Golang net.ListenUDP函數代碼示例

func ListenAndServe(addr string, port int) {
	//addr_tcp, err := net.ResolveTCPAddr("tcp", l)
	//if err != nil {
	//	panic(err)
	//}
	//listen_tcp, err := net.ListenTCP("tcp", addr_tcp)
	//if err != nil {
	//	panic(err)
	//}
	//go tcp_listen(listen_tcp)
	rtp_l := fmt.Sprintf("%v:%v", addr, port)
	rtcp_l := fmt.Sprintf("%v:%v", addr, port+1)
	addr1, err := net.ResolveUDPAddr("udp", rtp_l)
	if err != nil {
		panic(err)
	}
	listen_rtp, err := net.ListenUDP("udp", addr1)
	if err != nil {
		panic(err)
	}
	go udp_rtp_listen(listen_rtp)

	addr2, err := net.ResolveUDPAddr("udp", rtcp_l)
	if err != nil {
		panic(err)
	}
	listen_rtcp, err := net.ListenUDP("udp", addr2)
	if err != nil {
		panic(err)
	}
	go udp_rtcp_listen(listen_rtcp)
}

func main() {
	//測試手動注冊兩個通道
	sip.GetChannel("10.2.42.197", "10.2.42.133")
	sip.GetChannel("10.2.42.133", "10.2.42.197")
	//鏈接WebRTC 服務
	go webrtcSocket.Init()
	//開啟出測地址
	go sip.InitListener()

	//監聽視頻端口
	service := ":8088"
	udpAddr, err := net.ResolveUDPAddr("udp", service)
	checkError(err)
	conn, err := net.ListenUDP("udp", udpAddr)
	checkError(err)
	fmt.Println("監聽端口")
	for {
		handleVideo(conn)
	}

	//監聽語音端口
	go func() {
		serviceAudio := ":11113"
		udpAddrAudio, err := net.ResolveUDPAddr("udp", serviceAudio)
		checkError(err)
		connAudio, err := net.ListenUDP("udp", udpAddrAudio)
		checkError(err)

		for {
			handleAudio(connAudio)
		}
	}()

}

func Test_ContextCloseFuncWithConn(t *testing.T) {

	time.Sleep(1 * time.Second)

	testResult := make(chan error)

	conns := make([]*net.UDPConn, 3)
	for x := 0; x < 3; x++ {
		a := net.UDPAddr{
			IP:   net.ParseIP("127.0.0.1"),
			Port: 12345 + x,
		}
		c, err := net.ListenUDP("udp", &a)
		if err != nil {
			t.Fatal(err.Error())
		}
		conns[x] = c
	}

	ctx := NewContextWithConn(conns)

	// Test done channel
	testTimeout := time.After(200 * time.Millisecond)
	go func() {
		select {
		case <-testTimeout:
			errMsg := "Expect to close done channel"
			testResult <- errors.New(errMsg)
		case <-ctx.DoneChan:
			testResult <- nil
		}
	}()

	ctx.Done()

	// Test if a connection not closed
	for x := 0; x < 3; x++ {
		a := net.UDPAddr{
			IP:   net.ParseIP("127.0.0.1"),
			Port: 12345 + x,
		}
		c, err := net.ListenUDP("udp", &a)
		if err != nil {
			t.Fatal(err.Error())
		}

		err = c.Close()
		if err != nil {
			t.Fatal(err.Error())
		}

	}

	err := <-testResult
	if err != nil {
		t.Fatal(err.Error())
	}

	time.Sleep(1 * time.Second)
}

func Udp_init(localListenPort, broadcastListenPort, message_size int, send_ch, receive_ch chan Udp_message) (err error) {
	//Generating broadcast address
	baddr, err = net.ResolveUDPAddr("udp4", "255.255.255.255:"+strconv.Itoa(broadcastListenPort))
	if err != nil {
		return err
	}

	//Generating localaddress
	tempConn, err := net.DialUDP("udp4", nil, baddr)
	defer tempConn.Close()
	tempAddr := tempConn.LocalAddr()
	laddr, err = net.ResolveUDPAddr("udp4", tempAddr.String())
	laddr.Port = localListenPort

	//Creating local listening connections
	localListenConn, err := net.ListenUDP("udp4", laddr)
	if err != nil {
		return err
	}

