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.BGPParameter;
  24 import org.opendaylight.protocol.bgp.parser.BGPSession;
  25 import org.opendaylight.protocol.bgp.parser.BGPSessionListener;
  26 import org.opendaylight.protocol.bgp.parser.BGPTableType;
  27 import org.opendaylight.protocol.bgp.parser.BGPTerminationReason;
  28 import org.opendaylight.protocol.bgp.parser.message.BGPOpenMessage;
  29 import org.opendaylight.protocol.bgp.parser.parameter.MultiprotocolCapability;
  30 import org.opendaylight.protocol.framework.AbstractProtocolSession;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.Keepalive;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.KeepaliveBuilder;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.Notify;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.NotifyBuilder;
  35 import org.opendaylight.yangtools.yang.binding.Notification;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38
  39 import com.google.common.annotations.VisibleForTesting;
  40 import com.google.common.base.Objects;
  41 import com.google.common.base.Objects.ToStringHelper;
  42 import com.google.common.base.Preconditions;
  43 import com.google.common.collect.Sets;
  44
  45 @VisibleForTesting
  46 public class BGPSessionImpl extends AbstractProtocolSession<Notification> implements BGPSession {
  47
  48         private static final Logger logger = LoggerFactory.getLogger(BGPSessionImpl.class);
  49
  50         private static final int DEFAULT_HOLD_TIMER_VALUE = 15;
  51
  52         private static final Notification keepalive = new KeepaliveBuilder().build();
  53
  54         public static int HOLD_TIMER_VALUE = DEFAULT_HOLD_TIMER_VALUE; // 240
  55
  56         /**
  57          * Internal session state.
  58          */
  59         public enum State {
  60                 /**
  61                  * The session object is created by the negotiator in OpenConfirm state. While in this state, the session object
  62                  * is half-alive, e.g. the timers are running, but the session is not completely up, e.g. it has not been
  63                  * announced to the listener. If the session is torn down in this state, we do not inform the listener.
  64                  */
  65                 OpenConfirm,
  66                 /**
  67                  * The session has been completely established.
  68                  */
  69                 Up,
  70                 /**
  71                  * The session has been closed. It will not be resurrected.
  72                  */
  73                 Idle,
  74         }
  75
  76         /**
  77          * System.nanoTime value about when was sent the last message Protected to be updated also in tests.
  78          */
  79         protected long lastMessageSentAt;
  80
  81         /**
  82          * System.nanoTime value about when was received the last message
  83          */
  84         private long lastMessageReceivedAt;
  85
  86         private final BGPSessionListener listener;
  87
  88         /**
  89          * Timer object grouping FSM Timers
  90          */
  91         private final Timer stateTimer;
  92
  93         private final BGPSynchronization sync;
  94
  95         private int kaCounter = 0;
  96
  97         private final Channel channel;
  98
  99         @GuardedBy("this")
 100         private State state = State.OpenConfirm;
 101
 102         private final int keepAlive;
 103
 104         private final Set<BGPTableType> tableTypes;
 105
 106         BGPSessionImpl(final Timer timer, final BGPSessionListener listener, final Channel channel, final BGPOpenMessage remoteOpen) {
 107                 this.listener = Preconditions.checkNotNull(listener);
 108                 this.stateTimer = Preconditions.checkNotNull(timer);
 109                 this.channel = Preconditions.checkNotNull(channel);
 110                 this.keepAlive = remoteOpen.getHoldTime() / 3;
 111
 112                 final Set<BGPTableType> tts = Sets.newHashSet();
 113                 if (remoteOpen.getOptParams() != null) {
 114                         for (final BGPParameter param : remoteOpen.getOptParams()) {
 115                                 if (param instanceof MultiprotocolCapability) {
 116                                         tts.add(((MultiprotocolCapability) param).getTableType());
 117                                 }
 118                         }
 119                 }
 120
 121                 this.sync = new BGPSynchronization(this, this.listener, tts);
 122                 this.tableTypes = tts;
 123
 124                 if (remoteOpen.getHoldTime() != 0) {
 125                         this.stateTimer.newTimeout(new TimerTask() {
 126
 127                                 @Override
 128                                 public void run(final Timeout timeout) throws Exception {
 129                                         handleHoldTimer();
 130                                 }
 131                         }, remoteOpen.getHoldTime(), TimeUnit.SECONDS);
 132
 133                         this.stateTimer.newTimeout(new TimerTask() {
 134                                 @Override
 135                                 public void run(final Timeout timeout) throws Exception {
 136                                         handleKeepaliveTimer();
 137                                 }
 138                         }, this.keepAlive, TimeUnit.SECONDS);
 139                 }
 140         }
 141
 142         @Override
 143         public synchronized void close() {
 144                 logger.debug("Closing session: {}", this);
 145                 if (this.state != State.Idle) {
 146                         this.sendMessage(new NotifyBuilder().setErrorCode(BGPError.CEASE.getCode()).build());
 147                         this.channel.close();
 148                         this.state = State.Idle;
 149                 }
 150         }
 151
 152         /**
 153          * Handles incoming message based on their type.
