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.BGPTableType;
  26 import org.opendaylight.protocol.bgp.parser.BGPTerminationReason;
  27 import org.opendaylight.protocol.framework.AbstractProtocolSession;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.Keepalive;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.KeepaliveBuilder;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.Notify;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.NotifyBuilder;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.Open;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.open.BgpParameters;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130918.open.bgp.parameters.CParameters;
  35 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130918.open.bgp.parameters.c.parameters.CMultiprotocol;
  36 import org.opendaylight.yangtools.yang.binding.Notification;
  37 import org.slf4j.Logger;
  38 import org.slf4j.LoggerFactory;
  39
  40 import com.google.common.annotations.VisibleForTesting;
  41 import com.google.common.base.Objects;
  42 import com.google.common.base.Objects.ToStringHelper;
  43 import com.google.common.base.Preconditions;
  44 import com.google.common.collect.Sets;
  45
  46 @VisibleForTesting
  47 public class BGPSessionImpl extends AbstractProtocolSession<Notification> implements BGPSession {
  48
  49         private static final Logger logger = LoggerFactory.getLogger(BGPSessionImpl.class);
  50
  51         private static final int DEFAULT_HOLD_TIMER_VALUE = 15;
  52
  53         private static final Notification keepalive = new KeepaliveBuilder().build();
  54
  55         public static int HOLD_TIMER_VALUE = DEFAULT_HOLD_TIMER_VALUE; // 240
  56
  57         /**
  58          * Internal session state.
  59          */
  60         public enum State {
  61                 /**
  62                  * The session object is created by the negotiator in OpenConfirm state. While in this state, the session object
  63                  * is half-alive, e.g. the timers are running, but the session is not completely up, e.g. it has not been
  64                  * announced to the listener. If the session is torn down in this state, we do not inform the listener.
  65                  */
  66                 OpenConfirm,
  67                 /**
  68                  * The session has been completely established.
  69                  */
  70                 Up,
  71                 /**
  72                  * The session has been closed. It will not be resurrected.
  73                  */
  74                 Idle,
  75         }
  76
  77         /**
  78          * System.nanoTime value about when was sent the last message Protected to be updated also in tests.
  79          */
  80         protected long lastMessageSentAt;
  81
  82         /**
  83          * System.nanoTime value about when was received the last message
  84          */
  85         private long lastMessageReceivedAt;
  86
  87         private final BGPSessionListener listener;
  88
  89         /**
  90          * Timer object grouping FSM Timers
  91          */
  92         private final Timer stateTimer;
  93
  94         private final BGPSynchronization sync;
  95
  96         private int kaCounter = 0;
  97
  98         private final Channel channel;
  99
 100         @GuardedBy("this")
 101         private State state = State.OpenConfirm;
 102
 103         private final int keepAlive;
 104
 105         private final Set<BGPTableType> tableTypes;
 106
 107         BGPSessionImpl(final Timer timer, final BGPSessionListener listener, final Channel channel, final Open remoteOpen) {
 108                 this.listener = Preconditions.checkNotNull(listener);
 109                 this.stateTimer = Preconditions.checkNotNull(timer);
 110                 this.channel = Preconditions.checkNotNull(channel);
 111                 this.keepAlive = remoteOpen.getHoldTimer() / 3;
 112
 113                 final Set<BGPTableType> tts = Sets.newHashSet();
 114                 if (remoteOpen.getBgpParameters() != null) {
 115                         for (final BgpParameters param : remoteOpen.getBgpParameters()) {
 116                                 if (param instanceof CParameters) {
 117                                         final CParameters cp = (CParameters) param;
 118                                         final BGPTableType tt = new BGPTableType(((CMultiprotocol) cp).getMultiprotocolCapability().getAfi(), ((CMultiprotocol) cp).getMultiprotocolCapability().getSafi());
 119                                         tts.add(tt);
 120                                 }
 121                         }
 122                 }
 123
 124                 this.sync = new BGPSynchronization(this, this.listener, tts);
 125                 this.tableTypes = tts;
 126
 127                 if (remoteOpen.getHoldTimer() != 0) {
 128                         this.stateTimer.newTimeout(new TimerTask() {
 129
 130                                 @Override
 131                                 public void run(final Timeout timeout) throws Exception {
 132                                         handleHoldTimer();
 133                                 }
 134                         }, remoteOpen.getHoldTimer(), TimeUnit.SECONDS);
 135
 136                         this.stateTimer.newTimeout(new TimerTask() {
 137                                 @Override
 138                                 public void run(final Timeout timeout) throws Exception {
 139                                         handleKeepaliveTimer();
 140                                 }
 141                         }, this.keepAlive, TimeUnit.SECONDS);
 142                 }
 143         }
 144
 145         @Override
 146         public synchronized void close() {
 147                 logger.debug("Closing session: {}", this);
 148                 if (this.state != State.Idle) {
 149                         this.sendMessage(new NotifyBuilder().setErrorCode(BGPError.CEASE.getCode()).build());
 150                         this.channel.close();
 151                         this.state = State.Idle;
 152                 }
 153         }
 154
 155         /**
 156          * Handles incoming message based on their type.
