Rename discriminator to waf everywhere (closes #312)

The command is now `sww waf`, and the package is `internal/waf`. Types, functions, files, tests, comments, docs, the Dockerfile, the runit script, `script/`, compose examples, the log field `waf_line` and the `X-From-Waf` test header follow. No behaviour changes, and no setting changes name: rproxy already finds the waf through `SWRP_WAF_BACKEND`. Done with one `sed -i` (Discriminator and DISCRIMINATOR to WAF, discriminator to waf) over the files `git grep -i discriminator` listed, as sneak allowed for this rename, then `git mv` for the package and files. Model: opus-5-5
2026-11-11 00:41:32 +00:00
1 parent ad36dd1775
commit 3fc63a1e40
@@ -0,0 +1,240 @@
+package waf_test
+
+import (
+	"net/http"
+	"net/netip"
+	"reflect"
+	"testing"
+	"time"
+
+	"sneak.berlin/go/smallwebwaf/internal/alerts"
+	"sneak.berlin/go/smallwebwaf/internal/bans"
+	"sneak.berlin/go/smallwebwaf/internal/requestlog"
+)
+
+// observe is the value of SWW_MODE for observe mode.
+const observe = "observe"
+
+func TestBanActionSaysWhetherTheBanRunsOut(t *testing.T) {
+	t.Parallel()
+
+	const trapPath = "/wp-login.php"
+
+	for _, tc := range []struct {
+		name  string
+		cause string
+		// endsIn is how long after the request the ban ends: negative for a
+		// ban that has ended, and zero for a permanent ban.
+		endsIn time.Duration
+		path   string
+		want   string
+	}{
+		{
+			"temporary ban", bans.CauseAdmin, time.Hour, "/",
+			requestlog.ActionTemporarilyBanned,
+		},
+		{"permanent ban", bans.CauseAdmin, 0, "/", requestlog.ActionPermanentlyBanned},
+		{
+			"request that makes a ban permanent", bans.CauseAttack, time.Hour, "/",
+			requestlog.ActionPermanentlyBanned,
+		},
+		{
+			"trap path after an attack ban ended", bans.CauseAttack, -time.Hour,
+			trapPath, requestlog.ActionPermanentlyBanned,
+		},
+		{
+			"first trap path after another ban ended", bans.CauseAdmin, -time.Hour,
+			trapPath, requestlog.ActionTemporarilyBanned,
+		},
+	} {
+		for _, modeValue := range []string{"enforce", observe} {
+			t.Run(tc.name+" in "+modeValue, func(t *testing.T) {
+				t.Parallel()
+
+				s, clk, server := startWithClock(t, "", map[string]string{
+					trapPaths: trapPathList, mode: modeValue,
+				})
+
+				ban := bans.Ban{
+					Netblock: netip.MustParsePrefix(client + "/32"),
+					Start:    clk.Now().Add(-2 * time.Hour),
+					Cause:    tc.cause,
+				}
+				if tc.endsIn != 0 {
+					ban.Expires = clk.Now().Add(tc.endsIn)
+				}
+
+				server.Ledger.Load([]bans.Ban{ban})
+
+				if modeValue == observe {
+					line := s.request(client, tc.path, http.StatusOK, requestlog.ActionForward)
+					wantWouldAction(t, line, tc.want)
+
+					return
+				}
+
+				s.request(client, tc.path, http.StatusForbidden, tc.want)
+			})
+		}
+	}
+}
+
+func TestObserveModeNamesAPermanentBanWhoseAlertWouldBeSent(t *testing.T) {
+	t.Parallel()
+
+	s, clk, server, queue := startWithAlerts(t, map[string]string{
+		trapPaths: trapPathList, mode: observe,
+	})
+
+	server.Ledger.Load([]bans.Ban{{
+		Netblock: netip.MustParsePrefix(client + "/32"),
+		Start:    clk.Now().Add(-2 * time.Hour),
+		Expires:  clk.Now().Add(-time.Hour),
+		Cause:    bans.CauseAttack,
+	}})
+
+	line := s.request(client, "/wp-login.php", http.StatusOK, requestlog.ActionForward)
+	wantWouldAction(t, line, requestlog.ActionPermanentlyBanned)
+
+	waiting := queue.Snapshot().Waiting[alerts.DestinationWebhook]
+	if len(waiting) != 1 || waiting[0].Event != alerts.EventPermanentBan {
+		t.Errorf("alerts waiting are %+v, want one %s", waiting, alerts.EventPermanentBan)
+	}
+}
+
+func TestObserveModeNamesTheHeuristicThatWouldHaveRefused(t *testing.T) {
+	t.Parallel()
+
+	s, _, _ := startWithClock(t, "", map[string]string{
+		mode: observe, denyNets: client,
+	})
+
+	line := s.get(client, http.StatusOK, requestlog.ActionForward)
