nrf52-dk

shields/TARGET_ST_BLUENRG/source/BlueNRGGattConnectionClient.cpp

Committer:
mamont090671
Date:
2020-06-05
Revision:
0:70ce6da7a141

File content as of revision 0:70ce6da7a141:

/* mbed Microcontroller Library
* Copyright (c) 2006-2013 ARM Limited
*
* 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.
*/
/**
  ******************************************************************************
  * @file    BlueNRGGattServer.cpp
  * @author  STMicroelectronics
  * @brief   Implementation of BlueNRG BLE_API GattServer Class
  ******************************************************************************
  * @copy
  *
  * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
  * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
  * TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
  * DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
  * FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
  * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
  *
  * <h2><center>&copy; COPYRIGHT 2013 STMicroelectronics</center></h2>
  */

/** @defgroup BlueNRGGattConnectionClient
 *  @brief BlueNRG GattConnectionClient Adaptation
 *  @{
 */

#include "BlueNRGGattConnectionClient.h"
#ifdef YOTTA_CFG_MBED_OS
    #include "mbed-drivers/mbed.h"
#else
    #include "mbed.h"
#endif 
#include "BlueNRGGap.h" 
#include "BlueNRGGattClient.h"
#include "ble_utils.h"
#include "ble_debug.h"

// #define PRINTF printf

static uint8_t props_mask[] = {
  0x01,
  0x02,
  0x04,
  0x08,
  0x10,
  0x20,
  0x40,
  0x80
  };

void BlueNRGGattConnectionClient::gattProcedureCompleteCB(uint8_t error_code)
{
  if(error_code != BLE_STATUS_SUCCESS) {
    _currentState = GATT_IDLE;
    return;
  }

  // Service Discovery complete
/*
  if(_currentState != GATT_IDLE &&
     _currentState != GATT_DISCOVERY_TERMINATED &&
     _currentState != GATT_WRITE_CHAR &&
     _currentState != GATT_READ_CHAR) {
*/
  if(_currentState == GATT_SERVICE_DISCOVERY) {
    findServiceChars();
    return;
  }

  if(_currentState == GATT_CHAR_DESC_DISCOVERY) {
      _currentState = GATT_IDLE;
      if(charDescTerminationCallback != NULL) {
         CharacteristicDescriptorDiscovery::TerminationCallbackParams_t params = {
                                   _characteristic,
                                   BLE_ERROR_NONE
         };
         charDescTerminationCallback(&params);
       }
      return;
  }

  // Read complete
  if(_currentState == GATT_READ_CHAR) {
    _currentState = GATT_IDLE;
    BlueNRGGattClient::getInstance().processReadResponse(&readCBParams);
    free((void*)(readCBParams.data));
    readCBParams.data = NULL;
    return;
  }

  // Write complete
  if(_currentState == GATT_WRITE_CHAR) {
    _currentState = GATT_IDLE;
    BlueNRGGattClient::getInstance().processWriteResponse(&writeCBParams);
    return;
  }
}

void BlueNRGGattConnectionClient::primaryServicesCB(uint8_t event_data_length,
                                                    uint8_t attribute_data_length,
                                                    uint8_t *attribute_data_list)
{
  GattAttribute::Handle_t startHandle, endHandle;
  UUID uuid;
  uint8_t i, offset, numAttr;

  numAttr = (event_data_length - 1) / attribute_data_length;

  offset = 0;
  for (i=0; i<numAttr; i++) {
    startHandle = attribute_data_list[offset];
    endHandle = attribute_data_list[offset+2];

    // UUID Type
    if (attribute_data_length == 6) {

      PRINTF("UUID_TYPE_16\n\r");
      uuid = attribute_data_list[offset+5]<<8|attribute_data_list[offset+4];
      PRINTF("S UUID-%X attrs[%u %u]\r\n", uuid.getShortUUID(), startHandle, endHandle);

    } else {

      PRINTF("UUID_TYPE_128\n\r");
      uuid.setupLong(attribute_data_list+offset+4, UUID::LSB);

#ifdef DEBUG
      PRINTF("S UUID-");
      const uint8_t *longUUIDBytes = uuid.getBaseUUID();
      for (unsigned j = 0; j < UUID::LENGTH_OF_LONG_UUID; j++) {
        PRINTF("%02x", longUUIDBytes[j]);
      }
#endif
      PRINTF(" attrs[%u %u]\r\n", startHandle, endHandle);

