opendaylight/netconf/netconf-impl/src/main/java/org/opendaylight/controller/netconf/impl/NetconfServerSessionNegotiatorFactory.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.impl;
  10
  11 import com.google.common.base.Preconditions;
  12 import io.netty.channel.Channel;
  13 import io.netty.util.Timer;
  14 import io.netty.util.concurrent.Promise;
  15 import org.opendaylight.controller.netconf.api.NetconfMessage;
  16 import org.opendaylight.controller.netconf.api.NetconfServerSessionPreferences;
  17 import org.opendaylight.controller.netconf.impl.mapping.CapabilityProvider;
  18 import org.opendaylight.controller.netconf.impl.osgi.NetconfOperationServiceFactoryListener;
  19 import org.opendaylight.controller.netconf.util.NetconfUtil;
  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.opendaylight.protocol.framework.SessionListenerFactory;
  24 import org.opendaylight.protocol.framework.SessionNegotiator;
  25 import org.opendaylight.protocol.framework.SessionNegotiatorFactory;
  26 import org.w3c.dom.Document;
  27 import org.w3c.dom.Element;
  28 import org.w3c.dom.Node;
  29
  30 import javax.xml.xpath.XPathConstants;
  31 import javax.xml.xpath.XPathExpression;
  32 import java.io.InputStream;
  33
  34 public class NetconfServerSessionNegotiatorFactory implements SessionNegotiatorFactory {
  35
  36     public static final String SERVER_HELLO_XML_LOCATION = "/server_hello.xml";
  37
  38     private final Timer timer;
  39
  40     private static final Document helloMessageTemplate = loadHelloMessageTemplate();
  41     private final SessionIdProvider idProvider;
  42     private final NetconfOperationServiceFactoryListener factoriesListener;
  43
  44     public NetconfServerSessionNegotiatorFactory(Timer timer, NetconfOperationServiceFactoryListener factoriesListener,
  45             SessionIdProvider idProvider) {
  46         this.timer = timer;
  47         this.factoriesListener = factoriesListener;
  48         this.idProvider = idProvider;
  49     }
  50
  51     private static Document loadHelloMessageTemplate() {
  52         InputStream resourceAsStream = NetconfServerSessionNegotiatorFactory.class
  53                 .getResourceAsStream(SERVER_HELLO_XML_LOCATION);
  54         Preconditions.checkNotNull(resourceAsStream, "Unable to load server hello message blueprint from %s",
  55                 SERVER_HELLO_XML_LOCATION);
  56         return NetconfUtil.createMessage(resourceAsStream).getDocument();
  57     }
  58
  59     @Override
  60     public SessionNegotiator getSessionNegotiator(SessionListenerFactory sessionListenerFactory, Channel channel,
  61             Promise promise) {
  62         long sessionId = idProvider.getNextSessionId();
  63
  64         NetconfServerSessionPreferences proposal = new NetconfServerSessionPreferences(createHelloMessage(sessionId),
  65                 sessionId);
  66         return new NetconfServerSessionNegotiator(proposal, promise, channel, timer,
  67                 sessionListenerFactory.getSessionListener());
  68     }
  69
  70     private static final XPathExpression sessionIdXPath = XMLNetconfUtil
  71             .compileXPath("/netconf:hello/netconf:session-id");
  72     private static final XPathExpression capabilitiesXPath = XMLNetconfUtil
  73             .compileXPath("/netconf:hello/netconf:capabilities");
  74
  75     private NetconfMessage createHelloMessage(long sessionId) {
  76         Document helloMessageTemplate = getHelloTemplateClone();
  77
  78         // change session ID
  79         final Node sessionIdNode = (Node) XmlUtil.evaluateXPath(sessionIdXPath, helloMessageTemplate,
  80                 XPathConstants.NODE);
  81         sessionIdNode.setTextContent(String.valueOf(sessionId));
  82
  83         // add capabilities from yang store
  84         final Element capabilitiesElement = (Element) XmlUtil.evaluateXPath(capabilitiesXPath, helloMessageTemplate,
  85                 XPathConstants.NODE);
  86
  87         CapabilityProvider capabilityProvider = new CapabilityProviderImpl(factoriesListener.getSnapshot(sessionId));
  88
  89         for (String capability : capabilityProvider.getCapabilities()) {
  90             final Element capabilityElement = helloMessageTemplate.createElement(XmlNetconfConstants.CAPABILITY);
  91             capabilityElement.setTextContent(capability);
  92             capabilitiesElement.appendChild(capabilityElement);
  93         }
  94         return new NetconfMessage(helloMessageTemplate);
  95     }
  96
  97     private synchronized Document getHelloTemplateClone() {
  98         return (Document) this.helloMessageTemplate.cloneNode(true);
  99     }
 100 }