[asterisk-bugs] [Asterisk 0014994]: [patch] Invalid SDP connection information (c=) parsing leading to one way audio

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=14994 
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Reported By:                frawd
Assigned To:                mnicholson
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Project:                    Asterisk
Issue ID:                   14994
Category:                   Channels/chan_sip/General
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     ready for review
Asterisk Version:           SVN 
JIRA:                        
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2009-04-29 10:33 CDT
Last Modified:              2009-10-14 03:42 CDT
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Summary:                    [patch] Invalid SDP connection information (c=)
parsing leading to one way audio
Description: 
I have a one-way audio problem when a media-gateway was (re)inviting with
audio and video on two different IPs, with an SDP formatted like so:

m=audio
c=IN IP4 <ip1>
[...]
m=video
c=IN IP4 <ip2>
[...]

Looking at the code it appears that asterisk has the following algorithm
for parsing "c=" lines:

1. Look for the first "c=" line and initialize audio and video address
structure
	=> in my case, <ip1> is then initialized for audio and video
2. For each "m=" line found:
	2.1. Look for the next "c=" line STARTING AFTER THE LAST ONE (step 1.)
		=> in my case, <ip2> will be found
	2.2. Initialize audio or video structure depending on what was in "m="
		=> in my case, <ip2> is initialized for the audio part

As a result I have <ip2> for audio and <ip1> for video instead of the
contrary!!!

Could someone please confirm my analysis? I could be totally wrong..
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 (0112253) frawd (reporter) - 2009-10-14 03:42
 https://issues.asterisk.org/view.php?id=14994#c112253 
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Uploaded an example invite packet (from sip debug) where it would fail with
the current version, for having media specific connection info (c=) for
audio and video.

This packet also shows a media specific a=recvonly parameter that should
be applied to video only. 

Issue History 
Date Modified    Username       Field                    Change               
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2009-10-14 03:42 frawd          Note Added: 0112253                          
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