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nes-proj/apps/mqtt/mqtt.h

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/*
* Copyright (c) 2015, Texas Instruments Incorporated - http://www.ti.com/
* 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.
*/
/*---------------------------------------------------------------------------*/
/**
* \addtogroup apps
* @{
*
* \defgroup mqtt-engine An implementation of MQTT v3.1
* @{
*
* This application is an engine for MQTT v3.1. It supports QoS Levels 0 and 1.
*
* MQTT is a Client Server publish/subscribe messaging transport protocol.
* It is light weight, open, simple, and designed so as to be easy to implement.
* These characteristics make it ideal for use in many situations, including
* constrained environments such as for communication in Machine to Machine
* (M2M) and Internet of Things (IoT) contexts where a small code footprint is
* required and/or network bandwidth is at a premium.
*
* The protocol runs over TCP/IP, more specifically tcp_socket.
* Its features include:
*
* - Use of the publish/subscribe message pattern which provides
* one-to-many message distribution and decoupling of applications.
* - A messaging transport that is agnostic to the content of the payload.
* Three qualities of service for message delivery:
* -- "At most once" (0), where messages are delivered according to the best
* efforts of the operating environment. Message loss can occur.
* This level could be used, for example, with ambient sensor data where it
* does not matter if an individual reading is lost as the next one will be
* published soon after.
* --"At least once" (1), where messages are assured to arrive but duplicates
* can occur.
* -- "Exactly once" (2), where message are assured to arrive exactly once.
* This level could be used, for example, with billing systems where duplicate
* or lost messages could lead to incorrect charges being applied. This QoS
* level is currently not supported in this implementation.
*
* - A small transport overhead and protocol exchanges minimized to reduce
* network traffic.
* - A mechanism, Last Will, to notify interested parties when an abnormal
* disconnection occurs.
*
* The protocol specification and other useful information can be found
* here: http://mqtt.org
*
*/
/**
* \file
* Header file for the Contiki MQTT engine
*
* \author
* Texas Instruments
*/
/*---------------------------------------------------------------------------*/
#ifndef MQTT_H_
#define MQTT_H_
/*---------------------------------------------------------------------------*/
#include "contiki.h"
#include "contiki-net.h"
#include "contiki-lib.h"
#include "lib/random.h"
#include "sys/ctimer.h"
#include "sys/etimer.h"
#include "net/rpl/rpl.h"
#include "net/ip/uip.h"
#include "net/ipv6/uip-ds6.h"
#include "dev/leds.h"
#include "tcp-socket.h"
#include "udp-socket.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
/*---------------------------------------------------------------------------*/
/* Protocol constants */
#define MQTT_CLIENT_ID_MAX_LEN 23
/* Size of the underlying TCP buffers */
#define MQTT_TCP_INPUT_BUFF_SIZE 512
#define MQTT_TCP_OUTPUT_BUFF_SIZE 512
#define MQTT_INPUT_BUFF_SIZE 512
#define MQTT_MAX_TOPIC_LENGTH 64
#define MQTT_MAX_TOPICS_PER_SUBSCRIBE 1
#define MQTT_FHDR_SIZE 1
#define MQTT_MAX_REMAINING_LENGTH_BYTES 4
#define MQTT_PROTOCOL_VERSION 3
#define MQTT_PROTOCOL_NAME "MQIsdp"
#define MQTT_TOPIC_MAX_LENGTH 128
/*---------------------------------------------------------------------------*/
/*
* Debug configuration, this is similar but not exactly like the Debugging
* System discussion at https://github.com/contiki-os/contiki/wiki.
*/
#define DEBUG_MQTT 0
#if DEBUG_MQTT == 1
#define DBG(...) printf(__VA_ARGS__)
#else
#define DBG(...)