    }

    PRINTF("Setup serviceIndex = %d\n\r", _numServices);
    discoveredService[_numServices].setup(uuid, startHandle, endHandle);

    _numServices++;

    offset += attribute_data_length;
  }

  PRINTF("!!!Service Discovery complete (numAttr=%u)!!!\n\r", numAttr);

}

void BlueNRGGattConnectionClient::primaryServiceCB(uint8_t event_data_length, uint8_t *handles_info_list)
{
  GattAttribute::Handle_t startHandle, endHandle;
  UUID uuid;
  uint8_t i, offset, numHandlePairs;

  numHandlePairs = (event_data_length - 1) / 2;

  offset = 0;
  for (i=0; i<numHandlePairs; i++) {
    startHandle = handles_info_list[offset];
    endHandle = handles_info_list[offset+2];

    PRINTF("primaryServiceCB attrs[%u %u]\r\n", startHandle, endHandle);


    if (_matchingServiceUUID.shortOrLong() == UUID::UUID_TYPE_SHORT) {
        PRINTF("S UUID-%x attrs[%u %u]\r\n", _matchingServiceUUID.getShortUUID(), startHandle, endHandle);
        uuid = _matchingServiceUUID.getShortUUID();
    } else {
#ifdef DEBUG
        PRINTF("S UUID-");
        const uint8_t *longUUIDBytes = _matchingServiceUUID.getBaseUUID();
        for (unsigned i = 0; i < UUID::LENGTH_OF_LONG_UUID; i++) {
            PRINTF("%02x", longUUIDBytes[i]);
        }
#endif
        PRINTF(" attrs[%u %u]\r\n", startHandle, endHandle);
        uuid.setupLong(_matchingServiceUUID.getBaseUUID(), UUID::MSB);
    }

    discoveredService[i].setup(uuid, startHandle, endHandle);

    _numServices++;

    offset += 4;
  }
}

void BlueNRGGattConnectionClient::serviceCharsCB(uint8_t event_data_length,
                                                 uint8_t handle_value_pair_length,
                                                 uint8_t *handle_value_pair)
{
  // Charac Handle (2), Charac Properties(1), Charac Value Handle(2), Charac UUID(2/16)

  GattAttribute::Handle_t declHandle, valueHandle, lastHandle;
  UUID uuid;
  uint8_t i, numChar, offset;

  numChar = (event_data_length - 1) / handle_value_pair_length;

  PRINTF("event_data_length=%d handle_value_pair_length=%d numChar=%d\n\r", event_data_length, handle_value_pair_length, numChar);

  offset = 0;
  for (i=0; i<numChar; i++) {
    // UUID Type
    if (handle_value_pair_length == 7) {
      PRINTF("Char UUID_TYPE_16\n\r");
      uuid = handle_value_pair[offset+6]<<8|handle_value_pair[offset+5];
      PRINTF("C UUID-%X\r\n", uuid.getShortUUID());
    } else {
      PRINTF("Char UUID_TYPE_128\n\r");
      uuid.setupLong(handle_value_pair+offset+5, UUID::LSB);
#ifdef DEBUG
      PRINTF("C UUID-");
      const uint8_t *longUUIDBytes = uuid.getBaseUUID();
      for (unsigned i = 0; i < UUID::LENGTH_OF_LONG_UUID; i++) {
        PRINTF("%02X", longUUIDBytes[i]);
      }
      PRINTF("\r\n");
#endif
    }

    // Properties
    DiscoveredCharacteristic::Properties_t p;

    p._broadcast = (props_mask[0] & handle_value_pair[offset+2]);
    p._read = (props_mask[1] & handle_value_pair[offset+2])>>1;
    p._writeWoResp = (props_mask[2] & handle_value_pair[offset+2])>>2;
    p._write = (props_mask[3] & handle_value_pair[offset+2])>>3;
    p._notify = (props_mask[4] & handle_value_pair[offset+2])>>4;
    p._indicate = (props_mask[5] & handle_value_pair[offset+2])>>5;
    p._authSignedWrite = (props_mask[6] & handle_value_pair[offset+2])>>6;
    PRINTF("p._broadcast=%d\n\r", p._broadcast);
    PRINTF("p._read=%d\n\r", p._read);
    PRINTF("p._writeWoResp=%d\n\r", p._writeWoResp);
    PRINTF("p._write=%d\n\r", p._write);
    PRINTF("p._notify=%d\n\r", p._notify);
    PRINTF("p._indicate=%d\n\r", p._indicate);
    PRINTF("p._authSignedWrite=%d\n\r", p._authSignedWrite);

