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 static java.util.Objects.requireNonNull;
  11
  12 import com.google.common.annotations.VisibleForTesting;
  13 import com.google.common.base.MoreObjects;
  14 import com.google.common.base.MoreObjects.ToStringHelper;
  15 import com.google.common.base.Optional;
  16 import com.google.common.base.Preconditions;
  17 import com.google.common.collect.Lists;
  18 import com.google.common.collect.Sets;
  19 import io.netty.buffer.ByteBufUtil;
  20 import io.netty.channel.Channel;
  21 import io.netty.channel.ChannelFuture;
  22 import io.netty.channel.ChannelFutureListener;
  23 import io.netty.channel.ChannelHandlerContext;
  24 import io.netty.channel.ChannelPipeline;
  25 import io.netty.channel.SimpleChannelInboundHandler;
  26 import java.io.IOException;
  27 import java.nio.channels.NonWritableChannelException;
  28 import java.util.Collections;
  29 import java.util.Date;
  30 import java.util.List;
  31 import java.util.Set;
  32 import java.util.concurrent.TimeUnit;
  33 import javax.annotation.concurrent.GuardedBy;
  34 import org.opendaylight.controller.config.yang.bgp.rib.impl.BgpSessionState;
  35 import org.opendaylight.protocol.bgp.parser.AsNumberUtil;
  36 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  37 import org.opendaylight.protocol.bgp.parser.BGPError;
  38 import org.opendaylight.protocol.bgp.parser.BgpExtendedMessageUtil;
  39 import org.opendaylight.protocol.bgp.parser.BgpTableTypeImpl;
  40 import org.opendaylight.protocol.bgp.parser.spi.MultiPathSupport;
  41 import org.opendaylight.protocol.bgp.parser.spi.pojo.MultiPathSupportImpl;
  42 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPMessagesListener;
  43 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPPeerRegistry;
  44 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionPreferences;
  45 import org.opendaylight.protocol.bgp.rib.impl.state.BGPSessionStateImpl;
  46 import org.opendaylight.protocol.bgp.rib.impl.state.BGPSessionStateProvider;
  47 import org.opendaylight.protocol.bgp.rib.impl.stats.peer.BGPSessionStats;
  48 import org.opendaylight.protocol.bgp.rib.impl.stats.peer.BGPSessionStatsImpl;
  49 import org.opendaylight.protocol.bgp.rib.spi.BGPSession;
  50 import org.opendaylight.protocol.bgp.rib.spi.BGPSessionListener;
  51 import org.opendaylight.protocol.bgp.rib.spi.BGPTerminationReason;
  52 import org.opendaylight.protocol.bgp.rib.spi.State;
  53 import org.opendaylight.protocol.bgp.rib.spi.state.BGPSessionState;
  54 import org.opendaylight.protocol.bgp.rib.spi.state.BGPTimersState;
  55 import org.opendaylight.protocol.bgp.rib.spi.state.BGPTransportState;
  56 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.AsNumber;
  57 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Address;
  58 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Keepalive;
  59 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.KeepaliveBuilder;
  60 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Notify;
  61 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.NotifyBuilder;
  62 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Open;
  63 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Update;
  64 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.BgpParameters;
  65 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.OptionalCapabilities;
  66 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.optional.capabilities.CParameters;
  67 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.BgpTableType;
  68 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.CParameters1;
  69 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.RouteRefresh;
  70 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.AddPathCapability;
  71 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.MultiprotocolCapability;
  72 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.add.path.capability.AddressFamilies;
  73 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev130925.rib.TablesKey;
  74 import org.opendaylight.yangtools.yang.binding.Notification;
  75 import org.slf4j.Logger;
  76 import org.slf4j.LoggerFactory;
  77
  78 @VisibleForTesting
  79 public class BGPSessionImpl extends SimpleChannelInboundHandler<Notification> implements BGPSession, BGPSessionStats,
  80     BGPSessionStateProvider, AutoCloseable {
  81
  82     private static final Logger LOG = LoggerFactory.getLogger(BGPSessionImpl.class);
  83
  84     private static final Notification KEEP_ALIVE = new KeepaliveBuilder().build();
  85
  86     private static final int KA_TO_DEADTIMER_RATIO = 3;
  87
  88     private static final String EXTENDED_MSG_DECODER = "EXTENDED_MSG_DECODER";
  89
  90     static final String END_OF_INPUT = "End of input detected. Close the session.";
  91
  92     /**
  93      * System.nanoTime value about when was sent the last message.
