Bug-6346: Allow over-ride of non-module capabilities
[netconf.git] / netconf / sal-netconf-connector / src / main / java / org / opendaylight / netconf / sal / connect / netconf / NetconfDevice.java
index bb63554d5491d356cc13a5072a8563b1fb75a2ea..d2f73ae468b37d52f7e706ce59fc0a0a94ed18b8 100644 (file)
@@ -21,17 +21,21 @@ import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.ListeningExecutorService;
 import com.google.common.util.concurrent.MoreExecutors;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutorService;
+import java.util.stream.Collectors;
 import org.opendaylight.controller.md.sal.dom.api.DOMNotification;
 import org.opendaylight.controller.md.sal.dom.api.DOMRpcException;
 import org.opendaylight.controller.md.sal.dom.api.DOMRpcResult;
 import org.opendaylight.controller.md.sal.dom.api.DOMRpcService;
 import org.opendaylight.netconf.api.NetconfMessage;
 import org.opendaylight.netconf.sal.connect.api.MessageTransformer;
+import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemas;
+import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemasResolver;
 import org.opendaylight.netconf.sal.connect.api.RemoteDevice;
 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceCommunicator;
 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceHandler;
@@ -40,22 +44,30 @@ import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCommun
 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfSessionPreferences;
 import org.opendaylight.netconf.sal.connect.netconf.sal.NetconfDeviceRpc;
 import org.opendaylight.netconf.sal.connect.netconf.schema.NetconfRemoteSchemaYangSourceProvider;
+import org.opendaylight.netconf.sal.connect.netconf.schema.YangLibrarySchemaYangSourceProvider;
+import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.BaseSchema;
 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.NetconfMessageTransformer;
 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.netconf.notifications.rev120206.NetconfCapabilityChange;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.available.capabilities.AvailableCapabilityBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.unavailable.capabilities.UnavailableCapability;
 import org.opendaylight.yangtools.yang.common.QName;
 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
+import org.opendaylight.yangtools.yang.model.repo.api.RevisionSourceIdentifier;
 import org.opendaylight.yangtools.yang.model.repo.api.SchemaContextFactory;
+import org.opendaylight.yangtools.yang.model.repo.api.SchemaRepository;
 import org.opendaylight.yangtools.yang.model.repo.api.SchemaResolutionException;
+import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceException;
 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceRepresentation;
 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
 import org.opendaylight.yangtools.yang.model.repo.api.YangTextSchemaSource;
 import org.opendaylight.yangtools.yang.model.repo.spi.PotentialSchemaSource;
+import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceProvider;
 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistration;
 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
+import org.opendaylight.yangtools.yang.parser.util.ASTSchemaSource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -66,12 +78,9 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
 
     private static final Logger LOG = LoggerFactory.getLogger(NetconfDevice.class);
 
-    public static final Function<QName, SourceIdentifier> QNAME_TO_SOURCE_ID_FUNCTION = new Function<QName, SourceIdentifier>() {
-        @Override
-        public SourceIdentifier apply(final QName input) {
-            return new SourceIdentifier(input.getLocalName(), Optional.fromNullable(input.getFormattedRevision()));
-        }
-    };
+    public static final Function<QName, SourceIdentifier> QNAME_TO_SOURCE_ID_FUNCTION =
+            input -> RevisionSourceIdentifier.create(input.getLocalName(),
+                Optional.fromNullable(input.getFormattedRevision()));
 
     protected final RemoteDeviceId id;
     private final boolean reconnectOnSchemasChange;
@@ -80,36 +89,31 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
     private final RemoteDeviceHandler<NetconfSessionPreferences> salFacade;
     private final ListeningExecutorService processingExecutor;
     protected final SchemaSourceRegistry schemaRegistry;
-    private final NetconfStateSchemas.NetconfStateSchemasResolver stateSchemasResolver;
+    protected final SchemaRepository schemaRepository;
+    private final NetconfDeviceSchemasResolver stateSchemasResolver;
     private final NotificationHandler notificationHandler;
     protected final List<SchemaSourceRegistration<? extends SchemaSourceRepresentation>> sourceRegistrations = Lists.newArrayList();
 
