bgp/rib-impl/src/main/java/org/opendaylight/protocol/bgp/rib/impl/StrictBGPPeerRegistry.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
   9 package org.opendaylight.protocol.bgp.rib.impl;
  10
  11 import com.google.common.base.MoreObjects;
  12 import com.google.common.base.Optional;
  13 import com.google.common.base.Preconditions;
  14 import com.google.common.collect.Maps;
  15 import com.google.common.net.InetAddresses;
  16 import com.google.common.primitives.UnsignedInts;
  17 import io.netty.buffer.ByteBuf;
  18 import io.netty.buffer.Unpooled;
  19 import java.net.Inet4Address;
  20 import java.net.Inet6Address;
  21 import java.net.InetAddress;
  22 import java.net.InetSocketAddress;
  23 import java.net.SocketAddress;
  24 import java.util.HashSet;
  25 import java.util.List;
  26 import java.util.Map;
  27 import java.util.Map.Entry;
  28 import java.util.Set;
  29 import javax.annotation.concurrent.GuardedBy;
  30 import javax.annotation.concurrent.ThreadSafe;
  31 import org.opendaylight.protocol.bgp.parser.AsNumberUtil;
  32 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  33 import org.opendaylight.protocol.bgp.parser.BGPError;
  34 import org.opendaylight.protocol.bgp.parser.impl.message.open.As4CapabilityHandler;
  35 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPPeerRegistry;
  36 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionPreferences;
  37 import org.opendaylight.protocol.bgp.rib.impl.spi.PeerRegistryListener;
  38 import org.opendaylight.protocol.bgp.rib.impl.spi.PeerRegistrySessionListener;
  39 import org.opendaylight.protocol.bgp.rib.spi.BGPSessionListener;
  40 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.AsNumber;
  41 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IetfInetUtil;
  42 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
  43 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Address;
  44 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Open;
  45 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.BgpParameters;
  46 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.OptionalCapabilities;
  47 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.optional.capabilities.CParameters;
  48 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.optional.capabilities.CParametersBuilder;
  49 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.optional.capabilities.c.parameters.As4BytesCapability;
  50 import org.opendaylight.yangtools.concepts.AbstractRegistration;
  51 import org.slf4j.Logger;
  52 import org.slf4j.LoggerFactory;
  53
  54 /**
  55  * BGP peer registry that allows only 1 session per BGP peer.
  56  * If second session with peer is established, one of the sessions will be dropped.
  57  * The session with lower source BGP id will be dropped.
  58  */
  59 @ThreadSafe
  60 public final class StrictBGPPeerRegistry implements BGPPeerRegistry {
  61
  62     private static final Logger LOG = LoggerFactory.getLogger(StrictBGPPeerRegistry.class);
  63
  64     // TODO remove backwards compatibility
  65     public static final StrictBGPPeerRegistry GLOBAL = new StrictBGPPeerRegistry();
  66
  67     @GuardedBy("this")
  68     private final Map<IpAddress, BGPSessionListener> peers = Maps.newHashMap();
  69     @GuardedBy("this")
  70     private final Map<IpAddress, BGPSessionId> sessionIds = Maps.newHashMap();
  71     @GuardedBy("this")
  72     private final Map<IpAddress, BGPSessionPreferences> peerPreferences = Maps.newHashMap();
  73     @GuardedBy("this")
  74     private final Set<PeerRegistryListener> listeners = new HashSet<>();
  75     @GuardedBy("this")
  76     private final Set<PeerRegistrySessionListener> sessionListeners = new HashSet<>();
  77
  78     public static BGPPeerRegistry instance() {
  79         return GLOBAL;
  80     }
  81
  82     @Override
  83     public synchronized void addPeer(final IpAddress ip, final BGPSessionListener peer, final BGPSessionPreferences preferences) {
  84         Preconditions.checkNotNull(ip);
  85         Preconditions.checkArgument(!this.peers.containsKey(ip), "Peer for %s already present", ip);
  86         this.peers.put(ip, Preconditions.checkNotNull(peer));
  87         Preconditions.checkNotNull(preferences.getMyAs());
  88         Preconditions.checkNotNull(preferences.getHoldTime());
  89         Preconditions.checkNotNull(preferences.getParams());
  90         Preconditions.checkNotNull(preferences.getBgpId());
  91         this.peerPreferences.put(ip, preferences);
