opendaylight/protocol_plugins/openflow/src/main/java/org/opendaylight/controller/protocol_plugin/openflow/core/internal/SwitchHandler.java

   1 /*
   2  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.protocol_plugin.openflow.core.internal;
  10
  11 import java.io.IOException;
  12 import java.net.SocketException;
  13 import java.nio.channels.AsynchronousCloseException;
  14 import java.nio.channels.ClosedSelectorException;
  15 import java.nio.channels.SelectionKey;
  16 import java.nio.channels.Selector;
  17 import java.nio.channels.SocketChannel;
  18 import java.nio.channels.spi.SelectorProvider;
  19 import java.util.ArrayList;
  20 import java.util.Comparator;
  21 import java.util.Date;
  22 import java.util.HashMap;
  23 import java.util.Iterator;
  24 import java.util.List;
  25 import java.util.Map;
  26 import java.util.Set;
  27 import java.util.Timer;
  28 import java.util.TimerTask;
  29 import java.util.concurrent.Callable;
  30 import java.util.concurrent.ConcurrentHashMap;
  31 import java.util.concurrent.ExecutorService;
  32 import java.util.concurrent.Executors;
  33 import java.util.concurrent.Future;
  34 import java.util.concurrent.PriorityBlockingQueue;
  35 import java.util.concurrent.TimeUnit;
  36 import java.util.concurrent.atomic.AtomicInteger;
  37
  38 import org.opendaylight.controller.protocol_plugin.openflow.core.IController;
  39 import org.opendaylight.controller.protocol_plugin.openflow.core.ISwitch;
  40 import org.opendaylight.controller.protocol_plugin.openflow.core.IMessageReadWrite;
  41 import org.openflow.protocol.OFBarrierReply;
  42 import org.openflow.protocol.OFBarrierRequest;
  43 import org.openflow.protocol.OFEchoReply;
  44 import org.openflow.protocol.OFError;
  45 import org.openflow.protocol.OFFeaturesReply;
  46 import org.openflow.protocol.OFFlowMod;
  47 import org.openflow.protocol.OFGetConfigReply;
  48 import org.openflow.protocol.OFMatch;
  49 import org.openflow.protocol.OFMessage;
  50 import org.openflow.protocol.OFPhysicalPort;
  51 import org.openflow.protocol.OFPhysicalPort.OFPortConfig;
  52 import org.openflow.protocol.OFPhysicalPort.OFPortFeatures;
  53 import org.openflow.protocol.OFPhysicalPort.OFPortState;
  54 import org.openflow.protocol.OFPort;
  55 import org.openflow.protocol.OFPortStatus;
  56 import org.openflow.protocol.OFPortStatus.OFPortReason;
  57 import org.openflow.protocol.OFSetConfig;
  58 import org.openflow.protocol.OFStatisticsReply;
  59 import org.openflow.protocol.OFStatisticsRequest;
  60 import org.openflow.protocol.OFType;
  61 import org.openflow.protocol.factory.BasicFactory;
  62 import org.openflow.util.HexString;
  63 import org.slf4j.Logger;
  64 import org.slf4j.LoggerFactory;
  65
  66 public class SwitchHandler implements ISwitch {
  67     private static final Logger logger = LoggerFactory
  68             .getLogger(SwitchHandler.class);
  69     private static final int SWITCH_LIVENESS_TIMER = 5000;
  70     private static final int switchLivenessTimeout = getSwitchLivenessTimeout();
  71     private int MESSAGE_RESPONSE_TIMER = 2000;
  72
  73     private String instanceName;
  74     private ISwitch thisISwitch;
  75     private IController core;
  76     private Long sid;
  77     private Integer buffers;
  78     private Integer capabilities;
  79     private Byte tables;
  80     private Integer actions;
  81     private Selector selector;
  82     private SocketChannel socket;
  83     private BasicFactory factory;
  84     private AtomicInteger xid;
  85     private SwitchState state;
  86     private Timer periodicTimer;
  87     private Map<Short, OFPhysicalPort> physicalPorts;
  88     private Map<Short, Integer> portBandwidth;
  89     private Date connectedDate;
  90     private Long lastMsgReceivedTimeStamp;
  91     private Boolean probeSent;
  92     private ExecutorService executor;
  93     private ConcurrentHashMap<Integer, Callable<Object>> messageWaitingDone;
  94     private boolean running;
  95     private IMessageReadWrite msgReadWriteService;
  96     private Thread switchHandlerThread;
  97     private Integer responseTimerValue;
  98     private PriorityBlockingQueue<PriorityMessage> transmitQ;
  99     private Thread transmitThread;
 100
 101     private enum SwitchState {
 102         NON_OPERATIONAL(0), WAIT_FEATURES_REPLY(1), WAIT_CONFIG_REPLY(2), OPERATIONAL(
 103                 3);
 104
 105         private int value;
 106
 107         private SwitchState(int value) {
 108             this.value = value;
 109         }
 110
 111         @SuppressWarnings("unused")
