/*
 * Copyright (c) 2002-2018 ymnk, JCraft,Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of conditions
 * and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided with
 * the distribution.
 *
 * 3. The names of the authors may not be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL JCRAFT, INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.jcraft.jsch;

import java.io.PipedOutputStream;
import java.net.Socket;
import java.util.Vector;

public class ChannelForwardedTCPIP extends Channel {

  private static Vector<Config> pool = new Vector<>();

  private static final int LOCAL_WINDOW_SIZE_MAX = 0x20000;
  // static private final int LOCAL_WINDOW_SIZE_MAX=0x100000;
  private static final int LOCAL_MAXIMUM_PACKET_SIZE = 0x4000;

  private static final int TIMEOUT = 10 * 1000;

  private Socket socket = null;
  private ForwardedTCPIPDaemon daemon = null;
  private Config config = null;

  ChannelForwardedTCPIP() {
    super();
    lwsize_max = LOCAL_WINDOW_SIZE_MAX;
    lwsize = LOCAL_WINDOW_SIZE_MAX;
    lmpsize = LOCAL_MAXIMUM_PACKET_SIZE;
    io = new IO();
    connected = true;
  }

  @Override
  public void run() {
    try {
      if (config instanceof ConfigDaemon) {
        ConfigDaemon _config = (ConfigDaemon) config;
        Class<? extends ForwardedTCPIPDaemon> c =
            Class.forName(_config.target).asSubclass(ForwardedTCPIPDaemon.class);
        daemon = c.getDeclaredConstructor().newInstance();

        PipedOutputStream out = new PipedOutputStream();
        io.setInputStream(new PassiveInputStream(out, 32 * 1024), false);

        daemon.setChannel(this, getInputStream(), out);
        daemon.setArg(_config.arg);
        new Thread(daemon).start();
      } else {
        ConfigLHost _config = (ConfigLHost) config;
        socket =
            (_config.factory == null) ? Util.createSocket(_config.target, _config.lport, TIMEOUT)
                : _config.factory.createSocket(_config.target, _config.lport);
        socket.setTcpNoDelay(true);
        io.setInputStream(socket.getInputStream());
        io.setOutputStream(socket.getOutputStream());
      }
      sendOpenConfirmation();
    } catch (Exception e) {
      sendOpenFailure(SSH_OPEN_ADMINISTRATIVELY_PROHIBITED);
      close = true;
      disconnect();
      return;
    }

    thread = Thread.currentThread();
    Buffer buf = new Buffer(rmpsize);
    Packet packet = new Packet(buf);
    int i = 0;
    try {
      Session _session = getSession();
      while (thread != null && io != null && io.in != null) {
        i = io.in.read(buf.buffer, 14, buf.buffer.length - 14 - _session.getBufferMargin());
        if (i <= 0) {
          eof();
          break;
        }
        packet.reset();
        buf.putByte((byte) Session.SSH_MSG_CHANNEL_DATA);
        buf.putInt(recipient);
        buf.putInt(i);
        buf.skip(i);
        synchronized (this) {
          if (close)
            break;
          _session.write(packet, this, i);
        }
      }
    } catch (Exception e) {
      // System.err.println(e);
    }
    // thread = null;
    // eof();
    disconnect();
  }

  @Override
  void getData(Buffer buf) {
    setRecipient(buf.getInt());
    setRemoteWindowSize(buf.getUInt());
    setRemotePacketSize(buf.getInt());
    byte[] addr = buf.getString();
    int port = buf.getInt();
    byte[] orgaddr = buf.getString();
    int orgport = buf.getInt();

    /*
    System.err.println("addr: " + Util.byte2str(addr));
    System.err.println("port: " + port);
    System.err.println("orgaddr: " + Util.byte2str(orgaddr));
    System.err.println("orgport: " + orgport);
    */

    Session _session = null;
    try {
      _session = getSession();
    } catch (JSchException e) {
      // session has been already down.
    }

    this.config = getPort(_session, Util.byte2str(addr), port);
    if (this.config == null)
      this.config = getPort(_session, null, port);

    if (this.config == null) {
      if (_session.getLogger().isEnabled(Logger.ERROR)) {
        _session.getLogger().log(Logger.ERROR,
            "ChannelForwardedTCPIP: " + Util.byte2str(addr) + ":" + port + " is not registered.");
      }
    }
  }

  private static Config getPort(Session session, String address_to_bind, int rport) {
    synchronized (pool) {
      for (int i = 0; i < pool.size(); i++) {
        Config bar = pool.elementAt(i);
        if (bar.session != session)
          continue;
        if (bar.rport != rport) {
          if (bar.rport != 0 || bar.allocated_rport != rport)
            continue;
        }
        if (address_to_bind != null && !bar.address_to_bind.equals(address_to_bind))
          continue;
        return bar;
      }
      return null;
    }
  }

