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
9 package org.opendaylight.controller.netconf.nettyutil;
11 import com.google.common.base.Optional;
12 import com.google.common.base.Preconditions;
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.Future;
23 import io.netty.util.concurrent.GenericFutureListener;
24 import io.netty.util.concurrent.Promise;
25 import java.util.concurrent.TimeUnit;
26 import org.opendaylight.controller.netconf.api.NetconfDocumentedException;
27 import org.opendaylight.controller.netconf.api.NetconfMessage;
28 import org.opendaylight.controller.netconf.api.NetconfSessionListener;
29 import org.opendaylight.controller.netconf.api.NetconfSessionPreferences;
30 import org.opendaylight.controller.netconf.api.xml.XmlNetconfConstants;
31 import org.opendaylight.controller.netconf.nettyutil.handler.FramingMechanismHandlerFactory;
32 import org.opendaylight.controller.netconf.nettyutil.handler.NetconfChunkAggregator;
33 import org.opendaylight.controller.netconf.nettyutil.handler.NetconfMessageToXMLEncoder;
34 import org.opendaylight.controller.netconf.nettyutil.handler.NetconfXMLToHelloMessageDecoder;
35 import org.opendaylight.controller.netconf.nettyutil.handler.NetconfXMLToMessageDecoder;
36 import org.opendaylight.controller.netconf.util.messages.FramingMechanism;
37 import org.opendaylight.controller.netconf.util.messages.NetconfHelloMessage;
38 import org.opendaylight.protocol.framework.AbstractSessionNegotiator;
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, S extends AbstractNetconfSession<S, L>, L extends NetconfSessionListener<S>>
45 extends AbstractSessionNegotiator<NetconfHelloMessage, 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;
53 private final L sessionListener;
54 private Timeout timeout;
57 * Possible states for Finite State Machine
59 protected enum State {
60 IDLE, OPEN_WAIT, FAILED, ESTABLISHED
63 private State state = State.IDLE;
64 private final Promise<S> promise;
65 private final Timer timer;
66 private final long connectionTimeoutMillis;
68 // TODO shrink constructor
69 protected AbstractNetconfSessionNegotiator(final P sessionPreferences, final Promise<S> promise, final Channel channel, final Timer timer,
70 final L sessionListener, final long connectionTimeoutMillis) {
71 super(promise, channel);
72 this.sessionPreferences = sessionPreferences;
73 this.promise = promise;
75 this.sessionListener = sessionListener;
76 this.connectionTimeoutMillis = connectionTimeoutMillis;
80 protected final void startNegotiation() {
81 final Optional<SslHandler> sslHandler = getSslHandler(channel);
82 if (sslHandler.isPresent()) {
83 Future<Channel> future = sslHandler.get().handshakeFuture();
84 future.addListener(new GenericFutureListener<Future<? super Channel>>() {
86 public void operationComplete(final Future<? super Channel> future) {
87 Preconditions.checkState(future.isSuccess(), "Ssl handshake was not successful");
88 LOG.debug("Ssl handshake complete");
97 private static Optional<SslHandler> getSslHandler(final Channel channel) {
98 final SslHandler sslHandler = channel.pipeline().get(SslHandler.class);
99 return sslHandler == null ? Optional.<SslHandler> absent() : Optional.of(sslHandler);
102 public P getSessionPreferences() {
103 return sessionPreferences;
106 private void start() {
107 final NetconfMessage helloMessage = this.sessionPreferences.getHelloMessage();
108 LOG.debug("Session negotiation started with hello message {} on channel {}", helloMessage, channel);
110 channel.pipeline().addLast(NAME_OF_EXCEPTION_HANDLER, new ExceptionHandlingInboundChannelHandler());
112 // FIXME, make sessionPreferences return HelloMessage, move NetconfHelloMessage to API
113 sendMessage((NetconfHelloMessage)helloMessage);
115 replaceHelloMessageOutboundHandler();
116 changeState(State.OPEN_WAIT);
118 timeout = this.timer.newTimeout(new TimerTask() {
120 public void run(final Timeout timeout) {
121 synchronized (this) {
122 if (state != State.ESTABLISHED) {
124 LOG.debug("Connection timeout after {}, session is in state {}", timeout, state);
126 // Do not fail negotiation if promise is done or canceled
127 // It would result in setting result of the promise second time and that throws exception
128 if (isPromiseFinished() == false) {
129 negotiationFailed(new IllegalStateException("Session was not established after " + timeout));
130 changeState(State.FAILED);
132 channel.closeFuture().addListener(new GenericFutureListener<ChannelFuture>() {
134 public void operationComplete(final ChannelFuture future) throws Exception {
135 if(future.isSuccess()) {
136 LOG.debug("Channel {} closed: success", future.channel());
138 LOG.warn("Channel {} closed: fail", future.channel());
143 } else if(channel.isOpen()) {
144 channel.pipeline().remove(NAME_OF_EXCEPTION_HANDLER);
149 private boolean isPromiseFinished() {
150 return promise.isDone() || promise.isCancelled();
153 }, connectionTimeoutMillis, TimeUnit.MILLISECONDS);
156 private void cancelTimeout() {
162 protected final S getSessionForHelloMessage(final NetconfHelloMessage netconfMessage) throws NetconfDocumentedException {
163 Preconditions.checkNotNull(netconfMessage, "netconfMessage");
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.
