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.DOMNotification;
  36 import org.opendaylight.mdsal.dom.api.DOMRpcResult;
  37 import org.opendaylight.mdsal.dom.api.DOMRpcService;
  38 import org.opendaylight.netconf.api.NetconfMessage;
  39 import org.opendaylight.netconf.sal.connect.api.DeviceActionFactory;
  40 import org.opendaylight.netconf.sal.connect.api.MessageTransformer;
  41 import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemas;
  42 import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemasResolver;
  43 import org.opendaylight.netconf.sal.connect.api.RemoteDevice;
  44 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceCommunicator;
  45 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceHandler;
  46 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCapabilities;
  47 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCommunicator;
  48 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfSessionPreferences;
  49 import org.opendaylight.netconf.sal.connect.netconf.sal.NetconfDeviceRpc;
  50 import org.opendaylight.netconf.sal.connect.netconf.schema.NetconfRemoteSchemaYangSourceProvider;
  51 import org.opendaylight.netconf.sal.connect.netconf.schema.YangLibrarySchemaYangSourceProvider;
  52 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.BaseSchema;
  53 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.NetconfMessageTransformer;
  54 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  55 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  56 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.netconf.notifications.rev120206.NetconfCapabilityChange;
  57 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.optional.rev190614.NetconfNodeAugmentedOptional;
  58 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.NetconfNode;
  59 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.available.capabilities.AvailableCapabilityBuilder;
  60 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.unavailable.capabilities.UnavailableCapability;
  61 import org.opendaylight.yangtools.yang.common.QName;
  62 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  63 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  64 import org.opendaylight.yangtools.yang.model.repo.api.RevisionSourceIdentifier;
  65 import org.opendaylight.yangtools.yang.model.repo.api.SchemaContextFactory;
  66 import org.opendaylight.yangtools.yang.model.repo.api.SchemaRepository;
  67 import org.opendaylight.yangtools.yang.model.repo.api.SchemaResolutionException;
  68 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceRepresentation;
  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<? extends SchemaSourceRepresentation>> sourceRegistrations =
  92             new ArrayList<>();
  93
  94     private final RemoteDeviceHandler<NetconfSessionPreferences> salFacade;
  95     private final ListeningExecutorService processingExecutor;
  96     private final DeviceActionFactory deviceActionFactory;
  97     private final NetconfDeviceSchemasResolver stateSchemasResolver;
  98     private final NotificationHandler notificationHandler;
  99     private final boolean reconnectOnSchemasChange;
 100     private final NetconfNode node;
 101     private final EventExecutor eventExecutor;
 102     private final NetconfNodeAugmentedOptional nodeOptional;
 103
 104     @GuardedBy("this")
 105     private boolean connected = false;
 106
 107     // Message transformer is constructed once the schemas are available
 108     private MessageTransformer<NetconfMessage> messageTransformer;
 109
 110     /**
 111      * Create rpc implementation capable of handling RPC for monitoring and notifications
 112      * even before the schemas of remote device are downloaded.
 113      */
 114     static NetconfDeviceRpc getRpcForInitialization(final NetconfDeviceCommunicator listener,
 115                                                     final boolean notificationSupport) {
 116         final BaseSchema baseSchema = resolveBaseSchema(notificationSupport);
 117
 118         return new NetconfDeviceRpc(baseSchema.getSchemaContext(), listener,
 119                 new NetconfMessageTransformer(baseSchema.getSchemaContext(), false, baseSchema));
 120     }
 121
 122     private static BaseSchema resolveBaseSchema(final boolean notificationSupport) {
 123         return notificationSupport ? BaseSchema.BASE_NETCONF_CTX_WITH_NOTIFICATIONS : BaseSchema.BASE_NETCONF_CTX;
 124     }
 125
 126     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final RemoteDeviceId id,
 127                          final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
 128                          final ListeningExecutorService globalProcessingExecutor,
 129                          final boolean reconnectOnSchemasChange) {
 130         this(schemaResourcesDTO, id, salFacade, globalProcessingExecutor, reconnectOnSchemasChange, null, null, null,
 131                 null);
 132     }
 133
 134     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final RemoteDeviceId id,
 135             final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
