"SfR Fresh" - the SfR Freeware/Shareware Archive

Member "wormscan-1.6.1-src/net/websoup/wormscan/Resolver.java" of archive wormscan-1.6.1-src.tar.gz:

    1 package net.websoup.wormscan;
    2 
    3 /*
    4 *    This file is part of WormScan.
    5 *
    6 *    WormScan is free software; you can redistribute it and/or
    7 *    modify it under the terms of the GNU General Public License
    8 *    as published by the Free Software Foundation; either version 2
    9 *    of the License, or (at your option) any later version.
   10 *
   11 *    This program is distributed in the hope that it will be useful,
   12 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
   13 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   14 *    GNU General Public License for more details.
   15 *
   16 *    You should have received a copy of the GNU General Public License
   17 *    along with this program; if not, write to the Free Software
   18 *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
   19 */
   20 
   21 import java.util.Stack;
   22 
   23 import net.websoup.wormscan.AttackSource;
   24 import net.websoup.wormscan.Program;
   25 
   26 /**
   27  * Gathers AttackSource objects and resolves their hostnames.
   28  * The pool of AttackSource objects is shared between all Resolver threads.
   29  * Resolver threads will wait until AttackSource objects appear in the Stack.
   30  * Threads will exit only when areDone() method is called and no AttackSource objects
   31  * are waiting for resolution.
   32  * Copyright:    Copyright (c) 2001-2004 Andriy Rozeluk <arozeluk@websoup.net>
   33  * @author Andriy Rozeluk
   34  * @version 1.6.1
   35  */
   36 public class Resolver extends Thread {
   37   static int MAX_WAITING = 100;
   38   private static Stack sourceStack;
   39   private static boolean done = false;
   40 
   41   /**
   42    * Initialize our storage for AttackSource objects
   43    */
   44   static {
   45     sourceStack = new Stack();
   46   }
   47 
   48   /**
   49    * Signal that no more AttackSource objects will be added. Finish up!
   50    */
   51   public static void areDone(){
   52     done = true;
   53     synchronized( sourceStack ){
   54       sourceStack.notifyAll();
   55     }
   56   }
   57 
   58   /**
   59    * Add AttackSource object to the Stack for resolution
   60    */
   61   public static void addSource( AttackSource as ){
   62     if ( !Program.RESOLVE_DNS ) return;
   63     for (;;){
   64       synchronized(sourceStack){
   65         if ( MAX_WAITING <= 0 || sourceStack.size() < MAX_WAITING ){
   66           sourceStack.push( as );
   67           if ( Program.OUTPUT_LEVEL > 3 )
   68             System.out.println( "" + sourceStack.size() + " hostnames waiting to be resolved" );
   69           sourceStack.notifyAll();
   70           return;
   71         }
   72         else{
   73           try {
   74             sourceStack.wait();
   75           }
   76           catch( Exception e ){
   77             //ignore
   78           }
   79         }
   80       }
   81     }
   82   }
   83 
   84   /**
   85    * Go through stack, resolve hostnames of AttackSource objects that appear
   86    */
   87   public void run(){
   88     int lastcount = 0;
   89     while(!done || lastcount > 0){
   90       AttackSource as = null;
   91       synchronized( sourceStack ){
   92         lastcount = sourceStack.size();
   93         if ( lastcount > 0 ){
   94           as = (AttackSource)(sourceStack.pop());
   95           sourceStack.notifyAll();
   96         }
   97       }
   98       if ( as != null ){
   99         as.resolveHostnames();
  100       }
  101       else {
  102         synchronized( sourceStack ){
  103           if (!done ){
  104             try {
  105               sourceStack.wait();
  106             }
  107             catch( Exception e ){
  108               //ignore
  109             }
  110           }
  111         }
  112       }
  113     }
  114   }
  115 }