[OpenSIPS-Users] fix_route_dialog problem

[Guido Negro]

Hi,

thanks for your reply.

I am using the script reported in the Opensips book ("Building telephony 
systems with Opensips") at page 81, that is :


if (has_totag() ) {
   # sequential request withing a dialog should
   # take the path determined by record-routing
   if (loose_route() ) {
     if (is_method("BYE" ) ) {
       setflag(1) ; # do accounting . . .
       setflag(3 ) ; # . . . even if the transaction fails
     } else if ( is_method( "INVITE" ) ) {
       # even if in most of the cases is useless, do RR for
       # re-INVITEs alos, as some buggy clients do change route set
       # during the dialog.
       record_route() ;
     }
     # route it out to whatever destination was set by loose_route()
     # in $du (destination URI) .
     route( 1) ;
   } else {
     if ( is_method(" ACK") ) {
       if ( t_check_trans( ) ) {
         # non loose- route, but stateful ACK; must be an ACK after
         # a 487 or e. g. 4 04 from upstream server
         t_relay() ;
         exit;
       } else {
         # ACK without matching transaction ->
         # ignore and discard
         exit;
       }
     }
     sl_send_reply("4 04" , " Not here") ;
   }
   exit;
}


Now I've got 2 problems. When a BYE with correct to/from tag & correct 
call-id, but without any route headers arrives (a message I'd like to 
'fix'):

1) I get the variable $DLG_status to be <null> after loose_route() (I 
checked with specific experiments) and this also causes an error in the 
log: opensips[3216]: ERROR:dialog:w_validate_dialog: null dialog

2) loose_route() fails, so I always get a 404 response on the callee 
side that tried to disconnect, and the caller remains connected.


I am probably using fix_route_dialog not in the correct way, but what I 
wanted to do is something like this (very-pseudo code):

When loose_route fails (or more in general for every in-dialog 
subsequent request):
     Try to fix the request according to saved dialog infos:
         - Fix succesful: forward the request.
         - Couldnt fix it: reject the request (send 404 back).


Regards,

Guido.

On 24/01/11 11:34, Vlad Paiu wrote:
> Hello,
>
> The function fix_route_dialog() needs loose_route() to be called, in 
> order to set the current dialog pointer that fix_route_dialog() will 
> attempt to match and fix accordingly. It isn't mandatory to call 
> validate_dialog() first, but it is best practice, because a call to 
> validate_dialog() function is very light, while fix_route_dialog() 
> makes heavy changes to the SIP msg.
>
> A very basic example of script to fix only BYEs would be
>
> if (has_totag()) {
>         loose_route();
>
>         if (is_method("BYE"))
>             if (!validate_dialog())
>                 fix_route_dialog();
>     }
>
> The dialog structure is not cleared from OpenSIPS memory when BYE is 
> received. This happens when the respective transaction ends, so the 
> above example should work just fine.
>
> Could you please post the script you are using and a high level debug 
> log from OpenSIPS ?
>
>
> On 01/24/2011 12:26 PM, Guido Negro wrote:
>> Hi,
>>
>> I encountered some problems while trying to use fix_route_dialog() 
>> function.
>>
>> Basically what I'd like to do is to use this function to correct 
>> Route headers of the BYE messages that
>>
>>     * have wrong or no Route header at all
>>     * have valid to/from & call-id information ( 'valid' in respect 
>> to dialog infos saved in opensips )
>>
>> I tried to use it as suggested in the documentation, that is
>>
>>     if (has_totag()) {
>>         loose_route();
>>         if ($DLG_status!=NULL)
>>             if (!validate_dialog())
>>                 fix_route_dialog();
>>     }
>>
>>
>> The problem is that when a BYE comes in, the dialog is automatically 
>> deleted in opensips, so I can never really reach fix_route_dialog() 
>> call in the case I want to actually use it.
>>
>> Should I do something like
>>
>>     if (is_method("BYE"))
>>         fix_route_dialog();
>>
>>
>> Is fix_route_dialog() supposed to work even without the checks that 
>> are in the doc's code snippet?
>>
>>
>> Thank you very much,
>>
>>
>> Guido.
>>
>> _______________________________________________
>> Users mailing list
>> Users at lists.opensips.org
>> http://lists.opensips.org/cgi-bin/mailman/listinfo/users
>>
>
>