ast_channel_masquerade: Avoid recursive masquerades.

Check all 4 combinations of (original/clonechan) * (masq/masqr).

Initially original->masq and clonechan->masqr were only checked.

It's possible with multiple masq's planned - and not yet executed, that
 the 'original' chan could already have another masq'd into it - thus original->masqr
would be set, that masqr would lost.
Likewise for the clonechan->masq.

(closes issue #16057;#17363)
Reported by: amorsen;davidw,alecdavis
Patches: 
      based on bug16057.diff4.txt uploaded by alecdavis (license 585)
Tested by: ramonpeek, davidw, alecdavis



git-svn-id: http://svn.digium.com/svn/asterisk/branches/1.6.2@287685 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 15 insertions, 7 deletions

diff --git a/main/channel.c b/main/channel.c
index dc77a21e7..977825029 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -4497,19 +4497,27 @@ retrymasq:
 
 	ast_debug(1, "Planning to masquerade channel %s into the structure of %s\n",
 		clonechan->name, original->name);
-	if (original->masq) {
-		ast_log(LOG_WARNING, "%s is already going to masquerade as %s\n",
-			original->masq->name, original->name);
-	} else if (clonechan->masqr) {
-		ast_log(LOG_WARNING, "%s is already going to masquerade as %s\n",
-			clonechan->name, clonechan->masqr->name);
-	} else {
+
+	if (!original->masqr && !original->masq && !clonechan->masq && !clonechan->masqr) {
 		original->masq = clonechan;
 		clonechan->masqr = original;
 		ast_queue_frame(original, &ast_null_frame);
 		ast_queue_frame(clonechan, &ast_null_frame);
 		ast_debug(1, "Done planning to masquerade channel %s into the structure of %s\n", clonechan->name, original->name);
 		res = 0;
+	} else if (original->masq) {
+		ast_log(LOG_WARNING, "%s is already going to masquerade as %s\n",
+			original->masq->name, original->name);
+	} else if (original->masqr) {
+		/* not yet as a previously planned masq hasn't yet happened */
+		ast_log(LOG_WARNING, "%s is already going to masquerade as %s\n",
+			original->name, original->masqr->name);
+	} else if (clonechan->masq) {
+		ast_log(LOG_WARNING, "%s is already going to masquerade as %s\n",
+			clonechan->masq->name, clonechan->name);
+	} else { /* (clonechan->masqr) */
+		ast_log(LOG_WARNING, "%s is already going to masquerade as %s\n",
+		clonechan->name, clonechan->masqr->name);
 	}
 
 	ast_channel_unlock(clonechan);