func TestUDPMultiplePacketConnWithMultipleGroupListeners(t *testing.T) { switch runtime.GOOS { case "nacl", "plan9", "solaris", "windows": t.Skipf("not supported on %s", runtime.GOOS) } if testing.Short() { t.Skip("to avoid external network") } for _, gaddr := range udpMultipleGroupListenerTests { c1, err := net.ListenPacket("udp4", "224.0.0.0:1024") // wildcard address with reusable port if err != nil { t.Fatal(err) } defer c1.Close() c2, err := net.ListenPacket("udp4", "224.0.0.0:1024") // wildcard address with reusable port if err != nil { t.Fatal(err) } defer c2.Close() var ps [2]*ipv4.PacketConn ps[0] = ipv4.NewPacketConn(c1) ps[1] = ipv4.NewPacketConn(c2) var mift []*net.Interface ift, err := net.Interfaces() if err != nil { t.Fatal(err) } for i, ifi := range ift { if _, ok := nettest.IsMulticastCapable("ip4", &ifi); !ok { continue } for _, p := range ps { if err := p.JoinGroup(&ifi, gaddr); err != nil { t.Fatal(err) } } mift = append(mift, &ift[i]) } for _, ifi := range mift { for _, p := range ps { if err := p.LeaveGroup(ifi, gaddr); err != nil { t.Fatal(err) } } } } }
func TestSetICMPFilter(t *testing.T) { switch runtime.GOOS { case "linux": default: t.Skipf("not supported on %s", runtime.GOOS) } if m, ok := nettest.SupportsRawIPSocket(); !ok { t.Skip(m) } c, err := net.ListenPacket("ip4:icmp", "127.0.0.1") if err != nil { t.Fatal(err) } defer c.Close() p := ipv4.NewPacketConn(c) var f ipv4.ICMPFilter f.SetAll(true) f.Accept(ipv4.ICMPTypeEcho) f.Accept(ipv4.ICMPTypeEchoReply) if err := p.SetICMPFilter(&f); err != nil { t.Fatal(err) } kf, err := p.ICMPFilter() if err != nil { t.Fatal(err) } if !reflect.DeepEqual(kf, &f) { t.Fatalf("got %#v; want %#v", kf, f) } }
func TestPacketConnMulticastSocketOptions(t *testing.T) { switch runtime.GOOS { case "nacl", "plan9", "solaris": t.Skipf("not supported on %s", runtime.GOOS) } ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagMulticast|net.FlagLoopback) if ifi == nil { t.Skipf("not available on %s", runtime.GOOS) } m, ok := nettest.SupportsRawIPSocket() for _, tt := range packetConnMulticastSocketOptionTests { if tt.net == "ip4" && !ok { t.Log(m) continue } c, err := net.ListenPacket(tt.net+tt.proto, tt.addr) if err != nil { t.Fatal(err) } defer c.Close() p := ipv4.NewPacketConn(c) defer p.Close() if tt.src == nil { testMulticastSocketOptions(t, p, ifi, tt.grp) } else { testSourceSpecificMulticastSocketOptions(t, p, ifi, tt.grp, tt.src) } } }
// ListenPacket listens for incoming ICMP packets addressed to // address. See net.Dial for the syntax of address. // // For non-privileged datagram-oriented ICMP endpoints, network must // be "udp4" or "udp6". The endpoint allows to read, write a few // limited ICMP messages such as echo request and echo reply. // Currently only Darwin and Linux support this. // // Examples: // ListenPacket("udp4", "192.168.0.1") // ListenPacket("udp4", "0.0.0.0") // ListenPacket("udp6", "fe80::1%en0") // ListenPacket("udp6", "::") // // For privileged raw ICMP endpoints, network must be "ip4" or "ip6" // followed by a colon and an ICMP protocol number or name. // // Examples: // ListenPacket("ip4:icmp", "192.168.0.1") // ListenPacket("ip4:1", "0.0.0.0") // ListenPacket("ip6:ipv6-icmp", "fe80::1%en0") // ListenPacket("ip6:58", "::") func ListenPacket(network, address string) (*PacketConn, error) { var family, proto int switch network { case "udp4": family, proto = syscall.AF_INET, iana.ProtocolICMP case "udp6": family, proto = syscall.AF_INET6, iana.ProtocolIPv6ICMP