Upgrade ietf-{inet,yang}-types to 2013-07-15
[bgpcep.git] / bgp / rib-impl / src / main / java / org / opendaylight / protocol / bgp / rib / impl / BGPSessionImpl.java
index c7837329a29bef549ff83715c2c8cf7d1543b994..1bd5a3a2b7ffa6cbc24326f6df57fdace5a7bdde 100644 (file)
@@ -8,49 +8,74 @@
 package org.opendaylight.protocol.bgp.rib.impl;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Objects;
-import com.google.common.base.Objects.ToStringHelper;
+import com.google.common.base.MoreObjects;
+import com.google.common.base.MoreObjects.ToStringHelper;
+import com.google.common.base.Optional;
 import com.google.common.base.Preconditions;
+import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelPipeline;
+import io.netty.channel.SimpleChannelInboundHandler;
 import java.io.IOException;
+import java.nio.channels.NonWritableChannelException;
 import java.util.Date;
+import java.util.List;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import javax.annotation.concurrent.GuardedBy;
+import org.opendaylight.controller.config.yang.bgp.rib.impl.BgpSessionState;
 import org.opendaylight.protocol.bgp.parser.AsNumberUtil;
+import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
 import org.opendaylight.protocol.bgp.parser.BGPError;
+import org.opendaylight.protocol.bgp.parser.BgpExtendedMessageUtil;
 import org.opendaylight.protocol.bgp.parser.BgpTableTypeImpl;
+import org.opendaylight.protocol.bgp.parser.spi.MultiPathSupport;
+import org.opendaylight.protocol.bgp.parser.spi.pojo.MultiPathSupportImpl;
+import org.opendaylight.protocol.bgp.rib.impl.spi.BGPPeerRegistry;
+import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionPreferences;
+import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionStatistics;
 import org.opendaylight.protocol.bgp.rib.spi.BGPSession;
 import org.opendaylight.protocol.bgp.rib.spi.BGPSessionListener;
 import org.opendaylight.protocol.bgp.rib.spi.BGPTerminationReason;
-import org.opendaylight.protocol.framework.AbstractProtocolSession;
-import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.AsNumber;
-import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.Ipv4Address;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.AsNumber;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Address;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Keepalive;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.KeepaliveBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Notify;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.NotifyBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Open;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Update;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.BgpParameters;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.bgp.parameters.CParameters;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.BgpParameters;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.OptionalCapabilities;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.message.bgp.parameters.optional.capabilities.CParameters;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.BgpTableType;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.MultiprotocolCase;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.CParameters1;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.RouteRefresh;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.AddPathCapability;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.MultiprotocolCapability;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.mp.capabilities.add.path.capability.AddressFamilies;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev130925.rib.TablesKey;
 import org.opendaylight.yangtools.yang.binding.Notification;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 @VisibleForTesting
-public class BGPSessionImpl extends AbstractProtocolSession<Notification> implements BGPSession {
+public class BGPSessionImpl extends SimpleChannelInboundHandler<Notification> implements BGPSession, BGPSessionStatistics, AutoCloseable {
 
     private static final Logger LOG = LoggerFactory.getLogger(BGPSessionImpl.class);
 
     private static final Notification KEEP_ALIVE = new KeepaliveBuilder().build();
 
+    private static final int KA_TO_DEADTIMER_RATIO = 3;
+
+    private static final String EXTENDED_MSG_DECODER = "EXTENDED_MSG_DECODER";
+
+    static final String END_OF_INPUT = "End of input detected. Close the session.";
+
     /**
      * Internal session state.
      */
@@ -60,15 +85,15 @@ public class BGPSessionImpl extends AbstractProtocolSession<Notification> implem
          * is half-alive, e.g. the timers are running, but the session is not completely up, e.g. it has not been
          * announced to the listener. If the session is torn down in this state, we do not inform the listener.
          */
-        OpenConfirm,
+        OPEN_CONFIRM,
         /**
          * The session has been completely established.
          */
-        Up,
+        UP,
         /**
          * The session has been closed. It will not be resurrected.
          */
-        Idle,
+        IDLE,
     }
 
     /**
@@ -91,38 +116,75 @@ public class BGPSessionImpl extends AbstractProtocolSession<Notification> implem
     private final Channel channel;
 
