Merge pull request 'Honour shorewall INVALID_DISPOSITION and UNTRACKED_DISPOSITION' (#31) from benvin/invalid-disposition into main

Reviewed-on: #31

internal/nftables/compiler.go

@@ -70,21 +70,34 @@ func (c *Compiler) Compile() (*FirewallState, error) {
 }
 
 func (c *Compiler) compileConntrackFastPath(state *FirewallState) error {
+	invalid := c.cfg.Settings.InvalidDisposition
+	if invalid == "" {
+		invalid = config.PolicyDrop
+	}
 	for _, chain := range []string{"input", "forward", "output"} {
-		state.Rules[chain] = append(state.Rules[chain],
-			ManagedRule{
+		state.Rules[chain] = append(state.Rules[chain], ManagedRule{
+			Chain: chain,
+			Exprs: append(matchCtState(ctStateEstablished|ctStateRelated),
+				&expr.Verdict{Kind: expr.VerdictAccept}),
+			Tag: "ct:fastpath:" + chain,
+		})
+		for _, d := range []struct {
+			name   string
+			state  uint32
+			action config.PolicyAction
+		}{
+			{"invalid", ctStateInvalid, invalid},
+			{"untracked", ctStateUntracked, c.cfg.Settings.UntrackedDisposition},
+		} {
+			if d.action == "" || d.action == config.PolicyContinue {
+				continue
+			}
+			state.Rules[chain] = append(state.Rules[chain], ManagedRule{
 				Chain: chain,
-				Exprs: append(matchCtState(ctStateEstablished|ctStateRelated),
-					&expr.Verdict{Kind: expr.VerdictAccept}),
-				Tag: "ct:fastpath:" + chain,
-			},
-			ManagedRule{
-				Chain: chain,
-				Exprs: append(matchCtState(ctStateInvalid),
-					&expr.Verdict{Kind: expr.VerdictDrop}),
-				Tag: "ct:invalid:" + chain,
-			},
-		)
+				Exprs: append(matchCtState(d.state), policyVerdict(d.action, c.cfg.Settings.AddressFamily)...),
+				Tag:   "ct:" + d.name + ":" + chain,
+			})
+		}
 	}
 	return nil
 }

internal/nftables/compiler_test.go

@@ -3105,3 +3105,53 @@ func TestSpecCount_CommaAllMatchesExpansion(t *testing.T) {
 		}
 	}
 }
+
+func TestCompile_Dispositions(t *testing.T) {
+	cases := []struct {
+		invalid, untracked config.PolicyAction
+		want               map[string]expr.Any // tag prefix -> verdict expr, nil = absent
+	}{
+		{"", "", map[string]expr.Any{"ct:invalid:": &expr.Verdict{Kind: expr.VerdictDrop}, "ct:untracked:": nil}},
+		{config.PolicyContinue, config.PolicyContinue, map[string]expr.Any{"ct:invalid:": nil, "ct:untracked:": nil}},
+		{config.PolicyReject, config.PolicyAccept, map[string]expr.Any{
+			"ct:invalid:":   rejectExprs(0, config.FamilyINET)[0],
+			"ct:untracked:": &expr.Verdict{Kind: expr.VerdictAccept},
+		}},
+	}
+	for _, tc := range cases {
+		cfg := &config.Config{
+			Settings: config.Settings{
+				TableName:            "test",
+				AddressFamily:        config.FamilyINET,
+				InvalidDisposition:   tc.invalid,
+				UntrackedDisposition: tc.untracked,
+			},
+			Zones:      map[string]config.Zone{"fw": {Type: config.ZoneFirewall}, "net": {Type: config.ZoneIP}},
+			Interfaces: []config.Interface{{Zone: "net", Interface: "eth0"}},
+			Policy:     []config.Policy{{Source: "all", Dest: "all", Action: config.PolicyDrop}},
+			PortGroups: make(map[string]config.PortGroup),
+		}
+		state, err := NewCompiler(cfg).Compile()
+		if err != nil {
+			t.Fatalf("Compile: %v", err)
+		}
+		for _, chain := range []string{"input", "forward", "output"} {
+			for prefix, want := range tc.want {
+				var got *ManagedRule
+				for i, r := range state.Rules[chain] {
+					if r.Tag == prefix+chain {
+						got = &state.Rules[chain][i]
+					}
+				}
+				switch {
+				case want == nil && got != nil:
+					t.Errorf("%q/%q: unexpected %s%s rule", tc.invalid, tc.untracked, prefix, chain)
+				case want != nil && got == nil:
+					t.Errorf("%q/%q: missing %s%s rule", tc.invalid, tc.untracked, prefix, chain)
+				case want != nil && !reflect.DeepEqual(got.Exprs[len(got.Exprs)-1], want):
+					t.Errorf("%q/%q: %s%s verdict = %#v, want %#v", tc.invalid, tc.untracked, prefix, chain, got.Exprs[len(got.Exprs)-1], want)
+				}
+			}
+		}
+	}
+}