netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect/netconf/NetconfDevice.java

   1 /*
   2  * Copyright (c) 2014 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.sal.connect.netconf;
   9
  10 import com.google.common.base.Function;
  11 import com.google.common.base.Optional;
  12 import com.google.common.base.Preconditions;
  13 import com.google.common.base.Predicates;
  14 import com.google.common.collect.Collections2;
  15 import com.google.common.collect.Lists;
  16 import com.google.common.collect.Sets;
  17 import com.google.common.util.concurrent.CheckedFuture;
  18 import com.google.common.util.concurrent.FutureCallback;
  19 import com.google.common.util.concurrent.Futures;
  20 import com.google.common.util.concurrent.ListenableFuture;
  21 import com.google.common.util.concurrent.ListeningExecutorService;
  22 import com.google.common.util.concurrent.MoreExecutors;
  23 import java.util.Collection;
  24 import java.util.Collections;
  25 import java.util.LinkedList;
  26 import java.util.List;
  27 import java.util.Set;
  28 import java.util.concurrent.Callable;
  29 import java.util.concurrent.ExecutorService;
  30 import java.util.stream.Collectors;
  31 import org.opendaylight.controller.md.sal.dom.api.DOMNotification;
  32 import org.opendaylight.controller.md.sal.dom.api.DOMRpcException;
  33 import org.opendaylight.controller.md.sal.dom.api.DOMRpcResult;
  34 import org.opendaylight.controller.md.sal.dom.api.DOMRpcService;
  35 import org.opendaylight.netconf.api.NetconfMessage;
  36 import org.opendaylight.netconf.sal.connect.api.MessageTransformer;
  37 import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemas;
  38 import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemasResolver;
  39 import org.opendaylight.netconf.sal.connect.api.RemoteDevice;
  40 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceCommunicator;
  41 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceHandler;
  42 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCapabilities;
  43 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCommunicator;
  44 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfSessionPreferences;
  45 import org.opendaylight.netconf.sal.connect.netconf.sal.NetconfDeviceRpc;
  46 import org.opendaylight.netconf.sal.connect.netconf.schema.NetconfRemoteSchemaYangSourceProvider;
  47 import org.opendaylight.netconf.sal.connect.netconf.schema.YangLibrarySchemaYangSourceProvider;
  48 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.BaseSchema;
  49 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.NetconfMessageTransformer;
  50 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  51 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  52 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.netconf.notifications.rev120206.NetconfCapabilityChange;
  53 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.available.capabilities.AvailableCapabilityBuilder;
  54 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.unavailable.capabilities.UnavailableCapability;
  55 import org.opendaylight.yangtools.yang.common.QName;
  56 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  57 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  58 import org.opendaylight.yangtools.yang.model.repo.api.RevisionSourceIdentifier;
  59 import org.opendaylight.yangtools.yang.model.repo.api.SchemaContextFactory;
  60 import org.opendaylight.yangtools.yang.model.repo.api.SchemaRepository;
  61 import org.opendaylight.yangtools.yang.model.repo.api.SchemaResolutionException;
  62 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceException;
  63 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceRepresentation;
  64 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  65 import org.opendaylight.yangtools.yang.model.repo.api.YangTextSchemaSource;
  66 import org.opendaylight.yangtools.yang.model.repo.spi.PotentialSchemaSource;
  67 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceProvider;
  68 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistration;
  69 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  70 import org.opendaylight.yangtools.yang.parser.util.ASTSchemaSource;
  71 import org.slf4j.Logger;
  72 import org.slf4j.LoggerFactory;
  73
  74 /**
  75  *  This is a mediator between NetconfDeviceCommunicator and NetconfDeviceSalFacade.