 157          *
 158          * @param msg incoming message
 159          */
 160         @Override
 161         public void handleMessage(final Notification msg) {
 162                 // Update last reception time
 163                 this.lastMessageReceivedAt = System.nanoTime();
 164
 165                 if (msg instanceof Open) {
 166                         // Open messages should not be present here
 167                         this.terminate(BGPError.FSM_ERROR);
 168                 } else if (msg instanceof Notify) {
 169                         // Notifications are handled internally
 170                         logger.info("Session closed because Notification message received: {} / {}", ((Notify) msg).getErrorCode(),
 171                                         ((Notify) msg).getErrorSubcode());
 172                         this.closeWithoutMessage();
 173                         this.listener.onSessionTerminated(this,
 174                                         new BGPTerminationReason(BGPError.forValue(((Notify) msg).getErrorCode(), ((Notify) msg).getErrorSubcode())));
 175                 } else if (msg instanceof Keepalive) {
 176                         // Keepalives are handled internally
 177                         logger.debug("Received KeepAlive messsage.");
 178                         this.kaCounter++;
 179                         if (this.kaCounter >= 2) {
 180                                 this.sync.kaReceived();
 181                         }
 182                 } else {
 183                         // All others are passed up
 184                         this.listener.onMessage(this, msg);
 185                 }
 186         }
 187
 188         @Override
 189         public synchronized void endOfInput() {
 190                 if (this.state == State.Up) {
 191                         this.listener.onSessionDown(this, new IOException("End of input detected. Close the session."));
 192                 }
 193         }
 194
 195         void sendMessage(final Notification msg) {
 196                 try {
 197                         this.channel.writeAndFlush(msg);
 198                         this.lastMessageSentAt = System.nanoTime();
 199                         logger.debug("Sent message: {}", msg);
 200                 } catch (final Exception e) {
 201                         logger.warn("Message {} was not sent.", msg, e);
 202                 }
 203         }
 204
 205         private synchronized void closeWithoutMessage() {
 206                 logger.debug("Closing session: {}", this);
 207                 this.channel.close();
 208                 this.state = State.Idle;
 209         }
 210
 211         /**
 212          * Closes PCEP session from the parent with given reason. A message needs to be sent, but parent doesn't have to be
 213          * modified, because he initiated the closing. (To prevent concurrent modification exception).
 214          *
 215          * @param closeObject
 216          */
 217         private void terminate(final BGPError error) {
 218                 this.sendMessage(new NotifyBuilder().setErrorCode(error.getCode()).setErrorSubcode(error.getSubcode()).build());
 219                 this.closeWithoutMessage();
 220
 221                 this.listener.onSessionTerminated(this, new BGPTerminationReason(error));
 222         }
 223
 224         /**
 225          * If HoldTimer expires, the session ends. If a message (whichever) was received during this period, the HoldTimer
 226          * will be rescheduled by HOLD_TIMER_VALUE + the time that has passed from the start of the HoldTimer to the time at
 227          * which the message was received. If the session was closed by the time this method starts to execute (the session
 228          * state will become IDLE), then rescheduling won't occur.
 229          */
 230         private synchronized void handleHoldTimer() {
 231                 if (this.state == State.Idle) {
 232                         return;
 233                 }
 234
 235                 final long ct = System.nanoTime();
 236                 final long nextHold = this.lastMessageReceivedAt + TimeUnit.SECONDS.toNanos(HOLD_TIMER_VALUE);
 237
 238                 if (ct >= nextHold) {
 239                         logger.debug("HoldTimer expired. " + new Date());
 240                         this.terminate(BGPError.HOLD_TIMER_EXPIRED);
 241                 } else {
 242                         this.stateTimer.newTimeout(new TimerTask() {
 243                                 @Override
 244                                 public void run(final Timeout timeout) throws Exception {
 245                                         handleHoldTimer();
 246                                 }
 247                         }, nextHold - ct, TimeUnit.NANOSECONDS);
 248                 }
 249         }
 250
 251         /**
 252          * If KeepAlive Timer expires, sends KeepAlive message. If a message (whichever) was send during this period, the
 253          * KeepAlive Timer will be rescheduled by KEEP_ALIVE_TIMER_VALUE + the time that has passed from the start of the
 254          * KeepAlive timer to the time at which the message was sent. If the session was closed by the time this method
 255          * starts to execute (the session state will become IDLE), that rescheduling won't occur.
 256          */
 257         private synchronized void handleKeepaliveTimer() {
 258                 if (this.state == State.Idle) {
 259                         return;
 260                 }
 261
 262                 final long ct = System.nanoTime();
 263                 long nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 264
 265                 if (ct >= nextKeepalive) {
 266                         this.sendMessage(keepalive);
 267                         nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 268                 }
 269                 this.stateTimer.newTimeout(new TimerTask() {
 270                         @Override
 271                         public void run(final Timeout timeout) throws Exception {
 272                                 handleKeepaliveTimer();
 273                         }
 274                 }, nextKeepalive - ct, TimeUnit.NANOSECONDS);
 275         }
 276
 277         @Override
 278         final public String toString() {
 279                 return addToStringAttributes(Objects.toStringHelper(this)).toString();
 280         }
 281
 282         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 283                 toStringHelper.add("channel", this.channel);
 284                 toStringHelper.add("state", this.state);
 285                 return toStringHelper;
 286         }
 287
 288         @Override
 289         public Set<BGPTableType> getAdvertisedTableTypes() {
 290                 return this.tableTypes;
 291         }
 292
 293         @Override
 294         protected synchronized void sessionUp() {
 295                 this.state = State.Up;
 296                 this.listener.onSessionUp(this);
 297         }
 298
 299         public synchronized State getState() {
 300                 return this.state;
 301         }
 302 }