/** * @file * MQTT client * * @defgroup mqtt MQTT client * @ingroup apps * @verbinclude mqtt_client.txt */ /* * Copyright (c) 2016 Erik Andersson * 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. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. * * This file is part of the lwIP TCP/IP stack * * Author: Erik Andersson * * * @todo: * - Handle large outgoing payloads for PUBLISH messages * - Fix restriction of a single topic in each (UN)SUBSCRIBE message (protocol has support for multiple topics) * - Add support for legacy MQTT protocol version * * Please coordinate changes and requests with Erik Andersson * Erik Andersson * */ #include "lwip/apps/mqtt.h" #include "lwip/apps/mqtt_priv.h" #include "lwip/timeouts.h" #include "lwip/ip_addr.h" #include "lwip/mem.h" #include "lwip/err.h" #include "lwip/pbuf.h" #include "lwip/altcp.h" #include "lwip/altcp_tcp.h" #include "lwip/altcp_tls.h" #include #if LWIP_TCP && LWIP_CALLBACK_API /** * MQTT_DEBUG: Default is off. */ #if !defined MQTT_DEBUG || defined __DOXYGEN__ #define MQTT_DEBUG LWIP_DBG_OFF #endif #define MQTT_DEBUG_TRACE (MQTT_DEBUG | LWIP_DBG_TRACE) #define MQTT_DEBUG_STATE (MQTT_DEBUG | LWIP_DBG_STATE) #define MQTT_DEBUG_WARN (MQTT_DEBUG | LWIP_DBG_LEVEL_WARNING) #define MQTT_DEBUG_WARN_STATE (MQTT_DEBUG | LWIP_DBG_LEVEL_WARNING | LWIP_DBG_STATE) #define MQTT_DEBUG_SERIOUS (MQTT_DEBUG | LWIP_DBG_LEVEL_SERIOUS) /** * MQTT client connection states */ enum { TCP_DISCONNECTED, TCP_CONNECTING, MQTT_CONNECTING, MQTT_CONNECTED }; /** * MQTT control message types */ 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 }; /** Helpers to extract control packet type and qos from first byte in fixed header */ #define MQTT_CTL_PACKET_TYPE(fixed_hdr_byte0) ((fixed_hdr_byte0 & 0xf0) >> 4) #define MQTT_CTL_PACKET_QOS(fixed_hdr_byte0) ((fixed_hdr_byte0 & 0x6) >> 1) /** * MQTT connect flags, only used in CONNECT message */ enum mqtt_connect_flag { MQTT_CONNECT_FLAG_USERNAME = 1 << 7, MQTT_CONNECT_FLAG_PASSWORD = 1 << 6, MQTT_CONNECT_FLAG_WILL_RETAIN = 1 << 5, MQTT_CONNECT_FLAG_WILL = 1 << 2, MQTT_CONNECT_FLAG_CLEAN_SESSION = 1 << 1 }; static void mqtt_cyclic_timer(void *arg); #if defined(LWIP_DEBUG) static const char *const mqtt_message_type_str[15] = { "UNDEFINED", "CONNECT", "CONNACK", "PUBLISH", "PUBACK", "PUBREC", "PUBREL", "PUBCOMP", "SUBSCRIBE", "SUBACK", "UNSUBSCRIBE", "UNSUBACK", "PINGREQ", "PINGRESP", "DISCONNECT" }; /** * Message type value to string * @param msg_type see enum mqtt_message_type * * @return Control message type text string */ static const char * mqtt_msg_type_to_str(u8_t msg_type) { if (msg_type >= LWIP_ARRAYSIZE(mqtt_message_type_str)) { msg_type = 0; } return mqtt_message_type_str[msg_type]; } #endif /** * Generate MQTT packet identifier * @param client MQTT client * @return New packet identifier, range 1 to 65535 */ static u16_t msg_generate_packet_id(mqtt_client_t *client) { client->pkt_id_seq++; if (client->pkt_id_seq == 0) { client->pkt_id_seq++; } return client->pkt_id_seq; } /*--------------------------------------------------------------------------------------------------------------------- */ /* Output ring buffer */ /** Add single item to ring buffer */ static void mqtt_ringbuf_put(struct mqtt_ringbuf_t *rb, u8_t item) { rb->buf[rb->put] = item; rb->put++; if (rb->put >= MQTT_OUTPUT_RINGBUF_SIZE) { rb->put = 0; } } /** Return pointer to ring buffer get position */ static u8_t * mqtt_ringbuf_get_ptr(struct mqtt_ringbuf_t *rb) { return &rb->buf[rb->get]; } static void mqtt_ringbuf_advance_get_idx(struct mqtt_ringbuf_t *rb, u16_t len) { LWIP_ASSERT("mqtt_ringbuf_advance_get_idx: len < MQTT_OUTPUT_RINGBUF_SIZE", len < MQTT_OUTPUT_RINGBUF_SIZE); rb->get += len; if (rb->get >= MQTT_OUTPUT_RINGBUF_SIZE) { rb->get = rb->get - MQTT_OUTPUT_RINGBUF_SIZE; } } /** Return number of bytes in ring buffer */ static u16_t mqtt_ringbuf_len(struct mqtt_ringbuf_t *rb) { u32_t len = rb->put - rb->get; if (len > 0xFFFF) { len += MQTT_OUTPUT_RINGBUF_SIZE; } return (u16_t)len; } /** Return number of bytes free in ring buffer */ #define mqtt_ringbuf_free(rb) (MQTT_OUTPUT_RINGBUF_SIZE - mqtt_ringbuf_len(rb)) /** Return number of bytes possible to read without wrapping around */ #define mqtt_ringbuf_linear_read_length(rb) LWIP_MIN(mqtt_ringbuf_len(rb), (MQTT_OUTPUT_RINGBUF_SIZE - (rb)->get)) /** * Try send as many bytes as possible from output ring buffer * @param rb Output ring buffer * @param tpcb TCP connection handle */ static void mqtt_output_send(struct mqtt_ringbuf_t *rb, struct altcp_pcb *tpcb) { err_t err; u8_t wrap = 0; u16_t ringbuf_lin_len = mqtt_ringbuf_linear_read_length(rb); u16_t send_len = altcp_sndbuf(tpcb); LWIP_ASSERT("mqtt_output_send: tpcb != NULL", tpcb != NULL); if (send_len == 0 || ringbuf_lin_len == 0) { return; } LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_output_send: tcp_sndbuf: %d bytes, ringbuf_linear_available: %d, get %d, put %d\n", send_len, ringbuf_lin_len, rb->get, rb->put)); if (send_len > ringbuf_lin_len) { /* Space in TCP output buffer is larger than available in ring buffer linear portion */ send_len = ringbuf_lin_len; /* Wrap around if more data in ring buffer after linear portion */ wrap = (mqtt_ringbuf_len(rb) > ringbuf_lin_len); } err = altcp_write(tpcb, mqtt_ringbuf_get_ptr(rb), send_len, TCP_WRITE_FLAG_COPY | (wrap ? TCP_WRITE_FLAG_MORE : 0)); if ((err == ERR_OK) && wrap) { mqtt_ringbuf_advance_get_idx(rb, send_len); /* Use the lesser one of ring buffer linear length