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.concurrent.GenericFutureListener;
23 import io.netty.util.concurrent.Promise;
24 import java.util.concurrent.TimeUnit;
25 import org.checkerframework.checker.lock.qual.GuardedBy;
26 import org.checkerframework.checker.lock.qual.Holding;
27 import org.eclipse.jdt.annotation.Nullable;
28 import org.opendaylight.netconf.api.NetconfDocumentedException;
29 import org.opendaylight.netconf.api.NetconfMessage;
30 import org.opendaylight.netconf.api.NetconfSessionListener;
31 import org.opendaylight.netconf.api.NetconfSessionPreferences;
32 import org.opendaylight.netconf.api.messages.NetconfHelloMessage;
33 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
34 import org.opendaylight.netconf.nettyutil.handler.FramingMechanismHandlerFactory;
35 import org.opendaylight.netconf.nettyutil.handler.NetconfChunkAggregator;
36 import org.opendaylight.netconf.nettyutil.handler.NetconfMessageToXMLEncoder;
37 import org.opendaylight.netconf.nettyutil.handler.NetconfXMLToHelloMessageDecoder;
38 import org.opendaylight.netconf.nettyutil.handler.NetconfXMLToMessageDecoder;
39 import org.opendaylight.netconf.util.messages.FramingMechanism;
40 import org.slf4j.Logger;
41 import org.slf4j.LoggerFactory;
42 import org.w3c.dom.Document;
43 import org.w3c.dom.NodeList;
45 public abstract class AbstractNetconfSessionNegotiator<P extends NetconfSessionPreferences,
46 S extends AbstractNetconfSession<S, L>, L extends NetconfSessionListener<S>>
47 extends ChannelInboundHandlerAdapter implements NetconfSessionNegotiator<S> {
49 * Possible states for Finite State Machine.
51 protected enum State {
52 IDLE, OPEN_WAIT, FAILED, ESTABLISHED
55 private static final Logger LOG = LoggerFactory.getLogger(AbstractNetconfSessionNegotiator.class);
57 public static final String NAME_OF_EXCEPTION_HANDLER = "lastExceptionHandler";
59 protected final P sessionPreferences;
60 protected final Channel channel;
62 private final long connectionTimeoutMillis;
63 private final Promise<S> promise;
64 private final L sessionListener;
65 private final Timer timer;
68 private Timeout timeoutTask;
70 private State state = State.IDLE;
72 protected AbstractNetconfSessionNegotiator(final P sessionPreferences, final Promise<S> promise,
73 final Channel channel, final Timer timer,
74 final L sessionListener, final long connectionTimeoutMillis) {
75 this.channel = requireNonNull(channel);
76 this.promise = requireNonNull(promise);
77 this.sessionPreferences = sessionPreferences;
79 this.sessionListener = sessionListener;
80 this.connectionTimeoutMillis = connectionTimeoutMillis;
83 protected final void startNegotiation() {
84 if (ifNegotiatedAlready()) {
85 LOG.debug("Negotiation on channel {} already started", channel);
87 final var sslHandler = getSslHandler(channel);
88 if (sslHandler != null) {
89 sslHandler.handshakeFuture().addListener(future -> {
90 checkState(future.isSuccess(), "Ssl handshake was not successful");
91 LOG.debug("Ssl handshake complete");
100 protected final synchronized boolean ifNegotiatedAlready() {
101 // Indicates whether negotiation already started
102 return this.state != State.IDLE;
105 private static @Nullable SslHandler getSslHandler(final Channel channel) {
106 return channel.pipeline().get(SslHandler.class);
109 public P getSessionPreferences() {
110 return sessionPreferences;
113 private void start() {
114 final NetconfHelloMessage helloMessage = this.sessionPreferences.getHelloMessage();
115 LOG.debug("Session negotiation started with hello message {} on channel {}", helloMessage, channel);
117 channel.pipeline().addLast(NAME_OF_EXCEPTION_HANDLER, new ExceptionHandlingInboundChannelHandler());
119 sendMessage(helloMessage);
121 replaceHelloMessageOutboundHandler();
