first commit to draft up a way for Sending messages to loopback

tunnel/default.go

@@ -17,6 +17,9 @@ type tun struct {
 
 	sync.RWMutex
 
+	// tunnel token
+	token string
+
 	// to indicate if we're connected or not
 	connected bool
 
@@ -50,6 +53,7 @@ func newTunnel(opts ...Option) *tun {
 
 	return &tun{
 		options: options,
+		token:   uuid.New().String(),
 		send:    make(chan *message, 128),
 		closed:  make(chan bool),
 		sockets: make(map[string]*socket),
@@ -144,7 +148,7 @@ func (t *tun) process() {
 }
 
 // process incoming messages
-func (t *tun) listen(link transport.Socket, listener bool) {
+func (t *tun) listen(link transport.Socket) {
 	for {
 		// process anything via the net interface
 		msg := new(transport.Message)
@@ -154,11 +158,24 @@ func (t *tun) listen(link transport.Socket, listener bool) {
 			return
 		}
 
+		var loopback bool
+
 		switch msg.Header["Micro-Tunnel"] {
-		case "connect", "close":
-			// TODO: handle the connect/close message
-			// maybe used to create the dial/listen sockets
-			// or report io.EOF or maybe to kill the link
+		case "connect":
+			// TODO: handle the connect message
+			// check the Micro-Tunnel-Token
+			token, ok := msg.Header["Micro-Tunnel-Token"]
+			if !ok {
+				// no token found; bailing
+				continue
+			}
+			// are we connecting to ourselves?
+			if token == t.token {
+				loopback = true
+			}
+		case "close":
+			// TODO: handle the close message
+			// maybe report io.EOF or kill the link
 			continue
 		}
 
@@ -182,18 +199,17 @@ func (t *tun) listen(link transport.Socket, listener bool) {
 		var exists bool
 
 		log.Debugf("Received %+v from %s", msg, link.Remote())
-		// get the socket based on the tunnel id and session
-		// this could be something we dialed in which case
-		// we have a session for it otherwise its a listener
-		s, exists = t.getSocket(id, session)
-		if !exists {
-			// try get it based on just the tunnel id
-			// the assumption here is that a listener
-			// has no session but its set a listener session
-			s, exists = t.getSocket(id, "listener")
-		}
 
-		// no socket in existence
+		switch {
+		case loopback:
+			s, exists = t.getSocket(id, "listener")
+		default:
+			// get the socket based on the tunnel id and session
+			// this could be something we dialed in which case
+			// we have a session for it otherwise its a listener
+			s, exists = t.getSocket(id, session)
+		}
+		// bail if no socket has been found
 		if !exists {
 			log.Debugf("Tunnel skipping no socket exists")
 			// drop it, we don't care about
@@ -277,7 +293,7 @@ func (t *tun) connect() error {
 			}()
 
 			// listen for inbound messages
-			t.listen(sock, true)
+			t.listen(sock)
 		})
 
 		t.Lock()
@@ -306,14 +322,15 @@ func (t *tun) connect() error {
 
 		if err := c.Send(&transport.Message{
 			Header: map[string]string{
-				"Micro-Tunnel": "connect",
+				"Micro-Tunnel":       "connect",
+				"Micro-Tunnel-Token": t.token,
 			},
 		}); err != nil {
 			continue
 		}
 
 		// process incoming messages
-		go t.listen(c, false)
+		go t.listen(c)
 
 		// save the link
 		id := uuid.New().String()