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
8 package org.opendaylight.netconf.nettyutil;
10 import static com.google.common.base.Preconditions.checkState;
11 import static java.util.Objects.requireNonNull;
13 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
14 import io.netty.channel.Channel;
15 import io.netty.channel.ChannelFuture;
16 import io.netty.channel.ChannelHandler;
17 import io.netty.channel.ChannelHandlerContext;
18 import io.netty.channel.ChannelInboundHandlerAdapter;
19 import io.netty.handler.ssl.SslHandler;
20 import io.netty.util.Timeout;
21 import io.netty.util.Timer;
22 import io.netty.util.TimerTask;
23 import io.netty.util.concurrent.GenericFutureListener;
24 import io.netty.util.concurrent.Promise;
25 import java.util.Optional;
26 import java.util.concurrent.TimeUnit;
27 import org.opendaylight.netconf.api.NetconfDocumentedException;
28 import org.opendaylight.netconf.api.NetconfMessage;
29 import org.opendaylight.netconf.api.NetconfSessionListener;
30 import org.opendaylight.netconf.api.NetconfSessionPreferences;
31 import org.opendaylight.netconf.api.messages.NetconfHelloMessage;
32 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
33 import org.opendaylight.netconf.nettyutil.handler.FramingMechanismHandlerFactory;
34 import org.opendaylight.netconf.nettyutil.handler.NetconfChunkAggregator;
35 import org.opendaylight.netconf.nettyutil.handler.NetconfMessageToXMLEncoder;
36 import org.opendaylight.netconf.nettyutil.handler.NetconfXMLToHelloMessageDecoder;
37 import org.opendaylight.netconf.nettyutil.handler.NetconfXMLToMessageDecoder;
38 import org.opendaylight.netconf.util.messages.FramingMechanism;
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 ChannelInboundHandlerAdapter implements NetconfSessionNegotiator<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;
53 protected final Channel channel;
55 private final Promise<S> promise;
56 private final L sessionListener;
57 private Timeout timeout;
60 * Possible states for Finite State Machine.
62 protected enum State {
63 IDLE, OPEN_WAIT, FAILED, ESTABLISHED
66 private State state = State.IDLE;
67 private final Timer timer;
68 private final long connectionTimeoutMillis;
70 protected AbstractNetconfSessionNegotiator(final P sessionPreferences, final Promise<S> promise,
71 final Channel channel, final Timer timer,
72 final L sessionListener, final long connectionTimeoutMillis) {
73 this.channel = requireNonNull(channel);
74 this.promise = requireNonNull(promise);
75 this.sessionPreferences = sessionPreferences;
77 this.sessionListener = sessionListener;
78 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 sslHandler.get().handshakeFuture().addListener(future -> {
88 checkState(future.isSuccess(), "Ssl handshake was not successful");
89 LOG.debug("Ssl handshake complete");
98 protected final synchronized boolean ifNegotiatedAlready() {
99 // Indicates whether negotiation already started
100 return this.state != State.IDLE;
103 private static Optional<SslHandler> getSslHandler(final Channel channel) {
104 return Optional.ofNullable(channel.pipeline().get(SslHandler.class));
107 public P getSessionPreferences() {
108 return sessionPreferences;
111 private void start() {
112 final NetconfHelloMessage helloMessage = this.sessionPreferences.getHelloMessage();
113 LOG.debug("Session negotiation started with hello message {} on channel {}", helloMessage, channel);
115 channel.pipeline().addLast(NAME_OF_EXCEPTION_HANDLER, new ExceptionHandlingInboundChannelHandler());
117 sendMessage(helloMessage);
119 replaceHelloMessageOutboundHandler();
120 changeState(State.OPEN_WAIT);
122 timeout = this.timer.newTimeout(new TimerTask() {
124 @SuppressWarnings("checkstyle:hiddenField")
125 public void run(final Timeout timeout) {
126 synchronized (this) {
127 if (state != State.ESTABLISHED) {
129 LOG.debug("Connection timeout after {}, session backed by channel {} is in state {}",
130 timeout, channel, state);
132 // Do not fail negotiation if promise is done or canceled
133 // It would result in setting result of the promise second time and that throws exception
134 if (!isPromiseFinished()) {
135 LOG.warn("Netconf session backed by channel {} was not established after {}",
136 channel, connectionTimeoutMillis);
137 changeState(State.FAILED);
139 channel.close().addListener((GenericFutureListener<ChannelFuture>) future -> {
140 if (future.isSuccess()) {
141 LOG.debug("Channel {} closed: success", future.channel());
143 LOG.warn("Channel {} closed: fail", future.channel());
147 } else if (channel.isOpen()) {
148 channel.pipeline().remove(NAME_OF_EXCEPTION_HANDLER);
153 private boolean isPromiseFinished() {
154 return promise.isDone() || promise.isCancelled();
157 }, connectionTimeoutMillis, TimeUnit.MILLISECONDS);
160 @SuppressFBWarnings(value = "UPM_UNCALLED_PRIVATE_METHOD",
161 justification = "https://github.com/spotbugs/spotbugs/issues/811")
162 private void cancelTimeout() {
163 if (timeout != null) {
168 protected final S getSessionForHelloMessage(final NetconfHelloMessage netconfMessage)
169 throws NetconfDocumentedException {
170 final Document doc = netconfMessage.getDocument();
172 if (shouldUseChunkFraming(doc)) {
173 insertChunkFramingToPipeline();
176 changeState(State.ESTABLISHED);
177 return getSession(sessionListener, channel, netconfMessage);
181 * Insert chunk framing handlers into the pipeline.
