Refactored nicira extended actions

lib/openflow/actions/nx_stack_push.ex

@@ -9,26 +9,30 @@ defmodule Openflow.Action.NxStackPush do
   @nxast 27
 
   alias __MODULE__
+  alias Openflow.Action.Experimenter
 
   def new(options) do
-    field = Keyword.get(options, :field)
+    field = options[:field] || raise "field must be specified"
     default_n_bits = Openflow.Match.Field.n_bits_of(field)
-    n_bits = Keyword.get(options, :n_bits, default_n_bits)
-    ofs = Keyword.get(options, :offset, 0)
-    %NxStackPush{n_bits: n_bits, offset: ofs, field: field}
+
+    %NxStackPush{
+      n_bits: options[:n_bits] || default_n_bits,
+      offset: options[:offset] || 0,
+      field: field
+    }
   end
 
-  def to_binary(%NxStackPush{n_bits: n_bits, offset: ofs, field: field}) do
-    field_bin = Openflow.Match.codec_header(field)
+  def to_binary(%NxStackPush{} = stack_pop) do
+    field_bin = Openflow.Match.codec_header(stack_pop.field)
 
-    exp_body =
-      <<@experimenter::32, @nxast::16, ofs::16, field_bin::4-bytes, n_bits::16,
-        0::size(6)-unit(8)>>
-
-    exp_body_size = byte_size(exp_body)
-    padding_length = Openflow.Utils.padding(4 + exp_body_size, 8)
-    length = 4 + exp_body_size + padding_length
-    <<0xFFFF::16, length::16, exp_body::bytes, 0::size(padding_length)-unit(8)>>
+    Experimenter.pack_exp_header(<<
+      @experimenter::32,
+      @nxast::16,
+      stack_pop.offset::16,
+      field_bin::4-bytes,
+      stack_pop.n_bits::16,
+      0::size(6)-unit(8)
+    >>)
   end
 
   def read(