Merge pull request #1252 from woogerboy21/max_player_limit

Servatrice: Restrict the total number of users able to connect (Max User Limit)

cockatrice/src/localserver.h

@@ -27,6 +27,7 @@ public:
     AuthenticationResult checkUserPassword(Server_ProtocolHandler *handler, const QString &user, const QString &password, QString &reasonStr, int &secondsLeft);
     int getNextGameId() { return localServer->getNextLocalGameId(); }
     int getNextReplayId() { return -1; }
+    int getActiveUserCount() { return 0; }
 };
 
 #endif

cockatrice/src/window_main.cpp

@@ -71,6 +71,7 @@ void MainWindow::processConnectionClosedEvent(const Event_ConnectionClosed &even
     client->disconnectFromServer();
     QString reasonStr;
     switch (event.reason()) {
+	case Event_ConnectionClosed::USER_LIMIT_REACHED: reasonStr = tr("The server has reached its maximum user capacity, please check back later."); break;
         case Event_ConnectionClosed::TOO_MANY_CONNECTIONS: reasonStr = tr("There are too many concurrent connections from your address."); break;
         case Event_ConnectionClosed::BANNED: {
             reasonStr = tr("Banned by moderator");

common/pb/event_connection_closed.proto

@@ -10,6 +10,7 @@ message Event_ConnectionClosed {
 		TOO_MANY_CONNECTIONS = 3;
 		BANNED = 4;
 		USERNAMEINVALID = 5;
+		USER_LIMIT_REACHED = 6;
 	}
 	optional CloseReason reason = 1;
 	optional string reason_str = 2;

common/server_database_interface.h

@@ -31,6 +31,7 @@ public slots:
 public:
     virtual int getNextGameId() = 0;
     virtual int getNextReplayId() = 0;
+    virtual int getActiveUserCount() = 0;
     
     virtual void clearSessionTables() { }
     virtual void lockSessionTables() { }

servatrice/servatrice.ini.example

@@ -188,6 +188,11 @@ max_game_inactivity_time=120
 
 
 [security]
+; You may want to restrict the number of users that can connect to your server at any given time.
+enable_max_user_limit=false
+
+; Maximum number of users that can connect to the server, default is 500.
+max_users_total=500
 
 ; Maximum number of users that can connect from the same IP address; useful to avoid bots, default is 4
 max_users_per_address=4

servatrice/src/servatrice.cpp

@@ -160,6 +160,14 @@ bool Servatrice::initServer()
         authenticationMethod = AuthenticationNone;
     }
 
+	bool maxUserLimitEnabled = settingsCache->value("security/enable_max_user_limit", false).toBool();
+	qDebug() << "Maximum user limit enabled: " << maxUserLimitEnabled;
+
+	if (maxUserLimitEnabled){
+		int maxUserLimit = settingsCache->value("security/max_users_total", 500).toInt();
+		qDebug() << "Maximum user limit: " << maxUserLimit;
+	}
+
     bool registrationEnabled = settingsCache->value("registration/enabled", false).toBool();
     bool requireEmailForRegistration = settingsCache->value("registration/requireemail", true).toBool();
 

servatrice/src/servatrice_database_interface.cpp

@@ -805,3 +805,23 @@ bool Servatrice_DatabaseInterface::changeUserPassword(const QString &user, const
     }
     return false;
 }
+
+int Servatrice_DatabaseInterface::getActiveUserCount()
+{
+	int userCount = 0;
+
+	if (!checkSql())
+		return userCount;
+
+	QSqlQuery *query = prepareQuery("select count(*) from {prefix}_sessions where id_server = :serverid AND end_time is NULL");
+	query->bindValue(":serverid", server->getServerId());
+	if (!execSqlQuery(query)){
+		return userCount;
+	}
+
+	if (query->next()){
+		userCount = query->value(0).toInt();
+	}
+
+	return userCount;
+}
\ No newline at end of file

servatrice/src/servatrice_database_interface.h

@@ -58,6 +58,7 @@ public:
 
     int getNextGameId();
     int getNextReplayId();
+    int getActiveUserCount();
     qint64 startSession(const QString &userName, const QString &address);
     void endSession(qint64 sessionId);
     void clearSessionTables();

servatrice/src/serversocketinterface.cpp

@@ -18,6 +18,7 @@
  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  ***************************************************************************/
 
+#include <iostream>
 #include <QSqlQuery>
 #include <QHostAddress>
 #include <QDebug>
@@ -120,14 +121,33 @@ bool ServerSocketInterface::initSession()
     SessionEvent *identSe = prepareSessionEvent(identEvent);
     sendProtocolItem(*identSe);
     delete identSe;
-    
-    int maxUsers = servatrice->getMaxUsersPerAddress();
+
+	//limit the number of total users based on configuration settings
+	bool enforceUserLimit = settingsCache->value("security/enable_max_user_limit", false).toBool();
+	if (enforceUserLimit){
+		int userLimit = settingsCache->value("security/max_users_total", 500).toInt();
+		int playerCount = (databaseInterface->getActiveUserCount() + 1);
+		if (playerCount > userLimit){
+			std::cerr << "Max Users Total Limit Reached, please increase the max_users_total setting." << std::endl;
+			logger->logMessage(QString("Max Users Total Limit Reached, please increase the max_users_total setting."), this);
+			Event_ConnectionClosed event;
+			event.set_reason(Event_ConnectionClosed::USER_LIMIT_REACHED);
+			SessionEvent *se = prepareSessionEvent(event);
+			sendProtocolItem(*se);
+			delete se;
+			return false;
+		}
+		else {
+			std::cerr << "Player Count: " << playerCount << " / " << userLimit << std::endl;
+		}
+	}
 
     //allow unlimited number of connections from the trusted sources
-    QString trustedSources = settingsCache->value("server/trusted_sources","127.0.0.1,::1").toString();
+    QString trustedSources = settingsCache->value("security/trusted_sources","127.0.0.1,::1").toString();
     if (trustedSources.contains(socket->peerAddress().toString(),Qt::CaseInsensitive))
         return true;
     
+	int maxUsers = servatrice->getMaxUsersPerAddress();
     if ((maxUsers > 0) && (servatrice->getUsersWithAddress(socket->peerAddress()) >= maxUsers)) {
         Event_ConnectionClosed event;
         event.set_reason(Event_ConnectionClosed::TOO_MANY_CONNECTIONS);