opendaylight/netconf/netconf-util/src/main/java/org/opendaylight/controller/netconf/util/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.util;
  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.ChannelHandler;
  15 import io.netty.channel.ChannelHandlerContext;
  16 import io.netty.channel.ChannelInboundHandlerAdapter;
  17 import io.netty.handler.ssl.SslHandler;
  18 import io.netty.util.Timeout;
  19 import io.netty.util.Timer;
  20 import io.netty.util.TimerTask;
  21 import io.netty.util.concurrent.Future;
  22 import io.netty.util.concurrent.GenericFutureListener;
  23 import io.netty.util.concurrent.Promise;
  24 import org.opendaylight.controller.netconf.api.NetconfMessage;
  25 import org.opendaylight.controller.netconf.api.NetconfSessionListener;
  26 import org.opendaylight.controller.netconf.api.NetconfSessionPreferences;
  27 import org.opendaylight.controller.netconf.util.handler.FramingMechanismHandlerFactory;
  28 import org.opendaylight.controller.netconf.util.handler.NetconfChunkAggregator;
  29 import org.opendaylight.controller.netconf.util.handler.NetconfMessageToXMLEncoder;
  30 import org.opendaylight.controller.netconf.util.handler.NetconfXMLToMessageDecoder;
  31 import org.opendaylight.controller.netconf.util.messages.FramingMechanism;
  32 import org.opendaylight.controller.netconf.util.messages.NetconfHelloMessage;
  33 import org.opendaylight.controller.netconf.util.xml.XmlUtil;
  34 import org.opendaylight.protocol.framework.AbstractSessionNegotiator;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37 import org.w3c.dom.Document;
  38 import org.w3c.dom.NodeList;
  39
  40 import java.util.concurrent.TimeUnit;
  41
  42 public abstract class AbstractNetconfSessionNegotiator<P extends NetconfSessionPreferences, S extends AbstractNetconfSession<S, L>, L extends NetconfSessionListener<S>>
  43 extends AbstractSessionNegotiator<NetconfHelloMessage, S> {
  44
  45     private static final Logger logger = LoggerFactory.getLogger(AbstractNetconfSessionNegotiator.class);
  46
  47     public static final String NAME_OF_EXCEPTION_HANDLER = "lastExceptionHandler";
  48
  49     protected final P sessionPreferences;
  50
  51     private final L sessionListener;
  52     private Timeout timeout;
  53
  54     /**
  55      * Possible states for Finite State Machine
  56      */
  57     protected enum State {
  58         IDLE, OPEN_WAIT, FAILED, ESTABLISHED
  59     }
  60
  61     private State state = State.IDLE;
  62     private final Timer timer;
  63     private final long connectionTimeoutMillis;
  64
  65     // TODO shrink constructor
  66     protected AbstractNetconfSessionNegotiator(P sessionPreferences, Promise<S> promise, Channel channel, Timer timer,
  67             L sessionListener, long connectionTimeoutMillis) {
  68         super(promise, channel);
  69         this.sessionPreferences = sessionPreferences;
  70         this.timer = timer;
  71         this.sessionListener = sessionListener;
  72         this.connectionTimeoutMillis = connectionTimeoutMillis;
  73     }
  74
  75     @Override
  76     protected void startNegotiation() {
  77         final Optional<SslHandler> sslHandler = getSslHandler(channel);
  78         if (sslHandler.isPresent()) {
  79             Future<Channel> future = sslHandler.get().handshakeFuture();
  80             future.addListener(new GenericFutureListener<Future<? super Channel>>() {
  81                 @Override
  82                 public void operationComplete(Future<? super Channel> future) {
  83                     Preconditions.checkState(future.isSuccess(), "Ssl handshake was not successful");
  84                     logger.debug("Ssl handshake complete");
  85                     start();
  86                 }
  87             });
  88         } else {
  89             start();
  90         }
  91     }
  92
  93     private static Optional<SslHandler> getSslHandler(Channel channel) {
  94         final SslHandler sslHandler = channel.pipeline().get(SslHandler.class);
  95         return sslHandler == null ? Optional.<SslHandler> absent() : Optional.of(sslHandler);
  96     }
  97
  98     public P getSessionPreferences() {
  99         return sessionPreferences;
 100     }
 101
 102     private void start() {
 103         final NetconfMessage helloMessage = this.sessionPreferences.getHelloMessage();
 104         logger.debug("Session negotiation started with hello message {}", XmlUtil.toString(helloMessage.getDocument()));
 105
 106         channel.pipeline().addLast(NAME_OF_EXCEPTION_HANDLER, new ExceptionHandlingInboundChannelHandler());
 107
 108         timeout = this.timer.newTimeout(new TimerTask() {
 109             @Override
 110             public void run(final Timeout timeout) {
 111                 synchronized (this) {
 112                     if (state != State.ESTABLISHED) {
 113                         logger.debug("Connection timeout after {}, session is in state {}", timeout, state);
