/*
* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The OpenAirInterface Software Alliance licenses this file to You under
* the OAI Public License, Version 1.0 (the "License"); you may not use this file
* except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.openairinterface.org/?page_id=698
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*-------------------------------------------------------------------------------
* For more information about the OpenAirInterface (OAI) Software Alliance:
* contact@openairinterface.org
*/
/*****************************************************************************
Source PdnDisconnect.c
Version 0.1
Date 2013/05/15
Product NAS stack
Subsystem EPS Session Management
Author Frederic Maurel
Description Defines the PDN disconnect ESM procedure executed by the
Non-Access Stratum.
The PDN disconnect procedure is used by the UE to request
disconnection from one PDN.
All EPS bearer contexts established towards this PDN, inclu-
ding the default EPS bearer context, are released.
*****************************************************************************/
#include "esm_proc.h"
#include "commonDef.h"
#include "nas_log.h"
#include "esmData.h"
#include "esm_cause.h"
#include "esm_pt.h"
#include "esm_sap.h"
#include "emm_sap.h"
/****************************************************************************/
/**************** E X T E R N A L D E F I N I T I O N S ****************/
/****************************************************************************/
/****************************************************************************/
/******************* L O C A L D E F I N I T I O N S *******************/
/****************************************************************************/
/*
* --------------------------------------------------------------------------
* Internal data handled by the PDN disconnect procedure in the UE
* --------------------------------------------------------------------------
*/
/*
* PDN disconnection handlers
*/
static int _pdn_disconnect_get_default_ebi(esm_data_t *esm_data, int pti);
/*
* Timer handlers
*/
static void *_pdn_disconnect_t3492_handler(void *);
/* Maximum value of the PDN disconnect request retransmission counter */
#define ESM_PDN_DISCONNECT_COUNTER_MAX 5
/****************************************************************************/
/****************** E X P O R T E D F U N C T I O N S ******************/
/****************************************************************************/
/*
* --------------------------------------------------------------------------
* PDN disconnect procedure executed by the UE
* --------------------------------------------------------------------------
*/
/****************************************************************************
** **
** Name: esm_proc_pdn_disconnect() **
** **
** Description: Return the procedure transaction identity assigned to the **
** PDN connection and the EPS bearer identity of the default **
** bearer associated to the PDN context with specified iden- **
** tifier **
** **
** Inputs: cid: PDN context identifier **
** Others: _esm_data **
** **
** Outputs: pti: Procedure transaction identity assigned to **
** the PDN connection to be released **
** ebi: EPS bearer identity of the default bearer **
** associated to the specified PDN context **
** Return: RETURNok, RETURNerror **
** Others: None **
** **
***************************************************************************/
int esm_proc_pdn_disconnect(esm_data_t *esm_data, int cid, unsigned int *pti, unsigned int *ebi)
{
LOG_FUNC_IN;
int rc = RETURNerror;
int pid = cid - 1;
if (pid < ESM_DATA_PDN_MAX) {
if (pid != esm_data->pdn[pid].pid) {
LOG_TRACE(WARNING, "ESM-PROC - PDN connection identifier %d is "
"not valid", pid);
