/* * Copyright (c) 2016 Intel Corporation * * SPDX-License-Identifier: Apache-2.0 */ #ifndef _MQTT_H_ #define _MQTT_H_ #include #include /** * @brief MQTT library * @defgroup mqtt MQTT library * @{ */ /** * @brief mqtt_app MQTT application type */ enum mqtt_app { /** Publisher and Subscriber application */ MQTT_APP_PUBLISHER_SUBSCRIBER, /** Publisher only application */ MQTT_APP_PUBLISHER, /** Subscriber only application */ MQTT_APP_SUBSCRIBER, /** MQTT Server */ MQTT_APP_SERVER }; /** * @brief struct mqtt_ctx MQTT context structure * @details * Context structure for the MQTT high-level API with support for QoS. * * This API is designed for asynchronous operation, so callbacks are * executed when some events must be addressed outside the MQTT routines. * Those events are triggered by the reception or transmission of MQTT messages * and are defined by the MQTT v3.1.1 spec, see: * * http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/mqtt-v3.1.1.html * * For example, assume that Zephyr is operating as a MQTT_APP_SUBSCRIBER, so it * may receive the MQTT PUBLISH and MQTT PUBREL (QoS2) messages. Once the * messages are parsed and validated, the #publish_rx callback is executed. * * Internally, the #publish_rx callback must store the #mqtt_publish_msg message * when a MQTT PUBLISH msg is received. When a MQTT PUBREL message is received, * the application must evaluate if the PUBREL's Packet Identifier matches a * previous received MQTT PUBLISH message. In this case, the user may provide a * collection of #mqtt_publish_msg structs (array of structs) to store those * messages. * * NOTE: The application (and not the API) is in charge of keeping track of * the state of the received and sent messages. */ struct mqtt_ctx { /** IP stack context structure */ struct net_context *net_ctx; /** Network timeout for tx and rx routines */ int32_t net_timeout; /** Callback executed when a MQTT CONNACK msg is received and validated. * If this function pointer is not used, must be set to NULL. */ void (*connect)(struct mqtt_ctx *ctx); /** Callback executed when a MQTT DISCONNECT msg is sent. * If this function pointer is not used, must be set to NULL. */ void (*disconnect)(struct mqtt_ctx *ctx); /** Callback executed when a #MQTT_APP_PUBLISHER application receives * a MQTT PUBxxxx msg. * * Note: this callback must be not NULL * * @param [in] ctx MQTT context * @param [in] pkt_id Packet Identifier for the input MQTT msg * @param [in] type Packet type * @return If this callback returns 0, the caller will * continue. * * @return If type is MQTT_PUBACK, MQTT_PUBCOMP or * MQTT_PUBREC, this callback must return 0 if * pkt_id matches the packet id of a previously * received MQTT_PUBxxx message. * * @return Note: the application must discard all the * messages already processed * * @return Any other value will stop the QoS handshake * and the caller will return -EINVAL */ int (*publish_tx)(struct mqtt_ctx *ctx, uint16_t pkt_id, enum mqtt_packet type); /** Callback executed when a MQTT_APP_SUBSCRIBER, * MQTT_APP_PUBLISHER_SUBSCRIBER or MQTT_APP_SERVER application receive * a MQTT PUBxxxx msg. * * Note: this callback must be not NULL * * @param [in] ctx MQTT context * @param [in] msg Publish message, this parameter is only used * when the type is MQTT_PUBLISH * @param [in] pkt_id Packet Identifier for the input msg * @param [in] type Packet type * @return If this callback returns 0, the caller will * continue. * * @return If type is MQTT_PUBREL this callback must return * 0 if pkt_id matches the packet id of a * previously received MQTT_PUBxxx message. * * @return Note: the application must discard all the * messages already processed * * @return Any other value will stop the QoS handshake * and the caller will return -EINVAL */ int (*publish_rx)(struct mqtt_ctx *ctx, struct mqtt_publish_msg *msg, uint16_t pkt_id, enum mqtt_packet type); /** Callback executed when a MQTT_APP_SUBSCRIBER or * MQTT_APP_PUBLISHER_SUBSCRIBER receives the MQTT SUBACK message * * Note: this callback must be not NULL * * @param [in] ctx MQTT context * @param [in] pkt_id Packet Identifier for the MQTT SUBACK msg * @param [in] items Number of elements in the