  76  */
  77 public class NetconfDevice
  78         implements RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> {
  79
  80     private static final Logger LOG = LoggerFactory.getLogger(NetconfDevice.class);
  81
  82     public static final Function<QName, SourceIdentifier> QNAME_TO_SOURCE_ID_FUNCTION =
  83         input -> RevisionSourceIdentifier.create(input.getLocalName(),
  84                 Optional.fromNullable(input.getFormattedRevision()));
  85
  86     protected final RemoteDeviceId id;
  87     private final boolean reconnectOnSchemasChange;
  88
  89     protected final SchemaContextFactory schemaContextFactory;
  90     private final RemoteDeviceHandler<NetconfSessionPreferences> salFacade;
  91     private final ListeningExecutorService processingExecutor;
  92     protected final SchemaSourceRegistry schemaRegistry;
  93     protected final SchemaRepository schemaRepository;
  94     private final NetconfDeviceSchemasResolver stateSchemasResolver;
  95     private final NotificationHandler notificationHandler;
  96     protected final List<SchemaSourceRegistration<? extends SchemaSourceRepresentation>> sourceRegistrations =
  97             Lists.newArrayList();
  98
  99     // Message transformer is constructed once the schemas are available
 100     private MessageTransformer<NetconfMessage> messageTransformer;
 101
 102     /**
 103      * Create rpc implementation capable of handling RPC for monitoring and notifications
 104      * even before the schemas of remote device are downloaded.
 105      */
 106     static NetconfDeviceRpc getRpcForInitialization(final NetconfDeviceCommunicator listener,
 107                                                     final boolean notificationSupport) {
 108         final BaseSchema baseSchema = notificationSupport
 109                 ? BaseSchema.BASE_NETCONF_CTX_WITH_NOTIFICATIONS
 110                 : BaseSchema.BASE_NETCONF_CTX;
 111
 112         return new NetconfDeviceRpc(baseSchema.getSchemaContext(), listener,
 113                 new NetconfMessageTransformer(baseSchema.getSchemaContext(), false, baseSchema));
 114     }
 115
 116     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final RemoteDeviceId id,
 117                          final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
 118                          final ExecutorService globalProcessingExecutor, final boolean reconnectOnSchemasChange) {
 119         this.id = id;
 120         this.reconnectOnSchemasChange = reconnectOnSchemasChange;
 121         this.schemaRegistry = schemaResourcesDTO.getSchemaRegistry();
 122         this.schemaRepository = schemaResourcesDTO.getSchemaRepository();
 123         this.schemaContextFactory = schemaResourcesDTO.getSchemaContextFactory();
 124         this.salFacade = salFacade;
 125         this.stateSchemasResolver = schemaResourcesDTO.getStateSchemasResolver();
 126         this.processingExecutor = MoreExecutors.listeningDecorator(globalProcessingExecutor);
 127         this.notificationHandler = new NotificationHandler(salFacade, id);
 128     }
 129
 130     @Override
 131     public void onRemoteSessionUp(final NetconfSessionPreferences remoteSessionCapabilities,
 132                                   final NetconfDeviceCommunicator listener) {
 133         // SchemaContext setup has to be performed in a dedicated thread since
 134         // we are in a netty thread in this method
 135         // Yang models are being downloaded in this method and it would cause a
 136         // deadlock if we used the netty thread
 137         // http://netty.io/wiki/thread-model.html
 138         LOG.debug("{}: Session to remote device established with {}", id, remoteSessionCapabilities);
 139
 140         final NetconfDeviceRpc initRpc =
 141                 getRpcForInitialization(listener, remoteSessionCapabilities.isNotificationsSupported());
 142         final DeviceSourcesResolver task =
 143                 new DeviceSourcesResolver(remoteSessionCapabilities, id, stateSchemasResolver, initRpc);
 144         final ListenableFuture<DeviceSources> sourceResolverFuture = processingExecutor.submit(task);
 145
 146         if (shouldListenOnSchemaChange(remoteSessionCapabilities)) {
 147             registerToBaseNetconfStream(initRpc, listener);
 148         }
 149
 150         final FutureCallback<DeviceSources> resolvedSourceCallback = new FutureCallback<DeviceSources>() {
 151             @Override
 152             public void onSuccess(final DeviceSources result) {
 153                 addProvidedSourcesToSchemaRegistry(result);
 154                 setUpSchema(result);
 155             }
 156
 157             private void setUpSchema(final DeviceSources result) {
 158                 processingExecutor.submit(new SchemaSetup(result, remoteSessionCapabilities, listener));
 159             }
 160
 161             @Override
 162             public void onFailure(final Throwable throwable) {
 163                 LOG.warn("{}: Unexpected error resolving device sources: {}", id, throwable);
 164                 handleSalInitializationFailure(throwable, listener);
 165             }
 166         };
 167
 168         Futures.addCallback(sourceResolverFuture, resolvedSourceCallback);
 169     }
 170
 171     private void registerToBaseNetconfStream(final NetconfDeviceRpc deviceRpc,
 172                                              final NetconfDeviceCommunicator listener) {
 173        // TODO check whether the model describing create subscription is present in schema
