fix

client.go

@@ -7,7 +7,7 @@ import (
 	"time"
 )
 
-func NewClient(addr string, server string, target string, timeout int, proto int) (*Client, error) {
+func NewClient(addr string, server string, target string, timeout int, sproto int, rproto int) (*Client, error) {
 
 	ipaddr, err := net.ResolveUDPAddr("udp", addr)
 	if err != nil {
@@ -26,13 +26,15 @@ func NewClient(addr string, server string, target string, timeout int, proto int
 		addrServer:   server,
 		targetAddr:   target,
 		timeout:      timeout,
-		proto:        proto,
+		sproto:       sproto,
+		rproto:       rproto,
 	}, nil
 }
 
 type Client struct {
 	timeout int
-	proto   int
+	sproto  int
+	rproto  int
 
 	ipaddr *net.UDPAddr
 	addr   string
@@ -147,16 +149,12 @@ func (p *Client) Accept() error {
 		}
 
 		clientConn.activeTime = now
-		sendICMP(*p.conn, p.ipaddrServer, p.targetAddr, clientConn.id, (uint32)(DATA), bytes[:n], p.proto)
+		sendICMP(*p.conn, p.ipaddrServer, p.targetAddr, clientConn.id, (uint32)(DATA), bytes[:n], p.sproto, p.rproto)
 	}
 }
 
 func (p *Client) processPacket(packet *Packet) {
 
-	if packet.data == nil {
-		return
-	}
-
 	fmt.Printf("processPacket %s %s %d\n", packet.id, packet.src.String(), len(packet.data))
 
 	clientConn := p.localIdToConnMap[packet.id]

cmd/main.go

@@ -31,8 +31,11 @@ Usage:
     -timeout  本地记录连接超时的时间，单位是秒，默认60s
               The time when the local record connection timed out, in seconds, 60 seconds by default
 
-    -proto    ping的协议，默认是42
+    -sproto   客户端发送ping协议的协议，默认是42
-              Ping protocol, the default is 42
+              The protocol that the client sends the ping. The default is 42.
+
+    -rproto   客户端接收ping协议的协议，默认是42
+              The protocol that the client receives the ping. The default is 42.
 `
 
 func main() {
@@ -42,7 +45,8 @@ func main() {
 	target := flag.String("t", "", "target addr")
 	server := flag.String("s", "", "server addr")
 	timeout := flag.Int("timeout", 60, "conn timeout")
-	proto := flag.Int("proto", 2, "ping proto")
+	sproto := flag.Int("sproto", 42, "send ping proto")
+	rproto := flag.Int("rproto", 42, "recv ping proto")
 	flag.Usage = func() {
 		fmt.Printf(usage)
 	}
@@ -57,7 +61,7 @@ func main() {
 	fmt.Println("start...")
 
 	if *t == "server" {
-		s, err := pingtunnel.NewServer(*timeout, *proto)
+		s, err := pingtunnel.NewServer(*timeout)
 		if err != nil {
 			fmt.Printf("ERROR: %s\n", err.Error())
 			return
@@ -72,7 +76,7 @@ func main() {
 		fmt.Printf("server %s\n", *server)
 		fmt.Printf("target %s\n", *target)
 
-		c, err := pingtunnel.NewClient(*listen, *server, *target, *timeout, *proto)
+		c, err := pingtunnel.NewClient(*listen, *server, *target, *timeout, *sproto, *rproto)
 		if err != nil {
 			fmt.Printf("ERROR: %s\n", err.Error())
 			return

pingtunnel.go

@@ -21,10 +21,12 @@ const (
 
 // An Echo represents an ICMP echo request or reply message body.
 type MyMsg struct {
-	TYPE   uint32
+	TYPE    uint32
-	ID     string
+	ID      string
-	TARGET string
+	TARGET  string
-	Data   []byte
+	Data    []byte
+	RPROTO  uint16
+	ENDTYPE uint32
 }
 
 // Len implements the Len method of MessageBody interface.
@@ -32,13 +34,17 @@ func (p *MyMsg) Len(proto int) int {
 	if p == nil {
 		return 0
 	}
-	return 4 + p.LenString(p.ID) + p.LenString(p.TARGET) + len(p.Data)
+	return 4 + p.LenString(p.ID) + p.LenString(p.TARGET) + p.LenData(p.Data) + 2 + 4
 }
 
 func (p *MyMsg) LenString(s string) int {
 	return 2 + len(s)
 }
 
+func (p *MyMsg) LenData(data []byte) int {
+	return 2 + len(data)
+}
+
 // Marshal implements the Marshal method of MessageBody interface.
 func (p *MyMsg) Marshal(proto int) ([]byte, error) {
 
@@ -52,7 +58,12 @@ func (p *MyMsg) Marshal(proto int) ([]byte, error) {
 	target := p.MarshalString(p.TARGET)
 	copy(b[4+p.LenString(p.ID):], target)
 
-	copy(b[4+p.LenString(p.ID)+p.LenString(p.TARGET):], p.Data)
+	data := p.MarshalData(p.Data)
+	copy(b[4+p.LenString(p.ID)+p.LenString(p.TARGET):], data)
+
+	binary.BigEndian.PutUint16(b[4+p.LenString(p.ID)+p.LenString(p.TARGET)+p.LenData(p.Data):], uint16(p.RPROTO))
+
+	binary.BigEndian.PutUint32(b[4+p.LenString(p.ID)+p.LenString(p.TARGET)+p.LenData(p.Data)+2:], uint32(p.ENDTYPE))
 
 	return b, nil
 }
@@ -64,6 +75,13 @@ func (p *MyMsg) MarshalString(s string) []byte {
 	return b
 }
 