     @GuardedBy("this")
-    private State state = State.OpenConfirm;
+    private State state = State.OPEN_CONFIRM;
 
     private final Set<BgpTableType> tableTypes;
+    private final List<AddressFamilies> addPathTypes;
     private final int holdTimerValue;
     private final int keepAlive;
     private final AsNumber asNumber;
     private final Ipv4Address bgpId;
+    private final BGPPeerRegistry peerRegistry;
+    private final ChannelOutputLimiter limiter;
 
-    public BGPSessionImpl(final BGPSessionListener listener, final Channel channel, final Open remoteOpen, final int localHoldTimer) {
+    private BGPSessionStats sessionStats;
+
+    public BGPSessionImpl(final BGPSessionListener listener, final Channel channel, final Open remoteOpen, final BGPSessionPreferences localPreferences,
+            final BGPPeerRegistry peerRegistry) {
+        this(listener, channel, remoteOpen, localPreferences.getHoldTime(), peerRegistry);
+        this.sessionStats = new BGPSessionStats(remoteOpen, this.holdTimerValue, this.keepAlive, channel, Optional.of(localPreferences), this.tableTypes, this.addPathTypes);
+    }
+
+    public BGPSessionImpl(final BGPSessionListener listener, final Channel channel, final Open remoteOpen, final int localHoldTimer,
+            final BGPPeerRegistry peerRegistry) {
         this.listener = Preconditions.checkNotNull(listener);
         this.channel = Preconditions.checkNotNull(channel);
+        this.limiter = new ChannelOutputLimiter(this);
+        this.channel.pipeline().addLast(this.limiter);
         this.holdTimerValue = (remoteOpen.getHoldTimer() < localHoldTimer) ? remoteOpen.getHoldTimer() : localHoldTimer;
         LOG.info("BGP HoldTimer new value: {}", this.holdTimerValue);
-        this.keepAlive = this.holdTimerValue / 3;
+        this.keepAlive = this.holdTimerValue / KA_TO_DEADTIMER_RATIO;
         this.asNumber = AsNumberUtil.advertizedAsNumber(remoteOpen);
+        this.peerRegistry = peerRegistry;
+        final boolean enableExMess = BgpExtendedMessageUtil.advertizedBgpExtendedMessageCapability(remoteOpen);
+        if (enableExMess) {
+            this.channel.pipeline().replace(BGPMessageHeaderDecoder.class, EXTENDED_MSG_DECODER, BGPMessageHeaderDecoder.getExtendedBGPMessageHeaderDecoder());
+        }
 
         final Set<TablesKey> tts = Sets.newHashSet();
         final Set<BgpTableType> tats = Sets.newHashSet();
+        final List<AddressFamilies> addPathCapabilitiesList = Lists.newArrayList();
         if (remoteOpen.getBgpParameters() != null) {
             for (final BgpParameters param : remoteOpen.getBgpParameters()) {
-                final CParameters cp = param.getCParameters();
-                if (cp instanceof MultiprotocolCase) {
-                    final TablesKey tt = new TablesKey(((MultiprotocolCase) cp).getMultiprotocolCapability().getAfi(), ((MultiprotocolCase) cp).getMultiprotocolCapability().getSafi());
-                    LOG.trace("Added table type to sync {}", tt);
-                    tts.add(tt);
-                    tats.add(new BgpTableTypeImpl(tt.getAfi(), tt.getSafi()));
+                for (final OptionalCapabilities optCapa : param.getOptionalCapabilities()) {
+                    final CParameters cParam = optCapa.getCParameters();
+                    if ( cParam.getAugmentation(CParameters1.class) == null) {
+                        continue;
+                    }
+                    if(cParam.getAugmentation(CParameters1.class).getMultiprotocolCapability() != null) {
+                        final MultiprotocolCapability multi = cParam.getAugmentation(CParameters1.class).getMultiprotocolCapability();
+                        final TablesKey tt = new TablesKey(multi.getAfi(), multi.getSafi());
+                        LOG.trace("Added table type to sync {}", tt);
+                        tts.add(tt);
+                        tats.add(new BgpTableTypeImpl(tt.getAfi(), tt.getSafi()));
+                    } else if (cParam.getAugmentation(CParameters1.class).getAddPathCapability() != null) {
+                        final AddPathCapability addPathCap = cParam.getAugmentation(CParameters1.class).getAddPathCapability();
+                        addPathCapabilitiesList.addAll(addPathCap.getAddressFamilies());
+                    }
                 }
             }
         }
 
