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.Optional;
  11 import com.google.common.base.Preconditions;
  12 import com.google.common.base.Predicates;
  13 import com.google.common.collect.Collections2;
  14 import com.google.common.collect.Lists;
  15 import com.google.common.collect.Sets;
  16 import com.google.common.util.concurrent.CheckedFuture;
  17 import com.google.common.util.concurrent.FutureCallback;
  18 import com.google.common.util.concurrent.Futures;
  19 import com.google.common.util.concurrent.ListenableFuture;
  20 import com.google.common.util.concurrent.ListeningExecutorService;
  21 import com.google.common.util.concurrent.MoreExecutors;
  22 import java.util.ArrayList;
  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.ExecutionException;
  30 import java.util.concurrent.ExecutorService;
  31 import java.util.stream.Collectors;
  32 import javax.annotation.Nonnull;
  33 import javax.annotation.concurrent.GuardedBy;
  34 import org.opendaylight.controller.md.sal.dom.api.DOMNotification;
  35 import org.opendaylight.controller.md.sal.dom.api.DOMRpcException;
  36 import org.opendaylight.controller.md.sal.dom.api.DOMRpcResult;
  37 import org.opendaylight.controller.md.sal.dom.api.DOMRpcService;
  38 import org.opendaylight.netconf.api.NetconfMessage;
  39 import org.opendaylight.netconf.sal.connect.api.MessageTransformer;
  40 import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemas;
  41 import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemasResolver;
  42 import org.opendaylight.netconf.sal.connect.api.RemoteDevice;
  43 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceCommunicator;
  44 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceHandler;
  45 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCapabilities;
  46 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCommunicator;
  47 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfSessionPreferences;
  48 import org.opendaylight.netconf.sal.connect.netconf.sal.NetconfDeviceRpc;
  49 import org.opendaylight.netconf.sal.connect.netconf.schema.NetconfRemoteSchemaYangSourceProvider;
  50 import org.opendaylight.netconf.sal.connect.netconf.schema.YangLibrarySchemaYangSourceProvider;
  51 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.BaseSchema;
  52 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.NetconfMessageTransformer;
  53 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  54 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  55 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.netconf.notifications.rev120206.NetconfCapabilityChange;
  56 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.available.capabilities.AvailableCapabilityBuilder;
  57 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.unavailable.capabilities.UnavailableCapability;
  58 import org.opendaylight.yangtools.yang.common.QName;
  59 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  60 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  61 import org.opendaylight.yangtools.yang.model.repo.api.RevisionSourceIdentifier;
  62 import org.opendaylight.yangtools.yang.model.repo.api.SchemaContextFactory;
  63 import org.opendaylight.yangtools.yang.model.repo.api.SchemaRepository;
  64 import org.opendaylight.yangtools.yang.model.repo.api.SchemaResolutionException;
  65 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceRepresentation;
  66 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  67 import org.opendaylight.yangtools.yang.model.repo.api.YangTextSchemaSource;
  68 import org.opendaylight.yangtools.yang.model.repo.spi.PotentialSchemaSource;
  69 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceProvider;
  70 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistration;
  71 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  72 import org.opendaylight.yangtools.yang.parser.rfc7950.repo.ASTSchemaSource;
  73 import org.slf4j.Logger;
  74 import org.slf4j.LoggerFactory;
  75
  76 /**
  77  *  This is a mediator between NetconfDeviceCommunicator and NetconfDeviceSalFacade.
