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