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.rev130919.Keepalive;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.KeepaliveBuilder;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Notify;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.NotifyBuilder;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Open;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Update;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.BgpParameters;
  35 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.bgp.parameters.CParameters;
  36 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.BgpTableType;
  37 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.MultiprotocolCase;
  38 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev130925.rib.TablesKey;
  39 import org.opendaylight.yangtools.yang.binding.Notification;
  40 import org.slf4j.Logger;
  41 import org.slf4j.LoggerFactory;
  42
  43 import com.google.common.annotations.VisibleForTesting;
  44 import com.google.common.base.Objects;
  45 import com.google.common.base.Objects.ToStringHelper;
  46 import com.google.common.base.Preconditions;
  47 import com.google.common.collect.Sets;
  48
  49 @VisibleForTesting
  50 public class BGPSessionImpl extends AbstractProtocolSession<Notification> implements BGPSession {
  51
  52         private static final Logger LOG = LoggerFactory.getLogger(BGPSessionImpl.class);
  53
  54         /*
  55          * 240
  56          */
  57         private static final int DEFAULT_HOLD_TIMER_VALUE = 15;
  58
  59         private static final Notification KEEP_ALIVE = new KeepaliveBuilder().build();
  60
  61         private static int holdTimerValue = DEFAULT_HOLD_TIMER_VALUE;
  62
  63         /**
  64          * Internal session state.
  65          */
  66         public enum State {
  67                 /**
  68                  * The session object is created by the negotiator in OpenConfirm state. While in this state, the session object
  69                  * is half-alive, e.g. the timers are running, but the session is not completely up, e.g. it has not been
  70                  * announced to the listener. If the session is torn down in this state, we do not inform the listener.
  71                  */
  72                 OpenConfirm,
  73                 /**
  74                  * The session has been completely established.
  75                  */
  76                 Up,
  77                 /**
  78                  * The session has been closed. It will not be resurrected.
  79                  */
  80                 Idle,
  81         }
  82
  83         /**
  84          * System.nanoTime value about when was sent the last message Protected to be updated also in tests.
  85          */
  86         @VisibleForTesting
  87         protected long lastMessageSentAt;
  88
  89         /**
  90          * System.nanoTime value about when was received the last message
  91          */
  92         private long lastMessageReceivedAt;
  93
  94         private final BGPSessionListener listener;
  95
  96         /**
  97          * Timer object grouping FSM Timers
  98          */
  99         private final Timer stateTimer;
 100
 101         private final BGPSynchronization sync;
 102
 103         private int kaCounter = 0;
 104
 105         private final Channel channel;
 106
 107         @GuardedBy("this")
 108         private State state = State.OpenConfirm;
 109
 110         private final int keepAlive;
 111
 112         private final Set<BgpTableType> tableTypes;
 113
 114         BGPSessionImpl(final Timer timer, final BGPSessionListener listener, final Channel channel, final Open remoteOpen) {
 115                 this.listener = Preconditions.checkNotNull(listener);
 116                 this.stateTimer = Preconditions.checkNotNull(timer);
 117                 this.channel = Preconditions.checkNotNull(channel);
 118                 this.keepAlive = remoteOpen.getHoldTimer() / 3;
 119                 holdTimerValue = remoteOpen.getHoldTimer();
 120
 121                 final Set<TablesKey> tts = Sets.newHashSet();
 122                 final Set<BgpTableType> tats = Sets.newHashSet();
 123                 if (remoteOpen.getBgpParameters() != null) {
 124                         for (final BgpParameters param : remoteOpen.getBgpParameters()) {
 125                                 final CParameters cp = param.getCParameters();
 126                                 if (cp instanceof MultiprotocolCase) {
 127                                         final TablesKey tt = new TablesKey(((MultiprotocolCase) cp).getMultiprotocolCapability().getAfi(), ((MultiprotocolCase) cp).getMultiprotocolCapability().getSafi());
 128                                         LOG.trace("Added table type to sync {}", tt);
 129                                         tts.add(tt);
 130                                         tats.add(new BgpTableTypeImpl(tt.getAfi(), tt.getSafi()));
 131                                 }
 132                         }
 133                 }
 134
 135                 this.sync = new BGPSynchronization(this, this.listener, tts);
 136                 this.tableTypes = tats;
 137
 138                 if (remoteOpen.getHoldTimer() != 0) {
 139                         this.stateTimer.newTimeout(new TimerTask() {
 140
 141                                 @Override
 142                                 public void run(final Timeout timeout) throws Exception {
 143                                         handleHoldTimer();
 144                                 }
 145                         }, remoteOpen.getHoldTimer(), TimeUnit.SECONDS);
 146
 147                         this.stateTimer.newTimeout(new TimerTask() {
 148                                 @Override
 149                                 public void run(final Timeout timeout) throws Exception {
 150                                         handleKeepaliveTimer();
 151                                 }
 152                         }, this.keepAlive, TimeUnit.SECONDS);
 153                 }
 154         }
 155
 156         @Override
 157         public synchronized void close() {
 158                 LOG.debug("Closing session: {}", this);
 159                 if (this.state != State.Idle) {
 160                         this.sendMessage(new NotifyBuilder().setErrorCode(BGPError.CEASE.getCode()).build());
 161                         this.channel.close();
 162                         this.state = State.Idle;
 163                 }
 164         }
 165
 166         /**
 167          * Handles incoming message based on their type.
