diff --git a/src/python/loxi/of12/action.py b/src/python/loxi/of12/action.py
index 141d118..7a93a43 100644
--- a/src/python/loxi/of12/action.py
+++ b/src/python/loxi/of12/action.py
@@ -3,28 +3,61 @@
 # Copyright (c) 2012, 2013 Big Switch Networks, Inc.
 # See the file LICENSE.pyloxi which should have been included in the source distribution
 
-# Automatically generated by LOXI from template action.py
+# Automatically generated by LOXI from template module.py
 # Do not modify
 
 import struct
+import loxi
 import const
+import common
+import action
+import instruction
+import oxm
 import util
 import loxi.generic_util
-import loxi
-import oxm # for unpack
 
-def unpack_list(reader):
-    def deserializer(reader, typ):
-        parser = parsers.get(typ)
-        if not parser: raise loxi.ProtocolError("unknown action type %d" % typ)
-        return parser(reader)
-    return loxi.generic_util.unpack_list_tlv16(reader, deserializer)
+class action(loxi.OFObject):
+    subtypes = {}
 
-class Action(object):
-    type = None # override in subclass
-    pass
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!H', 0)
+        try:
+            subclass = action.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown action subtype %#x" % subtype)
+        return subclass.unpack(reader)
 
-class bsn_mirror(Action):
+
+class experimenter(action):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!L', 4)
+        try:
+            subclass = experimenter.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown experimenter action subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+action.subtypes[65535] = experimenter
+
+class bsn(experimenter):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!L', 8)
+        try:
+            subclass = bsn.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown bsn experimenter action subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+experimenter.subtypes[6035143] = bsn
+
+class bsn_mirror(bsn):
     type = 65535
     experimenter = 6035143
     subtype = 1
@@ -59,15 +92,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_mirror()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 65535)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -85,13 +116,6 @@
         if self.copy_stage != other.copy_stage: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_mirror {")
         with q.group():
@@ -108,7 +132,9 @@
             q.breakable()
         q.text('}')
 
-class bsn_set_tunnel_dst(Action):
+bsn.subtypes[1] = bsn_mirror
+
+class bsn_set_tunnel_dst(bsn):
     type = 65535
     experimenter = 6035143
     subtype = 2
@@ -132,15 +158,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_set_tunnel_dst()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 65535)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -153,13 +177,6 @@
         if self.dst != other.dst: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_set_tunnel_dst {")
         with q.group():
@@ -170,7 +187,9 @@
             q.breakable()
         q.text('}')
 
-class copy_ttl_in(Action):
+bsn.subtypes[2] = bsn_set_tunnel_dst
+
+class copy_ttl_in(action):
     type = 12
 
     def __init__(self):
@@ -186,15 +205,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = copy_ttl_in()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 12)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         reader.skip(4)
         return obj
 
@@ -202,13 +219,6 @@
         if type(self) != type(other): return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("copy_ttl_in {")
         with q.group():
@@ -217,7 +227,9 @@
             q.breakable()
         q.text('}')
 
-class copy_ttl_out(Action):
+action.subtypes[12] = copy_ttl_in
+
+class copy_ttl_out(action):
     type = 11
 
     def __init__(self):
@@ -233,15 +245,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = copy_ttl_out()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 11)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         reader.skip(4)
         return obj
 
@@ -249,13 +259,6 @@
         if type(self) != type(other): return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("copy_ttl_out {")
         with q.group():
@@ -264,7 +267,9 @@
             q.breakable()
         q.text('}')
 
-class dec_mpls_ttl(Action):
+action.subtypes[11] = copy_ttl_out
+
+class dec_mpls_ttl(action):
     type = 16
 
     def __init__(self):
@@ -280,15 +285,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = dec_mpls_ttl()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 16)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         reader.skip(4)
         return obj
 
@@ -296,13 +299,6 @@
         if type(self) != type(other): return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("dec_mpls_ttl {")
         with q.group():
@@ -311,7 +307,9 @@
             q.breakable()
         q.text('}')
 
-class dec_nw_ttl(Action):
+action.subtypes[16] = dec_mpls_ttl
+
+class dec_nw_ttl(action):
     type = 24
 
     def __init__(self):
@@ -327,15 +325,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = dec_nw_ttl()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 24)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         reader.skip(4)
         return obj
 
@@ -343,13 +339,6 @@
         if type(self) != type(other): return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("dec_nw_ttl {")
         with q.group():
@@ -358,7 +347,9 @@
             q.breakable()
         q.text('}')
 
-class group(Action):
+action.subtypes[24] = dec_nw_ttl
+
+class group(action):
     type = 22
 
     def __init__(self, group_id=None):
@@ -378,15 +369,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = group()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 22)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         obj.group_id = reader.read("!L")[0]
         return obj
 
@@ -395,13 +384,6 @@
         if self.group_id != other.group_id: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group {")
         with q.group():
@@ -412,7 +394,23 @@
             q.breakable()
         q.text('}')
 
-class nicira_dec_ttl(Action):
+action.subtypes[22] = group
+
+class nicira(experimenter):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!H', 8)
+        try:
+            subclass = nicira.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown nicira experimenter action subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+experimenter.subtypes[8992] = nicira
+
+class nicira_dec_ttl(nicira):
     type = 65535
     experimenter = 8992
     subtype = 18
@@ -433,15 +431,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = nicira_dec_ttl()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 65535)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 8992)
         _subtype = reader.read("!H")[0]
@@ -454,13 +450,6 @@
         if type(self) != type(other): return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("nicira_dec_ttl {")
         with q.group():
@@ -469,7 +458,9 @@
             q.breakable()
         q.text('}')
 
-class output(Action):
+nicira.subtypes[18] = nicira_dec_ttl
+
+class output(action):
     type = 0
 
     def __init__(self, port=None, max_len=None):
@@ -495,15 +486,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = output()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 0)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         obj.port = util.unpack_port_no(reader)
         obj.max_len = reader.read("!H")[0]
         reader.skip(6)
@@ -515,13 +504,6 @@
         if self.max_len != other.max_len: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("output {")
         with q.group():
@@ -535,7 +517,9 @@
             q.breakable()
         q.text('}')
 
-class pop_mpls(Action):
+action.subtypes[0] = output
+
+class pop_mpls(action):
     type = 20
 
     def __init__(self, ethertype=None):
@@ -556,15 +540,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = pop_mpls()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 20)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         obj.ethertype = reader.read("!H")[0]
         reader.skip(2)
         return obj
@@ -574,13 +556,6 @@
         if self.ethertype != other.ethertype: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("pop_mpls {")
         with q.group():
@@ -591,7 +566,9 @@
             q.breakable()
         q.text('}')
 
-class pop_vlan(Action):
+action.subtypes[20] = pop_mpls
+
+class pop_vlan(action):
     type = 18
 
     def __init__(self):
@@ -607,15 +584,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = pop_vlan()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 18)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         reader.skip(4)
         return obj
 
@@ -623,13 +598,6 @@
         if type(self) != type(other): return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("pop_vlan {")
         with q.group():
@@ -638,7 +606,9 @@
             q.breakable()
         q.text('}')
 
-class push_mpls(Action):
+action.subtypes[18] = pop_vlan
+
+class push_mpls(action):
     type = 19
 
     def __init__(self, ethertype=None):
@@ -659,15 +629,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = push_mpls()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 19)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         obj.ethertype = reader.read("!H")[0]
         reader.skip(2)
         return obj
@@ -677,13 +645,6 @@
         if self.ethertype != other.ethertype: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("push_mpls {")
         with q.group():
@@ -694,7 +655,9 @@
             q.breakable()
         q.text('}')
 
-class push_vlan(Action):
+action.subtypes[19] = push_mpls
+
+class push_vlan(action):
     type = 17
 
     def __init__(self, ethertype=None):
@@ -715,15 +678,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = push_vlan()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 17)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         obj.ethertype = reader.read("!H")[0]
         reader.skip(2)
         return obj
@@ -733,13 +694,6 @@
         if self.ethertype != other.ethertype: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("push_vlan {")
         with q.group():
@@ -750,7 +704,9 @@
             q.breakable()
         q.text('}')
 
-class set_field(Action):
+action.subtypes[17] = push_vlan
+
+class set_field(action):
     type = 25
 
     def __init__(self, field=None):
@@ -772,17 +728,14 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = set_field()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 25)
         _len = reader.read("!H")[0]
-        obj.field = oxm.unpack(reader)
-        reader.skip_align()
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
+        obj.field = oxm.oxm.unpack(reader)
         return obj
 
     def __eq__(self, other):
@@ -790,13 +743,6 @@
         if self.field != other.field: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("set_field {")
         with q.group():
@@ -807,7 +753,9 @@
             q.breakable()
         q.text('}')
 
-class set_mpls_ttl(Action):
+action.subtypes[25] = set_field
+
+class set_mpls_ttl(action):
     type = 15
 
     def __init__(self, mpls_ttl=None):
@@ -828,15 +776,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = set_mpls_ttl()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 15)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         obj.mpls_ttl = reader.read("!B")[0]
         reader.skip(3)
         return obj
@@ -846,13 +792,6 @@
         if self.mpls_ttl != other.mpls_ttl: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("set_mpls_ttl {")
         with q.group():
@@ -863,7 +802,9 @@
             q.breakable()
         q.text('}')
 
-class set_nw_ttl(Action):
+action.subtypes[15] = set_mpls_ttl
+
+class set_nw_ttl(action):
     type = 23
 
     def __init__(self, nw_ttl=None):
@@ -884,15 +825,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = set_nw_ttl()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 23)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         obj.nw_ttl = reader.read("!B")[0]
         reader.skip(3)
         return obj
@@ -902,13 +841,6 @@
         if self.nw_ttl != other.nw_ttl: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("set_nw_ttl {")
         with q.group():
@@ -919,7 +851,9 @@
             q.breakable()
         q.text('}')
 
-class set_queue(Action):
+action.subtypes[23] = set_nw_ttl
+
+class set_queue(action):
     type = 21
 
     def __init__(self, queue_id=None):
@@ -939,15 +873,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = set_queue()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 21)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         obj.queue_id = reader.read("!L")[0]
         return obj
 
@@ -956,13 +888,6 @@
         if self.queue_id != other.queue_id: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("set_queue {")
         with q.group():
@@ -973,45 +898,6 @@
             q.breakable()
         q.text('}')
 
+action.subtypes[21] = set_queue
 
-def parse_experimenter(reader):
-    experimenter, = reader.peek("!4xL")
-    if experimenter == 0x005c16c7: # Big Switch Networks
-        subtype, = reader.peek("!8xL")
-    elif experimenter == 0x00002320: # Nicira
-        subtype, = reader.peek("!8xH")
-    else:
-        raise loxi.ProtocolError("unexpected experimenter id %#x" % experimenter)
 
-    if subtype in experimenter_parsers[experimenter]:
-        return experimenter_parsers[experimenter][subtype](reader)
-    else:
-        raise loxi.ProtocolError("unexpected BSN experimenter subtype %#x" % subtype)
-
-parsers = {
-    const.OFPAT_OUTPUT : output.unpack,
-    const.OFPAT_COPY_TTL_OUT : copy_ttl_out.unpack,
-    const.OFPAT_COPY_TTL_IN : copy_ttl_in.unpack,
-    const.OFPAT_SET_MPLS_TTL : set_mpls_ttl.unpack,
-    const.OFPAT_DEC_MPLS_TTL : dec_mpls_ttl.unpack,
-    const.OFPAT_PUSH_VLAN : push_vlan.unpack,
-    const.OFPAT_POP_VLAN : pop_vlan.unpack,
-    const.OFPAT_PUSH_MPLS : push_mpls.unpack,
-    const.OFPAT_POP_MPLS : pop_mpls.unpack,
-    const.OFPAT_SET_QUEUE : set_queue.unpack,
-    const.OFPAT_GROUP : group.unpack,
-    const.OFPAT_SET_NW_TTL : set_nw_ttl.unpack,
-    const.OFPAT_DEC_NW_TTL : dec_nw_ttl.unpack,
-    const.OFPAT_SET_FIELD : set_field.unpack,
-    const.OFPAT_EXPERIMENTER : parse_experimenter,
-}
-
-experimenter_parsers = {
-    8992 : {
-        18: nicira_dec_ttl.unpack,
-    },
-    6035143 : {
-        1: bsn_mirror.unpack,
-        2: bsn_set_tunnel_dst.unpack,
-    },
-}
diff --git a/src/python/loxi/of12/common.py b/src/python/loxi/of12/common.py
index 3956aec..0b64bd6 100644
--- a/src/python/loxi/of12/common.py
+++ b/src/python/loxi/of12/common.py
@@ -2,63 +2,21 @@
 # Copyright (c) 2011, 2012 Open Networking Foundation
 # Copyright (c) 2012, 2013 Big Switch Networks, Inc.
 # See the file LICENSE.pyloxi which should have been included in the source distribution
-# Automatically generated by LOXI from template common.py
+
+# Automatically generated by LOXI from template module.py
 # Do not modify
 
-import sys
 import struct
-import action
-import instruction # for unpack_list
+import loxi
 import const
+import common
+import action
+import instruction
+import oxm
 import util
 import loxi.generic_util
 
-import oxm
-
-# HACK make this module visible as 'common' to simplify code generation
-common = sys.modules[__name__]
-
-def unpack_list_flow_stats_entry(reader):
-    return loxi.generic_util.unpack_list_lv16(reader, flow_stats_entry.unpack)
-
-def unpack_list_queue_prop(reader):
-    def deserializer(reader, typ):
-        if typ == const.OFPQT_MIN_RATE:
-            return queue_prop_min_rate.unpack(reader)
-        else:
-            raise loxi.ProtocolError("unknown queue prop %d" % typ)
-    return loxi.generic_util.unpack_list_tlv16(reader, deserializer)
-
-def unpack_list_packet_queue(reader):
-    def wrapper(reader):
-        length, = reader.peek('!4xH')
-        return packet_queue.unpack(reader.slice(length))
-    return loxi.generic_util.unpack_list(reader, wrapper)
-
-def unpack_list_hello_elem(reader):
-    def deserializer(reader, typ):
-        if typ == const.OFPHET_VERSIONBITMAP:
-            return hello_elem_versionbitmap.unpack(reader)
-        else:
-            return None
-    return [x for x in loxi.generic_util.unpack_list_tlv16(reader, deserializer) if x != None]
-
-def unpack_list_bucket(reader):
-    return loxi.generic_util.unpack_list_lv16(reader, bucket.unpack)
-
-def unpack_list_group_desc_stats_entry(reader):
-    return loxi.generic_util.unpack_list_lv16(reader, group_desc_stats_entry.unpack)
-
-def unpack_list_group_stats_entry(reader):
-    return loxi.generic_util.unpack_list_lv16(reader, group_stats_entry.unpack)
-
-def unpack_list_meter_stats(reader):
-    def wrapper(reader):
-        length, = reader.peek('!4xH')
-        return meter_stats.unpack(reader.slice(length))
-    return loxi.generic_util.unpack_list(reader, wrapper)
-
-class bsn_interface(object):
+class bsn_interface(loxi.OFObject):
 
     def __init__(self, hw_addr=None, name=None, ipv4_addr=None, ipv4_netmask=None):
         if hw_addr != None:
@@ -89,12 +47,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_interface()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         obj.hw_addr = list(reader.read('!6B'))
         reader.skip(2)
         obj.name = reader.read("!16s")[0].rstrip("\x00")
@@ -110,13 +64,6 @@
         if self.ipv4_netmask != other.ipv4_netmask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_interface {")
         with q.group():
@@ -136,7 +83,21 @@
             q.breakable()
         q.text('}')
 
-class bsn_vport_q_in_q(object):
+
+class bsn_vport(loxi.OFObject):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!H', 0)
+        try:
+            subclass = bsn_vport.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown bsn_vport subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+
+class bsn_vport_q_in_q(bsn_vport):
     type = 0
 
     def __init__(self, port_no=None, ingress_tpid=None, ingress_vlan_id=None, egress_tpid=None, egress_vlan_id=None, if_name=None):
@@ -181,15 +142,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_vport_q_in_q()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 0)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.port_no = reader.read("!L")[0]
         obj.ingress_tpid = reader.read("!H")[0]
         obj.ingress_vlan_id = reader.read("!H")[0]
@@ -208,13 +167,6 @@
         if self.if_name != other.if_name: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_vport_q_in_q {")
         with q.group():
@@ -240,7 +192,9 @@
             q.breakable()
         q.text('}')
 
-class bucket(object):
+bsn_vport.subtypes[0] = bsn_vport_q_in_q
+
+class bucket(loxi.OFObject):
 
     def __init__(self, weight=None, watch_port=None, watch_group=None, actions=None):
         if weight != None:
@@ -268,24 +222,22 @@
         packed.append(util.pack_port_no(self.watch_port))
         packed.append(struct.pack("!L", self.watch_group))
         packed.append('\x00' * 4)
-        packed.append(util.pack_list(self.actions))
+        packed.append(loxi.generic_util.pack_list(self.actions))
         length = sum([len(x) for x in packed])
         packed[0] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bucket()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (0 + 2))
         obj.weight = reader.read("!H")[0]
         obj.watch_port = util.unpack_port_no(reader)
         obj.watch_group = reader.read("!L")[0]
         reader.skip(4)
-        obj.actions = action.unpack_list(reader)
+        obj.actions = loxi.generic_util.unpack_list(reader, action.action.unpack)
         return obj
 
     def __eq__(self, other):
@@ -296,13 +248,6 @@
         if self.actions != other.actions: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bucket {")
         with q.group():
@@ -322,7 +267,8 @@
             q.breakable()
         q.text('}')
 
-class bucket_counter(object):
+
+class bucket_counter(loxi.OFObject):
 
     def __init__(self, packet_count=None, byte_count=None):
         if packet_count != None:
@@ -342,12 +288,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bucket_counter()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         obj.packet_count = reader.read("!Q")[0]
         obj.byte_count = reader.read("!Q")[0]
         return obj
@@ -358,13 +300,6 @@
         if self.byte_count != other.byte_count: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bucket_counter {")
         with q.group():
@@ -378,7 +313,8 @@
             q.breakable()
         q.text('}')
 
-class flow_stats_entry(object):
+
+class flow_stats_entry(loxi.OFObject):
 
     def __init__(self, table_id=None, duration_sec=None, duration_nsec=None, priority=None, idle_timeout=None, hard_timeout=None, cookie=None, packet_count=None, byte_count=None, match=None, instructions=None):
         if table_id != None:
@@ -442,19 +378,17 @@
         packed.append(struct.pack("!Q", self.packet_count))
         packed.append(struct.pack("!Q", self.byte_count))
         packed.append(self.match.pack())
-        packed.append(util.pack_list(self.instructions))
+        packed.append(loxi.generic_util.pack_list(self.instructions))
         length = sum([len(x) for x in packed])
         packed[0] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = flow_stats_entry()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (0 + 2))
         obj.table_id = reader.read("!B")[0]
         reader.skip(1)
         obj.duration_sec = reader.read("!L")[0]
@@ -467,7 +401,7 @@
         obj.packet_count = reader.read("!Q")[0]
         obj.byte_count = reader.read("!Q")[0]
         obj.match = common.match.unpack(reader)
-        obj.instructions = instruction.unpack_list(reader)
+        obj.instructions = loxi.generic_util.unpack_list(reader, instruction.instruction.unpack)
         return obj
 
     def __eq__(self, other):
@@ -485,13 +419,6 @@
         if self.instructions != other.instructions: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("flow_stats_entry {")
         with q.group():
@@ -532,7 +459,8 @@
             q.breakable()
         q.text('}')
 
