bgp/rib-impl/src/main/java/org/opendaylight/protocol/bgp/rib/impl/BGPSessionImpl.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 package org.opendaylight.protocol.bgp.rib.impl;
   9
  10 import com.google.common.annotations.VisibleForTesting;
  11 import com.google.common.base.MoreObjects;
  12 import com.google.common.base.MoreObjects.ToStringHelper;
  13 import com.google.common.base.Optional;
  14 import com.google.common.base.Preconditions;
  15 import com.google.common.collect.Lists;
  16 import com.google.common.collect.Sets;
  17 import io.netty.buffer.ByteBufUtil;
  18 import io.netty.channel.Channel;
  19 import io.netty.channel.ChannelFuture;
  20 import io.netty.channel.ChannelFutureListener;
  21 import io.netty.channel.ChannelHandlerContext;
  22 import io.netty.channel.ChannelPipeline;
  23 import io.netty.channel.SimpleChannelInboundHandler;
  24 import java.io.IOException;
  25 import java.nio.channels.NonWritableChannelException;
  26 import java.util.Collections;
  27 import java.util.Date;
  28 import java.util.List;
  29 import java.util.Set;
  30 import java.util.concurrent.TimeUnit;
  31 import javax.annotation.concurrent.GuardedBy;
  32 import org.opendaylight.controller.config.yang.bgp.rib.impl.BgpSessionState;
  33 import org.opendaylight.protocol.bgp.parser.AsNumberUtil;
  34 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  35 import org.opendaylight.protocol.bgp.parser.BGPError;
  36 import org.opendaylight.protocol.bgp.parser.BgpExtendedMessageUtil;
  37 import org.opendaylight.protocol.bgp.parser.BgpTableTypeImpl;
  38 import org.opendaylight.protocol.bgp.parser.spi.MultiPathSupport;
  39 import org.opendaylight.protocol.bgp.parser.spi.pojo.MultiPathSupportImpl;
  40 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPMessagesListener;
  41 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPPeerRegistry;
  42 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionPreferences;
  43 import org.opendaylight.protocol.bgp.rib.impl.state.BGPSessionStateImpl;
  44 import org.opendaylight.protocol.bgp.rib.impl.state.BGPSessionStateProvider;
  45 import org.opendaylight.protocol.bgp.rib.impl.stats.peer.BGPSessionStats;
  46 import org.opendaylight.protocol.bgp.rib.impl.stats.peer.BGPSessionStatsImpl;
  47 import org.opendaylight.protocol.bgp.rib.spi.BGPSession;
  48 import org.opendaylight.protocol.bgp.rib.spi.BGPSessionListener;
  49 import org.opendaylight.protocol.bgp.rib.spi.BGPTerminationReason;
  50 import org.opendaylight.protocol.bgp.rib.spi.State;
  51 import org.opendaylight.protocol.bgp.rib.spi.state.BGPSessionState;
  52 import org.opendaylight.protocol.bgp.rib.spi.state.BGPTimersState;
  53 import org.opendaylight.protocol.bgp.rib.spi.state.BGPTransportState;
  54 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.AsNumber;
  55 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Address;
  56 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Keepalive;
  57 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.KeepaliveBuilder;
  58 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Notify;
  59 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.NotifyBuilder;
  60 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Open;
  61 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Update;
  62 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.BgpParameters;
  63 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.OptionalCapabilities;
  64 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.optional.capabilities.CParameters;
  65 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.BgpTableType;
  66 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.CParameters1;
  67 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.RouteRefresh;
  68 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.AddPathCapability;
  69 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.MultiprotocolCapability;
  70 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.add.path.capability.AddressFamilies;
  71 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev130925.rib.TablesKey;
  72 import org.opendaylight.yangtools.yang.binding.Notification;
  73 import org.slf4j.Logger;
  74 import org.slf4j.LoggerFactory;
  75
  76 @VisibleForTesting
  77 public class BGPSessionImpl extends SimpleChannelInboundHandler<Notification> implements BGPSession, BGPSessionStats,
  78     BGPSessionStateProvider, AutoCloseable {
  79
  80     private static final Logger LOG = LoggerFactory.getLogger(BGPSessionImpl.class);
  81
  82     private static final Notification KEEP_ALIVE = new KeepaliveBuilder().build();
  83
  84     private static final int KA_TO_DEADTIMER_RATIO = 3;
  85
  86     private static final String EXTENDED_MSG_DECODER = "EXTENDED_MSG_DECODER";
  87
  88     static final String END_OF_INPUT = "End of input detected. Close the session.";
  89
  90     /**
  91      * System.nanoTime value about when was sent the last message.
