[asterisk-bugs] [Asterisk 0007403]: [patch] allow SIP Spiral to work instead of causing a '482 Loop Detected' condition

[noreply at bugs.digium.com]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=7403 
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Reported By:                stephen_dredge
Assigned To:                putnopvut
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Project:                    Asterisk
Issue ID:                   7403
Category:                   Channels/chan_sip/General
Reproducibility:            N/A
Severity:                   tweak
Priority:                   normal
Status:                     assigned
Asterisk Version:            SVN 
SVN Branch (only for SVN checkouts, not tarball releases):  trunk 
SVN Revision (number only!): 47646 
Disclaimer on File?:        No 
Request Review:              
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Date Submitted:             06-21-2006 00:13 CDT
Last Modified:              05-28-2008 11:27 CDT
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Summary:                    [patch] allow SIP Spiral to work instead of causing
a '482 Loop Detected' condition
Description: 
A sip call originating from asterisk causes a '482 Loop Detected' response
when forwarded back to asterisk from a external proxy. This should be
allowed when the request URI has been changed by the proxy and the call is
now targeted at a different user.
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---------------------------------------------------------------------- 
 ibc - 05-28-08 11:27  
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Hi, you said:
---
2. The comparison of request-uri's is a simple string comparison. The URI
comparison should probably be more refined to take into account the fact
that there could be differences in the parameters of the Request-URI. Also,
there could be a strange case where the host portion of the URI is changed
textually, but from a routing perspective equates to no change (i.e. a
hostname is replaced with one of its IP addresses).
---

Note that RFC 3261 says that an IP as URI hostpart **doesn't** match a
domain resolving that IP. There are also some complex rulex when comparing
URI parameters:
http://tools.ietf.org/html/rfc3261#section-19.1.4

19.1.4 URI Comparison

      o  An IP address that is the result of a DNS lookup of a host name
         does not match that host name. 

Issue History 
Date Modified   Username       Field                    Change               
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05-28-08 11:27  ibc            Note Added: 0087439                          
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