-class group_desc_stats_entry(object):
+
+class group_desc_stats_entry(loxi.OFObject):
 
     def __init__(self, group_type=None, group_id=None, buckets=None):
         if group_type != None:
@@ -555,23 +483,21 @@
         packed.append(struct.pack("!B", self.group_type))
         packed.append('\x00' * 1)
         packed.append(struct.pack("!L", self.group_id))
-        packed.append(util.pack_list(self.buckets))
+        packed.append(loxi.generic_util.pack_list(self.buckets))
         length = sum([len(x) for x in packed])
         packed[0] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = group_desc_stats_entry()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (0 + 2))
         obj.group_type = reader.read("!B")[0]
         reader.skip(1)
         obj.group_id = reader.read("!L")[0]
-        obj.buckets = common.unpack_list_bucket(reader)
+        obj.buckets = loxi.generic_util.unpack_list(reader, common.bucket.unpack)
         return obj
 
     def __eq__(self, other):
@@ -581,13 +507,6 @@
         if self.buckets != other.buckets: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group_desc_stats_entry {")
         with q.group():
@@ -604,7 +523,8 @@
             q.breakable()
         q.text('}')
 
-class group_stats_entry(object):
+
+class group_stats_entry(loxi.OFObject):
 
     def __init__(self, group_id=None, ref_count=None, packet_count=None, byte_count=None, bucket_stats=None):
         if group_id != None:
@@ -638,19 +558,17 @@
         packed.append('\x00' * 4)
         packed.append(struct.pack("!Q", self.packet_count))
         packed.append(struct.pack("!Q", self.byte_count))
-        packed.append(util.pack_list(self.bucket_stats))
+        packed.append(loxi.generic_util.pack_list(self.bucket_stats))
         length = sum([len(x) for x in packed])
         packed[0] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = group_stats_entry()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (0 + 2))
         reader.skip(2)
         obj.group_id = reader.read("!L")[0]
         obj.ref_count = reader.read("!L")[0]
@@ -669,13 +587,6 @@
         if self.bucket_stats != other.bucket_stats: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group_stats_entry {")
         with q.group():
@@ -698,7 +609,8 @@
             q.breakable()
         q.text('}')
 
-class match_v3(object):
+
+class match_v3(loxi.OFObject):
     type = 1
 
     def __init__(self, oxm_list=None):
@@ -712,24 +624,22 @@
         packed = []
         packed.append(struct.pack("!H", self.type))
         packed.append(struct.pack("!H", 0)) # placeholder for length at index 1
-        packed.append(util.pack_list(self.oxm_list))
+        packed.append(loxi.generic_util.pack_list(self.oxm_list))
         length = sum([len(x) for x in packed])
         packed[1] = struct.pack("!H", length)
         packed.append(loxi.generic_util.pad_to(8, length))
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = match_v3()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
-        obj.oxm_list = oxm.unpack_list(reader.slice(_length-4))
-        reader.skip_align()
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
+        obj.oxm_list = loxi.generic_util.unpack_list(reader, oxm.oxm.unpack)
+        orig_reader.skip_align()
         return obj
 
     def __eq__(self, other):
@@ -737,13 +647,6 @@
         if self.oxm_list != other.oxm_list: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("match_v3 {")
         with q.group():
@@ -754,7 +657,8 @@
             q.breakable()
         q.text('}')
 
-class packet_queue(object):
+
+class packet_queue(loxi.OFObject):
 
     def __init__(self, queue_id=None, port=None, properties=None):
         if queue_id != None:
@@ -777,23 +681,21 @@
         packed.append(util.pack_port_no(self.port))
         packed.append(struct.pack("!H", 0)) # placeholder for len at index 2
         packed.append('\x00' * 6)
-        packed.append(util.pack_list(self.properties))
+        packed.append(loxi.generic_util.pack_list(self.properties))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = packet_queue()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         obj.queue_id = reader.read("!L")[0]
         obj.port = util.unpack_port_no(reader)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (8 + 2))
         reader.skip(6)
-        obj.properties = common.unpack_list_queue_prop(reader)
+        obj.properties = loxi.generic_util.unpack_list(reader, common.queue_prop.unpack)
         return obj
 
     def __eq__(self, other):
@@ -803,13 +705,6 @@
         if self.properties != other.properties: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("packet_queue {")
         with q.group():
@@ -826,7 +721,8 @@
             q.breakable()
         q.text('}')
 
-class port_desc(object):
+
+class port_desc(loxi.OFObject):
 
     def __init__(self, port_no=None, hw_addr=None, name=None, config=None, state=None, curr=None, advertised=None, supported=None, peer=None, curr_speed=None, max_speed=None):
         if port_no != None:
@@ -893,12 +789,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = port_desc()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         obj.port_no = util.unpack_port_no(reader)
         reader.skip(4)
         obj.hw_addr = list(reader.read('!6B'))
@@ -929,13 +821,6 @@
         if self.max_speed != other.max_speed: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("port_desc {")
         with q.group():
@@ -976,7 +861,8 @@
             q.breakable()
         q.text('}')
 
-class port_stats_entry(object):
+
+class port_stats_entry(loxi.OFObject):
 
     def __init__(self, port_no=None, rx_packets=None, tx_packets=None, rx_bytes=None, tx_bytes=None, rx_dropped=None, tx_dropped=None, rx_errors=None, tx_errors=None, rx_frame_err=None, rx_over_err=None, rx_crc_err=None, collisions=None):
         if port_no != None:
@@ -1052,12 +938,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = port_stats_entry()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         obj.port_no = util.unpack_port_no(reader)
         reader.skip(4)
         obj.rx_packets = reader.read("!Q")[0]
@@ -1091,13 +973,6 @@
         if self.collisions != other.collisions: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("port_stats_entry {")
         with q.group():
@@ -1144,7 +1019,35 @@
             q.breakable()
         q.text('}')
 
-class queue_prop_max_rate(object):
+
+class queue_prop(loxi.OFObject):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!H', 0)
+        try:
+            subclass = queue_prop.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown queue_prop subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+
+class queue_prop_experimenter(queue_prop):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!L', 8)
+        try:
+            subclass = queue_prop_experimenter.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown queue_prop_experimenter queue_prop subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+queue_prop.subtypes[65535] = queue_prop_experimenter
+
+class queue_prop_max_rate(queue_prop):
     type = 2
 
     def __init__(self, rate=None):
@@ -1166,15 +1069,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = queue_prop_max_rate()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 2)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         reader.skip(4)
         obj.rate = reader.read("!H")[0]
         reader.skip(6)
@@ -1185,13 +1086,6 @@
         if self.rate != other.rate: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("queue_prop_max_rate {")
         with q.group():
@@ -1202,7 +1096,9 @@
             q.breakable()
         q.text('}')
 
-class queue_prop_min_rate(object):
+queue_prop.subtypes[2] = queue_prop_max_rate
+
+class queue_prop_min_rate(queue_prop):
     type = 1
 
     def __init__(self, rate=None):
@@ -1224,15 +1120,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = queue_prop_min_rate()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 1)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         reader.skip(4)
         obj.rate = reader.read("!H")[0]
         reader.skip(6)
@@ -1243,13 +1137,6 @@
         if self.rate != other.rate: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("queue_prop_min_rate {")
         with q.group():
@@ -1260,7 +1147,9 @@
             q.breakable()
         q.text('}')
 
-class queue_stats_entry(object):
+queue_prop.subtypes[1] = queue_prop_min_rate
+
+class queue_stats_entry(loxi.OFObject):
 
     def __init__(self, port_no=None, queue_id=None, tx_bytes=None, tx_packets=None, tx_errors=None):
         if port_no != None:
@@ -1295,12 +1184,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = queue_stats_entry()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         obj.port_no = util.unpack_port_no(reader)
         obj.queue_id = reader.read("!L")[0]
         obj.tx_bytes = reader.read("!Q")[0]
@@ -1317,13 +1202,6 @@
         if self.tx_errors != other.tx_errors: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("queue_stats_entry {")
         with q.group():
@@ -1346,7 +1224,8 @@
             q.breakable()
         q.text('}')
 
-class table_stats_entry(object):
+
+class table_stats_entry(loxi.OFObject):
 
     def __init__(self, table_id=None, name=None, match=None, wildcards=None, write_actions=None, apply_actions=None, write_setfields=None, apply_setfields=None, metadata_match=None, metadata_write=None, instructions=None, config=None, max_entries=None, active_count=None, lookup_count=None, matched_count=None):
         if table_id != None:
@@ -1437,12 +1316,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = table_stats_entry()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         obj.table_id = reader.read("!B")[0]
         reader.skip(7)
         obj.name = reader.read("!32s")[0].rstrip("\x00")
@@ -1482,13 +1357,6 @@
         if self.matched_count != other.matched_count: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("table_stats_entry {")
         with q.group():
@@ -1545,4 +1413,5 @@
         q.text('}')
 
 
+
 match = match_v3
diff --git a/src/python/loxi/of12/instruction.py b/src/python/loxi/of12/instruction.py
index 38bcdb6..e4472cd 100644
--- a/src/python/loxi/of12/instruction.py
+++ b/src/python/loxi/of12/instruction.py
@@ -3,28 +3,33 @@
 # Copyright (c) 2012, 2013 Big Switch Networks, Inc.
 # See the file LICENSE.pyloxi which should have been included in the source distribution
 
-# Automatically generated by LOXI from template instruction.py
+# Automatically generated by LOXI from template module.py
 # Do not modify
 
 import struct
-import action
+import loxi
 import const
+import common
+import action
+import instruction
+import oxm
 import util
 import loxi.generic_util
-import loxi
 
-def unpack_list(reader):
-    def deserializer(reader, typ):
-        parser = parsers.get(typ)
-        if not parser: raise loxi.ProtocolError("unknown instruction type %d" % typ)
-        return parser(reader)
-    return loxi.generic_util.unpack_list_tlv16(reader, deserializer)
+class instruction(loxi.OFObject):
+    subtypes = {}
 
-class Instruction(object):
-    type = None # override in subclass
-    pass
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!H', 0)
+        try:
+            subclass = instruction.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown instruction subtype %#x" % subtype)
+        return subclass.unpack(reader)
 
-class apply_actions(Instruction):
+
+class apply_actions(instruction):
     type = 4
 
     def __init__(self, actions=None):
@@ -39,23 +44,21 @@
         packed.append(struct.pack("!H", self.type))
         packed.append(struct.pack("!H", 0)) # placeholder for len at index 1
         packed.append('\x00' * 4)
-        packed.append(util.pack_list(self.actions))
+        packed.append(loxi.generic_util.pack_list(self.actions))
         length = sum([len(x) for x in packed])
         packed[1] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = apply_actions()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 4)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         reader.skip(4)
-        obj.actions = action.unpack_list(reader)
+        obj.actions = loxi.generic_util.unpack_list(reader, action.action.unpack)
         return obj
 
     def __eq__(self, other):
@@ -63,13 +66,6 @@
         if self.actions != other.actions: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("apply_actions {")
         with q.group():
@@ -80,7 +76,9 @@
             q.breakable()
         q.text('}')
 
-class clear_actions(Instruction):
+instruction.subtypes[4] = apply_actions
+
+class clear_actions(instruction):
     type = 5
 
     def __init__(self):
@@ -96,15 +94,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = clear_actions()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 5)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         reader.skip(4)
         return obj
 
@@ -112,13 +108,6 @@
         if type(self) != type(other): return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("clear_actions {")
         with q.group():
@@ -127,7 +116,23 @@
             q.breakable()
         q.text('}')
 
-class goto_table(Instruction):
+instruction.subtypes[5] = clear_actions
+
+class experimenter(instruction):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!L', 4)
+        try:
+            subclass = experimenter.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown experimenter instruction subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+instruction.subtypes[65535] = experimenter
+
+class goto_table(instruction):
     type = 1
 
     def __init__(self, table_id=None):
@@ -148,15 +153,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = goto_table()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 1)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         obj.table_id = reader.read("!B")[0]
         reader.skip(3)
         return obj
@@ -166,13 +169,6 @@
         if self.table_id != other.table_id: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("goto_table {")
         with q.group():
@@ -183,7 +179,9 @@
             q.breakable()
         q.text('}')
 
-class write_actions(Instruction):
+instruction.subtypes[1] = goto_table
+
+class write_actions(instruction):
     type = 3
 
     def __init__(self, actions=None):
@@ -198,23 +196,21 @@
         packed.append(struct.pack("!H", self.type))
         packed.append(struct.pack("!H", 0)) # placeholder for len at index 1
         packed.append('\x00' * 4)
-        packed.append(util.pack_list(self.actions))
+        packed.append(loxi.generic_util.pack_list(self.actions))
         length = sum([len(x) for x in packed])
         packed[1] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = write_actions()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 3)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         reader.skip(4)
-        obj.actions = action.unpack_list(reader)
+        obj.actions = loxi.generic_util.unpack_list(reader, action.action.unpack)
         return obj
 
     def __eq__(self, other):
@@ -222,13 +218,6 @@
         if self.actions != other.actions: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("write_actions {")
         with q.group():
@@ -239,7 +228,9 @@
             q.breakable()
         q.text('}')
 
-class write_metadata(Instruction):
+instruction.subtypes[3] = write_actions
+
+class write_metadata(instruction):
     type = 2
 
     def __init__(self, metadata=None, metadata_mask=None):
@@ -265,15 +256,13 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = write_metadata()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type = reader.read("!H")[0]
         assert(_type == 2)
         _len = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_len - (2 + 2))
         reader.skip(4)
         obj.metadata = reader.read("!Q")[0]
         obj.metadata_mask = reader.read("!Q")[0]
@@ -285,13 +274,6 @@
         if self.metadata_mask != other.metadata_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("write_metadata {")
         with q.group():
@@ -305,26 +287,6 @@
             q.breakable()
         q.text('}')
 
+instruction.subtypes[2] = write_metadata
 
-def parse_experimenter(reader):
-    experimenter, = reader.peek("!4xL")
-    if experimenter == 0x005c16c7: # Big Switch Networks
-        subtype, = reader.peek("!8xL")
-    else:
-        raise loxi.ProtocolError("unexpected experimenter id %#x" % experimenter)
 
-    if subtype in experimenter_parsers[experimenter]:
-        return experimenter_parsers[experimenter][subtype](reader)
-    else:
-        raise loxi.ProtocolError("unexpected experimenter id %#x subtype %#x" % (experimenter, subtype))
-
-parsers = {
-    const.OFPIT_GOTO_TABLE : goto_table.unpack,
-    const.OFPIT_WRITE_METADATA : write_metadata.unpack,
-    const.OFPIT_WRITE_ACTIONS : write_actions.unpack,
-    const.OFPIT_APPLY_ACTIONS : apply_actions.unpack,
-    const.OFPIT_CLEAR_ACTIONS : clear_actions.unpack,
-}
-
-experimenter_parsers = {
-}
diff --git a/src/python/loxi/of12/message.py b/src/python/loxi/of12/message.py
index a5956bc..72dad2a 100644
--- a/src/python/loxi/of12/message.py
+++ b/src/python/loxi/of12/message.py
@@ -3,30 +3,56 @@
 # Copyright (c) 2012, 2013 Big Switch Networks, Inc.
 # See the file LICENSE.pyloxi which should have been included in the source distribution
 
-# Automatically generated by LOXI from template message.py
+# Automatically generated by LOXI from template module.py
 # Do not modify
 
 import struct
 import loxi
 import const
 import common
-import action # for unpack_list
-import instruction # for unpack_list
+import action
+import instruction
+import oxm
 import util
 import loxi.generic_util
 
-class Message(object):
-    version = const.OFP_VERSION
-    type = None # override in subclass
-    xid = None
+class message(loxi.OFObject):
+    subtypes = {}
 
-class aggregate_stats_reply(Message):
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('B', 1)
+        try:
+            subclass = message.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+
+class stats_reply(message):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!H', 8)
+        try:
+            subclass = stats_reply.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown stats_reply message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+message.subtypes[19] = stats_reply
+
+class aggregate_stats_reply(stats_reply):
     version = 3
     type = 19
     stats_type = 2
 
     def __init__(self, xid=None, flags=None, packet_count=None, byte_count=None, flow_count=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -43,6 +69,7 @@
             self.flow_count = flow_count
         else:
             self.flow_count = 0
+        return
 
     def pack(self):
         packed = []
@@ -62,18 +89,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = aggregate_stats_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 19)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 2)
@@ -87,8 +111,6 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.packet_count != other.packet_count: return False
@@ -96,16 +118,6 @@
         if self.flow_count != other.flow_count: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("aggregate_stats_reply {")
         with q.group():
@@ -131,13 +143,32 @@
             q.breakable()
         q.text('}')
 
-class aggregate_stats_request(Message):
+stats_reply.subtypes[2] = aggregate_stats_reply
+
+class stats_request(message):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!H', 8)
+        try:
+            subclass = stats_request.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown stats_request message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+message.subtypes[18] = stats_request
+
+class aggregate_stats_request(stats_request):
     version = 3
     type = 18
     stats_type = 2
 
     def __init__(self, xid=None, flags=None, table_id=None, out_port=None, out_group=None, cookie=None, cookie_mask=None, match=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -166,6 +197,7 @@
             self.match = match
         else:
             self.match = common.match()
+        return
 
     def pack(self):
         packed = []
@@ -189,18 +221,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = aggregate_stats_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 18)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 2)
@@ -218,8 +247,6 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.table_id != other.table_id: return False
@@ -230,16 +257,6 @@
         if self.match != other.match: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("aggregate_stats_request {")
         with q.group():
@@ -274,13 +291,32 @@
             q.breakable()
         q.text('}')
 
-class bad_action_error_msg(Message):
+stats_request.subtypes[2] = aggregate_stats_request
+
+class error_msg(message):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!H', 8)
+        try:
+            subclass = error_msg.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown error_msg message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+message.subtypes[1] = error_msg
+
+class bad_action_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 2
 
     def __init__(self, xid=None, code=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if code != None:
             self.code = code
         else:
@@ -289,6 +325,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -304,18 +341,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bad_action_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 2)
@@ -325,23 +359,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.code != other.code: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bad_action_error_msg {")
         with q.group():
@@ -361,13 +383,18 @@
             q.breakable()
         q.text('}')
 
-class bad_instruction_error_msg(Message):
+error_msg.subtypes[2] = bad_action_error_msg
+
+class bad_instruction_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 3
 
     def __init__(self, xid=None, code=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if code != None:
             self.code = code
         else:
@@ -376,6 +403,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -391,18 +419,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bad_instruction_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 3)
@@ -412,23 +437,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.code != other.code: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bad_instruction_error_msg {")
         with q.group():
@@ -448,13 +461,18 @@
             q.breakable()
         q.text('}')
 
-class bad_match_error_msg(Message):
+error_msg.subtypes[3] = bad_instruction_error_msg
+
+class bad_match_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 4
 
     def __init__(self, xid=None, code=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if code != None:
             self.code = code
         else:
@@ -463,6 +481,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -478,18 +497,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bad_match_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 4)
@@ -499,23 +515,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.code != other.code: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bad_match_error_msg {")
         with q.group():
@@ -535,13 +539,18 @@
             q.breakable()
         q.text('}')
 
-class bad_request_error_msg(Message):
+error_msg.subtypes[4] = bad_match_error_msg
+
+class bad_request_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 1
 
     def __init__(self, xid=None, code=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if code != None:
             self.code = code
         else:
@@ -550,6 +559,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -565,18 +575,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bad_request_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 1)
@@ -586,23 +593,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.code != other.code: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bad_request_error_msg {")
         with q.group():
@@ -622,12 +617,18 @@
             q.breakable()
         q.text('}')
 
-class barrier_reply(Message):
+error_msg.subtypes[1] = bad_request_error_msg
+
+class barrier_reply(message):
     version = 3
     type = 21
 
     def __init__(self, xid=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
+        return
 
     def pack(self):
         packed = []
@@ -640,38 +641,23 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = barrier_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 21)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("barrier_reply {")
         with q.group():
@@ -685,12 +671,18 @@
             q.breakable()
         q.text('}')
 
-class barrier_request(Message):
+message.subtypes[21] = barrier_reply
+
+class barrier_request(message):
     version = 3
     type = 20
 
     def __init__(self, xid=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
+        return
 
     def pack(self):
         packed = []
@@ -703,38 +695,23 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = barrier_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 20)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("barrier_request {")
         with q.group():
@@ -748,18 +725,52 @@
             q.breakable()
         q.text('}')
 
