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 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.GenericFutureListener;
23 import io.netty.util.concurrent.Promise;
24 import java.util.Optional;
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.slf4j.Logger;
39 import org.slf4j.LoggerFactory;
40 import org.w3c.dom.Document;
41 import org.w3c.dom.NodeList;
43 public abstract class AbstractNetconfSessionNegotiator<P extends NetconfSessionPreferences,
44 S extends AbstractNetconfSession<S, L>, L extends NetconfSessionListener<S>>
45 extends ChannelInboundHandlerAdapter implements NetconfSessionNegotiator<S> {
47 private static final Logger LOG = LoggerFactory.getLogger(AbstractNetconfSessionNegotiator.class);
49 public static final String NAME_OF_EXCEPTION_HANDLER = "lastExceptionHandler";
51 protected final P sessionPreferences;
52 protected final Channel channel;
54 private final Promise<S> promise;
55 private final L sessionListener;
56 private Timeout timeout;
59 * Possible states for Finite State Machine.
61 protected enum State {
62 IDLE, OPEN_WAIT, FAILED, ESTABLISHED
65 private State state = State.IDLE;
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 this.channel = requireNonNull(channel);
73 this.promise = requireNonNull(promise);
74 this.sessionPreferences = sessionPreferences;
76 this.sessionListener = sessionListener;
77 this.connectionTimeoutMillis = connectionTimeoutMillis;
80 protected final void startNegotiation() {
81 if (ifNegotiatedAlready()) {
82 LOG.debug("Negotiation on channel {} already started", channel);
84 final Optional<SslHandler> sslHandler = getSslHandler(channel);
85 if (sslHandler.isPresent()) {
86 sslHandler.get().handshakeFuture().addListener(future -> {
87 checkState(future.isSuccess(), "Ssl handshake was not successful");
88 LOG.debug("Ssl handshake complete");
97 protected final synchronized boolean ifNegotiatedAlready() {
98 // Indicates whether negotiation already started
99 return this.state != State.IDLE;
102 private static Optional<SslHandler> getSslHandler(final Channel channel) {
103 return Optional.ofNullable(channel.pipeline().get(SslHandler.class));
106 public P getSessionPreferences() {
107 return sessionPreferences;
110 private void start() {
111 final NetconfHelloMessage helloMessage = this.sessionPreferences.getHelloMessage();
112 LOG.debug("Session negotiation started with hello message {} on channel {}", helloMessage, channel);
114 channel.pipeline().addLast(NAME_OF_EXCEPTION_HANDLER, new ExceptionHandlingInboundChannelHandler());
116 sendMessage(helloMessage);
118 replaceHelloMessageOutboundHandler();
119 changeState(State.OPEN_WAIT);
121 timeout = this.timer.newTimeout(new TimerTask() {
123 @SuppressWarnings("checkstyle:hiddenField")
124 public void run(final Timeout timeout) {
125 synchronized (this) {
126 if (state != State.ESTABLISHED) {
128 LOG.debug("Connection timeout after {}, session is in state {}", timeout, state);
130 // Do not fail negotiation if promise is done or canceled
131 // It would result in setting result of the promise second time and that throws exception
132 if (!isPromiseFinished()) {
133 LOG.warn("Netconf session was not established after {}", connectionTimeoutMillis);
134 changeState(State.FAILED);
136 channel.close().addListener((GenericFutureListener<ChannelFuture>) future -> {
137 if (future.isSuccess()) {
138 LOG.debug("Channel {} closed: success", future.channel());
140 LOG.warn("Channel {} closed: fail", future.channel());
144 } else if (channel.isOpen()) {
145 channel.pipeline().remove(NAME_OF_EXCEPTION_HANDLER);
150 private boolean isPromiseFinished() {
151 return promise.isDone() || promise.isCancelled();
154 }, connectionTimeoutMillis, TimeUnit.MILLISECONDS);
157 private void cancelTimeout() {
158 if (timeout != null) {
163 protected final S getSessionForHelloMessage(final NetconfHelloMessage netconfMessage)
164 throws NetconfDocumentedException {
165 final Document doc = netconfMessage.getDocument();
167 if (shouldUseChunkFraming(doc)) {
168 insertChunkFramingToPipeline();
171 changeState(State.ESTABLISHED);
172 return getSession(sessionListener, channel, netconfMessage);
176 * Insert chunk framing handlers into the pipeline.
178 private void insertChunkFramingToPipeline() {
179 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_FRAME_ENCODER,
180 FramingMechanismHandlerFactory.createHandler(FramingMechanism.CHUNK));
181 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_AGGREGATOR,
182 new NetconfChunkAggregator());
185 private boolean shouldUseChunkFraming(final Document doc) {
186 return containsBase11Capability(doc)
187 && containsBase11Capability(sessionPreferences.getHelloMessage().getDocument());
191 * Remove special inbound handler for hello message. Insert regular netconf xml message (en|de)coders.