  92      */
  93     @VisibleForTesting
  94     private long lastMessageSentAt;
  95
  96     /**
  97      * System.nanoTime value about when was received the last message
  98      */
  99     private long lastMessageReceivedAt;
 100
 101     private final BGPSessionListener listener;
 102
 103     private final BGPSynchronization sync;
 104
 105     private int kaCounter = 0;
 106
 107     private final Channel channel;
 108
 109     @GuardedBy("this")
 110     private State state = State.OPEN_CONFIRM;
 111
 112     private final Set<BgpTableType> tableTypes;
 113     private final List<AddressFamilies> addPathTypes;
 114     private final int holdTimerValue;
 115     private final int keepAlive;
 116     private final AsNumber asNumber;
 117     private final Ipv4Address bgpId;
 118     private final BGPPeerRegistry peerRegistry;
 119     private final ChannelOutputLimiter limiter;
 120     private final BGPSessionStateImpl sessionState;
 121
 122     private BGPSessionStatsImpl sessionStats;
 123     private boolean terminationReasonNotified;
 124
 125     public BGPSessionImpl(final BGPSessionListener listener, final Channel channel, final Open remoteOpen,
 126         final BGPSessionPreferences localPreferences, final BGPPeerRegistry peerRegistry) {
 127         this(listener, channel, remoteOpen, localPreferences.getHoldTime(), peerRegistry);
 128         this.sessionStats = new BGPSessionStatsImpl(this, remoteOpen, this.holdTimerValue, this.keepAlive, channel,
 129             Optional.of(localPreferences), this.tableTypes, this.addPathTypes);
 130     }
 131
 132     public BGPSessionImpl(final BGPSessionListener listener, final Channel channel, final Open remoteOpen,
 133         final int localHoldTimer, final BGPPeerRegistry peerRegistry) {
 134         this.listener = Preconditions.checkNotNull(listener);
 135         this.channel = Preconditions.checkNotNull(channel);
 136         this.limiter = new ChannelOutputLimiter(this);
 137         this.channel.pipeline().addLast(this.limiter);
 138         this.holdTimerValue = (remoteOpen.getHoldTimer() < localHoldTimer) ? remoteOpen.getHoldTimer() : localHoldTimer;
 139         LOG.info("BGP HoldTimer new value: {}", this.holdTimerValue);
 140         this.keepAlive = this.holdTimerValue / KA_TO_DEADTIMER_RATIO;
 141         this.asNumber = AsNumberUtil.advertizedAsNumber(remoteOpen);
 142         this.peerRegistry = peerRegistry;
 143         this.sessionState = new BGPSessionStateImpl();
 144
 145         final Set<TablesKey> tts = Sets.newHashSet();
 146         final Set<BgpTableType> tats = Sets.newHashSet();
 147         final List<AddressFamilies> addPathCapabilitiesList = Lists.newArrayList();
 148         if (remoteOpen.getBgpParameters() != null) {
 149             for (final BgpParameters param : remoteOpen.getBgpParameters()) {
 150                 for (final OptionalCapabilities optCapa : param.getOptionalCapabilities()) {
 151                     final CParameters cParam = optCapa.getCParameters();
 152                     if ( cParam.getAugmentation(CParameters1.class) == null) {
 153                         continue;
 154                     }
 155                     if(cParam.getAugmentation(CParameters1.class).getMultiprotocolCapability() != null) {
 156                         final MultiprotocolCapability multi = cParam.getAugmentation(CParameters1.class).getMultiprotocolCapability();
 157                         final TablesKey tt = new TablesKey(multi.getAfi(), multi.getSafi());
 158                         LOG.trace("Added table type to sync {}", tt);
 159                         tts.add(tt);
 160                         tats.add(new BgpTableTypeImpl(tt.getAfi(), tt.getSafi()));
 161                     } else if (cParam.getAugmentation(CParameters1.class).getAddPathCapability() != null) {
 162                         final AddPathCapability addPathCap = cParam.getAugmentation(CParameters1.class).getAddPathCapability();
 163                         addPathCapabilitiesList.addAll(addPathCap.getAddressFamilies());
 164                     }
 165                 }
 166             }
 167         }
 168
 169         this.sync = new BGPSynchronization(this.listener, tts);
 170         this.tableTypes = tats;
 171         this.addPathTypes = addPathCapabilitiesList;
 172
 173         if (! this.addPathTypes.isEmpty()) {
 174             final ChannelPipeline pipeline = this.channel.pipeline();
 175             final BGPByteToMessageDecoder decoder = pipeline.get(BGPByteToMessageDecoder.class);
 176             decoder.addDecoderConstraint(MultiPathSupport.class,
 177                     MultiPathSupportImpl.createParserMultiPathSupport(this.addPathTypes));
 178         }
 179
 180         if (this.holdTimerValue != 0) {
