esp-idf/components/bt/bluedroid/stack/gatt/gatt_main.c

/******************************************************************************
 *
 *  Copyright (C) 2008-2012 Broadcom Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 *
 *  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.
 *
 ******************************************************************************/

/******************************************************************************
 *
 *  this file contains the main ATT functions
 *
 ******************************************************************************/

#include "common/bt_target.h"

#if BLE_INCLUDED == TRUE

#include "gatt_int.h"
#include "stack/l2c_api.h"
#include "btm_int.h"
#include "btm_ble_int.h"
#include "osi/allocator.h"

/* Configuration flags. */
#define GATT_L2C_CFG_IND_DONE   (1<<0)
#define GATT_L2C_CFG_CFM_DONE   (1<<1)

/* minimum GATT MTU size over BR/EDR link
*/
#define GATT_MIN_BR_MTU_SIZE       48

/********************************************************************************/
/*              L O C A L    F U N C T I O N     P R O T O T Y P E S            */
/********************************************************************************/
static void gatt_le_connect_cback (UINT16 chan, BD_ADDR bd_addr, BOOLEAN connected,
                                   UINT16 reason, tBT_TRANSPORT transport);
static void gatt_le_data_ind (UINT16 chan, BD_ADDR bd_addr, BT_HDR *p_buf);
static void gatt_le_cong_cback(BD_ADDR remote_bda, BOOLEAN congest);
#if (CLASSIC_BT_GATT_INCLUDED == TRUE)
static void gatt_l2cif_connect_ind_cback (BD_ADDR  bd_addr, UINT16 l2cap_cid,
        UINT16 psm, UINT8 l2cap_id);
static void gatt_l2cif_connect_cfm_cback (UINT16 l2cap_cid, UINT16 result);
static void gatt_l2cif_config_ind_cback (UINT16 l2cap_cid, tL2CAP_CFG_INFO *p_cfg);
static void gatt_l2cif_config_cfm_cback (UINT16 l2cap_cid, tL2CAP_CFG_INFO *p_cfg);
static void gatt_l2cif_disconnect_ind_cback (UINT16 l2cap_cid, BOOLEAN ack_needed);
static void gatt_l2cif_disconnect_cfm_cback (UINT16 l2cap_cid, UINT16 result);
static void gatt_l2cif_data_ind_cback (UINT16 l2cap_cid, BT_HDR *p_msg);
#endif  ///CLASSIC_BT_GATT_INCLUDED == TRUE
static void gatt_send_conn_cback (tGATT_TCB *p_tcb);
#if (CLASSIC_BT_GATT_INCLUDED == TRUE)
static void gatt_l2cif_congest_cback (UINT16 cid, BOOLEAN congested);
static const tL2CAP_APPL_INFO dyn_info = {
    gatt_l2cif_connect_ind_cback,
    gatt_l2cif_connect_cfm_cback,
    NULL,
    gatt_l2cif_config_ind_cback,
    gatt_l2cif_config_cfm_cback,
    gatt_l2cif_disconnect_ind_cback,
    gatt_l2cif_disconnect_cfm_cback,
    NULL,
    gatt_l2cif_data_ind_cback,
    gatt_l2cif_congest_cback,
    NULL
} ;
#endif  ///CLASSIC_BT_GATT_INCLUDED == TRUE

#if GATT_DYNAMIC_MEMORY == FALSE
tGATT_CB  gatt_cb;
#else
tGATT_CB  *gatt_cb_ptr;
#endif

tGATT_DEFAULT gatt_default;

/*******************************************************************************
**
** Function         gatt_init
**
** Description      This function is enable the GATT profile on the device.
**                  It clears out the control blocks, and registers with L2CAP.
**
** Returns          void
**
*******************************************************************************/
void gatt_init (void)
{
    tL2CAP_FIXED_CHNL_REG  fixed_reg;
#if GATT_DYNAMIC_MEMORY
    gatt_cb_ptr = (tGATT_CB *)osi_malloc(sizeof(tGATT_CB));
#endif /* #if GATT_DYNAMIC_MEMORY */
    memset (&gatt_cb, 0, sizeof(tGATT_CB));
    memset (&fixed_reg, 0, sizeof(tL2CAP_FIXED_CHNL_REG));

#if defined(GATT_INITIAL_TRACE_LEVEL)
    gatt_cb.trace_level = GATT_INITIAL_TRACE_LEVEL;
#else
    gatt_cb.trace_level = BT_TRACE_LEVEL_NONE;    /* No traces */
#endif
    gatt_cb.def_mtu_size = GATT_DEF_BLE_MTU_SIZE;
    gatt_cb.sign_op_queue = fixed_queue_new(QUEUE_SIZE_MAX);
    gatt_cb.srv_chg_clt_q = fixed_queue_new(QUEUE_SIZE_MAX);
    gatt_cb.pending_new_srv_start_q = fixed_queue_new(QUEUE_SIZE_MAX);
    /* First, register fixed L2CAP channel for ATT over BLE */
    fixed_reg.fixed_chnl_opts.mode         = L2CAP_FCR_BASIC_MODE;
    fixed_reg.fixed_chnl_opts.max_transmit = 0xFF;
    fixed_reg.fixed_chnl_opts.rtrans_tout  = 2000;
    fixed_reg.fixed_chnl_opts.mon_tout     = 12000;
    fixed_reg.fixed_chnl_opts.mps          = 670;
    fixed_reg.fixed_chnl_opts.tx_win_sz    = 1;

    fixed_reg.pL2CA_FixedConn_Cb = gatt_le_connect_cback;
    fixed_reg.pL2CA_FixedData_Cb = gatt_le_data_ind;
    fixed_reg.pL2CA_FixedCong_Cb = gatt_le_cong_cback;      /* congestion callback */
    fixed_reg.default_idle_tout  = 0xffff;                  /* 0xffff default idle timeout */

    L2CA_RegisterFixedChannel (L2CAP_ATT_CID, &fixed_reg);

