off`. |
| `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_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_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_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_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. |
[`docs/settings.md`](docs/settings.md) gives the values each setting takes in
full, and the limits that are fixed rather than settings.
@@ -344,8 +345,8 @@ own, where each reaches the others by service name. Each example publishes
### Smallest setup
One app, `rproxy` in front of it, and `servewaf` with a volume for its state
files, every setting at its default.
One app, `rproxy` in front of it, and `discriminator` with a volume for its
state files, every setting at its default.
```yaml
services:
@@ -356,20 +357,20 @@ services:
rproxy:
image: smallwebwaf
environment:
SWRP_WAF_BACKEND: http://servewaf:8080
SWRP_WAF_BACKEND: http://discriminator:8080
SWRP_UPSTREAM_URL: http://app:8081
ports:
- "8080:8080"
servewaf:
discriminator:
image: smallwebwaf
environment:
SMALLWEBWAF_COMMAND: servewaf
SWW_COMMAND: discriminator
volumes:
- servewaf-state:/var/lib/smallwebwaf
- discriminator-state:/var/lib/sww
volumes:
servewaf-state:
discriminator-state:
```
### Custom per-address limits
@@ -392,46 +393,46 @@ services:
rproxy:
image: smallwebwaf
environment:
SWRP_WAF_BACKEND: http://servewaf:8080
SWRP_WAF_BACKEND: http://discriminator:8080
SWRP_UPSTREAM_URL: http://app:8081
ports:
- "8080:8080"
servewaf:
discriminator:
image: smallwebwaf
environment:
SMALLWEBWAF_COMMAND: servewaf
SWW_COMMAND: discriminator
# Monitoring skips every check.
SWWAF_ALLOW_NETS: 192.0.2.10
SWW_ALLOW_NETS: 192.0.2.10
# The office and the automation host are never rate limited.
SWWAF_RATE_LIMIT_EXEMPT_NETS: 203.0.113.0/24,198.51.100.7
SWW_RATE_LIMIT_EXEMPT_NETS: 203.0.113.0/24,198.51.100.7
# A netblock that sends nothing wanted.
SWWAF_DENY_NETS: 198.51.100.128/25
SWW_DENY_NETS: 198.51.100.128/25
# Tighter limits for everyone else: a small static site.
SWWAF_RATE_LIMIT_PER_MINUTE: "60"
SWWAF_RATE_LIMIT_PER_HOUR: "600"
SWWAF_RATE_LIMIT_PER_DAY: "3000"
SWW_RATE_LIMIT_PER_MINUTE: "60"
SWW_RATE_LIMIT_PER_HOUR: "600"
SWW_RATE_LIMIT_PER_DAY: "3000"
# Hosting networks and one country get a share of those limits.
SWWAF_ASN_LIMIT_PERCENT: AS14061:50,AS16276:25
SWWAF_COUNTRY_LIMIT_PERCENT: cn:25
SWW_ASN_LIMIT_PERCENT: AS14061:50,AS16276:25
SWW_COUNTRY_LIMIT_PERCENT: cn:25
# Paths only scanners ask for; one request bans the client.
SWWAF_TRAP_PATHS: /wp-login.php,/xmlrpc.php
SWW_TRAP_PATHS: /wp-login.php,/xmlrpc.php
# Answer a refused client with 429 rather than 403.
SWWAF_BAN_RESPONSE: "429"
SWWAF_LIMIT_BAN_DURATION: 30m
SWW_BAN_RESPONSE: "429"
SWW_LIMIT_BAN_DURATION: 30m
volumes:
- servewaf-state:/var/lib/smallwebwaf
- discriminator-state:/var/lib/sww
volumes:
servewaf-state:
discriminator-state:
```
### `rproxy` beside the app
The app is built on the `smallwebwaf` image, with `rproxy` inside its container.