     // Message transformer is constructed once the schemas are available
     private MessageTransformer<NetconfMessage> messageTransformer;
 
-    public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
-                         final ExecutorService globalProcessingExecutor) {
-        this(schemaResourcesDTO, id, salFacade, globalProcessingExecutor, false);
-    }
-
     /**
      * Create rpc implementation capable of handling RPC for monitoring and notifications even before the schemas of remote device are downloaded
      */
     static NetconfDeviceRpc getRpcForInitialization(final NetconfDeviceCommunicator listener, final boolean notificationSupport) {
-        NetconfMessageTransformer.BaseSchema baseSchema = notificationSupport ?
-                NetconfMessageTransformer.BaseSchema.BASE_NETCONF_CTX_WITH_NOTIFICATIONS :
-                NetconfMessageTransformer.BaseSchema.BASE_NETCONF_CTX;
+        final BaseSchema baseSchema = notificationSupport ?
+                BaseSchema.BASE_NETCONF_CTX_WITH_NOTIFICATIONS :
+                BaseSchema.BASE_NETCONF_CTX;
 
         return new NetconfDeviceRpc(baseSchema.getSchemaContext(), listener, new NetconfMessageTransformer(baseSchema.getSchemaContext(), false, baseSchema));
     }
 
-
-    // FIXME reduce parameters
     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
                          final ExecutorService globalProcessingExecutor, final boolean reconnectOnSchemasChange) {
         this.id = id;
         this.reconnectOnSchemasChange = reconnectOnSchemasChange;
         this.schemaRegistry = schemaResourcesDTO.getSchemaRegistry();
+        this.schemaRepository = schemaResourcesDTO.getSchemaRepository();
         this.schemaContextFactory = schemaResourcesDTO.getSchemaContextFactory();
         this.salFacade = salFacade;
         this.stateSchemasResolver = schemaResourcesDTO.getStateSchemasResolver();
@@ -138,12 +142,12 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
         final FutureCallback<DeviceSources> resolvedSourceCallback = new FutureCallback<DeviceSources>() {
             @Override
             public void onSuccess(final DeviceSources result) {
-                addProvidedSourcesToSchemaRegistry(initRpc, result);
+                addProvidedSourcesToSchemaRegistry(result);
                 setUpSchema(result);
             }
 
             private void setUpSchema(final DeviceSources result) {
-                processingExecutor.submit(new RecursiveSchemaSetup(result, remoteSessionCapabilities, listener));
+                processingExecutor.submit(new SchemaSetup(result, remoteSessionCapabilities, listener));
             }
 
             @Override
@@ -159,8 +163,9 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
     private void registerToBaseNetconfStream(final NetconfDeviceRpc deviceRpc, final NetconfDeviceCommunicator listener) {
        // TODO check whether the model describing create subscription is present in schema
         // Perhaps add a default schema context to support create-subscription if the model was not provided (same as what we do for base netconf operations in transformer)
-        final CheckedFuture<DOMRpcResult, DOMRpcException> rpcResultListenableFuture =
-                deviceRpc.invokeRpc(NetconfMessageTransformUtil.toPath(NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_QNAME), NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_CONTENT);
+        final CheckedFuture<DOMRpcResult, DOMRpcException> rpcResultListenableFuture = deviceRpc.invokeRpc(
+            NetconfMessageTransformUtil.toPath(NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_QNAME),
+            NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_CONTENT);
 
         final NotificationHandler.NotificationFilter filter = new NotificationHandler.NotificationFilter() {
             @Override
@@ -196,11 +201,11 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
         return remoteSessionCapabilities.isNotificationsSupported() && reconnectOnSchemasChange;
     }
 
