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: https://origsvn.digium.com/svn/asterisk/branches/1.6.2@287685 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/main/channel.c b/main/channel.c
index dc77a21e7d42191283809ca5b61fad7868fff33f..9778250298d43a3d31a96115223d764e449df338 100644 (file)
--- 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);