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
  14 import io.netty.channel.Channel;
  15 import io.netty.handler.ssl.SslHandler;
  16 import io.netty.util.Timeout;
  17 import io.netty.util.Timer;
  18 import io.netty.util.TimerTask;
  19 import io.netty.util.concurrent.Future;
  20 import io.netty.util.concurrent.GenericFutureListener;
  21 import io.netty.util.concurrent.Promise;
  22
  23 import org.opendaylight.controller.netconf.api.NetconfSession;
  24 import org.opendaylight.controller.netconf.api.NetconfMessage;
  25 import org.opendaylight.controller.netconf.api.NetconfSessionPreferences;
  26 import org.opendaylight.controller.netconf.util.handler.FramingMechanismHandlerFactory;
  27 import org.opendaylight.controller.netconf.util.handler.NetconfMessageAggregator;
  28 import org.opendaylight.controller.netconf.util.handler.NetconfMessageChunkDecoder;
  29 import org.opendaylight.controller.netconf.util.messages.FramingMechanism;
  30 import org.opendaylight.controller.netconf.util.xml.XmlElement;
  31 import org.opendaylight.controller.netconf.util.xml.XmlNetconfConstants;
  32 import org.opendaylight.controller.netconf.util.xml.XmlUtil;
  33 import org.opendaylight.protocol.framework.AbstractSessionNegotiator;
  34 import org.opendaylight.protocol.framework.SessionListener;
  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 NetconfSession>
  43         extends AbstractSessionNegotiator<NetconfMessage, S> {
  44
  45     // TODO what time ?
  46     private static final long INITIAL_HOLDTIMER = 1;
  47     private static final Logger logger = LoggerFactory.getLogger(AbstractNetconfSessionNegotiator.class);
  48
  49     protected final P sessionPreferences;
  50
  51     private final SessionListener sessionListener;
  52
  53     /**
  54      * Possible states for Finite State Machine
  55      */
  56     private enum State {
  57         IDLE, OPEN_WAIT, FAILED, ESTABLISHED
  58     }
  59
  60     private State state = State.IDLE;
  61     private final Timer timer;
  62
  63     protected AbstractNetconfSessionNegotiator(P sessionPreferences, Promise<S> promise, Channel channel, Timer timer,
  64             SessionListener sessionListener) {
  65         super(promise, channel);
  66         this.sessionPreferences = sessionPreferences;
  67         this.timer = timer;
  68         this.sessionListener = sessionListener;
  69     }
  70
  71     @Override
  72     protected void startNegotiation() throws Exception {
  73         final Optional<SslHandler> sslHandler = getSslHandler(channel);
  74         if (sslHandler.isPresent()) {
  75             Future<Channel> future = sslHandler.get().handshakeFuture();
  76             future.addListener(new GenericFutureListener<Future<? super Channel>>() {
  77                 @Override
  78                 public void operationComplete(Future<? super Channel> future) throws Exception {
  79                     Preconditions.checkState(future.isSuccess(), "Ssl handshake was not successful");
  80                     logger.debug("Ssl handshake complete");
  81                     start();
  82                 }
  83             });
  84         } else
  85             start();
  86     }
  87
  88     private static Optional<SslHandler> getSslHandler(Channel channel) {
  89         final SslHandler sslHandler = channel.pipeline().get(SslHandler.class);
  90         return sslHandler == null ? Optional.<SslHandler> absent() : Optional.of(sslHandler);
  91     }
  92
  93     private void start() {
  94         final NetconfMessage helloMessage = this.sessionPreferences.getHelloMessage();
  95         logger.debug("Session negotiation started with hello message {}", XmlUtil.toString(helloMessage.getDocument()));
  96
  97         sendMessage(helloMessage);
  98         changeState(State.OPEN_WAIT);
  99
 100         this.timer.newTimeout(new TimerTask() {
 101             @Override
 102             public void run(final Timeout timeout) throws Exception {
 103                 synchronized (this) {
 104                     if (state != State.ESTABLISHED) {
 105                         final IllegalStateException cause = new IllegalStateException(
 106                                 "Session was not established after " + timeout);
 107                         negotiationFailed(cause);
 108                         changeState(State.FAILED);
 109                     }
 110                 }
 111             }
 112         }, INITIAL_HOLDTIMER, TimeUnit.MINUTES);
 113     }
 114
 115     private void sendMessage(NetconfMessage message) {
 116         this.channel.writeAndFlush(message);
 117     }
 118
 119     @Override
 120     protected void handleMessage(NetconfMessage netconfMessage) {
 121         final Document doc = netconfMessage.getDocument();
 122
 123         if (isHelloMessage(doc)) {
 124             if (containsBase11Capability(doc)
 125                     && containsBase11Capability(sessionPreferences.getHelloMessage().getDocument())) {
 126                 channel.pipeline().replace("frameEncoder", "frameEncoder",
 127                         FramingMechanismHandlerFactory.createHandler(FramingMechanism.CHUNK));
 128                 channel.pipeline().replace("aggregator", "aggregator",
 129                         new NetconfMessageAggregator(FramingMechanism.CHUNK));
 130                 channel.pipeline().addAfter("aggregator", "chunkDecoder", new NetconfMessageChunkDecoder());
 131             }
 132             changeState(State.ESTABLISHED);
 133             S session = getSession(sessionListener, channel, netconfMessage);
 134             negotiationSuccessful(session);
 135         } else {
 136             final IllegalStateException cause = new IllegalStateException(
 137                     "Received message was not hello as expected, but was " + XmlUtil.toString(doc));
 138             logger.warn("Negotiation of netconf session failed", cause);
 139             negotiationFailed(cause);
 140         }
 141     }
 142
 143     protected abstract S getSession(SessionListener sessionListener, Channel channel, NetconfMessage message);
 144
 145     private boolean isHelloMessage(Document doc) {
 146         try {
 147             XmlElement.fromDomElementWithExpected(doc.getDocumentElement(), "hello",
 148                     XmlNetconfConstants.URN_IETF_PARAMS_XML_NS_NETCONF_BASE_1_0);
 149
 150         } catch (IllegalArgumentException | IllegalStateException e) {
 151             return false;
 152         }
 153         return true;
 154     }
 155
 156     private void changeState(final State newState) {
 157         logger.debug("Changing state from : {} to : {}", state, newState);
 158         Preconditions.checkState(isStateChangePermitted(state, newState), "Cannot change state from %s to %s", state,
 159                 newState);
 160         this.state = newState;
 161     }
 162
 163     private boolean containsBase11Capability(final Document doc) {
 164         final NodeList nList = doc.getElementsByTagName("capability");
 165         for (int i = 0; i < nList.getLength(); i++) {
 166             if (nList.item(i).getTextContent().contains("base:1.1")) {
 167                 return true;
 168             }
 169         }
 170         return false;
 171     }
 172
 173     private static boolean isStateChangePermitted(State state, State newState) {
 174         if (state == State.IDLE && newState == State.OPEN_WAIT)
 175             return true;
 176         if (state == State.OPEN_WAIT && newState == State.ESTABLISHED)
 177             return true;
 178         if (state == State.OPEN_WAIT && newState == State.FAILED)
 179             return true;
 180
 181         return false;
 182     }
 183 }