Files
smallwebwaf/internal/waf/refusallimit.go
T
clawbot 0b23352767
check / check (push) Waiting to run
Format Go with gofmt, then golines -m 77 (closes #215)
script/fmt now runs golines -m 77 after gofmt, repeating golines until
it changes nothing, since one pass can leave a line the next splits.
script/fmt-check fails when either would change a file.
script/bootstrap installs golines v0.13.0 with go install, pinned to
its commit, and checks the installed version with go version -m.

The tree is reformatted. The longer lines this makes are fixed by
hand: nolint directives moved onto their own line above the statement,
one string split, and 20 functions over funlen's 80 lines shortened or
split, RunWAF and limitPercentages among them.

Model: opus-5-5
2026-11-11 17:29:12 +01:00

61 lines
1.6 KiB
Go

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