opendaylight/netconf/netconf-netty-util/src/main/java/org/opendaylight/controller/netconf/nettyutil/AbstractNetconfSessionNegotiator.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
   9 package org.opendaylight.controller.netconf.nettyutil;
  10
  11 import com.google.common.base.Optional;
  12 import com.google.common.base.Preconditions;
  13 import io.netty.channel.Channel;
  14 import io.netty.channel.ChannelFuture;
  15 import io.netty.channel.ChannelHandler;
  16 import io.netty.channel.ChannelHandlerContext;
  17 import io.netty.channel.ChannelInboundHandlerAdapter;
  18 import io.netty.handler.ssl.SslHandler;
  19 import io.netty.util.Timeout;
  20 import io.netty.util.Timer;
  21 import io.netty.util.TimerTask;
  22 import io.netty.util.concurrent.Future;
  23 import io.netty.util.concurrent.GenericFutureListener;
  24 import io.netty.util.concurrent.Promise;
  25 import java.util.concurrent.TimeUnit;
  26 import org.opendaylight.controller.netconf.api.NetconfDocumentedException;
  27 import org.opendaylight.controller.netconf.api.NetconfMessage;
  28 import org.opendaylight.controller.netconf.api.NetconfSessionListener;
  29 import org.opendaylight.controller.netconf.api.NetconfSessionPreferences;
  30 import org.opendaylight.controller.netconf.nettyutil.handler.FramingMechanismHandlerFactory;
  31 import org.opendaylight.controller.netconf.nettyutil.handler.NetconfChunkAggregator;
  32 import org.opendaylight.controller.netconf.nettyutil.handler.NetconfMessageToXMLEncoder;
  33 import org.opendaylight.controller.netconf.nettyutil.handler.NetconfXMLToHelloMessageDecoder;
  34 import org.opendaylight.controller.netconf.nettyutil.handler.NetconfXMLToMessageDecoder;
  35 import org.opendaylight.controller.netconf.util.messages.FramingMechanism;
  36 import org.opendaylight.controller.netconf.util.messages.NetconfHelloMessage;
  37 import org.opendaylight.protocol.framework.AbstractSessionNegotiator;
  38 import org.slf4j.Logger;
  39 import org.slf4j.LoggerFactory;
  40 import org.w3c.dom.Document;
  41 import org.w3c.dom.NodeList;
  42
  43 public abstract class AbstractNetconfSessionNegotiator<P extends NetconfSessionPreferences, S extends AbstractNetconfSession<S, L>, L extends NetconfSessionListener<S>>
  44     extends AbstractSessionNegotiator<NetconfHelloMessage, S> {
  45
  46     private static final Logger LOG = LoggerFactory.getLogger(AbstractNetconfSessionNegotiator.class);
  47
  48     public static final String NAME_OF_EXCEPTION_HANDLER = "lastExceptionHandler";
  49
  50     protected final P sessionPreferences;
  51
  52     private final L sessionListener;
  53     private Timeout timeout;
  54
  55     /**
  56      * Possible states for Finite State Machine
  57      */
  58     protected enum State {
  59         IDLE, OPEN_WAIT, FAILED, ESTABLISHED
  60     }
  61
  62     private State state = State.IDLE;
  63     private final Promise<S> promise;
  64     private final Timer timer;
  65     private final long connectionTimeoutMillis;
  66
  67     // TODO shrink constructor
  68     protected AbstractNetconfSessionNegotiator(final P sessionPreferences, final Promise<S> promise, final Channel channel, final Timer timer,
  69             final L sessionListener, final long connectionTimeoutMillis) {
  70         super(promise, channel);
  71         this.sessionPreferences = sessionPreferences;
  72         this.promise = promise;
  73         this.timer = timer;
  74         this.sessionListener = sessionListener;
  75         this.connectionTimeoutMillis = connectionTimeoutMillis;
  76     }
  77
  78     @Override
  79     protected final void startNegotiation() {
  80         final Optional<SslHandler> sslHandler = getSslHandler(channel);
  81         if (sslHandler.isPresent()) {
  82             Future<Channel> future = sslHandler.get().handshakeFuture();
  83             future.addListener(new GenericFutureListener<Future<? super Channel>>() {
  84                 @Override
  85                 public void operationComplete(final Future<? super Channel> future) {
  86                     Preconditions.checkState(future.isSuccess(), "Ssl handshake was not successful");
  87                     LOG.debug("Ssl handshake complete");
  88                     start();
  89                 }
  90             });
  91         } else {
  92             start();
  93         }
  94     }
  95
  96     private static Optional<SslHandler> getSslHandler(final Channel channel) {