  92         for (final PeerRegistryListener peerRegistryListener : this.listeners) {
  93             peerRegistryListener.onPeerAdded(ip, preferences);
  94         }
  95     }
  96
  97     @Override
  98     public synchronized void removePeer(final IpAddress ip) {
  99         Preconditions.checkNotNull(ip);
 100         this.peers.remove(ip);
 101         for (final PeerRegistryListener peerRegistryListener : this.listeners) {
 102             peerRegistryListener.onPeerRemoved(ip);
 103         }
 104     }
 105
 106     @Override
 107     public synchronized void removePeerSession(final IpAddress ip) {
 108         Preconditions.checkNotNull(ip);
 109         this.sessionIds.remove(ip);
 110         for (final PeerRegistrySessionListener peerRegistrySessionListener : this.sessionListeners) {
 111             peerRegistrySessionListener.onSessionRemoved(ip);
 112         }
 113     }
 114
 115     @Override
 116     public boolean isPeerConfigured(final IpAddress ip) {
 117         Preconditions.checkNotNull(ip);
 118         return this.peers.containsKey(ip);
 119     }
 120
 121     private void checkPeerConfigured(final IpAddress ip) {
 122         Preconditions.checkState(isPeerConfigured(ip), "BGP peer with ip: %s not configured, configured peers are: %s", ip, this.peers.keySet());
 123     }
 124
 125     @Override
 126     public synchronized BGPSessionListener getPeer(final IpAddress ip, final Ipv4Address sourceId,
 127         final Ipv4Address remoteId, final Open openObj) throws BGPDocumentedException {
 128         Preconditions.checkNotNull(ip);
 129         Preconditions.checkNotNull(sourceId);
 130         Preconditions.checkNotNull(remoteId);
 131         final AsNumber remoteAsNumber = AsNumberUtil.advertizedAsNumber(openObj);
 132         Preconditions.checkNotNull(remoteAsNumber);
 133
 134         final BGPSessionPreferences prefs = getPeerPreferences(ip);
 135
 136         checkPeerConfigured(ip);
 137
 138         final BGPSessionId currentConnection = new BGPSessionId(sourceId, remoteId, remoteAsNumber);
 139         final BGPSessionListener p = this.peers.get(ip);
 140
 141         final BGPSessionId previousConnection = this.sessionIds.get(ip);
 142
 143         if (previousConnection != null) {
 144
 145             LOG.warn("Duplicate BGP session established with {}", ip);
 146
 147             // Session reestablished with different ids
 148             if (!previousConnection.equals(currentConnection)) {
 149                 LOG.warn("BGP session with {} {} has to be dropped. Same session already present {}", ip, currentConnection, previousConnection);
 150                 throw new BGPDocumentedException(
 151                     String.format("BGP session with %s %s has to be dropped. Same session already present %s",
 152                         ip, currentConnection, previousConnection),
 153                         BGPError.CEASE);
 154
 155                 // Session reestablished with lower source bgp id, dropping current
 156             } else if (previousConnection.isHigherDirection(currentConnection)) {
 157                 LOG.warn("BGP session with {} {} has to be dropped. Opposite session already present", ip, currentConnection);
 158                 throw new BGPDocumentedException(
 159                     String.format("BGP session with %s initiated %s has to be dropped. Opposite session already present",
 160                         ip, currentConnection),
 161                         BGPError.CEASE);
 162
 163                 // Session reestablished with higher source bgp id, dropping previous
 164             } else if (currentConnection.isHigherDirection(previousConnection)) {
 165                 LOG.warn("BGP session with {} {} released. Replaced by opposite session", ip, previousConnection);
 166                 this.peers.get(ip).releaseConnection();
 167                 return this.peers.get(ip);
 168
 169             } else if (previousConnection.hasHigherAsNumber(currentConnection)) {
 170                 LOG.warn("BGP session with {} {} has to be dropped. Opposite session already present", ip, currentConnection);
 171                 throw new BGPDocumentedException(
 172                     String.format("BGP session with %s initiated %s has to be dropped. Opposite session already present",
 173                         ip, currentConnection),
 174                         BGPError.CEASE);
