/*****************************************************************************
            Eurecom OpenAirInterface 3
            Copyright(c) 2012 Eurecom

Source      EmmRegistered.c

Version     0.1

Date        2012/10/03

Product     NAS stack

Subsystem   EPS Mobility Management

Author      Frederic Maurel

Description Implements the EPS Mobility Management procedures executed
        when the EMM-SAP is in EMM-REGISTERED state.

        In EMM-REGISTERED state, an EMM context has been established
        and a default EPS bearer context has been activated in the UE
        and the MME.
        The UE may initiate sending and receiving user data and signal-
        ling information and reply to paging. Additionally, tracking
        area updating or combined tracking area updating procedure is
        performed.

*****************************************************************************/

#include "emm_fsm.h"
#include "commonDef.h"
#include "networkDef.h"
#include "nas_log.h"

#include "emm_proc.h"

#include <assert.h>

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/****************************************************************************
 **                                                                        **
 ** Name:    EmmRegistered()                                           **
 **                                                                        **
 ** Description: Handles the behaviour of the UE and the MME while the     **
 **      EMM-SAP is in EMM-REGISTERED state.                       **
 **                                                                        **
 ** Inputs:  evt:       The received EMM-SAP event                 **
 **      Others:    emm_fsm_status                             **
 **                                                                        **
 ** Outputs:     None                                                      **
 **      Return:    RETURNok, RETURNerror                      **
 **      Others:    emm_fsm_status                             **
 **                                                                        **
 ***************************************************************************/
int EmmRegistered(const emm_reg_t *evt)
{
    LOG_FUNC_IN;

    int rc = RETURNerror;

#ifdef NAS_UE
    assert(emm_fsm_get_status() == EMM_REGISTERED);
#endif
#ifdef NAS_MME
    assert(emm_fsm_get_status(evt->ueid, evt->ctx) == EMM_REGISTERED);
#endif

    switch (evt->primitive) {
#ifdef NAS_UE
        case _EMMREG_DETACH_INIT:
            /*
             * Initiate detach procedure for EPS services
             */
            rc = emm_proc_detach(EMM_DETACH_TYPE_EPS, evt->u.detach.switch_off);
            break;

        case _EMMREG_DETACH_REQ:
            /*
             * Network detach has been requested (Detach Request
             * message successfully delivered to the network);
             * enter state EMM-DEREGISTERED-INITIATED
             */
            rc = emm_fsm_set_status(EMM_DEREGISTERED_INITIATED);
            break;

        case _EMMREG_DETACH_CNF:
            /*
             * The UE implicitly detached from the network (all EPS
             * bearer contexts may have been deactivated)
             */
            rc = emm_fsm_set_status(EMM_DEREGISTERED);
            break;

        case _EMMREG_TAU_REQ:
            /*
             * TODO: Tracking Area Update has been requested
             */
            LOG_TRACE(ERROR, "EMM-FSM   - Tracking Area Update procedure "
                      "is not implemented");
            break;

        case _EMMREG_SERVICE_REQ:
            /*
             * TODO: Service Request has been requested
             */
            LOG_TRACE(ERROR, "EMM-FSM   - Service Request procedure "
                      "is not implemented");
            break;

        case _EMMREG_LOWERLAYER_SUCCESS:
            /*
             * Data transfer message has been successfully delivered
             */
            rc = emm_proc_lowerlayer_success();
            break;

        case _EMMREG_LOWERLAYER_FAILURE:
            /*
             * Data transfer message failed to be delivered
             */
            rc = emm_proc_lowerlayer_failure(FALSE);
            break;

        case _EMMREG_LOWERLAYER_RELEASE:
            /*
             * NAS signalling connection has been released
             */
            rc = emm_proc_lowerlayer_release();
            break;
#endif

#ifdef NAS_MME
        case _EMMREG_DETACH_REQ:
            /*
             * Network detach has been requested (implicit detach);
             * enter state EMM-DEREGISTERED
             */
            rc = emm_fsm_set_status(evt->ueid, evt->ctx, EMM_DEREGISTERED);
            break;

        case _EMMREG_COMMON_PROC_REQ:
            /*
             * An EMM common procedure has been initiated;
             * enter state EMM-COMMON-PROCEDURE-INITIATED.
             */
            rc = emm_fsm_set_status(evt->ueid, evt->ctx, EMM_COMMON_PROCEDURE_INITIATED);
            break;

        case _EMMREG_TAU_REJ:
            /*
             * TODO: Tracking Area Update has been rejected
             */
            LOG_TRACE(ERROR, "EMM-FSM   - Tracking Area Update procedure "
                      "is not implemented");
            break;

        case _EMMREG_LOWERLAYER_SUCCESS:
            /*
             * Data successfully delivered to the network
             */
            rc = RETURNok;
            break;

        case _EMMREG_LOWERLAYER_FAILURE:
            /*
             * Data failed to be delivered to the network
             */
            rc = RETURNok;
            break;
#endif

        default:
            LOG_TRACE(ERROR, "EMM-FSM   - Primitive is not valid (%d)",
                      evt->primitive);
            break;
    }

    LOG_FUNC_RETURN (rc);
}

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