  97         final SslHandler sslHandler = channel.pipeline().get(SslHandler.class);
  98         return sslHandler == null ? Optional.<SslHandler> absent() : Optional.of(sslHandler);
  99     }
 100
 101     public P getSessionPreferences() {
 102         return sessionPreferences;
 103     }
 104
 105     private void start() {
 106         final NetconfMessage helloMessage = this.sessionPreferences.getHelloMessage();
 107         LOG.debug("Session negotiation started with hello message {} on channel {}", helloMessage, channel);
 108
 109         channel.pipeline().addLast(NAME_OF_EXCEPTION_HANDLER, new ExceptionHandlingInboundChannelHandler());
 110
 111         // FIXME, make sessionPreferences return HelloMessage, move NetconfHelloMessage to API
 112         sendMessage((NetconfHelloMessage)helloMessage);
 113
 114         replaceHelloMessageOutboundHandler();
 115         changeState(State.OPEN_WAIT);
 116
 117         timeout = this.timer.newTimeout(new TimerTask() {
 118             @Override
 119             public void run(final Timeout timeout) {
 120                 synchronized (this) {
 121                     if (state != State.ESTABLISHED) {
 122
 123                         LOG.debug("Connection timeout after {}, session is in state {}", timeout, state);
 124
 125                         // Do not fail negotiation if promise is done or canceled
 126                         // It would result in setting result of the promise second time and that throws exception
 127                         if (isPromiseFinished() == false) {
 128                             negotiationFailed(new IllegalStateException("Session was not established after " + timeout));
 129                             changeState(State.FAILED);
 130
 131                             channel.closeFuture().addListener(new GenericFutureListener<ChannelFuture>() {
 132                                 @Override
 133                                 public void operationComplete(final ChannelFuture future) throws Exception {
 134                                     if(future.isSuccess()) {
 135                                         LOG.debug("Channel {} closed: success", future.channel());
 136                                     } else {
 137                                         LOG.warn("Channel {} closed: fail", future.channel());
 138                                     }
 139                                 }
 140                             });
 141                         }
 142                     } else if(channel.isOpen()) {
 143                         channel.pipeline().remove(NAME_OF_EXCEPTION_HANDLER);
 144                     }
 145                 }
 146             }
 147
 148             private boolean isPromiseFinished() {
 149                 return promise.isDone() || promise.isCancelled();
 150             }
 151
 152         }, connectionTimeoutMillis, TimeUnit.MILLISECONDS);
 153     }
 154
 155     private void cancelTimeout() {
 156         if(timeout!=null) {
 157             timeout.cancel();
 158         }
 159     }
 160
 161     protected final S getSessionForHelloMessage(final NetconfHelloMessage netconfMessage) throws NetconfDocumentedException {
 162         Preconditions.checkNotNull(netconfMessage, "netconfMessage");
 163
 164         final Document doc = netconfMessage.getDocument();
 165
 166         if (shouldUseChunkFraming(doc)) {
 167             insertChunkFramingToPipeline();
 168         }
 169
 170         changeState(State.ESTABLISHED);
 171         return getSession(sessionListener, channel, netconfMessage);
 172     }
 173
 174     /**
 175      * Insert chunk framing handlers into the pipeline
 176      */
 177     private void insertChunkFramingToPipeline() {
 178         replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_FRAME_ENCODER,
 179                 FramingMechanismHandlerFactory.createHandler(FramingMechanism.CHUNK));
 180         replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_AGGREGATOR,
 181                 new NetconfChunkAggregator());
 182     }
 183
 184     private boolean shouldUseChunkFraming(final Document doc) {
 185         return containsBase11Capability(doc)
 186                 && containsBase11Capability(sessionPreferences.getHelloMessage().getDocument());
 187     }
 188
 189     /**
 190      * Remove special inbound handler for hello message. Insert regular netconf xml message (en|de)coders.