#if (CLASSIC_BT_GATT_INCLUDED == TRUE)
    /* Now, register with L2CAP for ATT PSM over BR/EDR */
    if (!L2CA_Register (BT_PSM_ATT, (tL2CAP_APPL_INFO *) &dyn_info)) {
        GATT_TRACE_ERROR ("ATT Dynamic Registration failed");
    }
#endif  ///CLASSIC_BT_GATT_INCLUDED == TRUE
    BTM_SetSecurityLevel(TRUE, "", BTM_SEC_SERVICE_ATT, BTM_SEC_NONE, BT_PSM_ATT, 0, 0);
    BTM_SetSecurityLevel(FALSE, "", BTM_SEC_SERVICE_ATT, BTM_SEC_NONE, BT_PSM_ATT, 0, 0);

    gatt_cb.hdl_cfg.gatt_start_hdl = GATT_GATT_START_HANDLE;
    gatt_cb.hdl_cfg.gap_start_hdl  = GATT_GAP_START_HANDLE;
    gatt_cb.hdl_cfg.app_start_hdl  = GATT_APP_START_HANDLE;
#if (GATTS_INCLUDED == TRUE)
    gatt_profile_db_init();
#endif  ///GATTS_INCLUDED == TRUE
    //init local MTU size
    gatt_default.local_mtu = GATT_MAX_MTU_SIZE;
}


/*******************************************************************************
**
** Function         gatt_free
**
** Description      This function frees resources used by the GATT profile.
**
** Returns          void
**
*******************************************************************************/
#if (GATT_INCLUDED == TRUE)
void gatt_free(void)
{
    int i;
    GATT_TRACE_DEBUG("gatt_free()");
    fixed_queue_free(gatt_cb.sign_op_queue, NULL);
    gatt_cb.sign_op_queue = NULL;
    fixed_queue_free(gatt_cb.srv_chg_clt_q, NULL);
    gatt_cb.srv_chg_clt_q = NULL;
    fixed_queue_free(gatt_cb.pending_new_srv_start_q, NULL);
    gatt_cb.pending_new_srv_start_q = NULL;

    for (i = 0; i < GATT_MAX_PHY_CHANNEL; i++)
    {
        fixed_queue_free(gatt_cb.tcb[i].pending_enc_clcb, NULL);
        gatt_cb.tcb[i].pending_enc_clcb = NULL;

        fixed_queue_free(gatt_cb.tcb[i].pending_ind_q, NULL);
        gatt_cb.tcb[i].pending_ind_q = NULL;

        btu_free_timer(&gatt_cb.tcb[i].conf_timer_ent);
        memset(&gatt_cb.tcb[i].conf_timer_ent, 0, sizeof(TIMER_LIST_ENT));

        btu_free_timer(&gatt_cb.tcb[i].ind_ack_timer_ent);
        memset(&gatt_cb.tcb[i].ind_ack_timer_ent, 0, sizeof(TIMER_LIST_ENT));

#if (GATTS_INCLUDED == TRUE)
        fixed_queue_free(gatt_cb.tcb[i].sr_cmd.multi_rsp_q, NULL);
        gatt_cb.tcb[i].sr_cmd.multi_rsp_q = NULL;
#endif /* #if (GATTS_INCLUDED == TRUE) */
    }

#if (GATTS_INCLUDED == TRUE)
    for (i = 0; i < GATT_MAX_SR_PROFILES; i++) {
        gatt_remove_an_item_from_list(&gatt_cb.hdl_list_info, &gatt_cb.hdl_list[i]);
        gatt_free_attr_value_buffer(&gatt_cb.hdl_list[i]);
        gatt_free_hdl_buffer(&gatt_cb.hdl_list[i]);
    }
#endif /* #if (GATTS_INCLUDED == TRUE) */
#if GATT_DYNAMIC_MEMORY
    FREE_AND_RESET(gatt_cb_ptr);
#endif /* #if GATT_DYNAMIC_MEMORY */
}
#endif  ///GATTS_INCLUDED == TRUE

/*******************************************************************************
**
** Function         gatt_connect
**
** Description      This function is called to initiate a connection to a peer device.
**
** Parameter        rem_bda: remote device address to connect to.
**                  bd_addr_type: emote device address type.
** Returns          TRUE if connection is started, otherwise return FALSE.
**
*******************************************************************************/
BOOLEAN gatt_connect (BD_ADDR rem_bda, tBLE_ADDR_TYPE bd_addr_type, tGATT_TCB *p_tcb, tBT_TRANSPORT transport)
{
    BOOLEAN             gatt_ret = FALSE;

    if (gatt_get_ch_state(p_tcb) != GATT_CH_OPEN) {
        gatt_set_ch_state(p_tcb, GATT_CH_CONN);
    }

    if (transport == BT_TRANSPORT_LE) {
        p_tcb->att_lcid = L2CAP_ATT_CID;
        gatt_ret = L2CA_ConnectFixedChnl (L2CAP_ATT_CID, rem_bda, bd_addr_type);
#if (CLASSIC_BT_GATT_INCLUDED == TRUE)
    } else {
        if ((p_tcb->att_lcid = L2CA_ConnectReq(BT_PSM_ATT, rem_bda)) != 0) {
            gatt_ret = TRUE;
        }
#endif  ///CLASSIC_BT_GATT_INCLUDED == TRUE

