Consolidating null providers and making them fully configurable and integrated w…

…ith the ConfigProvider to allow arbitrary topologies.

Change-Id: I899e27a9771af4013a3ce6da7f683a4927ffb438

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cli;
+
+import org.apache.karaf.shell.console.completer.StringsCompleter;
+
+import java.util.List;
+import java.util.SortedSet;
+
+/**
+ * Abstraction of a completer with preset choices.
+ */
+public abstract class AbstractChoicesCompleter extends AbstractCompleter {
+
+    protected abstract List<String> choices();
+
+    @Override
+    public int complete(String buffer, int cursor, List<String> candidates) {
+        StringsCompleter delegate = new StringsCompleter();
+        SortedSet<String> strings = delegate.getStrings();
+        choices().forEach(strings::add);
+        return delegate.complete(buffer, cursor, candidates);
+    }
+
+}

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * See the License for the specific language governing permissions and
  * limitations under the License.
  * limitations under the License.
  */
  */
-package org.onosproject.cli.net;
+package org.onosproject.cli;
 
 
 import org.apache.felix.service.command.CommandSession;
 import org.apache.felix.service.command.CommandSession;
 import org.apache.karaf.shell.console.CommandSessionHolder;
 import org.apache.karaf.shell.console.CommandSessionHolder;

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cli;
+
+import com.google.common.collect.ImmutableList;
+
+import java.util.List;
+
+/**
+ * Start/stop command completer.
+ */
+public class StartStopCompleter extends AbstractChoicesCompleter {
+
+    public static final String START = "start";
+    public static final String STOP = "stop";
+
+    @Override
+    public List<String> choices() {
+        return ImmutableList.of(START, STOP);
+    }
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cli;
+
+import com.google.common.collect.ImmutableList;
+
+import java.util.List;
+
+/**
+ * Up/down command completer.
+ */
+public class UpDownCompleter extends AbstractChoicesCompleter {
+
+    public static final String UP = "up";
+    public static final String DOWN = "down";
+
+    @Override
+    public List<String> choices() {
+        return ImmutableList.of(UP, DOWN);
+    }
+}

@@ -15,30 +15,20 @@
  */
  */
 package org.onosproject.cli.app;
 package org.onosproject.cli.app;
 
 
-import org.apache.karaf.shell.console.Completer;
-import org.apache.karaf.shell.console.completer.StringsCompleter;
+import com.google.common.collect.ImmutableList;
+import org.onosproject.cli.AbstractChoicesCompleter;
 
 
 import java.util.List;
 import java.util.List;
-import java.util.SortedSet;
 
 
 import static org.onosproject.cli.app.ApplicationCommand.*;
 import static org.onosproject.cli.app.ApplicationCommand.*;
 
 
 /**
 /**
- * Application name completer.
+ * Application command completer.
  */
  */
-public class ApplicationCommandCompleter implements Completer {
+public class ApplicationCommandCompleter extends AbstractChoicesCompleter {
     @Override
     @Override
-    public int complete(String buffer, int cursor, List<String> candidates) {
-        // Delegate string completer
-        StringsCompleter delegate = new StringsCompleter();
-        SortedSet<String> strings = delegate.getStrings();
-        strings.add(INSTALL);
-        strings.add(UNINSTALL);
-        strings.add(ACTIVATE);
-        strings.add(DEACTIVATE);
-
-        // Now let the completer do the work for figuring out what to offer.
-        return delegate.complete(buffer, cursor, candidates);
+    public List<String> choices() {
+        return ImmutableList.of(INSTALL, UNINSTALL, ACTIVATE, DEACTIVATE);
     }
     }
 
 
 }
 }

@@ -19,7 +19,7 @@ import org.apache.karaf.shell.console.completer.ArgumentCompleter;
 import org.apache.karaf.shell.console.completer.StringsCompleter;
 import org.apache.karaf.shell.console.completer.StringsCompleter;
 import org.onosproject.app.ApplicationService;
 import org.onosproject.app.ApplicationService;
 import org.onosproject.app.ApplicationState;
 import org.onosproject.app.ApplicationState;
-import org.onosproject.cli.net.AbstractCompleter;
+import org.onosproject.cli.AbstractCompleter;
 import org.onosproject.core.Application;
 import org.onosproject.core.Application;
 
 
 import java.util.Iterator;
 import java.util.Iterator;

@@ -19,7 +19,7 @@ import org.apache.karaf.shell.console.completer.ArgumentCompleter;
 import org.apache.karaf.shell.console.completer.StringsCompleter;
 import org.apache.karaf.shell.console.completer.StringsCompleter;
 import org.onosproject.cfg.ComponentConfigService;
 import org.onosproject.cfg.ComponentConfigService;
 import org.onosproject.cfg.ConfigProperty;
 import org.onosproject.cfg.ConfigProperty;
-import org.onosproject.cli.net.AbstractCompleter;
+import org.onosproject.cli.AbstractCompleter;
 
 
 import java.util.List;
 import java.util.List;
 import java.util.Set;
 import java.util.Set;

