ArduinoIoTCloudTCP.cpp

/*
   This file is part of ArduinoIoTCloud.

   Copyright 2019 ARDUINO SA (http://www.arduino.cc/)

   This software is released under the GNU General Public License version 3,
   which covers the main part of arduino-cli.
   The terms of this license can be found at:
   https://www.gnu.org/licenses/gpl-3.0.en.html

   You can be released from the requirements of the above licenses by purchasing
   a commercial license. Buying such a license is mandatory if you want to modify or
   otherwise use the software for commercial activities involving the Arduino
   software without disclosing the source code of your own applications. To purchase
   a commercial license, send an email to license@arduino.cc.
*/

/******************************************************************************
 * INCLUDE
 ******************************************************************************/

#include <ArduinoIoTCloud_Config.h>

#ifdef HAS_TCP
#include <ArduinoIoTCloudTCP.h>
#include "utility/time/TimeService.h"
#ifdef BOARD_HAS_ECCX08
  #include "tls/BearSSLTrustAnchors.h"
  #include "tls/utility/CryptoUtil.h"
#endif

#include "utility/ota/OTAStorage_SSU.h"
#include "utility/ota/OTAStorage_SFU.h"

#include "cbor/CBOREncoder.h"

/******************************************************************************
   GLOBAL VARIABLES
 ******************************************************************************/

TimeService time_service;

#if   OTA_STORAGE_SSU
  static OTAStorage_SSU ota_storage_ssu;
#elif OTA_STORAGE_SFU
  static OTAStorage_SFU ota_storage_sfu;
#endif

/******************************************************************************
   GLOBAL CONSTANTS
 ******************************************************************************/

static const int TIMEOUT_FOR_LASTVALUES_SYNC = 10000;

const static int CONNECT_SUCCESS							               = 1;
const static int CONNECT_FAILURE							               = 0;
const static int CONNECT_FAILURE_SUBSCRIBE					         = -1;

/******************************************************************************
   LOCAL MODULE FUNCTIONS
 ******************************************************************************/

extern "C" unsigned long getTime()
{
  return time_service.getTime();
}

/******************************************************************************
   CTOR/DTOR
 ******************************************************************************/

ArduinoIoTCloudTCP::ArduinoIoTCloudTCP()
: _lastSyncRequestTickTime{0}
, _mqtt_data_buf{0}
, _mqtt_data_len{0}
, _mqtt_data_request_retransmit{false}
#ifdef BOARD_HAS_ECCX08
, _sslClient(nullptr, ArduinoIoTCloudTrustAnchor, ArduinoIoTCloudTrustAnchor_NUM, getTime)
#endif
  #ifdef BOARD_ESP
, _password("")
  #endif
, _mqttClient{nullptr}
, _syncStatus{ArduinoIoTSynchronizationStatus::SYNC_STATUS_SYNCHRONIZED}
, _stdinTopic("")
, _stdoutTopic("")
, _shadowTopicOut("")
, _shadowTopicIn("")
, _dataTopicOut("")
, _dataTopicIn("")
, _ota_topic_in{""}
#if OTA_ENABLED
, _ota_error{static_cast<int>(OTAError::None)}
#endif /* OTA_ENABLED */
{

}

/******************************************************************************
 * PUBLIC MEMBER FUNCTIONS
 ******************************************************************************/

int ArduinoIoTCloudTCP::begin(ConnectionHandler & connection, String brokerAddress, uint16_t brokerPort)
{
  _connection = &connection;
  _brokerAddress = brokerAddress;
  _brokerPort = brokerPort;
  time_service.begin(&connection);
  return begin(_brokerAddress, _brokerPort);
}

int ArduinoIoTCloudTCP::begin(String brokerAddress, uint16_t brokerPort)
{

  _brokerAddress = brokerAddress;
  _brokerPort = brokerPort;

