Signed-off-by: arraykeys@gmail.com <arraykeys@gmail.com>

config.go

@@ -13,7 +13,7 @@ import (
 
 var (
 	app     *kingpin.Application
-	service services.ServiceItem
+	service *services.ServiceItem
 )
 
 func initConfig() (err error) {
@@ -21,7 +21,7 @@ func initConfig() (err error) {
 	//define  args
 	tcpArgs := services.TCPArgs{}
 	httpArgs := services.HTTPArgs{}
-	tlsArgs := services.TLSArgs{}
+	// tlsArgs := services.TLSArgs{}
 	udpArgs := services.UDPArgs{}
 
 	//build srvice args
@@ -31,8 +31,8 @@ func initConfig() (err error) {
 	args.Local = app.Flag("local", "local ip:port to listen").Short('p').Default(":33080").String()
 	certTLS := app.Flag("cert", "cert file for tls").Short('C').Default("proxy.crt").String()
 	keyTLS := app.Flag("key", "key file for tls").Short('K').Default("proxy.key").String()
-	args.PoolSize = app.Flag("pool-size", "conn pool size , which connect to parent proxy, zero: means turn off pool").Default("50").Int()
+	args.PoolSize = app.Flag("pool-size", "conn pool size , which connect to parent proxy, zero: means turn off pool").Short('L').Default("50").Int()
-	args.CheckParentInterval = app.Flag("check-parent-interval", "check if proxy is okay every interval seconds,zero: means no check").Default("3").Int()
+	args.CheckParentInterval = app.Flag("check-parent-interval", "check if proxy is okay every interval seconds,zero: means no check").Short('I').Default("3").Int()
 
 	//########http#########
 	http := app.Command("http", "proxy on http mode")
@@ -49,13 +49,13 @@ func initConfig() (err error) {
 
 	//########tcp#########
 	tcp := app.Command("tcp", "proxy on tcp mode")
-	tcpArgs.Timeout = tcp.Flag("timeout", "tcp timeout milliseconds when connect to real server or parent proxy").Default("2000").Int()
+	tcpArgs.Timeout = tcp.Flag("timeout", "tcp timeout milliseconds when connect to real server or parent proxy").Short('t').Default("2000").Int()
 	tcpArgs.ParentType = tcp.Flag("parent-type", "parent protocol type <tls|tcp|udp>").Short('T').Enum("tls", "tcp", "udp")
-
+	tcpArgs.IsTLS = tcp.Flag("tls", "proxy on tls mode").Default("false").Bool()
-	//########tls#########
+	//########udp#########
-	tls := app.Command("tls", "proxy on tls mode")
+	udp := app.Command("udp", "proxy on udp mode")
-	tlsArgs.Timeout = tls.Flag("timeout", "tcp timeout milliseconds when connect to real server or parent proxy").Default("2000").Int()
+	udpArgs.Timeout = udp.Flag("timeout", "tcp timeout milliseconds when connect to parent proxy").Short('t').Default("2000").Int()
-	tlsArgs.ParentType = tls.Flag("parent-type", "parent protocol type <tls|tcp|udp>").Short('T').Enum("tls", "tcp", "udp")
+	udpArgs.ParentType = udp.Flag("parent-type", "parent protocol type <tls|tcp|udp>").Short('T').Enum("tls", "tcp", "udp")
 
 	kingpin.MustParse(app.Parse(os.Args[1:]))
 
@@ -64,7 +64,7 @@ func initConfig() (err error) {
 	}
 	httpArgs.Args = args
 	tcpArgs.Args = args
-	tlsArgs.Args = args
+	// tlsArgs.Args = args
 	udpArgs.Args = args
 
 	//keygen
@@ -78,7 +78,6 @@ func initConfig() (err error) {
 	serviceName := kingpin.MustParse(app.Parse(os.Args[1:]))
 	services.Regist("http", services.NewHTTP(), httpArgs)
 	services.Regist("tcp", services.NewTCP(), tcpArgs)
-	services.Regist("tls", services.NewTLS(), tlsArgs)
 	services.Regist("udp", services.NewUDP(), udpArgs)
 	service, err = services.Run(serviceName)
 	if err != nil {

