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 static com.google.common.base.Preconditions.checkState;
  11 import static java.util.Objects.requireNonNull;
  12
  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.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 io.netty.util.concurrent.EventExecutor;
  23 import java.util.ArrayList;
  24 import java.util.Collection;
  25 import java.util.Collections;
  26 import java.util.LinkedList;
  27 import java.util.List;
  28 import java.util.Optional;
  29 import java.util.Set;
  30 import java.util.concurrent.Callable;
  31 import java.util.concurrent.ExecutionException;
  32 import java.util.concurrent.TimeUnit;
  33 import java.util.stream.Collectors;
  34 import org.checkerframework.checker.lock.qual.GuardedBy;
  35 import org.opendaylight.mdsal.dom.api.DOMRpcResult;
  36 import org.opendaylight.mdsal.dom.api.DOMRpcService;
  37 import org.opendaylight.netconf.api.NetconfMessage;
  38 import org.opendaylight.netconf.sal.connect.api.DeviceActionFactory;
  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.optional.rev190614.NetconfNodeAugmentedOptional;
  57 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.NetconfNode;
  58 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.available.capabilities.AvailableCapabilityBuilder;
  59 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.unavailable.capabilities.UnavailableCapability;
  60 import org.opendaylight.yangtools.rcf8528.data.util.EmptyMountPointContext;
  61 import org.opendaylight.yangtools.rfc8528.data.api.MountPointContext;
  62 import org.opendaylight.yangtools.yang.common.QName;
  63 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  64 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  65 import org.opendaylight.yangtools.yang.model.repo.api.RevisionSourceIdentifier;
  66 import org.opendaylight.yangtools.yang.model.repo.api.SchemaContextFactory;
  67 import org.opendaylight.yangtools.yang.model.repo.api.SchemaRepository;
  68 import org.opendaylight.yangtools.yang.model.repo.api.SchemaResolutionException;
  69 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  70 import org.opendaylight.yangtools.yang.model.repo.api.YangTextSchemaSource;
  71 import org.opendaylight.yangtools.yang.model.repo.spi.PotentialSchemaSource;
  72 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceProvider;
  73 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistration;
  74 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  75 import org.slf4j.Logger;
  76 import org.slf4j.LoggerFactory;
  77
  78 /**
  79  *  This is a mediator between NetconfDeviceCommunicator and NetconfDeviceSalFacade.
  80  */
  81 public class NetconfDevice
  82         implements RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> {
  83
  84     private static final Logger LOG = LoggerFactory.getLogger(NetconfDevice.class);
  85
  86     protected final RemoteDeviceId id;
  87     protected final SchemaContextFactory schemaContextFactory;
  88     protected final SchemaSourceRegistry schemaRegistry;
  89     protected final SchemaRepository schemaRepository;
  90
  91     protected final List<SchemaSourceRegistration<?>> sourceRegistrations = new ArrayList<>();
  92
  93     private final RemoteDeviceHandler<NetconfSessionPreferences> salFacade;
  94     private final ListeningExecutorService processingExecutor;
  95     private final DeviceActionFactory deviceActionFactory;
  96     private final NetconfDeviceSchemasResolver stateSchemasResolver;
  97     private final NotificationHandler notificationHandler;
  98     private final boolean reconnectOnSchemasChange;
  99     private final NetconfNode node;
 100     private final EventExecutor eventExecutor;
 101     private final NetconfNodeAugmentedOptional nodeOptional;
 102
 103     @GuardedBy("this")
 104     private boolean connected = false;
 105
 106     // Message transformer is constructed once the schemas are available
 107     private MessageTransformer<NetconfMessage> messageTransformer;
 108
 109     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final RemoteDeviceId id,
 110                          final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
 111                          final ListeningExecutorService globalProcessingExecutor,
 112                          final boolean reconnectOnSchemasChange) {
 113         this(schemaResourcesDTO, id, salFacade, globalProcessingExecutor, reconnectOnSchemasChange, null, null, null,
 114                 null);
 115     }
 116
 117     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final RemoteDeviceId id,
 118             final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
