ArduinoIoTCloudTCP.h

/*
   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.
*/

#ifndef ARDUINO_IOT_CLOUD_TCP_H
#define ARDUINO_IOT_CLOUD_TCP_H

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

#include <AIoTC_Config.h>
#include <ArduinoIoTCloud.h>
#include <ArduinoMqttClient.h>
#include <ArduinoIoTCloudThing.h>
#include <ArduinoIoTCloudDevice.h>

#if defined(BOARD_HAS_SECURE_ELEMENT)
  #include <Arduino_SecureElement.h>
  #include <utility/SElementArduinoCloudDeviceId.h>
  #include <utility/SElementArduinoCloudCertificate.h>
#endif

#include <tls/utility/TLSClientMqtt.h>
#include <tls/utility/TLSClientOta.h>

#if OTA_ENABLED
  #include <ota/OTA.h>
#endif

#include "cbor/MessageDecoder.h"
#include "cbor/MessageEncoder.h"

/******************************************************************************
   CONSTANTS
 ******************************************************************************/
static constexpr char DEFAULT_BROKER_ADDRESS[] = "iot.arduino.cc";
static constexpr uint16_t DEFAULT_BROKER_PORT_SECURE_AUTH = 8885;
static constexpr uint16_t DEPRECATED_BROKER_PORT_SECURE_AUTH = 8883;
static constexpr uint8_t DEPRECATED_BROKER_AUTHORITY_KEY_IDENTIFIER[] = {
                  0x5b, 0x3e, 0x2a, 0x6b, 0x8e, 0xc9, 0xb0, 0x1a, 0xa8, 0x54,
                  0xe6, 0x36, 0x9b, 0x8c, 0x09, 0xf9, 0xfc, 0xe1, 0xb9, 0x80 };
static constexpr uint16_t DEFAULT_BROKER_PORT_USER_PASS_AUTH = 8884;
static constexpr uint16_t DEFAULT_BROKER_PORT_AUTO = 0;

/******************************************************************************
 * TYPEDEF
 ******************************************************************************/

typedef bool (*onOTARequestCallbackFunc)(void);

/******************************************************************************
 * CLASS DECLARATION
 ******************************************************************************/

class ArduinoIoTCloudTCP: public ArduinoIoTCloudClass
{
  public:

             ArduinoIoTCloudTCP();
    virtual ~ArduinoIoTCloudTCP() { }

    virtual void update        () override;
    virtual int  connected     () override;
    virtual void printDebugInfo() override;

    int begin(ConnectionHandler & connection, bool const enable_watchdog = true, String brokerAddress = DEFAULT_BROKER_ADDRESS, uint16_t brokerPort = DEFAULT_BROKER_PORT_AUTO);
    int begin(bool const enable_watchdog = true, String brokerAddress = DEFAULT_BROKER_ADDRESS, uint16_t brokerPort = DEFAULT_BROKER_PORT_AUTO);

#if defined(BOARD_HAS_SECURE_ELEMENT)
    int updateCertificate(String authorityKeyIdentifier, String serialNumber, String notBefore, String notAfter, String signature);
#endif

#ifdef BOARD_HAS_SECRET_KEY
    inline void setBoardId        (String const device_id) { setDeviceId(device_id); }
    inline void setSecretDeviceKey(String const password)  { _password = password;  }
#endif

    inline String   getBrokerAddress() const { return _brokerAddress; }
    inline uint16_t getBrokerPort   () const { return _brokerPort; }

    inline PropertyContainer &getThingPropertyContainer() { return _thing.getPropertyContainer(); }

#if OTA_ENABLED
    /* The callback is triggered when the OTA is initiated and it gets executed until _ota_req flag is cleared.
     * It should return true when the OTA can be applied or false otherwise.
     * See example ArduinoIoTCloud-DeferredOTA.ino
     */
    void onOTARequestCb(onOTARequestCallbackFunc cb) {
      _get_ota_confirmation = cb;

      if(_get_ota_confirmation) {
        _ota.enableOtaPolicy(OTACloudProcessInterface::ApprovalRequired);
      } else {
        _ota.disableOtaPolicy(OTACloudProcessInterface::ApprovalRequired);
      }
    }

    /* Slower but more reliable in some corner cases */
    void setOTAChunkMode(bool enable = true) {
      if(enable) {
        _ota.enableOtaPolicy(OTACloudProcessInterface::ChunkDownload);
      } else {
        _ota.disableOtaPolicy(OTACloudProcessInterface::ChunkDownload);
      }
    }
#endif

  private:
    static const int MQTT_TRANSMIT_BUFFER_SIZE = 256;

    enum class State
    {
      ConnectPhy,
      SyncTime,
      ConnectMqttBroker,
      Connected,
      Disconnect,
    };

    State _state;
    TimedAttempt _connection_attempt;
    MessageStream _message_stream;
    ArduinoCloudThing _thing;
    ArduinoCloudDevice _device;

    String _brokerAddress;
    uint16_t _brokerPort;
    uint8_t _mqtt_data_buf[MQTT_TRANSMIT_BUFFER_SIZE];
    int _mqtt_data_len;
    bool _mqtt_data_request_retransmit;

#if defined(BOARD_HAS_SECRET_KEY)
    String _password;
#endif

#if defined(BOARD_HAS_SECURE_ELEMENT)
    SecureElement _selement;
    ECP256Certificate _cert;
    /* Flag used to store updated device certificate after broker connection has succeeded */
    bool _writeCertOnConnect;
#endif

    TLSClientMqtt _brokerClient;
    MqttClient _mqttClient;

    String _messageTopicOut;
    String _messageTopicIn;
    String _dataTopicOut;
    String _dataTopicIn;

#if OTA_ENABLED
    TLSClientOta _otaClient;
    ArduinoCloudOTA _ota;
    onOTARequestCallbackFunc _get_ota_confirmation;
#endif /* OTA_ENABLED */

    inline String getTopic_messageout() { return String("/a/d/" + getDeviceId() + "/c/up");}
    inline String getTopic_messagein () { return String("/a/d/" + getDeviceId() + "/c/dw");}

    inline String getTopic_dataout  () { return ( getThingId().length() == 0) ? String("") : String("/a/t/" + getThingId() + "/e/o"); }
    inline String getTopic_datain   () { return ( getThingId().length() == 0) ? String("") : String("/a/t/" + getThingId() + "/e/i"); }

    State handle_ConnectPhy();
    State handle_SyncTime();
    State handle_ConnectMqttBroker();
    State handle_Connected();
    State handle_Disconnect();

    static void onMessage(int length);
    void handleMessage(int length);
    void sendMessage(Message * msg);
    void sendPropertyContainerToCloud(String const topic, PropertyContainer & property_container, unsigned int & current_property_index);

    void attachThing(String thingId);
    void detachThing();
    int write(String const topic, byte const data[], int const length);

#if defined(BOARD_HAS_SECURE_ELEMENT)
    int mqttPort();
#endif

};

/******************************************************************************
 * EXTERN DECLARATION
 ******************************************************************************/

extern ArduinoIoTCloudTCP ArduinoCloud;

#endif