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.controller.netconf.util.xml.XmlUtil;
  38 import org.opendaylight.protocol.framework.AbstractSessionNegotiator;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41 import org.w3c.dom.Document;
  42 import org.w3c.dom.NodeList;
  43
  44 public abstract class AbstractNetconfSessionNegotiator<P extends NetconfSessionPreferences, S extends AbstractNetconfSession<S, L>, L extends NetconfSessionListener<S>>
  45 extends AbstractSessionNegotiator<NetconfHelloMessage, S> {
  46
  47     private static final Logger logger = LoggerFactory.getLogger(AbstractNetconfSessionNegotiator.class);
  48
  49     public static final String NAME_OF_EXCEPTION_HANDLER = "lastExceptionHandler";
  50
  51     protected final P sessionPreferences;
  52
  53     private final L sessionListener;
  54     private Timeout timeout;
  55
  56     /**
  57      * Possible states for Finite State Machine
  58      */
  59     protected enum State {
  60         IDLE, OPEN_WAIT, FAILED, ESTABLISHED
  61     }
  62
  63     private State state = State.IDLE;
  64     private final Promise<S> promise;
  65     private final Timer timer;
  66     private final long connectionTimeoutMillis;
  67
  68     // TODO shrink constructor
  69     protected AbstractNetconfSessionNegotiator(P sessionPreferences, Promise<S> promise, Channel channel, Timer timer,
  70             L sessionListener, long connectionTimeoutMillis) {
  71         super(promise, channel);
  72         this.sessionPreferences = sessionPreferences;
  73         this.promise = promise;
  74         this.timer = timer;
  75         this.sessionListener = sessionListener;
  76         this.connectionTimeoutMillis = connectionTimeoutMillis;
  77     }
  78
  79     @Override
  80     protected final void startNegotiation() {
  81         final Optional<SslHandler> sslHandler = getSslHandler(channel);
  82         if (sslHandler.isPresent()) {
  83             Future<Channel> future = sslHandler.get().handshakeFuture();
  84             future.addListener(new GenericFutureListener<Future<? super Channel>>() {
  85                 @Override
  86                 public void operationComplete(Future<? super Channel> future) {
  87                     Preconditions.checkState(future.isSuccess(), "Ssl handshake was not successful");
  88                     logger.debug("Ssl handshake complete");
  89                     start();
  90                 }
  91             });
  92         } else {
  93             start();
  94         }
  95     }
  96
  97     private static Optional<SslHandler> getSslHandler(Channel channel) {
  98         final SslHandler sslHandler = channel.pipeline().get(SslHandler.class);
  99         return sslHandler == null ? Optional.<SslHandler> absent() : Optional.of(sslHandler);
 100     }
 101
 102     public P getSessionPreferences() {
 103         return sessionPreferences;
 104     }
 105
 106     private void start() {
 107         final NetconfMessage helloMessage = this.sessionPreferences.getHelloMessage();
 108         logger.debug("Session negotiation started with hello message {} on channel {}", XmlUtil.toString(helloMessage.getDocument()), channel);
 109
 110         channel.pipeline().addLast(NAME_OF_EXCEPTION_HANDLER, new ExceptionHandlingInboundChannelHandler());
 111
 112         // FIXME, make sessionPreferences return HelloMessage, move NetconfHelloMessage to API
 113         sendMessage((NetconfHelloMessage)helloMessage);
 114
 115         replaceHelloMessageOutboundHandler();
 116         changeState(State.OPEN_WAIT);
 117
 118         timeout = this.timer.newTimeout(new TimerTask() {
 119             @Override
 120             public void run(final Timeout timeout) {
 121                 synchronized (this) {
 122                     if (state != State.ESTABLISHED) {
 123
 124                         logger.debug("Connection timeout after {}, session is in state {}", timeout, state);
 125
 126                         // Do not fail negotiation if promise is done or canceled
 127                         // It would result in setting result of the promise second time and that throws exception
 128                         if (isPromiseFinished() == false) {
 129                             negotiationFailed(new IllegalStateException("Session was not established after " + timeout));
 130                             changeState(State.FAILED);
 131
 132                             channel.closeFuture().addListener(new GenericFutureListener<ChannelFuture>() {
 133                                 @Override
 134                                 public void operationComplete(ChannelFuture future) throws Exception {
 135                                     if(future.isSuccess()) {
 136                                         logger.debug("Channel {} closed: success", future.channel());
 137                                     } else {
 138                                         logger.warn("Channel {} closed: fail", future.channel());
 139                                     }
 140                                 }
 141                             });
 142                         }
 143                     } else if(channel.isOpen()) {
 144                         channel.pipeline().remove(NAME_OF_EXCEPTION_HANDLER);
 145                     }
 146                 }
 147             }
 148
 149             private boolean isPromiseFinished() {
 150                 return promise.isDone() || promise.isCancelled();
