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