    }

    return gatt_ret;
}

/*******************************************************************************
**
** Function         gatt_disconnect
**
** Description      This function is called to disconnect to an ATT device.
**
** Parameter        p_tcb: pointer to the TCB to disconnect.
**
** Returns          TRUE: if connection found and to be disconnected; otherwise
**                  return FALSE.
**
*******************************************************************************/
BOOLEAN gatt_disconnect (tGATT_TCB *p_tcb)
{
    BOOLEAN             ret = FALSE;
    tGATT_CH_STATE      ch_state;
    GATT_TRACE_DEBUG ("gatt_disconnect ");

    if (p_tcb != NULL) {
        ret = TRUE;
        if ( (ch_state = gatt_get_ch_state(p_tcb)) != GATT_CH_CLOSING ) {
            if (p_tcb->att_lcid == L2CAP_ATT_CID) {
                if (ch_state == GATT_CH_OPEN) {
                    /* only LCB exist between remote device and local */
                    ret = L2CA_RemoveFixedChnl (L2CAP_ATT_CID, p_tcb->peer_bda);
                } else {
                    gatt_set_ch_state(p_tcb, GATT_CH_CLOSING);
                    ret = L2CA_CancelBleConnectReq (p_tcb->peer_bda);
                }
#if (CLASSIC_BT_GATT_INCLUDED == TRUE)
            } else {
                ret = L2CA_DisconnectReq(p_tcb->att_lcid);
#endif  ///CLASSIC_BT_GATT_INCLUDED == TRUE
            }
        } else {
            GATT_TRACE_DEBUG ("gatt_disconnect already in closing state");
        }
    }

    return ret;
}

/*******************************************************************************
**
** Function         gatt_update_app_hold_link_status
**
** Description      Update the application use link status
**
** Returns          void.
**
*******************************************************************************/
void gatt_update_app_hold_link_status (tGATT_IF gatt_if, tGATT_TCB *p_tcb, BOOLEAN is_add)
{
    UINT8 i;
    BOOLEAN found = FALSE;

    if (p_tcb == NULL) {
        GATT_TRACE_ERROR("gatt_update_app_hold_link_status p_tcb=NULL");
        return;
    }


    for (i = 0; i < GATT_MAX_APPS; i++) {
        if (p_tcb->app_hold_link[i] ==  gatt_if) {
            found = TRUE;
            if (!is_add) {
                p_tcb->app_hold_link[i] = 0;
                break;
            }
        }
    }

    if (!found && is_add) {
        for (i = 0; i < GATT_MAX_APPS; i++) {
            if (p_tcb->app_hold_link[i] ==  0) {
                p_tcb->app_hold_link[i] = gatt_if;
                found = TRUE;
                break;
            }
        }
    }

    GATT_TRACE_DEBUG("gatt_update_app_hold_link_status found=%d[1-found] idx=%d gatt_if=%d is_add=%d", found, i, gatt_if, is_add);

}

/*******************************************************************************
**
** Function         gatt_update_app_use_link_flag
**
** Description      Update the application use link flag and optional to check the acl link
**                  if the link is up then set the idle time out accordingly
**
** Returns          void.
**
*******************************************************************************/
void gatt_update_app_use_link_flag (tGATT_IF gatt_if, tGATT_TCB *p_tcb, BOOLEAN is_add, BOOLEAN check_acl_link)
{
    GATT_TRACE_DEBUG("gatt_update_app_use_link_flag  is_add=%d chk_link=%d",
                     is_add, check_acl_link);

    gatt_update_app_hold_link_status(gatt_if, p_tcb, is_add);

    if (check_acl_link &&
            p_tcb &&
            p_tcb->att_lcid == L2CAP_ATT_CID && /* only update link idle timer for fixed channel */
            (BTM_GetHCIConnHandle(p_tcb->peer_bda, p_tcb->transport) != GATT_INVALID_ACL_HANDLE)) {
        if (is_add) {
            GATT_TRACE_DEBUG("GATT disables link idle timer");
            /* acl link is connected disable the idle timeout */
            GATT_SetIdleTimeout(p_tcb->peer_bda, GATT_LINK_NO_IDLE_TIMEOUT, p_tcb->transport);
        } else {
            if (!gatt_num_apps_hold_link(p_tcb)) {
                /* acl link is connected but no application needs to use the link
                   so set the timeout value to GATT_LINK_IDLE_TIMEOUT_WHEN_NO_APP seconds */
                GATT_TRACE_DEBUG("GATT starts link idle timer =%d sec", GATT_LINK_IDLE_TIMEOUT_WHEN_NO_APP);
                GATT_SetIdleTimeout(p_tcb->peer_bda, GATT_LINK_IDLE_TIMEOUT_WHEN_NO_APP, p_tcb->transport);
            }

        }
    }
}

/*******************************************************************************
**
** Function         gatt_act_connect
**
** Description      GATT connection initiation.
**
** Returns          void.
**
*******************************************************************************/
BOOLEAN gatt_act_connect (tGATT_REG *p_reg, BD_ADDR bd_addr, tBLE_ADDR_TYPE bd_addr_type, tBT_TRANSPORT transport)
{
    BOOLEAN     ret = FALSE;
    tGATT_TCB   *p_tcb;
    UINT8       st;

    if ((p_tcb = gatt_find_tcb_by_addr(bd_addr, transport)) != NULL) {
        ret = TRUE;
        st = gatt_get_ch_state(p_tcb);

        /* before link down, another app try to open a GATT connection */
        if (st == GATT_CH_OPEN &&  gatt_num_apps_hold_link(p_tcb) == 0 &&
                transport == BT_TRANSPORT_LE ) {
            if (!gatt_connect(bd_addr, bd_addr_type, p_tcb, transport)) {
                ret = FALSE;
            }
        } else if (st == GATT_CH_CLOSING) {
            /* need to complete the closing first */
            ret = FALSE;
        }
    } else {
        if ((p_tcb = gatt_allocate_tcb_by_bdaddr(bd_addr, transport)) != NULL) {
            if (!gatt_connect(bd_addr, bd_addr_type, p_tcb, transport)) {
                GATT_TRACE_ERROR("gatt_connect failed");
                fixed_queue_free(p_tcb->pending_enc_clcb, NULL);
                fixed_queue_free(p_tcb->pending_ind_q, NULL);
                memset(p_tcb, 0, sizeof(tGATT_TCB));
            } else {
                ret = TRUE;
            }
        } else {
            ret = 0;
            GATT_TRACE_ERROR("Max TCB for gatt_if [%d] reached.", p_reg->gatt_if);
        }
    }

    if (ret) {
        gatt_update_app_use_link_flag(p_reg->gatt_if, p_tcb, TRUE, FALSE);
    }

    return ret;
}

/*******************************************************************************
**
** Function         gatt_le_connect_cback
**
** Description      This callback function is called by L2CAP to indicate that
**                  the ATT fixed channel for LE is
**                      connected (conn = TRUE)/disconnected (conn = FALSE).
**
*******************************************************************************/
static void gatt_le_connect_cback (UINT16 chan, BD_ADDR bd_addr, BOOLEAN connected,
                                   UINT16 reason, tBT_TRANSPORT transport)
{

    tGATT_TCB       *p_tcb = gatt_find_tcb_by_addr(bd_addr, transport);
    BOOLEAN                 check_srv_chg = FALSE;
    tGATTS_SRV_CHG          *p_srv_chg_clt = NULL;

