bgp/rib-impl/src/main/java/org/opendaylight/protocol/bgp/rib/impl/BGPSessionImpl.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
  15 import java.io.IOException;
  16 import java.util.Date;
  17 import java.util.Set;
  18 import java.util.concurrent.TimeUnit;
  19
  20 import javax.annotation.concurrent.GuardedBy;
  21
  22 import org.opendaylight.protocol.bgp.parser.BGPError;
  23 import org.opendaylight.protocol.bgp.parser.BGPSession;
  24 import org.opendaylight.protocol.bgp.parser.BGPSessionListener;
  25 import org.opendaylight.protocol.bgp.parser.BGPTerminationReason;
  26 import org.opendaylight.protocol.bgp.parser.BgpTableTypeImpl;
  27 import org.opendaylight.protocol.framework.AbstractProtocolSession;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Keepalive;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.KeepaliveBuilder;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Notify;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.NotifyBuilder;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Open;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.BgpParameters;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.bgp.parameters.CParameters;
  35 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.BgpTableType;
  36 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.MultiprotocolCase;
  37 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev130925.rib.TablesKey;
  38 import org.opendaylight.yangtools.yang.binding.Notification;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41
  42 import com.google.common.annotations.VisibleForTesting;
  43 import com.google.common.base.Objects;
  44 import com.google.common.base.Objects.ToStringHelper;
  45 import com.google.common.base.Preconditions;
  46 import com.google.common.collect.Sets;
  47
  48 @VisibleForTesting
  49 public class BGPSessionImpl extends AbstractProtocolSession<Notification> implements BGPSession {
  50
  51         private static final Logger logger = LoggerFactory.getLogger(BGPSessionImpl.class);
  52
  53         /*
  54          * 240
  55          */
  56         private static final int DEFAULT_HOLD_TIMER_VALUE = 15;
  57
  58         private static final Notification keepalive = new KeepaliveBuilder().build();
  59
  60         private static int holdTimerValue = DEFAULT_HOLD_TIMER_VALUE;
  61
  62         /**
  63          * Internal session state.
  64          */
  65         public enum State {
  66                 /**
  67                  * The session object is created by the negotiator in OpenConfirm state. While in this state, the session object
  68                  * is half-alive, e.g. the timers are running, but the session is not completely up, e.g. it has not been
  69                  * announced to the listener. If the session is torn down in this state, we do not inform the listener.
  70                  */
  71                 OpenConfirm,
  72                 /**
  73                  * The session has been completely established.
  74                  */
  75                 Up,
  76                 /**
  77                  * The session has been closed. It will not be resurrected.
  78                  */
  79                 Idle,
  80         }
  81
  82         /**
  83          * System.nanoTime value about when was sent the last message Protected to be updated also in tests.
  84          */
  85         @VisibleForTesting
  86         protected long lastMessageSentAt;
  87
  88         /**
  89          * System.nanoTime value about when was received the last message
  90          */
  91         private long lastMessageReceivedAt;
  92
  93         private final BGPSessionListener listener;
  94
  95         /**
  96          * Timer object grouping FSM Timers
  97          */
  98         private final Timer stateTimer;
  99
 100         private final BGPSynchronization sync;
 101
 102         private int kaCounter = 0;
 103
 104         private final Channel channel;
 105
 106         @GuardedBy("this")
 107         private State state = State.OpenConfirm;
 108
 109         private final int keepAlive;
 110
 111         private final Set<BgpTableType> tableTypes;
 112
 113         BGPSessionImpl(final Timer timer, final BGPSessionListener listener, final Channel channel, final Open remoteOpen) {
 114                 this.listener = Preconditions.checkNotNull(listener);
 115                 this.stateTimer = Preconditions.checkNotNull(timer);
 116                 this.channel = Preconditions.checkNotNull(channel);
 117                 this.keepAlive = remoteOpen.getHoldTimer() / 3;
 118                 holdTimerValue = remoteOpen.getHoldTimer();
 119
 120                 final Set<TablesKey> tts = Sets.newHashSet();
 121                 final Set<BgpTableType> tats = Sets.newHashSet();
 122                 if (remoteOpen.getBgpParameters() != null) {
 123                         for (final BgpParameters param : remoteOpen.getBgpParameters()) {
 124                                 if (param instanceof CParameters) {
