diff --git a/bridges/bridge_softmix.c b/bridges/bridge_softmix.c
index b35994895e1854ec5ff15982fecb264ec6d094d1..bae0b8c7a2d65d772aeed18034381e6edd2aa8a1 100644
--- a/bridges/bridge_softmix.c
+++ b/bridges/bridge_softmix.c
@@ -1690,7 +1690,8 @@ static void map_source_to_destinations(const char *source_stream_name, const cha
}
}
-/*\brief stream_topology_changed callback
+/*!
+ * \brief stream_topology_changed callback
*
* For most video modes, nothing beyond the ordinary is required.
* For the SFU case, though, we need to completely remap the streams
@@ -1728,34 +1729,52 @@ static void softmix_bridge_stream_topology_changed(struct ast_bridge *bridge, st
/* Second traversal: Map specific video channels from their source to their destinations.
*
- * This is similar to what is done in ast_stream_topology_map(), except that
- * video channels are handled differently. Each video source has it's own
- * unique index on the bridge. this way, a particular channel's source video
- * can be distributed to the appropriate destination streams on the other
- * channels
+ * This is similar to what is done in ast_stream_topology_map(),
+ * except that video channels are handled differently. Each video
+ * source has it's own unique index on the bridge. This way, a
+ * particular channel's source video can be distributed to the
+ * appropriate destination streams on the other channels.
*/
AST_LIST_TRAVERSE(&bridge->channels, participant, entry) {
int i;
struct ast_stream_topology *topology;
+ ast_bridge_channel_lock(participant);
ast_channel_lock(participant->chan);
topology = ast_channel_get_stream_topology(participant->chan);
+ if (topology) {
+ /*
+ * Sigh. We have to clone to avoid deadlock in
+ * map_source_to_destinations() because topology
+ * is not an ao2 object.
+ */
+ topology = ast_stream_topology_clone(topology);
+ }
+ if (!topology) {
+ /* Oh, my, we are in trouble. */
+ ast_channel_unlock(participant->chan);
+ ast_bridge_channel_unlock(participant);
+ continue;
+ }
for (i = 0; i < ast_stream_topology_get_count(topology); ++i) {
struct ast_stream *stream = ast_stream_topology_get_stream(topology, i);
- ast_bridge_channel_lock(participant);
+
if (is_video_source(stream)) {
AST_VECTOR_APPEND(&media_types, AST_MEDIA_TYPE_VIDEO);
AST_VECTOR_REPLACE(&participant->stream_map.to_bridge, i, AST_VECTOR_SIZE(&media_types) - 1);
AST_VECTOR_REPLACE(&participant->stream_map.to_channel, AST_VECTOR_SIZE(&media_types) - 1, -1);
- /* Unlock the participant to prevent potential deadlock
- * in map_source_to_destinations
+ /*
+ * Unlock the channel and participant to prevent
+ * potential deadlock in map_source_to_destinations().
*/
+ ast_channel_unlock(participant->chan);
ast_bridge_channel_unlock(participant);
map_source_to_destinations(ast_stream_get_name(stream), ast_channel_name(participant->chan),
AST_VECTOR_SIZE(&media_types) - 1, &bridge->channels);
ast_bridge_channel_lock(participant);
+ ast_channel_lock(participant->chan);
} else if (is_video_dest(stream, NULL, NULL)) {
/* We expect to never read media from video destination channels, but just
* in case, we should set their to_bridge value to -1.
@@ -1777,10 +1796,12 @@ static void softmix_bridge_stream_topology_changed(struct ast_bridge *bridge, st
AST_VECTOR_REPLACE(&participant->stream_map.to_bridge, i, index);
AST_VECTOR_REPLACE(&participant->stream_map.to_channel, index, i);
}
- ast_bridge_channel_unlock(participant);
}
+ ast_stream_topology_free(topology);
+
ast_channel_unlock(participant->chan);
+ ast_bridge_channel_unlock(participant);
}
}
diff --git a/include/asterisk/bridge_channel.h b/include/asterisk/bridge_channel.h
index 4d3326083a6e113cf78dfb95fc48e4818c39c80b..4504d6bcb7da0fb3fffb6e80dc69244c97677aa4 100644
--- a/include/asterisk/bridge_channel.h
+++ b/include/asterisk/bridge_channel.h
@@ -716,19 +716,24 @@ void ast_bridge_channel_feature_digit(struct ast_bridge_channel *bridge_channel,
* \brief Maps a channel's stream topology to and from the bridge
* \since 15.0.0
*
- * When a channel joins a bridge or its associated stream topology is updated, each stream
- * in the topology needs to be mapped according to its media type to the bridge. Calling
- * this method creates a mapping of each stream on the channel indexed to the bridge's
- * supported media types and vice versa (i.e. bridge's media types indexed to channel
- * streams).
- *
- * The first channel to join the bridge creates the initial order for the bridge's media
- * types (e.g. a one to one mapping is made). Subsequently added channels are mapped to
- * that order adding more media types if/when the newly added channel has more streams
- * and/or media types specified by the bridge.
+ * \details
+ * When a channel joins a bridge or its associated stream topology is
+ * updated, each stream in the topology needs to be mapped according
+ * to its media type to the bridge. Calling this method creates a
+ * mapping of each stream on the channel indexed to the bridge's
+ * supported media types and vice versa (i.e. bridge's media types
+ * indexed to channel streams).
+ *
+ * The first channel to join the bridge creates the initial order for
+ * the bridge's media types (e.g. a one to one mapping is made).
