From bc1f5729434e149464508f19e0f30d7d445d506d Mon Sep 17 00:00:00 2001
From: Mark Michelson <mmichelson@digium.com>
Date: Mon, 22 Jun 2009 14:36:26 +0000
Subject: [PATCH] Merged revisions 202337 via svnmerge from
 https://origsvn.digium.com/svn/asterisk/trunk

................
  r202337 | mmichelson | 2009-06-22 09:35:09 -0500 (Mon, 22 Jun 2009) | 31 lines

  Merged revisions 202336 via svnmerge from
  https://origsvn.digium.com/svn/asterisk/branches/1.4

  ........
    r202336 | mmichelson | 2009-06-22 09:34:05 -0500 (Mon, 22 Jun 2009) | 25 lines

    Fix a possible infinite loop in SDP parsing during glare situation.

    There was a while loop in get_ip_and_port_from_sdp which was controlled
    by a call to get_sdp_iterate. The loop would exit either if what we were
    searching for was found or if the return was NULL. The problem is that
    get_sdp_iterate never returns NULL. This means that if what we were searching
    for was not present, the loop would run infinitely. This modification of the
    loop fixes the problem.

    (closes issue #15213)
    Reported by: schmidts

    (closes issue #15349)
    Reported by: samy

    (closes issue #14464)
    Reported by: pj

    (closes issue #15345)
    Reported by: aragon
    Patches:
          sip_inf_loop.patch uploaded by mmichelson (license 60)
    Tested by: aragon
  ........
................


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.2@202340 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 channels/chan_sip.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 0c09a6e51b..8ac0efed0e 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -7485,7 +7485,7 @@ static int get_ip_and_port_from_sdp(struct sip_request *req, const enum media_ty
 		/* Continue since there may be a valid host in a c= line specific to the audio stream */
 	}
 	/* We only want the m and c lines for audio */
-	while ((m = get_sdp_iterate(&miterator, req, "m"))) {
+	for (m = get_sdp_iterate(&miterator, req, "m"); !ast_strlen_zero(m); m = get_sdp_iterate(&miterator, req, "m")) {
 		if ((media == SDP_AUDIO && ((sscanf(m, "audio %d/%d RTP/AVP %n", &x, &numberofports, &len) == 2 && len > 0) ||
 		    (sscanf(m, "audio %d RTP/AVP %n", &x, &len) == 1 && len > 0))) ||
 			(media == SDP_VIDEO && ((sscanf(m, "video %d/%d RTP/AVP %n", &x, &numberofports, &len) == 2 && len > 0) ||