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