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cli.net;
+
+import org.apache.karaf.shell.console.completer.ArgumentCompleter;
+import org.apache.karaf.shell.console.completer.StringsCompleter;
+import org.onosproject.cli.AbstractCompleter;
+import org.onosproject.cli.AbstractShellCommand;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.link.LinkService;
+
+import java.util.List;
+import java.util.SortedSet;
+
+import static org.onosproject.cli.net.AddPointToPointIntentCommand.getDeviceId;
+import static org.onosproject.cli.net.AddPointToPointIntentCommand.getPortNumber;
+import static org.onosproject.net.DeviceId.deviceId;
+import static org.onosproject.net.PortNumber.portNumber;
+
+/**
+ * Link end-point completer.
+ */
+public class LinkDstCompleter extends AbstractCompleter {
+    @Override
+    public int complete(String buffer, int cursor, List<String> candidates) {
+        // Delegate string completer
+        StringsCompleter delegate = new StringsCompleter();
+
+        // Fetch our service and feed it's offerings to the string completer
+        LinkService service = AbstractShellCommand.get(LinkService.class);
+
+        // Link source the previous argument.
+        ArgumentCompleter.ArgumentList list = getArgumentList();
+        String srcArg = list.getArguments()[list.getCursorArgumentIndex() - 1];
+
+        // Generate the device ID/port number identifiers
+        SortedSet<String> strings = delegate.getStrings();
+        try {
+            ConnectPoint src = new ConnectPoint(deviceId(getDeviceId(srcArg)),
+                                                portNumber(getPortNumber(srcArg)));
+            service.getEgressLinks(src)
+                    .forEach(link -> strings.add(link.dst().elementId().toString() +
+                                                         "/" + link.dst().port()));
+        } catch (NumberFormatException e) {
+            System.err.println("Invalid connect-point");
+        }
+
+        // Now let the completer do the work for figuring out what to offer.
+        return delegate.complete(buffer, cursor, candidates);
+    }
+
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cli.net;
+
+import org.apache.karaf.shell.console.completer.StringsCompleter;
+import org.onosproject.cli.AbstractCompleter;
+import org.onosproject.cli.AbstractShellCommand;
+import org.onosproject.net.link.LinkService;
+
+import java.util.List;
+import java.util.SortedSet;
+
+/**
+ * Link end-point completer.
+ */
+public class LinkSrcCompleter extends AbstractCompleter {
+    @Override
+    public int complete(String buffer, int cursor, List<String> candidates) {
+        // Delegate string completer
+        StringsCompleter delegate = new StringsCompleter();
+
+        // Fetch our service and feed it's offerings to the string completer
+        LinkService service = AbstractShellCommand.get(LinkService.class);
+
+        // Generate the device ID/port number identifiers
+        SortedSet<String> strings = delegate.getStrings();
+        service.getLinks()
+                .forEach(link -> strings.add(link.src().elementId().toString() +
+                                                     "/" + link.src().port()));
+
+        // Now let the completer do the work for figuring out what to offer.
+        return delegate.complete(buffer, cursor, candidates);
+    }
+
+}

@@ -332,4 +332,7 @@
     <bean id="ipProtocolCompleter" class="org.onosproject.cli.net.IpProtocolCompleter"/>
     <bean id="ipProtocolCompleter" class="org.onosproject.cli.net.IpProtocolCompleter"/>
     <bean id="driverNameCompleter" class="org.onosproject.cli.net.DriverNameCompleter"/>
     <bean id="driverNameCompleter" class="org.onosproject.cli.net.DriverNameCompleter"/>
 
 
+    <bean id="startStopCompleter" class="org.onosproject.cli.StartStopCompleter"/>
+    <bean id="upDownCompleter" class="org.onosproject.cli.UpDownCompleter"/>
+
 </blueprint>
 </blueprint>

@@ -20,7 +20,7 @@ import org.onosproject.net.DeviceId;
 /**
 /**
  * Service for administering the inventory of infrastructure devices.
  * Service for administering the inventory of infrastructure devices.
  */
  */
-public interface DeviceAdminService {
+public interface DeviceAdminService extends DeviceService {
 
 
     /**
     /**
      * Removes the device with the specified identifier.
      * Removes the device with the specified identifier.

@@ -21,7 +21,7 @@ import org.onosproject.net.HostId;
 /**
 /**
  * Service for administering the inventory of end-station hosts.
  * Service for administering the inventory of end-station hosts.
  */
  */
-public interface HostAdminService {
+public interface HostAdminService extends HostService {
 
 
     /**
     /**
      * Removes the end-station host with the specified identifier.
      * Removes the end-station host with the specified identifier.

@@ -21,7 +21,7 @@ import org.onosproject.net.DeviceId;
 /**
 /**
  * Service for administering the inventory of infrastructure links.
  * Service for administering the inventory of infrastructure links.
  */
  */
-public interface LinkAdminService {
+public interface LinkAdminService extends LinkService {
 
 
     /**
     /**
      * Removes all infrastructure links leading to and from the
      * Removes all infrastructure links leading to and from the

@@ -705,7 +705,8 @@ public class DistributedGroupStore
                         remove(new GroupStoreKeyMapKey(deviceId, group.appCookie()));
                         remove(new GroupStoreKeyMapKey(deviceId, group.appCookie()));
                 }
                 }
             } else {
             } else {
-                if (deviceAuditStatus.get(deviceId)) {
+                Boolean audited = deviceAuditStatus.get(deviceId);
+                if (audited != null && audited) {
                     log.debug("deviceInitialAuditCompleted: Clearing AUDIT "
                     log.debug("deviceInitialAuditCompleted: Clearing AUDIT "
                                       + "status for device {}", deviceId);
                                       + "status for device {}", deviceId);
                     deviceAuditStatus.put(deviceId, false);
                     deviceAuditStatus.put(deviceId, false);
@@ -717,8 +718,8 @@ public class DistributedGroupStore
     @Override
     @Override
     public boolean deviceInitialAuditStatus(DeviceId deviceId) {
     public boolean deviceInitialAuditStatus(DeviceId deviceId) {
         synchronized (deviceAuditStatus) {
         synchronized (deviceAuditStatus) {
-            return (deviceAuditStatus.get(deviceId) != null)
-                    ? deviceAuditStatus.get(deviceId) : false;
+            Boolean audited = deviceAuditStatus.get(deviceId);
+            return audited != null && audited;
         }
         }
     }
     }
 
