@ -3746,6 +3746,75 @@ static enum sip_get_destination_result get_destination(struct ast_sip_session *s
return SIP_GET_DEST_EXTEN_NOT_FOUND ;
}
/*
* / internal
* / brief Process initial answer for an incoming invite
*
* This function should only be called during the setup , and handling of a
* new incoming invite . Most , if not all of the time , this will be called
* when an error occurs and we need to respond as such .
*
* When a SIP session termination code is given for the answer it ' s assumed
* this call then will be the final bit of processing before ending session
* setup . As such , we ' ve been holding a lock , and a reference on the invite
* session ' s dialog . So before returning this function removes that reference ,
* and unlocks the dialog .
*
* \ param inv_session The session on which to answer
* \ param rdata The original request
* \ param answer_code The answer ' s numeric code
* \ param terminate_code The termination code if the answer fails
* \ param notify Whether or not to call on_state_changed
*
* \ retval 0 if invite successfully answered , - 1 if an error occurred
*/
static int new_invite_initial_answer ( pjsip_inv_session * inv_session , pjsip_rx_data * rdata ,
int answer_code , int terminate_code , pj_bool_t notify )
{
pjsip_tx_data * tdata = NULL ;
int res = 0 ;
if ( inv_session - > state ! = PJSIP_INV_STATE_DISCONNECTED ) {
if ( pjsip_inv_initial_answer (
inv_session , rdata , answer_code , NULL , NULL , & tdata ) ! = PJ_SUCCESS ) {
pjsip_inv_terminate ( inv_session , terminate_code ? terminate_code : answer_code , notify ) ;
res = - 1 ;
} else {
pjsip_inv_send_msg ( inv_session , tdata ) ;
}
}
if ( answer_code > = 300 ) {
/*
* A session is ending . The dialog has a reference that needs to be
* removed and holds a lock that needs to be unlocked before returning .
*/
pjsip_dlg_dec_lock ( inv_session - > dlg ) ;
}
return res ;
}
/*
* / internal
* / brief Create and initialize a pjsip invite session
* pjsip_inv_session adds , and maintains a reference to the dialog upon a successful
* invite session creation until the session is destroyed . However , we ' ll wait to
* remove the reference that was added for the dialog when it gets created since we ' re
* not ready to unlock the dialog in this function .
*
* So , if this function successfully returns that means it returns with its newly
* created , and associated dialog locked and with two references ( i . e . dialog ' s
* reference count should be 2 ) .
*
* \ param endpoint A pointer to the endpoint
* \ param rdata The request that is starting the dialog
*
* \ retval A pjsip invite session object
* \ retval NULL on error
*/
static pjsip_inv_session * pre_session_setup ( pjsip_rx_data * rdata , const struct ast_sip_endpoint * endpoint )
{
pjsip_tx_data * tdata ;
@ -3764,15 +3833,28 @@ static pjsip_inv_session *pre_session_setup(pjsip_rx_data *rdata, const struct a
}
return NULL ;
}
dlg = ast_sip_create_dialog_uas ( endpoint , rdata , & dlg_status ) ;
dlg = ast_sip_create_dialog_uas_locked ( endpoint , rdata , & dlg_status ) ;
if ( ! dlg ) {
if ( dlg_status ! = PJ_EEXISTS ) {
pjsip_endpt_respond_stateless ( ast_sip_get_pjsip_endpoint ( ) , rdata , 500 , NULL , NULL , NULL ) ;
}
return NULL ;
}
/*
* The returned dialog holds a lock and has a reference added . Any paths where the
* dialog invite session is not returned must unlock the dialog and remove its reference .
*/
if ( pjsip_inv_create_uas ( dlg , rdata , NULL , options , & inv_session ) ! = PJ_SUCCESS ) {
pjsip_endpt_respond_stateless ( ast_sip_get_pjsip_endpoint ( ) , rdata , 500 , NULL , NULL , NULL ) ;
/*
* The acquired dialog holds a lock , and a reference . Since the dialog is not
* going to be returned here it must first be unlocked and de - referenced . This
* must be done prior to calling dialog termination .
