bgp/rib-impl/src/main/java/org/opendaylight/protocol/bgp/rib/impl/AbstractBGPSessionNegotiator.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.annotations.VisibleForTesting;
  12 import com.google.common.base.Preconditions;
  13 import io.netty.channel.Channel;
  14 import io.netty.util.Timeout;
  15 import io.netty.util.Timer;
  16 import io.netty.util.TimerTask;
  17 import io.netty.util.concurrent.Promise;
  18 import java.util.concurrent.TimeUnit;
  19 import javax.annotation.concurrent.GuardedBy;
  20 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  21 import org.opendaylight.protocol.bgp.parser.BGPError;
  22 import org.opendaylight.protocol.bgp.parser.BGPSessionListener;
  23 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPPeerRegistry;
  24 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionPreferences;
  25 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionValidator;
  26 import org.opendaylight.protocol.framework.AbstractSessionNegotiator;
  27 import org.opendaylight.protocol.util.Values;
  28 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.IpAddress;
  29 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.Ipv4Address;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Keepalive;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.KeepaliveBuilder;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Notify;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.NotifyBuilder;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Open;
  35 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.OpenBuilder;
  36 import org.opendaylight.yangtools.yang.binding.Notification;
  37 import org.slf4j.Logger;
  38 import org.slf4j.LoggerFactory;
  39
  40 /**
  41  * Bgp Session negotiator. Common for local -> remote and remote -> local connections.
  42  * One difference is session validation performed by injected BGPSessionValidator when OPEN message is received.
  43  */
  44 public abstract class AbstractBGPSessionNegotiator extends AbstractSessionNegotiator<Notification, BGPSessionImpl> {
  45     // 4 minutes recommended in http://tools.ietf.org/html/rfc4271#section-8.2.2
  46     protected static final int INITIAL_HOLDTIMER = 4;
  47
  48     /**
  49      * @see <a href="http://tools.ietf.org/html/rfc6793">BGP Support for 4-Octet AS Number Space</a>
  50      */
  51     private static final int AS_TRANS = 23456;
  52
  53     @VisibleForTesting
  54     public enum State {
  55         /**
  56          * Negotiation has not started yet.
  57          */
  58         Idle,
  59         /**
  60          * We have sent our Open message, and are waiting for the peer's Open message.
  61          */
  62         OpenSent,
  63         /**
  64          * We have received the peer's Open message, which is acceptable, and we're waiting the acknowledgement of our
  65          * Open message.
  66          */
  67         OpenConfirm,
  68         /**
  69          * The negotiation finished.
  70          */
  71         Finished,
  72     }
  73
  74     private static final Logger LOG = LoggerFactory.getLogger(AbstractBGPSessionNegotiator.class);
  75     private final Timer timer;
  76     private final BGPPeerRegistry registry;
  77     private final BGPSessionValidator sessionValidator;
  78
  79     @GuardedBy("this")
  80     private State state = State.Idle;
  81
  82     @GuardedBy("this")
  83     private BGPSessionImpl session;
  84
  85     public AbstractBGPSessionNegotiator(final Timer timer, final Promise<BGPSessionImpl> promise, final Channel channel,
  86                                         final BGPPeerRegistry registry, final BGPSessionValidator sessionValidator) {
  87         super(promise, channel);
  88         this.registry = registry;
  89         this.sessionValidator = sessionValidator;
  90         this.timer = Preconditions.checkNotNull(timer);
  91     }
  92
  93     @Override
  94     protected void startNegotiation() {
  95         Preconditions.checkState(this.state == State.Idle);
  96
  97         // Check if peer is configured in registry before retrieving preferences
  98         if (!registry.isPeerConfigured(getRemoteIp())) {
  99             final BGPDocumentedException cause = new BGPDocumentedException(
 100                     "BGP peer with ip: " + getRemoteIp()
 101                             + " not configured, check configured peers in : "
 102                             + registry, BGPError.CEASE);
 103             negotiationFailed(cause);
 104             return;
 105         }
 106
 107         final BGPSessionPreferences preferences = getPreferences();
 108
 109         int as = preferences.getMyAs().getValue().intValue();
 110         // Set as AS_TRANS if the value is bigger than 2B
 111         if (as > Values.UNSIGNED_SHORT_MAX_VALUE) {
 112             as = AS_TRANS;
 113         }
