Golang NewChannel.Accept方法代码示例

func (s *server) handleChanReq(chanReq ssh.NewChannel, authInfo map[string]string) {
	if chanReq.ChannelType() != "session" {
		chanReq.Reject(ssh.Prohibited, "channel type is not a session")
		return
	}

	ch, reqs, err := chanReq.Accept()
	if err != nil {
		log.Errorf("fail to accept channel request %v", err)
		return
	}

	for {
		req := <-reqs

		switch req.Type {
		case "env":
		case "exec":
			s.handleExec(ch, req, authInfo)
			return
		default:
			ch.Write([]byte(fmt.Sprintf("request type %q not allowed\r\n", req.Type)))
			ch.Close()
			return
		}
	}
}

// HandleChannel handles one SSH channel
func (c *Client) HandleChannel(newChannel ssh.NewChannel) error {
	if newChannel.ChannelType() != "session" {
		log.Debugf("Unknown channel type: %s", newChannel.ChannelType())
		newChannel.Reject(ssh.UnknownChannelType, "unknown channel type")
		return nil
	}

	channel, requests, err := newChannel.Accept()
	if err != nil {
		log.Errorf("newChannel.Accept failed: %v", err)
		return err
	}
	c.ChannelIdx++
	log.Debugf("HandleChannel.channel (client=%d channel=%d)", c.Idx, c.ChannelIdx)

	log.Debug("Creating pty...")
	c.Pty, c.Tty, err = pty.Open()
	if err != nil {
		log.Errorf("pty.Open failed: %v", err)
		return nil
	}

	c.HandleChannelRequests(channel, requests)

	return nil
}

func handleChannel(chanRequest ssh.NewChannel) {
	handle, err := NewHandle(chanRequest.ChannelType())
	if err != nil {
		config.Log.Debug("wrong handler %v", err)
		chanRequest.Reject(ssh.UnknownChannelType, err.Error())
		return
	}

	ch, reqs, err := chanRequest.Accept()
	if err != nil {
		config.Log.Debug("fail to accept channel request %v", err)
		return
	}

	defer ch.Close()

	for req := range reqs {
		done, err := handle.Request(ch, req)
		if err != nil {
			config.Log.Debug("request errored out %v", err)
			_, err := ch.Write([]byte(fmt.Sprintf("%v\r\n", err)))
			if err != nil {
				config.Log.Debug(err.Error())
			}
		}
		if done {
			return
		}
	}
}

func (handler *DirectTcpipChannelHandler) HandleNewChannel(logger lager.Logger, newChannel ssh.NewChannel) {
	type channelOpenDirectTcpipMsg struct {
		TargetAddr string
		TargetPort uint32
		OriginAddr string
		OriginPort uint32
	}
	var directTcpipMessage channelOpenDirectTcpipMsg

	err := ssh.Unmarshal(newChannel.ExtraData(), &directTcpipMessage)
	if err != nil {
		newChannel.Reject(ssh.ConnectionFailed, "Failed to parse open channel message")
		return
	}

	destination := fmt.Sprintf("%s:%d", directTcpipMessage.TargetAddr, directTcpipMessage.TargetPort)
	conn, err := handler.dialer.Dial("tcp", destination)
	if err != nil {
		newChannel.Reject(ssh.ConnectionFailed, err.Error())
		return
	}

	channel, requests, err := newChannel.Accept()
	go ssh.DiscardRequests(requests)

	wg := &sync.WaitGroup{}

	wg.Add(2)
	go helpers.CopyAndClose(logger.Session("to-target"), wg, conn, channel)
	go helpers.CopyAndClose(logger.Session("to-channel"), wg, channel, conn)

	wg.Wait()
}

func sshHandleChannel(conn net.Conn, newChannel ssh.NewChannel) {
	// Channels have a type, depending on the application level protocol
	// intended. In the case of a shell, the type is "session" and ServerShell
	// may be used to present a simple terminal interface.
	if newChannel.ChannelType() != "session" {
		newChannel.Reject(ssh.UnknownChannelType, "unknown channel type")
		return
	}
	channel, requests, err := newChannel.Accept()
	if err != nil {
		log.Errorln(err)
		return
	}

