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 import static org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil.NETCONF_GET_NODEID;
  13
  14 import com.google.common.base.Predicates;
  15 import com.google.common.collect.Collections2;
  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 com.google.common.util.concurrent.SettableFuture;
  23 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  24 import io.netty.util.concurrent.EventExecutor;
  25 import java.util.ArrayList;
  26 import java.util.Arrays;
  27 import java.util.Collection;
  28 import java.util.Collections;
  29 import java.util.LinkedList;
  30 import java.util.List;
  31 import java.util.Optional;
  32 import java.util.Set;
  33 import java.util.concurrent.ExecutionException;
  34 import java.util.concurrent.TimeUnit;
  35 import java.util.stream.Collectors;
  36 import org.checkerframework.checker.lock.qual.GuardedBy;
  37 import org.opendaylight.mdsal.dom.api.DOMRpcResult;
  38 import org.opendaylight.mdsal.dom.api.DOMRpcService;
  39 import org.opendaylight.netconf.api.NetconfMessage;
  40 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
  41 import org.opendaylight.netconf.sal.connect.api.DeviceActionFactory;
  42 import org.opendaylight.netconf.sal.connect.api.MessageTransformer;
  43 import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemasResolver;
  44 import org.opendaylight.netconf.sal.connect.api.RemoteDevice;
  45 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceCommunicator;
  46 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceHandler;
  47 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCapabilities;
  48 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCommunicator;
  49 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfSessionPreferences;
  50 import org.opendaylight.netconf.sal.connect.netconf.sal.NetconfDeviceRpc;
  51 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.BaseNetconfSchemas;
  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.rfc8528.data.api.MountPointContext;
  62 import org.opendaylight.yangtools.rfc8528.data.util.EmptyMountPointContext;
  63 import org.opendaylight.yangtools.rfc8528.model.api.SchemaMountConstants;
  64 import org.opendaylight.yangtools.yang.common.QName;
  65 import org.opendaylight.yangtools.yang.common.RpcError;
  66 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  67 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  68 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  69 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  70 import org.opendaylight.yangtools.yang.data.impl.schema.Builders;
  71 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  72 import org.opendaylight.yangtools.yang.model.repo.api.EffectiveModelContextFactory;
  73 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  74 import org.opendaylight.yangtools.yang.model.repo.api.SchemaRepository;
  75 import org.opendaylight.yangtools.yang.model.repo.api.SchemaResolutionException;
  76 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  77 import org.opendaylight.yangtools.yang.model.repo.api.YangTextSchemaSource;
  78 import org.opendaylight.yangtools.yang.model.repo.spi.PotentialSchemaSource;
  79 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceProvider;
  80 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistration;
  81 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  82 import org.slf4j.Logger;
  83 import org.slf4j.LoggerFactory;
  84
  85 /**
  86  *  This is a mediator between NetconfDeviceCommunicator and NetconfDeviceSalFacade.
  87  */
  88 public class NetconfDevice
  89         implements RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> {
  90
  91     @SuppressFBWarnings(value = "SLF4J_LOGGER_SHOULD_BE_PRIVATE",
  92             justification = "Needed for common logging of related classes")
  93     static final Logger LOG = LoggerFactory.getLogger(NetconfDevice.class);
  94
  95     private static final QName RFC8528_SCHEMA_MOUNTS_QNAME = QName.create(
  96         SchemaMountConstants.RFC8528_MODULE, "schema-mounts").intern();
  97     private static final YangInstanceIdentifier RFC8528_SCHEMA_MOUNTS = YangInstanceIdentifier.create(
  98         NodeIdentifier.create(RFC8528_SCHEMA_MOUNTS_QNAME));
  99
 100     protected final RemoteDeviceId id;
 101     protected final EffectiveModelContextFactory schemaContextFactory;
 102     protected final SchemaSourceRegistry schemaRegistry;
 103     protected final SchemaRepository schemaRepository;
 104
 105     protected final List<SchemaSourceRegistration<?>> sourceRegistrations = new ArrayList<>();