	//Creating listener on broadcast connection
	broadcastListenConn, err := net.ListenUDP("udp", baddr)
	if err != nil {
		localListenConn.Close()
		return err
	}

	go udp_receive_server(localListenConn, broadcastListenConn, message_size, receive_ch)
	go udp_transmit_server(localListenConn, broadcastListenConn, send_ch)

	//	fmt.Printf("Generating local address: \t Network(): %s \t String(): %s \n", laddr.Network(), laddr.String())
	//	fmt.Printf("Generating broadcast address: \t Network(): %s \t String(): %s \n", baddr.Network(), baddr.String())
	return err
}

func udpInit(localListenPort, broadcastListenPort, messageSize int, sendCh, receiveCh chan udpMessage) (err error) {
	//Generating broadcast address
	baddr, err = net.ResolveUDPAddr("udp4", "255.255.255.255:"+strconv.Itoa(broadcastListenPort))
	if err != nil {
		return err
	}

	//Generating localaddress
	tempConn, err := net.DialUDP("udp4", nil, baddr)
	defer tempConn.Close()
	tempAddr := tempConn.LocalAddr()
	laddr, err := net.ResolveUDPAddr("udp4", tempAddr.String())
	laddr.Port = localListenPort
	def.LocalIP = laddr.String()

	//Creating local listening connections
	localListenConn, err := net.ListenUDP("udp4", laddr)
	if err != nil {
		return err
	}

	//Creating listener on broadcast connection
	broadcastListenConn, err := net.ListenUDP("udp", baddr)
	if err != nil {
		localListenConn.Close()
		return err
	}
	udpConnection = true
	go udpReceiveServer(localListenConn, broadcastListenConn, messageSize, receiveCh)
	go udpTransmitServer(localListenConn, broadcastListenConn, sendCh)

	return err
}

func initSockets(BROADCAST_IP string, PORTNUM_COST string, PORTNUM_ORDER string) bool {

	//Create broadcast socket for orders
	broadcast_udp_addr, err := net.ResolveUDPAddr("udp", BROADCAST_IP+PORTNUM_ORDER)
	if err != nil {
		log.Println(" ResolveUDPAddr failed", err)
	}

	broadcast_order_conn, err := net.DialUDP("udp", nil, broadcast_udp_addr)
	if err != nil {
		log.Println("Could not establish UDP connection. Enter single eleveator mode. \n", err)
		return false
	}
	broadcast_order_conn = broadcast_order_conn

	//Create broadcast socket for cost updates
	broadcast_udp_addr, err = net.ResolveUDPAddr("udp", BROADCAST_IP+PORTNUM_COST)
	if err != nil {
		log.Println("ResolveUDPAddr failed", err)
	}

	broadcast_cost_conn, err = net.DialUDP("udp", nil, broadcast_udp_addr)
	if err != nil {
		log.Println("Could not establish UDP connection. Enter single eleveator mode. \n", err)
		return false
	}
	broadcast_cost_conn = broadcast_cost_conn

	//Create receiver socket for external orders
	listen_addr, err := net.ResolveUDPAddr("udp", PORTNUM_ORDER)
	if err != nil {
		log.Println("ResolveUDPAddr failed ", err)
	}

	receive_order_conn, err := net.ListenUDP("udp", listen_addr)
	if err != nil {
		log.Println("Could not establish UDP connection. Enter single eleveator mode. \n", err)
		return false
	}
	receive_order_conn = receive_order_conn

	//Create receiver socket for cost updates
	listen_addr, err = net.ResolveUDPAddr("udp", PORTNUM_COST)
	if err != nil {
		log.Println("ResolveUDPAddr failed ", err)
	}

	receive_cost_conn, err := net.ListenUDP("udp", listen_addr)
	if err != nil {
		log.Println("Could not establish UDP connection. Enter single eleveator mode.\n", err)
		return false
	}
	receive_cost_conn = receive_cost_conn

	return true
}

func Dial(remote string) (*UDPSession, error) {
	// defer SavePanic()
	//log.Println("Dial")
	remoteAddr, err := net.ResolveUDPAddr("udp", remote)
	if err != nil {
		return nil, err
	}

	tmpSock, _err := net.ListenUDP("udp", nil)
	if _err != nil {
		return nil, _err
	}

	// 必須新建一個 否則服務端新socket發送過來的數據 會直接被丟棄 接收不到
	localSock, _err := net.ListenUDP("udp", nil)
	if _err != nil {
		return nil, _err
	}
	localAddr := localSock.LocalAddr().(*net.UDPAddr)