 174         // Perhaps add a default schema context to support create-subscription if the model was not provided
 175         // (same as what we do for base netconf operations in transformer)
 176         final CheckedFuture<DOMRpcResult, DOMRpcException> rpcResultListenableFuture = deviceRpc.invokeRpc(
 177             NetconfMessageTransformUtil.toPath(NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_QNAME),
 178             NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_CONTENT);
 179
 180         final NotificationHandler.NotificationFilter filter = new NotificationHandler.NotificationFilter() {
 181             @Override
 182             public Optional<DOMNotification> filterNotification(final DOMNotification notification) {
 183                 if (isCapabilityChanged(notification)) {
 184                     LOG.info("{}: Schemas change detected, reconnecting", id);
 185                     // Only disconnect is enough,
 186                     // the reconnecting nature of the connector will take care of reconnecting
 187                     listener.disconnect();
 188                     return Optional.absent();
 189                 }
 190                 return Optional.of(notification);
 191             }
 192
 193             private boolean isCapabilityChanged(final DOMNotification notification) {
 194                 return notification.getBody().getNodeType().equals(NetconfCapabilityChange.QNAME);
 195             }
 196         };
 197
 198         Futures.addCallback(rpcResultListenableFuture, new FutureCallback<DOMRpcResult>() {
 199             @Override
 200             public void onSuccess(final DOMRpcResult domRpcResult) {
 201                 notificationHandler.addNotificationFilter(filter);
 202             }
 203
 204             @Override
 205             public void onFailure(final Throwable throwable) {
 206                 LOG.warn("Unable to subscribe to base notification stream. Schemas will not be reloaded on the fly",
 207                         throwable);
 208             }
 209         });
 210     }
 211
 212     private boolean shouldListenOnSchemaChange(final NetconfSessionPreferences remoteSessionCapabilities) {
 213         return remoteSessionCapabilities.isNotificationsSupported() && reconnectOnSchemasChange;
 214     }
 215
 216     void handleSalInitializationSuccess(final SchemaContext result,
 217                                         final NetconfSessionPreferences remoteSessionCapabilities,
 218                                         final DOMRpcService deviceRpc) {
 219         final BaseSchema baseSchema =
 220                 remoteSessionCapabilities.isNotificationsSupported()
 221                         ? BaseSchema.BASE_NETCONF_CTX_WITH_NOTIFICATIONS : BaseSchema.BASE_NETCONF_CTX;
 222         messageTransformer = new NetconfMessageTransformer(result, true, baseSchema);
 223
 224         updateTransformer(messageTransformer);
 225         // salFacade.onDeviceConnected has to be called before the notification handler is initialized
 226         salFacade.onDeviceConnected(result, remoteSessionCapabilities, deviceRpc);
 227         notificationHandler.onRemoteSchemaUp(messageTransformer);
 228
 229         LOG.info("{}: Netconf connector initialized successfully", id);
 230     }
 231
 232     void handleSalInitializationFailure(final Throwable throwable,
 233                                         final RemoteDeviceCommunicator<NetconfMessage> listener) {
 234         LOG.error("{}: Initialization in sal failed, disconnecting from device", id, throwable);
 235         listener.close();
 236         onRemoteSessionDown();
 237         resetMessageTransformer();
 238     }
 239
 240     /**
 241      * Set the transformer to null as is in initial state.
 242      */
 243     private void resetMessageTransformer() {
 244         updateTransformer(null);
 245     }
 246
 247     private void updateTransformer(final MessageTransformer<NetconfMessage> transformer) {
 248         messageTransformer = transformer;
 249     }
 250
 251     private void addProvidedSourcesToSchemaRegistry(final DeviceSources deviceSources) {
 252         final SchemaSourceProvider<YangTextSchemaSource> yangProvider = deviceSources.getSourceProvider();
 253         for (final SourceIdentifier sourceId : deviceSources.getProvidedSources()) {
 254             sourceRegistrations.add(schemaRegistry.registerSchemaSource(yangProvider,
 255                     PotentialSchemaSource.create(
 256                             sourceId, YangTextSchemaSource.class, PotentialSchemaSource.Costs.REMOTE_IO.getValue())));
 257         }
 258     }
 259
 260     @Override
 261     public void onRemoteSessionDown() {
 262         notificationHandler.onRemoteSchemaDown();
 263
 264         salFacade.onDeviceDisconnected();
 265         for (final SchemaSourceRegistration<? extends SchemaSourceRepresentation> sourceRegistration
 266                 : sourceRegistrations) {
 267             sourceRegistration.close();
 268         }
 269         resetMessageTransformer();
 270     }
 271
 272     @Override
 273     public void onRemoteSessionFailed(final Throwable throwable) {
 274         salFacade.onDeviceFailed(throwable);
 275     }
 276
 277     @Override
 278     public void onNotification(final NetconfMessage notification) {
 279         notificationHandler.handleNotification(notification);
 280     }
 281
 282     /**
 283      * Just a transfer object containing schema related dependencies. Injected in constructor.
