Re: [reSIProcate] exception when receiving 200 from re-invite requestwith modified to: tag

["Scott Godin" <slgodin@xxxxxxxxxxxx>]

I don’t think this is quite right – it will not allow multiple 200’s to an initially forked invite request to create dialogs.

 

I think we should check the CSeq in response and only create a dialog if it matches the CSeq in the base creator.  This will make sure we only create multiple dialogs for an initial UAC request, but not mid dialog requests.

 

Scott

 

From: Justin Matthews [mailto:jmatthewsr@xxxxxxxxx]
Sent: Monday, December 11, 2006 10:24 AM
To: Scott Godin; resiprocate-devel@xxxxxxxxxxxxxxxxxxx
Subject: RE: [reSIProcate] exception when receiving 200 from re-invite requestwith modified to: tag

 

Further on this issue, although the patch fixes the exception and drops the 200 for the case where dum was initially the UAS, this scenario will still cause issues if dum was initially the UAC (since getLastRequest will contain a valid contact).

 

Propose the following, please note that I am not sure that “mState == Established” is the correct check here, please advise.

 

In DialogSet.cxx:

 

if (dialog == 0)

   {

      if (msg.isRequest() && msg.header(h_RequestLine).method() == CANCEL)

      {

         dispatchToAllDialogs(msg);

         return;

      }

 

      if (msg.isResponse())

      {                     

         int code = msg.header(h_StatusLine).statusCode();

        

             if( code > 100 && mState == Established )

             {

                InfoLog(<< "Cannot create a dialog, mid-dialog fork not allowed.");

                return;

             }

 

 

Thanks,

 

-justin

 

---

From: Scott Godin [mailto:slgodin@xxxxxxxxxxxx]
Sent: Sunday, December 10, 2006 10:50 AM
To: Justin Matthews; resiprocate-devel@xxxxxxxxxxxxxxxxxxx
Subject: RE: [reSIProcate] exception when receiving 200 from re-invite requestwith modified to: tag

 

That is pretty odd behaviour by the far end.  Mid-dialog forking is not allowed (3261 sec 14.1).  If we detect a 200 with a different to tag and the dialogset is a UAS dialogset (ie. no base creator) - then we should either:

1.  Ack the 200 and then send a bye.    or

2.  Just ignore the 200 - don't proceed to create a dialog for it - but log an error.

 

I'm leaning towards 2.

 

Scott

 

---

From: resiprocate-devel-bounces@xxxxxxxxxxxxxxxxxxxx on behalf of Justin Matthews
Sent: Sat 12/9/2006 5:26 PM
To: resiprocate-devel@xxxxxxxxxxxxxxxxxxx
Subject: [reSIProcate] exception when receiving 200 from re-invite requestwith modified to: tag

Exception occurs during following scenario:

 

DUM receives a call and establishes a session as the UAS.

 

DUM sends re-INVITE request

 

DUM receives 200 ok response with a different to: tag then the established session.

 

The dialogset is found, but dialogset.cxx tries to create a new dialog from this 200 and calls the following code:

 

Dialog.cxx, in Dialog constructor:

 

mLocalContact = creator->getLastRequest()->header(h_Contacts).front();

 

I believe that getLastRequest does not contain a contact because this call was established from an inbound session.

 

For now I just patched it this way, is there a better way?  If not I will commit this.

-------------------

BaseCreator* creator = mDialogSet.getCreator();

//assert(creator);// !jf! throw or something here

//assert(creator->getLastRequest()->exists(h_Contacts));

//assert(!creator->getLastRequest()->header(h_Contacts).empty());

if( NULL == creator )

{

ErrLog(<< "BaseCreator is null for DialogSet");

      ErrLog(<< response);

      throw Exception("BaseCreator is null for DialogSet", __FILE__, __LINE__);

}

                               

SharedPtr<SipMessage> lastRequest(creator->getLastRequest());

 

if( NULL == lastRequest ||

      !lastRequest->exists(h_Contacts) ||

      lastRequest->header(h_Contacts).empty())

{

      ErrLog(<< "No contact available for dialogset's last request");

      ErrLog(<< response);

      throw Exception("No contact available for dialogset's last request", __FILE__, __LINE__);

}

mLocalContact = creator->getLastRequest()->header(h_Contacts).front();

mRemoteTarget = contact;

----------------------

 

Thanks,

-justin