qos array * @param [in] qos Array of QoS values * @return If this callback returns 0, the caller will * continue * @return Any other value will make the caller return * -EINVAL */ int (*subscribe)(struct mqtt_ctx *ctx, uint16_t pkt_id, uint8_t items, enum mqtt_qos qos[]); /** Callback executed when a MQTT_APP_SUBSCRIBER or * MQTT_APP_PUBLISHER_SUBSCRIBER receives the MQTT UNSUBACK message * * Note: this callback must be not NULL * * @param [in] ctx MQTT context * @param [in] pkt_id Packet Identifier for the MQTT SUBACK msg * @return If this callback returns 0, the caller will * continue * @return Any other value will make the caller return * -EINVAL */ int (*unsubscribe)(struct mqtt_ctx *ctx, uint16_t pkt_id); /** Callback executed when an incoming message doesn't pass the * validation stage. This callback may be NULL. * The pkt_type variable may be set to MQTT_INVALID, if the parsing * stage is aborted before determining the MQTT msg packet type. * * @param [in] ctx MQTT context * @param [in] pkt_type MQTT Packet type */ void (*malformed)(struct mqtt_ctx *ctx, uint16_t pkt_type); /* Internal use only */ int (*rcv)(struct mqtt_ctx *ctx, struct net_buf *); /** Application type, see: enum mqtt_app */ uint8_t app_type; /* Clean session is also part of the MQTT CONNECT msg, however app * behavior is influenced by this parameter, so we keep a copy here */ /** MQTT Clean Session parameter */ uint8_t clean_session:1; /** 1 if the MQTT application is connected and 0 otherwise */ uint8_t connected:1; }; /** * @brief mqtt_init Initializes the MQTT context structure * @param ctx MQTT context structure * @param app_type See enum mqtt_app * @return 0, always. */ int mqtt_init(struct mqtt_ctx *ctx, enum mqtt_app app_type); /** * @brief mqtt_tx_connect Sends the MQTT CONNECT message * @param [in] ctx MQTT context structure * @param [in] msg MQTT CONNECT msg * @return 0 on success * @return -EIO on network error * @return -ENOMEM if no data/tx buffer is available * @return -EINVAL if invalid data was passed to this * routine */ int mqtt_tx_connect(struct mqtt_ctx *ctx, struct mqtt_connect_msg *msg); /** * @brief mqtt_tx_disconnect Send the MQTT DISCONNECT message * @param [in] ctx MQTT context structure * @return 0 on success * @return -EIO on network error * @return -ENOMEM if no data/tx buffer is available * @return -EINVAL if invalid data was passed to this * routine */ int mqtt_tx_disconnect(struct mqtt_ctx *ctx); /** * @brief mqtt_tx_puback Sends the MQTT PUBACK message with the given * packet id * @param [in] ctx MQTT context structure * @param [in] id MQTT Packet Identifier * @return 0 on success * @return -EINVAL if an invalid parameter was passed to * this routine * @return -ENOMEM if a tx buffer is not available * @return -EIO on network error */ int mqtt_tx_puback(struct mqtt_ctx *ctx, uint16_t id); /** * @brief mqtt_tx_pubcomp Sends the MQTT PUBCOMP message with the given * packet id * @param [in] ctx MQTT context structure * @param [in] id MQTT Packet Identifier * @return 0 on success * @return -EINVAL if an invalid parameter was passed to * this routine * @return -ENOMEM if a tx buffer is not available * @return -EIO on network error */ int mqtt_tx_pubcomp(struct mqtt_ctx *ctx, uint16_t id); /** * @brief mqtt_tx_pubrec Sends the MQTT PUBREC message with the given * packet id * @param [in] ctx MQTT context structure * @param [in] id MQTT Packet Identifier * @return 0 on success * @return -EINVAL if an invalid parameter was passed to * this routine * @return -ENOMEM if a tx buffer is not available * @return -EIO on network error */ int mqtt_tx_pubrec(struct mqtt_ctx *ctx, uint16_t id); /** * @brief mqtt_tx_pubrel Sends the MQTT PUBREL message with the given * packet id * @param [in] ctx MQTT context structure * @param [in] id MQTT Packet Identifier * @return 0 on success * @return -EINVAL if an invalid parameter was passed to * this routine * @return -ENOMEM if a tx buffer is not available * @return -EIO on network error */ int mqtt_tx_pubrel(struct mqtt_ctx *ctx, uint16_t id); /** * @brief mqtt_tx_publish Sends the MQTT PUBLISH message * @param [in] ctx MQTT context structure * @param [in] msg MQTT PUBLISH