    /*
    uint8_t props = handle_value_pair[offset+2];
    PRINTF("CHAR PROPS: %d\n\r", props);
    */

    // Handles
    declHandle = handle_value_pair[offset];
    valueHandle = handle_value_pair[offset+3];
    lastHandle = valueHandle+1;
    PRINTF("declHandle: %u valueHandle=%u lastHandle=%u\n\r", declHandle, valueHandle, lastHandle);

    discoveredChar[_numChars].setup(_gattClient,
                                    _connectionHandle,
                                    uuid,
                                    p,
                                    declHandle,
                                    valueHandle,
                                    lastHandle);

    if (_numChars != 0) {
        discoveredChar[_numChars - 1].setLastHandle(declHandle - 1);

        if(characteristicDiscoveryCallback) {
          characteristicDiscoveryCallback(&discoveredChar[_numChars - 1]);
        }
    }

    _numChars++;

    offset += handle_value_pair_length;
  }
}

void BlueNRGGattConnectionClient::serviceCharByUUIDCB(uint8_t event_data_length,
                                                      uint16_t attr_handle,
                                                      uint8_t *attr_value)
{
  // Charac Properties(1), Charac Value Handle(2), Charac UUID(2/16)
  GattAttribute::Handle_t declHandle, valueHandle, lastHandle;
  UUID uuid;

  PRINTF("serviceCharByUUIDCB\n\r");

  // UUID Type
  if (event_data_length == 7) {
    PRINTF("Char UUID_TYPE_16\n\r");
    uuid = attr_value[4]<<8|attr_value[3];
    PRINTF("C UUID-%X\r\n", uuid.getShortUUID());
  } else {
    PRINTF("Char UUID_TYPE_128\n\r");
    uuid.setupLong(attr_value+3, UUID::LSB);
#ifdef DEBUG
    PRINTF("C UUID-");
    const uint8_t *longUUIDBytes = uuid.getBaseUUID();
    for (unsigned i = 0; i < UUID::LENGTH_OF_LONG_UUID; i++) {
      PRINTF("%02X", longUUIDBytes[i]);
    }
    PRINTF("\r\n");
#endif
  }

  // Properties
  DiscoveredCharacteristic::Properties_t p;

  p._broadcast = (props_mask[0] & attr_value[0]);
  p._read = (props_mask[1] & attr_value[0])>>1;
  p._writeWoResp = (props_mask[2] & attr_value[0])>>2;
  p._write = (props_mask[3] & attr_value[0])>>3;
  p._notify = (props_mask[4] & attr_value[0])>>4;
  p._indicate = (props_mask[5] & attr_value[0])>>5;
  p._authSignedWrite = (props_mask[6] & attr_value[0])>>6;
  PRINTF("p._broadcast=%d\n\r", p._broadcast);
  PRINTF("p._read=%d\n\r", p._read);
  PRINTF("p._writeWoResp=%d\n\r", p._writeWoResp);
  PRINTF("p._write=%d\n\r", p._write);
  PRINTF("p._notify=%d\n\r", p._notify);
  PRINTF("p._indicate=%d\n\r", p._indicate);
  PRINTF("p._authSignedWrite=%d\n\r", p._authSignedWrite);

  /*
  uint8_t props = attr_value[0];
  PRINTF("CHAR PROPS: %d\n\r", props);
  */

  // Handles
  declHandle = attr_handle;
  valueHandle = attr_value[1];
  lastHandle = valueHandle+1;

  discoveredChar[_numChars].setup(_gattClient,
                                  _connectionHandle,
                                  uuid,
                                  p,
                                  declHandle,
                                  valueHandle,
                                  lastHandle);