  94      */
  95     @VisibleForTesting
  96     private long lastMessageSentAt;
  97
  98     /**
  99      * System.nanoTime value about when was received the last message
 100      */
 101     private long lastMessageReceivedAt;
 102
 103     private final BGPSessionListener listener;
 104
 105     private final BGPSynchronization sync;
 106
 107     private int kaCounter = 0;
 108
 109     private final Channel channel;
 110
 111     @GuardedBy("this")
 112     private State state = State.OPEN_CONFIRM;
 113
 114     private final Set<BgpTableType> tableTypes;
 115     private final List<AddressFamilies> addPathTypes;
 116     private final int holdTimerValue;
 117     private final int keepAlive;
 118     private final AsNumber asNumber;
 119     private final Ipv4Address bgpId;
 120     private final BGPPeerRegistry peerRegistry;
 121     private final ChannelOutputLimiter limiter;
 122     private final BGPSessionStateImpl sessionState;
 123
 124     private BGPSessionStatsImpl sessionStats;
 125     private boolean terminationReasonNotified;
 126
 127     public BGPSessionImpl(final BGPSessionListener listener, final Channel channel, final Open remoteOpen,
 128         final BGPSessionPreferences localPreferences, final BGPPeerRegistry peerRegistry) {
 129         this(listener, channel, remoteOpen, localPreferences.getHoldTime(), peerRegistry);
 130         this.sessionStats = new BGPSessionStatsImpl(this, remoteOpen, this.holdTimerValue, this.keepAlive, channel,
 131             Optional.of(localPreferences), this.tableTypes, this.addPathTypes);
 132     }
 133
 134     public BGPSessionImpl(final BGPSessionListener listener, final Channel channel, final Open remoteOpen,
 135         final int localHoldTimer, final BGPPeerRegistry peerRegistry) {
 136         this.listener = requireNonNull(listener);
 137         this.channel = requireNonNull(channel);
 138         this.limiter = new ChannelOutputLimiter(this);
 139         this.channel.pipeline().addLast(this.limiter);
 140         this.holdTimerValue = (remoteOpen.getHoldTimer() < localHoldTimer) ? remoteOpen.getHoldTimer() : localHoldTimer;
 141         LOG.info("BGP HoldTimer new value: {}", this.holdTimerValue);
 142         this.keepAlive = this.holdTimerValue / KA_TO_DEADTIMER_RATIO;
 143         this.asNumber = AsNumberUtil.advertizedAsNumber(remoteOpen);
 144         this.peerRegistry = peerRegistry;
 145         this.sessionState = new BGPSessionStateImpl();
 146
 147         final Set<TablesKey> tts = Sets.newHashSet();
 148         final Set<BgpTableType> tats = Sets.newHashSet();
 149         final List<AddressFamilies> addPathCapabilitiesList = Lists.newArrayList();
 150         if (remoteOpen.getBgpParameters() != null) {
 151             for (final BgpParameters param : remoteOpen.getBgpParameters()) {
 152                 for (final OptionalCapabilities optCapa : param.getOptionalCapabilities()) {
 153                     final CParameters cParam = optCapa.getCParameters();
 154                     if ( cParam.getAugmentation(CParameters1.class) == null) {
 155                         continue;
 156                     }
 157                     if(cParam.getAugmentation(CParameters1.class).getMultiprotocolCapability() != null) {
 158                         final MultiprotocolCapability multi = cParam.getAugmentation(CParameters1.class).getMultiprotocolCapability();
 159                         final TablesKey tt = new TablesKey(multi.getAfi(), multi.getSafi());
 160                         LOG.trace("Added table type to sync {}", tt);
 161                         tts.add(tt);
 162                         tats.add(new BgpTableTypeImpl(tt.getAfi(), tt.getSafi()));
 163                     } else if (cParam.getAugmentation(CParameters1.class).getAddPathCapability() != null) {
 164                         final AddPathCapability addPathCap = cParam.getAugmentation(CParameters1.class).getAddPathCapability();
 165                         addPathCapabilitiesList.addAll(addPathCap.getAddressFamilies());
 166                     }
 167                 }
 168             }
 169         }
 170
 171         this.sync = new BGPSynchronization(this.listener, tts);
 172         this.tableTypes = tats;
 173         this.addPathTypes = addPathCapabilitiesList;
 174
 175         if (! this.addPathTypes.isEmpty()) {
 176             final ChannelPipeline pipeline = this.channel.pipeline();
 177             final BGPByteToMessageDecoder decoder = pipeline.get(BGPByteToMessageDecoder.class);
 178             decoder.addDecoderConstraint(MultiPathSupport.class,
 179                     MultiPathSupportImpl.createParserMultiPathSupport(this.addPathTypes));
 180         }
 181
 182         if (this.holdTimerValue != 0) {
 183             channel.eventLoop().schedule(this::handleHoldTimer, this.holdTimerValue, TimeUnit.SECONDS);