#endif /* DEBUG */
/*---------------------------------------------------------------------------*/
extern process_event_t mqtt_update_event;
/* Forward declaration */
struct mqtt_connection;
typedef enum {
MQTT_RETAIN_OFF,
MQTT_RETAIN_ON,
} mqtt_retain_t;
/**
* \brief MQTT engine events
*/
typedef enum {
MQTT_EVENT_CONNECTED,
MQTT_EVENT_DISCONNECTED,
MQTT_EVENT_SUBACK,
MQTT_EVENT_UNSUBACK,
MQTT_EVENT_PUBLISH,
MQTT_EVENT_PUBACK,
/* Errors */
MQTT_EVENT_ERROR = 0x80,
MQTT_EVENT_PROTOCOL_ERROR,
MQTT_EVENT_CONNECTION_REFUSED_ERROR,
MQTT_EVENT_DNS_ERROR,
MQTT_EVENT_NOT_IMPLEMENTED_ERROR,
/* Add more */
} mqtt_event_t;
typedef enum {
MQTT_STATUS_OK,
MQTT_STATUS_OUT_QUEUE_FULL,
/* Errors */
MQTT_STATUS_ERROR = 0x80,
MQTT_STATUS_NOT_CONNECTED_ERROR,
MQTT_STATUS_INVALID_ARGS_ERROR,
MQTT_STATUS_DNS_ERROR,
} mqtt_status_t;
typedef enum {
MQTT_QOS_LEVEL_0,
MQTT_QOS_LEVEL_1,
MQTT_QOS_LEVEL_2,
} mqtt_qos_level_t;
typedef enum {
MQTT_QOS_STATE_NO_ACK,
MQTT_QOS_STATE_GOT_ACK,
/* Expand for QoS 2 */
} mqtt_qos_state_t;
/*---------------------------------------------------------------------------*/
/*
* This is the state of the connection itself.
*
* N.B. The order is important because of runtime checks on how far the
* connection has proceeded.
*/
typedef enum {
MQTT_CONN_STATE_ERROR,
MQTT_CONN_STATE_DNS_ERROR,
MQTT_CONN_STATE_DISCONNECTING,
MQTT_CONN_STATE_NOT_CONNECTED,
MQTT_CONN_STATE_DNS_LOOKUP,
MQTT_CONN_STATE_TCP_CONNECTING,
MQTT_CONN_STATE_TCP_CONNECTED,
MQTT_CONN_STATE_CONNECTING_TO_BROKER,
MQTT_CONN_STATE_CONNECTED_TO_BROKER,
MQTT_CONN_STATE_SENDING_MQTT_DISCONNECT,
MQTT_CONN_STATE_ABORT_IMMEDIATE,
} mqtt_conn_state_t;
/*---------------------------------------------------------------------------*/
struct mqtt_string {
char *string;
uint16_t length;
};
/*
* Note that the pairing mid <-> QoS level only applies one-to-one if we only
* allow the subscription of one topic at a time. Otherwise we will have an
* ordered list of QoS levels corresponding to the order of topics.
*
* This could be part of a union of event data structures.
*/
struct mqtt_suback_event {
uint16_t mid;
mqtt_qos_level_t qos_level;
};
/* This is the MQTT message that is exposed to the end user. */
struct mqtt_message {
uint32_t mid;
char topic[MQTT_MAX_TOPIC_LENGTH + 1]; /* +1 for string termination */
uint8_t *payload_chunk;
uint16_t payload_chunk_length;
uint8_t first_chunk;
uint16_t payload_length;
uint16_t payload_left;
};
/* This struct represents a packet received from the MQTT server. */
struct mqtt_in_packet {
/* Used by the list interface, must be first in the struct. */
struct mqtt_connection *next;
/* Total bytes read so far. Compared to the remaining length to to decide when
* we've read the payload. */
uint32_t byte_counter;
uint8_t packet_received;
uint8_t fhdr;
uint16_t remaining_length;
uint16_t mid;
/* Helper variables needed to decode the remaining_length */
uint8_t remaining_multiplier;
uint8_t has_remaining_length;
uint8_t remaining_length_bytes;
/* Not the same as payload in the MQTT sense, it also contains the variable
* header.