 112         public int value() {
 113             return this.value;
 114         }
 115     }
 116
 117     public SwitchHandler(Controller core, SocketChannel sc, String name) {
 118         this.instanceName = name;
 119         this.thisISwitch = this;
 120         this.sid = (long) 0;
 121         this.buffers = (int) 0;
 122         this.capabilities = (int) 0;
 123         this.tables = (byte) 0;
 124         this.actions = (int) 0;
 125         this.core = core;
 126         this.socket = sc;
 127         this.factory = new BasicFactory();
 128         this.connectedDate = new Date();
 129         this.lastMsgReceivedTimeStamp = connectedDate.getTime();
 130         this.physicalPorts = new HashMap<Short, OFPhysicalPort>();
 131         this.portBandwidth = new HashMap<Short, Integer>();
 132         this.state = SwitchState.NON_OPERATIONAL;
 133         this.probeSent = false;
 134         this.xid = new AtomicInteger(this.socket.hashCode());
 135         this.periodicTimer = null;
 136         this.executor = Executors.newFixedThreadPool(4);
 137         this.messageWaitingDone = new ConcurrentHashMap<Integer, Callable<Object>>();
 138         this.responseTimerValue = MESSAGE_RESPONSE_TIMER;
 139         String rTimer = System.getProperty("of.messageResponseTimer");
 140         if (rTimer != null) {
 141             try {
 142                 responseTimerValue = Integer.decode(rTimer);
 143             } catch (NumberFormatException e) {
 144                 logger.warn(
 145                         "Invalid of.messageResponseTimer: {} use default({})",
 146                         rTimer, MESSAGE_RESPONSE_TIMER);
 147             }
 148         }
 149     }
 150
 151     public void start() {
 152         try {
 153             startTransmitThread();
 154             setupCommChannel();
 155             sendFirstHello();
 156             startHandlerThread();
 157         } catch (Exception e) {
 158             reportError(e);
 159         }
 160     }
 161
 162     private void startHandlerThread() {
 163         switchHandlerThread = new Thread(new Runnable() {
 164             @Override
 165             public void run() {
 166                 running = true;
 167                 while (running) {
 168                     try {
 169                         // wait for an incoming connection
 170                         selector.select(0);
 171                         Iterator<SelectionKey> selectedKeys = selector
 172                                 .selectedKeys().iterator();
 173                         while (selectedKeys.hasNext()) {
 174                             SelectionKey skey = selectedKeys.next();
 175                             selectedKeys.remove();
 176                             if (skey.isValid() && skey.isWritable()) {
 177                                 resumeSend();
 178                             }
 179                             if (skey.isValid() && skey.isReadable()) {
 180                                 handleMessages();
 181                             }
 182                         }
 183                     } catch (Exception e) {
 184                         reportError(e);
 185                     }
 186                 }
 187             }
 188         }, instanceName);
 189         switchHandlerThread.start();
 190     }
 191
 192     public void stop() {
 193         running = false;
 194         cancelSwitchTimer();
 195         try {
 196             selector.wakeup();
 197             selector.close();
 198         } catch (Exception e) {
 199         }
 200         try {
 201             socket.close();
 202         } catch (Exception e) {
 203         }
 204         try {
 205             msgReadWriteService.stop();
 206         } catch (Exception e) {
 207         }
 208         executor.shutdown();
 209
 210         msgReadWriteService = null;
 211
 212         if (switchHandlerThread != null) {
 213             switchHandlerThread.interrupt();
 214         }
 215         if (transmitThread != null) {
 216             transmitThread.interrupt();
 217         }
 218     }
 219
 220     @Override
 221     public int getNextXid() {
 222         return this.xid.incrementAndGet();
 223     }
 224
 225     /**
 226      * This method puts the message in an outgoing priority queue with normal
 227      * priority. It will be served after high priority messages. The method
 228      * should be used for non-critical messages such as statistics request,
 229      * discovery packets, etc. An unique XID is generated automatically and
 230      * inserted into the message.
