improve error checking in mqtt module

connect(), close(), subscribe(), publish()

app/modules/mqtt.c

@@ -75,7 +75,7 @@ typedef struct lmqtt_userdata
   tConnState connState;
 }lmqtt_userdata;
 
-static void socket_connect(struct espconn *pesp_conn);
+static sint8 socket_connect(struct espconn *pesp_conn);
 static void mqtt_socket_reconnected(void *arg, sint8_t err);
 static void mqtt_socket_connected(void *arg);
 
@@ -397,12 +397,12 @@ READPACKET:
 #ifdef CLIENT_SSL_ENABLE
     if( mud->secure )
     {
-      espconn_secure_sent( pesp_conn, node->msg.data, node->msg.length );
+      espconn_secure_send( pesp_conn, node->msg.data, node->msg.length );
     }
     else
 #endif
     {
-      espconn_sent( pesp_conn, node->msg.data, node->msg.length );
+      espconn_send( pesp_conn, node->msg.data, node->msg.length );
     }
   }
   NODE_DBG("receive, queue size: %d\n", msg_size(&(mud->mqtt_state.pending_msg_q)));
@@ -479,12 +479,12 @@ static void mqtt_socket_connected(void *arg)
 #ifdef CLIENT_SSL_ENABLE
   if(mud->secure)
   {
-    espconn_secure_sent(pesp_conn, temp_msg->data, temp_msg->length);
+    espconn_secure_send(pesp_conn, temp_msg->data, temp_msg->length);
   }
   else
 #endif
   {
-    espconn_sent(pesp_conn, temp_msg->data, temp_msg->length);
+    espconn_send(pesp_conn, temp_msg->data, temp_msg->length);
   }
   mud->keep_alive_tick = 0;
 
@@ -547,12 +547,12 @@ void mqtt_socket_timer(void *arg)
 #ifdef CLIENT_SSL_ENABLE
       if(mud->secure)
       {
-        espconn_secure_sent(mud->pesp_conn, pending_msg->msg.data, pending_msg->msg.length);
+        espconn_secure_send(mud->pesp_conn, pending_msg->msg.data, pending_msg->msg.length);
       }
       else
 #endif
       {
-        espconn_sent(mud->pesp_conn, pending_msg->msg.data, pending_msg->msg.length);
+        espconn_send(mud->pesp_conn, pending_msg->msg.data, pending_msg->msg.length);
       }
       mud->keep_alive_tick = 0;
       NODE_DBG("id: %d - qos: %d, length: %d\n", pending_msg->msg_id, pending_msg->publish_qos, pending_msg->msg.length);
@@ -571,12 +571,12 @@ void mqtt_socket_timer(void *arg)
 #ifdef CLIENT_SSL_ENABLE
         if(mud->secure)
         {
-          espconn_secure_sent(mud->pesp_conn, temp_msg->data, temp_msg->length);
+          espconn_secure_send(mud->pesp_conn, temp_msg->data, temp_msg->length);
         }
         else
 #endif
         {
-          espconn_sent(mud->pesp_conn, temp_msg->data, temp_msg->length);
+          espconn_send(mud->pesp_conn, temp_msg->data, temp_msg->length);
         }
         mud->keep_alive_tick = 0;
       }
@@ -805,43 +805,55 @@ static int mqtt_delete( lua_State* L )
   return 0;
 }
 
-static void socket_connect(struct espconn *pesp_conn)
+static sint8 socket_connect(struct espconn *pesp_conn)
 {
   NODE_DBG("enter socket_connect.\n");
+  sint8 espconn_status;
+
   if(pesp_conn == NULL)
-    return;
+    return ESPCONN_CONN;
   lmqtt_userdata *mud = (lmqtt_userdata *)pesp_conn->reverse;
   if(mud == NULL)
-    return;
+    return ESPCONN_ARG;
 
   mud->event_timeout = MQTT_CONNECT_TIMEOUT;
   mud->connState = MQTT_INIT;
 #ifdef CLIENT_SSL_ENABLE
   if(mud->secure)
   {
-    espconn_secure_connect(pesp_conn);
+    espconn_status = espconn_secure_connect(pesp_conn);
   }
   else
 #endif
   {
-    espconn_connect(pesp_conn);
+    espconn_status = espconn_connect(pesp_conn);
   }
 
   os_timer_arm(&mud->mqttTimer, 1000, 1);
 
