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.concurrent.GenericFutureListener;
22 import io.netty.util.concurrent.Promise;
23 import java.util.Optional;
24 import java.util.concurrent.TimeUnit;
25 import org.checkerframework.checker.lock.qual.GuardedBy;
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 * Possible states for Finite State Machine.
49 protected enum State {
50 IDLE, OPEN_WAIT, FAILED, ESTABLISHED
53 private static final Logger LOG = LoggerFactory.getLogger(AbstractNetconfSessionNegotiator.class);
55 public static final String NAME_OF_EXCEPTION_HANDLER = "lastExceptionHandler";
57 protected final P sessionPreferences;
58 protected final Channel channel;
60 private final long connectionTimeoutMillis;
61 private final Promise<S> promise;
62 private final L sessionListener;
63 private final Timer timer;
65 private Timeout timeoutTask;
68 private State state = State.IDLE;
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 timeoutTask = this.timer.newTimeout(this::timeoutExpired, connectionTimeoutMillis, TimeUnit.MILLISECONDS);
125 private synchronized void timeoutExpired(final Timeout timeout) {
126 if (state != State.ESTABLISHED) {
127 LOG.debug("Connection timeout after {}, session backed by channel {} is in state {}", timeout, channel,
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 (!promise.isDone() && !promise.isCancelled()) {
133 LOG.warn("Netconf session backed by channel {} was not established after {}", channel,
134 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);
150 private void cancelTimeout() {
151 if (timeoutTask != null) {
152 timeoutTask.cancel();
156 protected final S getSessionForHelloMessage(final NetconfHelloMessage netconfMessage)
157 throws NetconfDocumentedException {
158 final Document doc = netconfMessage.getDocument();
160 if (shouldUseChunkFraming(doc)) {
161 insertChunkFramingToPipeline();
164 changeState(State.ESTABLISHED);
165 return getSession(sessionListener, channel, netconfMessage);
169 * Insert chunk framing handlers into the pipeline.
171 private void insertChunkFramingToPipeline() {
172 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_FRAME_ENCODER,
173 FramingMechanismHandlerFactory.createHandler(FramingMechanism.CHUNK));
174 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_AGGREGATOR,
175 new NetconfChunkAggregator());
178 private boolean shouldUseChunkFraming(final Document doc) {
179 return containsBase11Capability(doc)
180 && containsBase11Capability(sessionPreferences.getHelloMessage().getDocument());
184 * Remove special inbound handler for hello message. Insert regular netconf xml message (en|de)coders.
187 * Inbound hello message handler should be kept until negotiation is successful
188 * It caches any non-hello messages while negotiation is still in progress
190 protected final void replaceHelloMessageInboundHandler(final S session) {
191 ChannelHandler helloMessageHandler = replaceChannelHandler(channel,
192 AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, new NetconfXMLToMessageDecoder());
194 checkState(helloMessageHandler instanceof NetconfXMLToHelloMessageDecoder,
195 "Pipeline handlers misplaced on session: %s, pipeline: %s", session, channel.pipeline());
196 Iterable<NetconfMessage> netconfMessagesFromNegotiation =
197 ((NetconfXMLToHelloMessageDecoder) helloMessageHandler).getPostHelloNetconfMessages();
199 // Process messages received during negotiation
200 // The hello message handler does not have to be synchronized,
201 // since it is always call from the same thread by netty.
202 // It means, we are now using the thread now
203 for (NetconfMessage message : netconfMessagesFromNegotiation) {
204 session.handleMessage(message);
209 * Remove special outbound handler for hello message. Insert regular netconf xml message (en|de)coders.
211 private void replaceHelloMessageOutboundHandler() {
212 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_ENCODER,
213 new NetconfMessageToXMLEncoder());
216 private static ChannelHandler replaceChannelHandler(final Channel channel, final String handlerKey,
217 final ChannelHandler decoder) {
218 return channel.pipeline().replace(handlerKey, handlerKey, decoder);
221 @SuppressWarnings("checkstyle:hiddenField")
222 protected abstract S getSession(L sessionListener, Channel channel, NetconfHelloMessage message)
223 throws NetconfDocumentedException;
225 private synchronized void changeState(final State newState) {
226 LOG.debug("Changing state from : {} to : {} for channel: {}", state, newState, channel);
227 checkState(isStateChangePermitted(state, newState),
228 "Cannot change state from %s to %s for channel %s", state, newState, channel);
229 this.state = newState;
232 private static boolean containsBase11Capability(final Document doc) {
233 final NodeList nList = doc.getElementsByTagNameNS(
234 XmlNetconfConstants.URN_IETF_PARAMS_XML_NS_NETCONF_BASE_1_0,
235 XmlNetconfConstants.CAPABILITY);
236 for (int i = 0; i < nList.getLength(); i++) {
237 if (nList.item(i).getTextContent().contains(XmlNetconfConstants.URN_IETF_PARAMS_NETCONF_BASE_1_1)) {
244 private static boolean isStateChangePermitted(final State state, final State newState) {
245 if (state == State.IDLE && newState == State.OPEN_WAIT) {
248 if (state == State.OPEN_WAIT && newState == State.ESTABLISHED) {
251 if (state == State.OPEN_WAIT && newState == State.FAILED) {
254 LOG.debug("Transition from {} to {} is not allowed", state, newState);
259 * Handler to catch exceptions in pipeline during negotiation.
261 private final class ExceptionHandlingInboundChannelHandler extends ChannelInboundHandlerAdapter {
263 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
264 LOG.warn("An exception occurred during negotiation with {} on channel {}",
265 channel.remoteAddress(), channel, cause);
266 // FIXME: this is quite suspect as it is competing with timeoutExpired() without synchronization
268 negotiationFailed(cause);
269 changeState(State.FAILED);
273 protected final void negotiationSuccessful(final S session) {
274 LOG.debug("Negotiation on channel {} successful with session {}", channel, session);
275 channel.pipeline().replace(this, "session", session);
276 promise.setSuccess(session);
279 protected void negotiationFailed(final Throwable cause) {
280 LOG.debug("Negotiation on channel {} failed", channel, cause);
282 promise.setFailure(cause);
286 * Send a message to peer and fail negotiation if it does not reach
289 * @param msg Message which should be sent.
291 protected final void sendMessage(final NetconfMessage msg) {
292 this.channel.writeAndFlush(msg).addListener(f -> {
293 if (!f.isSuccess()) {
294 LOG.info("Failed to send message {} on channel {}", msg, channel, f.cause());
295 negotiationFailed(f.cause());
297 LOG.trace("Message {} sent to socket on channel {}", msg, channel);
303 @SuppressWarnings("checkstyle:illegalCatch")
304 public final void channelActive(final ChannelHandlerContext ctx) {
305 LOG.debug("Starting session negotiation on channel {}", channel);
308 } catch (final Exception e) {
309 LOG.warn("Unexpected negotiation failure on channel {}", channel, e);
310 negotiationFailed(e);
315 @SuppressWarnings("checkstyle:illegalCatch")
316 public final void channelRead(final ChannelHandlerContext ctx, final Object msg) {
317 LOG.debug("Negotiation read invoked on channel {}", channel);
319 handleMessage((NetconfHelloMessage) msg);
320 } catch (final Exception e) {
321 LOG.debug("Unexpected error while handling negotiation message {} on channel {}", msg, channel, e);
322 negotiationFailed(e);
327 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
328 LOG.info("Unexpected error during negotiation on channel {}", channel, cause);
329 negotiationFailed(cause);
332 protected abstract void handleMessage(NetconfHelloMessage msg) throws Exception;