 175             } else if (currentConnection.hasHigherAsNumber(previousConnection)) {
 176                 LOG.warn("BGP session with {} {} released. Replaced by opposite session", ip, previousConnection);
 177                 this.peers.get(ip).releaseConnection();
 178                 return this.peers.get(ip);
 179             // Session reestablished with same source bgp id, dropping current as duplicate
 180             } else {
 181                 LOG.warn("BGP session with %s initiated from %s to %s has to be dropped. Same session already present", ip, sourceId, remoteId);
 182                 throw new BGPDocumentedException(
 183                     String.format("BGP session with %s initiated %s has to be dropped. Same session already present",
 184                         ip, currentConnection),
 185                         BGPError.CEASE);
 186             }
 187         }
 188         validateAs(remoteAsNumber, openObj, prefs);
 189
 190         // Map session id to peer IP address
 191         this.sessionIds.put(ip, currentConnection);
 192         for (final PeerRegistrySessionListener peerRegistrySessionListener : this.sessionListeners) {
 193             peerRegistrySessionListener.onSessionCreated(ip);
 194         }
 195         return p;
 196     }
 197
 198     private static void validateAs(final AsNumber remoteAs, final Open openObj, final BGPSessionPreferences localPref) throws BGPDocumentedException {
 199         if (!remoteAs.equals(localPref.getExpectedRemoteAs())) {
 200             LOG.warn("Unexpected remote AS number. Expecting {}, got {}", remoteAs, localPref.getExpectedRemoteAs());
 201             throw new BGPDocumentedException("Peer AS number mismatch", BGPError.BAD_PEER_AS);
 202         }
 203
 204         // https://tools.ietf.org/html/rfc6286#section-2.2
 205         if (openObj.getBgpIdentifier() != null && openObj.getBgpIdentifier().getValue().equals(localPref.getBgpId().getValue())) {
 206             LOG.warn("Remote and local BGP Identifiers are the same: {}", openObj.getBgpIdentifier());
 207             throw new BGPDocumentedException("Remote and local BGP Identifiers are the same.", BGPError.BAD_BGP_ID);
 208         }
 209         final List<BgpParameters> prefs = openObj.getBgpParameters();
 210         if (prefs != null) {
 211             if (getAs4BytesCapability(localPref.getParams()).isPresent() && !getAs4BytesCapability(prefs).isPresent()) {
 212                 throw new BGPDocumentedException("The peer must advertise AS4Bytes capability.", BGPError.UNSUPPORTED_CAPABILITY, serializeAs4BytesCapability(getAs4BytesCapability(localPref.getParams()).get()));
 213             }
 214             if (!prefs.containsAll(localPref.getParams())) {
 215                 LOG.info("BGP Open message session parameters differ, session still accepted.");
 216             }
 217         } else {
 218             throw new BGPDocumentedException("Open message unacceptable. Check the configuration of BGP speaker.", BGPError.UNSPECIFIC_OPEN_ERROR);
 219         }
 220     }
 221
 222     private static Optional<As4BytesCapability> getAs4BytesCapability(final List<BgpParameters> prefs) {
 223         for (final BgpParameters param : prefs) {
 224             for (final OptionalCapabilities capa : param.getOptionalCapabilities()) {
 225                 final CParameters cParam = capa.getCParameters();
 226                 if (cParam.getAs4BytesCapability() != null) {
 227                     return Optional.of(cParam.getAs4BytesCapability());
 228                 }
 229             }
 230         }
 231         return Optional.absent();
 232     }
 233
 234     private static byte[] serializeAs4BytesCapability(final As4BytesCapability as4Capability) {
 235         final ByteBuf buffer = Unpooled.buffer(1 /*CODE*/ + 1 /*LENGTH*/ + Integer.SIZE / Byte.SIZE /*4 byte value*/);
 236         final As4CapabilityHandler serializer = new As4CapabilityHandler();
 237         serializer.serializeCapability(new CParametersBuilder().setAs4BytesCapability(as4Capability).build(), buffer);
 238         return buffer.array();
 239     }
 240
 241     @Override
 242     public BGPSessionPreferences getPeerPreferences(final IpAddress ip) {
 243         Preconditions.checkNotNull(ip);
 244         checkPeerConfigured(ip);
 245         return this.peerPreferences.get(ip);
 246     }
 247
 248     /**
 249      * Creates IpAddress from SocketAddress. Only InetSocketAddress is accepted with inner address: Inet4Address and Inet6Address.
