mqtt-msg.h

/*
 * Copyright (c) 2014, Stephen Robinson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 *  are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holder nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <stdint.h>

#ifndef MQTT_MSG_H_
#define MQTT_MSG_H_

enum mqtt_message_type
{
  MQTT_MSG_TYPE_CONNECT     = 1,
  MQTT_MSG_TYPE_CONNACK     = 2,
  MQTT_MSG_TYPE_PUBLISH     = 3,
  MQTT_MSG_TYPE_PUBACK      = 4,
  MQTT_MSG_TYPE_PUBREC      = 5,
  MQTT_MSG_TYPE_PUBREL      = 6,
  MQTT_MSG_TYPE_PUBCOMP     = 7,
  MQTT_MSG_TYPE_SUBSCRIBE   = 8,
  MQTT_MSG_TYPE_SUBACK      = 9,
  MQTT_MSG_TYPE_UNSUBSCRIBE = 10,
  MQTT_MSG_TYPE_UNSUBACK    = 11,
  MQTT_MSG_TYPE_PINGREQ     = 12,
  MQTT_MSG_TYPE_PINGRESP    = 13,
  MQTT_MSG_TYPE_DISCONNECT  = 14
};

typedef struct
{
  uint8_t* data;
  uint16_t length;

} mqtt_message_t;

typedef struct
{
  mqtt_message_t message;

  uint16_t message_id;
  uint8_t* buffer;
  uint16_t buffer_length;

} mqtt_connection_t;

typedef struct mqtt_connect_info
{
  const char* client_id;
  const char* username;
  const char* password;
  const char* will_topic;
  const char* will_message;
  int keepalive;
  int will_qos;
  int will_retain;
  int clean_session;

} mqtt_connect_info_t;


static inline int mqtt_get_type(uint8_t* buffer)   { return (buffer[0] & 0xf0) >> 4; }
static inline int mqtt_get_dup(uint8_t* buffer)    { return (buffer[0] & 0x08) >> 3; }
static inline int mqtt_get_qos(uint8_t* buffer)    { return (buffer[0] & 0x06) >> 1; }
static inline int mqtt_get_retain(uint8_t* buffer) { return (buffer[0] & 0x01); }

void mqtt_msg_init(mqtt_connection_t* connection, uint8_t* buffer, uint16_t buffer_length);
int mqtt_get_total_length(uint8_t* buffer, uint16_t length);
const char* mqtt_get_publish_topic(uint8_t* buffer, uint16_t* length);
const char* mqtt_get_publish_data(uint8_t* buffer, uint16_t* length);
uint16_t mqtt_get_id(uint8_t* buffer, uint16_t length);

mqtt_message_t* mqtt_msg_connect(mqtt_connection_t* connection, mqtt_connect_info_t* info);
mqtt_message_t* mqtt_msg_publish(mqtt_connection_t* connection, const char* topic, const char* data, int data_length, int qos, int retain, uint16_t* message_id);
mqtt_message_t* mqtt_msg_puback(mqtt_connection_t* connection, uint16_t message_id);
mqtt_message_t* mqtt_msg_pubrec(mqtt_connection_t* connection, uint16_t message_id);
mqtt_message_t* mqtt_msg_pubrel(mqtt_connection_t* connection, uint16_t message_id);
mqtt_message_t* mqtt_msg_pubcomp(mqtt_connection_t* connection, uint16_t message_id);
mqtt_message_t* mqtt_msg_subscribe(mqtt_connection_t* connection, const char* topic, int qos, uint16_t* message_id);
mqtt_message_t* mqtt_msg_unsubscribe(mqtt_connection_t* connection, const char* topic, uint16_t* message_id);
mqtt_message_t* mqtt_msg_pingreq(mqtt_connection_t* connection);
mqtt_message_t* mqtt_msg_pingresp(mqtt_connection_t* connection);
mqtt_message_t* mqtt_msg_disconnect(mqtt_connection_t* connection);

#endif