  // update the last handle and call the characteristic discovery callback for previous char
  if (_numChars != 0) {
    discoveredChar[_numChars - 1].setLastHandle(declHandle - 1);

    if(characteristicDiscoveryCallback) {
      characteristicDiscoveryCallback(&discoveredChar[_numChars - 1]);
    }
  }

  _numChars++;
}

ble_error_t BlueNRGGattConnectionClient::findServiceChars(void)
{
  PRINTF("findServiceChars\n\r");

  tBleStatus ret;
  uint8_t uuid_type = UUID_TYPE_16;
  uint8_t short_uuid[2];
  uint8_t *uuid = NULL;

  DiscoveredService *service;

  // complete the discovery of the last characteristic of the previous service.
  // Its last handle wasn't known before this point
  // update the handle and call the characteristic discovery callback.
  if (_servIndex != 0 && _numChars != 0) {
      discoveredChar[_numChars - 1].setLastHandle(discoveredService[_servIndex - 1].getEndHandle());

      if(characteristicDiscoveryCallback) {
        characteristicDiscoveryCallback(&discoveredChar[_numChars - 1]);
      }
  }

  _numChars = 0;

  // We finished chars discovery for all services
  if(_servIndex >= _numServices) {
    PRINTF("!!!We finished chars discovery for all services!!!\n\r");
    //_currentState = GATT_CHARS_DISCOVERY_COMPLETE;

    terminateServiceDiscovery();

    return BLE_ERROR_NONE;
  }

  service = &discoveredService[_servIndex];
  /*
  if (service->getUUID().shortOrLong() == UUID::UUID_TYPE_SHORT) {
    PRINTF("S UUID-%X\r\n", service->getUUID().getShortUUID());
  } else {
    PRINTF("S UUID-");
    const uint8_t *longUUIDBytes = service->getUUID().getBaseUUID();
    for (unsigned i = 0; i < UUID::LENGTH_OF_LONG_UUID; i++) {
      PRINTF("%02X", longUUIDBytes[i]);
    }
    PRINTF("\r\n");
  }
  */

  if(serviceDiscoveryCallback) {
    serviceDiscoveryCallback(service);
  }

  PRINTF("findServiceChars (_servIndex=%d)\n\r", _servIndex);
  //ret = aci_gatt_disc_all_charac_of_serv(connectionHandle, service->getStartHandle(), service->getEndHandle());

    if(_matchingCharacteristicUUIDIn == BLE_UUID_UNKNOWN) {
        PRINTF("findServiceChars (BLE_UUID_UNKNOWN)\n\r");
        ret = aci_gatt_disc_all_charac_of_serv(_connectionHandle, service->getStartHandle(), service->getEndHandle());
    } else {

        uint8_t type = _matchingCharacteristicUUIDIn.shortOrLong();

        if(type == UUID::UUID_TYPE_SHORT) {
            STORE_LE_16(short_uuid, _matchingCharacteristicUUIDIn.getShortUUID());

            uuid_type = UUID_TYPE_16;
            uuid = short_uuid;
#ifdef DEBUG
            PRINTF("findServiceChars C UUID-");
            for(unsigned i = 0; i < 2; i++) {
                PRINTF("%02X", short_uuid[i]);
            }
            PRINTF("\n\r");
#endif
        } else if(type==UUID::UUID_TYPE_LONG) {

            uuid_type = UUID_TYPE_128;
            uuid = (unsigned char*)_matchingCharacteristicUUIDIn.getBaseUUID();
#ifdef DEBUG
            PRINTF("(findServiceChars) C UUID-");
            for (unsigned i = 0; i < UUID::LENGTH_OF_LONG_UUID; i++) {
                PRINTF("%02X", uuid[i]);
            }
            PRINTF("\r\n");
#endif
        }

        ret = aci_gatt_disc_charac_by_uuid(_connectionHandle,
                                           service->getStartHandle(),
                                           service->getEndHandle(),
                                           uuid_type,
                                           uuid);
    }

  if(ret == BLE_STATUS_SUCCESS) {
    _servIndex++;
  }

  PRINTF("findServiceChars ret=%d\n\r", ret);

  return BLE_ERROR_NONE;
}

ble_error_t BlueNRGGattConnectionClient::launchServiceDiscovery(ServiceDiscovery::ServiceCallback_t         sc,
                                                                ServiceDiscovery::CharacteristicCallback_t  cc,
                                                                const UUID                                 &matchingServiceUUID,
                                                                const UUID                                 &matchingCharacteristicUUIDIn)
{
  PRINTF("BlueNRGGattConnectionClient launchServiceDiscovery\n\r");

