feat(ipv6): use ipv6 endpoint IPs if supported

internal/provider/utils/connection.go

@@ -33,6 +33,7 @@ func GetConnection(provider string,
 	storage Storage,
 	selection settings.ServerSelection,
 	defaults ConnectionDefaults,
+	ipv6Supported bool,
 	randSource rand.Source) (
 	connection models.Connection, err error) {
 	servers, err := storage.FilterServers(provider, selection)
@@ -47,8 +48,7 @@ func GetConnection(provider string,
 	connections := make([]models.Connection, 0, len(servers))
 	for _, server := range servers {
 		for _, ip := range server.IPs {
-			if ip.To4() == nil {
-				// do not use IPv6 connections for now
+			if !ipv6Supported && ip.To4() == nil {
 				continue
 			}
 

internal/provider/utils/connection_test.go

@@ -27,6 +27,7 @@ func Test_GetConnection(t *testing.T) {
 		filterError     error
 		serverSelection settings.ServerSelection
 		defaults        ConnectionDefaults
+		ipv6Supported   bool
 		randSource      rand.Source
 		connection      models.Connection
 		errWrapped      error
@@ -122,6 +123,29 @@ func Test_GetConnection(t *testing.T) {
 				Port:     1194,
 			},
 		},
+		"server with IPv4 and IPv6 and ipv6 supported": {
+			filteredServers: []models.Server{
+				{
+					VPN: vpn.OpenVPN,
+					UDP: true,
+					IPs: []net.IP{
+						net.IPv6zero,
+						net.IPv4(1, 1, 1, 1),
+					},
+				},
+			},
+			serverSelection: settings.ServerSelection{}.
+				WithDefaults(providers.Mullvad),
+			defaults:      NewConnectionDefaults(443, 1194, 58820),
+			ipv6Supported: true,
+			randSource:    rand.NewSource(0),
+			connection: models.Connection{
+				Type:     vpn.OpenVPN,
+				IP:       net.IPv6zero,
+				Protocol: constants.UDP,
+				Port:     1194,
+			},
+		},
 		"mixed servers": {
 			filteredServers: []models.Server{
 				{
@@ -172,7 +196,7 @@ func Test_GetConnection(t *testing.T) {
 				Return(testCase.filteredServers, testCase.filterError)
 
 			connection, err := GetConnection(testCase.provider, storage,
-				testCase.serverSelection, testCase.defaults,
+				testCase.serverSelection, testCase.defaults, testCase.ipv6Supported,
 				testCase.randSource)
 
 			assert.Equal(t, testCase.connection, connection)