simpleserver.java

基于人工免疫原理的入侵检测系统框架

/*=================
 * Copyright (C) 2001  Hajime Inoue
 *
 * Lisys is a program that monitors TCP SYN packets to detect network
 * traffic anomalies.
 *
 * Licensed under the GNU General Public License (GPL), version 2 or
 * higher.  Please see the COPYING and PATENT files included with the 
 * Lisys distribution, which can be found at:
 *
 *   http://www.cs.unm.edu/~judd/lisys/
 *
 * Also, the current text of the GPL can be found at: 
 *
 *   http://www.gnu.org/copyleft/gpl.html
 * 
 * Note that Lisys has NO WARRANTY!
 *=================*/

package edu.unm.cs.lisys.net;

import java.io.InputStream;
import java.io.OutputStream;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import edu.unm.cs.lisys.debug.*;

/**==========
 * SimpleServer.java
 *   A very simple single-threaded abstract class that allows for easy
 *   implementation of servers using a single function.
 *
 *   This is written to accomodate the new design of DetectionNode,
 *   though it is general enough to handle HTTP service duties as
 *   well, if they are very low bandwidth. 
 *
 * Here are the people who have worked on this code in the order they
 * have worked on it:
 *   @author Hajime Inoue <[e-mail]>
 *   @author Justin Balthrop <[e-mail]>
 *==========*/

public abstract class SimpleServer extends Thread implements Serializable
{
    protected int port;

    /**==========
     * run:
     *  The run function accepts connections and hands them off
     *  to the serveConnection function to deal with.
     *
     *  NOTE - this is not multithreaded.  No intensive computations
     *         should occur in serveConnection.
     *==========*/
    public void run()
    {
        Debug.verbose("In run()");
        ServerSocket server;
	try {
            server = new ServerSocket(port, 16);
	}
	catch(Exception e) {
	    Debug.exception(this,e);
	    return;
	}
        while(true) {
	    try {
		Socket s = server.accept();
		Debug.verbose("Opened Connection");
		try {
		    System.err.println("Serving Connection");
		    s.setSoTimeout(10000);
		    serveConnection(s.getInputStream(), s.getOutputStream());
		    s.close();
		}
		catch(Exception e) {
		    s.close();
		    Debug.exception(this,e);
		}
		Debug.verbose("Closed Connection");
	    } 
	    catch (Exception e) {
		Debug.exception(this,e);
	    }
	    System.gc();
        }
    }
    
    /**==========
     * serveConnection:
     *   Subclasses implement this function.
     *
     * @param in       The inputstream of the socket
     * @param out      The outputstream of the socket
     *==========*/
    public abstract void serveConnection (InputStream in, OutputStream out)
	throws Exception;   
}