 231      *
 232      * @param msg
 233      *            The OF message to be sent
 234      * @return The XID used
 235      */
 236     @Override
 237     public Integer asyncSend(OFMessage msg) {
 238         return asyncSend(msg, getNextXid());
 239     }
 240
 241     private Object syncSend(OFMessage msg, int xid) {
 242         return syncMessageInternal(msg, xid, true);
 243     }
 244
 245     /**
 246      * This method puts the message in an outgoing priority queue with normal
 247      * priority. It will be served after high priority messages. The method
 248      * should be used for non-critical messages such as statistics request,
 249      * discovery packets, etc. The specified XID is inserted into the message.
 250      *
 251      * @param msg
 252      *            The OF message to be Sent
 253      * @param xid
 254      *            The XID to be used in the message
 255      * @return The XID used
 256      */
 257     @Override
 258     public Integer asyncSend(OFMessage msg, int xid) {
 259         msg.setXid(xid);
 260         if (transmitQ != null) {
 261             transmitQ.add(new PriorityMessage(msg, 0));
 262         }
 263         return xid;
 264     }
 265
 266     /**
 267      * This method puts the message in an outgoing priority queue with high
 268      * priority. It will be served first before normal priority messages. The
 269      * method should be used for critical messages such as hello, echo reply
 270      * etc. An unique XID is generated automatically and inserted into the
 271      * message.
 272      *
 273      * @param msg
 274      *            The OF message to be sent
 275      * @return The XID used
 276      */
 277     @Override
 278     public Integer asyncFastSend(OFMessage msg) {
 279         return asyncFastSend(msg, getNextXid());
 280     }
 281
 282     /**
 283      * This method puts the message in an outgoing priority queue with high
 284      * priority. It will be served first before normal priority messages. The
 285      * method should be used for critical messages such as hello, echo reply
 286      * etc. The specified XID is inserted into the message.
 287      *
 288      * @param msg
 289      *            The OF message to be sent
 290      * @return The XID used
 291      */
 292     @Override
 293     public Integer asyncFastSend(OFMessage msg, int xid) {
 294         msg.setXid(xid);
 295         if (transmitQ != null) {
 296             transmitQ.add(new PriorityMessage(msg, 1));
 297         }
 298         return xid;
 299     }
 300
 301     public void resumeSend() {
 302         try {
 303             if (msgReadWriteService != null) {
 304                 msgReadWriteService.resumeSend();
 305             }
 306         } catch (Exception e) {
 307             reportError(e);
 308         }
 309     }
 310
 311     public void handleMessages() {
 312         List<OFMessage> msgs = null;
 313
 314         try {
 315             if (msgReadWriteService != null) {
 316                 msgs = msgReadWriteService.readMessages();
 317             }
 318         } catch (Exception e) {
 319             reportError(e);
 320         }
 321
 322         if (msgs == null) {
 323             logger.debug("{} is down", toString());
 324             // the connection is down, inform core
 325             reportSwitchStateChange(false);
 326             return;
 327         }
 328         for (OFMessage msg : msgs) {
 329             logger.trace("Message received: {}", msg.toString());
 330             this.lastMsgReceivedTimeStamp = System.currentTimeMillis();
 331             OFType type = msg.getType();
 332             switch (type) {
 333             case HELLO:
 334                 // send feature request
 335                 OFMessage featureRequest = factory
 336                         .getMessage(OFType.FEATURES_REQUEST);
 337                 asyncFastSend(featureRequest);
 338                 // delete all pre-existing flows
 339                 OFMatch match = new OFMatch().setWildcards(OFMatch.OFPFW_ALL);
 340                 OFFlowMod flowMod = (OFFlowMod) factory
 341                         .getMessage(OFType.FLOW_MOD);
 342                 flowMod.setMatch(match).setCommand(OFFlowMod.OFPFC_DELETE)
 343                         .setOutPort(OFPort.OFPP_NONE)