*/
pjsip_dlg_dec_lock ( dlg ) ;
pjsip_dlg_terminate ( dlg ) ;
return NULL ;
}
@ -3781,12 +3863,13 @@ static pjsip_inv_session *pre_session_setup(pjsip_rx_data *rdata, const struct a
inv_session - > sdp_neg_flags = PJMEDIA_SDP_NEG_ALLOW_MEDIA_CHANGE ;
# endif
if ( pjsip_dlg_add_usage ( dlg , & session_module , NULL ) ! = PJ_SUCCESS ) {
if ( pjsip_inv_initial_answer ( inv_session , rdata , 500 , NULL , NULL , & tdata ) ! = PJ_SUCCESS ) {
pjsip_inv_terminate ( inv_session , 500 , PJ_FALSE ) ;
}
pjsip_ inv_send_msg( inv_session , tdata ) ;
/* Dialog's lock and a reference are removed in new_invite_initial_answer */
new_invite_initial_answer ( inv_session , rdata , 500 , 500 , PJ_FALSE ) ;
/* Remove 2nd reference added at inv_session creation */
pjsip_ dlg_dec_session( inv_session - > dlg , & session_module ) ;
return NULL ;
}
return inv_session ;
}
@ -4003,7 +4086,6 @@ static void handle_new_invite_request(pjsip_rx_data *rdata)
{
RAII_VAR ( struct ast_sip_endpoint * , endpoint ,
ast_pjsip_rdata_get_endpoint ( rdata ) , ao2_cleanup ) ;
pjsip_tx_data * tdata = NULL ;
pjsip_inv_session * inv_session = NULL ;
struct ast_sip_session * session ;
struct new_invite invite ;
@ -4019,15 +4101,37 @@ static void handle_new_invite_request(pjsip_rx_data *rdata)
SCOPE_EXIT_RTN ( " Failure in pre session setup \n " ) ;
}
/*
* Upon a successful pre_session_setup the associated dialog is returned locked
* and with an added reference . Well actually two references . One added when the
* dialog itself was created , and another added when the pjsip invite session was
* created and the dialog was added to it .
*
* In order to ensure the dialog ' s , and any of its internal attributes , lifetimes
* we ' ll hold the lock and maintain the reference throughout the entire new invite
* handling process . See ast_sip_create_dialog_uas_locked for more details but ,
* basically we do this to make sure a transport failure does not destroy the dialog
* and / or transaction out from underneath us between pjsip calls . Alternatively , we
* could probably release the lock if we needed to , but then we ' d have to re - lock and
* check the dialog and transaction prior to every pjsip call .
*
* That means any off nominal / failure paths in this function must remove the associated
* dialog reference added at dialog creation , and remove the lock . As well the
* referenced pjsip invite session must be " cleaned up " , which should also then
* remove its reference to the dialog at that time .
*
* Nominally we ' ll unlock the dialog , and release the reference when all new invite
* process handling has successfully completed .
*/
# ifdef HAVE_PJSIP_INV_SESSION_REF
if ( pjsip_inv_add_ref ( inv_session ) ! = PJ_SUCCESS ) {
ast_log ( LOG_ERROR , " Can't increase the session reference counter \n " ) ;
if ( inv_session - > state ! = PJSIP_INV_STATE_DISCONNECTED ) {
if ( pjsip_inv_initial_answer ( inv_session , rdata , 500 , NULL , NULL , & tdata ) = = PJ_SUCCESS ) {
pjsip_inv_terminate ( inv_session , 500 , PJ_FALSE ) ;
} else {
pjsip_inv_send_msg ( inv_session , tdata ) ;
}
/* Dialog's lock and a reference are removed in new_invite_initial_answer */
if ( ! new_invite_initial_answer ( inv_session , rdata , 500 , 500 , PJ_FALSE ) ) {
/* Terminate the session if it wasn't done in the answer */
pjsip_inv_terminate ( inv_session , 500 , PJ_FALSE ) ;
}
SCOPE_EXIT_RTN ( " Couldn't add invite session reference \n " ) ;
}
@ -4035,10 +4139,10 @@ static void handle_new_invite_request(pjsip_rx_data *rdata)
session = ast_sip_session_alloc ( endpoint , NULL , inv_session , rdata ) ;
if ( ! session ) {
if ( pjsip_inv_initial_answer ( inv_session , rdata , 500 , NULL , NULL , & tdata ) = = PJ_SUCCESS ) {
/* Dialog's lock and reference are removed in new_invite_initial_answer */
if ( ! new_invite_initial_answer ( inv_session , rdata , 500 , 500 , PJ_FALSE ) ) {
/* Terminate the session if it wasn't done in the answer */
pjsip_inv_terminate ( inv_session , 500 , PJ_FALSE ) ;
} else {
pjsip_inv_send_msg ( inv_session , tdata ) ;
}
# ifdef HAVE_PJSIP_INV_SESSION_REF
pjsip_inv_dec_ref ( inv_session ) ;
@ -4058,6 +4162,17 @@ static void handle_new_invite_request(pjsip_rx_data *rdata)
invite . rdata = rdata ;
new_invite ( & invite ) ;
/*
* The dialog lock and reference added at dialog creation time must be
* maintained throughout the new invite process . Since we ' re pretty much
* done at this point with things it ' s safe to go ahead and remove the lock
* and the reference here . See ast_sip_create_dialog_uas_locked for more info .
*
* Note , any future functionality added that does work using the dialog must
* be done before this .
*/
pjsip_dlg_dec_lock ( inv_session - > dlg ) ;
SCOPE_EXIT ( " Request: %s Session: %s \n " , req_uri , ast_sip_session_get_name ( session ) ) ;
ao2_ref ( session , - 1 ) ;
}
Kevin Harwell
5 years ago
committed by
George Joseph