-    protected void handleSalInitializationSuccess(final SchemaContext result, final NetconfSessionPreferences remoteSessionCapabilities, final DOMRpcService deviceRpc) {
-        NetconfMessageTransformer.BaseSchema baseSchema =
+    void handleSalInitializationSuccess(final SchemaContext result, final NetconfSessionPreferences remoteSessionCapabilities, final DOMRpcService deviceRpc) {
+        final BaseSchema baseSchema =
                 remoteSessionCapabilities.isNotificationsSupported() ?
-                NetconfMessageTransformer.BaseSchema.BASE_NETCONF_CTX_WITH_NOTIFICATIONS :
-                NetconfMessageTransformer.BaseSchema.BASE_NETCONF_CTX;
+                BaseSchema.BASE_NETCONF_CTX_WITH_NOTIFICATIONS :
+                BaseSchema.BASE_NETCONF_CTX;
         messageTransformer = new NetconfMessageTransformer(result, true, baseSchema);
 
         updateTransformer(messageTransformer);
@@ -211,7 +216,7 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
         LOG.info("{}: Netconf connector initialized successfully", id);
     }
 
-    protected void handleSalInitializationFailure(final Throwable t, final RemoteDeviceCommunicator<NetconfMessage> listener) {
+    void handleSalInitializationFailure(final Throwable t, final RemoteDeviceCommunicator<NetconfMessage> listener) {
         LOG.error("{}: Initialization in sal failed, disconnecting from device", id, t);
         listener.close();
         onRemoteSessionDown();
@@ -229,8 +234,8 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
         messageTransformer = transformer;
     }
 
-    private void addProvidedSourcesToSchemaRegistry(final NetconfDeviceRpc deviceRpc, final DeviceSources deviceSources) {
-        final NetconfRemoteSchemaYangSourceProvider yangProvider = new NetconfRemoteSchemaYangSourceProvider(id, deviceRpc);
+    private void addProvidedSourcesToSchemaRegistry(final DeviceSources deviceSources) {
+        final SchemaSourceProvider<YangTextSchemaSource> yangProvider = deviceSources.getSourceProvider();
         for (final SourceIdentifier sourceId : deviceSources.getProvidedSources()) {
             sourceRegistrations.add(schemaRegistry.registerSchemaSource(yangProvider,
                     PotentialSchemaSource.create(sourceId, YangTextSchemaSource.class, PotentialSchemaSource.Costs.REMOTE_IO.getValue())));
@@ -263,24 +268,33 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
      */
     public static class SchemaResourcesDTO {
         private final SchemaSourceRegistry schemaRegistry;
+        private final SchemaRepository schemaRepository;
         private final SchemaContextFactory schemaContextFactory;
-        private final NetconfStateSchemas.NetconfStateSchemasResolver stateSchemasResolver;
+        private final NetconfDeviceSchemasResolver stateSchemasResolver;
 
-        public SchemaResourcesDTO(final SchemaSourceRegistry schemaRegistry, final SchemaContextFactory schemaContextFactory, final NetconfStateSchemas.NetconfStateSchemasResolver stateSchemasResolver) {
+        public SchemaResourcesDTO(final SchemaSourceRegistry schemaRegistry,
+                                  final SchemaRepository schemaRepository,
+                                  final SchemaContextFactory schemaContextFactory,
+                                  final NetconfDeviceSchemasResolver deviceSchemasResolver) {
             this.schemaRegistry = Preconditions.checkNotNull(schemaRegistry);
+            this.schemaRepository = Preconditions.checkNotNull(schemaRepository);
             this.schemaContextFactory = Preconditions.checkNotNull(schemaContextFactory);
-            this.stateSchemasResolver = Preconditions.checkNotNull(stateSchemasResolver);
+            this.stateSchemasResolver = Preconditions.checkNotNull(deviceSchemasResolver);
         }
 
         public SchemaSourceRegistry getSchemaRegistry() {
             return schemaRegistry;
         }
 
+        public SchemaRepository getSchemaRepository() {
+            return schemaRepository;
+        }
+
         public SchemaContextFactory getSchemaContextFactory() {
             return schemaContextFactory;
         }
 
-        public NetconfStateSchemas.NetconfStateSchemasResolver getStateSchemasResolver() {
+        public NetconfDeviceSchemasResolver getStateSchemasResolver() {
             return stateSchemasResolver;
         }
     }
@@ -293,23 +307,23 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
         private final NetconfDeviceRpc deviceRpc;
         private final NetconfSessionPreferences remoteSessionCapabilities;
         private final RemoteDeviceId id;
-        private final NetconfStateSchemas.NetconfStateSchemasResolver stateSchemasResolver;
+        private final NetconfDeviceSchemasResolver stateSchemasResolver;
 