 114                         final IllegalStateException cause = new IllegalStateException(
 115                                 "Session was not established after " + timeout);
 116                         negotiationFailed(cause);
 117                         changeState(State.FAILED);
 118                     } else if(channel.isOpen()) {
 119                         channel.pipeline().remove(NAME_OF_EXCEPTION_HANDLER);
 120                     }
 121                 }
 122             }
 123         }, connectionTimeoutMillis, TimeUnit.MILLISECONDS);
 124
 125         // FIXME, make sessionPreferences return HelloMessage, move NetconfHelloMessage to API
 126         sendMessage((NetconfHelloMessage)helloMessage);
 127         changeState(State.OPEN_WAIT);
 128     }
 129     private void cancelTimeout() {
 130         if(timeout!=null) {
 131             timeout.cancel();
 132         }
 133     }
 134
 135     @Override
 136     protected void handleMessage(NetconfHelloMessage netconfMessage) {
 137         S session = getSessionForHelloMessage(netconfMessage);
 138         negotiationSuccessful(session);
 139     }
 140
 141     protected final S getSessionForHelloMessage(NetconfHelloMessage netconfMessage) {
 142         Preconditions.checkNotNull(netconfMessage, "netconfMessage");
 143
 144         final Document doc = netconfMessage.getDocument();
 145
 146         replaceHelloMessageHandlers();
 147
 148         if (shouldUseChunkFraming(doc)) {
 149             insertChunkFramingToPipeline();
 150         }
 151
 152         changeState(State.ESTABLISHED);
 153         return getSession(sessionListener, channel, netconfMessage);
 154     }
 155
 156     /**
 157      * Insert chunk framing handlers into the pipeline
 158      */
 159     protected void insertChunkFramingToPipeline() {
 160         replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_FRAME_ENCODER,
 161                 FramingMechanismHandlerFactory.createHandler(FramingMechanism.CHUNK));
 162         replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_AGGREGATOR,
 163                 new NetconfChunkAggregator());
 164     }
 165
 166     protected boolean shouldUseChunkFraming(Document doc) {
 167         return containsBase11Capability(doc)
 168                 && containsBase11Capability(sessionPreferences.getHelloMessage().getDocument());
 169     }
 170
 171     /**
 172      * Remove special handlers for hello message. Insert regular netconf xml message (en|de)coders.
 173      */
 174     protected void replaceHelloMessageHandlers() {
 175         replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, new NetconfXMLToMessageDecoder());
 176         replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_ENCODER, new NetconfMessageToXMLEncoder());
 177     }
 178
 179     private static ChannelHandler replaceChannelHandler(Channel channel, String handlerKey, ChannelHandler decoder) {
 180         return channel.pipeline().replace(handlerKey, handlerKey, decoder);
 181     }
 182
 183     protected abstract S getSession(L sessionListener, Channel channel, NetconfHelloMessage message);
 184
 185     protected synchronized void changeState(final State newState) {
 186         logger.debug("Changing state from : {} to : {}", state, newState);
 187         Preconditions.checkState(isStateChangePermitted(state, newState), "Cannot change state from %s to %s", state,
 188                 newState);
 189         this.state = newState;
 190     }
 191
 192     private boolean containsBase11Capability(final Document doc) {
 193         final NodeList nList = doc.getElementsByTagName("capability");
 194         for (int i = 0; i < nList.getLength(); i++) {
 195             if (nList.item(i).getTextContent().contains("base:1.1")) {
 196                 return true;
 197             }
 198         }
 199         return false;
 200     }
 201
 202     private static boolean isStateChangePermitted(State state, State newState) {
 203         if (state == State.IDLE && newState == State.OPEN_WAIT) {
 204             return true;
 205         }
 206         if (state == State.OPEN_WAIT && newState == State.ESTABLISHED) {
 207             return true;
 208         }
 209         if (state == State.OPEN_WAIT && newState == State.FAILED) {
 210             return true;
 211         }
 212         logger.debug("Transition from {} to {} is not allowed", state, newState);
 213         return false;
 214     }
 215
 216     /**
 217      * Handler to catch exceptions in pipeline during negotiation
 218      */
 219     private final class ExceptionHandlingInboundChannelHandler extends ChannelInboundHandlerAdapter {
 220         @Override
 221         public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
 222             logger.warn("An exception occurred during negotiation on channel {}", channel.localAddress(), cause);
 223             cancelTimeout();
 224             negotiationFailed(cause);
 225             changeState(State.FAILED);
 226         }
 227     }
 228 }