 184             channel.eventLoop().schedule(this::handleKeepaliveTimer, this.keepAlive, TimeUnit.SECONDS);
 185         }
 186         this.bgpId = remoteOpen.getBgpIdentifier();
 187         this.sessionStats = new BGPSessionStatsImpl(this, remoteOpen, this.holdTimerValue, this.keepAlive, channel, Optional.absent(),
 188                 this.tableTypes, this.addPathTypes);
 189
 190         this.sessionState.advertizeCapabilities(this.holdTimerValue, channel.remoteAddress(), channel.localAddress(),
 191             this.tableTypes, remoteOpen.getBgpParameters());
 192     }
 193
 194     /**
 195      * Set the extend message coder for current channel
 196      * The reason for separating this part from constructor is, in #channel.pipeline().replace(..), the
 197      * invokeChannelRead() will be invoked after the original message coder handler got removed. And there
 198      * is chance that before the session instance is fully initiated (constructor returns), a KeepAlive
 199      * message arrived already in the channel buffer. Thus #AbstractBGPSessionNegotiator.handleMessage(..)
 200      * gets invoked again and a deadlock is caused.  A BGP final state machine error will happen as BGP
 201      * negotiator is still in OPEN_SENT state as the session constructor hasn't returned yet.
 202      *
 203      * @param remoteOpen
 204      */
 205     public synchronized void setChannelExtMsgCoder(final Open remoteOpen) {
 206         final boolean enableExMess = BgpExtendedMessageUtil.advertizedBgpExtendedMessageCapability(remoteOpen);
 207         if (enableExMess) {
 208             this.channel.pipeline().replace(BGPMessageHeaderDecoder.class, EXTENDED_MSG_DECODER, BGPMessageHeaderDecoder.getExtendedBGPMessageHeaderDecoder());
 209         }
 210     }
 211
 212     @Override
 213     public synchronized void close() {
 214         if (this.state != State.IDLE && !this.terminationReasonNotified) {
 215             this.writeAndFlush(new NotifyBuilder().setErrorCode(BGPError.CEASE.getCode()).setErrorSubcode(BGPError.CEASE.getSubcode()).build());
 216             this.closeWithoutMessage();
 217         }
 218     }
 219
 220     /**
 221      * Handles incoming message based on their type.
 222      *
 223      * @param msg incoming message
 224      */
 225     synchronized void handleMessage(final Notification msg) {
 226         if (this.state == State.IDLE) {
 227             return;
 228         }
 229         try {
 230             // Update last reception time
 231             this.lastMessageReceivedAt = System.nanoTime();
 232
 233             if (msg instanceof Open) {
 234                 // Open messages should not be present here
 235                 this.terminate(new BGPDocumentedException(null, BGPError.FSM_ERROR));
 236             } else if (msg instanceof Notify) {
 237                 final Notify notify = (Notify) msg;
 238                 // Notifications are handled internally
 239                 LOG.info("Session closed because Notification message received: {} / {}, data={}", notify.getErrorCode(),
 240                     notify.getErrorSubcode(), notify.getData() != null ? ByteBufUtil.hexDump(notify.getData()) : null);
 241                 notifyTerminationReasonAndCloseWithoutMessage(notify.getErrorCode(), notify.getErrorSubcode());
 242             } else if (msg instanceof Keepalive) {
 243                 // Keepalives are handled internally
 244                 LOG.trace("Received KeepAlive message.");
 245                 this.kaCounter++;
 246                 if (this.kaCounter >= 2) {
 247                     this.sync.kaReceived();
 248                 }
 249             } else if (msg instanceof RouteRefresh) {
 250                 this.listener.onMessage(this, msg);
 251             } else if (msg instanceof Update) {
 252                 this.listener.onMessage(this, msg);
 253                 this.sync.updReceived((Update) msg);
 254             } else {
 255                 LOG.warn("Ignoring unhandled message: {}.", msg.getClass());
 256             }
 257
 258             this.sessionStats.updateReceivedMsg(msg);
 259             this.sessionState.messageReceived(msg);
 260         } catch (final BGPDocumentedException e) {
 261             this.terminate(e);
 262         }
 263     }
 264
 265     private synchronized void notifyTerminationReasonAndCloseWithoutMessage(final Short errorCode, final Short errorSubcode) {
 266         this.terminationReasonNotified = true;
 267         this.listener.onSessionTerminated(this, new BGPTerminationReason(
 268             BGPError.forValue(errorCode, errorSubcode)));
 269         this.closeWithoutMessage();
 270     }
 271
 272     synchronized void endOfInput() {
 273         if (this.state == State.UP) {