 119             final ListeningExecutorService globalProcessingExecutor, final boolean reconnectOnSchemasChange,
 120             final DeviceActionFactory deviceActionFactory, final NetconfNode node, final EventExecutor eventExecutor,
 121             final NetconfNodeAugmentedOptional nodeOptional) {
 122         this.id = id;
 123         this.reconnectOnSchemasChange = reconnectOnSchemasChange;
 124         this.deviceActionFactory = deviceActionFactory;
 125         this.node = node;
 126         this.eventExecutor = eventExecutor;
 127         this.nodeOptional = nodeOptional;
 128         this.schemaRegistry = schemaResourcesDTO.getSchemaRegistry();
 129         this.schemaRepository = schemaResourcesDTO.getSchemaRepository();
 130         this.schemaContextFactory = schemaResourcesDTO.getSchemaContextFactory();
 131         this.salFacade = salFacade;
 132         this.stateSchemasResolver = schemaResourcesDTO.getStateSchemasResolver();
 133         this.processingExecutor = requireNonNull(globalProcessingExecutor);
 134         this.notificationHandler = new NotificationHandler(salFacade, id);
 135     }
 136
 137     @Override
 138     public void onRemoteSessionUp(final NetconfSessionPreferences remoteSessionCapabilities,
 139                                   final NetconfDeviceCommunicator listener) {
 140         // SchemaContext setup has to be performed in a dedicated thread since
 141         // we are in a netty thread in this method
 142         // Yang models are being downloaded in this method and it would cause a
 143         // deadlock if we used the netty thread
 144         // http://netty.io/wiki/thread-model.html
 145         setConnected(true);
 146         LOG.debug("{}: Session to remote device established with {}", id, remoteSessionCapabilities);
 147
 148         final BaseSchema baseSchema = resolveBaseSchema(remoteSessionCapabilities.isNotificationsSupported());
 149         final NetconfDeviceRpc initRpc = new NetconfDeviceRpc(baseSchema.getSchemaContext(), listener,
 150             new NetconfMessageTransformer(baseSchema.getMountPointContext(), false, baseSchema));
 151         final DeviceSourcesResolver task = new DeviceSourcesResolver(remoteSessionCapabilities, id,
 152             stateSchemasResolver, initRpc, baseSchema.getSchemaContext());
 153         final ListenableFuture<DeviceSources> sourceResolverFuture = processingExecutor.submit(task);
 154
 155         if (shouldListenOnSchemaChange(remoteSessionCapabilities)) {
 156             registerToBaseNetconfStream(initRpc, listener);
 157         }
 158
 159         final FutureCallback<DeviceSources> resolvedSourceCallback = new FutureCallback<DeviceSources>() {
 160             @Override
 161             public void onSuccess(final DeviceSources result) {
 162                 addProvidedSourcesToSchemaRegistry(result);
 163                 setUpSchema(result);
 164             }
 165
 166             private void setUpSchema(final DeviceSources result) {
 167                 processingExecutor.submit(new SchemaSetup(result, remoteSessionCapabilities, listener));
 168             }
 169
 170             @Override
 171             public void onFailure(final Throwable throwable) {
 172                 LOG.warn("{}: Unexpected error resolving device sources", id, throwable);
 173                 handleSalInitializationFailure(throwable, listener);
 174             }
 175         };
 176
 177         Futures.addCallback(sourceResolverFuture, resolvedSourceCallback, MoreExecutors.directExecutor());
 178     }
 179
 180     private void registerToBaseNetconfStream(final NetconfDeviceRpc deviceRpc,
 181                                              final NetconfDeviceCommunicator listener) {
 182         // TODO check whether the model describing create subscription is present in schema
 183         // Perhaps add a default schema context to support create-subscription if the model was not provided
 184         // (same as what we do for base netconf operations in transformer)
 185         final ListenableFuture<DOMRpcResult> rpcResultListenableFuture = deviceRpc.invokeRpc(
 186                 NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_PATH,
 187                 NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_CONTENT);
 188
 189         Futures.addCallback(rpcResultListenableFuture, new FutureCallback<DOMRpcResult>() {
 190             @Override
 191             public void onSuccess(final DOMRpcResult domRpcResult) {
 192                 notificationHandler.addNotificationFilter(notification -> {
 193                     if (NetconfCapabilityChange.QNAME.equals(notification.getBody().getNodeType())) {