	//buf := make([]byte, 1500) //udp包大小不超過1400
	wbuf := make([]byte, 5)
	buf := make([]byte, 5)
	wbuf[0] = CmdCreateSession
	binary.LittleEndian.PutUint32(wbuf[1:], uint32(localAddr.Port))
	for j := 0; j < 20; j = j + 1 {
		tmpSock.WriteTo(wbuf, remoteAddr)
		tmpSock.SetReadDeadline(time.Now().Add(300 * time.Millisecond))
		n, from, err := tmpSock.ReadFromUDP(buf)
		if n >= len(buf) && from.String() == remoteAddr.String() {
			if buf[0] == CmdCreateSessionRsp {
				//log.Println("CmdCreateSessionRsp")
				tmpSock.Close()
				newAddr := net.UDPAddr{
					IP:   from.IP,
					Port: int(binary.LittleEndian.Uint32(buf[1:])),
				}
				session := newUDPSession(nil, &newAddr, localSock, localAddr)
				go session.readLoop()
				go session.updateLoop()
				return session, nil
			}
		}
		if n < 0 {
			//log.Println("dial: n < 0 ")
			tmpSock.Close()
			localSock.Close()
			return nil, err
		}
	}

	tmpSock.Close()
	localSock.Close()
	return nil, errors.New("dial: no response")
}

/*
	This function initializes the UDP module. It sets the port for listening, broadcasting, the approved message size and the channels
	for communicating with the calling module. It returns the local IP-address of this system/module, and an error if if it fails(then ip is "").
*/
func Init(localListenPort, broadcastListenPort, messageSize int, sendChannel <-chan UDPMessage, receiveChannel chan<- UDPMessage) (localIP string, err error) {

	// Generate broadcast address
	broadcastAdress, err = net.ResolveUDPAddr(udp4, broadcastIp+strconv.Itoa(broadcastListenPort))
	if err != nil {
		log.Println("UDP:\t Could not resolve UDPAddress.")
		return "", err
	} else if debug {
		// We are in debug mode.
		log.Printf("UDP:\t Generating broadcast address:\t %s \n", broadcastAdress.String())
	}

	// Generate local address, uses the tempConnection to fetch address via the UDP dial.
	tempConnection, err := net.DialUDP(udp4, nil, broadcastAdress)
	if err != nil {
		log.Println("UDP:\t No network connection")
		return "", err
	}
	defer tempConnection.Close() // Makes sure the connection is closed when Init completes.
	tempAddress := tempConnection.LocalAddr()
	localAddress, err = net.ResolveUDPAddr(udp4, tempAddress.String())
	if err != nil {
		log.Println("UDP:\t Could not resolve local address.")
		return "", err
	} else if debug {
		log.Printf("UDP:\t Generating local address: \t%s \n", localAddress.String())
	}
	localAddress.Port = localListenPort // Set the port property of the *net.UDPAddr struct

	// Create local listening connections
	localListenConnection, err := net.ListenUDP(udp4, localAddress) // Listens for incoming UDP packets addressed to localAddress.
	if err != nil {
		log.Println("UDP:\t Couldn't create a UDP listener socket.")
		return "", err
	}
	if debug {
		log.Println("UDP:\t Created a UDP listener socket.")
	}

	// Create a listener on broadcast connection.
	broadcastListenConnection, err := net.ListenUDP(udp4, &net.UDPAddr{IP: net.IPv4(0, 0, 0, 0), Port: broadcastListenPort})
	if err != nil {
		log.Println("UDP:\t Could not create a UDP broadcast listen socket.")
		localListenConnection.Close()
		return "", err
	}
	if debug {
		log.Println("UDP:\t Created a UDP broadcast listen socket.")
	}
	// Start goroutines to handle incoming messages and sending outgoing messages.
	go udpReceiveServer(localListenConnection, broadcastListenConnection, messageSize, receiveChannel)
	go udpTransmitServer(localListenConnection, broadcastListenConnection, localListenPort, broadcastListenPort, sendChannel)
	return localAddress.IP.String(), err
}