-class bsn_bw_clear_data_reply(Message):
+message.subtypes[20] = barrier_request
+
+class experimenter(message):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!L', 8)
+        try:
+            subclass = experimenter.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown experimenter message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+message.subtypes[4] = experimenter
+
+class bsn_header(experimenter):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!L', 12)
+        try:
+            subclass = bsn_header.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown bsn_header experimenter message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+experimenter.subtypes[6035143] = bsn_header
+
+class bsn_bw_clear_data_reply(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 22
 
     def __init__(self, xid=None, status=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if status != None:
             self.status = status
         else:
             self.status = 0
+        return
 
     def pack(self):
         packed = []
@@ -775,18 +786,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_bw_clear_data_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -797,22 +805,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.status != other.status: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_bw_clear_data_reply {")
         with q.group():
@@ -829,14 +825,20 @@
             q.breakable()
         q.text('}')
 
-class bsn_bw_clear_data_request(Message):
+bsn_header.subtypes[22] = bsn_bw_clear_data_reply
+
+class bsn_bw_clear_data_request(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 21
 
     def __init__(self, xid=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
+        return
 
     def pack(self):
         packed = []
@@ -851,18 +853,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_bw_clear_data_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -872,21 +871,9 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_bw_clear_data_request {")
         with q.group():
@@ -900,18 +887,24 @@
             q.breakable()
         q.text('}')
 
-class bsn_bw_enable_get_reply(Message):
+bsn_header.subtypes[21] = bsn_bw_clear_data_request
+
+class bsn_bw_enable_get_reply(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 20
 
     def __init__(self, xid=None, enabled=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if enabled != None:
             self.enabled = enabled
         else:
             self.enabled = 0
+        return
 
     def pack(self):
         packed = []
@@ -927,18 +920,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_bw_enable_get_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -949,22 +939,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.enabled != other.enabled: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_bw_enable_get_reply {")
         with q.group():
@@ -981,14 +959,20 @@
             q.breakable()
         q.text('}')
 
-class bsn_bw_enable_get_request(Message):
+bsn_header.subtypes[20] = bsn_bw_enable_get_reply
+
+class bsn_bw_enable_get_request(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 19
 
     def __init__(self, xid=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
+        return
 
     def pack(self):
         packed = []
@@ -1003,18 +987,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_bw_enable_get_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -1024,21 +1005,9 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_bw_enable_get_request {")
         with q.group():
@@ -1052,14 +1021,19 @@
             q.breakable()
         q.text('}')
 
-class bsn_bw_enable_set_reply(Message):
+bsn_header.subtypes[19] = bsn_bw_enable_get_request
+
+class bsn_bw_enable_set_reply(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 23
 
     def __init__(self, xid=None, enable=None, status=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if enable != None:
             self.enable = enable
         else:
@@ -1068,6 +1042,7 @@
             self.status = status
         else:
             self.status = 0
+        return
 
     def pack(self):
         packed = []
@@ -1084,18 +1059,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_bw_enable_set_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -1107,23 +1079,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.enable != other.enable: return False
         if self.status != other.status: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_bw_enable_set_reply {")
         with q.group():
@@ -1143,18 +1103,24 @@
             q.breakable()
         q.text('}')
 
-class bsn_bw_enable_set_request(Message):
+bsn_header.subtypes[23] = bsn_bw_enable_set_reply
+
+class bsn_bw_enable_set_request(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 18
 
     def __init__(self, xid=None, enable=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if enable != None:
             self.enable = enable
         else:
             self.enable = 0
+        return
 
     def pack(self):
         packed = []
@@ -1170,18 +1136,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_bw_enable_set_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -1192,22 +1155,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.enable != other.enable: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_bw_enable_set_request {")
         with q.group():
@@ -1224,18 +1175,24 @@
             q.breakable()
         q.text('}')
 
-class bsn_get_interfaces_reply(Message):
+bsn_header.subtypes[18] = bsn_bw_enable_set_request
+
+class bsn_get_interfaces_reply(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 10
 
     def __init__(self, xid=None, interfaces=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if interfaces != None:
             self.interfaces = interfaces
         else:
             self.interfaces = []
+        return
 
     def pack(self):
         packed = []
@@ -1245,24 +1202,21 @@
         packed.append(struct.pack("!L", self.xid))
         packed.append(struct.pack("!L", self.experimenter))
         packed.append(struct.pack("!L", self.subtype))
-        packed.append(util.pack_list(self.interfaces))
+        packed.append(loxi.generic_util.pack_list(self.interfaces))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_get_interfaces_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -1273,22 +1227,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.interfaces != other.interfaces: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_get_interfaces_reply {")
         with q.group():
@@ -1305,14 +1247,20 @@
             q.breakable()
         q.text('}')
 
-class bsn_get_interfaces_request(Message):
+bsn_header.subtypes[10] = bsn_get_interfaces_reply
+
+class bsn_get_interfaces_request(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 9
 
     def __init__(self, xid=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
+        return
 
     def pack(self):
         packed = []
@@ -1327,18 +1275,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_get_interfaces_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -1348,21 +1293,9 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_get_interfaces_request {")
         with q.group():
@@ -1376,18 +1309,24 @@
             q.breakable()
         q.text('}')
 
-class bsn_get_mirroring_reply(Message):
+bsn_header.subtypes[9] = bsn_get_interfaces_request
+
+class bsn_get_mirroring_reply(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 5
 
     def __init__(self, xid=None, report_mirror_ports=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if report_mirror_ports != None:
             self.report_mirror_ports = report_mirror_ports
         else:
             self.report_mirror_ports = 0
+        return
 
     def pack(self):
         packed = []
@@ -1404,18 +1343,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_get_mirroring_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -1427,22 +1363,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.report_mirror_ports != other.report_mirror_ports: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_get_mirroring_reply {")
         with q.group():
@@ -1459,18 +1383,24 @@
             q.breakable()
         q.text('}')
 
-class bsn_get_mirroring_request(Message):
+bsn_header.subtypes[5] = bsn_get_mirroring_reply
+
+class bsn_get_mirroring_request(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 4
 
     def __init__(self, xid=None, report_mirror_ports=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if report_mirror_ports != None:
             self.report_mirror_ports = report_mirror_ports
         else:
             self.report_mirror_ports = 0
+        return
 
     def pack(self):
         packed = []
@@ -1487,18 +1417,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_get_mirroring_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -1510,22 +1437,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.report_mirror_ports != other.report_mirror_ports: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_get_mirroring_request {")
         with q.group():
@@ -1542,14 +1457,19 @@
             q.breakable()
         q.text('}')
 
-class bsn_pdu_rx_reply(Message):
+bsn_header.subtypes[4] = bsn_get_mirroring_request
+
+class bsn_pdu_rx_reply(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 34
 
     def __init__(self, xid=None, status=None, port_no=None, slot_num=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if status != None:
             self.status = status
         else:
@@ -1562,6 +1482,7 @@
             self.slot_num = slot_num
         else:
             self.slot_num = 0
+        return
 
     def pack(self):
         packed = []
@@ -1579,18 +1500,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_pdu_rx_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -1603,24 +1521,12 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.status != other.status: return False
         if self.port_no != other.port_no: return False
         if self.slot_num != other.slot_num: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_pdu_rx_reply {")
         with q.group():
@@ -1643,14 +1549,19 @@
             q.breakable()
         q.text('}')
 
-class bsn_pdu_rx_request(Message):
+bsn_header.subtypes[34] = bsn_pdu_rx_reply
+
+class bsn_pdu_rx_request(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 33
 
     def __init__(self, xid=None, timeout_ms=None, port_no=None, slot_num=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if timeout_ms != None:
             self.timeout_ms = timeout_ms
         else:
@@ -1667,6 +1578,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -1686,18 +1598,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_pdu_rx_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -1712,8 +1621,6 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.timeout_ms != other.timeout_ms: return False
         if self.port_no != other.port_no: return False
@@ -1721,16 +1628,6 @@
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_pdu_rx_request {")
         with q.group():
@@ -1756,14 +1653,19 @@
             q.breakable()
         q.text('}')
 
-class bsn_pdu_rx_timeout(Message):
+bsn_header.subtypes[33] = bsn_pdu_rx_request
+
+class bsn_pdu_rx_timeout(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 35
 
     def __init__(self, xid=None, port_no=None, slot_num=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if port_no != None:
             self.port_no = port_no
         else:
@@ -1772,6 +1674,7 @@
             self.slot_num = slot_num
         else:
             self.slot_num = 0
+        return
 
     def pack(self):
         packed = []
@@ -1788,18 +1691,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_pdu_rx_timeout()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -1811,23 +1711,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.port_no != other.port_no: return False
         if self.slot_num != other.slot_num: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_pdu_rx_timeout {")
         with q.group():
@@ -1847,14 +1735,19 @@
             q.breakable()
         q.text('}')
 
-class bsn_pdu_tx_reply(Message):
+bsn_header.subtypes[35] = bsn_pdu_rx_timeout
+
+class bsn_pdu_tx_reply(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 32
 
     def __init__(self, xid=None, status=None, port_no=None, slot_num=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if status != None:
             self.status = status
         else:
@@ -1867,6 +1760,7 @@
             self.slot_num = slot_num
         else:
             self.slot_num = 0
+        return
 
     def pack(self):
         packed = []
@@ -1884,18 +1778,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_pdu_tx_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -1908,24 +1799,12 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.status != other.status: return False
         if self.port_no != other.port_no: return False
         if self.slot_num != other.slot_num: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_pdu_tx_reply {")
         with q.group():
@@ -1948,14 +1827,19 @@
             q.breakable()
         q.text('}')
 
-class bsn_pdu_tx_request(Message):
+bsn_header.subtypes[32] = bsn_pdu_tx_reply
+
+class bsn_pdu_tx_request(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 31
 
     def __init__(self, xid=None, tx_interval_ms=None, port_no=None, slot_num=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if tx_interval_ms != None:
             self.tx_interval_ms = tx_interval_ms
         else:
@@ -1972,6 +1856,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -1991,18 +1876,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_pdu_tx_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -2017,8 +1899,6 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.tx_interval_ms != other.tx_interval_ms: return False
         if self.port_no != other.port_no: return False
@@ -2026,16 +1906,6 @@
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_pdu_tx_request {")
         with q.group():
@@ -2061,18 +1931,24 @@
             q.breakable()
         q.text('}')
 
-class bsn_set_mirroring(Message):
+bsn_header.subtypes[31] = bsn_pdu_tx_request
+
+class bsn_set_mirroring(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 3
 
     def __init__(self, xid=None, report_mirror_ports=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if report_mirror_ports != None:
             self.report_mirror_ports = report_mirror_ports
         else:
             self.report_mirror_ports = 0
+        return
 
     def pack(self):
         packed = []
@@ -2089,18 +1965,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_set_mirroring()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -2112,22 +1985,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.report_mirror_ports != other.report_mirror_ports: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_set_mirroring {")
         with q.group():
@@ -2144,18 +2005,24 @@
             q.breakable()
         q.text('}')
 
-class bsn_set_pktin_suppression_reply(Message):
+bsn_header.subtypes[3] = bsn_set_mirroring
+
+class bsn_set_pktin_suppression_reply(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 25
 
     def __init__(self, xid=None, status=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if status != None:
             self.status = status
         else:
             self.status = 0
+        return
 
     def pack(self):
         packed = []
@@ -2171,18 +2038,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_set_pktin_suppression_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -2193,22 +2057,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.status != other.status: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_set_pktin_suppression_reply {")
         with q.group():
@@ -2225,14 +2077,19 @@
             q.breakable()
         q.text('}')
 
-class bsn_set_pktin_suppression_request(Message):
+bsn_header.subtypes[25] = bsn_set_pktin_suppression_reply
+
+class bsn_set_pktin_suppression_request(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 11
 
     def __init__(self, xid=None, enabled=None, idle_timeout=None, hard_timeout=None, priority=None, cookie=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if enabled != None:
             self.enabled = enabled
         else:
@@ -2253,6 +2110,7 @@
             self.cookie = cookie
         else:
             self.cookie = 0
+        return
 
     def pack(self):
         packed = []
@@ -2273,18 +2131,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_set_pktin_suppression_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -2300,8 +2155,6 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.enabled != other.enabled: return False
         if self.idle_timeout != other.idle_timeout: return False
@@ -2310,16 +2163,6 @@
         if self.cookie != other.cookie: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_set_pktin_suppression_request {")
         with q.group():
@@ -2348,14 +2191,75 @@
             q.breakable()
         q.text('}')
 
-class bsn_virtual_port_create_reply(Message):
+bsn_header.subtypes[11] = bsn_set_pktin_suppression_request
+
+class experimenter_stats_reply(stats_reply):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!L', 16)
+        try:
+            subclass = experimenter_stats_reply.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown experimenter_stats_reply stats_reply message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+stats_reply.subtypes[65535] = experimenter_stats_reply
+
+class bsn_stats_reply(experimenter_stats_reply):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!L', 20)
+        try:
+            subclass = bsn_stats_reply.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown bsn_stats_reply experimenter_stats_reply stats_reply message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+experimenter_stats_reply.subtypes[6035143] = bsn_stats_reply
+
+class experimenter_stats_request(stats_request):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!L', 16)
+        try:
+            subclass = experimenter_stats_request.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown experimenter_stats_request stats_request message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+stats_request.subtypes[65535] = experimenter_stats_request
+
+class bsn_stats_request(experimenter_stats_request):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!L', 20)
+        try:
+            subclass = bsn_stats_request.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown bsn_stats_request experimenter_stats_request stats_request message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+experimenter_stats_request.subtypes[6035143] = bsn_stats_request
+
+class bsn_virtual_port_create_reply(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 16
 
     def __init__(self, xid=None, status=None, vport_no=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if status != None:
             self.status = status
         else:
@@ -2364,6 +2268,7 @@
             self.vport_no = vport_no
         else:
             self.vport_no = 0
+        return
 
     def pack(self):
         packed = []
@@ -2380,18 +2285,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_virtual_port_create_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -2403,23 +2305,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.status != other.status: return False
         if self.vport_no != other.vport_no: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_virtual_port_create_reply {")
         with q.group():
@@ -2439,18 +2329,24 @@
             q.breakable()
         q.text('}')
 
-class bsn_virtual_port_create_request(Message):
+bsn_header.subtypes[16] = bsn_virtual_port_create_reply
+
+class bsn_virtual_port_create_request(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 15
 
     def __init__(self, xid=None, vport=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if vport != None:
             self.vport = vport
         else:
             self.vport = common.bsn_vport_q_in_q()
+        return
 
     def pack(self):
         packed = []
@@ -2466,18 +2362,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_virtual_port_create_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -2488,22 +2381,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.vport != other.vport: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_virtual_port_create_request {")
         with q.group():
@@ -2520,18 +2401,24 @@
             q.breakable()
         q.text('}')
 
-class bsn_virtual_port_remove_reply(Message):
+bsn_header.subtypes[15] = bsn_virtual_port_create_request
+
+class bsn_virtual_port_remove_reply(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 26
 
     def __init__(self, xid=None, status=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if status != None:
             self.status = status
         else:
             self.status = 0
+        return
 
     def pack(self):
         packed = []
@@ -2547,18 +2434,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_virtual_port_remove_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -2569,22 +2453,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.status != other.status: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_virtual_port_remove_reply {")
         with q.group():
@@ -2601,18 +2473,24 @@
             q.breakable()
         q.text('}')
 
-class bsn_virtual_port_remove_request(Message):
+bsn_header.subtypes[26] = bsn_virtual_port_remove_reply
+
+class bsn_virtual_port_remove_request(bsn_header):
     version = 3
     type = 4
     experimenter = 6035143
     subtype = 17
 
     def __init__(self, xid=None, vport_no=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if vport_no != None:
             self.vport_no = vport_no
         else:
             self.vport_no = 0
+        return
 
     def pack(self):
         packed = []
@@ -2628,18 +2506,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = bsn_virtual_port_remove_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 4)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
@@ -2650,22 +2525,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.vport_no != other.vport_no: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_virtual_port_remove_request {")
         with q.group():
@@ -2682,13 +2545,18 @@
             q.breakable()
         q.text('}')
 
-class desc_stats_reply(Message):
+bsn_header.subtypes[17] = bsn_virtual_port_remove_request
+
+class desc_stats_reply(stats_reply):
     version = 3
     type = 19
     stats_type = 0
 
     def __init__(self, xid=None, flags=None, mfr_desc=None, hw_desc=None, sw_desc=None, serial_num=None, dp_desc=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -2713,6 +2581,7 @@
             self.dp_desc = dp_desc
         else:
             self.dp_desc = ""
+        return
 
     def pack(self):
         packed = []
@@ -2733,18 +2602,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = desc_stats_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 19)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 0)
@@ -2759,8 +2625,6 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.mfr_desc != other.mfr_desc: return False
@@ -2770,16 +2634,6 @@
         if self.dp_desc != other.dp_desc: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("desc_stats_reply {")
         with q.group():
@@ -2811,17 +2665,23 @@
             q.breakable()
         q.text('}')
 
-class desc_stats_request(Message):
+stats_reply.subtypes[0] = desc_stats_reply
+
+class desc_stats_request(stats_request):
     version = 3
     type = 18
     stats_type = 0
 
     def __init__(self, xid=None, flags=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
             self.flags = 0
+        return
 
     def pack(self):
         packed = []
@@ -2837,18 +2697,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = desc_stats_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 18)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 0)
@@ -2858,22 +2715,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("desc_stats_request {")
         with q.group():
@@ -2890,16 +2735,22 @@
             q.breakable()
         q.text('}')
 
-class echo_reply(Message):
+stats_request.subtypes[0] = desc_stats_request
+
+class echo_reply(message):
     version = 3
     type = 3
 
     def __init__(self, xid=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if data != None:
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -2913,40 +2764,25 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = echo_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 3)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.data = str(reader.read_all())
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("echo_reply {")
         with q.group():
@@ -2963,16 +2799,22 @@
             q.breakable()
         q.text('}')
 
-class echo_request(Message):
+message.subtypes[3] = echo_reply
+
+class echo_request(message):
     version = 3
     type = 2
 
     def __init__(self, xid=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if data != None:
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -2986,40 +2828,25 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = echo_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 2)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.data = str(reader.read_all())
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("echo_request {")
         with q.group():
@@ -3036,13 +2863,18 @@
             q.breakable()
         q.text('}')
 
-class experimenter_error_msg(Message):
+message.subtypes[2] = echo_request
+
+class experimenter_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 65535
 
     def __init__(self, xid=None, subtype=None, experimenter=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if subtype != None:
             self.subtype = subtype
         else:
@@ -3055,6 +2887,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -3071,18 +2904,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = experimenter_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 65535)
@@ -3093,24 +2923,12 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.subtype != other.subtype: return False
         if self.experimenter != other.experimenter: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("experimenter_error_msg {")
         with q.group():
@@ -3133,12 +2951,17 @@
             q.breakable()
         q.text('}')
 
-class features_reply(Message):
+error_msg.subtypes[65535] = experimenter_error_msg
+
+class features_reply(message):
     version = 3
     type = 6
 
     def __init__(self, xid=None, datapath_id=None, n_buffers=None, n_tables=None, capabilities=None, reserved=None, ports=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if datapath_id != None:
             self.datapath_id = datapath_id
         else:
@@ -3163,6 +2986,7 @@
             self.ports = ports
         else:
             self.ports = []
+        return
 
     def pack(self):
         packed = []
@@ -3176,24 +3000,21 @@
         packed.append('\x00' * 3)
         packed.append(struct.pack("!L", self.capabilities))
         packed.append(struct.pack("!L", self.reserved))
-        packed.append(util.pack_list(self.ports))
+        packed.append(loxi.generic_util.pack_list(self.ports))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = features_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 6)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.datapath_id = reader.read("!Q")[0]
         obj.n_buffers = reader.read("!L")[0]
@@ -3206,8 +3027,6 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.datapath_id != other.datapath_id: return False
         if self.n_buffers != other.n_buffers: return False
@@ -3217,16 +3036,6 @@
         if self.ports != other.ports: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("features_reply {")
         with q.group():
@@ -3258,12 +3067,18 @@
             q.breakable()
         q.text('}')
 