and TCP send buffer size */ send_len = LWIP_MIN(altcp_sndbuf(tpcb), mqtt_ringbuf_linear_read_length(rb)); err = altcp_write(tpcb, mqtt_ringbuf_get_ptr(rb), send_len, TCP_WRITE_FLAG_COPY); } if (err == ERR_OK) { mqtt_ringbuf_advance_get_idx(rb, send_len); /* Flush */ altcp_output(tpcb); } else { LWIP_DEBUGF(MQTT_DEBUG_WARN, ("mqtt_output_send: Send failed with err %d (\"%s\")\n", err, lwip_strerr(err))); } } /*--------------------------------------------------------------------------------------------------------------------- */ /* Request queue */ /** * Create request item * @param r_objs Pointer to request objects * @param r_objs_len Number of array entries * @param pkt_id Packet identifier of request * @param cb Packet callback to call when requests lifetime ends * @param arg Parameter following callback * @return Request or NULL if failed to create */ static struct mqtt_request_t * mqtt_create_request(struct mqtt_request_t *r_objs, size_t r_objs_len, u16_t pkt_id, mqtt_request_cb_t cb, void *arg) { struct mqtt_request_t *r = NULL; u8_t n; LWIP_ASSERT("mqtt_create_request: r_objs != NULL", r_objs != NULL); for (n = 0; n < r_objs_len; n++) { /* Item point to itself if not in use */ if (r_objs[n].next == &r_objs[n]) { r = &r_objs[n]; r->next = NULL; r->cb = cb; r->arg = arg; r->pkt_id = pkt_id; break; } } return r; } /** * Append request to pending request queue * @param tail Pointer to request queue tail pointer * @param r Request to append */ static void mqtt_append_request(struct mqtt_request_t **tail, struct mqtt_request_t *r) { struct mqtt_request_t *head = NULL; s16_t time_before = 0; struct mqtt_request_t *iter; LWIP_ASSERT("mqtt_append_request: tail != NULL", tail != NULL); /* Iterate trough queue to find head, and count total timeout time */ for (iter = *tail; iter != NULL; iter = iter->next) { time_before += iter->timeout_diff; head = iter; } LWIP_ASSERT("mqtt_append_request: time_before <= MQTT_REQ_TIMEOUT", time_before <= MQTT_REQ_TIMEOUT); r->timeout_diff = MQTT_REQ_TIMEOUT - time_before; if (head == NULL) { *tail = r; } else { head->next = r; } } /** * Delete request item * @param r Request item to delete */ static void mqtt_delete_request(struct mqtt_request_t *r) { if (r != NULL) { r->next = r; } } /** * Remove a request item with a specific packet identifier from request queue * @param tail Pointer to request queue tail pointer * @param pkt_id Packet identifier of request to take * @return Request item if found, NULL if not */ static struct mqtt_request_t * mqtt_take_request(struct mqtt_request_t **tail, u16_t pkt_id) { struct mqtt_request_t *iter = NULL, *prev = NULL; LWIP_ASSERT("mqtt_take_request: tail != NULL", tail != NULL); /* Search all request for pkt_id */ for (iter = *tail; iter != NULL; iter = iter->next) { if (iter->pkt_id == pkt_id) { break; } prev = iter; } /* If request was found */ if (iter != NULL) { /* unchain */ if (prev == NULL) { *tail = iter->next; } else { prev->next = iter->next; } /* If exists, add remaining timeout time for the request to next */ if (iter->next != NULL) { iter->next->timeout_diff += iter->timeout_diff; } iter->next = NULL; } return iter; } /** * Handle requests timeout * @param tail Pointer to request queue tail pointer * @param t Time since last call in seconds */ static void mqtt_request_time_elapsed(struct mqtt_request_t **tail, u8_t t) { struct mqtt_request_t *r; LWIP_ASSERT("mqtt_request_time_elapsed: tail != NULL", tail != NULL); r = *tail; while (t > 0 && r != NULL) { if (t >= r->timeout_diff) { t -= (u8_t)r->timeout_diff; /* Unchain */ *tail = r->next; /* Notify upper layer about timeout */ if (r->cb != NULL) { r->cb(r->arg, ERR_TIMEOUT); } mqtt_delete_request(r); /* Tail might be be modified in callback, so re-read it in every iteration */ r = *(struct mqtt_request_t *const volatile *)tail; } else { r->timeout_diff -= t; t = 0; } } } /** * Free all request items * @param tail Pointer to request queue tail pointer */ static void mqtt_clear_requests(struct mqtt_request_t **tail) { struct mqtt_request_t *iter, *next; LWIP_ASSERT("mqtt_clear_requests: tail != NULL", tail != NULL); for (iter = *tail; iter != NULL; iter = next) { next = iter->next; mqtt_delete_request(iter); } *tail = NULL; } /** * Initialize all request items * @param r_objs Pointer to request objects * @param r_objs_len Number of array entries */ static void mqtt_init_requests(struct mqtt_request_t *r_objs, size_t r_objs_len) { u8_t n; LWIP_ASSERT("mqtt_init_requests: r_objs != NULL", r_objs != NULL); for (n = 0; n < r_objs_len; n++) { /* Item pointing to itself indicates unused */ r_objs[n].next = &r_objs[n]; } } /*--------------------------------------------------------------------------------------------------------------------- */ /* Output message build helpers */ static void mqtt_output_append_u8(struct mqtt_ringbuf_t *rb, u8_t value) { mqtt_ringbuf_put(rb, value); } static void mqtt_output_append_u16(struct mqtt_ringbuf_t *rb, u16_t value) { mqtt_ringbuf_put(rb, value >> 8); mqtt_ringbuf_put(rb, value & 0xff); } static void mqtt_output_append_buf(struct mqtt_ringbuf_t *rb, const void *data, u16_t length) { u16_t n; for (n = 0; n < length; n++) { mqtt_ringbuf_put(rb, ((const u8_t *)data)[n]); } } static void mqtt_output_append_string(struct mqtt_ringbuf_t *rb, const char *str, u16_t length) { u16_t n; mqtt_ringbuf_put(rb, length >> 8); mqtt_ringbuf_put(rb, length & 0xff); for (n = 0; n < length; n++) { mqtt_ringbuf_put(rb, str[n]); } } /** * Append fixed header * @param rb Output ring buffer * @param msg_type see enum mqtt_message_type * @param fdup MQTT DUP flag * @param fqos MQTT QoS field * @param fretain MQTT retain flag * @param r_length Remaining length after fixed header */ static void mqtt_output_append_fixed_header(struct mqtt_ringbuf_t *rb, u8_t msg_type, u8_t fdup, u8_t fqos, u8_t fretain, u16_t r_length) { /* Start with control byte */ mqtt_output_append_u8(rb, (((msg_type & 0x0f) << 4) | ((fdup & 1) << 3) | ((fqos & 3) << 1) | (fretain & 1))); /* Encode remaining length field */ do { mqtt_output_append_u8(rb, (r_length & 0x7f) | (r_length >= 128 ? 