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