netconf/netconf-util/src/main/java/org/opendaylight/netconf/util/NetconfUtil.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 package org.opendaylight.netconf.util;
   9
  10 import static com.google.common.base.Preconditions.checkState;
  11
  12 import com.google.common.collect.ImmutableMap;
  13 import java.io.IOException;
  14 import java.net.URISyntaxException;
  15 import java.util.Iterator;
  16 import java.util.List;
  17 import java.util.Map.Entry;
  18 import java.util.stream.Collectors;
  19 import javax.xml.stream.XMLOutputFactory;
  20 import javax.xml.stream.XMLStreamException;
  21 import javax.xml.stream.XMLStreamWriter;
  22 import javax.xml.transform.dom.DOMResult;
  23 import javax.xml.transform.dom.DOMSource;
  24 import org.eclipse.jdt.annotation.Nullable;
  25 import org.opendaylight.netconf.api.DocumentedException;
  26 import org.opendaylight.netconf.api.xml.XmlElement;
  27 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
  28 import org.opendaylight.netconf.api.xml.XmlUtil;
  29 import org.opendaylight.yangtools.rfc7952.data.api.NormalizedMetadata;
  30 import org.opendaylight.yangtools.rfc7952.data.util.NormalizedMetadataWriter;
  31 import org.opendaylight.yangtools.rfc8528.data.api.MountPointContext;
  32 import org.opendaylight.yangtools.rfc8528.data.util.EmptyMountPointContext;
  33 import org.opendaylight.yangtools.yang.common.QName;
  34 import org.opendaylight.yangtools.yang.common.QNameModule;
  35 import org.opendaylight.yangtools.yang.common.Revision;
  36 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  37 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  38 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  39 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  40 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  41 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter;
  42 import org.opendaylight.yangtools.yang.data.codec.xml.XMLStreamNormalizedNodeStreamWriter;
  43 import org.opendaylight.yangtools.yang.data.codec.xml.XmlParserStream;
  44 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNormalizedNodeStreamWriter;
  45 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeResult;
  46 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  47 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  48 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  49 import org.slf4j.Logger;
  50 import org.slf4j.LoggerFactory;
  51 import org.w3c.dom.Document;
  52 import org.w3c.dom.Element;
  53 import org.xml.sax.SAXException;
  54
  55 public final class NetconfUtil {
  56     /**
  57      * Shim interface to handle differences around namespace handling between various XMLStreamWriter implementations.
  58      * Specifically:
  59      * <ul>
  60      *   <li>OpenJDK DOM writer (com.sun.xml.internal.stream.writers.XMLDOMWriterImpl) throws
  61      *       UnsupportedOperationException from its setNamespaceContext() method</li>
  62      *   <li>Woodstox DOM writer (com.ctc.wstx.dom.WstxDOMWrappingWriter) works with namespace context, but treats
  63      *       setPrefix() calls as hints -- which are not discoverable.</li>
  64      * </ul>
  65      *
  66      * <p>
  67      * Due to this we perform a quick test for behavior and decide the appropriate strategy.
  68      */
  69     @FunctionalInterface
  70     private interface NamespaceSetter {
  71         void initializeNamespace(XMLStreamWriter writer) throws XMLStreamException;
  72
  73         static NamespaceSetter forFactory(final XMLOutputFactory xmlFactory) {
  74             final String netconfNamespace = NETCONF_QNAME.getNamespace().toString();
  75             final AnyXmlNamespaceContext namespaceContext = new AnyXmlNamespaceContext(ImmutableMap.of(
  76                 "op", netconfNamespace));
  77
  78             try {
  79                 final XMLStreamWriter testWriter = xmlFactory.createXMLStreamWriter(new DOMResult(
  80                     XmlUtil.newDocument()));
  81                 testWriter.setNamespaceContext(namespaceContext);
  82             } catch (final UnsupportedOperationException e) {
  83                 // This happens with JDK's DOM writer, which we may be using
  84                 LOG.warn("Unable to set namespace context, falling back to setPrefix()", e);
  85                 return writer -> writer.setPrefix("op", netconfNamespace);
  86             } catch (XMLStreamException e) {
  87                 throw new ExceptionInInitializerError(e);
  88             }
  89
  90             // Success, we can use setNamespaceContext()
  91             return writer -> writer.setNamespaceContext(namespaceContext);
  92         }
  93     }
  94
  95     private static final Logger LOG = LoggerFactory.getLogger(NetconfUtil.class);
  96
  97     // FIXME: document what exactly this QName means, as it is not referring to a tangible node nor the ietf-module.
