restconf/restconf-nb-bierman02/src/main/java/org/opendaylight/netconf/sal/rest/impl/RestconfDocumentedExceptionMapper.java

   1 /*
   2  * Copyright (c) 2014 Brocade Communications 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.sal.rest.impl;
   9
  10 import static com.google.common.base.Preconditions.checkArgument;
  11 import static com.google.common.base.Preconditions.checkState;
  12 import static java.util.Objects.requireNonNull;
  13
  14 import com.google.common.collect.Iterables;
  15 import com.google.gson.stream.JsonWriter;
  16 import java.io.ByteArrayOutputStream;
  17 import java.io.IOException;
  18 import java.io.OutputStreamWriter;
  19 import java.net.URI;
  20 import java.nio.charset.StandardCharsets;
  21 import java.util.ArrayList;
  22 import java.util.List;
  23 import javax.ws.rs.core.Context;
  24 import javax.ws.rs.core.HttpHeaders;
  25 import javax.ws.rs.core.MediaType;
  26 import javax.ws.rs.core.Response;
  27 import javax.ws.rs.ext.ExceptionMapper;
  28 import javax.ws.rs.ext.Provider;
  29 import javax.xml.XMLConstants;
  30 import javax.xml.stream.FactoryConfigurationError;
  31 import javax.xml.stream.XMLOutputFactory;
  32 import javax.xml.stream.XMLStreamException;
  33 import javax.xml.stream.XMLStreamWriter;
  34 import org.opendaylight.netconf.sal.rest.api.Draft02;
  35 import org.opendaylight.netconf.sal.restconf.impl.ControllerContext;
  36 import org.opendaylight.restconf.common.context.InstanceIdentifierContext;
  37 import org.opendaylight.restconf.common.context.NormalizedNodeContext;
  38 import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
  39 import org.opendaylight.restconf.common.errors.RestconfError;
  40 import org.opendaylight.yangtools.yang.common.QName;
  41 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  42 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  43 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  44 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  45 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
  46 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  47 import org.opendaylight.yangtools.yang.data.api.schema.MapNode;
  48 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  49 import org.opendaylight.yangtools.yang.data.api.schema.stream.ForwardingNormalizedNodeStreamWriter;
  50 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  51 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter;
  52 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactorySupplier;
  53 import org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter;
  54 import org.opendaylight.yangtools.yang.data.codec.gson.JsonWriterFactory;
  55 import org.opendaylight.yangtools.yang.data.codec.xml.XMLStreamNormalizedNodeStreamWriter;
  56 import org.opendaylight.yangtools.yang.data.impl.schema.Builders;
  57 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
  58 import org.opendaylight.yangtools.yang.data.impl.schema.builder.api.CollectionNodeBuilder;
  59 import org.opendaylight.yangtools.yang.data.impl.schema.builder.api.DataContainerNodeBuilder;
  60 import org.opendaylight.yangtools.yang.model.api.ContainerSchemaNode;
  61 import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
  62 import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
  63 import org.opendaylight.yangtools.yang.model.api.LeafSchemaNode;
  64 import org.opendaylight.yangtools.yang.model.api.ListSchemaNode;
  65 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  66 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  67 import org.slf4j.Logger;
  68 import org.slf4j.LoggerFactory;
  69
  70 /**
  71  * This class defines an ExceptionMapper that handles RestconfDocumentedExceptions thrown by resource implementations
  72  * and translates appropriately to restconf error response as defined in the RESTCONF RFC draft.
