Java tutorial
/* * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.protocol.bgp.rib.impl; import com.google.common.base.MoreObjects; import com.google.common.base.Optional; import com.google.common.base.Preconditions; import com.google.common.collect.Maps; import com.google.common.net.InetAddresses; import com.google.common.primitives.UnsignedInts; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import java.net.Inet4Address; import java.net.Inet6Address; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.SocketAddress; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import javax.annotation.concurrent.GuardedBy; import javax.annotation.concurrent.ThreadSafe; import org.opendaylight.protocol.bgp.parser.AsNumberUtil; import org.opendaylight.protocol.bgp.parser.BGPDocumentedException; import org.opendaylight.protocol.bgp.parser.BGPError; import org.opendaylight.protocol.bgp.parser.impl.message.open.As4CapabilityHandler; import org.opendaylight.protocol.bgp.rib.impl.spi.BGPPeerRegistry; import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionPreferences; import org.opendaylight.protocol.bgp.rib.impl.spi.PeerRegistryListener; import org.opendaylight.protocol.bgp.rib.spi.BGPSessionListener; import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.AsNumber; import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IetfInetUtil; import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress; import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Address; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Open; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.BgpParameters; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.OptionalCapabilities; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.optional.capabilities.CParameters; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.optional.capabilities.CParametersBuilder; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.optional.capabilities.c.parameters.As4BytesCapability; import org.opendaylight.yangtools.concepts.AbstractRegistration; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * BGP peer registry that allows only 1 session per BGP peer. * If second session with peer is established, one of the sessions will be dropped. * The session with lower source BGP id will be dropped. */ @ThreadSafe public final class StrictBGPPeerRegistry implements BGPPeerRegistry { private static final Logger LOG = LoggerFactory.getLogger(StrictBGPPeerRegistry.class); // TODO remove backwards compatibility public static final StrictBGPPeerRegistry GLOBAL = new StrictBGPPeerRegistry(); @GuardedBy("this") private final Map<IpAddress, BGPSessionListener> peers = Maps.newHashMap(); @GuardedBy("this") private final Map<IpAddress, BGPSessionId> sessionIds = Maps.newHashMap(); @GuardedBy("this") private final Map<IpAddress, BGPSessionPreferences> peerPreferences = Maps.newHashMap(); @GuardedBy("this") private final Set<PeerRegistryListener> listeners = new HashSet<>(); public static BGPPeerRegistry instance() { return GLOBAL; } @Override public synchronized void addPeer(final IpAddress ip, final BGPSessionListener peer, final BGPSessionPreferences preferences) { Preconditions.checkNotNull(ip); Preconditions.checkArgument(!this.peers.containsKey(ip), "Peer for %s already present", ip); this.peers.put(ip, Preconditions.checkNotNull(peer)); Preconditions.checkNotNull(preferences.getMyAs()); Preconditions.checkNotNull(preferences.getHoldTime()); Preconditions.checkNotNull(preferences.getParams()); Preconditions.checkNotNull(preferences.getBgpId()); this.peerPreferences.put(ip, preferences); for (final PeerRegistryListener peerRegistryListener : this.listeners) { peerRegistryListener.onPeerAdded(ip, preferences); } } @Override public synchronized void removePeer(final IpAddress ip) { Preconditions.checkNotNull(ip); this.peers.remove(ip); for (final PeerRegistryListener peerRegistryListener : this.listeners) { peerRegistryListener.onPeerRemoved(ip); } } @Override public synchronized void removePeerSession(final IpAddress ip) { Preconditions.checkNotNull(ip); this.sessionIds.remove(ip); } @Override public boolean isPeerConfigured(final IpAddress ip) { Preconditions.checkNotNull(ip); return this.peers.containsKey(ip); } private void checkPeerConfigured(final IpAddress ip) { Preconditions.checkState(isPeerConfigured(ip), "BGP peer with ip: %s not configured, configured peers are: %s", ip, this.peers.keySet()); } @Override