 181             channel.eventLoop().schedule(this::handleHoldTimer, this.holdTimerValue, TimeUnit.SECONDS);
 182             channel.eventLoop().schedule(this::handleKeepaliveTimer, this.keepAlive, TimeUnit.SECONDS);
 183         }
 184         this.bgpId = remoteOpen.getBgpIdentifier();
 185         this.sessionStats = new BGPSessionStatsImpl(this, remoteOpen, this.holdTimerValue, this.keepAlive, channel, Optional.absent(),
 186                 this.tableTypes, this.addPathTypes);
 187
 188         this.sessionState.advertizeCapabilities(this.holdTimerValue, channel.remoteAddress(), channel.localAddress(),
 189             this.tableTypes, remoteOpen.getBgpParameters());
 190     }
 191
 192     /**
 193      * Set the extend message coder for current channel
 194      * The reason for separating this part from constructor is, in #channel.pipeline().replace(..), the
 195      * invokeChannelRead() will be invoked after the original message coder handler got removed. And there
 196      * is chance that before the session instance is fully initiated (constructor returns), a KeepAlive
 197      * message arrived already in the channel buffer. Thus #AbstractBGPSessionNegotiator.handleMessage(..)
 198      * gets invoked again and a deadlock is caused.  A BGP final state machine error will happen as BGP
 199      * negotiator is still in OPEN_SENT state as the session constructor hasn't returned yet.
 200      *
 201      * @param remoteOpen
 202      */
 203     public synchronized void setChannelExtMsgCoder(final Open remoteOpen) {
 204         final boolean enableExMess = BgpExtendedMessageUtil.advertizedBgpExtendedMessageCapability(remoteOpen);
 205         if (enableExMess) {
 206             this.channel.pipeline().replace(BGPMessageHeaderDecoder.class, EXTENDED_MSG_DECODER, BGPMessageHeaderDecoder.getExtendedBGPMessageHeaderDecoder());
 207         }
 208     }
 209
 210     @Override
 211     public synchronized void close() {
 212         if (this.state != State.IDLE && !this.terminationReasonNotified) {
 213             this.writeAndFlush(new NotifyBuilder().setErrorCode(BGPError.CEASE.getCode()).setErrorSubcode(BGPError.CEASE.getSubcode()).build());
 214             this.closeWithoutMessage();
 215         }
 216     }
 217
 218     /**
 219      * Handles incoming message based on their type.
 220      *
 221      * @param msg incoming message
 222      */
 223     synchronized void handleMessage(final Notification msg) {
 224         if (this.state == State.IDLE) {
 225             return;
 226         }
 227         try {
 228             // Update last reception time
 229             this.lastMessageReceivedAt = System.nanoTime();
 230
 231             if (msg instanceof Open) {
 232                 // Open messages should not be present here
 233                 this.terminate(new BGPDocumentedException(null, BGPError.FSM_ERROR));
 234             } else if (msg instanceof Notify) {
 235                 final Notify notify = (Notify) msg;
 236                 // Notifications are handled internally
 237                 LOG.info("Session closed because Notification message received: {} / {}, data={}", notify.getErrorCode(),
 238                     notify.getErrorSubcode(), notify.getData() != null ? ByteBufUtil.hexDump(notify.getData()) : null);
 239                 notifyTerminationReasonAndCloseWithoutMessage(notify.getErrorCode(), notify.getErrorSubcode());
 240             } else if (msg instanceof Keepalive) {
 241                 // Keepalives are handled internally
 242                 LOG.trace("Received KeepAlive message.");
 243                 this.kaCounter++;
 244                 if (this.kaCounter >= 2) {
 245                     this.sync.kaReceived();
 246                 }
 247             } else if (msg instanceof RouteRefresh) {
 248                 this.listener.onMessage(this, msg);
 249             } else if (msg instanceof Update) {
 250                 this.listener.onMessage(this, msg);
 251                 this.sync.updReceived((Update) msg);
 252             } else {
 253                 LOG.warn("Ignoring unhandled message: {}.", msg.getClass());
 254             }
 255
 256             this.sessionStats.updateReceivedMsg(msg);
 257             this.sessionState.messageReceived(msg);
 258         } catch (final BGPDocumentedException e) {
 259             this.terminate(e);
 260         }
 261     }
 262
 263     private synchronized void notifyTerminationReasonAndCloseWithoutMessage(final Short errorCode, final Short errorSubcode) {
 264         this.terminationReasonNotified = true;
 265         this.listener.onSessionTerminated(this, new BGPTerminationReason(
 266             BGPError.forValue(errorCode, errorSubcode)));
 267         this.closeWithoutMessage();
 268     }
 269
 270     synchronized void endOfInput() {
 271         if (this.state == State.UP) {
