[sr-dev] Suggesting fix for t_request and pua_dialoginfo

[Henning Westerholt]

On Wednesday 11 August 2010, Jasmin Schnatterbeck wrote:
> some months ago I reported a problem with pua_dialoginfo:
> Avps declared in request route are not available anymore in branch
> route, if pua_dialoginfo module is loaded.
> 
> I do not know whether there are some experiences with this problem or
> not, so I looked for the reason.
> 
> pua_dialoginfo uses pua for sending PUBLISH request
> pua uses tm t_request for sending PUBLISH request
> 
> t_request() is located in uac.c (tm):
> - in line 411 avp list is reset
> - in line 276 build_cell() is called:
>   build_cell() is located in h_table.c, where lines 305-323 delete avps
> 
> If I comment out the mentioned lines, which delete avps, then avps set
> in request route are also available in branch route.
> But I do not know, what is also affected by this change.
> 
> So would it be reasonable, to add a parameter to build_cell() for not
> changing the AVP list?

Hi Jasmin,

so this issue is just visible in the transaction on which the pua_dialoginfo 
module acts on, or its affects also unrelated transactions?

According my understanding the build_cell method is used for example during 
the creation of a new SIP transaction. This is probably necessary (in this 
case) for t_request to work correctly. So changing it globally would be 
probably not a good idea as it will probably have some side effects. But you 
can add a parameter as you suggested, and just see if it works in your setup. 

If its really harmless i can't confirm at the moment, as my insight into the 
details of the TM module is limited. If you want to get some feedback about a 
patch, Andrei as the maintainer of the module would be probably more qualified 
to give a sound answer. :-)

Cheers,

Henning