 284      */
 285     public static class SchemaResourcesDTO {
 286         private final SchemaSourceRegistry schemaRegistry;
 287         private final SchemaRepository schemaRepository;
 288         private final SchemaContextFactory schemaContextFactory;
 289         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 290
 291         public SchemaResourcesDTO(final SchemaSourceRegistry schemaRegistry,
 292                                   final SchemaRepository schemaRepository,
 293                                   final SchemaContextFactory schemaContextFactory,
 294                                   final NetconfDeviceSchemasResolver deviceSchemasResolver) {
 295             this.schemaRegistry = Preconditions.checkNotNull(schemaRegistry);
 296             this.schemaRepository = Preconditions.checkNotNull(schemaRepository);
 297             this.schemaContextFactory = Preconditions.checkNotNull(schemaContextFactory);
 298             this.stateSchemasResolver = Preconditions.checkNotNull(deviceSchemasResolver);
 299         }
 300
 301         public SchemaSourceRegistry getSchemaRegistry() {
 302             return schemaRegistry;
 303         }
 304
 305         public SchemaRepository getSchemaRepository() {
 306             return schemaRepository;
 307         }
 308
 309         public SchemaContextFactory getSchemaContextFactory() {
 310             return schemaContextFactory;
 311         }
 312
 313         public NetconfDeviceSchemasResolver getStateSchemasResolver() {
 314             return stateSchemasResolver;
 315         }
 316     }
 317
 318     /**
 319      * Schema building callable.
 320      */
 321     private static class DeviceSourcesResolver implements Callable<DeviceSources> {
 322
 323         private final NetconfDeviceRpc deviceRpc;
 324         private final NetconfSessionPreferences remoteSessionCapabilities;
 325         private final RemoteDeviceId id;
 326         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 327
 328         DeviceSourcesResolver(final NetconfDeviceRpc deviceRpc,
 329                               final NetconfSessionPreferences remoteSessionCapabilities,
 330                               final RemoteDeviceId id, final NetconfDeviceSchemasResolver stateSchemasResolver) {
 331             this.deviceRpc = deviceRpc;
 332             this.remoteSessionCapabilities = remoteSessionCapabilities;
 333             this.id = id;
 334             this.stateSchemasResolver = stateSchemasResolver;
 335         }
 336
 337         DeviceSourcesResolver(final NetconfSessionPreferences remoteSessionCapabilities, final RemoteDeviceId id,
 338                                      final NetconfDeviceSchemasResolver stateSchemasResolver,
 339                                      final NetconfDeviceRpc rpcForMonitoring) {
 340             this(rpcForMonitoring, remoteSessionCapabilities, id, stateSchemasResolver);
 341         }
 342
 343         @Override
 344         public DeviceSources call() throws Exception {
 345             final NetconfDeviceSchemas availableSchemas =
 346                     stateSchemasResolver.resolve(deviceRpc, remoteSessionCapabilities, id);
 347             LOG.debug("{}: Schemas exposed by ietf-netconf-monitoring: {}", id,
 348                     availableSchemas.getAvailableYangSchemasQNames());
 349
 350             final Set<QName> requiredSources = Sets.newHashSet(remoteSessionCapabilities.getModuleBasedCaps());
 351             final Set<QName> providedSources = availableSchemas.getAvailableYangSchemasQNames();
 352
 353             final Set<QName> requiredSourcesNotProvided = Sets.difference(requiredSources, providedSources);
 354             if (!requiredSourcesNotProvided.isEmpty()) {
 355                 LOG.warn("{}: Netconf device does not provide all yang models reported in hello message capabilities,"
 356                         + " required but not provided: {}", id, requiredSourcesNotProvided);
 357                 LOG.warn("{}: Attempting to build schema context from required sources", id);
 358             }
 359
 360             // Here all the sources reported in netconf monitoring are merged with those reported in hello.
