[ONOS-2607] Interface to implement BGP LS topology provider and listen on link changes of BGP Controller.

Change-Id: I860859bc8bb3a5ee9a7c9c0183371e1575dc4867

bgp/api/src/main/java/org/onosproject/bgp/controller/BgpLinkListener.java

@@ -0,0 +1,35 @@
+/*
+ * 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.bgp.controller;
+
+import org.onosproject.bgpio.protocol.linkstate.BgpLinkLsNlriVer4;
+
+/**
+ * Allows for providers interested in Link events to be notified.
+ */
+public interface BgpLinkListener {
+
+    /**
+     * Notify that got a packet of link from network and need do processing.
+     *
+     * @param linkNlri bgp link
+     */
+    void addLink(BgpLinkLsNlriVer4 linkNlri);
+
+    /**
+     * Notify that got a packet of link from network and need do processing.
+     *
+     * @param linkNlri bgp link
+     */
+    void deleteLink(BgpLinkLsNlriVer4 linkNlri);
+}