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.Objects;
  32 import java.util.Optional;
  33 import java.util.Set;
  34 import java.util.concurrent.ExecutionException;
  35 import java.util.concurrent.TimeUnit;
  36 import java.util.stream.Collectors;
  37 import org.checkerframework.checker.lock.qual.GuardedBy;
  38 import org.opendaylight.mdsal.dom.api.DOMRpcResult;
  39 import org.opendaylight.mdsal.dom.api.DOMRpcService;
  40 import org.opendaylight.netconf.api.NetconfMessage;
  41 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
  42 import org.opendaylight.netconf.sal.connect.api.DeviceActionFactory;
  43 import org.opendaylight.netconf.sal.connect.api.MessageTransformer;
  44 import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemasResolver;
  45 import org.opendaylight.netconf.sal.connect.api.RemoteDevice;
  46 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceCommunicator;
  47 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceHandler;
  48 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCapabilities;
  49 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCommunicator;
  50 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfSessionPreferences;
  51 import org.opendaylight.netconf.sal.connect.netconf.sal.NetconfDeviceRpc;
  52 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.BaseNetconfSchemas;
  53 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.BaseSchema;
  54 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.NetconfMessageTransformer;
  55 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  56 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  57 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.netconf.notifications.rev120206.NetconfCapabilityChange;
  58 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.optional.rev190614.NetconfNodeAugmentedOptional;
  59 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.NetconfNode;
  60 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.available.capabilities.AvailableCapabilityBuilder;
  61 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.unavailable.capabilities.UnavailableCapability;
  62 import org.opendaylight.yangtools.rfc8528.data.api.MountPointContext;
  63 import org.opendaylight.yangtools.rfc8528.data.util.EmptyMountPointContext;
  64 import org.opendaylight.yangtools.rfc8528.model.api.SchemaMountConstants;
  65 import org.opendaylight.yangtools.yang.common.QName;
  66 import org.opendaylight.yangtools.yang.common.RpcError;
  67 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  68 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  69 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  70 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  71 import org.opendaylight.yangtools.yang.data.impl.schema.Builders;
  72 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  73 import org.opendaylight.yangtools.yang.model.repo.api.EffectiveModelContextFactory;
  74 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  75 import org.opendaylight.yangtools.yang.model.repo.api.SchemaRepository;
  76 import org.opendaylight.yangtools.yang.model.repo.api.SchemaResolutionException;
  77 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  78 import org.opendaylight.yangtools.yang.model.repo.api.YangTextSchemaSource;
  79 import org.opendaylight.yangtools.yang.model.repo.spi.PotentialSchemaSource;
  80 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceProvider;
  81 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistration;
  82 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  83 import org.slf4j.Logger;
  84 import org.slf4j.LoggerFactory;
  85
  86 /**
  87  *  This is a mediator between NetconfDeviceCommunicator and NetconfDeviceSalFacade.
  88  */
  89 public class NetconfDevice
  90         implements RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> {
  91
  92     @SuppressFBWarnings(value = "SLF4J_LOGGER_SHOULD_BE_PRIVATE",
  93             justification = "Needed for common logging of related classes")
  94     static final Logger LOG = LoggerFactory.getLogger(NetconfDevice.class);
  95
  96     private static final QName RFC8528_SCHEMA_MOUNTS_QNAME = QName.create(
  97         SchemaMountConstants.RFC8528_MODULE, "schema-mounts").intern();
  98     private static final YangInstanceIdentifier RFC8528_SCHEMA_MOUNTS = YangInstanceIdentifier.create(
  99         NodeIdentifier.create(RFC8528_SCHEMA_MOUNTS_QNAME));
 100
 101     protected final RemoteDeviceId id;
 102     protected final EffectiveModelContextFactory schemaContextFactory;
 103     protected final SchemaSourceRegistry schemaRegistry;
 104     protected final SchemaRepository schemaRepository;
