[pjsip] [Fwd: Re: Exceptions when using ICE functionalities]

Pedro Gonçalves pedro.pandre at gmail.com
Fri Aug 8 14:33:02 EDT 2008


Benny Prijono wrote:
> On Fri, Aug 8, 2008 at 6:39 PM, Pedro Gonçalves 
> <pedro.pandre at gmail.com <mailto:pedro.pandre at gmail.com>> wrote:
>
>
>         The check->tdata is set to NULL once that particular
>         connectivity check completes (i.e. on_stun_request_complete()
>         has been called for that check).
>
>         The assertion is put there to make sure that
>         on_stun_request_complete() is not called more than once for
>         the same check.
>
>          -benny
>
>     OK. So basically if for some reason we receive 2 Binding Responses
>     to the same Binding Request, we'll get an assert error. 
>
>
> No, that's a wrong conclusion.
>  
>
>     Is this desirable? Should'nt the subsequent Binding Responses to
>     an already completed transaction be simply ignored?
>
>
> It will. Subsequent responses will be (or should be) treated as 
> retransmission by the transaction layer, and it will not call the 
> callback.
>  
>
>     However, what about in the case where neither tdata nor
>     check->tdata are null, and they are simply different from each other?
>     What can cause this?
>
>
> Frankly, I don't know. That's what we're trying to find out, aren't we. :)
>  
>
>     I am including the application log and the capture I made when
>     this exception happened.
>
>     In the last lines of the log we can see that a Binding success
>     response was received.
>     I've also added some debug in functions pj_stun_session_on_rx_pkt
>     (), on_incoming_response(), pj_stun_client_tsx_on_rx_msg(),
>     stun_tsx_on_complete(), in which we can see that
>     tdata and check->tdata were already different, thus causing the
>     assertion error.
>
>
> How can you print the tdata and check->tdata in 
> pj_stun_session_on_rx_pkt()? Where did you get the pointers from?
I had some work tracing back the variables, but here is how I am 
gettting them:

on *stun_tsx_on_complete*, *tdata* is
((pj_stun_tx_data*) pj_stun_client_tsx_get_data(tsx))
and *check->tdata* is
(((pj_ice_msg_data*) ((pj_stun_tx_data*) 
pj_stun_client_tsx_get_data(tsx))->token))->data.req.clist->checks[((pj_ice_msg_data*) 
((pj_stun_tx_data*) 
pj_stun_client_tsx_get_data(tsx))->token)->data.req.ckid].tdata

on *pj_stun_client_tsx_on_rx_msg*, *tdata* is
((pj_stun_tx_data*) pj_stun_client_tsx_get_data(tsx))
and *check->tdata* is
(((pj_ice_msg_data*) ((pj_stun_tx_data*) 
pj_stun_client_tsx_get_data(tsx))->token))->data.req.clist->checks[((pj_ice_msg_data*) 
((pj_stun_tx_data*) 
pj_stun_client_tsx_get_data(tsx))->token)->data.req.ckid].tdata

on *on_incoming_response*, *tdata* is
((pj_stun_tx_data*) pj_stun_client_tsx_get_data(tdata->client_tsx))
and *check->tdata* can be got making
pj_stun_tx_data *stun_tx_data = ((pj_stun_tx_data*) 
pj_stun_client_tsx_get_data(tdata->client_tsx));
pj_ice_msg_data *ice_msg_data = (((pj_ice_msg_data*) stun_tx_data->token));
this way, check->tdata is 
ice_msg_data->data.req.clist->checks[ice_msg_data->data.req.ckid].tdata

on *pj_stun_session_on_rx_pkt*, *tdata* is
((pj_stun_tx_data*) pj_stun_client_tsx_get_data(tsx_lookup(sess, 
msg)->client_tsx))
and *check->tdata* can be got making
pj_stun_tx_data *stun_tx_data = ((pj_stun_tx_data*) 
pj_stun_client_tsx_get_data(tsx_lookup(sess, msg)->client_tsx));
pj_ice_msg_data *ice_msg_data = (((pj_ice_msg_data*) stun_tx_data->token));
this way, check->tdata is 
ice_msg_data->data.req.clist->checks[ice_msg_data->data.req.ckid].tdata


Cheers
Pedro Gonçalves



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