-class features_request(Message):
+message.subtypes[6] = features_reply
+
+class features_request(message):
     version = 3
     type = 5
 
     def __init__(self, xid=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
+        return
 
     def pack(self):
         packed = []
@@ -3276,38 +3091,23 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = features_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 5)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("features_request {")
         with q.group():
@@ -3321,13 +3121,32 @@
             q.breakable()
         q.text('}')
 
-class flow_add(Message):
+message.subtypes[5] = features_request
+
+class flow_mod(message):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('B', 25)
+        try:
+            subclass = flow_mod.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown flow_mod message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+message.subtypes[14] = flow_mod
+
+class flow_add(flow_mod):
     version = 3
     type = 14
     _command = 0
 
     def __init__(self, xid=None, cookie=None, cookie_mask=None, table_id=None, idle_timeout=None, hard_timeout=None, priority=None, buffer_id=None, out_port=None, out_group=None, flags=None, match=None, instructions=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if cookie != None:
             self.cookie = cookie
         else:
@@ -3376,6 +3195,7 @@
             self.instructions = instructions
         else:
             self.instructions = []
+        return
 
     def pack(self):
         packed = []
@@ -3396,24 +3216,21 @@
         packed.append(struct.pack("!H", self.flags))
         packed.append('\x00' * 2)
         packed.append(self.match.pack())
-        packed.append(util.pack_list(self.instructions))
+        packed.append(loxi.generic_util.pack_list(self.instructions))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = flow_add()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 14)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.cookie = reader.read("!Q")[0]
         obj.cookie_mask = reader.read("!Q")[0]
@@ -3429,13 +3246,11 @@
         obj.flags = reader.read("!H")[0]
         reader.skip(2)
         obj.match = common.match.unpack(reader)
-        obj.instructions = instruction.unpack_list(reader)
+        obj.instructions = loxi.generic_util.unpack_list(reader, instruction.instruction.unpack)
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.cookie != other.cookie: return False
         if self.cookie_mask != other.cookie_mask: return False
@@ -3451,16 +3266,6 @@
         if self.instructions != other.instructions: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("flow_add {")
         with q.group():
@@ -3510,13 +3315,18 @@
             q.breakable()
         q.text('}')
 
-class flow_delete(Message):
+flow_mod.subtypes[0] = flow_add
+
+class flow_delete(flow_mod):
     version = 3
     type = 14
     _command = 3
 
     def __init__(self, xid=None, cookie=None, cookie_mask=None, table_id=None, idle_timeout=None, hard_timeout=None, priority=None, buffer_id=None, out_port=None, out_group=None, flags=None, match=None, instructions=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if cookie != None:
             self.cookie = cookie
         else:
@@ -3565,6 +3375,7 @@
             self.instructions = instructions
         else:
             self.instructions = []
+        return
 
     def pack(self):
         packed = []
@@ -3585,24 +3396,21 @@
         packed.append(struct.pack("!H", self.flags))
         packed.append('\x00' * 2)
         packed.append(self.match.pack())
-        packed.append(util.pack_list(self.instructions))
+        packed.append(loxi.generic_util.pack_list(self.instructions))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = flow_delete()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 14)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.cookie = reader.read("!Q")[0]
         obj.cookie_mask = reader.read("!Q")[0]
@@ -3618,13 +3426,11 @@
         obj.flags = reader.read("!H")[0]
         reader.skip(2)
         obj.match = common.match.unpack(reader)
-        obj.instructions = instruction.unpack_list(reader)
+        obj.instructions = loxi.generic_util.unpack_list(reader, instruction.instruction.unpack)
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.cookie != other.cookie: return False
         if self.cookie_mask != other.cookie_mask: return False
@@ -3640,16 +3446,6 @@
         if self.instructions != other.instructions: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("flow_delete {")
         with q.group():
@@ -3699,13 +3495,18 @@
             q.breakable()
         q.text('}')
 
-class flow_delete_strict(Message):
+flow_mod.subtypes[3] = flow_delete
+
+class flow_delete_strict(flow_mod):
     version = 3
     type = 14
     _command = 4
 
     def __init__(self, xid=None, cookie=None, cookie_mask=None, table_id=None, idle_timeout=None, hard_timeout=None, priority=None, buffer_id=None, out_port=None, out_group=None, flags=None, match=None, instructions=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if cookie != None:
             self.cookie = cookie
         else:
@@ -3754,6 +3555,7 @@
             self.instructions = instructions
         else:
             self.instructions = []
+        return
 
     def pack(self):
         packed = []
@@ -3774,24 +3576,21 @@
         packed.append(struct.pack("!H", self.flags))
         packed.append('\x00' * 2)
         packed.append(self.match.pack())
-        packed.append(util.pack_list(self.instructions))
+        packed.append(loxi.generic_util.pack_list(self.instructions))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = flow_delete_strict()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 14)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.cookie = reader.read("!Q")[0]
         obj.cookie_mask = reader.read("!Q")[0]
@@ -3807,13 +3606,11 @@
         obj.flags = reader.read("!H")[0]
         reader.skip(2)
         obj.match = common.match.unpack(reader)
-        obj.instructions = instruction.unpack_list(reader)
+        obj.instructions = loxi.generic_util.unpack_list(reader, instruction.instruction.unpack)
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.cookie != other.cookie: return False
         if self.cookie_mask != other.cookie_mask: return False
@@ -3829,16 +3626,6 @@
         if self.instructions != other.instructions: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("flow_delete_strict {")
         with q.group():
@@ -3888,13 +3675,18 @@
             q.breakable()
         q.text('}')
 
-class flow_mod_failed_error_msg(Message):
+flow_mod.subtypes[4] = flow_delete_strict
+
+class flow_mod_failed_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 5
 
     def __init__(self, xid=None, code=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if code != None:
             self.code = code
         else:
@@ -3903,6 +3695,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -3918,18 +3711,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = flow_mod_failed_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 5)
@@ -3939,23 +3729,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.code != other.code: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("flow_mod_failed_error_msg {")
         with q.group():
@@ -3975,13 +3753,18 @@
             q.breakable()
         q.text('}')
 
-class flow_modify(Message):
+error_msg.subtypes[5] = flow_mod_failed_error_msg
+
+class flow_modify(flow_mod):
     version = 3
     type = 14
     _command = 1
 
     def __init__(self, xid=None, cookie=None, cookie_mask=None, table_id=None, idle_timeout=None, hard_timeout=None, priority=None, buffer_id=None, out_port=None, out_group=None, flags=None, match=None, instructions=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if cookie != None:
             self.cookie = cookie
         else:
@@ -4030,6 +3813,7 @@
             self.instructions = instructions
         else:
             self.instructions = []
+        return
 
     def pack(self):
         packed = []
@@ -4050,24 +3834,21 @@
         packed.append(struct.pack("!H", self.flags))
         packed.append('\x00' * 2)
         packed.append(self.match.pack())
-        packed.append(util.pack_list(self.instructions))
+        packed.append(loxi.generic_util.pack_list(self.instructions))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = flow_modify()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 14)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.cookie = reader.read("!Q")[0]
         obj.cookie_mask = reader.read("!Q")[0]
@@ -4083,13 +3864,11 @@
         obj.flags = reader.read("!H")[0]
         reader.skip(2)
         obj.match = common.match.unpack(reader)
-        obj.instructions = instruction.unpack_list(reader)
+        obj.instructions = loxi.generic_util.unpack_list(reader, instruction.instruction.unpack)
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.cookie != other.cookie: return False
         if self.cookie_mask != other.cookie_mask: return False
@@ -4105,16 +3884,6 @@
         if self.instructions != other.instructions: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("flow_modify {")
         with q.group():
@@ -4164,13 +3933,18 @@
             q.breakable()
         q.text('}')
 
-class flow_modify_strict(Message):
+flow_mod.subtypes[1] = flow_modify
+
+class flow_modify_strict(flow_mod):
     version = 3
     type = 14
     _command = 2
 
     def __init__(self, xid=None, cookie=None, cookie_mask=None, table_id=None, idle_timeout=None, hard_timeout=None, priority=None, buffer_id=None, out_port=None, out_group=None, flags=None, match=None, instructions=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if cookie != None:
             self.cookie = cookie
         else:
@@ -4219,6 +3993,7 @@
             self.instructions = instructions
         else:
             self.instructions = []
+        return
 
     def pack(self):
         packed = []
@@ -4239,24 +4014,21 @@
         packed.append(struct.pack("!H", self.flags))
         packed.append('\x00' * 2)
         packed.append(self.match.pack())
-        packed.append(util.pack_list(self.instructions))
+        packed.append(loxi.generic_util.pack_list(self.instructions))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = flow_modify_strict()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 14)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.cookie = reader.read("!Q")[0]
         obj.cookie_mask = reader.read("!Q")[0]
@@ -4272,13 +4044,11 @@
         obj.flags = reader.read("!H")[0]
         reader.skip(2)
         obj.match = common.match.unpack(reader)
-        obj.instructions = instruction.unpack_list(reader)
+        obj.instructions = loxi.generic_util.unpack_list(reader, instruction.instruction.unpack)
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.cookie != other.cookie: return False
         if self.cookie_mask != other.cookie_mask: return False
@@ -4294,16 +4064,6 @@
         if self.instructions != other.instructions: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("flow_modify_strict {")
         with q.group():
@@ -4353,12 +4113,17 @@
             q.breakable()
         q.text('}')
 
-class flow_removed(Message):
+flow_mod.subtypes[2] = flow_modify_strict
+
+class flow_removed(message):
     version = 3
     type = 11
 
     def __init__(self, xid=None, cookie=None, priority=None, reason=None, table_id=None, duration_sec=None, duration_nsec=None, idle_timeout=None, hard_timeout=None, packet_count=None, byte_count=None, match=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if cookie != None:
             self.cookie = cookie
         else:
@@ -4403,6 +4168,7 @@
             self.match = match
         else:
             self.match = common.match()
+        return
 
     def pack(self):
         packed = []
@@ -4426,18 +4192,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = flow_removed()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 11)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.cookie = reader.read("!Q")[0]
         obj.priority = reader.read("!H")[0]
@@ -4454,8 +4217,6 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.cookie != other.cookie: return False
         if self.priority != other.priority: return False
@@ -4470,16 +4231,6 @@
         if self.match != other.match: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("flow_removed {")
         with q.group():
@@ -4526,13 +4277,18 @@
             q.breakable()
         q.text('}')
 
-class flow_stats_reply(Message):
+message.subtypes[11] = flow_removed
+
+class flow_stats_reply(stats_reply):
     version = 3
     type = 19
     stats_type = 1
 
     def __init__(self, xid=None, flags=None, entries=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -4541,6 +4297,7 @@
             self.entries = entries
         else:
             self.entries = []
+        return
 
     def pack(self):
         packed = []
@@ -4551,51 +4308,36 @@
         packed.append(struct.pack("!H", self.stats_type))
         packed.append(struct.pack("!H", self.flags))
         packed.append('\x00' * 4)
-        packed.append(util.pack_list(self.entries))
+        packed.append(loxi.generic_util.pack_list(self.entries))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = flow_stats_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 19)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 1)
         obj.flags = reader.read("!H")[0]
         reader.skip(4)
-        obj.entries = common.unpack_list_flow_stats_entry(reader)
+        obj.entries = loxi.generic_util.unpack_list(reader, common.flow_stats_entry.unpack)
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.entries != other.entries: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("flow_stats_reply {")
         with q.group():
@@ -4615,13 +4357,18 @@
             q.breakable()
         q.text('}')
 
-class flow_stats_request(Message):
+stats_reply.subtypes[1] = flow_stats_reply
+
+class flow_stats_request(stats_request):
     version = 3
     type = 18
     stats_type = 1
 
     def __init__(self, xid=None, flags=None, table_id=None, out_port=None, out_group=None, cookie=None, cookie_mask=None, match=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -4650,6 +4397,7 @@
             self.match = match
         else:
             self.match = common.match()
+        return
 
     def pack(self):
         packed = []
@@ -4673,18 +4421,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = flow_stats_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 18)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 1)
@@ -4702,8 +4447,6 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.table_id != other.table_id: return False
@@ -4714,16 +4457,6 @@
         if self.match != other.match: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("flow_stats_request {")
         with q.group():
@@ -4758,12 +4491,17 @@
             q.breakable()
         q.text('}')
 
-class get_config_reply(Message):
+stats_request.subtypes[1] = flow_stats_request
+
+class get_config_reply(message):
     version = 3
     type = 8
 
     def __init__(self, xid=None, flags=None, miss_send_len=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -4772,6 +4510,7 @@
             self.miss_send_len = miss_send_len
         else:
             self.miss_send_len = 0
+        return
 
     def pack(self):
         packed = []
@@ -4786,18 +4525,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = get_config_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 8)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.flags = reader.read("!H")[0]
         obj.miss_send_len = reader.read("!H")[0]
@@ -4805,23 +4541,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.miss_send_len != other.miss_send_len: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("get_config_reply {")
         with q.group():
@@ -4841,12 +4565,18 @@
             q.breakable()
         q.text('}')
 
-class get_config_request(Message):
+message.subtypes[8] = get_config_reply
+
+class get_config_request(message):
     version = 3
     type = 7
 
     def __init__(self, xid=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
+        return
 
     def pack(self):
         packed = []
@@ -4859,38 +4589,23 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = get_config_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 7)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("get_config_request {")
         with q.group():
@@ -4904,13 +4619,32 @@
             q.breakable()
         q.text('}')
 
-class group_add(Message):
+message.subtypes[7] = get_config_request
+
+class group_mod(message):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!H', 8)
+        try:
+            subclass = group_mod.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown group_mod message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+message.subtypes[15] = group_mod
+
+class group_add(group_mod):
     version = 3
     type = 15
     command = 0
 
     def __init__(self, xid=None, group_type=None, group_id=None, buckets=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if group_type != None:
             self.group_type = group_type
         else:
@@ -4923,6 +4657,7 @@
             self.buckets = buckets
         else:
             self.buckets = []
+        return
 
     def pack(self):
         packed = []
@@ -4934,53 +4669,38 @@
         packed.append(struct.pack("!B", self.group_type))
         packed.append('\x00' * 1)
         packed.append(struct.pack("!L", self.group_id))
-        packed.append(util.pack_list(self.buckets))
+        packed.append(loxi.generic_util.pack_list(self.buckets))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = group_add()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 15)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _command = reader.read("!H")[0]
         assert(_command == 0)
         obj.group_type = reader.read("!B")[0]
         reader.skip(1)
         obj.group_id = reader.read("!L")[0]
-        obj.buckets = common.unpack_list_bucket(reader)
+        obj.buckets = loxi.generic_util.unpack_list(reader, common.bucket.unpack)
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.group_type != other.group_type: return False
         if self.group_id != other.group_id: return False
         if self.buckets != other.buckets: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group_add {")
         with q.group():
@@ -5003,13 +4723,18 @@
             q.breakable()
         q.text('}')
 
-class group_delete(Message):
+group_mod.subtypes[0] = group_add
+
+class group_delete(group_mod):
     version = 3
     type = 15
     command = 2
 
     def __init__(self, xid=None, group_type=None, group_id=None, buckets=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if group_type != None:
             self.group_type = group_type
         else:
@@ -5022,6 +4747,7 @@
             self.buckets = buckets
         else:
             self.buckets = []
+        return
 
     def pack(self):
         packed = []
@@ -5033,53 +4759,38 @@
         packed.append(struct.pack("!B", self.group_type))
         packed.append('\x00' * 1)
         packed.append(struct.pack("!L", self.group_id))
-        packed.append(util.pack_list(self.buckets))
+        packed.append(loxi.generic_util.pack_list(self.buckets))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = group_delete()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 15)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _command = reader.read("!H")[0]
         assert(_command == 2)
         obj.group_type = reader.read("!B")[0]
         reader.skip(1)
         obj.group_id = reader.read("!L")[0]
-        obj.buckets = common.unpack_list_bucket(reader)
+        obj.buckets = loxi.generic_util.unpack_list(reader, common.bucket.unpack)
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.group_type != other.group_type: return False
         if self.group_id != other.group_id: return False
         if self.buckets != other.buckets: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group_delete {")
         with q.group():
@@ -5102,13 +4813,18 @@
             q.breakable()
         q.text('}')
 
-class group_desc_stats_reply(Message):
+group_mod.subtypes[2] = group_delete
+
+class group_desc_stats_reply(stats_reply):
     version = 3
     type = 19
     stats_type = 7
 
     def __init__(self, xid=None, flags=None, entries=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -5117,6 +4833,7 @@
             self.entries = entries
         else:
             self.entries = []
+        return
 
     def pack(self):
         packed = []
@@ -5127,51 +4844,36 @@
         packed.append(struct.pack("!H", self.stats_type))
         packed.append(struct.pack("!H", self.flags))
         packed.append('\x00' * 4)
-        packed.append(util.pack_list(self.entries))
+        packed.append(loxi.generic_util.pack_list(self.entries))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = group_desc_stats_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 19)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 7)
         obj.flags = reader.read("!H")[0]
         reader.skip(4)
-        obj.entries = common.unpack_list_group_desc_stats_entry(reader)
+        obj.entries = loxi.generic_util.unpack_list(reader, common.group_desc_stats_entry.unpack)
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.entries != other.entries: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group_desc_stats_reply {")
         with q.group():
@@ -5191,17 +4893,23 @@
             q.breakable()
         q.text('}')
 
-class group_desc_stats_request(Message):
+stats_reply.subtypes[7] = group_desc_stats_reply
+
+class group_desc_stats_request(stats_request):
     version = 3
     type = 18
     stats_type = 7
 
     def __init__(self, xid=None, flags=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
             self.flags = 0
+        return
 
     def pack(self):
         packed = []
@@ -5217,18 +4925,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = group_desc_stats_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 18)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 7)
@@ -5238,22 +4943,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group_desc_stats_request {")
         with q.group():
@@ -5270,13 +4963,18 @@
             q.breakable()
         q.text('}')
 
-class group_features_stats_reply(Message):
+stats_request.subtypes[7] = group_desc_stats_request
+
+class group_features_stats_reply(stats_reply):
     version = 3
     type = 19
     stats_type = 8
 
     def __init__(self, xid=None, flags=None, types=None, capabilities=None, max_groups_all=None, max_groups_select=None, max_groups_indirect=None, max_groups_ff=None, actions_all=None, actions_select=None, actions_indirect=None, actions_ff=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -5321,6 +5019,7 @@
             self.actions_ff = actions_ff
         else:
             self.actions_ff = 0
+        return
 
     def pack(self):
         packed = []
@@ -5346,18 +5045,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = group_features_stats_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 19)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 8)
@@ -5377,8 +5073,6 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.types != other.types: return False
@@ -5393,16 +5087,6 @@
         if self.actions_ff != other.actions_ff: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group_features_stats_reply {")
         with q.group():
@@ -5449,17 +5133,23 @@
             q.breakable()
         q.text('}')
 
-class group_features_stats_request(Message):
+stats_reply.subtypes[8] = group_features_stats_reply
+
+class group_features_stats_request(stats_request):
     version = 3
     type = 18
     stats_type = 8
 
     def __init__(self, xid=None, flags=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
             self.flags = 0
+        return
 
     def pack(self):
         packed = []
@@ -5475,18 +5165,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = group_features_stats_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 18)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 8)
@@ -5496,22 +5183,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group_features_stats_request {")
         with q.group():
@@ -5528,13 +5203,18 @@
             q.breakable()
         q.text('}')
 
