chan_sip: Fix missed locking of opposing pvt for directmedia acl from r366547

It also required deadlock avoidance since two sip_pvts structs needed to be
locked simultaneously. Trunk handles it differently, so this is a 1.8 and 10
patch only.

(issue AST-876)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@366791 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 93b191dfc75025491fee1ebbb1367227aa7a4426..7b89edb61bb8eb4922e9386aa8799fa7a4da49d2 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -29083,11 +29083,19 @@ static struct ast_udptl *sip_get_udptl_peer(struct ast_channel *chan)
        }
 
        sip_pvt_lock(p);
+       while (sip_pvt_trylock(opp)) {
+               sip_pvt_unlock(p);
+               usleep(1);
+               sip_pvt_lock(p);
+       }
+
        if (p->udptl && ast_test_flag(&p->flags[0], SIP_DIRECT_MEDIA)) {
                if (apply_directmedia_ha(p, opp, "UDPTL T.38 data")) {
                        udptl = p->udptl;
                }
        }
+
+       sip_pvt_unlock(opp);
        sip_pvt_unlock(p);
        return udptl;
 }
@@ -29153,7 +29161,14 @@ static enum ast_rtp_glue_result sip_get_rtp_peer(struct ast_channel *chan, struc
        }
 
        sip_pvt_lock(p);
+       while (sip_pvt_trylock(opp)) {
+               sip_pvt_unlock(p);
+               usleep(1);
+               sip_pvt_lock(p);
+       }
+
        if (!(p->rtp)) {
+               sip_pvt_unlock(opp);
                sip_pvt_unlock(p);
                return AST_RTP_GLUE_RESULT_FORBID;
        }
@@ -29172,6 +29187,8 @@ static enum ast_rtp_glue_result sip_get_rtp_peer(struct ast_channel *chan, struc
                res = AST_RTP_GLUE_RESULT_FORBID;
        }
 
+       sip_pvt_unlock(opp);
+
        if (p->srtp) {
                res = AST_RTP_GLUE_RESULT_FORBID;
        }
@@ -29199,7 +29216,14 @@ static enum ast_rtp_glue_result sip_get_vrtp_peer(struct ast_channel *chan, stru
        }
 
        sip_pvt_lock(p);
+       while (sip_pvt_trylock(opp)) {
+               sip_pvt_unlock(p);
+               usleep(1);
+               sip_pvt_lock(p);
+       }
+
        if (!(p->vrtp)) {
+               sip_pvt_unlock(opp);
                sip_pvt_unlock(p);
                return AST_RTP_GLUE_RESULT_FORBID;
        }
@@ -29214,6 +29238,7 @@ static enum ast_rtp_glue_result sip_get_vrtp_peer(struct ast_channel *chan, stru
                }
        }
 
+       sip_pvt_unlock(opp);
        sip_pvt_unlock(p);
 
        return res;
@@ -29237,7 +29262,14 @@ static enum ast_rtp_glue_result sip_get_trtp_peer(struct ast_channel *chan, stru
        }
 
        sip_pvt_lock(p);
+       while (sip_pvt_trylock(opp)) {
+               sip_pvt_unlock(p);
+               usleep(1);
+               sip_pvt_lock(p);
+       }
+
        if (!(p->trtp)) {
+               sip_pvt_unlock(opp);
                sip_pvt_unlock(p);
                return AST_RTP_GLUE_RESULT_FORBID;
        }
@@ -29252,6 +29284,7 @@ static enum ast_rtp_glue_result sip_get_trtp_peer(struct ast_channel *chan, stru
                }
        }
 
+       sip_pvt_unlock(opp);
        sip_pvt_unlock(p);
 
        return res;