Exemple #1
0
func forwardLocalConn(logger lager.Logger, localConn net.Conn, conn *ssh.ServerConn, forwardIP string, forwardPort uint32) {
	defer localConn.Close()

	var req forwardTCPIPChannelRequest
	req.ForwardIP = forwardIP
	req.ForwardPort = forwardPort

	host, port, err := net.SplitHostPort(localConn.RemoteAddr().String())
	if err != nil {
		logger.Error("failed-to-split-host-port", err)
		return
	}

	req.OriginIP = host
	_, err = fmt.Sscanf(port, "%d", &req.OriginPort)
	if err != nil {
		logger.Error("failed-to-parse-port", err)
		return
	}

	channel, reqs, err := conn.OpenChannel("forwarded-tcpip", ssh.Marshal(req))
	if err != nil {
		logger.Error("failed-to-open-channel", err)
		return
	}

	defer channel.Close()

	go func() {
		for r := range reqs {
			logger.Info("ignoring-request", lager.Data{
				"type": r.Type,
			})

			r.Reply(false, nil)
		}
	}()

	wg := new(sync.WaitGroup)

	pipe := func(to io.WriteCloser, from io.ReadCloser) {
		// if either end breaks, close both ends to ensure they're both unblocked,
		// otherwise io.Copy can block forever if e.g. reading after write end has
		// gone away
		defer to.Close()
		defer from.Close()
		defer wg.Done()

		io.Copy(to, from)
	}

	wg.Add(1)
	go pipe(localConn, channel)

	wg.Add(1)
	go pipe(channel, localConn)

	wg.Wait()
}
Exemple #2
0
func handleRegs(reqs <-chan *ssh.Request, sshConn *ssh.ServerConn) {
	defer sshConn.Close()
	for req := range reqs {
		if req.Type == "keepalive" && req.WantReply {
			req.Reply(true, nil)
			continue
		}

		var payload tcpipforwardPayload
		if err := ssh.Unmarshal(req.Payload, &payload); err != nil {
			fmt.Println("ERROR", err)
			continue
		}

		addr := fmt.Sprintf("%s:%d", payload.Addr, payload.Port)
		ln, err := net.Listen("tcp", addr)
		if err != nil {
			fmt.Println("Unable to listen on address: ", addr)
			req.Reply(false, nil)
			continue
		}
		defer ln.Close()

		reply := (payload.Port == 0) && req.WantReply
		if !reply {
			req.Reply(true, nil)
		} else {
			req.Reply(false, nil)
		}
		go func() {
			fmt.Println("Listening on address: ", ln.Addr().String())
			quit := make(chan bool)

			go func() {
				go func() {
					t := time.NewTicker(30 * time.Second)
					defer t.Stop()
					for {
						<-t.C
						_, _, err := sshConn.SendRequest("keepalive", true, nil)
						if err != nil {
							fmt.Println("closed", sshConn)
							sshConn.Close()
							return
						}
					}
				}()
				for {
					select {
					case <-quit:
						return
					default:
						conn, err := ln.Accept()
						if err != nil {
							continue
						}
						go func(conn net.Conn) {
							p := forwardedTCPPayload{}
							var err error
							var portnum int

							p.Addr = payload.Addr
							p.Port = payload.Port
							p.OriginAddr, portnum, err = getHostPortFromAddr(conn.RemoteAddr())
							if err != nil {
								conn.Close()
								return
							}

							p.OriginPort = uint32(portnum)
							ch, reqs, err := sshConn.OpenChannel("forwarded-tcpip", ssh.Marshal(p))
							if err != nil {
								conn.Close()
								log.Println("Open forwarded Channel: ", err.Error())
								return
							}

							go ssh.DiscardRequests(reqs)
							go func(ch ssh.Channel, conn net.Conn) {
								close := func() {
									ch.Close()
									conn.Close()
								}
								go copyConnections(conn, ch, close)
							}(ch, conn)
						}(conn)
					}
				}
			}()
			sshConn.Wait()
			fmt.Println("Stop forwarding/listening on ", ln.Addr())
			quit <- true
		}()
	}
}