  static String[] getPortForwarding(Session session) {
    Vector<String> foo = new Vector<>();
    synchronized (pool) {
      for (int i = 0; i < pool.size(); i++) {
        Config config = pool.elementAt(i);
        if (config.session == session) {
          if (config instanceof ConfigDaemon)
            foo.addElement(config.allocated_rport + ":" + config.target + ":");
          else
            foo.addElement(
                config.allocated_rport + ":" + config.target + ":" + ((ConfigLHost) config).lport);
        }
      }
    }
    String[] bar = new String[foo.size()];
    for (int i = 0; i < foo.size(); i++) {
      bar[i] = foo.elementAt(i);
    }
    return bar;
  }

  static String normalize(String address) {
    if (address == null) {
      return "localhost";
    } else if (address.length() == 0 || address.equals("*")) {
      return "";
    } else {
      return address;
    }
  }

  static void addPort(Session session, String _address_to_bind, int port, int allocated_port,
      String target, int lport, SocketFactory factory) throws JSchException {
    String address_to_bind = normalize(_address_to_bind);
    synchronized (pool) {
      if (getPort(session, address_to_bind, port) != null) {
        throw new JSchException("PortForwardingR: remote port " + port + " is already registered.");
      }
      ConfigLHost config = new ConfigLHost();
      config.session = session;
      config.rport = port;
      config.allocated_rport = allocated_port;
      config.target = target;
      config.lport = lport;
      config.address_to_bind = address_to_bind;
      config.factory = factory;
      pool.addElement(config);
    }
  }

  static void addPort(Session session, String _address_to_bind, int port, int allocated_port,
      String daemon, Object[] arg) throws JSchException {
    String address_to_bind = normalize(_address_to_bind);
    synchronized (pool) {
      if (getPort(session, address_to_bind, port) != null) {
        throw new JSchException("PortForwardingR: remote port " + port + " is already registered.");
      }
      ConfigDaemon config = new ConfigDaemon();
      config.session = session;
      config.rport = port;
      config.allocated_rport = port;
      config.target = daemon;
      config.arg = arg;
      config.address_to_bind = address_to_bind;
      pool.addElement(config);
    }
  }

  static void delPort(ChannelForwardedTCPIP c) {
    Session _session = null;
    try {
      _session = c.getSession();
    } catch (JSchException e) {
      // session has been already down.
    }
    if (_session != null && c.config != null)
      delPort(_session, c.config.rport);
  }

  static void delPort(Session session, int rport) {
    delPort(session, null, rport);
  }

  static void delPort(Session session, String address_to_bind, int rport) {
    synchronized (pool) {
      Config foo = getPort(session, normalize(address_to_bind), rport);
      if (foo == null)
        foo = getPort(session, null, rport);
      if (foo == null)
        return;
      pool.removeElement(foo);
      if (address_to_bind == null) {
        address_to_bind = foo.address_to_bind;
      }
      if (address_to_bind == null) {
        address_to_bind = "0.0.0.0";
      }
    }

    Buffer buf = new Buffer(200); // ??
    Packet packet = new Packet(buf);

    try {
      // byte      SSH_MSG_GLOBAL_REQUEST 80
      // string    "cancel-tcpip-forward"
      // boolean   want_reply
      // string    address_to_bind (e.g. "127.0.0.1")
      // uint32    port number to bind
      packet.reset();
      buf.putByte((byte) 80 /* SSH_MSG_GLOBAL_REQUEST */);
      buf.putString(Util.str2byte("cancel-tcpip-forward"));
      buf.putByte((byte) 0);
      buf.putString(Util.str2byte(address_to_bind));
      buf.putInt(rport);
      session.write(packet);
    } catch (Exception e) {
      // throw new JSchException(e.toString(), e);
    }
  }

  static void delPort(Session session) {
    int[] rport = null;
    int count = 0;
    synchronized (pool) {
      rport = new int[pool.size()];
      for (int i = 0; i < pool.size(); i++) {
        Config config = pool.elementAt(i);
        if (config.session == session) {
          rport[count++] = config.rport; // ((Integer)bar[1]).intValue();
        }
      }
    }
    for (int i = 0; i < count; i++) {
      delPort(session, rport[i]);
    }
  }

  public int getRemotePort() {
    return (config != null ? config.rport : 0);
  }

  private void setSocketFactory(SocketFactory factory) {
    if (config != null && (config instanceof ConfigLHost))
      ((ConfigLHost) config).factory = factory;
  }

  abstract static class Config {
    Session session;
    int rport;
    int allocated_rport;
    String address_to_bind;
    String target;
  }

  static class ConfigDaemon extends Config {
    Object[] arg;
  }

  static class ConfigLHost extends Config {
    int lport;
    SocketFactory factory;
  }
}
