[ONOS-3120] Service Function Forwarder Implementation

Change-Id: I483ce290be21ed35a30994d5685005a0dfd3f13d
diff --git a/apps/vtn/sfcmgr/src/main/java/org/onosproject/sfc/forwarder/ServiceFunctionForwarderService.java b/apps/vtn/sfcmgr/src/main/java/org/onosproject/sfc/forwarder/ServiceFunctionForwarderService.java
new file mode 100644
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--- /dev/null
+++ b/apps/vtn/sfcmgr/src/main/java/org/onosproject/sfc/forwarder/ServiceFunctionForwarderService.java
@@ -0,0 +1,51 @@
+/*
+ * 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.sfc.forwarder;
+
+import org.onosproject.net.flowobjective.Objective;
+import org.onosproject.net.NshServicePathId;
+import org.onosproject.vtnrsc.PortChain;
+
+/**
+ * Abstraction of an entity which provides Service function forwarder.
+ */
+public interface ServiceFunctionForwarderService {
+
+    /**
+     * Install Forwarding rule.
+     *
+     * @param portChain port-chain
+     * @param nshSPI nsh spi
+     */
+    void installForwardingRule(PortChain portChain, NshServicePathId nshSPI);
+
+    /**
+     * Uninstall Forwarding rule.
+     *
+     * @param portChain port-chain
+     * @param nshSPI nsh spi
+     */
+    void unInstallForwardingRule(PortChain portChain, NshServicePathId nshSPI);
+
+    /**
+     * Prepare forwarding object for Service Function.
+     *
+     * @param portChain port-chain
+     * @param nshSPI nsh spi
+     * @param type forwarding objective operation type
+     */
+    void prepareServiceFunctionForwarder(PortChain portChain, NshServicePathId nshSPI, Objective.Operation type);
+}