Golang net.ListenPacket函数代码示例

func TestUDPMultiplePacketConnWithMultipleGroupListeners(t *testing.T) {
	switch runtime.GOOS {
	case "nacl", "plan9", "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 TestUDPMultiplePacketConnWithMultipleGroupListeners(t *testing.T) {
	switch runtime.GOOS {
	case "dragonfly", "plan9", "solaris", "windows":
		t.Skipf("not supported on %q", runtime.GOOS)
	}
	if !supportsIPv6 {
		t.Skip("ipv6 is not supported")
	}

	for _, gaddr := range udpMultipleGroupListenerTests {
		c1, err := net.ListenPacket("udp6", "[ff02::]:1024") // wildcard address with reusable port
		if err != nil {
			t.Fatalf("net.ListenPacket failed: %v", err)
		}
		defer c1.Close()

		c2, err := net.ListenPacket("udp6", "[ff02::]:1024") // wildcard address with reusable port
		if err != nil {
			t.Fatalf("net.ListenPacket failed: %v", err)
		}
		defer c2.Close()

		var ps [2]*ipv6.PacketConn
		ps[0] = ipv6.NewPacketConn(c1)
		ps[1] = ipv6.NewPacketConn(c2)
		var mift []*net.Interface

		ift, err := net.Interfaces()
		if err != nil {
			t.Fatalf("net.Interfaces failed: %v", err)
		}
		for i, ifi := range ift {
			if _, ok := isMulticastAvailable(&ifi); !ok {
				continue
			}
			for _, p := range ps {
				if err := p.JoinGroup(&ifi, gaddr); err != nil {
					t.Fatalf("ipv6.PacketConn.JoinGroup %v on %v failed: %v", gaddr, ifi, err)
				}
			}
			mift = append(mift, &ift[i])
		}
		for _, ifi := range mift {
			for _, p := range ps {
				if err := p.LeaveGroup(ifi, gaddr); err != nil {
					t.Fatalf("ipv6.PacketConn.LeaveGroup %v on %v failed: %v", gaddr, ifi, err)
				}
			}
		}
	}
}

func TestUDPMultipleConnWithMultipleGroupListeners(t *testing.T) {
	if testing.Short() || !*testExternal {
		t.Logf("skipping test to avoid external network")
		return
	}

	for _, tt := range udpMultipleGroupListenerTests {
		// listen to a group address, actually a wildcard address
		// with reusable port
		c1, err := net.ListenPacket("udp4", "224.0.0.0:1024") // see RFC 4727
		if err != nil {
			t.Fatalf("net.ListenPacket failed: %v", err)
		}
		defer c1.Close()

		c2, err := net.ListenPacket("udp4", "224.0.0.0:1024") // see RFC 4727
		if err != nil {
			t.Fatalf("net.ListenPacket failed: %v", 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.Fatalf("net.Interfaces failed: %v", err)
		}
		for i, ifi := range ift {
			if _, ok := isGoodForMulticast(&ifi); !ok {
				continue
			}
			for _, p := range ps {
				if err := p.JoinGroup(&ifi, tt.gaddr); err != nil {
					t.Fatalf("ipv4.PacketConn.JoinGroup %v on %v failed: %v", tt.gaddr, ifi, err)
				}
			}
			mift = append(mift, &ift[i])
		}
		for _, ifi := range mift {
			for _, p := range ps {
				if err := p.LeaveGroup(ifi, tt.gaddr); err != nil {
					t.Fatalf("ipv4.PacketConn.LeaveGroup %v on %v failed: %v", tt.gaddr, ifi, err)
				}
			}
		}
	}
}

// addr is used to create a listening UDP conn which becomes the underlying
// net.PacketConn for the Socket.
func NewSocket(network, addr string) (s *Socket, err error) {
	pc, err := net.ListenPacket(network, addr)
	if err != nil {
		return
	}
	return NewSocketFromPacketConn(pc)
}

func mustListenPacket(addr string) net.PacketConn {
	c, err := net.ListenPacket("udp", addr)
	if err != nil {
		panic(err)
	}
	return c
}

func (s *serfDiscovery) Start() error {
	conn, err := net.ListenPacket("udp4", "0.0.0.0:1024")
	if err != nil {
		return err
	}

	s.pconn = ipv4.NewPacketConn(conn)
	if err := s.pconn.JoinGroup(s.iface, &net.UDPAddr{IP: s.group}); err != nil {
		conn.Close()
		return err
	}