    /* ignore all fixed channel connect/disconnect on BR/EDR link for GATT */
    if (transport == BT_TRANSPORT_BR_EDR) {
        return;
    }

    GATT_TRACE_DEBUG ("GATT   ATT protocol channel with BDA: %08x%04x is %s",
                      (bd_addr[0] << 24) + (bd_addr[1] << 16) + (bd_addr[2] << 8) + bd_addr[3],
                      (bd_addr[4] << 8) + bd_addr[5], (connected) ? "connected" : "disconnected");

    if ((p_srv_chg_clt = gatt_is_bda_in_the_srv_chg_clt_list(bd_addr)) != NULL) {
        check_srv_chg = TRUE;
    } else {
        if (btm_sec_is_a_bonded_dev(bd_addr)) {
            gatt_add_a_bonded_dev_for_srv_chg(bd_addr);
        }
    }

    if (connected) {
        /* do we have a channel initiating a connection? */
        if (p_tcb) {
            /* we are initiating connection */
            if ( gatt_get_ch_state(p_tcb) == GATT_CH_CONN) {
                /* send callback */
                gatt_set_ch_state(p_tcb, GATT_CH_OPEN);
                p_tcb->payload_size = GATT_DEF_BLE_MTU_SIZE;

                gatt_send_conn_cback(p_tcb);
            }
            if (check_srv_chg) {
#if (GATTS_INCLUDED == TRUE)
                gatt_chk_srv_chg (p_srv_chg_clt);
#endif  ///GATTS_INCLUDED == TRUE
            }
        }
        /* this is incoming connection or background connection callback */

        else {
            if ((p_tcb = gatt_allocate_tcb_by_bdaddr(bd_addr, BT_TRANSPORT_LE)) != NULL) {
                p_tcb->att_lcid = L2CAP_ATT_CID;

                gatt_set_ch_state(p_tcb, GATT_CH_OPEN);

                p_tcb->payload_size = GATT_DEF_BLE_MTU_SIZE;

                gatt_send_conn_cback (p_tcb);
                if (check_srv_chg) {
#if (GATTS_INCLUDED == TRUE)
                    gatt_chk_srv_chg (p_srv_chg_clt);
#endif  ///GATTS_INCLUDED == TRUE
                }
            } else {
                GATT_TRACE_ERROR("CCB max out, no rsources");
            }
        }
    } else {
        gatt_cleanup_upon_disc(bd_addr, reason, transport);
        GATT_TRACE_DEBUG ("ATT disconnected");
    }
}

/*******************************************************************************
**
** Function         gatt_channel_congestion
**
** Description      This function is called to process the congestion callback
**                  from lcb
**
** Returns          void
**
*******************************************************************************/
static void gatt_channel_congestion(tGATT_TCB *p_tcb, BOOLEAN congested)
{
    UINT8 i = 0;
    tGATT_REG *p_reg = NULL;
    UINT16 conn_id;
#if (GATTC_INCLUDED == TRUE)
    /* if uncongested, check to see if there is any more pending data */
    if (p_tcb != NULL && congested == FALSE) {
        gatt_cl_send_next_cmd_inq(p_tcb);
    }
#endif  ///GATTC_INCLUDED == TRUE
    /* notifying all applications for the connection up event */
    for (i = 0, p_reg = gatt_cb.cl_rcb ; i < GATT_MAX_APPS; i++, p_reg++) {
        if (p_reg->in_use) {
            if (p_reg->app_cb.p_congestion_cb) {
                conn_id = GATT_CREATE_CONN_ID(p_tcb->tcb_idx, p_reg->gatt_if);
                (*p_reg->app_cb.p_congestion_cb)(conn_id, congested);
            }
        }
    }
}

/*******************************************************************************
**
** Function         gatt_le_cong_cback
**
** Description      This function is called when GATT fixed channel is congested
**                  or uncongested.
**
** Returns          void
**
*******************************************************************************/
static void gatt_le_cong_cback(BD_ADDR remote_bda, BOOLEAN congested)
{
    tGATT_TCB *p_tcb = gatt_find_tcb_by_addr(remote_bda, BT_TRANSPORT_LE);

    /* if uncongested, check to see if there is any more pending data */
    if (p_tcb != NULL) {
        gatt_channel_congestion(p_tcb, congested);
    }
}

/*******************************************************************************
**
** Function         gatt_le_data_ind
**
** Description      This function is called when data is received from L2CAP.
**                  if we are the originator of the connection, we are the ATT
**                  client, and the received message is queued up for the client.
**
**                  If we are the destination of the connection, we are the ATT
**                  server, so the message is passed to the server processing
**                  function.
**
** Returns          void
**
*******************************************************************************/
static void gatt_le_data_ind (UINT16 chan, BD_ADDR bd_addr, BT_HDR *p_buf)
{
    tGATT_TCB    *p_tcb;

    /* Find CCB based on bd addr */
    if ((p_tcb = gatt_find_tcb_by_addr (bd_addr, BT_TRANSPORT_LE)) != NULL &&
            gatt_get_ch_state(p_tcb) >= GATT_CH_OPEN) {
        gatt_data_process(p_tcb, p_buf);
    } else {
        osi_free (p_buf);

        if (p_tcb != NULL) {
            GATT_TRACE_WARNING ("ATT - Ignored L2CAP data while in state: %d\n",
                                gatt_get_ch_state(p_tcb));
        }
    }
}

