opendaylight/arphandler/src/main/java/org/opendaylight/controller/arphandler/internal/ArpHandler.java

   1
   2 /*
   3  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   4  *
   5  * This program and the accompanying materials are made available under the
   6  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   7  * and is available at http://www.eclipse.org/legal/epl-v10.html
   8  */
   9
  10 /*
  11  *
  12  */
  13 package org.opendaylight.controller.arphandler.internal;
  14
  15 import java.net.InetAddress;
  16 import java.net.UnknownHostException;
  17 import java.util.Arrays;
  18 import java.util.Collections;
  19 import java.util.EnumSet;
  20 import java.util.HashSet;
  21 import java.util.Set;
  22 import java.util.Timer;
  23 import java.util.TimerTask;
  24 import java.util.concurrent.BlockingQueue;
  25 import java.util.concurrent.ConcurrentHashMap;
  26 import java.util.concurrent.ConcurrentMap;
  27 import java.util.concurrent.CopyOnWriteArraySet;
  28 import java.util.concurrent.LinkedBlockingQueue;
  29
  30 import org.opendaylight.controller.arphandler.ARPCacheEvent;
  31 import org.opendaylight.controller.arphandler.ARPEvent;
  32 import org.opendaylight.controller.arphandler.ARPReply;
  33 import org.opendaylight.controller.arphandler.ARPRequest;
  34 import org.opendaylight.controller.clustering.services.CacheConfigException;
  35 import org.opendaylight.controller.clustering.services.CacheExistException;
  36 import org.opendaylight.controller.clustering.services.ICacheUpdateAware;
  37 import org.opendaylight.controller.clustering.services.IClusterContainerServices;
  38 import org.opendaylight.controller.clustering.services.IClusterServices;
  39 import org.opendaylight.controller.connectionmanager.IConnectionManager;
  40 import org.opendaylight.controller.hosttracker.IfHostListener;
  41 import org.opendaylight.controller.hosttracker.IfIptoHost;
  42 import org.opendaylight.controller.hosttracker.hostAware.HostNodeConnector;
  43 import org.opendaylight.controller.hosttracker.hostAware.IHostFinder;
  44 import org.opendaylight.controller.sal.core.ConstructionException;
  45 import org.opendaylight.controller.sal.core.Node;
  46 import org.opendaylight.controller.sal.core.NodeConnector;
  47 import org.opendaylight.controller.sal.packet.ARP;
  48 import org.opendaylight.controller.sal.packet.Ethernet;
  49 import org.opendaylight.controller.sal.packet.IDataPacketService;
  50 import org.opendaylight.controller.sal.packet.IListenDataPacket;
  51 import org.opendaylight.controller.sal.packet.IPv4;
  52 import org.opendaylight.controller.sal.packet.Packet;
  53 import org.opendaylight.controller.sal.packet.PacketResult;
  54 import org.opendaylight.controller.sal.packet.RawPacket;
  55 import org.opendaylight.controller.sal.topology.TopoEdgeUpdate;
  56 import org.opendaylight.controller.sal.utils.EtherTypes;
  57 import org.opendaylight.controller.sal.utils.HexEncode;
  58 import org.opendaylight.controller.sal.utils.NetUtils;
  59 import org.opendaylight.controller.switchmanager.ISwitchManager;
  60 import org.opendaylight.controller.switchmanager.Subnet;
  61 import org.opendaylight.controller.topologymanager.ITopologyManager;
  62 import org.slf4j.Logger;
  63 import org.slf4j.LoggerFactory;
  64
  65 public class ArpHandler implements IHostFinder, IListenDataPacket, ICacheUpdateAware<ARPEvent, Boolean> {
  66     private static final Logger log = LoggerFactory.getLogger(ArpHandler.class);
  67     static final String ARP_EVENT_CACHE_NAME = "arphandler.arpRequestReplyEvent";
  68     private IfIptoHost hostTracker;
  69     private ISwitchManager switchManager;
  70     private ITopologyManager topologyManager;
  71     private IDataPacketService dataPacketService;
  72     private IClusterContainerServices clusterContainerService;
  73     private IConnectionManager connectionManager;
  74     private Set<IfHostListener> hostListeners = new CopyOnWriteArraySet<IfHostListener>();
  75     private ConcurrentMap<InetAddress, Set<HostNodeConnector>> arpRequestors;
  76     private ConcurrentMap<InetAddress, Short> countDownTimers;
  77     private Timer periodicTimer;
  78     private BlockingQueue<ARPCacheEvent> ARPCacheEvents = new LinkedBlockingQueue<ARPCacheEvent>();
  79     private Thread cacheEventHandler;
  80     private boolean stopping = false;
  81     /*
  82      * A cluster allocated cache. Used for synchronizing ARP request/reply
  83      * events across all cluster controllers. To raise an event, we put() a specific
  84      * event object (as key) and all nodes handle it in the entryUpdated callback.