183 private void insertChunkFramingToPipeline() {
184 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_FRAME_ENCODER,
185 FramingMechanismHandlerFactory.createHandler(FramingMechanism.CHUNK));
186 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_AGGREGATOR,
187 new NetconfChunkAggregator());
190 private boolean shouldUseChunkFraming(final Document doc) {
191 return containsBase11Capability(doc)
192 && containsBase11Capability(sessionPreferences.getHelloMessage().getDocument());
196 * Remove special inbound handler for hello message. Insert regular netconf xml message (en|de)coders.
199 * Inbound hello message handler should be kept until negotiation is successful
200 * It caches any non-hello messages while negotiation is still in progress
202 protected final void replaceHelloMessageInboundHandler(final S session) {
203 ChannelHandler helloMessageHandler = replaceChannelHandler(channel,
204 AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, new NetconfXMLToMessageDecoder());
206 checkState(helloMessageHandler instanceof NetconfXMLToHelloMessageDecoder,
207 "Pipeline handlers misplaced on session: %s, pipeline: %s", session, channel.pipeline());
208 Iterable<NetconfMessage> netconfMessagesFromNegotiation =
209 ((NetconfXMLToHelloMessageDecoder) helloMessageHandler).getPostHelloNetconfMessages();
211 // Process messages received during negotiation
212 // The hello message handler does not have to be synchronized,
213 // since it is always call from the same thread by netty.
214 // It means, we are now using the thread now
215 for (NetconfMessage message : netconfMessagesFromNegotiation) {
216 session.handleMessage(message);
221 * Remove special outbound handler for hello message. Insert regular netconf xml message (en|de)coders.
223 private void replaceHelloMessageOutboundHandler() {
224 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_ENCODER,
225 new NetconfMessageToXMLEncoder());
228 private static ChannelHandler replaceChannelHandler(final Channel channel, final String handlerKey,
229 final ChannelHandler decoder) {
230 return channel.pipeline().replace(handlerKey, handlerKey, decoder);
233 @SuppressWarnings("checkstyle:hiddenField")
234 protected abstract S getSession(L sessionListener, Channel channel, NetconfHelloMessage message)
235 throws NetconfDocumentedException;
237 private synchronized void changeState(final State newState) {
238 LOG.debug("Changing state from : {} to : {} for channel: {}", state, newState, channel);
239 checkState(isStateChangePermitted(state, newState),
240 "Cannot change state from %s to %s for channel %s", state, newState, channel);
241 this.state = newState;
244 private static boolean containsBase11Capability(final Document doc) {
245 final NodeList nList = doc.getElementsByTagNameNS(
246 XmlNetconfConstants.URN_IETF_PARAMS_XML_NS_NETCONF_BASE_1_0,
247 XmlNetconfConstants.CAPABILITY);
248 for (int i = 0; i < nList.getLength(); i++) {
249 if (nList.item(i).getTextContent().contains(XmlNetconfConstants.URN_IETF_PARAMS_NETCONF_BASE_1_1)) {
256 private static boolean isStateChangePermitted(final State state, final State newState) {
257 if (state == State.IDLE && newState == State.OPEN_WAIT) {
260 if (state == State.OPEN_WAIT && newState == State.ESTABLISHED) {
263 if (state == State.OPEN_WAIT && newState == State.FAILED) {
266 LOG.debug("Transition from {} to {} is not allowed", state, newState);
271 * Handler to catch exceptions in pipeline during negotiation.
273 private final class ExceptionHandlingInboundChannelHandler extends ChannelInboundHandlerAdapter {
275 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
276 LOG.warn("An exception occurred during negotiation with {} on channel {}",
277 channel.remoteAddress(), channel, cause);
279 negotiationFailed(cause);
280 changeState(State.FAILED);
284 protected final void negotiationSuccessful(final S session) {
285 LOG.debug("Negotiation on channel {} successful with session {}", channel, session);
286 channel.pipeline().replace(this, "session", session);
287 promise.setSuccess(session);
290 protected void negotiationFailed(final Throwable cause) {
291 LOG.debug("Negotiation on channel {} failed", channel, cause);
293 promise.setFailure(cause);
297 * Send a message to peer and fail negotiation if it does not reach
300 * @param msg Message which should be sent.
302 protected final void sendMessage(final NetconfMessage msg) {
303 this.channel.writeAndFlush(msg).addListener(f -> {
304 if (!f.isSuccess()) {
305 LOG.info("Failed to send message {} on channel {}", msg, channel, f.cause());
306 negotiationFailed(f.cause());
308 LOG.trace("Message {} sent to socket on channel {}", msg, channel);
314 @SuppressWarnings("checkstyle:illegalCatch")
315 public final void channelActive(final ChannelHandlerContext ctx) {
316 LOG.debug("Starting session negotiation on channel {}", channel);
319 } catch (final Exception e) {
320 LOG.warn("Unexpected negotiation failure on channel {}", channel, e);
321 negotiationFailed(e);
326 @SuppressWarnings("checkstyle:illegalCatch")
327 public final void channelRead(final ChannelHandlerContext ctx, final Object msg) {
328 LOG.debug("Negotiation read invoked on channel {}", channel);
330 handleMessage((NetconfHelloMessage) msg);
331 } catch (final Exception e) {
332 LOG.debug("Unexpected error while handling negotiation message {} on channel {}", msg, channel, e);
333 negotiationFailed(e);
338 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
339 LOG.info("Unexpected error during negotiation on channel {}", channel, cause);
340 negotiationFailed(cause);
343 protected abstract void handleMessage(NetconfHelloMessage msg) throws Exception;