default: i := last(network, ':') switch network[:i] { case "ip4": proto = iana.ProtocolICMP case "ip6": proto = iana.ProtocolIPv6ICMP } } var cerr error var c net.PacketConn switch family { case syscall.AF_INET, syscall.AF_INET6: s, err := syscall.Socket(family, syscall.SOCK_DGRAM, proto) if err != nil { return nil, os.NewSyscallError("socket", err) } defer syscall.Close(s) if runtime.GOOS == "darwin" && family == syscall.AF_INET { if err := syscall.SetsockoptInt(s, iana.ProtocolIP, sysIP_STRIPHDR, 1); err != nil { return nil, os.NewSyscallError("setsockopt", err) } } sa, err := sockaddr(family, address) if err != nil { return nil, err } if err := syscall.Bind(s, sa); err != nil { return nil, os.NewSyscallError("bind", err) } f := os.NewFile(uintptr(s), "datagram-oriented icmp") defer f.Close() c, cerr = net.FilePacketConn(f) default: c, cerr = net.ListenPacket(network, address) } if cerr != nil { return nil, cerr } switch proto { case iana.ProtocolICMP: return &PacketConn{c: c, ipc: ipv4.NewPacketConn(c)}, nil case iana.ProtocolIPv6ICMP: return &PacketConn{c: c, ipc: ipv6.NewPacketConn(c)}, nil default: return &PacketConn{c: c}, nil } }
func TestPacketConnReadWriteUnicastUDP(t *testing.T) { switch runtime.GOOS { case "nacl", "plan9", "solaris", "windows": t.Skipf("not supported on %s", runtime.GOOS) } ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagLoopback) if ifi == nil { t.Skipf("not available on %s", runtime.GOOS) } c, err := net.ListenPacket("udp4", "127.0.0.1:0") if err != nil { t.Fatal(err) } defer c.Close() dst, err := net.ResolveUDPAddr("udp4", c.LocalAddr().String()) if err != nil { t.Fatal(err) } p := ipv4.NewPacketConn(c) defer p.Close() cf := ipv4.FlagTTL | ipv4.FlagDst | ipv4.FlagInterface 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.Logf("not supported on %s", runtime.GOOS) continue } t.Fatal(err) } p.SetTTL(i + 1) if err := p.SetWriteDeadline(time.Now().Add(100 * time.Millisecond)); err != nil { t.Fatal(err) } if n, err := p.WriteTo(wb, nil, 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) } } }
func TestUDPPerInterfaceSinglePacketConnWithSingleGroupListener(t *testing.T) { switch runtime.GOOS { case "nacl", "plan9", "solaris", "windows": t.Skipf("not supported on %s", runtime.GOOS) } if testing.Short() { t.Skip("to avoid external network") } gaddr := net.IPAddr{IP: net.IPv4(224, 0, 0, 254)} // see RFC 4727 type ml struct { c *ipv4.PacketConn ifi *net.Interface } var mlt []*ml ift, err := net.Interfaces() if err != nil { t.Fatal(err) } for i, ifi := range ift { ip, ok := nettest.IsMulticastCapable("ip4", &ifi) if !ok { continue } c, err := net.ListenPacket("udp4", ip.String()+":"+"1024") // unicast address with non-reusable port if err != nil { t.Fatal(err) } defer c.Close() p := ipv4.NewPacketConn(c) if err := p.JoinGroup(&ifi, &gaddr); err != nil { t.Fatal(err) } mlt = append(mlt, &ml{p, &ift[i]}) } for _, m := range mlt { if err := m.c.LeaveGroup(m.ifi, &gaddr); err != nil { t.Fatal(err) } } }
func BenchmarkReadWriteIPv4UDP(b *testing.B) { c, dst, err := benchmarkUDPListener() if err != nil { b.Fatal(err) } defer c.Close() p := ipv4.NewPacketConn(c) defer p.Close() cf := ipv4.FlagTTL | ipv4.FlagInterface if err := p.SetControlMessage(cf, true); err != nil { b.Fatal(err) } ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagLoopback) wb, rb := []byte("HELLO-R-U-THERE"), make([]byte, 128) b.ResetTimer() for i := 0; i < b.N; i++ { benchmarkReadWriteIPv4UDP(b, p, wb, rb, dst, ifi) } }
