use different messaging channel IDs on initiator and responder side

pkg/messaging/chan_list.go

@@ -26,12 +26,6 @@ func (c *chanList) add(channel *channel) byte {
 	panic("no free channels")
 }
 
-func (c *chanList) set(id byte, channel *channel) {
-	c.Lock()
-	c.chans[id] = channel
-	c.Unlock()
-}
-
 func (c *chanList) get(id byte) *channel {
 	c.Lock()
 	ch := c.chans[id]

pkg/messaging/client.go

@@ -290,12 +290,13 @@ func (c *Client) onData(l *Link, frameType FrameType, body []byte) error {
 
 	c.Logger.Debugf("New frame %s from %s@%d", frameType, remotePK, channelID)
 	if frameType == FrameTypeOpenChannel {
-		if msg, err := c.openChannel(channelID, body[1:34], body[34:], clientLink); err != nil {
+		if lID, msg, err := c.openChannel(channelID, body[1:34], body[34:], clientLink); err != nil {
 			c.Logger.Warnf("Failed to open new channel for %s: %s", remotePK, err)
 			_, sendErr = l.SendChannelClosed(channelID)
 		} else {
-			c.Logger.Infof("Opened new channel ID %d with %s", channelID, hex.EncodeToString(body[1:34]))
-			_, sendErr = l.SendChannelOpened(channelID, msg)
+			c.Logger.Infof("Opened new channel local ID %d, remote ID %d with %s", lID, channelID,
+				hex.EncodeToString(body[1:34]))
+			_, sendErr = l.SendChannelOpened(lID, msg)
 		}
 
 		return c.warnSendError(remotePK, sendErr)
@@ -312,7 +313,7 @@ func (c *Client) onData(l *Link, frameType FrameType, body []byte) error {
 	switch frameType {
 	case FrameTypeCloseChannel:
 		clientLink.chans.remove(channelID)
-		_, sendErr = l.SendChannelClosed(channelID)
+		_, sendErr = l.SendChannelClosed(channel.ID)
 		c.Logger.Debugf("Closed channel ID %d", channelID)
 	case FrameTypeChannelOpened:
 		if err := channel.noise.ProcessMessage(body[1:]); err != nil {
@@ -324,6 +325,7 @@ func (c *Client) onData(l *Link, frameType FrameType, body []byte) error {
 		default:
 		}
 	case FrameTypeChannelClosed:
+		channel.ID = body[0]
 		select {
 		case channel.waitChan <- false:
 		case channel.closeChan <- struct{}{}:
@@ -350,6 +352,10 @@ func (c *Client) onClose(l *Link, remote bool) {
 	chanLink := c.links[remotePK]
 	c.mu.RUnlock()
 
+	for _, channel := range chanLink.chans.dropAll() {
+		channel.close()
+	}
+
 	select {
 	case <-c.doneChan:
 	default:
@@ -365,10 +371,6 @@ func (c *Client) onClose(l *Link, remote bool) {
 
 	c.Logger.Infof("Closing link with the server %s", remotePK)
 
-	for _, channel := range chanLink.chans.dropAll() {
-		channel.close()
-	}
-
 	c.mu.Lock()
 	delete(c.links, remotePK)
 	c.mu.Unlock()
@@ -378,41 +380,41 @@ func (c *Client) onClose(l *Link, remote bool) {
 	}
 }
 
-func (c *Client) openChannel(channelID byte, remotePK []byte, msg []byte, chanLink *clientLink) ([]byte, error) {
-	channel := chanLink.chans.get(channelID)
-	if channel != nil {
-		return nil, errors.New("channel is already opened")
-	}
-
-	pubKey, err := cipher.NewPubKey(remotePK)
+func (c *Client) openChannel(rID byte, remotePK []byte, noiseMsg []byte, chanLink *clientLink) (lID byte, noiseRes []byte, err error) {
+	var pubKey cipher.PubKey
+	pubKey, err = cipher.NewPubKey(remotePK)
 	if err != nil {
-		return nil, err
+		return
 	}
-	channel, err = newChannel(false, c.secKey, pubKey, chanLink.link)
+
+	channel, err := newChannel(false, c.secKey, pubKey, chanLink.link)
+	channel.ID = rID
 	if err != nil {
-		return nil, fmt.Errorf("noise setup: %s", err)
+		err = fmt.Errorf("noise setup: %s", err)
+		return
 	}
 
-	channel.ID = channelID
-	chanLink.chans.set(channelID, channel)
-
-	if err := channel.noise.ProcessMessage(msg); err != nil {
-		return nil, fmt.Errorf("noise handshake: %s", err)
+	if err = channel.noise.ProcessMessage(noiseMsg); err != nil {
+		err = fmt.Errorf("noise handshake: %s", err)
+		return
 	}
 
+	lID = chanLink.chans.add(channel)
+
 	go func() {
 		select {
 		case <-c.doneChan:
 		case c.newChan <- channel:
 		}
 	}()
 
-	res, err := channel.noise.HandshakeMessage()
+	noiseRes, err = channel.noise.HandshakeMessage()
 	if err != nil {
-		return nil, fmt.Errorf("noise handshake: %s", err)
+		err = fmt.Errorf("noise handshake: %s", err)
+		return
 	}
 
-	return res, nil
+	return lID, noiseRes, err
 }
 
 func (c *Client) warnSendError(remote cipher.PubKey, err error) error {