diff options
author | Alec L Davis <sivad.a@paradise.net.nz> | 2011-02-25 18:58:10 +0000 |
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committer | Alec L Davis <sivad.a@paradise.net.nz> | 2011-02-25 18:58:10 +0000 |
commit | b6e37118c9220f65e9bcb77bf88ccb46796906a2 (patch) | |
tree | 05b4cd119d2d4b9cd137ef9b72ab07da4fad9af7 /channels/chan_sip.c | |
parent | 642d6c306c8e9146bf85c3080ec9af4bef3fd011 (diff) |
Merged revisions 308945 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.8
........
r308945 | alecdavis | 2011-02-26 07:52:53 +1300 (Sat, 26 Feb 2011) | 21 lines
Fix Deadlock with attended transfer of SIP call
Call path
sip_set_rtp_peer (locks chan then pvt)
transmit_reinvite_with_sdp
try_suggested_sip_codec
pbx_builtin_getvar_helper (locks p->owner)
But by the time p->owner lock was attempted, seems as though chan and p->owner were different.
So in sip_set_rtp_peer, lock pvt first then lock p->owner using deadlocking methods.
(closes issue #18837)
Reported by: alecdavis
Patches:
bug18837-trunk.diff3.txt uploaded by alecdavis (license 585)
Tested by: alecdavis, Irontec, ZX81, cmaj
Review: [https://reviewboard.asterisk.org/r/1126/]
........
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@308946 65c4cc65-6c06-0410-ace0-fbb531ad65f3
Diffstat (limited to 'channels/chan_sip.c')
-rw-r--r-- | channels/chan_sip.c | 35 |
1 files changed, 31 insertions, 4 deletions
diff --git a/channels/chan_sip.c b/channels/chan_sip.c index e9ef2d695..79e570b39 100644 --- a/channels/chan_sip.c +++ b/channels/chan_sip.c @@ -27966,7 +27966,20 @@ static int sip_set_udptl_peer(struct ast_channel *chan, struct ast_udptl *udptl) if (!p) { return -1; } + /* + * Lock both the pvt and it's owner safely. + */ sip_pvt_lock(p); + while (p->owner && ast_channel_trylock(p->owner)) { + sip_pvt_unlock(p); + usleep(1); + sip_pvt_lock(p); + } + + if (!p->owner) { + sip_pvt_unlock(p); + return 0; + } if (udptl) { ast_udptl_get_peer(udptl, &p->udptlredirip); } else { @@ -27985,6 +27998,7 @@ static int sip_set_udptl_peer(struct ast_channel *chan, struct ast_udptl *udptl) } /* Reset lastrtprx timer */ p->lastrtprx = p->lastrtptx = time(NULL); + ast_channel_unlock(p->owner); sip_pvt_unlock(p); return 0; } @@ -28102,12 +28116,25 @@ static int sip_set_rtp_peer(struct ast_channel *chan, struct ast_rtp_instance *i return 0; } - ast_channel_lock(chan); + /* + * Lock both the pvt and it's owner safely. + */ sip_pvt_lock(p); + while (p->owner && ast_channel_trylock(p->owner)) { + sip_pvt_unlock(p); + usleep(1); + sip_pvt_lock(p); + } + + if (!p->owner) { + sip_pvt_unlock(p); + return 0; + } + if (p->alreadygone) { /* If we're destroyed, don't bother */ + ast_channel_unlock(p->owner); sip_pvt_unlock(p); - ast_channel_unlock(chan); return 0; } @@ -28115,8 +28142,8 @@ static int sip_set_rtp_peer(struct ast_channel *chan, struct ast_rtp_instance *i that are known to be behind a NAT, then stop the process now */ if (nat_active && !ast_test_flag(&p->flags[0], SIP_DIRECT_MEDIA_NAT)) { + ast_channel_unlock(p->owner); sip_pvt_unlock(p); - ast_channel_unlock(chan); return 0; } @@ -28158,8 +28185,8 @@ static int sip_set_rtp_peer(struct ast_channel *chan, struct ast_rtp_instance *i } /* Reset lastrtprx timer */ p->lastrtprx = p->lastrtptx = time(NULL); + ast_channel_unlock(p->owner); sip_pvt_unlock(p); - ast_channel_unlock(chan); return 0; } |