146 lines
3.8 KiB
Go
146 lines
3.8 KiB
Go
package main
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import (
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"bytes"
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"crypto/md5"
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"encoding/hex"
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"github.com/TransX/log"
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"github.com/TransX/tscipher"
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"net"
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"os"
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"strconv"
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"sync/atomic"
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"time"
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)
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var seed int32
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func init() {
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seed = 0
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}
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type TransTCP struct {
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}
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func NewTransTCP() *TransTCP {
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return &TransTCP{}
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}
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func (this *TransTCP) createTCPClient(ip, port string) (conn net.Conn, err error) {
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conn, err = net.Dial("tcp4", ip+":"+port)
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if err == nil {
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} else {
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conn = nil
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}
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return
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}
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func (this *TransTCP) createTCPListener(ip, port string) (listen net.Listener, err error) {
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listener, _err := net.Listen("tcp4", ip+":"+port)
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if _err == nil {
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listen = listener
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err = nil
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return
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} else {
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listen = nil
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err = _err
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}
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return
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}
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func (this *TransTCP) tunnel(src, dest net.Conn, id string, encrypDirection string) { //单向的，从src发送到dest
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defer func() {
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if r := recover(); r != nil {
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if src != nil {
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src.Close()
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}
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if dest != nil {
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dest.Close()
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}
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}
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}()
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cache := make([]byte, 1024*128) //128kB
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for {
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//构建Carrier
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revCarrier := &tscipher.Carrier{
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src,
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tscipher.NewCipher("XOR"),
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cache,
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}
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log.Debug("Encrypt Direction %s ID %s", encrypDirection, id)
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if encrypDirection != "receive" {
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revCarrier.Cipher = nil
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log.Debug("Read not crypted. Tunnel: %s", id)
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}
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nByte, err := tscipher.ReceiveData(revCarrier)
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if err != nil {
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log.Panic("Read panic. Tunnel id: %s. Remote Add: %s. Err:%s", id, src.RemoteAddr().String(), err)
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}
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log.Info("Reived %d bytes from %s. Tunnel: id %s", nByte, src.RemoteAddr().String(), id)
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log.Debug("Reived %s %s", id, cache[:nByte])
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sendCarrier := &tscipher.Carrier{
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dest,
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tscipher.NewCipher("XOR"),
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cache, //TODO:危险，cache的容量容易被不小心修改
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}
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if encrypDirection != "send" {
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sendCarrier.Cipher = nil
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log.Debug("Write not crypted. Tunnel: %s", id)
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}
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_, err = tscipher.SendData(sendCarrier, nByte)
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log.Info("Write %d bytes from %s to %s. Tunnel: %s", nByte, dest.LocalAddr(), dest.RemoteAddr().String(), id)
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log.Debug("Write %s %s", id, cache[:nByte])
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if err != nil {
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log.Panic("Write panic. ID: %s, Err: %s, Remote Add: %s", id, err, dest.RemoteAddr().String())
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}
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}
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}
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func (this *TransTCP) tunnelID() string {
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nowString := time.Now().String() + strconv.Itoa(int(seed))
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atomic.AddInt32(&seed, 1) //避免多线程情况下获得的种子相同
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md5Byte := md5.Sum(bytes.NewBufferString(nowString).Bytes())
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// log.Info("seed %d %s", seed, hex.EncodeToString(md5Byte[:]))
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return hex.EncodeToString(md5Byte[:])
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}
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func (this *TransTCP) Start(listenPort, destIP, destPort string, clientOrServer string) {
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listener, err := this.createTCPListener("0.0.0.0", listenPort)
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if err != nil {
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log.Panic("Failed to create listener. %s", err)
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os.Exit(0)
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}
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for {
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if listenerConn, err := listener.Accept(); err == nil {
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log.Info("Incoming %s", listenerConn.RemoteAddr().String())
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//创建到目标的连接
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destConn, err := this.createTCPClient(destIP, destPort)
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if err != nil {
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log.Panic("Failed to connect to destination. %s", err)
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os.Exit(0)
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}
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log.Info("Dial %s", destConn.RemoteAddr().String())
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//tunnel model : [ -->>server ---- client -->> ](this is a tunnel)
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tunnelIDA := this.tunnelID()
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tunnelIDB := this.tunnelID()
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if clientOrServer == "client" {
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go this.tunnel(listenerConn, destConn, tunnelIDA, "send")
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go this.tunnel(destConn, listenerConn, tunnelIDB, "receive")
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log.Debug("tow tunnel created: %s %s %s %s", tunnelIDA, "send", tunnelIDB, "receive")
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}
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if clientOrServer == "server" {
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go this.tunnel(listenerConn, destConn, tunnelIDA, "receive")
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go this.tunnel(destConn, listenerConn, tunnelIDB, "send")
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log.Debug("tow tunnel created: %s %s %s %s", tunnelIDA, "receive", tunnelIDB, "send")
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}
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} else {
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log.Info("Failed to accept incoming connection. %s", err)
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}
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}
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}
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