 136             final ListeningExecutorService globalProcessingExecutor, final boolean reconnectOnSchemasChange,
 137             final DeviceActionFactory deviceActionFactory, final NetconfNode node, final EventExecutor eventExecutor,
 138             final NetconfNodeAugmentedOptional nodeOptional) {
 139         this.id = id;
 140         this.reconnectOnSchemasChange = reconnectOnSchemasChange;
 141         this.deviceActionFactory = deviceActionFactory;
 142         this.node = node;
 143         this.eventExecutor = eventExecutor;
 144         this.nodeOptional = nodeOptional;
 145         this.schemaRegistry = schemaResourcesDTO.getSchemaRegistry();
 146         this.schemaRepository = schemaResourcesDTO.getSchemaRepository();
 147         this.schemaContextFactory = schemaResourcesDTO.getSchemaContextFactory();
 148         this.salFacade = salFacade;
 149         this.stateSchemasResolver = schemaResourcesDTO.getStateSchemasResolver();
 150         this.processingExecutor = requireNonNull(globalProcessingExecutor);
 151         this.notificationHandler = new NotificationHandler(salFacade, id);
 152     }
 153
 154     @Override
 155     public void onRemoteSessionUp(final NetconfSessionPreferences remoteSessionCapabilities,
 156                                   final NetconfDeviceCommunicator listener) {
 157         // SchemaContext setup has to be performed in a dedicated thread since
 158         // we are in a netty thread in this method
 159         // Yang models are being downloaded in this method and it would cause a
 160         // deadlock if we used the netty thread
 161         // http://netty.io/wiki/thread-model.html
 162         setConnected(true);
 163         LOG.debug("{}: Session to remote device established with {}", id, remoteSessionCapabilities);
 164
 165         final NetconfDeviceRpc initRpc =
 166                 getRpcForInitialization(listener, remoteSessionCapabilities.isNotificationsSupported());
 167         final DeviceSourcesResolver task =
 168                 new DeviceSourcesResolver(remoteSessionCapabilities, id, stateSchemasResolver, initRpc,
 169                         resolveBaseSchema(remoteSessionCapabilities.isNotificationsSupported()).getSchemaContext());
 170         final ListenableFuture<DeviceSources> sourceResolverFuture = processingExecutor.submit(task);
 171
 172         if (shouldListenOnSchemaChange(remoteSessionCapabilities)) {
 173             registerToBaseNetconfStream(initRpc, listener);
 174         }
 175
 176         final FutureCallback<DeviceSources> resolvedSourceCallback = new FutureCallback<DeviceSources>() {
 177             @Override
 178             public void onSuccess(final DeviceSources result) {
 179                 addProvidedSourcesToSchemaRegistry(result);
 180                 setUpSchema(result);
 181             }
 182
 183             private void setUpSchema(final DeviceSources result) {
 184                 processingExecutor.submit(new SchemaSetup(result, remoteSessionCapabilities, listener));
 185             }
 186
 187             @Override
 188             public void onFailure(final Throwable throwable) {
 189                 LOG.warn("{}: Unexpected error resolving device sources", id, throwable);
 190                 handleSalInitializationFailure(throwable, listener);
 191             }
 192         };
 193
 194         Futures.addCallback(sourceResolverFuture, resolvedSourceCallback, MoreExecutors.directExecutor());
 195     }
 196
 197     private void registerToBaseNetconfStream(final NetconfDeviceRpc deviceRpc,
 198                                              final NetconfDeviceCommunicator listener) {
 199         // TODO check whether the model describing create subscription is present in schema
 200         // Perhaps add a default schema context to support create-subscription if the model was not provided
 201         // (same as what we do for base netconf operations in transformer)
 202         final ListenableFuture<DOMRpcResult> rpcResultListenableFuture = deviceRpc.invokeRpc(
 203                 NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_PATH,
 204                 NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_CONTENT);
 205
 206         final NotificationHandler.NotificationFilter filter = new NotificationHandler.NotificationFilter() {
 207             @Override
 208             public Optional<DOMNotification> filterNotification(final DOMNotification notification) {
 209                 if (isCapabilityChanged(notification)) {
 210                     LOG.info("{}: Schemas change detected, reconnecting", id);
 211                     // Only disconnect is enough,
 212                     // the reconnecting nature of the connector will take care of reconnecting
 213                     listener.disconnect();
 214                     return Optional.empty();
 215                 }
 216                 return Optional.of(notification);
 217             }
 218
 219             private boolean isCapabilityChanged(final DOMNotification notification) {