 344                         .setLength((short) OFFlowMod.MINIMUM_LENGTH);
 345                 asyncFastSend(flowMod);
 346                 this.state = SwitchState.WAIT_FEATURES_REPLY;
 347                 startSwitchTimer();
 348                 break;
 349             case ECHO_REQUEST:
 350                 OFEchoReply echoReply = (OFEchoReply) factory
 351                         .getMessage(OFType.ECHO_REPLY);
 352                 asyncFastSend(echoReply);
 353                 break;
 354             case ECHO_REPLY:
 355                 this.probeSent = false;
 356                 break;
 357             case FEATURES_REPLY:
 358                 processFeaturesReply((OFFeaturesReply) msg);
 359                 break;
 360             case GET_CONFIG_REPLY:
 361                 // make sure that the switch can send the whole packet to the
 362                 // controller
 363                 if (((OFGetConfigReply) msg).getMissSendLength() == (short) 0xffff) {
 364                     this.state = SwitchState.OPERATIONAL;
 365                 }
 366                 break;
 367             case BARRIER_REPLY:
 368                 processBarrierReply((OFBarrierReply) msg);
 369                 break;
 370             case ERROR:
 371                 processErrorReply((OFError) msg);
 372                 break;
 373             case PORT_STATUS:
 374                 processPortStatusMsg((OFPortStatus) msg);
 375                 break;
 376             case STATS_REPLY:
 377                 processStatsReply((OFStatisticsReply) msg);
 378                 break;
 379             case PACKET_IN:
 380                 break;
 381             default:
 382                 break;
 383             } // end of switch
 384             if (isOperational()) {
 385                 ((Controller) core).takeSwitchEventMsg(thisISwitch, msg);
 386             }
 387         } // end of for
 388     }
 389
 390     private void processPortStatusMsg(OFPortStatus msg) {
 391         OFPhysicalPort port = msg.getDesc();
 392         if (msg.getReason() == (byte) OFPortReason.OFPPR_MODIFY.ordinal()) {
 393             updatePhysicalPort(port);
 394         } else if (msg.getReason() == (byte) OFPortReason.OFPPR_ADD.ordinal()) {
 395             updatePhysicalPort(port);
 396         } else if (msg.getReason() == (byte) OFPortReason.OFPPR_DELETE
 397                 .ordinal()) {
 398             deletePhysicalPort(port);
 399         }
 400
 401     }
 402
 403     private void startSwitchTimer() {
 404         this.periodicTimer = new Timer();
 405         this.periodicTimer.scheduleAtFixedRate(new TimerTask() {
 406             @Override
 407             public void run() {
 408                 try {
 409                     Long now = System.currentTimeMillis();
 410                     if ((now - lastMsgReceivedTimeStamp) > switchLivenessTimeout) {
 411                         if (probeSent) {
 412                             // switch failed to respond to our probe, consider
 413                             // it down
 414                             logger.warn("{} is idle for too long, disconnect",
 415                                     toString());
 416                             reportSwitchStateChange(false);
 417                         } else {
 418                             // send a probe to see if the switch is still alive
 419                             logger.debug(
 420                                     "Send idle probe (Echo Request) to {}",
 421                                     toString());
 422                             probeSent = true;
 423                             OFMessage echo = factory
 424                                     .getMessage(OFType.ECHO_REQUEST);
 425                             asyncFastSend(echo);
 426                         }
 427                     } else {
 428                         if (state == SwitchState.WAIT_FEATURES_REPLY) {
 429                             // send another features request
 430                             OFMessage request = factory
 431                                     .getMessage(OFType.FEATURES_REQUEST);
 432                             asyncFastSend(request);
 433                         } else {
