/* * ** Network and Service Differentiation Extensions to GridSim 3.0 ** * * Gokul Poduval & Chen-Khong Tham * Computer Communication Networks (CCN) Lab * Dept of Electrical & Computer Engineering * National University of Singapore * August 2004 * * Licence: GPL - http://www.gnu.org/copyleft/gpl.html * * RIPRouter.java - Simulates a network router with RIP as the advertising * protocol * */package gridsim.net;import eduni.simjava.*;import gridsim.*;import gridsim.util.*;import java.util.*;/** * This class implements a Router using a form of RIP for routing. The routing * protocol used here is similar to <a * href="http://www.ietf.org/rfc/rfc1058.txt">Routing Information Protocol * (RIP) </a>. The routing protocol is run before Gridlets etc. can be * submitted. * <p> * In case there are more than two routes to a destination, the * route with the lower hopcount is used. Since in this simulation routers * relay perfect information and links do not break down, RIP should be a * reliable protocol to use. * * @invariant $none * @since GridSim Toolkit 3.1 * @author Gokul Poduval & Chen-Khong Tham, National University of Singapore */public class RIPRouter extends Router{    private Hashtable linkTable;    private Hashtable schedTable; // table of schedulers    private Hashtable hostTable;    private Hashtable routerTable;    private Hashtable forwardTable;    private int id;    private static final int BITS = 8;     // 1 byte in bits    /**     * Creates a new RIPRouter object.      * By default, <b>no recording or logging</b>     * is done for packets' activities. If you want to log operations of this     * entity, please use {@link #RIPRouter(String, boolean)}.     *     * @param name Name of this router     * @throws NullPointerException This happens when name is empty or null     * @see #RIPRouter(String, boolean)     * @pre name != null     * @post $none     */    public RIPRouter(String name) throws NullPointerException {        this(name, false);    }    /**     * Creates a new RIPRouter object with logging facility if it is turned on.     * <br>     * NOTE: If logging facility is turned on, there are some overheads     * in terms of performance and memory consumption.     *     * @param name      Name of this router     * @param trace     <tt>true</tt> if you want to record this router's     *                  activity, <tt>false</tt> otherwise     * @throws NullPointerException This happens when name is empty or null     * @pre name != null     * @post $none     */    public RIPRouter(String name, boolean trace) throws NullPointerException    {        super(name, trace);        init();    }    /**     * Initialises all variables     * @pre $none     * @post $none     */    private void init()    {        this.id = super.get_id();        linkTable = new Hashtable();        hostTable = new Hashtable();        routerTable = new Hashtable();        forwardTable = new Hashtable();        schedTable = new Hashtable();    }    /**     * Informs the registered entities regarding to the end of a simulation.     * @pre $none     * @post $none     */    protected void processEndSimulation() {        // ... empty - maybe need to clean up all the hashtables    }    /**     * Joins two routers with a Link.     * @param router    The router on the other side to which this one will     *                  be attached.     * @param link      This is the link that will be used to connect the two     *                  routers.     * @param thisSched The scheduling policy used on this routers egress port     *                  when sending data through it.     * @param otherSched    The scheduling policy that will be used on the     *                      egress port of the router being connected to when     *                      sending data to this router.     * @pre router != null     * @pre link != null     * @pre thisSched != null     * @pre otherSched != null     * @post $none     */    public void attachRouter(Router router, Link link,                    PacketScheduler thisSched, PacketScheduler otherSched)    {        String msg = super.get_name() + ".attachRouter(): Error - ";        if (router == null)        {            System.out.println(msg + "the router is null.");            return;        }        if (link == null)        {            System.out.println(msg + "the link is null.");            return;        }        if (thisSched == null || otherSched == null)        {            System.out.println(msg +                    "the one or more packet schedulers are null.");            return;        }        thisSched.setBaudRate( link.getBaudRate() );        otherSched.setBaudRate( link.getBaudRate() );        link.attach(this, router);        this.attachRouter(router, link, thisSched);        router.attachRouter(this, link, otherSched);    }    /**     * Joins two routers together. This is called by the routers themselves     * and should not be called by other entities.     *     * @param router    The Router to which this router will be connected.     * @param link      The Link that will be used to join these routers.     * @param sched     The scheduling policy used on the egress port of the     *                  router when sending data through this route.     * @pre router != null     * @pre link != null     * @pre sched != null     * @post $none     */    public void attachRouter(Router router, Link link, PacketScheduler sched)    {        String msg = super.get_name() + ".attachRouter(): Error - ";        if (router == null)        {            System.out.println(msg + "the router is null.");            return;        }        if (link == null)        {            System.out.println(msg + "the link is null.");            return;        }        if (sched == null)        {            System.out.println(msg + "the packet scheduler is null.");            return;        }        linkTable.put(router.get_name(), link.get_name());        if (!schedTable.containsKey( link.get_name()) ) {            schedTable.put(link.get_name(), sched);        }        routerTable.put( link.get_name(), router.get_name() );        hostTable.put( link.get_name(), router.get_name() );        // logging or recording ...        if (reportWriter_ != null)        {            StringBuffer sb = null;            sb = new StringBuffer("attach this ROUTER, with router, ");            sb.append( router.get_name() );            sb.append(", with link, ");            sb.append( link.get_name() );            sb.append(", with packet scheduler, ");            sb.append( sched.getSchedName() );            super.write( sb.toString() );        }    }    /**     * Attaches an entity to this router. The link between the router and the     * entity being attached is taken from     * {@link gridsim.GridSimCore#getLink()}.     *     * @param entity    The entity to be attached.     * @param sched     The scheduling policy that will be used on the egress     *                  port when the router sends data to the entity being     *                  joined.     * @see gridsim.GridSimCore#getLink()     * @pre entity != null     * @pre sched != null     * @post $none     */    public void attachHost(GridSimCore entity, PacketScheduler sched)    {        String msg = super.get_name() + ".attachHost(): Error - ";        if (entity == null)        {            System.out.println(msg + "the entity is null.");            return;        }        if (sched == null)        {            System.out.println(msg + "the packet scheduler is null.");            return;        }        Link link = entity.getLink();        sched.setBaudRate( link.getBaudRate() );        link.attach(this, entity);        linkTable.put( entity.get_name(), link.get_name() );        if (!schedTable.containsKey( link.get_name() )) {            schedTable.put(link.get_name(), sched);        }        hostTable.put( link.get_name(), entity.get_name() );        // recording ...        if (reportWriter_ != null)        {            StringBuffer sb = null;            sb = new StringBuffer("attach this ROUTER, to entity, ");            sb.append( entity.get_name() );            sb.append(", with packet scheduler, ");            sb.append( sched.getSchedName() );            super.write( sb.toString() );        }    }    /**     * Processes incoming events     * @param ev    a Sim_event object     * @pre ev != null     * @post $none     */    protected synchronized void processEvent(Sim_event ev)    {        switch ( ev.get_tag() )        {            case GridSimTags.PKT_FORWARD:            case GridSimTags.JUNK_PKT:                processNetPacket(ev, ev.get_tag());                break;            case GridSimTags.ROUTER_AD:                receiveAd(ev);                break;            case GridSimTags.INSIGNIFICANT:                processInternalEvent(ev);                break;            default:                System.out.println(super.get_name() + ".body(): Unable to " +                        "handle request from GridSimTags " +                        "with constant number " + ev.get_tag() );                break;        }    }    /**     * Processes incoming network packets, one at a time.     * The incoming packet will be split up into smaller pieces if     * the packet size > MTU of the other end.     *     * @param ev    a Sim_event object     * @pre ev != null     * @post $none     */    private synchronized void processNetPacket(Sim_event ev, int tag)    {        double nextTime = 0;        Packet pkt = (Packet) ev.get_data();        PacketScheduler sched = getScheduler(pkt);        // if a packet scheduler is not found, then try reschedule this packet        // in the future        if (sched == null)        {            System.out.println(super.get_name() + ".processNetPacket(): " +                "Warning - can't find a packet scheduler for " + pkt);            System.out.println("-> Will reschedule it again in the future.");            super.sim_schedule(super.get_id(), Router.DELAY, tag, pkt);            return;        }        // process ping() request        if (pkt instanceof InfoPacket)        {            ((InfoPacket) pkt).addHop(id);            ((InfoPacket) pkt).addEntryTime( GridSim.clock() );            ((InfoPacket) pkt).addBaudRate(sched.getBaudRate());        }        // check downlink MTU, and split accordingly        String linkName = getLinkName( pkt.getDestID() );        Link downLink = (Link) Sim_system.get_entity(linkName);        int MTU = downLink.getMTU();        int numPackets = (int) Math.ceil(pkt.getSize() / (MTU * 1.0));        // if no packets at the moment        if (sched.size() == 0)        {            if (numPackets == 1) {                nextTime = (pkt.getSize() * BITS) / sched.getBaudRate();            }            else {                nextTime = (MTU * BITS * 1.0) / sched.getBaudRate();            }            sendInternalEvent(nextTime, sched);        }