natchecker.java

Azureus is a powerful, full-featured, cross-platform java BitTorrent client

/*
 * File    : NatChecker.java
 * Created : 12 oct. 2003 18:46:00
 * By      : Olivier 
 * 
 * Azureus - a Java Bittorrent client
 *
 * 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 2 of the License.
 *
 * 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 ( see the LICENSE file ).
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.gudy.azureus2.core3.ipchecker.natchecker;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Map;

import com.aelitis.azureus.core.*;
import org.gudy.azureus2.core3.util.BDecoder;
import org.gudy.azureus2.core3.util.Constants;
import org.gudy.azureus2.core3.util.Debug;

import org.gudy.azureus2.plugins.*;

import com.aelitis.azureus.plugins.upnp.*;

/**
 * @author Olivier
 * 
 */
public class NatChecker {

  public static final int NAT_OK = 1;
  public static final int NAT_KO = 2;
  public static final int NAT_UNABLE = 3;
  public static final int NAT_ALREADY_LISTENING = 4;
  
  private static final String[] urls = {
      Constants.AELITIS_WEB_SITE + "natcheck.php"       
  };

  public static int 
  test(
  		AzureusCore	azureus_core,
		int port) 
  {	
    String check = "azureus_rand_".concat(String.valueOf((int) (Math.random() * 100000)));
    NatCheckerServer server = new NatCheckerServer(port, check);
    if (server.isValid()) {
    	
    	PluginInterface pi_upnp = azureus_core.getPluginManager().getPluginInterfaceByClass( UPnPPlugin.class );
			
    	UPnPMapping	new_mapping = null;
		
		if ( pi_upnp != null ){
			
			UPnPPlugin	upnp = (UPnPPlugin)pi_upnp.getPlugin();
			
			UPnPMapping	mapping = upnp.getMapping( true, port );
			
			if ( mapping == null ){
				
				new_mapping = upnp.addMapping( "NAT Tester", true, port, true );
				
					// give UPnP a chance to work
				
				try{
					Thread.sleep(500);
					
				}catch( Throwable e ){
					
					Debug.printStackTrace( e );
				}
			}
		}

      try {
      	
        server.start();
        String urlStr = urls[0].concat("?port=").concat(String.valueOf(port)).concat("&check=").concat(check);
        URL url = new URL(urlStr);
        HttpURLConnection con = (HttpURLConnection) url.openConnection();
        con.connect();
        InputStream is = null;
        ByteArrayOutputStream message = new ByteArrayOutputStream();
        is = con.getInputStream();
        //      int length = con.getContentLength();
        //      System.out.println(length);
        byte[] data = new byte[1024];
        int nbRead = 0;
        while (nbRead >= 0) {
          nbRead = is.read(data);
          if (nbRead >= 0)
            message.write(data, 0, nbRead);
          Thread.sleep(20);
        }
        Map map = BDecoder.decode(message.toByteArray()); 
        int result = ((Long)map.get("result")).intValue();
        switch(result) {
          case 0 :
            return NAT_KO;
          case 1 :
            return NAT_OK;
          default:
            return NAT_UNABLE;            
        }
      }
      catch (Exception e) {       
        return NAT_UNABLE;
      }
      finally {
      	
      	if (new_mapping != null ){
      		
      		new_mapping.destroy();
      	}
      	
        server.stopIt();
      }
    }
    else {
        if (server.isAlreadyListening()) return NAT_ALREADY_LISTENING;
        return NAT_UNABLE;
    }
  }
}