-        this.sync = new BGPSynchronization(this, this.listener, tts);
+        this.sync = new BGPSynchronization(this.listener, tts);
         this.tableTypes = tats;
+        this.addPathTypes = addPathCapabilitiesList;
+
+        if (! this.addPathTypes.isEmpty()) {
+            final ChannelPipeline pipeline = this.channel.pipeline();
+            final BGPByteToMessageDecoder decoder = pipeline.get(BGPByteToMessageDecoder.class);
+            decoder.addDecoderConstraint(MultiPathSupport.class,
+                    MultiPathSupportImpl.createParserMultiPathSupport(this.addPathTypes));
+        }
 
         if (this.holdTimerValue != 0) {
             channel.eventLoop().schedule(new Runnable() {
@@ -140,16 +202,16 @@ public class BGPSessionImpl extends AbstractProtocolSession<Notification> implem
             }, this.keepAlive, TimeUnit.SECONDS);
         }
         this.bgpId = remoteOpen.getBgpIdentifier();
+        this.sessionStats = new BGPSessionStats(remoteOpen, this.holdTimerValue, this.keepAlive, channel, Optional.<BGPSessionPreferences>absent(),
+                this.tableTypes, this.addPathTypes);
     }
 
     @Override
     public synchronized void close() {
-        LOG.info("Closing session: {}", this);
-        if (this.state != State.Idle) {
-            this.sendMessage(new NotifyBuilder().setErrorCode(BGPError.CEASE.getCode()).setErrorSubcode((short)0).build());
-            this.channel.close();
-            this.state = State.Idle;
+        if (this.state != State.IDLE) {
+            this.writeAndFlush(new NotifyBuilder().setErrorCode(BGPError.CEASE.getCode()).setErrorSubcode(BGPError.CEASE.getSubcode()).build());
         }
+        this.closeWithoutMessage();
     }
 
     /**
@@ -157,80 +219,128 @@ public class BGPSessionImpl extends AbstractProtocolSession<Notification> implem
      *
      * @param msg incoming message
      */
-    @Override
-    public synchronized void handleMessage(final Notification msg) {
+    synchronized void handleMessage(final Notification msg) throws BGPDocumentedException {
         // Update last reception time
         this.lastMessageReceivedAt = System.nanoTime();
+        this.sessionStats.updateReceivedMsgTotal();
 
         if (msg instanceof Open) {
             // Open messages should not be present here
-            this.terminate(BGPError.FSM_ERROR);
+            this.terminate(new BGPDocumentedException(null, BGPError.FSM_ERROR));
         } else if (msg instanceof Notify) {
             // Notifications are handled internally
             LOG.info("Session closed because Notification message received: {} / {}", ((Notify) msg).getErrorCode(),
-                ((Notify) msg).getErrorSubcode());
+                    ((Notify) msg).getErrorSubcode());
             this.closeWithoutMessage();
-            this.listener.onSessionTerminated(this, new BGPTerminationReason(BGPError.forValue(((Notify) msg).getErrorCode(),
-                ((Notify) msg).getErrorSubcode())));
+            this.listener.onSessionTerminated(this, new BGPTerminationReason(
+                    BGPError.forValue(((Notify) msg).getErrorCode(), ((Notify) msg).getErrorSubcode())));
+            this.sessionStats.updateReceivedMsgErr((Notify) msg);
         } else if (msg instanceof Keepalive) {
             // Keepalives are handled internally
             LOG.trace("Received KeepAlive messsage.");
             this.kaCounter++;
+            this.sessionStats.updateReceivedMsgKA();
             if (this.kaCounter >= 2) {
                 this.sync.kaReceived();
             }
-        } else {
-            // All others are passed up
+        } else if (msg instanceof RouteRefresh) {
+            this.listener.onMessage(this, msg);
+            this.sessionStats.updateReceivedMsgRR();
+        } else if (msg instanceof Update) {
             this.listener.onMessage(this, msg);
             this.sync.updReceived((Update) msg);
+            this.sessionStats.updateReceivedMsgUpd();
+        } else {
+            LOG.warn("Ignoring unhandled message: {}.", msg.getClass());
         }
     }
 
-    @Override
-    public synchronized void endOfInput() {
-        if (this.state == State.Up) {
-            this.listener.onSessionDown(this, new IOException("End of input detected. Close the session."));
+    synchronized void endOfInput() {
+        if (this.state == State.UP) {
+            LOG.info(END_OF_INPUT);
+            this.listener.onSessionDown(this, new IOException(END_OF_INPUT));
         }
     }
 