} else if (esm_data->pdn[pid].data == NULL) {
LOG_TRACE(ERROR, "ESM-PROC - PDN connection %d has not been "
"allocated", pid);
} else if (!esm_data->pdn[pid].is_active) {
LOG_TRACE(WARNING, "ESM-PROC - PDN connection is not active");
} else {
/* Get the procedure transaction identity assigned to the PDN
* connection to be released */
*pti = esm_data->pdn[pid].data->pti;
/* Get the EPS bearer identity of the default bearer associated
* with the PDN to disconnect from */
*ebi = esm_data->pdn[pid].data->bearer[0]->ebi;
rc = RETURNok;
}
}
LOG_FUNC_RETURN(rc);
}
/****************************************************************************
** **
** Name: esm_proc_pdn_disconnect_request() **
** **
** Description: Initiates PDN disconnection procedure in order to request **
** disconnection from a PDN. **
** **
** 3GPP TS 24.301, section 6.5.2.2 **
** The UE requests PDN disconnection from a PDN by sending a **
** PDN DISCONNECT REQUEST message to the MME, starting timer **
** T3492 and entering state PROCEDURE TRANSACTION PENDING. **
** **
** Inputs: is_standalone: Should be always TRUE **
** pti: Procedure transaction identity **
** msg: Encoded PDN disconnect request message to **
** be sent **
** sent_by_ue: Not used **
** Others: None **
** **
** Outputs: None **
** Return: RETURNok, RETURNerror **
** Others: None **
** **
***************************************************************************/
int esm_proc_pdn_disconnect_request(nas_user_t *user, int is_standalone, int pti,
OctetString *msg, int sent_by_ue)
{
LOG_FUNC_IN;
int rc = RETURNok;
LOG_TRACE(INFO, "ESM-PROC - Initiate PDN disconnection (pti=%d)", pti);
if (is_standalone) {
emm_sap_t emm_sap;
emm_esm_data_t *emm_esm = &emm_sap.u.emm_esm.u.data;
/*
* Notity EMM that ESM PDU has to be forwarded to lower layers
*/
emm_sap.primitive = EMMESM_UNITDATA_REQ;
emm_sap.u.emm_esm.ueid = 0;
emm_esm->msg.length = msg->length;
emm_esm->msg.value = msg->value;
rc = emm_sap_send(user, &emm_sap);
if (rc != RETURNerror) {
/* Start T3482 retransmission timer */
rc = esm_pt_start_timer(user, pti, msg, T3492_DEFAULT_VALUE,
_pdn_disconnect_t3492_handler);
}
}
if (rc != RETURNerror) {
/* Set the procedure transaction state to PENDING */
rc = esm_pt_set_status(pti, ESM_PT_PENDING);
if (rc != RETURNok) {
/* The procedure transaction was already in PENDING state */
LOG_TRACE(WARNING, "ESM-PROC - PTI %d was already PENDING", pti);
}
}
LOG_FUNC_RETURN(rc);
}
/****************************************************************************
** **
** Name: esm_proc_pdn_disconnect_accept() **
** **
** Description: Performs PDN disconnection procedure accepted by the net- **
** work. **
** **
** 3GPP TS 24.301, section 6.5.2.3 **
** The shall stop timer T3492 and enter the state PROCEDURE **
** TRANSACTION INACTIVE. **
** **
** Inputs: pti: Identifies the UE requested PDN disconnect **
** procedure accepted by the network **
** Others: None **
** **
** Outputs: esm_cause: Cause code returned upon ESM procedure **
** failure **
** Return: The identifier of the PDN context to de- **
** activate when successfully found; **
** RETURNerror otherwise. **
** Others: None **
** **
***************************************************************************/
int esm_proc_pdn_disconnect_accept(int pti, int *esm_cause)
{
LOG_FUNC_IN;
LOG_TRACE(INFO, "ESM-PROC - PDN disconnection accepted by the network "
"(pti=%d)", pti);
/* Stop T3492 timer if running */
(void) esm_pt_stop_timer(pti);
/* Set the procedure transaction state to INACTIVE */
int rc = esm_pt_set_status(pti, ESM_PT_INACTIVE);
if (rc != RETURNok) {
/* The procedure transaction was already in INACTIVE state */
LOG_TRACE(WARNING, "ESM-PROC - PTI %d was already INACTIVE", pti);
*esm_cause = ESM_CAUSE_MESSAGE_TYPE_NOT_COMPATIBLE;
} else {
