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 static java.util.Objects.requireNonNull;
  12
  13 import com.google.common.base.MoreObjects;
  14 import com.google.common.base.Optional;
  15 import com.google.common.base.Preconditions;
  16 import com.google.common.collect.Maps;
  17 import com.google.common.net.InetAddresses;
  18 import com.google.common.primitives.UnsignedInts;
  19 import io.netty.buffer.ByteBuf;
  20 import io.netty.buffer.Unpooled;
  21 import java.net.Inet4Address;
  22 import java.net.Inet6Address;
  23 import java.net.InetAddress;
  24 import java.net.InetSocketAddress;
  25 import java.net.SocketAddress;
  26 import java.util.HashSet;
  27 import java.util.List;
  28 import java.util.Map;
  29 import java.util.Map.Entry;
  30 import java.util.Set;
  31 import javax.annotation.concurrent.GuardedBy;
  32 import javax.annotation.concurrent.ThreadSafe;
  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.impl.message.open.As4CapabilityHandler;
  37 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPPeerRegistry;
  38 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionPreferences;
  39 import org.opendaylight.protocol.bgp.rib.impl.spi.PeerRegistryListener;
  40 import org.opendaylight.protocol.bgp.rib.impl.spi.PeerRegistrySessionListener;
  41 import org.opendaylight.protocol.bgp.rib.spi.BGPSessionListener;
  42 import org.opendaylight.protocol.util.Ipv6Util;
  43 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.AsNumber;
  44 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IetfInetUtil;
  45 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
  46 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Address;
  47 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.Open;
  48 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.open.message.BgpParameters;
  49 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.open.message.bgp.parameters.OptionalCapabilities;
  50 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.open.message.bgp.parameters.optional.capabilities.CParameters;
  51 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.open.message.bgp.parameters.optional.capabilities.CParametersBuilder;
  52 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.open.message.bgp.parameters.optional.capabilities.c.parameters.As4BytesCapability;
  53 import org.opendaylight.yangtools.concepts.AbstractRegistration;
  54 import org.slf4j.Logger;
  55 import org.slf4j.LoggerFactory;
  56
  57 /**
  58  * BGP peer registry that allows only 1 session per BGP peer.
  59  * If second session with peer is established, one of the sessions will be dropped.
  60  * The session with lower source BGP id will be dropped.
  61  */
  62 @ThreadSafe
  63 public final class StrictBGPPeerRegistry implements BGPPeerRegistry {
  64
  65     private static final Logger LOG = LoggerFactory.getLogger(StrictBGPPeerRegistry.class);
  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 new StrictBGPPeerRegistry();
  80     }
  81
  82     @Override
  83     public synchronized void addPeer(final IpAddress oldIp, final BGPSessionListener peer,
  84             final BGPSessionPreferences preferences) {
  85         IpAddress fullIp = getFullIp(oldIp);
  86         Preconditions.checkArgument(!this.peers.containsKey(fullIp),
  87                 "Peer for %s already present", fullIp);
  88         this.peers.put(fullIp, requireNonNull(peer));
  89         requireNonNull(preferences.getMyAs());
  90         requireNonNull(preferences.getParams());
  91         requireNonNull(preferences.getBgpId());
  92         this.peerPreferences.put(fullIp, preferences);
  93         for (final PeerRegistryListener peerRegistryListener : this.listeners) {
  94             peerRegistryListener.onPeerAdded(fullIp, preferences);
  95         }
  96     }
  97
  98     private IpAddress getFullIp(final IpAddress ip) {
  99         requireNonNull(ip);
 100         if (ip.getIpv6Address() != null) {
 101             return new IpAddress(Ipv6Util.getFullForm(ip.getIpv6Address()));
 102         }
 103         return ip;
 104     }
 105
 106     @Override