 220                 return notification.getBody().getNodeType().equals(NetconfCapabilityChange.QNAME);
 221             }
 222         };
 223
 224         Futures.addCallback(rpcResultListenableFuture, new FutureCallback<DOMRpcResult>() {
 225             @Override
 226             public void onSuccess(final DOMRpcResult domRpcResult) {
 227                 notificationHandler.addNotificationFilter(filter);
 228             }
 229
 230             @Override
 231             public void onFailure(final Throwable throwable) {
 232                 LOG.warn("Unable to subscribe to base notification stream. Schemas will not be reloaded on the fly",
 233                         throwable);
 234             }
 235         }, MoreExecutors.directExecutor());
 236     }
 237
 238     private boolean shouldListenOnSchemaChange(final NetconfSessionPreferences remoteSessionCapabilities) {
 239         return remoteSessionCapabilities.isNotificationsSupported() && reconnectOnSchemasChange;
 240     }
 241
 242     private synchronized void handleSalInitializationSuccess(final SchemaContext result,
 243                                         final NetconfSessionPreferences remoteSessionCapabilities,
 244                                         final DOMRpcService deviceRpc,
 245                                         final RemoteDeviceCommunicator<NetconfMessage> listener) {
 246         //NetconfDevice.SchemaSetup can complete after NetconfDeviceCommunicator was closed. In that case do nothing,
 247         //since salFacade.onDeviceDisconnected was already called.
 248         if (connected) {
 249             final BaseSchema baseSchema =
 250                 remoteSessionCapabilities.isNotificationsSupported()
 251                         ? BaseSchema.BASE_NETCONF_CTX_WITH_NOTIFICATIONS : BaseSchema.BASE_NETCONF_CTX;
 252             this.messageTransformer = new NetconfMessageTransformer(result, true, baseSchema);
 253
 254             // salFacade.onDeviceConnected has to be called before the notification handler is initialized
 255             this.salFacade.onDeviceConnected(result, remoteSessionCapabilities, deviceRpc,
 256                     this.deviceActionFactory == null ? null : this.deviceActionFactory.createDeviceAction(
 257                             this.messageTransformer, listener, result));
 258             this.notificationHandler.onRemoteSchemaUp(this.messageTransformer);
 259
 260             LOG.info("{}: Netconf connector initialized successfully", id);
 261         } else {
 262             LOG.warn("{}: Device communicator was closed before schema setup finished.", id);
 263         }
 264     }
 265
 266     private void handleSalInitializationFailure(final Throwable throwable,
 267                                                 final RemoteDeviceCommunicator<NetconfMessage> listener) {
 268         LOG.error("{}: Initialization in sal failed, disconnecting from device", id, throwable);
 269         listener.close();
 270         onRemoteSessionDown();
 271         resetMessageTransformer();
 272     }
 273
 274     /**
 275      * Set the transformer to null as is in initial state.
 276      */
 277     private void resetMessageTransformer() {
 278         updateTransformer(null);
 279     }
 280
 281     private synchronized void updateTransformer(final MessageTransformer<NetconfMessage> transformer) {
 282         messageTransformer = transformer;
 283     }
 284
 285     private synchronized void setConnected(final boolean connected) {
 286         this.connected = connected;
 287     }
 288
 289     private void addProvidedSourcesToSchemaRegistry(final DeviceSources deviceSources) {
 290         final SchemaSourceProvider<YangTextSchemaSource> yangProvider = deviceSources.getSourceProvider();
 291         for (final SourceIdentifier sourceId : deviceSources.getProvidedSources()) {
 292             sourceRegistrations.add(schemaRegistry.registerSchemaSource(yangProvider,
 293                     PotentialSchemaSource.create(
 294                             sourceId, YangTextSchemaSource.class, PotentialSchemaSource.Costs.REMOTE_IO.getValue())));
 295         }
 296     }
 297
 298     @Override
 299     public void onRemoteSessionDown() {
 300         setConnected(false);
 301         notificationHandler.onRemoteSchemaDown();
 302
 303         salFacade.onDeviceDisconnected();
 304         for (final SchemaSourceRegistration<? extends SchemaSourceRepresentation> sourceRegistration
 305                 : sourceRegistrations) {
 306             sourceRegistration.close();
 307         }
 308         resetMessageTransformer();
 309     }
 310
 311     @Override
 312     public void onRemoteSessionFailed(final Throwable throwable) {
 313         setConnected(false);
 314         salFacade.onDeviceFailed(throwable);
 315     }
 316
 317     @Override
 318     public void onNotification(final NetconfMessage notification) {
 319         notificationHandler.handleNotification(notification);
 320     }
 321
 322     /**
 323      * Just a transfer object containing schema related dependencies. Injected in constructor.