 272             LOG.info(END_OF_INPUT);
 273             this.listener.onSessionDown(this, new IOException(END_OF_INPUT));
 274         }
 275     }
 276
 277     @GuardedBy("this")
 278     private ChannelFuture writeEpilogue(final ChannelFuture future, final Notification msg) {
 279         future.addListener(
 280             (ChannelFutureListener) f -> {
 281                 if (!f.isSuccess()) {
 282                     LOG.warn("Failed to send message {} to socket {}", msg, BGPSessionImpl.this.channel, f.cause());
 283                 } else {
 284                     LOG.trace("Message {} sent to socket {}", msg, BGPSessionImpl.this.channel);
 285                 }
 286             });
 287         this.lastMessageSentAt = System.nanoTime();
 288         this.sessionStats.updateSentMsg(msg);
 289         this.sessionState.messageSent(msg);
 290         return future;
 291     }
 292
 293     void flush() {
 294         this.channel.flush();
 295     }
 296
 297     synchronized void write(final Notification msg) {
 298         try {
 299             writeEpilogue(this.channel.write(msg), msg);
 300         } catch (final Exception e) {
 301             LOG.warn("Message {} was not sent.", msg, e);
 302         }
 303     }
 304
 305     synchronized ChannelFuture writeAndFlush(final Notification msg) {
 306         if (isWritable()) {
 307             return writeEpilogue(this.channel.writeAndFlush(msg), msg);
 308         }
 309         return this.channel.newFailedFuture(new NonWritableChannelException());
 310     }
 311
 312     private synchronized void closeWithoutMessage() {
 313         if (this.state == State.IDLE) {
 314             return;
 315         }
 316         LOG.info("Closing session: {}", this);
 317         this.channel.close().addListener((ChannelFutureListener) future -> Preconditions.checkArgument(future.isSuccess(), "Channel failed to close: %s", future.cause()));
 318         this.state = State.IDLE;
 319         removePeerSession();
 320         this.sessionState.setSessionState(this.state);
 321     }
 322
 323     /**
 324      * Closes BGP session from the parent with given reason. A message needs to be sent, but parent doesn't have to be
 325      * modified, because he initiated the closing. (To prevent concurrent modification exception).
 326      *
 327      * @param e BGPDocumentedException
 328      */
 329     private synchronized void terminate(final BGPDocumentedException e) {
 330         final BGPError error = e.getError();
 331         final byte[] data = e.getData();
 332         final NotifyBuilder builder = new NotifyBuilder().setErrorCode(error.getCode()).setErrorSubcode(error.getSubcode());
 333         if (data != null && data.length != 0) {
 334             builder.setData(data);
 335         }
 336         this.writeAndFlush(builder.build());
 337         notifyTerminationReasonAndCloseWithoutMessage(error.getCode(), error.getSubcode());
 338     }
 339
 340     private void removePeerSession() {
 341         if (this.peerRegistry != null) {
 342             this.peerRegistry.removePeerSession(StrictBGPPeerRegistry.getIpAddress(this.channel.remoteAddress()));
 343         }
 344     }
 345
 346     /**
 347      * If HoldTimer expires, the session ends. If a message (whichever) was received during this period, the HoldTimer
 348      * will be rescheduled by HOLD_TIMER_VALUE + the time that has passed from the start of the HoldTimer to the time at
 349      * which the message was received. If the session was closed by the time this method starts to execute (the session
 350      * state will become IDLE), then rescheduling won't occur.
 351      */
 352     private synchronized void handleHoldTimer() {
 353         if (this.state == State.IDLE) {
 354             return;
 355         }
 356
 357         final long ct = System.nanoTime();
 358         final long nextHold = this.lastMessageReceivedAt + TimeUnit.SECONDS.toNanos(this.holdTimerValue);
 359
 360         if (ct >= nextHold) {
 361             LOG.debug("HoldTimer expired. {}", new Date());
 362             this.terminate(new BGPDocumentedException(BGPError.HOLD_TIMER_EXPIRED));
 363         } else {
 364             this.channel.eventLoop().schedule(this::handleHoldTimer, nextHold - ct, TimeUnit.NANOSECONDS);
 365         }
 366     }
 367
 368     /**
 369      * If KeepAlive Timer expires, sends KeepAlive message. If a message (whichever) was send during this period, the
 370      * KeepAlive Timer will be rescheduled by KEEP_ALIVE_TIMER_VALUE + the time that has passed from the start of the
 371      * KeepAlive timer to the time at which the message was sent. If the session was closed by the time this method
 372      * starts to execute (the session state will become IDLE), that rescheduling won't occur.
