From c840cee404cfd25c67bdd3e10c084036834554ec Mon Sep 17 00:00:00 2001
From: Asim Aslam <asim@aslam.me>
Date: Sun, 1 Dec 2019 19:36:16 +0000
Subject: [PATCH] A variety of fixes to try combat the multicast issue

---
 network/default.go | 10 +++++-----
 tunnel/default.go  | 17 +++++++++++------
 tunnel/listener.go |  2 +-
 tunnel/session.go  |  5 -----
 4 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/network/default.go b/network/default.go
index 5d4a9711..0b19a848 100644
--- a/network/default.go
+++ b/network/default.go
@@ -939,17 +939,17 @@ func (n *network) Connect() error {
 		log.Debugf("Network failed to resolve nodes: %v", err)
 	}
 
-	// initialize the tunnel to resolved nodes
-	n.tunnel.Init(
-		tunnel.Nodes(nodes...),
-	)
-
 	// connect network tunnel
 	if err := n.tunnel.Connect(); err != nil {
 		n.Unlock()
 		return err
 	}
 
+	// initialize the tunnel to resolved nodes
+	n.tunnel.Init(
+		tunnel.Nodes(nodes...),
+	)
+
 	// return if already connected
 	if n.connected {
 		// unlock first
diff --git a/tunnel/default.go b/tunnel/default.go
index fc24ee9d..1a3e3c35 100644
--- a/tunnel/default.go
+++ b/tunnel/default.go
@@ -502,22 +502,26 @@ func (t *tun) listen(link *link) {
 			// TODO: handle the close message
 			// maybe report io.EOF or kill the link
 
-			// close the link entirely
+			// if there is no channel then we close the link
+			// as its a signal from the other side to close the connection
 			if len(channel) == 0 {
 				log.Debugf("Tunnel link %s received close message", link.Remote())
 				return
 			}
 
-			// the entire listener was closed so remove it from the mapping
+			// the entire listener was closed by the remote side so we need to
+			// remove the channel mapping for it. should we also close sessions?
 			if sessionId == "listener" {
 				link.delChannel(channel)
 				continue
 			}
 
+			// assuming there's a channel and session
 			// try get the dialing socket
-			_, exists := t.getSession(channel, sessionId)
-			if exists {
-				// delete and continue
+			s, exists := t.getSession(channel, sessionId)
+			if exists && s.mode == Unicast && !loopback {
+				// only delete this if its unicast
+				// but not if its a loopback conn
 				t.delSession(channel, sessionId)
 				continue
 			}
@@ -673,6 +677,7 @@ func (t *tun) listen(link *link) {
 			typ:      mtype,
 			channel:  channel,
 			session:  sessionId,
+			mode:     s.mode,
 			data:     tmsg,
 			link:     link.id,
 			loopback: loopback,
@@ -703,7 +708,7 @@ func (t *tun) discover(link *link) {
 					"Micro-Tunnel-Id": t.id,
 				},
 			}); err != nil {
-				log.Debugf("Tunnel failed to send discover to link %s: %v", link.id, err)
+				log.Debugf("Tunnel failed to send discover to link %s: %v", link.Remote(), err)
 			}
 		case <-link.closed:
 			return
diff --git a/tunnel/listener.go b/tunnel/listener.go
index 62883777..7ba6074e 100644
--- a/tunnel/listener.go
+++ b/tunnel/listener.go
@@ -88,7 +88,7 @@ func (t *tunListener) process() {
 					// the link the message was received on
 					link: m.link,
 					// set the connection mode
-					mode: t.session.mode,
+					mode: m.mode,
 					// close chan
 					closed: make(chan bool),
 					// recv called by the acceptor
diff --git a/tunnel/session.go b/tunnel/session.go
index a0dbef93..4b8721aa 100644
--- a/tunnel/session.go
+++ b/tunnel/session.go
@@ -413,11 +413,6 @@ func (s *session) Close() error {
 	default:
 		close(s.closed)
 
-		// don't broadcast the close for multicast
-		if s.mode != Unicast {
-			return nil
-		}
-
 		// append to backlog
 		msg := s.newMessage("close")
 		// no error response on close