esp-mqtt/lib/include/mqtt_msg.h

#ifndef MQTT_MSG_H
#define MQTT_MSG_H
#include <stdint.h>
#include <stdbool.h>

#include "mqtt_config.h"
#include "mqtt_client.h"
#ifdef  __cplusplus
extern "C" {
#endif

/*
* 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.
*
*/
/* 7      6     5     4     3     2     1     0 */
/*|      --- Message Type----     |  DUP Flag |    QoS Level    | Retain  | */
/*                    Remaining Length                 */


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 mqtt_message {
    uint8_t *data;
    size_t length;
    size_t fragmented_msg_total_length;       /*!< total len of fragmented messages (zero for all other messages) */
    size_t fragmented_msg_data_offset;        /*!< data offset of fragmented messages (zero for all other messages) */
} mqtt_message_t;

typedef struct mqtt_connection {
    mqtt_message_t message;
#if MQTT_MSG_ID_INCREMENTAL
    uint16_t last_message_id;   /*!< last used id if incremental message id configured */
#endif
    uint8_t *buffer;
    size_t buffer_length;

} mqtt_connection_t;

typedef struct mqtt_connect_info {
    char *client_id;
    char *username;
    char *password;
    char *will_topic;
    char *will_message;
    int64_t keepalive;          /*!< keepalive=0 -> keepalive is disabled */
    int will_length;
    int will_qos;
    int will_retain;
    int clean_session;
    esp_mqtt_protocol_ver_t protocol_ver;

} mqtt_connect_info_t;


static inline int mqtt_get_type(const uint8_t *buffer)
{
    return (buffer[0] & 0xf0) >> 4;
}
static inline int mqtt_get_connect_session_present(const uint8_t *buffer)
{
    return buffer[2] & 0x01;
}
static inline int mqtt_get_connect_return_code(const uint8_t *buffer)
{
    return buffer[3];
}
static inline int mqtt_get_dup(const uint8_t *buffer)
{
    return (buffer[0] & 0x08) >> 3;
}
static inline void mqtt_set_dup(uint8_t *buffer)
{
    buffer[0] |= 0x08;
}
static inline int mqtt_get_qos(const uint8_t *buffer)
{
    return (buffer[0] & 0x06) >> 1;
}
static inline int mqtt_get_retain(const uint8_t *buffer)
{
    return (buffer[0] & 0x01);
}

void mqtt_msg_init(mqtt_connection_t *connection, uint8_t *buffer, size_t buffer_length);
bool mqtt_header_complete(uint8_t *buffer, size_t buffer_length);
size_t mqtt_get_total_length(const uint8_t *buffer, size_t length, int *fixed_size_len);
char *mqtt_get_publish_topic(uint8_t *buffer, size_t *length);
char *mqtt_get_publish_data(uint8_t *buffer, size_t *length);
char *mqtt_get_suback_data(uint8_t *buffer, size_t *length);
uint16_t mqtt_get_id(uint8_t *buffer, size_t length);
int mqtt_has_valid_msg_hdr(uint8_t *buffer, size_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);


#ifdef  __cplusplus
}
#endif

#endif  /* MQTT_MSG_H */