 106
 107     private final RemoteDeviceHandler<NetconfSessionPreferences> salFacade;
 108     private final ListeningExecutorService processingExecutor;
 109     private final DeviceActionFactory deviceActionFactory;
 110     private final NetconfDeviceSchemasResolver stateSchemasResolver;
 111     private final NotificationHandler notificationHandler;
 112     private final boolean reconnectOnSchemasChange;
 113     private final BaseNetconfSchemas baseSchemas;
 114     private final NetconfNode node;
 115     private final EventExecutor eventExecutor;
 116     private final NetconfNodeAugmentedOptional nodeOptional;
 117
 118     @GuardedBy("this")
 119     private boolean connected = false;
 120
 121     // Message transformer is constructed once the schemas are available
 122     private MessageTransformer<NetconfMessage> messageTransformer;
 123
 124     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final BaseNetconfSchemas baseSchemas,
 125             final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
 126             final ListeningExecutorService globalProcessingExecutor, final boolean reconnectOnSchemasChange) {
 127         this(schemaResourcesDTO, baseSchemas, id, salFacade, globalProcessingExecutor, reconnectOnSchemasChange, null,
 128             null, null, null);
 129     }
 130
 131     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final BaseNetconfSchemas baseSchemas,
 132             final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
 133             final ListeningExecutorService globalProcessingExecutor, final boolean reconnectOnSchemasChange,
 134             final DeviceActionFactory deviceActionFactory, final NetconfNode node, final EventExecutor eventExecutor,
 135             final NetconfNodeAugmentedOptional nodeOptional) {
 136         this.baseSchemas = requireNonNull(baseSchemas);
 137         this.id = id;
 138         this.reconnectOnSchemasChange = reconnectOnSchemasChange;
 139         this.deviceActionFactory = deviceActionFactory;
 140         this.node = node;
 141         this.eventExecutor = eventExecutor;
 142         this.nodeOptional = nodeOptional;
 143         this.schemaRegistry = schemaResourcesDTO.getSchemaRegistry();
 144         this.schemaRepository = schemaResourcesDTO.getSchemaRepository();
 145         this.schemaContextFactory = schemaResourcesDTO.getSchemaContextFactory();
 146         this.salFacade = salFacade;
 147         this.stateSchemasResolver = schemaResourcesDTO.getStateSchemasResolver();
 148         this.processingExecutor = requireNonNull(globalProcessingExecutor);
 149         this.notificationHandler = new NotificationHandler(salFacade, id);
 150     }
 151
 152     @Override
 153     public void onRemoteSessionUp(final NetconfSessionPreferences remoteSessionCapabilities,
 154                                   final NetconfDeviceCommunicator listener) {
 155         // SchemaContext setup has to be performed in a dedicated thread since
 156         // we are in a netty thread in this method
 157         // Yang models are being downloaded in this method and it would cause a
 158         // deadlock if we used the netty thread
 159         // http://netty.io/wiki/thread-model.html
 160         setConnected(true);
 161         LOG.debug("{}: Session to remote device established with {}", id, remoteSessionCapabilities);
 162
 163         final BaseSchema baseSchema = resolveBaseSchema(remoteSessionCapabilities.isNotificationsSupported());
 164         final NetconfDeviceRpc initRpc = new NetconfDeviceRpc(baseSchema.getEffectiveModelContext(), listener,
 165             new NetconfMessageTransformer(baseSchema.getMountPointContext(), false, baseSchema));
 166         final ListenableFuture<DeviceSources> sourceResolverFuture = processingExecutor.submit(
 167             new DeviceSourcesResolver(id, baseSchema, initRpc, remoteSessionCapabilities, stateSchemasResolver));
 168
 169         if (shouldListenOnSchemaChange(remoteSessionCapabilities)) {
 170             registerToBaseNetconfStream(initRpc, listener);
 171         }
 172
 173         // Set up the SchemaContext for the device
 174         final ListenableFuture<EffectiveModelContext> futureSchema = Futures.transformAsync(sourceResolverFuture,
 175             deviceSources -> assembleSchemaContext(deviceSources, remoteSessionCapabilities), processingExecutor);
 176
 177         // Potentially acquire mount point list and interpret it
 178         final ListenableFuture<MountPointContext> futureContext = Futures.transformAsync(futureSchema,
 179             schemaContext -> createMountPointContext(schemaContext, baseSchema, listener), processingExecutor);