services/args.go

@@ -22,12 +22,9 @@ type TCPArgs struct {
 	Args
 	Timeout    *int
 	ParentType *string
+	IsTLS      *bool
 }
-type TLSArgs struct {
+
-	Args
-	Timeout    *int
-	ParentType *string
-}
 type HTTPArgs struct {
 	Args
 	Always      *bool
@@ -43,4 +40,13 @@ type HTTPArgs struct {
 }
 type UDPArgs struct {
 	Args
+	ParentType *string
+	Timeout    *int
+}
+
+func (a *TCPArgs) Protocol() string {
+	if *a.IsTLS {
+		return "tls"
+	}
+	return "tcp"
 }

services/http.go

@@ -2,6 +2,7 @@ package services
 
 import (
 	"fmt"
+	"io"
 	"log"
 	"net"
 	"proxy/utils"
@@ -61,7 +62,6 @@ func (s *HTTP) Clean() {
 	s.StopService()
 }
 func (s *HTTP) callback(inConn net.Conn) {
-	go func() {
 	defer func() {
 		if err := recover(); err != nil {
 			log.Printf("http(s) conn handler crashed with err : %s \nstack: %s", err, string(debug.Stack()))
@@ -69,7 +69,9 @@ func (s *HTTP) callback(inConn net.Conn) {
 	}()
 	req, err := utils.NewHTTPRequest(&inConn, 4096, s.IsBasicAuth(), &s.basicAuth)
 	if err != nil {
+		if err != io.EOF {
 			log.Printf("decoder error , form %s, ERR:%s", err, inConn.RemoteAddr())
+		}
 		utils.CloseConn(&inConn)
 		return
 	}
@@ -93,7 +95,6 @@ func (s *HTTP) callback(inConn net.Conn) {
 		}
 		utils.CloseConn(&inConn)
 	}
-	}()
 }
 func (s *HTTP) OutToTCP(useProxy bool, address string, inConn *net.Conn, req *utils.HTTPRequest) (err error) {
 	inAddr := (*inConn).RemoteAddr().String()

services/service.go

@@ -16,16 +16,16 @@ type ServiceItem struct {
 	Name string
 }
 
-var servicesMap = map[string]ServiceItem{}
+var servicesMap = map[string]*ServiceItem{}
 
 func Regist(name string, s Service, args interface{}) {
-	servicesMap[name] = ServiceItem{
+	servicesMap[name] = &ServiceItem{
 		S:    s,
 		Args: args,
 		Name: name,
 	}
 }
-func Run(name string) (service ServiceItem, err error) {
+func Run(name string) (service *ServiceItem, err error) {
 	service, ok := servicesMap[name]
 	if ok {
 		go func() {

services/tcp.go

@@ -2,10 +2,12 @@ package services
 
 import (
 	"fmt"
+	"io"
 	"log"
 	"net"
 	"proxy/utils"
 	"runtime/debug"
+	"time"
 
 	"strconv"
 )
@@ -34,7 +36,7 @@ func (s *TCP) Start(args interface{}) (err error) {
 	if *s.cfg.Parent != "" {
 		log.Printf("use %s parent %s", *s.cfg.ParentType, *s.cfg.Parent)
 	} else {
-		log.Fatalf("parent required for tcp", *s.cfg.Local)
+		log.Fatalf("parent required for %s %s", s.cfg.Protocol(), *s.cfg.Local)
 	}
 