  tBleStatus ret;
  uint8_t uuid_type = UUID_TYPE_16;
  uint8_t short_uuid[2];
  uint8_t *uuid = NULL;
  unsigned j;

  if(isServiceDiscoveryActive()) {
    return BLE_ERROR_OPERATION_NOT_PERMITTED;
  }

  if(!sc && !cc) {
    // nothing to do
    PRINTF("BlueNRGGattConnectionClient launchServiceDiscovery: nothing to do\n\r");
    return BLE_ERROR_NONE;
  }

  serviceDiscoveryCallback = sc;
  characteristicDiscoveryCallback = cc;
  _matchingServiceUUID = matchingServiceUUID;
  _matchingCharacteristicUUIDIn = matchingCharacteristicUUIDIn;

  //reset services
  _numServices = 0;
  _numChars = 0;
  _servIndex = 0;
  for(j = 0; j < BLE_TOTAL_DISCOVERED_SERVICES; j++) {
    discoveredService[j].setup(BLE_UUID_UNKNOWN, GattAttribute::INVALID_HANDLE, GattAttribute::INVALID_HANDLE);
  }

  if(matchingServiceUUID == BLE_UUID_UNKNOWN) {

    // Wildcard: search for all services
    PRINTF("Wildcard: search for all services\r\n");
    ret = aci_gatt_disc_all_prim_services((uint16_t)_connectionHandle);

  } else {
    PRINTF("search for specific services\r\n");

    uint8_t type = matchingServiceUUID.shortOrLong();

    if(type == UUID::UUID_TYPE_SHORT) {
      STORE_LE_16(short_uuid, matchingServiceUUID.getShortUUID());
#ifdef DEBUG
      PRINTF("BlueNRGGattConnectionClient launchServiceDiscovery short_uuid=0x");
      for(j = 0; j < 2; j++) {
        PRINTF("%02X", short_uuid[j]);
      }
      PRINTF("\n\r");
#endif

      uuid_type = UUID_TYPE_16;
      uuid = short_uuid;

    } else if(type==UUID::UUID_TYPE_LONG) {

      uuid_type = UUID_TYPE_128;
      uuid = (unsigned char*)matchingServiceUUID.getBaseUUID();

#ifdef DEBUG
      PRINTF("BlueNRGGattConnectionClient launchServiceDiscovery base_uuid=0x");
      for(j = 0; j < 16; j++) {
        PRINTF("%02X", uuid[j]);
      }
      PRINTF("\n\r");
#endif
    }

    // search for specific service by UUID
    ret = aci_gatt_disc_prim_service_by_uuid((uint16_t)_connectionHandle, uuid_type, uuid);
  }

  if(ret == BLE_STATUS_SUCCESS) {
    _currentState = GATT_SERVICE_DISCOVERY;
  }

  PRINTF("BlueNRGGattConnectionClient launchServiceDiscovery ret=%d\n\r", ret);

  return BLE_ERROR_NONE;
}

ble_error_t BlueNRGGattConnectionClient::discoverServices(ServiceDiscovery::ServiceCallback_t  callback,
                                                          const UUID                          &matchingServiceUUID)
{
  /* avoid compiler warnings about unused variables */
  (void)callback;
  (void)matchingServiceUUID;

  return BLE_ERROR_NOT_IMPLEMENTED;
}

ble_error_t BlueNRGGattConnectionClient::discoverServices(ServiceDiscovery::ServiceCallback_t  callback,
                                                          GattAttribute::Handle_t              startHandle,
                                                          GattAttribute::Handle_t              endHandle)
{
  /* avoid compiler warnings about unused variables */
  (void)callback;
  (void)startHandle;
  (void)endHandle;

  return BLE_ERROR_NOT_IMPLEMENTED;
}

bool BlueNRGGattConnectionClient::isServiceDiscoveryActive(void) const
{
  if(_currentState == GATT_SERVICE_DISCOVERY) {
    return true;
  }