 434                             if (state == SwitchState.WAIT_CONFIG_REPLY) {
 435                                 // send another config request
 436                                 OFSetConfig config = (OFSetConfig) factory
 437                                         .getMessage(OFType.SET_CONFIG);
 438                                 config.setMissSendLength((short) 0xffff)
 439                                         .setLengthU(OFSetConfig.MINIMUM_LENGTH);
 440                                 asyncFastSend(config);
 441                                 OFMessage getConfig = factory
 442                                         .getMessage(OFType.GET_CONFIG_REQUEST);
 443                                 asyncFastSend(getConfig);
 444                             }
 445                         }
 446                     }
 447                 } catch (Exception e) {
 448                     reportError(e);
 449                 }
 450             }
 451         }, SWITCH_LIVENESS_TIMER, SWITCH_LIVENESS_TIMER);
 452     }
 453
 454     private void cancelSwitchTimer() {
 455         if (this.periodicTimer != null) {
 456             this.periodicTimer.cancel();
 457         }
 458     }
 459
 460     private void reportError(Exception e) {
 461         if (e instanceof AsynchronousCloseException
 462                 || e instanceof InterruptedException
 463                 || e instanceof SocketException || e instanceof IOException
 464                 || e instanceof ClosedSelectorException) {
 465             logger.debug("Caught exception {}", e.getMessage());
 466         } else {
 467             logger.warn("Caught exception ", e);
 468         }
 469         // notify core of this error event and disconnect the switch
 470         ((Controller) core).takeSwitchEventError(this);
 471     }
 472
 473     private void reportSwitchStateChange(boolean added) {
 474         if (added) {
 475             ((Controller) core).takeSwitchEventAdd(this);
 476         } else {
 477             ((Controller) core).takeSwitchEventDelete(this);
 478         }
 479     }
 480
 481     @Override
 482     public Long getId() {
 483         return this.sid;
 484     }
 485
 486     private void processFeaturesReply(OFFeaturesReply reply) {
 487         if (this.state == SwitchState.WAIT_FEATURES_REPLY) {
 488             this.sid = reply.getDatapathId();
 489             this.buffers = reply.getBuffers();
 490             this.capabilities = reply.getCapabilities();
 491             this.tables = reply.getTables();
 492             this.actions = reply.getActions();
 493             // notify core of this error event
 494             for (OFPhysicalPort port : reply.getPorts()) {
 495                 updatePhysicalPort(port);
 496             }
 497             // config the switch to send full data packet
 498             OFSetConfig config = (OFSetConfig) factory
 499                     .getMessage(OFType.SET_CONFIG);
 500             config.setMissSendLength((short) 0xffff).setLengthU(
 501                     OFSetConfig.MINIMUM_LENGTH);
 502             asyncFastSend(config);
 503             // send config request to make sure the switch can handle the set
 504             // config
 505             OFMessage getConfig = factory.getMessage(OFType.GET_CONFIG_REQUEST);
 506             asyncFastSend(getConfig);
 507             this.state = SwitchState.WAIT_CONFIG_REPLY;
 508             // inform core that a new switch is now operational
 509             reportSwitchStateChange(true);
 510         }
 511     }
 512
 513     private void updatePhysicalPort(OFPhysicalPort port) {
 514         Short portNumber = port.getPortNumber();
 515         physicalPorts.put(portNumber, port);
 516         portBandwidth
 517                 .put(portNumber,
 518                         port.getCurrentFeatures()
 519                                 & (OFPortFeatures.OFPPF_10MB_FD.getValue()
 520                                         | OFPortFeatures.OFPPF_10MB_HD
 521                                                 .getValue()
 522                                         | OFPortFeatures.OFPPF_100MB_FD
 523                                                 .getValue()
 524                                         | OFPortFeatures.OFPPF_100MB_HD
 525                                                 .getValue()
