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.BGPTerminationReason;
  26 import org.opendaylight.protocol.bgp.parser.BgpTableTypeImpl;
  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.BgpTableType;
  36 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130918.open.bgp.parameters.c.parameters.CMultiprotocol;
  37 import org.opendaylight.yangtools.yang.binding.Notification;
  38 import org.slf4j.Logger;
  39 import org.slf4j.LoggerFactory;
  40
  41 import com.google.common.annotations.VisibleForTesting;
  42 import com.google.common.base.Objects;
  43 import com.google.common.base.Objects.ToStringHelper;
  44 import com.google.common.base.Preconditions;
  45 import com.google.common.collect.Sets;
  46
  47 @VisibleForTesting
  48 public class BGPSessionImpl extends AbstractProtocolSession<Notification> implements BGPSession {
  49
  50         private static final Logger logger = LoggerFactory.getLogger(BGPSessionImpl.class);
  51
  52         private static final int DEFAULT_HOLD_TIMER_VALUE = 15;
  53
  54         private static final Notification keepalive = new KeepaliveBuilder().build();
  55
  56         public static int HOLD_TIMER_VALUE = DEFAULT_HOLD_TIMER_VALUE; // 240
  57
  58         /**
  59          * Internal session state.
  60          */
  61         public enum State {
  62                 /**
  63                  * The session object is created by the negotiator in OpenConfirm state. While in this state, the session object
  64                  * is half-alive, e.g. the timers are running, but the session is not completely up, e.g. it has not been
  65                  * announced to the listener. If the session is torn down in this state, we do not inform the listener.
  66                  */
  67                 OpenConfirm,
  68                 /**
  69                  * The session has been completely established.
  70                  */
  71                 Up,
  72                 /**
  73                  * The session has been closed. It will not be resurrected.
  74                  */
  75                 Idle,
  76         }
  77
  78         /**
  79          * System.nanoTime value about when was sent the last message Protected to be updated also in tests.
  80          */
  81         protected long lastMessageSentAt;
  82
  83         /**
  84          * System.nanoTime value about when was received the last message
  85          */
  86         private long lastMessageReceivedAt;
  87
  88         private final BGPSessionListener listener;
  89
  90         /**
  91          * Timer object grouping FSM Timers
  92          */
  93         private final Timer stateTimer;
  94
  95         private final BGPSynchronization sync;
  96
  97         private int kaCounter = 0;
  98
  99         private final Channel channel;
 100
 101         @GuardedBy("this")
 102         private State state = State.OpenConfirm;
 103
 104         private final int keepAlive;
 105
 106         private final Set<BgpTableType> tableTypes;
 107
 108         BGPSessionImpl(final Timer timer, final BGPSessionListener listener, final Channel channel, final Open remoteOpen) {
 109                 this.listener = Preconditions.checkNotNull(listener);
 110                 this.stateTimer = Preconditions.checkNotNull(timer);
 111                 this.channel = Preconditions.checkNotNull(channel);
 112                 this.keepAlive = remoteOpen.getHoldTimer() / 3;
 113
 114                 final Set<BgpTableType> tts = Sets.newHashSet();
 115                 if (remoteOpen.getBgpParameters() != null) {
 116                         for (final BgpParameters param : remoteOpen.getBgpParameters()) {
 117                                 if (param instanceof CParameters) {
 118                                         final CParameters cp = (CParameters) param;
 119                                         final BgpTableType tt = new BgpTableTypeImpl(((CMultiprotocol) cp).getMultiprotocolCapability().getAfi(), ((CMultiprotocol) cp).getMultiprotocolCapability().getSafi());
 120                                         tts.add(tt);
 121                                 }
 122                         }
 123                 }
 124
 125                 this.sync = new BGPSynchronization(this, this.listener, tts);
 126                 this.tableTypes = tts;
 127
 128                 if (remoteOpen.getHoldTimer() != 0) {
 129                         this.stateTimer.newTimeout(new TimerTask() {
 130
 131                                 @Override
 132                                 public void run(final Timeout timeout) throws Exception {
 133                                         handleHoldTimer();
 134                                 }
 135                         }, remoteOpen.getHoldTimer(), TimeUnit.SECONDS);
 136
 137                         this.stateTimer.newTimeout(new TimerTask() {
 138                                 @Override
 139                                 public void run(final Timeout timeout) throws Exception {
 140                                         handleKeepaliveTimer();
 141                                 }
 142                         }, this.keepAlive, TimeUnit.SECONDS);
 143                 }
 144         }
 145
 146         @Override
 147         public synchronized void close() {
 148                 logger.debug("Closing session: {}", this);
 149                 if (this.state != State.Idle) {
 150                         this.sendMessage(new NotifyBuilder().setErrorCode(BGPError.CEASE.getCode()).build());
 151                         this.channel.close();
 152                         this.state = State.Idle;
 153                 }
 154         }
 155
 156         /**
 157          * Handles incoming message based on their type.
