[ONOS-5238] Add neighbour message handler for vpls

Change-Id: Iaef04233402864874af0c83231117c279e946d64
diff --git a/apps/vpls/src/main/java/org/onosproject/vpls/IntentInstaller.java b/apps/vpls/src/main/java/org/onosproject/vpls/IntentInstaller.java
index 013461e..d1d1d1a 100644
--- a/apps/vpls/src/main/java/org/onosproject/vpls/IntentInstaller.java
+++ b/apps/vpls/src/main/java/org/onosproject/vpls/IntentInstaller.java
@@ -100,12 +100,13 @@
                                 .filter(cp -> !cp.equals(src))
                                 .collect(Collectors.toSet());
                         Key brcKey = buildKey(PREFIX_BROADCAST, src, vlanId);
-                        if (intentService.getIntent(brcKey) == null) {
-                            SinglePointToMultiPointIntent brcIntent =
-                                    buildBrcIntent(brcKey, src, dsts, vlanId);
-                            intents.add(brcIntent);
+
+                        if (intentService.getIntent(brcKey) == null && dsts.size() > 0) {
+                            intents.add(buildBrcIntent(brcKey, src, dsts, vlanId));
                         }
-                        if (mac != null && countMacInCPoints(cPoints) > 1) {
+
+                        if (mac != null && countMacInCPoints(cPoints) > 1 &&
+                                dsts.size() > 0) {
                             Key uniKey = buildKey(PREFIX_UNICAST, src, vlanId);
                             if (intentService.getIntent(uniKey) == null) {
                                 MultiPointToSinglePointIntent uniIntent =
diff --git a/apps/vpls/src/main/java/org/onosproject/vpls/Vpls.java b/apps/vpls/src/main/java/org/onosproject/vpls/Vpls.java
index 5551435..298615b 100644
--- a/apps/vpls/src/main/java/org/onosproject/vpls/Vpls.java
+++ b/apps/vpls/src/main/java/org/onosproject/vpls/Vpls.java
@@ -38,7 +38,6 @@
 import org.onosproject.net.host.HostListener;
 import org.onosproject.net.host.HostService;
 import org.onosproject.net.intent.IntentService;
-import org.onosproject.routing.IntentSynchronizationAdminService;
 import org.onosproject.routing.IntentSynchronizationService;
 import org.slf4j.Logger;
 
@@ -52,7 +51,8 @@
  */
 @Component(immediate = true)
 public class Vpls {
-    private static final String VPLS_APP = "org.onosproject.vpls";
+    protected static final String VPLS_APP = "org.onosproject.vpls";
+
     private final Logger log = getLogger(getClass());
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
@@ -73,9 +73,6 @@
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected IntentSynchronizationService intentSynchronizer;
 
-    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
-    protected IntentSynchronizationAdminService intentSynchronizerAdmin;
-
     private final HostListener hostListener = new InternalHostListener();
 
     private final InternalInterfaceListener interfaceListener
@@ -85,6 +82,7 @@
 
     private ApplicationId appId;
 
+
     @Activate
     public void activate() {
         appId = coreService.registerApplication(VPLS_APP);
@@ -102,12 +100,13 @@
 
         setupConnectivity();
 
-        log.info("Started");
+        log.debug("Activated");
     }
 
     @Deactivate
     public void deactivate() {
-        log.info("Stopped");
+        intentSynchronizer.removeIntentsByAppId(appId);
+        log.debug("Deactivated");
     }
 
     protected void setupConnectivity() {
@@ -130,6 +129,7 @@
          * hosts attached.
          */
         intentInstaller.installIntents(confHostPresentCPoint);
+
     }
 
     /**
@@ -146,21 +146,20 @@
         interfaceService.getInterfaces()
                 .stream()
                 .filter(intf -> intf.ipAddressesList().isEmpty())
-                .forEach(intf -> confCPointsByVlan.put(intf.vlan(),
-                                                       intf.connectPoint()));
+                .forEach(intf -> confCPointsByVlan.put(intf.vlan(), intf.connectPoint()));
         return confCPointsByVlan;
     }
 
     /**
-     * Checks if for any ConnectPoint configured there's an host present
-     * and in case it associate them together.
+     * Checks if for any ConnectPoint configured there's an host presents
+     * and in case it associates them together.
      *
-     * @param confCPointsByVlan the configured ConnectPoints grouped by vlan id
+     * @param confCPointsByVlan the configured ConnectPoints grouped by VLAN Id
      * @return the configured ConnectPoints with eventual hosts associated.
      */
     protected SetMultimap<VlanId, Pair<ConnectPoint, MacAddress>> pairAvailableHosts(
             SetMultimap<VlanId, ConnectPoint> confCPointsByVlan) {
-        log.debug("Binding connected hosts mac addresses");
+        log.debug("Binding connected hosts MAC addresses");
 
         SetMultimap<VlanId, Pair<ConnectPoint, MacAddress>> confHostPresentCPoint =
                 HashMultimap.create();
@@ -171,9 +170,10 @@
         return confHostPresentCPoint;
     }
 