  73  *
  74  * @author Thomas Pantelis
  75  */
  76 @Provider
  77 public class RestconfDocumentedExceptionMapper implements ExceptionMapper<RestconfDocumentedException> {
  78
  79     private static final Logger LOG = LoggerFactory.getLogger(RestconfDocumentedExceptionMapper.class);
  80
  81     private static final XMLOutputFactory XML_FACTORY;
  82
  83     static {
  84         XML_FACTORY = XMLOutputFactory.newFactory();
  85         XML_FACTORY.setProperty(XMLOutputFactory.IS_REPAIRING_NAMESPACES, true);
  86     }
  87
  88     @Context
  89     private HttpHeaders headers;
  90
  91     private final ControllerContext controllerContext;
  92
  93     public RestconfDocumentedExceptionMapper(final ControllerContext controllerContext) {
  94         this.controllerContext = requireNonNull(controllerContext);
  95     }
  96
  97     @Override
  98     public Response toResponse(final RestconfDocumentedException exception) {
  99
 100         LOG.debug("In toResponse: {}", exception.getMessage());
 101
 102         final List<MediaType> mediaTypeList = new ArrayList<>();
 103         if (headers.getMediaType() != null) {
 104             mediaTypeList.add(headers.getMediaType());
 105         }
 106
 107         mediaTypeList.addAll(headers.getAcceptableMediaTypes());
 108         final MediaType mediaType = mediaTypeList.stream().filter(type -> !type.equals(MediaType.WILDCARD_TYPE))
 109                 .findFirst().orElse(MediaType.APPLICATION_JSON_TYPE);
 110
 111         LOG.debug("Using MediaType: {}", mediaType);
 112
 113         final List<RestconfError> errors = exception.getErrors();
 114         if (errors.isEmpty()) {
 115             // We don't actually want to send any content but, if we don't set any content here,
 116             // the tomcat front-end will send back an html error report. To prevent that, set a
 117             // single space char in the entity.
 118
 119             return Response.status(exception.getStatus()).type(MediaType.TEXT_PLAIN_TYPE).entity(" ").build();
 120         }
 121
 122         final int status = errors.iterator().next().getErrorTag().getStatusCode();
 123
 124         final DataNodeContainer errorsSchemaNode =
 125                 (DataNodeContainer) controllerContext.getRestconfModuleErrorsSchemaNode();
 126
 127         if (errorsSchemaNode == null) {
 128             return Response.status(status).type(MediaType.TEXT_PLAIN_TYPE).entity(exception.getMessage()).build();
 129         }
 130
 131         checkState(errorsSchemaNode instanceof ContainerSchemaNode, "Found Errors SchemaNode isn't ContainerNode");
 132         final DataContainerNodeBuilder<NodeIdentifier, ContainerNode> errContBuild =
 133                 Builders.containerBuilder((ContainerSchemaNode) errorsSchemaNode);
 134
 135         final List<DataSchemaNode> schemaList = ControllerContext.findInstanceDataChildrenByName(errorsSchemaNode,
 136                 Draft02.RestConfModule.ERROR_LIST_SCHEMA_NODE);
 137         final DataSchemaNode errListSchemaNode = Iterables.getFirst(schemaList, null);
 138         checkState(errListSchemaNode instanceof ListSchemaNode, "Found Error SchemaNode isn't ListSchemaNode");
 139         final CollectionNodeBuilder<MapEntryNode, MapNode> listErorsBuilder = Builders
 140                 .mapBuilder((ListSchemaNode) errListSchemaNode);
 141
 142
 143         for (final RestconfError error : errors) {
 144             listErorsBuilder.withChild(toErrorEntryNode(error, errListSchemaNode));
 145         }
 146         errContBuild.withChild(listErorsBuilder.build());
 147
 148         final NormalizedNodeContext errContext =  new NormalizedNodeContext(new InstanceIdentifierContext<>(null,
 149                 (DataSchemaNode) errorsSchemaNode, null, controllerContext.getGlobalSchema()), errContBuild.build());
 150
 151         Object responseBody;
 152         if (mediaType.getSubtype().endsWith("json")) {
 153             responseBody = toJsonResponseBody(errContext, errorsSchemaNode);
 154         } else {
 155             responseBody = toXMLResponseBody(errContext, errorsSchemaNode);
 156         }
 157
 158         return Response.status(status).type(mediaType).entity(responseBody).build();
 159     }
 160