 

@@ -79,7 +79,7 @@
                         <group>
                         <group>
                             <title>Null Providers</title>
                             <title>Null Providers</title>
                             <packages>
                             <packages>
-                                org.onosproject.provider.nil.*
+                                org.onosproject.provider.nil:org.onosproject.provider.nil.*
                             </packages>
                             </packages>
                         </group>
                         </group>
                         <group>
                         <group>

@@ -131,13 +131,7 @@
     <feature name="onos-null" version="@FEATURE-VERSION"
     <feature name="onos-null" version="@FEATURE-VERSION"
              description="ONOS Null providers">
              description="ONOS Null providers">
         <feature>onos-api</feature>
         <feature>onos-api</feature>
-
-        <bundle>mvn:org.onosproject/onos-null-provider-device/@ONOS-VERSION</bundle>
-        <bundle>mvn:org.onosproject/onos-null-provider-link/@ONOS-VERSION</bundle>
-        <bundle>mvn:org.onosproject/onos-null-provider-host/@ONOS-VERSION</bundle>
-        <bundle>mvn:org.onosproject/onos-null-provider-packet/@ONOS-VERSION</bundle>
-        <bundle>mvn:org.onosproject/onos-null-provider-flow/@ONOS-VERSION</bundle>
-
+        <bundle>mvn:org.onosproject/onos-null-provider/@ONOS-VERSION</bundle>
     </feature>
     </feature>
 
 
     <feature name="onos-openflow" version="@FEATURE-VERSION"
     <feature name="onos-openflow" version="@FEATURE-VERSION"

@@ -26,20 +26,25 @@
         <relativePath>../pom.xml</relativePath>
         <relativePath>../pom.xml</relativePath>
     </parent>
     </parent>
 
 
-    <artifactId>onos-null-providers</artifactId>
-    <packaging>pom</packaging>
+    <artifactId>onos-null-provider</artifactId>
+    <packaging>bundle</packaging>
 
 
     <description>ONOS null protocol adapters</description>
     <description>ONOS null protocol adapters</description>
 
 
-    <modules>
-        <module>device</module>
-        <module>link</module>
-        <module>host</module>
-        <module>packet</module>
-        <module>flow</module>
-    </modules>
-
     <dependencies>
     <dependencies>
+        <dependency>
+            <groupId>org.osgi</groupId>
+            <artifactId>org.osgi.compendium</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.karaf.shell</groupId>
+            <artifactId>org.apache.karaf.shell.console</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-cli</artifactId>
+            <version>${project.version}</version>
+        </dependency>
 
 
         <dependency>
         <dependency>
             <groupId>org.onosproject</groupId>
             <groupId>org.onosproject</groupId>

