bgp/rib-impl/src/main/java/org/opendaylight/protocol/bgp/rib/impl/BGPSessionNegotiator.java

   1 /*
   2  * Copyright (c) 2013 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 package org.opendaylight.protocol.bgp.rib.impl;
   9
  10 import io.netty.channel.Channel;
  11 import io.netty.util.Timeout;
  12 import io.netty.util.Timer;
  13 import io.netty.util.TimerTask;
  14 import io.netty.util.concurrent.Promise;
  15
  16 import java.util.List;
  17 import java.util.concurrent.TimeUnit;
  18
  19 import javax.annotation.concurrent.GuardedBy;
  20
  21 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
  22 import org.opendaylight.protocol.bgp.parser.BGPError;
  23 import org.opendaylight.protocol.bgp.parser.BGPSessionListener;
  24 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionPreferences;
  25 import org.opendaylight.protocol.framework.AbstractSessionNegotiator;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Keepalive;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.KeepaliveBuilder;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Notify;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.NotifyBuilder;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Open;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.OpenBuilder;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.BgpParameters;
  33 import org.opendaylight.yangtools.yang.binding.Notification;
  34 import org.slf4j.Logger;
  35 import org.slf4j.LoggerFactory;
  36
  37 import com.google.common.annotations.VisibleForTesting;
  38 import com.google.common.base.Preconditions;
  39
  40 public final class BGPSessionNegotiator extends AbstractSessionNegotiator<Notification, BGPSessionImpl> {
  41         // 4 minutes recommended in http://tools.ietf.org/html/rfc4271#section-8.2.2
  42         protected static final int INITIAL_HOLDTIMER = 4;
  43
  44         @VisibleForTesting
  45         public enum State {
  46                 /**
  47                  * Negotiation has not started yet.
  48                  */
  49                 Idle,
  50                 /**
  51                  * We have sent our Open message, and are waiting for the peer's Open message.
  52                  */
  53                 OpenSent,
  54                 /**
  55                  * We have received the peer's Open message, which is acceptable, and we're waiting the acknowledgement of our
  56                  * Open message.
  57                  */
  58                 OpenConfirm,
  59                 /**
  60                  * The negotiation finished.
  61                  */
  62                 Finished,
  63         }
  64
  65         private static final Logger LOG = LoggerFactory.getLogger(BGPSessionNegotiator.class);
  66         private final BGPSessionListener listener;
  67         private final Timer timer;
  68         private final BGPSessionPreferences localPref;
  69
  70         @GuardedBy("this")
  71         private Open remotePref;
  72
  73         @GuardedBy("this")
  74         private State state = State.Idle;
  75
  76         @GuardedBy("this")
  77         private BGPSessionImpl session;
  78
  79         public BGPSessionNegotiator(final Timer timer, final Promise<BGPSessionImpl> promise, final Channel channel,
  80                         final BGPSessionPreferences initialPrefs, final BGPSessionListener listener) {
  81                 super(promise, channel);
  82                 this.listener = Preconditions.checkNotNull(listener);
  83                 this.localPref = Preconditions.checkNotNull(initialPrefs);
  84                 this.timer = Preconditions.checkNotNull(timer);
  85         }
  86
  87         @Override
  88         protected void startNegotiation() {
  89                 Preconditions.checkState(this.state == State.Idle);
  90                 this.sendMessage(new OpenBuilder().setMyAsNumber(this.localPref.getMyAs().getValue().intValue()).setHoldTimer(
  91                                 this.localPref.getHoldTime()).setBgpIdentifier(this.localPref.getBgpId()).setBgpParameters(this.localPref.getParams()).build());
  92                 this.state = State.OpenSent;
  93
  94                 final Object lock = this;
  95                 this.timer.newTimeout(new TimerTask() {
  96                         @Override
  97                         public void run(final Timeout timeout) throws Exception {
  98                                 synchronized (lock) {
