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