 	s.InitService()
@@ -42,11 +44,25 @@ func (s *TCP) Start(args interface{}) (err error) {
 	host, port, _ := net.SplitHostPort(*s.cfg.Local)
 	p, _ := strconv.Atoi(port)
 	sc := utils.NewServerChannel(host, p)
-	err = sc.ListenTCP(func(inConn net.Conn) {
+	if !*s.cfg.IsTLS {
-		go func() {
+		err = sc.ListenTCP(s.callback)
+	} else {
+		err = sc.ListenTls(s.cfg.CertBytes, s.cfg.KeyBytes, s.callback)
+	}
+	if err != nil {
+		return
+	}
+	log.Printf("%s proxy on %s", s.cfg.Protocol(), (*sc.Listener).Addr())
+	return
+}
+
+func (s *TCP) Clean() {
+	s.StopService()
+}
+func (s *TCP) callback(inConn net.Conn) {
 	defer func() {
 		if err := recover(); err != nil {
-					log.Printf("tcp conn handler crashed with err : %s \nstack: %s", err, string(debug.Stack()))
+			log.Printf("%s conn handler crashed with err : %s \nstack: %s", s.cfg.Protocol(), err, string(debug.Stack()))
 		}
 	}()
 	var err error
@@ -64,19 +80,7 @@ func (s *TCP) Start(args interface{}) (err error) {
 		log.Printf("connect to %s parent %s fail, ERR:%s", *s.cfg.ParentType, *s.cfg.Parent, err)
 		utils.CloseConn(&inConn)
 	}
-		}()
-	})
-	if err != nil {
-		return
 }
-	log.Printf("tcp proxy on %s", (*sc.Listener).Addr())
-	return
-}
-
-func (s *TCP) Clean() {
-	s.StopService()
-}
-
 func (s *TCP) OutToTCP(inConn *net.Conn) (err error) {
 	var outConn net.Conn
 	var _outConn interface{}
@@ -102,7 +106,52 @@ func (s *TCP) OutToTCP(inConn *net.Conn) (err error) {
 	return
 }
 func (s *TCP) OutToUDP(inConn *net.Conn) (err error) {
+	log.Printf("conn created , remote : %s ", (*inConn).RemoteAddr())
+	for {
+		srcAddr, body, err := utils.ReadUDPPacket(inConn)
+		if err == io.EOF || err == io.ErrUnexpectedEOF {
+			//log.Printf("connection %s released", srcAddr)
+			utils.CloseConn(inConn)
+			break
+		}
+		//log.Debugf("udp packet revecived:%s,%v", srcAddr, body)
+		dstAddr, err := net.ResolveUDPAddr("udp", *s.cfg.Parent)
+		if err != nil {
+			log.Printf("can't resolve address: %s", err)
+			utils.CloseConn(inConn)
+			break
+		}
+		clientSrcAddr := &net.UDPAddr{IP: net.IPv4zero, Port: 0}
+		conn, err := net.DialUDP("udp", clientSrcAddr, dstAddr)
+		if err != nil {
+			log.Printf("connect to udp %s fail,ERR:%s", dstAddr.String(), err)
+			continue
+		}
+		conn.SetDeadline(time.Now().Add(time.Millisecond * time.Duration(*s.cfg.Timeout)))
+		_, err = conn.Write(body)
+		if err != nil {
+			log.Printf("send udp packet to %s fail,ERR:%s", dstAddr.String(), err)
+			continue
+		}
+		//log.Debugf("send udp packet to %s success", dstAddr.String())
+		buf := make([]byte, 512)
+		len, _, err := conn.ReadFromUDP(buf)
+		if err != nil {
+			log.Printf("read udp response from %s fail ,ERR:%s", dstAddr.String(), err)
+			continue
+		}
+		respBody := buf[0:len]
+		//log.Debugf("revecived udp packet from %s , %v", dstAddr.String(), respBody)
+		_, err = (*inConn).Write(utils.UDPPacket(srcAddr, respBody))
+		if err != nil {
+			log.Printf("send udp response fail ,ERR:%s", err)
+			utils.CloseConn(inConn)
+			break
+		}
+		//log.Printf("send udp response success ,from:%s", dstAddr.String())
+	}
 	return
+
 }
 func (s *TCP) InitOutConnPool() {
 	if *s.cfg.ParentType == TYPE_TLS || *s.cfg.ParentType == TYPE_TCP {