 107     public synchronized void removePeer(final IpAddress oldIp) {
 108         IpAddress fullIp = getFullIp(oldIp);
 109         this.peers.remove(fullIp);
 110         for (final PeerRegistryListener peerRegistryListener : this.listeners) {
 111             peerRegistryListener.onPeerRemoved(fullIp);
 112         }
 113     }
 114
 115     @Override
 116     public synchronized void removePeerSession(final IpAddress oldIp) {
 117         IpAddress fullIp = getFullIp(oldIp);
 118         this.sessionIds.remove(fullIp);
 119         for (final PeerRegistrySessionListener peerRegistrySessionListener : this.sessionListeners) {
 120             peerRegistrySessionListener.onSessionRemoved(fullIp);
 121         }
 122     }
 123
 124     @Override
 125     public boolean isPeerConfigured(final IpAddress oldIp) {
 126         IpAddress fullIp = getFullIp(oldIp);
 127         return this.peers.containsKey(fullIp);
 128     }
 129
 130     private void checkPeerConfigured(final IpAddress ip) {
 131         Preconditions.checkState(isPeerConfigured(ip),
 132                 "BGP peer with ip: %s not configured, configured peers are: %s",
 133                 ip, this.peers.keySet());
 134     }
 135
 136     @Override
 137     public synchronized BGPSessionListener getPeer(final IpAddress ip, final Ipv4Address sourceId,
 138         final Ipv4Address remoteId, final Open openObj) throws BGPDocumentedException {
 139         requireNonNull(ip);
 140         requireNonNull(sourceId);
 141         requireNonNull(remoteId);
 142         final AsNumber remoteAsNumber = AsNumberUtil.advertizedAsNumber(openObj);
 143         requireNonNull(remoteAsNumber);
 144
 145         final BGPSessionPreferences prefs = getPeerPreferences(ip);
 146
 147         checkPeerConfigured(ip);
 148
 149         final BGPSessionId currentConnection = new BGPSessionId(sourceId, remoteId, remoteAsNumber);
 150         final BGPSessionListener p = this.peers.get(ip);
 151
 152         final BGPSessionId previousConnection = this.sessionIds.get(ip);
 153
 154         if (previousConnection != null) {
 155
 156             LOG.warn("Duplicate BGP session established with {}", ip);
 157
 158             // Session reestablished with different ids
 159             if (!previousConnection.equals(currentConnection)) {
 160                 LOG.warn("BGP session with {} {} has to be dropped. Same session already present {}", ip,
 161                         currentConnection, previousConnection);
 162                 throw new BGPDocumentedException(
 163                         String.format("BGP session with %s %s has to be dropped. Same session already present %s",
 164                                 ip, currentConnection, previousConnection),
 165                         BGPError.CEASE);
 166
 167                 // Session reestablished with lower source bgp id, dropping current
 168             } else if (previousConnection.isHigherDirection(currentConnection) ||
 169                     previousConnection.hasHigherAsNumber(currentConnection)) {
 170                 LOG.warn("BGP session with {} {} has to be dropped. Opposite session already present",
 171                         ip, currentConnection);
 172                 throw new BGPDocumentedException(
 173                         String.format("BGP session with %s initiated %s has to be dropped. "
 174                                 + "Opposite session already present", ip, currentConnection), BGPError.CEASE);
 175
 176                 // Session reestablished with higher source bgp id, dropping previous
 177             } else if (currentConnection.isHigherDirection(previousConnection) ||
 178                     currentConnection.hasHigherAsNumber(previousConnection)) {
 179                 LOG.warn("BGP session with {} {} released. Replaced by opposite session", ip, previousConnection);
 180                 this.peers.get(ip).releaseConnection();
 181                 return this.peers.get(ip);
 182                 // Session reestablished with same source bgp id, dropping current as duplicate
 183             } else {
 184                 LOG.warn("BGP session with %s initiated from %s to %s has to be dropped. Same session already present",