  78  */
  79 public class NetconfDevice
  80         implements RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> {
  81
  82     private static final Logger LOG = LoggerFactory.getLogger(NetconfDevice.class);
  83
  84     protected final RemoteDeviceId id;
  85     private final boolean reconnectOnSchemasChange;
  86
  87     protected final SchemaContextFactory schemaContextFactory;
  88     private final RemoteDeviceHandler<NetconfSessionPreferences> salFacade;
  89     private final ListeningExecutorService processingExecutor;
  90     protected final SchemaSourceRegistry schemaRegistry;
  91     protected final SchemaRepository schemaRepository;
  92     private final NetconfDeviceSchemasResolver stateSchemasResolver;
  93     private final NotificationHandler notificationHandler;
  94     protected final List<SchemaSourceRegistration<? extends SchemaSourceRepresentation>> sourceRegistrations =
  95             new ArrayList<>();
  96     @GuardedBy("this")
  97     private boolean connected = false;
  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         setConnected(true);
 139         LOG.debug("{}: Session to remote device established with {}", id, remoteSessionCapabilities);
 140
 141         final NetconfDeviceRpc initRpc =
 142                 getRpcForInitialization(listener, remoteSessionCapabilities.isNotificationsSupported());
 143         final DeviceSourcesResolver task =
 144                 new DeviceSourcesResolver(remoteSessionCapabilities, id, stateSchemasResolver, initRpc);
 145         final ListenableFuture<DeviceSources> sourceResolverFuture = processingExecutor.submit(task);
 146
 147         if (shouldListenOnSchemaChange(remoteSessionCapabilities)) {
 148             registerToBaseNetconfStream(initRpc, listener);
 149         }
 150
 151         final FutureCallback<DeviceSources> resolvedSourceCallback = new FutureCallback<DeviceSources>() {
 152             @Override
 153             public void onSuccess(@Nonnull final DeviceSources result) {
 154                 addProvidedSourcesToSchemaRegistry(result);
 155                 setUpSchema(result);
 156             }
 157
 158             private void setUpSchema(final DeviceSources result) {
 159                 processingExecutor.submit(new SchemaSetup(result, remoteSessionCapabilities, listener));
 160             }
 161
 162             @Override
 163             public void onFailure(final Throwable throwable) {
 164                 LOG.warn("{}: Unexpected error resolving device sources: {}", id, throwable);
 165                 handleSalInitializationFailure(throwable, listener);
 166             }
 167         };
 168
 169         Futures.addCallback(sourceResolverFuture, resolvedSourceCallback, MoreExecutors.directExecutor());
 170     }
 171
 172     private void registerToBaseNetconfStream(final NetconfDeviceRpc deviceRpc,
 173                                              final NetconfDeviceCommunicator listener) {
 174         // TODO check whether the model describing create subscription is present in schema
 175         // Perhaps add a default schema context to support create-subscription if the model was not provided
 176         // (same as what we do for base netconf operations in transformer)
 177         final CheckedFuture<DOMRpcResult, DOMRpcException> rpcResultListenableFuture = deviceRpc.invokeRpc(
 178                 NetconfMessageTransformUtil.toPath(NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_QNAME),
 179                 NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_CONTENT);
 180
 181         final NotificationHandler.NotificationFilter filter = new NotificationHandler.NotificationFilter() {
 182             @Override
 183             public Optional<DOMNotification> filterNotification(final DOMNotification notification) {
 184                 if (isCapabilityChanged(notification)) {
 185                     LOG.info("{}: Schemas change detected, reconnecting", id);
 186                     // Only disconnect is enough,
 187                     // the reconnecting nature of the connector will take care of reconnecting
 188                     listener.disconnect();
 189                     return Optional.absent();
 190                 }
 191                 return Optional.of(notification);
 192             }
 193
 194             private boolean isCapabilityChanged(final DOMNotification notification) {
 195                 return notification.getBody().getNodeType().equals(NetconfCapabilityChange.QNAME);
 196             }
 197         };
 198
 199         Futures.addCallback(rpcResultListenableFuture, new FutureCallback<DOMRpcResult>() {
 200             @Override
 201             public void onSuccess(final DOMRpcResult domRpcResult) {
 202                 notificationHandler.addNotificationFilter(filter);
 203             }
 204
 205             @Override
 206             public void onFailure(final Throwable throwable) {
 207                 LOG.warn("Unable to subscribe to base notification stream. Schemas will not be reloaded on the fly",
 208                         throwable);
 209             }
 210         }, MoreExecutors.directExecutor());
 211     }
 212
 213     private boolean shouldListenOnSchemaChange(final NetconfSessionPreferences remoteSessionCapabilities) {
 214         return remoteSessionCapabilities.isNotificationsSupported() && reconnectOnSchemasChange;
 215     }
 216
 217     private synchronized void handleSalInitializationSuccess(final SchemaContext result,
 218                                         final NetconfSessionPreferences remoteSessionCapabilities,
 219                                         final DOMRpcService deviceRpc) {
 220         //NetconfDevice.SchemaSetup can complete after NetconfDeviceCommunicator was closed. In that case do nothing,
 221         //since salFacade.onDeviceDisconnected was already called.
