Add pong delegate support for websoket connection and resource (#2156)

Add ability to call delegate on pong frame reception. This is useful for
closing stalled connections.
Remove websocket state change before calling close() in
WebsocketConnection destructor. Without this change if connection was
removed by WebsocketRecource, onDisconnect delegate for Websocket
connection will not run.

Sming/Core/Network/Http/Websocket/WebsocketConnection.cpp

@@ -166,6 +166,9 @@ int WebsocketConnection::staticOnControlEnd(void* userData)
 		connection->send(connection->controlFrame.payload, connection->controlFrame.payloadLength, WS_FRAME_PONG);
 	}
 
+	if(connection->controlFrame.type == WS_FRAME_PONG && connection->wsPong) {
+		connection->wsPong(*connection);
+	}
 	return WS_OK;
 }
 

Sming/Core/Network/Http/Websocket/WebsocketConnection.h

@@ -73,7 +73,6 @@ class WebsocketConnection
 
 	virtual ~WebsocketConnection()
 	{
-		state = eWSCS_Closed;
 		close();
 	}
 
@@ -214,7 +213,14 @@ class WebsocketConnection
 	{
 		wsBinary = handler;
 	}
-
+	/**
+	 * @brief Sets the callback handler to be called when pong reply received
+	 * @param handler
+	 */
+	void setPongHandler(WebsocketDelegate handler)
+	{
+		wsPong = handler;
+	}
 	/**
 	 * @brief Sets the callback handler to be called before closing a websocket connection
 	 * @param handler
@@ -298,6 +304,7 @@ class WebsocketConnection
 	WebsocketDelegate wsConnect = nullptr;
 	WebsocketMessageDelegate wsMessage = nullptr;
 	WebsocketBinaryDelegate wsBinary = nullptr;
+	WebsocketDelegate wsPong = nullptr;
 	WebsocketDelegate wsDisconnect = nullptr;
 
 	void* userData = nullptr;

Sming/Core/Network/Http/Websocket/WebsocketResource.cpp

@@ -23,6 +23,7 @@ int WebsocketResource::checkHeaders(HttpServerConnection& connection, HttpReques
 	socket->setBinaryHandler(wsBinary);
 	socket->setMessageHandler(wsMessage);
 	socket->setConnectionHandler(wsConnect);
+	socket->setPongHandler(wsPong);
 	socket->setDisconnectionHandler(wsDisconnect);
 	if(!socket->bind(request, response)) {
 		debug_w("Not a valid WebsocketRequest?");

Sming/Core/Network/Http/Websocket/WebsocketResource.h

@@ -48,6 +48,11 @@ class WebsocketResource : public HttpResource
 		wsBinary = handler;
 	}
 
+	void setPongHandler(WebsocketDelegate handler)
+	{
+		wsPong = handler;
+	}
+
 	void setDisconnectionHandler(WebsocketDelegate handler)
 	{
 		wsDisconnect = handler;
@@ -60,5 +65,6 @@ class WebsocketResource : public HttpResource
 	WebsocketDelegate wsConnect = nullptr;
 	WebsocketMessageDelegate wsMessage = nullptr;
 	WebsocketBinaryDelegate wsBinary = nullptr;
+	WebsocketDelegate wsPong = nullptr;
 	WebsocketDelegate wsDisconnect = nullptr;
 };