 194                         LOG.info("{}: Schemas change detected, reconnecting", id);
 195                         // Only disconnect is enough,
 196                         // the reconnecting nature of the connector will take care of reconnecting
 197                         listener.disconnect();
 198                         return Optional.empty();
 199                     }
 200                     return Optional.of(notification);
 201                 });
 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         }, MoreExecutors.directExecutor());
 210     }
 211
 212     private boolean shouldListenOnSchemaChange(final NetconfSessionPreferences remoteSessionCapabilities) {
 213         return remoteSessionCapabilities.isNotificationsSupported() && reconnectOnSchemasChange;
 214     }
 215
 216     private synchronized void handleSalInitializationSuccess(final MountPointContext result,
 217                                         final NetconfSessionPreferences remoteSessionCapabilities,
 218                                         final DOMRpcService deviceRpc,
 219                                         final RemoteDeviceCommunicator<NetconfMessage> listener) {
 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             this.messageTransformer = new NetconfMessageTransformer(result, true, baseSchema);
 227
 228             // salFacade.onDeviceConnected has to be called before the notification handler is initialized
 229             this.salFacade.onDeviceConnected(result, remoteSessionCapabilities, deviceRpc,
 230                     this.deviceActionFactory == null ? null : this.deviceActionFactory.createDeviceAction(
 231                             this.messageTransformer, listener, result.getSchemaContext()));
 232             this.notificationHandler.onRemoteSchemaUp(this.messageTransformer);
 233
 234             LOG.info("{}: Netconf connector initialized successfully", id);
 235         } else {
 236             LOG.warn("{}: Device communicator was closed before schema setup finished.", id);
 237         }
 238     }
 239
 240     private void handleSalInitializationFailure(final Throwable throwable,
 241                                                 final RemoteDeviceCommunicator<NetconfMessage> listener) {
 242         LOG.error("{}: Initialization in sal failed, disconnecting from device", id, throwable);
 243         listener.close();
 244         onRemoteSessionDown();
 245         resetMessageTransformer();
 246     }
 247
 248     /**
 249      * Set the transformer to null as is in initial state.
 250      */
 251     private void resetMessageTransformer() {
 252         updateTransformer(null);
 253     }
 254
 255     private synchronized void updateTransformer(final MessageTransformer<NetconfMessage> transformer) {
 256         messageTransformer = transformer;
 257     }
 258
 259     private synchronized void setConnected(final boolean connected) {
 260         this.connected = connected;
 261     }
 262
 263     private void addProvidedSourcesToSchemaRegistry(final DeviceSources deviceSources) {
 264         final SchemaSourceProvider<YangTextSchemaSource> yangProvider = deviceSources.getSourceProvider();
 265         for (final SourceIdentifier sourceId : deviceSources.getProvidedSources()) {
 266             sourceRegistrations.add(schemaRegistry.registerSchemaSource(yangProvider,
 267                     PotentialSchemaSource.create(
 268                             sourceId, YangTextSchemaSource.class, PotentialSchemaSource.Costs.REMOTE_IO.getValue())));
 269         }
 270     }
 271
 272     @Override
 273     public void onRemoteSessionDown() {
 274         setConnected(false);
 275         notificationHandler.onRemoteSchemaDown();
 276
 277         salFacade.onDeviceDisconnected();
 278         sourceRegistrations.forEach(SchemaSourceRegistration::close);
 279         sourceRegistrations.clear();
 280         resetMessageTransformer();
 281     }
 282
 283     @Override
 284     public void onRemoteSessionFailed(final Throwable throwable) {
 285         setConnected(false);
 286         salFacade.onDeviceFailed(throwable);
 287     }
 288
 289     @Override
 290     public void onNotification(final NetconfMessage notification) {
 291         notificationHandler.handleNotification(notification);
 292     }
 293
 294     private static BaseSchema resolveBaseSchema(final boolean notificationSupport) {
 295         return notificationSupport ? BaseSchema.BASE_NETCONF_CTX_WITH_NOTIFICATIONS : BaseSchema.BASE_NETCONF_CTX;
 296     }
 297
 298     /**
 299      * Just a transfer object containing schema related dependencies. Injected in constructor.