	if err := s.pconn.SetControlMessage(ipv4.FlagDst, true); err != nil {
		conn.Close()
		return err
	}

	go func() {
		<-s.stop
		conn.Close()
	}()

	go func() {
		b := make([]byte, 1500)
		for {
			_, cm, src, err := s.pconn.ReadFrom(b)
			if err != nil {
				if strings.Contains(err.Error(), "closed network connection") {
					log.Printf("Closed connection, stopping discovery listener...")
					return
				}

				log.Printf("Failed to read packet: %s", err)
				continue
			}

			if cm.Dst.IsMulticast() {
				if cm.Dst.Equal(s.group) {
					sip, _, err := net.SplitHostPort(src.String())
					if err != nil {
						log.Printf("Multicast src '%s' has unexpected format: %s", src, err)
					}

					if sip == s.self.String() {
						continue
					}

					err = s.serf.Join(sip)
					if err != nil {
						log.Printf("Failed to join serf gossip at '%s': %s ", sip, err)
					}
				} else {
					continue
				}
			}
		}
	}()

	return nil
}

func TestAnnounceLocalhost(t *testing.T) {
	t.Parallel()
	srv := server{
		t: map[[20]byte]torrent{
			[20]byte{0xa3, 0x56, 0x41, 0x43, 0x74, 0x23, 0xe6, 0x26, 0xd9, 0x38, 0x25, 0x4a, 0x6b, 0x80, 0x49, 0x10, 0xa6, 0x67, 0xa, 0xc1}: {
				Seeders:  1,
				Leechers: 2,
				Peers: []util.CompactPeer{
					{[]byte{1, 2, 3, 4}, 5},
					{[]byte{6, 7, 8, 9}, 10},
				},
			},
		},
	}
	var err error
	srv.pc, err = net.ListenPacket("udp", ":0")
	require.NoError(t, err)
	defer srv.pc.Close()
	go func() {
		require.NoError(t, srv.serveOne())
	}()
	req := AnnounceRequest{
		NumWant: -1,
		Event:   Started,
	}
	rand.Read(req.PeerId[:])
	copy(req.InfoHash[:], []uint8{0xa3, 0x56, 0x41, 0x43, 0x74, 0x23, 0xe6, 0x26, 0xd9, 0x38, 0x25, 0x4a, 0x6b, 0x80, 0x49, 0x10, 0xa6, 0x67, 0xa, 0xc1})
	go func() {
		require.NoError(t, srv.serveOne())
	}()
	ar, err := Announce(fmt.Sprintf("udp://%s/announce", srv.pc.LocalAddr().String()), &req)
	require.NoError(t, err)
	assert.EqualValues(t, 1, ar.Seeders)
	assert.EqualValues(t, 2, len(ar.Peers))
}

// NewUDPHook returns logrus-compatible hook that sends data to UDP socket
func NewUDPHook(opts ...UDPOptionSetter) (*UDPHook, error) {
	f := &UDPHook{}
	for _, o := range opts {
		o(f)
	}
	if f.Clock == nil {
		f.Clock = clockwork.NewRealClock()
	}
	if f.clientNet == "" {
		f.clientNet = UDPDefaultNet
	}
	if f.clientAddr == "" {
		f.clientAddr = UDPDefaultAddr
	}
	addr, err := net.ResolveUDPAddr(f.clientNet, f.clientAddr)
	if err != nil {
		return nil, Wrap(err)
	}
	conn, err := net.ListenPacket("udp", ":0")
	if err != nil {
		return nil, Wrap(err)
	}
	f.addr = addr
	f.conn = conn.(*net.UDPConn)
	return f, nil
}

func (nr *NetworkReader) Start() {
	connection, err := net.ListenPacket("udp4", nr.host)
	if err != nil {
		nr.logger.Fatalf("Failed to listen on port. %s", err)
	}
	nr.logger.Infof("Listening on port %s", nr.host)
	nr.lock.Lock()
	nr.connection = connection
	nr.lock.Unlock()

	readBuffer := make([]byte, 65535) //buffer with size = max theoretical UDP size
	for {
		readCount, senderAddr, err := connection.ReadFrom(readBuffer)
		if err != nil {
			nr.logger.Debugf("Error while reading. %s", err)
			return
		}
		nr.logger.Debugf("NetworkReader: Read %d bytes from address %s", readCount, senderAddr)
		readData := make([]byte, readCount) //pass on buffer in size only of read data
		copy(readData, readBuffer[:readCount])