193 * Inbound hello message handler should be kept until negotiation is successful
194 * It caches any non-hello messages while negotiation is still in progress
196 protected final void replaceHelloMessageInboundHandler(final S session) {
197 ChannelHandler helloMessageHandler = replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, new NetconfXMLToMessageDecoder());
199 Preconditions.checkState(helloMessageHandler instanceof NetconfXMLToHelloMessageDecoder,
200 "Pipeline handlers misplaced on session: %s, pipeline: %s", session, channel.pipeline());
201 Iterable<NetconfMessage> netconfMessagesFromNegotiation =
202 ((NetconfXMLToHelloMessageDecoder) helloMessageHandler).getPostHelloNetconfMessages();
204 // Process messages received during negotiation
205 // The hello message handler does not have to be synchronized, since it is always call from the same thread by netty
206 // It means, we are now using the thread now
207 for (NetconfMessage message : netconfMessagesFromNegotiation) {
208 session.handleMessage(message);
213 * Remove special outbound handler for hello message. Insert regular netconf xml message (en|de)coders.
215 private void replaceHelloMessageOutboundHandler() {
216 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_ENCODER, new NetconfMessageToXMLEncoder());
219 private static ChannelHandler replaceChannelHandler(final Channel channel, final String handlerKey, final ChannelHandler decoder) {
220 return channel.pipeline().replace(handlerKey, handlerKey, decoder);
223 protected abstract S getSession(L sessionListener, Channel channel, NetconfHelloMessage message) throws NetconfDocumentedException;
225 private synchronized void changeState(final State newState) {
226 LOG.debug("Changing state from : {} to : {} for channel: {}", state, newState, channel);
227 Preconditions.checkState(isStateChangePermitted(state, newState), "Cannot change state from %s to %s for chanel %s", state,
229 this.state = newState;
232 private boolean containsBase11Capability(final Document doc) {
233 final NodeList nList = doc.getElementsByTagName(XmlNetconfConstants.CAPABILITY);
234 for (int i = 0; i < nList.getLength(); i++) {
235 if (nList.item(i).getTextContent().contains(XmlNetconfConstants.URN_IETF_PARAMS_NETCONF_BASE_1_1)) {
242 private static boolean isStateChangePermitted(final State state, final State newState) {
243 if (state == State.IDLE && newState == State.OPEN_WAIT) {
246 if (state == State.OPEN_WAIT && newState == State.ESTABLISHED) {
249 if (state == State.OPEN_WAIT && newState == State.FAILED) {
252 LOG.debug("Transition from {} to {} is not allowed", state, newState);
257 * Handler to catch exceptions in pipeline during negotiation
259 private final class ExceptionHandlingInboundChannelHandler extends ChannelInboundHandlerAdapter {
261 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
262 LOG.warn("An exception occurred during negotiation with {}", channel.remoteAddress(), cause);
264 negotiationFailed(cause);
265 changeState(State.FAILED);