+    // Bind VLAN Id with hosts and connect points
     private void bindMacAddr(Map.Entry<VlanId, ConnectPoint> e,
                              SetMultimap<VlanId, Pair<ConnectPoint,
-                             MacAddress>> confHostPresentCPoint) {
+                                     MacAddress>> confHostPresentCPoint) {
         VlanId vlanId = e.getKey();
         ConnectPoint cp = e.getValue();
         Set<Host> connectedHosts = hostService.getConnectedHosts(cp);
diff --git a/apps/vpls/src/main/java/org/onosproject/vpls/VplsNeighbourHandler.java b/apps/vpls/src/main/java/org/onosproject/vpls/VplsNeighbourHandler.java
new file mode 100644
index 0000000..9f3ea06
--- /dev/null
+++ b/apps/vpls/src/main/java/org/onosproject/vpls/VplsNeighbourHandler.java
@@ -0,0 +1,158 @@
+/*
+ * Copyright 2016-present 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.vpls;
+
+import com.google.common.collect.Maps;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.incubator.net.intf.Interface;
+import org.onosproject.incubator.net.intf.InterfaceEvent;
+import org.onosproject.incubator.net.intf.InterfaceListener;
+import org.onosproject.incubator.net.intf.InterfaceService;
+import org.onosproject.incubator.net.neighbour.NeighbourMessageContext;
+import org.onosproject.incubator.net.neighbour.NeighbourMessageHandler;
+import org.onosproject.incubator.net.neighbour.NeighbourResolutionService;
+import org.onosproject.net.Host;
+import org.onosproject.net.host.HostService;
+import org.slf4j.Logger;
+
+import java.util.Map;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Handles neighbour messages for VPLS use case.
+ * Handlers will be changed automatically by interface or network configuration
+ * events.
+ */
+@Component(immediate = true)
+public class VplsNeighbourHandler {
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected CoreService coreService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected InterfaceService interfaceService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected NeighbourResolutionService neighbourService;
+
+    private VplsInterfaceListener interfaceListener
+            = new VplsInterfaceListener();
+
+    private VplsNeighbourMessageHandler neighbourHandler =
+            new VplsNeighbourMessageHandler();
+
+    private final Logger log = getLogger(getClass());
+
+    private Map<Interface, NeighbourMessageHandler> neighbourHandlers =
+            Maps.newHashMap();
+
+    private ApplicationId appId;
+
+
+    @Activate
+    protected void activate() {
+        appId = coreService.registerApplication(Vpls.VPLS_APP);
+        interfaceService.addListener(interfaceListener);
+
+        interfaceService.getInterfaces().forEach(intf -> {
+            neighbourHandlers.put(intf, neighbourHandler);
+
+            neighbourService.registerNeighbourHandler(intf, neighbourHandler, appId);
+        });
+
+        log.debug("Activated");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        interfaceService.removeListener(interfaceListener);
+        neighbourHandlers.entrySet().forEach(e -> {
+            neighbourService.unregisterNeighbourHandler(e.getKey(), e.getValue(), appId);
+        });
+        log.debug("Deactivated");
+    }
+
+    private void configNeighbourHandler(Interface intf,
+                                          NeighbourMessageHandler handler,
+                                          InterfaceEvent.Type eventType) {
+        switch (eventType) {
+            case INTERFACE_ADDED:
+                neighbourHandlers.put(intf, handler);
+                neighbourService.registerNeighbourHandler(intf, handler, appId);
+                break;
+            case INTERFACE_REMOVED:
+                neighbourHandlers.remove(intf, handler);
+                neighbourService.unregisterNeighbourHandler(intf, handler, appId);
+                break;
+            case INTERFACE_UPDATED:
+                break;
+            default:
+                break;
+        }
+    }
+
+    /**
+     * Handler for neighbour messages.
+     */
+    private class VplsNeighbourMessageHandler implements NeighbourMessageHandler {
+
+        @Override
+        public void handleMessage(NeighbourMessageContext context,
+                                  HostService hostService) {
+
+            switch (context.type()) {
+                case REQUEST:
+                    interfaceService.getInterfacesByVlan(context.vlan())
+                            .stream()
+                            .map(Interface::connectPoint)
+                            .forEach(context::proxy);
+                    break;
+                case REPLY:
+                    hostService.getHostsByMac(context.dstMac())
+                            .stream()
+                            .filter(host -> host.vlan().equals(context.vlan()))
+                            .map(Host::location)
+                            .forEach(context::proxy);
+                    break;
+
+                default:
+                    log.warn("Unknown context type: {}", context.type());
+                    break;
+            }
+        }
+    }
+
+    /**
+     * Listener for interface configuration events.
+     */
+    private class VplsInterfaceListener implements InterfaceListener {
+
+        @Override
+        public void event(InterfaceEvent event) {
+            configNeighbourHandler(event.subject(), neighbourHandler, event.type());
+        }
+    }
+
+}