-class group_mod_failed_error_msg(Message):
+stats_request.subtypes[8] = group_features_stats_request
+
+class group_mod_failed_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 6
 
     def __init__(self, xid=None, code=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if code != None:
             self.code = code
         else:
@@ -5543,6 +5223,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -5558,18 +5239,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = group_mod_failed_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 6)
@@ -5579,23 +5257,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.code != other.code: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group_mod_failed_error_msg {")
         with q.group():
@@ -5615,13 +5281,18 @@
             q.breakable()
         q.text('}')
 
-class group_modify(Message):
+error_msg.subtypes[6] = group_mod_failed_error_msg
+
+class group_modify(group_mod):
     version = 3
     type = 15
     command = 1
 
     def __init__(self, xid=None, group_type=None, group_id=None, buckets=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if group_type != None:
             self.group_type = group_type
         else:
@@ -5634,6 +5305,7 @@
             self.buckets = buckets
         else:
             self.buckets = []
+        return
 
     def pack(self):
         packed = []
@@ -5645,53 +5317,38 @@
         packed.append(struct.pack("!B", self.group_type))
         packed.append('\x00' * 1)
         packed.append(struct.pack("!L", self.group_id))
-        packed.append(util.pack_list(self.buckets))
+        packed.append(loxi.generic_util.pack_list(self.buckets))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = group_modify()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 15)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _command = reader.read("!H")[0]
         assert(_command == 1)
         obj.group_type = reader.read("!B")[0]
         reader.skip(1)
         obj.group_id = reader.read("!L")[0]
-        obj.buckets = common.unpack_list_bucket(reader)
+        obj.buckets = loxi.generic_util.unpack_list(reader, common.bucket.unpack)
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.group_type != other.group_type: return False
         if self.group_id != other.group_id: return False
         if self.buckets != other.buckets: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group_modify {")
         with q.group():
@@ -5714,13 +5371,18 @@
             q.breakable()
         q.text('}')
 
-class group_stats_reply(Message):
+group_mod.subtypes[1] = group_modify
+
+class group_stats_reply(stats_reply):
     version = 3
     type = 19
     stats_type = 6
 
     def __init__(self, xid=None, flags=None, entries=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -5729,6 +5391,7 @@
             self.entries = entries
         else:
             self.entries = []
+        return
 
     def pack(self):
         packed = []
@@ -5739,51 +5402,36 @@
         packed.append(struct.pack("!H", self.stats_type))
         packed.append(struct.pack("!H", self.flags))
         packed.append('\x00' * 4)
-        packed.append(util.pack_list(self.entries))
+        packed.append(loxi.generic_util.pack_list(self.entries))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = group_stats_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 19)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 6)
         obj.flags = reader.read("!H")[0]
         reader.skip(4)
-        obj.entries = common.unpack_list_group_stats_entry(reader)
+        obj.entries = loxi.generic_util.unpack_list(reader, common.group_stats_entry.unpack)
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.entries != other.entries: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group_stats_reply {")
         with q.group():
@@ -5803,13 +5451,18 @@
             q.breakable()
         q.text('}')
 
-class group_stats_request(Message):
+stats_reply.subtypes[6] = group_stats_reply
+
+class group_stats_request(stats_request):
     version = 3
     type = 18
     stats_type = 6
 
     def __init__(self, xid=None, flags=None, group_id=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -5818,6 +5471,7 @@
             self.group_id = group_id
         else:
             self.group_id = 0
+        return
 
     def pack(self):
         packed = []
@@ -5835,18 +5489,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = group_stats_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 18)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 6)
@@ -5858,23 +5509,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.group_id != other.group_id: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("group_stats_request {")
         with q.group():
@@ -5894,12 +5533,18 @@
             q.breakable()
         q.text('}')
 
-class hello(Message):
+stats_request.subtypes[6] = group_stats_request
+
+class hello(message):
     version = 3
     type = 0
 
     def __init__(self, xid=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
+        return
 
     def pack(self):
         packed = []
@@ -5912,38 +5557,23 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = hello()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 0)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("hello {")
         with q.group():
@@ -5957,13 +5587,18 @@
             q.breakable()
         q.text('}')
 
-class hello_failed_error_msg(Message):
+message.subtypes[0] = hello
+
+class hello_failed_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 0
 
     def __init__(self, xid=None, code=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if code != None:
             self.code = code
         else:
@@ -5972,6 +5607,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -5987,18 +5623,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = hello_failed_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 0)
@@ -6008,23 +5641,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.code != other.code: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("hello_failed_error_msg {")
         with q.group():
@@ -6044,12 +5665,31 @@
             q.breakable()
         q.text('}')
 
-class packet_in(Message):
+error_msg.subtypes[0] = hello_failed_error_msg
+
+class nicira_header(experimenter):
+    subtypes = {}
+
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!L', 12)
+        try:
+            subclass = nicira_header.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown nicira_header experimenter message subtype %#x" % subtype)
+        return subclass.unpack(reader)
+
+experimenter.subtypes[8992] = nicira_header
+
+class packet_in(message):
     version = 3
     type = 10
 
     def __init__(self, xid=None, buffer_id=None, total_len=None, reason=None, table_id=None, match=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if buffer_id != None:
             self.buffer_id = buffer_id
         else:
@@ -6074,6 +5714,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -6093,18 +5734,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = packet_in()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 10)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.buffer_id = reader.read("!L")[0]
         obj.total_len = reader.read("!H")[0]
@@ -6117,8 +5755,6 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.buffer_id != other.buffer_id: return False
         if self.total_len != other.total_len: return False
@@ -6128,16 +5764,6 @@
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("packet_in {")
         with q.group():
@@ -6169,12 +5795,17 @@
             q.breakable()
         q.text('}')
 
-class packet_out(Message):
+message.subtypes[10] = packet_in
+
+class packet_out(message):
     version = 3
     type = 13
 
     def __init__(self, xid=None, buffer_id=None, in_port=None, actions=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if buffer_id != None:
             self.buffer_id = buffer_id
         else:
@@ -6191,6 +5822,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -6202,7 +5834,7 @@
         packed.append(util.pack_port_no(self.in_port))
         packed.append(struct.pack("!H", 0)) # placeholder for actions_len at index 6
         packed.append('\x00' * 6)
-        packed.append(util.pack_list(self.actions))
+        packed.append(loxi.generic_util.pack_list(self.actions))
         packed[6] = struct.pack("!H", len(packed[-1]))
         packed.append(self.data)
         length = sum([len(x) for x in packed])
@@ -6210,31 +5842,26 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = packet_out()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 13)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.buffer_id = reader.read("!L")[0]
         obj.in_port = util.unpack_port_no(reader)
         _actions_len = reader.read("!H")[0]
         reader.skip(6)
-        obj.actions = action.unpack_list(reader.slice(_actions_len))
+        obj.actions = loxi.generic_util.unpack_list(reader.slice(_actions_len), action.action.unpack)
         obj.data = str(reader.read_all())
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.buffer_id != other.buffer_id: return False
         if self.in_port != other.in_port: return False
@@ -6242,16 +5869,6 @@
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("packet_out {")
         with q.group():
@@ -6277,12 +5894,17 @@
             q.breakable()
         q.text('}')
 
-class port_mod(Message):
+message.subtypes[13] = packet_out
+
+class port_mod(message):
     version = 3
     type = 16
 
     def __init__(self, xid=None, port_no=None, hw_addr=None, config=None, mask=None, advertise=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if port_no != None:
             self.port_no = port_no
         else:
@@ -6303,6 +5925,7 @@
             self.advertise = advertise
         else:
             self.advertise = 0
+        return
 
     def pack(self):
         packed = []
@@ -6323,18 +5946,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = port_mod()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 16)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.port_no = util.unpack_port_no(reader)
         reader.skip(4)
@@ -6348,8 +5968,6 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.port_no != other.port_no: return False
         if self.hw_addr != other.hw_addr: return False
@@ -6358,16 +5976,6 @@
         if self.advertise != other.advertise: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("port_mod {")
         with q.group():
@@ -6396,13 +6004,18 @@
             q.breakable()
         q.text('}')
 
-class port_mod_failed_error_msg(Message):
+message.subtypes[16] = port_mod
+
+class port_mod_failed_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 7
 
     def __init__(self, xid=None, code=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if code != None:
             self.code = code
         else:
@@ -6411,6 +6024,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -6426,18 +6040,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = port_mod_failed_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 7)
@@ -6447,23 +6058,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.code != other.code: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("port_mod_failed_error_msg {")
         with q.group():
@@ -6483,13 +6082,18 @@
             q.breakable()
         q.text('}')
 
-class port_stats_reply(Message):
+error_msg.subtypes[7] = port_mod_failed_error_msg
+
+class port_stats_reply(stats_reply):
     version = 3
     type = 19
     stats_type = 4
 
     def __init__(self, xid=None, flags=None, entries=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -6498,6 +6102,7 @@
             self.entries = entries
         else:
             self.entries = []
+        return
 
     def pack(self):
         packed = []
@@ -6508,24 +6113,21 @@
         packed.append(struct.pack("!H", self.stats_type))
         packed.append(struct.pack("!H", self.flags))
         packed.append('\x00' * 4)
-        packed.append(util.pack_list(self.entries))
+        packed.append(loxi.generic_util.pack_list(self.entries))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = port_stats_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 19)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 4)
@@ -6536,23 +6138,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.entries != other.entries: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("port_stats_reply {")
         with q.group():
@@ -6572,13 +6162,18 @@
             q.breakable()
         q.text('}')
 
-class port_stats_request(Message):
+stats_reply.subtypes[4] = port_stats_reply
+
+class port_stats_request(stats_request):
     version = 3
     type = 18
     stats_type = 4
 
     def __init__(self, xid=None, flags=None, port_no=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -6587,6 +6182,7 @@
             self.port_no = port_no
         else:
             self.port_no = 0
+        return
 
     def pack(self):
         packed = []
@@ -6604,18 +6200,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = port_stats_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 18)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 4)
@@ -6627,23 +6220,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.port_no != other.port_no: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("port_stats_request {")
         with q.group():
@@ -6663,12 +6244,17 @@
             q.breakable()
         q.text('}')
 
-class port_status(Message):
+stats_request.subtypes[4] = port_stats_request
+
+class port_status(message):
     version = 3
     type = 12
 
     def __init__(self, xid=None, reason=None, desc=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if reason != None:
             self.reason = reason
         else:
@@ -6677,6 +6263,7 @@
             self.desc = desc
         else:
             self.desc = common.port_desc()
+        return
 
     def pack(self):
         packed = []
@@ -6692,18 +6279,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = port_status()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 12)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.reason = reader.read("!B")[0]
         reader.skip(7)
@@ -6712,23 +6296,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.reason != other.reason: return False
         if self.desc != other.desc: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("port_status {")
         with q.group():
@@ -6748,12 +6320,17 @@
             q.breakable()
         q.text('}')
 
-class queue_get_config_reply(Message):
+message.subtypes[12] = port_status
+
+class queue_get_config_reply(message):
     version = 3
     type = 23
 
     def __init__(self, xid=None, port=None, queues=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if port != None:
             self.port = port
         else:
@@ -6762,6 +6339,7 @@
             self.queues = queues
         else:
             self.queues = []
+        return
 
     def pack(self):
         packed = []
@@ -6771,49 +6349,34 @@
         packed.append(struct.pack("!L", self.xid))
         packed.append(util.pack_port_no(self.port))
         packed.append('\x00' * 4)
-        packed.append(util.pack_list(self.queues))
+        packed.append(loxi.generic_util.pack_list(self.queues))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = queue_get_config_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 23)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.port = util.unpack_port_no(reader)
         reader.skip(4)
-        obj.queues = common.unpack_list_packet_queue(reader)
+        obj.queues = loxi.generic_util.unpack_list(reader, common.packet_queue.unpack)
         return obj
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.port != other.port: return False
         if self.queues != other.queues: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("queue_get_config_reply {")
         with q.group():
@@ -6833,16 +6396,22 @@
             q.breakable()
         q.text('}')
 
-class queue_get_config_request(Message):
+message.subtypes[23] = queue_get_config_reply
+
+class queue_get_config_request(message):
     version = 3
     type = 22
 
     def __init__(self, xid=None, port=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if port != None:
             self.port = port
         else:
             self.port = 0
+        return
 
     def pack(self):
         packed = []
@@ -6857,18 +6426,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = queue_get_config_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 22)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.port = util.unpack_port_no(reader)
         reader.skip(4)
@@ -6876,22 +6442,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.port != other.port: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("queue_get_config_request {")
         with q.group():
@@ -6908,13 +6462,18 @@
             q.breakable()
         q.text('}')
 
-class queue_op_failed_error_msg(Message):
+message.subtypes[22] = queue_get_config_request
+
+class queue_op_failed_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 9
 
     def __init__(self, xid=None, code=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if code != None:
             self.code = code
         else:
@@ -6923,6 +6482,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -6938,18 +6498,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = queue_op_failed_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 9)
@@ -6959,23 +6516,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.code != other.code: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("queue_op_failed_error_msg {")
         with q.group():
@@ -6995,13 +6540,18 @@
             q.breakable()
         q.text('}')
 
-class queue_stats_reply(Message):
+error_msg.subtypes[9] = queue_op_failed_error_msg
+
+class queue_stats_reply(stats_reply):
     version = 3
     type = 19
     stats_type = 5
 
     def __init__(self, xid=None, flags=None, entries=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -7010,6 +6560,7 @@
             self.entries = entries
         else:
             self.entries = []
+        return
 
     def pack(self):
         packed = []
@@ -7020,24 +6571,21 @@
         packed.append(struct.pack("!H", self.stats_type))
         packed.append(struct.pack("!H", self.flags))
         packed.append('\x00' * 4)
-        packed.append(util.pack_list(self.entries))
+        packed.append(loxi.generic_util.pack_list(self.entries))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = queue_stats_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 19)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 5)
@@ -7048,23 +6596,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.entries != other.entries: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("queue_stats_reply {")
         with q.group():
@@ -7084,13 +6620,18 @@
             q.breakable()
         q.text('}')
 
-class queue_stats_request(Message):
+stats_reply.subtypes[5] = queue_stats_reply
+
+class queue_stats_request(stats_request):
     version = 3
     type = 18
     stats_type = 5
 
     def __init__(self, xid=None, flags=None, port_no=None, queue_id=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -7103,6 +6644,7 @@
             self.queue_id = queue_id
         else:
             self.queue_id = 0
+        return
 
     def pack(self):
         packed = []
@@ -7120,18 +6662,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = queue_stats_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 18)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 5)
@@ -7143,24 +6682,12 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.port_no != other.port_no: return False
         if self.queue_id != other.queue_id: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("queue_stats_request {")
         with q.group():
@@ -7183,12 +6710,17 @@
             q.breakable()
         q.text('}')
 
-class role_reply(Message):
+stats_request.subtypes[5] = queue_stats_request
+
+class role_reply(message):
     version = 3
     type = 25
 
     def __init__(self, xid=None, role=None, generation_id=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if role != None:
             self.role = role
         else:
@@ -7197,6 +6729,7 @@
             self.generation_id = generation_id
         else:
             self.generation_id = 0
+        return
 
     def pack(self):
         packed = []
@@ -7212,18 +6745,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = role_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 25)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.role = reader.read("!L")[0]
         reader.skip(4)
@@ -7232,23 +6762,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.role != other.role: return False
         if self.generation_id != other.generation_id: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("role_reply {")
         with q.group():
@@ -7268,12 +6786,17 @@
             q.breakable()
         q.text('}')
 
-class role_request(Message):
+message.subtypes[25] = role_reply
+
+class role_request(message):
     version = 3
     type = 24
 
     def __init__(self, xid=None, role=None, generation_id=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if role != None:
             self.role = role
         else:
@@ -7282,6 +6805,7 @@
             self.generation_id = generation_id
         else:
             self.generation_id = 0
+        return
 
     def pack(self):
         packed = []
@@ -7297,18 +6821,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = role_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 24)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.role = reader.read("!L")[0]
         reader.skip(4)
@@ -7317,23 +6838,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.role != other.role: return False
         if self.generation_id != other.generation_id: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("role_request {")
         with q.group():
@@ -7353,13 +6862,18 @@
             q.breakable()
         q.text('}')
 
-class role_request_failed_error_msg(Message):
+message.subtypes[24] = role_request
+
+class role_request_failed_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 11
 
     def __init__(self, xid=None, code=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if code != None:
             self.code = code
         else:
@@ -7368,6 +6882,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -7383,18 +6898,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = role_request_failed_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 11)
@@ -7404,23 +6916,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.code != other.code: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("role_request_failed_error_msg {")
         with q.group():
@@ -7440,12 +6940,17 @@
             q.breakable()
         q.text('}')
 
-class set_config(Message):
+error_msg.subtypes[11] = role_request_failed_error_msg
+
+class set_config(message):
     version = 3
     type = 9
 
     def __init__(self, xid=None, flags=None, miss_send_len=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -7454,6 +6959,7 @@
             self.miss_send_len = miss_send_len
         else:
             self.miss_send_len = 0
+        return
 
     def pack(self):
         packed = []
@@ -7468,18 +6974,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = set_config()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 9)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.flags = reader.read("!H")[0]
         obj.miss_send_len = reader.read("!H")[0]
@@ -7487,23 +6990,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.miss_send_len != other.miss_send_len: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("set_config {")
         with q.group():
@@ -7523,13 +7014,18 @@
             q.breakable()
         q.text('}')
 
-class switch_config_failed_error_msg(Message):
+message.subtypes[9] = set_config
+
+class switch_config_failed_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 10
 
     def __init__(self, xid=None, code=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if code != None:
             self.code = code
         else:
@@ -7538,6 +7034,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -7553,18 +7050,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = switch_config_failed_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 10)
@@ -7574,23 +7068,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.code != other.code: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("switch_config_failed_error_msg {")
         with q.group():
@@ -7610,12 +7092,17 @@
             q.breakable()
         q.text('}')
 
-class table_mod(Message):
+error_msg.subtypes[10] = switch_config_failed_error_msg
+
+class table_mod(message):
     version = 3
     type = 17
 
     def __init__(self, xid=None, table_id=None, config=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if table_id != None:
             self.table_id = table_id
         else:
@@ -7624,6 +7111,7 @@
             self.config = config
         else:
             self.config = 0
+        return
 
     def pack(self):
         packed = []
@@ -7639,18 +7127,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = table_mod()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 17)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         obj.table_id = reader.read("!B")[0]
         reader.skip(3)
@@ -7659,23 +7144,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.table_id != other.table_id: return False
         if self.config != other.config: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("table_mod {")
         with q.group():
@@ -7695,13 +7168,18 @@
             q.breakable()
         q.text('}')
 
-class table_mod_failed_error_msg(Message):
+message.subtypes[17] = table_mod
+
+class table_mod_failed_error_msg(error_msg):
     version = 3
     type = 1
     err_type = 8
 
     def __init__(self, xid=None, code=None, data=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if code != None:
             self.code = code
         else:
@@ -7710,6 +7188,7 @@
             self.data = data
         else:
             self.data = ''
+        return
 
     def pack(self):
         packed = []
@@ -7725,18 +7204,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = table_mod_failed_error_msg()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 1)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _err_type = reader.read("!H")[0]
         assert(_err_type == 8)
@@ -7746,23 +7222,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.code != other.code: return False
         if self.data != other.data: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("table_mod_failed_error_msg {")
         with q.group():
@@ -7782,13 +7246,18 @@
             q.breakable()
         q.text('}')
 
-class table_stats_reply(Message):
+error_msg.subtypes[8] = table_mod_failed_error_msg
+
+class table_stats_reply(stats_reply):
     version = 3
     type = 19
     stats_type = 3
 
     def __init__(self, xid=None, flags=None, entries=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
@@ -7797,6 +7266,7 @@
             self.entries = entries
         else:
             self.entries = []
+        return
 
     def pack(self):
         packed = []
@@ -7807,24 +7277,21 @@
         packed.append(struct.pack("!H", self.stats_type))
         packed.append(struct.pack("!H", self.flags))
         packed.append('\x00' * 4)
-        packed.append(util.pack_list(self.entries))
+        packed.append(loxi.generic_util.pack_list(self.entries))
         length = sum([len(x) for x in packed])
         packed[2] = struct.pack("!H", length)
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = table_stats_reply()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 19)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 3)
@@ -7835,23 +7302,11 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         if self.entries != other.entries: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("table_stats_reply {")
         with q.group():
@@ -7871,17 +7326,23 @@
             q.breakable()
         q.text('}')
 