 361             // It is necessary to perform this since submodules are not mentioned in hello but still required.
 362             // This clashes with the option of a user to specify supported yang models manually in configuration
 363             // for netconf-connector and as a result one is not able to fully override yang models of a device.
 364             // It is only possible to add additional models.
 365             final Set<QName> providedSourcesNotRequired = Sets.difference(providedSources, requiredSources);
 366             if (!providedSourcesNotRequired.isEmpty()) {
 367                 LOG.warn("{}: Netconf device provides additional yang models not reported in "
 368                         + "hello message capabilities: {}", id, providedSourcesNotRequired);
 369                 LOG.warn("{}: Adding provided but not required sources as required to prevent failures", id);
 370                 LOG.debug("{}: Netconf device reported in hello: {}", id, requiredSources);
 371                 requiredSources.addAll(providedSourcesNotRequired);
 372             }
 373
 374             final SchemaSourceProvider<YangTextSchemaSource> sourceProvider;
 375             if (availableSchemas instanceof LibraryModulesSchemas) {
 376                 sourceProvider = new YangLibrarySchemaYangSourceProvider(id,
 377                         ((LibraryModulesSchemas) availableSchemas).getAvailableModels());
 378             } else {
 379                 sourceProvider = new NetconfRemoteSchemaYangSourceProvider(id, deviceRpc);
 380             }
 381
 382             return new DeviceSources(requiredSources, providedSources, sourceProvider);
 383         }
 384     }
 385
 386     /**
 387      * Contains RequiredSources - sources from capabilities.
 388      */
 389     private static final class DeviceSources {
 390         private final Set<QName> requiredSources;
 391         private final Set<QName> providedSources;
 392         private final SchemaSourceProvider<YangTextSchemaSource> sourceProvider;
 393
 394         DeviceSources(final Set<QName> requiredSources, final Set<QName> providedSources,
 395                              final SchemaSourceProvider<YangTextSchemaSource> sourceProvider) {
 396             this.requiredSources = requiredSources;
 397             this.providedSources = providedSources;
 398             this.sourceProvider = sourceProvider;
 399         }
 400
 401         public Set<QName> getRequiredSourcesQName() {
 402             return requiredSources;
 403         }
 404
 405         public Set<QName> getProvidedSourcesQName() {
 406             return providedSources;
 407         }
 408
 409         public Collection<SourceIdentifier> getRequiredSources() {
 410             return Collections2.transform(requiredSources, QNAME_TO_SOURCE_ID_FUNCTION);
 411         }
 412
 413         public Collection<SourceIdentifier> getProvidedSources() {
 414             return Collections2.transform(providedSources, QNAME_TO_SOURCE_ID_FUNCTION);
 415         }
 416
 417         public SchemaSourceProvider<YangTextSchemaSource> getSourceProvider() {
 418             return sourceProvider;
 419         }
 420     }
 421
 422     /**
 423      * Schema builder that tries to build schema context from provided sources or biggest subset of it.
 424      */
 425     private final class SchemaSetup implements Runnable {
 426         private final DeviceSources deviceSources;
 427         private final NetconfSessionPreferences remoteSessionCapabilities;
 428         private final RemoteDeviceCommunicator<NetconfMessage> listener;
 429         private final NetconfDeviceCapabilities capabilities;
 430
 431         SchemaSetup(final DeviceSources deviceSources, final NetconfSessionPreferences remoteSessionCapabilities,
 432                            final RemoteDeviceCommunicator<NetconfMessage> listener) {
 433             this.deviceSources = deviceSources;
 434             this.remoteSessionCapabilities = remoteSessionCapabilities;
 435             this.listener = listener;
 436             this.capabilities = remoteSessionCapabilities.getNetconfDeviceCapabilities();
 437         }
 438
 439         @Override
 440         public void run() {
 441
 442             final Collection<SourceIdentifier> requiredSources = deviceSources.getRequiredSources();
 443             final Collection<SourceIdentifier> missingSources = filterMissingSources(requiredSources);
 444
 445             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(missingSources),
 446                     UnavailableCapability.FailureReason.MissingSource);
 447
 448             requiredSources.removeAll(missingSources);
 449             setUpSchema(requiredSources);
 450         }
 451
 452         private Collection<SourceIdentifier> filterMissingSources(final Collection<SourceIdentifier> requiredSources) {
 453
 454             return requiredSources.parallelStream().filter(sourceIdentifier -> {
 455                 boolean remove = false;
 456                 try {
 457                     schemaRepository.getSchemaSource(sourceIdentifier, ASTSchemaSource.class).checkedGet();
 458                 } catch (SchemaSourceException e) {
 459                     remove = true;
 460                 }
 461                 return remove;
 462             }).collect(Collectors.toList());
 463         }
 464
 465         /**
 466          * Build schema context, in case of success or final failure notify device.
