OpenLCP/rdm/responder.cpp

/*
  responder.cpp

  Copyright (c) 2021 Kevin Matz (kevin.matz@gmail.com)

  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/
#include "responder.h"

#include <limits>

namespace RDM {

/**
 * @brief Responder::Responder
 */
Responder::Responder()
  : Device()
{
  deviceModelID = 1;
  deviceModelDescription = "Basic RDM Responder";

//  /// Category – Network Management
//  static const PID DISC_UNIQUE_BRANCH    = 0x0001;
//  static const PID DISC_MUTE             = 0x0002;
//  static const PID DISC_UN_MUTE          = 0x0003;
//  static const PID PROXIED_DEVICES       = 0x0010;
//  static const PID PROXIED_DEVICE_COUNT  = 0x0011;
//  static const PID COMMS_STATUS          = 0x0015;
//  /// Category - Status Collection
//  static const PID QUEUED_MESSAGE        = 0x0020; // See Table A-4
//  static const PID STATUS_MESSAGES       = 0x0030; // See Table A-4
//  static const PID STATUS_ID_DESCRIPTION = 0x0031;
//  static const PID CLEAR_STATUS_ID       = 0x0032;
//  static const PID SUB_DEVICE_STATUS_REPORT_THRESHOLD = 0x0033; // See Table A-4
}


/**
 * @brief Responder::~Responder
 */
Responder::~Responder()
{
}


/**
 * @brief Responder::send
 * @param data
 */
void Responder::send(__attribute__((unused)) const std::vector<uint8_t> &data)
{

}


/**
 * @brief Responder::send
 * @param message
 */
void Responder::send(Message *response)
{
  if (!response)
    return;

  // 6.2.8.2 Message Count field for Responder Generated Messages
  // If a responder has more than 255 messages queued, then the Message Count
  // field shall remain at 255 until the number of queued messages is reduced
  // below that number.
  if (queued_messages_.size() > std::numeric_limits<uint8_t>::max())
    response->messageCount = std::numeric_limits<uint8_t>::max();
  else
    response->messageCount = queued_messages_.size();

  std::vector<uint8_t> data;
  response->write(data);
  send(data);
  delete response;
  response = nullptr;
}


/**
 * @brief Responder::receive
 * @param data
 */
void Responder::receive(const std::vector<uint8_t> &data)
{
  auto message = new Message(data);
  receive(message);
  delete message;
}


/**
 * @brief Responder::receive
 * @param message
 */
void Responder::receive(const Message *message)
{
  if (message->short_message)
    {
      if (short_message_counter_ != std::numeric_limits<uint16_t>::max())
        short_message_counter_++;
      return;
    }

  // RDM::UID::operator== also returns true for broadcast messages
  if (message->destination != id ||
      message->incorrect_sc ||
      message->incorrect_sub_sc)
    return;

  if (message->length_mismatch)
    {
      if (length_mismatch_counter_ != std::numeric_limits<uint16_t>::max())
        length_mismatch_counter_++;
      return;
    }

  if (message->checksum_fail)
    {
      if (checksum_fail_counter_ != std::numeric_limits<uint16_t>::max())
        checksum_fail_counter_++;
      return;
    }

  // all other uncaught errors
  if (message->failure_mode != 0)
    return;

  // responder can ignore _COMMAND_RESPONSE class messages
  if (message->commandClass == DISCOVERY_COMMAND_RESPONSE ||
      message->commandClass == GET_COMMAND_RESPONSE ||
      message->commandClass == SET_COMMAND_RESPONSE)
    return;

  auto response = new Message();
  response->source = id;
  response->destination = message->source;
  response->subDevice = message->subDevice;
  response->propertyID = message->propertyID;
  response->transaction = message->transaction;

  switch (message->commandClass) {
    case DISCOVERY_COMMAND:
      rxDiscovery(message, response);
      break;
    case GET_COMMAND:
      rxGet(message, response);
      break;
    case SET_COMMAND:
      rxSet(message, response);
      break;
    default:
      delete response;
      return;
  }

  if (!response)
    return;

  /// 5.3 Broadcast Message Addressing
  /// When Broadcast Addressing is used for non-Discovery messages, the
  /// responders shall not send a response.
  if (message->destination.isBroadcast() &&
      message->commandClass != DISCOVERY_COMMAND)
    {
      delete response;
      return;
    }

  if (response->do_no_send)
    {
      delete response;
      return;
    }

  queued_messages_.push(response);
}


/**
 * @brief Responder::reset
 * @param hard
 */
void Responder::reset(bool hard)
{
  (void)hard;

  /// 10.11.2 Reset Device (RESET_DEVICE)
  /// This parameter shall also clear the Discovery Mute flag.
  discovery_mute_flag_ = false;
}


/**
 * @brief Responder::rxDiscovery
 * @param message
 */
void Responder::rxDiscovery(__attribute__((unused)) const Message *message,
                            Message* response)
{
  response->commandClass = DISCOVERY_COMMAND_RESPONSE;
}


/**
 * @brief Responder::rxGet
 * @param message
 */
void Responder::rxGet(const Message *message, Message* response)
{
  // 9.2.2 Using Sub-Devices
  // Broadcast GET commands sent to the SUB_DEVICE_ALL_CALL Sub-Device ID are
  // not allowed. Any responder receiving a GET command sent to this Sub-Device
  // ID shall respond with a NACK with a NACK Reason Code of
  // NR_SUB_DEVICE_OUT_OF_RANGE.
  if (message->subDevice == SUB_DEVICE_ALL_CALL)
    {
      response->nak(NR_SUB_DEVICE_OUT_OF_RANGE);
      return;
    }

  if (message->subDevice == 0)
    {
      get(message, response);
      return;
    }

  if (!sub_devices_.count(message->subDevice))
    {
      response->nak(NR_SUB_DEVICE_OUT_OF_RANGE);
      return;
    }

  sub_devices_.at(message->subDevice)->get(message, response);
}


/**
 * @brief Responder::rxSet
 * @param message
 */
void Responder::rxSet(const Message *message, Message* response)
{
  if (message->subDevice == 0)
    {
      set(message, response);
      return;
    }

  if (message->subDevice == SUB_DEVICE_ALL_CALL)
    {
      for (auto& [num, dev] : sub_devices_)
        {
          Message * rsp = new Message(*response);
          rsp->subDevice = num;
          dev->set(message, rsp);
          if (message->destination.isBroadcast())
            delete rsp;
          else
            queued_messages_.push(rsp);
        }
      response->do_no_send = true;
      return;
    }

  if (!sub_devices_.count(message->subDevice))
    {
      response->nak(NR_SUB_DEVICE_OUT_OF_RANGE);
      return;
    }

  sub_devices_.at(message->subDevice)->set(message, response);
}


} // namespace RDM