func ExamplePacketConn_servingOneShotMulticastDNS() { c, err := net.ListenPacket("udp4", "0.0.0.0:5353") // mDNS over UDP if err != nil { log.Fatal(err) } defer c.Close() p := ipv4.NewPacketConn(c) en0, err := net.InterfaceByName("en0") if err != nil { log.Fatal(err) } mDNSLinkLocal := net.UDPAddr{IP: net.IPv4(224, 0, 0, 251)} if err := p.JoinGroup(en0, &mDNSLinkLocal); err != nil { log.Fatal(err) } defer p.LeaveGroup(en0, &mDNSLinkLocal) if err := p.SetControlMessage(ipv4.FlagDst, true); err != nil { log.Fatal(err) } b := make([]byte, 1500) for { _, cm, peer, err := p.ReadFrom(b) if err != nil { log.Fatal(err) } if !cm.Dst.IsMulticast() || !cm.Dst.Equal(mDNSLinkLocal.IP) { continue } answers := []byte("FAKE-MDNS-ANSWERS") // fake mDNS answers, you need to implement this if _, err := p.WriteTo(answers, nil, peer); err != nil { log.Fatal(err) } } }
func TestPacketConnConcurrentReadWriteUnicastUDP(t *testing.T) { switch runtime.GOOS { case "nacl", "plan9", "solaris", "windows": t.Skipf("not supported on %s", runtime.GOOS) } c, err := net.ListenPacket("udp4", "127.0.0.1:0") if err != nil { t.Fatal(err) } defer c.Close() p := ipv4.NewPacketConn(c) defer p.Close() dst, err := net.ResolveUDPAddr("udp4", c.LocalAddr().String()) if err != nil { t.Fatal(err) } ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagLoopback) cf := ipv4.FlagTTL | ipv4.FlagSrc | ipv4.FlagDst | ipv4.FlagInterface 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 %s", runtime.GOOS) } t.Fatal(err) } var wg sync.WaitGroup reader := func() { defer wg.Done() rb := make([]byte, 128) if n, cm, _, err := p.ReadFrom(rb); err != nil { t.Error(err) return } else if !bytes.Equal(rb[:n], wb) { t.Errorf("got %v; want %v", rb[:n], wb) return } else { t.Logf("rcvd cmsg: %v", cm) } } writer := func(toggle bool) { defer wg.Done() cm := ipv4.ControlMessage{ Src: net.IPv4(127, 0, 0, 1), } if ifi != nil { cm.IfIndex = ifi.Index } if err := p.SetControlMessage(cf, toggle); err != nil { t.Error(err) return } if n, err := p.WriteTo(wb, &cm, dst); err != nil { t.Error(err) return } else if n != len(wb) { t.Errorf("short write: %v", n) return } } const N = 10 wg.Add(N) for i := 0; i < N; i++ { go reader() } wg.Add(2 * N) for i := 0; i < 2*N; i++ { go writer(i%2 != 0) } wg.Add(N) for i := 0; i < N; i++ { go reader() } wg.Wait() }
func ExamplePacketConn_tracingIPPacketRoute() { // Tracing an IP packet route to www.google.com. const host = "www.google.com" ips, err := net.LookupIP(host) if err != nil { log.Fatal(err) } var dst net.IPAddr for _, ip := range ips { if ip.To4() != nil { dst.IP = ip fmt.Printf("using %v for tracing an IP packet route to %s\n", dst.IP, host) break } } if dst.IP == nil { log.Fatal("no A record found") } c, err := net.ListenPacket(fmt.Sprintf("ip4:%d", iana.ProtocolICMP), "0.0.0.0") // ICMP for IPv4 if err != nil { log.Fatal(err) } defer c.Close() p := ipv4.NewPacketConn(c) if err := p.SetControlMessage(ipv4.FlagTTL|ipv4.FlagSrc|ipv4.FlagDst|ipv4.FlagInterface, true); err != nil { log.Fatal(err) } wm := icmp.Message{ Type: ipv4.ICMPTypeEcho, Code: 0, Body: &icmp.Echo{ ID: os.Getpid() & 0xffff, Data: []byte("HELLO-R-U-THERE"), }, } rb := make([]byte, 1500) for i := 1; i <= 64; i++ { // up to 64 hops wm.Body.