123 synchronized (this) {
124 lockedChangeState(State.OPEN_WAIT);
126 // Service the timeout on channel's eventloop, so that we do not get state transition problems
127 timeoutTask = timer.newTimeout(unused -> channel.eventLoop().execute(this::timeoutExpired),
128 connectionTimeoutMillis, TimeUnit.MILLISECONDS);
132 private synchronized void timeoutExpired() {
133 if (timeoutTask == null) {
134 // cancelTimeout() between expiry and execution on the loop
139 if (state != State.ESTABLISHED) {
140 LOG.debug("Connection timeout after {}ms, session backed by channel {} is in state {}",
141 connectionTimeoutMillis, channel, state);
143 // Do not fail negotiation if promise is done or canceled
144 // It would result in setting result of the promise second time and that throws exception
145 if (!promise.isDone() && !promise.isCancelled()) {
146 LOG.warn("Netconf session backed by channel {} was not established after {}", channel,
147 connectionTimeoutMillis);
148 changeState(State.FAILED);
150 channel.close().addListener((GenericFutureListener<ChannelFuture>) future -> {
151 if (future.isSuccess()) {
152 LOG.debug("Channel {} closed: success", future.channel());
154 LOG.warn("Channel {} closed: fail", future.channel());
158 } else if (channel.isOpen()) {
159 channel.pipeline().remove(NAME_OF_EXCEPTION_HANDLER);
163 @SuppressFBWarnings(value = "UPM_UNCALLED_PRIVATE_METHOD",
164 justification = "https://github.com/spotbugs/spotbugs/issues/811")
165 private synchronized void cancelTimeout() {
166 if (timeoutTask != null && !timeoutTask.cancel()) {
167 // Late-coming cancel: make sure
172 protected final S getSessionForHelloMessage(final NetconfHelloMessage netconfMessage)
173 throws NetconfDocumentedException {
174 final Document doc = netconfMessage.getDocument();
176 if (shouldUseChunkFraming(doc)) {
177 insertChunkFramingToPipeline();
180 changeState(State.ESTABLISHED);
181 return getSession(sessionListener, channel, netconfMessage);
185 * Insert chunk framing handlers into the pipeline.
187 private void insertChunkFramingToPipeline() {
188 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_FRAME_ENCODER,
189 FramingMechanismHandlerFactory.createHandler(FramingMechanism.CHUNK));
190 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_AGGREGATOR,
191 new NetconfChunkAggregator());
194 private boolean shouldUseChunkFraming(final Document doc) {
195 return containsBase11Capability(doc)
196 && containsBase11Capability(sessionPreferences.getHelloMessage().getDocument());
200 * Remove special inbound handler for hello message. Insert regular netconf xml message (en|de)coders.
203 * Inbound hello message handler should be kept until negotiation is successful
204 * It caches any non-hello messages while negotiation is still in progress
206 protected final void replaceHelloMessageInboundHandler(final S session) {
207 ChannelHandler helloMessageHandler = replaceChannelHandler(channel,
208 AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, new NetconfXMLToMessageDecoder());
210 checkState(helloMessageHandler instanceof NetconfXMLToHelloMessageDecoder,
211 "Pipeline handlers misplaced on session: %s, pipeline: %s", session, channel.pipeline());
212 Iterable<NetconfMessage> netconfMessagesFromNegotiation =
213 ((NetconfXMLToHelloMessageDecoder) helloMessageHandler).getPostHelloNetconfMessages();
215 // Process messages received during negotiation
216 // The hello message handler does not have to be synchronized,
217 // since it is always call from the same thread by netty.
218 // It means, we are now using the thread now
219 for (NetconfMessage message : netconfMessagesFromNegotiation) {
220 session.handleMessage(message);
225 * Remove special outbound handler for hello message. Insert regular netconf xml message (en|de)coders.