  #ifdef BOARD_HAS_ECCX08
  if (!ECCX08.begin())                                                                                                                                                         { Debug.print(DBG_ERROR, "Cryptography processor failure. Make sure you have a compatible board."); return 0; }
  if (!CryptoUtil::readDeviceId(ECCX08, getDeviceId(), ECCX08Slot::DeviceId))                                                                                                  { Debug.print(DBG_ERROR, "Cryptography processor read failure."); return 0; }
  if (!CryptoUtil::reconstructCertificate(_eccx08_cert, getDeviceId(), ECCX08Slot::Key, ECCX08Slot::CompressedCertificate, ECCX08Slot::SerialNumberAndAuthorityKeyIdentifier)) { Debug.print(DBG_ERROR, "Cryptography certificate reconstruction failure."); return 0; }
  _sslClient.setClient(_connection->getClient());
  _sslClient.setEccSlot(static_cast<int>(ECCX08Slot::Key), _eccx08_cert.bytes(), _eccx08_cert.length());
  #elif defined(BOARD_ESP)
  _sslClient.setInsecure();
  #endif

  _mqttClient.setClient(_sslClient);
  #ifdef BOARD_ESP
  _mqttClient.setUsernamePassword(getDeviceId(), _password);
  #endif
  _mqttClient.onMessage(ArduinoIoTCloudTCP::onMessage);
  _mqttClient.setKeepAliveInterval(30 * 1000);
  _mqttClient.setConnectionTimeout(1500);
  _mqttClient.setId(getDeviceId().c_str());

  _stdinTopic     = getTopic_stdin();
  _stdoutTopic    = getTopic_stdout();
  _shadowTopicOut = getTopic_shadowout();
  _shadowTopicIn  = getTopic_shadowin();
  _dataTopicOut   = getTopic_dataout();
  _dataTopicIn    = getTopic_datain();
  _ota_topic_in   = getTopic_ota_in();

  printConnectionStatus(_iot_status);

#if   OTA_STORAGE_SSU
  setOTAStorage(ota_storage_ssu);
#elif OTA_STORAGE_SFU
  setOTAStorage(ota_storage_sfu);
#endif

  return 1;
}

void ArduinoIoTCloudTCP::update()
{
#if OTA_ENABLED
  /* If a _ota_logic object has been instantiated then we are spinning its
   * 'update' method here in order to process incoming data and generally
   * to transition to the OTA logic update states.
   */
  OTAError const err = _ota_logic.update();
  _ota_error = static_cast<int>(err);
#endif /* OTA_ENABLED */

  if(checkPhyConnection()   != NetworkConnectionState::CONNECTED)     return;
  if(checkCloudConnection() != ArduinoIoTConnectionStatus::CONNECTED) return;

  /* Check if a primitive property wrapper is locally changed.
   * This function requires an existing time service which in
   * turn requires an established connection. Not having that
   * leads to a wrong time set in the time service which inhibits
   * the connection from being established due to a wrong data
   * in the reconstructed certificate.
   */
  updateTimestampOnLocallyChangedProperties(_property_container);

  if(_mqtt_data_request_retransmit && (_mqtt_data_len > 0)) {
    write(_dataTopicOut, _mqtt_data_buf, _mqtt_data_len);
    _mqtt_data_request_retransmit = false;
  }

  // MTTQClient connected!, poll() used to retrieve data from MQTT broker
  _mqttClient.poll();

  switch (_syncStatus)
  {
    case ArduinoIoTSynchronizationStatus::SYNC_STATUS_SYNCHRONIZED: sendPropertiesToCloud(); break;

    case ArduinoIoTSynchronizationStatus::SYNC_STATUS_WAIT_FOR_CLOUD_VALUES:
    {
      if (millis() - _lastSyncRequestTickTime > TIMEOUT_FOR_LASTVALUES_SYNC)
      {
        requestLastValue();
        _lastSyncRequestTickTime = millis();
      }
    }
    break;

    case ArduinoIoTSynchronizationStatus::SYNC_STATUS_VALUES_PROCESSED:
    {
      execCloudEventCallback(ArduinoIoTCloudEvent::SYNC);
      _syncStatus = ArduinoIoTSynchronizationStatus::SYNC_STATUS_SYNCHRONIZED;
    }
    break;
  }
}

int ArduinoIoTCloudTCP::connected()
{
  return _mqttClient.connected();
}

void ArduinoIoTCloudTCP::printDebugInfo()
{
  Debug.print(DBG_INFO, "***** Arduino IoT Cloud - configuration info *****");
  Debug.print(DBG_INFO, "Device ID: %s", getDeviceId().c_str());
  Debug.print(DBG_INFO, "Thing ID: %s", getThingId().c_str());
  Debug.print(DBG_INFO, "MQTT Broker: %s:%d", _brokerAddress.c_str(), _brokerPort);
}

