bmp/bmp-impl/src/main/java/org/opendaylight/protocol/bmp/impl/session/BmpSessionImpl.java

   1 /*
   2  * Copyright (c) 2015 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
   9 package org.opendaylight.protocol.bmp.impl.session;
  10
  11 import static java.util.Objects.requireNonNull;
  12
  13 import com.google.common.base.MoreObjects;
  14 import com.google.common.base.MoreObjects.ToStringHelper;
  15 import com.google.common.base.Preconditions;
  16 import io.netty.channel.Channel;
  17 import io.netty.channel.ChannelHandlerContext;
  18 import io.netty.channel.SimpleChannelInboundHandler;
  19 import java.io.IOException;
  20 import java.net.InetAddress;
  21 import java.net.InetSocketAddress;
  22 import javax.annotation.Nonnull;
  23 import javax.annotation.concurrent.GuardedBy;
  24 import org.opendaylight.protocol.bmp.api.BmpSession;
  25 import org.opendaylight.protocol.bmp.api.BmpSessionListener;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bmp.message.rev171207.InitiationMessage;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bmp.message.rev171207.Reason;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bmp.message.rev171207.TerminationMessage;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bmp.message.rev171207.termination.Tlvs;
  30 import org.opendaylight.yangtools.yang.binding.Notification;
  31 import org.slf4j.Logger;
  32 import org.slf4j.LoggerFactory;
  33
  34 public final class BmpSessionImpl extends SimpleChannelInboundHandler<Notification> implements BmpSession {
  35
  36     private static final Logger LOG = LoggerFactory.getLogger(BmpSessionImpl.class);
  37
  38     private final BmpSessionListener listener;
  39     @GuardedBy("this")
  40     private Channel channel;
  41     @GuardedBy("this")
  42     private State state;
  43
  44     public BmpSessionImpl(@Nonnull final BmpSessionListener listener) {
  45         this.listener = requireNonNull(listener);
  46         this.state = State.IDLE;
  47     }
  48
  49     @Override
  50     protected void channelRead0(final ChannelHandlerContext channelHandlerContext, final Notification msg) {
  51         this.handleMessage(msg);
  52     }
  53
  54     @Override
  55     @SuppressWarnings("checkstyle:IllegalCatch")
  56     public void channelInactive(final ChannelHandlerContext ctx) {
  57         LOG.debug("Channel {} inactive.", ctx.channel());
  58         this.endOfInput();
  59
  60         try {
  61             super.channelInactive(ctx);
  62         } catch (final Exception e) {
  63             throw new IllegalStateException("Failed to delegate channel inactive event on channel " + ctx.channel(), e);
  64         }
  65     }
  66
  67     @Override
  68     public synchronized void channelActive(final ChannelHandlerContext ctx) {
  69         this.channel = ctx.channel();
  70         LOG.info("Starting session {} <-> {}.", this.channel.localAddress(), this.channel.remoteAddress());
  71         Preconditions.checkArgument(State.IDLE == this.state);
  72         this.listener.onSessionUp(this);
  73         this.state = State.UP;
  74     }
  75
  76     @Override
  77     public synchronized void close() {
  78         LOG.info("Closing session: {}", this);
  79         if (this.channel != null) {
  80             this.channel.close();
  81             this.channel = null;
  82             this.state = State.IDLE;
  83         }
  84     }
  85
  86     @Override
  87     public synchronized InetAddress getRemoteAddress() {
  88         final InetSocketAddress address = (InetSocketAddress) this.channel.remoteAddress();
  89         requireNonNull(address, "BMP Channel doesn't have a valid remote address.");
  90         return address.getAddress();
  91     }
  92
  93     @Override
  94     public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) throws Exception {
  95         LOG.error("Exception caught in BMP Session.", cause);
  96         close();
  97         this.listener.onSessionDown(new IllegalStateException(cause));
  98     }
  99
 100     @Override
 101     public String toString() {
 102         return addToStringAttributes(MoreObjects.toStringHelper(this)).toString();
 103     }
 104
 105     private synchronized ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 106         toStringHelper.add("channel", this.channel);
 107         return toStringHelper;
 108     }
 109
 110     private synchronized void handleMessage(final Notification msg) {
 111         switch (this.state) {
 112             case UP:
 113                 if (msg instanceof InitiationMessage) {
 114                     this.state = State.INITIATED;
 115                     this.listener.onMessage(msg);
 116                 } else {
 117                     LOG.warn("Unexpected message received {}, "
 118                             + "expected was BMP Initiation Message. Closing session.", msg);
 119                     close();
 120                 }
 121                 break;
 122             case INITIATED:
 123                 if (msg instanceof TerminationMessage) {
 124                     LOG.info("Session {} terminated by remote with reason: {}",
 125                             this, getTerminationReason((TerminationMessage) msg));
 126                     close();
 127                 } else {
 128                     this.listener.onMessage(msg);
 129                 }
 130                 break;
 131             case IDLE:
 132                 throw new IllegalStateException("Received message " + msg
 133                         + " while BMP Session " + this + " was not active.");
 134             default:
 135                 break;
 136         }
 137     }
 138
 139     private static Reason getTerminationReason(final TerminationMessage terminationMessage) {
 140         final Tlvs tlvs = terminationMessage.getTlvs();
 141         if (tlvs != null && tlvs.getReasonTlv() != null) {
 142             return tlvs.getReasonTlv().getReason();
 143         }
 144         return null;
 145     }
 146
 147     private void endOfInput() {
 148         this.listener.onSessionDown(new IOException("End of input detected. Closing the session."));
 149     }
 150
 151     protected enum State {
 152         /**
 153          * Waiting for connection to be established.
 154          */
 155         IDLE,
 156         /**
 157          * The connection has been established. Waiting for Initiation Message.
 158          */
 159         UP,
 160         /**
 161          * The Initiation Messages has been received. Pass incoming messages to session listener.
 162          */
 163         INITIATED
 164     }
 165
 166 }