 222         if (connected) {
 223             final BaseSchema baseSchema =
 224                 remoteSessionCapabilities.isNotificationsSupported()
 225                         ? BaseSchema.BASE_NETCONF_CTX_WITH_NOTIFICATIONS : BaseSchema.BASE_NETCONF_CTX;
 226             messageTransformer = new NetconfMessageTransformer(result, true, baseSchema);
 227
 228             updateTransformer(messageTransformer);
 229             // salFacade.onDeviceConnected has to be called before the notification handler is initialized
 230             salFacade.onDeviceConnected(result, remoteSessionCapabilities, deviceRpc);
 231             notificationHandler.onRemoteSchemaUp(messageTransformer);
 232
 233             LOG.info("{}: Netconf connector initialized successfully", id);
 234         } else {
 235             LOG.warn("{}: Device communicator was closed before schema setup finished.", id);
 236         }
 237     }
 238
 239     private void handleSalInitializationFailure(final Throwable throwable,
 240                                                 final RemoteDeviceCommunicator<NetconfMessage> listener) {
 241         LOG.error("{}: Initialization in sal failed, disconnecting from device", id, throwable);
 242         listener.close();
 243         onRemoteSessionDown();
 244         resetMessageTransformer();
 245     }
 246
 247     /**
 248      * Set the transformer to null as is in initial state.
 249      */
 250     private void resetMessageTransformer() {
 251         updateTransformer(null);
 252     }
 253
 254     private synchronized void updateTransformer(final MessageTransformer<NetconfMessage> transformer) {
 255         messageTransformer = transformer;
 256     }
 257
 258     private synchronized void setConnected(final boolean connected) {
 259         this.connected = connected;
 260     }
 261
 262     private void addProvidedSourcesToSchemaRegistry(final DeviceSources deviceSources) {
 263         final SchemaSourceProvider<YangTextSchemaSource> yangProvider = deviceSources.getSourceProvider();
 264         for (final SourceIdentifier sourceId : deviceSources.getProvidedSources()) {
 265             sourceRegistrations.add(schemaRegistry.registerSchemaSource(yangProvider,
 266                     PotentialSchemaSource.create(
 267                             sourceId, YangTextSchemaSource.class, PotentialSchemaSource.Costs.REMOTE_IO.getValue())));
 268         }
 269     }
 270
 271     @Override
 272     public void onRemoteSessionDown() {
 273         setConnected(false);
 274         notificationHandler.onRemoteSchemaDown();
 275
 276         salFacade.onDeviceDisconnected();
 277         for (final SchemaSourceRegistration<? extends SchemaSourceRepresentation> sourceRegistration
 278                 : sourceRegistrations) {
 279             sourceRegistration.close();
 280         }
 281         resetMessageTransformer();
 282     }
 283
 284     @Override
 285     public void onRemoteSessionFailed(final Throwable throwable) {
 286         setConnected(false);
 287         salFacade.onDeviceFailed(throwable);
 288     }
 289
 290     @Override
 291     public void onNotification(final NetconfMessage notification) {
 292         notificationHandler.handleNotification(notification);
 293     }
 294
 295     /**
 296      * Just a transfer object containing schema related dependencies. Injected in constructor.
