Check broker IP conversion. Adjust state machine accordingly

The result of converting the IP address of the broker wasn't checked. As a result, the pointer was left uninitialised and the IPv6 address used for connecting was some random data. The function now returns an error. Before connect_to_broker is called, mqtt_register is executed, which memsets conn to 0, making its state 0 (MQTT_CONN_STATE_ERROR). In order to recover from this error state, the extra check was added in the MQTT_CLIENT_STATE_NEWCONFIG state.

This was discovered using [CodeSonar](https://www.grammatech.com/products/codesonar)
This commit is contained in:
Alexandru-Ioan Pop 2017-03-12 20:59:00 +00:00
parent 4425a67433
commit f15b86158b
2 changed files with 13 additions and 6 deletions

View file

@ -1333,7 +1333,9 @@ mqtt_connect(struct mqtt_connection *conn, char *host, uint16_t port,
conn->connect_vhdr_flags |= MQTT_VHDR_CLEAN_SESSION_FLAG;
/* convert the string IPv6 address to a numeric IPv6 address */
uiplib_ip6addrconv(host, &ip6addr);
if(uiplib_ip6addrconv(host, &ip6addr) == 0) {
return MQTT_STATUS_ERROR;
}
uip_ipaddr_copy(&(conn->server_ip), ipaddr);

View file

@ -698,10 +698,15 @@ static void
connect_to_broker(void)
{
/* Connect to MQTT server */
mqtt_connect(&conn, conf->broker_ip, conf->broker_port,
conf->pub_interval * 3);
mqtt_status_t conn_attempt_result = mqtt_connect(&conn, conf->broker_ip,
conf->broker_port,
conf->pub_interval * 3);
state = MQTT_CLIENT_STATE_CONNECTING;
if(conn_attempt_result == MQTT_STATUS_OK) {
state = MQTT_CLIENT_STATE_CONNECTING;
} else {
state = MQTT_CLIENT_STATE_CONFIG_ERROR;
}
}
/*---------------------------------------------------------------------------*/
static void
@ -827,8 +832,8 @@ state_machine(void)
}
break;
case MQTT_CLIENT_STATE_NEWCONFIG:
/* Only update config after we have disconnected */
if(conn.state == MQTT_CONN_STATE_NOT_CONNECTED) {
/* Only update config after we have disconnected or in the case of an error */
if(conn.state == MQTT_CONN_STATE_NOT_CONNECTED || conn.state == MQTT_CONN_STATE_ERROR) {
update_config();
DBG("New config\n");