Separated ARP proxy as an independent component and some renaming

- Renamed CordVtnService to DependencyService
- Renamed CordVtnInstanceManager to InstanceManager and added
  InstanceService as an interface of the manager implementation
- Renamed package name impl.service to impl.handler
- Added Constants class

Change-Id: I249708c008d5105957aa1d1a796f0ca32025e75c
diff --git a/src/main/java/org/opencord/cordvtn/impl/handler/ManagementInstanceHandler.java b/src/main/java/org/opencord/cordvtn/impl/handler/ManagementInstanceHandler.java
new file mode 100644
index 0000000..fe30781
--- /dev/null
+++ b/src/main/java/org/opencord/cordvtn/impl/handler/ManagementInstanceHandler.java
@@ -0,0 +1,210 @@
+/*
+ * 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.opencord.cordvtn.impl.handler;
+
+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.onlab.packet.Ethernet;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.flow.DefaultFlowRule;
+import org.onosproject.net.flow.DefaultTrafficSelector;
+import org.onosproject.net.flow.DefaultTrafficTreatment;
+import org.onosproject.net.flow.FlowRule;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.xosclient.api.VtnService;
+import org.opencord.cordvtn.impl.AbstractInstanceHandler;
+import org.opencord.cordvtn.api.Instance;
+import org.opencord.cordvtn.api.InstanceHandler;
+import org.opencord.cordvtn.impl.CordVtnPipeline;
+
+import java.util.Optional;
+
+import static org.onosproject.xosclient.api.VtnServiceApi.ServiceType.MANAGEMENT;
+
+/**
+ * Provides network connectivity for management network connected instances.
+ */
+@Component(immediate = true)
+public class ManagementInstanceHandler extends AbstractInstanceHandler implements InstanceHandler {
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected CordVtnPipeline pipeline;
+
+    @Activate
+    protected void activate() {
+        serviceType = Optional.of(MANAGEMENT);
+        super.activate();
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        super.deactivate();
+    }
+
+    @Override
+    public void instanceDetected(Instance instance) {
+        log.info("Instance is detected {}", instance);
+
+        VtnService service = getVtnService(instance.serviceId());
+        if (service == null) {
+            log.warn("Failed to get VtnService for {}", instance);
+            return;
+        }
+        localMgmtNetworkRules(instance, service, true);
+    }
+
+    @Override
+    public void instanceRemoved(Instance instance) {
+        log.info("Instance is removed {}", instance);
+
+        VtnService service = getVtnService(instance.serviceId());
+        if (service == null) {
+            log.warn("Failed to get VtnService for {}", instance);
+            return;
+        }
+
+        // TODO check if any stale management network rules are
+        localMgmtNetworkRules(instance, service, false);
+    }
+
+    private void localMgmtNetworkRules(Instance instance, VtnService service, boolean install) {
+        managementPerInstanceRule(instance, install);
+        if (install) {
+            managementBaseRule(instance, service, true);
+        } else if (!hostService.getConnectedHosts(instance.deviceId()).stream()
+                .filter(host -> Instance.of(host).serviceId().equals(service.id()))
+                .findAny()
+                .isPresent()) {
+            managementBaseRule(instance, service, false);
+        }
+    }
+
+    private void managementBaseRule(Instance instance, VtnService service, boolean install) {
+        TrafficSelector selector = DefaultTrafficSelector.builder()
+                .matchEthType(Ethernet.TYPE_ARP)
+                .matchArpTpa(service.serviceIp().getIp4Address())
+                .build();
+
+        TrafficTreatment treatment = DefaultTrafficTreatment.builder()
+                .setOutput(PortNumber.LOCAL)
+                .build();
+
+        FlowRule flowRule = DefaultFlowRule.builder()
+                .fromApp(appId)
+                .withSelector(selector)
+                .withTreatment(treatment)
+                .withPriority(CordVtnPipeline.PRIORITY_MANAGEMENT)
+                .forDevice(instance.deviceId())
+                .forTable(CordVtnPipeline.TABLE_ZERO)
+                .makePermanent()
+                .build();
+
+        pipeline.processFlowRule(install, flowRule);
+
+        selector = DefaultTrafficSelector.builder()
+                .matchInPort(PortNumber.LOCAL)
+                .matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPDst(service.subnet())
+                .build();
+
+        treatment = DefaultTrafficTreatment.builder()
+                .transition(CordVtnPipeline.TABLE_DST_IP)
+                .build();
+
+        flowRule = DefaultFlowRule.builder()
+                .fromApp(appId)
+                .withSelector(selector)
+                .withTreatment(treatment)
+                .withPriority(CordVtnPipeline.PRIORITY_MANAGEMENT)
+                .forDevice(instance.deviceId())
+                .forTable(CordVtnPipeline.TABLE_ZERO)
+                .makePermanent()
+                .build();
+
+        pipeline.processFlowRule(install, flowRule);
+
+        selector = DefaultTrafficSelector.builder()
+                .matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPDst(service.serviceIp().toIpPrefix())
+                .build();
+
+        treatment = DefaultTrafficTreatment.builder()
+                .setOutput(PortNumber.LOCAL)
+                .build();
+
+        flowRule = DefaultFlowRule.builder()
+                .fromApp(appId)
+                .withSelector(selector)
+                .withTreatment(treatment)
+                .withPriority(CordVtnPipeline.PRIORITY_MANAGEMENT)
+                .forDevice(instance.deviceId())
+                .forTable(CordVtnPipeline.TABLE_ZERO)
+                .makePermanent()
+                .build();
+
+        pipeline.processFlowRule(install, flowRule);
+    }
+
+    private void managementPerInstanceRule(Instance instance, boolean install) {
+        TrafficSelector selector = DefaultTrafficSelector.builder()
+                .matchInPort(PortNumber.LOCAL)
+                .matchEthType(Ethernet.TYPE_ARP)
+                .matchArpTpa(instance.ipAddress().getIp4Address())
+                .build();
+
+        TrafficTreatment treatment = DefaultTrafficTreatment.builder()
+                .setOutput(instance.portNumber())
+                .build();
+
+        FlowRule flowRule = DefaultFlowRule.builder()
+                .fromApp(appId)
+                .withSelector(selector)
+                .withTreatment(treatment)
+                .withPriority(CordVtnPipeline.PRIORITY_MANAGEMENT)
+                .forDevice(instance.deviceId())
+                .forTable(CordVtnPipeline.TABLE_ZERO)
+                .makePermanent()
+                .build();
+
+        pipeline.processFlowRule(install, flowRule);
+
+        selector = DefaultTrafficSelector.builder()
+                .matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPDst(instance.ipAddress().toIpPrefix())
+                .build();
+
+        treatment = DefaultTrafficTreatment.builder()
+                .setEthDst(instance.mac())
+                .setOutput(instance.portNumber())
+                .build();
+
+        flowRule = DefaultFlowRule.builder()
+                .fromApp(appId)
+                .withSelector(selector)
+                .withTreatment(treatment)
+                .withPriority(CordVtnPipeline.PRIORITY_DEFAULT)
+                .forDevice(instance.deviceId())
+                .forTable(CordVtnPipeline.TABLE_DST_IP)
+                .makePermanent()
+                .build();
+
+        pipeline.processFlowRule(install, flowRule);
+    }
+}