#if OTA_ENABLED
void ArduinoIoTCloudTCP::setOTAStorage(OTAStorage & ota_storage)
{
  addPropertyReal(_ota_error, "OTA_ERROR", Permission::Read);
  _ota_logic.setOTAStorage(ota_storage);
}
#endif /* OTA_ENABLED */

int ArduinoIoTCloudTCP::reconnect()
{
  if (_mqttClient.connected()) {
    _mqttClient.stop();
  }
  return connect();
}

/******************************************************************************
 * PROTECTED MEMBER FUNCTIONS
 ******************************************************************************/

int ArduinoIoTCloudTCP::connect()
{
  if (!_mqttClient.connect(_brokerAddress.c_str(), _brokerPort)) return CONNECT_FAILURE;
  if (_mqttClient.subscribe(_stdinTopic) == 0)                   return CONNECT_FAILURE_SUBSCRIBE;
  if (_mqttClient.subscribe(_dataTopicIn) == 0)                  return CONNECT_FAILURE_SUBSCRIBE;
  if (_mqttClient.subscribe(_ota_topic_in) == 0)                 return CONNECT_FAILURE_SUBSCRIBE;

  if (_shadowTopicIn != "")
  {
    if (_mqttClient.subscribe(_shadowTopicIn) == 0)              return CONNECT_FAILURE_SUBSCRIBE;
    _syncStatus = ArduinoIoTSynchronizationStatus::SYNC_STATUS_WAIT_FOR_CLOUD_VALUES;
    _lastSyncRequestTickTime = 0;
  }

  return CONNECT_SUCCESS;
}

void ArduinoIoTCloudTCP::disconnect()
{
  _mqttClient.stop();
}

/******************************************************************************
 * PRIVATE MEMBER FUNCTIONS
 ******************************************************************************/

void ArduinoIoTCloudTCP::onMessage(int length)
{
  ArduinoCloud.handleMessage(length);
}

void ArduinoIoTCloudTCP::handleMessage(int length)
{
  String topic = _mqttClient.messageTopic();

  byte bytes[length];

  for (int i = 0; i < length; i++) {
    bytes[i] = _mqttClient.read();
  }

  if (_stdinTopic == topic) {
    CloudSerial.appendStdin((uint8_t*)bytes, length);
  }
  if (_dataTopicIn == topic) {
    CBORDecoder::decode(_property_container, (uint8_t*)bytes, length);
  }
  if ((_shadowTopicIn == topic) && _syncStatus == ArduinoIoTSynchronizationStatus::SYNC_STATUS_WAIT_FOR_CLOUD_VALUES) {
    CBORDecoder::decode(_property_container, (uint8_t*)bytes, length, true);
    sendPropertiesToCloud();
    _syncStatus = ArduinoIoTSynchronizationStatus::SYNC_STATUS_VALUES_PROCESSED;
  }
#if OTA_ENABLED
  if (_ota_topic_in == topic) {
    _ota_logic.onOTADataReceived(bytes, length);
  }
#endif /* OTA_ENABLED */
}

void ArduinoIoTCloudTCP::sendPropertiesToCloud()
{
  int bytes_encoded = 0;
  uint8_t data[MQTT_TRANSMIT_BUFFER_SIZE];

  if (CBOREncoder::encode(_property_container, data, sizeof(data), bytes_encoded, false) == CborNoError)
    if (bytes_encoded > 0)
    {
      /* If properties have been encoded store them in the back-up buffer
       * in order to allow retransmission in case of failure.
       */
      _mqtt_data_len = bytes_encoded;
      memcpy(_mqtt_data_buf, data, _mqtt_data_len);
      /* Transmit the properties to the MQTT broker */
      write(_dataTopicOut, _mqtt_data_buf, _mqtt_data_len);
    }
}