  98     // FIXME: what is this contract saying?
  99     //        - is it saying all data is going to be interpreted with this root?
 100     //        - is this saying we are following a specific interface contract (i.e. do we have schema mounts?)
 101     //        - is it also inferring some abilities w.r.t. RFC8342?
 102     public static final QName NETCONF_QNAME = QName.create(QNameModule.create(SchemaContext.NAME.getNamespace(),
 103         Revision.of("2011-06-01")), "netconf").intern();
 104     // FIXME: is this the device-bound revision?
 105     public static final QName NETCONF_DATA_QNAME = QName.create(NETCONF_QNAME, "data").intern();
 106
 107     public static final XMLOutputFactory XML_FACTORY;
 108
 109     static {
 110         final XMLOutputFactory f = XMLOutputFactory.newFactory();
 111         // FIXME: not repairing namespaces is probably common, this should be availabe as common XML constant.
 112         f.setProperty(XMLOutputFactory.IS_REPAIRING_NAMESPACES, false);
 113         XML_FACTORY = f;
 114     }
 115
 116     private static final NamespaceSetter XML_NAMESPACE_SETTER = NamespaceSetter.forFactory(XML_FACTORY);
 117
 118     private NetconfUtil() {
 119         // No-op
 120     }
 121
 122     public static Document checkIsMessageOk(final Document response) throws DocumentedException {
 123         final XmlElement docElement = XmlElement.fromDomDocument(response);
 124         // FIXME: we should throw DocumentedException here
 125         checkState(XmlNetconfConstants.RPC_REPLY_KEY.equals(docElement.getName()));
 126         final XmlElement element = docElement.getOnlyChildElement();
 127         if (XmlNetconfConstants.OK.equals(element.getName())) {
 128             return response;
 129         }
 130
 131         LOG.warn("Can not load last configuration. Operation failed.");
 132         // FIXME: we should be throwing a DocumentedException here
 133         throw new IllegalStateException("Can not load last configuration. Operation failed: "
 134                 + XmlUtil.toString(response));
 135     }
 136
 137     @SuppressWarnings("checkstyle:IllegalCatch")
 138     public static void writeNormalizedNode(final NormalizedNode normalized, final DOMResult result,
 139                                            final SchemaPath schemaPath, final EffectiveModelContext context)
 140             throws IOException, XMLStreamException {
 141         final XMLStreamWriter writer = XML_FACTORY.createXMLStreamWriter(result);
 142         try (
 143              NormalizedNodeStreamWriter normalizedNodeStreamWriter =
 144                      XMLStreamNormalizedNodeStreamWriter.create(writer, context, schemaPath);
 145              NormalizedNodeWriter normalizedNodeWriter =
 146                      NormalizedNodeWriter.forStreamWriter(normalizedNodeStreamWriter)
 147         ) {
 148             normalizedNodeWriter.write(normalized);
 149             normalizedNodeWriter.flush();
 150         } finally {
 151             try {
 152                 if (writer != null) {
 153                     writer.close();
 154                 }
 155             } catch (final Exception e) {
 156                 LOG.warn("Unable to close resource properly", e);
 157             }
 158         }
 159     }
 160
 161     @SuppressWarnings("checkstyle:IllegalCatch")
 162     public static void writeNormalizedNode(final NormalizedNode normalized,
 163                                            final @Nullable NormalizedMetadata metadata,
 164                                            final DOMResult result, final SchemaPath schemaPath,
 165                                            final EffectiveModelContext context) throws IOException, XMLStreamException {
 166         if (metadata == null) {
 167             writeNormalizedNode(normalized, result, schemaPath, context);
 168             return;
 169         }
 170
 171         final XMLStreamWriter writer = XML_FACTORY.createXMLStreamWriter(result);
 172         XML_NAMESPACE_SETTER.initializeNamespace(writer);
 173         try (
 174              NormalizedNodeStreamWriter normalizedNodeStreamWriter =
 175                      XMLStreamNormalizedNodeStreamWriter.create(writer, context, schemaPath);
 176                 NormalizedMetadataWriter normalizedNodeWriter =
 177                      NormalizedMetadataWriter.forStreamWriter(normalizedNodeStreamWriter)
 178         ) {
 179             normalizedNodeWriter.write(normalized, metadata);
 180             normalizedNodeWriter.flush();
 181         } finally {
 182             try {
 183                 if (writer != null) {
 184                     writer.close();
 185                 }
 186             } catch (final Exception e) {
 187                 LOG.warn("Unable to close resource properly", e);
 188             }
 189         }
 190     }
 191
 192     /**
 193      * Writing subtree filter specified by {@link YangInstanceIdentifier} into {@link DOMResult}.
