fixes deadlock in chan_sip caused by usage of MASTER_CHANNEL dialplan function

(closes issue #16767)
Reported by: lmsteffan
Patches:
      deadlock_16767v3.diff uploaded by dvossel (license 671)

Review: https://reviewboard.asterisk.org/r/606/

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@256319 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 934a925f0d5dd667787f1facaa585cbe9b67ba5c..f2308fabe96d833b8379d1b1e7c2343834d9966e 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -17495,7 +17495,6 @@ static void handle_response(struct sip_pvt *p, int resp, const char *rest, struc
 
        owner = p->owner;
        if (owner) {
-               char causevar[256], causeval[256];
                const char *rp = NULL, *rh = NULL;
 
                owner->hangupcause = 0;
@@ -17513,10 +17512,6 @@ static void handle_response(struct sip_pvt *p, int resp, const char *rest, struc
 
                if (!owner->hangupcause)
                        owner->hangupcause = hangup_sip2cause(resp);
-
-               snprintf(causevar, sizeof(causevar), "MASTER_CHANNEL(HASH(SIP_CAUSE,%s))", owner->name);
-               snprintf(causeval, sizeof(causeval), "SIP %s", REQ_OFFSET_TO_STR(req, rlPart2));
-               pbx_builtin_setvar_helper(owner, causevar, causeval);
        }
 
        if (p->socket.type == SIP_TRANSPORT_UDP) {
@@ -20922,10 +20917,26 @@ static int handle_incoming(struct sip_pvt *p, struct sip_request *req, struct so
                                ast_log(LOG_DEBUG, "Ignoring out of order response %d (expecting %d)\n", seqno, p->ocseq);
                        return -1;
                } else {
+                       char causevar[256], causeval[256];
+
                        if ((respid == 200) || ((respid >= 300) && (respid <= 399))) {
                                extract_uri(p, req);
                        }
+
                        handle_response(p, respid, e + len, req, seqno);
+
+                       if (p->owner) {
+                               struct ast_channel *owner = p->owner;
+
+                               snprintf(causevar, sizeof(causevar), "MASTER_CHANNEL(HASH(SIP_CAUSE,%s))", owner->name);
+                               snprintf(causeval, sizeof(causeval), "SIP %s", REQ_OFFSET_TO_STR(req, rlPart2));
+
+                               sip_pvt_unlock(p);
+                               ast_channel_unlock(owner);
+                               *nounlock = 1;
+                               pbx_builtin_setvar_helper(owner, causevar, causeval);
+                               sip_pvt_lock(p);
+                       }
                }
                return 0;
        }