CLOUD: Add "minimal mode" in LocalWebserver

StorageWizardDialog now runs LocalWebserver in "minimal mode" for
security reasons. In this mode server uses only those handlers which
state to support it.

There are two handlers which support minimal mode: IndexPageHandler
(which handles `code` requests needed by StorageWizardDialog) and
ResourceHandler (which provides inner resources like `style.css` or
`logo.png` from `wwwroot.zip` archive).

backends/networking/sdl_net/handlers/basehandler.h

@@ -33,6 +33,7 @@ public:
 	virtual ~BaseHandler() {}
 
 	virtual void handle(Client &) = 0;
+	virtual bool minimalModeSupported() { return false; }
 };
 
 } // End of namespace Networking

backends/networking/sdl_net/handlers/indexpagehandler.cpp

@@ -58,4 +58,8 @@ void IndexPageHandler::handle(Client &client) {
 	HandlerUtils::setMessageHandler(client, _("ScummVM got the code and already connects to your cloud storage!"));
 }
 
+bool IndexPageHandler::minimalModeSupported() {
+	return true;
+}
+
 } // End of namespace Networking

backends/networking/sdl_net/handlers/indexpagehandler.h

@@ -37,6 +37,7 @@ public:
 
 	Common::String code() const;
 	virtual void handle(Client &client);
+	virtual bool minimalModeSupported();
 };
 
 } // End of namespace Networking

backends/networking/sdl_net/handlers/resourcehandler.cpp

@@ -68,4 +68,8 @@ void ResourceHandler::handle(Client &client) {
 	LocalWebserver::setClientGetHandler(client, file, 200, determineMimeType(filename));
 }
 
+bool ResourceHandler::minimalModeSupported() {
+	return true;
+}
+
 } // End of namespace Networking

backends/networking/sdl_net/handlers/resourcehandler.h

@@ -34,6 +34,7 @@ public:
 	virtual ~ResourceHandler();
 
 	virtual void handle(Client &client);
+	virtual bool minimalModeSupported();
 };
 
 } // End of namespace Networking

backends/networking/sdl_net/localwebserver.cpp

@@ -49,7 +49,7 @@ DECLARE_SINGLETON(Networking::LocalWebserver);
 namespace Networking {
 
 LocalWebserver::LocalWebserver(): _set(nullptr), _serverSocket(nullptr), _timerStarted(false),
-	_stopOnIdle(false), _clients(0), _idlingFrames(0), _serverPort(DEFAULT_SERVER_PORT) {
+	_stopOnIdle(false), _minimalMode(false), _clients(0), _idlingFrames(0), _serverPort(DEFAULT_SERVER_PORT) {
 	addPathHandler("/", &_indexPageHandler);
 	addPathHandler("/files", &_filesPageHandler);
 	addPathHandler("/create", &_createDirectoryHandler);
@@ -83,7 +83,7 @@ void LocalWebserver::stopTimer() {
 	_timerStarted = false;
 }
 
-void LocalWebserver::start() {
+void LocalWebserver::start(bool useMinimalMode) {
 	_handleMutex.lock();
 	_serverPort = getPort();
 	_stopOnIdle = false;
@@ -91,6 +91,7 @@ void LocalWebserver::start() {
 		_handleMutex.unlock();
 		return;
 	}
+	_minimalMode = useMinimalMode;
 	startTimer();
 
 	// Create a listening TCP socket
@@ -211,18 +212,28 @@ void LocalWebserver::handleClient(uint32 i) {
 	case READING_HEADERS:
 		_client[i].readHeaders();
 		break;
-	case READ_HEADERS: //decide what to do next with that client
-		//if GET, check whether we know a handler for such URL
-		//if PUT, check whether we know a handler for that URL
-		if (_pathHandlers.contains(_client[i].path()))
-			_pathHandlers[_client[i].path()]->handle(_client[i]);
-		else if (_defaultHandler)
-			_defaultHandler->handle(_client[i]); //try default handler
+	case READ_HEADERS: {
+		// decide what to do next with that client
+		// check whether we know a handler for such URL
+		BaseHandler *handler = nullptr;
+		if (_pathHandlers.contains(_client[i].path())) {
+			handler = _pathHandlers[_client[i].path()];
+		} else {
+			// try default handler
+			handler = _defaultHandler;
+		}
+
+		// if server's in "minimal mode", only handlers which support it are used
+		if (handler && (!_minimalMode || handler->minimalModeSupported()))
+			handler->handle(_client[i]);
 
 		if (_client[i].state() == BEING_HANDLED || _client[i].state() == INVALID)
 			break;
-		//if no handler, answer with default BAD REQUEST
-		//fallthrough
+
+		// if no handler, answer with default BAD REQUEST
+		// fallthrough
+	}
+
 	case BAD_REQUEST:
 		setClientGetHandler(_client[i], "<html><head><title>ScummVM - Bad Request</title></head><body>BAD REQUEST</body></html>", 400);
 		break;

backends/networking/sdl_net/localwebserver.h

@@ -60,7 +60,7 @@ class LocalWebserver : public Common::Singleton<LocalWebserver> {
 	TCPsocket _serverSocket;
 	Client _client[MAX_CONNECTIONS];
 	int _clients;
-	bool _timerStarted, _stopOnIdle;
+	bool _timerStarted, _stopOnIdle, _minimalMode;
 	Common::HashMap<Common::String, BaseHandler*> _pathHandlers;
 	BaseHandler *_defaultHandler;
 	IndexPageHandler _indexPageHandler;
@@ -90,7 +90,7 @@ public:
 	LocalWebserver();
 	virtual ~LocalWebserver();
 
-	void start();
+	void start(bool useMinimalMode = false);
 	void stop();
 	void stopOnIdle();
 

gui/storagewizarddialog.cpp

@@ -132,7 +132,7 @@ void StorageWizardDialog::open() {
 #ifdef USE_SDL_NET
 	if (Cloud::CloudManager::couldUseLocalServer()) {
 		_stopServerOnClose = !LocalServer.isRunning();
-		LocalServer.start();
+		LocalServer.start(true); // using "minimal mode" (no "/files", "/download", etc available)
 		LocalServer.indexPageHandler().setTarget(this);
 	}
 #endif