227 private void replaceHelloMessageOutboundHandler() {
228 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_ENCODER,
229 new NetconfMessageToXMLEncoder());
232 private static ChannelHandler replaceChannelHandler(final Channel channel, final String handlerKey,
233 final ChannelHandler decoder) {
234 return channel.pipeline().replace(handlerKey, handlerKey, decoder);
237 @SuppressWarnings("checkstyle:hiddenField")
238 protected abstract S getSession(L sessionListener, Channel channel, NetconfHelloMessage message)
239 throws NetconfDocumentedException;
241 private synchronized void changeState(final State newState) {
242 lockedChangeState(newState);
246 private void lockedChangeState(final State newState) {
247 LOG.debug("Changing state from : {} to : {} for channel: {}", state, newState, channel);
248 checkState(isStateChangePermitted(state, newState),
249 "Cannot change state from %s to %s for channel %s", state, newState, channel);
250 this.state = newState;
253 private static boolean containsBase11Capability(final Document doc) {
254 final NodeList nList = doc.getElementsByTagNameNS(
255 XmlNetconfConstants.URN_IETF_PARAMS_XML_NS_NETCONF_BASE_1_0,
256 XmlNetconfConstants.CAPABILITY);
257 for (int i = 0; i < nList.getLength(); i++) {
258 if (nList.item(i).getTextContent().contains(XmlNetconfConstants.URN_IETF_PARAMS_NETCONF_BASE_1_1)) {
265 private static boolean isStateChangePermitted(final State state, final State newState) {
266 if (state == State.IDLE && newState == State.OPEN_WAIT) {
269 if (state == State.OPEN_WAIT && newState == State.ESTABLISHED) {
272 if (state == State.OPEN_WAIT && newState == State.FAILED) {
275 LOG.debug("Transition from {} to {} is not allowed", state, newState);
280 * Handler to catch exceptions in pipeline during negotiation.
282 private final class ExceptionHandlingInboundChannelHandler extends ChannelInboundHandlerAdapter {
284 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
285 LOG.warn("An exception occurred during negotiation with {} on channel {}",
286 channel.remoteAddress(), channel, cause);
287 // FIXME: this is quite suspect as it is competing with timeoutExpired() without synchronization
289 negotiationFailed(cause);
290 changeState(State.FAILED);
294 protected final void negotiationSuccessful(final S session) {
295 LOG.debug("Negotiation on channel {} successful with session {}", channel, session);
296 channel.pipeline().replace(this, "session", session);
297 promise.setSuccess(session);
300 protected void negotiationFailed(final Throwable cause) {
301 LOG.debug("Negotiation on channel {} failed", channel, cause);
303 promise.setFailure(cause);
307 * Send a message to peer and fail negotiation if it does not reach
310 * @param msg Message which should be sent.
312 protected final void sendMessage(final NetconfMessage msg) {
313 this.channel.writeAndFlush(msg).addListener(f -> {
314 if (!f.isSuccess()) {
315 LOG.info("Failed to send message {} on channel {}", msg, channel, f.cause());
316 negotiationFailed(f.cause());
318 LOG.trace("Message {} sent to socket on channel {}", msg, channel);
324 @SuppressWarnings("checkstyle:illegalCatch")
325 public final void channelActive(final ChannelHandlerContext ctx) {
326 LOG.debug("Starting session negotiation on channel {}", channel);
329 } catch (final Exception e) {
330 LOG.warn("Unexpected negotiation failure on channel {}", channel, e);
331 negotiationFailed(e);
336 @SuppressWarnings("checkstyle:illegalCatch")
337 public final void channelRead(final ChannelHandlerContext ctx, final Object msg) {
338 LOG.debug("Negotiation read invoked on channel {}", channel);
340 handleMessage((NetconfHelloMessage) msg);
341 } catch (final Exception e) {
342 LOG.debug("Unexpected error while handling negotiation message {} on channel {}", msg, channel, e);
343 negotiationFailed(e);
348 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
349 LOG.info("Unexpected error during negotiation on channel {}", channel, cause);
350 negotiationFailed(cause);
353 protected abstract void handleMessage(NetconfHelloMessage msg) throws Exception;