-class table_stats_request(Message):
+stats_reply.subtypes[3] = table_stats_reply
+
+class table_stats_request(stats_request):
     version = 3
     type = 18
     stats_type = 3
 
     def __init__(self, xid=None, flags=None):
-        self.xid = xid
+        if xid != None:
+            self.xid = xid
+        else:
+            self.xid = None
         if flags != None:
             self.flags = flags
         else:
             self.flags = 0
+        return
 
     def pack(self):
         packed = []
@@ -7897,18 +7358,15 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
-        if len(buf) < 8: raise loxi.ProtocolError("buffer too short to contain an OpenFlow message")
+    def unpack(reader):
         obj = table_stats_request()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _version = reader.read("!B")[0]
         assert(_version == 3)
         _type = reader.read("!B")[0]
         assert(_type == 18)
         _length = reader.read("!H")[0]
+        orig_reader = reader
+        reader = orig_reader.slice(_length - (2 + 2))
         obj.xid = reader.read("!L")[0]
         _stats_type = reader.read("!H")[0]
         assert(_stats_type == 3)
@@ -7918,22 +7376,10 @@
 
     def __eq__(self, other):
         if type(self) != type(other): return False
-        if self.version != other.version: return False
-        if self.type != other.type: return False
         if self.xid != other.xid: return False
         if self.flags != other.flags: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __str__(self):
-        return self.show()
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("table_stats_request {")
         with q.group():
@@ -7950,6 +7396,8 @@
             q.breakable()
         q.text('}')
 
+stats_request.subtypes[3] = table_stats_request
+
 
 def parse_header(buf):
     if len(buf) < 8:
@@ -7962,216 +7410,4 @@
         raise loxi.ProtocolError("wrong OpenFlow version (expected %d, got %d)" % (const.OFP_VERSION, msg_ver))
     if len(buf) != msg_len:
         raise loxi.ProtocolError("incorrect message size")
-    if msg_type in parsers:
-        return parsers[msg_type](buf)
-    else:
-        raise loxi.ProtocolError("unexpected message type")
-
-def parse_error(buf):
-    if len(buf) < 8 + 2:
-        raise loxi.ProtocolError("message too short")
-    err_type, = struct.unpack_from("!H", buf, 8)
-    if err_type in error_msg_parsers:
-        return error_msg_parsers[err_type](buf)
-    else:
-        raise loxi.ProtocolError("unexpected error type %u" % err_type)
-
-def parse_flow_mod(buf):
-    if len(buf) < 25 + 1:
-        raise loxi.ProtocolError("message too short")
-    # Technically uint16_t for OF 1.0
-    cmd, = struct.unpack_from("!B", buf, 25)
-    if cmd in flow_mod_parsers:
-        return flow_mod_parsers[cmd](buf)
-    else:
-        raise loxi.ProtocolError("unexpected flow mod cmd %u" % cmd)
-
-def parse_group_mod(buf):
-    if len(buf) < 8 + 2:
-        raise loxi.ProtocolError("message too short")
-    cmd, = struct.unpack_from("!H", buf, 8)
-    if cmd in flow_mod_parsers:
-        return group_mod_parsers[cmd](buf)
-    else:
-        raise loxi.ProtocolError("unexpected group mod cmd %u" % cmd)
-
-def parse_stats_reply(buf):
-    if len(buf) < 8 + 2:
-        raise loxi.ProtocolError("message too short")
-    stats_type, = struct.unpack_from("!H", buf, 8)
-    if stats_type in stats_reply_parsers:
-        return stats_reply_parsers[stats_type](buf)
-    else:
-        raise loxi.ProtocolError("unexpected stats type %u" % stats_type)
-
-def parse_stats_request(buf):
-    if len(buf) < 8 + 2:
-        raise loxi.ProtocolError("message too short")
-    stats_type, = struct.unpack_from("!H", buf, 8)
-    if stats_type in stats_request_parsers:
-        return stats_request_parsers[stats_type](buf)
-    else:
-        raise loxi.ProtocolError("unexpected stats type %u" % stats_type)
-
-def parse_experimenter_stats_request(buf):
-    if len(buf) < 24:
-        raise loxi.ProtocolError("experimenter stats request message too short")
-
-    experimenter, exp_type = struct.unpack_from("!LL", buf, 16)
-
-    if experimenter in experimenter_stats_request_parsers and \
-            exp_type in experimenter_stats_request_parsers[experimenter]:
-        return experimenter_stats_request_parsers[experimenter][exp_type](buf)
-    else:
-        raise loxi.ProtocolError("unexpected stats request experimenter %#x exp_type %#x" % (experimenter, exp_type))
-
-def parse_experimenter_stats_reply(buf):
-    if len(buf) < 24:
-        raise loxi.ProtocolError("experimenter stats reply message too short")
-
-    experimenter, exp_type = struct.unpack_from("!LL", buf, 16)
-
-    if experimenter in experimenter_stats_reply_parsers and \
-            exp_type in experimenter_stats_reply_parsers[experimenter]:
-        return experimenter_stats_reply_parsers[experimenter][exp_type](buf)
-    else:
-        raise loxi.ProtocolError("unexpected stats reply experimenter %#x exp_type %#x" % (experimenter, exp_type))
-
-def parse_experimenter(buf):
-    if len(buf) < 16:
-        raise loxi.ProtocolError("experimenter message too short")
-
-    experimenter, = struct.unpack_from("!L", buf, 8)
-    if experimenter == 0x005c16c7: # Big Switch Networks
-        subtype, = struct.unpack_from("!L", buf, 12)
-    elif experimenter == 0x00002320: # Nicira
-        subtype, = struct.unpack_from("!L", buf, 12)
-    else:
-        raise loxi.ProtocolError("unexpected experimenter id %#x" % experimenter)
-
-    if subtype in experimenter_parsers[experimenter]:
-        return experimenter_parsers[experimenter][subtype](buf)
-    else:
-        raise loxi.ProtocolError("unexpected experimenter %#x subtype %#x" % (experimenter, subtype))
-
-parsers = {
-    const.OFPT_HELLO : hello.unpack,
-    const.OFPT_ERROR : parse_error,
-    const.OFPT_ECHO_REQUEST : echo_request.unpack,
-    const.OFPT_ECHO_REPLY : echo_reply.unpack,
-    const.OFPT_EXPERIMENTER : parse_experimenter,
-    const.OFPT_FEATURES_REQUEST : features_request.unpack,
-    const.OFPT_FEATURES_REPLY : features_reply.unpack,
-    const.OFPT_GET_CONFIG_REQUEST : get_config_request.unpack,
-    const.OFPT_GET_CONFIG_REPLY : get_config_reply.unpack,
-    const.OFPT_SET_CONFIG : set_config.unpack,
-    const.OFPT_PACKET_IN : packet_in.unpack,
-    const.OFPT_FLOW_REMOVED : flow_removed.unpack,
-    const.OFPT_PORT_STATUS : port_status.unpack,
-    const.OFPT_PACKET_OUT : packet_out.unpack,
-    const.OFPT_FLOW_MOD : parse_flow_mod,
-    const.OFPT_GROUP_MOD : parse_group_mod,
-    const.OFPT_PORT_MOD : port_mod.unpack,
-    const.OFPT_TABLE_MOD : table_mod.unpack,
-    const.OFPT_STATS_REQUEST : parse_stats_request,
-    const.OFPT_STATS_REPLY : parse_stats_reply,
-    const.OFPT_BARRIER_REQUEST : barrier_request.unpack,
-    const.OFPT_BARRIER_REPLY : barrier_reply.unpack,
-    const.OFPT_QUEUE_GET_CONFIG_REQUEST : queue_get_config_request.unpack,
-    const.OFPT_QUEUE_GET_CONFIG_REPLY : queue_get_config_reply.unpack,
-    const.OFPT_ROLE_REQUEST : role_request.unpack,
-    const.OFPT_ROLE_REPLY : role_reply.unpack,
-}
-
-error_msg_parsers = {
-    const.OFPET_HELLO_FAILED : hello_failed_error_msg.unpack,
-    const.OFPET_BAD_REQUEST : bad_request_error_msg.unpack,
-    const.OFPET_BAD_ACTION : bad_action_error_msg.unpack,
-    const.OFPET_FLOW_MOD_FAILED : flow_mod_failed_error_msg.unpack,
-    const.OFPET_PORT_MOD_FAILED : port_mod_failed_error_msg.unpack,
-    const.OFPET_QUEUE_OP_FAILED : queue_op_failed_error_msg.unpack,
-    const.OFPET_BAD_INSTRUCTION : bad_instruction_error_msg.unpack,
-    const.OFPET_BAD_MATCH : bad_match_error_msg.unpack,
-    const.OFPET_GROUP_MOD_FAILED : group_mod_failed_error_msg.unpack,
-    const.OFPET_TABLE_MOD_FAILED : table_mod_failed_error_msg.unpack,
-    const.OFPET_SWITCH_CONFIG_FAILED : switch_config_failed_error_msg.unpack,
-    const.OFPET_ROLE_REQUEST_FAILED : role_request_failed_error_msg.unpack,
-    const.OFPET_EXPERIMENTER : experimenter_error_msg.unpack,
-}
-
-flow_mod_parsers = {
-    const.OFPFC_ADD : flow_add.unpack,
-    const.OFPFC_MODIFY : flow_modify.unpack,
-    const.OFPFC_MODIFY_STRICT : flow_modify_strict.unpack,
-    const.OFPFC_DELETE : flow_delete.unpack,
-    const.OFPFC_DELETE_STRICT : flow_delete_strict.unpack,
-}
-
-group_mod_parsers = {
-    const.OFPGC_ADD : group_add.unpack,
-    const.OFPGC_MODIFY : group_modify.unpack,
-    const.OFPGC_DELETE : group_delete.unpack,
-}
-
-stats_reply_parsers = {
-    const.OFPST_DESC : desc_stats_reply.unpack,
-    const.OFPST_FLOW : flow_stats_reply.unpack,
-    const.OFPST_AGGREGATE : aggregate_stats_reply.unpack,
-    const.OFPST_TABLE : table_stats_reply.unpack,
-    const.OFPST_PORT : port_stats_reply.unpack,
-    const.OFPST_QUEUE : queue_stats_reply.unpack,
-    const.OFPST_EXPERIMENTER : parse_experimenter_stats_reply,
-    const.OFPST_GROUP : group_stats_reply.unpack,
-    const.OFPST_GROUP_DESC : group_desc_stats_reply.unpack,
-    const.OFPST_GROUP_FEATURES : group_features_stats_reply.unpack,
-}
-
-stats_request_parsers = {
-    const.OFPST_DESC : desc_stats_request.unpack,
-    const.OFPST_FLOW : flow_stats_request.unpack,
-    const.OFPST_AGGREGATE : aggregate_stats_request.unpack,
-    const.OFPST_TABLE : table_stats_request.unpack,
-    const.OFPST_PORT : port_stats_request.unpack,
-    const.OFPST_QUEUE : queue_stats_request.unpack,
-    const.OFPST_EXPERIMENTER : parse_experimenter_stats_request,
-    const.OFPST_GROUP : group_stats_request.unpack,
-    const.OFPST_GROUP_DESC : group_desc_stats_request.unpack,
-    const.OFPST_GROUP_FEATURES : group_features_stats_request.unpack,
-}
-
-experimenter_parsers = {
-    6035143 : {
-        22: bsn_bw_clear_data_reply.unpack,
-        21: bsn_bw_clear_data_request.unpack,
-        20: bsn_bw_enable_get_reply.unpack,
-        19: bsn_bw_enable_get_request.unpack,
-        23: bsn_bw_enable_set_reply.unpack,
-        18: bsn_bw_enable_set_request.unpack,
-        10: bsn_get_interfaces_reply.unpack,
-        9: bsn_get_interfaces_request.unpack,
-        5: bsn_get_mirroring_reply.unpack,
-        4: bsn_get_mirroring_request.unpack,
-        34: bsn_pdu_rx_reply.unpack,
-        33: bsn_pdu_rx_request.unpack,
-        35: bsn_pdu_rx_timeout.unpack,
-        32: bsn_pdu_tx_reply.unpack,
-        31: bsn_pdu_tx_request.unpack,
-        3: bsn_set_mirroring.unpack,
-        25: bsn_set_pktin_suppression_reply.unpack,
-        11: bsn_set_pktin_suppression_request.unpack,
-        16: bsn_virtual_port_create_reply.unpack,
-        15: bsn_virtual_port_create_request.unpack,
-        26: bsn_virtual_port_remove_reply.unpack,
-        17: bsn_virtual_port_remove_request.unpack,
-    },
-}
-
-experimenter_stats_request_parsers = {
-    0x005c16c7: {
-    },
-}
-
-experimenter_stats_reply_parsers = {
-    0x005c16c7: {
-    },
-}
+    return message.unpack(loxi.generic_util.OFReader(buf))
diff --git a/src/python/loxi/of12/oxm.py b/src/python/loxi/of12/oxm.py
index de53112..56da4d0 100644
--- a/src/python/loxi/of12/oxm.py
+++ b/src/python/loxi/of12/oxm.py
@@ -3,31 +3,33 @@
 # Copyright (c) 2012, 2013 Big Switch Networks, Inc.
 # See the file LICENSE.pyloxi which should have been included in the source distribution
 
-# Automatically generated by LOXI from template oxm.py
+# Automatically generated by LOXI from template module.py
 # Do not modify
 
 import struct
+import loxi
 import const
+import common
+import action
+import instruction
+import oxm
 import util
 import loxi.generic_util
-import loxi
 
-def unpack(reader):
-    type_len, = reader.peek('!L')
-    if type_len in parsers:
-        return parsers[type_len](reader)
-    else:
-        raise loxi.ProtocolError("unknown OXM cls=%#x type=%#x masked=%d len=%d (%#x)" % \
-            ((type_len >> 16) & 0xffff, (type_len >> 9) & 0x7f, (type_len >> 8) & 1, type_len & 0xff, type_len))
+class oxm(loxi.OFObject):
+    subtypes = {}
 
-def unpack_list(reader):
-    return loxi.generic_util.unpack_list(reader, unpack)
+    @staticmethod
+    def unpack(reader):
+        subtype, = reader.peek('!L', 0)
+        try:
+            subclass = oxm.subtypes[subtype]
+        except KeyError:
+            raise loxi.ProtocolError("unknown oxm subtype %#x" % subtype)
+        return subclass.unpack(reader)
 
-class OXM(object):
-    type_len = None # override in subclass
-    pass
 
-class arp_op(OXM):
+class arp_op(oxm):
     type_len = 2147494402
 
     def __init__(self, value=None):
@@ -35,6 +37,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -43,12 +46,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = arp_op()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147494402)
         obj.value = reader.read("!H")[0]
@@ -59,13 +58,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("arp_op {")
         with q.group():
@@ -76,7 +68,9 @@
             q.breakable()
         q.text('}')
 
-class arp_op_masked(OXM):
+oxm.subtypes[2147494402] = arp_op
+
+class arp_op_masked(oxm):
     type_len = 2147494660
 
     def __init__(self, value=None, value_mask=None):
@@ -88,6 +82,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -97,12 +92,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = arp_op_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147494660)
         obj.value = reader.read("!H")[0]
@@ -115,13 +106,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("arp_op_masked {")
         with q.group():
@@ -135,7 +119,9 @@
             q.breakable()
         q.text('}')
 
-class arp_sha(OXM):
+oxm.subtypes[2147494660] = arp_op_masked
+
+class arp_sha(oxm):
     type_len = 2147495942
 
     def __init__(self, value=None):
@@ -143,6 +129,7 @@
             self.value = value
         else:
             self.value = [0,0,0,0,0,0]
+        return
 
     def pack(self):
         packed = []
@@ -151,12 +138,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = arp_sha()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147495942)
         obj.value = list(reader.read('!6B'))
@@ -167,13 +150,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("arp_sha {")
         with q.group():
@@ -184,7 +160,9 @@
             q.breakable()
         q.text('}')
 
-class arp_sha_masked(OXM):
+oxm.subtypes[2147495942] = arp_sha
+
+class arp_sha_masked(oxm):
     type_len = 2147496204
 
     def __init__(self, value=None, value_mask=None):
@@ -196,6 +174,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = [0,0,0,0,0,0]
+        return
 
     def pack(self):
         packed = []
@@ -205,12 +184,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = arp_sha_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147496204)
         obj.value = list(reader.read('!6B'))
@@ -223,13 +198,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("arp_sha_masked {")
         with q.group():
@@ -243,7 +211,9 @@
             q.breakable()
         q.text('}')
 
-class arp_spa(OXM):
+oxm.subtypes[2147496204] = arp_sha_masked
+
+class arp_spa(oxm):
     type_len = 2147494916
 
     def __init__(self, value=None):
@@ -251,6 +221,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -259,12 +230,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = arp_spa()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147494916)
         obj.value = reader.read("!L")[0]
@@ -275,13 +242,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("arp_spa {")
         with q.group():
@@ -292,7 +252,9 @@
             q.breakable()
         q.text('}')
 
-class arp_spa_masked(OXM):
+oxm.subtypes[2147494916] = arp_spa
+
+class arp_spa_masked(oxm):
     type_len = 2147495176
 
     def __init__(self, value=None, value_mask=None):
@@ -304,6 +266,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -313,12 +276,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = arp_spa_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147495176)
         obj.value = reader.read("!L")[0]
@@ -331,13 +290,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("arp_spa_masked {")
         with q.group():
@@ -351,7 +303,9 @@
             q.breakable()
         q.text('}')
 
-class arp_tha(OXM):
+oxm.subtypes[2147495176] = arp_spa_masked
+
+class arp_tha(oxm):
     type_len = 2147496454
 
     def __init__(self, value=None):
@@ -359,6 +313,7 @@
             self.value = value
         else:
             self.value = [0,0,0,0,0,0]
+        return
 
     def pack(self):
         packed = []
@@ -367,12 +322,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = arp_tha()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147496454)
         obj.value = list(reader.read('!6B'))
@@ -383,13 +334,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("arp_tha {")
         with q.group():
@@ -400,7 +344,9 @@
             q.breakable()
         q.text('}')
 
-class arp_tha_masked(OXM):
+oxm.subtypes[2147496454] = arp_tha
+
+class arp_tha_masked(oxm):
     type_len = 2147496716
 
     def __init__(self, value=None, value_mask=None):
@@ -412,6 +358,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = [0,0,0,0,0,0]
+        return
 
     def pack(self):
         packed = []
@@ -421,12 +368,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = arp_tha_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147496716)
         obj.value = list(reader.read('!6B'))
@@ -439,13 +382,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("arp_tha_masked {")
         with q.group():
@@ -459,7 +395,9 @@
             q.breakable()
         q.text('}')
 
-class arp_tpa(OXM):
+oxm.subtypes[2147496716] = arp_tha_masked
+
+class arp_tpa(oxm):
     type_len = 2147495428
 
     def __init__(self, value=None):
@@ -467,6 +405,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -475,12 +414,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = arp_tpa()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147495428)
         obj.value = reader.read("!L")[0]
@@ -491,13 +426,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("arp_tpa {")
         with q.group():
@@ -508,7 +436,9 @@
             q.breakable()
         q.text('}')
 
-class arp_tpa_masked(OXM):
+oxm.subtypes[2147495428] = arp_tpa
+
+class arp_tpa_masked(oxm):
     type_len = 2147495688
 
     def __init__(self, value=None, value_mask=None):
@@ -520,6 +450,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -529,12 +460,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = arp_tpa_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147495688)
         obj.value = reader.read("!L")[0]
@@ -547,13 +474,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("arp_tpa_masked {")
         with q.group():
@@ -567,7 +487,9 @@
             q.breakable()
         q.text('}')
 