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil;
+
+/**
+ * Linear topology with hosts on every device.
+ */
+public class CentipedeTopologySimulator extends LinearTopologySimulator {
+
+    /**
+     * Creates simulated hosts.
+     */
+    protected void createHosts() {
+        deviceIds.forEach(id -> createHosts(id, infrastructurePorts));
+    }
+
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil;
+
+/**
+ * Topology simulator which operates on topology configured via the REST API
+ * config service.
+ */
+public class ConfiguredTopologySimulator extends TopologySimulator {
+
+    @Override
+    protected void createDevices() {
+        deviceService.getDevices()
+                .forEach(device -> deviceProviderService
+                        .deviceConnected(device.id(), description(device)));
+    }
+
+    @Override
+    protected void createLinks() {
+        linkService.getLinks()
+                .forEach(link -> linkProviderService
+                        .linkDetected(description(link)));
+    }
+
+    @Override
+    protected void createHosts() {
+        hostService.getHosts()
+                .forEach(host -> hostProviderService
+                        .hostDetected(host.id(), description(host)));
+    }
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+/**
+ * Linear topology simulator.
+ */
+public class LinearTopologySimulator extends TopologySimulator {
+
+    @Override
+    protected void processTopoShape(String shape) {
+        super.processTopoShape(shape);
+        deviceCount = (topoShape.length == 1) ? deviceCount : Integer.parseInt(topoShape[1]);
+    }
+
+    @Override
+    public void setUpTopology() {
+        checkArgument(deviceCount > 1, "There must be at least 2 devices");
+
+        prepareForDeviceEvents(deviceCount);
+        createDevices();
+        waitForDeviceEvents();
+
+        createLinks();
+        createHosts();
+    }
+
+    @Override
+    protected void createLinks() {
+        for (int i = 0, n = deviceCount - 1; i < n; i++) {
+            createLink(i, i + 1);
+        }
+    }
+
+    @Override
+    protected void createHosts() {
+        createHosts(deviceIds.get(0), infrastructurePorts);
+        createHosts(deviceIds.get(deviceCount - 1), infrastructurePorts);
+    }
+
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil;
+
+/**
+ * Full mesh topology with hosts at each device.
+ */
+public class MeshTopologySimulator extends TopologySimulator {
+
+    @Override
+    protected void processTopoShape(String shape) {
+        super.processTopoShape(shape);
+        // FIXME: implement this
+    }
+
+    @Override
+    public void setUpTopology() {
+        // FIXME: implement this
+        // checkArgument(FIXME, "There must be at least ...");
+        super.setUpTopology();
+    }
+
+    @Override
+    protected void createLinks() {
+    }
+
+    @Override
+    protected void createHosts() {
+    }
+
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil;
+
+import com.google.common.collect.Sets;
+import org.jboss.netty.util.HashedWheelTimer;
+import org.jboss.netty.util.Timeout;
+import org.jboss.netty.util.TimerTask;
+import org.onlab.util.Timer;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.flow.CompletedBatchOperation;
+import org.onosproject.net.flow.DefaultFlowEntry;
+import org.onosproject.net.flow.FlowEntry;
+import org.onosproject.net.flow.FlowRule;
+import org.onosproject.net.flow.FlowRuleBatchEntry;
+import org.onosproject.net.flow.FlowRuleBatchOperation;
+import org.onosproject.net.flow.FlowRuleProvider;
+import org.onosproject.net.flow.FlowRuleProviderService;
+import org.slf4j.Logger;
+
+import java.util.Collections;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.TimeUnit;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Null provider to accept any flow and report them.
+ */
+class NullFlowRuleProvider extends NullProviders.AbstractNullProvider
+        implements FlowRuleProvider {
+
+    private final Logger log = getLogger(getClass());
+
+    private ConcurrentMap<DeviceId, Set<FlowEntry>> flowTable = new ConcurrentHashMap<>();
+
+    private FlowRuleProviderService providerService;
+
+    private HashedWheelTimer timer = Timer.getTimer();
+    private Timeout timeout;
+
+    /**
+     * Starts the flow rule provider simulation.
+     *
+     * @param providerService flow rule provider service
+     */
+    void start(FlowRuleProviderService providerService) {
+        this.providerService = providerService;
+        timeout = timer.newTimeout(new StatisticTask(), 5, TimeUnit.SECONDS);
+    }
+
+    /**
+     * Stops the flow rule provider simulation.
+     */
+    void stop() {
+        timeout.cancel();
+    }
+
+    @Override
+    public void applyFlowRule(FlowRule... flowRules) {
+        // FIXME: invoke executeBatch
+    }
+
+    @Override
+    public void removeFlowRule(FlowRule... flowRules) {
+        // FIXME: invoke executeBatch
+    }
+
+    @Override
+    public void removeRulesById(ApplicationId id, FlowRule... flowRules) {
+        throw new UnsupportedOperationException("Cannot remove by appId from null provider");
+    }
+
+    @Override
+    public void executeBatch(FlowRuleBatchOperation batch) {
+        // TODO: consider checking mastership
+        Set<FlowEntry> entries =
+                flowTable.getOrDefault(batch.deviceId(),
+                                       Sets.newConcurrentHashSet());
+        for (FlowRuleBatchEntry fbe : batch.getOperations()) {
+            switch (fbe.operator()) {
+                case ADD:
+                    entries.add(new DefaultFlowEntry(fbe.target()));
+                    break;
+                case REMOVE:
+                    entries.remove(new DefaultFlowEntry(fbe.target()));
+                    break;
+                case MODIFY:
+                    FlowEntry entry = new DefaultFlowEntry(fbe.target());
+                    entries.remove(entry);
+                    entries.add(entry);
+                    break;
+                default:
+                    log.error("Unknown flow operation: {}", fbe);
+            }
+        }
+        flowTable.put(batch.deviceId(), entries);
+        CompletedBatchOperation op =
+                new CompletedBatchOperation(true, Collections.emptySet(),
+                                            batch.deviceId());
+        providerService.batchOperationCompleted(batch.id(), op);
+    }
+
+    // Periodically reports flow rule statistics.
+    private class StatisticTask implements TimerTask {
+        @Override
+        public void run(Timeout to) throws Exception {
+            for (DeviceId devId : flowTable.keySet()) {
+                Set<FlowEntry> entries =
+                        flowTable.getOrDefault(devId, Collections.emptySet());
+                providerService.pushFlowMetrics(devId, entries);
+            }
+            timeout = timer.newTimeout(to.getTask(), 5, TimeUnit.SECONDS);
+        }
+    }
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil;
+
+import org.jboss.netty.util.HashedWheelTimer;
+import org.jboss.netty.util.Timeout;
+import org.jboss.netty.util.TimerTask;
+import org.onlab.packet.Ethernet;
+import org.onlab.packet.ICMP;
+import org.onlab.util.Timer;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.Device;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.device.DeviceAdminService;
+import org.onosproject.net.host.HostService;
+import org.onosproject.net.packet.DefaultInboundPacket;
+import org.onosproject.net.packet.DefaultPacketContext;
+import org.onosproject.net.packet.InboundPacket;
+import org.onosproject.net.packet.OutboundPacket;
+import org.onosproject.net.packet.PacketProvider;
+import org.onosproject.net.packet.PacketProviderService;
+import org.slf4j.Logger;
+
+import java.nio.ByteBuffer;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+
+import static com.google.common.collect.ImmutableList.copyOf;
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static org.onosproject.net.MastershipRole.MASTER;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Provider which generates simulated packets and acts as a sink for outbound
+ * packets. To be used for benchmarking only.
+ */
+class NullPacketProvider extends NullProviders.AbstractNullProvider
+        implements PacketProvider {
+
+    private static final int INITIAL_DELAY = 5;
+    private final Logger log = getLogger(getClass());
+
+    // Arbitrary host src/dst
+    private static final int SRC_HOST = 2;
+    private static final int DST_HOST = 5;
+
+    // Time between event firing, in milliseconds
+    private int delay;
+
+    // TODO: use host service to pick legitimate hosts connected to devices
+    private HostService hostService;
+    private PacketProviderService providerService;
+
+    private List<Device> devices;
+    private int currentDevice = 0;
+
+    private HashedWheelTimer timer = Timer.getTimer();
+    private Timeout timeout;
+
+    /**
+     * Starts the packet generation process.
+     *
+     * @param packetRate      packets per second
+     * @param hostService     host service