         DeviceSourcesResolver(final NetconfDeviceRpc deviceRpc, final NetconfSessionPreferences remoteSessionCapabilities,
-                                     final RemoteDeviceId id, final NetconfStateSchemas.NetconfStateSchemasResolver stateSchemasResolver) {
+                                     final RemoteDeviceId id, final NetconfDeviceSchemasResolver stateSchemasResolver) {
             this.deviceRpc = deviceRpc;
             this.remoteSessionCapabilities = remoteSessionCapabilities;
             this.id = id;
             this.stateSchemasResolver = stateSchemasResolver;
         }
 
-        public DeviceSourcesResolver(final NetconfSessionPreferences remoteSessionCapabilities, final RemoteDeviceId id, final NetconfStateSchemas.NetconfStateSchemasResolver stateSchemasResolver, final NetconfDeviceRpc rpcForMonitoring) {
+        public DeviceSourcesResolver(final NetconfSessionPreferences remoteSessionCapabilities, final RemoteDeviceId id, final NetconfDeviceSchemasResolver stateSchemasResolver, final NetconfDeviceRpc rpcForMonitoring) {
             this(rpcForMonitoring, remoteSessionCapabilities, id, stateSchemasResolver);
         }
 
         @Override
         public DeviceSources call() throws Exception {
-            final NetconfStateSchemas availableSchemas = stateSchemasResolver.resolve(deviceRpc, remoteSessionCapabilities, id);
+            final NetconfDeviceSchemas availableSchemas = stateSchemasResolver.resolve(deviceRpc, remoteSessionCapabilities, id);
             LOG.debug("{}: Schemas exposed by ietf-netconf-monitoring: {}", id, availableSchemas.getAvailableYangSchemasQNames());
 
             final Set<QName> requiredSources = Sets.newHashSet(remoteSessionCapabilities.getModuleBasedCaps());
@@ -335,7 +349,15 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
                 requiredSources.addAll(providedSourcesNotRequired);
             }
 
-            return new DeviceSources(requiredSources, providedSources);
+            final SchemaSourceProvider<YangTextSchemaSource> sourceProvider;
+            if(availableSchemas instanceof LibraryModulesSchemas) {
+                sourceProvider = new YangLibrarySchemaYangSourceProvider(id,
+                        ((LibraryModulesSchemas) availableSchemas).getAvailableModels());
+            } else {
+                sourceProvider = new NetconfRemoteSchemaYangSourceProvider(id, deviceRpc);
+            }
+
+            return new DeviceSources(requiredSources, providedSources, sourceProvider);
         }
     }
 
@@ -345,10 +367,13 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
     private static final class DeviceSources {
         private final Set<QName> requiredSources;
         private final Set<QName> providedSources;
+        private final SchemaSourceProvider<YangTextSchemaSource> sourceProvider;
 
-        public DeviceSources(final Set<QName> requiredSources, final Set<QName> providedSources) {
+        public DeviceSources(final Set<QName> requiredSources, final Set<QName> providedSources,
+                             final SchemaSourceProvider<YangTextSchemaSource> sourceProvider) {
             this.requiredSources = requiredSources;
             this.providedSources = providedSources;
+            this.sourceProvider = sourceProvider;
         }
 
         public Set<QName> getRequiredSourcesQName() {
@@ -367,18 +392,21 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
             return Collections2.transform(providedSources, QNAME_TO_SOURCE_ID_FUNCTION);
         }
 
+        public SchemaSourceProvider<YangTextSchemaSource> getSourceProvider() {
+            return sourceProvider;
+        }
     }
 
     /**
      * Schema builder that tries to build schema context from provided sources or biggest subset of it.
      */
-    private final class RecursiveSchemaSetup implements Runnable {
+    private final class SchemaSetup implements Runnable {
         private final DeviceSources deviceSources;
         private final NetconfSessionPreferences remoteSessionCapabilities;
         private final RemoteDeviceCommunicator<NetconfMessage> listener;
         private final NetconfDeviceCapabilities capabilities;
 