func TestSecureUdp(t *testing.T) {
	data := []byte{0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff}
	port := ":0"
	udpAddr, err := net.ResolveUDPAddr("udp", port)
	if err != nil {
		t.Fatal(err)
	}
	ln, err := net.ListenUDP("udp", udpAddr)
	if err != nil {
		t.Fatal(err)
	}
	Addr := ln.LocalAddr()
	defer ln.Close()
	cipher, err := NewCipher("aes-256-cfb", "password")
	if err != nil {
		t.Fatal(err)
	}
	go func() {
		secureConn := NewPacketConn(ln, cipher.Copy())
		buf := make([]byte, 1500)
		n, src, err := secureConn.ReadFrom(buf)
		if err != nil {
			t.Fatal(err)
		}
		if !bytes.Equal(buf[:n], data) {
			t.Error("UDP server recieved data does not match.")
		}
		_, err = secureConn.WriteTo(buf[:n], src)
		if err != nil {
			t.Fatal(err)
		}
		return
	}()
	time.Sleep(100 * time.Millisecond)
	ln2, err := net.ListenUDP("udp", udpAddr)
	if err != nil {
		t.Fatal(err)
	}
	secureconn := NewPacketConn(ln2, cipher.Copy())
	_, err = secureconn.WriteTo(data, Addr)
	if err != nil {
		t.Fatal(err)
	}
	buf := make([]byte, 1500)
	n, _, err := secureconn.ReadFrom(buf)
	if err != nil {
		t.Fatal(err)
	}
	if !bytes.Equal(buf[:n], data) {
		t.Error("UDP client read does not match.")
	}

}

// Constructs server structure
func newServer(iface *net.Interface) (*Server, error) {
	// Create wildcard connections (because :5353 can be already taken by other apps)
	ipv4conn, err := net.ListenUDP("udp4", mdnsWildcardAddrIPv4)
	if err != nil {
		log.Printf("[ERR] bonjour: Failed to bind to udp4 port: %v", err)
	}
	ipv6conn, err := net.ListenUDP("udp6", mdnsWildcardAddrIPv6)
	if err != nil {
		log.Printf("[ERR] bonjour: Failed to bind to udp6 port: %v", err)
	}
	if ipv4conn == nil && ipv6conn == nil {
		return nil, fmt.Errorf("[ERR] bonjour: Failed to bind to any udp port!")
	}

	// Join multicast groups to receive announcements
	p1 := ipv4.NewPacketConn(ipv4conn)
	p2 := ipv6.NewPacketConn(ipv6conn)
	if iface != nil {
		if err := p1.JoinGroup(iface, &net.UDPAddr{IP: mdnsGroupIPv4}); err != nil {
			return nil, err
		}
		if err := p2.JoinGroup(iface, &net.UDPAddr{IP: mdnsGroupIPv6}); err != nil {
			return nil, err
		}
	} else {
		ifaces, err := net.Interfaces()
		if err != nil {
			return nil, err
		}
		errCount1, errCount2 := 0, 0
		for _, iface := range ifaces {
			if err := p1.JoinGroup(&iface, &net.UDPAddr{IP: mdnsGroupIPv4}); err != nil {
				errCount1++
			}
			if err := p2.JoinGroup(&iface, &net.UDPAddr{IP: mdnsGroupIPv6}); err != nil {
				errCount2++
			}
		}
		if len(ifaces) == errCount1 && len(ifaces) == errCount2 {
			return nil, fmt.Errorf("Failed to join multicast group on all interfaces!")
		}
	}

	s := &Server{
		ipv4conn: ipv4conn,
		ipv6conn: ipv6conn,
		ttl:      3200,
	}

	return s, nil
}

// Client structure constructor
func newClient(iface *net.Interface, serviceChan chan<- *ServiceEntry) (*client, error) {
	// Create wildcard connections (because :5353 can be already taken by other apps)
	ipv4conn, err := net.ListenUDP("udp4", mdnsWildcardAddrIPv4)
	if err != nil {
		log.Printf("[ERR] bonjour: Failed to bind to udp4 port: %v", err)
	}
	ipv6conn, err := net.ListenUDP("udp6", mdnsWildcardAddrIPv6)
	if ipv4conn == nil && ipv6conn == nil {
		return nil, fmt.Errorf("[ERR] bonjour: Failed to bind to any udp port!")
	}

