Golang ipv4.NewPacketConn函數代碼示例

func TestUDPMultiplePacketConnWithMultipleGroupListeners(t *testing.T) {
	switch runtime.GOOS {
	case "plan9", "windows":
		t.Skipf("not supported on %q", 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.Fatalf("net.ListenPacket failed: %v", err)
		}
		defer c1.Close()

		c2, err := net.ListenPacket("udp4", "224.0.0.0:1024") // wildcard address with reusable port
		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 := nettest.IsMulticastCapable("ip4", &ifi); !ok {
				continue
			}
			for _, p := range ps {
				if err := p.JoinGroup(&ifi, gaddr); err != nil {
					t.Fatalf("ipv4.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("ipv4.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)
				}
			}
		}
	}
}

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

	c, err := net.ListenPacket("udp4", "224.0.0.0:1024") // see RFC 4727
	if err != nil {
		t.Fatalf("net.ListenPacket failed: %v", err)
	}
	defer c.Close()

	ifi := loopbackInterface()
	if ifi == nil {
		t.Logf("skipping test; an appropriate interface not found")
		return
	}
	dst, err := net.ResolveUDPAddr("udp4", "224.0.0.254:1024") // see RFC 4727
	if err != nil {
		t.Fatalf("net.ResolveUDPAddr failed: %v", err)
	}

	p := ipv4.NewPacketConn(c)
	if err := p.JoinGroup(ifi, dst); err != nil {
		t.Fatalf("ipv4.PacketConn.JoinGroup on %v failed: %v", ifi, err)
	}
	if err := p.SetMulticastInterface(ifi); err != nil {
		t.Fatalf("ipv4.PacketConn.SetMulticastInterface failed: %v", err)
	}
	if err := p.SetMulticastLoopback(true); err != nil {
		t.Fatalf("ipv4.PacketConn.SetMulticastLoopback failed: %v", err)
	}
	runPayloadTransponder(t, p, []byte("HELLO-R-U-THERE"), dst)
}

// ServeIf does the same job as Serve(), but listens and responds on the
// specified network interface (by index).  It also doubles as an example of
// how to leverage the dhcp4.ServeConn interface.
//
// If your target only has one interface, use Serve(). ServeIf() requires an
// import outside the std library.  Serving DHCP over multiple interfaces will
// require your own dhcp4.ServeConn, as listening to broadcasts utilises all
// interfaces (so you cannot have more than on listener).
func ServeIf(ifIndex int, conn net.PacketConn, handler Handler) error {
	p := ipv4.NewPacketConn(conn)
	if err := p.SetControlMessage(ipv4.FlagInterface, true); err != nil {
		return err
	}
	return Serve(&serveIfConn{ifIndex: ifIndex, conn: p}, handler)
}

func TestReadWriteMulticastIPPayloadICMP(t *testing.T) {
	if testing.Short() || !*testExternal {
		t.Logf("skipping test to avoid external network")
		return
	}
	if os.Getuid() != 0 {
		t.Logf("skipping test; must be root")
		return
	}

	c, err := net.ListenPacket("ip4:icmp", "0.0.0.0")
	if err != nil {
		t.Fatalf("net.ListenPacket failed: %v", err)
	}
	defer c.Close()

	ifi := loopbackInterface()
	if ifi == nil {
		t.Logf("skipping test; an appropriate interface not found")
		return
	}
	dst, err := net.ResolveIPAddr("ip4", "224.0.0.254") // see RFC 4727
	if err != nil {
		t.Fatalf("net.ResolveIPAddr failed: %v", err)
	}

