iot_mqtt_protocol.h

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/*
 * IoT MQTT V2.1.0
 * Copyright (C) 2018 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * 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.
 */

#ifndef IOT_MQTT_PROTOCOL_H_
#define IOT_MQTT_PROTOCOL_H_

/*
 * MQTT control packet type and flags. Always the first byte of an MQTT
 * packet.
 *
 * For details, see
 * http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/csprd02/mqtt-v3.1.1-csprd02.html#_Toc385349757
 */
#define MQTT_PACKET_TYPE_CONNECT         ( ( uint8_t ) 0x10U )                       
#define MQTT_PACKET_TYPE_CONNACK         ( ( uint8_t ) 0x20U )                       
#define MQTT_PACKET_TYPE_PUBLISH         ( ( uint8_t ) 0x30U )                       
#define MQTT_PACKET_TYPE_PUBACK          ( ( uint8_t ) 0x40U )                       
#define MQTT_PACKET_TYPE_SUBSCRIBE       ( ( uint8_t ) 0x82U )                       
#define MQTT_PACKET_TYPE_SUBACK          ( ( uint8_t ) 0x90U )                       
#define MQTT_PACKET_TYPE_UNSUBSCRIBE     ( ( uint8_t ) 0xa2U )                       
#define MQTT_PACKET_TYPE_UNSUBACK        ( ( uint8_t ) 0xb0U )                       
#define MQTT_PACKET_TYPE_PINGREQ         ( ( uint8_t ) 0xc0U )                       
#define MQTT_PACKET_TYPE_PINGRESP        ( ( uint8_t ) 0xd0U )                       
#define MQTT_PACKET_TYPE_DISCONNECT      ( ( uint8_t ) 0xe0U )                       
/*
 * Positions of each flag in the "Connect Flag" field of an MQTT CONNECT
 * packet.
 */
#define MQTT_CONNECT_FLAG_CLEAN          ( 1 )             
#define MQTT_CONNECT_FLAG_WILL           ( 2 )             
#define MQTT_CONNECT_FLAG_WILL_QOS1      ( 3 )             
#define MQTT_CONNECT_FLAG_WILL_QOS2      ( 4 )             
#define MQTT_CONNECT_FLAG_WILL_RETAIN    ( 5 )             
#define MQTT_CONNECT_FLAG_PASSWORD       ( 6 )             
#define MQTT_CONNECT_FLAG_USERNAME       ( 7 )             
/*
 * Positions of each flag in the first byte of an MQTT PUBLISH packet's
 * fixed header.
 */
#define MQTT_PUBLISH_FLAG_RETAIN         ( 0 )             
#define MQTT_PUBLISH_FLAG_QOS1           ( 1 )             
#define MQTT_PUBLISH_FLAG_QOS2           ( 2 )             
#define MQTT_PUBLISH_FLAG_DUP            ( 3 )             
#define MQTT_REMAINING_LENGTH_INVALID               ( ( size_t ) 268435456 )

#define MQTT_PACKET_CONNECT_MAX_SIZE                ( 327700UL )

#define MQTT_MIN_PUBLISH_REMAINING_LENGTH_QOS0      ( 3U )

#define MQTT_MAX_REMAINING_LENGTH                   ( 268435455UL )

#define MQTT_VERSION_3_1_1                          ( ( uint8_t ) 4U )

/*
 * Constants relating to CONNACK packets, defined by MQTT 3.1.1 spec.
 */
#define MQTT_PACKET_CONNACK_REMAINING_LENGTH        ( ( uint8_t ) 2U )    
#define MQTT_PACKET_CONNACK_SESSION_PRESENT_MASK    ( ( uint8_t ) 0x01U ) 
/*
 * Constants relating to PUBLISH and PUBACK packets, defined by MQTT
 * 3.1.1 spec.
 */
#define MQTT_PACKET_PUBACK_SIZE                     ( 4U )              
#define MQTT_PACKET_PUBACK_REMAINING_LENGTH         ( ( uint8_t ) 2 )   
/*
 * Constants relating to SUBACK and UNSUBACK packets, defined by MQTT
 * 3.1.1 spec.
 */
#define MQTT_PACKET_SUBACK_MINIMUM_SIZE             ( 5U )              
#define MQTT_PACKET_UNSUBACK_REMAINING_LENGTH       ( ( uint8_t ) 2 )   
/*
 * Constants relating to PINGREQ and PINGRESP packets, defined by MQTT 3.1.1 spec.
 */
#define MQTT_PACKET_PINGREQ_SIZE                    ( 2U ) 
#define MQTT_PACKET_PINGRESP_REMAINING_LENGTH       ( 0U ) 
/*
 * Constants relating to DISCONNECT packets, defined by MQTT 3.1.1 spec.
 */
#define MQTT_PACKET_DISCONNECT_SIZE                 ( 2U ) 
#endif /* ifndef _IOT_MQTT_PROTOCOL_H_ */