TimedDynamicPool.java

/*******************************************************************************
 * gMix open source project - https://svs.informatik.uni-hamburg.de/gmix/
 * Copyright (C) 2014  SVS
 *
 * This program is free software: you can redistribute it and/or modify 
 * it under the terms of the GNU General Public License as published by 
 * the Free Software Foundation, either version 3 of the License, or 
 * (at your option) any later version.
 *  
 * This program is distributed in the hope that it will be useful, 
 * but WITHOUT ANY WARRANTY; without even the implied warranty of 
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License 
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *******************************************************************************/
package userGeneratedContent.simulatorPlugIns.plugins.outputStrategy;

import java.security.SecureRandom;
import java.util.Vector;

import staticContent.evaluation.simulator.Simulator;
import staticContent.evaluation.simulator.annotations.plugin.Plugin;
import staticContent.evaluation.simulator.annotations.property.DoubleSimulationProperty;
import staticContent.evaluation.simulator.annotations.property.IntSimulationProperty;
import staticContent.evaluation.simulator.core.event.Event;
import staticContent.evaluation.simulator.core.event.EventExecutor;
import staticContent.evaluation.simulator.core.message.MixMessage;
import staticContent.evaluation.simulator.core.networkComponent.AbstractClient;
import staticContent.evaluation.simulator.core.networkComponent.Mix;
import userGeneratedContent.simulatorPlugIns.pluginRegistry.ClientSendStyle;
import userGeneratedContent.simulatorPlugIns.pluginRegistry.MixSendStyle;
import userGeneratedContent.simulatorPlugIns.plugins.clientSendStyle.ClientSendStyleImpl;
import userGeneratedContent.simulatorPlugIns.plugins.mixSendStyle.MixSendStyleImpl;


//Cottrell 1995 ("Mixmaster & Remailer Attacks")
//"The mix fires every t seconds, provided there are n + f(min) messages in the 
//mix; however, instead of sending n messages (as in a timed- and-threshold
//constant-pool mix), the mix sends the greater of 1 and m * frac messages,
//and retains the rest in the pool, where m + fmin is the number of messages
//in the mix (m >=n). If n = 1, this is the mix that has been used in the 
//Mixmaster remailer system for years."
// implemented as described in "Generalising Mixes" (Diaz)
@Plugin(pluginKey = "TIMED_DYNAMIC_POOL", pluginName="Timed Dynamic Pool")
public class TimedDynamicPool extends OutputStrategyImpl {

	private SimplexTimedDynamicPool requestPool;
	private SimplexTimedDynamicPool replyPool;
	private static SecureRandom secureRandom = new SecureRandom();
	
	@IntSimulationProperty( name = "Send rate (ms)",
			key = "TIMED_DYNAMIC_POOL_SEND_INTERVAL_IN_MS",
			min = 0)
	private int sendingRate;
	
	@IntSimulationProperty( name = "Minimum messages in pool (requests)",
			key = "TIMED_DYNAMIC_POOL_MIN_MESSAGES_IN_POOL",
			min = 0)
	private int minMessages;
	
	@DoubleSimulationProperty( name = "Fraction",
			key = "TIMED_DYNAMIC_POOL_FRACTION",
			min = 0,
			max = 1)
	private double fraction;
	
	public TimedDynamicPool(Mix mix, Simulator simulator) {
		super(mix, simulator);
		this.sendingRate = Simulator.settings.getPropertyAsInt("TIMED_DYNAMIC_POOL_SEND_INTERVAL_IN_MS");
		this.minMessages = Simulator.settings.getPropertyAsInt("TIMED_DYNAMIC_POOL_MIN_MESSAGES_IN_POOL");
		this.fraction = Simulator.settings.getPropertyAsDouble("TIMED_DYNAMIC_POOL_FRACTION");
		this.requestPool = new SimplexTimedDynamicPool(true, this.sendingRate, this.minMessages, this.fraction);
		this.replyPool = new SimplexTimedDynamicPool(false, this.sendingRate, this.minMessages, this.fraction);
	}

	@Override
	public void incomingRequest(MixMessage mixMessage) {
		requestPool.addMessage(mixMessage);
	}

	@Override
	public void incomingReply(MixMessage mixMessage) {
		replyPool.addMessage(mixMessage);
	}
	
	public class SimplexTimedDynamicPool implements EventExecutor {

		private boolean isRequestPool;
		private Vector<MixMessage> collectedMessages;
		private boolean isFirstMessage = true;
		private int sendingRate;
		private double minMessages;
		private double fraction;
		
		public SimplexTimedDynamicPool(boolean isRequestPool, int sendingRate, int minMessages, double fraction) {
			
			this.collectedMessages = new Vector<MixMessage>(simulator.getClients().size()*2);	
			this.isRequestPool = isRequestPool;
			this.sendingRate = sendingRate;
			this.minMessages = minMessages;
			this.fraction = fraction;
			
		}
		
		
		public void addMessage(MixMessage mixMessage) {
			
			if (isFirstMessage) {
				isFirstMessage = false;
				scheduleNextOutput();
			}
			
			collectedMessages.add(mixMessage);

		}

		
		public void putOutMessages() {
			
			if (collectedMessages.size() > minMessages) {
				
				int numberOfMessagesToPutOut = (int) Math.floor(fraction * (collectedMessages.size() - minMessages));
				
				for (int i=0; i<numberOfMessagesToPutOut; i++) {
					
					int chosen = secureRandom.nextInt(collectedMessages.size());
					
					if (isRequestPool)
						mix.putOutRequest(collectedMessages.remove(chosen));
					else
						mix.putOutReply(collectedMessages.remove(chosen));
				}
				
			}
	
		}
		
		
		private void scheduleNextOutput() {
			
			simulator.scheduleEvent(new Event(this, Simulator.getNow() + sendingRate, OutputStrategyEvent.TIMEOUT), this);
		
		}

		
		@Override
		public void executeEvent(Event e) {
			
			if (e.getEventType() == OutputStrategyEvent.TIMEOUT) {
				putOutMessages();
				scheduleNextOutput();
			} else 
				throw new RuntimeException("ERROR: TimedBatch received unknown Event: " +e); 
			
		}
		
	}

	
	@Override
	public ClientSendStyleImpl getClientSendStyle(AbstractClient client) {
		return ClientSendStyle.getInstance(client);
	}


	@Override
	public MixSendStyleImpl getMixSendStyle() {
		return MixSendStyle.getInstance(mix, mix);
	}
	
}