 300      */
 301     public static class SchemaResourcesDTO {
 302         private final SchemaSourceRegistry schemaRegistry;
 303         private final SchemaRepository schemaRepository;
 304         private final SchemaContextFactory schemaContextFactory;
 305         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 306
 307         public SchemaResourcesDTO(final SchemaSourceRegistry schemaRegistry,
 308                                   final SchemaRepository schemaRepository,
 309                                   final SchemaContextFactory schemaContextFactory,
 310                                   final NetconfDeviceSchemasResolver deviceSchemasResolver) {
 311             this.schemaRegistry = requireNonNull(schemaRegistry);
 312             this.schemaRepository = requireNonNull(schemaRepository);
 313             this.schemaContextFactory = requireNonNull(schemaContextFactory);
 314             this.stateSchemasResolver = requireNonNull(deviceSchemasResolver);
 315         }
 316
 317         public SchemaSourceRegistry getSchemaRegistry() {
 318             return schemaRegistry;
 319         }
 320
 321         public SchemaRepository getSchemaRepository() {
 322             return schemaRepository;
 323         }
 324
 325         public SchemaContextFactory getSchemaContextFactory() {
 326             return schemaContextFactory;
 327         }
 328
 329         public NetconfDeviceSchemasResolver getStateSchemasResolver() {
 330             return stateSchemasResolver;
 331         }
 332     }
 333
 334     /**
 335      * Schema building callable.
 336      */
 337     private static class DeviceSourcesResolver implements Callable<DeviceSources> {
 338
 339         private final NetconfDeviceRpc deviceRpc;
 340         private final NetconfSessionPreferences remoteSessionCapabilities;
 341         private final RemoteDeviceId id;
 342         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 343         private final SchemaContext schemaContext;
 344
 345         DeviceSourcesResolver(final NetconfDeviceRpc deviceRpc,
 346                               final NetconfSessionPreferences remoteSessionCapabilities,
 347                               final RemoteDeviceId id, final NetconfDeviceSchemasResolver stateSchemasResolver,
 348                               final SchemaContext schemaContext) {
 349             this.deviceRpc = deviceRpc;
 350             this.remoteSessionCapabilities = remoteSessionCapabilities;
 351             this.id = id;
 352             this.stateSchemasResolver = stateSchemasResolver;
 353             this.schemaContext = schemaContext;
 354         }
 355
 356         DeviceSourcesResolver(final NetconfSessionPreferences remoteSessionCapabilities, final RemoteDeviceId id,
 357                                      final NetconfDeviceSchemasResolver stateSchemasResolver,
 358                                      final NetconfDeviceRpc rpcForMonitoring, final SchemaContext schemaCtx) {
 359             this(rpcForMonitoring, remoteSessionCapabilities, id, stateSchemasResolver, schemaCtx);
 360         }
 361
 362         @Override
 363         public DeviceSources call() {
 364             final NetconfDeviceSchemas availableSchemas =
 365                     stateSchemasResolver.resolve(deviceRpc, remoteSessionCapabilities, id, schemaContext);
 366             LOG.debug("{}: Schemas exposed by ietf-netconf-monitoring: {}", id,
 367                     availableSchemas.getAvailableYangSchemasQNames());
 368
 369             final Set<QName> requiredSources = Sets.newHashSet(remoteSessionCapabilities.getModuleBasedCaps());
 370             final Set<QName> providedSources = availableSchemas.getAvailableYangSchemasQNames();
 371
 372             final Set<QName> requiredSourcesNotProvided = Sets.difference(requiredSources, providedSources);
 373             if (!requiredSourcesNotProvided.isEmpty()) {
 374                 LOG.warn("{}: Netconf device does not provide all yang models reported in hello message capabilities,"
 375                         + " required but not provided: {}", id, requiredSourcesNotProvided);
 376                 LOG.warn("{}: Attempting to build schema context from required sources", id);
 377             }
 378
 379             // Here all the sources reported in netconf monitoring are merged with those reported in hello.
 380             // It is necessary to perform this since submodules are not mentioned in hello but still required.
 381             // This clashes with the option of a user to specify supported yang models manually in configuration
 382             // for netconf-connector and as a result one is not able to fully override yang models of a device.
 383             // It is only possible to add additional models.
