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/**
* @file
* MQTT client
*
* @defgroup mqtt MQTT client
* @ingroup apps
* @verbinclude mqtt_client.txt
*/
/*
* Copyright (c) 2016 Erik Andersson <erian747@gmail.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. 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 <erian747@gmail.com>
*
*
* @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 <erian747@gmail.com>
*
*/
#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 <string.h>
#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 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, 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 < MQTT_REQ_MAX_IN_FLIGHT; 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
*/
static void
mqtt_init_requests(struct mqtt_request_t *r_objs)
{
u8_t n;
LWIP_ASSERT("mqtt_init_requests: r_objs != NULL", r_objs != NULL);
for (n = 0; n < MQTT_REQ_MAX_IN_FLIGHT; 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 */
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 {
client->cyclic_tick++;
}
}
} 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_incomming_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_idx header index
* @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_idx, u16_t length, u32_t remaining_length)
{
mqtt_connection_status_t res = MQTT_CONNECT_ACCEPTED;
u8_t *var_hdr_payload = client->rx_buffer + fixed_hdr_idx;
/* Control packet type */
u8_t pkt_type = MQTT_CTL_PACKET_TYPE(client->rx_buffer[0]);
u16_t pkt_id = 0;
LWIP_ERROR("buffer length mismatch", fixed_hdr_idx + length <= MQTT_VAR_HEADER_BUFFER_LEN,
return MQTT_CONNECT_DISCONNECTED);
if (pkt_type == MQTT_MSG_TYPE_CONNACK) {
if (client->conn_state == MQTT_CONNECTING) {
/* 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 != 0) {
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 <= MQTT_VAR_HEADER_BUFFER_LEN) {
/* Should have topic and pkt id*/
u8_t *topic;
u16_t after_topic;
u8_t bkp;
u16_t topic_len = var_hdr_payload[0];
topic_len = (topic_len << 8) + (u16_t)(var_hdr_payload[1]);
topic = var_hdr_payload + 2;
after_topic = 2 + topic_len;
/* Check length, add one byte even for QoS 0 so that zero termination will fit */
if ((after_topic + (qos ? 2 : 1)) > length) {
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) {
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_incomming_publish: Received message with QoS %d at topic: %s, payload length %d\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) {
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_incomming_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 {
/* 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_incomming_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_idx = 0;
u8_t b = 0;
while (p->tot_len > in_offset) {
if ((fixed_hdr_idx < 2) || ((b & 0x80) != 0)) {
if (fixed_hdr_idx < client->msg_idx) {
b = client->rx_buffer[fixed_hdr_idx];
} else {
b = pbuf_get_at(p, in_offset++);
client->rx_buffer[client->msg_idx++] = b;
}
fixed_hdr_idx++;
if (fixed_hdr_idx >= 2) {
msg_rem_len |= (u32_t)(b & 0x7f) << ((fixed_hdr_idx - 2) * 7);
if ((b & 0x80) == 0) {
LWIP_DEBUGF(MQTT_DEBUG_TRACE, ("mqtt_parse_incoming: Remaining length after fixed header: %d\n", msg_rem_len));
if (msg_rem_len == 0) {
/* Complete message with no extra headers of payload received */
mqtt_message_received(client, fixed_hdr_idx, 0, 0);
client->msg_idx = 0;
fixed_hdr_idx = 0;
} else {
/* Bytes remaining in message */
msg_rem_len = (msg_rem_len + fixed_hdr_idx) - client->msg_idx;
}
}
}
} else {
u16_t cpy_len, cpy_start, buffer_space;
cpy_start = (client->msg_idx - fixed_hdr_idx) % (MQTT_VAR_HEADER_BUFFER_LEN - fixed_hdr_idx) + fixed_hdr_idx;
/* 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 - cpy_start;
if (cpy_len > buffer_space) {
cpy_len = buffer_space;
}
pbuf_copy_partial(p, client->rx_buffer + cpy_start, 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: %d, cpy_len: %d, remaining %d\n", client->msg_idx, cpy_len, msg_rem_len));
if (msg_rem_len == 0 || cpy_len == buffer_space) {
/* Whole message received or buffer is full */
mqtt_connection_status_t res = mqtt_message_received(client, fixed_hdr_idx, (cpy_start + cpy_len) - fixed_hdr_idx, msg_rem_len);
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_idx = 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 = 0;
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("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;
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));
if (qos > 0) {
remaining_length += 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;
}
r = mqtt_create_request(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 reponse 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("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, 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("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)
{
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;
u8_t client_user_len = 0, client_pass_len = 0;
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 */
memset(client, 0, sizeof(mqtt_client_t));
client->connect_arg = arg;
client->connect_cb = cb;
client->keep_alive = client_info->keep_alive;
mqtt_init_requests(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 <= 0xFF, return ERR_VAL);
LWIP_ERROR("mqtt_client_connect: client_info->client_user length must be > 0", len > 0, return ERR_VAL);
client_user_len = (u8_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 <= 0xFF, return ERR_VAL);
LWIP_ERROR("mqtt_client_connect: client_info->client_pass length must be > 0", len > 0, return ERR_VAL);
client_pass_len = (u8_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;
}
client->conn = altcp_tcp_new();
if (client->conn == NULL) {
return ERR_MEM;
}
#if LWIP_ALTCP && LWIP_ALTCP_TLS
if (client_info->tls_config) {
struct altcp_pcb *pcb_tls = altcp_tls_new(client_info->tls_config, client->conn);
if (pcb_tls == NULL) {
altcp_close(client->conn);
return ERR_MEM;
}
client->conn = pcb_tls;
}
#endif
/* 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("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("mqtt_client_is_connected: client != NULL", client);
return client->conn_state == MQTT_CONNECTED;
}
#endif /* LWIP_TCP && LWIP_CALLBACK_API */