194 * Inbound hello message handler should be kept until negotiation is successful
195 * It caches any non-hello messages while negotiation is still in progress
197 protected final void replaceHelloMessageInboundHandler(final S session) {
198 ChannelHandler helloMessageHandler = replaceChannelHandler(channel,
199 AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, new NetconfXMLToMessageDecoder());
201 checkState(helloMessageHandler instanceof NetconfXMLToHelloMessageDecoder,
202 "Pipeline handlers misplaced on session: %s, pipeline: %s", session, channel.pipeline());
203 Iterable<NetconfMessage> netconfMessagesFromNegotiation =
204 ((NetconfXMLToHelloMessageDecoder) helloMessageHandler).getPostHelloNetconfMessages();
206 // Process messages received during negotiation
207 // The hello message handler does not have to be synchronized,
208 // since it is always call from the same thread by netty.
209 // It means, we are now using the thread now
210 for (NetconfMessage message : netconfMessagesFromNegotiation) {
211 session.handleMessage(message);
216 * Remove special outbound handler for hello message. Insert regular netconf xml message (en|de)coders.
218 private void replaceHelloMessageOutboundHandler() {
219 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_ENCODER,
220 new NetconfMessageToXMLEncoder());
223 private static ChannelHandler replaceChannelHandler(final Channel channel, final String handlerKey,
224 final ChannelHandler decoder) {
225 return channel.pipeline().replace(handlerKey, handlerKey, decoder);
228 @SuppressWarnings("checkstyle:hiddenField")
229 protected abstract S getSession(L sessionListener, Channel channel, NetconfHelloMessage message)
230 throws NetconfDocumentedException;
232 private synchronized void changeState(final State newState) {
233 LOG.debug("Changing state from : {} to : {} for channel: {}", state, newState, channel);
234 checkState(isStateChangePermitted(state, newState),
235 "Cannot change state from %s to %s for chanel %s", state, newState, channel);
236 this.state = newState;
239 private static boolean containsBase11Capability(final Document doc) {
240 final NodeList nList = doc.getElementsByTagNameNS(
241 XmlNetconfConstants.URN_IETF_PARAMS_XML_NS_NETCONF_BASE_1_0,
242 XmlNetconfConstants.CAPABILITY);
243 for (int i = 0; i < nList.getLength(); i++) {
244 if (nList.item(i).getTextContent().contains(XmlNetconfConstants.URN_IETF_PARAMS_NETCONF_BASE_1_1)) {
251 private static boolean isStateChangePermitted(final State state, final State newState) {
252 if (state == State.IDLE && newState == State.OPEN_WAIT) {
255 if (state == State.OPEN_WAIT && newState == State.ESTABLISHED) {
258 if (state == State.OPEN_WAIT && newState == State.FAILED) {
261 LOG.debug("Transition from {} to {} is not allowed", state, newState);
266 * Handler to catch exceptions in pipeline during negotiation.
268 private final class ExceptionHandlingInboundChannelHandler extends ChannelInboundHandlerAdapter {
270 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
271 LOG.warn("An exception occurred during negotiation with {}", channel.remoteAddress(), cause);
273 negotiationFailed(cause);
274 changeState(State.FAILED);
278 protected final void negotiationSuccessful(final S session) {
279 LOG.debug("Negotiation on channel {} successful with session {}", channel, session);
280 channel.pipeline().replace(this, "session", session);
281 promise.setSuccess(session);
284 protected void negotiationFailed(final Throwable cause) {
285 LOG.debug("Negotiation on channel {} failed", channel, cause);
287 promise.setFailure(cause);
291 * Send a message to peer and fail negotiation if it does not reach
294 * @param msg Message which should be sent.
296 protected final void sendMessage(final NetconfMessage msg) {
297 this.channel.writeAndFlush(msg).addListener(f -> {
298 if (!f.isSuccess()) {
299 LOG.info("Failed to send message {}", msg, f.cause());
300 negotiationFailed(f.cause());
302 LOG.trace("Message {} sent to socket", msg);
308 @SuppressWarnings("checkstyle:illegalCatch")
309 public final void channelActive(final ChannelHandlerContext ctx) {
310 LOG.debug("Starting session negotiation on channel {}", channel);
313 } catch (final Exception e) {
314 LOG.warn("Unexpected negotiation failure", e);
315 negotiationFailed(e);
320 @SuppressWarnings("checkstyle:illegalCatch")
321 public final void channelRead(final ChannelHandlerContext ctx, final Object msg) {
322 LOG.debug("Negotiation read invoked on channel {}", channel);
324 handleMessage((NetconfHelloMessage) msg);
325 } catch (final Exception e) {
326 LOG.debug("Unexpected error while handling negotiation message {}", msg, e);
327 negotiationFailed(e);
332 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
333 LOG.info("Unexpected error during negotiation", cause);
334 negotiationFailed(cause);
337 protected abstract void handleMessage(NetconfHelloMessage msg) throws Exception;