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.util;
11 import io.netty.channel.Channel;
12 import io.netty.channel.ChannelHandler;
13 import io.netty.channel.ChannelHandlerContext;
14 import io.netty.handler.ssl.SslHandler;
15 import io.netty.util.Timeout;
16 import io.netty.util.Timer;
17 import io.netty.util.TimerTask;
18 import io.netty.util.concurrent.Future;
19 import io.netty.util.concurrent.GenericFutureListener;
20 import io.netty.util.concurrent.Promise;
22 import java.util.concurrent.TimeUnit;
24 import org.opendaylight.controller.netconf.api.AbstractNetconfSession;
25 import org.opendaylight.controller.netconf.api.NetconfMessage;
26 import org.opendaylight.controller.netconf.api.NetconfSessionListener;
27 import org.opendaylight.controller.netconf.api.NetconfSessionPreferences;
28 import org.opendaylight.controller.netconf.util.handler.FramingMechanismHandlerFactory;
29 import org.opendaylight.controller.netconf.util.handler.NetconfChunkAggregator;
30 import org.opendaylight.controller.netconf.util.handler.NetconfMessageToXMLEncoder;
31 import org.opendaylight.controller.netconf.util.handler.NetconfXMLToMessageDecoder;
32 import org.opendaylight.controller.netconf.util.messages.FramingMechanism;
33 import org.opendaylight.controller.netconf.util.messages.NetconfHelloMessage;
34 import org.opendaylight.controller.netconf.util.xml.XmlUtil;
35 import org.opendaylight.protocol.framework.AbstractSessionNegotiator;
36 import org.slf4j.Logger;
37 import org.slf4j.LoggerFactory;
38 import org.w3c.dom.Document;
39 import org.w3c.dom.NodeList;
41 import com.google.common.base.Optional;
42 import com.google.common.base.Preconditions;
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 logger = LoggerFactory.getLogger(AbstractNetconfSessionNegotiator.class);
48 public static final String NAME_OF_EXCEPTION_HANDLER = "lastExceptionHandler";
50 protected final P sessionPreferences;
52 private final L sessionListener;
53 private Timeout timeout;
56 * Possible states for Finite State Machine
59 IDLE, OPEN_WAIT, FAILED, ESTABLISHED
62 private State state = State.IDLE;
63 private final Timer timer;
64 private final long connectionTimeoutMillis;
66 protected AbstractNetconfSessionNegotiator(P sessionPreferences, Promise<S> promise, Channel channel, Timer timer,
67 L sessionListener, long connectionTimeoutMillis) {
68 super(promise, channel);
69 this.sessionPreferences = sessionPreferences;
71 this.sessionListener = sessionListener;
72 this.connectionTimeoutMillis = connectionTimeoutMillis;
76 protected void startNegotiation() {
77 final Optional<SslHandler> sslHandler = getSslHandler(channel);
78 if (sslHandler.isPresent()) {
79 Future<Channel> future = sslHandler.get().handshakeFuture();
80 future.addListener(new GenericFutureListener<Future<? super Channel>>() {
82 public void operationComplete(Future<? super Channel> future) throws Exception {
83 Preconditions.checkState(future.isSuccess(), "Ssl handshake was not successful");
84 logger.debug("Ssl handshake complete");
92 private static Optional<SslHandler> getSslHandler(Channel channel) {
93 final SslHandler sslHandler = channel.pipeline().get(SslHandler.class);
94 return sslHandler == null ? Optional.<SslHandler> absent() : Optional.of(sslHandler);
97 private void start() {
98 final NetconfMessage helloMessage = this.sessionPreferences.getHelloMessage();
99 logger.debug("Session negotiation started with hello message {}", XmlUtil.toString(helloMessage.getDocument()));
101 channel.pipeline().addLast(NAME_OF_EXCEPTION_HANDLER, new ChannelHandler() {
103 public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
107 public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
111 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
112 logger.warn("An exception occurred during negotiation on channel {}", channel.localAddress(), cause);
114 negotiationFailed(cause);
115 changeState(State.FAILED);
119 timeout = this.timer.newTimeout(new TimerTask() {
121 public void run(final Timeout timeout) throws Exception {
122 synchronized (this) {
123 if (state != State.ESTABLISHED) {
124 logger.debug("Connection timeout after {}, session is in state {}", timeout, state);
125 final IllegalStateException cause = new IllegalStateException(
126 "Session was not established after " + timeout);
127 negotiationFailed(cause);
128 changeState(State.FAILED);
129 } else if(channel.isOpen()) {
130 channel.pipeline().remove(NAME_OF_EXCEPTION_HANDLER);
134 }, connectionTimeoutMillis, TimeUnit.MILLISECONDS);
136 sendMessage(helloMessage);
137 changeState(State.OPEN_WAIT);
140 private void cancelTimeout() {
145 private void sendMessage(NetconfMessage message) {
146 this.channel.writeAndFlush(message);
150 protected void handleMessage(NetconfHelloMessage netconfMessage) {
151 final Document doc = netconfMessage.getDocument();
153 // Only Hello message should arrive during negotiation
154 if (netconfMessage instanceof NetconfHelloMessage) {
156 replaceHelloMessageHandlers();
158 if (shouldUseChunkFraming(doc)) {
159 insertChunkFramingToPipeline();
162 changeState(State.ESTABLISHED);
163 S session = getSession(sessionListener, channel, netconfMessage);
165 negotiationSuccessful(session);
167 final IllegalStateException cause = new IllegalStateException(
168 "Received message was not hello as expected, but was " + XmlUtil.toString(doc));
169 logger.warn("Negotiation of netconf session failed", cause);
170 negotiationFailed(cause);
175 * Insert chunk framing handlers into the pipeline
177 private void insertChunkFramingToPipeline() {
178 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_FRAME_ENCODER,
179 FramingMechanismHandlerFactory.createHandler(FramingMechanism.CHUNK));
180 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_AGGREGATOR,
181 new NetconfChunkAggregator());
184 private boolean shouldUseChunkFraming(Document doc) {
185 return containsBase11Capability(doc)
186 && containsBase11Capability(sessionPreferences.getHelloMessage().getDocument());
190 * Remove special handlers for hello message. Insert regular netconf xml message (en|de)coders.
192 private void replaceHelloMessageHandlers() {
193 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, new NetconfXMLToMessageDecoder());
194 replaceChannelHandler(channel, AbstractChannelInitializer.NETCONF_MESSAGE_ENCODER, new NetconfMessageToXMLEncoder());
197 private static ChannelHandler replaceChannelHandler(Channel channel, String handlerKey, ChannelHandler decoder) {
198 return channel.pipeline().replace(handlerKey, handlerKey, decoder);
201 protected abstract S getSession(L sessionListener, Channel channel, NetconfHelloMessage message);
203 private synchronized void changeState(final State newState) {
204 logger.debug("Changing state from : {} to : {}", state, newState);
205 Preconditions.checkState(isStateChangePermitted(state, newState), "Cannot change state from %s to %s", state,
207 this.state = newState;
210 private boolean containsBase11Capability(final Document doc) {
211 final NodeList nList = doc.getElementsByTagName("capability");
212 for (int i = 0; i < nList.getLength(); i++) {
213 if (nList.item(i).getTextContent().contains("base:1.1")) {
220 private static boolean isStateChangePermitted(State state, State newState) {
221 if (state == State.IDLE && newState == State.OPEN_WAIT)
223 if (state == State.OPEN_WAIT && newState == State.ESTABLISHED)
225 if (state == State.OPEN_WAIT && newState == State.FAILED)
228 logger.debug("Transition from {} to {} is not allowed", state, newState);