 526                                         | OFPortFeatures.OFPPF_1GB_FD
 527                                                 .getValue()
 528                                         | OFPortFeatures.OFPPF_1GB_HD
 529                                                 .getValue() | OFPortFeatures.OFPPF_10GB_FD
 530                                             .getValue()));
 531     }
 532
 533     private void deletePhysicalPort(OFPhysicalPort port) {
 534         Short portNumber = port.getPortNumber();
 535         physicalPorts.remove(portNumber);
 536         portBandwidth.remove(portNumber);
 537     }
 538
 539     @Override
 540     public boolean isOperational() {
 541         return ((this.state == SwitchState.WAIT_CONFIG_REPLY) || (this.state == SwitchState.OPERATIONAL));
 542     }
 543
 544     @Override
 545     public String toString() {
 546         try {
 547             return ("Switch:"
 548                     + socket.socket().getRemoteSocketAddress().toString().split("/")[1]
 549                     + " SWID:" + (isOperational() ? HexString
 550                     .toHexString(this.sid) : "unknown"));
 551         } catch (Exception e) {
 552             return (isOperational() ? HexString.toHexString(this.sid)
 553                     : "unknown");
 554         }
 555
 556     }
 557
 558     @Override
 559     public Date getConnectedDate() {
 560         return this.connectedDate;
 561     }
 562
 563     public String getInstanceName() {
 564         return instanceName;
 565     }
 566
 567     @Override
 568     public Object getStatistics(OFStatisticsRequest req) {
 569         int xid = getNextXid();
 570         StatisticsCollector worker = new StatisticsCollector(this, xid, req);
 571         messageWaitingDone.put(xid, worker);
 572         Future<Object> submit = executor.submit(worker);
 573         Object result = null;
 574         try {
 575             result = submit.get(responseTimerValue, TimeUnit.MILLISECONDS);
 576             return result;
 577         } catch (Exception e) {
 578             logger.warn("Timeout while waiting for {} replies", req.getType());
 579             result = null; // to indicate timeout has occurred
 580             return result;
 581         }
 582     }
 583
 584     @Override
 585     public Object syncSend(OFMessage msg) {
 586         int xid = getNextXid();
 587         return syncSend(msg, xid);
 588     }
 589
 590     /*
 591      * Either a BarrierReply or a OFError is received. If this is a reply for an
 592      * outstanding sync message, wake up associated task so that it can continue
 593      */
 594     private void processBarrierReply(OFBarrierReply msg) {
 595         Integer xid = msg.getXid();
 596         SynchronousMessage worker = (SynchronousMessage) messageWaitingDone
 597                 .remove(xid);
 598         if (worker == null) {
 599             return;
 600         }
 601         worker.wakeup();
 602     }
 603
 604     private void processErrorReply(OFError errorMsg) {
 605         OFMessage offendingMsg = errorMsg.getOffendingMsg();
 606         Integer xid;
 607         if (offendingMsg != null) {
 608             xid = offendingMsg.getXid();
 609         } else {
 610             xid = errorMsg.getXid();
 611         }
 612         /*
 613          * the error can be a reply to a synchronous message or to a statistic
 614          * request message
 615          */
 616         Callable<?> worker = messageWaitingDone.remove(xid);
 617         if (worker == null) {
 618             return;
 619         }
 620         if (worker instanceof SynchronousMessage) {
 621             ((SynchronousMessage) worker).wakeup(errorMsg);
 622         } else {
 623             ((StatisticsCollector) worker).wakeup(errorMsg);
 624         }
 625     }
 626
 627     private void processStatsReply(OFStatisticsReply reply) {
 628         Integer xid = reply.getXid();
 629         StatisticsCollector worker = (StatisticsCollector) messageWaitingDone
 630                 .get(xid);
 631         if (worker == null) {
 632             return;
 633         }
 634         if (worker.collect(reply)) {
 635             // if all the stats records are received (collect() returns true)
 636             // then we are done.