  85      *
  86      * In case of ARPReply, we put true value to send replies to any requestors
  87      * by calling generateAndSendReply
  88      */
  89     private ConcurrentMap<ARPEvent, Boolean> arpRequestReplyEvent;
  90
  91     void setConnectionManager(IConnectionManager cm){
  92         this.connectionManager = cm;
  93     }
  94
  95     void unsetConnectionManager(IConnectionManager cm){
  96         if (this.connectionManager == cm){
  97             connectionManager = null;
  98         }
  99     }
 100
 101     void setClusterContainerService(IClusterContainerServices s){
 102         this.clusterContainerService = s;
 103     }
 104
 105     void unsetClusterContainerService(IClusterContainerServices s) {
 106         if (this.clusterContainerService == s) {
 107             this.clusterContainerService = null;
 108         }
 109     }
 110
 111     void setHostListener(IfHostListener s) {
 112         if (this.hostListeners != null) {
 113             this.hostListeners.add(s);
 114         }
 115     }
 116
 117     void unsetHostListener(IfHostListener s) {
 118         if (this.hostListeners != null) {
 119             this.hostListeners.remove(s);
 120         }
 121     }
 122
 123     void setDataPacketService(IDataPacketService s) {
 124         this.dataPacketService = s;
 125     }
 126
 127     void unsetDataPacketService(IDataPacketService s) {
 128         if (this.dataPacketService == s) {
 129             this.dataPacketService = null;
 130         }
 131     }
 132
 133     public void setHostTracker(IfIptoHost hostTracker) {
 134         log.debug("Setting HostTracker");
 135         this.hostTracker = hostTracker;
 136     }
 137
 138     public void unsetHostTracker(IfIptoHost s) {
 139         log.debug("UNSetting HostTracker");
 140         if (this.hostTracker == s) {
 141             this.hostTracker = null;
 142         }
 143     }
 144
 145     public void setTopologyManager(ITopologyManager tm) {
 146         this.topologyManager = tm;
 147     }
 148
 149     public void unsetTopologyManager(ITopologyManager tm) {
 150         if (this.topologyManager == tm) {
 151             this.topologyManager = null;
 152         }
 153     }
 154
 155     protected void sendARPReply(NodeConnector p, byte[] sMAC, InetAddress sIP,
 156             byte[] tMAC, InetAddress tIP) {
 157         byte[] senderIP = sIP.getAddress();
 158         byte[] targetIP = tIP.getAddress();
 159         ARP arp = new ARP();
 160         arp.setHardwareType(ARP.HW_TYPE_ETHERNET)
 161             .setProtocolType(EtherTypes.IPv4.shortValue())
 162             .setHardwareAddressLength((byte) 6)
 163             .setProtocolAddressLength((byte) 4)
 164             .setOpCode(ARP.REPLY)
 165             .setSenderHardwareAddress(sMAC)
 166             .setSenderProtocolAddress(senderIP)
 167             .setTargetHardwareAddress(tMAC)
 168             .setTargetProtocolAddress(targetIP);
 169
 170         Ethernet ethernet = new Ethernet();
 171         ethernet.setSourceMACAddress(sMAC)
 172             .setDestinationMACAddress(tMAC)
 173             .setEtherType(EtherTypes.ARP.shortValue())
 174             .setPayload(arp);
 175
 176         RawPacket destPkt = this.dataPacketService.encodeDataPacket(ethernet);
 177         destPkt.setOutgoingNodeConnector(p);
 178
 179         this.dataPacketService.transmitDataPacket(destPkt);
 180     }
 181
 182     protected void handleARPPacket(Ethernet eHeader, ARP pkt, NodeConnector p) {
 183
 184         byte[] sourceMAC = eHeader.getSourceMACAddress();
 185         byte[] targetMAC = eHeader.getDestinationMACAddress();
 186         /*
 187          * Sanity Check; drop ARP packets originated by the controller itself.