	// Sessions have out-of-band requests such as "shell", "pty-req" and "env".
	// Here we handle only the "shell" request.
	go func(in <-chan *ssh.Request) {
		for req := range in {
			ok := false
			switch req.Type {
			case "shell":
				ok = true
				if len(req.Payload) > 0 {
					// We don't accept any commands, only the default shell.
					ok = false
				}
			case "pty-req":
				ok = true
			}
			req.Reply(ok, nil)
		}
	}(requests)

	term := terminal.NewTerminal(channel, "> ")

	go func() {
		defer channel.Close()

		for {
			line, err := term.ReadLine()
			start := time.Now().UnixNano()
			if err != nil {
				if err != io.EOF {
					log.Errorln(err)
				}
				return
			}
			sshReportChan <- uint64(len(line))
			// just echo the message
			log.Debugln("ssh received: ", line)
			term.Write([]byte(line))
			term.Write([]byte{'\r', '\n'})

			stop := time.Now().UnixNano()
			log.Info("ssh %v %vns", conn.RemoteAddr(), uint64(stop-start))
		}
	}()
}

func handleSSHChannel(newChan ssh.NewChannel, session *Session) {
	ch, reqs, err := newChan.Accept()
	if err != nil {
		log.Println("handle channel failed:", err)
		return
	}
	exitCh := make(chan int)
	go func() {
		status := struct{ Status uint32 }{uint32(<-exitCh)}
		_, err = ch.SendRequest("exit-status", false, ssh.Marshal(&status))
		assert(err)
		ch.Close()
	}()
	for req := range reqs {
		go func(req *ssh.Request) {
			if req.WantReply {
				req.Reply(true, nil)
			}
			switch req.Type {
			case "exec":
				var payload = struct{ Value string }{}
				ssh.Unmarshal(req.Payload, &payload)
				line := strings.Trim(payload.Value, "\n")
				var args []string
				if line != "" {
					args = strings.Split(line, " ")
				}
				RunCmd(args, ch, ch, ch.Stderr(), exitCh, session)
			}
		}(req)
	}
}

func (s *Session) HandleDirectChannel(newChannel ssh.NewChannel) (bool, ssh.RejectionReason) {

	data, err := UnmarshalTunnelData(newChannel.ExtraData())
	if err != nil {
		return false, ssh.UnknownChannelType
	}

	// look up session by name
	session, host, port := s.Gateway().LookupSessionService(data.Host, uint16(data.Port))
	if session == nil {
		return false, ssh.ConnectionFailed
	}

	// found the service, attempt to open a channel
	data.Host = host
	data.Port = uint32(port)

	c2, err := session.OpenChannel("forwarded-tcpip", MarshalTunnelData(data))
	if err != nil {
		return false, ssh.ConnectionFailed
	}
	defer func() {
		if c2 != nil {
			c2.Close()
		}
	}()

	// accept the channel
	channel, requests, err := newChannel.Accept()
	if err != nil {
		return false, ssh.ResourceShortage
	}

	// cannot return false from this point on
	// also need to accepted close the channel
	defer func() {
		if channel != nil {
			if err := channel.Close(); err != nil {
				glog.Warningf("failed to close accepted channel: %s", err)
			}
		}
	}()

	c, err := NewChannel(s, channel, newChannel.ChannelType(), newChannel.ExtraData())
	if err != nil {
		glog.Errorf("failed to create accepted channel: %s", err)
		return true, 0
	}
	s.AddChannel(c)

	// no failure
	go c.HandleRequests(requests)
	go c.HandleTunnelChannel(c2)

	// do not close channel on exit
	channel = nil
	c2 = nil
	return true, 0
}

func (handler *SessionChannelHandler) HandleNewChannel(logger lager.Logger, newChannel ssh.NewChannel) {
	channel, requests, err := newChannel.Accept()
	if err != nil {
		logger.Error("handle-new-session-channel-failed", err)
		return
	}

	handler.newSession(logger, channel, handler.keepalive).serviceRequests(requests)
}

func (s *Server) handleChannel(ch ssh.NewChannel) {
	id := rand.Int()
	s.Debug("Handling Channel", "id", id, "chan", ch.ChannelType())

	if ch.ChannelType() != "session" {
		s.Info("Received unknown channel type", "chan", ch.ChannelType())
		ch.Reject(ssh.UnknownChannelType, "unknown channel type")
		return
	}

	channel, requests, err := ch.Accept()
	if err != nil {
		s.Error("Failed to accept channe", "err", err)
		return
	}