`app/` holds the `Dockerfile` and `app.run` from "`rproxy` in the app's
container". `rproxy` answers `503` to every request while `servewaf` is down,
and `servewaf`:
container". `rproxy` answers `503` to every request while `discriminator` is
down, and `discriminator`:
- observes before it enforces;
- looks addresses up in a local database rather than GeoJS;
@@ -444,46 +445,46 @@ services:
# A Dockerfile built FROM the smallwebwaf image, with rproxy inside.
build: ./app
environment:
SWRP_WAF_BACKEND: http://servewaf:8080
# Answer 503 rather than pass a request on while servewaf is down.
SWRP_WAF_BACKEND: http://discriminator:8080
# Answer 503 rather than pass a request on while discriminator is down.
SWRP_DEFAULT_DISPOSITION: deny
ports:
- "8080:8080"
servewaf:
discriminator:
image: smallwebwaf
environment:
SMALLWEBWAF_COMMAND: servewaf
SWWAF_INSTANCE_NAME: fsn1/servewaf
SWW_COMMAND: discriminator
SWW_INSTANCE_NAME: fsn1/discriminator
# Refuse nothing yet; log what enforce mode would have done.
SWWAF_MODE: observe
SWW_MODE: observe
# Look addresses up in a local IPinfo Lite database, never GeoJS.
SWWAF_LOOKUP_SOURCE: file
SWWAF_LOOKUP_DB_PATH: /var/lib/ipinfo/ipinfo_lite.mmdb
SWW_LOOKUP_SOURCE: file
SWW_LOOKUP_DB_PATH: /var/lib/ipinfo/ipinfo_lite.mmdb
# Alerts to an ntfy topic, with its token read from a file.
SWWAF_ALERT_NTFY_URL: https://ntfy.example/smallwebwaf
SWWAF_ALERT_NTFY_TOKEN_FILE: /etc/smallwebwaf/tokens/ntfy
SWWAF_ALERT_EVENTS: ban,permanent_ban,waf_block,source_failure,file_error
SWW_ALERT_NTFY_URL: https://ntfy.example/smallwebwaf
SWW_ALERT_NTFY_TOKEN_FILE: /etc/sww/tokens/ntfy
SWW_ALERT_EVENTS: ban,permanent_ban,waf_block,source_failure,file_error
volumes:
- servewaf-state:/var/lib/smallwebwaf
- discriminator-state:/var/lib/sww
- /srv/ipinfo:/var/lib/ipinfo:ro
- /srv/smallwebwaf/tokens:/etc/smallwebwaf/tokens:ro
- /srv/sww/tokens:/etc/sww/tokens:ro
volumes:
servewaf-state:
discriminator-state:
```
The database is mounted by its directory, not by file, so that a replaced
database is seen. A token file belongs to uid 65532, the `smallwebwaf` user,
with mode `0400`. This one holds an access token the ntfy server issued, which
database is seen. A token file belongs to uid 65532, the `sww` user, with mode
`0400`. This one holds an access token the ntfy server issued, which
`ntfy token add <user>` prints there:
```sh
mkdir -p /srv/smallwebwaf/tokens
mkdir -p /srv/sww/tokens
# <token> is the access token that ntfy printed.
echo '<token>' > /srv/smallwebwaf/tokens/ntfy
chown 65532:65532 /srv/smallwebwaf/tokens/ntfy
chmod 0400 /srv/smallwebwaf/tokens/ntfy
echo '<token>' > /srv/sww/tokens/ntfy
chown 65532:65532 /srv/sww/tokens/ntfy
chmod 0400 /srv/sww/tokens/ntfy
```
## Design
@@ -492,20 +493,20 @@ How it works inside. [`SPEC.md`](SPEC.md) gives every rule in full, and why.
### What happens to a request
A request goes through these steps, in this order. Once `servewaf` refuses a
request, the steps after that are skipped, apart from the report, and nothing of
the request reaches the app.
A request goes through these steps, in this order. Once `discriminator` refuses
a request, the steps after that are skipped, apart from the report, and nothing
of the request reaches the app.
`rproxy` takes the first two:
1. The health check, `GET /_smallwebwaf/healthz`, is answered at once.
1. The health check, `GET /_sww/healthz`, is answered at once.
2. The visitor's address is worked out from `X-Forwarded-For`, believed only
from `SWRP_TRUSTED_PROXIES`. `rproxy` sends `servewaf` the request as the
visitor sent it, with the first 64 KiB of its body.
from `SWRP_TRUSTED_PROXIES`. `rproxy` sends `discriminator` the request as
the visitor sent it, with the first 64 KiB of its body.
`servewaf` takes the checks:
`discriminator` takes the checks:
3. The static lists, `SWWAF_ALLOW_NETS` and `SWWAF_DENY_NETS`.
3. The static lists, `SWW_ALLOW_NETS` and `SWW_DENY_NETS`.
4. The bans.
5. The lookup of the client's AS number and country.
6. The country lists.
@@ -516,30 +517,30 @@ the request reaches the app.