-    synchronized void sendMessage(final Notification msg) {
-        try {
-            this.channel.writeAndFlush(msg).addListener(
-                new ChannelFutureListener() {
-                    @Override
-                    public void operationComplete(final ChannelFuture f) {
-                        if (!f.isSuccess()) {
-                            LOG.info("Failed to send message {} to socket {}", msg, f.cause(), BGPSessionImpl.this.channel);
-                        } else {
-                            LOG.trace("Message {} sent to socket {}", msg, BGPSessionImpl.this.channel);
-                        }
+    @GuardedBy("this")
+    private ChannelFuture writeEpilogue(final ChannelFuture future, final Notification msg) {
+        future.addListener(
+            new ChannelFutureListener() {
+                @Override
+                public void operationComplete(final ChannelFuture f) {
+                    if (!f.isSuccess()) {
+                        LOG.warn("Failed to send message {} to socket {}", msg, BGPSessionImpl.this.channel, f.cause());
+                    } else {
+                        LOG.trace("Message {} sent to socket {}", msg, BGPSessionImpl.this.channel);
                     }
-                });
-            this.lastMessageSentAt = System.nanoTime();
+                }
+            });
+        this.lastMessageSentAt = System.nanoTime();
+        this.sessionStats.updateSentMsgTotal();
+        if (msg instanceof Update) {
+            this.sessionStats.updateSentMsgUpd();
+        } else if (msg instanceof Notify) {
+            this.sessionStats.updateSentMsgErr((Notify) msg);
+        }
+        return future;
+    }
+
+    void flush() {
+        this.channel.flush();
+    }
+
+    synchronized void write(final Notification msg) {
+        try {
+            writeEpilogue(this.channel.write(msg), msg);
         } catch (final Exception e) {
             LOG.warn("Message {} was not sent.", msg, e);
         }
     }
 
+    synchronized ChannelFuture writeAndFlush(final Notification msg) {
+        if (isWritable()) {
+            return writeEpilogue(this.channel.writeAndFlush(msg), msg);
+        }
+        return this.channel.newFailedFuture(new NonWritableChannelException());
+    }
+
     private synchronized void closeWithoutMessage() {
-        LOG.debug("Closing session: {}", this);
-        this.channel.close();
-        this.state = State.Idle;
+        LOG.info("Closing session: {}", this);
+        removePeerSession();
+        this.channel.close().addListener(new ChannelFutureListener() {
+            @Override
+            public void operationComplete(final ChannelFuture future) throws Exception {
+                Preconditions.checkArgument(future.isSuccess(), "Channel failed to close: %s", future.cause());
+            }
+        });
+        this.state = State.IDLE;
     }
 
     /**
-     * Closes PCEP session from the parent with given reason. A message needs to be sent, but parent doesn't have to be
+     * Closes BGP session from the parent with given reason. A message needs to be sent, but parent doesn't have to be
      * modified, because he initiated the closing. (To prevent concurrent modification exception).
      *
-     * @param closeObject
+     * @param e BGPDocumentedException
      */
-    private void terminate(final BGPError error) {
-        this.sendMessage(new NotifyBuilder().setErrorCode(error.getCode()).setErrorSubcode(error.getSubcode()).build());
+    private synchronized void terminate(final BGPDocumentedException e) {
+        final BGPError error = e.getError();
+        final byte[] data = e.getData();
+        final NotifyBuilder builder = new NotifyBuilder().setErrorCode(error.getCode()).setErrorSubcode(error.getSubcode());
+        if (data != null && data.length != 0) {
+            builder.setData(data);
+        }
+        this.writeAndFlush(builder.build());
         this.closeWithoutMessage();
 
         this.listener.onSessionTerminated(this, new BGPTerminationReason(error));
     }
 
+    private void removePeerSession() {
+        if (this.peerRegistry != null) {
+            this.peerRegistry.removePeerSession(StrictBGPPeerRegistry.getIpAddress(this.channel.remoteAddress()));
+        }
+    }
+
     /**
      * If HoldTimer expires, the session ends. If a message (whichever) was received during this period, the HoldTimer
      * will be rescheduled by HOLD_TIMER_VALUE + the time that has passed from the start of the HoldTimer to the time at
@@ -238,7 +348,7 @@ public class BGPSessionImpl extends AbstractProtocolSession<Notification> implem
      * state will become IDLE), then rescheduling won't occur.
      */
     private synchronized void handleHoldTimer() {
-        if (this.state == State.Idle) {
+        if (this.state == State.IDLE) {
             return;
         }
 
