bgp/rib-impl/src/main/java/org/opendaylight/protocol/bgp/rib/impl/BGPPeer.java

   1 /*
   2  * Copyright (c) 2014 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.base.MoreObjects;
  13 import com.google.common.base.MoreObjects.ToStringHelper;
  14 import com.google.common.base.Objects;
  15 import com.google.common.cache.CacheBuilder;
  16 import com.google.common.cache.CacheLoader;
  17 import com.google.common.cache.LoadingCache;
  18 import com.google.common.collect.ImmutableMap;
  19 import com.google.common.collect.ImmutableSet;
  20 import com.google.common.collect.Sets;
  21 import com.google.common.net.InetAddresses;
  22 import com.google.common.util.concurrent.Futures;
  23 import com.google.common.util.concurrent.ListenableFuture;
  24 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  25 import java.util.ArrayList;
  26 import java.util.Arrays;
  27 import java.util.Collections;
  28 import java.util.HashMap;
  29 import java.util.HashSet;
  30 import java.util.List;
  31 import java.util.Map;
  32 import java.util.Optional;
  33 import java.util.Set;
  34 import java.util.stream.Collectors;
  35 import javax.annotation.concurrent.GuardedBy;
  36 import org.opendaylight.controller.md.sal.common.api.data.AsyncTransaction;
  37 import org.opendaylight.controller.md.sal.common.api.data.TransactionChain;
  38 import org.opendaylight.controller.md.sal.common.api.data.TransactionChainListener;
  39 import org.opendaylight.controller.md.sal.dom.api.DOMTransactionChain;
  40 import org.opendaylight.controller.sal.binding.api.BindingAwareBroker.RoutedRpcRegistration;
  41 import org.opendaylight.controller.sal.binding.api.RpcProviderRegistry;
  42 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  43 import org.opendaylight.protocol.bgp.parser.BGPError;
  44 import org.opendaylight.protocol.bgp.parser.impl.message.update.LocalPreferenceAttributeParser;
  45 import org.opendaylight.protocol.bgp.parser.spi.MessageUtil;
  46 import org.opendaylight.protocol.bgp.rib.impl.spi.RIB;
  47 import org.opendaylight.protocol.bgp.rib.impl.state.BGPPeerStateImpl;
  48 import org.opendaylight.protocol.bgp.rib.impl.state.BGPSessionStateProvider;
  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.Peer;
  53 import org.opendaylight.protocol.bgp.rib.spi.RIBSupport;
  54 import org.opendaylight.protocol.bgp.rib.spi.RouterIds;
  55 import org.opendaylight.protocol.bgp.rib.spi.policy.BGPRouteEntryImportParameters;
  56 import org.opendaylight.protocol.bgp.rib.spi.state.BGPAfiSafiState;
  57 import org.opendaylight.protocol.bgp.rib.spi.state.BGPErrorHandlingState;
  58 import org.opendaylight.protocol.bgp.rib.spi.state.BGPSessionState;
  59 import org.opendaylight.protocol.bgp.rib.spi.state.BGPTimersState;
  60 import org.opendaylight.protocol.bgp.rib.spi.state.BGPTransportState;
  61 import org.opendaylight.protocol.concepts.AbstractRegistration;
  62 import org.opendaylight.protocol.util.Ipv4Util;
  63 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
  64 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.inet.rev171207.ipv4.prefixes.DestinationIpv4Builder;
  65 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.inet.rev171207.ipv4.prefixes.destination.ipv4.Ipv4Prefixes;
  66 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.inet.rev171207.ipv4.prefixes.destination.ipv4.Ipv4PrefixesBuilder;
  67 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.inet.rev171207.update.attributes.mp.reach.nlri.advertized.routes.destination.type.DestinationIpv4CaseBuilder;
  68 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.Update;
  69 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.path.attributes.Attributes;
  70 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.path.attributes.AttributesBuilder;
  71 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.update.message.Nlri;
  72 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.BgpAddPathTableType;
  73 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.BgpTableType;
  74 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.RouteRefresh;
  75 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.SendReceive;
  76 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.mp.capabilities.add.path.capability.AddressFamilies;
  77 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.update.attributes.MpReachNlri;
  78 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.update.attributes.MpReachNlriBuilder;
  79 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.update.attributes.MpUnreachNlri;
  80 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.update.attributes.MpUnreachNlriBuilder;
  81 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.update.attributes.mp.reach.nlri.AdvertizedRoutesBuilder;
  82 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.update.attributes.mp.unreach.nlri.WithdrawnRoutesBuilder;
  83 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.peer.rpc.rev171207.BgpPeerRpcService;
  84 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.peer.rpc.rev171207.PeerContext;
  85 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.PeerId;
  86 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.PeerRole;
  87 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.bgp.rib.rib.PeerKey;
  88 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.bgp.rib.rib.peer.AdjRibOut;
  89 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.rib.Tables;
  90 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.rib.TablesKey;
  91 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.AddressFamily;
  92 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.Ipv4AddressFamily;
  93 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.SubsequentAddressFamily;
  94 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.UnicastSubsequentAddressFamily;
  95 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  96 import org.opendaylight.yangtools.yang.binding.KeyedInstanceIdentifier;
  97 import org.opendaylight.yangtools.yang.binding.Notification;
  98 import org.slf4j.Logger;
  99 import org.slf4j.LoggerFactory;
 100
 101 /**
 102  * Class representing a peer. We have a single instance for each peer, which provides translation from BGP events into
 103  * RIB actions.