 194      *
 195      * @param query      path to the root node
 196      * @param result     DOM result holder
 197      * @param schemaPath schema path of the parent node
 198      * @param context    mountpoint schema context
 199      * @throws IOException        failed to write filter into {@link NormalizedNodeStreamWriter}
 200      * @throws XMLStreamException failed to serialize filter into XML document
 201      */
 202     public static void writeFilter(final YangInstanceIdentifier query, final DOMResult result,
 203             final SchemaPath schemaPath, final EffectiveModelContext context) throws IOException, XMLStreamException {
 204         if (query.isEmpty()) {
 205             // No query at all
 206             return;
 207         }
 208
 209         final XMLStreamWriter xmlWriter = XML_FACTORY.createXMLStreamWriter(result);
 210         try {
 211             try (NormalizedNodeStreamWriter streamWriter =
 212                     XMLStreamNormalizedNodeStreamWriter.create(xmlWriter, context, schemaPath);
 213                  EmptyListXmlWriter writer = new EmptyListXmlWriter(streamWriter, xmlWriter)) {
 214                 final Iterator<PathArgument> it = query.getPathArguments().iterator();
 215                 final PathArgument first = it.next();
 216                 StreamingContext.fromSchemaAndQNameChecked(context, first.getNodeType()).streamToWriter(writer, first,
 217                     it);
 218             }
 219         } finally {
 220             xmlWriter.close();
 221         }
 222     }
 223
 224     /**
 225      * Writing subtree filter specified by parent {@link YangInstanceIdentifier} and specific fields
 226      * into {@link DOMResult}. Field paths are relative to parent query path.
 227      *
 228      * @param query      path to the root node
 229      * @param result     DOM result holder
 230      * @param schemaPath schema path of the parent node
 231      * @param context    mountpoint schema context
 232      * @param fields     list of specific fields for which the filter should be created
 233      * @throws IOException        failed to write filter into {@link NormalizedNodeStreamWriter}
 234      * @throws XMLStreamException failed to serialize filter into XML document
 235      * @throws NullPointerException if any argument is null
 236      */
 237     public static void writeFilter(final YangInstanceIdentifier query, final DOMResult result,
 238                                    final SchemaPath schemaPath, final EffectiveModelContext context,
 239                                    final List<YangInstanceIdentifier> fields) throws IOException, XMLStreamException {
 240         if (query.isEmpty() || fields.isEmpty()) {
 241             // No query at all
 242             return;
 243         }
 244         final List<YangInstanceIdentifier> aggregatedFields = aggregateFields(fields);
 245         final PathNode rootNode = constructPathArgumentTree(query, aggregatedFields);
 246
 247         final XMLStreamWriter xmlWriter = XML_FACTORY.createXMLStreamWriter(result);
 248         try {
 249             try (NormalizedNodeStreamWriter streamWriter =
 250                     XMLStreamNormalizedNodeStreamWriter.create(xmlWriter, context, schemaPath);
 251                  EmptyListXmlWriter writer = new EmptyListXmlWriter(streamWriter, xmlWriter)) {
 252                 final PathArgument first = rootNode.element();
 253                 StreamingContext.fromSchemaAndQNameChecked(context, first.getNodeType())
 254                         .streamToWriter(writer, first, rootNode);
 255             }
 256         } finally {
 257             xmlWriter.close();
 258         }
 259     }
 260
 261     /**
 262      * Writing subtree filter specified by parent {@link YangInstanceIdentifier} and specific fields
 263      * into {@link Element}. Field paths are relative to parent query path. Filter is created without following
 264      * {@link EffectiveModelContext}.
 265      *
 266      * @param query         path to the root node
 267      * @param fields        list of specific fields for which the filter should be created
 268      * @param filterElement XML filter element to which the created filter will be written
 269      */
 270     public static void writeSchemalessFilter(final YangInstanceIdentifier query,
 271                                              final List<YangInstanceIdentifier> fields, final Element filterElement) {
 272         pathArgumentTreeToXmlStructure(constructPathArgumentTree(query, aggregateFields(fields)), filterElement);
 273     }
 274
 275     private static void pathArgumentTreeToXmlStructure(final PathNode pathArgumentTree, final Element data) {
 276         final PathArgument pathArg = pathArgumentTree.element();
 277
 278         final QName nodeType = pathArg.getNodeType();
 279         final String elementNamespace = nodeType.getNamespace().toString();
 280
 281         if (data.getElementsByTagNameNS(elementNamespace, nodeType.getLocalName()).getLength() != 0) {
 282             // element has already been written as list key
 283             return;
 284         }
 285
 286         final Element childElement = data.getOwnerDocument().createElementNS(elementNamespace, nodeType.getLocalName());
 287         data.appendChild(childElement);
 288         if (pathArg instanceof NodeIdentifierWithPredicates) {
 289             appendListKeyNodes(childElement, (NodeIdentifierWithPredicates) pathArg);
 290         }
 291         for (final PathNode childrenNode : pathArgumentTree.children()) {
 292             pathArgumentTreeToXmlStructure(childrenNode, childElement);
 293         }
 294     }
 295
 296     /**
 297      * Appending list key elements to parent element.
