LinkLayer.java example

Explorer
jop-master
/*
 * Copyright (c) Martin Schoeberl, martin@jopdesign.com
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Martin Schoeberl
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS 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 THE REGENTS OR CONTRIBUTORS 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 jembench.ejip;

/**
*	LinkLayer.java
*
*/



/**
 * LinkLayer driver.
 */
public abstract class LinkLayer implements Runnable {
	
	protected Ejip ejip;
	
	/** Own IP address */
	protected int ip; // own ip address
// TODO: make ip, gateway, netmask package visible again

	/** */
	private int gateway;

	/** Subnet mask */
	private int netmask;
	
	PacketQueue txQueue;
	PacketQueue rxQueue;
	
	public LinkLayer(Ejip ejipRef, int ipAddress) {
		ip = ipAddress;
		ejip = ejipRef;
		txQueue = new PacketQueue(ejip.getMaxPackets());
		rxQueue = new PacketQueue(ejip.getMaxPackets());
		ejip.registerLinkLayer(this);
	}

	public int getIpAddress() {
		return ip;
	}
	
	public void enqTxPacket(Packet p) {
		txQueue.enq(p);
	}
	
	/**
	*	Set connection strings and connect.
	*/
	public void startConnection(StringBuffer dialstr, StringBuffer connect, StringBuffer user, StringBuffer passwd) {
		// default implementation does nothing
	}

	/**
	*	Forces the connection to be new established.
	*	On Slip and CS8900 ignored.
	*/
	public void reconnect() {
	}

	/**
	 * Used for PPP and Oebb project.
	 * @return
	 */
	public int getConnCount() {
		return 0;
	}

	public void disconnect() {
		// only usefull for PPP
	}

	/**
	 * @param remoteAddr
	 * @return true if the remote address is in the same subnet or if no gateway
	 *         is given
	 */
	public boolean isSameSubnet(int remoteAddr) {
		if (gateway == 0)
			return true;

		int test1 = /* ip & */ netmask;
		int test2 = remoteAddr & netmask;

		return (test1 ^ test2) == 0;
	}
	
	// TODO: JOPizer needs the run method here, don't know why?
	public void run() {}
}