 104  */
 105 public class BGPPeer extends BGPPeerStateImpl implements BGPRouteEntryImportParameters,
 106         BGPSessionListener, Peer, TransactionChainListener {
 107     private static final Logger LOG = LoggerFactory.getLogger(BGPPeer.class);
 108
 109     private Set<TablesKey> tables = Collections.emptySet();
 110     private final RIB rib;
 111     private final String name;
 112     private final Map<TablesKey, AdjRibOutListener> adjRibOutListenerSet = new HashMap<>();
 113     private final RpcProviderRegistry rpcRegistry;
 114     private final PeerRole peerRole;
 115     private final InstanceIdentifier<AdjRibOut> peerRibOutIId;
 116     private final KeyedInstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib
 117             .rev171207.bgp.rib.rib.Peer, PeerKey> peerIId;
 118     @GuardedBy("this")
 119     private AbstractRegistration trackerRegistration;
 120     private final PeerId peerId;
 121     private final LoadingCache<TablesKey, KeyedInstanceIdentifier<Tables, TablesKey>> tablesIId
 122             = CacheBuilder.newBuilder()
 123             .build(new CacheLoader<TablesKey, KeyedInstanceIdentifier<Tables, TablesKey>>() {
 124                 @Override
 125                 public KeyedInstanceIdentifier<Tables, TablesKey> load(final TablesKey tablesKey) {
 126                     return BGPPeer.this.peerRibOutIId.child(Tables.class, tablesKey);
 127                 }
 128             });
 129
 130     @GuardedBy("this")
 131     private BGPSession session;
 132     @GuardedBy("this")
 133     private byte[] rawIdentifier;
 134     @GuardedBy("this")
 135     private DOMTransactionChain chain;
 136     @GuardedBy("this")
 137     private AdjRibInWriter ribWriter;
 138     @GuardedBy("this")
 139     private EffectiveRibInWriter effRibInWriter;
 140     private RoutedRpcRegistration<BgpPeerRpcService> rpcRegistration;
 141     private Map<TablesKey, SendReceive> addPathTableMaps = Collections.emptyMap();
 142
 143     public BGPPeer(final IpAddress neighborAddress, final RIB rib, final PeerRole role,
 144             final RpcProviderRegistry rpcRegistry,
 145             final Set<TablesKey> afiSafisAdvertized,
 146             final Set<TablesKey> afiSafisGracefulAdvertized) {
 147         //FIXME BUG-6971 Once Peer Group is implemented, pass it
 148         super(rib.getInstanceIdentifier(), null, neighborAddress, afiSafisAdvertized,
 149                 afiSafisGracefulAdvertized);
 150         this.peerRole = role;
 151         this.rib = requireNonNull(rib);
 152         this.name = Ipv4Util.toStringIP(neighborAddress);
 153         this.rpcRegistry = rpcRegistry;
 154         this.peerId = RouterIds.createPeerId(neighborAddress);
 155         this.peerIId = getInstanceIdentifier().child(org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns
 156                 .yang.bgp.rib.rev171207.bgp.rib.rib.Peer.class, new PeerKey(this.peerId));
 157         this.peerRibOutIId = this.peerIId.child(AdjRibOut.class);
 158         this.chain = rib.createPeerDOMChain(this);
 159     }
 160
 161     private static Attributes nextHopToAttribute(final Attributes attrs, final MpReachNlri mpReach) {
 162         if (attrs.getCNextHop() == null && mpReach.getCNextHop() != null) {
 163             final AttributesBuilder attributesBuilder = new AttributesBuilder(attrs);
 164             attributesBuilder.setCNextHop(mpReach.getCNextHop());
 165             return attributesBuilder.build();
 166         }
 167         return attrs;
 168     }
 169
 170     /**
 171      * Creates MPReach for the prefixes to be handled in the same way as linkstate routes.