	p := ipv4.NewPacketConn(c)
	if err := p.JoinGroup(ifi, dst); err != nil {
		t.Fatalf("ipv4.PacketConn.JoinGroup on %v failed: %v", ifi, err)
	}
	if err := p.SetMulticastInterface(ifi); err != nil {
		t.Fatalf("ipv4.PacketConn.SetMulticastInterface failed: %v", err)
	}
	cf := ipv4.FlagTTL | ipv4.FlagDst | ipv4.FlagInterface
	for i, toggle := range []bool{true, false, true} {
		wb, err := (&icmpMessage{
			Type: icmpv4EchoRequest, Code: 0,
			Body: &icmpEcho{
				ID: os.Getpid() & 0xffff, Seq: i + 1,
				Data: []byte("HELLO-R-U-THERE"),
			},
		}).Marshal()
		if err != nil {
			t.Fatalf("icmpMessage.Marshal failed: %v", err)
		}
		if err := p.SetControlMessage(cf, toggle); err != nil {
			t.Fatalf("ipv4.PacketConn.SetControlMessage failed: %v", err)
		}
		rb := writeThenReadPayload(t, i, p, wb, dst)
		m, err := parseICMPMessage(rb)
		if err != nil {
			t.Fatalf("parseICMPMessage failed: %v", err)
		}
		if m.Type != icmpv4EchoReply || m.Code != 0 {
			t.Fatalf("got type=%v, code=%v; expected type=%v, code=%v", m.Type, m.Code, icmpv4EchoReply, 0)
		}
	}
}

// setInterface is used to set the query interface, uses sytem
// default if not provided
func (c *client) setInterface(iface *net.Interface) error {
	p := ipv4.NewPacketConn(c.ipv4UnicastConn)
	if err := p.SetMulticastInterface(iface); err != nil {
		return err
	}
	p2 := ipv6.NewPacketConn(c.ipv6UnicastConn)
	if err := p2.SetMulticastInterface(iface); err != nil {
		return err
	}
	p = ipv4.NewPacketConn(c.ipv4MulticastConn)
	if err := p.SetMulticastInterface(iface); err != nil {
		return err
	}
	p2 = ipv6.NewPacketConn(c.ipv6MulticastConn)
	if err := p2.SetMulticastInterface(iface); err != nil {
		return err
	}
	return nil
}

// args:
// - addr: multicast group/address to listen to
// - port: port number; addr:port builds the mcast socket
// - iface: name of network interface to listen to
// - d_dl_sock:
// - stopch:
func ListenUDPMcast(addr, port, iface string, d_dl_sock *zmq.Socket,
	stopch chan bool) {
	eth, err := net.InterfaceByName(iface)
	if err != nil {
		fmt.Println("Error interface:", err.Error())
		os.Exit(1)
	}

	group := net.ParseIP(addr)
	if group == nil {
		fmt.Println("Error: invalid group address:", addr)
		os.Exit(1)
	}

	// listen to all udp packets on mcast port
	c, err := net.ListenPacket("udp4", "0.0.0.0:"+port)
	if err != nil {
		fmt.Println("Error listening for mcast:", err.Error())
		os.Exit(1)
	}
	// close the listener when the application closes
	defer c.Close()

	// join mcast group
	p := ipv4.NewPacketConn(c)
	if err := p.JoinGroup(eth, &net.UDPAddr{IP: group}); err != nil {
		fmt.Println("Error joining:", err.Error())
		os.Exit(1)
	}
	fmt.Println("Listening on " + addr + ":" + port)

	// enable transmissons of control message
	if err := p.SetControlMessage(ipv4.FlagDst, true); err != nil {
		fmt.Println("Error control message", err.Error())
	}

	c1 := devreader.MakeChannel(UMSocket{p, group})

