diff options
author | Kevin Harwell <kharwell@digium.com> | 2014-12-12 15:31:38 +0000 |
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committer | Kevin Harwell <kharwell@digium.com> | 2014-12-12 15:31:38 +0000 |
commit | 72499dc6970e6679c35f8732a0a840f9e3f303b7 (patch) | |
tree | b66e2ee6cd6eb96a01bcdbfaf2a7d90c241a195d /channels | |
parent | 2e6d2b148496c43ffaafd6c8c463f77749d3feee (diff) |
chan_pjsip: Race between channel answer and bridge setup when using direct media
When direct media is enabled and a pjsip channel is answered a race would occur
between the handling of the answer and bridge setup. Sometimes the media
negotiation would take place after the native bridge was setup. This resulted
in a NULL media address, which in turn resulted in Asterisk using its address
as the remote media address when sending a reinvite. This patch makes the
chan_pjsip answer handler synchronous thus alleviating the race condition (the
bridge won't start setting things up until after it returns).
ASTERISK-24563 #close
Reported by: Steve Pitts
Review: https://reviewboard.asterisk.org/r/4257/
........
Merged revisions 429477 from http://svn.asterisk.org/svn/asterisk/branches/13
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@429478 65c4cc65-6c06-0410-ace0-fbb531ad65f3
Diffstat (limited to 'channels')
-rw-r--r-- | channels/chan_pjsip.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/channels/chan_pjsip.c b/channels/chan_pjsip.c index b6bfeb5b4..cad0a7c5f 100644 --- a/channels/chan_pjsip.c +++ b/channels/chan_pjsip.c @@ -490,7 +490,6 @@ static int answer(void *data) struct ast_sip_session *session = data; if (session->inv_session->state == PJSIP_INV_STATE_DISCONNECTED) { - ao2_ref(session, -1); return 0; } @@ -507,8 +506,6 @@ static int answer(void *data) ast_sip_session_send_response(session, packet); } - ao2_ref(session, -1); - return (status == PJ_SUCCESS) ? 0 : -1; } @@ -516,19 +513,27 @@ static int answer(void *data) static int chan_pjsip_answer(struct ast_channel *ast) { struct ast_sip_channel_pvt *channel = ast_channel_tech_pvt(ast); + struct ast_sip_session *session; if (ast_channel_state(ast) == AST_STATE_UP) { return 0; } ast_setstate(ast, AST_STATE_UP); + session = ao2_bump(channel->session); - ao2_ref(channel->session, +1); - if (ast_sip_push_task(channel->session->serializer, answer, channel->session)) { + /* the answer task needs to be pushed synchronously otherwise a race condition + can occur between this thread and bridging (specifically when native bridging + attempts to do direct media) */ + ast_channel_unlock(ast); + if (ast_sip_push_task_synchronous(session->serializer, answer, session)) { ast_log(LOG_WARNING, "Unable to push answer task to the threadpool. Cannot answer call\n"); - ao2_cleanup(channel->session); + ao2_ref(session, -1); + ast_channel_lock(ast); return -1; } + ao2_ref(session, -1); + ast_channel_lock(ast); return 0; } |