+func (p *MyMsg) MarshalData(data []byte) []byte {
+	b := make([]byte, p.LenData(data))
+	binary.BigEndian.PutUint16(b[:2], uint16(len(data)))
+	copy(b[2:], []byte(data))
+	return b
+}
+
 // Marshal implements the Marshal method of MessageBody interface.
 func (p *MyMsg) Unmarshal(b []byte) error {
 	defer func() {
@@ -76,30 +94,48 @@ func (p *MyMsg) Unmarshal(b []byte) error {
 
 	p.TARGET = p.UnmarshalString(b[4+p.LenString(p.ID):])
 
-	p.Data = make([]byte, len(b[4+p.LenString(p.ID)+p.LenString(p.TARGET):]))
+	p.Data = p.UnmarshalData(b[4+p.LenString(p.ID)+p.LenString(p.TARGET):])
-	copy(p.Data, b[4+p.LenString(p.ID)+p.LenString(p.TARGET):])
+
+	p.RPROTO = binary.BigEndian.Uint16(b[4+p.LenString(p.ID)+p.LenString(p.TARGET)+p.LenData(p.Data):])
+
+	p.ENDTYPE = binary.BigEndian.Uint32(b[4+p.LenString(p.ID)+p.LenString(p.TARGET)+p.LenData(p.Data)+2:])
 
 	return nil
 }
 
 func (p *MyMsg) UnmarshalString(b []byte) string {
 	len := binary.BigEndian.Uint16(b[:2])
+	if len > 32 || len < 0 {
+		panic(nil)
+	}
 	data := make([]byte, len)
 	copy(data, b[2:])
 	return string(data)
 }
 
-func sendICMP(conn icmp.PacketConn, server *net.IPAddr, target string, connId string, msgType uint32, data []byte, proto int) {
+func (p *MyMsg) UnmarshalData(b []byte) []byte {
+	len := binary.BigEndian.Uint16(b[:2])
+	if len > 2048 || len < 0 {
+		panic(nil)
+	}
+	data := make([]byte, len)
+	copy(data, b[2:])
+	return data
+}
+
+func sendICMP(conn icmp.PacketConn, server *net.IPAddr, target string, connId string, msgType uint32, data []byte, sproto int, rproto int) {
 
 	m := &MyMsg{
-		ID:     connId,
+		ID:      connId,
-		TYPE:   msgType,
+		TYPE:    msgType,
-		TARGET: target,
+		TARGET:  target,
-		Data:   data,
+		Data:    data,
+		RPROTO:  (uint16)(rproto),
+		ENDTYPE: msgType,
 	}
 
 	msg := &icmp.Message{
-		Type: (ipv4.ICMPType)(proto),
+		Type: (ipv4.ICMPType)(sproto),
 		Code: 0,
 		Body: m,
 	}
@@ -148,12 +184,17 @@ func recvICMP(conn icmp.PacketConn, recv chan<- *Packet) {
 		}
 		my.Unmarshal(bytes[4:n])
 
-		if my.TYPE != (uint32)(DATA) {
+		if my.TYPE != (uint32)(DATA) || my.ENDTYPE != (uint32)(DATA) {
-			fmt.Printf("processPacket diff type %d \n", my.TYPE)
+			fmt.Printf("processPacket diff type %s %d %d \n", my.ID, my.TYPE, my.ENDTYPE)
 			continue
 		}
 
-		recv <- &Packet{data: my.Data, id: my.ID, target: my.TARGET, src: srcaddr.(*net.IPAddr)}
+		if my.Data == nil {
+			fmt.Printf("processPacket data nil %s\n", my.ID)
+			return
+		}
+
+		recv <- &Packet{data: my.Data, id: my.ID, target: my.TARGET, src: srcaddr.(*net.IPAddr), rproto: (int)(my.RPROTO)}
 	}
 }
 
@@ -162,6 +203,7 @@ type Packet struct {
 	id     string
 	target string
 	src    *net.IPAddr
+	rproto int
 }
 
 func UniqueId() string {

server.go

@@ -7,16 +7,14 @@ import (
 	"time"
 )
 
-func NewServer(timeout int, proto int) (*Server, error) {
+func NewServer(timeout int) (*Server, error) {
 	return &Server{
 		timeout: timeout,
-		proto:   proto,
 	}, nil
 }
 
 type Server struct {
 	timeout int
-	proto   int
 
 	conn *icmp.PacketConn
 
@@ -29,6 +27,7 @@ type ServerConn struct {
 	id           string
 	activeTime   time.Time
 	close        bool
+	rproto       int
 }
 
 func (p *Server) Run() {
@@ -80,7 +79,7 @@ func (p *Server) processPacket(packet *Packet) {
 			fmt.Printf("Error listening for udp packets: %s\n", err.Error())
 			return
 		}
-		udpConn = &ServerConn{conn: targetConn, ipaddrTarget: ipaddrTarget, id: id, activeTime: now, close: false}
+		udpConn = &ServerConn{conn: targetConn, ipaddrTarget: ipaddrTarget, id: id, activeTime: now, close: false, rproto: packet.rproto}
 		p.localConnMap[id] = udpConn
 		go p.Recv(udpConn, id, packet.src)
 	}
@@ -120,7 +119,7 @@ func (p *Server) Recv(conn *ServerConn, id string, src *net.IPAddr) {
 		now := time.Now()
 		conn.activeTime = now
 
-		sendICMP(*p.conn, src, "", id, (uint32)(DATA), bytes[:n], p.proto)
+		sendICMP(*p.conn, src, "", id, (uint32)(DATA), bytes[:n], conn.rproto, 0)
 	}
 }