 185                         ip, sourceId, remoteId);
 186                 throw new BGPDocumentedException(
 187                         String.format("BGP session with %s initiated %s has to be dropped. "
 188                                         + "Same session already present", ip, currentConnection), BGPError.CEASE);
 189             }
 190         }
 191         validateAs(remoteAsNumber, openObj, prefs);
 192
 193         // Map session id to peer IP address
 194         this.sessionIds.put(ip, currentConnection);
 195         for (final PeerRegistrySessionListener peerRegistrySessionListener : this.sessionListeners) {
 196             peerRegistrySessionListener.onSessionCreated(ip);
 197         }
 198         return p;
 199     }
 200
 201     private static void validateAs(final AsNumber remoteAs, final Open openObj, final BGPSessionPreferences localPref)
 202             throws BGPDocumentedException {
 203         if (!remoteAs.equals(localPref.getExpectedRemoteAs())) {
 204             LOG.warn("Unexpected remote AS number. Expecting {}, got {}", localPref.getExpectedRemoteAs(), remoteAs);
 205             throw new BGPDocumentedException("Peer AS number mismatch", BGPError.BAD_PEER_AS);
 206         }
 207
 208         // https://tools.ietf.org/html/rfc6286#section-2.2
 209         if (openObj.getBgpIdentifier() != null
 210                 && openObj.getBgpIdentifier().getValue().equals(localPref.getBgpId().getValue())) {
 211             LOG.warn("Remote and local BGP Identifiers are the same: {}", openObj.getBgpIdentifier());
 212             throw new BGPDocumentedException("Remote and local BGP Identifiers are the same.", BGPError.BAD_BGP_ID);
 213         }
 214         final List<BgpParameters> prefs = openObj.getBgpParameters();
 215         if (prefs != null) {
 216             if (getAs4BytesCapability(localPref.getParams()).isPresent() && !getAs4BytesCapability(prefs).isPresent()) {
 217                 throw new BGPDocumentedException("The peer must advertise AS4Bytes capability.",
 218                         BGPError.UNSUPPORTED_CAPABILITY,
 219                         serializeAs4BytesCapability(getAs4BytesCapability(localPref.getParams()).get()));
 220             }
 221             if (!prefs.containsAll(localPref.getParams())) {
 222                 LOG.info("BGP Open message session parameters differ, session still accepted.");
 223             }
 224         } else {
 225             throw new BGPDocumentedException("Open message unacceptable. Check the configuration of BGP speaker.",
 226                     BGPError.UNSPECIFIC_OPEN_ERROR);
 227         }
 228     }
 229
 230     private static Optional<As4BytesCapability> getAs4BytesCapability(final List<BgpParameters> prefs) {
 231         for (final BgpParameters param : prefs) {
 232             for (final OptionalCapabilities capa : param.getOptionalCapabilities()) {
 233                 final CParameters cParam = capa.getCParameters();
 234                 if (cParam.getAs4BytesCapability() != null) {
 235                     return Optional.of(cParam.getAs4BytesCapability());
 236                 }
 237             }
 238         }
 239         return Optional.absent();
 240     }
 241
 242     private static byte[] serializeAs4BytesCapability(final As4BytesCapability as4Capability) {
 243         final ByteBuf buffer = Unpooled.buffer(1 /*CODE*/ + 1 /*LENGTH*/
 244                 + Integer.SIZE / Byte.SIZE /*4 byte value*/);
 245         final As4CapabilityHandler serializer = new As4CapabilityHandler();
 246         serializer.serializeCapability(new CParametersBuilder().setAs4BytesCapability(as4Capability).build(), buffer);
 247         return buffer.array();
 248     }
 249
 250     @Override
 251     public BGPSessionPreferences getPeerPreferences(final IpAddress ip) {
 252         requireNonNull(ip);
 253         checkPeerConfigured(ip);
 254         return this.peerPreferences.get(ip);
 255     }
 256
 257     /**
 258      * Creates IpAddress from SocketAddress. Only InetSocketAddress
 259      * is accepted with inner address: Inet4Address and Inet6Address.