0x80 : 0)); r_length >>= 7; } while (r_length > 0); } /** * Check output buffer space * @param rb Output ring buffer * @param r_length Remaining length after fixed header * @return 1 if message will fit, 0 if not enough buffer space */ static u8_t mqtt_output_check_space(struct mqtt_ringbuf_t *rb, u16_t r_length) { /* Start with length of type byte + remaining length */ u16_t total_len = 1 + r_length; LWIP_ASSERT("mqtt_output_check_space: rb != NULL", rb != NULL); /* Calculate number of required bytes to contain the remaining bytes field and add to total*/ do { total_len++; r_length >>= 7; } while (r_length > 0); return (total_len <= mqtt_ringbuf_free(rb)); } /** * Close connection to server * @param client MQTT client * @param reason Reason for disconnection */ static void mqtt_close(mqtt_client_t *client, mqtt_connection_status_t reason) { LWIP_ASSERT("mqtt_close: client != NULL", client != NULL); /* Bring down TCP connection if not already done */ if (client->conn != NULL) { err_t res; altcp_recv(client->conn, NULL); altcp_err(client->conn, NULL); altcp_sent(client->conn, NULL); res = altcp_close(client->conn); if (res != ERR_OK) { altcp_abort(client->conn); LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_close: Close err=%s\n", lwip_strerr(res))); } client->conn = NULL; } /* Remove all pending requests */ mqtt_clear_requests(&client->pend_req_queue); /* Stop cyclic timer */ sys_untimeout(mqtt_cyclic_timer, client); /* Notify upper layer of disconnection if changed state */ if (client->conn_state != TCP_DISCONNECTED) { client->conn_state = TCP_DISCONNECTED; if (client->connect_cb != NULL) { client->connect_cb(client, client->connect_arg, reason); } } } /** * Interval timer, called every MQTT_CYCLIC_TIMER_INTERVAL seconds in MQTT_CONNECTING and MQTT_CONNECTED states * @param arg MQTT client */ static void mqtt_cyclic_timer(void *arg) { u8_t restart_timer = 1; mqtt_client_t *client = (mqtt_client_t *)arg; LWIP_ASSERT("mqtt_cyclic_timer: client != NULL", client != NULL); if (client->conn_state == MQTT_CONNECTING) { client->cyclic_tick++; if ((client->cyclic_tick * MQTT_CYCLIC_TIMER_INTERVAL) >= MQTT_CONNECT_TIMOUT) { LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_cyclic_timer: CONNECT attempt to server timed out\n")); /* Disconnect TCP */ mqtt_close(client, MQTT_CONNECT_TIMEOUT); restart_timer = 0; } } else if (client->conn_state == MQTT_CONNECTED) { /* Handle timeout for pending requests */ mqtt_request_time_elapsed(&client->pend_req_queue, MQTT_CYCLIC_TIMER_INTERVAL); /* keep_alive > 0 means keep alive functionality shall be used */ if (client->keep_alive > 0) { client->server_watchdog++; /* If reception from server has been idle for 1.5*keep_alive time, server is considered unresponsive */ if ((client->server_watchdog * MQTT_CYCLIC_TIMER_INTERVAL) > (client->keep_alive + client->keep_alive / 2)) { LWIP_DEBUGF(MQTT_DEBUG_WARN, ("mqtt_cyclic_timer: Server incoming keep-alive timeout\n")); mqtt_close(client, MQTT_CONNECT_TIMEOUT); restart_timer = 0; } /* If time for a keep alive message to be sent, transmission has been idle for keep_alive time */ client->cyclic_tick++; if ((client->cyclic_tick * MQTT_CYCLIC_TIMER_INTERVAL) >= client->keep_alive) { LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_cyclic_timer: Sending keep-alive message to server\n")); if (mqtt_output_check_space(&client->output, 0) != 0) { mqtt_output_append_fixed_header(&client->output, MQTT_MSG_TYPE_PINGREQ, 0, 0, 0, 0); client->cyclic_tick = 0; } } } } else { LWIP_DEBUGF(MQTT_DEBUG_WARN, ("mqtt_cyclic_timer: Timer should not be running in state %d\n", client->conn_state)); restart_timer = 0; } if (restart_timer) { sys_timeout(MQTT_CYCLIC_TIMER_INTERVAL * 1000, mqtt_cyclic_timer, arg); } } /** * Send PUBACK, PUBREC or PUBREL response message * @param client MQTT client * @param msg PUBACK, PUBREC or PUBREL * @param pkt_id Packet identifier * @param qos QoS value * @return ERR_OK if successful, ERR_MEM if out of memory */ static err_t pub_ack_rec_rel_response(mqtt_client_t *client, u8_t msg, u16_t pkt_id, u8_t qos) { err_t err = ERR_OK; if (mqtt_output_check_space(&client->output, 2)) { mqtt_output_append_fixed_header(&client->output, msg, 0, qos, 0, 2); mqtt_output_append_u16(&client->output, pkt_id); mqtt_output_send(&client->output, client->conn); } else { LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("pub_ack_rec_rel_response: OOM creating response: %s with pkt_id: %d\n", mqtt_msg_type_to_str(msg), pkt_id)); err = ERR_MEM; } return err; } /** * Subscribe response from server * @param r Matching request * @param result Result code from server */ static void mqtt_incoming_suback(struct mqtt_request_t *r, u8_t result) { if (r->cb != NULL) { r->cb(r->arg, result < 3 ? ERR_OK : ERR_ABRT); } } /** * Complete MQTT message received or buffer full * @param client MQTT