public synchronized BGPSessionListener getPeer(final IpAddress ip, final Ipv4Address sourceId, final Ipv4Address remoteId, final Open openObj) throws BGPDocumentedException { Preconditions.checkNotNull(ip); Preconditions.checkNotNull(sourceId); Preconditions.checkNotNull(remoteId); final AsNumber remoteAsNumber = AsNumberUtil.advertizedAsNumber(openObj); Preconditions.checkNotNull(remoteAsNumber); final BGPSessionPreferences prefs = getPeerPreferences(ip); checkPeerConfigured(ip); final BGPSessionId currentConnection = new BGPSessionId(sourceId, remoteId, remoteAsNumber); final BGPSessionListener p = this.peers.get(ip); final BGPSessionId previousConnection = this.sessionIds.get(ip); if (previousConnection != null) { LOG.warn("Duplicate BGP session established with {}", ip); // Session reestablished with different ids if (!previousConnection.equals(currentConnection)) { LOG.warn("BGP session with {} {} has to be dropped. Same session already present {}", ip, currentConnection, previousConnection); throw new BGPDocumentedException( String.format("BGP session with %s %s has to be dropped. Same session already present %s", ip, currentConnection, previousConnection), BGPError.CEASE); // Session reestablished with lower source bgp id, dropping current } else if (previousConnection.isHigherDirection(currentConnection)) { LOG.warn("BGP session with {} {} has to be dropped. Opposite session already present", ip, currentConnection); throw new BGPDocumentedException(String.format( "BGP session with %s initiated %s has to be dropped. Opposite session already present", ip, currentConnection), BGPError.CEASE); // Session reestablished with higher source bgp id, dropping previous } else if (currentConnection.isHigherDirection(previousConnection)) { LOG.warn("BGP session with {} {} released. Replaced by opposite session", ip, previousConnection); this.peers.get(ip).releaseConnection(); return this.peers.get(ip); } else if (previousConnection.hasHigherAsNumber(currentConnection)) { LOG.warn("BGP session with {} {} has to be dropped. Opposite session already present", ip, currentConnection); throw new BGPDocumentedException(String.format( "BGP session with %s initiated %s has to be dropped. Opposite session already present", ip, currentConnection), BGPError.CEASE); } else if (currentConnection.hasHigherAsNumber(previousConnection)) { LOG.warn("BGP session with {} {} released. Replaced by opposite session", ip, previousConnection); this.peers.get(ip).releaseConnection(); return this.peers.get(ip); // Session reestablished with same source bgp id, dropping current as duplicate } else { LOG.warn( "BGP session with %s initiated from %s to %s has to be dropped. Same session already present", ip, sourceId, remoteId); throw new BGPDocumentedException(String.format( "BGP session with %s initiated %s has to be dropped. Same session already present", ip, currentConnection), BGPError.CEASE); } } validateAs(remoteAsNumber, openObj, prefs); // Map session id to peer IP address this.sessionIds.put(ip, currentConnection); return p; } private static void validateAs(final AsNumber remoteAs, final Open openObj, final BGPSessionPreferences localPref) throws BGPDocumentedException { if (!remoteAs.equals(localPref.getExpectedRemoteAs())) { LOG.warn("Unexpected remote AS number. Expecting {}, got {}", remoteAs, localPref.getExpectedRemoteAs()); throw new BGPDocumentedException("Peer AS number mismatch", BGPError.BAD_PEER_AS); } // https://tools.ietf.org/html/rfc6286#section-2.2 if (openObj.getBgpIdentifier() != null && openObj.getBgpIdentifier().getValue().equals(localPref.getBgpId().getValue())) { LOG.warn("Remote and local BGP Identifiers are the same: {}", openObj.getBgpIdentifier()); throw new BGPDocumentedException("Remote and local BGP Identifiers are the same.", BGPError.BAD_BGP_ID); } final List<BgpParameters> prefs = openObj.getBgpParameters(); if (prefs != null) { if (getAs4BytesCapability(localPref.getParams()).isPresent() && !getAs4BytesCapability(prefs).isPresent()) { throw new BGPDocumentedException("The peer must advertise AS4Bytes capability.", BGPError.UNSUPPORTED_CAPABILITY, serializeAs4BytesCapability(getAs4BytesCapability(localPref.getParams()).get())); } if (!prefs.containsAll(localPref.getParams())) { LOG.info("BGP Open message session parameters differ, session still accepted."); } } else { throw new BGPDocumentedException("Open message unacceptable. Check the configuration