Files
smallwebwaf/internal/discriminator/refusallimit.go
T
clawbot 2349b2a081
check / check (push) Failing after 1m53s
discriminator: each decision heuristic is its own module (closes #195)
Each discriminator check is now a type in its own file behind one small interface, listed in `heuristics.go`. Adding a heuristic is one file and one line. Behaviour does not change.

Refusal and ban log lines gain `heuristic` and `heuristic_figures`. A ban after the answer, by `refusal_limit` or `byte_limits`, logs `after_answer_heuristic` and its figures, so one line can name both.

Deviation: four lists, not the planned three, so `refusal_limit` still bans at the decision.
Rule suppressed: `//nolint:lll` on one struct tag.

Model: opus-5-5
2026-11-09 01:14:24 +01:00

55 lines
1.5 KiB
Go

package discriminator
// 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 discriminator
// 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.ruleBlocked && !rq.wafBlocked {
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.ActionRuleBlocked, requestlog.ActionWAFBlocked:
status = http.StatusForbidden
case requestlog.ActionBanned:
status = cfg.BanResponse
}
rq.banForLimit(now, hit, status)
return &verdict{action: requestlog.ActionBanned, figures: limitFigures(hit)}
}