   NODE_DBG("leave socket_connect.\n");
+
+  return espconn_status;
 }
 
-static void socket_dns_found(const char *name, ip_addr_t *ipaddr, void *arg);
+static sint8 socket_dns_found(const char *name, ip_addr_t *ipaddr, void *arg);
 static int dns_reconn_count = 0;
 static ip_addr_t host_ip; // for dns
-static void socket_dns_found(const char *name, ip_addr_t *ipaddr, void *arg)
+
+/* wrapper for using socket_dns_found() as callback function */
+static void socket_dns_foundcb(const char *name, ip_addr_t *ipaddr, void *arg)
+{
+  socket_dns_found(name, ipaddr, arg);
+}
+
+static sint8 socket_dns_found(const char *name, ip_addr_t *ipaddr, void *arg)
 {
   NODE_DBG("enter socket_dns_found.\n");
+  sint8 espconn_status = ESPCONN_OK;
   struct espconn *pesp_conn = arg;
   if(pesp_conn == NULL){
     NODE_DBG("pesp_conn null.\n");
-    return;
+    return -1;
   }
 
   if(ipaddr == NULL)
@@ -851,12 +863,11 @@ static void socket_dns_found(const char *name, ip_addr_t *ipaddr, void *arg)
       NODE_ERR( "DNS Fail!\n" );
       // Note: should delete the pesp_conn or unref self_ref here.
       mqtt_socket_disconnected(arg);   // although not connected, but fire disconnect callback to release every thing.
-      return;
+      return -1;
     }
     NODE_ERR( "DNS retry %d!\n", dns_reconn_count );
     host_ip.addr = 0;
-    espconn_gethostbyname(pesp_conn, name, &host_ip, socket_dns_found);
+    return espconn_gethostbyname(pesp_conn, name, &host_ip, socket_dns_foundcb);
-    return;
   }
 
   // ipaddr->addr is a uint32_t ip
@@ -867,9 +878,11 @@ static void socket_dns_found(const char *name, ip_addr_t *ipaddr, void *arg)
     NODE_DBG("TCP ip is set: ");
     NODE_DBG(IPSTR, IP2STR(&(ipaddr->addr)));
     NODE_DBG("\n");
-    socket_connect(pesp_conn);
+    espconn_status = socket_connect(pesp_conn);
   }
   NODE_DBG("leave socket_dns_found.\n");
+
+  return espconn_status;
 }
 
 // Lua: mqtt:connect( host, port, secure, auto_reconnect, function(client) )
@@ -884,6 +897,7 @@ static int mqtt_socket_connect( lua_State* L )
   int stack = 1;
   unsigned secure = 0, auto_reconnect = 0;
   int top = lua_gettop(L);
+  sint8 espconn_status;
 
   mud = (lmqtt_userdata *)luaL_checkudata(L, stack, "mqtt.socket");
   luaL_argcheck(L, mud, stack, "mqtt.socket expected");
@@ -993,8 +1007,8 @@ static int mqtt_socket_connect( lua_State* L )
     luaL_unref(L, LUA_REGISTRYINDEX, mud->self_ref);
   mud->self_ref = luaL_ref(L, LUA_REGISTRYINDEX);
 
-  espconn_regist_connectcb(pesp_conn, mqtt_socket_connected);
+  espconn_status = espconn_regist_connectcb(pesp_conn, mqtt_socket_connected);
-  espconn_regist_reconcb(pesp_conn, mqtt_socket_reconnected);
+  espconn_status |= espconn_regist_reconcb(pesp_conn, mqtt_socket_reconnected);
 
   os_timer_disarm(&mud->mqttTimer);
   os_timer_setfn(&mud->mqttTimer, (os_timer_func_t *)mqtt_socket_timer, mud);
@@ -1004,17 +1018,23 @@ static int mqtt_socket_connect( lua_State* L )
   {
     host_ip.addr = 0;
     dns_reconn_count = 0;
-    if(ESPCONN_OK == espconn_gethostbyname(pesp_conn, domain, &host_ip, socket_dns_found)){
+    if(ESPCONN_OK == espconn_gethostbyname(pesp_conn, domain, &host_ip, socket_dns_foundcb)){
-      socket_dns_found(domain, &host_ip, pesp_conn);  // ip is returned in host_ip.
+      espconn_status |= socket_dns_found(domain, &host_ip, pesp_conn);  // ip is returned in host_ip.
     }
   }
   else
   {
-    socket_connect(pesp_conn);
+    espconn_status |= socket_connect(pesp_conn);
   }
 