 105
 106     protected final List<SchemaSourceRegistration<?>> sourceRegistrations = new ArrayList<>();
 107
 108     private final RemoteDeviceHandler<NetconfSessionPreferences> salFacade;
 109     private final ListeningExecutorService processingExecutor;
 110     private final DeviceActionFactory deviceActionFactory;
 111     private final NetconfDeviceSchemasResolver stateSchemasResolver;
 112     private final NotificationHandler notificationHandler;
 113     private final boolean reconnectOnSchemasChange;
 114     private final BaseNetconfSchemas baseSchemas;
 115     private final NetconfNode node;
 116     private final EventExecutor eventExecutor;
 117     private final NetconfNodeAugmentedOptional nodeOptional;
 118
 119     @GuardedBy("this")
 120     private boolean connected = false;
 121
 122     // Message transformer is constructed once the schemas are available
 123     private MessageTransformer<NetconfMessage> messageTransformer;
 124
 125     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final BaseNetconfSchemas baseSchemas,
 126             final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
 127             final ListeningExecutorService globalProcessingExecutor, final boolean reconnectOnSchemasChange) {
 128         this(schemaResourcesDTO, baseSchemas, id, salFacade, globalProcessingExecutor, reconnectOnSchemasChange, null,
 129             null, null, null);
 130     }
 131
 132     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final BaseNetconfSchemas baseSchemas,
 133             final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
 134             final ListeningExecutorService globalProcessingExecutor, final boolean reconnectOnSchemasChange,
 135             final DeviceActionFactory deviceActionFactory, final NetconfNode node, final EventExecutor eventExecutor,
 136             final NetconfNodeAugmentedOptional nodeOptional) {
 137         this.baseSchemas = requireNonNull(baseSchemas);
 138         this.id = id;
 139         this.reconnectOnSchemasChange = reconnectOnSchemasChange;
 140         this.deviceActionFactory = deviceActionFactory;
 141         this.node = node;
 142         this.eventExecutor = eventExecutor;
 143         this.nodeOptional = nodeOptional;
 144         schemaRegistry = schemaResourcesDTO.getSchemaRegistry();
 145         schemaRepository = schemaResourcesDTO.getSchemaRepository();
 146         schemaContextFactory = schemaResourcesDTO.getSchemaContextFactory();
 147         this.salFacade = salFacade;
 148         stateSchemasResolver = schemaResourcesDTO.getStateSchemasResolver();
 149         processingExecutor = requireNonNull(globalProcessingExecutor);
 150         notificationHandler = new NotificationHandler(salFacade, id);
 151     }
 152
 153     @Override
 154     public void onRemoteSessionUp(final NetconfSessionPreferences remoteSessionCapabilities,
 155                                   final NetconfDeviceCommunicator listener) {
 156         // SchemaContext setup has to be performed in a dedicated thread since
 157         // we are in a netty thread in this method
 158         // Yang models are being downloaded in this method and it would cause a
 159         // deadlock if we used the netty thread
 160         // http://netty.io/wiki/thread-model.html
 161         setConnected(true);
 162         LOG.debug("{}: Session to remote device established with {}", id, remoteSessionCapabilities);
 163
 164         final BaseSchema baseSchema = resolveBaseSchema(remoteSessionCapabilities.isNotificationsSupported());
 165         final NetconfDeviceRpc initRpc = new NetconfDeviceRpc(baseSchema.getEffectiveModelContext(), listener,
 166             new NetconfMessageTransformer(baseSchema.getMountPointContext(), false, baseSchema));
 167         final ListenableFuture<DeviceSources> sourceResolverFuture = processingExecutor.submit(
 168             new DeviceSourcesResolver(id, baseSchema, initRpc, remoteSessionCapabilities, stateSchemasResolver));
 169
 170         if (shouldListenOnSchemaChange(remoteSessionCapabilities)) {
 171             registerToBaseNetconfStream(initRpc, listener);
 172         }
 173
 174         // Set up the SchemaContext for the device
 175         final ListenableFuture<EffectiveModelContext> futureSchema = Futures.transformAsync(sourceResolverFuture,
 176             deviceSources -> assembleSchemaContext(deviceSources, remoteSessionCapabilities), processingExecutor);
 177
 178         // Potentially acquire mount point list and interpret it
 179         final ListenableFuture<MountPointContext> futureContext = Futures.transformAsync(futureSchema,