 168          *
 169          * @param msg incoming message
 170          */
 171         @Override
 172         public void handleMessage(final Notification msg) {
 173                 // Update last reception time
 174                 this.lastMessageReceivedAt = System.nanoTime();
 175
 176                 if (msg instanceof Open) {
 177                         // Open messages should not be present here
 178                         this.terminate(BGPError.FSM_ERROR);
 179                 } else if (msg instanceof Notify) {
 180                         // Notifications are handled internally
 181                         LOG.info("Session closed because Notification message received: {} / {}", ((Notify) msg).getErrorCode(),
 182                                         ((Notify) msg).getErrorSubcode());
 183                         this.closeWithoutMessage();
 184                         this.listener.onSessionTerminated(this,
 185                                         new BGPTerminationReason(BGPError.forValue(((Notify) msg).getErrorCode(), ((Notify) msg).getErrorSubcode())));
 186                 } else if (msg instanceof Keepalive) {
 187                         // Keepalives are handled internally
 188                         LOG.debug("Received KeepAlive messsage.");
 189                         this.kaCounter++;
 190                         if (this.kaCounter >= 2) {
 191                                 this.sync.kaReceived();
 192                         }
 193                 } else {
 194                         // All others are passed up
 195                         this.listener.onMessage(this, msg);
 196                         this.sync.updReceived((Update) msg);
 197                 }
 198         }
 199
 200         @Override
 201         public synchronized void endOfInput() {
 202                 if (this.state == State.Up) {
 203                         this.listener.onSessionDown(this, new IOException("End of input detected. Close the session."));
 204                 }
 205         }
 206
 207         void sendMessage(final Notification msg) {
 208                 try {
 209                         this.channel.writeAndFlush(msg);
 210                         this.lastMessageSentAt = System.nanoTime();
 211                         LOG.debug("Sent message: {}", msg);
 212                 } catch (final Exception e) {
 213                         LOG.warn("Message {} was not sent.", msg, e);
 214                 }
 215         }
 216
 217         private synchronized void closeWithoutMessage() {
 218                 LOG.debug("Closing session: {}", this);
 219                 this.channel.close();
 220                 this.state = State.Idle;
 221         }
 222
 223         /**
 224          * Closes PCEP session from the parent with given reason. A message needs to be sent, but parent doesn't have to be
 225          * modified, because he initiated the closing. (To prevent concurrent modification exception).
 226          *
 227          * @param closeObject
 228          */
 229         private void terminate(final BGPError error) {
 230                 this.sendMessage(new NotifyBuilder().setErrorCode(error.getCode()).setErrorSubcode(error.getSubcode()).build());
 231                 this.closeWithoutMessage();
 232
 233                 this.listener.onSessionTerminated(this, new BGPTerminationReason(error));
 234         }
 235
 236         /**
 237          * If HoldTimer expires, the session ends. If a message (whichever) was received during this period, the HoldTimer
 238          * will be rescheduled by HOLD_TIMER_VALUE + the time that has passed from the start of the HoldTimer to the time at
 239          * which the message was received. If the session was closed by the time this method starts to execute (the session
 240          * state will become IDLE), then rescheduling won't occur.
 241          */
 242         private synchronized void handleHoldTimer() {
 243                 if (this.state == State.Idle) {
 244                         return;
 245                 }
 246
 247                 final long ct = System.nanoTime();
 248                 final long nextHold = this.lastMessageReceivedAt + TimeUnit.SECONDS.toNanos(holdTimerValue);
 249
 250                 if (ct >= nextHold) {
 251                         LOG.debug("HoldTimer expired. " + new Date());
 252                         this.terminate(BGPError.HOLD_TIMER_EXPIRED);
 253                 } else {
 254                         this.stateTimer.newTimeout(new TimerTask() {
 255                                 @Override
 256                                 public void run(final Timeout timeout) throws Exception {
 257                                         handleHoldTimer();
 258                                 }
 259                         }, nextHold - ct, TimeUnit.NANOSECONDS);
 260                 }
 261         }
 262
 263         /**
 264          * If KeepAlive Timer expires, sends KeepAlive message. If a message (whichever) was send during this period, the
 265          * KeepAlive Timer will be rescheduled by KEEP_ALIVE_TIMER_VALUE + the time that has passed from the start of the
 266          * KeepAlive timer to the time at which the message was sent. If the session was closed by the time this method
 267          * starts to execute (the session state will become IDLE), that rescheduling won't occur.
 268          */
 269         private synchronized void handleKeepaliveTimer() {
 270                 if (this.state == State.Idle) {
 271                         return;
 272                 }
 273
 274                 final long ct = System.nanoTime();
 275                 long nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 276
 277                 if (ct >= nextKeepalive) {
 278                         this.sendMessage(KEEP_ALIVE);
 279                         nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 280                 }
 281                 this.stateTimer.newTimeout(new TimerTask() {
 282                         @Override
 283                         public void run(final Timeout timeout) throws Exception {
 284                                 handleKeepaliveTimer();
 285                         }
 286                 }, nextKeepalive - ct, TimeUnit.NANOSECONDS);
 287         }
 288
 289         @Override
 290         public final String toString() {
 291                 return addToStringAttributes(Objects.toStringHelper(this)).toString();
 292         }
 293
 294         protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 295                 toStringHelper.add("channel", this.channel);
 296                 toStringHelper.add("state", this.state);
 297                 return toStringHelper;
 298         }
 299
 300         @Override
 301         public Set<BgpTableType> getAdvertisedTableTypes() {
 302                 return this.tableTypes;
 303         }
 304
 305         @Override
 306         protected synchronized void sessionUp() {
 307                 this.state = State.Up;
 308                 this.listener.onSessionUp(this);
 309         }
 310
 311         public synchronized State getState() {
 312                 return this.state;
 313         }
 314 }