 324      */
 325     public static class SchemaResourcesDTO {
 326         private final SchemaSourceRegistry schemaRegistry;
 327         private final SchemaRepository schemaRepository;
 328         private final SchemaContextFactory schemaContextFactory;
 329         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 330
 331         public SchemaResourcesDTO(final SchemaSourceRegistry schemaRegistry,
 332                                   final SchemaRepository schemaRepository,
 333                                   final SchemaContextFactory schemaContextFactory,
 334                                   final NetconfDeviceSchemasResolver deviceSchemasResolver) {
 335             this.schemaRegistry = requireNonNull(schemaRegistry);
 336             this.schemaRepository = requireNonNull(schemaRepository);
 337             this.schemaContextFactory = requireNonNull(schemaContextFactory);
 338             this.stateSchemasResolver = requireNonNull(deviceSchemasResolver);
 339         }
 340
 341         public SchemaSourceRegistry getSchemaRegistry() {
 342             return schemaRegistry;
 343         }
 344
 345         public SchemaRepository getSchemaRepository() {
 346             return schemaRepository;
 347         }
 348
 349         public SchemaContextFactory getSchemaContextFactory() {
 350             return schemaContextFactory;
 351         }
 352
 353         public NetconfDeviceSchemasResolver getStateSchemasResolver() {
 354             return stateSchemasResolver;
 355         }
 356     }
 357
 358     /**
 359      * Schema building callable.
 360      */
 361     private static class DeviceSourcesResolver implements Callable<DeviceSources> {
 362
 363         private final NetconfDeviceRpc deviceRpc;
 364         private final NetconfSessionPreferences remoteSessionCapabilities;
 365         private final RemoteDeviceId id;
 366         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 367         private final SchemaContext schemaContext;
 368
 369         DeviceSourcesResolver(final NetconfDeviceRpc deviceRpc,
 370                               final NetconfSessionPreferences remoteSessionCapabilities,
 371                               final RemoteDeviceId id, final NetconfDeviceSchemasResolver stateSchemasResolver,
 372                               final SchemaContext schemaContext) {
 373             this.deviceRpc = deviceRpc;
 374             this.remoteSessionCapabilities = remoteSessionCapabilities;
 375             this.id = id;
 376             this.stateSchemasResolver = stateSchemasResolver;
 377             this.schemaContext = schemaContext;
 378         }
 379
 380         DeviceSourcesResolver(final NetconfSessionPreferences remoteSessionCapabilities, final RemoteDeviceId id,
 381                                      final NetconfDeviceSchemasResolver stateSchemasResolver,
 382                                      final NetconfDeviceRpc rpcForMonitoring, final SchemaContext schemaCtx) {
 383             this(rpcForMonitoring, remoteSessionCapabilities, id, stateSchemasResolver, schemaCtx);
 384         }
 385
 386         @Override
 387         public DeviceSources call() {
 388             final NetconfDeviceSchemas availableSchemas =
 389                     stateSchemasResolver.resolve(deviceRpc, remoteSessionCapabilities, id, schemaContext);
 390             LOG.debug("{}: Schemas exposed by ietf-netconf-monitoring: {}", id,
 391                     availableSchemas.getAvailableYangSchemasQNames());
 392
 393             final Set<QName> requiredSources = Sets.newHashSet(remoteSessionCapabilities.getModuleBasedCaps());
 394             final Set<QName> providedSources = availableSchemas.getAvailableYangSchemasQNames();
 395
 396             final Set<QName> requiredSourcesNotProvided = Sets.difference(requiredSources, providedSources);
 397             if (!requiredSourcesNotProvided.isEmpty()) {
 398                 LOG.warn("{}: Netconf device does not provide all yang models reported in hello message capabilities,"
 399                         + " required but not provided: {}", id, requiredSourcesNotProvided);
 400                 LOG.warn("{}: Attempting to build schema context from required sources", id);
 401             }
 402
 403             // Here all the sources reported in netconf monitoring are merged with those reported in hello.
 404             // It is necessary to perform this since submodules are not mentioned in hello but still required.
 405             // This clashes with the option of a user to specify supported yang models manually in configuration
 406             // for netconf-connector and as a result one is not able to fully override yang models of a device.