 384             final Set<QName> providedSourcesNotRequired = Sets.difference(providedSources, requiredSources);
 385             if (!providedSourcesNotRequired.isEmpty()) {
 386                 LOG.warn("{}: Netconf device provides additional yang models not reported in "
 387                         + "hello message capabilities: {}", id, providedSourcesNotRequired);
 388                 LOG.warn("{}: Adding provided but not required sources as required to prevent failures", id);
 389                 LOG.debug("{}: Netconf device reported in hello: {}", id, requiredSources);
 390                 requiredSources.addAll(providedSourcesNotRequired);
 391             }
 392
 393             final SchemaSourceProvider<YangTextSchemaSource> sourceProvider;
 394             if (availableSchemas instanceof LibraryModulesSchemas) {
 395                 sourceProvider = new YangLibrarySchemaYangSourceProvider(id,
 396                         ((LibraryModulesSchemas) availableSchemas).getAvailableModels());
 397             } else {
 398                 sourceProvider = new NetconfRemoteSchemaYangSourceProvider(id, deviceRpc);
 399             }
 400
 401             return new DeviceSources(requiredSources, providedSources, sourceProvider);
 402         }
 403     }
 404
 405     /**
 406      * Contains RequiredSources - sources from capabilities.
 407      */
 408     private static final class DeviceSources {
 409         private final Set<QName> requiredSources;
 410         private final Set<QName> providedSources;
 411         private final SchemaSourceProvider<YangTextSchemaSource> sourceProvider;
 412
 413         DeviceSources(final Set<QName> requiredSources, final Set<QName> providedSources,
 414                              final SchemaSourceProvider<YangTextSchemaSource> sourceProvider) {
 415             this.requiredSources = requiredSources;
 416             this.providedSources = providedSources;
 417             this.sourceProvider = sourceProvider;
 418         }
 419
 420         public Set<QName> getRequiredSourcesQName() {
 421             return requiredSources;
 422         }
 423
 424         public Set<QName> getProvidedSourcesQName() {
 425             return providedSources;
 426         }
 427
 428         public Collection<SourceIdentifier> getRequiredSources() {
 429             return Collections2.transform(requiredSources, DeviceSources::toSourceId);
 430         }
 431
 432         public Collection<SourceIdentifier> getProvidedSources() {
 433             return Collections2.transform(providedSources, DeviceSources::toSourceId);
 434         }
 435
 436         public SchemaSourceProvider<YangTextSchemaSource> getSourceProvider() {
 437             return sourceProvider;
 438         }
 439
 440         private static SourceIdentifier toSourceId(final QName input) {
 441             return RevisionSourceIdentifier.create(input.getLocalName(), input.getRevision());
 442         }
 443     }
 444
 445     /**
 446      * Schema builder that tries to build schema context from provided sources or biggest subset of it.
 447      */
 448     private final class SchemaSetup implements Runnable {
 449         private final DeviceSources deviceSources;
 450         private final NetconfSessionPreferences remoteSessionCapabilities;
 451         private final RemoteDeviceCommunicator<NetconfMessage> listener;
 452         private final NetconfDeviceCapabilities capabilities;
 453
 454         SchemaSetup(final DeviceSources deviceSources, final NetconfSessionPreferences remoteSessionCapabilities,
 455                            final RemoteDeviceCommunicator<NetconfMessage> listener) {
 456             this.deviceSources = deviceSources;
 457             this.remoteSessionCapabilities = remoteSessionCapabilities;
 458             this.listener = listener;
 459             this.capabilities = remoteSessionCapabilities.getNetconfDeviceCapabilities();
 460         }
 461
 462         @Override
 463         public void run() {
 464
 465             final Collection<SourceIdentifier> requiredSources = deviceSources.getRequiredSources();
 466             final Collection<SourceIdentifier> missingSources = filterMissingSources(requiredSources);
 467
 468             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(missingSources),
 469                     UnavailableCapability.FailureReason.MissingSource);
 470
 471             requiredSources.removeAll(missingSources);
 472             setUpSchema(requiredSources);
 473         }
 474
 475         private Collection<SourceIdentifier> filterMissingSources(final Collection<SourceIdentifier> requiredSources) {
 476             return requiredSources.parallelStream().filter(sourceIdentifier -> {
 477                 try {
 478                     schemaRepository.getSchemaSource(sourceIdentifier, YangTextSchemaSource.class).get();
 479                     return false;
 480                 } catch (InterruptedException | ExecutionException e) {
 481                     return true;
 482                 }
 483             }).collect(Collectors.toList());
 484         }
 485
 486         /**
 487          * Build schema context, in case of success or final failure notify device.