+     * @param deviceService   device service
+     * @param providerService packet provider service
+     */
+    void start(int packetRate, HostService hostService,
+               DeviceAdminService deviceService,
+               PacketProviderService providerService) {
+        this.hostService = hostService;
+        this.providerService = providerService;
+
+        this.devices = copyOf(deviceService.getDevices()).stream()
+                .filter(d -> deviceService.getRole(d.id()) == MASTER)
+                .collect(Collectors.toList());
+
+        adjustRate(packetRate);
+        timeout = timer.newTimeout(new PacketDriverTask(), INITIAL_DELAY, SECONDS);
+    }
+
+    /**
+     * Adjusts packet rate.
+     *
+     * @param packetRate new packet rate
+     */
+    void adjustRate(int packetRate) {
+        delay = 1000 / packetRate;
+        log.info("Settings: packetRate={}, delay={}", packetRate, delay);
+    }
+
+    /**
+     * Stops the packet generation process.
+     */
+    void stop() {
+        if (timeout != null) {
+            timeout.cancel();
+        }
+    }
+
+    @Override
+    public void emit(OutboundPacket packet) {
+        // We don't have a network to emit to. Keep a counter here, maybe?
+    }
+
+    /**
+     * Generates packet events at a given rate.
+     */
+    private class PacketDriverTask implements TimerTask {
+
+        // Filler echo request
+        ICMP icmp;
+        Ethernet eth;
+
+        public PacketDriverTask() {
+            icmp = new ICMP();
+            icmp.setIcmpType((byte) 8).setIcmpCode((byte) 0).setChecksum((short) 0);
+            eth = new Ethernet();
+            eth.setEtherType(Ethernet.TYPE_IPV4);
+            eth.setPayload(icmp);
+        }
+
+        @Override
+        public void run(Timeout to) {
+            if (!devices.isEmpty()) {
+                sendEvent(devices.get(currentDevice));
+                currentDevice = (currentDevice + 1) % devices.size();
+                timeout = timer.newTimeout(to.getTask(), delay, TimeUnit.MILLISECONDS);
+            }
+        }
+
+        private void sendEvent(Device device) {
+            // Make it look like things came from ports attached to hosts
+            eth.setSourceMACAddress("00:00:10:00:00:0" + SRC_HOST)
+                    .setDestinationMACAddress("00:00:10:00:00:0" + DST_HOST);
+            InboundPacket inPkt = new DefaultInboundPacket(
+                    new ConnectPoint(device.id(), PortNumber.portNumber(SRC_HOST)),
+                    eth, ByteBuffer.wrap(eth.serialize()));
+            providerService.processPacket(new NullPacketContext(inPkt, null));
+        }
+    }
+
+     // Minimal PacketContext to make core and applications happy.
+    private final class NullPacketContext extends DefaultPacketContext {
+        private NullPacketContext(InboundPacket inPkt, OutboundPacket outPkt) {
+            super(System.currentTimeMillis(), inPkt, outPkt, false);
+        }
+
+        @Override
+        public void send() {
+            // We don't send anything out.
+        }
+    }
+
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+/**
+ * Re-routable linear topology simulator with an alternate path in the middle.
+ */
+public class RerouteTopologySimulator extends LinearTopologySimulator {
+
+    @Override
+    protected void processTopoShape(String shape) {
+        super.processTopoShape(shape);
+        infrastructurePorts = 3;
+        deviceCount = (topoShape.length == 1) ? deviceCount : Integer.parseInt(topoShape[1]);
+    }
+
+    @Override
+    public void setUpTopology() {
+        checkArgument(deviceCount > 2, "There must be at least 3 devices");
+        super.setUpTopology();
+    }
+
+    @Override
+    protected void createLinks() {
+        for (int i = 0, n = deviceCount - 2; i < n; i++) {
+            createLink(i, i + 1);
+        }
+        int middle = (deviceCount - 1) / 2;
+        int alternate = deviceCount - 1;
+        createLink(middle - 1, alternate);
+        createLink(middle, alternate);
+    }
+
+    @Override
+    protected void createHosts() {
+        createHosts(deviceIds.get(0), infrastructurePorts);
+        createHosts(deviceIds.get(deviceCount - 2), infrastructurePorts);
+    }
+
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil;
+
+/**
+ * Spine-leaf topology with hosts at the leaf devices.
+ */
+public class SpineLeafTopologySimulator extends TopologySimulator {
+
+    @Override
+    protected void processTopoShape(String shape) {
+        super.processTopoShape(shape);
+        // FIXME: implement this
+    }
+
+    @Override
+    public void setUpTopology() {
+        // checkArgument(FIXME, "There must be at least one spine tier");
+        super.setUpTopology();
+    }
+
+    @Override
+    protected void createLinks() {
+    }
+
+    @Override
+    protected void createHosts() {
+    }
+
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil;
+
+import com.google.common.collect.Lists;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.device.DeviceService;
+import org.onosproject.net.link.DefaultLinkDescription;
+import org.onosproject.net.link.LinkDescription;
+import org.onosproject.net.link.LinkProviderService;
+import org.onosproject.net.link.LinkService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.ExecutorService;
+import java.util.stream.Collectors;
+
+import static java.util.concurrent.Executors.newSingleThreadScheduledExecutor;
+import static org.onlab.util.Tools.delay;
+import static org.onlab.util.Tools.groupedThreads;
+import static org.onosproject.net.Link.Type.DIRECT;
+import static org.onosproject.net.MastershipRole.MASTER;
+import static org.onosproject.provider.nil.TopologySimulator.description;
+
+/**
+ * Drives topology mutations at a specified rate of events per second.
+ */
+class TopologyMutationDriver implements Runnable {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private static final int WAIT_DELAY = 2_000;
+    private static final int MAX_DOWN_LINKS = 5;
+
+    private final Random random = new Random();
+
+    private volatile boolean stopped = true;
+
+    private double mutationRate;
+    private int millis, nanos;
+
+    private LinkService linkService;
+    private DeviceService deviceService;
+    private LinkProviderService linkProviderService;
+
+    private List<LinkDescription> activeLinks;
+    private List<LinkDescription> inactiveLinks;
+
+    private final ExecutorService executor =
+            newSingleThreadScheduledExecutor(groupedThreads("onos/null", "topo-mutator"));
+
+    /**
+     * Starts the mutation process.
+     *
+     * @param mutationRate        link events per second
+     * @param linkService         link service
+     * @param deviceService       device service
+     * @param linkProviderService link provider service
+     */
+    void start(double mutationRate,
+               LinkService linkService, DeviceService deviceService,
+               LinkProviderService linkProviderService) {
+        stopped = false;
+        this.linkService = linkService;
+        this.deviceService = deviceService;
+        this.linkProviderService = linkProviderService;
+        activeLinks = reduceLinks();
+        inactiveLinks = Lists.newArrayList();
+        adjustRate(mutationRate);
+        executor.submit(this);
+    }
+
+    /**
+     * Adjusts the topology mutation rate.
+     *
+     * @param mutationRate new topology mutation rate
+     */
+    void adjustRate(double mutationRate) {
+        this.mutationRate = mutationRate;
+        if (mutationRate > 0) {
+            this.millis = (int) (1_000 / mutationRate / 2);
+            this.nanos = (int) (1_000_000 / mutationRate / 2) % 1_000_000;
+        } else {
+            this.millis = 0;
+            this.nanos = 0;
+        }
+        log.info("Settings: millis={}, nanos={}", millis, nanos);
+    }
+
+    /**
+     * Stops the mutation process.
+     */
+    void stop() {
+        stopped = true;
+    }
+
+    /**
+     * Severs the link between the specified end-points in both directions.
+     *
+     * @param one link endpoint
+     * @param two link endpoint
+     */
+    void severLink(ConnectPoint one, ConnectPoint two) {
+        LinkDescription link = new DefaultLinkDescription(one, two, DIRECT);
+        linkProviderService.linkVanished(link);
+        linkProviderService.linkVanished(reverse(link));
+
+    }
+
+    /**
+     * Repairs the link between the specified end-points in both directions.
+     *
+     * @param one link endpoint
+     * @param two link endpoint
+     */
+    void repairLink(ConnectPoint one, ConnectPoint two) {
+        LinkDescription link = new DefaultLinkDescription(one, two, DIRECT);
+        linkProviderService.linkDetected(link);
+        linkProviderService.linkDetected(reverse(link));
+    }
+
+    @Override
+    public void run() {
+        delay(WAIT_DELAY);
+
+        while (!stopped) {
+            if (mutationRate > 0 && inactiveLinks.isEmpty()) {
+                primeInactiveLinks();
+            } else if (mutationRate <= 0 && !inactiveLinks.isEmpty()) {
