Author: kharwell Date: Fri Dec 12 09:30:28 2014 New Revision: 429477 URL: http://svnview.digium.com/svn/asterisk?view=rev&rev=429477 Log: 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/ Modified: branches/13/channels/chan_pjsip.c Modified: branches/13/channels/chan_pjsip.c URL: http://svnview.digium.com/svn/asterisk/branches/13/channels/chan_pjsip.c?view=diff&rev=429477&r1=429476&r2=429477 ============================================================================== --- branches/13/channels/chan_pjsip.c (original) +++ branches/13/channels/chan_pjsip.c Fri Dec 12 09:30:28 2014 @@ -490,7 +490,6 @@ 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 @@ ast_sip_session_send_response(session, packet); } - ao2_ref(session, -1); - return (status == PJ_SUCCESS) ? 0 : -1; } @@ -516,19 +513,27 @@ 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); - - ao2_ref(channel->session, +1); - if (ast_sip_push_task(channel->session->serializer, answer, channel->session)) { + session = ao2_bump(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; } -- _____________________________________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- svn-commits mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/svn-commits
