Keep rule match extras on the limited log rule

2026-10-04 15:56:23 +11:00
parent 2e8d51759d
commit be391ed385
2 changed files with 114 additions and 20 deletions
@@ -72,7 +72,8 @@ func (c *Compiler) Compile() (*FirewallState, error) {

 // limitLogs puts a limit in front of every log expression. A limit stops the
 // whole rule, so like shorewall's separate LOG rule, a log followed by an action
-// splits into a limited log-only rule and the same rule without the log.
+// splits into a limited log-only rule and the same rule without the log. A
+// LOG-action rule (nothing but rate limits after the log) keeps only the log rule.
 func limitLogs(state *FirewallState, spec string) {
 	if spec == "" {
 		return
@@ -88,7 +89,7 @@ func limitLogs(state *FirewallState, spec string) {
 			logRule := r
 			logRule.Exprs = slices.Concat(r.Exprs[:i], parseRateLimit(spec), r.Exprs[i:i+1])
 			out = append(out, logRule)
-			if i < len(r.Exprs)-1 {
+			if slices.ContainsFunc(r.Exprs[i+1:], func(e expr.Any) bool { _, ok := e.(*expr.Limit); return !ok }) {
 				r.Exprs = slices.Concat(r.Exprs[:i], r.Exprs[i+1:])
 				out = append(out, r)
 			}
@@ -442,24 +443,24 @@ func (c *Compiler) applyChainExtras(state *FirewallState, chain, tag string, rul
 			break
 		}

-		var extra []expr.Any
+		var match, extra []expr.Any
 		var replaceVerdict []expr.Any

 		if rule.User != "" {
-			extra = append(extra, matchUID(rule.User)...)
+			match = append(match, matchUID(rule.User)...)
 		}
 		if rule.Mark != "" {
-			extra = append(extra, matchMark(rule.Mark)...)
+			match = append(match, matchMark(rule.Mark)...)
+		}
+		if rule.ConnLimit != "" {
+			match = append(match, matchConnLimit(rule.ConnLimit)...)
+		}
+		if rule.Time != nil {
+			match = append(match, matchTime(rule.Time)...)
 		}
 		if rule.RateLimit != "" {
 			extra = append(extra, parseRateLimit(rule.RateLimit)...)
 		}
-		if rule.ConnLimit != "" {
-			extra = append(extra, matchConnLimit(rule.ConnLimit)...)
-		}
-		if rule.Time != nil {
-			extra = append(extra, matchTime(rule.Time)...)
-		}
 		if rule.SetMark != "" {
 			extra = append(extra, setMarkExprs(rule.SetMark)...)
 		}
@@ -467,21 +468,27 @@ func (c *Compiler) applyChainExtras(state *FirewallState, chain, tag string, rul
 			replaceVerdict = []expr.Any{&expr.Queue{Num: uint16(rule.NFQueue), Total: 1}}
 		}

