IpPrefix fix

- addied  method #prefixLength()
- ANY: array is mutable, should not be exposed public

Change-Id: I4197dbd79370fa39c92468b9c31f0ae04bc01fcd

@@ -36,7 +36,6 @@ import org.onlab.onos.openflow.controller.PacketListener;
 import org.onlab.onos.openflow.controller.RoleState;
 import org.onlab.packet.ARP;
 import org.onlab.packet.Ethernet;
-import org.onlab.packet.IpPrefix;
 import org.projectfloodlight.openflow.protocol.OFFactory;
 import org.projectfloodlight.openflow.protocol.OFMessage;
 import org.projectfloodlight.openflow.protocol.OFPacketIn;
@@ -76,6 +75,8 @@ public class OpenFlowPacketProviderTest {
     private static final TrafficTreatment TR = treatment(INST1, INST2);
     private static final TrafficTreatment TR_MISSING = treatment(INST1, INST3);
 
+    private static final byte[] ANY = new byte [] {0, 0, 0, 0};
+
     private final OpenFlowPacketProvider provider = new OpenFlowPacketProvider();
     private final TestPacketRegistry registry = new TestPacketRegistry();
     private final TestController controller = new TestController();
@@ -113,10 +114,10 @@ public class OpenFlowPacketProviderTest {
         MacAddress mac2 = MacAddress.of("00:00:00:22:00:02");
 
         ARP arp = new ARP();
-        arp.setSenderProtocolAddress(IpPrefix.ANY)
+        arp.setSenderProtocolAddress(ANY)
         .setSenderHardwareAddress(mac1.getBytes())
         .setTargetHardwareAddress(mac2.getBytes())
-        .setTargetProtocolAddress(IpPrefix.ANY)
+        .setTargetProtocolAddress(ANY)
         .setHardwareType((short) 0)
         .setProtocolType((short) 0)
         .setHardwareAddressLength((byte) 6)

@@ -24,7 +24,7 @@ public final class IpPrefix {
     /**
      * Default value indicating an unspecified address.
      */
-    public static final byte [] ANY = new byte [] {0, 0, 0, 0};
+    static final byte[] ANY = new byte [] {0, 0, 0, 0};
 
     protected Version version;
 
@@ -152,11 +152,20 @@ public final class IpPrefix {
      *
      * @return a byte array
      */
-    public byte [] toOctets() {
+    public byte[] toOctets() {
         return Arrays.copyOf(this.octets, INET_LEN);
     }
 
     /**
+     * Returns the IP address prefix length.
+     *
+     * @return prefix length
+     */
+    public int prefixLength() {
+        return netmask;
+    }
+
+    /**
      * Returns the integral value of this IP address.
      *
      * @return the IP address's value as an integer