 188          * This is to avoid continuous flooding
 189          */
 190         if (Arrays.equals(sourceMAC, getControllerMAC())) {
 191             if (log.isDebugEnabled()) {
 192                 log.debug("Receive a self originated ARP pkt (srcMAC {}) --> DROP",
 193                         HexEncode.bytesToHexString(sourceMAC));
 194             }
 195             return;
 196         }
 197
 198         InetAddress targetIP, sourceIP;
 199         try {
 200             targetIP = InetAddress.getByAddress(pkt.getTargetProtocolAddress());
 201             sourceIP = InetAddress.getByAddress(pkt.getSenderProtocolAddress());
 202         } catch (UnknownHostException e1) {
 203             log.debug("Invalid host in ARP packet: {}", e1.getMessage());
 204             return;
 205         }
 206
 207         Subnet subnet = null;
 208         if (switchManager != null) {
 209             subnet = switchManager.getSubnetByNetworkAddress(sourceIP);
 210         }
 211         if (subnet == null) {
 212             log.debug("ARPHandler: can't find subnet matching {}, drop packet", sourceIP);
 213             return;
 214         }
 215
 216         // Make sure that the host is a legitimate member of this subnet
 217         if (!subnet.hasNodeConnector(p)) {
 218             log.debug("{} showing up on {} does not belong to {}",
 219                     new Object[] { sourceIP, p, subnet });
 220             return;
 221         }
 222
 223         HostNodeConnector requestor = null;
 224         if (NetUtils.isUnicastMACAddr(sourceMAC) && p.getNode() != null) {
 225             try {
 226                 requestor = new HostNodeConnector(sourceMAC, sourceIP, p, subnet.getVlan());
 227             } catch (ConstructionException e) {
 228                 log.debug("Received ARP packet with invalid MAC: {}", HexEncode.bytesToHexString(sourceMAC));
 229                 return;
 230             }
 231             /*
 232              * Learn host from the received ARP REQ/REPLY, inform Host Tracker
 233              */
 234             log.trace("Inform Host tracker of new host {}", requestor.getNetworkAddress());
 235             for (IfHostListener listener : this.hostListeners) {
 236                 listener.hostListener(requestor);
 237             }
 238         }
 239
 240         /*
 241          * OpCode != request -> ARP Reply. If there are hosts (in
 242          * arpRequestors) waiting for the ARP reply for this sourceIP, it's
 243          * time to generate the reply and send it to these hosts.
 244          *
 245          * If sourceIP==targetIP, it is a Gratuitous ARP. If there are hosts (in
 246          * arpRequestors) waiting for the ARP reply for this sourceIP, it's time
 247          * to generate the reply and send it to these hosts
 248          */
 249
 250         if (pkt.getOpCode() != ARP.REQUEST || sourceIP.equals(targetIP)) {
 251             // Raise a reply event so that any waiting requestors will be sent a reply
 252             // the true value indicates we should generate replies to requestors across the cluster
 253             log.trace("Received ARP reply packet from {}, reply to all requestors.", sourceIP);
 254             arpRequestReplyEvent.put(new ARPReply(sourceIP, sourceMAC), true);
 255             return;
 256         }
 257
 258         /*
 259          * ARP Request Handling:
 260          * If targetIP is the IP of the subnet, reply with ARP REPLY
 261          * If targetIP is a known host, PROXY ARP (by sending ARP REPLY) on behalf of known target hosts.