   NODE_DBG("leave mqtt_socket_connect.\n");
-  return 0;
+
+  if (espconn_status == ESPCONN_OK) {
+    lua_pushboolean(L, 1);
+  } else {
+    lua_pushboolean(L, 0);
+  }
+  return 1;
 }
 
 // Lua: mqtt:close()
@@ -1027,37 +1047,44 @@ static int mqtt_socket_close( lua_State* L )
 
   mud = (lmqtt_userdata *)luaL_checkudata(L, 1, "mqtt.socket");
   luaL_argcheck(L, mud, 1, "mqtt.socket expected");
-  if(mud == NULL)
+  if (mud == NULL || mud->pesp_conn == NULL) {
-    return 0;
+    lua_pushboolean(L, 0);
-
+    return 1;
-  if(mud->pesp_conn == NULL)
+  }
-    return 0;
 
   // Send disconnect message
   mqtt_message_t* temp_msg = mqtt_msg_disconnect(&mud->mqtt_state.mqtt_connection);
   NODE_DBG("Send MQTT disconnect infomation, data len: %d, d[0]=%d \r\n", temp_msg->length,  temp_msg->data[0]);
+
+  sint8 espconn_status;
 #ifdef CLIENT_SSL_ENABLE
   if(mud->secure)
-    espconn_secure_sent(mud->pesp_conn, temp_msg->data, temp_msg->length);
+    espconn_status = espconn_secure_send(mud->pesp_conn, temp_msg->data, temp_msg->length);
   else
 #endif
-    espconn_sent(mud->pesp_conn, temp_msg->data, temp_msg->length);
+    espconn_status = espconn_send(mud->pesp_conn, temp_msg->data, temp_msg->length);
 
   mud->mqtt_state.auto_reconnect = 0;   // stop auto reconnect.
 
 #ifdef CLIENT_SSL_ENABLE
   if(mud->secure){
     if(mud->pesp_conn->proto.tcp->remote_port || mud->pesp_conn->proto.tcp->local_port)
-      espconn_secure_disconnect(mud->pesp_conn);
+      espconn_status |= espconn_secure_disconnect(mud->pesp_conn);
   }
   else
 #endif
   {
     if(mud->pesp_conn->proto.tcp->remote_port || mud->pesp_conn->proto.tcp->local_port)
-      espconn_disconnect(mud->pesp_conn);
+      espconn_status |= espconn_disconnect(mud->pesp_conn);
   }
   NODE_DBG("leave mqtt_socket_close.\n");
-  return 0;
+
+  if (espconn_status == ESPCONN_OK) {
+    lua_pushboolean(L, 1);
+  } else {
+    lua_pushboolean(L, 0);
+  }
+  return 1;
 }
 
 // Lua: mqtt:on( "method", function() )
@@ -1143,6 +1170,7 @@ static int mqtt_socket_subscribe( lua_State* L ) {
 
     uint8_t temp_buf[MQTT_BUF_SIZE];
     uint32_t temp_pos = 0;
+    uint8_t overflow = 0;
 
     while( lua_next( L, stack ) != 0 ) {
       topic = luaL_checkstring( L, -2 );
@@ -1153,6 +1181,7 @@ static int mqtt_socket_subscribe( lua_State* L ) {
 
       if (temp_pos + temp_msg->length > MQTT_BUF_SIZE){
         lua_pop(L, 1);
+        overflow = 1;
         break;  // too long message for the outbuffer.
       }
       c_memcpy( temp_buf + temp_pos, temp_msg->data, temp_msg->length );
@@ -1166,6 +1195,11 @@ static int mqtt_socket_subscribe( lua_State* L ) {
       lua_pushboolean(L, 0);
       return 1;
     }
+    if (overflow != 0){
+      luaL_error( L, "buffer overflow, can't enqueue all subscriptions" );
+      lua_pushboolean(L, 0);
+      return 1;
+    }
 
     c_memcpy( temp_buffer, temp_buf, temp_pos );
     temp_msg->data = temp_buffer;
@@ -1197,23 +1231,25 @@ static int mqtt_socket_subscribe( lua_State* L ) {
 
   NODE_DBG("topic: %s - id: %d - qos: %d, length: %d\n", topic, node->msg_id, node->publish_qos, node->msg.length);
 
