Add support NXT_RESUME (#7)

* Add support NXT_RESUME

lib/openflow.ex

@@ -15,22 +15,23 @@ defmodule Openflow do
   end
 
   def read(<<ver::8, type::8, len::16, xid::32, binary2::bytes>>) do
-      try do
-        body_len = len - @ofp_header_size
-        <<body_bin::bytes-size(body_len), rest::bytes>> = binary2
+    try do
+      body_len = len - @ofp_header_size
+      <<body_bin::bytes-size(body_len), rest::bytes>> = binary2
 
-        result = type
+      result =
+        type
         |> Openflow.Enums.to_atom(:openflow_codec)
         |> do_read(body_bin)
 
-        case result do
-          {:ok, struct} -> {:ok, %{struct | version: ver, xid: xid}, rest}
-          {:error, reason} -> {:error, reason}
-        end
-      catch
-        _c, _e ->
-          {:error, :malformed_packet}
+      case result do
+        {:ok, struct} -> {:ok, %{struct | version: ver, xid: xid}, rest}
+        {:error, reason} -> {:error, reason}
       end
+    catch
+      _c, reason ->
+        {:error, {:malformed_packet, {reason, __STACKTRACE__}}}
+    end
   end
 
   def to_binary(messages) when is_list(messages) do