 297      */
 298     public static class SchemaResourcesDTO {
 299         private final SchemaSourceRegistry schemaRegistry;
 300         private final SchemaRepository schemaRepository;
 301         private final SchemaContextFactory schemaContextFactory;
 302         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 303
 304         public SchemaResourcesDTO(final SchemaSourceRegistry schemaRegistry,
 305                                   final SchemaRepository schemaRepository,
 306                                   final SchemaContextFactory schemaContextFactory,
 307                                   final NetconfDeviceSchemasResolver deviceSchemasResolver) {
 308             this.schemaRegistry = Preconditions.checkNotNull(schemaRegistry);
 309             this.schemaRepository = Preconditions.checkNotNull(schemaRepository);
 310             this.schemaContextFactory = Preconditions.checkNotNull(schemaContextFactory);
 311             this.stateSchemasResolver = Preconditions.checkNotNull(deviceSchemasResolver);
 312         }
 313
 314         public SchemaSourceRegistry getSchemaRegistry() {
 315             return schemaRegistry;
 316         }
 317
 318         public SchemaRepository getSchemaRepository() {
 319             return schemaRepository;
 320         }
 321
 322         public SchemaContextFactory getSchemaContextFactory() {
 323             return schemaContextFactory;
 324         }
 325
 326         public NetconfDeviceSchemasResolver getStateSchemasResolver() {
 327             return stateSchemasResolver;
 328         }
 329     }
 330
 331     /**
 332      * Schema building callable.
 333      */
 334     private static class DeviceSourcesResolver implements Callable<DeviceSources> {
 335
 336         private final NetconfDeviceRpc deviceRpc;
 337         private final NetconfSessionPreferences remoteSessionCapabilities;
 338         private final RemoteDeviceId id;
 339         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 340
 341         DeviceSourcesResolver(final NetconfDeviceRpc deviceRpc,
 342                               final NetconfSessionPreferences remoteSessionCapabilities,
 343                               final RemoteDeviceId id, final NetconfDeviceSchemasResolver stateSchemasResolver) {
 344             this.deviceRpc = deviceRpc;
 345             this.remoteSessionCapabilities = remoteSessionCapabilities;
 346             this.id = id;
 347             this.stateSchemasResolver = stateSchemasResolver;
 348         }
 349
 350         DeviceSourcesResolver(final NetconfSessionPreferences remoteSessionCapabilities, final RemoteDeviceId id,
 351                                      final NetconfDeviceSchemasResolver stateSchemasResolver,
 352                                      final NetconfDeviceRpc rpcForMonitoring) {
 353             this(rpcForMonitoring, remoteSessionCapabilities, id, stateSchemasResolver);
 354         }
 355
 356         @Override
 357         public DeviceSources call() throws Exception {
 358             final NetconfDeviceSchemas availableSchemas =
 359                     stateSchemasResolver.resolve(deviceRpc, remoteSessionCapabilities, id);
 360             LOG.debug("{}: Schemas exposed by ietf-netconf-monitoring: {}", id,
 361                     availableSchemas.getAvailableYangSchemasQNames());
 362
 363             final Set<QName> requiredSources = Sets.newHashSet(remoteSessionCapabilities.getModuleBasedCaps());
 364             final Set<QName> providedSources = availableSchemas.getAvailableYangSchemasQNames();
 365
 366             final Set<QName> requiredSourcesNotProvided = Sets.difference(requiredSources, providedSources);
 367             if (!requiredSourcesNotProvided.isEmpty()) {
 368                 LOG.warn("{}: Netconf device does not provide all yang models reported in hello message capabilities,"
 369                         + " required but not provided: {}", id, requiredSourcesNotProvided);
 370                 LOG.warn("{}: Attempting to build schema context from required sources", id);
 371             }
 372
 373             // Here all the sources reported in netconf monitoring are merged with those reported in hello.
 374             // It is necessary to perform this since submodules are not mentioned in hello but still required.
 375             // This clashes with the option of a user to specify supported yang models manually in configuration
 376             // for netconf-connector and as a result one is not able to fully override yang models of a device.
 377             // It is only possible to add additional models.