-        public RecursiveSchemaSetup(final DeviceSources deviceSources, final NetconfSessionPreferences remoteSessionCapabilities, final RemoteDeviceCommunicator<NetconfMessage> listener) {
+        public SchemaSetup(final DeviceSources deviceSources, final NetconfSessionPreferences remoteSessionCapabilities, final RemoteDeviceCommunicator<NetconfMessage> listener) {
             this.deviceSources = deviceSources;
             this.remoteSessionCapabilities = remoteSessionCapabilities;
             this.listener = listener;
@@ -387,74 +415,114 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
 
         @Override
         public void run() {
-            setUpSchema(deviceSources.getRequiredSources());
-        }
 
-        /**
-         * Recursively build schema context, in case of success or final failure notify device
-         */
-        // FIXME reimplement without recursion
-        private void setUpSchema(final Collection<SourceIdentifier> requiredSources) {
-            LOG.trace("{}: Trying to build schema context from {}", id, requiredSources);
-
-            // If no more sources, fail
-            if(requiredSources.isEmpty()) {
-                final IllegalStateException cause = new IllegalStateException(id + ": No more sources for schema context");
-                handleSalInitializationFailure(cause, listener);
-                salFacade.onDeviceFailed(cause);
-                return;
-            }
+            final Collection<SourceIdentifier> requiredSources = deviceSources.getRequiredSources();
+            final Collection<SourceIdentifier> missingSources = filterMissingSources(requiredSources);
 
-            final CheckedFuture<SchemaContext, SchemaResolutionException> schemaBuilderFuture = schemaContextFactory.createSchemaContext(requiredSources);
+            capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(missingSources),
+                    UnavailableCapability.FailureReason.MissingSource);
 
-            final FutureCallback<SchemaContext> RecursiveSchemaBuilderCallback = new FutureCallback<SchemaContext>() {
+            requiredSources.removeAll(missingSources);
+            setUpSchema(requiredSources);
+        }
+
+        private Collection<SourceIdentifier> filterMissingSources(final Collection<SourceIdentifier> requiredSources) {
+
+            return requiredSources.parallelStream().filter(sourceIdentifier -> {
+                    boolean remove = false;
+                    try {
+                        schemaRepository.getSchemaSource(sourceIdentifier, ASTSchemaSource.class).checkedGet();
+                    } catch (SchemaSourceException e) {
+                        remove = true;
+                    }
+                    return remove;
+                }).collect(Collectors.toList());
+        }
 
-                @Override
-                public void onSuccess(final SchemaContext result) {
+        /**
+         * Build schema context, in case of success or final failure notify device
+         */
+        private void setUpSchema(Collection<SourceIdentifier> requiredSources) {
+            while (!requiredSources.isEmpty()) {
+                LOG.trace("{}: Trying to build schema context from {}", id, requiredSources);
+                try {
+                    final CheckedFuture<SchemaContext, SchemaResolutionException> schemaBuilderFuture = schemaContextFactory.createSchemaContext(requiredSources);
+                    final SchemaContext result = schemaBuilderFuture.checkedGet();
                     LOG.debug("{}: Schema context built successfully from {}", id, requiredSources);
                     final Collection<QName> filteredQNames = Sets.difference(deviceSources.getRequiredSourcesQName(), capabilities.getUnresolvedCapabilites().keySet());
-                    capabilities.addCapabilities(filteredQNames);
-                    capabilities.addNonModuleBasedCapabilities(remoteSessionCapabilities.getNonModuleCaps());
-                    handleSalInitializationSuccess(result, remoteSessionCapabilities, getDeviceSpecificRpc(result));
-                }
+                    capabilities.addCapabilities(filteredQNames.stream().map(entry -> new AvailableCapabilityBuilder()
+                            .setCapability(entry.toString()).setCapabilityOrigin(remoteSessionCapabilities.getModuleBasedCapsOrigin().get(entry)).build())
+                            .collect(Collectors.toList()));
 