services/tls.go

@@ -1,117 +0,0 @@
-package services
-
-import (
-	"fmt"
-	"log"
-	"net"
-	"proxy/utils"
-	"runtime/debug"
-	"strconv"
-)
-
-type TLS struct {
-	outPool utils.OutPool
-	cfg     TLSArgs
-}
-
-func NewTLS() Service {
-	return &TLS{}
-}
-func (s *TLS) InitService() {
-	s.InitOutConnPool()
-}
-func (s *TLS) StopService() {
-	if s.outPool.Pool != nil {
-		s.outPool.Pool.ReleaseAll()
-	}
-}
-func (s *TLS) Start(args interface{}) (err error) {
-	s.cfg = args.(TLSArgs)
-	if *s.cfg.Parent != "" {
-		log.Printf("use %s parent %s", *s.cfg.ParentType, *s.cfg.Parent)
-	} else {
-		log.Fatalf("parent required for tls")
-	}
-
-	s.InitService()
-
-	host, port, _ := net.SplitHostPort(*s.cfg.Local)
-	p, _ := strconv.Atoi(port)
-	sc := utils.NewServerChannel(host, p)
-	err = sc.ListenTls(s.cfg.CertBytes, s.cfg.KeyBytes, func(inConn net.Conn) {
-		go func() {
-			defer func() {
-				if err := recover(); err != nil {
-					log.Printf("tls conn handler crashed with err : %s \nstack: %s", err, string(debug.Stack()))
-				}
-			}()
-			var err error
-			switch *s.cfg.ParentType {
-			case TYPE_TCP:
-				fallthrough
-			case TYPE_TLS:
-				err = s.OutToTCP(&inConn)
-			case TYPE_UDP:
-				err = s.OutToUDP(&inConn)
-			default:
-				err = fmt.Errorf("unkown parent type %s", *s.cfg.ParentType)
-			}
-			if err != nil {
-				log.Printf("connect to %s parent %s fail, ERR:%s", *s.cfg.ParentType, *s.cfg.Parent, err)
-				utils.CloseConn(&inConn)
-			}
-		}()
-	})
-	if err != nil {
-		return
-	}
-	log.Printf("tls proxy on %s", (*sc.Listener).Addr())
-	return
-}
-
-func (s *TLS) Clean() {
-	s.StopService()
-}
-
-func (s *TLS) OutToTCP(inConn *net.Conn) (err error) {
-	var outConn net.Conn
-	var _outConn interface{}
-	_outConn, err = s.outPool.Pool.Get()
-	if err == nil {
-		outConn = _outConn.(net.Conn)
-	}
-	if err != nil {
-		log.Printf("connect to %s , err:%s", *s.cfg.Parent, err)
-		utils.CloseConn(inConn)
-		return
-	}
-	inAddr := (*inConn).RemoteAddr().String()
-	inLocalAddr := (*inConn).LocalAddr().String()
-	outAddr := outConn.RemoteAddr().String()
-	outLocalAddr := outConn.LocalAddr().String()
-	utils.IoBind((*inConn), outConn, func(err error) {
-		log.Printf("conn %s - %s - %s -%s released", inAddr, inLocalAddr, outLocalAddr, outAddr)
-		utils.CloseConn(inConn)
-		utils.CloseConn(&outConn)
-	}, func(n int, d bool) {}, 0)
-	log.Printf("conn %s - %s - %s -%s connected", inAddr, inLocalAddr, outLocalAddr, outAddr)
-	return
-}
-func (s *TLS) OutToUDP(inConn *net.Conn) (err error) {
-	return
-}
-func (s *TLS) InitOutConnPool() {
-	if *s.cfg.ParentType == TYPE_TLS || *s.cfg.ParentType == TYPE_TCP {
-		//dur int, isTLS bool, certBytes, keyBytes []byte,
-		//parent string, timeout int, InitialCap int, MaxCap int
-		s.outPool = utils.NewOutPool(
-			*s.cfg.CheckParentInterval,
-			*s.cfg.ParentType == TYPE_TLS,
-			s.cfg.CertBytes, s.cfg.KeyBytes,
-			*s.cfg.Parent,
-			*s.cfg.Timeout,
-			*s.cfg.PoolSize,
-			*s.cfg.PoolSize*2,
-		)
-	}
-}

services/udp.go

@@ -1,19 +1,207 @@
 package services
 
 import (
+	"bufio"
+	"fmt"
+	"hash/crc32"
+	"io"
 	"log"
+	"net"
+	"proxy/utils"
+	"runtime/debug"
+	"strconv"
+	"strings"
+	"time"
 )
 
 type UDP struct {
+	p       utils.ConcurrentMap
+	outPool utils.OutPool
+	cfg     UDPArgs
+	sc      *utils.ServerChannel
 }
 
