mqtt plugin: Compile fixes.

This compiles with libmosquitto 0.15.0. It appears newer versions of the
library have some interface changes, so we should add a version check.
Luckily, libmosquitto provides everything we need.

diff --git a/src/mqtt.c b/src/mqtt.c
index 3bed0a5..7adc7f7 100644 (file)
--- a/src/mqtt.c
+++ b/src/mqtt.c
@@ -56,6 +56,30 @@ struct mqtt_client_conf
     pthread_mutex_t     lock;
 };
 
+static char const *mosquitto_strerror (int code)
+{
+    switch (code)
+    {
+        case MOSQ_ERR_SUCCESS: return "MOSQ_ERR_SUCCESS";
+        case MOSQ_ERR_NOMEM: return "MOSQ_ERR_NOMEM";
+        case MOSQ_ERR_PROTOCOL: return "MOSQ_ERR_PROTOCOL";
+        case MOSQ_ERR_INVAL: return "MOSQ_ERR_INVAL";
+        case MOSQ_ERR_NO_CONN: return "MOSQ_ERR_NO_CONN";
+        case MOSQ_ERR_CONN_REFUSED: return "MOSQ_ERR_CONN_REFUSED";
+        case MOSQ_ERR_NOT_FOUND: return "MOSQ_ERR_NOT_FOUND";
+        case MOSQ_ERR_CONN_LOST: return "MOSQ_ERR_CONN_LOST";
+        case MOSQ_ERR_SSL: return "MOSQ_ERR_SSL";
+        case MOSQ_ERR_PAYLOAD_SIZE: return "MOSQ_ERR_PAYLOAD_SIZE";
+        case MOSQ_ERR_NOT_SUPPORTED: return "MOSQ_ERR_NOT_SUPPORTED";
+        case MOSQ_ERR_AUTH: return "MOSQ_ERR_AUTH";
+        case MOSQ_ERR_ACL_DENIED: return "MOSQ_ERR_ACL_DENIED";
+        case MOSQ_ERR_UNKNOWN: return "MOSQ_ERR_UNKNOWN";
+        case MOSQ_ERR_ERRNO: return "MOSQ_ERR_ERRNO";
+    }
+
+    return "UNKNOWN ERROR CODE";
+}
+
 /*
  * Functions
  */
@@ -91,7 +115,7 @@ static int mqtt_reconnect_broker (struct mqtt_client_conf *conf)
 } /* mqtt_reconnect_broker */
 
 static int mqtt_publish_message (struct mqtt_client_conf *conf, char *topic,
-    char *payload, size_t payload_len)
+    void const *payload, size_t payload_len)
 {
     char errbuf[1024];
     int status;
@@ -329,13 +353,16 @@ static int mqtt_config (oconfig_item_t *ci)
     memset (&user_data, 0, sizeof (user_data));
     user_data.data = conf;
 
-    if ((conf->mosq = mosquitto_new (conf->client_id, true, NULL)) == NULL) {
-        ERROR ("mqtt_config: mosquitto_new failed");
+    conf->mosq = mosquitto_new (conf->client_id, /* user data = */ conf);
+    if (conf->mosq == NULL)
+    {
+        ERROR ("mqtt plugin: mosquitto_new failed");
+        free (conf);
         return (-1);
     }
 
-    status = mosquitto_connect (conf->mosq, conf->host, conf->port, 10);
-
+    status = mosquitto_connect (conf->mosq, conf->host, conf->port,
+            /* keepalive = */ 10, /* clean session = */ 1);
     if (status != MOSQ_ERR_SUCCESS) {
         ERROR ("mqtt_config: mosquitto_connect failed: %s",
             (status == MOSQ_ERR_ERRNO ?