Method HandleSSHRequest

tcpip.go:97–193

(ctx Context, srv *Server, req *gossh.Request)

}

func (h *ForwardedTCPHandler) HandleSSHRequest(ctx Context, srv *Server, req *gossh.Request) (bool, []byte) {
	h.Lock()
	if h.forwards == nil {
		h.forwards = make(map[string]net.Listener)
	}
	h.Unlock()
	conn := ctx.Value(ContextKeyConn).(*gossh.ServerConn)
	switch req.Type {
	case "tcpip-forward":
		var reqPayload remoteForwardRequest
		if err := gossh.Unmarshal(req.Payload, &reqPayload); err != nil {
			// TODO: log parse failure
			return false, []byte{}
		}
		if srv.ReversePortForwardingCallback == nil || !srv.ReversePortForwardingCallback(ctx, reqPayload.BindAddr, reqPayload.BindPort) {
			return false, []byte("port forwarding is disabled")
		}
		addr := net.JoinHostPort(reqPayload.BindAddr, strconv.Itoa(int(reqPayload.BindPort)))
		ln, err := net.Listen("tcp", addr)
		if err != nil {
			// TODO: log listen failure
			return false, []byte{}
		}
		_, destPortStr, _ := net.SplitHostPort(ln.Addr().String())
		destPort, _ := strconv.Atoi(destPortStr)
		h.Lock()
		h.forwards[addr] = ln
		h.Unlock()
		go func() {
			<-ctx.Done()
			h.Lock()
			ln, ok := h.forwards[addr]
			h.Unlock()
			if ok {
				ln.Close()
			}
		}()
		go func() {
			for {
				c, err := ln.Accept()
				if err != nil {
					// TODO: log accept failure
					break
				}
				originAddr, orignPortStr, _ := net.SplitHostPort(c.RemoteAddr().String())
				originPort, _ := strconv.Atoi(orignPortStr)
				payload := gossh.Marshal(&remoteForwardChannelData{
					DestAddr:   reqPayload.BindAddr,
					DestPort:   uint32(destPort),
					OriginAddr: originAddr,
					OriginPort: uint32(originPort),
				})
				go func() {
					ch, reqs, err := conn.OpenChannel(forwardedTCPChannelType, payload)
					if err != nil {
						// TODO: log failure to open channel
						log.Println(err)
						c.Close()