 373      */
 374     private synchronized void handleKeepaliveTimer() {
 375         if (this.state == State.IDLE) {
 376             return;
 377         }
 378
 379         final long ct = System.nanoTime();
 380         long nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 381
 382         if (ct >= nextKeepalive) {
 383             this.writeAndFlush(KEEP_ALIVE);
 384             nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 385             this.sessionStats.updateSentMsgKA();
 386         }
 387         this.channel.eventLoop().schedule(this::handleKeepaliveTimer, nextKeepalive - ct, TimeUnit.NANOSECONDS);
 388     }
 389
 390     @Override
 391     public final String toString() {
 392         return addToStringAttributes(MoreObjects.toStringHelper(this)).toString();
 393     }
 394
 395     protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 396         toStringHelper.add("channel", this.channel);
 397         toStringHelper.add("state", this.getState());
 398         return toStringHelper;
 399     }
 400
 401     @Override
 402     public Set<BgpTableType> getAdvertisedTableTypes() {
 403         return this.tableTypes;
 404     }
 405
 406     @Override
 407     public List<AddressFamilies> getAdvertisedAddPathTableTypes() {
 408         return this.addPathTypes;
 409     }
 410
 411     @Override
 412     public List<BgpTableType> getAdvertisedGracefulRestartTableTypes() {
 413         return Collections.emptyList();
 414     }
 415
 416     protected synchronized void sessionUp() {
 417         this.sessionStats.startSessionStopwatch();
 418         this.state = State.UP;
 419         this.sessionState.setSessionState(this.state);
 420         this.listener.onSessionUp(this);
 421     }
 422
 423     public synchronized State getState() {
 424         return this.state;
 425     }
 426
 427     @Override
 428     public final Ipv4Address getBgpId() {
 429         return this.bgpId;
 430     }
 431
 432     @Override
 433     public final AsNumber getAsNumber() {
 434         return this.asNumber;
 435     }
 436
 437     synchronized boolean isWritable() {
 438         return this.channel != null && this.channel.isWritable();
 439     }
 440
 441     @Override
 442     public synchronized BgpSessionState getBgpSessionState() {
 443         return this.sessionStats.getBgpSessionState();
 444     }
 445
 446     @Override
 447     public synchronized void resetBgpSessionStats() {
 448         this.sessionStats.resetBgpSessionStats();
 449     }
 450
 451     public ChannelOutputLimiter getLimiter() {
 452         return this.limiter;
 453     }
 454
 455     @Override
 456     public final void channelInactive(final ChannelHandlerContext ctx) {
 457         LOG.debug("Channel {} inactive.", ctx.channel());
 458         this.endOfInput();
 459
 460         try {
 461             super.channelInactive(ctx);
 462         } catch (final Exception e) {
 463             throw new IllegalStateException("Failed to delegate channel inactive event on channel " + ctx.channel(), e);
 464         }
 465     }
 466
 467     @Override
 468     protected final void channelRead0(final ChannelHandlerContext ctx, final Notification msg) {
 469         LOG.debug("Message was received: {}", msg);
 470         this.handleMessage(msg);
 471     }
 472
 473     @Override
 474     public final void handlerAdded(final ChannelHandlerContext ctx) {
 475         this.sessionUp();
 476     }
 477
 478     @Override
 479     public synchronized void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
 480         LOG.warn("BGP session encountered error", cause);
 481         if (cause.getCause() instanceof BGPDocumentedException) {
 482             this.terminate((BGPDocumentedException) cause.getCause());
 483         } else {
 484             this.close();
 485         }
 486     }
 487
 488     @Override
 489     public BGPSessionState getBGPSessionState() {
 490         return this.sessionState;
 491     }
 492
 493     @Override
 494     public BGPTimersState getBGPTimersState() {
 495         return this.sessionState;
 496     }
 497
 498     @Override
 499     public BGPTransportState getBGPTransportState() {
 500         return this.sessionState;
 501     }
 502
 503     @Override
 504     public void registerMessagesCounter(final BGPMessagesListener bgpMessagesListener) {
 505         this.sessionState.registerMessagesCounter(bgpMessagesListener);
 506     }
 507 }