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.netconf.nettyutil;
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.netconf.api.NetconfDocumentedException;
27 import org.opendaylight.netconf.api.NetconfMessage;
28 import org.opendaylight.netconf.api.NetconfSessionListener;
29 import org.opendaylight.netconf.api.NetconfSessionPreferences;
30 import org.opendaylight.netconf.api.messages.NetconfHelloMessage;
31 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
32 import org.opendaylight.netconf.nettyutil.handler.FramingMechanismHandlerFactory;
33 import org.opendaylight.netconf.nettyutil.handler.NetconfChunkAggregator;
34 import org.opendaylight.netconf.nettyutil.handler.NetconfMessageToXMLEncoder;
35 import org.opendaylight.netconf.nettyutil.handler.NetconfXMLToHelloMessageDecoder;
36 import org.opendaylight.netconf.nettyutil.handler.NetconfXMLToMessageDecoder;
37 import org.opendaylight.netconf.util.messages.FramingMechanism;
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;
44 public abstract class AbstractNetconfSessionNegotiator<P extends NetconfSessionPreferences,
45 S extends AbstractNetconfSession<S, L>, L extends NetconfSessionListener<S>>
46 extends AbstractSessionNegotiator<NetconfHelloMessage, S> {
48 private static final Logger LOG = LoggerFactory.getLogger(AbstractNetconfSessionNegotiator.class);
50 public static final String NAME_OF_EXCEPTION_HANDLER = "lastExceptionHandler";
52 protected final P sessionPreferences;
54 private final L sessionListener;
55 private Timeout timeout;
58 * Possible states for Finite State Machine.
60 protected enum State {
61 IDLE, OPEN_WAIT, FAILED, ESTABLISHED
64 private State state = State.IDLE;
65 private final Promise<S> promise;
66 private final Timer timer;
67 private final long connectionTimeoutMillis;
69 protected AbstractNetconfSessionNegotiator(final P sessionPreferences, final Promise<S> promise,
70 final Channel channel, final Timer timer,
71 final L sessionListener, final long connectionTimeoutMillis) {
72 super(promise, channel);
73 this.sessionPreferences = sessionPreferences;
74 this.promise = promise;
76 this.sessionListener = sessionListener;
77 this.connectionTimeoutMillis = connectionTimeoutMillis;
81 protected final void startNegotiation() {
82 if (ifNegotiatedAlready()) {
83 LOG.debug("Negotiation on channel {} already started", channel);
85 final Optional<SslHandler> sslHandler = getSslHandler(channel);
86 if (sslHandler.isPresent()) {
87 Future<Channel> future = sslHandler.get().handshakeFuture();
88 future.addListener(new GenericFutureListener<Future<? super Channel>>() {
90 public void operationComplete(final Future<? super Channel> future) {
91 Preconditions.checkState(future.isSuccess(), "Ssl handshake was not successful");
92 LOG.debug("Ssl handshake complete");
102 protected final synchronized boolean ifNegotiatedAlready() {
103 // Indicates whether negotiation already started
104 return this.state != State.IDLE;
107 private static Optional<SslHandler> getSslHandler(final Channel channel) {
108 final SslHandler sslHandler = channel.pipeline().get(SslHandler.class);
109 return sslHandler == null ? Optional.absent() : Optional.of(sslHandler);
112 public P getSessionPreferences() {
113 return sessionPreferences;
116 private void start() {
117 final NetconfHelloMessage helloMessage = this.sessionPreferences.getHelloMessage();
118 LOG.debug("Session negotiation started with hello message {} on channel {}", helloMessage, channel);
120 channel.pipeline().addLast(NAME_OF_EXCEPTION_HANDLER, new ExceptionHandlingInboundChannelHandler());
122 sendMessage(helloMessage);
124 replaceHelloMessageOutboundHandler();
125 changeState(State.OPEN_WAIT);
127 timeout = this.timer.newTimeout(new TimerTask() {
129 @SuppressWarnings("checkstyle:hiddenField")
130 public void run(final Timeout timeout) {
131 synchronized (this) {
132 if (state != State.ESTABLISHED) {
134 LOG.debug("Connection timeout after {}, session is in state {}", timeout, state);
136 // Do not fail negotiation if promise is done or canceled
137 // It would result in setting result of the promise second time and that throws exception
138 if (!isPromiseFinished()) {
139 LOG.warn("Netconf session was not established after {}", connectionTimeoutMillis);
140 changeState(State.FAILED);
142 channel.close().addListener(new GenericFutureListener<ChannelFuture>() {
144 public void operationComplete(final ChannelFuture future) {
145 if (future.isSuccess()) {
146 LOG.debug("Channel {} closed: success", future.channel());
148 LOG.warn("Channel {} closed: fail", future.channel());
153 } else if (channel.isOpen()) {
154 channel.pipeline().remove(NAME_OF_EXCEPTION_HANDLER);
159 private boolean isPromiseFinished() {
160 return promise.isDone() || promise.isCancelled();
163 }, connectionTimeoutMillis, TimeUnit.MILLISECONDS);
166 private void cancelTimeout() {
167 if (timeout != null) {
172 protected final S getSessionForHelloMessage(final NetconfHelloMessage netconfMessage)
173 throws NetconfDocumentedException {
174 Preconditions.checkNotNull(netconfMessage, "netconfMessage");
176 final Document doc = netconfMessage.getDocument();
178 if (shouldUseChunkFraming(doc)) {
179 insertChunkFramingToPipeline();
182 changeState(State.ESTABLISHED);
183 return getSession(sessionListener, channel, netconfMessage);
187 * Insert chunk framing handlers into the pipeline.