 125                                         final CParameters cp = (CParameters) param;
 126                                         final TablesKey tt = new TablesKey(((MultiprotocolCase) cp).getMultiprotocolCapability().getAfi(), ((MultiprotocolCase) cp).getMultiprotocolCapability().getSafi());
 127                                         tts.add(tt);
 128                                         tats.add(new BgpTableTypeImpl(tt.getAfi(), tt.getSafi()));
 129                                 }
 130                         }
 131                 }
 132
 133                 this.sync = new BGPSynchronization(this, this.listener, tts);
 134                 this.tableTypes = tats;
 135
 136                 if (remoteOpen.getHoldTimer() != 0) {
 137                         this.stateTimer.newTimeout(new TimerTask() {
 138
 139                                 @Override
 140                                 public void run(final Timeout timeout) throws Exception {
 141                                         handleHoldTimer();
 142                                 }
 143                         }, remoteOpen.getHoldTimer(), TimeUnit.SECONDS);
 144
 145                         this.stateTimer.newTimeout(new TimerTask() {
 146                                 @Override
 147                                 public void run(final Timeout timeout) throws Exception {
 148                                         handleKeepaliveTimer();
 149                                 }
 150                         }, this.keepAlive, TimeUnit.SECONDS);
 151                 }
 152         }
 153
 154         @Override
 155         public synchronized void close() {
 156                 logger.debug("Closing session: {}", this);
 157                 if (this.state != State.Idle) {
 158                         this.sendMessage(new NotifyBuilder().setErrorCode(BGPError.CEASE.getCode()).build());
 159                         this.channel.close();
 160                         this.state = State.Idle;
 161                 }
 162         }
 163
 164         /**
 165          * Handles incoming message based on their type.
 166          *
 167          * @param msg incoming message
 168          */
 169         @Override
 170         public void handleMessage(final Notification msg) {
 171                 // Update last reception time
 172                 this.lastMessageReceivedAt = System.nanoTime();
 173
 174                 if (msg instanceof Open) {
 175                         // Open messages should not be present here
 176                         this.terminate(BGPError.FSM_ERROR);
 177                 } else if (msg instanceof Notify) {
 178                         // Notifications are handled internally
 179                         logger.info("Session closed because Notification message received: {} / {}", ((Notify) msg).getErrorCode(),
 180                                         ((Notify) msg).getErrorSubcode());
 181                         this.closeWithoutMessage();
 182                         this.listener.onSessionTerminated(this,
 183                                         new BGPTerminationReason(BGPError.forValue(((Notify) msg).getErrorCode(), ((Notify) msg).getErrorSubcode())));
 184                 } else if (msg instanceof Keepalive) {
 185                         // Keepalives are handled internally
 186                         logger.debug("Received KeepAlive messsage.");
 187                         this.kaCounter++;
 188                         if (this.kaCounter >= 2) {
 189                                 this.sync.kaReceived();
 190                         }
 191                 } else {
 192                         // All others are passed up
 193                         this.listener.onMessage(this, msg);
 194                 }
 195         }
 196
 197         @Override
 198         public synchronized void endOfInput() {
 199                 if (this.state == State.Up) {
 200                         this.listener.onSessionDown(this, new IOException("End of input detected. Close the session."));
 201                 }
 202         }
 203
 204         void sendMessage(final Notification msg) {
 205                 try {
 206                         this.channel.writeAndFlush(msg);
 207                         this.lastMessageSentAt = System.nanoTime();
 208                         logger.debug("Sent message: {}", msg);
 209                 } catch (final Exception e) {
 210                         logger.warn("Message {} was not sent.", msg, e);
 211                 }
 212         }
 213
 214         private synchronized void closeWithoutMessage() {
 215                 logger.debug("Closing session: {}", this);
 216                 this.channel.close();
 217                 this.state = State.Idle;
 218         }
 219
 220         /**
 221          * Closes PCEP session from the parent with given reason. A message needs to be sent, but parent doesn't have to be
 222          * modified, because he initiated the closing. (To prevent concurrent modification exception).