 180             schemaContext -> createMountPointContext(schemaContext, baseSchema, listener), processingExecutor);
 181
 182         Futures.addCallback(futureContext, new FutureCallback<MountPointContext>() {
 183             @Override
 184             public void onSuccess(final MountPointContext result) {
 185                 handleSalInitializationSuccess(result, remoteSessionCapabilities,
 186                         getDeviceSpecificRpc(result, listener, baseSchema), listener);
 187             }
 188
 189             @Override
 190             public void onFailure(final Throwable cause) {
 191                 LOG.warn("{}: Unexpected error resolving device sources", id, cause);
 192
 193                 // No more sources, fail or try to reconnect
 194                 if (cause instanceof EmptySchemaContextException) {
 195                     if (nodeOptional != null && nodeOptional.getIgnoreMissingSchemaSources().getAllowed()) {
 196                         eventExecutor.schedule(() -> {
 197                             LOG.warn("Reconnection is allowed! This can lead to unexpected errors at runtime.");
 198                             LOG.warn("{} : No more sources for schema context.", id);
 199                             LOG.info("{} : Try to remount device.", id);
 200                             onRemoteSessionDown();
 201                             salFacade.onDeviceReconnected(remoteSessionCapabilities, node);
 202                         }, nodeOptional.getIgnoreMissingSchemaSources().getReconnectTime().toJava(),
 203                             TimeUnit.MILLISECONDS);
 204                         return;
 205                     }
 206                 }
 207
 208                 handleSalInitializationFailure(cause, listener);
 209                 salFacade.onDeviceFailed(cause);
 210             }
 211         }, MoreExecutors.directExecutor());
 212     }
 213
 214     private void registerToBaseNetconfStream(final NetconfDeviceRpc deviceRpc,
 215                                              final NetconfDeviceCommunicator listener) {
 216         // TODO check whether the model describing create subscription is present in schema
 217         // Perhaps add a default schema context to support create-subscription if the model was not provided
 218         // (same as what we do for base netconf operations in transformer)
 219         final ListenableFuture<DOMRpcResult> rpcResultListenableFuture = deviceRpc.invokeRpc(
 220                 NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_QNAME,
 221                 NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_CONTENT);
 222
 223         Futures.addCallback(rpcResultListenableFuture, new FutureCallback<DOMRpcResult>() {
 224             @Override
 225             public void onSuccess(final DOMRpcResult domRpcResult) {
 226                 notificationHandler.addNotificationFilter(notification -> {
 227                     if (NetconfCapabilityChange.QNAME.equals(notification.getBody().getIdentifier().getNodeType())) {
 228                         LOG.info("{}: Schemas change detected, reconnecting", id);
 229                         // Only disconnect is enough,
 230                         // the reconnecting nature of the connector will take care of reconnecting
 231                         listener.disconnect();
 232                         return Optional.empty();
 233                     }
 234                     return Optional.of(notification);
 235                 });
 236             }
 237
 238             @Override
 239             public void onFailure(final Throwable throwable) {
 240                 LOG.warn("Unable to subscribe to base notification stream. Schemas will not be reloaded on the fly",
 241                         throwable);
 242             }
 243         }, MoreExecutors.directExecutor());
 244     }
 245
 246     private boolean shouldListenOnSchemaChange(final NetconfSessionPreferences remoteSessionCapabilities) {
 247         return remoteSessionCapabilities.isNotificationsSupported() && reconnectOnSchemasChange;
 248     }
 249
 250     private synchronized void handleSalInitializationSuccess(final MountPointContext result,
 251                                         final NetconfSessionPreferences remoteSessionCapabilities,
 252                                         final DOMRpcService deviceRpc,
 253                                         final RemoteDeviceCommunicator<NetconfMessage> listener) {
 254         //NetconfDevice.SchemaSetup can complete after NetconfDeviceCommunicator was closed. In that case do nothing,
 255         //since salFacade.onDeviceDisconnected was already called.