(*icmp.Echo).Seq = i wb, err := wm.Marshal(nil) if err != nil { log.Fatal(err) } if err := p.SetTTL(i); err != nil { log.Fatal(err) } // In the real world usually there are several // multiple traffic-engineered paths for each hop. // You may need to probe a few times to each hop. begin := time.Now() if _, err := p.WriteTo(wb, nil, &dst); err != nil { log.Fatal(err) } if err := p.SetReadDeadline(time.Now().Add(3 * time.Second)); err != nil { log.Fatal(err) } n, cm, peer, err := p.ReadFrom(rb) if err != nil { if err, ok := err.(net.Error); ok && err.Timeout() { fmt.Printf("%v\t*\n", i) continue } log.Fatal(err) } rm, err := icmp.ParseMessage(iana.ProtocolICMP, rb[:n]) if err != nil { log.Fatal(err) } rtt := time.Since(begin) // In the real world you need to determine whether the // received message is yours using ControlMessage.Src, // ControlMessage.Dst, icmp.Echo.ID and icmp.Echo.Seq. switch rm.Type { case ipv4.ICMPTypeTimeExceeded: names, _ := net.LookupAddr(peer.String()) fmt.Printf("%d\t%v %+v %v\n\t%+v\n", i, peer, names, rtt, cm) case ipv4.ICMPTypeEchoReply: names, _ := net.LookupAddr(peer.String()) fmt.Printf("%d\t%v %+v %v\n\t%+v\n", i, peer, names, rtt, cm) return default: log.Printf("unknown ICMP message: %+v\n", rm) } } }
func TestPacketConnReadWriteUnicastICMP(t *testing.T) { switch runtime.GOOS { case "nacl", "plan9", "solaris", "windows": t.Skipf("not supported on %s", runtime.GOOS) } if m, ok := nettest.SupportsRawIPSocket(); !ok { t.Skip(m) } ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagLoopback) if ifi == nil { t.Skipf("not available on %s", runtime.GOOS) } c, err := net.ListenPacket("ip4:icmp", "0.0.0.0") if err != nil { t.Fatal(err) } defer c.Close() dst, err := net.ResolveIPAddr("ip4", "127.0.0.1") if err != nil { t.Fatal(err) } p := ipv4.NewPacketConn(c) defer p.Close() cf := ipv4.FlagTTL | ipv4.FlagDst | ipv4.FlagInterface for i, toggle := range []bool{true, false, true} { wb, err := (&icmp.Message{ Type: ipv4.ICMPTypeEcho, Code: 0, Body: &icmp.Echo{ ID: os.Getpid() & 0xffff, Seq: i + 1, Data: []byte("HELLO-R-U-THERE"), }, }).Marshal(nil) if err != nil { t.Fatal(err) } if err := p.SetControlMessage(cf, toggle); err != nil { if nettest.ProtocolNotSupported(err) { t.Logf("not supported on %s", runtime.GOOS) continue } t.Fatal(err) } p.SetTTL(i + 1) if err := p.SetWriteDeadline(time.Now().Add(100 * time.Millisecond)); err != nil { t.Fatal(err) } if n, err := p.WriteTo(wb, nil, dst); err != nil { t.Fatal(err) } else if n != len(wb) { t.Fatalf("got %v; want %v", n, len(wb)) } rb := make([]byte, 128) loop: 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) m, err := icmp.ParseMessage(iana.ProtocolICMP, rb[:n]) if err != nil { t.Fatal(err) } if runtime.GOOS == "linux" && m.Type == ipv4.ICMPTypeEcho { // On Linux we must handle own sent packets. goto loop } if m.Type != ipv4.ICMPTypeEchoReply || m.Code != 0 { t.Fatalf("got type=%v, code=%v; want type=%v, code=%v", m.Type, m.Code, ipv4.ICMPTypeEchoReply, 0) } } } }
func TestPacketConnReadWriteMulticastUDP(t *testing.T) { switch runtime.GOOS { case "nacl", "plan9", "solaris", "windows": t.Skipf("not supported on %s", runtime.GOOS) } ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagMulticast|net.FlagLoopback) if ifi == nil { t.Skipf("not available on %s", runtime.GOOS) } for _, tt := range packetConnReadWriteMulticastUDPTests { c, err := net.ListenPacket("udp4", tt.addr) if err != nil { t.Fatal(err) } defer c.Close() grp := *tt.grp grp.Port = c.LocalAddr().