 172      *
 173      * @param message Update message containing prefixes in NLRI
 174      * @return MpReachNlri with prefixes from the nlri field
 175      */
 176     private static MpReachNlri prefixesToMpReach(final Update message) {
 177         final List<Ipv4Prefixes> prefixes = message.getNlri().stream()
 178                 .map(n -> new Ipv4PrefixesBuilder().setPrefix(n.getPrefix()).setPathId(n.getPathId()).build())
 179                 .collect(Collectors.toList());
 180         final MpReachNlriBuilder b = new MpReachNlriBuilder().setAfi(Ipv4AddressFamily.class).setSafi(
 181                 UnicastSubsequentAddressFamily.class).setAdvertizedRoutes(
 182                 new AdvertizedRoutesBuilder().setDestinationType(
 183                         new DestinationIpv4CaseBuilder().setDestinationIpv4(
 184                                 new DestinationIpv4Builder().setIpv4Prefixes(prefixes).build()).build()).build());
 185         if (message.getAttributes() != null) {
 186             b.setCNextHop(message.getAttributes().getCNextHop());
 187         }
 188         return b.build();
 189     }
 190
 191     /**
 192      * Create MPUnreach for the prefixes to be handled in the same way as linkstate routes.
 193      *
 194      * @param message            Update message containing withdrawn routes
 195      * @param isAnyNlriAnnounced isAnyNlriAnnounced
 196      * @return MpUnreachNlri with prefixes from the withdrawn routes field
 197      */
 198     private static MpUnreachNlri prefixesToMpUnreach(final Update message, final boolean isAnyNlriAnnounced) {
 199         final List<Ipv4Prefixes> prefixes = new ArrayList<>();
 200         message.getWithdrawnRoutes().forEach(w -> {
 201
 202             Optional<Nlri> nlriAnounced = Optional.empty();
 203             if (isAnyNlriAnnounced) {
 204                 nlriAnounced = message.getNlri().stream().filter(n -> Objects.equal(n.getPrefix(), w.getPrefix())
 205                         && Objects.equal(n.getPathId(), w.getPathId()))
 206                         .findAny();
 207             }
 208             if (!nlriAnounced.isPresent()) {
 209                 prefixes.add(new Ipv4PrefixesBuilder().setPrefix(w.getPrefix()).setPathId(w.getPathId()).build());
 210             }
 211         });
 212         return new MpUnreachNlriBuilder().setAfi(Ipv4AddressFamily.class).setSafi(UnicastSubsequentAddressFamily.class)
 213                 .setWithdrawnRoutes(new WithdrawnRoutesBuilder().setDestinationType(new org.opendaylight.yang.gen.v1
 214                         .urn.opendaylight.params.xml.ns.yang.bgp.inet.rev171207.update.attributes.mp.unreach.nlri
 215                         .withdrawn.routes.destination.type.DestinationIpv4CaseBuilder().setDestinationIpv4(
 216                         new DestinationIpv4Builder().setIpv4Prefixes(prefixes).build()).build()).build()).build();
 217     }
 218
 219     private static Map<TablesKey, SendReceive> mapTableTypesFamilies(final List<AddressFamilies> addPathTablesType) {
 220         return ImmutableMap.copyOf(addPathTablesType.stream().collect(Collectors.toMap(af -> new TablesKey(af.getAfi(),
 221                         af.getSafi()), BgpAddPathTableType::getSendReceive)));
 222     }
 223
 224     public synchronized void instantiateServiceInstance() {
 225         this.ribWriter = AdjRibInWriter.create(this.rib.getYangRibId(), this.peerRole, this.chain);
 226         setActive(true);
 227     }
 228
 229     // FIXME ListenableFuture<?> should be used once closeServiceInstance uses wildcard too
 230     @Override
 231     public synchronized ListenableFuture<Void> close() {
 232         final ListenableFuture<Void> future = releaseConnection();
 233         this.chain.close();
 234         setActive(false);
 235         return future;
 236     }
 237
 238     @Override
 239     public void onMessage(final BGPSession session, final Notification msg) throws BGPDocumentedException {
 240         if (!(msg instanceof Update) && !(msg instanceof RouteRefresh)) {
 241             LOG.info("Ignoring unhandled message class {}", msg.getClass());
 242             return;
 243         }
 244         if (msg instanceof Update) {
 245             onUpdateMessage((Update) msg);
 246         } else {
 247             onRouteRefreshMessage((RouteRefresh) msg);
 248         }
 249     }
 250
 251     private void onRouteRefreshMessage(final RouteRefresh message) {
 252         final Class<? extends AddressFamily> rrAfi = message.getAfi();
 253         final Class<? extends SubsequentAddressFamily> rrSafi = message.getSafi();
 254
 255         final TablesKey key = new TablesKey(rrAfi, rrSafi);
 256         final AdjRibOutListener listener = this.adjRibOutListenerSet.get(key);
 257         if (listener != null) {
 258             listener.close();
 259             this.adjRibOutListenerSet.remove(key);
 260             createAdjRibOutListener(key, listener.isMpSupported());
 261         } else {
 262             LOG.info("Ignoring RouteRefresh message. Afi/Safi is not supported: {}, {}.", rrAfi, rrSafi);
 263         }
 264     }
 265
 266     /**
 267      * Check for presence of well known mandatory attribute LOCAL_PREF in Update message.
