fix remaining signing issues in treatments.

Change-Id: Id5ae44e529a516a4b2593778491ea16ca8dc7937

@@ -292,7 +292,7 @@ public final class DefaultTrafficTreatment implements TrafficTreatment {
         }
 
         @Override
-        public Builder popMpls(Short etherType) {
+        public Builder popMpls(int etherType) {
             return add(Instructions.popMpls(etherType));
         }
 

@@ -190,7 +190,7 @@ public interface TrafficTreatment {
          * @param etherType an ether type
          * @return a treatment builder.
          */
-        Builder popMpls(Short etherType);
+        Builder popMpls(int etherType);
 
         /**
          * Sets the mpls label.

@@ -285,7 +285,7 @@ public final class Instructions {
      * @param etherType Ethernet type to set
      * @return a L2 modification.
      */
-    public static Instruction popMpls(Short etherType) {
+    public static Instruction popMpls(int etherType) {
         checkNotNull(etherType, "Ethernet type cannot be null");
         return new L2ModificationInstruction.PushHeaderInstructions(
                 L2ModificationInstruction.L2SubType.MPLS_POP, etherType);

@@ -145,16 +145,17 @@ public abstract class L2ModificationInstruction implements Instruction {
     public static final class PushHeaderInstructions extends
             L2ModificationInstruction {
 
+        private static final int MASK = 0xffff;
         private final L2SubType subtype;
-        private final short ethernetType; // uint16_t
+        private final int ethernetType; // Ethernet type value: 16 bits
 
-        PushHeaderInstructions(L2SubType subType, short ethernetType) {
+        PushHeaderInstructions(L2SubType subType, int ethernetType) {
             this.subtype = subType;
-            this.ethernetType = ethernetType;
+            this.ethernetType = ethernetType & MASK;
         }
 
         public int ethernetType() {
-            return Short.toUnsignedInt(ethernetType);
+            return ethernetType;
         }
 
         @Override
@@ -239,10 +240,11 @@ public abstract class L2ModificationInstruction implements Instruction {
      */
     public static final class ModVlanPcpInstruction extends L2ModificationInstruction {
 
-        private final Byte vlanPcp;
+        private static final byte MASK = 0x7;
+        private final byte vlanPcp;
 
-        ModVlanPcpInstruction(Byte vlanPcp) {
-            this.vlanPcp = vlanPcp;
+        ModVlanPcpInstruction(byte vlanPcp) {
+            this.vlanPcp = (byte) (vlanPcp & MASK);
         }
 
         @Override
@@ -250,7 +252,7 @@ public abstract class L2ModificationInstruction implements Instruction {
             return L2SubType.VLAN_PCP;
         }
 
-        public Byte vlanPcp() {
+        public byte vlanPcp() {
             return this.vlanPcp;
         }