	var closer sync.Once
	closeChannel := func() {
		s.Debug("Closed Channel", "id", id)
		channel.Close()
	}

	defer closer.Do(closeChannel)

	for req := range requests {
		spew.Dump(req.Type)
		switch req.Type {
		case "exec":
			// Let it through
		case "env":
			if req.WantReply {
				if err = req.Reply(true, nil); err != nil {
					s.Error("Failed to ignore env command", "err", err)
				}
			}
			continue
		default:
			s.Info("Received unhandled request type", "type", req.Type)
			continue
		}

		r := &scpRequest{db: s.DB}
		processors := []processor{
			r.ParseSCPRequest, r.DownloadFile, r.EndConnectionGracefully,
		}

		for _, proc := range processors {
			if err := proc(channel, req); err != nil {
				fmt.Fprintln(channel, "failed to process request:", err.Error())
				// log.Printf("%+v", err)
				break
			}
		}

		closer.Do(closeChannel)
	}
}

func (server *SshServer) handleChannel(user string, newChannel ssh.NewChannel) {
	if t := newChannel.ChannelType(); t != "session" {
		newChannel.Reject(ssh.UnknownChannelType, fmt.Sprintf("unknown channel type: %s", t))
		return
	}

	connection, requests, err := newChannel.Accept()
	if err != nil {
		fmt.Printf("Could not accept channel (%s)", err)
		return
	}
	defer connection.Close()

	logfile, err := os.Create(fmt.Sprintf("%s_%s", user, storyLogFilename(server.story)))
	if err != nil {
		panic(err)
	}
	defer logfile.Close()

	logger := log.New(logfile, "", log.LstdFlags)

	terminal := terminal.NewTerminal(connection, "")
	zsshterm := &gork.ZSshTerminal{Term: terminal}

	zm, err := gork.NewZMachine(server.mem, server.header, zsshterm, logger)
	if err != nil {
		fmt.Println(err)
		return
	}

	go func() {
		for req := range requests {
			switch req.Type {
			case "shell":
				if len(req.Payload) == 0 {
					req.Reply(true, nil)
				}
			case "pty-req":
				termLen := req.Payload[3]
				w, h := parseDims(req.Payload[termLen+4:])
				terminal.SetSize(w, h)
			case "window-change":
				w, h := parseDims(req.Payload)
				terminal.SetSize(w, h)
			}
		}
	}()

	defer func() {
		recover()
	}()

	zm.InterpretAll()

}

func (u *UrlDispatcher) Dispatch(c context.Context, conn *ssh.ServerConn, ch ssh.NewChannel) {
	defer conn.Close()

	// Get channel type
	chType := ch.ChannelType()

	// Parse channel URI
	uri, err := url.ParseRequestURI(chType)
	if err != nil {
		u.Logger.Warn("Error parsing channel type", "type", chType, "err", err)
		ch.Reject(InvalidChannelType, "invalid channel URI")
		return
	} else if reject(chType, uri, ch, u.Logger) {
		return
	}
	chType = uri.Path

	// Parse query params
	values, err := url.ParseQuery(uri.RawQuery)
	if err != nil {
		u.Logger.Warn("Error parsing query params", "values", values, "err", err)
		ch.Reject(InvalidQueryParams, "invalid query params in channel type")
		return
	}

	// Determine if channel is acceptable (has a registered handler)
	if !u.Router.HasRoute(chType) {
		u.Logger.Info("UnknownChannelType", "type", chType)
		ch.Reject(ssh.UnknownChannelType, chType)
		return
	}

	// Otherwise, accept the channel
	channel, requests, err := ch.Accept()
	if err != nil {
		u.Logger.Warn("Error creating channel", "type", chType, "err", err)
		ch.Reject(ChannelAcceptError, chType)
		return
	}

	// Handle the channel
	err = u.Router.Handle(&router.UrlContext{
		Path:     uri.Path,
		Context:  c,
		Values:   values,
		Channel:  channel,
		Requests: requests,
	})
	if err != nil {
		u.Logger.Warn("Error handling channel", "type", chType, "err", err)
		ch.Reject(ChannelHandleError, fmt.Sprintf("error handling channel: %s", err.Error()))
		return
	}
}

