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.concepts.BGPTableType;
  23 import org.opendaylight.protocol.bgp.parser.BGPError;
  24 import org.opendaylight.protocol.bgp.parser.BGPParameter;
  25 import org.opendaylight.protocol.bgp.parser.BGPSession;
  26 import org.opendaylight.protocol.bgp.parser.BGPSessionListener;
  27 import org.opendaylight.protocol.bgp.parser.BGPTerminationReason;
  28 import org.opendaylight.protocol.bgp.parser.message.BGPNotificationMessage;
  29 import org.opendaylight.protocol.bgp.parser.message.BGPOpenMessage;
  30 import org.opendaylight.protocol.bgp.parser.parameter.MultiprotocolCapability;
  31 import org.opendaylight.protocol.framework.AbstractProtocolSession;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.Keepalive;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.KeepaliveBuilder;
  34 import org.opendaylight.yangtools.yang.binding.Notification;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37
  38 import com.google.common.annotations.VisibleForTesting;
  39 import com.google.common.base.Objects;
  40 import com.google.common.base.Objects.ToStringHelper;
  41 import com.google.common.base.Preconditions;
  42 import com.google.common.collect.Sets;
  43
  44 @VisibleForTesting
  45 public class BGPSessionImpl extends AbstractProtocolSession<Notification> implements BGPSession {
  46
  47         private static final Logger logger = LoggerFactory.getLogger(BGPSessionImpl.class);
  48
  49         private static final int DEFAULT_HOLD_TIMER_VALUE = 15;
  50
  51         private static final Notification keepalive = new KeepaliveBuilder().build();
  52
  53         public static int HOLD_TIMER_VALUE = DEFAULT_HOLD_TIMER_VALUE; // 240
  54
  55         /**
  56          * Internal session state.
  57          */
  58         public enum State {
  59                 /**
  60                  * The session object is created by the negotiator in OpenConfirm state. While in this state, the session object
  61                  * is half-alive, e.g. the timers are running, but the session is not completely up, e.g. it has not been
  62                  * announced to the listener. If the session is torn down in this state, we do not inform the listener.
  63                  */
  64                 OpenConfirm,
  65                 /**
  66                  * The session has been completely established.
  67                  */
  68                 Up,
  69                 /**
  70                  * The session has been closed. It will not be resurrected.
  71                  */
  72                 Idle,
  73         }
  74
  75         /**
  76          * System.nanoTime value about when was sent the last message Protected to be updated also in tests.
  77          */
  78         protected long lastMessageSentAt;
  79
  80         /**
  81          * System.nanoTime value about when was received the last message
  82          */
  83         private long lastMessageReceivedAt;
  84
  85         private final BGPSessionListener listener;
  86
  87         /**
  88          * Timer object grouping FSM Timers
  89          */
  90         private final Timer stateTimer;
  91
  92         private final BGPSynchronization sync;
  93
  94         private int kaCounter = 0;
  95
  96         private final Channel channel;
  97
  98         @GuardedBy("this")
  99         private State state = State.OpenConfirm;
 100
 101         private final int keepAlive;
 102
 103         private final Set<BGPTableType> tableTypes;
 104
 105         BGPSessionImpl(final Timer timer, final BGPSessionListener listener, final Channel channel, final BGPOpenMessage remoteOpen) {
 106                 this.listener = Preconditions.checkNotNull(listener);
 107                 this.stateTimer = Preconditions.checkNotNull(timer);
 108                 this.channel = Preconditions.checkNotNull(channel);
 109                 this.keepAlive = remoteOpen.getHoldTime() / 3;
 110
 111                 final Set<BGPTableType> tts = Sets.newHashSet();
 112                 if (remoteOpen.getOptParams() != null) {
 113                         for (final BGPParameter param : remoteOpen.getOptParams()) {
 114                                 if (param instanceof MultiprotocolCapability) {
 115                                         tts.add(((MultiprotocolCapability) param).getTableType());
 116                                 }
 117                         }
 118                 }
 119
 120                 this.sync = new BGPSynchronization(this, this.listener, tts);
 121                 this.tableTypes = tts;
 122
 123                 if (remoteOpen.getHoldTime() != 0) {
 124                         this.stateTimer.newTimeout(new TimerTask() {
 125
 126                                 @Override
 127                                 public void run(final Timeout timeout) throws Exception {
 128                                         handleHoldTimer();
 129                                 }
 130                         }, remoteOpen.getHoldTime(), TimeUnit.SECONDS);
 131
 132                         this.stateTimer.newTimeout(new TimerTask() {
 133                                 @Override
 134                                 public void run(final Timeout timeout) throws Exception {
 135                                         handleKeepaliveTimer();
 136                                 }
 137                         }, this.keepAlive, TimeUnit.SECONDS);
 138                 }
 139         }
 140
 141         @Override
 142         public synchronized void close() {
 143                 logger.debug("Closing session: {}", this);
 144                 if (this.state != State.Idle) {
 145                         this.sendMessage(new BGPNotificationMessage(BGPError.CEASE));
 146                         this.channel.close();
 147                         this.state = State.Idle;
 148                 }
 149         }
 150
 151         /**
 152          * Handles incoming message based on their type.