(*net.UDPAddr).Port p := ipv4.NewPacketConn(c) defer p.Close() if tt.src == nil { if err := p.JoinGroup(ifi, &grp); err != nil { t.Fatal(err) } defer p.LeaveGroup(ifi, &grp) } else { if err := p.JoinSourceSpecificGroup(ifi, &grp, tt.src); err != nil { switch runtime.GOOS { case "freebsd", "linux": default: // platforms that don't support IGMPv2/3 fail here t.Logf("not supported on %s", runtime.GOOS) continue } t.Fatal(err) } defer p.LeaveSourceSpecificGroup(ifi, &grp, tt.src) } if err := p.SetMulticastInterface(ifi); err != nil { t.Fatal(err) } if _, err := p.MulticastInterface(); err != nil { t.Fatal(err) } if err := p.SetMulticastLoopback(true); err != nil { t.Fatal(err) } if _, err := p.MulticastLoopback(); err != nil { t.Fatal(err) } cf := ipv4.FlagTTL | ipv4.FlagDst | ipv4.FlagInterface 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.Logf("not supported on %s", runtime.GOOS) continue } t.Fatal(err) } if err := p.SetDeadline(time.Now().Add(200 * time.Millisecond)); err != nil { t.Fatal(err) } p.SetMulticastTTL(i + 1) if n, err := p.WriteTo(wb, nil, &grp); err != nil { t.Fatal(err) } else if n != len(wb) { t.Fatalf("got %v; want %v", n, len(wb)) } rb := make([]byte, 128) 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) } } } }
func TestPacketConnReadWriteMulticastICMP(t *testing.T) { switch runtime.GOOS { case "nacl", "plan9", "solaris", "windows": t.Skipf("not supported on %s", runtime.GOOS) } if m, ok := nettest.SupportsRawIPSocket(); !ok { t.Skip(m) } ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagMulticast|net.FlagLoopback) if ifi == nil { t.Skipf("not available on %s", runtime.GOOS) } for _, tt := range packetConnReadWriteMulticastICMPTests { c, err := net.ListenPacket("ip4:icmp", "0.0.0.0") if err != nil { t.Fatal(err) } defer c.Close() p := ipv4.NewPacketConn(c) defer p.Close() if tt.src == nil { if err := p.JoinGroup(ifi, tt.grp); err != nil { t.Fatal(err) } defer p.LeaveGroup(ifi, tt.grp) } else { if err := p.JoinSourceSpecificGroup(ifi, tt.grp, tt.src); err != nil { switch runtime.GOOS { case "freebsd", "linux": default: // platforms that don't support IGMPv2/3 fail here t.Logf("not supported on %s", runtime.GOOS) continue } t.Fatal(err) } defer p.LeaveSourceSpecificGroup(ifi, tt.grp, tt.src) } if err := p.SetMulticastInterface(ifi); err != nil { t.Fatal(err) } if _, err := p.MulticastInterface(); err != nil { t.Fatal(err) } if err := p.SetMulticastLoopback(true); err != nil { t.Fatal(err) } if _, err := p.MulticastLoopback(); err != nil { t.Fatal(err) } cf := ipv4.FlagTTL | ipv4.FlagDst | ipv4.FlagInterface for i, toggle := range []bool{true, false, true} { wb, err := (&icmp.Message{ Type: ipv4.ICMPTypeEcho, Code: 0, Body: &icmp.Echo{ ID: os.Getpid() & 0xffff, Seq: i + 1, Data: []byte("HELLO-R-U-THERE"), }, }).Marshal(nil) if err != nil { t.Fatal(err) } if err := p.SetControlMessage(cf, toggle); err != nil { if nettest.ProtocolNotSupported(err) { t.Logf("not supported on %s", runtime.GOOS) continue } t.Fatal(err) } if err := p.SetDeadline(time.Now().Add(200 * time.Millisecond)); err != nil { t.Fatal(err) } p.SetMulticastTTL(i + 1) if n, err := p.WriteTo(wb, nil, tt.grp); err != nil { t.Fatal(err) } else if n != len(wb) { t.Fatalf("got %v; want %v", n, len(wb)) } rb := make([]byte, 128) if n, cm, _, err := p.ReadFrom(rb); err != nil { t.Fatal(err) } else { t.Logf("rcvd cmsg: %v", cm) m, err := icmp.ParseMessage(iana.ProtocolICMP, rb[:n]) if err != nil { t.Fatal(err) } switch { case m.Type == ipv4.ICMPTypeEchoReply && m.Code == 0: // net.inet.icmp.bmcastecho=1 case m.Type == ipv4.ICMPTypeEcho && m.Code == 0: // net.inet.icmp.bmcastecho=0 default: t.Fatalf("got type=%v, code=%v; want type=%v, code=%v", m.Type, m.Code, ipv4.ICMPTypeEchoReply, 0) } } } } }