 262          * For unknown target hosts, generate and send an ARP request to ALL switches/ports using
 263          * the IP address defined in the subnet as source address
 264          */
 265         /*
 266          * If target IP is gateway IP, Send ARP reply
 267          */
 268         if ((targetIP.equals(subnet.getNetworkAddress()))
 269                 && (NetUtils.isBroadcastMACAddr(targetMAC) || Arrays.equals(targetMAC, getControllerMAC()))) {
 270             if (connectionManager.isLocal(p.getNode())){
 271                 if (log.isTraceEnabled()){
 272                     log.trace("Received local ARP req. for default gateway. Replying with controller MAC: {}",
 273                             HexEncode.bytesToHexString(getControllerMAC()));
 274                 }
 275                 sendARPReply(p, getControllerMAC(), targetIP, pkt.getSenderHardwareAddress(), sourceIP);
 276             } else {
 277                 log.trace("Received non-local ARP req. for default gateway. Raising reply event");
 278                 arpRequestReplyEvent.put(
 279                         new ARPReply(p, targetIP, getControllerMAC(), sourceIP, pkt.getSenderHardwareAddress()), false);
 280             }
 281             return;
 282         }
 283
 284
 285         HostNodeConnector host = hostTracker.hostQuery(targetIP);
 286         // unknown host, initiate ARP request
 287         if (host == null) {
 288             // add the requestor to the list so that we can replay the reply
 289             // when the host responds
 290             if (requestor != null) {
 291                 Set<HostNodeConnector> requestorSet = arpRequestors.get(targetIP);
 292                 if (requestorSet == null) {
 293                     requestorSet = Collections.newSetFromMap(new ConcurrentHashMap<HostNodeConnector, Boolean>());
 294                     arpRequestors.put(targetIP, requestorSet);
 295                 }
 296                 requestorSet.add(requestor);
 297                 countDownTimers.put(targetIP, (short) 2); // reset timeout to 2sec
 298             }
 299             //Raise a bcast request event, all controllers need to send one
 300             log.trace("Sending a bcast ARP request for {}", targetIP);
 301             arpRequestReplyEvent.put(new ARPRequest(targetIP, subnet), false);
 302         } else {
 303             /*
 304              * Target host known (across the cluster), send ARP REPLY make sure that targetMAC
 305              * matches the host's MAC if it is not broadcastMAC
 306              */
 307             if (NetUtils.isBroadcastMACAddr(targetMAC) || Arrays.equals(host.getDataLayerAddressBytes(), targetMAC)) {
 308                 log.trace("Received ARP req. for known host {}, sending reply...", targetIP);
 309                 if (connectionManager.isLocal(p.getNode())) {
 310                     sendARPReply(p,
 311                             host.getDataLayerAddressBytes(),
 312                             host.getNetworkAddress(),
 313                             pkt.getSenderHardwareAddress(),
 314                             sourceIP);
 315                 } else {
 316                     arpRequestReplyEvent.put(new ARPReply(
 317                             p,
 318                             host.getNetworkAddress(),
 319                             host.getDataLayerAddressBytes(),
 320                             sourceIP,
 321                             pkt.getSenderHardwareAddress()), false);
 322                 }
 323             } else {
 324                 /*
 325                  * Target MAC has been changed. For now, discard it.
 326                  * TODO: We may need to send unicast ARP REQUEST on behalf of
 327                  * the target back to the sender to trigger the sender to update
 328                  * its table
 329                  */
 330             }
 331         }
 332     }
 333
 334     /*
 335      *  Send a broadcast ARP Request to the switch/ ports  using
 336      *  the networkAddress of the subnet as sender IP
 337      *  the controller's MAC as sender MAC
 338      *  the targetIP as the target Network Address
 339      */
 340     protected void sendBcastARPRequest(InetAddress targetIP, Subnet subnet) {
 341         log.trace("sendBcatARPRequest targetIP:{} subnet:{}", targetIP, subnet);
 342         Set<NodeConnector> nodeConnectors;
 343         if (subnet.isFlatLayer2()) {
 344             nodeConnectors = new HashSet<NodeConnector>();
 345             for (Node n : this.switchManager.getNodes()) {
 346                 nodeConnectors.addAll(this.switchManager.getUpNodeConnectors(n));
 347             }
 348         } else {
 349             nodeConnectors = subnet.getNodeConnectors();
 350         }
 351
 352         for (NodeConnector p : nodeConnectors) {
 353             //fiter out any non-local or internal ports
 354             if (! connectionManager.isLocal(p.getNode()) || topologyManager.isInternal(p)) {
 355                 continue;
 356             }
 357             log.trace("Sending toward nodeConnector:{}", p);
 358             ARP arp = new ARP();
 359             byte[] senderIP = subnet.getNetworkAddress().getAddress();
 360             byte[] targetIPByte = targetIP.getAddress();
 361             arp.setHardwareType(ARP.HW_TYPE_ETHERNET)
 362                .setProtocolType(EtherTypes.IPv4.shortValue())
 363                .setHardwareAddressLength((byte) 6)
 364                .setProtocolAddressLength((byte) 4)
 365                .setOpCode(ARP.REQUEST)
 366                .setSenderHardwareAddress(getControllerMAC())
 367                .setSenderProtocolAddress(senderIP)
 368                .setTargetHardwareAddress(
 369                        new byte[] { (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0 })
 370                .setTargetProtocolAddress(targetIPByte);
 371
 372             Ethernet ethernet = new Ethernet();
 373             ethernet.setSourceMACAddress(getControllerMAC())
 374                     .setDestinationMACAddress(new byte[] {(byte) -1,
 375                                                           (byte) -1,
 376                                                           (byte) -1,
 377                                                           (byte) -1,
 378                                                           (byte) -1,
 379                                                           (byte) -1 })
 380                     .setEtherType(EtherTypes.ARP.shortValue()).setPayload(arp);
 381
 382             // TODO For now send port-by-port, see how to optimize to
 383             // send to multiple ports at once
 384             RawPacket destPkt = this.dataPacketService.encodeDataPacket(ethernet);
 385             destPkt.setOutgoingNodeConnector(p);
 386
 387             this.dataPacketService.transmitDataPacket(destPkt);
 388         }
 389     }
 390
 391     /*
 392      * Send a unicast ARP Request to the known host on a specific switch/port as
 393      * defined in the host.