client * @param fixed_hdr_len length of fixed header * @param length length received part * @param remaining_length Remaining length of complete message */ static mqtt_connection_status_t mqtt_message_received(mqtt_client_t *client, u8_t fixed_hdr_len, u16_t length, u32_t remaining_length, u8_t *var_hdr_payload) { mqtt_connection_status_t res = MQTT_CONNECT_ACCEPTED; /* Control packet type */ u8_t pkt_type = MQTT_CTL_PACKET_TYPE(client->rx_buffer[0]); u16_t pkt_id = 0; LWIP_ASSERT("fixed_hdr_len <= client->msg_idx", fixed_hdr_len <= client->msg_idx); LWIP_ERROR("buffer length mismatch", fixed_hdr_len + length <= MQTT_VAR_HEADER_BUFFER_LEN, return MQTT_CONNECT_DISCONNECTED); if (pkt_type == MQTT_MSG_TYPE_CONNACK) { if (client->conn_state == MQTT_CONNECTING) { if (length < 2) { LWIP_DEBUGF(MQTT_DEBUG_WARN,( "mqtt_message_received: Received short CONNACK message\n")); goto out_disconnect; } /* Get result code from CONNACK */ res = (mqtt_connection_status_t)var_hdr_payload[1]; LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_message_received: Connect response code %d\n", res)); if (res == MQTT_CONNECT_ACCEPTED) { /* Reset cyclic_tick when changing to connected state */ client->cyclic_tick = 0; client->conn_state = MQTT_CONNECTED; /* Notify upper layer */ if (client->connect_cb != NULL) { client->connect_cb(client, client->connect_arg, res); } } } else { LWIP_DEBUGF(MQTT_DEBUG_WARN, ("mqtt_message_received: Received CONNACK in connected state\n")); } } else if (pkt_type == MQTT_MSG_TYPE_PINGRESP) { LWIP_DEBUGF(MQTT_DEBUG_TRACE, ( "mqtt_message_received: Received PINGRESP from server\n")); } else if (pkt_type == MQTT_MSG_TYPE_PUBLISH) { u16_t payload_offset = 0; u16_t payload_length = length; u8_t qos = MQTT_CTL_PACKET_QOS(client->rx_buffer[0]); if (client->msg_idx == (u32_t)(fixed_hdr_len + length)) { /* First publish message frame. Should have topic and pkt id*/ size_t var_hdr_payload_bufsize = sizeof(client->rx_buffer) - fixed_hdr_len; u8_t *topic; u16_t after_topic; u8_t bkp; u16_t topic_len; u16_t qos_len = (qos ? 2U : 0U); if (length < 2 + qos_len) { LWIP_DEBUGF(MQTT_DEBUG_WARN,( "mqtt_message_received: Received short PUBLISH packet\n")); goto out_disconnect; } topic_len = var_hdr_payload[0]; topic_len = (topic_len << 8) + (u16_t)(var_hdr_payload[1]); if ((topic_len > length - (2 + qos_len)) || (topic_len > var_hdr_payload_bufsize - (2 + qos_len))) { LWIP_DEBUGF(MQTT_DEBUG_WARN,( "mqtt_message_received: Received short PUBLISH packet (topic)\n")); goto out_disconnect; } topic = var_hdr_payload + 2; after_topic = 2 + topic_len; /* Check buffer length, add one byte even for QoS 0 so that zero termination will fit */ if ((after_topic + (qos ? 2U : 1U)) > var_hdr_payload_bufsize) { LWIP_DEBUGF(MQTT_DEBUG_WARN, ("mqtt_message_received: Receive buffer can not fit topic + pkt_id\n")); goto out_disconnect; } /* id for QoS 1 and 2 */ if (qos > 0) { if (length < after_topic + 2U) { LWIP_DEBUGF(MQTT_DEBUG_WARN,( "mqtt_message_received: Received short PUBLISH packet (after_topic)\n")); goto out_disconnect; } client->inpub_pkt_id = ((u16_t)var_hdr_payload[after_topic] << 8) + (u16_t)var_hdr_payload[after_topic + 1]; after_topic += 2; } else { client->inpub_pkt_id = 0; } /* Take backup of byte after topic */ bkp = topic[topic_len]; /* Zero terminate string */ topic[topic_len] = 0; /* Payload data remaining in receive buffer */ payload_length = length - after_topic; payload_offset = after_topic; LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_incoming_publish: Received message with QoS %d at topic: %s, payload length %"U32_F"\n", qos, topic, remaining_length + payload_length)); if (client->pub_cb != NULL) { client->pub_cb(client->inpub_arg, (const char *)topic, remaining_length + payload_length); } /* Restore byte after topic */ topic[topic_len] = bkp; } if (payload_length > 0 || remaining_length == 0) { if (length < (size_t)(payload_offset + payload_length)) { LWIP_DEBUGF(MQTT_DEBUG_WARN,( "mqtt_message_received: Received short packet (payload)\n")); goto out_disconnect; } if (client->data_cb != NULL) { client->data_cb(client->inpub_arg, var_hdr_payload + payload_offset, payload_length, remaining_length == 0 ? MQTT_DATA_FLAG_LAST : 0); } /* Reply if QoS > 0 */ if (remaining_length == 0 && qos > 0) { /* Send PUBACK for QoS 1 or PUBREC for QoS 2 */ u8_t resp_msg = (qos == 1) ? MQTT_MSG_TYPE_PUBACK : MQTT_MSG_TYPE_PUBREC; LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_incoming_publish: Sending publish response: %s with pkt_id: %d\n", mqtt_msg_type_to_str(resp_msg), client->inpub_pkt_id)); pub_ack_rec_rel_response(client, resp_msg, client->inpub_pkt_id, 0); } } } else { if (length < 2) { LWIP_DEBUGF(MQTT_DEBUG_WARN,( "mqtt_message_received: Received short message\n")); goto out_disconnect; } /* Get packet identifier */ pkt_id = (u16_t)var_hdr_payload[0] << 8; pkt_id |= (u16_t)var_hdr_payload[1]; if (pkt_id == 0) { LWIP_DEBUGF(MQTT_DEBUG_WARN, ("mqtt_message_received: Got message with illegal packet identifier: 0\n")); goto out_disconnect; } if (pkt_type == MQTT_MSG_TYPE_PUBREC) { LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_message_received: PUBREC, sending PUBREL with pkt_id: %d\n", pkt_id)); pub_ack_rec_rel_response(client, MQTT_MSG_TYPE_PUBREL, pkt_id, 1); } else if (pkt_type == MQTT_MSG_TYPE_PUBREL) { LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_message_received: PUBREL, sending PUBCOMP response with pkt_id: %d\n", pkt_id)); pub_ack_rec_rel_response(client, MQTT_MSG_TYPE_PUBCOMP, pkt_id, 