Merged revisions 319997 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.8

........
  r319997 | rmudgett | 2011-05-20 10:48:25 -0500 (Fri, 20 May 2011) | 25 lines
  
  Crash when using directed pickup applications.
  
  The directed pickup applications can cause a crash if the pickup was
  successful because the dialplan keeps executing.
  
  This patch does the following:
  
  * Completes the channel masquerade on a successful pickup before the
  application returns.  The channel is now guaranteed a zombie and must not
  continue executing the dialplan.
  
  * Changes the return value of the directed pickup applications to return
  zero if the pickup failed and nonzero(-1) if the pickup succeeded.
  
  * Made some code optimizations that no longer require re-checking the
  pickup channel to see if it is still available to pickup.
  
  (closes issue #19310)
  Reported by: remiq
  Patches:
        issue19310_v1.8_v2.patch uploaded by rmudgett (license 664)
  Tested by: alecdavis, remiq, rmudgett
  
  Review: https://reviewboard.asterisk.org/r/1221/
........


git-svn-id: http://svn.digium.com/svn/asterisk/trunk@319998 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 32 insertions, 36 deletions

diff --git a/main/features.c b/main/features.c
index e11081bb9..db52417a2 100644
--- a/main/features.c
+++ b/main/features.c
@@ -5759,21 +5759,21 @@ static int manager_park(struct mansession *s, const struct message *m)
 
 static int find_channel_by_group(void *obj, void *arg, void *data, int flags)
 {
-	struct ast_channel *c = data;
 	struct ast_channel *chan = obj;
-	int i;
+	struct ast_channel *c = data;
 
-	i = !chan->pbx &&
-		/* Accessing 'chan' here is safe without locking, because there is no way for
-		   the channel to disappear from under us at this point.  pickupgroup *could*
-		   change while we're here, but that isn't a problem. */
-		(c != chan) &&
-		(c->pickupgroup & chan->callgroup) &&
+	ast_channel_lock(chan);
+	if (c != chan && (c->pickupgroup & chan->callgroup) &&
+		!chan->pbx &&
 		((chan->_state == AST_STATE_RINGING) || (chan->_state == AST_STATE_RING)) &&
 		!chan->masq &&
-		!ast_test_flag(chan, AST_FLAG_ZOMBIE);
+		!ast_test_flag(chan, AST_FLAG_ZOMBIE)) {
+		/* Return with the channel still locked on purpose */
+		return CMP_MATCH | CMP_STOP;
+	}
+	ast_channel_unlock(chan);
 
-	return i ? CMP_MATCH | CMP_STOP : 0;
+	return 0;
 }
 
 /*!
@@ -5790,35 +5790,26 @@ int ast_pickup_call(struct ast_channel *chan)
 	int res = -1;
 	ast_debug(1, "pickup attempt by %s\n", chan->name);
 
-	/* If 2 callers try to pickup the same call, allow 1 to win, and other to fail early.*/
-	if ((target = ast_channel_callback(find_channel_by_group, NULL, chan, 0))) {
-		ast_channel_lock(target);
-
-		/* We now have the target locked, but is the target still available to pickup */
-		if (!target->masq && !ast_test_flag(target, AST_FLAG_ZOMBIE) &&
-			((target->_state == AST_STATE_RINGING) || (target->_state == AST_STATE_RING))) {
-
-			ast_log(LOG_NOTICE, "pickup %s attempt by %s\n", target->name, chan->name);
-
-			/* A 2nd pickup attempt will bail out when we unlock the target */
-			if (!(res = ast_do_pickup(chan, target))) {
-				ast_channel_unlock(target);
-				if (!(res = ast_do_masquerade(target))) {
-					if (!ast_strlen_zero(pickupsound)) {
-						ast_channel_lock(target);
-						ast_stream_and_wait(target, pickupsound, "");
-						ast_channel_unlock(target);
-					}
-				} else {
-					ast_log(LOG_WARNING, "Failed to perform masquerade\n");
-				}
-			} else {
-				ast_log(LOG_WARNING, "pickup %s failed by %s\n", target->name, chan->name);
-				ast_channel_unlock(target);
+	/* The found channel is already locked. */
+	target = ast_channel_callback(find_channel_by_group, NULL, chan, 0);
+	if (target) {
+		ast_log(LOG_NOTICE, "pickup %s attempt by %s\n", target->name, chan->name);
+
+		res = ast_do_pickup(chan, target);
+		if (!res) {
+			if (!ast_strlen_zero(pickupsound)) {
+				/*!
+				 * \todo We are not the bridge thread when we inject this sound
+				 * so we need to hold the target channel lock while the sound is
+				 * played.  A better way needs to be found as this pauses the
+				 * system.
+				 */
+				ast_stream_and_wait(target, pickupsound, "");
 			}
 		} else {
-			ast_channel_unlock(target);
+			ast_log(LOG_WARNING, "pickup %s failed by %s\n", target->name, chan->name);
 		}
+		ast_channel_unlock(target);
 		target = ast_channel_unref(target);
 	}
 
@@ -5882,6 +5873,11 @@ int ast_do_pickup(struct ast_channel *chan, struct ast_channel *target)
 	ast_manager_event_multichan(EVENT_FLAG_CALL, "Pickup", 2, chans,
 		"Channel: %s\r\nTargetChannel: %s\r\n", chan->name, target->name);
 
+	/* Do the masquerade manually to make sure that is is completed. */
+	ast_channel_unlock(target);
+	ast_do_masquerade(target);
+	ast_channel_lock(target);
+
 	return 0;
 }