+                repairInactiveLinks();
+            } else if (inactiveLinks.isEmpty()) {
+                delay(WAIT_DELAY);
+
+            } else {
+                activeLinks.add(repairLink());
+                pause();
+                inactiveLinks.add(severLink());
+                pause();
+            }
+        }
+    }
+
+    // Primes the inactive links with a few random links.
+    private void primeInactiveLinks() {
+        for (int i = 0, n = Math.min(MAX_DOWN_LINKS, activeLinks.size()); i < n; i++) {
+            inactiveLinks.add(severLink());
+        }
+    }
+
+    // Repairs all inactive links.
+    private void repairInactiveLinks() {
+        while (!inactiveLinks.isEmpty()) {
+            repairLink();
+        }
+    }
+
+    // Picks a random active link and severs it.
+    private LinkDescription severLink() {
+        LinkDescription link = getRandomLink(activeLinks);
+        linkProviderService.linkVanished(link);
+        linkProviderService.linkVanished(reverse(link));
+        return link;
+    }
+
+    // Picks a random inactive link and repairs it.
+    private LinkDescription repairLink() {
+        LinkDescription link = getRandomLink(inactiveLinks);
+        linkProviderService.linkDetected(link);
+        linkProviderService.linkDetected(reverse(link));
+        return link;
+    }
+
+    // Produces a reverse of the specified link.
+    private LinkDescription reverse(LinkDescription link) {
+        return new DefaultLinkDescription(link.dst(), link.src(), link.type());
+    }
+
+    // Returns a random link from the specified list of links.
+    private LinkDescription getRandomLink(List<LinkDescription> links) {
+        return links.remove(random.nextInt(links.size()));
+    }
+
+    // Reduces the given list of links to just a single link in each original pair.
+    private List<LinkDescription> reduceLinks() {
+        List<LinkDescription> links = Lists.newArrayList();
+        linkService.getLinks().forEach(link -> links.add(description(link)));
+        return links.stream()
+                .filter(this::isOurLink)
+                .filter(this::isRightDirection)
+                .collect(Collectors.toList());
+    }
+
+    // Returns true if the specified link is ours.
+    private boolean isOurLink(LinkDescription linkDescription) {
+        return deviceService.getRole(linkDescription.src().deviceId()) == MASTER;
+    }
+
+    // Returns true if the link source is greater than the link destination.
+    private boolean isRightDirection(LinkDescription link) {
+        return link.src().deviceId().toString().compareTo(link.dst().deviceId().toString()) > 0;
+    }
+
+    // Pauses the current thread for the pre-computed time of millis & nanos.
+    private void pause() {
+        delay(millis, nanos);
+    }
+
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+/**
+ * Tree topology with hosts at the leaf devices.
+ */
+public class TreeTopologySimulator extends TopologySimulator {
+
+    private int[] tierMultiplier;
+    private int[] tierDeviceCount;
+    private int[] tierOffset;
+
+    @Override
+    protected void processTopoShape(String shape) {
+        super.processTopoShape(shape);
+        tierOffset = new int[topoShape.length];
+        tierMultiplier = new int[topoShape.length];
+        tierDeviceCount = new int[topoShape.length];
+
+        deviceCount = 1;
+
+        tierOffset[0] = 0;
+        tierMultiplier[0] = 1;
+        tierDeviceCount[0] = deviceCount;
+
+        for (int i = 1; i < topoShape.length; i++) {
+            tierOffset[i] = deviceCount;
+            tierMultiplier[i] = Integer.parseInt(topoShape[i]);
+            tierDeviceCount[i] = tierDeviceCount[i - 1] * tierMultiplier[i];
+            deviceCount = deviceCount + tierDeviceCount[i];
+        }
+    }
+
+    @Override
+    public void setUpTopology() {
+        checkArgument(tierDeviceCount.length > 0, "There must be at least one tree tier");
+        super.setUpTopology();
+    }
+
+    @Override
+    protected void createLinks() {
+        for (int t = 1; t < tierOffset.length; t++) {
+            int child = tierOffset[t];
+            for (int parent = tierOffset[t - 1]; parent < tierOffset[t]; parent++) {
+                for (int i = 0; i < tierMultiplier[t]; i++) {
+                    createLink(parent, child);
+                    child++;
+                }
+            }
+        }
+    }
+
+    @Override
+    protected void createHosts() {
+        for (int i = tierOffset[tierOffset.length - 1]; i < deviceCount; i++) {
+            createHosts(deviceIds.get(i), hostCount);
+        }
+    }
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil.cli;
+
+import org.apache.karaf.shell.commands.Argument;
+import org.apache.karaf.shell.commands.Command;
+import org.onosproject.cfg.ComponentConfigService;
+import org.onosproject.cli.AbstractShellCommand;
+import org.onosproject.provider.nil.NullProviders;
+
+import static org.onosproject.cli.StartStopCompleter.START;
+
+/**
+ * Starts or stops topology simulation.
+ */
+@Command(scope = "onos", name = "null-simulation",
+        description = "Starts or stops topology simulation")
+public class NullControlCommand extends AbstractShellCommand {
+
+    @Argument(index = 0, name = "cmd", description = "Control command: start/stop",
+            required = true, multiValued = false)
+    String cmd = null;
+
+    @Argument(index = 1, name = "topoShape",
+            description = "Topology shape: e.g. configured, linear, reroute, centipede, tree, spineleaf, mesh",
+            required = false, multiValued = false)
+    String topoShape = null;
+
+    @Override
+    protected void execute() {
+        ComponentConfigService service = get(ComponentConfigService.class);
+        if (topoShape != null) {
+            service.setProperty(NullProviders.class.getName(), "topoShape", topoShape);
+        }
+        service.setProperty(NullProviders.class.getName(), "enabled",
+                            cmd.equals(START) ? "true" : "false");
+    }
+
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil.cli;
+
+import org.apache.karaf.shell.commands.Argument;
+import org.apache.karaf.shell.commands.Command;
+import org.onosproject.cli.AbstractShellCommand;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.PortNumber;
+import org.onosproject.provider.nil.NullProviders;
+
+import static org.onosproject.cli.UpDownCompleter.DOWN;
+import static org.onosproject.cli.UpDownCompleter.UP;
+import static org.onosproject.cli.net.AddPointToPointIntentCommand.getDeviceId;
+import static org.onosproject.cli.net.AddPointToPointIntentCommand.getPortNumber;
+import static org.onosproject.net.DeviceId.deviceId;
+import static org.onosproject.net.PortNumber.portNumber;
+
+/**
+ * Servers or repairs a simulated link.
+ */
+@Command(scope = "onos", name = "null-link",
+        description = "Severs or repairs a simulated link")
+public class NullLinkCommand extends AbstractShellCommand {
+
+    @Argument(index = 0, name = "one", description = "One link end-point as device/port",
+            required = true, multiValued = false)
+    String one = null;
+
+    @Argument(index = 1, name = "two", description = "Another link end-point as device/port",
+            required = true, multiValued = false)
+    String two = null;
+
+    @Argument(index = 2, name = "cmd", description = "up/down",
+            required = true, multiValued = false)
+    String cmd = null;
+
+
+    @Override
+    protected void execute() {
+        NullProviders service = get(NullProviders.class);
+
+        try {
+            DeviceId oneId = deviceId(getDeviceId(one));
+            PortNumber onePort = portNumber(getPortNumber(one));
+            ConnectPoint onePoint = new ConnectPoint(oneId, onePort);
+
+            DeviceId twoId = deviceId(getDeviceId(two));
+            PortNumber twoPort = portNumber(getPortNumber(two));
+            ConnectPoint twoPoint = new ConnectPoint(twoId, twoPort);
+
+            if (cmd.equals(UP)) {
+                service.repairLink(onePoint, twoPoint);
+            } else if (cmd.equals(DOWN)) {
+                service.severLink(onePoint, twoPoint);
+            } else {
+                error("Illegal command %s; must be up or down", cmd);
+            }
+        } catch (NumberFormatException e) {
+            error("Invalid port number specified", e);
+        }
+    }
+
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.provider.nil.cli;
+
+import com.google.common.collect.ImmutableList;
+import org.onosproject.cli.AbstractChoicesCompleter;
+
+import java.util.List;
+
+/**
+ * Topology shape completer.
+ */
+public class TopologyShapeCompleter extends AbstractChoicesCompleter {
+    @Override
+    public List<String> choices() {
+        return ImmutableList.of("configured", "linear", "reroute", "centipede",
+                                "tree", "spineleaf", "mesh");
+    }
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Null provider CLI commands and completers.
+ */
+package org.onosproject.provider.nil.cli;

