From ac24ceb9a5976628dd4ac31b2b502f1caac2b2ec Mon Sep 17 00:00:00 2001
From: Guus Sliepen <guus@meshlink.io>
Date: Sun, 14 Sep 2014 17:49:09 +0200
Subject: [PATCH] Ensure receive_cb and utcp structures have been properly
 initialized after setting channel_accept_cb.

This allows the channels example to initiate a chat from one side only.
---
 src/graph.c             |  3 +--
 src/meshlink.c          | 25 ++++++++++++++++++++-----
 src/meshlink_internal.h |  1 +
 3 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/src/graph.c b/src/graph.c
index 2453d6f1..b18d0610 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -223,8 +223,7 @@ static void check_reachability(meshlink_handle_t *mesh) {
 
 			timeout_del(&mesh->loop, &n->mtutimeout);
 
-			if(mesh->node_status_cb)
-				mesh->node_status_cb(mesh, (meshlink_node_t *)n, n->status.reachable);
+			update_node_status(mesh, n);
 
 			if(!n->status.reachable) {
 				update_node_udp(mesh, n, NULL);
diff --git a/src/meshlink.c b/src/meshlink.c
index 9a462c27..bd74b1d8 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -1947,10 +1947,6 @@ static ssize_t channel_send(struct utcp *utcp, const void *data, size_t len) {
 	return meshlink_send(mesh, (meshlink_node_t *)n, data, len) ? len : -1;
 }
 
-void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_accept_cb_t cb) {
-	mesh->channel_accept_cb = cb;
-}
-
 void meshlink_set_channel_receive_cb(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_channel_receive_cb_t cb) {
 	channel->receive_cb = cb;
 }
@@ -1965,6 +1961,19 @@ static void channel_receive(meshlink_handle_t *mesh, meshlink_node_t *source, co
 	utcp_recv(n->utcp, data, len);
 }
 
+void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_accept_cb_t cb) {
+	pthread_mutex_lock(&mesh->mesh_mutex);
+	mesh->channel_accept_cb = cb;
+	mesh->receive_cb = channel_receive;
+	for splay_each(node_t, n, mesh->nodes) {
+		if(!n->utcp && n != mesh->self) {
+			logger(mesh, MESHLINK_WARNING, "utcp_init on node %s", n->name);
+			n->utcp = utcp_init(channel_accept, channel_pre_accept, channel_send, n);
+		}
+	}
+	pthread_mutex_unlock(&mesh->mesh_mutex);
+}
+
 void meshlink_channel_init(meshlink_handle_t *mesh) {
 }
 
@@ -2008,6 +2017,13 @@ ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *chann
 	return utcp_send(channel->c, data, len);
 }
 
+void update_node_status(meshlink_handle_t *mesh, node_t *n) {
+	if(n->status.reachable && mesh->channel_accept_cb && !n->utcp)
+		n->utcp = utcp_init(channel_accept, channel_pre_accept, channel_send, n);
+	if(mesh->node_status_cb)
+		mesh->node_status_cb(mesh, (meshlink_node_t *)n, n->status.reachable);
+}
+
 static void __attribute__((constructor)) meshlink_init(void) {
 	crypto_init();
 }
@@ -2016,7 +2032,6 @@ static void __attribute__((destructor)) meshlink_exit(void) {
 	crypto_exit();
 }
 
-
 /// Device class traits
 dev_class_traits_t dev_class_traits[_DEV_CLASS_MAX +1] = {
 	{ .min_connects = 3, .max_connects = 10000, .edge_weight = 1 },	// DEV_CLASS_BACKBONE
diff --git a/src/meshlink_internal.h b/src/meshlink_internal.h
index 6c7ac7bd..782cc76e 100644
--- a/src/meshlink_internal.h
+++ b/src/meshlink_internal.h
@@ -161,6 +161,7 @@ typedef struct meshlink_packethdr {
 } __attribute__ ((__packed__)) meshlink_packethdr_t;
 
 extern void meshlink_send_from_queue(event_loop_t* el,meshlink_handle_t *mesh);
+extern void update_node_status(meshlink_handle_t *mesh, struct node_t *n);
 extern meshlink_log_level_t global_log_level;
 extern meshlink_log_cb_t global_log_cb;
 
-- 
2.39.2