void mqtt_sn_receive_connack(int sock)
{
connack_packet_t *packet = mqtt_sn_receive_packet(sock);
if (packet == NULL) {
log_err("Failed to connect to MQTT-SN gateway.");
exit(EXIT_FAILURE);
}
if (packet->type != MQTT_SN_TYPE_CONNACK) {
log_err("Was expecting CONNACK packet but received: %s", mqtt_sn_type_string(packet->type));
exit(EXIT_FAILURE);
}
// Check Connack return code
log_debug("CONNACK return code: 0x%2.2x", packet->return_code);
if (packet->return_code) {
log_err("CONNECT error: %s", mqtt_sn_return_code_string(packet->return_code));
exit(packet->return_code);
}
}
void* mqtt_sn_wait_for(uint8_t type, int sock)
{
while(TRUE) {
time_t now = time(NULL);
int ret;
// Time to send a ping?
if (keep_alive > 0 && (now - last_transmit) >= keep_alive) {
mqtt_sn_send_pingreq(sock);
}
ret = mqtt_sn_select(sock);
if (ret < 0) {
break;
} else if (ret > 0) {
char* packet = mqtt_sn_receive_packet(sock);
if (packet) {
switch(packet[1]) {
case MQTT_SN_TYPE_PUBLISH:
mqtt_sn_print_publish_packet((publish_packet_t *)packet);
break;
case MQTT_SN_TYPE_REGISTER:
mqtt_sn_process_register(sock, (register_packet_t*)packet);
break;
case MQTT_SN_TYPE_PINGRESP:
// do nothing
break;
case MQTT_SN_TYPE_DISCONNECT:
if (type != MQTT_SN_TYPE_DISCONNECT) {
log_warn("Received DISCONNECT from gateway.");
exit(EXIT_FAILURE);
}
break;
default:
if (packet[1] != type) {
log_warn(
"Was expecting %s packet but received: %s",
mqtt_sn_type_string(type),
mqtt_sn_type_string(packet[1])
);
}
break;
}
// Did we find what we were looking for?
if (packet[1] == type) {
return packet;
}
}
}
// Check for receive timeout
if (keep_alive > 0 && (now - last_receive) >= (keep_alive * 1.5)) {
log_err("Keep alive error: timed out while waiting for a %s from gateway.", mqtt_sn_type_string(type));
exit(EXIT_FAILURE);
}
}
return NULL;
}
int main(int argc, char* argv[])
{
int sock;
// Parse the command-line options
parse_opts(argc, argv);
// Enable debugging?
mqtt_sn_set_debug(debug);
// Create a UDP socket
sock = mqtt_sn_create_socket(mqtt_sn_host, mqtt_sn_port);
if (sock) {
// Connect to gateway
if (qos >= 0) {
if (qos==0) {
mqtt_sn_send_connect(sock, client_id, MQTT_SN_FLAG_CLEAN, keep_alive);
mqtt_sn_receive_connack(sock);
} else if (qos==1) {
mqtt_sn_send_connect(sock, client_id, MQTT_SN_FLAG_CLEAN | MQTT_SN_FLAG_WILL , keep_alive);
connack_packet_t *p= mqtt_sn_receive_packet(sock);
if ( p!= NULL && p->type==MQTT_SN_TYPE_WILLTOPICREQ) {
mqtt_sn_send_will_topic(sock, t_topic_name, MQTT_SN_FLAG_QOS_1 | MQTT_SN_FLAG_RETAIN);
p= mqtt_sn_receive_packet(sock);
if ( p!= NULL && p->type==MQTT_SN_TYPE_WILLMSGREQ) {
mqtt_sn_send_will_msg(sock, t_message_data);
} else {
fprintf(stderr,"Error: did not get MQTT_SN_TYPE_WILLMSGREQ.\n");
exit(-1);
}
} else {
fprintf(stderr,"Error: did not get MQTT_SN_TYPE_WILLTOPICREQ.\n");
exit(-1);
}
mqtt_sn_receive_connack(sock);
}
}
if (topic_id) {
// Use pre-defined topic ID
topic_id_type = MQTT_SN_TOPIC_TYPE_PREDEFINED;
} else if (strlen(topic_name) == 2) {
// Convert the 2 character topic name into a 2 byte topic id
topic_id = (topic_name[0] << 8) + topic_name[1];
topic_id_type = MQTT_SN_TOPIC_TYPE_SHORT;
} else if (qos >= 0) {
// Register the topic name
mqtt_sn_send_register(sock, topic_name);
topic_id = mqtt_sn_receive_regack(sock);
topic_id_type = MQTT_SN_TOPIC_TYPE_NORMAL;
}
// Publish to the topic
mqtt_sn_send_publish(sock, topic_id, topic_id_type, message_data, qos, retain);
if (qos==1) {
int retries=0;
while (1) {
connack_packet_t *p= mqtt_sn_receive_packet(sock);
if ( p!= NULL && p->type==MQTT_SN_TYPE_PUBACK) {
break;
} else
fprintf(stderr,"Warn: QoS 1 and send not acked -- retrying.. (%d/10)\n",retries);
if (retries++>10) {
fprintf(stderr,"Error: QoS 1 and send not acked, tried %d times\n",retries);
exit(-1);
}
sleep(1);
mqtt_sn_send_publish(sock, topic_id, topic_id_type, message_data, qos, retain);
}
if (retries)
fprintf(stderr,"Warn: Send required %d times, but was successful.\n",retries);
}
// Finally, disconnect
if (qos >= 0) {
mqtt_sn_send_disconnect(sock);
connack_packet_t *p= mqtt_sn_receive_packet(sock);
if ( p!= NULL && p->type==MQTT_SN_TYPE_DISCONNECT) {
// disconnect acked ok
} else
fprintf(stderr,"Warn: QoS >=0 and DISCONNECT not acked\n");
}
close(sock);
}
mqtt_sn_cleanup();
return 0;
}
