[Asterisk-code-review] bridge softmix.c: Fix crash if channel fails to join mixing ... (asterisk[master])

[Richard Mudgett]

Richard Mudgett has uploaded a new change for review.

  https://gerrit.asterisk.org/2589

Change subject: bridge_softmix.c: Fix crash if channel fails to join mixing tech.
......................................................................

bridge_softmix.c: Fix crash if channel fails to join mixing tech.

softmix_bridge_join() failed because of an allocation failure.  To address
this, the softmix bridge technology now checks if the channel failed to
join softmix successfully.  In addition, the bridge now begins the process
of kicking the channel out of the bridge so we don't have channels
partially in the bridge for very long.

Change-Id: I97e2ade6a2bcd1214f24fb839fda948825b61a2b
---
M bridges/bridge_softmix.c
M include/asterisk/bridge_technology.h
M main/bridge.c
3 files changed, 17 insertions(+), 3 deletions(-)


  git pull ssh://gerrit.asterisk.org:29418/asterisk refs/changes/89/2589/1

diff --git a/bridges/bridge_softmix.c b/bridges/bridge_softmix.c
index bad3e43..0991e28 100644
--- a/bridges/bridge_softmix.c
+++ b/bridges/bridge_softmix.c
@@ -359,6 +359,9 @@
 	struct ast_format *slin_format;
 	int setup_fail;
 
+	/* The callers have already ensured that sc is never NULL. */
+	ast_assert(sc != NULL);
+
 	slin_format = ast_format_cache_get_slin_by_rate(rate);
 
 	ast_mutex_lock(&sc->lock);
@@ -714,7 +717,7 @@
 {
 	int res = 0;
 
-	if (!bridge->tech_pvt || (bridge_channel && !bridge_channel->tech_pvt)) {
+	if (!bridge->tech_pvt || !bridge_channel || !bridge_channel->tech_pvt) {
 		/* "Accept" the frame and discard it. */
 		return 0;
 	}
@@ -984,6 +987,11 @@
 		AST_LIST_TRAVERSE(&bridge->channels, bridge_channel, entry) {
 			struct softmix_channel *sc = bridge_channel->tech_pvt;
 
+			if (!sc) {
+				/* This channel failed to join successfully. */
+				continue;
+			}
+
 			/* Update the sample rate to match the bridge's native sample rate if necessary. */
 			if (update_all_rates) {
 				set_softmix_bridge_data(softmix_data->internal_rate, softmix_data->internal_mixing_interval, bridge_channel, 1);
@@ -1019,7 +1027,8 @@
 		AST_LIST_TRAVERSE(&bridge->channels, bridge_channel, entry) {
 			struct softmix_channel *sc = bridge_channel->tech_pvt;
 
-			if (bridge_channel->suspended) {
+			if (!sc || bridge_channel->suspended) {
+				/* This channel failed to join successfully or is suspended. */
 				continue;
 			}
 
diff --git a/include/asterisk/bridge_technology.h b/include/asterisk/bridge_technology.h
index b83a51b..8df19d9 100644
--- a/include/asterisk/bridge_technology.h
+++ b/include/asterisk/bridge_technology.h
@@ -107,6 +107,9 @@
 	 * \retval -1 on failure
 	 *
 	 * \note On entry, bridge is already locked.
+	 *
+	 * \note The bridge technology must tollerate a failed to join channel
+	 * until it can be kicked from the bridge.
 	 */
 	int (*join)(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel);
 	/*!
diff --git a/main/bridge.c b/main/bridge.c
index b9a436e..a56555b 100644
--- a/main/bridge.c
+++ b/main/bridge.c
@@ -420,10 +420,12 @@
 		bridge->technology->name);
 	if (bridge->technology->join
 		&& bridge->technology->join(bridge, bridge_channel)) {
-		ast_debug(1, "Bridge %s: %p(%s) failed to join %s technology\n",
+		/* We cannot leave the channel partially in the bridge so we must kick it out */
+		ast_debug(1, "Bridge %s: %p(%s) failed to join %s technology (Kicking it out)\n",
 			bridge->uniqueid, bridge_channel, ast_channel_name(bridge_channel->chan),
 			bridge->technology->name);
 		bridge_channel->just_joined = 1;
+		ast_bridge_channel_leave_bridge(bridge_channel, BRIDGE_CHANNEL_STATE_END, 0);
 		return;
 	}
 

-- 
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Gerrit-MessageType: newchange
Gerrit-Change-Id: I97e2ade6a2bcd1214f24fb839fda948825b61a2b
Gerrit-PatchSet: 1
Gerrit-Project: asterisk
Gerrit-Branch: master
Gerrit-Owner: Richard Mudgett <rmudgett at digium.com>