void ArduinoIoTCloudTCP::requestLastValue()
{
  // Send the getLastValues CBOR message to the cloud
  // [{0: "r:m", 3: "getLastValues"}] = 81 A2 00 63 72 3A 6D 03 6D 67 65 74 4C 61 73 74 56 61 6C 75 65 73
  // Use http://cbor.me to easily generate CBOR encoding
  const uint8_t CBOR_REQUEST_LAST_VALUE_MSG[] = { 0x81, 0xA2, 0x00, 0x63, 0x72, 0x3A, 0x6D, 0x03, 0x6D, 0x67, 0x65, 0x74, 0x4C, 0x61, 0x73, 0x74, 0x56, 0x61, 0x6C, 0x75, 0x65, 0x73 };
  write(_shadowTopicOut, CBOR_REQUEST_LAST_VALUE_MSG, sizeof(CBOR_REQUEST_LAST_VALUE_MSG));
}

ArduinoIoTConnectionStatus ArduinoIoTCloudTCP::checkCloudConnection()
{
  ArduinoIoTConnectionStatus next_iot_status = _iot_status;

  switch (_iot_status)
  {
    case ArduinoIoTConnectionStatus::IDLE:         next_iot_status = ArduinoIoTConnectionStatus::CONNECTING;   break;
    case ArduinoIoTConnectionStatus::ERROR:        next_iot_status = ArduinoIoTConnectionStatus::RECONNECTING; break;
    case ArduinoIoTConnectionStatus::DISCONNECTED: next_iot_status = ArduinoIoTConnectionStatus::RECONNECTING; break;
    case ArduinoIoTConnectionStatus::CONNECTING:
    {
      Debug.print(DBG_INFO, "Arduino IoT Cloud connecting ...");
      int const ret = connect();
      if (ret == CONNECT_SUCCESS)
      {
        next_iot_status = ArduinoIoTConnectionStatus::CONNECTED;
        CloudSerial.begin(9600);
        CloudSerial.println("Hello from Cloud Serial!");
      }
      else if (ret == CONNECT_FAILURE_SUBSCRIBE)
      {
        Debug.print(DBG_ERROR, "ERROR - Please verify your THING ID");
      }
    }
    break;

    case ArduinoIoTConnectionStatus::RECONNECTING:
    {
      Debug.print(DBG_INFO, "Arduino IoT Cloud reconnecting ...");
      if (reconnect() == CONNECT_SUCCESS)
      {
        next_iot_status = ArduinoIoTConnectionStatus::CONNECTED;
        CloudSerial.begin(9600);
        CloudSerial.println("Hello from Cloud Serial!");
      }
    }
    break;

    case ArduinoIoTConnectionStatus::CONNECTED:
    {
      if (!_mqttClient.connected())
      {
        next_iot_status = ArduinoIoTConnectionStatus::DISCONNECTED;
        _mqtt_data_request_retransmit = true;
      }
    }
    break;
  }

  if(next_iot_status != _iot_status)
  {
    printConnectionStatus(next_iot_status);
    if     (next_iot_status == ArduinoIoTConnectionStatus::DISCONNECTED) execCloudEventCallback(ArduinoIoTCloudEvent::DISCONNECT);
    else if(next_iot_status == ArduinoIoTConnectionStatus::CONNECTED)    execCloudEventCallback(ArduinoIoTCloudEvent::CONNECT);
    _iot_status = next_iot_status;
  }

  return _iot_status;
}

int ArduinoIoTCloudTCP::write(String const topic, byte const data[], int const length)
{
  if (_mqttClient.beginMessage(topic, length, false, 0)) {
    if (_mqttClient.write(data, length)) {
      if (_mqttClient.endMessage()) {
        return 1;
      }
    }
  }
  return 0;
}

/******************************************************************************
 * EXTERN DEFINITION
 ******************************************************************************/

ArduinoIoTCloudTCP ArduinoCloud;

#endif