SWWAF_ANOMALY_CLIENT_*, _NET_*, _ASN_*, _TOTAL_* and SWWAF_WATCH_* with
SWWAF_WATCH_NETS: requests and bytes per minute and per hour, each off by
default; with all off, nothing is counted. Otherwise every request but the
health check is counted, allow-listed and exempt ones included; a count
over its threshold raises an anomaly alert, with a cooldown per scope. At
most 20,000 counters, kept in alerts.json. A per-AS-number threshold with
lookups off, or a malformed SWWAF_WATCH_NETS, stops the start. A cooldown
that has run out is dropped as the hour ends, whatever it held back; the
hour's summary gives its repeats.
Judgement call: refused requests are counted too.
Judgement call: per-client counters are kept in alerts.json, which SPEC.md does not list.
Judgement call: a request counts for an AS number only if the lookup answered before it ended.
Model: opus-5-5
SWWAF_LOOKUP_SOURCE=file looks every client up in the file
SWWAF_LOOKUP_DB_PATH names, without GeoJS. file without the path, the
path with another source, or a file that cannot be read stops the start.
The file is read whole into memory, so overwriting it in place cannot
disturb a lookup, and read again 2 seconds after its last change; a
replacement that cannot be read is logged, counted and sent as a
file_error alert, and the old one stays in use. Metrics give when it
was read and the failed reads. Tests write their databases through
internal/lookup/lookuptest.
Deviation: go.mod and go.sum written by hand; go runs only through make.
Judgement call: the 2-second wait, as the rule files have.
Model: opus-5-5
GeoJS's geo.json is asked about every new visitor unless
SWWAF_LOOKUP_SOURCE is off. A request waits for its client's first
answer only while a country list or SWWAF_ADD_LOOKUP_HEADERS needs it;
otherwise the answer reaches the client's history and ban notes when it
comes. The AS number and name go beside the country in the request log,
history, ban notes, alerts and lookups.json, with metrics by AS number;
64512 counts as unknown. A client's own X-Client-ASN and
X-Client-Country never reach the app, whatever the setting says, and
make example-app sends no address to GeoJS.
Judgement call: AS numbers are written AS64496, as SPEC's settings write them.
Judgement call: SWWAF_LOOKUP_TIMEOUT is added, default 1s, and cannot be off.
Model: opus-5-5
Each alert is posted as a message to the Slack incoming webhook
SWWAF_ALERT_SLACK_WEBHOOK_URL names, and published to the ntfy topic
SWWAF_ALERT_NTFY_URL names, with SWWAF_ALERT_NTFY_TOKEN as a bearer
token and a priority and tag by event. The cooldown and the hourly
limit stay shared; past them, each destination has its own bounded
queue and backoff, and its own sent, failed and dropped counts.
alerts.json keeps the alerts waiting by destination; one whose waiting
is still a list stops the start, saying what to change. A control
character in the ntfy token, or in the instance name ntfy is sent,
stops the start.
Judgement call: messages also give the detail's file, source, error and mode.
Judgement call: alerts_suppressed_total is the same for every destination.
Model: opus-5-5
SWWAF_ALERT_WEBHOOK_URL gets one JSON POST per alert, in SPEC.md's
schema, with SWWAF_ALERT_WEBHOOK_HEADERS: ban and permanent_ban, with
the ban's notes, in observe mode too, marked mode observe and worked
out only when the alert would be sent; source_failure for GeoJS;
file_error for a rule or state file with an error. SWWAF_ALERT_EVENTS
chooses; SWWAF_ALERT_COOLDOWN holds back repeats by netblock, file or
source; past SWWAF_ALERT_MAX_PER_HOUR the hour ends in one summary. A
bounded queue, retried with backoff, holds up no request; a 4xx other
than 408 and 429 gives the alert up. alerts.json keeps the queue, the
cooldowns and the hour. Nothing shows the URL's path or query.
Judgement call: the summary's event is summary, which SPEC.md omits.
Judgement call: an admin's ban raises no alert.
Model: opus-5-5
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