 407             // It is only possible to add additional models.
 408             final Set<QName> providedSourcesNotRequired = Sets.difference(providedSources, requiredSources);
 409             if (!providedSourcesNotRequired.isEmpty()) {
 410                 LOG.warn("{}: Netconf device provides additional yang models not reported in "
 411                         + "hello message capabilities: {}", id, providedSourcesNotRequired);
 412                 LOG.warn("{}: Adding provided but not required sources as required to prevent failures", id);
 413                 LOG.debug("{}: Netconf device reported in hello: {}", id, requiredSources);
 414                 requiredSources.addAll(providedSourcesNotRequired);
 415             }
 416
 417             final SchemaSourceProvider<YangTextSchemaSource> sourceProvider;
 418             if (availableSchemas instanceof LibraryModulesSchemas) {
 419                 sourceProvider = new YangLibrarySchemaYangSourceProvider(id,
 420                         ((LibraryModulesSchemas) availableSchemas).getAvailableModels());
 421             } else {
 422                 sourceProvider = new NetconfRemoteSchemaYangSourceProvider(id, deviceRpc);
 423             }
 424
 425             return new DeviceSources(requiredSources, providedSources, sourceProvider);
 426         }
 427     }
 428
 429     /**
 430      * Contains RequiredSources - sources from capabilities.
 431      */
 432     private static final class DeviceSources {
 433         private final Set<QName> requiredSources;
 434         private final Set<QName> providedSources;
 435         private final SchemaSourceProvider<YangTextSchemaSource> sourceProvider;
 436
 437         DeviceSources(final Set<QName> requiredSources, final Set<QName> providedSources,
 438                              final SchemaSourceProvider<YangTextSchemaSource> sourceProvider) {
 439             this.requiredSources = requiredSources;
 440             this.providedSources = providedSources;
 441             this.sourceProvider = sourceProvider;
 442         }
 443
 444         public Set<QName> getRequiredSourcesQName() {
 445             return requiredSources;
 446         }
 447
 448         public Set<QName> getProvidedSourcesQName() {
 449             return providedSources;
 450         }
 451
 452         public Collection<SourceIdentifier> getRequiredSources() {
 453             return Collections2.transform(requiredSources, DeviceSources::toSourceId);
 454         }
 455
 456         public Collection<SourceIdentifier> getProvidedSources() {
 457             return Collections2.transform(providedSources, DeviceSources::toSourceId);
 458         }
 459
 460         public SchemaSourceProvider<YangTextSchemaSource> getSourceProvider() {
 461             return sourceProvider;
 462         }
 463
 464         private static SourceIdentifier toSourceId(final QName input) {
 465             return RevisionSourceIdentifier.create(input.getLocalName(), input.getRevision());
 466         }
 467     }
 468
 469     /**
 470      * Schema builder that tries to build schema context from provided sources or biggest subset of it.
 471      */
 472     private final class SchemaSetup implements Runnable {
 473         private final DeviceSources deviceSources;
 474         private final NetconfSessionPreferences remoteSessionCapabilities;
 475         private final RemoteDeviceCommunicator<NetconfMessage> listener;
 476         private final NetconfDeviceCapabilities capabilities;
 477
 478         SchemaSetup(final DeviceSources deviceSources, final NetconfSessionPreferences remoteSessionCapabilities,
 479                            final RemoteDeviceCommunicator<NetconfMessage> listener) {
 480             this.deviceSources = deviceSources;
 481             this.remoteSessionCapabilities = remoteSessionCapabilities;
 482             this.listener = listener;
 483             this.capabilities = remoteSessionCapabilities.getNetconfDeviceCapabilities();
 484         }
 485
 486         @Override
 487         public void run() {
 488
 489             final Collection<SourceIdentifier> requiredSources = deviceSources.getRequiredSources();
 490             final Collection<SourceIdentifier> missingSources = filterMissingSources(requiredSources);
 491
 492             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(missingSources),
 493                     UnavailableCapability.FailureReason.MissingSource);
 494
 495             requiredSources.removeAll(missingSources);
 496             setUpSchema(requiredSources);
 497         }
 498
 499         private Collection<SourceIdentifier> filterMissingSources(final Collection<SourceIdentifier> requiredSources) {
 500             return requiredSources.parallelStream().filter(sourceIdentifier -> {
 501                 try {
 502                     schemaRepository.getSchemaSource(sourceIdentifier, YangTextSchemaSource.class).get();
 503                     return false;
 504                 } catch (InterruptedException | ExecutionException e) {
 505                     return true;
 506                 }
 507             }).collect(Collectors.toList());
 508         }
 509
 510         /**
 511          * Build schema context, in case of success or final failure notify device.
