int MQTTConnect(MQTTClient* c, MQTTPacket_connectData* options)
{
Timer connect_timer;
int rc = FAILURE;
MQTTPacket_connectData default_options = MQTTPacket_connectData_initializer;
int len = 0;
#if defined(MQTT_TASK)
FreeRTOS_MutexLock(&c->mutex);
#endif
if (c->isconnected) /* don't send connect packet again if we are already connected */
goto exit;
TimerInit(&connect_timer);
TimerCountdownMS(&connect_timer, c->command_timeout_ms);
if (options == 0)
options = &default_options; /* set default options if none were supplied */
c->keepAliveInterval = options->keepAliveInterval;
TimerCountdown(&c->ping_timer, c->keepAliveInterval);
if ((len = MQTTSerialize_connect(c->buf, c->buf_size, options)) <= 0)
goto exit;
if ((rc = sendPacket(c, len, &connect_timer)) != SUCCESS)
goto exit;
// this will be a blocking call, wait for the connack
if (waitfor(c, CONNACK, &connect_timer) == CONNACK) {
unsigned char connack_rc = 255;
unsigned char sessionPresent = 0;
if (MQTTDeserialize_connack(&sessionPresent, &connack_rc, c->readbuf, c->readbuf_size) == 1)
rc = connack_rc;
else
rc = FAILURE;
} else
rc = FAILURE;
exit:
if (rc == SUCCESS)
c->isconnected = 1;
#if defined(MQTT_TASK)
FreeRTOS_MutexUnlock(&c->mutex);
#endif
return rc;
}
static int readPacket(MQTTClient *c, Timer *timer)
{
MQTTHeader header = {0};
int len = 0;
int rem_len = 0;
/* 1. read the header byte. This has the packet type in it */
int rc = c->ipstack->mqttread(c->ipstack, c->readbuf, 1, TimerLeftMS(timer));
if (rc != 1) {
goto exit;
}
len = 1;
/* 2. read the remaining length. This is variable in itself */
decodePacket(c, &rem_len, TimerLeftMS(timer));
len += MQTTPacket_encode(c->readbuf + 1, rem_len); /* put the original remaining length back into the buffer */
if (rem_len > (c->readbuf_size - len)) {
rc = BUFFER_OVERFLOW;
goto exit;
}
/* 3. read the rest of the buffer using a callback to supply the rest of the data */
if (rem_len > 0 && (rc = c->ipstack->mqttread(c->ipstack, c->readbuf + len, rem_len, TimerLeftMS(timer)) != rem_len)) {
rc = 0;
goto exit;
}
header.byte = c->readbuf[0];
rc = header.bits.type;
if (c->keepAliveInterval > 0) {
TimerCountdown(&c->last_received, c->keepAliveInterval); // record the fact that we have successfully received a packet
}
exit:
return rc;
}
static int sendPacket(MQTTClient *c, int length, Timer *timer)
{
int rc = FAILURE,
sent = 0;
while (sent < length && !TimerIsExpired(timer)) {
rc = c->ipstack->mqttwrite(c->ipstack, &c->buf[sent], length, TimerLeftMS(timer));
if (rc < 0) { // there was an error writing the data
break;
}
sent += rc;
}
if (sent == length) {
TimerCountdown(&c->last_sent, c->keepAliveInterval); // record the fact that we have successfully sent the packet
rc = SUCCESS;
} else {
rc = FAILURE;
}
return rc;
}
int keepalive(MQTTClient* c)
{
int rc = SUCCESS;
if (c->keepAliveInterval == 0) {
rc = SUCCESS;
goto exit;
}
if (TimerIsExpired(&c->ping_timer)) {
printf("keep alive counter expired\n");
if (!c->ping_outstanding) {
printf("keep alive counter reset\n");
//Set the pingreq send timeout
Timer timer;
TimerInit(&timer);
TimerCountdownMS(&timer, 1000);
int len = MQTTSerialize_pingreq(c->buf, c->buf_size);
/* If the sendPacket success, the keep alive works with keepAliveInterval */
if (len > 0 && (rc = sendPacket(c, len, &timer)) == SUCCESS) {// send the ping packet
c->ping_outstanding = 1;
TimerCountdown(&c->ping_timer, c->keepAliveInterval); // record the fact that we have successfully sent the packet
} else {
rc = FAILURE;
}
} else {
printf("keep alive counter failure\n");
rc = FAILURE;
}
}
exit:
return rc;
}
int MQTTConnectWithResults(MQTTClient *c, MQTTPacket_connectData *options, MQTTConnackData *data)
{
Timer connect_timer;
int rc = FAILURE;
MQTTPacket_connectData default_options = MQTTPacket_connectData_initializer;
int len = 0;
#if defined(MQTT_TASK)
MutexLock(&c->mutex);
#endif
if (c->isconnected) { /* don't send connect packet again if we are already connected */
goto exit;
}
TimerInit(&connect_timer);
TimerCountdownMS(&connect_timer, c->command_timeout_ms);
if (options == 0) {
options = &default_options; /* set default options if none were supplied */
}
c->keepAliveInterval = options->keepAliveInterval;
c->cleansession = options->cleansession;
TimerCountdown(&c->last_received, c->keepAliveInterval);
if ((len = MQTTSerialize_connect(c->buf, c->buf_size, options)) <= 0) {
goto exit;
}
if ((rc = sendPacket(c, len, &connect_timer)) != SUCCESS) { // send the connect packet
goto exit; // there was a problem
}
// this will be a blocking call, wait for the connack
if (waitfor(c, CONNACK, &connect_timer) == CONNACK) {
data->rc = 0;
data->sessionPresent = 0;
if (MQTTDeserialize_connack(&data->sessionPresent, &data->rc, c->readbuf, c->readbuf_size) == 1) {
rc = data->rc;
} else {
rc = FAILURE;
}
} else {
rc = FAILURE;
}
exit:
if (rc == SUCCESS) {
c->isconnected = 1;
c->ping_outstanding = 0;
}
#if defined(MQTT_TASK)
MutexUnlock(&c->mutex);
#endif
return rc;
}