189 private void insertChunkFramingToPipeline() {
190 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_FRAME_ENCODER,
191 FramingMechanismHandlerFactory.createHandler(FramingMechanism.CHUNK));
192 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_AGGREGATOR,
193 new NetconfChunkAggregator());
196 private boolean shouldUseChunkFraming(final Document doc) {
197 return containsBase11Capability(doc)
198 && containsBase11Capability(sessionPreferences.getHelloMessage().getDocument());
202 * Remove special inbound handler for hello message. Insert regular netconf xml message (en|de)coders.
205 * Inbound hello message handler should be kept until negotiation is successful
206 * It caches any non-hello messages while negotiation is still in progress
208 protected final void replaceHelloMessageInboundHandler(final S session) {
209 ChannelHandler helloMessageHandler = replaceChannelHandler(channel,
210 AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, new NetconfXMLToMessageDecoder());
212 Preconditions.checkState(helloMessageHandler instanceof NetconfXMLToHelloMessageDecoder,
213 "Pipeline handlers misplaced on session: %s, pipeline: %s", session, channel.pipeline());
214 Iterable<NetconfMessage> netconfMessagesFromNegotiation =
215 ((NetconfXMLToHelloMessageDecoder) helloMessageHandler).getPostHelloNetconfMessages();
217 // Process messages received during negotiation
218 // The hello message handler does not have to be synchronized,
219 // since it is always call from the same thread by netty.
220 // It means, we are now using the thread now
221 for (NetconfMessage message : netconfMessagesFromNegotiation) {
222 session.handleMessage(message);
227 * Remove special outbound handler for hello message. Insert regular netconf xml message (en|de)coders.
229 private void replaceHelloMessageOutboundHandler() {
230 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_ENCODER,
231 new NetconfMessageToXMLEncoder());
234 private static ChannelHandler replaceChannelHandler(final Channel channel, final String handlerKey,
235 final ChannelHandler decoder) {
236 return channel.pipeline().replace(handlerKey, handlerKey, decoder);
239 @SuppressWarnings("checkstyle:hiddenField")
240 protected abstract S getSession(L sessionListener, Channel channel, NetconfHelloMessage message)
241 throws NetconfDocumentedException;
243 private synchronized void changeState(final State newState) {
244 LOG.debug("Changing state from : {} to : {} for channel: {}", state, newState, channel);
245 Preconditions.checkState(isStateChangePermitted(state, newState),
246 "Cannot change state from %s to %s for chanel %s", state, newState, channel);
247 this.state = newState;
250 private static boolean containsBase11Capability(final Document doc) {
251 final NodeList nList = doc.getElementsByTagNameNS(
252 XmlNetconfConstants.URN_IETF_PARAMS_XML_NS_NETCONF_BASE_1_0,
253 XmlNetconfConstants.CAPABILITY);
254 for (int i = 0; i < nList.getLength(); i++) {
255 if (nList.item(i).getTextContent().contains(XmlNetconfConstants.URN_IETF_PARAMS_NETCONF_BASE_1_1)) {
262 private static boolean isStateChangePermitted(final State state, final State newState) {
263 if (state == State.IDLE && newState == State.OPEN_WAIT) {
266 if (state == State.OPEN_WAIT && newState == State.ESTABLISHED) {
269 if (state == State.OPEN_WAIT && newState == State.FAILED) {
272 LOG.debug("Transition from {} to {} is not allowed", state, newState);
277 * Handler to catch exceptions in pipeline during negotiation.
279 private final class ExceptionHandlingInboundChannelHandler extends ChannelInboundHandlerAdapter {
281 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
282 LOG.warn("An exception occurred during negotiation with {}", channel.remoteAddress(), cause);
284 negotiationFailed(cause);
285 changeState(State.FAILED);