[OpenSIPS-Devel] CANCELs and negative ACKs are constructed from the outgoing INVITE ?

[Noman Siddiqui]

Hi Bogdan,

Thanks for looking into this. Yes, the problem is when the From and To 
headers are changed in the outgoing INVITE and the CANCEL comes in and we 
try to send the CANCEL out using t_relay, it picks up the To and From 
headers from the original incoming INVITE. Trying to change the headers in 
the CANCEL also doesn't work as the outgoing CANCEL is getting built locally 
afterwards:
cancel_branch(t, branch )
.. build_cancel(t, branch, &len)
..... build_local( Trans, branch, len,CANCEL, CANCEL_LEN, &Trans->to )

In case of negative ACK To Header is updated but the From header is not.

Thanks,
Noman

----Original Message Follows----
From: Bogdan-Andrei Iancu <bogdan at voice-system.ro>
To: Noman Siddiqui <nomansi at hotmail.com>
CC: devel at lists.opensips.org
Subject: Re: [OpenSIPS-Devel] CANCELs and negative ACKs are constructed from 
the	outgoing INVITE ?
Date: Thu, 09 Oct 2008 12:05:51 +0300

Hi Noman,

There is no similar functionality because there is no need - the CANCELs and 
local ACKs are build based on the received INVITEs, but taking into 
consideration the changes that were applied on the INVITE (like changing 
FROM hdr, ROUTE headers, etc).

Have you spotted a functionality bug - some info that is not updated?

Regards,
Bogdan

Noman Siddiqui wrote:
>Hi All,
>
>Does anyone know if the support for reparse_invite tm configuration and 
>tm_relay_cancel is present in openSER-1.3.1 or later releases.
>
>I found the related patch SER-212 
>(http://lists.iptel.org/pipermail/serdev/2007-May/010212.html) to fix the 
>issue with CANCEL and negative ACK being built using the incoming INVITE 
>instead of outgoing INVITE. However, I searched through the 1.3.1 openSER 
>codebase and couldn't find this or similar feature. If its covered through 
>some other feature then kindly provide more details. If its not already 
>there then is there any enhancement request already in place to cover this 
>or does it require new feature request to be opened ?
>
>Here is the pacth detail of SER-212:
>http://lists.iptel.org/pipermail/serdev/2007-May/010212.html
>===================
>   SER CVS Repository
>
>   Modified files:
>     modules/tm           t_cancel.c t_fwd.c t_fwd.h t_msgbuilder.c
>                          t_msgbuilder.h t_reply.c tm.c
>   Added files:
>     modules/tm           lw_parser.c lw_parser.h
>   Log:
>   CANCELs and negative ACKs are constructed from the INVITE which was sent 
>out
>   instead of building them from the received one. The disadvantage is
>   that the outgoing INVITE has to be partially reparsed, the advantage is 
>that
>   the CANCEL/ACK is always RFC-compliant, it always contains the same 
>route-set
>   as the INVITE message. (closes SER-212)
>
>   build_local_reparse() function can be used to construct a CANCEL or ACK, 
>it
>   reparses the outgoing INVITE and applies the modifications specified by 
>the RFC.
>
>   new module parameters:
>    - reparse_invite: set it to 0 in order to revert to the old behaviour)
>    - ac_extra_hdrs: prefix for additional headers which are kept by 
>build_local_reparse()
>
>   new script function:
>    - t_relay_cancel() - can be used to catch CANCEL requests at the 
>beginning of the script
>                         and bypass the rest of the script processing:
>
>   if (!t_relay_cancel()) {  # implicit drop if relaying was successful,
>                             # nothing to do
>
>           # corresponding INVITE transaction found but error occurred
>           sl_reply("500", "Internal Server Error");
>           drop;
>   }
>   # bad luck, corresponding INVITE transaction is missing,
>   # do the same as for INVITEs
>   ...
>
>   Revision  Changes    Path
>   1.1       +258 -0    sip_router/modules/tm/lw_parser.c (new)
>http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/lw_parser.c?rev=1.1&content-type=text/plain
>   1.1       +46 -0     sip_router/modules/tm/lw_parser.h (new)
>http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/lw_parser.h?rev=1.1&content-type=text/plain
>   1.23      +12 -3     sip_router/modules/tm/t_cancel.c
>http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/t_cancel.c.diff?r1=1.22&r2=1.23
>   1.87      +64 -2     sip_router/modules/tm/t_fwd.c
>http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/t_fwd.c.diff?r1=1.86&r2=1.87
>   1.15      +2 -1      sip_router/modules/tm/t_fwd.h
>http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/t_fwd.h.diff?r1=1.14&r2=1.15
>   1.46      +161 -1    sip_router/modules/tm/t_msgbuilder.c
>http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/t_msgbuilder.c.diff?r1=1.45&r2=1.46
>   1.18      +7 -1      sip_router/modules/tm/t_msgbuilder.h
>http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/t_msgbuilder.h.diff?r1=1.17&r2=1.18
>   1.140     +14 -3     sip_router/modules/tm/t_reply.c
>http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/t_reply.c.diff?r1=1.139&r2=1.140
>   1.153     +23 -1     sip_router/modules/tm/tm.c
>http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/tm/tm.c.diff?r1=1.152&r2=1.153
>=============================
>
>Thanks and appreciate your help.
>
>
>
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