Blocklists and an AS percentage file fetched by URL (closes #29)

SWWAF_BLOCKLIST_URLS names lists of addresses and netblocks, fetched every
SWWAF_BLOCKLIST_REFRESH (24h, never under 1h); an IPv4-mapped line stands
for its IPv4 address or netblock. reputation.json keeps each list's last
try, failed or not, which a restart waits on as a running instance does,
and its last good copy, whole, used while a fetch fails.
SWWAF_BLOCKLIST_ACTION denies, limits or only logs a listed client; the log
line names the lists, each raises reputation_hit, and a failed fetch raises
source_failure. SWWAF_ASN_LIMIT_PERCENT_URL is fetched the same way and
counts as SWWAF_ASN_LIMIT_PERCENT does, the lower winning.

Judgement call: a failed fetch is retried after the refresh, not sooner.
Not done: ban notes do not name the lists yet.

Model: opus-5-5

internal/proxy/request.go

@@ -213,14 +213,14 @@ func (rq *request) check(ctx context.Context) *refusal {
 // client in SWWAF_ALLOW_NETS skips them, and is not looked up. For any
 // other client, SWWAF_DENY_NETS comes first, then a ban on its netblock,
 // so that a client either refuses is not looked up, then the lookup of
-// its AS number and country, and then the country lists; a request any of
-// them refuses is not counted for the rate limits. Then come the rate
-// limits, unless the client is in SWWAF_RATE_LIMIT_EXEMPT_NETS or the
-// request's path is exempt under SWWAF_RATE_LIMIT_EXEMPT_PATHS, so that
-// every other request is counted, each of them by the client's limit
-// percentages, and last the rule files. A request exempt from the rate
-// limits is exempt from the byte limits too. ctx is the request's own
-// context.
+// its AS number and country, then the country lists, and then the
+// blocklists; a request any of them refuses is not counted for the rate
+// limits. Then come the rate limits, unless the client is in
+// SWWAF_RATE_LIMIT_EXEMPT_NETS or the request's path is exempt under
+// SWWAF_RATE_LIMIT_EXEMPT_PATHS, so that every other request is counted,
+// each of them by the client's limit percentages, and last the rule
+// files. A request exempt from the rate limits is exempt from the byte
+// limits too. ctx is the request's own context.
 func (rq *request) checkClient(ctx context.Context) string {
 	cfg := rq.h.config
 	if isInside(rq.client, cfg.AllowNets) {
@@ -243,10 +243,14 @@ func (rq *request) checkClient(ctx context.Context) string {
 		return requestlog.ActionCountryDenied
 	}
 
+	if rq.blocklistDenied() {
+		return requestlog.ActionDenied
+	}
+
 	rq.counted = !isInside(rq.client, cfg.RateLimitExemptNets) &&
 		!pathExempt(rq.in.URL, cfg.RateLimitExemptPaths)
 	if rq.counted {
-		rq.limitPercent, rq.bytesPercent = limitPercentages(cfg, rq.line.ASN, rq.line.Country)
+		rq.limitPercent, rq.bytesPercent = rq.limitPercentages()
 		rq.line.LimitPercent, rq.line.LimitPercentSetting = rq.limitPercent.logged()
 		rq.line.BytesPercent, rq.line.BytesPercentSetting = rq.bytesPercent.logged()
 	}