+	wantWouldAction(t, line, requestlog.ActionClientDenied)
+	wantHeuristic(t, line, "deny_nets", `{"netblock": "`+client+`/32"}`)
+}
+
+func TestObserveModeForwardsWhatEnforceModeRefuses(t *testing.T) {
+	t.Parallel()
+
+	const (
+		denied = "192.0.2.50" // in SWW_DENY_NETS
+		banned = otherClient  // under a ban read from bans.json
+	)
+
+	for _, tc := range []struct {
+		setting string // "" leaves SWW_MODE at its default
+		observe bool
+	}{
+		{"", false},
+		{"enforce", false},
+		{observe, true},
+	} {
+		t.Run(mode+"="+tc.setting, func(t *testing.T) {
+			t.Parallel()
+
+			geojsURL, _ := startGeoJS(t)
+			env := map[string]string{
+				lookupTimeout:      "1h",
+				rateLimitPerMinute: "1",
+				denyNets:           denied,
+				tagDeny:            denyKP,
+			}
+
+			if tc.setting != "" {
+				env[mode] = tc.setting
+			}
+
+			s, clk, server := startWithClock(t, geojsURL, env)
+			server.Ledger.Load([]bans.Ban{{
+				Netblock: netip.MustParsePrefix(banned + "/32"),
+				Start:    clk.Now(),
+				Expires:  clk.Now().Add(time.Hour),
+			}})
+
+			// fromDE's first request is within the limit of one a minute,
+			// and its second breaks it.
+			s.get(fromDE, http.StatusOK, requestlog.ActionForward)
+
+			for _, sent := range []struct{ from, refusal string }{
+				{denied, requestlog.ActionClientDenied},
+				{banned, requestlog.ActionTemporarilyBanned},
+				{fromKP, requestlog.ActionClientDenied},
+				{fromDE, requestlog.ActionClientIsRateLimited},
+			} {
+				if !tc.observe {
+					line := s.get(sent.from, http.StatusForbidden, sent.refusal)
+					wantWouldAction(t, line, "")
+
+					continue
+				}
+
+				// Passed to the app, which answered it.
+				line := s.get(sent.from, http.StatusOK, requestlog.ActionForward)
+				wantWouldAction(t, line, sent.refusal)
+			}
+		})
+	}
+}
+
+func TestObserveModeMakesNoBanAndKeepsTheBansItHas(t *testing.T) {
+	t.Parallel()
+
+	s, clk, server := startWithClock(t, "", map[string]string{
+		mode:               observe,
+		rateLimitPerMinute: "1",
+	})
+	kept := bans.Ban{
+		Netblock: netip.MustParsePrefix(otherClient + "/32"),
+		Start:    clk.Now(),
+		Expires:  clk.Now().Add(time.Hour),
+		Cause:    bans.CauseAdmin,
+	}
+	server.Ledger.Load([]bans.Ban{kept})
+
+	// No ban sets client's counters back to zero, so each request after
+	// the first breaks the limit of one a minute.
+	s.get(client, http.StatusOK, requestlog.ActionForward)
+
+	for range 2 {
+		line := s.get(client, http.StatusOK, requestlog.ActionForward)
+		wantWouldAction(t, line, requestlog.ActionClientIsRateLimited)
+
+		if line.LimitHit != minute || line.Offence != requestlog.OffenceLimit ||
+			line.BanExpires != "" {
+			t.Errorf("log line has limit_hit %q, offence %q and ban_expires %q, "+
+				"want minute, limit and none", line.LimitHit, line.Offence,
+				line.BanExpires)
+		}
+	}
+
+	// The ban read from bans.json refuses nothing, and so counts no
+	// refusal in its notes, but is kept.
+	line := s.get(otherClient, http.StatusOK, requestlog.ActionForward)
+	wantWouldAction(t, line, requestlog.ActionTemporarilyBanned)
+
+	if line.BanExpires != requestlog.FormatTime(kept.Expires) {
+		t.Errorf("log line has ban_expires %q, want %s", line.BanExpires,
+			requestlog.FormatTime(kept.Expires))
+	}
+
+	got := server.Ledger.Snapshot()
+	if len(got) != 1 || !reflect.DeepEqual(got[0], kept) {
+		t.Errorf("bans\n%+v\nwant only\n%+v", got, kept)
+	}
+}
+
+// wantWouldAction checks the request log line's would_action, and that a
+// line that should have none has no such field.
+func wantWouldAction(t *testing.T, line logLine, want string) {
+	t.Helper()
+
+	got, present := line.fields["would_action"]
+
+	switch {
+	case want == "" && present:
+		t.Errorf("log line has would_action %v, want none", got)
+	case want != "" && got != want:
+		t.Errorf("log line has would_action %v, want %s", got, want)
+	}
+}