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.base.Throwables;
  13 import com.google.common.collect.Iterables;
  14 import com.google.gson.stream.JsonWriter;
  15 import java.io.ByteArrayOutputStream;
  16 import java.io.IOException;
  17 import java.io.OutputStreamWriter;
  18 import java.io.UnsupportedEncodingException;
  19 import java.net.URI;
  20 import java.nio.charset.StandardCharsets;
  21 import java.util.Iterator;
  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.JSONCodecFactory;
  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.DataContainerNodeAttrBuilder;
  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(ControllerContext controllerContext) {
  94         this.controllerContext = Preconditions.checkNotNull(controllerContext);
  95     }
  96
  97     @Override
  98     public Response toResponse(final RestconfDocumentedException exception) {
  99
 100         LOG.debug("In toResponse: {}", exception.getMessage());
 101
 102         final MediaType mediaType = headers.getAcceptableMediaTypes().stream()
 103                 .filter(type -> !type.equals(MediaType.WILDCARD_TYPE)).findFirst()
 104                         .orElse(MediaType.APPLICATION_JSON_TYPE);
 105
 106         LOG.debug("Using MediaType: {}", mediaType);
 107
 108         final List<RestconfError> errors = exception.getErrors();
 109         if (errors.isEmpty()) {
 110             // We don't actually want to send any content but, if we don't set any content here,
 111             // the tomcat front-end will send back an html error report. To prevent that, set a
 112             // single space char in the entity.
 113
 114             return Response.status(exception.getStatus()).type(MediaType.TEXT_PLAIN_TYPE).entity(" ").build();
 115         }
 116
 117         final int status = errors.iterator().next().getErrorTag().getStatusCode();
 118
 119         final DataNodeContainer errorsSchemaNode =
 120                 (DataNodeContainer) controllerContext.getRestconfModuleErrorsSchemaNode();
 121
 122         if (errorsSchemaNode == null) {
 123             return Response.status(status).type(MediaType.TEXT_PLAIN_TYPE).entity(exception.getMessage()).build();
 124         }
 125
 126         Preconditions.checkState(errorsSchemaNode instanceof ContainerSchemaNode,
 127                 "Found Errors SchemaNode isn't ContainerNode");
 128         final DataContainerNodeAttrBuilder<NodeIdentifier, ContainerNode> errContBuild =
 129                 Builders.containerBuilder((ContainerSchemaNode) errorsSchemaNode);
 130
 131         final List<DataSchemaNode> schemaList = ControllerContext.findInstanceDataChildrenByName(errorsSchemaNode,
 132                 Draft02.RestConfModule.ERROR_LIST_SCHEMA_NODE);
 133         final DataSchemaNode errListSchemaNode = Iterables.getFirst(schemaList, null);
 134         Preconditions.checkState(
 135                 errListSchemaNode instanceof ListSchemaNode, "Found Error SchemaNode isn't ListSchemaNode");
 136         final CollectionNodeBuilder<MapEntryNode, MapNode> listErorsBuilder = Builders
 137                 .mapBuilder((ListSchemaNode) errListSchemaNode);
 138
 139
 140         for (final RestconfError error : errors) {
 141             listErorsBuilder.withChild(toErrorEntryNode(error, errListSchemaNode));
 142         }
 143         errContBuild.withChild(listErorsBuilder.build());
 144
 145         final NormalizedNodeContext errContext =  new NormalizedNodeContext(new InstanceIdentifierContext<>(null,
 146                 (DataSchemaNode) errorsSchemaNode, null, controllerContext.getGlobalSchema()), errContBuild.build());
 147
 148         Object responseBody;
 149         if (mediaType.getSubtype().endsWith("json")) {
 150             responseBody = toJsonResponseBody(errContext, errorsSchemaNode);
 151         } else {
 152             responseBody = toXMLResponseBody(errContext, errorsSchemaNode);
 153         }
 154
 155         return Response.status(status).type(mediaType).entity(responseBody).build();
 156     }
 157
 158     private static MapEntryNode toErrorEntryNode(final RestconfError error, final DataSchemaNode errListSchemaNode) {
 159         Preconditions.checkArgument(errListSchemaNode instanceof ListSchemaNode,