 223          *
 224          * @param closeObject
 225          */
 226         private void terminate(final BGPError error) {
 227                 this.sendMessage(new NotifyBuilder().setErrorCode(error.getCode()).setErrorSubcode(error.getSubcode()).build());
 228                 this.closeWithoutMessage();
 229
 230                 this.listener.onSessionTerminated(this, new BGPTerminationReason(error));
 231         }
 232
 233         /**
 234          * If HoldTimer expires, the session ends. If a message (whichever) was received during this period, the HoldTimer
 235          * will be rescheduled by HOLD_TIMER_VALUE + the time that has passed from the start of the HoldTimer to the time at
 236          * which the message was received. If the session was closed by the time this method starts to execute (the session
 237          * state will become IDLE), then rescheduling won't occur.
 238          */
 239         private synchronized void handleHoldTimer() {
 240                 if (this.state == State.Idle) {
 241                         return;
 242                 }
 243
 244                 final long ct = System.nanoTime();
 245                 final long nextHold = this.lastMessageReceivedAt + TimeUnit.SECONDS.toNanos(holdTimerValue);
 246
 247                 if (ct >= nextHold) {
 248                         logger.debug("HoldTimer expired. " + new Date());
 249                         this.terminate(BGPError.HOLD_TIMER_EXPIRED);
 250                 } else {
 251                         this.stateTimer.newTimeout(new TimerTask() {
 252                                 @Override
 253                                 public void run(final Timeout timeout) throws Exception {
 254                                         handleHoldTimer();
 255                                 }
 256                         }, nextHold - ct, TimeUnit.NANOSECONDS);
 257                 }
 258         }
 259
 260         /**
 261          * If KeepAlive Timer expires, sends KeepAlive message. If a message (whichever) was send during this period, the
 262          * KeepAlive Timer will be rescheduled by KEEP_ALIVE_TIMER_VALUE + the time that has passed from the start of the
 263          * KeepAlive timer to the time at which the message was sent. If the session was closed by the time this method
 264          * starts to execute (the session state will become IDLE), that rescheduling won't occur.
 265          */
 266         private synchronized void handleKeepaliveTimer() {
 267                 if (this.state == State.Idle) {
 268                         return;
 269                 }
 270
 271                 final long ct = System.nanoTime();
 272                 long nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 273
 274                 if (ct >= nextKeepalive) {
 275                         this.sendMessage(keepalive);
 276                         nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 277                 }
 278                 this.stateTimer.newTimeout(new TimerTask() {
 279                         @Override
 280                         public void run(final Timeout timeout) throws Exception {
 281                                 handleKeepaliveTimer();
 282                         }
 283                 }, nextKeepalive - ct, TimeUnit.NANOSECONDS);
 284         }
 285
 286         @Override
 287         public final String toString() {
 288                 return addToStringAttributes(Objects.toStringHelper(this)).toString();
 289         }
 290
 291         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 292                 toStringHelper.add("channel", this.channel);
 293                 toStringHelper.add("state", this.state);
 294                 return toStringHelper;
 295         }
 296
 297         @Override
 298         public Set<BgpTableType> getAdvertisedTableTypes() {
 299                 return this.tableTypes;
 300         }
 301
 302         @Override
 303         protected synchronized void sessionUp() {
 304                 this.state = State.Up;
 305                 this.listener.onSessionUp(this);
 306         }
 307
 308         public synchronized State getState() {
 309                 return this.state;
 310         }
 311 }