 180
 181         Futures.addCallback(futureContext, new FutureCallback<MountPointContext>() {
 182             @Override
 183             public void onSuccess(final MountPointContext result) {
 184                 handleSalInitializationSuccess(result, remoteSessionCapabilities,
 185                         getDeviceSpecificRpc(result, listener, baseSchema), listener);
 186             }
 187
 188             @Override
 189             public void onFailure(final Throwable cause) {
 190                 LOG.warn("{}: Unexpected error resolving device sources", id, cause);
 191
 192                 // No more sources, fail or try to reconnect
 193                 if (cause instanceof EmptySchemaContextException) {
 194                     if (nodeOptional != null && nodeOptional.getIgnoreMissingSchemaSources().getAllowed()) {
 195                         eventExecutor.schedule(() -> {
 196                             LOG.warn("Reconnection is allowed! This can lead to unexpected errors at runtime.");
 197                             LOG.warn("{} : No more sources for schema context.", id);
 198                             LOG.info("{} : Try to remount device.", id);
 199                             onRemoteSessionDown();
 200                             salFacade.onDeviceReconnected(remoteSessionCapabilities, node);
 201                         }, nodeOptional.getIgnoreMissingSchemaSources().getReconnectTime().toJava(),
 202                             TimeUnit.MILLISECONDS);
 203                         return;
 204                     }
 205                 }
 206
 207                 handleSalInitializationFailure(cause, listener);
 208                 salFacade.onDeviceFailed(cause);
 209             }
 210         }, MoreExecutors.directExecutor());
 211     }
 212
 213     private void registerToBaseNetconfStream(final NetconfDeviceRpc deviceRpc,
 214                                              final NetconfDeviceCommunicator listener) {
 215         // TODO check whether the model describing create subscription is present in schema
 216         // Perhaps add a default schema context to support create-subscription if the model was not provided
 217         // (same as what we do for base netconf operations in transformer)
 218         final ListenableFuture<DOMRpcResult> rpcResultListenableFuture = deviceRpc.invokeRpc(
 219                 NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_QNAME,
 220                 NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_CONTENT);
 221
 222         Futures.addCallback(rpcResultListenableFuture, new FutureCallback<DOMRpcResult>() {
 223             @Override
 224             public void onSuccess(final DOMRpcResult domRpcResult) {
 225                 notificationHandler.addNotificationFilter(notification -> {
 226                     if (NetconfCapabilityChange.QNAME.equals(notification.getBody().getIdentifier().getNodeType())) {
 227                         LOG.info("{}: Schemas change detected, reconnecting", id);
 228                         // Only disconnect is enough,
 229                         // the reconnecting nature of the connector will take care of reconnecting
 230                         listener.disconnect();
 231                         return Optional.empty();
 232                     }
 233                     return Optional.of(notification);
 234                 });
 235             }
 236
 237             @Override
 238             public void onFailure(final Throwable throwable) {
 239                 LOG.warn("Unable to subscribe to base notification stream. Schemas will not be reloaded on the fly",
 240                         throwable);
 241             }
 242         }, MoreExecutors.directExecutor());
 243     }
 244
 245     private boolean shouldListenOnSchemaChange(final NetconfSessionPreferences remoteSessionCapabilities) {
 246         return remoteSessionCapabilities.isNotificationsSupported() && reconnectOnSchemasChange;
 247     }
 248
 249     private synchronized void handleSalInitializationSuccess(final MountPointContext result,
 250                                         final NetconfSessionPreferences remoteSessionCapabilities,
 251                                         final DOMRpcService deviceRpc,
 252                                         final RemoteDeviceCommunicator<NetconfMessage> listener) {
 253         //NetconfDevice.SchemaSetup can complete after NetconfDeviceCommunicator was closed. In that case do nothing,
 254         //since salFacade.onDeviceDisconnected was already called.