 func NewUDP() Service {
-	return &UDP{}
+	return &UDP{
+		outPool: utils.OutPool{},
+		p:       utils.NewConcurrentMap(),
+	}
+}
+func (s *UDP) InitService() {
+	if *s.cfg.ParentType != TYPE_UDP {
+		s.InitOutConnPool()
+	}
+}
+func (s *UDP) StopService() {
+	if s.outPool.Pool != nil {
+		s.outPool.Pool.ReleaseAll()
+	}
 }
 func (s *UDP) Start(args interface{}) (err error) {
-	log.Printf("called")
+	s.cfg = args.(UDPArgs)
+	if *s.cfg.Parent != "" {
+		log.Printf("use %s parent %s", *s.cfg.ParentType, *s.cfg.Parent)
+	} else {
+		log.Fatalf("parent required for udp %s", *s.cfg.Local)
+	}
+
+	s.InitService()
+
+	host, port, _ := net.SplitHostPort(*s.cfg.Local)
+	p, _ := strconv.Atoi(port)
+	sc := utils.NewServerChannel(host, p)
+	s.sc = &sc
+	err = sc.ListenUDP(s.callback)
+	if err != nil {
 		return
 	}
-func (s *UDP) Clean() {
+	log.Printf("udp proxy on %s", (*sc.UDPListener).LocalAddr())
-
+	return
+}
+
+func (s *UDP) Clean() {
+	s.StopService()
+}
+func (s *UDP) callback(packet []byte, localAddr, srcAddr *net.UDPAddr) {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Printf("udp conn handler crashed with err : %s \nstack: %s", err, string(debug.Stack()))
+		}
+	}()
+	var err error
+	switch *s.cfg.ParentType {
+	case TYPE_TCP:
+		fallthrough
+	case TYPE_TLS:
+		err = s.OutToTCP(packet, localAddr, srcAddr)
+	case TYPE_UDP:
+		err = s.OutToUDP(packet, localAddr, srcAddr)
+	default:
+		err = fmt.Errorf("unkown parent type %s", *s.cfg.ParentType)
+	}
+	if err != nil {
+		log.Printf("connect to %s parent %s fail, ERR:%s", *s.cfg.ParentType, *s.cfg.Parent, err)
+	}
+}
+func (s *UDP) GetConn(connKey string) (conn net.Conn, isNew bool, err error) {
+	isNew = !s.p.Has(connKey)
+	var _conn interface{}
+	if isNew {
+		_conn, err = s.outPool.Pool.Get()
+		if err != nil {
+			return nil, false, err
+		}
+		s.p.Set(connKey, _conn)
+	} else {
+		_conn, _ = s.p.Get(connKey)
+	}
+	conn = _conn.(net.Conn)
+	return
+}
+func (s *UDP) OutToTCP(packet []byte, localAddr, srcAddr *net.UDPAddr) (err error) {
+	numLocal := crc32.ChecksumIEEE([]byte(localAddr.String()))
+	numSrc := crc32.ChecksumIEEE([]byte(srcAddr.String()))
+	connKey := uint64((numLocal/10)*10 + numSrc%10)
+	conn, isNew, err := s.GetConn(fmt.Sprintf("%d", connKey))
+	if err != nil {
+		log.Printf("upd get conn to %s parent %s fail, ERR:%s", *s.cfg.ParentType, *s.cfg.Parent, err)
+		return
+	}
+	if isNew {
+		go func() {
+			defer func() {
+				if err := recover(); err != nil {
+					log.Printf("udp conn handler out to tcp crashed with err : %s \nstack: %s", err, string(debug.Stack()))
+				}
+			}()
+			log.Printf("conn %d created , local: %s", connKey, srcAddr.String())
+			for {
+				srcAddrFromConn, body, err := utils.ReadUDPPacket(&conn)
+				if err == io.EOF || err == io.ErrUnexpectedEOF {
+					//log.Printf("connection %d released", connKey)
+					s.p.Remove(fmt.Sprintf("%d", connKey))
+					break
+				}
+				if err != nil {
+					log.Printf("parse revecived udp packet fail, err: %s", err)
+					continue
+				}
+				//log.Printf("udp packet revecived over parent , local:%s", srcAddrFromConn)
+				_srcAddr := strings.Split(srcAddrFromConn, ":")
+				if len(_srcAddr) != 2 {
+					log.Printf("parse revecived udp packet fail, addr error : %s", srcAddrFromConn)
+					continue
+				}
+				port, _ := strconv.Atoi(_srcAddr[1])
+				dstAddr := &net.UDPAddr{IP: net.ParseIP(_srcAddr[0]), Port: port}
+				_, err = s.sc.UDPListener.WriteToUDP(body, dstAddr)
+				if err != nil {
+					log.Printf("udp response to local %s fail,ERR:%s", srcAddr, err)
+					continue
+				}
+				//log.Printf("udp response to local %s success", srcAddr)
+			}
+		}()
+	}
+	//log.Printf("select conn %d , local: %s", connKey, srcAddr.String())
+	writer := bufio.NewWriter(conn)
+	//fmt.Println(conn, writer)
+	writer.Write(utils.UDPPacket(srcAddr.String(), packet))
+	err = writer.Flush()
+	if err != nil {
+		log.Printf("write udp packet to %s fail ,flush err:%s", *s.cfg.Parent, err)
+		return
+	}
+	//log.Printf("write packet %v", packet)
+	return
+}
+func (s *UDP) OutToUDP(packet []byte, localAddr, srcAddr *net.UDPAddr) (err error) {
+	//log.Printf("udp packet revecived:%s,%v", srcAddr, packet)
+	dstAddr, err := net.ResolveUDPAddr("udp", *s.cfg.Parent)
+	if err != nil {
+		log.Printf("resolve udp addr %s fail  fail,ERR:%s", dstAddr.String(), err)
+		return
+	}
+	clientSrcAddr := &net.UDPAddr{IP: net.IPv4zero, Port: 0}
+	conn, err := net.DialUDP("udp", clientSrcAddr, dstAddr)
+	if err != nil {
+		log.Printf("connect to udp %s fail,ERR:%s", dstAddr.String(), err)
+		return
+	}
+	conn.SetDeadline(time.Now().Add(time.Millisecond * time.Duration(*s.cfg.Timeout)))
+	_, err = conn.Write(packet)
+	if err != nil {
+		log.Printf("send udp packet to %s fail,ERR:%s", dstAddr.String(), err)
+		return
+	}
+	//log.Printf("send udp packet to %s success", dstAddr.String())
+	buf := make([]byte, 512)
+	len, _, err := conn.ReadFromUDP(buf)
+	if err != nil {
+		log.Printf("read udp response from %s fail ,ERR:%s", dstAddr.String(), err)
+		return
+	}
+	//log.Printf("revecived udp packet from %s , %v", dstAddr.String(), respBody)
+	_, err = s.sc.UDPListener.WriteToUDP(buf[0:len], srcAddr)
+	if err != nil {
+		log.Printf("send udp response to cluster fail ,ERR:%s", err)
+		return
+	}
+	//log.Printf("send udp response to cluster success ,from:%s", dstAddr.String())
+	return
+}
+func (s *UDP) InitOutConnPool() {
+	if *s.cfg.ParentType == TYPE_TLS || *s.cfg.ParentType == TYPE_TCP {
+		//dur int, isTLS bool, certBytes, keyBytes []byte,
+		//parent string, timeout int, InitialCap int, MaxCap int
+		s.outPool = utils.NewOutPool(
+			*s.cfg.CheckParentInterval,
+			*s.cfg.ParentType == TYPE_TLS,
+			s.cfg.CertBytes, s.cfg.KeyBytes,
+			*s.cfg.Parent,
+			*s.cfg.Timeout,
+			*s.cfg.PoolSize,
+			*s.cfg.PoolSize*2,
+		)
+	}
 }

