x/net/ipv6: skip ancillary data socket option tests on non-supported kernels

For old darwin kernels.

LGTM=iant
R=iant
CC=golang-codereviews
https://golang.org/cl/166410043

ipv6/multicast_test.go

@@ -77,6 +77,9 @@ func TestPacketConnReadWriteMulticastUDP(t *testing.T) {
 
 	for i, toggle := range []bool{true, false, true} {
 		if err := p.SetControlMessage(cf, toggle); err != nil {
+			if nettest.ProtocolNotSupported(err) {
+				t.Skipf("not supported on %q", runtime.GOOS)
+			}
 			t.Fatalf("ipv6.PacketConn.SetControlMessage failed: %v", err)
 		}
 		if err := p.SetDeadline(time.Now().Add(200 * time.Millisecond)); err != nil {
@@ -183,6 +186,9 @@ func TestPacketConnReadWriteMulticastICMP(t *testing.T) {
 			t.Fatalf("icmp.Message.Marshal failed: %v", err)
 		}
 		if err := p.SetControlMessage(cf, toggle); err != nil {
+			if nettest.ProtocolNotSupported(err) {
+				t.Skipf("not supported on %q", runtime.GOOS)
+			}
 			t.Fatalf("ipv6.PacketConn.SetControlMessage failed: %v", err)
 		}
 		if err := p.SetDeadline(time.Now().Add(200 * time.Millisecond)); err != nil {

ipv6/readwrite_test.go

@@ -60,7 +60,7 @@ func BenchmarkReadWriteIPv6UDP(b *testing.B) {
 	defer c.Close()
 
 	p := ipv6.NewPacketConn(c)
-	cf := ipv6.FlagTrafficClass | ipv6.FlagHopLimit | ipv6.FlagInterface | ipv6.FlagPathMTU
+	cf := ipv6.FlagTrafficClass | ipv6.FlagHopLimit | ipv6.FlagSrc | ipv6.FlagDst | ipv6.FlagInterface | ipv6.FlagPathMTU
 	if err := p.SetControlMessage(cf, true); err != nil {
 		b.Fatalf("ipv6.PacketConn.SetControlMessage failed: %v", err)
 	}
@@ -117,6 +117,13 @@ func TestPacketConnConcurrentReadWriteUnicastUDP(t *testing.T) {
 	cf := ipv6.FlagTrafficClass | ipv6.FlagHopLimit | ipv6.FlagSrc | ipv6.FlagDst | ipv6.FlagInterface | ipv6.FlagPathMTU
 	wb := []byte("HELLO-R-U-THERE")
 
+	if err := p.SetControlMessage(cf, true); err != nil { // probe before test
+		if nettest.ProtocolNotSupported(err) {
+			t.Skipf("not supported on %q", runtime.GOOS)
+		}
+		t.Fatalf("ipv6.PacketConn.SetControlMessage failed: %v", err)
+	}
+
 	var wg sync.WaitGroup
 	reader := func() {
 		defer wg.Done()

ipv6/unicast_test.go

@@ -53,6 +53,9 @@ func TestPacketConnReadWriteUnicastUDP(t *testing.T) {
 
 	for i, toggle := range []bool{true, false, true} {
 		if err := p.SetControlMessage(cf, toggle); err != nil {
+			if nettest.ProtocolNotSupported(err) {
+				t.Skipf("not supported on %q", runtime.GOOS)
+			}
 			t.Fatalf("ipv6.PacketConn.SetControlMessage failed: %v", err)
 		}
 		cm.HopLimit = i + 1
@@ -145,6 +148,9 @@ func TestPacketConnReadWriteUnicastICMP(t *testing.T) {
 			t.Fatalf("icmp.Message.Marshal failed: %v", err)
 		}
 		if err := p.SetControlMessage(cf, toggle); err != nil {
+			if nettest.ProtocolNotSupported(err) {
+				t.Skipf("not supported on %q", runtime.GOOS)
+			}
 			t.Fatalf("ipv6.PacketConn.SetControlMessage failed: %v", err)
 		}
 		cm.HopLimit = i + 1