 151             }
 152
 153         }, connectionTimeoutMillis, TimeUnit.MILLISECONDS);
 154     }
 155
 156     private void cancelTimeout() {
 157         if(timeout!=null) {
 158             timeout.cancel();
 159         }
 160     }
 161
 162     protected final S getSessionForHelloMessage(NetconfHelloMessage netconfMessage) throws NetconfDocumentedException {
 163         Preconditions.checkNotNull(netconfMessage, "netconfMessage");
 164
 165         final Document doc = netconfMessage.getDocument();
 166
 167         if (shouldUseChunkFraming(doc)) {
 168             insertChunkFramingToPipeline();
 169         }
 170
 171         changeState(State.ESTABLISHED);
 172         return getSession(sessionListener, channel, netconfMessage);
 173     }
 174
 175     /**
 176      * Insert chunk framing handlers into the pipeline
 177      */
 178     private void insertChunkFramingToPipeline() {
 179         replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_FRAME_ENCODER,
 180                 FramingMechanismHandlerFactory.createHandler(FramingMechanism.CHUNK));
 181         replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_AGGREGATOR,
 182                 new NetconfChunkAggregator());
 183     }
 184
 185     private boolean shouldUseChunkFraming(Document doc) {
 186         return containsBase11Capability(doc)
 187                 && containsBase11Capability(sessionPreferences.getHelloMessage().getDocument());
 188     }
 189
 190     /**
 191      * Remove special inbound handler for hello message. Insert regular netconf xml message (en|de)coders.
 192      *
 193      * Inbound hello message handler should be kept until negotiation is successful
 194      * It caches any non-hello messages while negotiation is still in progress
 195      */
 196     protected final void replaceHelloMessageInboundHandler(final S session) {
 197         ChannelHandler helloMessageHandler = replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, new NetconfXMLToMessageDecoder());
 198
 199         Preconditions.checkState(helloMessageHandler instanceof NetconfXMLToHelloMessageDecoder,
 200                 "Pipeline handlers misplaced on session: %s, pipeline: %s", session, channel.pipeline());
 201         Iterable<NetconfMessage> netconfMessagesFromNegotiation =
 202                 ((NetconfXMLToHelloMessageDecoder) helloMessageHandler).getPostHelloNetconfMessages();
 203
 204         // Process messages received during negotiation
 205         // The hello message handler does not have to be synchronized, since it is always call from the same thread by netty
 206         // It means, we are now using the thread now
 207         for (NetconfMessage message : netconfMessagesFromNegotiation) {
 208             session.handleMessage(message);
 209         }
 210     }
 211
 212     /**
 213      * Remove special outbound handler for hello message. Insert regular netconf xml message (en|de)coders.
 214      */
 215     private void replaceHelloMessageOutboundHandler() {
 216         replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_ENCODER, new NetconfMessageToXMLEncoder());
 217     }
 218
 219     private static ChannelHandler replaceChannelHandler(Channel channel, String handlerKey, ChannelHandler decoder) {
 220         return channel.pipeline().replace(handlerKey, handlerKey, decoder);
 221     }
 222
 223     protected abstract S getSession(L sessionListener, Channel channel, NetconfHelloMessage message) throws NetconfDocumentedException;
 224
 225     private synchronized void changeState(final State newState) {
 226         logger.debug("Changing state from : {} to : {} for channel: {}", state, newState, channel);
 227         Preconditions.checkState(isStateChangePermitted(state, newState), "Cannot change state from %s to %s for chanel %s", state,
 228                 newState, channel);
 229         this.state = newState;
 230     }
 231
 232     private boolean containsBase11Capability(final Document doc) {
 233         final NodeList nList = doc.getElementsByTagName("capability");
 234         for (int i = 0; i < nList.getLength(); i++) {
 235             if (nList.item(i).getTextContent().contains("base:1.1")) {
 236                 return true;
 237             }
 238         }
 239         return false;
 240     }
 241
 242     private static boolean isStateChangePermitted(State state, State newState) {
 243         if (state == State.IDLE && newState == State.OPEN_WAIT) {
 244             return true;
 245         }
 246         if (state == State.OPEN_WAIT && newState == State.ESTABLISHED) {
 247             return true;
 248         }
 249         if (state == State.OPEN_WAIT && newState == State.FAILED) {
 250             return true;
 251         }
 252         logger.debug("Transition from {} to {} is not allowed", state, newState);
 253         return false;
 254     }
 255
 256     /**
 257      * Handler to catch exceptions in pipeline during negotiation
 258      */
 259     private final class ExceptionHandlingInboundChannelHandler extends ChannelInboundHandlerAdapter {
 260         @Override
 261         public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
 262             logger.warn("An exception occurred during negotiation with {}", channel.remoteAddress(), cause);
 263             cancelTimeout();
 264             negotiationFailed(cause);
 265             changeState(State.FAILED);
 266         }
 267     }
 268 }