 488          *
 489          * @param requiredSources required sources
 490          */
 491         @SuppressWarnings("checkstyle:IllegalCatch")
 492         private void setUpSchema(Collection<SourceIdentifier> requiredSources) {
 493             while (!requiredSources.isEmpty()) {
 494                 LOG.trace("{}: Trying to build schema context from {}", id, requiredSources);
 495                 try {
 496                     final ListenableFuture<SchemaContext> schemaBuilderFuture = schemaContextFactory
 497                             .createSchemaContext(requiredSources);
 498                     final SchemaContext result = schemaBuilderFuture.get();
 499                     LOG.debug("{}: Schema context built successfully from {}", id, requiredSources);
 500                     final Collection<QName> filteredQNames = Sets.difference(deviceSources.getRequiredSourcesQName(),
 501                             capabilities.getUnresolvedCapabilites().keySet());
 502                     capabilities.addCapabilities(filteredQNames.stream().map(entry -> new AvailableCapabilityBuilder()
 503                             .setCapability(entry.toString()).setCapabilityOrigin(
 504                                     remoteSessionCapabilities.getModuleBasedCapsOrigin().get(entry)).build())
 505                             .collect(Collectors.toList()));
 506
 507                     capabilities.addNonModuleBasedCapabilities(remoteSessionCapabilities
 508                             .getNonModuleCaps().stream().map(entry -> new AvailableCapabilityBuilder()
 509                                     .setCapability(entry).setCapabilityOrigin(
 510                                             remoteSessionCapabilities.getNonModuleBasedCapsOrigin().get(entry)).build())
 511                             .collect(Collectors.toList()));
 512
 513                     final MountPointContext mountContext = new EmptyMountPointContext(result);
 514                     handleSalInitializationSuccess(mountContext, remoteSessionCapabilities,
 515                         getDeviceSpecificRpc(mountContext), listener);
 516                     return;
 517                 } catch (final ExecutionException e) {
 518                     // schemaBuilderFuture.checkedGet() throws only SchemaResolutionException
 519                     // that might be wrapping a MissingSchemaSourceException so we need to look
 520                     // at the cause of the exception to make sure we don't misinterpret it.
 521                     final Throwable cause = e.getCause();
 522
 523                     if (cause instanceof MissingSchemaSourceException) {
 524                         requiredSources = handleMissingSchemaSourceException(
 525                                 requiredSources, (MissingSchemaSourceException) cause);
 526                         continue;
 527                     }
 528                     if (cause instanceof SchemaResolutionException) {
 529                         requiredSources = handleSchemaResolutionException(requiredSources,
 530                             (SchemaResolutionException) cause);
 531                     } else {
 532                         handleSalInitializationFailure(e, listener);
 533                         return;
 534                     }
 535                 } catch (final Exception e) {
 536                     // unknown error, fail
 537                     handleSalInitializationFailure(e, listener);
 538                     return;
 539                 }
 540             }
 541             // No more sources, fail or try to reconnect
 542             if (nodeOptional != null && nodeOptional.getIgnoreMissingSchemaSources().isAllowed()) {
 543                 eventExecutor.schedule(() -> {
 544                     LOG.warn("Reconnection is allowed! This can lead to unexpected errors at runtime.");
 545                     LOG.warn("{} : No more sources for schema context.", id);
 546                     LOG.info("{} : Try to remount device.", id);
 547                     onRemoteSessionDown();
 548                     salFacade.onDeviceReconnected(remoteSessionCapabilities, node);
 549                 }, nodeOptional.getIgnoreMissingSchemaSources().getReconnectTime(), TimeUnit.MILLISECONDS);
 550             } else {
 551                 final IllegalStateException cause =
 552                         new IllegalStateException(id + ": No more sources for schema context");
 553                 handleSalInitializationFailure(cause, listener);
 554                 salFacade.onDeviceFailed(cause);
 555             }
 556         }
 557
 558         private Collection<SourceIdentifier> handleMissingSchemaSourceException(
 559                 final Collection<SourceIdentifier> requiredSources, final MissingSchemaSourceException exception) {
 560             // In case source missing, try without it
 561             final SourceIdentifier missingSource = exception.getSourceId();
 562             LOG.warn("{}: Unable to build schema context, missing source {}, will reattempt without it",
 563                 id, missingSource);
 564             LOG.debug("{}: Unable to build schema context, missing source {}, will reattempt without it",
 565                 id, missingSource, exception);
 566             final Collection<QName> qNameOfMissingSource =
 567                 getQNameFromSourceIdentifiers(Sets.newHashSet(missingSource));
 568             if (!qNameOfMissingSource.isEmpty()) {
 569                 capabilities.addUnresolvedCapabilities(
 570                         qNameOfMissingSource, UnavailableCapability.FailureReason.MissingSource);
 571             }
 572             return stripUnavailableSource(requiredSources, missingSource);
 573         }
 574
 575         private Collection<SourceIdentifier> handleSchemaResolutionException(
 576             final Collection<SourceIdentifier> requiredSources, final SchemaResolutionException resolutionException) {
 577             // In case resolution error, try only with resolved sources
 578             // There are two options why schema resolution exception occurred : unsatisfied imports or flawed model
 579             // FIXME Do we really have assurance that these two cases cannot happen at once?