 256         if (connected) {
 257             messageTransformer = new NetconfMessageTransformer(result, true,
 258                 resolveBaseSchema(remoteSessionCapabilities.isNotificationsSupported()));
 259
 260             // salFacade.onDeviceConnected has to be called before the notification handler is initialized
 261             salFacade.onDeviceConnected(result, remoteSessionCapabilities, deviceRpc,
 262                     deviceActionFactory == null ? null : deviceActionFactory.createDeviceAction(
 263                             messageTransformer, listener, result.getEffectiveModelContext()));
 264             notificationHandler.onRemoteSchemaUp(messageTransformer);
 265
 266             LOG.info("{}: Netconf connector initialized successfully", id);
 267         } else {
 268             LOG.warn("{}: Device communicator was closed before schema setup finished.", id);
 269         }
 270     }
 271
 272     private void handleSalInitializationFailure(final Throwable throwable,
 273                                                 final RemoteDeviceCommunicator<NetconfMessage> listener) {
 274         LOG.error("{}: Initialization in sal failed, disconnecting from device", id, throwable);
 275         listener.close();
 276         onRemoteSessionDown();
 277         resetMessageTransformer();
 278     }
 279
 280     /**
 281      * Set the transformer to null as is in initial state.
 282      */
 283     private void resetMessageTransformer() {
 284         updateTransformer(null);
 285     }
 286
 287     private synchronized void updateTransformer(final MessageTransformer<NetconfMessage> transformer) {
 288         messageTransformer = transformer;
 289     }
 290
 291     private synchronized void setConnected(final boolean connected) {
 292         this.connected = connected;
 293     }
 294
 295     private ListenableFuture<EffectiveModelContext> assembleSchemaContext(final DeviceSources deviceSources,
 296             final NetconfSessionPreferences remoteSessionCapabilities) {
 297         LOG.debug("{}: Resolved device sources to {}", id, deviceSources);
 298         final SchemaSourceProvider<YangTextSchemaSource> yangProvider = deviceSources.getSourceProvider();
 299         for (final SourceIdentifier sourceId : deviceSources.getProvidedSources()) {
 300             sourceRegistrations.add(schemaRegistry.registerSchemaSource(yangProvider,
 301                 PotentialSchemaSource.create(sourceId, YangTextSchemaSource.class,
 302                     PotentialSchemaSource.Costs.REMOTE_IO.getValue())));
 303         }
 304
 305         return new SchemaSetup(deviceSources, remoteSessionCapabilities).startResolution();
 306     }
 307
 308     private ListenableFuture<MountPointContext> createMountPointContext(final EffectiveModelContext schemaContext,
 309             final BaseSchema baseSchema, final NetconfDeviceCommunicator listener) {
 310         final MountPointContext emptyContext = new EmptyMountPointContext(schemaContext);
 311         if (schemaContext.findModule(SchemaMountConstants.RFC8528_MODULE).isEmpty()) {
 312             return Futures.immediateFuture(emptyContext);
 313         }
 314
 315         // Create a temporary RPC invoker and acquire the mount point tree
 316         LOG.debug("{}: Acquiring available mount points", id);
 317         final NetconfDeviceRpc deviceRpc = new NetconfDeviceRpc(schemaContext, listener,
 318             new NetconfMessageTransformer(emptyContext, false, baseSchema));
 319
 320         return Futures.transform(deviceRpc.invokeRpc(NetconfMessageTransformUtil.NETCONF_GET_QNAME,
 321             Builders.containerBuilder().withNodeIdentifier(NETCONF_GET_NODEID)
 322                 .withChild(NetconfMessageTransformUtil.toFilterStructure(RFC8528_SCHEMA_MOUNTS, schemaContext))
 323                 .build()), rpcResult -> processSchemaMounts(rpcResult, emptyContext), MoreExecutors.directExecutor());
 324     }
 325
 326     private MountPointContext processSchemaMounts(final DOMRpcResult rpcResult, final MountPointContext emptyContext) {
 327         final Collection<? extends RpcError> errors = rpcResult.getErrors();
 328         if (!errors.isEmpty()) {