LOOP:
	for {
		select {
		case v1 := <-c1:
			fmt.Println("received UDP multicast")
			// forward to coord node
			d_dl_sock.Send(string(v1), 0)

		case <-stopch:
			break LOOP
		}

	}
}

func TestPacketConnReadWriteUnicastUDP(t *testing.T) {
	switch runtime.GOOS {
	case "nacl", "plan9", "solaris", "windows":
		t.Skipf("not supported on %q", runtime.GOOS)
	}
	ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagLoopback)
	if ifi == nil {
		t.Skipf("not available on %q", runtime.GOOS)
	}

	c, err := net.ListenPacket("udp4", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("net.ListenPacket failed: %v", err)
	}
	defer c.Close()

	dst, err := net.ResolveUDPAddr("udp4", c.LocalAddr().String())
	if err != nil {
		t.Fatalf("net.ResolveUDPAddr failed: %v", err)
	}
	p := ipv4.NewPacketConn(c)
	defer p.Close()
	cf := ipv4.FlagTTL | ipv4.FlagDst | ipv4.FlagInterface

	for i, toggle := range []bool{true, false, true} {
		if err := p.SetControlMessage(cf, toggle); err != nil {
			if protocolNotSupported(err) {
				t.Skipf("not supported on %q", runtime.GOOS)
			}
			t.Fatalf("ipv4.PacketConn.SetControlMessage failed: %v", err)
		}
		p.SetTTL(i + 1)
		if err := p.SetWriteDeadline(time.Now().Add(100 * time.Millisecond)); err != nil {
			t.Fatalf("ipv4.PacketConn.SetWriteDeadline failed: %v", err)
		}
		if _, err := p.WriteTo([]byte("HELLO-R-U-THERE"), nil, dst); err != nil {
			t.Fatalf("ipv4.PacketConn.WriteTo failed: %v", err)
		}
		rb := make([]byte, 128)
		if err := p.SetReadDeadline(time.Now().Add(100 * time.Millisecond)); err != nil {
			t.Fatalf("ipv4.PacketConn.SetReadDeadline failed: %v", err)
		}
		if _, cm, _, err := p.ReadFrom(rb); err != nil {
			t.Fatalf("ipv4.PacketConn.ReadFrom failed: %v", err)
		} else {
			t.Logf("rcvd cmsg: %v", cm)
		}
	}
}

func TestUDPUnicastSockopt(t *testing.T) {
	for _, tt := range unicastSockoptTests {
		c, err := net.ListenPacket("udp4", "127.0.0.1:0")
		if err != nil {
			t.Errorf("net.ListenPacket failed: %v", err)
			return
		}
		defer c.Close()

		p := ipv4.NewPacketConn(c)
		if err := testUnicastSockopt(t, tt, p); err != nil {
			break
		}
	}
}

func TestReadWriteUnicastIPPayloadUDP(t *testing.T) {
	c, err := net.ListenPacket("udp4", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("net.ListenPacket failed: %v", err)
	}
	defer c.Close()

	dst, err := net.ResolveUDPAddr("udp4", c.LocalAddr().String())
	if err != nil {
		t.Fatalf("net.ResolveUDPAddr failed: %v", err)
	}

	p := ipv4.NewPacketConn(c)
	runPayloadTransponder(t, p, []byte("HELLO-R-U-THERE"), dst)
}

func TestUDPMulticastSockopt(t *testing.T) {
	if testing.Short() || !*testExternal {
		t.Skip("to avoid external network")
	}

	for _, tt := range multicastSockoptTests {
		c, err := net.ListenPacket("udp4", "0.0.0.0:0")
		if err != nil {
			t.Fatalf("net.ListenPacket failed: %v", err)
		}
		defer c.Close()

		p := ipv4.NewPacketConn(c)
		testMulticastSockopt(t, tt, p, &net.UDPAddr{IP: tt.gaddr})
	}
}