*/
uint8_t payload_pos;
uint8_t payload[MQTT_INPUT_BUFF_SIZE];
/* Message specific data */
uint16_t topic_len;
uint16_t topic_pos;
uint8_t topic_len_received;
uint8_t topic_received;
};
/* This struct represents a packet sent to the MQTT server. */
struct mqtt_out_packet {
uint8_t fhdr;
uint32_t remaining_length;
uint8_t remaining_length_enc[MQTT_MAX_REMAINING_LENGTH_BYTES];
uint8_t remaining_length_enc_bytes;
uint16_t mid;
char *topic;
uint16_t topic_length;
uint8_t *payload;
uint32_t payload_size;
mqtt_qos_level_t qos;
mqtt_qos_state_t qos_state;
mqtt_retain_t retain;
};
/*---------------------------------------------------------------------------*/
/**
* \brief MQTT event callback function
* \param m A pointer to a MQTT connection
* \param event The event number
* \param data A user-defined pointer
*
* The MQTT socket event callback function gets called whenever there is an
* event on a MQTT connection, such as the connection getting connected
* or closed.
*/
typedef void (*mqtt_event_callback_t)(struct mqtt_connection *m,
mqtt_event_t event,
void *data);
typedef void (*mqtt_topic_callback_t)(struct mqtt_connection *m,
struct mqtt_message *msg);
/*---------------------------------------------------------------------------*/
struct mqtt_will {
struct mqtt_string topic;
struct mqtt_string message;
mqtt_qos_level_t qos;
};
struct mqtt_credentials {
struct mqtt_string username;
struct mqtt_string password;
};
struct mqtt_connection {
/* Used by the list interface, must be first in the struct */
struct mqtt_connection *next;
struct timer t;
struct mqtt_string client_id;
uint8_t connect_vhdr_flags;
uint8_t auto_reconnect;
uint16_t keep_alive;
struct ctimer keep_alive_timer;
uint8_t waiting_for_pingresp;
struct mqtt_will will;
struct mqtt_credentials credentials;
mqtt_conn_state_t state;
mqtt_event_callback_t event_callback;
/* Internal data */
uint16_t mid_counter;
/* Used for communication between MQTT API and APP */
uint8_t out_queue_full;
struct process *app_process;
/* Outgoing data related */
uint8_t *out_buffer_ptr;
uint8_t out_buffer[MQTT_TCP_OUTPUT_BUFF_SIZE];
uint8_t out_buffer_sent;
struct mqtt_out_packet out_packet;
struct pt out_proto_thread;
uint32_t out_write_pos;
uint16_t max_segment_size;
/* Incoming data related */
uint8_t in_buffer[MQTT_TCP_INPUT_BUFF_SIZE];
struct mqtt_in_packet in_packet;
struct mqtt_message in_publish_msg;
/* TCP related information */
char *server_host;
uip_ipaddr_t server_ip;
uint16_t server_port;
struct tcp_socket socket;
};
/* This is the API exposed to the user. */
/*---------------------------------------------------------------------------*/
/**
* \brief Initializes the MQTT engine.
* \param conn A pointer to the MQTT connection.
* \param app_process A pointer to the application process handling the MQTT
* connection.
* \param client_id A pointer to the MQTT client ID.
* \param event_callback Callback function responsible for handling the
* callback from MQTT engine.
* \param max_segment_size The TCP segment size to use for this MQTT/TCP
* connection.
* \return MQTT_STATUS_OK or MQTT_STATUS_INVALID_ARGS_ERROR
*
* This function initializes the MQTT engine and shall be called before any
* other MQTT function.
*/
mqtt_status_t mqtt_register(struct mqtt_connection *conn,
struct process *app_process,
char *client_id,
mqtt_event_callback_t event_callback,
uint16_t max_segment_size);
/*---------------------------------------------------------------------------*/
/**
* \brief Connects to a MQTT broker.
* \param conn A pointer to the MQTT connection.
* \param host IP address of the broker to connect to.
* \param port Port of the broker to connect to, default is MQTT port is 1883.
* \param keep_alive Keep alive timer in seconds. Used by broker to handle
* client disc. Defines the maximum time interval between two messages
* from the client. Shall be min 1.5 x report interval.
* \return MQTT_STATUS_OK or an error status
*
* This function connects to a MQTT broker.