0); } else if (pkt_type == MQTT_MSG_TYPE_SUBACK || pkt_type == MQTT_MSG_TYPE_UNSUBACK || pkt_type == MQTT_MSG_TYPE_PUBCOMP || pkt_type == MQTT_MSG_TYPE_PUBACK) { struct mqtt_request_t *r = mqtt_take_request(&client->pend_req_queue, pkt_id); if (r != NULL) { LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_message_received: %s response with id %d\n", mqtt_msg_type_to_str(pkt_type), pkt_id)); if (pkt_type == MQTT_MSG_TYPE_SUBACK) { if (length < 3) { LWIP_DEBUGF(MQTT_DEBUG_WARN, ("mqtt_message_received: To small SUBACK packet\n")); goto out_disconnect; } else { mqtt_incoming_suback(r, var_hdr_payload[2]); } } else if (r->cb != NULL) { r->cb(r->arg, ERR_OK); } mqtt_delete_request(r); } else { LWIP_DEBUGF(MQTT_DEBUG_WARN, ( "mqtt_message_received: Received %s reply, with wrong pkt_id: %d\n", mqtt_msg_type_to_str(pkt_type), pkt_id)); } } else { LWIP_DEBUGF(MQTT_DEBUG_WARN, ( "mqtt_message_received: Received unknown message type: %d\n", pkt_type)); goto out_disconnect; } } return res; out_disconnect: return MQTT_CONNECT_DISCONNECTED; } /** * MQTT incoming message parser * @param client MQTT client * @param p PBUF chain of received data * @return Connection status */ static mqtt_connection_status_t mqtt_parse_incoming(mqtt_client_t *client, struct pbuf *p) { u16_t in_offset = 0; u32_t msg_rem_len = 0; u8_t fixed_hdr_len = 0; u8_t b = 0; while (p->tot_len > in_offset) { /* We ALWAYS parse the header here first. Even if the header was not included in this segment, we re-parse it here by buffering it in client->rx_buffer. client->msg_idx keeps track of this. */ if ((fixed_hdr_len < 2) || ((b & 0x80) != 0)) { if (fixed_hdr_len < client->msg_idx) { /* parse header from old pbuf (buffered in client->rx_buffer) */ b = client->rx_buffer[fixed_hdr_len]; } else { /* parse header from this pbuf and save it in client->rx_buffer in case it comes in segmented */ b = pbuf_get_at(p, in_offset++); client->rx_buffer[client->msg_idx++] = b; } fixed_hdr_len++; if (fixed_hdr_len >= 2) { /* fixed header contains at least 2 bytes but can contain more, depending on 'remaining length'. All bytes but the last of this have 0x80 set to indicate more bytes are coming. */ msg_rem_len |= (u32_t)(b & 0x7f) << ((fixed_hdr_len - 2) * 7); if ((b & 0x80) == 0) { /* fixed header is done */ LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_parse_incoming: Remaining length after fixed header: %"U32_F"\n", msg_rem_len)); if (msg_rem_len == 0) { /* Complete message with no extra headers of payload received */ mqtt_message_received(client, fixed_hdr_len, 0, 0, NULL); client->msg_idx = 0; fixed_hdr_len = 0; } else { /* Bytes remaining in message (changes remaining length if this is not the first segment of this message) */ msg_rem_len = (msg_rem_len + fixed_hdr_len) - client->msg_idx; } } } } else { /* Fixed header has been parsed, parse variable header */ u16_t cpy_len, buffer_space; u8_t *var_hdr_payload; mqtt_connection_status_t res; /* Allow to copy the lesser one of available length in input data or bytes remaining in message */ cpy_len = (u16_t)LWIP_MIN((u16_t)(p->tot_len - in_offset), msg_rem_len); /* Limit to available space in buffer */ buffer_space = MQTT_VAR_HEADER_BUFFER_LEN - fixed_hdr_len; if (cpy_len > buffer_space) { cpy_len = buffer_space; } /* Adjust cpy_len to ensure zero-copy operation for remaining parts of current message */ if (client->msg_idx >= MQTT_VAR_HEADER_BUFFER_LEN) { if (cpy_len > (p->len - in_offset)) cpy_len = p->len - in_offset; } var_hdr_payload = (u8_t*)pbuf_get_contiguous(p, client->rx_buffer + fixed_hdr_len, buffer_space, cpy_len, in_offset); /* Advance get and put indexes */ client->msg_idx += cpy_len; in_offset += cpy_len; msg_rem_len -= cpy_len; LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_parse_incoming: msg_idx: %"U32_F", cpy_len: %"U16_F", remaining %"U32_F"\n", client->msg_idx, cpy_len, msg_rem_len)); /* Whole or partial message received */ res = mqtt_message_received(client, fixed_hdr_len, cpy_len, msg_rem_len, var_hdr_payload); if (res != MQTT_CONNECT_ACCEPTED) { return res; } if (msg_rem_len == 0) { /* Reset parser state */ client->msg_idx = 0; /* msg_tot_len = 0; */ fixed_hdr_len = 0; } } } return MQTT_CONNECT_ACCEPTED; } /** * TCP received callback function. @see tcp_recv_fn * @param arg MQTT client * @param p PBUF chain of received data * @param err Passed as return value if not ERR_OK * @return ERR_OK or err passed into callback */ static err_t mqtt_tcp_recv_cb(void *arg, struct altcp_pcb *pcb, struct pbuf *p, err_t err) { mqtt_client_t *client = (mqtt_client_t *)arg; LWIP_ASSERT("mqtt_tcp_recv_cb: client != NULL", client != NULL); LWIP_ASSERT("mqtt_tcp_recv_cb: client->conn == pcb", client->conn == pcb); if (p == NULL) { LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_tcp_recv_cb: Recv pbuf=NULL, remote has closed connection\n")); mqtt_close(client, MQTT_CONNECT_DISCONNECTED); } else { mqtt_connection_status_t res; if (err != ERR_OK) { LWIP_DEBUGF(MQTT_DEBUG_WARN, ("mqtt_tcp_recv_cb: Recv err=%d\n", err)); pbuf_free(p); return err; } /* Tell remote that data has been received */ altcp_recved(pcb, p->tot_len); res = mqtt_parse_incoming(client, p); pbuf_free(p); if (res != MQTT_CONNECT_ACCEPTED) { mqtt_close(client, res); } /* If keep alive functionality is used */ if (client->keep_alive != 0) { /* Reset server alive watchdog */ client->server_watchdog = 0; } } return ERR_OK; } /** * TCP data sent callback function. @see