/*******************************************************************************
**
** Function         gatt_l2cif_connect_ind
**
** Description      This function handles an inbound connection indication
**                  from L2CAP. This is the case where we are acting as a
**                  server.
**
** Returns          void
**
*******************************************************************************/
#if (CLASSIC_BT_GATT_INCLUDED == TRUE)
static void gatt_l2cif_connect_ind_cback (BD_ADDR  bd_addr, UINT16 lcid, UINT16 psm, UINT8 id)
{
    /* do we already have a control channel for this peer? */
    UINT8       result = L2CAP_CONN_OK;
    tL2CAP_CFG_INFO cfg;
    tGATT_TCB       *p_tcb = gatt_find_tcb_by_addr(bd_addr, BT_TRANSPORT_BR_EDR);
    UNUSED(psm);

    GATT_TRACE_ERROR("Connection indication cid = %d", lcid);
    /* new connection ? */
    if (p_tcb == NULL) {
        /* allocate tcb */
        if ((p_tcb = gatt_allocate_tcb_by_bdaddr(bd_addr, BT_TRANSPORT_BR_EDR)) == NULL) {
            /* no tcb available, reject L2CAP connection */
            result = L2CAP_CONN_NO_RESOURCES;
        } else {
            p_tcb->att_lcid = lcid;
        }

    } else { /* existing connection , reject it */
        result = L2CAP_CONN_NO_RESOURCES;
    }

    /* Send L2CAP connect rsp */
    L2CA_ConnectRsp(bd_addr, id, lcid, result, 0);

    /* if result ok, proceed with connection */
    if (result == L2CAP_CONN_OK) {
        /* transition to configuration state */
        gatt_set_ch_state(p_tcb, GATT_CH_CFG);

        /* Send L2CAP config req */
        memset(&cfg, 0, sizeof(tL2CAP_CFG_INFO));
        cfg.mtu_present = TRUE;
        cfg.mtu = gatt_default.local_mtu;

        L2CA_ConfigReq(lcid, &cfg);
    }

}

/*******************************************************************************
**
** Function         gatt_l2c_connect_cfm_cback
**
** Description      This is the L2CAP connect confirm callback function.
**
**
** Returns          void
**
*******************************************************************************/
static void gatt_l2cif_connect_cfm_cback(UINT16 lcid, UINT16 result)
{
    tGATT_TCB       *p_tcb;
    tL2CAP_CFG_INFO cfg;

    /* look up clcb for this channel */
    if ((p_tcb = gatt_find_tcb_by_cid(lcid)) != NULL) {
        GATT_TRACE_DEBUG("gatt_l2c_connect_cfm_cback result: %d ch_state: %d, lcid:0x%x", result, gatt_get_ch_state(p_tcb), p_tcb->att_lcid);

        /* if in correct state */
        if (gatt_get_ch_state(p_tcb) == GATT_CH_CONN) {
            /* if result successful */
            if (result == L2CAP_CONN_OK) {
                /* set channel state */
                gatt_set_ch_state(p_tcb, GATT_CH_CFG);

                /* Send L2CAP config req */
                memset(&cfg, 0, sizeof(tL2CAP_CFG_INFO));
                cfg.mtu_present = TRUE;
                cfg.mtu = gatt_default.local_mtu;
                L2CA_ConfigReq(lcid, &cfg);
            }
            /* else initiating connection failure */
            else {
                gatt_cleanup_upon_disc(p_tcb->peer_bda, result, GATT_TRANSPORT_BR_EDR);
            }
        } else { /* wrong state, disconnect it */
            if (result == L2CAP_CONN_OK) {
                /* just in case the peer also accepts our connection - Send L2CAP disconnect req */
                L2CA_DisconnectReq(lcid);
            }
        }
    }
}

/*******************************************************************************
**
** Function         gatt_l2cif_config_cfm_cback
**
** Description      This is the L2CAP config confirm callback function.
**
**
** Returns          void
**
*******************************************************************************/
void gatt_l2cif_config_cfm_cback(UINT16 lcid, tL2CAP_CFG_INFO *p_cfg)
{
    tGATT_TCB       *p_tcb;
    tGATTS_SRV_CHG  *p_srv_chg_clt = NULL;

    /* look up clcb for this channel */
    if ((p_tcb = gatt_find_tcb_by_cid(lcid)) != NULL) {
        /* if in correct state */
        if ( gatt_get_ch_state(p_tcb) == GATT_CH_CFG) {
            /* if result successful */
            if (p_cfg->result == L2CAP_CFG_OK) {
                /* update flags */
                p_tcb->ch_flags |= GATT_L2C_CFG_CFM_DONE;

                /* if configuration complete */
                if (p_tcb->ch_flags & GATT_L2C_CFG_IND_DONE) {
                    gatt_set_ch_state(p_tcb, GATT_CH_OPEN);

                    if ((p_srv_chg_clt = gatt_is_bda_in_the_srv_chg_clt_list(p_tcb->peer_bda)) != NULL) {
#if (GATTS_INCLUDED == TRUE)
                        gatt_chk_srv_chg(p_srv_chg_clt);
#endif  ///GATTS_INCLUDED == TRUE
                    } else {
                        if (btm_sec_is_a_bonded_dev(p_tcb->peer_bda)) {
                            gatt_add_a_bonded_dev_for_srv_chg(p_tcb->peer_bda);
                        }
                    }

                    /* send callback */
                    gatt_send_conn_cback(p_tcb);
                }
            }
            /* else failure */
            else {
                /* Send L2CAP disconnect req */
                L2CA_DisconnectReq(lcid);
            }
        }
    }
}

