/**
 * @file
 * @brief
 * This file implements the disassociation functionality.
 *
 * $Id: disassociate.c,v 1.44 2007/05/15 08:36:42 sschneid Exp $
 */
/**
 *  \author
 *      Atmel Corporation: http://www.atmel.com
 *      Support email: avr@atmel.com
 */
/*
 * Copyright (c) 2006, Atmel Corporation All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. The name of ATMEL may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY ATMEL ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY AND
 * SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* === Includes ============================================================ */

#include <string.h>
#include "mac.h"

#if APP_TYPE >= APP_L2 || defined(DOXYGEN)

/* === Globals ============================================================= */


/* === Prototypes ========================================================== */
static void build_disassociate_command_frame(frame_buffer_t *fbuf, mlme_disassociate_req_t *dar,
                                             bool from_coord);

/* === Implementation ====================================================== */
/**
 * @brief   Implement an MLME-DISASSIOCIATE.request
 *
 * The MLME-DISASSOCIATE.request primitive is generated by the next
 * higher layer of an associated device and issued to its MLME to
 * request disassociation from the PAN. It is also generated by the
 * next higher layer of the coordinator and issued to its MLME to
 * instruct an associated device to leave the PAN.
 *
 * @param m Pointer to the message
 */

void mlme_disassociate_request(uint8_t *m)
{
    mlme_disassociate_req_t *dar = (mlme_disassociate_req_t *)m;
    mlme_disassociate_conf_t dac;
    frame_buffer_t *fbuf;

    // Build the request from the coordinator perspective.
    if (mac_i_pan_coordinator)
    {
#if DEVICE_TYPE == FD1 || DEVICE_TYPE == FD1_NOGTS
        // We are the coordinator, and if the DeviceAddress is not ours,
        // we need to send via indirect transmission.
        if (dar->DeviceAddress != mac_pib_macCoordExtendedAddress )
        {
            fbuf = mac_buffer_request_indirect();
            if (fbuf == NULL)
            {
                dac.size = sizeof(mlme_disassociate_conf_t) - sizeof(dac.size);
                dac.cmdcode = MLME_DISASSOCIATE_CONFIRM;
                dac.status = MAC_TRANSACTION_OVERFLOW;
                bios_pushback_event((uint8_t *)&dac);
                return;
            }

            if (mac_pib_macBeaconOrder == NON_BEACON_NETWORK && !mac_run_beacon_timer)
            {
                mac_run_beacon_timer = true;
                mac_start_beacon_timer();
            }

            build_disassociate_command_frame(fbuf, dar, true);
        }
        else
#endif /* DEVICE_TYPE == FD1 || DEVICE_TYPE == FD1_NOGTS */
        {
            dac.size = sizeof(mlme_disassociate_conf_t) - sizeof(dac.size);
            dac.cmdcode = MLME_DISASSOCIATE_CONFIRM;
            dac.status = MAC_INVALID_PARAMETER;
            bios_pushback_event((uint8_t *)&dac);
            return;
        }
    }
    else    // We are a device.
    {
        fbuf = mac_buffer_request();
        if (fbuf == NULL)
        {
            dac.size = sizeof(mlme_disassociate_conf_t) - sizeof(dac.size);
            dac.cmdcode = MLME_DISASSOCIATE_CONFIRM;
            dac.status = MAC_TRANSACTION_OVERFLOW;
            bios_pushback_event((uint8_t *)&dac);
            return;
        }

        build_disassociate_command_frame(fbuf, dar, false);

        ASSERT(mac_message == NULL);
        mac_message = fbuf;

        // remember the original MAC state
        mac_original_state = mac_state;

        // do we need to wake up the radio first?
        if (mac_radio_sleep_state == RADIO_SLEEPING)
        {
            mac_state = MAC_WAKEUP_DISASSOC;

            // wake up radio first
            mac_phy_wakeup();
        }
        else
        {
            mac_awake_disassociate();
        }
    }
}

/**
 * @brief Continues handling of MLME-DISASSOCIATE.request once the radio is awake
 */
void mac_awake_disassociate(void)
{
    // set the MAC to it's original state
    mac_state = mac_original_state;

    // Start CSMA-CA using backoff and retry (direct transmission)
    mac_csma_ca(true, true);

    // Once a device is disassociated from a coordinator, the
    // coordinator's address info. should be cleared.
    mac_pib_macCoordExtendedAddress = CLEAR_ADDR_64;
    mac_pib_macCoordShortAddress = BROADCAST;
}

/**
 * @brief Internal function to build the disassociation command frame.
 *
 * If "from_coord" is set, then the destination address of the frame
 * is taken from dar->DeviceAddress, otherwise our current
 * coordinator's long address is used as the destination address.
 *
 * The buffer passed as fbuf is filled with the respective data.  It
 * is left up to the caller to initiate the data transmission (in the
 * direct transmission case only, i. e. on the device).
 *
 * @param out fbuf Frame buffer to fill in
 * @param in dar The disassociation request causing this command
 * @param in from_coord Whether this is going to be sent from a coordinator
 */
static void build_disassociate_command_frame(frame_buffer_t *fbuf, mlme_disassociate_req_t *dar,
                                             bool from_coord)
{
    uint8_t index;
    uint16_t fcf;

    // Construct FCF first.

