Refactored nicira extended actions

lib/openflow/actions/nx_conjunction.ex

@@ -9,18 +9,27 @@ defmodule Openflow.Action.NxConjunction do
   @nxast 34
 
   alias __MODULE__
+  alias Openflow.Action.Experimenter
+
+  def new(options \\ []) do
+    n_clauses = options[:n_clauses] || raise "n_clauses must be specified"
+    n_clauses >= 2 || raise "n_clauses must be greater than 1"
 
-  def new(options) do
     %NxConjunction{
-      clause: options[:clause] || 0,
-      n_clauses: options[:n_clauses] || 0,
+      clause: (options[:clause] || 0) + 1,
+      n_clauses: n_clauses,
       id: options[:id] || 0
     }
   end
 
   def to_binary(%NxConjunction{clause: clause, n_clauses: n_clauses, id: id}) do
-    exp_body = <<@experimenter::32, @nxast::16, clause::8, n_clauses::8, id::32>>
-    <<0xFFFF::16, 16::16, exp_body::bytes>>
+    Experimenter.pack_exp_header(<<
+      @experimenter::32,
+      @nxast::16,
+      clause::8,
+      n_clauses::8,
+      id::32
+    >>)
   end
 
   def read(<<@experimenter::32, @nxast::16, clause::8, n_clauses::8, id::32>>) do