-		if len(extra) > 0 || len(replaceVerdict) > 0 {
-			existingExprs := rules[idx].Exprs
-			var verdict []expr.Any
-			var nonVerdict []expr.Any
-			for _, e := range existingExprs {
-				if _, ok := e.(*expr.Verdict); ok {
+		if len(match) > 0 || len(extra) > 0 || len(replaceVerdict) > 0 {
+			var pre, post, verdict []expr.Any
+			for _, e := range rules[idx].Exprs {
+				switch e.(type) {
+				case *expr.Verdict:
 					verdict = append(verdict, e)
-				} else {
-					nonVerdict = append(nonVerdict, e)
+				case *expr.Log:
+					post = append(post, e)
+				default:
+					if len(post) > 0 {
+						post = append(post, e)
+					} else {
+						pre = append(pre, e)
+					}
 				}
 			}
 			if len(replaceVerdict) > 0 {
 				verdict = replaceVerdict
 			}
-			rules[idx].Exprs = append(append(nonVerdict, extra...), verdict...)
+			// matches go before the log so it only fires for packets the rule matches
+			rules[idx].Exprs = slices.Concat(pre, match, post, extra, verdict)
 		}
 	}
 	state.Rules[chain] = rules
@@ -3233,3 +3233,90 @@ func TestCompile_NoLogLimitKeepsInlineLog(t *testing.T) {
 		}
 	}
 }
+
+func TestCompile_LogLimitSplitsAroundExtrasAndNAT(t *testing.T) {
+	cfg := listCfg(func(c *config.Config) {
+		c.Settings.LogLimit = "1/sec:10"
+		c.Zones["loc"] = config.Zone{Type: config.ZoneIP}
+		c.Interfaces = append(c.Interfaces, config.Interface{Zone: "loc", Interface: "eth1"})
+		c.Rules = []config.Rule{
+			{Action: config.RuleAccept, Source: "net:192.0.2.1", Dest: "fw", Proto: "tcp", DPort: config.PortSpec{"22"}, Log: "info",
+				Mark: "0x1", User: "0", Time: &config.TimeSpec{Start: "08:00", Stop: "17:00"}, RateLimit: "5/sec:20"},
+			{Action: config.RuleLog, Source: "net:192.0.2.2", Dest: "fw", Proto: "tcp", DPort: config.PortSpec{"23"}, Log: "info",
+				Mark: "0x2", RateLimit: "5/sec:20"},
+			{Action: config.RuleDNAT, Source: "net", Dest: "loc:198.51.100.10:80", Proto: "tcp", DPort: config.PortSpec{"8000"}, Log: "info"},
+			{Action: config.RuleAccept, Source: "net:192.0.2.3", Dest: "loc", Proto: "tcp", DPort: config.PortSpec{"443"}, Log: "info"},
+		}
+		c.SNAT = []config.SNATRule{{Action: config.SNATAddress, Source: "198.51.100.0/24", Dest: "eth0", Address: "203.0.113.7", Mark: "0x3", Log: "info"}}
+	})
+	state, err := NewCompiler(cfg).Compile()
+	if err != nil {
+		t.Fatalf("Compile() error: %v", err)
+	}
+	logLimit := &expr.Limit{Type: expr.LimitTypePkts, Rate: 1, Unit: expr.LimitTimeSecond, Burst: 10}
+	kinds := func(exprs []expr.Any) (logs, limits, marks, uids int) {
+		for _, e := range exprs {
+			switch v := e.(type) {
+			case *expr.Log:
+				logs++
+			case *expr.Limit:
+				limits++
+			case *expr.Meta:
+				if v.Key == expr.MetaKeyMARK && !v.SourceRegister {
+					marks++
+				}
+				if v.Key == expr.MetaKeySKUID {
+					uids++
+				}
+			}
+		}
+		return
+	}
+	check := func(name string, rs []ManagedRule, n, wantMarks, wantUIDs int) []expr.Any {
+		t.Helper()
+		if len(rs) != n {
+			t.Fatalf("%s: %d rules, want %d", name, len(rs), n)
+		}
+		l := rs[0].Exprs
+		if len(l) < 2 || !reflect.DeepEqual(l[len(l)-2], logLimit) {
+			t.Errorf("%s: log rule must end limit+log, got %#v", name, l)
+		}
+		if logs, limits, marks, uids := kinds(l); logs != 1 || limits != 1 || marks != wantMarks || uids != wantUIDs {
+			t.Errorf("%s: log rule logs=%d limits=%d marks=%d uids=%d, want 1/1/%d/%d", name, logs, limits, marks, uids, wantMarks, wantUIDs)
+		}
+		if n == 1 {
+			return nil
+		}
+		v := rs[1].Exprs
+		if logs, _, marks, uids := kinds(v); logs != 0 || marks != wantMarks || uids != wantUIDs {
+			t.Errorf("%s: action rule logs=%d marks=%d uids=%d, want 0/%d/%d", name, logs, marks, uids, wantMarks, wantUIDs)
+		}
+		return v
+	}
+
+	v := check("rule:0", taggedRules(state, "input", "rule:0"), 2, 1, 1)
+	if _, limits, _, _ := kinds(v); limits != 1 {
+		t.Errorf("rule:0: action rule must keep its ratelimit, got %d limits", limits)
+	}
+	if _, ok := v[len(v)-1].(*expr.Verdict); !ok {
+		t.Errorf("rule:0: action rule must end in a verdict, got %T", v[len(v)-1])
+	}
+	check("rule:1", taggedRules(state, "input", "rule:1"), 1, 1, 0)
+	if v := check("rule:2", taggedRules(state, "prerouting", "rule:2"), 2, 0, 0); v != nil {
+		if _, ok := v[len(v)-1].(*expr.NAT); !ok {
+			t.Errorf("rule:2: DNAT rule must end in nat, got %T", v[len(v)-1])
+		}
+	}
+	check("rule:3", taggedRules(state, "forward", "rule:3"), 2, 0, 0)
+	var snat []ManagedRule
+	for _, r := range state.Rules["postrouting"] {
+		if logs, _, _, _ := kinds(r.Exprs); logs > 0 || strings.HasPrefix(r.Tag, "snat:0") {
+			snat = append(snat, r)
+		}
+	}
+	if v := check("snat:0", snat, 2, 1, 0); v != nil {
+		if _, ok := v[len(v)-1].(*expr.NAT); !ok {
+			t.Errorf("snat:0: rule must end in nat, got %T", v[len(v)-1])
+		}
+	}
+}