From: Matthew Nicholson <mnicholson@digium.com>
Date: Fri, 19 Jun 2009 21:08:11 +0000 (+0000)
Subject: Added deadlock protection to try_suggested_sip_codec in chan_sip.c.
X-Git-Tag: 1.6.1.3-rc1~134
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e8a03ddfddd4f70a9bc40df0225312ab4544fef2;p=thirdparty%2Fasterisk.git

Added deadlock protection to try_suggested_sip_codec in chan_sip.c.

Review: https://reviewboard.asterisk.org/r/287/


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.1@202008 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index e24f391860..74fff4f900 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -5395,8 +5395,20 @@ static void try_suggested_sip_codec(struct sip_pvt *p)
 	int fmt;
 	const char *codec;
 
-	codec = pbx_builtin_getvar_helper(p->owner, "SIP_CODEC");
-	if (!codec) 
+	while (p->owner && ast_channel_trylock(p->owner)) {
+		sip_pvt_unlock(p);
+		sched_yield();
+		sip_pvt_lock(p);
+	}
+
+	if (!p->owner)
+		return;
+
+	codec = ast_strdupa(S_OR(pbx_builtin_getvar_helper(p->owner, "SIP_CODEC"), ""));
+
+	ast_channel_unlock(p->owner);
+
+	if (ast_strlen_zero(codec))
 		return;
 
 	fmt = ast_getformatbyname(codec);