 250      *
 251      * @param socketAddress socket address to transform
 252      * @return IpAddress equivalent to given socket address
 253      * @throws IllegalArgumentException if submitted socket address is not InetSocketAddress[ipv4 | ipv6]
 254      */
 255     public static IpAddress getIpAddress(final SocketAddress socketAddress) {
 256         Preconditions.checkNotNull(socketAddress);
 257         Preconditions.checkArgument(socketAddress instanceof InetSocketAddress, "Expecting InetSocketAddress but was %s", socketAddress.getClass());
 258         final InetAddress inetAddress = ((InetSocketAddress) socketAddress).getAddress();
 259
 260         Preconditions.checkArgument(inetAddress instanceof Inet4Address || inetAddress instanceof Inet6Address, "Expecting %s or %s but was %s", Inet4Address.class, Inet6Address.class, inetAddress.getClass());
 261         return IetfInetUtil.INSTANCE.ipAddressFor(inetAddress);
 262     }
 263
 264     @Override
 265     public synchronized void close() {
 266         this.peers.clear();
 267         this.sessionIds.clear();
 268     }
 269
 270     @Override
 271     public String toString() {
 272         return MoreObjects.toStringHelper(this)
 273             .add("peers", this.peers.keySet())
 274             .toString();
 275     }
 276
 277     /**
 278      * Session identifier that contains (source Bgp Id) -> (destination Bgp Id) AsNumber is the remoteAs coming from
 279      * remote Open message
 280      */
 281     private static final class BGPSessionId {
 282
 283         private final Ipv4Address from, to;
 284         private final AsNumber asNumber;
 285
 286         BGPSessionId(final Ipv4Address from, final Ipv4Address to, final AsNumber asNumber) {
 287             this.from = Preconditions.checkNotNull(from);
 288             this.to = Preconditions.checkNotNull(to);
 289             this.asNumber = Preconditions.checkNotNull(asNumber);
 290         }
 291
 292         /**
 293          * Equals does not take direction of connection into account id1 -> id2 and id2 -> id1 are equal
 294          */
 295         @Override
 296         public boolean equals(final Object o) {
 297             if (this == o) {
 298                 return true;
 299             }
 300             if (o == null || getClass() != o.getClass()) {
 301                 return false;
 302             }
 303
 304             final BGPSessionId bGPSessionId = (BGPSessionId) o;
 305
 306             if (!this.from.equals(bGPSessionId.from) && !this.from.equals(bGPSessionId.to)) {
 307                 return false;
 308             }
 309             if (!this.to.equals(bGPSessionId.to) && !this.to.equals(bGPSessionId.from)) {
 310                 return false;
 311             }
 312
 313             return true;
 314         }
 315
 316         @Override
 317         public int hashCode() {
 318             final int prime = 31;
 319             int result = this.from.hashCode() + this.to.hashCode();
 320             result = prime * result;
 321             return result;
 322         }
 323
 324         /**
 325          * Check if this connection is equal to other and if it contains higher source bgp id
 326          */
 327         boolean isHigherDirection(final BGPSessionId other) {
 328             return toLong(this.from) > toLong(other.from);
 329         }
 330
 331         boolean hasHigherAsNumber(final BGPSessionId other) {
 332             return this.asNumber.getValue() > other.asNumber.getValue();
 333         }
 334
 335         private static long toLong(final Ipv4Address from) {
 336             final int i = InetAddresses.coerceToInteger(InetAddresses.forString(from.getValue()));
 337             return UnsignedInts.toLong(i);
 338         }
 339
 340         @Override
 341         public String toString() {
 342             return MoreObjects.toStringHelper(this)
 343                 .add("from", this.from)
 344                 .add("to", this.to)
 345                 .toString();
 346         }
 347     }
 348
 349     @Override
 350     public synchronized AutoCloseable registerPeerRegisterListener(final PeerRegistryListener listener) {
 351         this.listeners.add(listener);
 352         for (final Entry<IpAddress, BGPSessionPreferences> entry : this.peerPreferences.entrySet()) {
 353             listener.onPeerAdded(entry.getKey(), entry.getValue());
 354         }
 355         return new AbstractRegistration() {
 356             @Override
 357             protected void removeRegistration() {
 358                 synchronized (StrictBGPPeerRegistry.this) {
 359                     StrictBGPPeerRegistry.this.listeners.remove(listener);
 360                 }
 361             }
 362         };
 363     }
 364
 365     @Override
 366     public synchronized AutoCloseable registerPeerSessionListener(final PeerRegistrySessionListener listener) {
 367         this.sessionListeners.add(listener);
 368         for (final IpAddress ipAddress : this.sessionIds.keySet()) {
 369             listener.onSessionCreated(ipAddress);
 370         }
 371         return new AbstractRegistration() {
 372             @Override
 373             protected void removeRegistration() {
 374                 synchronized (StrictBGPPeerRegistry.this) {
 375                     StrictBGPPeerRegistry.this.sessionListeners.remove(listener);
 376                 }
 377             }
 378         };
 379     }
 380 }