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Set of null south-bound providers which permit simulating a network
+ * topology using fake devices, links, hosts, etc.
+ */
+package org.onosproject.provider.nil;

+<!--
+  ~ Copyright 2015 Open Networking Laboratory
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0">
+
+    <command-bundle xmlns="http://karaf.apache.org/xmlns/shell/v1.1.0">
+        <command>
+            <action class="org.onosproject.provider.nil.cli.NullControlCommand"/>
+            <completers>
+                <ref component-id="startStopCompleter"/>
+                <ref component-id="topoShapeCompleter"/>
+                <null/>
+            </completers>
+        </command>
+        <command>
+            <action class="org.onosproject.provider.nil.cli.NullLinkCommand"/>
+            <completers>
+                <ref component-id="linkSrcCompleter"/>
+                <ref component-id="linkDstCompleter"/>
+                <ref component-id="upDownCompleter"/>
+                <null/>
+            </completers>
+        </command>
+    </command-bundle>
+
+    <bean id="startStopCompleter" class="org.onosproject.cli.StartStopCompleter"/>
+    <bean id="upDownCompleter" class="org.onosproject.cli.UpDownCompleter"/>
+    <bean id="topoShapeCompleter" class="org.onosproject.provider.nil.cli.TopologyShapeCompleter"/>
+    <bean id="linkSrcCompleter" class="org.onosproject.cli.net.LinkSrcCompleter"/>
+    <bean id="linkDstCompleter" class="org.onosproject.cli.net.LinkDstCompleter"/>
+
+</blueprint>