10. The trap paths.
11. The rule files.
12. The header limits, and then the Core Rule Set.
13. A path under `/_smallwebwaf/` is answered `404`, so that the app never sees
that prefix.
13. A path under `/_sww/` is answered `404`, so that the app never sees that
prefix.
`rproxy` takes the rest, with `servewaf` counting at the end:
`rproxy` takes the rest, with `discriminator` counting at the end:
14. The request is passed to the app, streaming.
15. After the answer, `rproxy` sends `servewaf` a report with the status and the
bytes each way. For an allowed request, `servewaf` counts the bytes toward
the byte limits and adds the request to the client's history.
15. 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.
A refused visitor is answered with `SWWAF_BAN_RESPONSE`. A `block` rule or a
Core Rule Set match answers `403` and bans nobody, since the Core Rule Set has
false positives; such refusals count toward `SWWAF_ERROR_BURST_THRESHOLD`
instead. A request over the header limits of step 12 is answered `431`, and bans
nobody either. `rproxy` itself answers `405` to a method it does not pass on,
and the status for a size or time limit, such as `413` for a body too large.
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
positives; such refusals count toward `SWW_ERROR_BURST_THRESHOLD` instead. A
request over the header limits of step 12 is answered `431`, and bans nobody
either. `rproxy` itself answers `405` to a method it does not pass on, and the
status for a size or time limit, such as `413` for a body too large.
### Clients and bans
- A client is one IPv4 address or one IPv6 netblock of
`SWWAF_IPV6_GROUP_PREFIX`, since one abuser usually controls a whole /64.
- A client is one IPv4 address or one IPv6 netblock of `SWW_IPV6_GROUP_PREFIX`,
since one abuser usually controls a whole /64.
- Each limit is counted over a sliding window with a few integers per client.
The table of clients and the table of bans each have a bound
(`SWWAF_MAX_TRACKED_CLIENTS`, `SWWAF_MAX_BANS`), so memory is bounded too.
(`SWW_MAX_TRACKED_CLIENTS`, `SWW_MAX_BANS`), so memory is bounded too.
- A ban refuses every request from its netblock until it ends. Requests refused
under a ban count toward no limit. A permanent ban ends only when an admin
lifts it.
@@ -551,7 +552,7 @@ and the status for a size or time limit, such as `413` for a body too large.
### Attack detection
- The Core Rule Set reads the method, the URL with its query string, and the
headers of every request, and no body unless `SWWAF_WAF_BODY_LIMIT` is set. In
headers of every request, and no body unless `SWW_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 eight ways so that it lets ordinary
@@ -559,20 +560,20 @@ and the status for a size or time limit, such as `413` for a body too large.
Git Credential Manager. On gitea's own paths, its searches, file names and
branch names get through too. No setting undoes the changes; "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.
- `SWW_CORE_RULE_SET_EXCLUSIONS_FILE` switches single rules off for an app's own
fields or paths.
- 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
while `discriminator` runs. The image ships one file of probes no real visitor
sends (see [`docs/rules.md`](docs/rules.md)).
### State files
`servewaf` keeps everything in memory, and the five JSON files in
`SWWAF_STATE_DIR` hold a copy: `bans.json`, `clients.json`, `lookups.json`,
`discriminator` keeps everything in memory, and the five JSON files in
`SWW_STATE_DIR` hold a copy: `bans.json`, `clients.json`, `lookups.json`,
`reputation.json` and `alerts.json`. Each is written whole, to a temporary file
renamed over the real one, so a crash leaves a complete file. `servewaf` notices
a file edited on disk and takes the edit in; an edit that does not parse is set
aside as `<name>.bad`, and never stops the running process (see
renamed over the real one, so a crash leaves a complete file. `discriminator`
notices a file edited on disk and takes the edit in; an edit that does not parse
is set aside as `<name>.bad`, and never stops the running process (see
[`docs/state-files.md`](docs/state-files.md)).
### The image and its processes
@@ -581,30 +582,30 @@ aside as `<name>.bad`, and never stops the running process (see
come from Ubuntu's archive, and nixpkgs is fixed at one release. An app's
`Dockerfile` installs a package with `nix-env -iA nixpkgs.<name>` and gets the
same package each time it is built (see [`docs/image.md`](docs/image.md)).