 467          */
 468         @SuppressWarnings("checkstyle:IllegalCatch")
 469         private void setUpSchema(Collection<SourceIdentifier> requiredSources) {
 470             while (!requiredSources.isEmpty()) {
 471                 LOG.trace("{}: Trying to build schema context from {}", id, requiredSources);
 472                 try {
 473                     final CheckedFuture<SchemaContext, SchemaResolutionException> schemaBuilderFuture =
 474                             schemaContextFactory.createSchemaContext(requiredSources);
 475                     final SchemaContext result = schemaBuilderFuture.checkedGet();
 476                     LOG.debug("{}: Schema context built successfully from {}", id, requiredSources);
 477                     final Collection<QName> filteredQNames = Sets.difference(deviceSources.getRequiredSourcesQName(),
 478                             capabilities.getUnresolvedCapabilites().keySet());
 479                     capabilities.addCapabilities(filteredQNames.stream().map(entry -> new AvailableCapabilityBuilder()
 480                             .setCapability(entry.toString()).setCapabilityOrigin(
 481                                     remoteSessionCapabilities.getModuleBasedCapsOrigin().get(entry)).build())
 482                             .collect(Collectors.toList()));
 483
 484                     capabilities.addNonModuleBasedCapabilities(remoteSessionCapabilities
 485                             .getNonModuleCaps().stream().map(entry -> new AvailableCapabilityBuilder()
 486                             .setCapability(entry).setCapabilityOrigin(
 487                                             remoteSessionCapabilities.getNonModuleBasedCapsOrigin().get(entry)).build())
 488                             .collect(Collectors.toList()));
 489
 490                     handleSalInitializationSuccess(result, remoteSessionCapabilities, getDeviceSpecificRpc(result));
 491                     return;
 492                 } catch (final Throwable t) {
 493                     if (t instanceof MissingSchemaSourceException) {
 494                         requiredSources =
 495                                 handleMissingSchemaSourceException(requiredSources, (MissingSchemaSourceException) t);
 496                     } else if (t instanceof SchemaResolutionException) {
 497                         // schemaBuilderFuture.checkedGet() throws only SchemaResolutionException
 498                         // that might be wrapping a MissingSchemaSourceException so we need to look
 499                         // at the cause of the exception to make sure we don't misinterpret it.
 500                         if (t.getCause() instanceof MissingSchemaSourceException) {
 501                             requiredSources = handleMissingSchemaSourceException(
 502                                     requiredSources, (MissingSchemaSourceException) t.getCause());
 503                             continue;
 504                         }
 505                         requiredSources =
 506                                 handleSchemaResolutionException(requiredSources, (SchemaResolutionException) t);
 507                     } else {
 508                         // unknown error, fail
 509                         handleSalInitializationFailure(t, listener);
 510                         return;
 511                     }
 512                 }
 513             }
 514             // No more sources, fail
 515             final IllegalStateException cause = new IllegalStateException(id + ": No more sources for schema context");
 516             handleSalInitializationFailure(cause, listener);
 517             salFacade.onDeviceFailed(cause);
 518         }
 519
 520         private Collection<SourceIdentifier> handleMissingSchemaSourceException(
 521                 final Collection<SourceIdentifier> requiredSources, final MissingSchemaSourceException exception) {
 522             // In case source missing, try without it
 523             final SourceIdentifier missingSource = exception.getSourceId();
 524             LOG.warn("{}: Unable to build schema context, missing source {}, will reattempt without it", id,
 525                     missingSource);
 526             LOG.debug("{}: Unable to build schema context, missing source {}, will reattempt without it",
 527                     exception);
 528             final Collection<QName> qNameOfMissingSource =
 529                     getQNameFromSourceIdentifiers(Sets.newHashSet(missingSource));
 530             if (!qNameOfMissingSource.isEmpty()) {
 531                 capabilities.addUnresolvedCapabilities(
 532                         qNameOfMissingSource, UnavailableCapability.FailureReason.MissingSource);
 533             }
 534             return stripUnavailableSource(requiredSources, missingSource);
 535         }
 536
 537         private Collection<SourceIdentifier> handleSchemaResolutionException(
 538             final Collection<SourceIdentifier> requiredSources, final SchemaResolutionException resolutionException) {
 539             // In case resolution error, try only with resolved sources
 540             // There are two options why schema resolution exception occurred : unsatisfied imports or flawed model
 541             // FIXME Do we really have assurance that these two cases cannot happen at once?