		atomic.AddUint64(&nr.receivedMessageCount, 1)
		atomic.AddUint64(&nr.receivedByteCount, uint64(readCount))
		metrics.BatchIncrementCounter(nr.contextName + ".receivedMessageCount")
		metrics.BatchAddCounter(nr.contextName+".receivedByteCount", uint64(readCount))
		nr.writer.Write(readData)
	}
}

func TestPacketConnMulticastSocketOptions(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")
	}
	ifi := nettest.RoutedInterface("ip6", 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 == "ip6" && !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 := ipv6.NewPacketConn(c)
		defer p.Close()

		if tt.src == nil {
			testMulticastSocketOptions(t, p, ifi, tt.grp)
		} else {
			testSourceSpecificMulticastSocketOptions(t, p, ifi, tt.grp, tt.src)
		}
	}
}

func icmpListen(v6 bool, ch chan ICMPMessage) {
	afnet := "ip4:icmp"
	if v6 {
		afnet = "ip6:ipv6-icmp"
	}

	c, err := net.ListenPacket(afnet, "")
	if err != nil {
		debug.Printf("ListenPacket failed: %v", err)
		return
	}
	defer c.Close()

	rawICMP := make([]byte, 256)
	for {
		_, fromAddr, err := c.ReadFrom(rawICMP)
		if err != nil {
			debug.Printf("ReadFrom failed: %v", err)
			return
		}
		msg, err := parseICMP(v6, fromAddr, rawICMP)
		if err != nil {
			debug.Printf("parseICMP failed: %v", err)
			continue
		}
		ch <- msg
	}
}

func newLocalPacketListener(network string) (net.PacketConn, error) {
	switch network {
	case "udp":
		if c, err := net.ListenPacket("udp4", "127.0.0.1:0"); err == nil {
			return c, nil
		}
		return net.ListenPacket("udp6", "[::1]:0")
	case "udp4":
		return net.ListenPacket("udp4", "127.0.0.1:0")
	case "udp6":
		return net.ListenPacket("udp6", "[::1]:0")
	case "unixgram":
		return net.ListenPacket(network, localPath())
	}
	return nil, fmt.Errorf("%s is not supported", network)
}

func main() {
	flag.Parse()
	ip, n, err := net.ParseCIDR(*src)
	if err != nil {
		log.Fatal(err)
	}

	c, err := net.ListenPacket("udp", net.JoinHostPort("0.0.0.0", fmt.Sprintf("%d", *port)))
	if err != nil {
		log.Fatal(err)
	}
	defer c.Close()

	go func() {
		dst := broadcast(n)
		for {
			if err := advert(c, ip, dst, n); err != nil {
				log.Println(err)
			}
			time.Sleep(5 * time.Second)
		}
	}()

	b := make([]byte, 8192)
	for {
		n, peer, err := c.ReadFrom(b)
		if err != nil {
			log.Println(err)
			continue
		}
		log.Printf("%d bytes rcvd from %v, %q\n", n, peer, string(b[:n]))
	}
}

func newUDPEchoServer() (*udpEchoServer, error) {
	packetconn, err := net.ListenPacket("udp", ":0")
	if err != nil {
		return nil, err
	}
	return &udpEchoServer{packetconn}, nil
}

func main() {
	listen = flag.String("listen", "127.0.0.1:4443", "Listen on this address.")
	quite = flag.Bool("quite", false, "Quite mode.")
	statsonly = flag.Bool(
		"statsonly", false, "Only prints stats on stdout and discard data.",
	)
	flag.Parse()

	conn, err := net.ListenPacket("udp4", *listen)

	if err != nil {
		fmt.Println(err)
		return
	}

	if !*quite {
		if *statsonly {
			fmt.Printf(
				"UDP: Server started on %s in statsonly mode.\n", *listen,
			)
		} else {
			fmt.Printf("UDP: Server started on %s.\n", *listen)
		}
	}

	obytes := make([]byte, 64*1024)
	start := time.Now()
	var bcount, count time.Duration

	for {
		bytes := obytes
		n, _, err := conn.ReadFrom(bytes)

		if err != nil {
			fmt.Println(err)
			continue
		}

		if *statsonly {
			count += 1
			bcount += time.Duration(n)

			now := time.Now()
			diff := now.Sub(start)

			if diff > 1e9 {
				fmt.Printf(
					"bps = %sps, pps = %d.\n",
					gutils.FormatBytes(float64(bcount)), count,
				)
				start = now
				bcount, count = 0, 0
			}

		} else {
			bytes = bytes[:n]
			fmt.Printf(string(bytes))
		}
	}
}