 160                 "errListSchemaNode has to be of type ListSchemaNode");
 161         final ListSchemaNode listStreamSchemaNode = (ListSchemaNode) errListSchemaNode;
 162         final DataContainerNodeAttrBuilder<NodeIdentifierWithPredicates, MapEntryNode> errNodeValues = Builders
 163                 .mapEntryBuilder(listStreamSchemaNode);
 164
 165         List<DataSchemaNode> lsChildDataSchemaNode = ControllerContext.findInstanceDataChildrenByName(
 166                 listStreamSchemaNode, "error-type");
 167         final DataSchemaNode errTypSchemaNode = Iterables.getFirst(lsChildDataSchemaNode, null);
 168         Preconditions.checkState(errTypSchemaNode instanceof LeafSchemaNode);
 169         errNodeValues.withChild(Builders.leafBuilder((LeafSchemaNode) errTypSchemaNode)
 170                 .withValue(error.getErrorType().getErrorTypeTag()).build());
 171
 172         lsChildDataSchemaNode = ControllerContext.findInstanceDataChildrenByName(
 173                 listStreamSchemaNode, "error-tag");
 174         final DataSchemaNode errTagSchemaNode = Iterables.getFirst(lsChildDataSchemaNode, null);
 175         Preconditions.checkState(errTagSchemaNode instanceof LeafSchemaNode);
 176         errNodeValues.withChild(Builders.leafBuilder((LeafSchemaNode) errTagSchemaNode)
 177                 .withValue(error.getErrorTag().getTagValue()).build());
 178
 179         if (error.getErrorAppTag() != null) {
 180             lsChildDataSchemaNode = ControllerContext.findInstanceDataChildrenByName(
 181                     listStreamSchemaNode, "error-app-tag");
 182             final DataSchemaNode errAppTagSchemaNode = Iterables.getFirst(lsChildDataSchemaNode, null);
 183             Preconditions.checkState(errAppTagSchemaNode instanceof LeafSchemaNode);
 184             errNodeValues.withChild(Builders.leafBuilder((LeafSchemaNode) errAppTagSchemaNode)
 185                     .withValue(error.getErrorAppTag()).build());
 186         }
 187
 188         lsChildDataSchemaNode = ControllerContext.findInstanceDataChildrenByName(
 189                 listStreamSchemaNode, "error-message");
 190         final DataSchemaNode errMsgSchemaNode = Iterables.getFirst(lsChildDataSchemaNode, null);
 191         Preconditions.checkState(errMsgSchemaNode instanceof LeafSchemaNode);
 192         errNodeValues.withChild(Builders.leafBuilder((LeafSchemaNode) errMsgSchemaNode)
 193                 .withValue(error.getErrorMessage()).build());
 194
 195         if (error.getErrorInfo() != null) {
 196             // Oddly, error-info is defined as an empty container in the restconf yang. Apparently the
 197             // intention is for implementors to define their own data content so we'll just treat it as a leaf
 198             // with string data.
 199             errNodeValues.withChild(ImmutableNodes.leafNode(Draft02.RestConfModule.ERROR_INFO_QNAME,
 200                     error.getErrorInfo()));
 201         }
 202
 203         // TODO : find how could we add possible "error-path"
 204
 205         return errNodeValues.build();
 206     }
 207
 208     private static Object toJsonResponseBody(final NormalizedNodeContext errorsNode,
 209                                              final DataNodeContainer errorsSchemaNode) {
 210         final ByteArrayOutputStream outStream = new ByteArrayOutputStream();
 211         NormalizedNode<?, ?> data = errorsNode.getData();
 212         final InstanceIdentifierContext<?> context = errorsNode.getInstanceIdentifierContext();
 213         final DataSchemaNode schema = (DataSchemaNode) context.getSchemaNode();
 214
 215         SchemaPath path = context.getSchemaNode().getPath();
 216         final OutputStreamWriter outputWriter = new OutputStreamWriter(outStream, StandardCharsets.UTF_8);
 217         if (data == null) {
 218             throw new RestconfDocumentedException(Response.Status.NOT_FOUND);
 219         }
 220
 221         boolean isDataRoot = false;
 222         URI initialNs = null;
 223         if (SchemaPath.ROOT.equals(path)) {
 224             isDataRoot = true;
 225         } else {
 226             path = path.getParent();
 227             // FIXME: Add proper handling of reading root.