 191      *
 192      * Inbound hello message handler should be kept until negotiation is successful
 193      * It caches any non-hello messages while negotiation is still in progress
 194      */
 195     protected final void replaceHelloMessageInboundHandler(final S session) {
 196         ChannelHandler helloMessageHandler = replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, new NetconfXMLToMessageDecoder());
 197
 198         Preconditions.checkState(helloMessageHandler instanceof NetconfXMLToHelloMessageDecoder,
 199                 "Pipeline handlers misplaced on session: %s, pipeline: %s", session, channel.pipeline());
 200         Iterable<NetconfMessage> netconfMessagesFromNegotiation =
 201                 ((NetconfXMLToHelloMessageDecoder) helloMessageHandler).getPostHelloNetconfMessages();
 202
 203         // Process messages received during negotiation
 204         // The hello message handler does not have to be synchronized, since it is always call from the same thread by netty
 205         // It means, we are now using the thread now
 206         for (NetconfMessage message : netconfMessagesFromNegotiation) {
 207             session.handleMessage(message);
 208         }
 209     }
 210
 211     /**
 212      * Remove special outbound handler for hello message. Insert regular netconf xml message (en|de)coders.
 213      */
 214     private void replaceHelloMessageOutboundHandler() {
 215         replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_ENCODER, new NetconfMessageToXMLEncoder());
 216     }
 217
 218     private static ChannelHandler replaceChannelHandler(final Channel channel, final String handlerKey, final ChannelHandler decoder) {
 219         return channel.pipeline().replace(handlerKey, handlerKey, decoder);
 220     }
 221
 222     protected abstract S getSession(L sessionListener, Channel channel, NetconfHelloMessage message) throws NetconfDocumentedException;
 223
 224     private synchronized void changeState(final State newState) {
 225         LOG.debug("Changing state from : {} to : {} for channel: {}", state, newState, channel);
 226         Preconditions.checkState(isStateChangePermitted(state, newState), "Cannot change state from %s to %s for chanel %s", state,
 227                 newState, channel);
 228         this.state = newState;
 229     }
 230
 231     private boolean containsBase11Capability(final Document doc) {
 232         final NodeList nList = doc.getElementsByTagName("capability");
 233         for (int i = 0; i < nList.getLength(); i++) {
 234             if (nList.item(i).getTextContent().contains("base:1.1")) {
 235                 return true;
 236             }
 237         }
 238         return false;
 239     }
 240
 241     private static boolean isStateChangePermitted(final State state, final State newState) {
 242         if (state == State.IDLE && newState == State.OPEN_WAIT) {
 243             return true;
 244         }
 245         if (state == State.OPEN_WAIT && newState == State.ESTABLISHED) {
 246             return true;
 247         }
 248         if (state == State.OPEN_WAIT && newState == State.FAILED) {
 249             return true;
 250         }
 251         LOG.debug("Transition from {} to {} is not allowed", state, newState);
 252         return false;
 253     }
 254
 255     /**
 256      * Handler to catch exceptions in pipeline during negotiation
 257      */
 258     private final class ExceptionHandlingInboundChannelHandler extends ChannelInboundHandlerAdapter {
 259         @Override
 260         public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
 261             LOG.warn("An exception occurred during negotiation with {}", channel.remoteAddress(), cause);
 262             cancelTimeout();
 263             negotiationFailed(cause);
 264             changeState(State.FAILED);
 265         }
 266     }
 267 }