 274             LOG.info(END_OF_INPUT);
 275             this.listener.onSessionDown(this, new IOException(END_OF_INPUT));
 276         }
 277     }
 278
 279     @GuardedBy("this")
 280     private ChannelFuture writeEpilogue(final ChannelFuture future, final Notification msg) {
 281         future.addListener(
 282             (ChannelFutureListener) f -> {
 283                 if (!f.isSuccess()) {
 284                     LOG.warn("Failed to send message {} to socket {}", msg, BGPSessionImpl.this.channel, f.cause());
 285                 } else {
 286                     LOG.trace("Message {} sent to socket {}", msg, BGPSessionImpl.this.channel);
 287                 }
 288             });
 289         this.lastMessageSentAt = System.nanoTime();
 290         this.sessionStats.updateSentMsg(msg);
 291         this.sessionState.messageSent(msg);
 292         return future;
 293     }
 294
 295     void flush() {
 296         this.channel.flush();
 297     }
 298
 299     synchronized void write(final Notification msg) {
 300         try {
 301             writeEpilogue(this.channel.write(msg), msg);
 302         } catch (final Exception e) {
 303             LOG.warn("Message {} was not sent.", msg, e);
 304         }
 305     }
 306
 307     synchronized ChannelFuture writeAndFlush(final Notification msg) {
 308         if (isWritable()) {
 309             return writeEpilogue(this.channel.writeAndFlush(msg), msg);
 310         }
 311         return this.channel.newFailedFuture(new NonWritableChannelException());
 312     }
 313
 314     private synchronized void closeWithoutMessage() {
 315         if (this.state == State.IDLE) {
 316             return;
 317         }
 318         LOG.info("Closing session: {}", this);
 319         this.channel.close().addListener((ChannelFutureListener) future -> Preconditions.checkArgument(future.isSuccess(), "Channel failed to close: %s", future.cause()));
 320         this.state = State.IDLE;
 321         removePeerSession();
 322         this.sessionState.setSessionState(this.state);
 323     }
 324
 325     /**
 326      * Closes BGP session from the parent with given reason. A message needs to be sent, but parent doesn't have to be
 327      * modified, because he initiated the closing. (To prevent concurrent modification exception).
 328      *
 329      * @param e BGPDocumentedException
 330      */
 331     private synchronized void terminate(final BGPDocumentedException e) {
 332         final BGPError error = e.getError();
 333         final byte[] data = e.getData();
 334         final NotifyBuilder builder = new NotifyBuilder().setErrorCode(error.getCode()).setErrorSubcode(error.getSubcode());
 335         if (data != null && data.length != 0) {
 336             builder.setData(data);
 337         }
 338         this.writeAndFlush(builder.build());
 339         notifyTerminationReasonAndCloseWithoutMessage(error.getCode(), error.getSubcode());
 340     }
 341
 342     private void removePeerSession() {
 343         if (this.peerRegistry != null) {
 344             this.peerRegistry.removePeerSession(StrictBGPPeerRegistry.getIpAddress(this.channel.remoteAddress()));
 345         }
 346     }
 347
 348     /**
 349      * If HoldTimer expires, the session ends. If a message (whichever) was received during this period, the HoldTimer
 350      * will be rescheduled by HOLD_TIMER_VALUE + the time that has passed from the start of the HoldTimer to the time at
 351      * which the message was received. If the session was closed by the time this method starts to execute (the session
 352      * state will become IDLE), then rescheduling won't occur.
 353      */
 354     private synchronized void handleHoldTimer() {
 355         if (this.state == State.IDLE) {
 356             return;
 357         }
 358
 359         final long ct = System.nanoTime();
 360         final long nextHold = this.lastMessageReceivedAt + TimeUnit.SECONDS.toNanos(this.holdTimerValue);
 361
 362         if (ct >= nextHold) {
 363             LOG.debug("HoldTimer expired. {}", new Date());
 364             this.terminate(new BGPDocumentedException(BGPError.HOLD_TIMER_EXPIRED));
 365         } else {
 366             this.channel.eventLoop().schedule(this::handleHoldTimer, nextHold - ct, TimeUnit.NANOSECONDS);
 367         }
 368     }
 369
 370     /**
 371      * If KeepAlive Timer expires, sends KeepAlive message. If a message (whichever) was send during this period, the
 372      * KeepAlive Timer will be rescheduled by KEEP_ALIVE_TIMER_VALUE + the time that has passed from the start of the
 373      * KeepAlive timer to the time at which the message was sent. If the session was closed by the time this method
 374      * starts to execute (the session state will become IDLE), that rescheduling won't occur.