+  sint8 espconn_status = ESPCONN_IF;
+
   if(node && (1==msg_size(&(mud->mqtt_state.pending_msg_q))) && mud->event_timeout == 0){
     mud->event_timeout = MQTT_SEND_TIMEOUT;
     NODE_DBG("Sent: %d\n", node->msg.length);
 #ifdef CLIENT_SSL_ENABLE
     if( mud->secure )
     {
-          espconn_secure_sent( mud->pesp_conn, node->msg.data, node->msg.length );
+      espconn_status = espconn_secure_send( mud->pesp_conn, node->msg.data, node->msg.length );
     }
     else
 #endif
     {
-          espconn_sent( mud->pesp_conn, node->msg.data, node->msg.length );
+      espconn_status = espconn_send( mud->pesp_conn, node->msg.data, node->msg.length );
     }
     mud->keep_alive_tick = 0;
   }
 
-  if(!node){
+  if(!node || espconn_status != ESPCONN_OK){
     lua_pushboolean(L, 0);
   } else {
     lua_pushboolean(L, 1);  // enqueued succeed.
@@ -1232,6 +1268,7 @@ static int mqtt_socket_publish( lua_State* L )
   size_t l;
   uint8_t stack = 1;
   uint16_t msg_id = 0;
+
   mud = (lmqtt_userdata *)luaL_checkudata(L, stack, "mqtt.socket");
   luaL_argcheck(L, mud, stack, "mqtt.socket expected");
   stack++;
@@ -1285,23 +1322,25 @@ static int mqtt_socket_publish( lua_State* L )
   msg_queue_t *node = msg_enqueue(&(mud->mqtt_state.pending_msg_q), temp_msg,
                       msg_id, MQTT_MSG_TYPE_PUBLISH, (int)qos );
 
+  sint8 espconn_status = ESPCONN_IF;
+
   if(node && (1==msg_size(&(mud->mqtt_state.pending_msg_q))) && mud->event_timeout == 0){
     mud->event_timeout = MQTT_SEND_TIMEOUT;
     NODE_DBG("Sent: %d\n", node->msg.length);
 #ifdef CLIENT_SSL_ENABLE
     if( mud->secure )
     {
-      espconn_secure_sent( mud->pesp_conn, node->msg.data, node->msg.length );
+      espconn_status = espconn_secure_send( mud->pesp_conn, node->msg.data, node->msg.length );
     }
     else
 #endif
     {
-      espconn_sent( mud->pesp_conn, node->msg.data, node->msg.length );
+      espconn_status = espconn_send( mud->pesp_conn, node->msg.data, node->msg.length );
     }
     mud->keep_alive_tick = 0;
   }
 
-  if(!node){
+  if(!node || espconn_status != ESPCONN_OK){
     lua_pushboolean(L, 0);
   } else {
     lua_pushboolean(L, 1);  // enqueued succeed.

docs/en/modules/mqtt.md

@@ -71,7 +71,7 @@ Closes connection to the broker.
 none
 
 #### Returns
-`nil`
+`true` on success, `false` otherwise
 
 ## mqtt.client:connect()
 
@@ -88,7 +88,7 @@ Connects to the broker specified by the given host, port, and secure options.
 - `function(client)` call back function for when the connection was established
 
 #### Returns
-`nil`
+`true` on success, `false` otherwise
 
 ## mqtt.client:lwt()
 
@@ -135,7 +135,7 @@ Publishes a message.
 - `function(client)` optional callback fired when PUBACK received
 
 #### Returns
-`nil`
+`true` on success, `false` otherwise
 
 ## mqtt.client:subscribe()
 
@@ -143,11 +143,21 @@ Subscribes to one or several topics.
 
 #### Syntax
 `mqtt:subscribe(topic, qos[, function(client, topic, message)])`
+`mqtt:subscribe(table[, function(client, topic, message)])`
 
 #### Parameters
 - `topic` a [topic string](http://www.hivemq.com/blog/mqtt-essentials-part-5-mqtt-topics-best-practices)
 - `qos` QoS subscription level, default 0
+- `table` array of 'topic, qos' pairs to subscribe to
 - `function(client, topic, message)` optional callback fired when message received
 
 #### Returns
-`nil`
+`true` on success, `false` otherwise
+
+#### Example
+```lua
+-- subscribe topic with qos = 0
+m:subscribe("/topic",0, function(conn) print("subscribe success") end)
+
+-- or subscribe multiple topic (topic/0, qos = 0; topic/1, qos = 1; topic2 , qos = 2)
+m:subscribe({["topic/0"]=0,["topic/1"]=1,topic2=2}, function(conn) print("subscribe success") end)