-class bsn_global_vrf_allowed(OXM):
+oxm.subtypes[2147495688] = arp_tpa_masked
+
+class bsn_global_vrf_allowed(oxm):
     type_len = 198145
 
     def __init__(self, value=None):
@@ -575,6 +497,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -583,12 +506,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_global_vrf_allowed()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 198145)
         obj.value = reader.read("!B")[0]
@@ -599,13 +518,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_global_vrf_allowed {")
         with q.group():
@@ -616,8 +528,10 @@
             q.breakable()
         q.text('}')
 
-class bsn_global_vrf_allowed_masked(OXM):
-    type_len = 198401
+oxm.subtypes[198145] = bsn_global_vrf_allowed
+
+class bsn_global_vrf_allowed_masked(oxm):
+    type_len = 198402
 
     def __init__(self, value=None, value_mask=None):
         if value != None:
@@ -628,6 +542,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -637,14 +552,10 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_global_vrf_allowed_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
-        assert(_type_len == 198401)
+        assert(_type_len == 198402)
         obj.value = reader.read("!B")[0]
         obj.value_mask = reader.read("!B")[0]
         return obj
@@ -655,13 +566,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_global_vrf_allowed_masked {")
         with q.group():
@@ -675,14 +579,17 @@
             q.breakable()
         q.text('}')
 
-class bsn_in_ports_128(OXM):
-    type_len = 196640
+oxm.subtypes[198402] = bsn_global_vrf_allowed_masked
+
+class bsn_in_ports_128(oxm):
+    type_len = 196624
 
     def __init__(self, value=None):
         if value != None:
             self.value = value
         else:
             self.value = set()
+        return
 
     def pack(self):
         packed = []
@@ -691,14 +598,10 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_in_ports_128()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
-        assert(_type_len == 196640)
+        assert(_type_len == 196624)
         obj.value = util.unpack_bitmap_128(reader)
         return obj
 
@@ -707,13 +610,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_in_ports_128 {")
         with q.group():
@@ -724,7 +620,9 @@
             q.breakable()
         q.text('}')
 
-class bsn_in_ports_128_masked(OXM):
+oxm.subtypes[196624] = bsn_in_ports_128
+
+class bsn_in_ports_128_masked(oxm):
     type_len = 196896
 
     def __init__(self, value=None, value_mask=None):
@@ -736,6 +634,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = set()
+        return
 
     def pack(self):
         packed = []
@@ -745,12 +644,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_in_ports_128_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 196896)
         obj.value = util.unpack_bitmap_128(reader)
@@ -763,13 +658,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_in_ports_128_masked {")
         with q.group():
@@ -783,7 +671,9 @@
             q.breakable()
         q.text('}')
 
-class bsn_l3_dst_class_id(OXM):
+oxm.subtypes[196896] = bsn_in_ports_128_masked
+
+class bsn_l3_dst_class_id(oxm):
     type_len = 199684
 
     def __init__(self, value=None):
@@ -791,6 +681,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -799,12 +690,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_l3_dst_class_id()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 199684)
         obj.value = reader.read("!L")[0]
@@ -815,13 +702,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_l3_dst_class_id {")
         with q.group():
@@ -832,8 +712,10 @@
             q.breakable()
         q.text('}')
 
-class bsn_l3_dst_class_id_masked(OXM):
-    type_len = 199940
+oxm.subtypes[199684] = bsn_l3_dst_class_id
+
+class bsn_l3_dst_class_id_masked(oxm):
+    type_len = 199944
 
     def __init__(self, value=None, value_mask=None):
         if value != None:
@@ -844,6 +726,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -853,14 +736,10 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_l3_dst_class_id_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
-        assert(_type_len == 199940)
+        assert(_type_len == 199944)
         obj.value = reader.read("!L")[0]
         obj.value_mask = reader.read("!L")[0]
         return obj
@@ -871,13 +750,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_l3_dst_class_id_masked {")
         with q.group():
@@ -891,7 +763,9 @@
             q.breakable()
         q.text('}')
 
-class bsn_l3_interface_class_id(OXM):
+oxm.subtypes[199944] = bsn_l3_dst_class_id_masked
+
+class bsn_l3_interface_class_id(oxm):
     type_len = 198660
 
     def __init__(self, value=None):
@@ -899,6 +773,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -907,12 +782,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_l3_interface_class_id()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 198660)
         obj.value = reader.read("!L")[0]
@@ -923,13 +794,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_l3_interface_class_id {")
         with q.group():
@@ -940,8 +804,10 @@
             q.breakable()
         q.text('}')
 
-class bsn_l3_interface_class_id_masked(OXM):
-    type_len = 198916
+oxm.subtypes[198660] = bsn_l3_interface_class_id
+
+class bsn_l3_interface_class_id_masked(oxm):
+    type_len = 198920
 
     def __init__(self, value=None, value_mask=None):
         if value != None:
@@ -952,6 +818,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -961,14 +828,10 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_l3_interface_class_id_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
-        assert(_type_len == 198916)
+        assert(_type_len == 198920)
         obj.value = reader.read("!L")[0]
         obj.value_mask = reader.read("!L")[0]
         return obj
@@ -979,13 +842,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_l3_interface_class_id_masked {")
         with q.group():
@@ -999,7 +855,9 @@
             q.breakable()
         q.text('}')
 
-class bsn_l3_src_class_id(OXM):
+oxm.subtypes[198920] = bsn_l3_interface_class_id_masked
+
+class bsn_l3_src_class_id(oxm):
     type_len = 199172
 
     def __init__(self, value=None):
@@ -1007,6 +865,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -1015,12 +874,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_l3_src_class_id()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 199172)
         obj.value = reader.read("!L")[0]
@@ -1031,13 +886,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_l3_src_class_id {")
         with q.group():
@@ -1048,8 +896,10 @@
             q.breakable()
         q.text('}')
 
-class bsn_l3_src_class_id_masked(OXM):
-    type_len = 199428
+oxm.subtypes[199172] = bsn_l3_src_class_id
+
+class bsn_l3_src_class_id_masked(oxm):
+    type_len = 199432
 
     def __init__(self, value=None, value_mask=None):
         if value != None:
@@ -1060,6 +910,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -1069,14 +920,10 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_l3_src_class_id_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
-        assert(_type_len == 199428)
+        assert(_type_len == 199432)
         obj.value = reader.read("!L")[0]
         obj.value_mask = reader.read("!L")[0]
         return obj
@@ -1087,13 +934,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_l3_src_class_id_masked {")
         with q.group():
@@ -1107,7 +947,9 @@
             q.breakable()
         q.text('}')
 
-class bsn_lag_id(OXM):
+oxm.subtypes[199432] = bsn_l3_src_class_id_masked
+
+class bsn_lag_id(oxm):
     type_len = 197124
 
     def __init__(self, value=None):
@@ -1115,6 +957,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -1123,12 +966,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_lag_id()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 197124)
         obj.value = reader.read("!L")[0]
@@ -1139,13 +978,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_lag_id {")
         with q.group():
@@ -1156,8 +988,10 @@
             q.breakable()
         q.text('}')
 
-class bsn_lag_id_masked(OXM):
-    type_len = 197380
+oxm.subtypes[197124] = bsn_lag_id
+
+class bsn_lag_id_masked(oxm):
+    type_len = 197384
 
     def __init__(self, value=None, value_mask=None):
         if value != None:
@@ -1168,6 +1002,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -1177,14 +1012,10 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_lag_id_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
-        assert(_type_len == 197380)
+        assert(_type_len == 197384)
         obj.value = reader.read("!L")[0]
         obj.value_mask = reader.read("!L")[0]
         return obj
@@ -1195,13 +1026,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_lag_id_masked {")
         with q.group():
@@ -1215,7 +1039,9 @@
             q.breakable()
         q.text('}')
 
-class bsn_vrf(OXM):
+oxm.subtypes[197384] = bsn_lag_id_masked
+
+class bsn_vrf(oxm):
     type_len = 197636
 
     def __init__(self, value=None):
@@ -1223,6 +1049,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -1231,12 +1058,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_vrf()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 197636)
         obj.value = reader.read("!L")[0]
@@ -1247,13 +1070,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_vrf {")
         with q.group():
@@ -1264,8 +1080,10 @@
             q.breakable()
         q.text('}')
 
-class bsn_vrf_masked(OXM):
-    type_len = 197892
+oxm.subtypes[197636] = bsn_vrf
+
+class bsn_vrf_masked(oxm):
+    type_len = 197896
 
     def __init__(self, value=None, value_mask=None):
         if value != None:
@@ -1276,6 +1094,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -1285,14 +1104,10 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = bsn_vrf_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
-        assert(_type_len == 197892)
+        assert(_type_len == 197896)
         obj.value = reader.read("!L")[0]
         obj.value_mask = reader.read("!L")[0]
         return obj
@@ -1303,13 +1118,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("bsn_vrf_masked {")
         with q.group():
@@ -1323,7 +1131,9 @@
             q.breakable()
         q.text('}')
 
-class eth_dst(OXM):
+oxm.subtypes[197896] = bsn_vrf_masked
+
+class eth_dst(oxm):
     type_len = 2147485190
 
     def __init__(self, value=None):
@@ -1331,6 +1141,7 @@
             self.value = value
         else:
             self.value = [0,0,0,0,0,0]
+        return
 
     def pack(self):
         packed = []
@@ -1339,12 +1150,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = eth_dst()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147485190)
         obj.value = list(reader.read('!6B'))
@@ -1355,13 +1162,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("eth_dst {")
         with q.group():
@@ -1372,7 +1172,9 @@
             q.breakable()
         q.text('}')
 
-class eth_dst_masked(OXM):
+oxm.subtypes[2147485190] = eth_dst
+
+class eth_dst_masked(oxm):
     type_len = 2147485452
 
     def __init__(self, value=None, value_mask=None):
@@ -1384,6 +1186,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = [0,0,0,0,0,0]
+        return
 
     def pack(self):
         packed = []
@@ -1393,12 +1196,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = eth_dst_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147485452)
         obj.value = list(reader.read('!6B'))
@@ -1411,13 +1210,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("eth_dst_masked {")
         with q.group():
@@ -1431,7 +1223,9 @@
             q.breakable()
         q.text('}')
 
-class eth_src(OXM):
+oxm.subtypes[2147485452] = eth_dst_masked
+
+class eth_src(oxm):
     type_len = 2147485702
 
     def __init__(self, value=None):
@@ -1439,6 +1233,7 @@
             self.value = value
         else:
             self.value = [0,0,0,0,0,0]
+        return
 
     def pack(self):
         packed = []
@@ -1447,12 +1242,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = eth_src()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147485702)
         obj.value = list(reader.read('!6B'))
@@ -1463,13 +1254,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("eth_src {")
         with q.group():
@@ -1480,7 +1264,9 @@
             q.breakable()
         q.text('}')
 
-class eth_src_masked(OXM):
+oxm.subtypes[2147485702] = eth_src
+
+class eth_src_masked(oxm):
     type_len = 2147485964
 
     def __init__(self, value=None, value_mask=None):
@@ -1492,6 +1278,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = [0,0,0,0,0,0]
+        return
 
     def pack(self):
         packed = []
@@ -1501,12 +1288,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = eth_src_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147485964)
         obj.value = list(reader.read('!6B'))
@@ -1519,13 +1302,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("eth_src_masked {")
         with q.group():
@@ -1539,7 +1315,9 @@
             q.breakable()
         q.text('}')
 
-class eth_type(OXM):
+oxm.subtypes[2147485964] = eth_src_masked
+
+class eth_type(oxm):
     type_len = 2147486210
 
     def __init__(self, value=None):
@@ -1547,6 +1325,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -1555,12 +1334,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = eth_type()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147486210)
         obj.value = reader.read("!H")[0]
@@ -1571,13 +1346,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("eth_type {")
         with q.group():
@@ -1588,7 +1356,9 @@
             q.breakable()
         q.text('}')
 
-class eth_type_masked(OXM):
+oxm.subtypes[2147486210] = eth_type
+
+class eth_type_masked(oxm):
     type_len = 2147486468
 
     def __init__(self, value=None, value_mask=None):
@@ -1600,6 +1370,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -1609,12 +1380,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = eth_type_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147486468)
         obj.value = reader.read("!H")[0]
@@ -1627,13 +1394,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("eth_type_masked {")
         with q.group():
@@ -1647,7 +1407,9 @@
             q.breakable()
         q.text('}')
 
-class icmpv4_code(OXM):
+oxm.subtypes[2147486468] = eth_type_masked
+
+class icmpv4_code(oxm):
     type_len = 2147493889
 
     def __init__(self, value=None):
@@ -1655,6 +1417,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -1663,12 +1426,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = icmpv4_code()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147493889)
         obj.value = reader.read("!B")[0]
@@ -1679,13 +1438,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("icmpv4_code {")
         with q.group():
@@ -1696,7 +1448,9 @@
             q.breakable()
         q.text('}')
 
-class icmpv4_code_masked(OXM):
+oxm.subtypes[2147493889] = icmpv4_code
+
+class icmpv4_code_masked(oxm):
     type_len = 2147494146
 
     def __init__(self, value=None, value_mask=None):
@@ -1708,6 +1462,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -1717,12 +1472,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = icmpv4_code_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147494146)
         obj.value = reader.read("!B")[0]
@@ -1735,13 +1486,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("icmpv4_code_masked {")
         with q.group():
@@ -1755,7 +1499,9 @@
             q.breakable()
         q.text('}')
 
-class icmpv4_type(OXM):
+oxm.subtypes[2147494146] = icmpv4_code_masked
+
+class icmpv4_type(oxm):
     type_len = 2147493377
 
     def __init__(self, value=None):
@@ -1763,6 +1509,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -1771,12 +1518,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = icmpv4_type()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147493377)
         obj.value = reader.read("!B")[0]
@@ -1787,13 +1530,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("icmpv4_type {")
         with q.group():
@@ -1804,7 +1540,9 @@
             q.breakable()
         q.text('}')
 
-class icmpv4_type_masked(OXM):
+oxm.subtypes[2147493377] = icmpv4_type
+
+class icmpv4_type_masked(oxm):
     type_len = 2147493634
 
     def __init__(self, value=None, value_mask=None):
@@ -1816,6 +1554,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -1825,12 +1564,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = icmpv4_type_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147493634)
         obj.value = reader.read("!B")[0]
@@ -1843,13 +1578,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("icmpv4_type_masked {")
         with q.group():
@@ -1863,7 +1591,9 @@
             q.breakable()
         q.text('}')
 
-class icmpv6_code(OXM):
+oxm.subtypes[2147493634] = icmpv4_type_masked
+
+class icmpv6_code(oxm):
     type_len = 2147499009
 
     def __init__(self, value=None):
@@ -1871,6 +1601,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -1879,12 +1610,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = icmpv6_code()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147499009)
         obj.value = reader.read("!B")[0]
@@ -1895,13 +1622,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("icmpv6_code {")
         with q.group():
@@ -1912,7 +1632,9 @@
             q.breakable()
         q.text('}')
 
-class icmpv6_code_masked(OXM):
+oxm.subtypes[2147499009] = icmpv6_code
+
+class icmpv6_code_masked(oxm):
     type_len = 2147499266
 
     def __init__(self, value=None, value_mask=None):
@@ -1924,6 +1646,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -1933,12 +1656,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = icmpv6_code_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147499266)
         obj.value = reader.read("!B")[0]
@@ -1951,13 +1670,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("icmpv6_code_masked {")
         with q.group():
@@ -1971,7 +1683,9 @@
             q.breakable()
         q.text('}')
 
-class icmpv6_type(OXM):
+oxm.subtypes[2147499266] = icmpv6_code_masked
+
+class icmpv6_type(oxm):
     type_len = 2147498497
 
     def __init__(self, value=None):
@@ -1979,6 +1693,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -1987,12 +1702,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = icmpv6_type()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147498497)
         obj.value = reader.read("!B")[0]
@@ -2003,13 +1714,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("icmpv6_type {")
         with q.group():
@@ -2020,7 +1724,9 @@
             q.breakable()
         q.text('}')
 
-class icmpv6_type_masked(OXM):
+oxm.subtypes[2147498497] = icmpv6_type
+
+class icmpv6_type_masked(oxm):
     type_len = 2147498754
 
     def __init__(self, value=None, value_mask=None):
@@ -2032,6 +1738,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -2041,12 +1748,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = icmpv6_type_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147498754)
         obj.value = reader.read("!B")[0]
@@ -2059,13 +1762,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("icmpv6_type_masked {")
         with q.group():
@@ -2079,7 +1775,9 @@
             q.breakable()
         q.text('}')
 
-class in_phy_port(OXM):
+oxm.subtypes[2147498754] = icmpv6_type_masked
+
+class in_phy_port(oxm):
     type_len = 2147484164
 
     def __init__(self, value=None):
@@ -2087,6 +1785,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -2095,12 +1794,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = in_phy_port()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147484164)
         obj.value = util.unpack_port_no(reader)
@@ -2111,13 +1806,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("in_phy_port {")
         with q.group():
@@ -2128,7 +1816,9 @@
             q.breakable()
         q.text('}')
 
-class in_phy_port_masked(OXM):
+oxm.subtypes[2147484164] = in_phy_port
+
+class in_phy_port_masked(oxm):
     type_len = 2147484424
 
     def __init__(self, value=None, value_mask=None):
@@ -2140,6 +1830,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -2149,12 +1840,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = in_phy_port_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147484424)
         obj.value = util.unpack_port_no(reader)
@@ -2167,13 +1854,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("in_phy_port_masked {")
         with q.group():
@@ -2187,7 +1867,9 @@
             q.breakable()
         q.text('}')
 
-class in_port(OXM):
+oxm.subtypes[2147484424] = in_phy_port_masked
+
+class in_port(oxm):
     type_len = 2147483652
 
     def __init__(self, value=None):
@@ -2195,6 +1877,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -2203,12 +1886,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = in_port()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147483652)
         obj.value = util.unpack_port_no(reader)
@@ -2219,13 +1898,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("in_port {")
         with q.group():
@@ -2236,7 +1908,9 @@
             q.breakable()
         q.text('}')
 
-class in_port_masked(OXM):
+oxm.subtypes[2147483652] = in_port
+
+class in_port_masked(oxm):
     type_len = 2147483912
 
     def __init__(self, value=None, value_mask=None):
@@ -2248,6 +1922,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -2257,12 +1932,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = in_port_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147483912)
         obj.value = util.unpack_port_no(reader)
@@ -2275,13 +1946,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("in_port_masked {")
         with q.group():
@@ -2295,7 +1959,9 @@
             q.breakable()
         q.text('}')
 
-class ip_dscp(OXM):
+oxm.subtypes[2147483912] = in_port_masked
+
+class ip_dscp(oxm):
     type_len = 2147487745
 
     def __init__(self, value=None):
@@ -2303,6 +1969,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -2311,12 +1978,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ip_dscp()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147487745)
         obj.value = reader.read("!B")[0]
@@ -2327,13 +1990,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ip_dscp {")
         with q.group():
@@ -2344,7 +2000,9 @@
             q.breakable()
         q.text('}')
 
-class ip_dscp_masked(OXM):
+oxm.subtypes[2147487745] = ip_dscp
+
+class ip_dscp_masked(oxm):
     type_len = 2147488002
 
     def __init__(self, value=None, value_mask=None):
@@ -2356,6 +2014,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -2365,12 +2024,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ip_dscp_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147488002)
         obj.value = reader.read("!B")[0]
@@ -2383,13 +2038,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ip_dscp_masked {")
         with q.group():
@@ -2403,7 +2051,9 @@
             q.breakable()
         q.text('}')
 