  return false;
}

void BlueNRGGattConnectionClient::terminateServiceDiscovery(void)
{
  _currentState = GATT_IDLE;//GATT_DISCOVERY_TERMINATED;

  if (terminationCallback) {
    terminationCallback(_connectionHandle);
  }
}

void BlueNRGGattConnectionClient::charReadCB(uint8_t event_data_length, uint8_t* attribute_value)
{
  // copy the data read, they will be forwarded to the user once the procedure
  // has completed
  readCBParams.connHandle = _connectionHandle;
  readCBParams.offset = 0;
  readCBParams.len = event_data_length;
  readCBParams.data = static_cast<uint8_t*>(malloc(event_data_length));
  memcpy((void*)(readCBParams.data), attribute_value, event_data_length);
}

ble_error_t BlueNRGGattConnectionClient::read(GattAttribute::Handle_t attributeHandle, uint16_t offset) const
{
  /* avoid compiler warnings about unused variables */
  (void)offset;

  tBleStatus ret;

  BlueNRGGattConnectionClient *gattc = const_cast<BlueNRGGattConnectionClient*>(this);

  // Save the attribute_handle not provided by evt_att_read_resp
  gattc->readCBParams.handle = attributeHandle;

  ret = aci_gatt_read_charac_val(_connectionHandle, attributeHandle);

  if(ret == BLE_STATUS_SUCCESS) {
    gattc->_currentState = GATT_READ_CHAR;
    return BLE_ERROR_NONE;
  }
  switch (ret) {
  case ERR_CONTROLLER_BUSY:
    return BLE_STACK_BUSY;
  default:
    return BLE_ERROR_INVALID_STATE;
  }
}

void BlueNRGGattConnectionClient::charWritePrepareCB(uint8_t event_data_length,
                                                     uint16_t attribute_handle,
                                                     uint16_t offset,
                                                     uint8_t *part_attr_value)
{
  // Update the write response params
  writeCBParams.handle = attribute_handle;
  writeCBParams.offset = offset;
  writeCBParams.len = event_data_length-4; //(?)
  writeCBParams.data = part_attr_value;

  BlueNRGGattClient::getInstance().processWriteResponse(&writeCBParams);
}

void BlueNRGGattConnectionClient::charWriteExecCB(uint8_t event_data_length)
{
  /* avoid compiler warnings about unused variables */
  (void)event_data_length;

  writeCBParams.connHandle = _connectionHandle;

  BlueNRGGattClient::getInstance().processWriteResponse(&writeCBParams);
}

ble_error_t BlueNRGGattConnectionClient::write(GattClient::WriteOp_t    cmd,
                                     GattAttribute::Handle_t  attributeHandle,
                                     size_t                   length,
                                     const uint8_t           *value) const
{
  /* avoid compiler warnings about unused variables */
  (void)cmd;

  tBleStatus ret;

  BlueNRGGattConnectionClient *gattc = const_cast<BlueNRGGattConnectionClient*>(this);

  // We save the write response params (used by the callback) because
  // when the aci_gatt_write_charac_value() is used the only event received is the EVT_BLUE_GATT_PROCEDURE_COMPLETE
  gattc->writeCBParams.connHandle = _connectionHandle;
  gattc->writeCBParams.writeOp = GattWriteCallbackParams::OP_WRITE_CMD;
  gattc->writeCBParams.handle = attributeHandle;
  gattc->writeCBParams.offset = 0;
  gattc->writeCBParams.len = length;
  gattc->writeCBParams.data = value;

  ret = aci_gatt_write_charac_value(_connectionHandle, attributeHandle, length, const_cast<uint8_t *>(value));

  if (ret == BLE_STATUS_SUCCESS) {
    gattc->_currentState = GATT_WRITE_CHAR;
    return BLE_ERROR_NONE;
  }
  switch (ret) {
  case ERR_CONTROLLER_BUSY:
    return BLE_STACK_BUSY;
  default:
    return BLE_ERROR_INVALID_STATE;
  }

}

void BlueNRGGattConnectionClient::discAllCharacDescCB(uint8_t event_data_length,
                                                      uint8_t format,
                                                      uint8_t *handle_uuid_pair) {
  GattAttribute::Handle_t attHandle;
  UUID uuid;
  uint8_t i, numCharacDesc, offset, handle_uuid_length;

  handle_uuid_length = 4; //Handle + UUID_16
  if (format == 2)
    handle_uuid_length = 18; //Handle + UUID_128

  numCharacDesc = (event_data_length - 1) / handle_uuid_length;

  offset = 0;