 637             messageWaitingDone.remove(xid);
 638             worker.wakeup();
 639         }
 640     }
 641
 642     @Override
 643     public Map<Short, OFPhysicalPort> getPhysicalPorts() {
 644         return this.physicalPorts;
 645     }
 646
 647     @Override
 648     public OFPhysicalPort getPhysicalPort(Short portNumber) {
 649         return this.physicalPorts.get(portNumber);
 650     }
 651
 652     @Override
 653     public Integer getPortBandwidth(Short portNumber) {
 654         return this.portBandwidth.get(portNumber);
 655     }
 656
 657     @Override
 658     public Set<Short> getPorts() {
 659         return this.physicalPorts.keySet();
 660     }
 661
 662     @Override
 663     public Byte getTables() {
 664         return this.tables;
 665     }
 666
 667     @Override
 668     public Integer getActions() {
 669         return this.actions;
 670     }
 671
 672     @Override
 673     public Integer getCapabilities() {
 674         return this.capabilities;
 675     }
 676
 677     @Override
 678     public Integer getBuffers() {
 679         return this.buffers;
 680     }
 681
 682     @Override
 683     public boolean isPortEnabled(short portNumber) {
 684         return isPortEnabled(physicalPorts.get(portNumber));
 685     }
 686
 687     @Override
 688     public boolean isPortEnabled(OFPhysicalPort port) {
 689         if (port == null) {
 690             return false;
 691         }
 692         int portConfig = port.getConfig();
 693         int portState = port.getState();
 694         if ((portConfig & OFPortConfig.OFPPC_PORT_DOWN.getValue()) > 0) {
 695             return false;
 696         }
 697         if ((portState & OFPortState.OFPPS_LINK_DOWN.getValue()) > 0) {
 698             return false;
 699         }
 700         if ((portState & OFPortState.OFPPS_STP_MASK.getValue()) == OFPortState.OFPPS_STP_BLOCK
 701                 .getValue()) {
 702             return false;
 703         }
 704         return true;
 705     }
 706
 707     @Override
 708     public List<OFPhysicalPort> getEnabledPorts() {
 709         List<OFPhysicalPort> result = new ArrayList<OFPhysicalPort>();
 710         synchronized (this.physicalPorts) {
 711             for (OFPhysicalPort port : physicalPorts.values()) {
 712                 if (isPortEnabled(port)) {
 713                     result.add(port);
 714                 }
 715             }
 716         }
 717         return result;
 718     }
 719
 720     /*
 721      * Transmit thread polls the message out of the priority queue and invokes
 722      * messaging service to transmit it over the socket channel
 723      */
 724     class PriorityMessageTransmit implements Runnable {
 725         public void run() {
 726             running = true;
 727             while (running) {
 728                 try {
 729                     if (!transmitQ.isEmpty()) {
 730                         PriorityMessage pmsg = transmitQ.poll();
 731                         msgReadWriteService.asyncSend(pmsg.msg);
 732                         logger.trace("Message sent: {}", pmsg.toString());
 733                         /*
 734                          * If syncReply is set to true, wait for the response
 735                          * back.
 736                          */
 737                         if (pmsg.syncReply) {
 738                             syncMessageInternal(pmsg.msg, pmsg.msg.getXid(), false);
 739                         }
 740                     }
 741                     Thread.sleep(10);
 742                 } catch (InterruptedException ie) {
 743                     reportError(new InterruptedException(
 744                             "PriorityMessageTransmit thread interrupted"));
 745                 } catch (Exception e) {
 746                     reportError(e);
 747                 }
 748             }
 749             transmitQ = null;
 750         }
 751     }
 752
 753     /*
 754      * Setup and start the transmit thread
 755      */
 756     private void startTransmitThread() {
 757         this.transmitQ = new PriorityBlockingQueue<PriorityMessage>(11,
 758                 new Comparator<PriorityMessage>() {
 759                     public int compare(PriorityMessage p1, PriorityMessage p2) {
 760                         if (p2.priority != p1.priority) {
 761                             return p2.priority - p1.priority;
 762                         } else {
 763                             return (p2.seqNum < p1.seqNum) ? 1 : -1;
 764                         }
 765                     }
 766                 });
 767         this.transmitThread = new Thread(new PriorityMessageTransmit());
 768         this.transmitThread.start();
 769     }
 770
 771     /*
 772      * Setup communication services
 773      */
 774     private void setupCommChannel() throws Exception {
 775         this.selector = SelectorProvider.provider().openSelector();
 776         this.socket.configureBlocking(false);
 777         this.socket.socket().setTcpNoDelay(true);
 778         this.msgReadWriteService = getMessageReadWriteService();
 779     }
 780
 781     private void sendFirstHello() {
 782         try {
 783             OFMessage msg = factory.getMessage(OFType.HELLO);
 784             asyncFastSend(msg);
 785         } catch (Exception e) {
 786             reportError(e);
 787         }
 788     }
 789
 790     private IMessageReadWrite getMessageReadWriteService() throws Exception {
 791         String str = System.getProperty("secureChannelEnabled");
 792         return ((str != null) && (str.trim().equalsIgnoreCase("true"))) ? new SecureMessageReadWriteService(
 793                 socket, selector) : new MessageReadWriteService(socket,
 794                 selector);
 795     }
 796
 797     /**
 798      * Send Barrier message synchronously. The caller will be blocked until the
 799      * Barrier reply is received.