 378             final Set<QName> providedSourcesNotRequired = Sets.difference(providedSources, requiredSources);
 379             if (!providedSourcesNotRequired.isEmpty()) {
 380                 LOG.warn("{}: Netconf device provides additional yang models not reported in "
 381                         + "hello message capabilities: {}", id, providedSourcesNotRequired);
 382                 LOG.warn("{}: Adding provided but not required sources as required to prevent failures", id);
 383                 LOG.debug("{}: Netconf device reported in hello: {}", id, requiredSources);
 384                 requiredSources.addAll(providedSourcesNotRequired);
 385             }
 386
 387             final SchemaSourceProvider<YangTextSchemaSource> sourceProvider;
 388             if (availableSchemas instanceof LibraryModulesSchemas) {
 389                 sourceProvider = new YangLibrarySchemaYangSourceProvider(id,
 390                         ((LibraryModulesSchemas) availableSchemas).getAvailableModels());
 391             } else {
 392                 sourceProvider = new NetconfRemoteSchemaYangSourceProvider(id, deviceRpc);
 393             }
 394
 395             return new DeviceSources(requiredSources, providedSources, sourceProvider);
 396         }
 397     }
 398
 399     /**
 400      * Contains RequiredSources - sources from capabilities.
 401      */
 402     private static final class DeviceSources {
 403         private final Set<QName> requiredSources;
 404         private final Set<QName> providedSources;
 405         private final SchemaSourceProvider<YangTextSchemaSource> sourceProvider;
 406
 407         DeviceSources(final Set<QName> requiredSources, final Set<QName> providedSources,
 408                              final SchemaSourceProvider<YangTextSchemaSource> sourceProvider) {
 409             this.requiredSources = requiredSources;
 410             this.providedSources = providedSources;
 411             this.sourceProvider = sourceProvider;
 412         }
 413
 414         public Set<QName> getRequiredSourcesQName() {
 415             return requiredSources;
 416         }
 417
 418         public Set<QName> getProvidedSourcesQName() {
 419             return providedSources;
 420         }
 421
 422         public Collection<SourceIdentifier> getRequiredSources() {
 423             return Collections2.transform(requiredSources, DeviceSources::toSourceId);
 424         }
 425
 426         public Collection<SourceIdentifier> getProvidedSources() {
 427             return Collections2.transform(providedSources, DeviceSources::toSourceId);
 428         }
 429
 430         public SchemaSourceProvider<YangTextSchemaSource> getSourceProvider() {
 431             return sourceProvider;
 432         }
 433
 434         private static SourceIdentifier toSourceId(final QName input) {
 435             return RevisionSourceIdentifier.create(input.getLocalName(), input.getRevision());
 436         }
 437     }
 438
 439     /**
 440      * Schema builder that tries to build schema context from provided sources or biggest subset of it.
 441      */
 442     private final class SchemaSetup implements Runnable {
 443         private final DeviceSources deviceSources;
 444         private final NetconfSessionPreferences remoteSessionCapabilities;
 445         private final RemoteDeviceCommunicator<NetconfMessage> listener;
 446         private final NetconfDeviceCapabilities capabilities;
 447
 448         SchemaSetup(final DeviceSources deviceSources, final NetconfSessionPreferences remoteSessionCapabilities,
 449                            final RemoteDeviceCommunicator<NetconfMessage> listener) {
 450             this.deviceSources = deviceSources;
 451             this.remoteSessionCapabilities = remoteSessionCapabilities;
 452             this.listener = listener;
 453             this.capabilities = remoteSessionCapabilities.getNetconfDeviceCapabilities();
 454         }
 455
 456         @Override
 457         public void run() {
 458
 459             final Collection<SourceIdentifier> requiredSources = deviceSources.getRequiredSources();
 460             final Collection<SourceIdentifier> missingSources = filterMissingSources(requiredSources);
 461
 462             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(missingSources),
 463                     UnavailableCapability.FailureReason.MissingSource);
 464
 465             requiredSources.removeAll(missingSources);
 466             setUpSchema(requiredSources);
 467         }
 468
 469         private Collection<SourceIdentifier> filterMissingSources(final Collection<SourceIdentifier> requiredSources) {
 470             return requiredSources.parallelStream().filter(sourceIdentifier -> {
 471                 try {
 472                     schemaRepository.getSchemaSource(sourceIdentifier, ASTSchemaSource.class).get();
 473                     return false;
 474                 } catch (InterruptedException | ExecutionException e) {
 475                     return true;
 476                 }
 477             }).collect(Collectors.toList());
 478         }
 479
 480         /**
 481          * Build schema context, in case of success or final failure notify device.