 114         this.sendMessage(new OpenBuilder().setMyAsNumber(as).setHoldTimer(preferences.getHoldTime()).setBgpIdentifier(
 115                 preferences.getBgpId()).setBgpParameters(preferences.getParams()).build());
 116         this.state = State.OpenSent;
 117
 118         final Object lock = this;
 119         this.timer.newTimeout(new TimerTask() {
 120             @Override
 121             public void run(final Timeout timeout) {
 122                 synchronized (lock) {
 123                     if (AbstractBGPSessionNegotiator.this.state != State.Finished) {
 124                         AbstractBGPSessionNegotiator.this.sendMessage(buildErrorNotify(BGPError.HOLD_TIMER_EXPIRED));
 125                         negotiationFailed(new BGPDocumentedException("HoldTimer expired", BGPError.FSM_ERROR));
 126                         AbstractBGPSessionNegotiator.this.state = State.Finished;
 127                     }
 128                 }
 129             }
 130         }, INITIAL_HOLDTIMER, TimeUnit.MINUTES);
 131     }
 132
 133     private BGPSessionPreferences getPreferences() {
 134         return registry.getPeerPreferences(getRemoteIp());
 135     }
 136
 137     private IpAddress getRemoteIp() {
 138         return StrictBGPPeerRegistry.getIpAddress(channel.remoteAddress());
 139     }
 140
 141     @Override
 142     protected synchronized void handleMessage(final Notification msg) {
 143         LOG.debug("Channel {} handling message in state {}", this.channel, this.state);
 144
 145         switch (this.state) {
 146         case Finished:
 147         case Idle:
 148             this.sendMessage(buildErrorNotify(BGPError.FSM_ERROR));
 149             return;
 150         case OpenConfirm:
 151             if (msg instanceof Keepalive) {
 152                 negotiationSuccessful(this.session);
 153                 LOG.info("BGP Session with peer {} established successfully.", this.channel);
 154             } else if (msg instanceof Notify) {
 155                 final Notify ntf = (Notify) msg;
 156                 negotiationFailed(new BGPDocumentedException("Peer refusal", BGPError.forValue(ntf.getErrorCode(), ntf.getErrorSubcode())));
 157             }
 158             this.state = State.Finished;
 159             return;
 160         case OpenSent:
 161             if (msg instanceof Open) {
 162                 final Open openObj = (Open) msg;
 163                 handleOpen(openObj);
 164                 return;
 165             }
 166             break;
 167         }
 168
 169         // Catch-all for unexpected message
 170         LOG.warn("Channel {} state {} unexpected message {}", this.channel, this.state, msg);
 171         this.sendMessage(buildErrorNotify(BGPError.FSM_ERROR));
 172         negotiationFailed(new BGPDocumentedException("Unexpected message", BGPError.FSM_ERROR));
 173         this.state = State.Finished;
 174     }
 175
 176     private static Notify buildErrorNotify(final BGPError err) {
 177         return new NotifyBuilder().setErrorCode(err.getCode()).setErrorSubcode(err.getSubcode()).build();
 178     }
 179
 180     private void handleOpen(final Open openObj) {
 181         try {
 182             sessionValidator.validate(openObj, getPreferences());
 183         } catch (final BGPDocumentedException e) {
 184             negotiationFailed(e);
 185             return;
 186         }
 187
 188         try {
 189             final BGPSessionListener peer = registry.getPeer(getRemoteIp(), getSourceId(openObj, getPreferences()), getDestinationId(openObj, getPreferences()));
 190             this.sendMessage(new KeepaliveBuilder().build());
 191             this.session = new BGPSessionImpl(this.timer, peer, this.channel, openObj, getPreferences().getHoldTime());
 192             this.state = State.OpenConfirm;
 193             LOG.debug("Channel {} moved to OpenConfirm state with remote proposal {}", this.channel, openObj);
 194         } catch (final BGPDocumentedException e) {
 195             LOG.warn("Channel {} negotiation failed", this.channel, e);
 196             negotiationFailed(e);
 197         }
 198     }
 199
 200     private void negotiationFailed(final BGPDocumentedException e) {
 201         LOG.warn("Channel {} negotiation failed: {}", this.channel, e.getMessage());
 202         this.sendMessage(buildErrorNotify(e.getError()));
 203         super.negotiationFailed(e);
 204         this.state = State.Finished;
 205     }
 206
 207     /**
 208      * @return BGP Id of device that accepted the connection
 209      */
 210     protected abstract Ipv4Address getDestinationId(final Open openMsg, final BGPSessionPreferences preferences);
 211
 212     /**
 213      * @return BGP Id of device that initiated the connection
 214      */
 215     protected abstract Ipv4Address getSourceId(final Open openMsg, final BGPSessionPreferences preferences);
 216
 217     public synchronized State getState() {
 218         return this.state;
 219     }
 220 }