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 com.google.common.base.Optional;
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.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 final SslHandler sslHandler = channel.pipeline().get(SslHandler.class);
104 return sslHandler == null ? Optional.absent() : Optional.of(sslHandler);
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 is in state {}", timeout, state);
131 // Do not fail negotiation if promise is done or canceled
132 // It would result in setting result of the promise second time and that throws exception
133 if (!isPromiseFinished()) {
134 LOG.warn("Netconf session was not established after {}", connectionTimeoutMillis);
135 changeState(State.FAILED);
137 channel.close().addListener((GenericFutureListener<ChannelFuture>) future -> {
138 if (future.isSuccess()) {
139 LOG.debug("Channel {} closed: success", future.channel());
141 LOG.warn("Channel {} closed: fail", future.channel());
145 } else if (channel.isOpen()) {
146 channel.pipeline().remove(NAME_OF_EXCEPTION_HANDLER);
151 private boolean isPromiseFinished() {
152 return promise.isDone() || promise.isCancelled();
155 }, connectionTimeoutMillis, TimeUnit.MILLISECONDS);
158 private void cancelTimeout() {
159 if (timeout != null) {
164 protected final S getSessionForHelloMessage(final NetconfHelloMessage netconfMessage)
165 throws NetconfDocumentedException {
166 final Document doc = netconfMessage.getDocument();
168 if (shouldUseChunkFraming(doc)) {
169 insertChunkFramingToPipeline();
172 changeState(State.ESTABLISHED);
173 return getSession(sessionListener, channel, netconfMessage);
177 * Insert chunk framing handlers into the pipeline.
179 private void insertChunkFramingToPipeline() {
180 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_FRAME_ENCODER,
181 FramingMechanismHandlerFactory.createHandler(FramingMechanism.CHUNK));
182 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_AGGREGATOR,
183 new NetconfChunkAggregator());
186 private boolean shouldUseChunkFraming(final Document doc) {
187 return containsBase11Capability(doc)
188 && containsBase11Capability(sessionPreferences.getHelloMessage().getDocument());
192 * Remove special inbound handler for hello message. Insert regular netconf xml message (en|de)coders.
195 * Inbound hello message handler should be kept until negotiation is successful
196 * It caches any non-hello messages while negotiation is still in progress
198 protected final void replaceHelloMessageInboundHandler(final S session) {
199 ChannelHandler helloMessageHandler = replaceChannelHandler(channel,
200 AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, new NetconfXMLToMessageDecoder());
202 checkState(helloMessageHandler instanceof NetconfXMLToHelloMessageDecoder,
203 "Pipeline handlers misplaced on session: %s, pipeline: %s", session, channel.pipeline());
204 Iterable<NetconfMessage> netconfMessagesFromNegotiation =
205 ((NetconfXMLToHelloMessageDecoder) helloMessageHandler).getPostHelloNetconfMessages();
207 // Process messages received during negotiation
208 // The hello message handler does not have to be synchronized,
209 // since it is always call from the same thread by netty.
210 // It means, we are now using the thread now
211 for (NetconfMessage message : netconfMessagesFromNegotiation) {
212 session.handleMessage(message);
217 * Remove special outbound handler for hello message. Insert regular netconf xml message (en|de)coders.
219 private void replaceHelloMessageOutboundHandler() {
220 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_ENCODER,
221 new NetconfMessageToXMLEncoder());
224 private static ChannelHandler replaceChannelHandler(final Channel channel, final String handlerKey,
225 final ChannelHandler decoder) {
226 return channel.pipeline().replace(handlerKey, handlerKey, decoder);
229 @SuppressWarnings("checkstyle:hiddenField")
230 protected abstract S getSession(L sessionListener, Channel channel, NetconfHelloMessage message)
231 throws NetconfDocumentedException;
233 private synchronized void changeState(final State newState) {
234 LOG.debug("Changing state from : {} to : {} for channel: {}", state, newState, channel);
235 checkState(isStateChangePermitted(state, newState),
236 "Cannot change state from %s to %s for chanel %s", state, newState, channel);
237 this.state = newState;
240 private static boolean containsBase11Capability(final Document doc) {
241 final NodeList nList = doc.getElementsByTagNameNS(
242 XmlNetconfConstants.URN_IETF_PARAMS_XML_NS_NETCONF_BASE_1_0,
243 XmlNetconfConstants.CAPABILITY);
244 for (int i = 0; i < nList.getLength(); i++) {
245 if (nList.item(i).getTextContent().contains(XmlNetconfConstants.URN_IETF_PARAMS_NETCONF_BASE_1_1)) {
252 private static boolean isStateChangePermitted(final State state, final State newState) {
253 if (state == State.IDLE && newState == State.OPEN_WAIT) {
256 if (state == State.OPEN_WAIT && newState == State.ESTABLISHED) {
259 if (state == State.OPEN_WAIT && newState == State.FAILED) {
262 LOG.debug("Transition from {} to {} is not allowed", state, newState);
267 * Handler to catch exceptions in pipeline during negotiation.
269 private final class ExceptionHandlingInboundChannelHandler extends ChannelInboundHandlerAdapter {
271 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
272 LOG.warn("An exception occurred during negotiation with {}", channel.remoteAddress(), cause);
274 negotiationFailed(cause);
275 changeState(State.FAILED);
279 protected final void negotiationSuccessful(final S session) {
280 LOG.debug("Negotiation on channel {} successful with session {}", channel, session);
281 channel.pipeline().replace(this, "session", session);
282 promise.setSuccess(session);
285 protected void negotiationFailed(final Throwable cause) {
286 LOG.debug("Negotiation on channel {} failed", channel, cause);
288 promise.setFailure(cause);
292 * Send a message to peer and fail negotiation if it does not reach
295 * @param msg Message which should be sent.
297 protected final void sendMessage(final NetconfMessage msg) {
298 this.channel.writeAndFlush(msg).addListener(f -> {
299 if (!f.isSuccess()) {
300 LOG.info("Failed to send message {}", msg, f.cause());
301 negotiationFailed(f.cause());
303 LOG.trace("Message {} sent to socket", msg);
309 @SuppressWarnings("checkstyle:illegalCatch")
310 public final void channelActive(final ChannelHandlerContext ctx) {
311 LOG.debug("Starting session negotiation on channel {}", channel);
314 } catch (final Exception e) {
315 LOG.warn("Unexpected negotiation failure", e);
316 negotiationFailed(e);
321 @SuppressWarnings("checkstyle:illegalCatch")
322 public final void channelRead(final ChannelHandlerContext ctx, final Object msg) {
323 LOG.debug("Negotiation read invoked on channel {}", channel);
325 handleMessage((NetconfHelloMessage) msg);
326 } catch (final Exception e) {
327 LOG.debug("Unexpected error while handling negotiation message {}", msg, e);
328 negotiationFailed(e);
333 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
334 LOG.info("Unexpected error during negotiation", cause);
335 negotiationFailed(cause);
338 protected abstract void handleMessage(NetconfHelloMessage msg) throws Exception;