net: re-enable raw socket tests on windows

Since CL 38bf89161a72 raw socket tests are not executed
on windows builders. This change re-enable them again.
It will attempt to run raw socket tests only if user
is permitted to create raw socket by OS.

Fixes #6392

R=golang-dev
CC=golang-dev, mikioh.mikioh, rsc
https://golang.org/cl/13422044

src/pkg/net/fd_plan9.go

@@ -125,3 +125,7 @@ func setReadBuffer(fd *netFD, bytes int) error {
 func setWriteBuffer(fd *netFD, bytes int) error {
 	return syscall.EPLAN9
 }
+
+func skipRawSocketTests() (skip bool, skipmsg string, err error) {
+	return true, "skipping test on plan9", nil
+}

src/pkg/net/fd_unix.go

@@ -473,3 +473,10 @@ func (fd *netFD) dup() (f *os.File, err error) {
 func closesocket(s int) error {
 	return syscall.Close(s)
 }
+
+func skipRawSocketTests() (skip bool, skipmsg string, err error) {
+	if os.Getuid() != 0 {
+		return true, "skipping test; must be root", nil
+	}
+	return false, "", nil
+}

src/pkg/net/fd_windows.go

@@ -568,6 +568,25 @@ func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (*netFD, error) {
 	return netfd, nil
 }
 
+func skipRawSocketTests() (skip bool, skipmsg string, err error) {
+	// From http://msdn.microsoft.com/en-us/library/windows/desktop/ms740548.aspx:
+	// Note: To use a socket of type SOCK_RAW requires administrative privileges.
+	// Users running Winsock applications that use raw sockets must be a member of
+	// the Administrators group on the local computer, otherwise raw socket calls
+	// will fail with an error code of WSAEACCES. On Windows Vista and later, access
+	// for raw sockets is enforced at socket creation. In earlier versions of Windows,
+	// access for raw sockets is enforced during other socket operations.
+	s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_RAW, 0)
+	if err == syscall.WSAEACCES {
+		return true, "skipping test; no access to raw socket allowed", nil
+	}
+	if err != nil {
+		return true, "", err
+	}
+	defer syscall.Closesocket(s)
+	return false, "", nil
+}
+
 // Unimplemented functions.
 
 func (fd *netFD) dup() (*os.File, error) {

src/pkg/net/ipraw_test.go

@@ -59,6 +59,14 @@ func init() {
 	}
 }
 
+func skipRawSocketTest(t *testing.T) (skip bool, skipmsg string) {
+	skip, skipmsg, err := skipRawSocketTests()
+	if err != nil {
+		t.Fatal(err)
+	}
+	return skip, skipmsg
+}
+
 func TestResolveIPAddr(t *testing.T) {
 	for _, tt := range resolveIPAddrTests {
 		addr, err := ResolveIPAddr(tt.net, tt.litAddrOrName)
@@ -80,17 +88,8 @@ var icmpEchoTests = []struct {
 }
 
 func TestConnICMPEcho(t *testing.T) {
-	switch runtime.GOOS {
-	case "plan9":
-		t.Skipf("skipping test on %q", runtime.GOOS)
-	case "windows":
-		if testing.Short() || !*testExternal {
-			t.Skipf("skipping test on %q to avoid network firewall", runtime.GOOS)
-		}
-	default:
-		if os.Getuid() != 0 {
-			t.Skip("skipping test; must be root")
-		}
+	if skip, skipmsg := skipRawSocketTest(t); skip {
+		t.Skip(skipmsg)
 	}
 
 	for i, tt := range icmpEchoTests {
@@ -157,17 +156,8 @@ func TestConnICMPEcho(t *testing.T) {
 }
 
 func TestPacketConnICMPEcho(t *testing.T) {
-	switch runtime.GOOS {
-	case "plan9":
-		t.Skipf("skipping test on %q", runtime.GOOS)
-	case "windows":
-		if testing.Short() || !*testExternal {
-			t.Skipf("skipping test on %q to avoid network firewall", runtime.GOOS)
-		}
-	default:
-		if os.Getuid() != 0 {
-			t.Skip("skipping test; must be root")
-		}
+	if skip, skipmsg := skipRawSocketTest(t); skip {
+		t.Skip(skipmsg)
 	}
 
 	for i, tt := range icmpEchoTests {

src/pkg/net/multicast_test.go

@@ -25,10 +25,6 @@ var ipv4MulticastListenerTests = []struct {
 // port.
 func TestIPv4MulticastListener(t *testing.T) {
 	switch runtime.GOOS {
-	case "windows":
-		if testing.Short() || !*testExternal {
-			t.Skipf("skipping test on %q to avoid network firewall", runtime.GOOS)
-		}
 	case "plan9":
 		t.Skipf("skipping test on %q", runtime.GOOS)
 	}

src/pkg/net/packetconn_test.go

@@ -26,20 +26,9 @@ func packetConnTestData(t *testing.T, net string, i int) ([]byte, func()) {
 	case "udp":
 		return []byte("UDP PACKETCONN TEST"), nil
 	case "ip":
-		switch runtime.GOOS {
-		case "plan9":
+		if skip, skipmsg := skipRawSocketTest(t); skip {
 			return nil, func() {
-				t.Logf("skipping %q test on %q", net, runtime.GOOS)
-			}
-		case "windows":
-			if testing.Short() || !*testExternal {
-				t.Skipf("skipping test on %q to avoid network firewall", runtime.GOOS)
-			}
-		default:
-			if os.Getuid() != 0 {
-				return nil, func() {
-					t.Logf("skipping %q test; must be root", net)
-				}
+				t.Logf(skipmsg)
 			}
 		}
 		b, err := (&icmpMessage{

src/pkg/net/protoconn_test.go

@@ -173,17 +173,8 @@ func TestUDPConnSpecificMethods(t *testing.T) {
 }
 
 func TestIPConnSpecificMethods(t *testing.T) {
-	switch runtime.GOOS {
-	case "plan9":
-		t.Skipf("skipping test on %q", runtime.GOOS)
-	case "windows":
-		if testing.Short() || !*testExternal {
-			t.Skipf("skipping test on %q to avoid network firewall", runtime.GOOS)
-		}
-	default:
-		if os.Getuid() != 0 {
-			t.Skipf("skipping test; must be root")
-		}
+	if skip, skipmsg := skipRawSocketTest(t); skip {
+		t.Skip(skipmsg)
 	}
 
 	la, err := ResolveIPAddr("ip4", "127.0.0.1")

src/pkg/syscall/ztypes_windows.go

@@ -22,6 +22,7 @@ const (
 	ERROR_OPERATION_ABORTED   Errno = 995
 	ERROR_IO_PENDING          Errno = 997
 	ERROR_NOT_FOUND           Errno = 1168
+	WSAEACCES                 Errno = 10013
 )
 
 const (