/*
* Copyright (c) 2012 Alexander Diener,
*
* 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 de.fhkn.in.uce.directconnection.core;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import de.fhkn.in.uce.directconnection.message.DirectconnectionAttribute;
import de.fhkn.in.uce.stun.message.Message;
/**
* Target of direct connection. No specific NAT traversal technique is used.
*
* @author Alexander Diener (aldiener@htwg-konstanz.de)
*
*/
public final class DirectconnectionTarget {
private static final Logger logger = LoggerFactory.getLogger(DirectconnectionTarget.class);
/**
* Creates a {@link DirectconnectionTarget} object.
*/
public DirectconnectionTarget() {
super();
}
/**
* Creates a server socket and waits for incoming connections. The local
* address of the control connection is used to bind the server socket.
*
* @param controlConnection
* the control connection to the mediator
* @return the socket which is connected to the source
* @throws Exception
*/
public Socket establishTargetSideConnection(final Socket controlConnection, final Message connectionRequestMessage)
throws Exception {
final InetSocketAddress localAddress = new InetSocketAddress(controlConnection.getLocalAddress(),
controlConnection.getLocalPort());
logger.debug("LocalAddress={}", localAddress.toString()); //$NON-NLS-1$
final ServerSocket serverSocket = this.createBoundServerSocket(localAddress);
logger.debug(
"Server socket listening on {}:{}", serverSocket.getLocalSocketAddress().toString(), serverSocket.getLocalPort()); //$NON-NLS-1$
this.sendResponseForTargetIsReady(controlConnection, connectionRequestMessage);
logger.debug("response sent and waiting for incoming connection"); //$NON-NLS-1$
final Socket result = serverSocket.accept();
logger.debug("Returning connected socket"); //$NON-NLS-1$
return result;
}
private ServerSocket createBoundServerSocket(final InetSocketAddress bindAddress) throws IOException {
final ServerSocket serverSocket = new ServerSocket();
serverSocket.setReuseAddress(true);
serverSocket.bind(bindAddress);
return serverSocket;
}
private void sendResponseForTargetIsReady(final Socket controlConnection, final Message connectionRequestMessage)
throws IOException {
final Message response = connectionRequestMessage.buildSuccessResponse();
response.addAttribute(new DirectconnectionAttribute());
response.writeTo(controlConnection.getOutputStream());
}
}