2 * Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved.
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
9 package org.opendaylight.controller.netconf.util;
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;
40 import java.util.concurrent.TimeUnit;
42 public abstract class AbstractNetconfSessionNegotiator<P extends NetconfSessionPreferences, S extends AbstractNetconfSession<S, L>, L extends NetconfSessionListener<S>>
43 extends AbstractSessionNegotiator<NetconfHelloMessage, S> {
45 private static final Logger logger = LoggerFactory.getLogger(AbstractNetconfSessionNegotiator.class);
47 public static final String NAME_OF_EXCEPTION_HANDLER = "lastExceptionHandler";
49 protected final P sessionPreferences;
51 private final L sessionListener;
52 private Timeout timeout;
55 * Possible states for Finite State Machine
57 protected enum State {
58 IDLE, OPEN_WAIT, FAILED, ESTABLISHED
61 private State state = State.IDLE;
62 private final Timer timer;
63 private final long connectionTimeoutMillis;
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;
71 this.sessionListener = sessionListener;
72 this.connectionTimeoutMillis = connectionTimeoutMillis;
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>>() {
82 public void operationComplete(Future<? super Channel> future) {
83 Preconditions.checkState(future.isSuccess(), "Ssl handshake was not successful");
84 logger.debug("Ssl handshake complete");
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);
98 public P getSessionPreferences() {
99 return sessionPreferences;
102 private void start() {
103 final NetconfMessage helloMessage = this.sessionPreferences.getHelloMessage();
104 logger.debug("Session negotiation started with hello message {}", XmlUtil.toString(helloMessage.getDocument()));
106 channel.pipeline().addLast(NAME_OF_EXCEPTION_HANDLER, new ExceptionHandlingInboundChannelHandler());
108 timeout = this.timer.newTimeout(new TimerTask() {
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);
123 }, connectionTimeoutMillis, TimeUnit.MILLISECONDS);
125 // FIXME, make sessionPreferences return HelloMessage, move NetconfHelloMessage to API
126 sendMessage((NetconfHelloMessage)helloMessage);
127 changeState(State.OPEN_WAIT);
129 private void cancelTimeout() {
136 protected void handleMessage(NetconfHelloMessage netconfMessage) {
137 S session = getSessionForHelloMessage(netconfMessage);
138 negotiationSuccessful(session);
141 protected final S getSessionForHelloMessage(NetconfHelloMessage netconfMessage) {
142 Preconditions.checkNotNull(netconfMessage, "netconfMessage");
144 final Document doc = netconfMessage.getDocument();
146 replaceHelloMessageHandlers();
148 if (shouldUseChunkFraming(doc)) {
149 insertChunkFramingToPipeline();
152 changeState(State.ESTABLISHED);
153 return getSession(sessionListener, channel, netconfMessage);
157 * Insert chunk framing handlers into the pipeline
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());
166 protected boolean shouldUseChunkFraming(Document doc) {
167 return containsBase11Capability(doc)
168 && containsBase11Capability(sessionPreferences.getHelloMessage().getDocument());
172 * Remove special handlers for hello message. Insert regular netconf xml message (en|de)coders.
174 protected void replaceHelloMessageHandlers() {
175 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, new NetconfXMLToMessageDecoder());
176 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_ENCODER, new NetconfMessageToXMLEncoder());
179 private static ChannelHandler replaceChannelHandler(Channel channel, String handlerKey, ChannelHandler decoder) {
180 return channel.pipeline().replace(handlerKey, handlerKey, decoder);
183 protected abstract S getSession(L sessionListener, Channel channel, NetconfHelloMessage message);
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,
189 this.state = newState;
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")) {
202 private static boolean isStateChangePermitted(State state, State newState) {
203 if (state == State.IDLE && newState == State.OPEN_WAIT) {
206 if (state == State.OPEN_WAIT && newState == State.ESTABLISHED) {
209 if (state == State.OPEN_WAIT && newState == State.FAILED) {
212 logger.debug("Transition from {} to {} is not allowed", state, newState);
217 * Handler to catch exceptions in pipeline during negotiation
219 private final class ExceptionHandlingInboundChannelHandler extends ChannelInboundHandlerAdapter {
221 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
222 logger.warn("An exception occurred during negotiation on channel {}", channel.localAddress(), cause);
224 negotiationFailed(cause);
225 changeState(State.FAILED);