fix(wireguard): ignore IPv6 addresses if IPv6 disabled

internal/wireguard/address.go

@@ -10,6 +10,11 @@ import (
 func (w *Wireguard) addAddresses(link netlink.Link,
 	addresses []*net.IPNet) (err error) {
 	for _, ipNet := range addresses {
+		ipNetIsIPv6 := ipNet.IP.To4() == nil
+		if !*w.settings.IPv6 && ipNetIsIPv6 {
+			continue
+		}
+
 		address := &netlink.Addr{
 			IPNet: ipNet,
 		}

internal/wireguard/address_test.go

@@ -15,7 +15,7 @@ func Test_Wireguard_addAddresses(t *testing.T) {
 	t.Parallel()
 
 	ipNetOne := &net.IPNet{IP: net.IPv4(1, 2, 3, 4), Mask: net.IPv4Mask(255, 255, 255, 255)}
-	ipNetTwo := &net.IPNet{IP: net.IPv4(4, 5, 6, 7), Mask: net.IPv4Mask(255, 255, 255, 128)}
+	ipNetTwo := &net.IPNet{IP: net.ParseIP("::1234"), Mask: net.CIDRMask(64, 128)}
 
 	newLink := func() netlink.Link {
 		linkAttrs := netlink.NewLinkAttrs()
@@ -28,37 +28,77 @@ func Test_Wireguard_addAddresses(t *testing.T) {
 	errDummy := errors.New("dummy")
 
 	testCases := map[string]struct {
-		link          netlink.Link
-		addrs         []*net.IPNet
-		expectedAddrs []*netlink.Addr
-		addrAddErrs   []error
-		err           error
+		link      netlink.Link
+		addrs     []*net.IPNet
+		wgBuilder func(ctrl *gomock.Controller, link netlink.Link) *Wireguard
+		err       error
 	}{
 		"success": {
 			link:  newLink(),
 			addrs: []*net.IPNet{ipNetOne, ipNetTwo},
-			expectedAddrs: []*netlink.Addr{
-				{IPNet: ipNetOne}, {IPNet: ipNetTwo},
+			wgBuilder: func(ctrl *gomock.Controller, link netlink.Link) *Wireguard {
+				netLinker := NewMockNetLinker(ctrl)
+				firstCall := netLinker.EXPECT().
+					AddrAdd(link, &netlink.Addr{IPNet: ipNetOne}).
+					Return(nil)
+				netLinker.EXPECT().
+					AddrAdd(link, &netlink.Addr{IPNet: ipNetTwo}).
+					Return(nil).After(firstCall)
+				return &Wireguard{
+					netlink: netLinker,
+					settings: Settings{
+						IPv6: ptrTo(true),
+					},
+				}
 			},
-			addrAddErrs: []error{nil, nil},
 		},
 		"first add error": {
 			link:  newLink(),
 			addrs: []*net.IPNet{ipNetOne, ipNetTwo},
-			expectedAddrs: []*netlink.Addr{
-				{IPNet: ipNetOne},
+			wgBuilder: func(ctrl *gomock.Controller, link netlink.Link) *Wireguard {
+				netLinker := NewMockNetLinker(ctrl)
+				netLinker.EXPECT().
+					AddrAdd(link, &netlink.Addr{IPNet: ipNetOne}).
+					Return(errDummy)
+				return &Wireguard{
+					netlink: netLinker,
+					settings: Settings{
+						IPv6: ptrTo(true),
+					},
+				}
 			},
-			addrAddErrs: []error{errDummy},
-			err:         errors.New("dummy: when adding address 1.2.3.4/32 to link a_bridge"),
+			err: errors.New("dummy: when adding address 1.2.3.4/32 to link a_bridge"),
 		},
 		"second add error": {
 			link:  newLink(),
 			addrs: []*net.IPNet{ipNetOne, ipNetTwo},
-			expectedAddrs: []*netlink.Addr{
-				{IPNet: ipNetOne}, {IPNet: ipNetTwo},
+			wgBuilder: func(ctrl *gomock.Controller, link netlink.Link) *Wireguard {
+				netLinker := NewMockNetLinker(ctrl)
+				firstCall := netLinker.EXPECT().
+					AddrAdd(link, &netlink.Addr{IPNet: ipNetOne}).
+					Return(nil)
+				netLinker.EXPECT().
+					AddrAdd(link, &netlink.Addr{IPNet: ipNetTwo}).
+					Return(errDummy).After(firstCall)
+				return &Wireguard{
+					netlink: netLinker,
+					settings: Settings{
+						IPv6: ptrTo(true),
+					},
+				}
+			},
+			err: errors.New("dummy: when adding address ::1234/64 to link a_bridge"),
+		},
+		"ignore IPv6": {
+			link:  newLink(),
+			addrs: []*net.IPNet{ipNetTwo},
+			wgBuilder: func(ctrl *gomock.Controller, link netlink.Link) *Wireguard {
+				return &Wireguard{
+					settings: Settings{
+						IPv6: ptrTo(false),
+					},
+				}
 			},
-			addrAddErrs: []error{nil, errDummy},
-			err:         errors.New("dummy: when adding address 4.5.6.7/25 to link a_bridge"),
 		},
 	}
 
@@ -68,18 +108,7 @@ func Test_Wireguard_addAddresses(t *testing.T) {
 			t.Parallel()
 			ctrl := gomock.NewController(t)
 
-			require.Equal(t, len(testCase.expectedAddrs), len(testCase.addrAddErrs))
-
-			netLinker := NewMockNetLinker(ctrl)
-			wg := Wireguard{
-				netlink: netLinker,
-			}
-
-			for i := range testCase.expectedAddrs {
-				netLinker.EXPECT().
-					AddrAdd(testCase.link, testCase.expectedAddrs[i]).
-					Return(testCase.addrAddErrs[i])
-			}
+			wg := testCase.wgBuilder(ctrl, testCase.link)
 
 			err := wg.addAddresses(testCase.link, testCase.addrs)
 

internal/wireguard/helpers_test.go

@@ -0,0 +1,3 @@
+package wireguard
+
+func ptrTo[T any](x T) *T { return &x }