nettest: use RoutedInterface for probing network stack capability

The ipv4/ipv6 support capability is done by explicitly listening on loopback interface. However, it can lead to false positive, especially for ipv6 case. For example, ipv6 can be enabled, but explicitly disable for loopback interface (for security, policy ...). This CL changes probeStack to use another approach, by looking for any interface that can route IP traffic and in "UP" state. If there's one, then the platform can do ipv4/ipv6 networking functionality. Fixes golang/go#57386 Change-Id: If911bc223b52c5a4562d3f61b4ee1032bdbec47c Reviewed-on: https://go-review.googlesource.com/c/net/+/458096 TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Benny Siegert <bsiegert@gmail.com> Reviewed-by: Matt Layher <mdlayher@gmail.com> Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: David Chase <drchase@google.com>
golang · Dec 23, 2022 · 2aa8215 · 2aa8215
1 parent ad92d3d
commit 2aa8215
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Showing 6 changed files with 18 additions and 20 deletions.
diff --git a/ipv6/bpf_test.go b/ipv6/bpf_test.go
@@ -19,8 +19,8 @@ func TestBPF(t *testing.T) {
 	if runtime.GOOS != "linux" {
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
-	if !nettest.SupportsIPv6() {
-		t.Skip("ipv6 is not supported")
+	if _, err := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagLoopback); err != nil {
+		t.Skip("ipv6 is not enabled for loopback interface")
 	}
 
 	l, err := net.ListenPacket("udp6", "[::1]:0")

diff --git a/ipv6/readwrite_test.go b/ipv6/readwrite_test.go
@@ -223,10 +223,10 @@ func TestPacketConnConcurrentReadWriteUnicastUDP(t *testing.T) {
 	case "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
-	if !nettest.SupportsIPv6() {
-		t.Skip("ipv6 is not supported")
+	ifi, err := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagLoopback)
+	if err != nil {
+		t.Skip("ipv6 is not enabled for loopback interface")
 	}
-
 	c, err := nettest.NewLocalPacketListener("udp6")
 	if err != nil {
 		t.Fatal(err)
@@ -236,7 +236,6 @@ func TestPacketConnConcurrentReadWriteUnicastUDP(t *testing.T) {
 	defer p.Close()
 
 	dst := c.LocalAddr()
-	ifi, _ := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagLoopback)
 	cf := ipv6.FlagTrafficClass | ipv6.FlagHopLimit | ipv6.FlagSrc | ipv6.FlagDst | ipv6.FlagInterface | ipv6.FlagPathMTU
 	wb := []byte("HELLO-R-U-THERE")
 

diff --git a/ipv6/sockopt_test.go b/ipv6/sockopt_test.go
@@ -20,8 +20,9 @@ func TestConnInitiatorPathMTU(t *testing.T) {
 	case "fuchsia", "hurd", "js", "nacl", "plan9", "windows", "zos":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
-	if !nettest.SupportsIPv6() {
-		t.Skip("ipv6 is not supported")
+
+	if _, err := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagLoopback); err != nil {
+		t.Skip("ipv6 is not enabled for loopback interface")
 	}
 
 	ln, err := net.Listen("tcp6", "[::1]:0")
@@ -53,8 +54,8 @@ func TestConnResponderPathMTU(t *testing.T) {
 	case "fuchsia", "hurd", "js", "nacl", "plan9", "windows", "zos":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
-	if !nettest.SupportsIPv6() {
-		t.Skip("ipv6 is not supported")
+	if _, err := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagLoopback); err != nil {
+		t.Skip("ipv6 is not enabled for loopback interface")
 	}
 
 	ln, err := net.Listen("tcp6", "[::1]:0")

diff --git a/ipv6/unicast_test.go b/ipv6/unicast_test.go
@@ -23,8 +23,8 @@ func TestPacketConnReadWriteUnicastUDP(t *testing.T) {
 	case "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
-	if !nettest.SupportsIPv6() {
-		t.Skip("ipv6 is not supported")
+	if _, err := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagLoopback); err != nil {
+		t.Skip("ipv6 is not enabled for loopback interface")
 	}
 
 	c, err := nettest.NewLocalPacketListener("udp6")

diff --git a/ipv6/unicastsockopt_test.go b/ipv6/unicastsockopt_test.go
@@ -19,8 +19,8 @@ func TestConnUnicastSocketOptions(t *testing.T) {
 	case "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
-	if !nettest.SupportsIPv6() {
-		t.Skip("ipv6 is not supported")
+	if _, err := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagLoopback); err != nil {
+		t.Skip("ipv6 is not enabled for loopback interface")
 	}
 
 	ln, err := net.Listen("tcp6", "[::1]:0")
@@ -64,8 +64,8 @@ func TestPacketConnUnicastSocketOptions(t *testing.T) {
 	case "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
-	if !nettest.SupportsIPv6() {
-		t.Skip("ipv6 is not supported")
+	if _, err := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagLoopback); err != nil {
+		t.Skip("ipv6 is not enabled for loopback interface")
 	}
 
 	ok := nettest.SupportsRawSocket()

diff --git a/nettest/nettest.go b/nettest/nettest.go
@@ -34,12 +34,10 @@ var (
 )
 
 func probeStack() {
-	if ln, err := net.Listen("tcp4", "127.0.0.1:0"); err == nil {
-		ln.Close()
+	if _, err := RoutedInterface("ip4", net.FlagUp); err == nil {
 		ipv4Enabled = true
 	}
-	if ln, err := net.Listen("tcp6", "[::1]:0"); err == nil {
-		ln.Close()
+	if _, err := RoutedInterface("ip6", net.FlagUp); err == nil {
 		ipv6Enabled = true
 	}
 	rawSocketSess = supportsRawSocket()