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