    // Note that 802.15.4-2006 would also set the intra_pan (resp.
    // panid_compression) bit but 802.15.4-2003 says we should include
    // both PANIds.
    fcf = FCF_SET_FRAMETYPE(FCF_FRAMETYPE_MAC_CMD) |
        FCF_SET_DEST_ADDR_MODE(FCF_LONG_ADDR) |
        FCF_SET_SOURCE_ADDR_MODE(FCF_LONG_ADDR) |
        FCF_ACK_REQUEST;

    index = 1;

    // Build the Frame Control Field
    fbuf->pd_data.data[index++] = fcf & 0xff;
    fbuf->pd_data.data[index++] = (fcf >> 8) & 0xff;

    // Populate the DSN.
    fbuf->pd_data.data[index++] = mac_pib_macDSN++;

    // Set destination pan id.
    fbuf->pd_data.data[index++] = mac_pib_macPANId;
    fbuf->pd_data.data[index++] = (mac_pib_macPANId>>8);

    // if a coord, then dest addr is 64 bit addr of the device.
    // if a dev, then the dest addr is "macCoordExtendedAddress".
    if (from_coord)
    {
        memcpy(&fbuf->pd_data.data[index], &dar->DeviceAddress, sizeof(uint64_t));
        fbuf->transactiontime = mac_pib_macTransactionPersistenceTime;
    }
    else
    {
        memcpy(&fbuf->pd_data.data[index], &mac_pib_macCoordExtendedAddress, sizeof(uint64_t));
    }
    index += sizeof(uint64_t);

    // Set the source pan id.
    fbuf->pd_data.data[index++] = mac_pib_macPANId;
    fbuf->pd_data.data[index++] = (mac_pib_macPANId>>8);

    // Set the source address, the source address of the device sending the command.
    memcpy(&fbuf->pd_data.data[index], &mac_ieee_address, sizeof(uint64_t));
    index += sizeof(uint64_t);

    // Set up the command frame identifier.
    fbuf->pd_data.data[index++] = DISASSOCIATIONNOTIFICATION;

    // Set up the disassociation reason code.
    fbuf->pd_data.data[index++] = dar->DisassociateReason;

    /* begin MFR */
    index += CRC_SIZE - sizeof(fbuf->pd_data.size);
    fbuf->pd_data.data[0] = fbuf->pd_data.psduLength = index;
    /* end MFR */

    fbuf->msgtype = DISASSOCIATIONNOTIFICATION;

    fbuf->pd_data.size = sizeof(pd_data_req_t) - sizeof(fbuf->pd_data.size) + index;
    fbuf->pd_data.cmdcode = PD_DATA_REQUEST;
}

/**
 * @brief Process a disassociation notification command we received.
 *
 * Actual data are taken from the incoming frame in mac_parse_buffer.
 */
void mac_process_disassociate_notification(void)
{
    mlme_disassociate_ind_t dai;

    // Set up the header portion of the mlme_disassociate_ind_t.
    dai.size = sizeof(mlme_disassociate_ind_t) - sizeof(dai.size);
    dai.cmdcode = MLME_DISASSOCIATE_INDICATION;

    // Build the indication parameters.

    // Set the DeviceAddress first. The device address is the address
    // of the device requesting the disassociaton which is always
    // contained in the source address.
    memcpy(&dai.DeviceAddress, &mac_parse_data.src_addr, sizeof(uint64_t));

    dai.DisassociateReason = mac_parse_data.payload_data.disassoc_req_data.disassoc_reason;
    dai.SecurityUse = false;
    dai.ACLEntry = MAC_NOACLENTRYFOUND;

    bios_pushback_event((uint8_t *)&dai);

    // Once a device is disassociated from a coordinator, the
    // coordinator's address info. should be cleared.
    mac_pib_macCoordExtendedAddress = CLEAR_ADDR_64;
    mac_pib_macCoordShortAddress = BROADCAST;
}


#endif /* APP_TYPE >= APP_L2 || defined(DOXYGEN) */
/* EOF */