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