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         private static int holdTimerValue = 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         @VisibleForTesting
  82         protected long lastMessageSentAt;
  83
  84         /**
  85          * System.nanoTime value about when was received the last message
  86          */
  87         private long lastMessageReceivedAt;
  88
  89         private final BGPSessionListener listener;
  90
  91         /**
  92          * Timer object grouping FSM Timers
  93          */
  94         private final Timer stateTimer;
  95
  96         private final BGPSynchronization sync;
  97
  98         private int kaCounter = 0;
  99
 100         private final Channel channel;
 101
 102         @GuardedBy("this")
 103         private State state = State.OpenConfirm;
 104
 105         private final int keepAlive;
 106
 107         private final Set<BgpTableType> tableTypes;
 108
 109         BGPSessionImpl(final Timer timer, final BGPSessionListener listener, final Channel channel, final Open remoteOpen) {
 110                 this.listener = Preconditions.checkNotNull(listener);
 111                 this.stateTimer = Preconditions.checkNotNull(timer);
 112                 this.channel = Preconditions.checkNotNull(channel);
 113                 this.keepAlive = remoteOpen.getHoldTimer() / 3;
 114                 holdTimerValue = remoteOpen.getHoldTimer();
 115
 116                 final Set<BgpTableType> tts = Sets.newHashSet();
 117                 if (remoteOpen.getBgpParameters() != null) {
 118                         for (final BgpParameters param : remoteOpen.getBgpParameters()) {
 119                                 if (param instanceof CParameters) {
 120                                         final CParameters cp = (CParameters) param;
 121                                         final BgpTableType tt = new BgpTableTypeImpl(((CMultiprotocol) cp).getMultiprotocolCapability().getAfi(), ((CMultiprotocol) cp).getMultiprotocolCapability().getSafi());
 122                                         tts.add(tt);
 123                                 }
 124                         }
 125                 }
 126
 127                 this.sync = new BGPSynchronization(this, this.listener, tts);
 128                 this.tableTypes = tts;
 129
 130                 if (remoteOpen.getHoldTimer() != 0) {
 131                         this.stateTimer.newTimeout(new TimerTask() {
 132
 133                                 @Override
 134                                 public void run(final Timeout timeout) throws Exception {
 135                                         handleHoldTimer();
 136                                 }
 137                         }, remoteOpen.getHoldTimer(), TimeUnit.SECONDS);
 138
 139                         this.stateTimer.newTimeout(new TimerTask() {
 140                                 @Override
 141                                 public void run(final Timeout timeout) throws Exception {
 142                                         handleKeepaliveTimer();
 143                                 }
 144                         }, this.keepAlive, TimeUnit.SECONDS);
 145                 }
 146         }
 147
 148         @Override
 149         public synchronized void close() {
 150                 logger.debug("Closing session: {}", this);
 151                 if (this.state != State.Idle) {
 152                         this.sendMessage(new NotifyBuilder().setErrorCode(BGPError.CEASE.getCode()).build());
 153                         this.channel.close();
 154                         this.state = State.Idle;
 155                 }
 156         }
 157
 158         /**
 159          * Handles incoming message based on their type.
 160          *
 161          * @param msg incoming message
 162          */
 163         @Override
 164         public void handleMessage(final Notification msg) {
 165                 // Update last reception time
 166                 this.lastMessageReceivedAt = System.nanoTime();
 167
 168                 if (msg instanceof Open) {
 169                         // Open messages should not be present here
 170                         this.terminate(BGPError.FSM_ERROR);
 171                 } else if (msg instanceof Notify) {
 172                         // Notifications are handled internally
 173                         logger.info("Session closed because Notification message received: {} / {}", ((Notify) msg).getErrorCode(),
 174                                         ((Notify) msg).getErrorSubcode());
 175                         this.closeWithoutMessage();
 176                         this.listener.onSessionTerminated(this,
 177                                         new BGPTerminationReason(BGPError.forValue(((Notify) msg).getErrorCode(), ((Notify) msg).getErrorSubcode())));
 178                 } else if (msg instanceof Keepalive) {
 179                         // Keepalives are handled internally
 180                         logger.debug("Received KeepAlive messsage.");
 181                         this.kaCounter++;
 182                         if (this.kaCounter >= 2) {
 183                                 this.sync.kaReceived();
 184                         }
 185                 } else {
 186                         // All others are passed up
 187                         this.listener.onMessage(this, msg);
 188                 }
 189         }
 190
 191         @Override
 192         public synchronized void endOfInput() {
 193                 if (this.state == State.Up) {
 194                         this.listener.onSessionDown(this, new IOException("End of input detected. Close the session."));
 195                 }
 196         }
 197
 198         void sendMessage(final Notification msg) {
 199                 try {
 200                         this.channel.writeAndFlush(msg);
 201                         this.lastMessageSentAt = System.nanoTime();
 202                         logger.debug("Sent message: {}", msg);
 203                 } catch (final Exception e) {
 204                         logger.warn("Message {} was not sent.", msg, e);
 205                 }
 206         }
 207
 208         private synchronized void closeWithoutMessage() {
 209                 logger.debug("Closing session: {}", this);
 210                 this.channel.close();
 211                 this.state = State.Idle;
 212         }
 213
 214         /**
 215          * Closes PCEP session from the parent with given reason. A message needs to be sent, but parent doesn't have to be
 216          * modified, because he initiated the closing. (To prevent concurrent modification exception).