 329             LOG.warn("{}: Schema-mounts acquisition resulted in errors {}", id, errors);
 330         }
 331         final NormalizedNode schemaMounts = rpcResult.getResult();
 332         if (schemaMounts == null) {
 333             LOG.debug("{}: device does not define any schema mounts", id);
 334             return emptyContext;
 335         }
 336         if (!(schemaMounts instanceof ContainerNode)) {
 337             LOG.warn("{}: ignoring non-container schema mounts {}", id, schemaMounts);
 338             return emptyContext;
 339         }
 340
 341         return DeviceMountPointContext.create(emptyContext, (ContainerNode) schemaMounts);
 342     }
 343
 344     @Override
 345     public void onRemoteSessionDown() {
 346         setConnected(false);
 347         notificationHandler.onRemoteSchemaDown();
 348
 349         salFacade.onDeviceDisconnected();
 350         sourceRegistrations.forEach(SchemaSourceRegistration::close);
 351         sourceRegistrations.clear();
 352         resetMessageTransformer();
 353     }
 354
 355     @Override
 356     public void onRemoteSessionFailed(final Throwable throwable) {
 357         setConnected(false);
 358         salFacade.onDeviceFailed(throwable);
 359     }
 360
 361     @Override
 362     public void onNotification(final NetconfMessage notification) {
 363         notificationHandler.handleNotification(notification);
 364     }
 365
 366     private BaseSchema resolveBaseSchema(final boolean notificationSupport) {
 367         return notificationSupport ? baseSchemas.getBaseSchemaWithNotifications() : baseSchemas.getBaseSchema();
 368     }
 369
 370     protected NetconfDeviceRpc getDeviceSpecificRpc(final MountPointContext result,
 371             final RemoteDeviceCommunicator<NetconfMessage> listener, final BaseSchema schema) {
 372         return new NetconfDeviceRpc(result.getEffectiveModelContext(), listener,
 373             new NetconfMessageTransformer(result, true, schema));
 374     }
 375
 376     /**
 377      * Just a transfer object containing schema related dependencies. Injected in constructor.
 378      */
 379     public static class SchemaResourcesDTO {
 380         private final SchemaSourceRegistry schemaRegistry;
 381         private final SchemaRepository schemaRepository;
 382         private final EffectiveModelContextFactory schemaContextFactory;
 383         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 384
 385         public SchemaResourcesDTO(final SchemaSourceRegistry schemaRegistry,
 386                                   final SchemaRepository schemaRepository,
 387                                   final EffectiveModelContextFactory schemaContextFactory,
 388                                   final NetconfDeviceSchemasResolver deviceSchemasResolver) {
 389             this.schemaRegistry = requireNonNull(schemaRegistry);
 390             this.schemaRepository = requireNonNull(schemaRepository);
 391             this.schemaContextFactory = requireNonNull(schemaContextFactory);
 392             stateSchemasResolver = requireNonNull(deviceSchemasResolver);
 393         }
 394
 395         public SchemaSourceRegistry getSchemaRegistry() {
 396             return schemaRegistry;
 397         }
 398
 399         public SchemaRepository getSchemaRepository() {
 400             return schemaRepository;
 401         }
 402
 403         public EffectiveModelContextFactory getSchemaContextFactory() {
 404             return schemaContextFactory;
 405         }
 406
 407         public NetconfDeviceSchemasResolver getStateSchemasResolver() {
 408             return stateSchemasResolver;
 409         }
 410     }
 411
 412     /**
 413      * A dedicated exception to indicate when we fail to setup a SchemaContext.
 414      *
 415      * @author Robert Varga
 416      */
 417     private static final class EmptySchemaContextException extends Exception {
 418         private static final long serialVersionUID = 1L;
 419
 420         EmptySchemaContextException(final String message) {
 421             super(message);
 422         }
 423     }
 424
 425     /**
 426      * Schema builder that tries to build schema context from provided sources or biggest subset of it.