 260      *
 261      * @param socketAddress socket address to transform
 262      * @return IpAddress equivalent to given socket address
 263      * @throws IllegalArgumentException if submitted socket address is not InetSocketAddress[ipv4 | ipv6]
 264      */
 265     public static IpAddress getIpAddress(final SocketAddress socketAddress) {
 266         requireNonNull(socketAddress);
 267         Preconditions.checkArgument(socketAddress instanceof InetSocketAddress,
 268                 "Expecting InetSocketAddress but was %s", socketAddress.getClass());
 269         final InetAddress inetAddress = ((InetSocketAddress) socketAddress).getAddress();
 270
 271         Preconditions.checkArgument(inetAddress instanceof Inet4Address
 272                 || inetAddress instanceof Inet6Address, "Expecting %s or %s but was %s",
 273                 Inet4Address.class, Inet6Address.class, inetAddress.getClass());
 274         return IetfInetUtil.INSTANCE.ipAddressFor(inetAddress);
 275     }
 276
 277     @Override
 278     public synchronized void close() {
 279         this.peers.clear();
 280         this.sessionIds.clear();
 281     }
 282
 283     @Override
 284     public String toString() {
 285         return MoreObjects.toStringHelper(this)
 286             .add("peers", this.peers.keySet())
 287             .toString();
 288     }
 289
 290     /**
 291      * Session identifier that contains (source Bgp Id) -> (destination Bgp Id) AsNumber is the remoteAs coming from
 292      * remote Open message
 293      */
 294     private static final class BGPSessionId {
 295
 296         private final Ipv4Address from, to;
 297         private final AsNumber asNumber;
 298
 299         BGPSessionId(final Ipv4Address from, final Ipv4Address to, final AsNumber asNumber) {
 300             this.from = requireNonNull(from);
 301             this.to = requireNonNull(to);
 302             this.asNumber = requireNonNull(asNumber);
 303         }
 304
 305         /**
 306          * Equals does not take direction of connection into account id1 -> id2 and id2 -> id1 are equal
 307          */
 308         @Override
 309         public boolean equals(final Object o) {
 310             if (this == o) {
 311                 return true;
 312             }
 313             if (o == null || getClass() != o.getClass()) {
 314                 return false;
 315             }
 316
 317             final BGPSessionId bGPSessionId = (BGPSessionId) o;
 318
 319             if (!this.from.equals(bGPSessionId.from) && !this.from.equals(bGPSessionId.to)) {
 320                 return false;
 321             }
 322             if (!this.to.equals(bGPSessionId.to) && !this.to.equals(bGPSessionId.from)) {
 323                 return false;
 324             }
 325
 326             return true;
 327         }
 328
 329         @Override
 330         public int hashCode() {
 331             final int prime = 31;
 332             int result = this.from.hashCode() + this.to.hashCode();
 333             result = prime * result;
 334             return result;
 335         }
 336
 337         /**
 338          * Check if this connection is equal to other and if it contains higher source bgp id
 339          */
 340         boolean isHigherDirection(final BGPSessionId other) {
 341             return toLong(this.from) > toLong(other.from);
 342         }
 343
 344         boolean hasHigherAsNumber(final BGPSessionId other) {
 345             return this.asNumber.getValue() > other.asNumber.getValue();
 346         }
 347
 348         private static long toLong(final Ipv4Address from) {
 349             final int i = InetAddresses.coerceToInteger(InetAddresses.forString(from.getValue()));
 350             return UnsignedInts.toLong(i);
 351         }
 352
 353         @Override
 354         public String toString() {
 355             return MoreObjects.toStringHelper(this)
 356                 .add("from", this.from)
 357                 .add("to", this.to)
 358                 .toString();
 359         }
 360     }
 361
 362     @Override
 363     public synchronized AutoCloseable registerPeerRegisterListener(final PeerRegistryListener listener) {
 364         this.listeners.add(listener);
 365         for (final Entry<IpAddress, BGPSessionPreferences> entry : this.peerPreferences.entrySet()) {
 366             listener.onPeerAdded(entry.getKey(), entry.getValue());
 367         }
 368         return new AbstractRegistration() {
 369             @Override
 370             protected void removeRegistration() {
 371                 synchronized (StrictBGPPeerRegistry.this) {
 372                     StrictBGPPeerRegistry.this.listeners.remove(listener);
 373                 }
 374             }
 375         };
 376     }
 377
 378     @Override
 379     public synchronized AutoCloseable registerPeerSessionListener(final PeerRegistrySessionListener listener) {
 380         this.sessionListeners.add(listener);
 381         for (final IpAddress ipAddress : this.sessionIds.keySet()) {
 382             listener.onSessionCreated(ipAddress);
 383         }
 384         return new AbstractRegistration() {
 385             @Override
 386             protected void removeRegistration() {
 387                 synchronized (StrictBGPPeerRegistry.this) {
 388                     StrictBGPPeerRegistry.this.sessionListeners.remove(listener);
 389                 }
 390             }
 391         };
 392     }
 393 }