[ONOS-4718] Initial implementation of LISP address serializer

Change-Id: I71e1923f6daf1abdf2bf9798a9e421c81926a45c
diff --git a/protocols/lisp/msg/src/main/java/org/onosproject/lisp/msg/types/LispIpv4Address.java b/protocols/lisp/msg/src/main/java/org/onosproject/lisp/msg/types/LispIpv4Address.java
index 1cc5829..a0df8d8 100644
--- a/protocols/lisp/msg/src/main/java/org/onosproject/lisp/msg/types/LispIpv4Address.java
+++ b/protocols/lisp/msg/src/main/java/org/onosproject/lisp/msg/types/LispIpv4Address.java
@@ -18,6 +18,7 @@
 import io.netty.buffer.ByteBuf;
 import org.onlab.packet.IpAddress;
 import org.onosproject.lisp.msg.exceptions.LispParseError;
+import org.onosproject.lisp.msg.exceptions.LispWriterException;
 
 import java.util.Objects;
 
@@ -74,4 +75,16 @@
             return new LispIpv4Address(ipAddress);
         }
     }
+
+    /**
+     * IPv4 address writer class.
+     */
+    public static class Ipv4AddressWriter implements LispAddressWriter<LispIpv4Address> {
+
+        @Override
+        public void writeTo(ByteBuf byteBuf, LispIpv4Address address) throws LispWriterException {
+            byte[] ipByte = address.getAddress().getIp4Address().toOctets();
+            byteBuf.writeBytes(ipByte);
+        }
+    }
 }