 427      */
 428     private final class SchemaSetup implements FutureCallback<EffectiveModelContext> {
 429         private final SettableFuture<EffectiveModelContext> resultFuture = SettableFuture.create();
 430
 431         private final DeviceSources deviceSources;
 432         private final NetconfSessionPreferences remoteSessionCapabilities;
 433         private final NetconfDeviceCapabilities capabilities;
 434
 435         private Collection<SourceIdentifier> requiredSources;
 436
 437         SchemaSetup(final DeviceSources deviceSources, final NetconfSessionPreferences remoteSessionCapabilities) {
 438             this.deviceSources = deviceSources;
 439             this.remoteSessionCapabilities = remoteSessionCapabilities;
 440             capabilities = remoteSessionCapabilities.getNetconfDeviceCapabilities();
 441
 442             // If device supports notifications and does not contain necessary modules, add them automatically
 443             if (remoteSessionCapabilities.containsNonModuleCapability(
 444                     XmlNetconfConstants.URN_IETF_PARAMS_NETCONF_CAPABILITY_NOTIFICATION_1_0)) {
 445                 deviceSources.getRequiredSourcesQName().addAll(
 446                         Arrays.asList(
 447                                 org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714
 448                                         .$YangModuleInfoImpl.getInstance().getName(),
 449                                 org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715
 450                                         .$YangModuleInfoImpl.getInstance().getName()
 451                         )
 452                 );
 453             }
 454
 455             requiredSources = deviceSources.getRequiredSources();
 456             final Collection<SourceIdentifier> missingSources = filterMissingSources(requiredSources);
 457
 458             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(missingSources),
 459                     UnavailableCapability.FailureReason.MissingSource);
 460             requiredSources.removeAll(missingSources);
 461         }
 462
 463         ListenableFuture<EffectiveModelContext> startResolution() {
 464             trySetupSchema();
 465             return resultFuture;
 466         }
 467
 468         @Override
 469         public void onSuccess(final EffectiveModelContext result) {
 470             LOG.debug("{}: Schema context built successfully from {}", id, requiredSources);
 471
 472             final Collection<QName> filteredQNames = Sets.difference(deviceSources.getRequiredSourcesQName(),
 473                     capabilities.getUnresolvedCapabilites().keySet());
 474             capabilities.addCapabilities(filteredQNames.stream().map(entry -> new AvailableCapabilityBuilder()
 475                     .setCapability(entry.toString()).setCapabilityOrigin(
 476                             remoteSessionCapabilities.getModuleBasedCapsOrigin().get(entry)).build())
 477                     .collect(Collectors.toList()));
 478
 479             capabilities.addNonModuleBasedCapabilities(remoteSessionCapabilities
 480                     .getNonModuleCaps().stream().map(entry -> new AvailableCapabilityBuilder()
 481                             .setCapability(entry).setCapabilityOrigin(
 482                                     remoteSessionCapabilities.getNonModuleBasedCapsOrigin().get(entry)).build())
 483                     .collect(Collectors.toList()));
 484
 485             resultFuture.set(result);
 486         }
 487
 488         @Override
 489         public void onFailure(final Throwable cause) {
 490             // schemaBuilderFuture.checkedGet() throws only SchemaResolutionException
 491             // that might be wrapping a MissingSchemaSourceException so we need to look
 492             // at the cause of the exception to make sure we don't misinterpret it.
 493             if (cause instanceof MissingSchemaSourceException) {
 494                 requiredSources = handleMissingSchemaSourceException((MissingSchemaSourceException) cause);
 495             } else if (cause instanceof SchemaResolutionException) {
 496                 requiredSources = handleSchemaResolutionException((SchemaResolutionException) cause);
 497             } else {
 498                 LOG.debug("Unhandled failure", cause);
 499                 resultFuture.setException(cause);
 500                 // No more trying...