func handleChannel(c ssh.NewChannel) {
	if t := c.ChannelType(); t != "session" {
		log.Println("rejected unknown channel type:", t)
		c.Reject(ssh.UnknownChannelType, "unknown channel type")
	}
	connection, requests, err := c.Accept()
	if err != nil {
		log.Println("channel not accepted:", err)
		return
	}
	bash := exec.Command("/bin/bash")
	close := func() {
		connection.Close()
		_, err := bash.Process.Wait()
		if err != nil {
			log.Println("bash not exited:", err)
		}
		log.Println("session closed")
	}
	bashf, err := pty.Start(bash)
	if err != nil {
		log.Println("pty not started:", err)
		close()
		return
	}
	var once sync.Once
	go func() {
		io.Copy(connection, bashf)
		once.Do(close)
	}()
	go func() {
		io.Copy(bashf, connection)
		once.Do(close)
	}()
	go func() {
		for req := range requests {
			log.Println("got request:", req.Type, "want reply:", req.WantReply)
			switch req.Type {
			case "shell":
				if len(req.Payload) == 0 {
					req.Reply(true, nil)
				}
			case "pty-req":
				termLen := req.Payload[3]
				w, h := parseDims(req.Payload[termLen+4:])
				SetWinsize(bashf.Fd(), w, h)
				req.Reply(true, nil)
			case "window-change":
				w, h := parseDims(req.Payload)
				SetWinsize(bashf.Fd(), w, h)
			}
		}
	}()
}

func handleChannel(newChannel ssh.NewChannel, sh SessionHandler) {
	// At this point, we have the opportunity to reject the client's
	// request for another logical connection
	channel, requests, err := newChannel.Accept()
	if err != nil {
		log.Printf("Could not accept channel (%s)", err)
		return
	}

	// Prepare teardown function
	close := func() {
		channel.Close()
		log.Printf("Session closed")
	}
	defer close()

	sh.SetChannel(&channel)
	var payload []byte
	ok := true

	for req := range requests {

		if len(req.Payload) == 0 {
			req.Reply(true, nil)
		}

		path := string(req.Payload)
		typ := Mode(req.Type)

		switch typ {
		// in reality, this would be an scp with the appropriate args,
		// but for testing this is fine.
		case SOURCE:
			ok, payload = sh.Source(path)
		case DEST:
			ok, payload = sh.Destination(path)
		default:
			return
		}

		// make sure that errors get send back if we failed
		if req.WantReply {
			log.Printf("Wants reply %s", string(payload))
			req.Reply(ok, payload)
		}

		// run any pending work now that a reply has been sent
		pendingFn := sh.GetPendingWork()
		if pendingFn != nil {
			pendingFn()
		}
	}
}

// ChannelForward establishes a secure channel forward (ssh -W) to the server
// requested by the user, assuming it is a permitted host.
func (s *Server) ChannelForward(session *Session, newChannel ssh.NewChannel) {
	var msg channelOpenDirectMsg
	ssh.Unmarshal(newChannel.ExtraData(), &msg)
	address := fmt.Sprintf("%s:%d", msg.RAddr, msg.RPort)

	permitted := false
	for _, remote := range session.Remotes {
		if remote == address {
			permitted = true
			break
		}
	}

	if !permitted {
		log.Printf("Disallowed access to %s for user %s", address, session.User.Name)
		newChannel.Reject(ssh.Prohibited, "remote host access denied for user")
		return
	}

	// Log the selection
	if s.Selected != nil {
		if err := s.Selected(session, address); err != nil {
			newChannel.Reject(ssh.Prohibited, "access denied")
			return
		}
	}

	conn, err := net.Dial("tcp", address)
	if err != nil {
		newChannel.Reject(ssh.ConnectionFailed, fmt.Sprintf("error: %v", err))
		return
	}

	channel, reqs, err := newChannel.Accept()

	go ssh.DiscardRequests(reqs)
	var closer sync.Once
	closeFunc := func() {
		channel.Close()
		conn.Close()
	}

	go func() {
		io.Copy(channel, conn)
		closer.Do(closeFunc)
	}()

	go func() {
		io.Copy(conn, channel)
		closer.Do(closeFunc)
	}()
}

func (s *sshServer) handleChannel(newChannel ssh.NewChannel) error {
	if newChannel.ChannelType() != "session" {
		newChannel.Reject(ssh.UnknownChannelType, "unknown channel type")
		return nil
	}

	channel, requests, err := newChannel.Accept()
	if err != nil {
		log.Println("newChannel accept failed: ", err)
		return nil
	}

	return s.handleRequests(channel, requests)
}