opendaylight/netconf/netconf-client/src/main/java/org/opendaylight/controller/netconf/client/NetconfClientSessionNegotiator.java

   1 /*
   2  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   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
   7  */
   8
   9 package org.opendaylight.controller.netconf.client;
  10
  11 import javax.xml.xpath.XPathConstants;
  12 import javax.xml.xpath.XPathExpression;
  13
  14 import org.opendaylight.controller.netconf.api.NetconfClientSessionPreferences;
  15 import org.opendaylight.controller.netconf.api.NetconfMessage;
  16 import org.opendaylight.controller.netconf.util.AbstractChannelInitializer;
  17 import org.opendaylight.controller.netconf.util.AbstractNetconfSessionNegotiator;
  18 import org.opendaylight.controller.netconf.util.messages.NetconfHelloMessage;
  19 import org.opendaylight.controller.netconf.util.messages.NetconfMessageUtil;
  20 import org.opendaylight.controller.netconf.util.xml.XMLNetconfUtil;
  21 import org.opendaylight.controller.netconf.util.xml.XmlNetconfConstants;
  22 import org.opendaylight.controller.netconf.util.xml.XmlUtil;
  23 import org.slf4j.Logger;
  24 import org.slf4j.LoggerFactory;
  25 import org.w3c.dom.Document;
  26 import org.w3c.dom.Node;
  27 import org.w3c.dom.NodeList;
  28
  29 import io.netty.channel.Channel;
  30 import io.netty.channel.ChannelFuture;
  31 import io.netty.channel.ChannelFutureListener;
  32 import io.netty.channel.ChannelHandlerContext;
  33 import io.netty.channel.ChannelInboundHandlerAdapter;
  34 import io.netty.util.Timer;
  35 import io.netty.util.concurrent.Promise;
  36
  37 public class NetconfClientSessionNegotiator extends
  38         AbstractNetconfSessionNegotiator<NetconfClientSessionPreferences, NetconfClientSession, NetconfClientSessionListener>
  39 {
  40     private static final Logger logger = LoggerFactory.getLogger(NetconfClientSessionNegotiator.class);
  41
  42     private static final XPathExpression sessionIdXPath = XMLNetconfUtil
  43             .compileXPath("/netconf:hello/netconf:session-id");
  44
  45     private static final String EXI_1_0_CAPABILITY_MARKER = "exi:1.0";
  46
  47     protected NetconfClientSessionNegotiator(NetconfClientSessionPreferences sessionPreferences,
  48                                              Promise<NetconfClientSession> promise,
  49                                              Channel channel,
  50                                              Timer timer,
  51                                              NetconfClientSessionListener sessionListener,
  52                                              long connectionTimeoutMillis) {
  53         super(sessionPreferences, promise, channel, timer, sessionListener, connectionTimeoutMillis);
  54     }
  55
  56     @Override
  57     protected void handleMessage(NetconfHelloMessage netconfMessage) {
  58         NetconfClientSession session = super.getSessionForHelloMessage(netconfMessage);
  59
  60         if (shouldUseExi(netconfMessage.getDocument())){
  61             logger.info("Netconf session: {} should use exi.", session);
  62             tryToStartExi(session);
  63         } else {
  64             logger.info("Netconf session {} isn't capable using exi.", session);
  65             negotiationSuccessful(session);
  66         }
  67     }
  68
  69     private boolean shouldUseExi(Document doc) {
  70         return containsExi10Capability(doc)
  71                 && containsExi10Capability(sessionPreferences.getHelloMessage().getDocument());
  72     }
  73
  74     private boolean containsExi10Capability(final Document doc) {
  75         final NodeList nList = doc.getElementsByTagName(XmlNetconfConstants.CAPABILITY);
  76         for (int i = 0; i < nList.getLength(); i++) {
  77             if (nList.item(i).getTextContent().contains(EXI_1_0_CAPABILITY_MARKER)) {
  78                 return true;
  79             }
  80         }
  81         return false;
  82     }
  83
  84     private void tryToStartExi(final NetconfClientSession session) {
  85         final NetconfMessage startExi = sessionPreferences.getStartExiMessage();
  86         session.sendMessage(startExi).addListener(new ChannelFutureListener() {
  87             @Override
  88             public void operationComplete(final ChannelFuture f) {
  89                 if (!f.isSuccess()) {
  90                     logger.warn("Failed to send start-exi message {} on session {}", startExi, session, f.cause());
  91                 } else {
  92                     logger.trace("Start-exi message {} sent to socket on session {}", startExi, session);
  93                     NetconfClientSessionNegotiator.this.channel.pipeline().addAfter(
  94                             AbstractChannelInitializer.NETCONF_MESSAGE_DECODER, ExiConfirmationInboundHandler.EXI_CONFIRMED_HANDLER,
  95                             new ExiConfirmationInboundHandler(session));
  96                 }
  97             }
  98         });
  99     }
 100
 101     private long extractSessionId(Document doc) {
 102         final Node sessionIdNode = (Node) XmlUtil.evaluateXPath(sessionIdXPath, doc, XPathConstants.NODE);
 103         String textContent = sessionIdNode.getTextContent();
 104         if (textContent == null || textContent.equals("")) {
 105             throw new IllegalStateException("Session id not received from server");
 106         }
 107
 108         return Long.valueOf(textContent);
 109     }
 110
 111     @Override
 112     protected NetconfClientSession getSession(NetconfClientSessionListener sessionListener, Channel channel, NetconfHelloMessage message) {
 113         return new NetconfClientSession(sessionListener, channel, extractSessionId(message.getDocument()),
 114                 NetconfMessageUtil.extractCapabilitiesFromHello(message.getDocument()));
 115     }
 116
 117     /**
 118      * Handler to process response for start-exi message
 119      */
 120     private final class ExiConfirmationInboundHandler extends ChannelInboundHandlerAdapter {
 121         private static final String EXI_CONFIRMED_HANDLER = "exiConfirmedHandler";
 122
 123         private final NetconfClientSession session;
 124
 125         ExiConfirmationInboundHandler(NetconfClientSession session) {
 126             this.session = session;
 127         }
 128
 129         @Override
 130         public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
 131             ctx.pipeline().remove(ExiConfirmationInboundHandler.EXI_CONFIRMED_HANDLER);
 132
 133             NetconfMessage netconfMessage = (NetconfMessage) msg;
 134
 135             // Ok response to start-exi, try to add exi handlers
 136             if (NetconfMessageUtil.isOKMessage(netconfMessage)) {
 137                 logger.trace("Positive response on start-exi call received on session {}", session);
 138                 try {
 139                     session.startExiCommunication(sessionPreferences.getStartExiMessage());
 140                 } catch (RuntimeException e) {
 141                     // Unable to add exi, continue without exi
 142                     logger.warn("Unable to start exi communication, Communication will continue without exi on session {}", session, e);
 143                 }
 144
 145             // Error response
 146             } else if(NetconfMessageUtil.isErrorMessage(netconfMessage)) {
 147                 logger.warn(
 148                         "Error response to start-exi message {}, Communication will continue without exi on session {}",
 149                         XmlUtil.toString(netconfMessage.getDocument()), session);
 150
 151             // Unexpected response to start-exi, throwing message away, continue without exi
 152             } else {
 153                 logger.warn(
 154                         "Unexpected response to start-exi message, should be ok, was {}, " +
 155                                 "Communication will continue without exi and response message will be thrown away on session {}",
 156                         XmlUtil.toString(netconfMessage.getDocument()), session);
 157             }
 158
 159             negotiationSuccessful(session);
 160         }
 161     }
 162 }