@@ -247,7 +357,7 @@ public class BGPSessionImpl extends AbstractProtocolSession<Notification> implem
 
         if (ct >= nextHold) {
             LOG.debug("HoldTimer expired. {}", new Date());
-            this.terminate(BGPError.HOLD_TIMER_EXPIRED);
+            this.terminate(new BGPDocumentedException(BGPError.HOLD_TIMER_EXPIRED));
         } else {
             this.channel.eventLoop().schedule(new Runnable() {
                 @Override
@@ -265,7 +375,7 @@ public class BGPSessionImpl extends AbstractProtocolSession<Notification> implem
      * starts to execute (the session state will become IDLE), that rescheduling won't occur.
      */
     private synchronized void handleKeepaliveTimer() {
-        if (this.state == State.Idle) {
+        if (this.state == State.IDLE) {
             return;
         }
 
@@ -273,8 +383,9 @@ public class BGPSessionImpl extends AbstractProtocolSession<Notification> implem
         long nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
 
         if (ct >= nextKeepalive) {
-            this.sendMessage(KEEP_ALIVE);
+            this.writeAndFlush(KEEP_ALIVE);
             nextKeepalive = this.lastMessageSentAt + TimeUnit.SECONDS.toNanos(this.keepAlive);
+            this.sessionStats.updateSentMsgKA();
         }
         this.channel.eventLoop().schedule(new Runnable() {
             @Override
@@ -286,7 +397,7 @@ public class BGPSessionImpl extends AbstractProtocolSession<Notification> implem
 
     @Override
     public final String toString() {
-        return addToStringAttributes(Objects.toStringHelper(this)).toString();
+        return addToStringAttributes(MoreObjects.toStringHelper(this)).toString();
     }
 
     protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
@@ -301,8 +412,13 @@ public class BGPSessionImpl extends AbstractProtocolSession<Notification> implem
     }
 
     @Override
+    public List<AddressFamilies> getAdvertisedAddPathTableTypes() {
+        return this.addPathTypes;
+    }
+
     protected synchronized void sessionUp() {
-        this.state = State.Up;
+        this.sessionStats.startSessionStopwatch();
+        this.state = State.UP;
         this.listener.onSessionUp(this);
     }
 
@@ -324,14 +440,64 @@ public class BGPSessionImpl extends AbstractProtocolSession<Notification> implem
         return this.channel != null && this.channel.isWritable();
     }
 
-    synchronized void schedule(final Runnable task) {
+    void schedule(final Runnable task) {
         Preconditions.checkState(this.channel != null);
         this.channel.eventLoop().submit(task);
-
     }
 
     @VisibleForTesting
     protected synchronized void setLastMessageSentAt(final long lastMessageSentAt) {
         this.lastMessageSentAt = lastMessageSentAt;
     }
+
+    @Override
+    public synchronized BgpSessionState getBgpSessionState() {
+        return this.sessionStats.getBgpSessionState(this.state);
+    }
+
+    @Override
+    public synchronized void resetSessionStats() {
+        this.sessionStats.resetStats();
+    }
+
+    public ChannelOutputLimiter getLimiter() {
+        return this.limiter;
+    }
+
+    @Override
+    public final void channelInactive(final ChannelHandlerContext ctx) {
+        LOG.debug("Channel {} inactive.", ctx.channel());
+        this.endOfInput();
+
+        try {
+            super.channelInactive(ctx);
+        } catch (final Exception e) {
+            throw new IllegalStateException("Failed to delegate channel inactive event on channel " + ctx.channel(), e);
+        }
+    }
+
+    @Override
+    protected final void channelRead0(final ChannelHandlerContext ctx, final Notification msg) {
+        LOG.debug("Message was received: {}", msg);
+        try {
+            this.handleMessage(msg);
+        } catch (final BGPDocumentedException e) {
+            this.terminate(e);
+        }
+    }
+
+    @Override
+    public final void handlerAdded(final ChannelHandlerContext ctx) {
+        this.sessionUp();
+    }
+
+    @Override
+    public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
+        LOG.warn("BGP session encountered error", cause);
+        if (cause.getCause() instanceof BGPDocumentedException) {
+            this.terminate((BGPDocumentedException) cause.getCause());
+        } else {
+            this.close();
+        }
+    }
 }