 228         }
 229         if (!schema.isAugmenting() && !(schema instanceof SchemaContext)) {
 230             initialNs = schema.getQName().getNamespace();
 231         }
 232
 233         final JsonWriter jsonWriter = JsonWriterFactory.createJsonWriter(outputWriter);
 234         final NormalizedNodeStreamWriter jsonStreamWriter = JSONNormalizedNodeStreamWriter.createExclusiveWriter(
 235                 JSONCodecFactory.getShared(context.getSchemaContext()), path, initialNs, jsonWriter);
 236
 237         // We create a delegating writer to special-case error-info as error-info is defined as an empty
 238         // container in the restconf yang schema but we create a leaf node so we can output it. The delegate
 239         // stream writer validates the node type against the schema and thus will expect a LeafSchemaNode but
 240         // the schema has a ContainerSchemaNode so, to avoid an error, we override the leafNode behavior
 241         // for error-info.
 242         final NormalizedNodeStreamWriter streamWriter = new ForwardingNormalizedNodeStreamWriter() {
 243             @Override
 244             protected NormalizedNodeStreamWriter delegate() {
 245                 return jsonStreamWriter;
 246             }
 247
 248             @Override
 249             public void leafNode(final NodeIdentifier name, final Object value) throws IOException {
 250                 if (name.getNodeType().equals(Draft02.RestConfModule.ERROR_INFO_QNAME)) {
 251                     jsonWriter.name(Draft02.RestConfModule.ERROR_INFO_QNAME.getLocalName());
 252                     jsonWriter.value(value.toString());
 253                 } else {
 254                     super.leafNode(name, value);
 255                 }
 256             }
 257         };
 258
 259         final NormalizedNodeWriter nnWriter = NormalizedNodeWriter.forStreamWriter(streamWriter);
 260         try {
 261             if (isDataRoot) {
 262                 writeDataRoot(outputWriter,nnWriter,(ContainerNode) data);
 263             } else {
 264                 if (data instanceof MapEntryNode) {
 265                     data = ImmutableNodes.mapNodeBuilder(data.getNodeType()).withChild((MapEntryNode) data).build();
 266                 }
 267                 nnWriter.write(data);
 268             }
 269             nnWriter.flush();
 270             outputWriter.flush();
 271         } catch (final IOException e) {
 272             LOG.warn("Error writing error response body", e);
 273         }
 274
 275         try {
 276             return outStream.toString(StandardCharsets.UTF_8.name());
 277         } catch (UnsupportedEncodingException e) {
 278             // Shouldn't happen
 279             return "Failure encoding error response: " + e;
 280         }
 281     }
 282
 283     private static Object toXMLResponseBody(final NormalizedNodeContext errorsNode,
 284                                             final DataNodeContainer errorsSchemaNode) {
 285         final InstanceIdentifierContext<?> pathContext = errorsNode.getInstanceIdentifierContext();
 286         final ByteArrayOutputStream outStream = new ByteArrayOutputStream();
 287
 288         final XMLStreamWriter xmlWriter;
 289         try {
 290             xmlWriter = XML_FACTORY.createXMLStreamWriter(outStream, StandardCharsets.UTF_8.name());
 291         } catch (final XMLStreamException e) {
 292             throw new IllegalStateException(e);
 293         } catch (final FactoryConfigurationError e) {
 294             throw new IllegalStateException(e);
 295         }
 296         NormalizedNode<?, ?> data = errorsNode.getData();
 297         SchemaPath schemaPath = pathContext.getSchemaNode().getPath();
 298
 299         boolean isDataRoot = false;
 300         if (SchemaPath.ROOT.equals(schemaPath)) {
 301             isDataRoot = true;
 302         } else {
 303             schemaPath = schemaPath.getParent();
 304         }
 305
 306         final NormalizedNodeStreamWriter xmlStreamWriter = XMLStreamNormalizedNodeStreamWriter.create(xmlWriter,
 307                 pathContext.getSchemaContext(), schemaPath);
 308
 309         // We create a delegating writer to special-case error-info as error-info is defined as an empty
 310         // container in the restconf yang schema but we create a leaf node so we can output it. The delegate
 311         // stream writer validates the node type against the schema and thus will expect a LeafSchemaNode but
 312         // the schema has a ContainerSchemaNode so, to avoid an error, we override the leafNode behavior
 313         // for error-info.