 394      * The sender IP is the networkAddress of the subnet
 395      * The sender MAC is the controller's MAC
 396      */
 397     protected void sendUcastARPRequest(HostNodeConnector host, Subnet subnet) {
 398         log.trace("sendUcastARPRequest host:{} subnet:{}", host, subnet);
 399         NodeConnector outPort = host.getnodeConnector();
 400         if (outPort == null) {
 401             log.error("Failed sending UcastARP because cannot extract output port from Host: {}", host);
 402             return;
 403         }
 404
 405         byte[] senderIP = subnet.getNetworkAddress().getAddress();
 406         byte[] targetIP = host.getNetworkAddress().getAddress();
 407         byte[] targetMAC = host.getDataLayerAddressBytes();
 408         ARP arp = new ARP();
 409         arp.setHardwareType(ARP.HW_TYPE_ETHERNET)
 410             .setProtocolType(EtherTypes.IPv4.shortValue())
 411             .setHardwareAddressLength((byte) 6)
 412             .setProtocolAddressLength((byte) 4)
 413             .setOpCode(ARP.REQUEST)
 414             .setSenderHardwareAddress(getControllerMAC())
 415             .setSenderProtocolAddress(senderIP)
 416             .setTargetHardwareAddress(targetMAC)
 417             .setTargetProtocolAddress(targetIP);
 418
 419         Ethernet ethernet = new Ethernet();
 420         ethernet.setSourceMACAddress(getControllerMAC())
 421                 .setDestinationMACAddress(targetMAC)
 422                 .setEtherType(EtherTypes.ARP.shortValue())
 423                 .setPayload(arp);
 424
 425         RawPacket destPkt = this.dataPacketService.encodeDataPacket(ethernet);
 426         destPkt.setOutgoingNodeConnector(outPort);
 427
 428         this.dataPacketService.transmitDataPacket(destPkt);
 429     }
 430
 431     @Override
 432     public void find(InetAddress networkAddress) {
 433         log.trace("Received find IP {}", networkAddress);
 434
 435         Subnet subnet = null;
 436         if (switchManager != null) {
 437             subnet = switchManager.getSubnetByNetworkAddress(networkAddress);
 438         }
 439         if (subnet == null) {
 440             log.debug("Can't find subnet matching IP {}", networkAddress);
 441             return;
 442         }
 443
 444         // send a broadcast ARP Request to this IP
 445         arpRequestReplyEvent.put(new ARPRequest(networkAddress, subnet), false);
 446     }
 447
 448     /*
 449      * Probe the host by sending a unicast ARP Request to the host
 450      */
 451     @Override
 452     public void probe(HostNodeConnector host) {
 453         log.trace("Received probe host {}", host);
 454
 455         Subnet subnet = null;
 456         if (switchManager != null) {
 457             subnet = switchManager.getSubnetByNetworkAddress(host
 458                     .getNetworkAddress());
 459         }
 460         if (subnet == null) {
 461             log.debug("can't find subnet matching {}", host.getNetworkAddress());
 462             return;
 463         }
 464
 465         if (connectionManager.isLocal(host.getnodeconnectorNode())){
 466             log.trace("Send a ucast ARP req. to: {}", host);
 467             sendUcastARPRequest(host, subnet);
 468         } else {
 469             log.trace("Raise a ucast ARP req. event to: {}", host);
 470             arpRequestReplyEvent.put(new ARPRequest(host, subnet), false);
 471         }
 472     }
 473
 474     /*
 475      * An IP packet is punted to the controller, this means that the
 476      * destination host is not known to the controller.
