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 io.netty.channel.Channel;
  12 import io.netty.util.Timer;
  13 import io.netty.util.concurrent.Promise;
  14
  15 import java.io.InputStream;
  16
  17 import javax.xml.xpath.XPathConstants;
  18 import javax.xml.xpath.XPathExpression;
  19
  20 import org.opendaylight.controller.netconf.api.NetconfServerSessionPreferences;
  21 import org.opendaylight.controller.netconf.impl.mapping.CapabilityProvider;
  22 import org.opendaylight.controller.netconf.impl.osgi.NetconfOperationServiceFactoryListener;
  23 import org.opendaylight.controller.netconf.util.NetconfUtil;
  24 import org.opendaylight.controller.netconf.util.messages.NetconfHelloMessage;
  25 import org.opendaylight.controller.netconf.util.xml.XMLNetconfUtil;
  26 import org.opendaylight.controller.netconf.util.xml.XmlNetconfConstants;
  27 import org.opendaylight.controller.netconf.util.xml.XmlUtil;
  28 import org.opendaylight.protocol.framework.SessionListenerFactory;
  29 import org.opendaylight.protocol.framework.SessionNegotiator;
  30 import org.opendaylight.protocol.framework.SessionNegotiatorFactory;
  31 import org.w3c.dom.Document;
  32 import org.w3c.dom.Element;
  33 import org.w3c.dom.Node;
  34
  35 import com.google.common.base.Optional;
  36 import com.google.common.base.Preconditions;
  37
  38 public class NetconfServerSessionNegotiatorFactory implements SessionNegotiatorFactory<NetconfHelloMessage, NetconfServerSession, NetconfServerSessionListener> {
  39
  40     public static final String SERVER_HELLO_XML_LOCATION = "/server_hello.xml";
  41
  42     private final Timer timer;
  43
  44     private static final Document helloMessageTemplate = loadHelloMessageTemplate();
  45     private final SessionIdProvider idProvider;
  46     private final NetconfOperationServiceFactoryListener factoriesListener;
  47     private final long connectionTimeoutMillis;
  48
  49     public NetconfServerSessionNegotiatorFactory(Timer timer, NetconfOperationServiceFactoryListener factoriesListener,
  50             SessionIdProvider idProvider, long connectionTimeoutMillis) {
  51         this.timer = timer;
  52         this.factoriesListener = factoriesListener;
  53         this.idProvider = idProvider;
  54         this.connectionTimeoutMillis = connectionTimeoutMillis;
  55     }
  56
  57     private static Document loadHelloMessageTemplate() {
  58         InputStream resourceAsStream = NetconfServerSessionNegotiatorFactory.class
  59                 .getResourceAsStream(SERVER_HELLO_XML_LOCATION);
  60         Preconditions.checkNotNull(resourceAsStream, "Unable to load server hello message blueprint from %s",
  61                 SERVER_HELLO_XML_LOCATION);
  62         return NetconfUtil.createMessage(resourceAsStream).getDocument();
  63     }
  64
  65     @Override
  66     public SessionNegotiator<NetconfServerSession> getSessionNegotiator(SessionListenerFactory<NetconfServerSessionListener> sessionListenerFactory, Channel channel,
  67             Promise<NetconfServerSession> promise) {
  68         long sessionId = idProvider.getNextSessionId();
  69
  70         NetconfServerSessionPreferences proposal = new NetconfServerSessionPreferences(createHelloMessage(sessionId),
  71                 sessionId);
  72         return new NetconfServerSessionNegotiator(proposal, promise, channel, timer,
  73                 sessionListenerFactory.getSessionListener(), connectionTimeoutMillis);
  74     }
  75
  76     private static final XPathExpression sessionIdXPath = XMLNetconfUtil
  77             .compileXPath("/netconf:hello/netconf:session-id");
  78     private static final XPathExpression capabilitiesXPath = XMLNetconfUtil
  79             .compileXPath("/netconf:hello/netconf:capabilities");
  80
  81     private NetconfHelloMessage createHelloMessage(long sessionId) {
  82         Document helloMessageTemplate = getHelloTemplateClone();
  83
  84         // change session ID
  85         final Node sessionIdNode = (Node) XmlUtil.evaluateXPath(sessionIdXPath, helloMessageTemplate,
  86                 XPathConstants.NODE);
  87         sessionIdNode.setTextContent(String.valueOf(sessionId));
  88
  89         // add capabilities from yang store
  90         final Element capabilitiesElement = (Element) XmlUtil.evaluateXPath(capabilitiesXPath, helloMessageTemplate,
  91                 XPathConstants.NODE);
  92
  93         CapabilityProvider capabilityProvider = new CapabilityProviderImpl(factoriesListener.getSnapshot(sessionId));
  94
  95         for (String capability : capabilityProvider.getCapabilities()) {
  96             final Element capabilityElement = XmlUtil.createElement(helloMessageTemplate, XmlNetconfConstants.CAPABILITY, Optional.<String>absent());
  97             capabilityElement.setTextContent(capability);
  98             capabilitiesElement.appendChild(capabilityElement);
  99         }
 100         return new NetconfHelloMessage(helloMessageTemplate);
 101     }
 102
 103     private synchronized Document getHelloTemplateClone() {
 104         return (Document) helloMessageTemplate.cloneNode(true);
 105     }
 106 }