	// Join multicast groups to receive announcements from server
	p1 := ipv4.NewPacketConn(ipv4conn)
	p2 := ipv6.NewPacketConn(ipv6conn)
	if iface != nil {
		if err := p1.JoinGroup(iface, &net.UDPAddr{IP: mdnsGroupIPv4}); err != nil {
			return nil, err
		}
		if err := p2.JoinGroup(iface, &net.UDPAddr{IP: mdnsGroupIPv6}); err != nil {
			return nil, err
		}
	} else {
		ifaces, err := net.Interfaces()
		if err != nil {
			return nil, err
		}
		errCount1, errCount2 := 0, 0
		for _, iface := range ifaces {
			if err := p1.JoinGroup(&iface, &net.UDPAddr{IP: mdnsGroupIPv4}); err != nil {
				errCount1++
			}
			if err := p2.JoinGroup(&iface, &net.UDPAddr{IP: mdnsGroupIPv6}); err != nil {
				errCount2++
			}
		}
		if len(ifaces) == errCount1 && len(ifaces) == errCount2 {
			return nil, fmt.Errorf("Failed to join multicast group on all interfaces!")
		}
	}

	c := &client{
		lookupParams: make(map[string]*LookupParams),
		serviceChan:  serviceChan,
		ipv4conn:     ipv4conn,
		ipv6conn:     ipv6conn,
		closedCh:     make(chan bool),
	}

	return c, nil
}

// ListenOnTransports listens for incoming RTP and RTCP packets addressed
// to this transport.
//
func (tp *TransportUDP) ListenOnTransports() (err error) {
	tp.dataConn, err = net.ListenUDP(tp.localAddrRtp.Network(), tp.localAddrRtp)
	if err != nil {
		return
	}
	tp.ctrlConn, err = net.ListenUDP(tp.localAddrRtcp.Network(), tp.localAddrRtcp)
	if err != nil {
		tp.dataConn.Close()
		tp.dataConn = nil
		return
	}
	go tp.readDataPacket()
	go tp.readCtrlPacket()
	return nil
}

func InitSendService(speed int64, from string, to string) (service *SendService, err error) {
	service = new(SendService)
	service.speed = speed

	addr, err := net.ResolveUDPAddr("udp4", from)
	if err != nil {
		return nil, err
	}
	service.addr, err = net.ResolveUDPAddr("udp4", to)
	if err != nil {
		return nil, err
	}
	service.conn, err = net.ListenUDP("udp4", addr)
	if err != nil {
		return nil, err
	}

	// conn, err := net.Dial("udp", "127.0.0.1:12345")

	// if err != nil {
	// 	panic(err)
	// }

	// service.conn = conn

	return service, nil
}

func NewDiscoverer(id string, port int, extPort int, extServer string) (*Discoverer, error) {
	local4 := &net.UDPAddr{IP: net.IP{0, 0, 0, 0}, Port: AnnouncementPort}
	conn, err := net.ListenUDP("udp4", local4)
	if err != nil {
		return nil, err
	}

	disc := &Discoverer{
		MyID:             id,
		ListenPort:       port,
		BroadcastIntv:    30 * time.Second,
		ExtListenPort:    extPort,
		ExtBroadcastIntv: 1800 * time.Second,

		conn:      conn,
		registry:  make(map[string]string),
		extServer: extServer,
	}

	go disc.recvAnnouncements()

	if disc.ListenPort > 0 {
		disc.sendAnnouncements()
	}
	if len(disc.extServer) > 0 && disc.ExtListenPort > 0 {
		disc.sendExtAnnouncements()
	}

	return disc, nil
}

// Listen creates a UDP server that parses statsd data into metrics and
// sends them over a channel.
func Listen(addr string, c chan Packet, clean bool) {
	cleaner := NewCleaner()
	laddr, err := net.ResolveUDPAddr("udp", addr)
	if err != nil {
		log.Fatalln("fatal: failed to resolve address", err)
	}
	conn, err := net.ListenUDP("udp", laddr)
	if err != nil {
		log.Fatalln("fatal: failed to listen", err)
	}
	for {
		buf := make([]byte, 1452)
		n, raddr, err := conn.ReadFrom(buf[:])
		t := time.Now().UTC()
		if err != nil {
			log.Println("error: Failed to recieve packet", err)
		} else {
			metrics, err := Parse(buf[0:n])
			if err != nil {
				log.Println("error: Failed to recieve packet", err)
			}
			if metrics != nil {
				var p Packet
				if clean {
					cleaned := cleaner.CleanMetrics(*metrics)
					p = Packet{&cleaned, raddr, t}
				} else {
					p = Packet{metrics, raddr, t}
				}

				c <- p
			}
		}
	}
}