func (s *Socks5Server) handleUDPConnect(req *gosocks5.Request) {
cc, err := s.Base.Chain.GetConn()
// connection error
if err != nil && err != ErrEmptyChain {
glog.V(LWARNING).Infof("[udp] %s <- %s : %s", s.conn.RemoteAddr(), req.Addr, err)
reply := gosocks5.NewReply(gosocks5.Failure, nil)
reply.Write(s.conn)
glog.V(LDEBUG).Infof("[udp] %s <- %s\n%s", s.conn.RemoteAddr(), req.Addr, reply)
return
}
// serve udp connect
if err == ErrEmptyChain {
s.udpConnect(req.Addr.String())
return
}
defer cc.Close()
// forward request
if err := req.Write(cc); err != nil {
glog.V(LINFO).Infof("[udp] %s -> %s : %s", s.conn.RemoteAddr(), req.Addr, err)
gosocks5.NewReply(gosocks5.Failure, nil).Write(s.conn)
return
}
glog.V(LINFO).Infof("[udp] %s <-> %s", s.conn.RemoteAddr(), req.Addr)
s.Base.transport(s.conn, cc)
glog.V(LINFO).Infof("[udp] %s >-< %s", s.conn.RemoteAddr(), req.Addr)
}
func requestSocks5(conn net.Conn, req *gosocks5.Request) (*gosocks5.Reply, error) {
if err := req.Write(conn); err != nil {
return nil, err
}
if glog.V(LDEBUG) {
glog.Infoln(req.String())
}
rep, err := gosocks5.ReadReply(conn)
if err != nil {
return nil, err
}
if glog.V(LDEBUG) {
glog.Infoln(rep.String())
}
return rep, nil
}
func (s *Socks5Server) handleUDPTunnel(req *gosocks5.Request) {
cc, err := s.Base.Chain.GetConn()
// connection error
if err != nil && err != ErrEmptyChain {
glog.V(LWARNING).Infof("[socks5-udp] %s -> %s : %s", s.conn.RemoteAddr(), req.Addr, err)
reply := gosocks5.NewReply(gosocks5.Failure, nil)
reply.Write(s.conn)
glog.V(LDEBUG).Infof("[socks5-udp] %s -> %s\n%s", s.conn.RemoteAddr(), req.Addr, reply)
return
}
// serve tunnel udp, tunnel <-> remote, handle tunnel udp request
if err == ErrEmptyChain {
bindAddr, _ := net.ResolveUDPAddr("udp", req.Addr.String())
uc, err := net.ListenUDP("udp", bindAddr)
if err != nil {
glog.V(LWARNING).Infof("[socks5-udp] %s -> %s : %s", s.conn.RemoteAddr(), req.Addr, err)
return
}
defer uc.Close()
socksAddr := ToSocksAddr(uc.LocalAddr())
socksAddr.Host, _, _ = net.SplitHostPort(s.conn.LocalAddr().String())
reply := gosocks5.NewReply(gosocks5.Succeeded, socksAddr)
if err := reply.Write(s.conn); err != nil {
glog.V(LWARNING).Infof("[socks5-udp] %s <- %s : %s", s.conn.RemoteAddr(), socksAddr, err)
return
}
glog.V(LDEBUG).Infof("[socks5-udp] %s <- %s\n%s", s.conn.RemoteAddr(), socksAddr, reply)
glog.V(LINFO).Infof("[socks5-udp] %s <-> %s", s.conn.RemoteAddr(), socksAddr)
s.tunnelUDP(uc, s.conn, false)
glog.V(LINFO).Infof("[socks5-udp] %s >-< %s", s.conn.RemoteAddr(), socksAddr)
return
}
defer cc.Close()
// tunnel <-> tunnel, direct forwarding
req.Write(cc)
glog.V(LINFO).Infof("[socks5-udp] %s <-> %s [tun]", s.conn.RemoteAddr(), cc.RemoteAddr())
s.Base.transport(s.conn, cc)
glog.V(LINFO).Infof("[socks5-udp] %s >-< %s [tun]", s.conn.RemoteAddr(), cc.RemoteAddr())
}
func forwardBind(req *gosocks5.Request, conn net.Conn) error {
fconn, _, err := forwardChain(forwardArgs...)