tcp_sent_fn * @param arg MQTT client * @param tpcb TCP connection handle * @param len Number of bytes sent * @return ERR_OK */ static err_t mqtt_tcp_sent_cb(void *arg, struct altcp_pcb *tpcb, u16_t len) { mqtt_client_t *client = (mqtt_client_t *)arg; LWIP_UNUSED_ARG(tpcb); LWIP_UNUSED_ARG(len); if (client->conn_state == MQTT_CONNECTED) { struct mqtt_request_t *r; /* Reset keep-alive send timer and server watchdog */ client->cyclic_tick = 0; client->server_watchdog = 0; /* QoS 0 publish has no response from server, so call its callbacks here */ while ((r = mqtt_take_request(&client->pend_req_queue, 0)) != NULL) { LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_tcp_sent_cb: Calling QoS 0 publish complete callback\n")); if (r->cb != NULL) { r->cb(r->arg, ERR_OK); } mqtt_delete_request(r); } /* Try send any remaining buffers from output queue */ mqtt_output_send(&client->output, client->conn); } return ERR_OK; } /** * TCP error callback function. @see tcp_err_fn * @param arg MQTT client * @param err Error encountered */ static void mqtt_tcp_err_cb(void *arg, err_t err) { mqtt_client_t *client = (mqtt_client_t *)arg; LWIP_UNUSED_ARG(err); /* only used for debug output */ LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_tcp_err_cb: TCP error callback: error %d, arg: %p\n", err, arg)); LWIP_ASSERT("mqtt_tcp_err_cb: client != NULL", client != NULL); /* Set conn to null before calling close as pcb is already deallocated*/ client->conn = NULL; mqtt_close(client, MQTT_CONNECT_DISCONNECTED); } /** * TCP poll callback function. @see tcp_poll_fn * @param arg MQTT client * @param tpcb TCP connection handle * @return err ERR_OK */ static err_t mqtt_tcp_poll_cb(void *arg, struct altcp_pcb *tpcb) { mqtt_client_t *client = (mqtt_client_t *)arg; if (client->conn_state == MQTT_CONNECTED) { /* Try send any remaining buffers from output queue */ mqtt_output_send(&client->output, tpcb); } return ERR_OK; } /** * TCP connect callback function. @see tcp_connected_fn * @param arg MQTT client * @param err Always ERR_OK, mqtt_tcp_err_cb is called in case of error * @return ERR_OK */ static err_t mqtt_tcp_connect_cb(void *arg, struct altcp_pcb *tpcb, err_t err) { mqtt_client_t *client = (mqtt_client_t *)arg; if (err != ERR_OK) { LWIP_DEBUGF(MQTT_DEBUG_WARN, ("mqtt_tcp_connect_cb: TCP connect error %d\n", err)); return err; } /* Initiate receiver state */ client->msg_idx = 0; /* Setup TCP callbacks */ altcp_recv(tpcb, mqtt_tcp_recv_cb); altcp_sent(tpcb, mqtt_tcp_sent_cb); altcp_poll(tpcb, mqtt_tcp_poll_cb, 2); LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_tcp_connect_cb: TCP connection established to server\n")); /* Enter MQTT connect state */ client->conn_state = MQTT_CONNECTING; /* Start cyclic timer */ sys_timeout(MQTT_CYCLIC_TIMER_INTERVAL * 1000, mqtt_cyclic_timer, client); client->cyclic_tick = 0; /* Start transmission from output queue, connect message is the first one out*/ mqtt_output_send(&client->output, client->conn); return ERR_OK; } /*---------------------------------------------------------------------------------------------------- */ /* Public API */ /** * @ingroup mqtt * MQTT publish function. * @param client MQTT client * @param topic Publish topic string * @param payload Data to publish (NULL is allowed) * @param payload_length Length of payload (0 is allowed) * @param qos Quality of service, 0 1 or 2 * @param retain MQTT retain flag * @param cb Callback to call when publish is complete or has timed out * @param arg User supplied argument to publish callback * @return ERR_OK if successful * ERR_CONN if client is disconnected * ERR_MEM if short on memory */ err_t mqtt_publish(mqtt_client_t *client, const char *topic, const void *payload, u16_t payload_length, u8_t qos, u8_t retain, mqtt_request_cb_t cb, void *arg) { struct mqtt_request_t *r; u16_t pkt_id; size_t topic_strlen; size_t total_len; u16_t topic_len; u16_t remaining_length; LWIP_ASSERT_CORE_LOCKED(); LWIP_ASSERT("mqtt_publish: client != NULL", client); LWIP_ASSERT("mqtt_publish: topic != NULL", topic); LWIP_ERROR("mqtt_publish: TCP disconnected", (client->conn_state != TCP_DISCONNECTED), return ERR_CONN); topic_strlen = strlen(topic); LWIP_ERROR("mqtt_publish: topic length overflow", (topic_strlen <= (0xFFFF - 2)), return ERR_ARG); topic_len = (u16_t)topic_strlen; total_len = 2 + topic_len + payload_length; if (qos > 0) { total_len += 2; /* Generate pkt_id id for QoS1 and 2 */ pkt_id = msg_generate_packet_id(client); } else { /* Use reserved value pkt_id 0 for QoS 0 in request handle */ pkt_id = 0; } LWIP_ERROR("mqtt_publish: total length overflow", (total_len <= 0xFFFF), return ERR_ARG); remaining_length = (u16_t)total_len; LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_publish: Publish with payload length %d to topic \"%s\"\n", payload_length, topic)); r = mqtt_create_request(client->req_list, LWIP_ARRAYSIZE(client->req_list), pkt_id, cb, arg); if (r == NULL) { return ERR_MEM; } if (mqtt_output_check_space(&client->output, remaining_length) == 0) { mqtt_delete_request(r); return ERR_MEM; } /* Append fixed header */ mqtt_output_append_fixed_header(&client->output, MQTT_MSG_TYPE_PUBLISH, 0, qos, retain, remaining_length); /* Append Topic */ mqtt_output_append_string(&client->output, topic, topic_len); /* Append packet if for QoS 1 and 2*/ if (qos > 0) { mqtt_output_append_u16(&client->output, pkt_id); } /* Append optional publish payload */ if ((payload != NULL) && (payload_length > 