/*
 * Copyright (c) 2006-2013 Christian Plattner. All rights reserved.
 * Please refer to the LICENSE.txt for licensing details.
 */

package ch.ethz.ssh2;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;

import ch.ethz.ssh2.channel.ChannelManager;
import ch.ethz.ssh2.channel.LocalAcceptThread;

/**
 * A <code>LocalPortForwarder</code> forwards TCP/IP connections to a local
 * port via the secure tunnel to another host (which may or may not be identical
 * to the remote SSH-2 server). Checkout {@link Connection#createLocalPortForwarder(int, String, int)}
 * on how to create one.
 *
 * @author Christian Plattner
 * @version 2.50, 03/15/10
 */
public class LocalPortForwarder {
    final ChannelManager cm;

    final String host_to_connect;

    final int port_to_connect;

    final LocalAcceptThread lat;

    LocalPortForwarder(ChannelManager cm, int local_port, String host_to_connect, int port_to_connect)
    throws IOException {
        this.cm = cm;
        this.host_to_connect = host_to_connect;
        this.port_to_connect = port_to_connect;
        lat = new LocalAcceptThread(cm, local_port, host_to_connect, port_to_connect);
        lat.setDaemon(true);
        lat.start();
    }

    LocalPortForwarder(ChannelManager cm, InetSocketAddress addr, String host_to_connect, int port_to_connect)
    throws IOException {
        this.cm = cm;
        this.host_to_connect = host_to_connect;
        this.port_to_connect = port_to_connect;
        lat = new LocalAcceptThread(cm, addr, host_to_connect, port_to_connect);
        lat.setDaemon(true);
        lat.start();
    }

    /**
     * Return the local socket address of the {@link ServerSocket} used to accept connections.
     * @return
     */
    public InetSocketAddress getLocalSocketAddress() {
        return (InetSocketAddress) lat.getServerSocket().getLocalSocketAddress();
    }

    /**
     * Stop TCP/IP forwarding of newly arriving connections.
     *
     * @throws IOException
     */
    public void close() throws IOException {
        lat.stopWorking();
    }
}