 158          *
 159          * @param msg incoming message
 160          */
 161         @Override
 162         public void handleMessage(final Notification msg) {
 163                 // Update last reception time
 164                 this.lastMessageReceivedAt = System.nanoTime();
 165
 166                 if (msg instanceof Open) {
 167                         // Open messages should not be present here
 168                         this.terminate(BGPError.FSM_ERROR);
 169                 } else if (msg instanceof Notify) {
 170                         // Notifications are handled internally
 171                         logger.info("Session closed because Notification message received: {} / {}", ((Notify) msg).getErrorCode(),
 172                                         ((Notify) msg).getErrorSubcode());
 173                         this.closeWithoutMessage();
 174                         this.listener.onSessionTerminated(this,
 175                                         new BGPTerminationReason(BGPError.forValue(((Notify) msg).getErrorCode(), ((Notify) msg).getErrorSubcode())));
 176                 } else if (msg instanceof Keepalive) {
 177                         // Keepalives are handled internally
 178                         logger.debug("Received KeepAlive messsage.");
 179                         this.kaCounter++;
 180                         if (this.kaCounter >= 2) {
 181                                 this.sync.kaReceived();
 182                         }
 183                 } else {
 184                         // All others are passed up
 185                         this.listener.onMessage(this, msg);
 186                 }
 187         }
 188
 189         @Override
 190         public synchronized void endOfInput() {
 191                 if (this.state == State.Up) {
 192                         this.listener.onSessionDown(this, new IOException("End of input detected. Close the session."));
 193                 }
 194         }
 195
 196         void sendMessage(final Notification msg) {
 197                 try {
 198                         this.channel.writeAndFlush(msg);
 199                         this.lastMessageSentAt = System.nanoTime();
 200                         logger.debug("Sent message: {}", msg);
 201                 } catch (final Exception e) {
 202                         logger.warn("Message {} was not sent.", msg, e);
 203                 }
 204         }
 205
 206         private synchronized void closeWithoutMessage() {
 207                 logger.debug("Closing session: {}", this);
 208                 this.channel.close();
 209                 this.state = State.Idle;
 210         }
 211
 212         /**
 213          * Closes PCEP session from the parent with given reason. A message needs to be sent, but parent doesn't have to be
 214          * modified, because he initiated the closing. (To prevent concurrent modification exception).
 215          *
 216          * @param closeObject
 217          */
 218         private void terminate(final BGPError error) {
 219                 this.sendMessage(new NotifyBuilder().setErrorCode(error.getCode()).setErrorSubcode(error.getSubcode()).build());
 220                 this.closeWithoutMessage();
 221
 222                 this.listener.onSessionTerminated(this, new BGPTerminationReason(error));
 223         }
 224
 225         /**
 226          * If HoldTimer expires, the session ends. If a message (whichever) was received during this period, the HoldTimer
 227          * will be rescheduled by HOLD_TIMER_VALUE + the time that has passed from the start of the HoldTimer to the time at
 228          * which the message was received. If the session was closed by the time this method starts to execute (the session
 229          * state will become IDLE), then rescheduling won't occur.
 230          */
 231         private synchronized void handleHoldTimer() {
 232                 if (this.state == State.Idle) {
 233                         return;
 234                 }
 235
 236                 final long ct = System.nanoTime();
 237                 final long nextHold = this.lastMessageReceivedAt + TimeUnit.SECONDS.toNanos(HOLD_TIMER_VALUE);
 238
 239                 if (ct >= nextHold) {
 240                         logger.debug("HoldTimer expired. " + new Date());
 241                         this.terminate(BGPError.HOLD_TIMER_EXPIRED);
 242                 } else {
 243                         this.stateTimer.newTimeout(new TimerTask() {
 244                                 @Override
 245                                 public void run(final Timeout timeout) throws Exception {
 246                                         handleHoldTimer();
 247                                 }
 248                         }, nextHold - ct, TimeUnit.NANOSECONDS);
 249                 }
 250         }
 251
 252         /**
 253          * If KeepAlive Timer expires, sends KeepAlive message. If a message (whichever) was send during this period, the
 254          * KeepAlive Timer will be rescheduled by KEEP_ALIVE_TIMER_VALUE + the time that has passed from the start of the
 255          * KeepAlive timer to the time at which the message was sent. If the session was closed by the time this method
 256          * starts to execute (the session state will become IDLE), that rescheduling won't occur.
 257          */
 258         private synchronized void handleKeepaliveTimer() {
 259                 if (this.state == State.Idle) {
 260                         return;
 261                 }
 262
 263                 final long ct = System.nanoTime();
 264                 long nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 265
 266                 if (ct >= nextKeepalive) {
 267                         this.sendMessage(keepalive);
 268                         nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 269                 }
 270                 this.stateTimer.newTimeout(new TimerTask() {
 271                         @Override
 272                         public void run(final Timeout timeout) throws Exception {
 273                                 handleKeepaliveTimer();
 274                         }
 275                 }, nextKeepalive - ct, TimeUnit.NANOSECONDS);
 276         }
 277
 278         @Override
 279         final public String toString() {
 280                 return addToStringAttributes(Objects.toStringHelper(this)).toString();
 281         }
 282
 283         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 284                 toStringHelper.add("channel", this.channel);
 285                 toStringHelper.add("state", this.state);
 286                 return toStringHelper;
 287         }
 288
 289         @Override
 290         public Set<BgpTableType> getAdvertisedTableTypes() {
 291                 return this.tableTypes;
 292         }
 293
 294         @Override
 295         protected synchronized void sessionUp() {
 296                 this.state = State.Up;
 297                 this.listener.onSessionUp(this);
 298         }
 299
 300         public synchronized State getState() {
 301                 return this.state;
 302         }
 303 }