import jicmp.*;

import java.io.IOException;
import java.net.UnknownHostException;
import java.util.Random;

class Ping extends Thread {
   static int number = 0;
   static String host = "";

   public static void main(String args[]) {	
      host = args[0];
      Ping t1 = new Ping();
      t1.setPriority(Thread.MIN_PRIORITY);
      t1.start();	
   }
   
   public synchronized void run() {
      ++number;
      int how_many_packets_to_send = 5;
      short contor;
      short seq_no = 0;
      jICMP socket = null;
      Thread t;
      
      // create a raw socket to localhost, with 10000ms timeout.
      socket = new jICMP(host);
      socket.setTimeout(3);

      try {
         for(contor = 0;contor < how_many_packets_to_send; contor++ ) {
				
            // create an ICMP packet with type ECHO_REQUEST, code 0, ID 12,and
            // secquence number starting from 0. Do not run this program while another
            // one is running. The packets sent by one will be received by the other
            // because the both have the same ID.
            ICMPPacket sendpak = new ICMPPacket(ICMPPacket.ICMP_ECHOREQ, (byte)0, (short)number, (short)(seq_no++ % 127));
				
            // The packet can also carry data. The maximum length is 996 bytes.
            // The data could be anything ( usualy is the time when the packet
            // was sended so we can compute the roundtrip.). Use the
            // pak.setBuffer(buffer) to set the data. For now, we don't send
            // anything.
				
            // send it!
            try {
               System.out.println("Pinging " + socket.getHostName() + " with " + sendpak.getSize() + " bytes.");	
               socket.send(sendpak);
            } catch(TimeOutException toe) {
               System.out.println(toe.getMessage());
               continue;				
            } catch(UnknownHostException uhe) {
               System.out.println("Unknoen Host: " + uhe.getMessage());
               System.exit(0);
            } catch(IOException ioe) {
               System.out.println("An IO Exception has occured.");
               System.out.println(ioe.getMessage());
               System.exit(0);
            }
					
            // make place for the answer!
            ICMPPacket recvpak = null;
			
            // start listening for the answer.
            for(;;) {
               try {
                  recvpak = null;
                  recvpak = socket.read();
                  
                  // if nothing happens, then it could be a timeout error, so keep trying.
                  if (recvpak == null) continue;
                     
                  // if it is an answer
                  if(recvpak.getType() == ICMPPacket.ICMP_ECHOREPLY)
                     // if it is OUR answer
                     if ( recvpak.getID() == number ) {
                        System.out.println("Replied. The packet no :" + recvpak.getSequenceNumber());
                        break;
                     }
               } catch(TimeOutException toe) {
                  System.out.println("timed out.");
               } catch(UnknownHostException uhe) {
                  System.out.println("Unknown Host: " + uhe.getMessage());
                  System.exit(0);
               } catch(IOException ioe) {
                  System.out.println("An IO Exception has occured.");
                  System.out.println(ioe.getMessage());
                  System.exit(0);
               }
            }
		
            try {
               t = Thread.currentThread();
               t.sleep(1000);
            } catch(InterruptedException ie) {
               System.out.println("Intrerupt");
            }
         }
      } finally {
         socket.destroy();
      }
   }
}