 501                 return;
 502             }
 503
 504             trySetupSchema();
 505         }
 506
 507         private void trySetupSchema() {
 508             if (!requiredSources.isEmpty()) {
 509                 // Initiate async resolution, drive it back based on the result
 510                 LOG.trace("{}: Trying to build schema context from {}", id, requiredSources);
 511                 Futures.addCallback(schemaContextFactory.createEffectiveModelContext(requiredSources), this,
 512                     MoreExecutors.directExecutor());
 513             } else {
 514                 LOG.debug("{}: no more sources for schema context", id);
 515                 resultFuture.setException(new EmptySchemaContextException(id + ": No more sources for schema context"));
 516             }
 517         }
 518
 519         private Collection<SourceIdentifier> filterMissingSources(final Collection<SourceIdentifier> origSources) {
 520             return origSources.parallelStream().filter(sourceIdentifier -> {
 521                 try {
 522                     schemaRepository.getSchemaSource(sourceIdentifier, YangTextSchemaSource.class).get();
 523                     return false;
 524                 } catch (InterruptedException | ExecutionException e) {
 525                     return true;
 526                 }
 527             }).collect(Collectors.toList());
 528         }
 529
 530         private Collection<SourceIdentifier> handleMissingSchemaSourceException(
 531                 final MissingSchemaSourceException exception) {
 532             // In case source missing, try without it
 533             final SourceIdentifier missingSource = exception.getSourceId();
 534             LOG.warn("{}: Unable to build schema context, missing source {}, will reattempt without it",
 535                 id, missingSource);
 536             LOG.debug("{}: Unable to build schema context, missing source {}, will reattempt without it",
 537                 id, missingSource, exception);
 538             final Collection<QName> qNameOfMissingSource =
 539                 getQNameFromSourceIdentifiers(Sets.newHashSet(missingSource));
 540             if (!qNameOfMissingSource.isEmpty()) {
 541                 capabilities.addUnresolvedCapabilities(
 542                         qNameOfMissingSource, UnavailableCapability.FailureReason.MissingSource);
 543             }
 544             return stripUnavailableSource(missingSource);
 545         }
 546
 547         private Collection<SourceIdentifier> handleSchemaResolutionException(
 548                 final SchemaResolutionException resolutionException) {
 549             // In case resolution error, try only with resolved sources
 550             // There are two options why schema resolution exception occurred : unsatisfied imports or flawed model
 551             // FIXME Do we really have assurance that these two cases cannot happen at once?
 552             if (resolutionException.getFailedSource() != null) {
 553                 // flawed model - exclude it
 554                 final SourceIdentifier failedSourceId = resolutionException.getFailedSource();
 555                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 556                     id, failedSourceId);
 557                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 558                     id, failedSourceId, resolutionException);
 559                 capabilities.addUnresolvedCapabilities(
 560                         getQNameFromSourceIdentifiers(Collections.singleton(failedSourceId)),
 561                         UnavailableCapability.FailureReason.UnableToResolve);
 562                 return stripUnavailableSource(resolutionException.getFailedSource());
 563             }
 564             // unsatisfied imports
 565             final Set<SourceIdentifier> unresolvedSources = resolutionException.getUnsatisfiedImports().keySet();
 566             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(unresolvedSources),
 567                 UnavailableCapability.FailureReason.UnableToResolve);
 568             LOG.warn("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 569                 id, resolutionException.getUnsatisfiedImports());
 570             LOG.debug("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 571                 id, resolutionException.getUnsatisfiedImports(), resolutionException);
 572             return resolutionException.getResolvedSources();
 573         }
 574
 575         private Collection<SourceIdentifier> stripUnavailableSource(final SourceIdentifier sourceIdToRemove) {
 576             final LinkedList<SourceIdentifier> sourceIdentifiers = new LinkedList<>(requiredSources);
 577             checkState(sourceIdentifiers.remove(sourceIdToRemove),
 578                     "%s: Trying to remove %s from %s failed", id, sourceIdToRemove, requiredSources);
 579             return sourceIdentifiers;
 580         }
 581
 582         private Collection<QName> getQNameFromSourceIdentifiers(final Collection<SourceIdentifier> identifiers) {
 583             final Collection<QName> qNames = Collections2.transform(identifiers, this::getQNameFromSourceIdentifier);
 584
 585             if (qNames.isEmpty()) {
 586                 LOG.debug("{}: Unable to map any source identifiers to a capability reported by device : {}", id,
 587                         identifiers);
 588             }
 589             return Collections2.filter(qNames, Predicates.notNull());
 590         }
 591
 592         private QName getQNameFromSourceIdentifier(final SourceIdentifier identifier) {
 593             // Required sources are all required and provided merged in DeviceSourcesResolver
 594             for (final QName qname : deviceSources.getRequiredSourcesQName()) {
 595                 if (!qname.getLocalName().equals(identifier.name().getLocalName())) {
 596                     continue;
 597                 }
 598
 599                 if (Objects.equals(identifier.revision(), qname.getRevision().orElse(null))) {
 600                     return qname;
 601                 }
 602             }
 603             LOG.warn("Unable to map identifier to a devices reported capability: {} Available: {}",identifier,
 604                     deviceSources.getRequiredSourcesQName());
 605             // return null since we cannot find the QName,
 606             // this capability will be removed from required sources and not reported as unresolved-capability
 607             return null;
 608         }
 609     }
 610 }