if err != nil {
glog.V(LWARNING).Infoln("[socks5] BIND(forward)", req.Addr, err)
if fconn != nil {
fconn.Close()
}
rep := gosocks5.NewReply(gosocks5.Failure, nil)
if err := rep.Write(conn); err != nil {
glog.V(LWARNING).Infoln("socks5 bind forward:", err)
} else {
glog.V(LDEBUG).Infoln(rep)
}
return err
}
defer fconn.Close()
if err := req.Write(fconn); err != nil {
glog.V(LWARNING).Infoln("[socks5] BIND(forward)", err)
gosocks5.NewReply(gosocks5.Failure, nil).Write(conn)
return err
}
glog.V(LDEBUG).Infoln(req)
// first reply
rep, err := peekReply(conn, fconn)
if err != nil {
glog.V(LWARNING).Infoln("[socks5] BIND(forward)", err)
return err
}
glog.V(LINFO).Infoln("[socks5] BIND(forward) on", rep.Addr, "OK")
// second reply
rep, err = peekReply(conn, fconn)
if err != nil {
glog.V(LWARNING).Infoln("[socks5] BIND(forward) accept", err)
return err
}
glog.V(LINFO).Infoln("[socks5] BIND(forward) accept", rep.Addr)
return Transport(conn, fconn)
}
func (s *Socks5Server) handleUDPRelay(req *gosocks5.Request) {
bindAddr, _ := net.ResolveUDPAddr("udp", req.Addr.String())
relay, err := net.ListenUDP("udp", bindAddr) // udp associate, strict mode: if the port already in use, it will return error
if err != nil {
glog.V(LWARNING).Infof("[socks5-udp] %s -> %s : %s", s.conn.RemoteAddr(), req.Addr, err)
reply := gosocks5.NewReply(gosocks5.Failure, nil)
reply.Write(s.conn)
glog.V(LDEBUG).Infof("[socks5-udp] %s <- %s\n%s", s.conn.RemoteAddr(), req.Addr, reply)
return
}
defer relay.Close()
socksAddr := ToSocksAddr(relay.LocalAddr())
socksAddr.Host, _, _ = net.SplitHostPort(s.conn.LocalAddr().String())
reply := gosocks5.NewReply(gosocks5.Succeeded, socksAddr)
if err := reply.Write(s.conn); err != nil {
glog.V(LWARNING).Infof("[socks5-udp] %s <- %s : %s", s.conn.RemoteAddr(), req.Addr, err)
return
}
glog.V(LDEBUG).Infof("[socks5-udp] %s <- %s\n%s", s.conn.RemoteAddr(), reply.Addr, reply)
glog.V(LINFO).Infof("[socks5-udp] %s - %s BIND ON %s OK", s.conn.RemoteAddr(), req.Addr, socksAddr)
cc, err := s.Base.Chain.GetConn()
// connection error
if err != nil && err != ErrEmptyChain {
glog.V(LWARNING).Infof("[socks5-udp] %s -> %s : %s", s.conn.RemoteAddr(), socksAddr, err)
return
}
// serve as standard socks5 udp relay local <-> remote
if err == ErrEmptyChain {
peer, er := net.ListenUDP("udp", nil)
if er != nil {
glog.V(LWARNING).Infof("[socks5-udp] %s -> %s : %s", s.conn.RemoteAddr(), socksAddr, er)
return
}
defer peer.Close()
go s.transportUDP(relay, peer)
}
// forward udp local <-> tunnel
if err == nil {
defer cc.Close()
cc.SetWriteDeadline(time.Now().Add(WriteTimeout))
req := gosocks5.NewRequest(CmdUdpTun, nil)
if err := req.Write(cc); err != nil {
glog.V(LWARNING).Infoln("[socks5-udp] %s -> %s : %s", s.conn.RemoteAddr(), cc.RemoteAddr(), err)
return
}
cc.SetWriteDeadline(time.Time{})
glog.V(LDEBUG).Infof("[socks5-udp] %s -> %s\n%s", s.conn.RemoteAddr(), cc.RemoteAddr(), req)
cc.SetReadDeadline(time.Now().Add(ReadTimeout))
reply, err = gosocks5.ReadReply(cc)
if err != nil {
glog.V(LWARNING).Infoln("[socks5-udp] %s -> %s : %s", s.conn.RemoteAddr(), cc.RemoteAddr(), err)
return
}
glog.V(LDEBUG).Infof("[socks5-udp] %s <- %s\n%s", s.conn.RemoteAddr(), cc.RemoteAddr(), reply)
if reply.Rep != gosocks5.Succeeded {
glog.V(LWARNING).Infoln("[socks5-udp] %s <- %s : udp associate failed", s.conn.RemoteAddr(), cc.RemoteAddr())
return
}
cc.SetReadDeadline(time.Time{})
glog.V(LINFO).Infof("[socks5-udp] %s <-> %s [tun: %s]", s.conn.RemoteAddr(), socksAddr, reply.Addr)
go s.tunnelUDP(relay, cc, true)
}
glog.V(LINFO).Infof("[socks5-udp] %s <-> %s", s.conn.RemoteAddr(), socksAddr)
b := make([]byte, SmallBufferSize)
for {
_, err := s.conn.Read(b) // discard any data from tcp connection
if err != nil {
glog.V(LWARNING).Infof("[socks5-udp] %s - %s : %s", s.conn.RemoteAddr(), socksAddr, err)
break // client disconnected
}
}
glog.V(LINFO).Infof("[socks5-udp] %s >-< %s", s.conn.RemoteAddr(), socksAddr)
}