 314         final NormalizedNodeStreamWriter streamWriter = new ForwardingNormalizedNodeStreamWriter() {
 315             @Override
 316             protected NormalizedNodeStreamWriter delegate() {
 317                 return xmlStreamWriter;
 318             }
 319
 320             @Override
 321             public void leafNode(final NodeIdentifier name, final Object value) throws IOException {
 322                 if (name.getNodeType().equals(Draft02.RestConfModule.ERROR_INFO_QNAME)) {
 323                     String ns = Draft02.RestConfModule.ERROR_INFO_QNAME.getNamespace().toString();
 324                     try {
 325                         xmlWriter.writeStartElement(XMLConstants.DEFAULT_NS_PREFIX,
 326                                 Draft02.RestConfModule.ERROR_INFO_QNAME.getLocalName(), ns);
 327                         xmlWriter.writeCharacters(value.toString());
 328                         xmlWriter.writeEndElement();
 329                     } catch (XMLStreamException e) {
 330                         throw new IOException("Error writing error-info", e);
 331                     }
 332                 } else {
 333                     super.leafNode(name, value);
 334                 }
 335             }
 336         };
 337
 338         final NormalizedNodeWriter nnWriter = NormalizedNodeWriter.forStreamWriter(streamWriter);
 339         try {
 340             if (isDataRoot) {
 341                 writeRootElement(xmlWriter, nnWriter, (ContainerNode) data);
 342             } else {
 343                 if (data instanceof MapEntryNode) {
 344                     // Restconf allows returning one list item. We need to wrap it
 345                     // in map node in order to serialize it properly
 346                     data = ImmutableNodes.mapNodeBuilder(data.getNodeType()).addChild((MapEntryNode) data).build();
 347                 }
 348                 nnWriter.write(data);
 349                 nnWriter.flush();
 350             }
 351         } catch (final IOException e) {
 352             LOG.warn("Error writing error response body.", e);
 353         }
 354
 355         try {
 356             return outStream.toString(StandardCharsets.UTF_8.name());
 357         } catch (UnsupportedEncodingException e) {
 358             // Shouldn't happen
 359             return "Failure encoding error response: " + e;
 360         }
 361     }
 362
 363     private static void writeRootElement(final XMLStreamWriter xmlWriter, final NormalizedNodeWriter nnWriter,
 364                                          final ContainerNode data)
 365             throws IOException {
 366         try {
 367             final QName name = SchemaContext.NAME;
 368             xmlWriter.writeStartElement(name.getNamespace().toString(), name.getLocalName());
 369             for (final DataContainerChild<? extends PathArgument, ?> child : data.getValue()) {
 370                 nnWriter.write(child);
 371             }
 372             nnWriter.flush();
 373             xmlWriter.writeEndElement();
 374             xmlWriter.flush();
 375         } catch (final XMLStreamException e) {
 376             Throwables.propagate(e);
 377         }
 378     }
 379
 380     private static void writeDataRoot(final OutputStreamWriter outputWriter, final NormalizedNodeWriter nnWriter,
 381                                       final ContainerNode data) throws IOException {
 382         final Iterator<DataContainerChild<? extends PathArgument, ?>> iterator = data.getValue().iterator();
 383         while (iterator.hasNext()) {
 384             final DataContainerChild<? extends PathArgument, ?> child = iterator.next();
 385             nnWriter.write(child);
 386             nnWriter.flush();
 387         }
 388     }
 389 }