@@ -192,6 +192,20 @@ public abstract class Tools {
     }
     }
 
 
     /**
     /**
+     * Suspends the current thread for a specified number of millis and nanos.
+     *
+     * @param ms    number of millis
+     * @param nanos number of nanos
+     */
+    public static void delay(int ms, int nanos) {
+        try {
+            Thread.sleep(ms, nanos);
+        } catch (InterruptedException e) {
+            throw new RuntimeException("Interrupted", e);
+        }
+    }
+
+    /**
      * Slurps the contents of a file into a list of strings, one per line.
      * Slurps the contents of a file into a list of strings, one per line.
      *
      *
      * @param path file path
      * @param path file path

@@ -18,6 +18,7 @@ package org.onosproject.rest;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import org.onosproject.net.device.DeviceProviderRegistry;
 import org.onosproject.net.device.DeviceProviderRegistry;
+import org.onosproject.net.device.DeviceService;
 import org.onosproject.net.host.HostProviderRegistry;
 import org.onosproject.net.host.HostProviderRegistry;
 import org.onosproject.net.link.LinkProviderRegistry;
 import org.onosproject.net.link.LinkProviderRegistry;
 import org.onlab.rest.BaseResource;
 import org.onlab.rest.BaseResource;
@@ -40,9 +41,9 @@ import static javax.ws.rs.core.Response.Status.INTERNAL_SERVER_ERROR;
  * devices, ports and links.
  * devices, ports and links.
  */
  */
 @Path("config")
 @Path("config")
-public class ConfigResource extends BaseResource {
+public class ConfigWebResource extends BaseResource {
 
 
-    private static Logger log = LoggerFactory.getLogger(ConfigResource.class);
+    private static Logger log = LoggerFactory.getLogger(ConfigWebResource.class);
 
 
     @POST
     @POST
     @Path("topology")
     @Path("topology")
@@ -52,7 +53,8 @@ public class ConfigResource extends BaseResource {
         try {
         try {
             ObjectMapper mapper = new ObjectMapper();
             ObjectMapper mapper = new ObjectMapper();
             JsonNode cfg = mapper.readTree(input);
             JsonNode cfg = mapper.readTree(input);
-            new ConfigProvider(cfg, get(DeviceProviderRegistry.class),
+            new ConfigProvider(cfg, get(DeviceService.class),
+                               get(DeviceProviderRegistry.class),
                                get(LinkProviderRegistry.class),
                                get(LinkProviderRegistry.class),
                                get(HostProviderRegistry.class)).parse();
                                get(HostProviderRegistry.class)).parse();
             return Response.ok().build();
             return Response.ok().build();

@@ -72,7 +72,7 @@
                 org.onosproject.rest.IntentsWebResource,
                 org.onosproject.rest.IntentsWebResource,
                 org.onosproject.rest.FlowsWebResource,
                 org.onosproject.rest.FlowsWebResource,
                 org.onosproject.rest.TopologyWebResource,
                 org.onosproject.rest.TopologyWebResource,
-                org.onosproject.rest.ConfigResource,
+                org.onosproject.rest.ConfigWebResource,
                 org.onosproject.rest.PathsWebResource
                 org.onosproject.rest.PathsWebResource
             </param-value>
             </param-value>
         </init-param>
         </init-param>