 542             if (resolutionException.getFailedSource() != null) {
 543                 // flawed model - exclude it
 544                 final SourceIdentifier failedSourceId = resolutionException.getFailedSource();
 545                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 546                         id, failedSourceId);
 547                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 548                         id, resolutionException);
 549                 capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(
 550                         Collections.singleton(failedSourceId)), UnavailableCapability.FailureReason.UnableToResolve);
 551                 return stripUnavailableSource(requiredSources, resolutionException.getFailedSource());
 552             }
 553             // unsatisfied imports
 554             final Set<SourceIdentifier> unresolvedSources = resolutionException.getUnsatisfiedImports().keySet();
 555             capabilities.addUnresolvedCapabilities(
 556                 getQNameFromSourceIdentifiers(unresolvedSources), UnavailableCapability.FailureReason.UnableToResolve);
 557             LOG.warn("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 558                     id, resolutionException.getUnsatisfiedImports());
 559             LOG.debug("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 560                     resolutionException);
 561             return resolutionException.getResolvedSources();
 562         }
 563
 564         protected NetconfDeviceRpc getDeviceSpecificRpc(final SchemaContext result) {
 565             return new NetconfDeviceRpc(result, listener, new NetconfMessageTransformer(result, true));
 566         }
 567
 568         private Collection<SourceIdentifier> stripUnavailableSource(final Collection<SourceIdentifier> requiredSources,
 569                                                                     final SourceIdentifier sourceIdToRemove) {
 570             final LinkedList<SourceIdentifier> sourceIdentifiers = Lists.newLinkedList(requiredSources);
 571             final boolean removed = sourceIdentifiers.remove(sourceIdToRemove);
 572             Preconditions.checkState(
 573                     removed, "{}: Trying to remove {} from {} failed", id, sourceIdToRemove, requiredSources);
 574             return sourceIdentifiers;
 575         }
 576
 577         private Collection<QName> getQNameFromSourceIdentifiers(final Collection<SourceIdentifier> identifiers) {
 578             final Collection<QName> qNames = Collections2.transform(identifiers, this::getQNameFromSourceIdentifier);
 579
 580             if (qNames.isEmpty()) {
 581                 LOG.debug("{}: Unable to map any source identifiers to a capability reported by device : {}", id,
 582                         identifiers);
 583             }
 584             return Collections2.filter(qNames, Predicates.notNull());
 585         }
 586
 587         private QName getQNameFromSourceIdentifier(final SourceIdentifier identifier) {
 588             // Required sources are all required and provided merged in DeviceSourcesResolver
 589             for (final QName qname : deviceSources.getRequiredSourcesQName()) {
 590                 if (!qname.getLocalName().equals(identifier.getName())) {
 591                     continue;
 592                 }
 593
 594                 final String rev = getNullableRev(identifier);
 595                 if (rev == null) {
 596                     if (qname.getRevision() == null) {
 597                         return qname;
 598                     }
 599                 } else if (qname.getFormattedRevision().equals(rev)) {
 600                     return qname;
 601                 }
 602             }
 603             LOG.warn("Unable to map identifier to a devices reported capability: {} Available: {}",identifier,
 604                     deviceSources.getRequiredSourcesQName());
 605             // return null since we cannot find the QName,
 606             // this capability will be removed from required sources and not reported as unresolved-capability
 607             return null;
 608         }
 609
 610         private String getNullableRev(final SourceIdentifier identifier) {
 611             final String rev = identifier.getRevision();
 612             return rev == null || SourceIdentifier.NOT_PRESENT_FORMATTED_REVISION.equals(rev) ? null : rev;
 613         }
 614     }
 615 }