-                @Override
-                public void onFailure(final Throwable t) {
-                    // In case source missing, try without it
-                    if (t instanceof MissingSchemaSourceException) {
-                        final SourceIdentifier missingSource = ((MissingSchemaSourceException) t).getSourceId();
-                        LOG.warn("{}: Unable to build schema context, missing source {}, will reattempt without it", id, missingSource);
-                        LOG.debug("{}: Unable to build schema context, missing source {}, will reattempt without it", t);
-                        final Collection<QName> qNameOfMissingSource = getQNameFromSourceIdentifiers(Sets.newHashSet(missingSource));
-                        if (!qNameOfMissingSource.isEmpty()) {
-                            capabilities.addUnresolvedCapabilities(qNameOfMissingSource, UnavailableCapability.FailureReason.MissingSource);
-                        }
-                        setUpSchema(stripMissingSource(requiredSources, missingSource));
+                    capabilities.addNonModuleBasedCapabilities(remoteSessionCapabilities.getNonModuleCaps().stream().map(entry -> new AvailableCapabilityBuilder()
+                            .setCapability(entry).setCapabilityOrigin(remoteSessionCapabilities.getNonModuleBasedCapsOrigin().get(entry)).build())
+                            .collect(Collectors.toList()));
 
-                    // In case resolution error, try only with resolved sources
+                    handleSalInitializationSuccess(result, remoteSessionCapabilities, getDeviceSpecificRpc(result));
+                    return;
+                } catch (final Throwable t) {
+                    if (t instanceof MissingSchemaSourceException){
+                        requiredSources = handleMissingSchemaSourceException(requiredSources, (MissingSchemaSourceException) t);
                     } else if (t instanceof SchemaResolutionException) {
-                        // TODO check for infinite loop
-                        final SchemaResolutionException resolutionException = (SchemaResolutionException) t;
-                        final Set<SourceIdentifier> unresolvedSources = resolutionException.getUnsatisfiedImports().keySet();
-                        capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(unresolvedSources), UnavailableCapability.FailureReason.UnableToResolve);
-                        LOG.warn("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only", id, resolutionException.getUnsatisfiedImports());
-                        LOG.debug("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only", resolutionException);
-                        setUpSchema(resolutionException.getResolvedSources());
-                    // unknown error, fail
+                        // schemaBuilderFuture.checkedGet() throws only SchemaResolutionException
+                        // that might be wrapping a MissingSchemaSourceException so we need to look
+                        // at the cause of the exception to make sure we don't misinterpret it.
+                        if (t.getCause() instanceof MissingSchemaSourceException) {
+                            requiredSources = handleMissingSchemaSourceException(requiredSources, (MissingSchemaSourceException) t.getCause());
+                            continue;
+                        }
+                        requiredSources = handleSchemaResolutionException(requiredSources, (SchemaResolutionException) t);
                     } else {
+                        // unknown error, fail
                         handleSalInitializationFailure(t, listener);
+                        return;
                     }
                 }
-            };
+            }
+            // No more sources, fail
+            final IllegalStateException cause = new IllegalStateException(id + ": No more sources for schema context");
+            handleSalInitializationFailure(cause, listener);
+            salFacade.onDeviceFailed(cause);
+        }
+
+        private Collection<SourceIdentifier> handleMissingSchemaSourceException(final Collection<SourceIdentifier> requiredSources, final MissingSchemaSourceException t) {
+            // In case source missing, try without it
+            final SourceIdentifier missingSource = t.getSourceId();
+            LOG.warn("{}: Unable to build schema context, missing source {}, will reattempt without it", id, missingSource);
+            LOG.debug("{}: Unable to build schema context, missing source {}, will reattempt without it", t);
+            final Collection<QName> qNameOfMissingSource = getQNameFromSourceIdentifiers(Sets.newHashSet(missingSource));
+            if (!qNameOfMissingSource.isEmpty()) {
+                capabilities.addUnresolvedCapabilities(qNameOfMissingSource, UnavailableCapability.FailureReason.MissingSource);
+            }
+            return stripUnavailableSource(requiredSources, missingSource);
+        }
 