 482          */
 483         @SuppressWarnings("checkstyle:IllegalCatch")
 484         private void setUpSchema(Collection<SourceIdentifier> requiredSources) {
 485             while (!requiredSources.isEmpty()) {
 486                 LOG.trace("{}: Trying to build schema context from {}", id, requiredSources);
 487                 try {
 488                     final ListenableFuture<SchemaContext> schemaBuilderFuture = schemaContextFactory
 489                             .createSchemaContext(requiredSources);
 490                     final SchemaContext result = schemaBuilderFuture.get();
 491                     LOG.debug("{}: Schema context built successfully from {}", id, requiredSources);
 492                     final Collection<QName> filteredQNames = Sets.difference(deviceSources.getRequiredSourcesQName(),
 493                             capabilities.getUnresolvedCapabilites().keySet());
 494                     capabilities.addCapabilities(filteredQNames.stream().map(entry -> new AvailableCapabilityBuilder()
 495                             .setCapability(entry.toString()).setCapabilityOrigin(
 496                                     remoteSessionCapabilities.getModuleBasedCapsOrigin().get(entry)).build())
 497                             .collect(Collectors.toList()));
 498
 499                     capabilities.addNonModuleBasedCapabilities(remoteSessionCapabilities
 500                             .getNonModuleCaps().stream().map(entry -> new AvailableCapabilityBuilder()
 501                                     .setCapability(entry).setCapabilityOrigin(
 502                                             remoteSessionCapabilities.getNonModuleBasedCapsOrigin().get(entry)).build())
 503                             .collect(Collectors.toList()));
 504
 505                     handleSalInitializationSuccess(result, remoteSessionCapabilities, getDeviceSpecificRpc(result));
 506                     return;
 507                 } catch (final ExecutionException e) {
 508                     // schemaBuilderFuture.checkedGet() throws only SchemaResolutionException
 509                     // that might be wrapping a MissingSchemaSourceException so we need to look
 510                     // at the cause of the exception to make sure we don't misinterpret it.
 511                     final Throwable cause = e.getCause();
 512
 513                     if (cause instanceof MissingSchemaSourceException) {
 514                         requiredSources = handleMissingSchemaSourceException(
 515                                 requiredSources, (MissingSchemaSourceException) cause);
 516                         continue;
 517                     }
 518                     if (cause instanceof SchemaResolutionException) {
 519                         requiredSources = handleSchemaResolutionException(requiredSources,
 520                             (SchemaResolutionException) cause);
 521                     } else {
 522                         handleSalInitializationFailure(e, listener);
 523                         return;
 524                     }
 525                 } catch (final Exception e) {
 526                     // unknown error, fail
 527                     handleSalInitializationFailure(e, listener);
 528                     return;
 529                 }
 530             }
 531             // No more sources, fail
 532             final IllegalStateException cause = new IllegalStateException(id + ": No more sources for schema context");
 533             handleSalInitializationFailure(cause, listener);
 534             salFacade.onDeviceFailed(cause);
 535         }
 536
 537         private Collection<SourceIdentifier> handleMissingSchemaSourceException(
 538                 final Collection<SourceIdentifier> requiredSources, final MissingSchemaSourceException exception) {
 539             // In case source missing, try without it
 540             final SourceIdentifier missingSource = exception.getSourceId();
 541             LOG.warn("{}: Unable to build schema context, missing source {}, will reattempt without it", id,
 542                     missingSource);
 543             LOG.debug("{}: Unable to build schema context, missing source {}, will reattempt without it",
 544                     exception);
 545             final Collection<QName> qNameOfMissingSource =
 546                     getQNameFromSourceIdentifiers(Sets.newHashSet(missingSource));
 547             if (!qNameOfMissingSource.isEmpty()) {
 548                 capabilities.addUnresolvedCapabilities(
 549                         qNameOfMissingSource, UnavailableCapability.FailureReason.MissingSource);
 550             }
 551             return stripUnavailableSource(requiredSources, missingSource);
 552         }
 553
 554         private Collection<SourceIdentifier> handleSchemaResolutionException(
 555             final Collection<SourceIdentifier> requiredSources, final SchemaResolutionException resolutionException) {
 556             // In case resolution error, try only with resolved sources
 557             // There are two options why schema resolution exception occurred : unsatisfied imports or flawed model
 558             // FIXME Do we really have assurance that these two cases cannot happen at once?
