diff options
author | Richard Mudgett <rmudgett@digium.com> | 2017-07-05 13:39:45 -0500 |
---|---|---|
committer | Richard Mudgett <rmudgett@digium.com> | 2017-07-06 16:14:36 -0500 |
commit | 3c8725a8cd6c91f6231dc86004d015cf120bb231 (patch) | |
tree | 904e46593c5a51de83a3923118040e7075d652fb /res/res_rtp_asterisk.c | |
parent | 725a4637cf4840e49ccad3d7f7cf31630299a97e (diff) |
res_rtp_asterisk.c: Fix TURN deadlock by using ICE session group lock.
When a message is received on the TURN socket, the code processing the
message needs to call into the ICE/STUN session for further processing.
This code path locks the TURN group lock then the ICE/STUN group lock. In
another thread an ICE/STUN timer can fire off to send a keep alive message
over the TURN socket. In this code path, the ICE/STUN group lock is
obtained then the TURN group lock is obtained to send the packet. A
classic deadlock case if the group locks are not the same.
* Made TURN get created using the ICE/STUN session's group lock.
NOTE: I was originally concerned that the ICE/STUN session can get
recreated by ice_reset_session() for an event like RTCP multiplexing
causing a change during SDP negotiation. In this case the TURN group lock
would become different. However, TURN is also recreated as part of the
ICE/STUN recreation in ice_create() when all known ICE candidates are
added to the new ICE session. While the ICE/STUN and TURN sessions are
being recreated there is a period where the group locks could be
different.
ASTERISK-27023 #close
Patches:
res_rtp_asterisk-turn-deadlock-fix.patch (license #6502)
patch uploaded by Michael Walton (modified)
Change-Id: Ic870edb99ce4988a8c8eb6e678ca7f19da1432b9
Diffstat (limited to 'res/res_rtp_asterisk.c')
-rw-r--r-- | res/res_rtp_asterisk.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/res/res_rtp_asterisk.c b/res/res_rtp_asterisk.c index 67140732a..2a2fbf744 100644 --- a/res/res_rtp_asterisk.c +++ b/res/res_rtp_asterisk.c @@ -1291,6 +1291,8 @@ static void ast_rtp_ice_turn_request(struct ast_rtp_instance *instance, enum ast pj_turn_session_info info; struct ast_sockaddr local, loop; pj_status_t status; + pj_turn_sock_cfg turn_sock_cfg; + struct ice_wrap *ice; ast_rtp_instance_get_local_address(instance, &local); if (ast_sockaddr_is_ipv4(&local)) { @@ -1353,11 +1355,20 @@ static void ast_rtp_ice_turn_request(struct ast_rtp_instance *instance, enum ast pj_stun_config_init(&stun_config, &cachingpool.factory, 0, rtp->ioqueue->ioqueue, rtp->ioqueue->timerheap); + /* Use ICE session group lock for TURN session to avoid deadlock */ + pj_turn_sock_cfg_default(&turn_sock_cfg); + ice = rtp->ice; + if (ice) { + turn_sock_cfg.grp_lock = ice->real_ice->grp_lock; + ao2_ref(ice, +1); + } + /* Release the instance lock to avoid deadlock with PJPROJECT group lock */ ao2_unlock(instance); status = pj_turn_sock_create(&stun_config, ast_sockaddr_is_ipv4(&addr) ? pj_AF_INET() : pj_AF_INET6(), conn_type, - turn_cb, NULL, instance, turn_sock); + turn_cb, &turn_sock_cfg, instance, turn_sock); + ao2_cleanup(ice); if (status != PJ_SUCCESS) { ast_log(LOG_WARNING, "Could not create a TURN client socket\n"); ao2_lock(instance); |