- runit, a service supervisor, runs `smallwebwaf` as the `smallwebwaf` user (uid
and gid 65532) and starts it again when it exits. The `run` script of
`servewaf` gives the state directory to the `smallwebwaf` user at each start,
so a volume needs no change of owner.
- `rproxy` and `servewaf` use no token between them. `servewaf`'s own endpoints,
under `/_smallwebwaf/`, are for your admin tools and your metrics collector,
at its own address on the private network; nothing routes the internet there.
- runit, a service supervisor, runs `sww` as the `sww` user (uid and gid 65532)
and starts it again when it exits. The `run` script of `discriminator` gives
the state directory to the `sww` user at each start, so a volume needs no
change of owner.
- `rproxy` and `discriminator` use no token between them. `discriminator`'s own
endpoints, under `/_sww/`, are for your admin tools and your metrics
collector, at its own address on the private network; nothing routes the
internet there.
- `docker stop` gives requests in progress five seconds to finish. With `rproxy`
in the app's container, the app must keep answering for five seconds after
`SIGTERM` for that to help them.
- Only faults found at start stop a process: an invalid setting, a rule file or
state file that does not parse, a lookup database that cannot be read, or an
address it cannot listen on. Once running, a failing lookup service,
reputation source or alert destination never takes `servewaf` down.
reputation source or alert destination never takes `discriminator` down.
### Packages
- `cmd/smallwebwaf`: the binary, which only calls `internal/smallwebwaf`.
- `internal/smallwebwaf`: the process, as the command it is given, and the
health check.
- `cmd/sww`: the binary, which only calls `internal/sww`.
- `internal/sww`: the process, as the command it is given, and the health check.
- `internal/config`: reads the settings, the one place they are read.
- `internal/rproxy`: the reverse proxy in front of one app.
- `internal/servewaf`: `servewaf`'s server, which runs the checks and answers
its own endpoints.
- `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.
@@ -668,27 +669,26 @@ on the host.
image build.
- `script/precommit`: run by the git pre-commit hook; runs `script/check`.
- `script/install-precommit`: installs that hook. `make hooks`.
- `script/build`: builds `bin/smallwebwaf` with the Go on your host.
`make build`.
- `script/run`: builds `bin/smallwebwaf` and runs `servewaf` and `rproxy` on the
- `script/build`: builds `bin/sww` with the Go on your host. `make build`.
- `script/run`: builds `bin/sww` and runs `discriminator` and `rproxy` on the
host, with the settings in your environment. `make run`. Unless your settings
say otherwise:
- `rproxy` listens on port 8080, in front of an app at
`http://127.0.0.1:8081`;
- `servewaf` listens on port 8090;
- `discriminator` listens on port 8090;
- its state files go in `bin/state`;
- its rule files are those of `share/rules.d`.
- `script/example-app`: builds the image and the example app
(`deploy/example-app`) on it, runs the app with `rproxy` in its container and
`servewaf` in another, and checks them. Then it removes the containers, the
network, the volumes and the images. Needs network access. `make example-app`.
It checks:
`discriminator` in another, and checks them. Then it removes the containers,
the network, the volumes and the images. Needs network access.
`make example-app`. It checks:
- the health checks;
- a request passed to the app;
- a ban for a broken limit, and a ban for a probe made permanent;
- that only `servewaf`'s container changes the state directory's owner;
- with `servewaf` stopped, the app still answering through `rproxy`;
- with `servewaf` started again, bans applying again;
- that only `discriminator`'s container changes the state directory's owner;
- with `discriminator` stopped, the app still answering through `rproxy`;
- with `discriminator` started again, bans applying again;
- orderly stops with `sv stop` and `docker stop`;
- bans surviving a new container on the same volume;
- a setting given as a file.
@@ -707,7 +707,7 @@ on the host.
- [`docs/settings.md`](docs/settings.md): every setting and the values it takes.
- [`docs/rules.md`](docs/rules.md): the rule file format and the default file.
- [`docs/admin-endpoints.md`](docs/admin-endpoints.md): the endpoints under
`/_smallwebwaf/`, with examples.
`/_sww/`, with examples.
- [`docs/request-log.md`](docs/request-log.md): the request log's fields.
- [`docs/alerts.md`](docs/alerts.md): the alert events and what each destination
gets.