 268      *
 269      * @param message Update message
 270      */
 271     private void checkMandatoryAttributesPresence(final Update message) throws BGPDocumentedException {
 272         if (MessageUtil.isAnyNlriPresent(message)) {
 273             final Attributes attrs = message.getAttributes();
 274             if (this.peerRole == PeerRole.Ibgp && (attrs == null || attrs.getLocalPref() == null)) {
 275                 throw new BGPDocumentedException(BGPError.MANDATORY_ATTR_MISSING_MSG + "LOCAL_PREF",
 276                         BGPError.WELL_KNOWN_ATTR_MISSING,
 277                         new byte[]{LocalPreferenceAttributeParser.TYPE});
 278             }
 279         }
 280     }
 281
 282     /**
 283      * Process Update message received.
 284      * Calls {@link #checkMandatoryAttributesPresence(Update)} to check for presence of mandatory attributes.
 285      *
 286      * @param message Update message
 287      */
 288     private synchronized void onUpdateMessage(final Update message) throws BGPDocumentedException {
 289         checkMandatoryAttributesPresence(message);
 290
 291         // update AdjRibs
 292         final Attributes attrs = message.getAttributes();
 293         MpReachNlri mpReach;
 294         final boolean isAnyNlriAnnounced = message.getNlri() != null;
 295         if (isAnyNlriAnnounced) {
 296             mpReach = prefixesToMpReach(message);
 297         } else {
 298             mpReach = MessageUtil.getMpReachNlri(attrs);
 299         }
 300         if (mpReach != null) {
 301             this.ribWriter.updateRoutes(mpReach, nextHopToAttribute(attrs, mpReach));
 302         }
 303         MpUnreachNlri mpUnreach;
 304         if (message.getWithdrawnRoutes() != null) {
 305             mpUnreach = prefixesToMpUnreach(message, isAnyNlriAnnounced);
 306         } else {
 307             mpUnreach = MessageUtil.getMpUnreachNlri(attrs);
 308         }
 309         if (mpUnreach != null) {
 310             this.ribWriter.removeRoutes(mpUnreach);
 311         }
 312     }
 313
 314     @Override
 315     public synchronized void onSessionUp(final BGPSession session) {
 316         this.session = session;
 317         if (this.session instanceof BGPSessionStateProvider) {
 318             ((BGPSessionStateProvider) this.session).registerMessagesCounter(this);
 319         }
 320         final List<AddressFamilies> addPathTablesType = session.getAdvertisedAddPathTableTypes();
 321         final Set<BgpTableType> advertizedTableTypes = session.getAdvertisedTableTypes();
 322         final List<BgpTableType> advertizedGracefulRestartTableTypes = session.getAdvertisedGracefulRestartTableTypes();
 323         LOG.info("Session with peer {} went up with tables {} and Add Path tables {}", this.name,
 324                 advertizedTableTypes, addPathTablesType);
 325         this.rawIdentifier = InetAddresses.forString(session.getBgpId().getValue()).getAddress();
 326         final Set<TablesKey> setTables = advertizedTableTypes.stream().map(t -> new TablesKey(t.getAfi(), t.getSafi()))
 327                 .collect(Collectors.toSet());
 328         this.tables = ImmutableSet.copyOf(setTables);
 329
 330         setAdvertizedGracefulRestartTableTypes(advertizedGracefulRestartTableTypes.stream()
 331                 .map(t -> new TablesKey(t.getAfi(), t.getSafi())).collect(Collectors.toList()));
 332         this.addPathTableMaps = ImmutableMap.copyOf(mapTableTypesFamilies(addPathTablesType));
 333         this.trackerRegistration = this.rib.getPeerTracker().registerPeer(this);
 334
 335         for (final TablesKey key : this.tables) {
 336             createAdjRibOutListener(key, true);
 337         }
 338
 339         addBgp4Support();
 340
 341         this.effRibInWriter = EffectiveRibInWriter.create(this, this.rib, this.rib.createPeerChain(this),
 342                 this.peerIId, this.tables);
 343
 344
 345         registerPrefixesCounters(this.effRibInWriter, this.effRibInWriter);
 346         this.ribWriter = this.ribWriter.transform(this.peerId, this.rib.getRibSupportContext(), this.tables,