 559             if (resolutionException.getFailedSource() != null) {
 560                 // flawed model - exclude it
 561                 final SourceIdentifier failedSourceId = resolutionException.getFailedSource();
 562                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 563                         id, failedSourceId);
 564                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 565                         id, resolutionException);
 566                 capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(
 567                         Collections.singleton(failedSourceId)), UnavailableCapability.FailureReason.UnableToResolve);
 568                 return stripUnavailableSource(requiredSources, resolutionException.getFailedSource());
 569             }
 570             // unsatisfied imports
 571             final Set<SourceIdentifier> unresolvedSources = resolutionException.getUnsatisfiedImports().keySet();
 572             capabilities.addUnresolvedCapabilities(
 573                 getQNameFromSourceIdentifiers(unresolvedSources), UnavailableCapability.FailureReason.UnableToResolve);
 574             LOG.warn("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 575                     id, resolutionException.getUnsatisfiedImports());
 576             LOG.debug("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 577                     resolutionException);
 578             return resolutionException.getResolvedSources();
 579         }
 580
 581         protected NetconfDeviceRpc getDeviceSpecificRpc(final SchemaContext result) {
 582             return new NetconfDeviceRpc(result, listener, new NetconfMessageTransformer(result, true));
 583         }
 584
 585         private Collection<SourceIdentifier> stripUnavailableSource(final Collection<SourceIdentifier> requiredSources,
 586                                                                     final SourceIdentifier sourceIdToRemove) {
 587             final LinkedList<SourceIdentifier> sourceIdentifiers = Lists.newLinkedList(requiredSources);
 588             final boolean removed = sourceIdentifiers.remove(sourceIdToRemove);
 589             Preconditions.checkState(
 590                     removed, "{}: Trying to remove {} from {} failed", id, sourceIdToRemove, requiredSources);
 591             return sourceIdentifiers;
 592         }
 593
 594         private Collection<QName> getQNameFromSourceIdentifiers(final Collection<SourceIdentifier> identifiers) {
 595             final Collection<QName> qNames = Collections2.transform(identifiers, this::getQNameFromSourceIdentifier);
 596
 597             if (qNames.isEmpty()) {
 598                 LOG.debug("{}: Unable to map any source identifiers to a capability reported by device : {}", id,
 599                         identifiers);
 600             }
 601             return Collections2.filter(qNames, Predicates.notNull());
 602         }
 603
 604         private QName getQNameFromSourceIdentifier(final SourceIdentifier identifier) {
 605             // Required sources are all required and provided merged in DeviceSourcesResolver
 606             for (final QName qname : deviceSources.getRequiredSourcesQName()) {
 607                 if (!qname.getLocalName().equals(identifier.getName())) {
 608                     continue;
 609                 }
 610
 611                 if (identifier.getRevision().equals(qname.getRevision())) {
 612                     return qname;
 613                 }
 614             }
 615             LOG.warn("Unable to map identifier to a devices reported capability: {} Available: {}",identifier,
 616                     deviceSources.getRequiredSourcesQName());
 617             // return null since we cannot find the QName,
 618             // this capability will be removed from required sources and not reported as unresolved-capability
 619             return null;
 620         }
 621     }
 622 }