 255         if (connected) {
 256             this.messageTransformer = new NetconfMessageTransformer(result, true,
 257                 resolveBaseSchema(remoteSessionCapabilities.isNotificationsSupported()));
 258
 259             // salFacade.onDeviceConnected has to be called before the notification handler is initialized
 260             this.salFacade.onDeviceConnected(result, remoteSessionCapabilities, deviceRpc,
 261                     this.deviceActionFactory == null ? null : this.deviceActionFactory.createDeviceAction(
 262                             this.messageTransformer, listener, result.getEffectiveModelContext()));
 263             this.notificationHandler.onRemoteSchemaUp(this.messageTransformer);
 264
 265             LOG.info("{}: Netconf connector initialized successfully", id);
 266         } else {
 267             LOG.warn("{}: Device communicator was closed before schema setup finished.", id);
 268         }
 269     }
 270
 271     private void handleSalInitializationFailure(final Throwable throwable,
 272                                                 final RemoteDeviceCommunicator<NetconfMessage> listener) {
 273         LOG.error("{}: Initialization in sal failed, disconnecting from device", id, throwable);
 274         listener.close();
 275         onRemoteSessionDown();
 276         resetMessageTransformer();
 277     }
 278
 279     /**
 280      * Set the transformer to null as is in initial state.
 281      */
 282     private void resetMessageTransformer() {
 283         updateTransformer(null);
 284     }
 285
 286     private synchronized void updateTransformer(final MessageTransformer<NetconfMessage> transformer) {
 287         messageTransformer = transformer;
 288     }
 289
 290     private synchronized void setConnected(final boolean connected) {
 291         this.connected = connected;
 292     }
 293
 294     private ListenableFuture<EffectiveModelContext> assembleSchemaContext(final DeviceSources deviceSources,
 295             final NetconfSessionPreferences remoteSessionCapabilities) {
 296         LOG.debug("{}: Resolved device sources to {}", id, deviceSources);
 297         final SchemaSourceProvider<YangTextSchemaSource> yangProvider = deviceSources.getSourceProvider();
 298         for (final SourceIdentifier sourceId : deviceSources.getProvidedSources()) {
 299             sourceRegistrations.add(schemaRegistry.registerSchemaSource(yangProvider,
 300                 PotentialSchemaSource.create(sourceId, YangTextSchemaSource.class,
 301                     PotentialSchemaSource.Costs.REMOTE_IO.getValue())));
 302         }
 303
 304         return new SchemaSetup(deviceSources, remoteSessionCapabilities).startResolution();
 305     }
 306
 307     private ListenableFuture<MountPointContext> createMountPointContext(final EffectiveModelContext schemaContext,
 308             final BaseSchema baseSchema, final NetconfDeviceCommunicator listener) {
 309         final MountPointContext emptyContext = new EmptyMountPointContext(schemaContext);
 310         if (schemaContext.findModule(SchemaMountConstants.RFC8528_MODULE).isEmpty()) {
 311             return Futures.immediateFuture(emptyContext);
 312         }
 313
 314         // Create a temporary RPC invoker and acquire the mount point tree
 315         LOG.debug("{}: Acquiring available mount points", id);
 316         final NetconfDeviceRpc deviceRpc = new NetconfDeviceRpc(schemaContext, listener,
 317             new NetconfMessageTransformer(emptyContext, false, baseSchema));
 318
 319         return Futures.transform(deviceRpc.invokeRpc(NetconfMessageTransformUtil.NETCONF_GET_QNAME,
 320             Builders.containerBuilder().withNodeIdentifier(NETCONF_GET_NODEID)
 321                 .withChild(NetconfMessageTransformUtil.toFilterStructure(RFC8528_SCHEMA_MOUNTS, schemaContext))
 322                 .build()), rpcResult -> processSchemaMounts(rpcResult, emptyContext), MoreExecutors.directExecutor());
 323     }
 324
 325     private MountPointContext processSchemaMounts(final DOMRpcResult rpcResult, final MountPointContext emptyContext) {
 326         final Collection<? extends RpcError> errors = rpcResult.getErrors();
 327         if (!errors.isEmpty()) {