 347                 this.addPathTableMaps);
 348
 349         if (this.rpcRegistry != null) {
 350             this.rpcRegistration = this.rpcRegistry.addRoutedRpcImplementation(BgpPeerRpcService.class,
 351                     new BgpPeerRpc(this, session, this.tables));
 352             final KeyedInstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib
 353                     .rev171207.bgp.rib.rib.Peer, PeerKey> path = this.rib.getInstanceIdentifier()
 354                     .child(org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.bgp.rib
 355                              .rib.Peer.class, new PeerKey(this.peerId));
 356             this.rpcRegistration.registerPath(PeerContext.class, path);
 357         }
 358     }
 359
 360     //try to add a support for old-school BGP-4, if peer did not advertise IPv4-Unicast MP capability
 361     private synchronized void addBgp4Support() {
 362         final TablesKey key = new TablesKey(Ipv4AddressFamily.class, UnicastSubsequentAddressFamily.class);
 363         if (!this.tables.contains(key)) {
 364             final HashSet<TablesKey> newSet = new HashSet<>(this.tables);
 365             newSet.add(key);
 366             this.tables = ImmutableSet.copyOf(newSet);
 367             createAdjRibOutListener(key, false);
 368         }
 369     }
 370
 371     private synchronized void createAdjRibOutListener(final TablesKey key,
 372             final boolean mpSupport) {
 373         final RIBSupport ribSupport = this.rib.getRibSupportContext().getRIBSupport(key);
 374
 375         // not particularly nice
 376         if (ribSupport != null && this.session instanceof BGPSessionImpl) {
 377             final ChannelOutputLimiter limiter = ((BGPSessionImpl) this.session).getLimiter();
 378             final AdjRibOutListener adjRibOut = AdjRibOutListener.create(this.peerId, key,
 379                     this.rib.getYangRibId(), this.rib.getCodecsRegistry(), ribSupport,
 380                     this.rib.getService(), limiter, mpSupport);
 381             this.adjRibOutListenerSet.put(key, adjRibOut);
 382             registerPrefixesSentCounter(key, adjRibOut);
 383         }
 384     }
 385
 386     private synchronized ListenableFuture<Void> cleanup() {
 387         // FIXME: BUG-196: support graceful
 388         this.adjRibOutListenerSet.values().forEach(AdjRibOutListener::close);
 389         this.adjRibOutListenerSet.clear();
 390         if (this.effRibInWriter != null) {
 391             this.effRibInWriter.close();
 392         }
 393         this.tables = Collections.emptySet();
 394         this.addPathTableMaps = Collections.emptyMap();
 395         if (this.ribWriter != null) {
 396             return this.ribWriter.removePeer();
 397         }
 398         return Futures.immediateFuture(null);
 399     }
 400
 401     @Override
 402     public synchronized void onSessionDown(final BGPSession session, final Exception e) {
 403         if (e.getMessage().equals(BGPSessionImpl.END_OF_INPUT)) {
 404             LOG.info("Session with peer {} went down", this.name);
 405         } else {
 406             LOG.info("Session with peer {} went down", this.name, e);
 407         }
 408         releaseConnection();
 409     }
 410
 411     @Override
 412     public synchronized void onSessionTerminated(final BGPSession session, final BGPTerminationReason cause) {
 413         LOG.info("Session with peer {} terminated: {}", this.name, cause);
 414         releaseConnection();
 415     }
 416
 417     @Override
 418     public String toString() {
 419         return addToStringAttributes(MoreObjects.toStringHelper(this)).toString();
 420     }
 421
 422     protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 423         toStringHelper.add("name", this.name);
 424         toStringHelper.add("tables", this.tables);
 425         return toStringHelper;
 426     }
 427
 428     @Override
 429     public String getName() {
 430         return this.name;
 431     }
 432
 433     @Override