msg * @return 0 on success * @return -EINVAL if an invalid parameter was passed to * this routine * @return -ENOMEM if a tx buffer is not available * @return -EIO on network error */ int mqtt_tx_publish(struct mqtt_ctx *ctx, struct mqtt_publish_msg *msg); /** * @brief mqtt_tx_pingreq Sends the MQTT PINGREQ message * @param [in] ctx MQTT context structure * @return 0 on success * @return -EINVAL if an invalid parameter was passed to * this routine * @return -ENOMEM if a tx buffer is not available * @return -EIO on network error */ int mqtt_tx_pingreq(struct mqtt_ctx *ctx); /** * @brief mqtt_tx_subscribe Sends the MQTT SUBSCRIBE message * @param [in] ctx MQTT context structure * @param [in] pkt_id Packet identifier for the MQTT SUBSCRIBE msg * @param [in] items Number of elements in 'topics' and 'qos' arrays * @param [in] topics Array of 'items' elements containing C strings. * For example: {"sensors", "lights", "doors"} * @param [in] qos Array of 'items' elements containing MQTT QoS * values: MQTT_QoS0, MQTT_QoS1, MQTT_QoS2. For * example for the 'topics' array above the * following QoS may be used: * {MQTT_QoS0, MQTT_QoS2, MQTT_QoS1}, indicating * that the subscription to 'lights' must be done * with MQTT_QoS2 * @return 0 on success * @return -EINVAL if an invalid parameter was passed to * this routine * @return -ENOMEM if a tx buffer is not available * @return -EIO on network error */ int mqtt_tx_subscribe(struct mqtt_ctx *ctx, uint16_t pkt_id, uint8_t items, const char *topics[], const enum mqtt_qos qos[]); /** * @brief mqtt_tx_unsubscribe Sends the MQTT UNSUBSCRIBE message * @param [in] ctx MQTT context structure * @param [in] pkt_id Packet identifier for the MQTT UNSUBSCRIBE msg * @param [in] items Number of elements in the 'topics' array * @param [in] topics Array of 'items' elements containing C strings * @return */ int mqtt_tx_unsubscribe(struct mqtt_ctx *ctx, uint16_t pkt_id, uint8_t items, const char *topics[]); int mqtt_rx_connack(struct mqtt_ctx *ctx, struct net_buf *rx, int clean_session); /** * @brief mqtt_rx_puback Parses and validates the MQTT PUBACK message * @param [in] ctx MQTT context structure * @param [in] rx Data buffer * @return 0 on success * @return -EINVAL on error */ int mqtt_rx_puback(struct mqtt_ctx *ctx, struct net_buf *rx); /** * @brief mqtt_rx_pubcomp Parses and validates the MQTT PUBCOMP message * @param [in] ctx MQTT context structure * @param [in] rx Data buffer * @return 0 on success * @return -EINVAL on error */ int mqtt_rx_pubcomp(struct mqtt_ctx *ctx, struct net_buf *rx); /** * @brief mqtt_rx_pubrec Parses and validates the MQTT PUBREC message * @param [in] ctx MQTT context structure * @param [in] rx Data buffer * @return 0 on success * @return -EINVAL on error */ int mqtt_rx_pubrec(struct mqtt_ctx *ctx, struct net_buf *rx); /** * @brief mqtt_rx_pubrel Parses and validates the MQTT PUBREL message * @details rx is an RX buffer from the IP stack * @param [in] ctx MQTT context structure * @param [in] rx Data buffer * @return 0 on success * @return -EINVAL on error */ int mqtt_rx_pubrel(struct mqtt_ctx *ctx, struct net_buf *rx); /** * @brief mqtt_rx_pingresp Parses the MQTT PINGRESP message * @param [in] ctx MQTT context structure * @param [in] rx Data buffer * @return 0 on success * @return -EINVAL on error */ int mqtt_rx_pingresp(struct mqtt_ctx *ctx, struct net_buf *rx); /** * @brief mqtt_rx_suback Parses the MQTT SUBACK message * @param [in] ctx MQTT context structure * @param [in] rx Data buffer * @return 0 on success * @return -EINVAL on error */ int mqtt_rx_suback(struct mqtt_ctx *ctx, struct net_buf *rx); /** * @brief mqtt_rx_unsuback Parses the MQTT UNSUBACK message * @param [in] ctx MQTT context structure * @param [in] rx Data buffer * @return 0 on success * @return -EINVAL on error */ int mqtt_rx_unsuback(struct mqtt_ctx *ctx, struct net_buf *rx); /** * @brief mqtt_rx_publish Parses the MQTT PUBLISH message * @param [in] ctx MQTT context structure * @param [in] rx Data buffer * @return 0 on success * @return -EINVAL on error * @return -ENOMEM if no data buffer is available */ int mqtt_rx_publish(struct mqtt_ctx *ctx, struct net_buf *rx); /** * @} */ #endif