 800      */
 801     @Override
 802     public Object syncSendBarrierMessage() {
 803         OFBarrierRequest barrierMsg = new OFBarrierRequest();
 804         return syncSend(barrierMsg);
 805     }
 806
 807     /**
 808      * Send Barrier message asynchronously. The caller is not blocked. The
 809      * Barrier message will be sent in a transmit thread which will be blocked
 810      * until the Barrier reply is received.
 811      */
 812     @Override
 813     public Object asyncSendBarrierMessage() {
 814         if (transmitQ == null) {
 815             return Boolean.FALSE;
 816         }
 817
 818         OFBarrierRequest barrierMsg = new OFBarrierRequest();
 819         int xid = getNextXid();
 820
 821         barrierMsg.setXid(xid);
 822         transmitQ.add(new PriorityMessage(barrierMsg, 0, true));
 823
 824         return Boolean.TRUE;
 825     }
 826
 827     /**
 828      * This method returns the switch liveness timeout value. If controller did
 829      * not receive any message from the switch for such a long period,
 830      * controller will tear down the connection to the switch.
 831      *
 832      * @return The timeout value
 833      */
 834     private static int getSwitchLivenessTimeout() {
 835         String timeout = System.getProperty("of.switchLivenessTimeout");
 836         int rv = 60500;
 837
 838         try {
 839             if (timeout != null) {
 840                 rv = Integer.parseInt(timeout);
 841             }
 842         } catch (Exception e) {
 843         }
 844
 845         return rv;
 846     }
 847
 848     /**
 849      * This method performs synchronous operations for a given message. If
 850      * syncRequest is set to true, the message will be sent out followed by a
 851      * Barrier request message. Then it's blocked until the Barrier rely arrives
 852      * or timeout. If syncRequest is false, it simply skips the message send and
 853      * just waits for the response back.
 854      *
 855      * @param msg
 856      *            Message to be sent
 857      * @param xid
 858      *            Message XID
 859      * @param request
 860      *            If set to true, the message the message will be sent out
 861      *            followed by a Barrier request message. If set to false, it
 862      *            simply skips the sending and just waits for the Barrier reply.
 863      * @return the result
 864      */
 865     private Object syncMessageInternal(OFMessage msg, int xid, boolean syncRequest) {
 866         SynchronousMessage worker = new SynchronousMessage(this, xid, msg, syncRequest);
 867         messageWaitingDone.put(xid, worker);
 868         Object result = null;
 869         Boolean status = false;
 870         Future<Object> submit = executor.submit(worker);
 871         try {
 872             result = submit.get(responseTimerValue, TimeUnit.MILLISECONDS);
 873             messageWaitingDone.remove(xid);
 874             if (result == null) {
 875                 // if result is null, then it means the switch can handle this
 876                 // message successfully
 877                 // convert the result into a Boolean with value true
 878                 status = true;
 879                 // logger.debug("Successfully send " +
 880                 // msg.getType().toString());
 881                 result = status;
 882             } else {
 883                 // if result is not null, this means the switch can't handle
 884                 // this message
 885                 // the result if OFError already
 886                 logger.debug("Send {} failed --> {}", msg.getType().toString(),
 887                         ((OFError) result).toString());
 888             }
 889             return result;
 890         } catch (Exception e) {
 891             logger.warn("Timeout while waiting for {} reply", msg.getType()
 892                     .toString());
 893             // convert the result into a Boolean with value false
 894             status = false;
 895             result = status;
 896             return result;
 897         }
 898     }
 899 }