 512          *
 513          * @param requiredSources required sources
 514          */
 515         @SuppressWarnings("checkstyle:IllegalCatch")
 516         private void setUpSchema(Collection<SourceIdentifier> requiredSources) {
 517             while (!requiredSources.isEmpty()) {
 518                 LOG.trace("{}: Trying to build schema context from {}", id, requiredSources);
 519                 try {
 520                     final ListenableFuture<SchemaContext> schemaBuilderFuture = schemaContextFactory
 521                             .createSchemaContext(requiredSources);
 522                     final SchemaContext result = schemaBuilderFuture.get();
 523                     LOG.debug("{}: Schema context built successfully from {}", id, requiredSources);
 524                     final Collection<QName> filteredQNames = Sets.difference(deviceSources.getRequiredSourcesQName(),
 525                             capabilities.getUnresolvedCapabilites().keySet());
 526                     capabilities.addCapabilities(filteredQNames.stream().map(entry -> new AvailableCapabilityBuilder()
 527                             .setCapability(entry.toString()).setCapabilityOrigin(
 528                                     remoteSessionCapabilities.getModuleBasedCapsOrigin().get(entry)).build())
 529                             .collect(Collectors.toList()));
 530
 531                     capabilities.addNonModuleBasedCapabilities(remoteSessionCapabilities
 532                             .getNonModuleCaps().stream().map(entry -> new AvailableCapabilityBuilder()
 533                                     .setCapability(entry).setCapabilityOrigin(
 534                                             remoteSessionCapabilities.getNonModuleBasedCapsOrigin().get(entry)).build())
 535                             .collect(Collectors.toList()));
 536
 537                     handleSalInitializationSuccess(result, remoteSessionCapabilities, getDeviceSpecificRpc(result),
 538                             listener);
 539                     return;
 540                 } catch (final ExecutionException e) {
 541                     // schemaBuilderFuture.checkedGet() throws only SchemaResolutionException
 542                     // that might be wrapping a MissingSchemaSourceException so we need to look
 543                     // at the cause of the exception to make sure we don't misinterpret it.
 544                     final Throwable cause = e.getCause();
 545
 546                     if (cause instanceof MissingSchemaSourceException) {
 547                         requiredSources = handleMissingSchemaSourceException(
 548                                 requiredSources, (MissingSchemaSourceException) cause);
 549                         continue;
 550                     }
 551                     if (cause instanceof SchemaResolutionException) {
 552                         requiredSources = handleSchemaResolutionException(requiredSources,
 553                             (SchemaResolutionException) cause);
 554                     } else {
 555                         handleSalInitializationFailure(e, listener);
 556                         return;
 557                     }
 558                 } catch (final Exception e) {
 559                     // unknown error, fail
 560                     handleSalInitializationFailure(e, listener);
 561                     return;
 562                 }
 563             }
 564             // No more sources, fail or try to reconnect
 565             if (nodeOptional != null && nodeOptional.getIgnoreMissingSchemaSources().isAllowed()) {
 566                 eventExecutor.schedule(() -> {
 567                     LOG.warn("Reconnection is allowed! This can lead to unexpected errors at runtime.");
 568                     LOG.warn("{} : No more sources for schema context.", id);
 569                     LOG.info("{} : Try to remount device.", id);
 570                     onRemoteSessionDown();
 571                     salFacade.onDeviceReconnected(remoteSessionCapabilities, node);
 572                 }, nodeOptional.getIgnoreMissingSchemaSources().getReconnectTime(), TimeUnit.MILLISECONDS);
 573             } else {
 574                 final IllegalStateException cause =
 575                         new IllegalStateException(id + ": No more sources for schema context");
 576                 handleSalInitializationFailure(cause, listener);
 577                 salFacade.onDeviceFailed(cause);
 578             }
 579         }
 580
 581         private Collection<SourceIdentifier> handleMissingSchemaSourceException(
 582                 final Collection<SourceIdentifier> requiredSources, final MissingSchemaSourceException exception) {
 583             // In case source missing, try without it
 584             final SourceIdentifier missingSource = exception.getSourceId();
 585             LOG.warn("{}: Unable to build schema context, missing source {}, will reattempt without it",
 586                 id, missingSource);
 587             LOG.debug("{}: Unable to build schema context, missing source {}, will reattempt without it",
 588                 id, missingSource, exception);
 589             final Collection<QName> qNameOfMissingSource =
 590                 getQNameFromSourceIdentifiers(Sets.newHashSet(missingSource));
 591             if (!qNameOfMissingSource.isEmpty()) {
 592                 capabilities.addUnresolvedCapabilities(
 593                         qNameOfMissingSource, UnavailableCapability.FailureReason.MissingSource);
 594             }
 595             return stripUnavailableSource(requiredSources, missingSource);
 596         }
 597
 598         private Collection<SourceIdentifier> handleSchemaResolutionException(
 599             final Collection<SourceIdentifier> requiredSources, final SchemaResolutionException resolutionException) {
 600             // In case resolution error, try only with resolved sources
 601             // There are two options why schema resolution exception occurred : unsatisfied imports or flawed model
 602             // FIXME Do we really have assurance that these two cases cannot happen at once?
