[internal-branch.go1.17-vendor] ipv6: OpenBSD does not appear to support multicast loopback

Skip the tests for it, as we already skip them on FreeBSD.

For golang/go#42064
For golang/go#49909

Change-Id: I058f25309020367e686625033b4f25cb614c7f99
Reviewed-on: https://go-review.googlesource.com/c/net/+/366355
Trust: Ian Lance Taylor <[email protected]>
Run-TryBot: Ian Lance Taylor <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: Bryan C. Mills <[email protected]>
Reviewed-on: https://go-review.googlesource.com/c/net/+/368534
Trust: Damien Neil <[email protected]>
Run-TryBot: Damien Neil <[email protected]>

Author: ianlancetaylor

ipv6/helper_unix_test.go

@@ -20,6 +20,10 @@ func supportsIPv6MulticastDeliveryOnLoopback() (string, bool) {
 		// kernels don't deliver link-local scoped multicast
 		// packets correctly.
 		return fmt.Sprintf("not supported on %s/%s", runtime.GOOS, runtime.GOARCH), false
+	case "openbsd":
+		// Multicast packets don't seem to be delivered locally.
+		// Issue 42064.
+		return fmt.Sprintf("not supported on %s/%s", runtime.GOOS, runtime.GOARCH), false
 	default:
 		return "", true
 	}

ipv6/multicast_test.go

@@ -28,11 +28,6 @@ var packetConnReadWriteMulticastUDPTests = []struct {
 }
 
 func TestPacketConnReadWriteMulticastUDP(t *testing.T) {
-	switch os.Getenv("GO_BUILDER_NAME") {
-	case "openbsd-amd64-68", "openbsd-386-68", "openbsd-arm-jsing", "openbsd-arm64-jsing", "openbsd-mips64-jsing":
-		t.Skip(`this test is currently failing on OpenBSD 6.8 builders with "raw-read udp6: i/o timeout" ` +
-			`and needs investigation, see golang.org/issue/42064`)
-	}
 	switch runtime.GOOS {
 	case "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)