/*******************************************************************************
**
** Function         gatt_l2cif_config_ind_cback
**
** Description      This is the L2CAP config indication callback function.
**
**
** Returns          void
**
*******************************************************************************/
void gatt_l2cif_config_ind_cback(UINT16 lcid, tL2CAP_CFG_INFO *p_cfg)
{
    tGATT_TCB       *p_tcb;
    tGATTS_SRV_CHG  *p_srv_chg_clt = NULL;
    /* look up clcb for this channel */
    if ((p_tcb = gatt_find_tcb_by_cid(lcid)) != NULL) {
        /* GATT uses the smaller of our MTU and peer's MTU  */
        if ( p_cfg->mtu_present &&
                (p_cfg->mtu >= GATT_MIN_BR_MTU_SIZE && p_cfg->mtu < L2CAP_DEFAULT_MTU)) {
            p_tcb->payload_size = p_cfg->mtu;
        } else {
            p_tcb->payload_size = L2CAP_DEFAULT_MTU;
        }

        /* send L2CAP configure response */
        memset(p_cfg, 0, sizeof(tL2CAP_CFG_INFO));
        p_cfg->result = L2CAP_CFG_OK;
        L2CA_ConfigRsp(lcid, p_cfg);

        /* if first config ind */
        if ((p_tcb->ch_flags & GATT_L2C_CFG_IND_DONE) == 0) {
            /* update flags */
            p_tcb->ch_flags |= GATT_L2C_CFG_IND_DONE;

            /* if configuration complete */
            if (p_tcb->ch_flags & GATT_L2C_CFG_CFM_DONE) {
                gatt_set_ch_state(p_tcb, GATT_CH_OPEN);
                if ((p_srv_chg_clt = gatt_is_bda_in_the_srv_chg_clt_list(p_tcb->peer_bda)) != NULL) {
#if (GATTS_INCLUDED == TRUE)
                    gatt_chk_srv_chg(p_srv_chg_clt);
#endif  ///GATTS_INCLUDED == TRUE
                } else {
                    if (btm_sec_is_a_bonded_dev(p_tcb->peer_bda)) {
                        gatt_add_a_bonded_dev_for_srv_chg(p_tcb->peer_bda);
                    }
                }

                /* send callback */
                gatt_send_conn_cback(p_tcb);
            }
        }
    }
}

/*******************************************************************************
**
** Function         gatt_l2cif_disconnect_ind_cback
**
** Description      This is the L2CAP disconnect indication callback function.
**
**
** Returns          void
**
*******************************************************************************/
void gatt_l2cif_disconnect_ind_cback(UINT16 lcid, BOOLEAN ack_needed)
{
    tGATT_TCB       *p_tcb;
    UINT16          reason;

    /* look up clcb for this channel */
    if ((p_tcb = gatt_find_tcb_by_cid(lcid)) != NULL) {
        if (ack_needed) {
            /* send L2CAP disconnect response */
            L2CA_DisconnectRsp(lcid);
        }
        if (gatt_is_bda_in_the_srv_chg_clt_list(p_tcb->peer_bda) == NULL) {
            if (btm_sec_is_a_bonded_dev(p_tcb->peer_bda)) {
                gatt_add_a_bonded_dev_for_srv_chg(p_tcb->peer_bda);
            }
        }
        /* if ACL link is still up, no reason is logged, l2cap is disconnect from peer */
        if ((reason = L2CA_GetDisconnectReason(p_tcb->peer_bda, p_tcb->transport)) == 0) {
            reason = GATT_CONN_TERMINATE_PEER_USER;
        }

        /* send disconnect callback */
        gatt_cleanup_upon_disc(p_tcb->peer_bda, reason, GATT_TRANSPORT_BR_EDR);
    }
}

/*******************************************************************************
**
** Function         gatt_l2cif_disconnect_cfm_cback
**
** Description      This is the L2CAP disconnect confirm callback function.
**
**
** Returns          void
**
*******************************************************************************/
static void gatt_l2cif_disconnect_cfm_cback(UINT16 lcid, UINT16 result)
{
    tGATT_TCB       *p_tcb;
    UINT16          reason;
    UNUSED(result);

    /* look up clcb for this channel */
    if ((p_tcb = gatt_find_tcb_by_cid(lcid)) != NULL) {
        /* If the device is not in the service changed client list, add it... */
        if (gatt_is_bda_in_the_srv_chg_clt_list(p_tcb->peer_bda) == NULL) {
            if (btm_sec_is_a_bonded_dev(p_tcb->peer_bda)) {
                gatt_add_a_bonded_dev_for_srv_chg(p_tcb->peer_bda);
            }
        }

        /* send disconnect callback */
        /* if ACL link is still up, no reason is logged, l2cap is disconnect from peer */
        if ((reason = L2CA_GetDisconnectReason(p_tcb->peer_bda, p_tcb->transport)) == 0) {
            reason = GATT_CONN_TERMINATE_LOCAL_HOST;
        }

        gatt_cleanup_upon_disc(p_tcb->peer_bda, reason, GATT_TRANSPORT_BR_EDR);
    }
}

/*******************************************************************************
**
** Function         gatt_l2cif_data_ind_cback
**
** Description      This is the L2CAP data indication callback function.
**
**
** Returns          void
**
*******************************************************************************/
static void gatt_l2cif_data_ind_cback(UINT16 lcid, BT_HDR *p_buf)
{
    tGATT_TCB       *p_tcb;

    /* look up clcb for this channel */
    if ((p_tcb = gatt_find_tcb_by_cid(lcid)) != NULL &&
            gatt_get_ch_state(p_tcb) == GATT_CH_OPEN) {
        /* process the data */
        gatt_data_process(p_tcb, p_buf);
    } else { /* prevent buffer leak */
        osi_free(p_buf);
    }

}

/*******************************************************************************
**
** Function         gatt_l2cif_congest_cback
**
** Description      L2CAP congestion callback
**
** Returns          void
**
*******************************************************************************/
static void gatt_l2cif_congest_cback (UINT16 lcid, BOOLEAN congested)
{
    tGATT_TCB *p_tcb = gatt_find_tcb_by_cid(lcid);

    if (p_tcb != NULL) {
        gatt_channel_congestion(p_tcb, congested);
    }

}
#endif  ///CLASSIC_BT_GATT_INCLUDED == TRUE

/*******************************************************************************
**
** Function         gatt_send_conn_cback
**
** Description      Callback used to notify layer above about a connection.
**
**
** Returns          void
**
*******************************************************************************/
static void gatt_send_conn_cback(tGATT_TCB *p_tcb)
{
    UINT8               i;
    tGATT_REG           *p_reg;
    tGATT_BG_CONN_DEV   *p_bg_dev = NULL;
    UINT16              conn_id;

    p_bg_dev = gatt_find_bg_dev(p_tcb->peer_bda);