 153          *
 154          * @param msg incoming message
 155          */
 156         @Override
 157         public void handleMessage(final Notification msg) {
 158                 // Update last reception time
 159                 this.lastMessageReceivedAt = System.nanoTime();
 160
 161                 if (msg instanceof BGPOpenMessage) {
 162                         // Open messages should not be present here
 163                         this.terminate(BGPError.FSM_ERROR);
 164                 } else if (msg instanceof BGPNotificationMessage) {
 165                         // Notifications are handled internally
 166                         logger.info("Session closed because Notification message received: {}", ((BGPNotificationMessage) msg).getError());
 167                         this.closeWithoutMessage();
 168                         this.listener.onSessionTerminated(this, new BGPTerminationReason(((BGPNotificationMessage) msg).getError()));
 169                 } else if (msg instanceof Keepalive) {
 170                         // Keepalives are handled internally
 171                         logger.debug("Received KeepAlive messsage.");
 172                         this.kaCounter++;
 173                         if (this.kaCounter >= 2) {
 174                                 this.sync.kaReceived();
 175                         }
 176                 } else {
 177                         // All others are passed up
 178                         this.listener.onMessage(this, msg);
 179                 }
 180         }
 181
 182         @Override
 183         public synchronized void endOfInput() {
 184                 if (this.state == State.Up) {
 185                         this.listener.onSessionDown(this, new IOException("End of input detected. Close the session."));
 186                 }
 187         }
 188
 189         void sendMessage(final Notification msg) {
 190                 try {
 191                         this.channel.writeAndFlush(msg);
 192                         this.lastMessageSentAt = System.nanoTime();
 193                         logger.debug("Sent message: {}", msg);
 194                 } catch (final Exception e) {
 195                         logger.warn("Message {} was not sent.", msg, e);
 196                 }
 197         }
 198
 199         private synchronized void closeWithoutMessage() {
 200                 logger.debug("Closing session: {}", this);
 201                 this.channel.close();
 202                 this.state = State.Idle;
 203         }
 204
 205         /**
 206          * Closes PCEP session from the parent with given reason. A message needs to be sent, but parent doesn't have to be
 207          * modified, because he initiated the closing. (To prevent concurrent modification exception).
 208          *
 209          * @param closeObject
 210          */
 211         private void terminate(final BGPError error) {
 212                 this.sendMessage(new BGPNotificationMessage(error));
 213                 this.closeWithoutMessage();
 214
 215                 this.listener.onSessionTerminated(this, new BGPTerminationReason(error));
 216         }
 217
 218         /**
 219          * If HoldTimer expires, the session ends. If a message (whichever) was received during this period, the HoldTimer
 220          * will be rescheduled by HOLD_TIMER_VALUE + the time that has passed from the start of the HoldTimer to the time at
 221          * which the message was received. If the session was closed by the time this method starts to execute (the session
 222          * state will become IDLE), then rescheduling won't occur.
 223          */
 224         private synchronized void handleHoldTimer() {
 225                 if (this.state == State.Idle) {
 226                         return;
 227                 }
 228
 229                 final long ct = System.nanoTime();
 230                 final long nextHold = this.lastMessageReceivedAt + TimeUnit.SECONDS.toNanos(HOLD_TIMER_VALUE);
 231
 232                 if (ct >= nextHold) {
 233                         logger.debug("HoldTimer expired. " + new Date());
 234                         this.terminate(BGPError.HOLD_TIMER_EXPIRED);
 235                 } else {
 236                         this.stateTimer.newTimeout(new TimerTask() {
 237                                 @Override
 238                                 public void run(final Timeout timeout) throws Exception {
 239                                         handleHoldTimer();
 240                                 }
 241                         }, nextHold - ct, TimeUnit.NANOSECONDS);
 242                 }
 243         }
 244
 245         /**
 246          * If KeepAlive Timer expires, sends KeepAlive message. If a message (whichever) was send during this period, the
 247          * KeepAlive Timer will be rescheduled by KEEP_ALIVE_TIMER_VALUE + the time that has passed from the start of the
 248          * KeepAlive timer to the time at which the message was sent. If the session was closed by the time this method
 249          * starts to execute (the session state will become IDLE), that rescheduling won't occur.
 250          */
 251         private synchronized void handleKeepaliveTimer() {
 252                 if (this.state == State.Idle) {
 253                         return;
 254                 }
 255
 256                 final long ct = System.nanoTime();
 257                 long nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 258
 259                 if (ct >= nextKeepalive) {
 260                         this.sendMessage(keepalive);
 261                         nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 262                 }
 263                 this.stateTimer.newTimeout(new TimerTask() {
 264                         @Override
 265                         public void run(final Timeout timeout) throws Exception {
 266                                 handleKeepaliveTimer();
 267                         }
 268                 }, nextKeepalive - ct, TimeUnit.NANOSECONDS);
 269         }
 270
 271         @Override
 272         final public String toString() {
 273                 return addToStringAttributes(Objects.toStringHelper(this)).toString();
 274         }
 275
 276         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 277                 toStringHelper.add("channel", this.channel);
 278                 toStringHelper.add("state", this.state);
 279                 return toStringHelper;
 280         }
 281
 282         @Override
 283         public Set<BGPTableType> getAdvertisedTableTypes() {
 284                 return this.tableTypes;
 285         }
 286
 287         @Override
 288         protected synchronized void sessionUp() {
 289                 this.state = State.Up;
 290                 this.listener.onSessionUp(this);
 291         }
 292
 293         public synchronized State getState() {
 294                 return this.state;
 295         }
 296 }