 477      * Need to discover it by sending a Broadcast ARP Request
 478      */
 479     protected void handlePuntedIPPacket(IPv4 pkt, NodeConnector p) {
 480
 481         InetAddress dIP = NetUtils.getInetAddress(pkt.getDestinationAddress());
 482         if (dIP == null) {
 483            return;
 484         }
 485
 486         Subnet subnet = null;
 487         if (switchManager != null) {
 488             subnet = switchManager.getSubnetByNetworkAddress(dIP);
 489         }
 490         if (subnet == null) {
 491             log.debug("Can't find subnet matching {}, drop packet", dIP);
 492             return;
 493         }
 494         log.trace("Punted IP pkt from {}, sending bcast ARP event...", dIP);
 495         /*
 496          * unknown destination host, initiate bcast ARP request
 497          */
 498         arpRequestReplyEvent.put(new ARPRequest(dIP, subnet), false);
 499         return;
 500     }
 501
 502     public byte[] getControllerMAC() {
 503         if (switchManager == null) {
 504             return null;
 505         }
 506         return switchManager.getControllerMAC();
 507     }
 508
 509     /**
 510      * Function called by the dependency manager when all the required
 511      * dependencies are satisfied
 512      *
 513      */
 514     void init() {
 515         arpRequestors = new ConcurrentHashMap<InetAddress, Set<HostNodeConnector>>();
 516         countDownTimers = new ConcurrentHashMap<InetAddress, Short>();
 517         cacheEventHandler = new Thread(new ARPCacheEventHandler(), "ARPCacheEventHandler Thread");
 518
 519         allocateCaches();
 520         retrieveCaches();
 521     }
 522
 523     @SuppressWarnings({ "unchecked", "deprecation" })
 524     private void retrieveCaches() {
 525         ConcurrentMap<?,?> map;
 526
 527         if (this.clusterContainerService == null){
 528             log.error("Cluster service unavailable, can't retieve ARPHandler caches!");
 529             return;
 530         }
 531
 532         map = clusterContainerService.getCache(ARP_EVENT_CACHE_NAME);
 533         if (map != null){
 534             this.arpRequestReplyEvent = (ConcurrentMap<ARPEvent, Boolean>) map;
 535         } else {
 536             log.error("Cache allocation failed for {}", ARP_EVENT_CACHE_NAME);
 537         }
 538     }
 539
 540     @SuppressWarnings("deprecation")
 541     private void allocateCaches() {
 542         if (clusterContainerService == null){
 543             nonClusterObjectCreate();
 544             log.error("Clustering service unavailable. Allocated non-cluster caches for ARPHandler.");
 545             return;
 546         }
 547
 548         try{
 549             clusterContainerService.createCache(ARP_EVENT_CACHE_NAME,
 550                     EnumSet.of(IClusterServices.cacheMode.TRANSACTIONAL));
 551         } catch (CacheConfigException e){
 552             log.error("ARPHandler cache configuration invalid!");
 553         } catch (CacheExistException e){
 554             log.debug("ARPHandler cache exists, skipped allocation.");
 555         }
 556
 557     }
 558
 559     private void nonClusterObjectCreate(){
 560         arpRequestReplyEvent = new ConcurrentHashMap<ARPEvent, Boolean>();
 561     }
 562     /**
 563      * Function called by the dependency manager when at least one
 564      * dependency become unsatisfied or when the component is shutting
 565      * down because for example bundle is being stopped.
