audiohook: Don't allow audiohooks to attach to hung up channels.

Given a scenario where MixMonitor was initiated over AMI it
was possible for the channel and MixMonitor thread to remain
alive past hang up of the channel. This scenario required
the AMI initiated MixMonitor to retrieve the channel, a
hangup to occur on the channel in another thread, and then
for MixMonitor to actually start. If this occurred the
MixMonitor thread would remain alive indefinitely and
the channel reference would remain.

This change ensures that audiohooks are never able to
be attached to channels that have been hung up. An
additional fix has also been done in app_mixmonitor to
properly release the channel reference if this occurs.

ASTERISK-28780

Change-Id: I8044c06daa06f0f16607788c596f55623be26f58

diff --git a/apps/app_mixmonitor.c b/apps/app_mixmonitor.c
index a5c27bfc8b115d4e67ff2047fc49f0e26e6e61c1..09148ccf1dd3ffc77e2196fd0e0decd415650580 100644 (file)
--- a/apps/app_mixmonitor.c
+++ b/apps/app_mixmonitor.c
@@ -987,6 +987,7 @@ static int launch_monitor_thread(struct ast_channel *chan, const char *filename,
        if (startmon(chan, &mixmonitor->audiohook)) {
                ast_log(LOG_WARNING, "Unable to add '%s' spy to channel '%s'\n",
                        mixmonitor_spy_type, ast_channel_name(chan));
+               ast_autochan_destroy(mixmonitor->autochan);
                ast_audiohook_destroy(&mixmonitor->audiohook);
                mixmonitor_free(mixmonitor);
                return -1;

diff --git a/main/audiohook.c b/main/audiohook.c
index 4db32ea7c0de0222150306e4d46a4f9e80bece3f..ed16897be05de03e398b5688d74f025a6bcd9aaf 100644 (file)
--- a/main/audiohook.c
+++ b/main/audiohook.c
@@ -502,6 +502,15 @@ int ast_audiohook_attach(struct ast_channel *chan, struct ast_audiohook *audioho
 {
        ast_channel_lock(chan);
 
+       /* Don't allow an audiohook to be attached to a channel that is already hung up.
+        * The hang up process is what actually notifies the audiohook that it should
+        * stop.
+        */
+       if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_ZOMBIE)) {
+               ast_channel_unlock(chan);
+               return -1;
+       }
+
        if (!ast_channel_audiohooks(chan)) {
                struct ast_audiohook_list *ahlist;
                /* Whoops... allocate a new structure */