func ExamplePacketConn_servingOneShotMulticastDNS() {
c, err := net.ListenPacket("udp6", "[::]:5353") // mDNS over UDP
if err != nil {
log.Fatal(err)
}
defer c.Close()
p := ipv6.NewPacketConn(c)
en0, err := net.InterfaceByName("en0")
if err != nil {
log.Fatal(err)
}
mDNSLinkLocal := net.UDPAddr{IP: net.ParseIP("ff02::fb")}
if err := p.JoinGroup(en0, &mDNSLinkLocal); err != nil {
log.Fatal(err)
}
defer p.LeaveGroup(en0, &mDNSLinkLocal)
if err := p.SetControlMessage(ipv6.FlagDst|ipv6.FlagInterface, true); err != nil {
log.Fatal(err)
}
var wcm ipv6.ControlMessage
b := make([]byte, 1500)
for {
_, rcm, peer, err := p.ReadFrom(b)
if err != nil {
log.Fatal(err)
}
if !rcm.Dst.IsMulticast() || !rcm.Dst.Equal(mDNSLinkLocal.IP) {
continue
}
wcm.IfIndex = rcm.IfIndex
answers := []byte("FAKE-MDNS-ANSWERS") // fake mDNS answers, you need to implement this
if _, err := p.WriteTo(answers, &wcm, peer); err != nil {
log.Fatal(err)
}
}
}
func TestPacketConnReadWriteUnicastICMP(t *testing.T) {
switch runtime.GOOS {
case "nacl", "plan9", "solaris", "windows":
t.Skipf("not supported on %s", runtime.GOOS)
}
if !supportsIPv6 {
t.Skip("ipv6 is not supported")
}
if m, ok := nettest.SupportsRawIPSocket(); !ok {
t.Skip(m)
}
c, err := net.ListenPacket("ip6:ipv6-icmp", "::1")
if err != nil {
t.Fatal(err)
}
defer c.Close()
p := ipv6.NewPacketConn(c)
defer p.Close()
dst, err := net.ResolveIPAddr("ip6", "::1")
if err != nil {
t.Fatal(err)
}
pshicmp := icmp.IPv6PseudoHeader(c.LocalAddr().(*net.IPAddr).IP, dst.IP)
cm := ipv6.ControlMessage{
TrafficClass: iana.DiffServAF11 | iana.CongestionExperienced,
Src: net.IPv6loopback,
}
cf := ipv6.FlagTrafficClass | ipv6.FlagHopLimit | ipv6.FlagSrc | ipv6.FlagDst | ipv6.FlagInterface | ipv6.FlagPathMTU
ifi := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagLoopback)
if ifi != nil {
cm.IfIndex = ifi.Index
}
var f ipv6.ICMPFilter
f.SetAll(true)
f.Accept(ipv6.ICMPTypeEchoReply)
if err := p.SetICMPFilter(&f); err != nil {
t.Fatal(err)
}
var psh []byte
for i, toggle := range []bool{true, false, true} {
if toggle {
psh = nil
if err := p.SetChecksum(true, 2); err != nil {
t.Fatal(err)
}
} else {
psh = pshicmp
// Some platforms never allow to disable the
// kernel checksum processing.
p.SetChecksum(false, -1)
}
wb, err := (&icmp.Message{
Type: ipv6.ICMPTypeEchoRequest, Code: 0,
Body: &icmp.Echo{
ID: os.Getpid() & 0xffff, Seq: i + 1,
Data: []byte("HELLO-R-U-THERE"),
},
}).Marshal(psh)
if err != nil {
t.Fatal(err)
}
if err := p.SetControlMessage(cf, toggle); err != nil {
if nettest.ProtocolNotSupported(err) {
t.Skipf("not supported on %s", runtime.GOOS)
}
t.Fatal(err)
}
cm.HopLimit = i + 1
if err := p.SetWriteDeadline(time.Now().Add(100 * time.Millisecond)); err != nil {
t.Fatal(err)
}
if n, err := p.WriteTo(wb, &cm, dst); err != nil {
t.Fatal(err)
} else if n != len(wb) {
t.Fatalf("got %v; want %v", n, len(wb))
}
rb := make([]byte, 128)
if err := p.SetReadDeadline(time.Now().Add(100 * time.Millisecond)); err != nil {
t.Fatal(err)
}
if n, cm, _, err := p.ReadFrom(rb); err != nil {
switch runtime.GOOS {
case "darwin": // older darwin kernels have some limitation on receiving icmp packet through raw socket
t.Logf("not supported on %s", runtime.GOOS)
continue
}
t.Fatal(err)
} else {
t.Logf("rcvd cmsg: %v", cm)
if m, err := icmp.ParseMessage(iana.ProtocolIPv6ICMP, rb[:n]); err != nil {
t.Fatal(err)
} else if m.Type != ipv6.ICMPTypeEchoReply || m.Code != 0 {
t.Fatalf("got type=%v, code=%v; want type=%v, code=%v", m.Type, m.Code, ipv6.ICMPTypeEchoReply, 0)
}
}
}
}
func TestPacketConnReadWriteUnicastUDP(t *testing.T) {
switch runtime.GOOS {
case "nacl", "plan9", "solaris", "windows":
t.Skipf("not supported on %s", runtime.GOOS)
}
if !supportsIPv6 {
t.Skip("ipv6 is not supported")
}
c, err := net.ListenPacket("udp6", "[::1]:0")
if err != nil {
t.Fatal(err)
}
defer c.Close()
p := ipv6.NewPacketConn(c)
defer p.Close()
dst, err := net.ResolveUDPAddr("udp6", c.LocalAddr().String())
if err != nil {
t.Fatal(err)
}
cm := ipv6.ControlMessage{
TrafficClass: iana.DiffServAF11 | iana.CongestionExperienced,
Src: net.IPv6loopback,
}
cf := ipv6.FlagTrafficClass | ipv6.FlagHopLimit | ipv6.FlagSrc | ipv6.FlagDst | ipv6.FlagInterface | ipv6.FlagPathMTU
ifi := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagLoopback)
if ifi != nil {
cm.IfIndex = ifi.Index
}
wb := []byte("HELLO-R-U-THERE")
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 %s", runtime.GOOS)
}
t.Fatal(err)
}
cm.HopLimit = i + 1
if err := p.SetWriteDeadline(time.Now().Add(100 * time.Millisecond)); err != nil {
t.Fatal(err)
}
if n, err := p.WriteTo(wb, &cm, dst); err != nil {
t.Fatal(err)
} else if n != len(wb) {
t.Fatalf("got %v; want %v", n, len(wb))
}
rb := make([]byte, 128)
if err := p.SetReadDeadline(time.Now().Add(100 * time.Millisecond)); err != nil {
t.Fatal(err)
}
if n, cm, _, err := p.ReadFrom(rb); err != nil {
t.Fatal(err)
} else if !bytes.Equal(rb[:n], wb) {
t.Fatalf("got %v; want %v", rb[:n], wb)
} else {
t.Logf("rcvd cmsg: %v", cm)
}
}
}