 603             if (resolutionException.getFailedSource() != null) {
 604                 // flawed model - exclude it
 605                 final SourceIdentifier failedSourceId = resolutionException.getFailedSource();
 606                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 607                     id, failedSourceId);
 608                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 609                     id, failedSourceId, resolutionException);
 610                 capabilities.addUnresolvedCapabilities(
 611                         getQNameFromSourceIdentifiers(Collections.singleton(failedSourceId)),
 612                         UnavailableCapability.FailureReason.UnableToResolve);
 613                 return stripUnavailableSource(requiredSources, resolutionException.getFailedSource());
 614             }
 615             // unsatisfied imports
 616             final Set<SourceIdentifier> unresolvedSources = resolutionException.getUnsatisfiedImports().keySet();
 617             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(unresolvedSources),
 618                 UnavailableCapability.FailureReason.UnableToResolve);
 619             LOG.warn("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 620                 id, resolutionException.getUnsatisfiedImports());
 621             LOG.debug("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 622                 id, resolutionException.getUnsatisfiedImports(), resolutionException);
 623             return resolutionException.getResolvedSources();
 624         }
 625
 626         protected NetconfDeviceRpc getDeviceSpecificRpc(final SchemaContext result) {
 627             return new NetconfDeviceRpc(result, listener, new NetconfMessageTransformer(result, true));
 628         }
 629
 630         private Collection<SourceIdentifier> stripUnavailableSource(final Collection<SourceIdentifier> requiredSources,
 631                                                                     final SourceIdentifier sourceIdToRemove) {
 632             final LinkedList<SourceIdentifier> sourceIdentifiers = Lists.newLinkedList(requiredSources);
 633             checkState(sourceIdentifiers.remove(sourceIdToRemove),
 634                     "%s: Trying to remove %s from %s failed", id, sourceIdToRemove, requiredSources);
 635             return sourceIdentifiers;
 636         }
 637
 638         private Collection<QName> getQNameFromSourceIdentifiers(final Collection<SourceIdentifier> identifiers) {
 639             final Collection<QName> qNames = Collections2.transform(identifiers, this::getQNameFromSourceIdentifier);
 640
 641             if (qNames.isEmpty()) {
 642                 LOG.debug("{}: Unable to map any source identifiers to a capability reported by device : {}", id,
 643                         identifiers);
 644             }
 645             return Collections2.filter(qNames, Predicates.notNull());
 646         }
 647
 648         private QName getQNameFromSourceIdentifier(final SourceIdentifier identifier) {
 649             // Required sources are all required and provided merged in DeviceSourcesResolver
 650             for (final QName qname : deviceSources.getRequiredSourcesQName()) {
 651                 if (!qname.getLocalName().equals(identifier.getName())) {
 652                     continue;
 653                 }
 654
 655                 if (identifier.getRevision().equals(qname.getRevision())) {
 656                     return qname;
 657                 }
 658             }
 659             LOG.warn("Unable to map identifier to a devices reported capability: {} Available: {}",identifier,
 660                     deviceSources.getRequiredSourcesQName());
 661             // return null since we cannot find the QName,
 662             // this capability will be removed from required sources and not reported as unresolved-capability
 663             return null;
 664         }
 665     }
 666 }