 375      */
 376     private synchronized void handleKeepaliveTimer() {
 377         if (this.state == State.IDLE) {
 378             return;
 379         }
 380
 381         final long ct = System.nanoTime();
 382         long nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 383
 384         if (ct >= nextKeepalive) {
 385             this.writeAndFlush(KEEP_ALIVE);
 386             nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 387             this.sessionStats.updateSentMsgKA();
 388         }
 389         this.channel.eventLoop().schedule(this::handleKeepaliveTimer, nextKeepalive - ct, TimeUnit.NANOSECONDS);
 390     }
 391
 392     @Override
 393     public final String toString() {
 394         return addToStringAttributes(MoreObjects.toStringHelper(this)).toString();
 395     }
 396
 397     protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 398         toStringHelper.add("channel", this.channel);
 399         toStringHelper.add("state", this.getState());
 400         return toStringHelper;
 401     }
 402
 403     @Override
 404     public Set<BgpTableType> getAdvertisedTableTypes() {
 405         return this.tableTypes;
 406     }
 407
 408     @Override
 409     public List<AddressFamilies> getAdvertisedAddPathTableTypes() {
 410         return this.addPathTypes;
 411     }
 412
 413     @Override
 414     public List<BgpTableType> getAdvertisedGracefulRestartTableTypes() {
 415         return Collections.emptyList();
 416     }
 417
 418     protected synchronized void sessionUp() {
 419         this.sessionStats.startSessionStopwatch();
 420         this.state = State.UP;
 421         this.sessionState.setSessionState(this.state);
 422         this.listener.onSessionUp(this);
 423     }
 424
 425     public synchronized State getState() {
 426         return this.state;
 427     }
 428
 429     @Override
 430     public final Ipv4Address getBgpId() {
 431         return this.bgpId;
 432     }
 433
 434     @Override
 435     public final AsNumber getAsNumber() {
 436         return this.asNumber;
 437     }
 438
 439     synchronized boolean isWritable() {
 440         return this.channel != null && this.channel.isWritable();
 441     }
 442
 443     @Override
 444     public synchronized BgpSessionState getBgpSessionState() {
 445         return this.sessionStats.getBgpSessionState();
 446     }
 447
 448     @Override
 449     public synchronized void resetBgpSessionStats() {
 450         this.sessionStats.resetBgpSessionStats();
 451     }
 452
 453     public ChannelOutputLimiter getLimiter() {
 454         return this.limiter;
 455     }
 456
 457     @Override
 458     public final void channelInactive(final ChannelHandlerContext ctx) {
 459         LOG.debug("Channel {} inactive.", ctx.channel());
 460         this.endOfInput();
 461
 462         try {
 463             super.channelInactive(ctx);
 464         } catch (final Exception e) {
 465             throw new IllegalStateException("Failed to delegate channel inactive event on channel " + ctx.channel(), e);
 466         }
 467     }
 468
 469     @Override
 470     protected final void channelRead0(final ChannelHandlerContext ctx, final Notification msg) {
 471         LOG.debug("Message was received: {}", msg);
 472         this.handleMessage(msg);
 473     }
 474
 475     @Override
 476     public final void handlerAdded(final ChannelHandlerContext ctx) {
 477         this.sessionUp();
 478     }
 479
 480     @Override
 481     public synchronized void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
 482         LOG.warn("BGP session encountered error", cause);
 483         if (cause.getCause() instanceof BGPDocumentedException) {
 484             this.terminate((BGPDocumentedException) cause.getCause());
 485         } else {
 486             this.close();
 487         }
 488     }
 489
 490     @Override
 491     public BGPSessionState getBGPSessionState() {
 492         return this.sessionState;
 493     }
 494
 495     @Override
 496     public BGPTimersState getBGPTimersState() {
 497         return this.sessionState;
 498     }
 499
 500     @Override
 501     public BGPTransportState getBGPTransportState() {
 502         return this.sessionState;
 503     }
 504
 505     @Override
 506     public void registerMessagesCounter(final BGPMessagesListener bgpMessagesListener) {
 507         this.sessionState.registerMessagesCounter(bgpMessagesListener);
 508     }
 509 }