 161     private static MapEntryNode toErrorEntryNode(final RestconfError error, final DataSchemaNode errListSchemaNode) {
 162         checkArgument(errListSchemaNode instanceof ListSchemaNode,
 163                 "errListSchemaNode has to be of type ListSchemaNode");
 164         final ListSchemaNode listStreamSchemaNode = (ListSchemaNode) errListSchemaNode;
 165         final DataContainerNodeBuilder<NodeIdentifierWithPredicates, MapEntryNode> errNodeValues = Builders
 166                 .mapEntryBuilder(listStreamSchemaNode);
 167
 168         List<DataSchemaNode> lsChildDataSchemaNode = ControllerContext.findInstanceDataChildrenByName(
 169                 listStreamSchemaNode, "error-type");
 170         final DataSchemaNode errTypSchemaNode = Iterables.getFirst(lsChildDataSchemaNode, null);
 171         checkState(errTypSchemaNode instanceof LeafSchemaNode);
 172         errNodeValues.withChild(Builders.leafBuilder((LeafSchemaNode) errTypSchemaNode)
 173                 .withValue(error.getErrorType().getErrorTypeTag()).build());
 174
 175         lsChildDataSchemaNode = ControllerContext.findInstanceDataChildrenByName(
 176                 listStreamSchemaNode, "error-tag");
 177         final DataSchemaNode errTagSchemaNode = Iterables.getFirst(lsChildDataSchemaNode, null);
 178         checkState(errTagSchemaNode instanceof LeafSchemaNode);
 179         errNodeValues.withChild(Builders.leafBuilder((LeafSchemaNode) errTagSchemaNode)
 180                 .withValue(error.getErrorTag().getTagValue()).build());
 181
 182         if (error.getErrorAppTag() != null) {
 183             lsChildDataSchemaNode = ControllerContext.findInstanceDataChildrenByName(
 184                     listStreamSchemaNode, "error-app-tag");
 185             final DataSchemaNode errAppTagSchemaNode = Iterables.getFirst(lsChildDataSchemaNode, null);
 186             checkState(errAppTagSchemaNode instanceof LeafSchemaNode);
 187             errNodeValues.withChild(Builders.leafBuilder((LeafSchemaNode) errAppTagSchemaNode)
 188                     .withValue(error.getErrorAppTag()).build());
 189         }
 190
 191         lsChildDataSchemaNode = ControllerContext.findInstanceDataChildrenByName(
 192                 listStreamSchemaNode, "error-message");
 193         final DataSchemaNode errMsgSchemaNode = Iterables.getFirst(lsChildDataSchemaNode, null);
 194         checkState(errMsgSchemaNode instanceof LeafSchemaNode);
 195         errNodeValues.withChild(Builders.leafBuilder((LeafSchemaNode) errMsgSchemaNode)
 196                 .withValue(error.getErrorMessage()).build());
 197
 198         if (error.getErrorInfo() != null) {
 199             // Oddly, error-info is defined as an empty container in the restconf yang. Apparently the
 200             // intention is for implementors to define their own data content so we'll just treat it as a leaf
 201             // with string data.
 202             errNodeValues.withChild(ImmutableNodes.leafNode(Draft02.RestConfModule.ERROR_INFO_QNAME,
 203                     error.getErrorInfo()));
 204         }
 205
 206         // TODO : find how could we add possible "error-path"
 207
 208         return errNodeValues.build();
 209     }
 210
 211     private static Object toJsonResponseBody(final NormalizedNodeContext errorsNode,
 212                                              final DataNodeContainer errorsSchemaNode) {
 213         final ByteArrayOutputStream outStream = new ByteArrayOutputStream();
 214         NormalizedNode<?, ?> data = errorsNode.getData();
 215         final InstanceIdentifierContext<?> context = errorsNode.getInstanceIdentifierContext();
 216         final DataSchemaNode schema = (DataSchemaNode) context.getSchemaNode();
 217
 218         SchemaPath path = context.getSchemaNode().getPath();
 219         final OutputStreamWriter outputWriter = new OutputStreamWriter(outStream, StandardCharsets.UTF_8);
 220         if (data == null) {
 221             throw new RestconfDocumentedException(Response.Status.NOT_FOUND);
 222         }
 223
 224         boolean isDataRoot = false;
 225         URI initialNs = null;
 226         if (SchemaPath.ROOT.equals(path)) {
 227             isDataRoot = true;
 228         } else {
 229             path = path.getParent();
 230             // FIXME: Add proper handling of reading root.