 328             LOG.warn("{}: Schema-mounts acquisition resulted in errors {}", id, errors);
 329         }
 330         final NormalizedNode schemaMounts = rpcResult.getResult();
 331         if (schemaMounts == null) {
 332             LOG.debug("{}: device does not define any schema mounts", id);
 333             return emptyContext;
 334         }
 335         if (!(schemaMounts instanceof ContainerNode)) {
 336             LOG.warn("{}: ignoring non-container schema mounts {}", id, schemaMounts);
 337             return emptyContext;
 338         }
 339
 340         return DeviceMountPointContext.create(emptyContext, (ContainerNode) schemaMounts);
 341     }
 342
 343     @Override
 344     public void onRemoteSessionDown() {
 345         setConnected(false);
 346         notificationHandler.onRemoteSchemaDown();
 347
 348         salFacade.onDeviceDisconnected();
 349         sourceRegistrations.forEach(SchemaSourceRegistration::close);
 350         sourceRegistrations.clear();
 351         resetMessageTransformer();
 352     }
 353
 354     @Override
 355     public void onRemoteSessionFailed(final Throwable throwable) {
 356         setConnected(false);
 357         salFacade.onDeviceFailed(throwable);
 358     }
 359
 360     @Override
 361     public void onNotification(final NetconfMessage notification) {
 362         notificationHandler.handleNotification(notification);
 363     }
 364
 365     private BaseSchema resolveBaseSchema(final boolean notificationSupport) {
 366         return notificationSupport ? baseSchemas.getBaseSchemaWithNotifications() : baseSchemas.getBaseSchema();
 367     }
 368
 369     protected NetconfDeviceRpc getDeviceSpecificRpc(final MountPointContext result,
 370             final RemoteDeviceCommunicator<NetconfMessage> listener, final BaseSchema schema) {
 371         return new NetconfDeviceRpc(result.getEffectiveModelContext(), listener,
 372             new NetconfMessageTransformer(result, true, schema));
 373     }
 374
 375     /**
 376      * Just a transfer object containing schema related dependencies. Injected in constructor.
 377      */
 378     public static class SchemaResourcesDTO {
 379         private final SchemaSourceRegistry schemaRegistry;
 380         private final SchemaRepository schemaRepository;
 381         private final EffectiveModelContextFactory schemaContextFactory;
 382         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 383
 384         public SchemaResourcesDTO(final SchemaSourceRegistry schemaRegistry,
 385                                   final SchemaRepository schemaRepository,
 386                                   final EffectiveModelContextFactory schemaContextFactory,
 387                                   final NetconfDeviceSchemasResolver deviceSchemasResolver) {
 388             this.schemaRegistry = requireNonNull(schemaRegistry);
 389             this.schemaRepository = requireNonNull(schemaRepository);
 390             this.schemaContextFactory = requireNonNull(schemaContextFactory);
 391             this.stateSchemasResolver = requireNonNull(deviceSchemasResolver);
 392         }
 393
 394         public SchemaSourceRegistry getSchemaRegistry() {
 395             return schemaRegistry;
 396         }
 397
 398         public SchemaRepository getSchemaRepository() {
 399             return schemaRepository;
 400         }
 401
 402         public EffectiveModelContextFactory getSchemaContextFactory() {
 403             return schemaContextFactory;
 404         }
 405
 406         public NetconfDeviceSchemasResolver getStateSchemasResolver() {
 407             return stateSchemasResolver;
 408         }
 409     }
 410
 411     /**
 412      * A dedicated exception to indicate when we fail to setup a SchemaContext.
 413      *
 414      * @author Robert Varga
 415      */
 416     private static final class EmptySchemaContextException extends Exception {
 417         private static final long serialVersionUID = 1L;
 418
 419         EmptySchemaContextException(final String message) {
 420             super(message);
 421         }
 422     }
 423
 424     /**
 425      * Schema builder that tries to build schema context from provided sources or biggest subset of it.