  PRINTF("\r\ncharacteristic descriptor discovered: data length %u, format %u\r\n",
    event_data_length, format);


  for (i=0; i<numCharacDesc; i++) {
    memcpy(&attHandle, handle_uuid_pair + offset, sizeof(attHandle));

    // UUID Type
    if (handle_uuid_length == 4) {

      PRINTF("UUID_TYPE_16\n\r");
      uuid = handle_uuid_pair[offset+3]<<8|handle_uuid_pair[offset+2];
      PRINTF("D UUID-%X attHandle=%u\r\n", uuid.getShortUUID(), attHandle);

    } else {

      PRINTF("UUID_TYPE_128\n\r");
      uuid.setupLong(handle_uuid_pair+offset+2, UUID::LSB);
#ifdef DEBUG
      PRINTF("D UUID-");
      const uint8_t *longUUIDBytes = uuid.getBaseUUID();
      for (unsigned j = 0; j < UUID::LENGTH_OF_LONG_UUID; j++) {
        PRINTF("%02x", longUUIDBytes[j]);
      }
#endif
     }

     if(charDescDiscoveryCallback != NULL) {
       CharacteristicDescriptorDiscovery::DiscoveryCallbackParams_t params = {
                                 _characteristic,
                                 DiscoveredCharacteristicDescriptor(
                                   _characteristic.getGattClient(),
                                   _connectionHandle,
                                   attHandle,
                                   uuid
                                 )
       };
       charDescDiscoveryCallback(&params);
     }

    _numCharDesc++;

    offset += handle_uuid_length;
  }
}

ble_error_t BlueNRGGattConnectionClient::discoverCharacteristicDescriptors(
        const DiscoveredCharacteristic& characteristic,
        const CharacteristicDescriptorDiscovery::DiscoveryCallback_t& discoveryCallback,
        const CharacteristicDescriptorDiscovery::TerminationCallback_t& terminationCallback) {

  tBleStatus ret;

  if(_currentState != GATT_IDLE) {
    return BLE_ERROR_OPERATION_NOT_PERMITTED;
  }

  charDescDiscoveryCallback = discoveryCallback;
  charDescTerminationCallback = terminationCallback;

  GattAttribute::Handle_t valueHandle = characteristic.getValueHandle();
  GattAttribute::Handle_t lastHandle = characteristic.getLastHandle();

  PRINTF("Starting aci_gatt_disc_all_charac_descriptors... [%u : %u]\n\r", valueHandle, lastHandle);
  ret = aci_gatt_disc_all_charac_descriptors(_connectionHandle, valueHandle, lastHandle);

  if (ret == BLE_STATUS_SUCCESS) {
    _currentState = GATT_CHAR_DESC_DISCOVERY;
    _characteristic = characteristic;
    return BLE_ERROR_NONE;
  }
  switch (ret) {
  case BLE_STATUS_INVALID_PARAMS:
    return BLE_ERROR_INVALID_PARAM;
  default:
    return BLE_ERROR_OPERATION_NOT_PERMITTED;
  }
}

/**************************************************************************/
/*!
    @brief  Clear BlueNRGGattServer's state.

    @returns    ble_error_t

    @retval     BLE_ERROR_NONE
                Everything executed properly
*/
/**************************************************************************/
ble_error_t BlueNRGGattConnectionClient::reset(void) {
  PRINTF("BlueNRGGattConnectionClient::reset\n");

  /* Clear all state, including private members */

  _currentState = GATT_IDLE;
  _matchingServiceUUID = BLE_UUID_UNKNOWN;
  _matchingCharacteristicUUIDIn = BLE_UUID_UNKNOWN;

  _numServices = 0;
  _servIndex = 0;
  _numChars = 0;
  _numCharDesc = 0;

  /* Clear class members */
  memset(discoveredService, 0, sizeof(discoveredService));
  memset(discoveredChar, 0, sizeof(discoveredChar));

  // free response if allocated
  if(readCBParams.data) {
    free((void*)(readCBParams.data));
  }

  return BLE_ERROR_NONE;
}