 434     public synchronized ListenableFuture<Void> releaseConnection() {
 435         if (this.rpcRegistration != null) {
 436             this.rpcRegistration.close();
 437         }
 438         closeRegistration();
 439         final ListenableFuture<Void> future = cleanup();
 440
 441         if (this.session != null) {
 442             try {
 443                 this.session.close();
 444             } catch (final Exception e) {
 445                 LOG.warn("Error closing session with peer", e);
 446             }
 447             this.session = null;
 448         }
 449         resetState();
 450         return future;
 451     }
 452
 453     private synchronized void closeRegistration() {
 454         if (this.trackerRegistration != null) {
 455             this.trackerRegistration.close();
 456             this.trackerRegistration = null;
 457         }
 458     }
 459
 460     @Override
 461     public synchronized byte[] getRawIdentifier() {
 462         return Arrays.copyOf(this.rawIdentifier, this.rawIdentifier.length);
 463     }
 464
 465     @Override
 466     public PeerId getPeerId() {
 467         return this.peerId;
 468     }
 469
 470     @SuppressFBWarnings("IS2_INCONSISTENT_SYNC")
 471     @Override
 472     public SendReceive getSupportedAddPathTables(final TablesKey tableKey) {
 473         return this.addPathTableMaps.get(tableKey);
 474     }
 475
 476     @Override
 477     public boolean supportsTable(final TablesKey tableKey) {
 478         return this.tables.contains(tableKey);
 479     }
 480
 481     @Override
 482     public PeerRole getRole() {
 483         return this.peerRole;
 484     }
 485
 486     @Override
 487     public KeyedInstanceIdentifier<Tables, TablesKey> getRibOutIId(final TablesKey tablesKey) {
 488         return this.tablesIId.getUnchecked(tablesKey);
 489     }
 490
 491     @Override
 492     public synchronized void onTransactionChainFailed(final TransactionChain<?, ?> chain,
 493             final AsyncTransaction<?, ?> transaction, final Throwable cause) {
 494         LOG.error("Transaction chain failed.", cause);
 495         this.chain.close();
 496         this.chain = this.rib.createPeerDOMChain(this);
 497         this.ribWriter = AdjRibInWriter.create(this.rib.getYangRibId(), this.peerRole, this.chain);
 498         releaseConnection();
 499     }
 500
 501     @Override
 502     public void onTransactionChainSuccessful(final TransactionChain<?, ?> chain) {
 503         LOG.debug("Transaction chain {} successful.", chain);
 504     }
 505
 506     @Override
 507     public synchronized void markUptodate(final TablesKey tablesKey) {
 508         this.ribWriter.markTableUptodate(tablesKey);
 509     }
 510
 511     @Override
 512     public BGPErrorHandlingState getBGPErrorHandlingState() {
 513         return this;
 514     }
 515
 516     @Override
 517     public BGPAfiSafiState getBGPAfiSafiState() {
 518         return this;
 519     }
 520
 521     @Override
 522     public synchronized BGPSessionState getBGPSessionState() {
 523         if (this.session instanceof BGPSessionStateProvider) {
 524             return ((BGPSessionStateProvider) this.session).getBGPSessionState();
 525         }
 526         return null;
 527     }
 528
 529     @Override
 530     public synchronized BGPTimersState getBGPTimersState() {
 531         if (this.session instanceof BGPSessionStateProvider) {
 532             return ((BGPSessionStateProvider) this.session).getBGPTimersState();
 533         }
 534         return null;
 535     }
 536
 537     @Override
 538     public synchronized BGPTransportState getBGPTransportState() {
 539         if (this.session instanceof BGPSessionStateProvider) {
 540             return ((BGPSessionStateProvider) this.session).getBGPTransportState();
 541         }
 542         return null;
 543     }
 544
 545     @Override
 546     public PeerRole getFromPeerRole() {
 547         return getRole();
 548     }
 549
 550     @Override
 551     public PeerId getFromPeerId() {
 552         return getPeerId();
 553     }
 554 }