 426      */
 427     private final class SchemaSetup implements FutureCallback<EffectiveModelContext> {
 428         private final SettableFuture<EffectiveModelContext> resultFuture = SettableFuture.create();
 429
 430         private final DeviceSources deviceSources;
 431         private final NetconfSessionPreferences remoteSessionCapabilities;
 432         private final NetconfDeviceCapabilities capabilities;
 433
 434         private Collection<SourceIdentifier> requiredSources;
 435
 436         SchemaSetup(final DeviceSources deviceSources, final NetconfSessionPreferences remoteSessionCapabilities) {
 437             this.deviceSources = deviceSources;
 438             this.remoteSessionCapabilities = remoteSessionCapabilities;
 439             this.capabilities = remoteSessionCapabilities.getNetconfDeviceCapabilities();
 440
 441             // If device supports notifications and does not contain necessary modules, add them automatically
 442             if (remoteSessionCapabilities.containsNonModuleCapability(
 443                     XmlNetconfConstants.URN_IETF_PARAMS_NETCONF_CAPABILITY_NOTIFICATION_1_0)) {
 444                 deviceSources.getRequiredSourcesQName().addAll(
 445                         Arrays.asList(
 446                                 org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714
 447                                         .$YangModuleInfoImpl.getInstance().getName(),
 448                                 org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715
 449                                         .$YangModuleInfoImpl.getInstance().getName()
 450                         )
 451                 );
 452             }
 453
 454             requiredSources = deviceSources.getRequiredSources();
 455             final Collection<SourceIdentifier> missingSources = filterMissingSources(requiredSources);
 456
 457             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(missingSources),
 458                     UnavailableCapability.FailureReason.MissingSource);
 459             requiredSources.removeAll(missingSources);
 460         }
 461
 462         ListenableFuture<EffectiveModelContext> startResolution() {
 463             trySetupSchema();
 464             return resultFuture;
 465         }
 466
 467         @Override
 468         public void onSuccess(final EffectiveModelContext result) {
 469             LOG.debug("{}: Schema context built successfully from {}", id, requiredSources);
 470
 471             final Collection<QName> filteredQNames = Sets.difference(deviceSources.getRequiredSourcesQName(),
 472                     capabilities.getUnresolvedCapabilites().keySet());
 473             capabilities.addCapabilities(filteredQNames.stream().map(entry -> new AvailableCapabilityBuilder()
 474                     .setCapability(entry.toString()).setCapabilityOrigin(
 475                             remoteSessionCapabilities.getModuleBasedCapsOrigin().get(entry)).build())
 476                     .collect(Collectors.toList()));
 477
 478             capabilities.addNonModuleBasedCapabilities(remoteSessionCapabilities
 479                     .getNonModuleCaps().stream().map(entry -> new AvailableCapabilityBuilder()
 480                             .setCapability(entry).setCapabilityOrigin(
 481                                     remoteSessionCapabilities.getNonModuleBasedCapsOrigin().get(entry)).build())
 482                     .collect(Collectors.toList()));
 483
 484             resultFuture.set(result);
 485         }
 486
 487         @Override
 488         public void onFailure(final Throwable cause) {
 489             // schemaBuilderFuture.checkedGet() throws only SchemaResolutionException
 490             // that might be wrapping a MissingSchemaSourceException so we need to look
 491             // at the cause of the exception to make sure we don't misinterpret it.
 492             if (cause instanceof MissingSchemaSourceException) {
 493                 requiredSources = handleMissingSchemaSourceException((MissingSchemaSourceException) cause);
 494             } else if (cause instanceof SchemaResolutionException) {
 495                 requiredSources = handleSchemaResolutionException((SchemaResolutionException) cause);
 496             } else {
 497                 LOG.debug("Unhandled failure", cause);
 498                 resultFuture.setException(cause);
 499                 // No more trying...