*/
mqtt_status_t mqtt_connect(struct mqtt_connection *conn,
char *host,
uint16_t port,
uint16_t keep_alive);
/*---------------------------------------------------------------------------*/
/**
* \brief Disconnects from a MQTT broker.
* \param conn A pointer to the MQTT connection.
*
* This function disconnects from a MQTT broker.
*/
void mqtt_disconnect(struct mqtt_connection *conn);
/*---------------------------------------------------------------------------*/
/**
* \brief Subscribes to a MQTT topic.
* \param conn A pointer to the MQTT connection.
* \param mid A pointer to message ID.
* \param topic A pointer to the topic to subscribe to.
* \param qos_level Quality Of Service level to use. Currently supports 0, 1.
* \return MQTT_STATUS_OK or some error status
*
* This function subscribes to a topic on a MQTT broker.
*/
mqtt_status_t mqtt_subscribe(struct mqtt_connection *conn,
uint16_t *mid,
char *topic,
mqtt_qos_level_t qos_level);
/*---------------------------------------------------------------------------*/
/**
* \brief Unsubscribes from a MQTT topic.
* \param conn A pointer to the MQTT connection.
* \param mid A pointer to message ID.
* \param topic A pointer to the topic to unsubscribe from.
* \return MQTT_STATUS_OK or some error status
*
* This function unsubscribes from a topic on a MQTT broker.
*/
mqtt_status_t mqtt_unsubscribe(struct mqtt_connection *conn,
uint16_t *mid,
char *topic);
/*---------------------------------------------------------------------------*/
/**
* \brief Publish to a MQTT topic.
* \param conn A pointer to the MQTT connection.
* \param mid A pointer to message ID.
* \param topic A pointer to the topic to subscribe to.
* \param payload A pointer to the topic payload.
* \param payload_size Payload size.
* \param qos_level Quality Of Service level to use. Currently supports 0, 1.
* \param retain If the RETAIN flag is set to 1, in a PUBLISH Packet sent by a
* Client to a Server, the Server MUST store the Application Message
* and its QoS, so that it can be delivered to future subscribers whose
* subscriptions match its topic name
* \return MQTT_STATUS_OK or some error status
*
* This function publishes to a topic on a MQTT broker.
*/
mqtt_status_t mqtt_publish(struct mqtt_connection *conn,
uint16_t *mid,
char *topic,
uint8_t *payload,
uint32_t payload_size,
mqtt_qos_level_t qos_level,
mqtt_retain_t retain);
/*---------------------------------------------------------------------------*/
/**
* \brief Set the user name and password for a MQTT client.
* \param conn A pointer to the MQTT connection.
* \param username A pointer to the user name.
* \param password A pointer to the password.
*
* This function sets clients user name and password to use when connecting to
* a MQTT broker.
*/
void mqtt_set_username_password(struct mqtt_connection *conn,
char *username,
char *password);
/*---------------------------------------------------------------------------*/
/**
* \brief Set the last will topic and message for a MQTT client.
* \param conn A pointer to the MQTT connection.
* \param topic A pointer to the Last Will topic.
* \param message A pointer to the Last Will message (payload).
* \param qos The desired QoS level.
*
* This function sets clients Last Will topic and message (payload).
* If the Will Flag is set to 1 (using the function) this indicates that,
* if the Connect request is accepted, a Will Message MUST be stored on the
* Server and associated with the Network Connection. The Will Message MUST
* be published when the Network Connection is subsequently closed.
*
* This functionality can be used to get notified that a device has
* disconnected from the broker.
*
*/
void mqtt_set_last_will(struct mqtt_connection *conn,
char *topic,
char *message,
mqtt_qos_level_t qos);
#define mqtt_connected(conn) \
((conn)->state == MQTT_CONN_STATE_CONNECTED_TO_BROKER ? 1 : 0)
#define mqtt_ready(conn) \
(!(conn)->out_queue_full && mqtt_connected((conn)))
/*---------------------------------------------------------------------------*/
#endif /* MQTT_H_ */
/*---------------------------------------------------------------------------*/
/**
* @}
* @}
*/
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