/* Immediately release the transaction identity assigned to this
* procedure */
rc = esm_pt_release(pti);
if (rc != RETURNok) {
LOG_TRACE(WARNING, "ESM-PROC - Failed to release PTI %d", pti);
}
}
LOG_FUNC_RETURN (rc);
}
/****************************************************************************
** **
** Name: esm_proc_pdn_disconnect_reject() **
** **
** Description: Performs PDN disconnection procedure not accepted by the **
** network. **
** **
** 3GPP TS 24.301, section 6.5.2.4 **
** Upon receipt of the PDN DISCONNECT REJECT message, the UE **
** shall stop timer T3492 and enter the state PROCEDURE **
** TRANSACTION INACTIVE and abort the PDN disconnection pro- **
** cedure. **
** **
** Inputs: pti: Identifies the UE requested PDN disconnec- **
** tion procedure rejected by the network **
** Others: None **
** **
** Outputs: esm_cause: Cause code returned upon ESM procedure **
** failure **
** Return: RETURNok, RETURNerror **
** Others: None **
** **
***************************************************************************/
int esm_proc_pdn_disconnect_reject(nas_user_t *user, int pti, int *esm_cause)
{
LOG_FUNC_IN;
esm_data_t *esm_data = _esm_data;
int rc;
LOG_TRACE(WARNING, "ESM-PROC - PDN disconnection rejected by the network "
"(pti=%d), ESM cause = %d", pti, *esm_cause);
/* Stop T3492 timer if running */
(void) esm_pt_stop_timer(pti);
/* Set the procedure transaction state to INACTIVE */
rc = esm_pt_set_status(pti, ESM_PT_INACTIVE);
if (rc != RETURNok) {
/* The procedure transaction was already in INACTIVE state
* as the request may have already been rejected */
LOG_TRACE(WARNING, "ESM-PROC - PTI %d was already INACTIVE", pti);
*esm_cause = ESM_CAUSE_MESSAGE_TYPE_NOT_COMPATIBLE;
} else {
/* Release the transaction identity assigned to this procedure */
rc = esm_pt_release(pti);
if (rc != RETURNok) {
LOG_TRACE(WARNING, "ESM-PROC - Failed to release PTI %d", pti);
*esm_cause = ESM_CAUSE_REQUEST_REJECTED_UNSPECIFIED;
} else if (*esm_cause != ESM_CAUSE_LAST_PDN_DISCONNECTION_NOT_ALLOWED) {
/* Get the identity of the default EPS bearer context allocated to
* the PDN connection entry assigned to this procedure transaction */
int ebi = _pdn_disconnect_get_default_ebi(esm_data, pti);
if (ebi < 0) {
LOG_TRACE(ERROR, "ESM-PROC - No default EPS bearer found");
*esm_cause = ESM_CAUSE_PROTOCOL_ERROR;
LOG_FUNC_RETURN (RETURNerror);
}
/*
* Notify ESM that all EPS bearer contexts to this PDN have to be
* locally deactivated
*/
esm_sap_t esm_sap;
esm_sap.primitive = ESM_EPS_BEARER_CONTEXT_DEACTIVATE_REQ;
esm_sap.is_standalone = TRUE;
esm_sap.recv = NULL;
esm_sap.send.length = 0;
esm_sap.data.eps_bearer_context_deactivate.ebi = ebi;
rc = esm_sap_send(user, &esm_sap);
if (rc != RETURNok) {
*esm_cause = ESM_CAUSE_PROTOCOL_ERROR;
}
}
}
LOG_FUNC_RETURN(rc);
}
/****************************************************************************/
/********************* L O C A L F U N C T I O N S *********************/
/****************************************************************************/
/*
* --------------------------------------------------------------------------
* Timer handlers
* --------------------------------------------------------------------------
*/
/****************************************************************************
** **
** Name: _pdn_disconnect_t3492_handler() **
** **
** Description: T3492 timeout handler **
** **
** 3GPP TS 24.301, section 6.5.2.5, case a **
** On the first expiry of the timer T3492, the UE shall re- **
** send the PDN DISCONNECT REQUEST and shall reset and re- **
** start timer T3492. This retransmission is repeated four **
** times, i.e. on the fifth expiry of timer T3492, the UE **
** shall abort the procedure, deactivate all EPS bearer con- **
** texts for this PDN connection locally, release the PTI **
** allocated for this invocation and enter the state PROCE- **
** DURE TRANSACTION INACTIVE. **
** **
** Inputs: args: handler parameters **
** Others: None **
** **
** Outputs: None **
** Return: None **
** Others: None **
** **
***************************************************************************/
static void *_pdn_disconnect_t3492_handler(void *args)