 298      *
 299      * @param parentElement parent XML element to which children elements are appended
 300      * @param listEntryId   list entry identifier
 301      */
 302     public static void appendListKeyNodes(final Element parentElement, final NodeIdentifierWithPredicates listEntryId) {
 303         for (Entry<QName, Object> key : listEntryId.entrySet()) {
 304             final Element keyElement = parentElement.getOwnerDocument().createElementNS(
 305                     key.getKey().getNamespace().toString(), key.getKey().getLocalName());
 306             keyElement.setTextContent(key.getValue().toString());
 307             parentElement.appendChild(keyElement);
 308         }
 309     }
 310
 311     /**
 312      * Aggregation of the fields paths based on parenthesis. Only parent/enclosing {@link YangInstanceIdentifier}
 313      * are kept. For example, paths '/x/y/z', '/x/y', and '/x' are aggregated into single field path: '/x'
 314      *
 315      * @param fields paths of fields
 316      * @return filtered {@link List} of paths
 317      */
 318     private static List<YangInstanceIdentifier> aggregateFields(final List<YangInstanceIdentifier> fields) {
 319         return fields.stream()
 320                 .filter(field -> fields.stream()
 321                         .filter(fieldYiid -> !field.equals(fieldYiid))
 322                         .noneMatch(fieldYiid -> fieldYiid.contains(field)))
 323                 .collect(Collectors.toList());
 324     }
 325
 326     /**
 327      * Construct a tree based on the parent {@link YangInstanceIdentifier} and provided list of fields. The goal of this
 328      * procedure is the elimination of the redundancy that is introduced by potentially overlapping parts of the fields
 329      * paths.
 330      *
 331      * @param query  path to parent element
 332      * @param fields subpaths relative to parent path that identify specific fields
 333      * @return created {@link TreeNode} structure
 334      */
 335     private static PathNode constructPathArgumentTree(final YangInstanceIdentifier query,
 336             final List<YangInstanceIdentifier> fields) {
 337         final Iterator<PathArgument> queryIterator = query.getPathArguments().iterator();
 338         final PathNode rootTreeNode = new PathNode(queryIterator.next());
 339
 340         PathNode queryTreeNode = rootTreeNode;
 341         while (queryIterator.hasNext()) {
 342             queryTreeNode = queryTreeNode.ensureChild(queryIterator.next());
 343         }
 344
 345         for (final YangInstanceIdentifier field : fields) {
 346             PathNode actualFieldTreeNode = queryTreeNode;
 347             for (final PathArgument fieldPathArg : field.getPathArguments()) {
 348                 actualFieldTreeNode = actualFieldTreeNode.ensureChild(fieldPathArg);
 349             }
 350         }
 351         return rootTreeNode;
 352     }
 353
 354     public static NormalizedNodeResult transformDOMSourceToNormalizedNode(final MountPointContext mount,
 355             final DOMSource value) throws XMLStreamException, URISyntaxException, IOException, SAXException {
 356         final NormalizedNodeResult resultHolder = new NormalizedNodeResult();
 357         final NormalizedNodeStreamWriter writer = ImmutableNormalizedNodeStreamWriter.from(resultHolder);
 358         try (XmlParserStream xmlParserStream = XmlParserStream.create(writer, new ProxyMountPointContext(mount))) {
 359             xmlParserStream.traverse(value);
 360         }
 361         return resultHolder;
 362     }
 363
 364     // FIXME: document this interface contract. Does it support RFC8528/RFC8542? How?
 365     public static NormalizedNodeResult transformDOMSourceToNormalizedNode(final EffectiveModelContext schemaContext,
 366             final DOMSource value) throws XMLStreamException, URISyntaxException, IOException, SAXException {
 367         return transformDOMSourceToNormalizedNode(new EmptyMountPointContext(schemaContext), value);
 368     }
 369 }