-            Futures.addCallback(schemaBuilderFuture, RecursiveSchemaBuilderCallback);
+        private Collection<SourceIdentifier> handleSchemaResolutionException(final Collection<SourceIdentifier> requiredSources, final SchemaResolutionException resolutionException) {
+            // In case resolution error, try only with resolved sources
+            // There are two options why schema resolution exception occurred : unsatisfied imports or flawed model
+            // FIXME Do we really have assurance that these two cases cannot happen at once?
+            if (resolutionException.getFailedSource() != null) {
+                // flawed model - exclude it
+                final SourceIdentifier failedSourceId = resolutionException.getFailedSource();
+                LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it", id, failedSourceId);
+                LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it", id, resolutionException);
+                capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(Collections.singleton(failedSourceId)),
+                        UnavailableCapability.FailureReason.UnableToResolve);
+                return stripUnavailableSource(requiredSources, resolutionException.getFailedSource());
+            }
+            // unsatisfied imports
+            final Set<SourceIdentifier> unresolvedSources = resolutionException.getUnsatisfiedImports().keySet();
+            capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(unresolvedSources), UnavailableCapability.FailureReason.UnableToResolve);
+            LOG.warn("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only", id, resolutionException.getUnsatisfiedImports());
+            LOG.debug("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only", resolutionException);
+            return resolutionException.getResolvedSources();
         }
 
         protected NetconfDeviceRpc getDeviceSpecificRpc(final SchemaContext result) {
             return new NetconfDeviceRpc(result, listener, new NetconfMessageTransformer(result, true));
         }
 
-        private Collection<SourceIdentifier> stripMissingSource(final Collection<SourceIdentifier> requiredSources, final SourceIdentifier sIdToRemove) {
+        private Collection<SourceIdentifier> stripUnavailableSource(final Collection<SourceIdentifier> requiredSources, final SourceIdentifier sIdToRemove) {
             final LinkedList<SourceIdentifier> sourceIdentifiers = Lists.newLinkedList(requiredSources);
             final boolean removed = sourceIdentifiers.remove(sIdToRemove);
             Preconditions.checkState(removed, "{}: Trying to remove {} from {} failed", id, sIdToRemove, requiredSources);
@@ -462,12 +530,7 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
         }
 
         private Collection<QName> getQNameFromSourceIdentifiers(final Collection<SourceIdentifier> identifiers) {
-            final Collection<QName> qNames = Collections2.transform(identifiers, new Function<SourceIdentifier, QName>() {
-                @Override
-                public QName apply(final SourceIdentifier sourceIdentifier) {
-                    return getQNameFromSourceIdentifier(sourceIdentifier);
-                }
-            });
+            final Collection<QName> qNames = Collections2.transform(identifiers, this::getQNameFromSourceIdentifier);
 
             if (qNames.isEmpty()) {
                 LOG.debug("{}: Unable to map any source identifiers to a capability reported by device : {}", id, identifiers);
@@ -478,16 +541,16 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
         private QName getQNameFromSourceIdentifier(final SourceIdentifier identifier) {
             // Required sources are all required and provided merged in DeviceSourcesResolver
             for (final QName qname : deviceSources.getRequiredSourcesQName()) {
-                if(qname.getLocalName().equals(identifier.getName()) == false) {
+                if (!qname.getLocalName().equals(identifier.getName())) {
                     continue;
                 }
 
-                if(identifier.getRevision().equals(SourceIdentifier.NOT_PRESENT_FORMATTED_REVISION) &&
-                        qname.getRevision() == null) {
-                    return qname;
-                }
-
-                if (qname.getFormattedRevision().equals(identifier.getRevision())) {
+                final String rev = getNullableRev(identifier);
+                if (rev == null) {
+                    if (qname.getRevision() == null) {
+                        return qname;
+                    }
+                } else if (qname.getFormattedRevision().equals(rev)) {
                     return qname;
                 }
             }
@@ -495,5 +558,10 @@ public class NetconfDevice implements RemoteDevice<NetconfSessionPreferences, Ne
             // return null since we cannot find the QName, this capability will be removed from required sources and not reported as unresolved-capability
             return null;
         }
+
+        private String getNullableRev(final SourceIdentifier identifier) {
+            final String rev = identifier.getRevision();
+            return rev == null || SourceIdentifier.NOT_PRESENT_FORMATTED_REVISION.equals(rev) ? null : rev;
+        }
     }
 }