 154          *
 155          * @param msg incoming message
 156          */
 157         @Override
 158         public void handleMessage(final Notification msg) {
 159                 // Update last reception time
 160                 this.lastMessageReceivedAt = System.nanoTime();
 161
 162                 if (msg instanceof BGPOpenMessage) {
 163                         // Open messages should not be present here
 164                         this.terminate(BGPError.FSM_ERROR);
 165                 } else if (msg instanceof Notify) {
 166                         // Notifications are handled internally
 167                         logger.info("Session closed because Notification message received: {} / {}", ((Notify) msg).getErrorCode(),
 168                                         ((Notify) msg).getErrorSubcode());
 169                         this.closeWithoutMessage();
 170                         this.listener.onSessionTerminated(this,
 171                                         new BGPTerminationReason(BGPError.forValue(((Notify) msg).getErrorCode(), ((Notify) msg).getErrorSubcode())));
 172                 } else if (msg instanceof Keepalive) {
 173                         // Keepalives are handled internally
 174                         logger.debug("Received KeepAlive messsage.");
 175                         this.kaCounter++;
 176                         if (this.kaCounter >= 2) {
 177                                 this.sync.kaReceived();
 178                         }
 179                 } else {
 180                         // All others are passed up
 181                         this.listener.onMessage(this, msg);
 182                 }
 183         }
 184
 185         @Override
 186         public synchronized void endOfInput() {
 187                 if (this.state == State.Up) {
 188                         this.listener.onSessionDown(this, new IOException("End of input detected. Close the session."));
 189                 }
 190         }
 191
 192         void sendMessage(final Notification msg) {
 193                 try {
 194                         this.channel.writeAndFlush(msg);
 195                         this.lastMessageSentAt = System.nanoTime();
 196                         logger.debug("Sent message: {}", msg);
 197                 } catch (final Exception e) {
 198                         logger.warn("Message {} was not sent.", msg, e);
 199                 }
 200         }
 201
 202         private synchronized void closeWithoutMessage() {
 203                 logger.debug("Closing session: {}", this);
 204                 this.channel.close();
 205                 this.state = State.Idle;
 206         }
 207
 208         /**
 209          * Closes PCEP session from the parent with given reason. A message needs to be sent, but parent doesn't have to be
 210          * modified, because he initiated the closing. (To prevent concurrent modification exception).
 211          *
 212          * @param closeObject
 213          */
 214         private void terminate(final BGPError error) {
 215                 this.sendMessage(new NotifyBuilder().setErrorCode(error.getCode()).setErrorSubcode(error.getSubcode()).build());
 216                 this.closeWithoutMessage();
 217
 218                 this.listener.onSessionTerminated(this, new BGPTerminationReason(error));
 219         }
 220
 221         /**
 222          * If HoldTimer expires, the session ends. If a message (whichever) was received during this period, the HoldTimer
 223          * will be rescheduled by HOLD_TIMER_VALUE + the time that has passed from the start of the HoldTimer to the time at
 224          * which the message was received. If the session was closed by the time this method starts to execute (the session
 225          * state will become IDLE), then rescheduling won't occur.
 226          */
 227         private synchronized void handleHoldTimer() {
 228                 if (this.state == State.Idle) {
 229                         return;
 230                 }
 231
 232                 final long ct = System.nanoTime();
 233                 final long nextHold = this.lastMessageReceivedAt + TimeUnit.SECONDS.toNanos(HOLD_TIMER_VALUE);
 234
 235                 if (ct >= nextHold) {
 236                         logger.debug("HoldTimer expired. " + new Date());
 237                         this.terminate(BGPError.HOLD_TIMER_EXPIRED);
 238                 } else {
 239                         this.stateTimer.newTimeout(new TimerTask() {
 240                                 @Override
 241                                 public void run(final Timeout timeout) throws Exception {
 242                                         handleHoldTimer();
 243                                 }
 244                         }, nextHold - ct, TimeUnit.NANOSECONDS);
 245                 }
 246         }
 247
 248         /**
 249          * If KeepAlive Timer expires, sends KeepAlive message. If a message (whichever) was send during this period, the
 250          * KeepAlive Timer will be rescheduled by KEEP_ALIVE_TIMER_VALUE + the time that has passed from the start of the
 251          * KeepAlive timer to the time at which the message was sent. If the session was closed by the time this method
 252          * starts to execute (the session state will become IDLE), that rescheduling won't occur.
 253          */
 254         private synchronized void handleKeepaliveTimer() {
 255                 if (this.state == State.Idle) {
 256                         return;
 257                 }
 258
 259                 final long ct = System.nanoTime();
 260                 long nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 261
 262                 if (ct >= nextKeepalive) {
 263                         this.sendMessage(keepalive);
 264                         nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 265                 }
 266                 this.stateTimer.newTimeout(new TimerTask() {
 267                         @Override
 268                         public void run(final Timeout timeout) throws Exception {
 269                                 handleKeepaliveTimer();
 270                         }
 271                 }, nextKeepalive - ct, TimeUnit.NANOSECONDS);
 272         }
 273
 274         @Override
 275         final public String toString() {
 276                 return addToStringAttributes(Objects.toStringHelper(this)).toString();
 277         }
 278
 279         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 280                 toStringHelper.add("channel", this.channel);
 281                 toStringHelper.add("state", this.state);
 282                 return toStringHelper;
 283         }
 284
 285         @Override
 286         public Set<BGPTableType> getAdvertisedTableTypes() {
 287                 return this.tableTypes;
 288         }
 289
 290         @Override
 291         protected synchronized void sessionUp() {
 292                 this.state = State.Up;
 293                 this.listener.onSessionUp(this);
 294         }
 295
 296         public synchronized State getState() {
 297                 return this.state;
 298         }
 299 }