    /* notifying all applications for the connection up event */
    for (i = 0,  p_reg = gatt_cb.cl_rcb ; i < GATT_MAX_APPS; i++, p_reg++) {
        if (p_reg->in_use) {
            if (p_bg_dev && gatt_is_bg_dev_for_app(p_bg_dev, p_reg->gatt_if)) {
                gatt_update_app_use_link_flag(p_reg->gatt_if, p_tcb, TRUE, TRUE);
            }

            if (p_reg->app_cb.p_conn_cb) {
                conn_id = GATT_CREATE_CONN_ID(p_tcb->tcb_idx, p_reg->gatt_if);
                (*p_reg->app_cb.p_conn_cb)(p_reg->gatt_if, p_tcb->peer_bda, conn_id,
                                           TRUE, 0, p_tcb->transport);
            }
        }
    }


    if (gatt_num_apps_hold_link(p_tcb) &&  p_tcb->att_lcid == L2CAP_ATT_CID ) {
        /* disable idle timeout if one or more clients are holding the link disable the idle timer */
        GATT_SetIdleTimeout(p_tcb->peer_bda, GATT_LINK_NO_IDLE_TIMEOUT, p_tcb->transport);
    }
}

/*******************************************************************************
**
** Function         gatt_le_data_ind
**
** Description      This function is called when data is received from L2CAP.
**                  if we are the originator of the connection, we are the ATT
**                  client, and the received message is queued up for the client.
**
**                  If we are the destination of the connection, we are the ATT
**                  server, so the message is passed to the server processing
**                  function.
**
** Returns          void
**
*******************************************************************************/
void gatt_data_process (tGATT_TCB *p_tcb, BT_HDR *p_buf)
{
    UINT8   *p = (UINT8 *)(p_buf + 1) + p_buf->offset;
    UINT8   op_code, pseudo_op_code;
#if (GATTS_INCLUDED == TRUE) || (GATTC_INCLUDED == TRUE)
    UINT16  msg_len;
#endif ///(GATTS_INCLUDED == TRUE) || (GATTC_INCLUDED == TRUE)


    if (p_buf->len > 0) {
#if (GATTS_INCLUDED == TRUE) || (GATTC_INCLUDED == TRUE)
        msg_len = p_buf->len - 1;
#endif ///(GATTS_INCLUDED == TRUE) || (GATTC_INCLUDED == TRUE)
        STREAM_TO_UINT8(op_code, p);

        /* remove the two MSBs associated with sign write and write cmd */
        pseudo_op_code = op_code & (~GATT_WRITE_CMD_MASK);

        if (pseudo_op_code < GATT_OP_CODE_MAX) {
            if (op_code == GATT_SIGN_CMD_WRITE) {
#if (SMP_INCLUDED == TRUE)
                gatt_verify_signature(p_tcb, p_buf);
#endif  ///SMP_INCLUDED == TRUE
            } else {
                /* message from client */
                if ((op_code % 2) == 0) {
#if (GATTS_INCLUDED == TRUE)
                    gatt_server_handle_client_req (p_tcb, op_code, msg_len, p);
#endif  ///GATTS_INCLUDED == TRUE
                } else {
#if (GATTC_INCLUDED == TRUE)
                    gatt_client_handle_server_rsp (p_tcb, op_code, msg_len, p);
#endif  ///GATTC_INCLUDED == TRUE
                }
            }
        } else {
            if (op_code & GATT_COMMAND_FLAG) {
                GATT_TRACE_ERROR ("ATT - Rcvd L2CAP data, unknown cmd: 0x%x\n", op_code);
            } else {
                GATT_TRACE_ERROR ("ATT - Rcvd L2CAP data, unknown req: 0x%x\n", op_code);
                gatt_send_error_rsp (p_tcb, GATT_REQ_NOT_SUPPORTED, op_code, 0, FALSE);
            }
        }
    } else {
        GATT_TRACE_ERROR ("invalid data length, ignore\n");
    }

    osi_free (p_buf);
}

/*******************************************************************************
**
** Function         gatt_add_a_bonded_dev_for_srv_chg
**
** Description      Add a bonded dev to the service changed client list
**
** Returns          void
**
*******************************************************************************/
void gatt_add_a_bonded_dev_for_srv_chg (BD_ADDR bda)
{
    tGATTS_SRV_CHG_REQ req;
    tGATTS_SRV_CHG srv_chg_clt;

    memcpy(srv_chg_clt.bda, bda, BD_ADDR_LEN);
    srv_chg_clt.srv_changed = FALSE;
    if (gatt_add_srv_chg_clt(&srv_chg_clt) != NULL) {
        memcpy(req.srv_chg.bda, bda, BD_ADDR_LEN);
        req.srv_chg.srv_changed = FALSE;
        if (gatt_cb.cb_info.p_srv_chg_callback) {
            (*gatt_cb.cb_info.p_srv_chg_callback)(GATTS_SRV_CHG_CMD_ADD_CLIENT, &req, NULL);
        }
    }
}

