smallwebwaf watches SWWAF_STATE_DIR with fsnotify and takes in a saved
edit of a state file in place of what it held. It knows its own writes
by the SHA-256 of what it last read or wrote; each write first takes in
an edit made since. An edit that does not parse is renamed to
<name>.bad at the next write. Each edit taken in or set aside is logged
and counted. Every ban on a netblock is checked, and the next ban is
worked out from the one that ended last. README.md says how to add and
lift a ban.
Judgement call: a broken edit is set aside at the next write, since an
editor's file can be read half written.
Model: opus-5-5
GET /_smallwebwaf/metrics answers in the Prometheus text format for a
request carrying SWWAF_METRICS_TOKEN, 401 without it and 404 while it is
unset. Every request under /_smallwebwaf/ but the health check now goes
through the checks and is answered where it would be forwarded, 404 for
any path but the metrics, so none reaches the app. In the client's
history a 401 counts as refused, the metrics and the 404s as neither.
SWWAF_METRICS_TOP_N bounds the series by country, the rest counted as
other.
Deviation: go.mod and go.sum written by hand, as go runs only through
make.
Deviation: no metrics yet for state files read again after an edit or
edits set aside; that work is not merged.
Model: opus-5-5
The tests that have GeoJS asked now run in a synctest bubble, so a wait
lasts exactly as long as it should however slowly the test process runs:
a new client's wait is checked to be exactly one second, and its next
request exactly no wait. A request waiting on the network would stop the
bubble's clock, so the stand-in for GeoJS now answers in place of the
network, through a transport that a test-only file lets the tests set.
The test of the failure log uses an abandoned request instead of a
closed port.
Model: opus-5-5
smallwebwaf now copies its state to bans.json, clients.json and
lookups.json in SWWAF_STATE_DIR, as "Persistent state" in SPEC.md
describes, and reads them back at start, so a restart lifts no ban and
gives no client a fresh allowance. Each client gains a history, and a
ban's notes count the netblock's requests. bans.json is written
SWWAF_STATE_WRITE_DELAY after a ban, and every file every
SWWAF_STATE_COUNTER_INTERVAL and at the stop. A ban read back is masked
to its netblock and refuses every client in it. A file that does not
parse, an unknown version, an entry without a field it needs, or an
unwritable directory stops the start.
Deviation: no AS number or name, and no ban cause, reason or lifting yet.
Model: opus-5-5
SWWAF_DENIED_COUNTRIES and SWWAF_EXCLUSIVELY_ALLOWED_COUNTRIES refuse a
request with 403 before its body is read or rate-limited, logged as
country_denied. internal/lookup asks GeoJS only while a list is set, 200
clients per request, one at a time, keeping answers 7 days. Failures, a
redirect or an answer leaving an address out included, are logged without
addresses; GeoJS is then left alone a second, doubling to five minutes.
Private, loopback and link-local clients are never sent.
Deviation, per the issue: no SWWAF_LOOKUP_SOURCE or SWWAF_LOOKUP_TIMEOUT; 403, not SWWAF_BAN_RESPONSE.
Deviation: GeoJS's country endpoint, not geo.json.
Judgement call: an IPv6 /64 is asked about by its first address; at most 10,000 clients wait.
Judgement call: config.go lists the ISO 3166-1 codes; no widely used library holds them.
Model: opus-5-5
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