0)) { mqtt_output_append_buf(&client->output, payload, payload_length); } mqtt_append_request(&client->pend_req_queue, r); mqtt_output_send(&client->output, client->conn); return ERR_OK; } /** * @ingroup mqtt * MQTT subscribe/unsubscribe function. * @param client MQTT client * @param topic topic to subscribe to * @param qos Quality of service, 0 1 or 2 (only used for subscribe) * @param cb Callback to call when subscribe/unsubscribe response is received * @param arg User supplied argument to publish callback * @param sub 1 for subscribe, 0 for unsubscribe * @return ERR_OK if successful, @see err_t enum for other results */ err_t mqtt_sub_unsub(mqtt_client_t *client, const char *topic, u8_t qos, mqtt_request_cb_t cb, void *arg, u8_t sub) { size_t topic_strlen; size_t total_len; u16_t topic_len; u16_t remaining_length; u16_t pkt_id; struct mqtt_request_t *r; LWIP_ASSERT_CORE_LOCKED(); LWIP_ASSERT("mqtt_sub_unsub: client != NULL", client); LWIP_ASSERT("mqtt_sub_unsub: topic != NULL", topic); topic_strlen = strlen(topic); LWIP_ERROR("mqtt_sub_unsub: topic length overflow", (topic_strlen <= (0xFFFF - 2)), return ERR_ARG); topic_len = (u16_t)topic_strlen; /* Topic string, pkt_id, qos for subscribe */ total_len = topic_len + 2 + 2 + (sub != 0); LWIP_ERROR("mqtt_sub_unsub: total length overflow", (total_len <= 0xFFFF), return ERR_ARG); remaining_length = (u16_t)total_len; LWIP_ASSERT("mqtt_sub_unsub: qos < 3", qos < 3); if (client->conn_state == TCP_DISCONNECTED) { LWIP_DEBUGF(MQTT_DEBUG_WARN, ("mqtt_sub_unsub: Can not (un)subscribe in disconnected state\n")); return ERR_CONN; } pkt_id = msg_generate_packet_id(client); r = mqtt_create_request(client->req_list, LWIP_ARRAYSIZE(client->req_list), pkt_id, cb, arg); if (r == NULL) { return ERR_MEM; } if (mqtt_output_check_space(&client->output, remaining_length) == 0) { mqtt_delete_request(r); return ERR_MEM; } LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_sub_unsub: Client (un)subscribe to topic \"%s\", id: %d\n", topic, pkt_id)); mqtt_output_append_fixed_header(&client->output, sub ? MQTT_MSG_TYPE_SUBSCRIBE : MQTT_MSG_TYPE_UNSUBSCRIBE, 0, 1, 0, remaining_length); /* Packet id */ mqtt_output_append_u16(&client->output, pkt_id); /* Topic */ mqtt_output_append_string(&client->output, topic, topic_len); /* QoS */ if (sub != 0) { mqtt_output_append_u8(&client->output, LWIP_MIN(qos, 2)); } mqtt_append_request(&client->pend_req_queue, r); mqtt_output_send(&client->output, client->conn); return ERR_OK; } /** * @ingroup mqtt * Set callback to handle incoming publish requests from server * @param client MQTT client * @param pub_cb Callback invoked when publish starts, contain topic and total length of payload * @param data_cb Callback for each fragment of payload that arrives * @param arg User supplied argument to both callbacks */ void mqtt_set_inpub_callback(mqtt_client_t *client, mqtt_incoming_publish_cb_t pub_cb, mqtt_incoming_data_cb_t data_cb, void *arg) { LWIP_ASSERT_CORE_LOCKED(); LWIP_ASSERT("mqtt_set_inpub_callback: client != NULL", client != NULL); client->data_cb = data_cb; client->pub_cb = pub_cb; client->inpub_arg = arg; } /** * @ingroup mqtt * Create a new MQTT client instance * @return Pointer to instance on success, NULL otherwise */ mqtt_client_t * mqtt_client_new(void) { LWIP_ASSERT_CORE_LOCKED(); return (mqtt_client_t *)mem_calloc(1, sizeof(mqtt_client_t)); } /** * @ingroup mqtt * Free MQTT client instance * @param client Pointer to instance to be freed */ void mqtt_client_free(mqtt_client_t *client) { mem_free(client); } /** * @ingroup mqtt * Connect to MQTT server * @param client MQTT client * @param ip_addr Server IP * @param port Server port * @param cb Connection state change callback * @param arg User supplied argument to connection callback * @param client_info Client identification and connection options * @return ERR_OK if successful, @see err_t enum for other results */ err_t mqtt_client_connect(mqtt_client_t *client, const ip_addr_t *ip_addr, u16_t port, mqtt_connection_cb_t cb, void *arg, const struct mqtt_connect_client_info_t *client_info) { err_t err; size_t len; u16_t client_id_length; /* Length is the sum of 2+"MQTT", protocol level, flags and keep alive */ u16_t remaining_length = 2 + 4 + 1 + 1 + 2; u8_t flags = 0, will_topic_len = 0, will_msg_len = 0; u16_t client_user_len = 0, client_pass_len = 0; mqtt_incoming_data_cb_t data_cb; mqtt_incoming_publish_cb_t pub_cb; void *inpub_arg; LWIP_ASSERT_CORE_LOCKED(); LWIP_ASSERT("mqtt_client_connect: client != NULL", client != NULL); LWIP_ASSERT("mqtt_client_connect: ip_addr != NULL", ip_addr != NULL); LWIP_ASSERT("mqtt_client_connect: client_info != NULL", client_info != NULL); LWIP_ASSERT("mqtt_client_connect: client_info->client_id != NULL", client_info->client_id != NULL); if (client->conn_state != TCP_DISCONNECTED) { LWIP_DEBUGF(MQTT_DEBUG_WARN, ("mqtt_client_connect: Already connected\n")); return ERR_ISCONN; } /* Wipe clean, but keep callbacks */ data_cb = client->data_cb; pub_cb = client->pub_cb; inpub_arg = client->inpub_arg; memset(client, 0, sizeof(mqtt_client_t)); client->data_cb = data_cb; client->pub_cb = pub_cb; client->inpub_arg = inpub_arg; client->connect_arg = arg; client->connect_cb = cb; client->keep_alive = client_info->keep_alive; mqtt_init_requests(client->req_list, LWIP_ARRAYSIZE(client->req_list)); /* Build connect message */ if (client_info->will_topic != NULL && client_info->will_msg != NULL) { flags |= MQTT_CONNECT_FLAG_WILL; flags |= (client_info->will_qos & 3) << 3; if (client_info->will_retain) { flags |= MQTT_CONNECT_FLAG_WILL_RETAIN; } len = strlen(client_info->will_topic); LWIP_ERROR("mqtt_client_connect: client_info->will_topic length overflow", len <= 0xFF, return ERR_VAL); LWIP_ERROR("mqtt_client_connect: client_info->will_topic length must be > 0", len > 0, return ERR_VAL); will_topic_len = (u8_t)len; len = strlen(client_info->will_msg); LWIP_ERROR("mqtt_client_connect: client_info->will_msg length overflow", len <= 0xFF, return ERR_VAL); will_msg_len = (u8_t)len; len = remaining_length + 2 + will_topic_len + 2 + will_msg_len; LWIP_ERROR("mqtt_client_connect: remaining_length overflow", len <= 0xFFFF, return ERR_VAL); remaining_length = (u16_t)len; } if (client_info->client_user != NULL) { flags |= MQTT_CONNECT_FLAG_USERNAME; len = strlen(client_info->client_user); LWIP_ERROR("mqtt_client_connect: client_info->client_user length overflow", len <= 0xFFFF, return ERR_VAL); LWIP_ERROR("mqtt_client_connect: client_info->client_user length must be > 0", len > 0, return ERR_VAL); client_user_len = (u16_t)len; len = remaining_length + 2 + client_user_len; LWIP_ERROR("mqtt_client_connect: remaining_length overflow", len <= 0xFFFF, return ERR_VAL); remaining_length = (u16_t)len; } if (client_info->client_pass != NULL) { flags |= MQTT_CONNECT_FLAG_PASSWORD; len = strlen(client_info->client_pass); LWIP_ERROR("mqtt_client_connect: client_info->client_pass length overflow", len <= 0xFFFF, return ERR_VAL); LWIP_ERROR("mqtt_client_connect: client_info->client_pass length must be > 0", len > 0, return ERR_VAL); client_pass_len = (u16_t)len; len = remaining_length + 2 + client_pass_len; LWIP_ERROR("mqtt_client_connect: remaining_length overflow", len <= 0xFFFF, return ERR_VAL); remaining_length = (u16_t)len; } /* Don't complicate things, always connect using clean session */ flags |= MQTT_CONNECT_FLAG_CLEAN_SESSION; len = strlen(client_info->client_id); LWIP_ERROR("mqtt_client_connect: client_info->client_id length overflow", len <= 0xFFFF, return ERR_VAL); client_id_length = (u16_t)len; len = remaining_length + 2 + client_id_length; LWIP_ERROR("mqtt_client_connect: remaining_length overflow", len <= 0xFFFF, return ERR_VAL); remaining_length = (u16_t)len; if (mqtt_output_check_space(&client->output, remaining_length) == 0) { return ERR_MEM; } #if LWIP_ALTCP && LWIP_ALTCP_TLS if (client_info->tls_config) { client->conn = altcp_tls_new(client_info->tls_config, IP_GET_TYPE(ip_addr)); } else #endif { client->conn = altcp_tcp_new_ip_type(IP_GET_TYPE(ip_addr)); } if (client->conn == NULL) { return ERR_MEM; } /* Set arg pointer for callbacks */ altcp_arg(client->conn, client); /* Any local address, pick random local port number */ err = altcp_bind(client->conn, IP_ADDR_ANY, 0); if (err != ERR_OK) { LWIP_DEBUGF(MQTT_DEBUG_WARN, ("mqtt_client_connect: Error binding to local ip/port, %d\n", err)); goto tcp_fail; } LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_client_connect: Connecting to host: %s at port:%"U16_F"\n", ipaddr_ntoa(ip_addr), port)); /* Connect to server */ err = altcp_connect(client->conn, ip_addr, port, mqtt_tcp_connect_cb); if (err != ERR_OK) { LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_client_connect: Error connecting to remote ip/port, %d\n", err)); goto tcp_fail; } /* Set error callback */ altcp_err(client->conn, mqtt_tcp_err_cb); client->conn_state = TCP_CONNECTING; /* Append fixed header */ mqtt_output_append_fixed_header(&client->output, MQTT_MSG_TYPE_CONNECT, 0, 0, 0, remaining_length); /* Append Protocol string */ mqtt_output_append_string(&client->output, "MQTT", 4); /* Append Protocol level */ mqtt_output_append_u8(&client->output, 4); /* Append connect flags */ mqtt_output_append_u8(&client->output, flags); /* Append keep-alive */ mqtt_output_append_u16(&client->output, client_info->keep_alive); /* Append client id */ mqtt_output_append_string(&client->output, client_info->client_id, client_id_length); /* Append will message if used */ if ((flags & MQTT_CONNECT_FLAG_WILL) != 0) { mqtt_output_append_string(&client->output, client_info->will_topic, will_topic_len); mqtt_output_append_string(&client->output, client_info->will_msg, will_msg_len); } /* Append user name if given */ if ((flags & MQTT_CONNECT_FLAG_USERNAME) != 0) { mqtt_output_append_string(&client->output, client_info->client_user, client_user_len); } /* Append password if given */ if ((flags & MQTT_CONNECT_FLAG_PASSWORD) != 0) { mqtt_output_append_string(&client->output, client_info->client_pass, client_pass_len); } return ERR_OK; tcp_fail: altcp_abort(client->conn); client->conn = NULL; return err; } /** * @ingroup mqtt * Disconnect from MQTT server * @param client MQTT client */ void mqtt_disconnect(mqtt_client_t *client) { LWIP_ASSERT_CORE_LOCKED(); LWIP_ASSERT("mqtt_disconnect: client != NULL", client); /* If connection in not already closed */ if (client->conn_state != TCP_DISCONNECTED) { /* Set conn_state before calling mqtt_close to prevent callback from being called */ client->conn_state = TCP_DISCONNECTED; mqtt_close(client, (mqtt_connection_status_t)0); } } /** * @ingroup mqtt * Check connection with server * @param client MQTT client * @return 1 if connected to server, 0 otherwise */ u8_t mqtt_client_is_connected(mqtt_client_t *client) { LWIP_ASSERT_CORE_LOCKED(); LWIP_ASSERT("mqtt_client_is_connected: client != NULL", client); return client->conn_state == MQTT_CONNECTED; } #endif /* LWIP_TCP && LWIP_CALLBACK_API */