 217          *
 218          * @param closeObject
 219          */
 220         private void terminate(final BGPError error) {
 221                 this.sendMessage(new NotifyBuilder().setErrorCode(error.getCode()).setErrorSubcode(error.getSubcode()).build());
 222                 this.closeWithoutMessage();
 223
 224                 this.listener.onSessionTerminated(this, new BGPTerminationReason(error));
 225         }
 226
 227         /**
 228          * If HoldTimer expires, the session ends. If a message (whichever) was received during this period, the HoldTimer
 229          * will be rescheduled by HOLD_TIMER_VALUE + the time that has passed from the start of the HoldTimer to the time at
 230          * which the message was received. If the session was closed by the time this method starts to execute (the session
 231          * state will become IDLE), then rescheduling won't occur.
 232          */
 233         private synchronized void handleHoldTimer() {
 234                 if (this.state == State.Idle) {
 235                         return;
 236                 }
 237
 238                 final long ct = System.nanoTime();
 239                 final long nextHold = this.lastMessageReceivedAt + TimeUnit.SECONDS.toNanos(holdTimerValue);
 240
 241                 if (ct >= nextHold) {
 242                         logger.debug("HoldTimer expired. " + new Date());
 243                         this.terminate(BGPError.HOLD_TIMER_EXPIRED);
 244                 } else {
 245                         this.stateTimer.newTimeout(new TimerTask() {
 246                                 @Override
 247                                 public void run(final Timeout timeout) throws Exception {
 248                                         handleHoldTimer();
 249                                 }
 250                         }, nextHold - ct, TimeUnit.NANOSECONDS);
 251                 }
 252         }
 253
 254         /**
 255          * If KeepAlive Timer expires, sends KeepAlive message. If a message (whichever) was send during this period, the
 256          * KeepAlive Timer will be rescheduled by KEEP_ALIVE_TIMER_VALUE + the time that has passed from the start of the
 257          * KeepAlive timer to the time at which the message was sent. If the session was closed by the time this method
 258          * starts to execute (the session state will become IDLE), that rescheduling won't occur.
 259          */
 260         private synchronized void handleKeepaliveTimer() {
 261                 if (this.state == State.Idle) {
 262                         return;
 263                 }
 264
 265                 final long ct = System.nanoTime();
 266                 long nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 267
 268                 if (ct >= nextKeepalive) {
 269                         this.sendMessage(keepalive);
 270                         nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 271                 }
 272                 this.stateTimer.newTimeout(new TimerTask() {
 273                         @Override
 274                         public void run(final Timeout timeout) throws Exception {
 275                                 handleKeepaliveTimer();
 276                         }
 277                 }, nextKeepalive - ct, TimeUnit.NANOSECONDS);
 278         }
 279
 280         @Override
 281         final public String toString() {
 282                 return addToStringAttributes(Objects.toStringHelper(this)).toString();
 283         }
 284
 285         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 286                 toStringHelper.add("channel", this.channel);
 287                 toStringHelper.add("state", this.state);
 288                 return toStringHelper;
 289         }
 290
 291         @Override
 292         public Set<BgpTableType> getAdvertisedTableTypes() {
 293                 return this.tableTypes;
 294         }
 295
 296         @Override
 297         protected synchronized void sessionUp() {
 298                 this.state = State.Up;
 299                 this.listener.onSessionUp(this);
 300         }
 301
 302         public synchronized State getState() {
 303                 return this.state;
 304         }
 305 }