 566      *
 567      */
 568     void destroy() {
 569         cacheEventHandler.interrupt();
 570     }
 571
 572     /**
 573      * Function called by dependency manager after "init ()" is called
 574      * and after the services provided by the class are registered in
 575      * the service registry
 576      *
 577      */
 578     void start() {
 579         stopping = false;
 580         startPeriodicTimer();
 581         cacheEventHandler.start();
 582     }
 583
 584     /**
 585      * Function called by the dependency manager before the services
 586      * exported by the component are unregistered, this will be
 587      * followed by a "destroy ()" calls
 588      *
 589      */
 590     void stop(){
 591     }
 592
 593     void stopping() {
 594         stopping = true;
 595         cancelPeriodicTimer();
 596     }
 597
 598     void setSwitchManager(ISwitchManager s) {
 599         log.debug("SwitchManager service set.");
 600         this.switchManager = s;
 601     }
 602
 603     void unsetSwitchManager(ISwitchManager s) {
 604         if (this.switchManager == s) {
 605             log.debug("SwitchManager service UNset.");
 606             this.switchManager = null;
 607         }
 608     }
 609
 610     @Override
 611     public PacketResult receiveDataPacket(RawPacket inPkt) {
 612         if (inPkt == null) {
 613             return PacketResult.IGNORED;
 614         }
 615         log.trace("Received a frame of size: {}", inPkt.getPacketData().length);
 616         Packet formattedPak = this.dataPacketService.decodeDataPacket(inPkt);
 617         if (formattedPak instanceof Ethernet) {
 618             Object nextPak = formattedPak.getPayload();
 619             if (nextPak instanceof IPv4) {
 620                 log.trace("Handle IP packet: {}", formattedPak);
 621                 handlePuntedIPPacket((IPv4) nextPak, inPkt.getIncomingNodeConnector());
 622             } else if (nextPak instanceof ARP) {
 623                 log.trace("Handle ARP packet: {}", formattedPak);
 624                 handleARPPacket((Ethernet) formattedPak, (ARP) nextPak, inPkt
 625                         .getIncomingNodeConnector());
 626             }
 627         }
 628         return PacketResult.IGNORED;
 629     }
 630
 631     private void startPeriodicTimer() {
 632         this.periodicTimer = new Timer("ArpHandler Periodic Timer");
 633         this.periodicTimer.scheduleAtFixedRate(new TimerTask() {
 634             @SuppressWarnings("deprecation")
 635             @Override
 636             public void run() {
 637                 Set<InetAddress> targetIPs = countDownTimers.keySet();
 638                 Set<InetAddress> expiredTargets = new HashSet<InetAddress>();
 639                 for (InetAddress t : targetIPs) {
 640                     short tick = countDownTimers.get(t);
 641                     tick--;
 642                     if (tick <= 0) {
 643                         expiredTargets.add(t);
 644                     } else {
 645                         countDownTimers.replace(t, tick);
 646                     }
 647                 }
 648                 for (InetAddress tIP : expiredTargets) {
 649                     countDownTimers.remove(tIP);
 650                     // Remove the requestor(s) who have been waiting for the ARP
 651                     // reply from this target for more than 1sec
 652                     arpRequestors.remove(tIP);
 653                     log.debug("ARP reply was not received from {}", tIP);
 654                 }
 655
 656                 // Clean up ARP event cache
 657                 try {
 658                     if (clusterContainerService.amICoordinator() && ! arpRequestReplyEvent.isEmpty()){
 659                         arpRequestReplyEvent.clear();
 660                     }
 661                 } catch (Exception e){
 662                     log.warn("ARPHandler: A cluster member failed to clear event cache.");
 663                 }
 664             }
 665         }, 0, 1000);
 666     }
 667
 668     private void cancelPeriodicTimer() {
 669         if (this.periodicTimer != null) {
 670             this.periodicTimer.cancel();
 671         }
 672     }
 673
 674     private void generateAndSendReply(InetAddress sourceIP, byte[] sourceMAC) {
 675         if (log.isTraceEnabled()) {
 676             log.trace("generateAndSendReply called with params sourceIP:{} sourceMAC:{}", sourceIP,
 677                       HexEncode.bytesToHexString(sourceMAC));
 678         }
 679         Set<HostNodeConnector> hosts = arpRequestors.remove(sourceIP);
 680         if ((hosts == null) || hosts.isEmpty()) {
 681             log.trace("Bailing out no requestors Hosts");
 682             return;
 683         }
 684         countDownTimers.remove(sourceIP);
 685         for (HostNodeConnector host : hosts) {
 686             if (log.isTraceEnabled()) {
 687                 log.trace("Sending ARP Reply with src {}/{}, target {}/{}",
 688                           new Object[] {
 689                               HexEncode.bytesToHexString(sourceMAC),