func (s *Ssdp) createSocket() error {
	group := net.IPv4(239, 255, 255, 250)
	interfaces, err := net.Interfaces()
	if err != nil {
		s.logger.Errorf("net.Interfaces error", err)
		return err
	}
	con, err := net.ListenPacket("udp4", "0.0.0.0:1900")
	if err != nil {
		s.logger.Errorf("net.ListenPacket error: %v", err)
		return err
	}
	p := ipv4.NewPacketConn(con)
	p.SetMulticastLoopback(true)
	didFindInterface := false
	for i, v := range interfaces {
		ef, err := v.Addrs()
		if err != nil {
			continue
		}
		hasRealAddress := false
		for k := range ef {
			asIp := net.ParseIP(ef[k].String())
			if asIp.IsUnspecified() {
				continue
			}
			hasRealAddress = true
			break
		}
		if !hasRealAddress {
			continue
		}
		err = p.JoinGroup(&v, &net.UDPAddr{IP: group})
		if err != nil {
			s.logger.Warnf("join group %d %v", i, err)
			continue
		}
		didFindInterface = true
	}
	if !didFindInterface {
		return errors.New("Unable to find a compatible network interface!")
	}
	s.socket.socket = p
	s.socket.rawSocket = con
	s.socket.readBytes = make([]byte, 2048)
	return nil
}

func TestUDPPerInterfaceSinglePacketConnWithSingleGroupListener(t *testing.T) {
	switch runtime.GOOS {
	case "plan9", "windows":
		t.Skipf("not supported on %q", 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.Fatalf("net.Interfaces failed: %v", 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.Fatalf("net.ListenPacket with %v failed: %v", ip, err)
		}
		defer c.Close()
		p := ipv4.NewPacketConn(c)
		if err := p.JoinGroup(&ifi, &gaddr); err != nil {
			t.Fatalf("ipv4.PacketConn.JoinGroup on %v failed: %v", ifi, err)
		}
		mlt = append(mlt, &ml{p, &ift[i]})
	}
	for _, m := range mlt {
		if err := m.c.LeaveGroup(m.ifi, &gaddr); err != nil {
			t.Fatalf("ipv4.PacketConn.LeaveGroup on %v failed: %v", m.ifi, err)
		}
	}
}

func TestReadWriteUnicastIPPayloadICMP(t *testing.T) {
	if os.Getuid() != 0 {
		t.Logf("skipping test; must be root")
		return
	}

	c, err := net.ListenPacket("ip4:icmp", "0.0.0.0")
	if err != nil {
		t.Fatalf("net.ListenPacket failed: %v", err)
	}
	defer c.Close()

	dst, err := net.ResolveIPAddr("ip4", "127.0.0.1")
	if err != nil {
		t.Fatalf("ResolveIPAddr failed: %v", err)
	}
	p := ipv4.NewPacketConn(c)
	cf := ipv4.FlagTTL | ipv4.FlagDst | ipv4.FlagInterface
	for i, toggle := range []bool{true, false, true} {
		wb, err := (&icmpMessage{
			Type: icmpv4EchoRequest, Code: 0,
			Body: &icmpEcho{
				ID: os.Getpid() & 0xffff, Seq: i + 1,
				Data: []byte("HELLO-R-U-THERE"),
			},
		}).Marshal()
		if err != nil {
			t.Fatalf("icmpMessage.Marshal failed: %v", err)
		}
		if err := p.SetControlMessage(cf, toggle); err != nil {
			t.Fatalf("ipv4.PacketConn.SetControlMessage failed: %v", err)
		}
		rb := writeThenReadPayload(t, i, p, wb, dst)
		m, err := parseICMPMessage(rb)
		if err != nil {
			t.Fatalf("parseICMPMessage failed: %v", err)
		}
		if m.Type != icmpv4EchoReply || m.Code != 0 {
			t.Fatalf("got type=%v, code=%v; expected type=%v, code=%v", m.Type, m.Code, icmpv4EchoReply, 0)
		}
	}
}

func BenchmarkReadWriteIPv4UDP(b *testing.B) {
	c, dst, err := benchmarkUDPListener()
	if err != nil {
		b.Fatalf("benchmarkUDPListener failed: %v", err)
	}
	defer c.Close()

	p := ipv4.NewPacketConn(c)
	cf := ipv4.FlagTTL | ipv4.FlagInterface
	if err := p.SetControlMessage(cf, true); err != nil {
		b.Fatalf("ipv4.PacketConn.SetControlMessage failed: %v", err)
	}
	ifi := loopbackInterface()

	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)
	}
}