 231         }
 232         if (!schema.isAugmenting() && !(schema instanceof SchemaContext)) {
 233             initialNs = schema.getQName().getNamespace();
 234         }
 235
 236         final JsonWriter jsonWriter = JsonWriterFactory.createJsonWriter(outputWriter);
 237         final NormalizedNodeStreamWriter jsonStreamWriter = JSONNormalizedNodeStreamWriter.createExclusiveWriter(
 238             JSONCodecFactorySupplier.DRAFT_LHOTKA_NETMOD_YANG_JSON_02.getShared(context.getSchemaContext()), path,
 239             initialNs, jsonWriter);
 240
 241         // We create a delegating writer to special-case error-info as error-info is defined as an empty
 242         // container in the restconf yang schema but we create a leaf node so we can output it. The delegate
 243         // stream writer validates the node type against the schema and thus will expect a LeafSchemaNode but
 244         // the schema has a ContainerSchemaNode so, to avoid an error, we override the leafNode behavior
 245         // for error-info.
 246         final NormalizedNodeStreamWriter streamWriter = new ForwardingNormalizedNodeStreamWriter() {
 247             private boolean inOurLeaf;
 248
 249             @Override
 250             protected NormalizedNodeStreamWriter delegate() {
 251                 return jsonStreamWriter;
 252             }
 253
 254             @Override
 255             public void startLeafNode(final NodeIdentifier name) throws IOException {
 256                 if (name.getNodeType().equals(Draft02.RestConfModule.ERROR_INFO_QNAME)) {
 257                     inOurLeaf = true;
 258                     jsonWriter.name(Draft02.RestConfModule.ERROR_INFO_QNAME.getLocalName());
 259                 } else {
 260                     super.startLeafNode(name);
 261                 }
 262             }
 263
 264             @Override
 265             public void scalarValue(final Object value) throws IOException {
 266                 if (inOurLeaf) {
 267                     jsonWriter.value(value.toString());
 268                 } else {
 269                     super.scalarValue(value);
 270                 }
 271             }
 272
 273             @Override
 274             public void endNode() throws IOException {
 275                 if (inOurLeaf) {
 276                     inOurLeaf = false;
 277                 } else {
 278                     super.endNode();
 279                 }
 280             }
 281         };
 282
 283         final NormalizedNodeWriter nnWriter = NormalizedNodeWriter.forStreamWriter(streamWriter);
 284         try {
 285             if (isDataRoot) {
 286                 writeDataRoot(outputWriter,nnWriter,(ContainerNode) data);
 287             } else {
 288                 if (data instanceof MapEntryNode) {
 289                     data = ImmutableNodes.mapNodeBuilder(data.getNodeType()).withChild((MapEntryNode) data).build();
 290                 }
 291                 nnWriter.write(data);
 292             }
 293             nnWriter.flush();
 294             outputWriter.flush();
 295         } catch (final IOException e) {
 296             LOG.warn("Error writing error response body", e);
 297         }
 298
 299         try {
 300             streamWriter.close();
 301         } catch (IOException e) {
 302             LOG.warn("Failed to close stream writer", e);
 303         }
 304
 305         return outStream.toString(StandardCharsets.UTF_8);
 306     }
 307
 308     private static Object toXMLResponseBody(final NormalizedNodeContext errorsNode,
 309                                             final DataNodeContainer errorsSchemaNode) {
 310         final InstanceIdentifierContext<?> pathContext = errorsNode.getInstanceIdentifierContext();
 311         final ByteArrayOutputStream outStream = new ByteArrayOutputStream();
 312
 313         final XMLStreamWriter xmlWriter;
 314         try {
 315             xmlWriter = XML_FACTORY.createXMLStreamWriter(outStream, StandardCharsets.UTF_8.name());
 316         } catch (final XMLStreamException | FactoryConfigurationError e) {
 317             throw new IllegalStateException(e);
 318         }
 319         NormalizedNode<?, ?> data = errorsNode.getData();
 320         SchemaPath schemaPath = pathContext.getSchemaNode().getPath();
 321
 322         boolean isDataRoot = false;
 323         if (SchemaPath.ROOT.equals(schemaPath)) {
 324             isDataRoot = true;
 325         } else {
 326             schemaPath = schemaPath.getParent();
 327         }
 328
 329         final NormalizedNodeStreamWriter xmlStreamWriter = XMLStreamNormalizedNodeStreamWriter.create(xmlWriter,
 330                 pathContext.getSchemaContext(), schemaPath);
 331
 332         // We create a delegating writer to special-case error-info as error-info is defined as an empty
 333         // container in the restconf yang schema but we create a leaf node so we can output it. The delegate
 334         // stream writer validates the node type against the schema and thus will expect a LeafSchemaNode but
 335         // the schema has a ContainerSchemaNode so, to avoid an error, we override the leafNode behavior
 336         // for error-info.