 500                 return;
 501             }
 502
 503             trySetupSchema();
 504         }
 505
 506         private void trySetupSchema() {
 507             if (!requiredSources.isEmpty()) {
 508                 // Initiate async resolution, drive it back based on the result
 509                 LOG.trace("{}: Trying to build schema context from {}", id, requiredSources);
 510                 Futures.addCallback(schemaContextFactory.createEffectiveModelContext(requiredSources), this,
 511                     MoreExecutors.directExecutor());
 512             } else {
 513                 LOG.debug("{}: no more sources for schema context", id);
 514                 resultFuture.setException(new EmptySchemaContextException(id + ": No more sources for schema context"));
 515             }
 516         }
 517
 518         private Collection<SourceIdentifier> filterMissingSources(final Collection<SourceIdentifier> origSources) {
 519             return origSources.parallelStream().filter(sourceIdentifier -> {
 520                 try {
 521                     schemaRepository.getSchemaSource(sourceIdentifier, YangTextSchemaSource.class).get();
 522                     return false;
 523                 } catch (InterruptedException | ExecutionException e) {
 524                     return true;
 525                 }
 526             }).collect(Collectors.toList());
 527         }
 528
 529         private Collection<SourceIdentifier> handleMissingSchemaSourceException(
 530                 final MissingSchemaSourceException exception) {
 531             // In case source missing, try without it
 532             final SourceIdentifier missingSource = exception.getSourceId();
 533             LOG.warn("{}: Unable to build schema context, missing source {}, will reattempt without it",
 534                 id, missingSource);
 535             LOG.debug("{}: Unable to build schema context, missing source {}, will reattempt without it",
 536                 id, missingSource, exception);
 537             final Collection<QName> qNameOfMissingSource =
 538                 getQNameFromSourceIdentifiers(Sets.newHashSet(missingSource));
 539             if (!qNameOfMissingSource.isEmpty()) {
 540                 capabilities.addUnresolvedCapabilities(
 541                         qNameOfMissingSource, UnavailableCapability.FailureReason.MissingSource);
 542             }
 543             return stripUnavailableSource(missingSource);
 544         }
 545
 546         private Collection<SourceIdentifier> handleSchemaResolutionException(
 547                 final SchemaResolutionException resolutionException) {
 548             // In case resolution error, try only with resolved sources
 549             // There are two options why schema resolution exception occurred : unsatisfied imports or flawed model
 550             // FIXME Do we really have assurance that these two cases cannot happen at once?
 551             if (resolutionException.getFailedSource() != null) {
 552                 // flawed model - exclude it
 553                 final SourceIdentifier failedSourceId = resolutionException.getFailedSource();
 554                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 555                     id, failedSourceId);
 556                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 557                     id, failedSourceId, resolutionException);
 558                 capabilities.addUnresolvedCapabilities(
 559                         getQNameFromSourceIdentifiers(Collections.singleton(failedSourceId)),
 560                         UnavailableCapability.FailureReason.UnableToResolve);
 561                 return stripUnavailableSource(resolutionException.getFailedSource());
 562             }
 563             // unsatisfied imports
 564             final Set<SourceIdentifier> unresolvedSources = resolutionException.getUnsatisfiedImports().keySet();
 565             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(unresolvedSources),
 566                 UnavailableCapability.FailureReason.UnableToResolve);
 567             LOG.warn("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 568                 id, resolutionException.getUnsatisfiedImports());
 569             LOG.debug("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 570                 id, resolutionException.getUnsatisfiedImports(), resolutionException);
 571             return resolutionException.getResolvedSources();
 572         }
 573
 574         private Collection<SourceIdentifier> stripUnavailableSource(final SourceIdentifier sourceIdToRemove) {
 575             final LinkedList<SourceIdentifier> sourceIdentifiers = new LinkedList<>(requiredSources);
 576             checkState(sourceIdentifiers.remove(sourceIdToRemove),
 577                     "%s: Trying to remove %s from %s failed", id, sourceIdToRemove, requiredSources);
 578             return sourceIdentifiers;
 579         }
 580
 581         private Collection<QName> getQNameFromSourceIdentifiers(final Collection<SourceIdentifier> identifiers) {
 582             final Collection<QName> qNames = Collections2.transform(identifiers, this::getQNameFromSourceIdentifier);
 583
 584             if (qNames.isEmpty()) {
 585                 LOG.debug("{}: Unable to map any source identifiers to a capability reported by device : {}", id,
 586                         identifiers);
 587             }
 588             return Collections2.filter(qNames, Predicates.notNull());
 589         }
 590
 591         private QName getQNameFromSourceIdentifier(final SourceIdentifier identifier) {
 592             // Required sources are all required and provided merged in DeviceSourcesResolver
 593             for (final QName qname : deviceSources.getRequiredSourcesQName()) {
 594                 if (!qname.getLocalName().equals(identifier.getName())) {
 595                     continue;
 596                 }
 597
 598                 if (identifier.getRevision().equals(qname.getRevision())) {
 599                     return qname;
 600                 }
 601             }
 602             LOG.warn("Unable to map identifier to a devices reported capability: {} Available: {}",identifier,
 603                     deviceSources.getRequiredSourcesQName());
 604             // return null since we cannot find the QName,
 605             // this capability will be removed from required sources and not reported as unresolved-capability
 606             return null;
 607         }
 608     }
 609 }