{
LOG_FUNC_IN;
nas_user_t *user = args;
esm_data_t *esm_data = _esm_data;;
int rc;
/* Get retransmission timer parameters data */
esm_pt_timer_data_t *data = (esm_pt_timer_data_t *)(args);
/* Increment the retransmission counter */
data->count += 1;
LOG_TRACE(WARNING, "ESM-PROC - T3492 timer expired (pti=%d), "
"retransmission counter = %d", data->pti, data->count);
if (data->count < ESM_PDN_DISCONNECT_COUNTER_MAX) {
emm_sap_t emm_sap;
emm_esm_data_t *emm_esm = &emm_sap.u.emm_esm.u.data;
/*
* Notify EMM that the PDN connectivity request message
* has to be sent again
*/
emm_sap.primitive = EMMESM_UNITDATA_REQ;
emm_sap.u.emm_esm.ueid = 0;
emm_esm->msg.length = data->msg.length;
emm_esm->msg.value = data->msg.value;
rc = emm_sap_send(user, &emm_sap);
if (rc != RETURNerror) {
/* Restart the timer T3492 */
rc = esm_pt_start_timer(user, data->pti, &data->msg, T3492_DEFAULT_VALUE,
_pdn_disconnect_t3492_handler);
}
} else {
/* Set the procedure transaction state to INACTIVE */
rc = esm_pt_set_status(data->pti, ESM_PT_INACTIVE);
if (rc != RETURNok) {
/* The procedure transaction was already in INACTIVE state */
LOG_TRACE(WARNING, "ESM-PROC - PTI %d was already INACTIVE",
data->pti);
} else {
/* Release the transaction identity assigned to this procedure */
rc = esm_pt_release(data->pti);
if (rc != RETURNok) {
LOG_TRACE(WARNING, "ESM-PROC - Failed to release PTI %d",
data->pti);
} else {
/* Get the identity of the default EPS bearer context
* allocated to the PDN connection entry assigned to
* this procedure transaction */
int ebi = _pdn_disconnect_get_default_ebi(esm_data, data->pti);
if (ebi < 0) {
LOG_TRACE(ERROR, "ESM-PROC - No default EPS bearer found");
LOG_FUNC_RETURN (NULL);
}
/*
* Notify ESM that all EPS bearer contexts to this PDN have
* to be locally deactivated
*/
esm_sap_t esm_sap;
esm_sap.primitive = ESM_EPS_BEARER_CONTEXT_DEACTIVATE_REQ;
esm_sap.is_standalone = TRUE;
esm_sap.recv = NULL;
esm_sap.send.length = 0;
esm_sap.data.eps_bearer_context_deactivate.ebi = ebi;
rc = esm_sap_send(user, &esm_sap);
}
}
}
LOG_FUNC_RETURN(NULL);
}
/*
*---------------------------------------------------------------------------
* PDN disconnection handlers
*---------------------------------------------------------------------------
*/
/****************************************************************************
** **
** Name: _pdn_disconnect_get_default_ebi() **
** **
** Description: Returns the EPS bearer identity of the default EPS bearer **
** context allocated to the PDN connection to which the gi- **
** ven procedure transaction identity has been assigned **
** **
** Inputs: pti: The procedure transaction identity **
** Others: _esm_data **
** **
** Outputs: None **
** Return: The EPS bearer identity of the default EPS **
** bearer context, if it exists; -1 otherwise **
** Others: None **
** **
***************************************************************************/
static int _pdn_disconnect_get_default_ebi(esm_data_t *esm_data, int pti)
{
int ebi = -1;
int i;
for (i = 0; i < ESM_DATA_PDN_MAX; i++) {
if ( (esm_data->pdn[i].pid != -1) && esm_data->pdn[i].data ) {
if (esm_data->pdn[i].data->pti != pti) {
continue;
}
/* PDN entry found */
if (esm_data->pdn[i].data->bearer[0] != NULL) {
/* Get the EPS bearer identity of the default EPS bearer
* context associated to the PDN connection */
ebi = esm_data->pdn[i].data->bearer[0]->ebi;
}
break;
}
}
return (ebi);
}