of BGP speaker.", BGPError.UNSPECIFIC_OPEN_ERROR); } } private static Optional<As4BytesCapability> getAs4BytesCapability(final List<BgpParameters> prefs) { for (final BgpParameters param : prefs) { for (final OptionalCapabilities capa : param.getOptionalCapabilities()) { final CParameters cParam = capa.getCParameters(); if (cParam.getAs4BytesCapability() != null) { return Optional.of(cParam.getAs4BytesCapability()); } } } return Optional.absent(); } private static byte[] serializeAs4BytesCapability(final As4BytesCapability as4Capability) { final ByteBuf buffer = Unpooled .buffer(1 /*CODE*/ + 1 /*LENGTH*/ + Integer.SIZE / Byte.SIZE /*4 byte value*/); final As4CapabilityHandler serializer = new As4CapabilityHandler(); serializer.serializeCapability(new CParametersBuilder().setAs4BytesCapability(as4Capability).build(), buffer); return buffer.array(); } @Override public BGPSessionPreferences getPeerPreferences(final IpAddress ip) { Preconditions.checkNotNull(ip); checkPeerConfigured(ip); return this.peerPreferences.get(ip); } /** * Creates IpAddress from SocketAddress. Only InetSocketAddress is accepted with inner address: Inet4Address and Inet6Address. * * @param socketAddress socket address to transform * @return IpAddress equivalent to given socket address * @throws IllegalArgumentException if submitted socket address is not InetSocketAddress[ipv4 | ipv6] */ public static IpAddress getIpAddress(final SocketAddress socketAddress) { Preconditions.checkNotNull(socketAddress); Preconditions.checkArgument(socketAddress instanceof InetSocketAddress, "Expecting InetSocketAddress but was %s", socketAddress.getClass()); final InetAddress inetAddress = ((InetSocketAddress) socketAddress).getAddress(); Preconditions.checkArgument(inetAddress instanceof Inet4Address || inetAddress instanceof Inet6Address, "Expecting %s or %s but was %s", Inet4Address.class, Inet6Address.class, inetAddress.getClass()); return IetfInetUtil.INSTANCE.ipAddressFor(inetAddress); } @Override public synchronized void close() { this.peers.clear(); this.sessionIds.clear(); } @Override public String toString() { return MoreObjects.toStringHelper(this).add("peers", this.peers.keySet()).toString(); } /** * Session identifier that contains (source Bgp Id) -> (destination Bgp Id) AsNumber is the remoteAs coming from * remote Open message */ private static final class BGPSessionId { private final Ipv4Address from, to; private final AsNumber asNumber; BGPSessionId(final Ipv4Address from, final Ipv4Address to, final AsNumber asNumber) { this.from = Preconditions.checkNotNull(from); this.to = Preconditions.checkNotNull(to); this.asNumber = Preconditions.checkNotNull(asNumber); } /** * Equals does not take direction of connection into account id1 -> id2 and id2 -> id1 are equal */ @Override public boolean equals(final Object o) { if (this == o) { return true; } if (o == null || getClass() != o.getClass()) { return false; } final BGPSessionId bGPSessionId = (BGPSessionId) o; if (!this.from.equals(bGPSessionId.from) && !this.from.equals(bGPSessionId.to)) { return false; } if (!this.to.equals(bGPSessionId.to) && !this.to.equals(bGPSessionId.from)) { return false; } return true; } @Override public int hashCode() { final int prime = 31; int result = this.from.hashCode() + this.to.hashCode(); result = prime * result; return result; } /** * Check if this connection is equal to other and if it contains higher source bgp id */ boolean isHigherDirection(final BGPSessionId other) { return toLong(this.from) > toLong(other.from); } boolean hasHigherAsNumber(final BGPSessionId other) { return this.asNumber.getValue() > other.asNumber.getValue(); } private static long toLong(final Ipv4Address from) { final int i = InetAddresses.coerceToInteger(InetAddresses.forString(from.getValue())); return UnsignedInts.toLong(i); } @Override public String toString() { return MoreObjects.toStringHelper(this).add("from", this.from).add("to", this.to).toString(); } } @Override public synchronized AutoCloseable registerPeerRegisterListener(final PeerRegistryListener listener) { this.listeners.add(listener); for (final Entry<IpAddress, BGPSessionPreferences> entry : this.peerPreferences.entrySet()) { listener.onPeerAdded(entry.getKey(), entry.getValue()); } return new AbstractRegistration() { @Override protected void removeRegistration() { synchronized (StrictBGPPeerRegistry.this) { StrictBGPPeerRegistry.this.listeners.remove(listener); } } }; } }