utils/functions.go

@@ -1,8 +1,11 @@
 package utils
 
 import (
+	"bufio"
+	"bytes"
 	"crypto/tls"
 	"crypto/x509"
+	"encoding/binary"
 	"errors"
 	"fmt"
 	"io"
@@ -254,6 +257,49 @@ func GetAllInterfaceAddr() ([]net.IP, error) {
 	//only need first
 	return addresses, nil
 }
+func UDPPacket(srcAddr string, packet []byte) []byte {
+	addrBytes := []byte(srcAddr)
+	addrLength := uint16(len(addrBytes))
+	bodyLength := uint16(len(packet))
+	pkg := new(bytes.Buffer)
+	binary.Write(pkg, binary.LittleEndian, addrLength)
+	binary.Write(pkg, binary.LittleEndian, addrBytes)
+	binary.Write(pkg, binary.LittleEndian, bodyLength)
+	binary.Write(pkg, binary.LittleEndian, packet)
+	return pkg.Bytes()
+}
+func ReadUDPPacket(conn *net.Conn) (srcAddr string, packet []byte, err error) {
+	reader := bufio.NewReader(*conn)
+	var addrLength uint16
+	var bodyLength uint16
+	err = binary.Read(reader, binary.LittleEndian, &addrLength)
+	if err != nil {
+		return
+	}
+	_srcAddr := make([]byte, addrLength)
+	n, err := reader.Read(_srcAddr)
+	if err != nil {
+		return
+	}
+	if n != int(addrLength) {
+		return
+	}
+	srcAddr = string(_srcAddr)
+
+	err = binary.Read(reader, binary.LittleEndian, &bodyLength)
+	if err != nil {
+		return
+	}
+	packet = make([]byte, bodyLength)
+	n, err = reader.Read(packet)
+	if err != nil {
+		return
+	}
+	if n != int(bodyLength) {
+		return
+	}
+	return
+}
 
 // type sockaddr struct {
 // 	family uint16