+ * Subsequently added channels are mapped to that order adding more
+ * media types if/when the newly added channel has more streams and/or
+ * media types specified by the bridge.
*
* \param bridge_channel Channel to map
*
+ * \note The bridge_channel's bridge must be locked prior to calling this function.
+ *
* \return Nothing
*/
void ast_bridge_channel_stream_map(struct ast_bridge_channel *bridge_channel);
diff --git a/include/asterisk/bridge_technology.h b/include/asterisk/bridge_technology.h
index 8cebe93266feaa311677d2fc4954c17b4eca4a0f..def7b19335f8fd144a86ee00b46e99e6d07b3a62 100644
--- a/include/asterisk/bridge_technology.h
+++ b/include/asterisk/bridge_technology.h
@@ -164,20 +164,30 @@ struct ast_bridge_technology {
/*!
* \brief Callback for when a request has been made to change a stream topology on a channel
*
- * This is called when a bridge receives a request to change the topology on the channel. A bridge
- * technology should define a handler for this callback if it needs to update internals or intercept
- * the request and not pass it on to other channels. This can be done by returning a nonzero value.
+ * \details
+ * This is called when a bridge receives a request to change the
+ * topology on the channel. A bridge technology should define a
+ * handler for this callback if it needs to update internals or
+ * intercept the request and not pass it on to other channels.
+ * This can be done by returning a nonzero value.
*
- * \retval 0 Frame accepted by the bridge.
- * \retval -1 Frame rejected.
+ * \retval 0 Frame can pass to the bridge technology.
+ * \retval non-zero Frame intercepted by the bridge technology.
+ *
+ * \note On entry, bridge is already locked.
*/
int (*stream_topology_request_change)(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel);
/*!
* \brief Callback for when a stream topology changes on the channel
*
- * This is called when a bridge receives an indication that a topology has been changed on a channel
- * and the new topology has been mapped to the bridge. A bridge technology should define a handler for
- * this callback if it needs to update internals due to a channel's topology changing.
+ * \details
+ * This is called when a bridge receives an indication that a
+ * topology has been changed on a channel and the new topology has
+ * been mapped to the bridge. A bridge technology should define a
+ * handler for this callback if it needs to update internals due
+ * to a channel's topology changing.
+ *
+ * \note On entry, bridge is already locked.
*/
void (*stream_topology_changed)(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel);
/*! TRUE if the bridge technology is currently suspended. */
diff --git a/main/bridge_channel.c b/main/bridge_channel.c
index 1427fd0141f0bc9d0326bd241110238fc512acee..c465ec16eb4a63664dcf99a2e8413d5d9f236313 100644
--- a/main/bridge_channel.c
+++ b/main/bridge_channel.c
@@ -2434,6 +2434,7 @@ static const char *controls[] = {
static void bridge_handle_trip(struct ast_bridge_channel *bridge_channel)
{
struct ast_frame *frame;
+ int blocked;
if (!ast_strlen_zero(ast_channel_call_forward(bridge_channel->chan))) {
/* TODO If early bridging is ever used by anything other than ARI,
@@ -2485,10 +2486,16 @@ static void bridge_handle_trip(struct ast_bridge_channel *bridge_channel)
ast_channel_publish_dial(NULL, bridge_channel->chan, NULL, controls[frame->subclass.integer]);
break;
case AST_CONTROL_STREAM_TOPOLOGY_REQUEST_CHANGE:
- if (bridge_channel->bridge->technology->stream_topology_request_change &&
- bridge_channel->bridge->technology->stream_topology_request_change(
- bridge_channel->bridge, bridge_channel)) {
- /* Topology change was denied so drop frame */
+ ast_bridge_channel_lock_bridge(bridge_channel);
+ blocked = bridge_channel->bridge->technology->stream_topology_request_change
+ && bridge_channel->bridge->technology->stream_topology_request_change(
+ bridge_channel->bridge, bridge_channel);
+ ast_bridge_unlock(bridge_channel->bridge);
+ if (blocked) {
+ /*
+ * Topology change was intercepted by the bridge technology
+ * so drop frame.
+ */
bridge_frame_free(frame);
return;
}
@@ -2498,12 +2505,14 @@ static void bridge_handle_trip(struct ast_bridge_channel *bridge_channel)
* If a stream topology has changed then the bridge_channel's
* media mapping needs to be updated.
*/
+ ast_bridge_channel_lock_bridge(bridge_channel);
if (bridge_channel->bridge->technology->stream_topology_changed) {
bridge_channel->bridge->technology->stream_topology_changed(
bridge_channel->bridge, bridge_channel);
} else {
ast_bridge_channel_stream_map(bridge_channel);
}
+ ast_bridge_unlock(bridge_channel->bridge);
break;
default:
break;
@@ -2990,9 +2999,11 @@ struct ast_bridge_channel *bridge_channel_internal_alloc(struct ast_bridge *brid
void ast_bridge_channel_stream_map(struct ast_bridge_channel *bridge_channel)
{
+ ast_bridge_channel_lock(bridge_channel);
ast_channel_lock(bridge_channel->chan);
ast_stream_topology_map(ast_channel_get_stream_topology(bridge_channel->chan),
&bridge_channel->bridge->media_types, &bridge_channel->stream_map.to_bridge,
&bridge_channel->stream_map.to_channel);
ast_channel_unlock(bridge_channel->chan);
+ ast_bridge_channel_unlock(bridge_channel);
}