 337         final NormalizedNodeStreamWriter streamWriter = new ForwardingNormalizedNodeStreamWriter() {
 338             private boolean inOurLeaf;
 339
 340             @Override
 341             protected NormalizedNodeStreamWriter delegate() {
 342                 return xmlStreamWriter;
 343             }
 344
 345             @Override
 346             public void startLeafNode(final NodeIdentifier name) throws IOException {
 347                 if (name.getNodeType().equals(Draft02.RestConfModule.ERROR_INFO_QNAME)) {
 348                     String ns = Draft02.RestConfModule.ERROR_INFO_QNAME.getNamespace().toString();
 349                     try {
 350                         xmlWriter.writeStartElement(XMLConstants.DEFAULT_NS_PREFIX,
 351                                 Draft02.RestConfModule.ERROR_INFO_QNAME.getLocalName(), ns);
 352                     } catch (XMLStreamException e) {
 353                         throw new IOException("Error writing error-info", e);
 354                     }
 355                     inOurLeaf = true;
 356                 } else {
 357                     super.startLeafNode(name);
 358                 }
 359             }
 360
 361             @Override
 362             public void scalarValue(final Object value) throws IOException {
 363                 if (inOurLeaf) {
 364                     try {
 365                         xmlWriter.writeCharacters(value.toString());
 366                     } catch (XMLStreamException e) {
 367                         throw new IOException("Error writing error-info", e);
 368                     }
 369                 } else {
 370                     super.scalarValue(value);
 371                 }
 372             }
 373
 374             @Override
 375             public void endNode() throws IOException {
 376                 if (inOurLeaf) {
 377                     try {
 378                         xmlWriter.writeEndElement();
 379                     } catch (XMLStreamException e) {
 380                         throw new IOException("Error writing error-info", e);
 381                     }
 382                     inOurLeaf = false;
 383                 } else {
 384                     super.endNode();
 385                 }
 386             }
 387         };
 388
 389         final NormalizedNodeWriter nnWriter = NormalizedNodeWriter.forStreamWriter(streamWriter);
 390         try {
 391             if (isDataRoot) {
 392                 writeRootElement(xmlWriter, nnWriter, (ContainerNode) data);
 393             } else {
 394                 if (data instanceof MapEntryNode) {
 395                     // Restconf allows returning one list item. We need to wrap it
 396                     // in map node in order to serialize it properly
 397                     data = ImmutableNodes.mapNodeBuilder(data.getNodeType()).addChild((MapEntryNode) data).build();
 398                 }
 399                 nnWriter.write(data);
 400                 nnWriter.flush();
 401             }
 402         } catch (final IOException e) {
 403             LOG.warn("Error writing error response body.", e);
 404         }
 405
 406         return outStream.toString(StandardCharsets.UTF_8);
 407     }
 408
 409     private static void writeRootElement(final XMLStreamWriter xmlWriter, final NormalizedNodeWriter nnWriter,
 410                                          final ContainerNode data) throws IOException {
 411         final QName name = SchemaContext.NAME;
 412         try {
 413             xmlWriter.writeStartElement(name.getNamespace().toString(), name.getLocalName());
 414             for (final DataContainerChild<? extends PathArgument, ?> child : data.getValue()) {
 415                 nnWriter.write(child);
 416             }
 417             nnWriter.flush();
 418             xmlWriter.writeEndElement();
 419             xmlWriter.flush();
 420         } catch (final XMLStreamException e) {
 421             throw new IOException("Failed to write elements", e);
 422         }
 423     }
 424
 425     private static void writeDataRoot(final OutputStreamWriter outputWriter, final NormalizedNodeWriter nnWriter,
 426                                       final ContainerNode data) throws IOException {
 427         for (final DataContainerChild<? extends PathArgument, ?> child : data.getValue()) {
 428             nnWriter.write(child);
 429             nnWriter.flush();
 430         }
 431     }
 432 }