[asterisk-bugs] [Asterisk 0014446]: [patch] chan_sip does not support the maddr attribute in Via headers

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=14446 
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Reported By:                frawd
Assigned To:                oej
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Project:                    Asterisk
Issue ID:                   14446
Category:                   Channels/chan_sip/Interoperability
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     assigned
Asterisk Version:           1.4.23 
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2009-02-10 04:12 CST
Last Modified:              2009-02-10 13:03 CST
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Summary:                    [patch] chan_sip does not support the maddr
attribute in Via headers
Description: 
I recently connected Asterisk with a badly configured Nortel CS2K, which
sends me the following Via header:

Via: SIP/2.0/UDP
CS2KSSTEMAG:5060;maddr=213.60.204.48;branch=z9hG4bK-142abd7-ec6f41f2-4aeebdaf

CS2KSSTEMAG not being a valid DNS entry, the reply is never sent (Asterisk
blocks trying to resolve the name). Even tho it is a configuration error,
maddr should be used as reply address.

The attached patch fixes the issue in 1.4.23.1
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 (0099825) frawd (reporter) - 2009-02-10 13:03
 http://bugs.digium.com/view.php?id=14446#c99825 
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This patch is far from being perfect (you'd also need to take into account
the ttl parameters, ...), and it appears that chan_sip is also quite far
from being compliant with RFC 3261.

But it just works and would probably resolve a few basic issues while
chan_sip is replaced with chan_sofia. :-)

BTW, even with "nat" configured in sip.conf, it still tries to look-up the
host address from the Via instead of sending the reply to whatever address
we got it from. I noticed this issue as my server does not have access to
DNS and those synchronous DNS requests just block everything. 

Issue History 
Date Modified    Username       Field                    Change               
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2009-02-10 13:03 frawd          Note Added: 0099825                          
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