 580             if (resolutionException.getFailedSource() != null) {
 581                 // flawed model - exclude it
 582                 final SourceIdentifier failedSourceId = resolutionException.getFailedSource();
 583                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 584                     id, failedSourceId);
 585                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 586                     id, failedSourceId, resolutionException);
 587                 capabilities.addUnresolvedCapabilities(
 588                         getQNameFromSourceIdentifiers(Collections.singleton(failedSourceId)),
 589                         UnavailableCapability.FailureReason.UnableToResolve);
 590                 return stripUnavailableSource(requiredSources, resolutionException.getFailedSource());
 591             }
 592             // unsatisfied imports
 593             final Set<SourceIdentifier> unresolvedSources = resolutionException.getUnsatisfiedImports().keySet();
 594             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(unresolvedSources),
 595                 UnavailableCapability.FailureReason.UnableToResolve);
 596             LOG.warn("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 597                 id, resolutionException.getUnsatisfiedImports());
 598             LOG.debug("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 599                 id, resolutionException.getUnsatisfiedImports(), resolutionException);
 600             return resolutionException.getResolvedSources();
 601         }
 602
 603         protected NetconfDeviceRpc getDeviceSpecificRpc(final MountPointContext result) {
 604             return new NetconfDeviceRpc(result.getSchemaContext(), listener,
 605                 new NetconfMessageTransformer(result, true));
 606         }
 607
 608         private Collection<SourceIdentifier> stripUnavailableSource(final Collection<SourceIdentifier> requiredSources,
 609                                                                     final SourceIdentifier sourceIdToRemove) {
 610             final LinkedList<SourceIdentifier> sourceIdentifiers = Lists.newLinkedList(requiredSources);
 611             checkState(sourceIdentifiers.remove(sourceIdToRemove),
 612                     "%s: Trying to remove %s from %s failed", id, sourceIdToRemove, requiredSources);
 613             return sourceIdentifiers;
 614         }
 615
 616         private Collection<QName> getQNameFromSourceIdentifiers(final Collection<SourceIdentifier> identifiers) {
 617             final Collection<QName> qNames = Collections2.transform(identifiers, this::getQNameFromSourceIdentifier);
 618
 619             if (qNames.isEmpty()) {
 620                 LOG.debug("{}: Unable to map any source identifiers to a capability reported by device : {}", id,
 621                         identifiers);
 622             }
 623             return Collections2.filter(qNames, Predicates.notNull());
 624         }
 625
 626         private QName getQNameFromSourceIdentifier(final SourceIdentifier identifier) {
 627             // Required sources are all required and provided merged in DeviceSourcesResolver
 628             for (final QName qname : deviceSources.getRequiredSourcesQName()) {
 629                 if (!qname.getLocalName().equals(identifier.getName())) {
 630                     continue;
 631                 }
 632
 633                 if (identifier.getRevision().equals(qname.getRevision())) {
 634                     return qname;
 635                 }
 636             }
 637             LOG.warn("Unable to map identifier to a devices reported capability: {} Available: {}",identifier,
 638                     deviceSources.getRequiredSourcesQName());
 639             // return null since we cannot find the QName,
 640             // this capability will be removed from required sources and not reported as unresolved-capability
 641             return null;
 642         }
 643     }
 644 }