 690                               sourceIP,
 691                               HexEncode.bytesToHexString(host.getDataLayerAddressBytes()),
 692                               host.getNetworkAddress() });
 693             }
 694             if (connectionManager.isLocal(host.getnodeconnectorNode())){
 695                 sendARPReply(host.getnodeConnector(),
 696                         sourceMAC,
 697                         sourceIP,
 698                         host.getDataLayerAddressBytes(),
 699                         host.getNetworkAddress());
 700             } else {
 701                 /*
 702                  * In the remote event a requestor moved to another
 703                  * controller it may turn out it now we need to send
 704                  * the ARP reply from a different controller, this
 705                  * cover the case
 706                  */
 707                 arpRequestReplyEvent.put(
 708                         new ARPReply(
 709                             host.getnodeConnector(),
 710                             sourceIP,
 711                             sourceMAC,
 712                             host.getNetworkAddress(),
 713                             host.getDataLayerAddressBytes()), false);
 714             }
 715         }
 716     }
 717
 718
 719     @Override
 720     public void entryUpdated(ARPEvent key, Boolean new_value, String cacheName, boolean originLocal) {
 721         log.trace("Got and entryUpdated for cacheName {} key {} isNew {}", cacheName, key, new_value);
 722         enqueueARPCacheEvent(key, new_value);
 723     }
 724
 725     @Override
 726     public void entryCreated(ARPEvent key, String cacheName, boolean originLocal) {
 727         // nothing to do
 728     }
 729     @Override
 730     public void entryDeleted(ARPEvent key, String cacheName, boolean originLocal) {
 731         // nothing to do
 732     }
 733
 734     private void enqueueARPCacheEvent (ARPEvent event, boolean new_value) {
 735         try {
 736             ARPCacheEvent cacheEvent = new ARPCacheEvent(event, new_value);
 737             if (!ARPCacheEvents.contains(cacheEvent)) {
 738                 this.ARPCacheEvents.add(cacheEvent);
 739                 log.trace("Enqueued {}", event);
 740             }
 741         } catch (Exception e) {
 742             log.debug("enqueueARPCacheEvent caught Interrupt Exception for event {}", event);
 743         }
 744     }
 745
 746     /*
 747      * this thread monitors the connectionEvent queue for new incoming events from
 748      */
 749     private class ARPCacheEventHandler implements Runnable {
 750         @Override
 751         public void run() {
 752             while (!stopping) {
 753                 try {
 754                     ARPCacheEvent ev = ARPCacheEvents.take();
 755                     ARPEvent event = ev.getEvent();
 756                     if (event instanceof ARPRequest) {
 757                         ARPRequest req = (ARPRequest) event;
 758                         // If broadcast request
 759                         if (req.getHost() == null) {
 760                             log.trace("Trigger and ARP Broadcast Request upon receipt of {}", req);
 761                             sendBcastARPRequest(req.getTargetIP(), req.getSubnet());
 762
 763                         //If unicast and local, send reply
 764                         } else if (connectionManager.isLocal(req.getHost().getnodeconnectorNode())) {
 765                             log.trace("ARPCacheEventHandler - sendUcatARPRequest upon receipt of {}", req);
 766                             sendUcastARPRequest(req.getHost(), req.getSubnet());
 767                         }
 768                     } else if (event instanceof ARPReply) {
 769                         ARPReply rep = (ARPReply) event;
 770                         // New reply received by controller, notify all awaiting requestors across the cluster
 771                         if (ev.isNewReply()) {
 772                             log.trace("Trigger a generateAndSendReply in response to {}", rep);
 773                             generateAndSendReply(rep.getTargetIP(), rep.getTargetMac());
 774                         // Otherwise, a specific reply. If local, send out.
 775                         } else if (connectionManager.isLocal(rep.getPort().getNode())) {
 776                             log.trace("ARPCacheEventHandler - sendUcatARPReply locally in response to {}", rep);
 777                             sendARPReply(rep.getPort(),
 778                                     rep.getSourceMac(),
 779                                     rep.getSourceIP(),
 780                                     rep.getTargetMac(),
 781                                     rep.getTargetIP());
 782                         }
 783                     }
 784                 } catch (InterruptedException e) {
 785                     ARPCacheEvents.clear();
 786                     return;
 787                 }
 788             }
 789         }
 790     }
 791 }