/*******************************************************************************
**
** Function         gatt_send_srv_chg_ind
**
** Description      This function is called to send a service changed indication to
**                  the specified bd address
**
** Returns          GATT_SUCCESS if sucessfully sent; otherwise error code
**
*******************************************************************************/
#if (GATTS_INCLUDED == TRUE)
tGATT_STATUS gatt_send_srv_chg_ind (BD_ADDR peer_bda)
{
    UINT8   handle_range[GATT_SIZE_OF_SRV_CHG_HNDL_RANGE];
    UINT8   *p = handle_range;
    UINT16  conn_id;
    tGATT_STATUS  status = GATT_ERROR;
    GATT_TRACE_DEBUG("gatt_send_srv_chg_ind");

    if (gatt_cb.handle_of_h_r) {
        if ((conn_id = gatt_profile_find_conn_id_by_bd_addr(peer_bda)) != GATT_INVALID_CONN_ID) {
            UINT16_TO_STREAM (p, 1);
            UINT16_TO_STREAM (p, 0xFFFF);
            status = GATTS_HandleValueIndication (conn_id,
                                         gatt_cb.handle_of_h_r,
                                         GATT_SIZE_OF_SRV_CHG_HNDL_RANGE,
                                         handle_range);
        } else {
            status = GATT_NOT_FOUND;
            GATT_TRACE_ERROR("Unable to find conn_id for  %02x%02x%02x%02x%02x%02x ",
                             peer_bda[0], peer_bda[1],  peer_bda[2], peer_bda[3], peer_bda[4], peer_bda[5]);
        }
    }
    return status;
}


/*******************************************************************************
**
** Function         gatt_chk_srv_chg
**
** Description      Check sending service changed Indication is required or not
**                  if required then send the Indication
**
** Returns          void
**
*******************************************************************************/
void gatt_chk_srv_chg(tGATTS_SRV_CHG *p_srv_chg_clt)
{
    GATT_TRACE_DEBUG("gatt_chk_srv_chg srv_changed=%d", p_srv_chg_clt->srv_changed );

    if (p_srv_chg_clt->srv_changed) {
        gatt_send_srv_chg_ind(p_srv_chg_clt->bda);
    }
}
#endif  ///GATTS_INCLUDED == TRUE


/*******************************************************************************
**
** Function         gatt_init_srv_chg
**
** Description      This function is used to initialize the service changed
**                  attribute value
**
** Returns          void
**
*******************************************************************************/
void gatt_init_srv_chg (void)
{
    tGATTS_SRV_CHG_REQ req;
    tGATTS_SRV_CHG_RSP rsp;
    BOOLEAN status;
    UINT8 num_clients, i;
    tGATTS_SRV_CHG  srv_chg_clt;

    GATT_TRACE_DEBUG("gatt_init_srv_chg");
    if (gatt_cb.cb_info.p_srv_chg_callback) {
        status = (*gatt_cb.cb_info.p_srv_chg_callback)(GATTS_SRV_CHG_CMD_READ_NUM_CLENTS, NULL, &rsp);

        if (status && rsp.num_clients) {
            GATT_TRACE_DEBUG("gatt_init_srv_chg num_srv_chg_clt_clients=%d", rsp.num_clients);
            num_clients = rsp.num_clients;
            i = 1; /* use one based index */
            while ((i <= num_clients) && status) {
                req.client_read_index = i;
                if ((status = (*gatt_cb.cb_info.p_srv_chg_callback)(GATTS_SRV_CHG_CMD_READ_CLENT, &req, &rsp)) == TRUE) {
                    memcpy(&srv_chg_clt, &rsp.srv_chg , sizeof(tGATTS_SRV_CHG));
                    if (gatt_add_srv_chg_clt(&srv_chg_clt) == NULL) {
                        GATT_TRACE_ERROR("Unable to add a service change client");
                        status = FALSE;
                    }
                }
                i++;
            }
        }
    } else {
        GATT_TRACE_DEBUG("gatt_init_srv_chg callback not registered yet");
    }
}

/*******************************************************************************
**
** Function         gatt_proc_srv_chg
**
** Description      This function is process the service changed request
**
** Returns          void
**
*******************************************************************************/
#if (GATTS_INCLUDED == TRUE)
void gatt_proc_srv_chg (void)
{
    UINT8               start_idx, found_idx;
    BD_ADDR             bda;
    BOOLEAN             srv_chg_ind_pending = FALSE;
    tGATT_TCB           *p_tcb;
    tBT_TRANSPORT      transport;

    GATT_TRACE_DEBUG ("gatt_proc_srv_chg");

    if (gatt_cb.cb_info.p_srv_chg_callback && gatt_cb.handle_of_h_r) {
        gatt_set_srv_chg();
        start_idx = 0;
        while (gatt_find_the_connected_bda(start_idx, bda, &found_idx, &transport)) {
            p_tcb = &gatt_cb.tcb[found_idx];
            srv_chg_ind_pending  = gatt_is_srv_chg_ind_pending(p_tcb);

            if (!srv_chg_ind_pending) {
                gatt_send_srv_chg_ind(bda);
            } else {
                GATT_TRACE_DEBUG ("discard srv chg - already has one in the queue");
            }
            start_idx = ++found_idx;
        }
    }
}
#endif  ///GATTS_INCLUDED == TRUE

/*******************************************************************************
**
** Function         gatt_set_ch_state
**
** Description      This function set the ch_state in tcb
**
** Returns          none
**
*******************************************************************************/
void gatt_set_ch_state(tGATT_TCB *p_tcb, tGATT_CH_STATE ch_state)
{
    if (p_tcb) {
        GATT_TRACE_DEBUG ("gatt_set_ch_state: old=%d new=%d", p_tcb->ch_state, ch_state);
        p_tcb->ch_state = ch_state;
    }
}

/*******************************************************************************
**
** Function         gatt_get_ch_state
**
** Description      This function get the ch_state in tcb
**
** Returns          none
**
*******************************************************************************/
tGATT_CH_STATE gatt_get_ch_state(tGATT_TCB *p_tcb)
{
    tGATT_CH_STATE ch_state = GATT_CH_CLOSE;
    if (p_tcb) {
        GATT_TRACE_DEBUG ("gatt_get_ch_state: ch_state=%d", p_tcb->ch_state);
        ch_state = p_tcb->ch_state;
    }
    return ch_state;
}

uint16_t gatt_get_local_mtu(void)
{
    return gatt_default.local_mtu;
}

void gatt_set_local_mtu(uint16_t mtu)
{
    gatt_default.local_mtu = mtu;
}

#endif /* BLE_INCLUDED */