  99                                         if (BGPSessionNegotiator.this.state != State.Finished) {
 100                                                 BGPSessionNegotiator.this.sendMessage(new NotifyBuilder().setErrorCode(BGPError.HOLD_TIMER_EXPIRED.getCode()).setErrorSubcode(
 101                                                                 BGPError.HOLD_TIMER_EXPIRED.getSubcode()).build());
 102                                                 negotiationFailed(new BGPDocumentedException("HoldTimer expired", BGPError.FSM_ERROR));
 103                                                 BGPSessionNegotiator.this.state = State.Finished;
 104                                         }
 105                                 }
 106                         }
 107                 }, INITIAL_HOLDTIMER, TimeUnit.MINUTES);
 108         }
 109
 110         @Override
 111         protected synchronized void handleMessage(final Notification msg) {
 112                 LOG.debug("Channel {} handling message in state {}", this.channel, this.state);
 113
 114                 switch (this.state) {
 115                 case Finished:
 116                 case Idle:
 117                         final Notify fsmError = new NotifyBuilder().setErrorCode(BGPError.FSM_ERROR.getCode()).setErrorSubcode(
 118                                         BGPError.FSM_ERROR.getSubcode()).build();
 119                         this.sendMessage(fsmError);
 120                 case OpenConfirm:
 121                         if (msg instanceof Keepalive) {
 122                                 negotiationSuccessful(this.session);
 123                         } else if (msg instanceof Notify) {
 124                                 final Notify ntf = (Notify) msg;
 125                                 negotiationFailed(new BGPDocumentedException("Peer refusal", BGPError.forValue(ntf.getErrorCode(), ntf.getErrorSubcode())));
 126                         }
 127                         this.state = State.Finished;
 128                         return;
 129                 case OpenSent:
 130                         if (msg instanceof Open) {
 131                                 final Open openObj = (Open) msg;
 132                                 handleOpen(openObj);
 133                                 return;
 134                         }
 135                         break;
 136                 }
 137
 138                 // Catch-all for unexpected message
 139                 LOG.warn("Channel {} state {} unexpected message {}", this.channel, this.state, msg);
 140                 this.sendMessage(new NotifyBuilder().setErrorCode(BGPError.FSM_ERROR.getCode()).setErrorSubcode(BGPError.FSM_ERROR.getSubcode()).build());
 141                 negotiationFailed(new BGPDocumentedException("Unexpected message", BGPError.FSM_ERROR));
 142                 this.state = State.Finished;
 143         }
 144
 145         private void handleOpen(final Open openObj) {
 146                 final List<BgpParameters> prefs = openObj.getBgpParameters();
 147                 if (prefs != null && !prefs.isEmpty()) {
 148                         if (!prefs.containsAll(this.localPref.getParams())) {
 149                                 LOG.info("Open message unacceptable. Check the configuration of BGP speaker.");
 150                         }
 151                         this.remotePref = openObj;
 152                         this.sendMessage(new KeepaliveBuilder().build());
 153                         this.session = new BGPSessionImpl(this.timer, this.listener, this.channel, this.remotePref);
 154                         this.state = State.OpenConfirm;
 155                         LOG.debug("Channel {} moved to OpenConfirm state with remote proposal {}", this.channel, this.remotePref);
 156                         return;
 157                 }
 158                 final Notify ntf = new NotifyBuilder().setErrorCode(BGPError.UNSPECIFIC_OPEN_ERROR.getCode()).setErrorSubcode(
 159                                 BGPError.UNSPECIFIC_OPEN_ERROR.getSubcode()).build();
 160                 this.sendMessage(ntf);
 161                 negotiationFailed(new BGPDocumentedException("Open message unacceptable. Check the configuration of BGP speaker.", BGPError.forValue(
 162                                 ntf.getErrorCode(), ntf.getErrorSubcode())));
 163                 this.state = State.Finished;
 164         }
 165
 166         public synchronized State getState() {
 167                 return this.state;
 168         }
 169 }