-class ip_ecn(OXM):
+oxm.subtypes[2147488002] = ip_dscp_masked
+
+class ip_ecn(oxm):
     type_len = 2147488257
 
     def __init__(self, value=None):
@@ -2411,6 +2061,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -2419,12 +2070,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ip_ecn()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147488257)
         obj.value = reader.read("!B")[0]
@@ -2435,13 +2082,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ip_ecn {")
         with q.group():
@@ -2452,7 +2092,9 @@
             q.breakable()
         q.text('}')
 
-class ip_ecn_masked(OXM):
+oxm.subtypes[2147488257] = ip_ecn
+
+class ip_ecn_masked(oxm):
     type_len = 2147488514
 
     def __init__(self, value=None, value_mask=None):
@@ -2464,6 +2106,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -2473,12 +2116,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ip_ecn_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147488514)
         obj.value = reader.read("!B")[0]
@@ -2491,13 +2130,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ip_ecn_masked {")
         with q.group():
@@ -2511,7 +2143,9 @@
             q.breakable()
         q.text('}')
 
-class ip_proto(OXM):
+oxm.subtypes[2147488514] = ip_ecn_masked
+
+class ip_proto(oxm):
     type_len = 2147488769
 
     def __init__(self, value=None):
@@ -2519,6 +2153,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -2527,12 +2162,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ip_proto()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147488769)
         obj.value = reader.read("!B")[0]
@@ -2543,13 +2174,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ip_proto {")
         with q.group():
@@ -2560,7 +2184,9 @@
             q.breakable()
         q.text('}')
 
-class ip_proto_masked(OXM):
+oxm.subtypes[2147488769] = ip_proto
+
+class ip_proto_masked(oxm):
     type_len = 2147489026
 
     def __init__(self, value=None, value_mask=None):
@@ -2572,6 +2198,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -2581,12 +2208,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ip_proto_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147489026)
         obj.value = reader.read("!B")[0]
@@ -2599,13 +2222,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ip_proto_masked {")
         with q.group():
@@ -2619,7 +2235,9 @@
             q.breakable()
         q.text('}')
 
-class ipv4_dst(OXM):
+oxm.subtypes[2147489026] = ip_proto_masked
+
+class ipv4_dst(oxm):
     type_len = 2147489796
 
     def __init__(self, value=None):
@@ -2627,6 +2245,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -2635,12 +2254,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv4_dst()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147489796)
         obj.value = reader.read("!L")[0]
@@ -2651,13 +2266,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv4_dst {")
         with q.group():
@@ -2668,7 +2276,9 @@
             q.breakable()
         q.text('}')
 
-class ipv4_dst_masked(OXM):
+oxm.subtypes[2147489796] = ipv4_dst
+
+class ipv4_dst_masked(oxm):
     type_len = 2147490056
 
     def __init__(self, value=None, value_mask=None):
@@ -2680,6 +2290,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -2689,12 +2300,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv4_dst_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147490056)
         obj.value = reader.read("!L")[0]
@@ -2707,13 +2314,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv4_dst_masked {")
         with q.group():
@@ -2727,7 +2327,9 @@
             q.breakable()
         q.text('}')
 
-class ipv4_src(OXM):
+oxm.subtypes[2147490056] = ipv4_dst_masked
+
+class ipv4_src(oxm):
     type_len = 2147489284
 
     def __init__(self, value=None):
@@ -2735,6 +2337,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -2743,12 +2346,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv4_src()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147489284)
         obj.value = reader.read("!L")[0]
@@ -2759,13 +2358,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv4_src {")
         with q.group():
@@ -2776,7 +2368,9 @@
             q.breakable()
         q.text('}')
 
-class ipv4_src_masked(OXM):
+oxm.subtypes[2147489284] = ipv4_src
+
+class ipv4_src_masked(oxm):
     type_len = 2147489544
 
     def __init__(self, value=None, value_mask=None):
@@ -2788,6 +2382,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -2797,12 +2392,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv4_src_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147489544)
         obj.value = reader.read("!L")[0]
@@ -2815,13 +2406,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv4_src_masked {")
         with q.group():
@@ -2835,7 +2419,9 @@
             q.breakable()
         q.text('}')
 
-class ipv6_dst(OXM):
+oxm.subtypes[2147489544] = ipv4_src_masked
+
+class ipv6_dst(oxm):
     type_len = 2147497488
 
     def __init__(self, value=None):
@@ -2843,6 +2429,7 @@
             self.value = value
         else:
             self.value = '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        return
 
     def pack(self):
         packed = []
@@ -2851,12 +2438,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv6_dst()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147497488)
         obj.value = reader.read('!16s')[0]
@@ -2867,13 +2450,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv6_dst {")
         with q.group():
@@ -2884,7 +2460,9 @@
             q.breakable()
         q.text('}')
 
-class ipv6_dst_masked(OXM):
+oxm.subtypes[2147497488] = ipv6_dst
+
+class ipv6_dst_masked(oxm):
     type_len = 2147497760
 
     def __init__(self, value=None, value_mask=None):
@@ -2896,6 +2474,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        return
 
     def pack(self):
         packed = []
@@ -2905,12 +2484,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv6_dst_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147497760)
         obj.value = reader.read('!16s')[0]
@@ -2923,13 +2498,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv6_dst_masked {")
         with q.group():
@@ -2943,7 +2511,9 @@
             q.breakable()
         q.text('}')
 
-class ipv6_flabel(OXM):
+oxm.subtypes[2147497760] = ipv6_dst_masked
+
+class ipv6_flabel(oxm):
     type_len = 2147497988
 
     def __init__(self, value=None):
@@ -2951,6 +2521,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -2959,12 +2530,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv6_flabel()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147497988)
         obj.value = reader.read("!L")[0]
@@ -2975,13 +2542,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv6_flabel {")
         with q.group():
@@ -2992,7 +2552,9 @@
             q.breakable()
         q.text('}')
 
-class ipv6_flabel_masked(OXM):
+oxm.subtypes[2147497988] = ipv6_flabel
+
+class ipv6_flabel_masked(oxm):
     type_len = 2147498248
 
     def __init__(self, value=None, value_mask=None):
@@ -3004,6 +2566,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -3013,12 +2576,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv6_flabel_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147498248)
         obj.value = reader.read("!L")[0]
@@ -3031,13 +2590,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv6_flabel_masked {")
         with q.group():
@@ -3051,7 +2603,9 @@
             q.breakable()
         q.text('}')
 
-class ipv6_nd_sll(OXM):
+oxm.subtypes[2147498248] = ipv6_flabel_masked
+
+class ipv6_nd_sll(oxm):
     type_len = 2147500038
 
     def __init__(self, value=None):
@@ -3059,6 +2613,7 @@
             self.value = value
         else:
             self.value = [0,0,0,0,0,0]
+        return
 
     def pack(self):
         packed = []
@@ -3067,12 +2622,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv6_nd_sll()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147500038)
         obj.value = list(reader.read('!6B'))
@@ -3083,13 +2634,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv6_nd_sll {")
         with q.group():
@@ -3100,7 +2644,9 @@
             q.breakable()
         q.text('}')
 
-class ipv6_nd_sll_masked(OXM):
+oxm.subtypes[2147500038] = ipv6_nd_sll
+
+class ipv6_nd_sll_masked(oxm):
     type_len = 2147500300
 
     def __init__(self, value=None, value_mask=None):
@@ -3112,6 +2658,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = [0,0,0,0,0,0]
+        return
 
     def pack(self):
         packed = []
@@ -3121,12 +2668,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv6_nd_sll_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147500300)
         obj.value = list(reader.read('!6B'))
@@ -3139,13 +2682,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv6_nd_sll_masked {")
         with q.group():
@@ -3159,7 +2695,9 @@
             q.breakable()
         q.text('}')
 
-class ipv6_nd_target(OXM):
+oxm.subtypes[2147500300] = ipv6_nd_sll_masked
+
+class ipv6_nd_target(oxm):
     type_len = 2147499536
 
     def __init__(self, value=None):
@@ -3167,6 +2705,7 @@
             self.value = value
         else:
             self.value = '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        return
 
     def pack(self):
         packed = []
@@ -3175,12 +2714,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv6_nd_target()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147499536)
         obj.value = reader.read('!16s')[0]
@@ -3191,13 +2726,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv6_nd_target {")
         with q.group():
@@ -3208,7 +2736,9 @@
             q.breakable()
         q.text('}')
 
-class ipv6_nd_target_masked(OXM):
+oxm.subtypes[2147499536] = ipv6_nd_target
+
+class ipv6_nd_target_masked(oxm):
     type_len = 2147499808
 
     def __init__(self, value=None, value_mask=None):
@@ -3220,6 +2750,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        return
 
     def pack(self):
         packed = []
@@ -3229,12 +2760,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv6_nd_target_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147499808)
         obj.value = reader.read('!16s')[0]
@@ -3247,13 +2774,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv6_nd_target_masked {")
         with q.group():
@@ -3267,7 +2787,9 @@
             q.breakable()
         q.text('}')
 
-class ipv6_nd_tll(OXM):
+oxm.subtypes[2147499808] = ipv6_nd_target_masked
+
+class ipv6_nd_tll(oxm):
     type_len = 2147500550
 
     def __init__(self, value=None):
@@ -3275,6 +2797,7 @@
             self.value = value
         else:
             self.value = [0,0,0,0,0,0]
+        return
 
     def pack(self):
         packed = []
@@ -3283,12 +2806,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv6_nd_tll()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147500550)
         obj.value = list(reader.read('!6B'))
@@ -3299,13 +2818,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv6_nd_tll {")
         with q.group():
@@ -3316,7 +2828,9 @@
             q.breakable()
         q.text('}')
 
-class ipv6_nd_tll_masked(OXM):
+oxm.subtypes[2147500550] = ipv6_nd_tll
+
+class ipv6_nd_tll_masked(oxm):
     type_len = 2147500812
 
     def __init__(self, value=None, value_mask=None):
@@ -3328,6 +2842,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = [0,0,0,0,0,0]
+        return
 
     def pack(self):
         packed = []
@@ -3337,12 +2852,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv6_nd_tll_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147500812)
         obj.value = list(reader.read('!6B'))
@@ -3355,13 +2866,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv6_nd_tll_masked {")
         with q.group():
@@ -3375,7 +2879,9 @@
             q.breakable()
         q.text('}')
 
-class ipv6_src(OXM):
+oxm.subtypes[2147500812] = ipv6_nd_tll_masked
+
+class ipv6_src(oxm):
     type_len = 2147496976
 
     def __init__(self, value=None):
@@ -3383,6 +2889,7 @@
             self.value = value
         else:
             self.value = '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        return
 
     def pack(self):
         packed = []
@@ -3391,12 +2898,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv6_src()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147496976)
         obj.value = reader.read('!16s')[0]
@@ -3407,13 +2910,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv6_src {")
         with q.group():
@@ -3424,7 +2920,9 @@
             q.breakable()
         q.text('}')
 
-class ipv6_src_masked(OXM):
+oxm.subtypes[2147496976] = ipv6_src
+
+class ipv6_src_masked(oxm):
     type_len = 2147497248
 
     def __init__(self, value=None, value_mask=None):
@@ -3436,6 +2934,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        return
 
     def pack(self):
         packed = []
@@ -3445,12 +2944,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = ipv6_src_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147497248)
         obj.value = reader.read('!16s')[0]
@@ -3463,13 +2958,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("ipv6_src_masked {")
         with q.group():
@@ -3483,7 +2971,9 @@
             q.breakable()
         q.text('}')
 
-class metadata(OXM):
+oxm.subtypes[2147497248] = ipv6_src_masked
+
+class metadata(oxm):
     type_len = 2147484680
 
     def __init__(self, value=None):
@@ -3491,6 +2981,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -3499,12 +2990,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = metadata()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147484680)
         obj.value = reader.read("!Q")[0]
@@ -3515,13 +3002,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("metadata {")
         with q.group():
@@ -3532,7 +3012,9 @@
             q.breakable()
         q.text('}')
 
-class metadata_masked(OXM):
+oxm.subtypes[2147484680] = metadata
+
+class metadata_masked(oxm):
     type_len = 2147484944
 
     def __init__(self, value=None, value_mask=None):
@@ -3544,6 +3026,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -3553,12 +3036,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = metadata_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147484944)
         obj.value = reader.read("!Q")[0]
@@ -3571,13 +3050,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("metadata_masked {")
         with q.group():
@@ -3591,7 +3063,9 @@
             q.breakable()
         q.text('}')
 
-class mpls_label(OXM):
+oxm.subtypes[2147484944] = metadata_masked
+
+class mpls_label(oxm):
     type_len = 2147501060
 
     def __init__(self, value=None):
@@ -3599,6 +3073,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -3607,12 +3082,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = mpls_label()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147501060)
         obj.value = reader.read("!L")[0]
@@ -3623,13 +3094,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("mpls_label {")
         with q.group():
@@ -3640,7 +3104,9 @@
             q.breakable()
         q.text('}')
 
-class mpls_label_masked(OXM):
+oxm.subtypes[2147501060] = mpls_label
+
+class mpls_label_masked(oxm):
     type_len = 2147501320
 
     def __init__(self, value=None, value_mask=None):
@@ -3652,6 +3118,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -3661,12 +3128,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = mpls_label_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147501320)
         obj.value = reader.read("!L")[0]
@@ -3679,13 +3142,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("mpls_label_masked {")
         with q.group():
@@ -3699,7 +3155,9 @@
             q.breakable()
         q.text('}')
 
-class mpls_tc(OXM):
+oxm.subtypes[2147501320] = mpls_label_masked
+
+class mpls_tc(oxm):
     type_len = 2147501569
 
     def __init__(self, value=None):
@@ -3707,6 +3165,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -3715,12 +3174,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = mpls_tc()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147501569)
         obj.value = reader.read("!B")[0]
@@ -3731,13 +3186,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("mpls_tc {")
         with q.group():
@@ -3748,7 +3196,9 @@
             q.breakable()
         q.text('}')
 
-class mpls_tc_masked(OXM):
+oxm.subtypes[2147501569] = mpls_tc
+
+class mpls_tc_masked(oxm):
     type_len = 2147501826
 
     def __init__(self, value=None, value_mask=None):
@@ -3760,6 +3210,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -3769,12 +3220,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = mpls_tc_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147501826)
         obj.value = reader.read("!B")[0]
@@ -3787,13 +3234,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("mpls_tc_masked {")
         with q.group():
@@ -3807,7 +3247,9 @@
             q.breakable()
         q.text('}')
 
-class sctp_dst(OXM):
+oxm.subtypes[2147501826] = mpls_tc_masked
+
+class sctp_dst(oxm):
     type_len = 2147492866
 
     def __init__(self, value=None):
@@ -3815,6 +3257,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -3823,12 +3266,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = sctp_dst()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147492866)
         obj.value = reader.read("!H")[0]
@@ -3839,13 +3278,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("sctp_dst {")
         with q.group():
@@ -3856,7 +3288,9 @@
             q.breakable()
         q.text('}')
 
-class sctp_dst_masked(OXM):
+oxm.subtypes[2147492866] = sctp_dst
+
+class sctp_dst_masked(oxm):
     type_len = 2147493124
 
     def __init__(self, value=None, value_mask=None):
@@ -3868,6 +3302,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -3877,12 +3312,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = sctp_dst_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147493124)
         obj.value = reader.read("!H")[0]
@@ -3895,13 +3326,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("sctp_dst_masked {")
         with q.group():
@@ -3915,7 +3339,9 @@
             q.breakable()
         q.text('}')
 
-class sctp_src(OXM):
+oxm.subtypes[2147493124] = sctp_dst_masked
+
+class sctp_src(oxm):
     type_len = 2147492354
 
     def __init__(self, value=None):
@@ -3923,6 +3349,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -3931,12 +3358,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = sctp_src()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147492354)
         obj.value = reader.read("!H")[0]
@@ -3947,13 +3370,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("sctp_src {")
         with q.group():
@@ -3964,7 +3380,9 @@
             q.breakable()
         q.text('}')
 
-class sctp_src_masked(OXM):
+oxm.subtypes[2147492354] = sctp_src
+
+class sctp_src_masked(oxm):
     type_len = 2147492612
 
     def __init__(self, value=None, value_mask=None):
@@ -3976,6 +3394,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -3985,12 +3404,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = sctp_src_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147492612)
         obj.value = reader.read("!H")[0]
@@ -4003,13 +3418,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("sctp_src_masked {")
         with q.group():
@@ -4023,7 +3431,9 @@
             q.breakable()
         q.text('}')
 
-class tcp_dst(OXM):
+oxm.subtypes[2147492612] = sctp_src_masked
+
+class tcp_dst(oxm):
     type_len = 2147490818
 
     def __init__(self, value=None):
@@ -4031,6 +3441,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -4039,12 +3450,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = tcp_dst()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147490818)
         obj.value = reader.read("!H")[0]
@@ -4055,13 +3462,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("tcp_dst {")
         with q.group():
@@ -4072,7 +3472,9 @@
             q.breakable()
         q.text('}')
 
-class tcp_dst_masked(OXM):
+oxm.subtypes[2147490818] = tcp_dst
+
+class tcp_dst_masked(oxm):
     type_len = 2147491076
 
     def __init__(self, value=None, value_mask=None):
@@ -4084,6 +3486,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -4093,12 +3496,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = tcp_dst_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147491076)
         obj.value = reader.read("!H")[0]
@@ -4111,13 +3510,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("tcp_dst_masked {")
         with q.group():
@@ -4131,7 +3523,9 @@
             q.breakable()
         q.text('}')
 
-class tcp_src(OXM):
+oxm.subtypes[2147491076] = tcp_dst_masked
+
+class tcp_src(oxm):
     type_len = 2147490306
 
     def __init__(self, value=None):
@@ -4139,6 +3533,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -4147,12 +3542,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = tcp_src()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147490306)
         obj.value = reader.read("!H")[0]
@@ -4163,13 +3554,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("tcp_src {")
         with q.group():
@@ -4180,7 +3564,9 @@
             q.breakable()
         q.text('}')
 
-class tcp_src_masked(OXM):
+oxm.subtypes[2147490306] = tcp_src
+
+class tcp_src_masked(oxm):
     type_len = 2147490564
 
     def __init__(self, value=None, value_mask=None):
@@ -4192,6 +3578,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -4201,12 +3588,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = tcp_src_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147490564)
         obj.value = reader.read("!H")[0]
@@ -4219,13 +3602,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("tcp_src_masked {")
         with q.group():
@@ -4239,7 +3615,9 @@
             q.breakable()
         q.text('}')
 
-class udp_dst(OXM):
+oxm.subtypes[2147490564] = tcp_src_masked
+
+class udp_dst(oxm):
     type_len = 2147491842
 
     def __init__(self, value=None):
@@ -4247,6 +3625,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -4255,12 +3634,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = udp_dst()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147491842)
         obj.value = reader.read("!H")[0]
@@ -4271,13 +3646,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("udp_dst {")
         with q.group():
@@ -4288,7 +3656,9 @@
             q.breakable()
         q.text('}')
 
-class udp_dst_masked(OXM):
+oxm.subtypes[2147491842] = udp_dst
+
+class udp_dst_masked(oxm):
     type_len = 2147492100
 
     def __init__(self, value=None, value_mask=None):
@@ -4300,6 +3670,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -4309,12 +3680,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = udp_dst_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147492100)
         obj.value = reader.read("!H")[0]
@@ -4327,13 +3694,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("udp_dst_masked {")
         with q.group():
@@ -4347,7 +3707,9 @@
             q.breakable()
         q.text('}')
 
-class udp_src(OXM):
+oxm.subtypes[2147492100] = udp_dst_masked
+
+class udp_src(oxm):
     type_len = 2147491330
 
     def __init__(self, value=None):
@@ -4355,6 +3717,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -4363,12 +3726,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = udp_src()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147491330)
         obj.value = reader.read("!H")[0]
@@ -4379,13 +3738,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("udp_src {")
         with q.group():
@@ -4396,7 +3748,9 @@
             q.breakable()
         q.text('}')
 
-class udp_src_masked(OXM):
+oxm.subtypes[2147491330] = udp_src
+
+class udp_src_masked(oxm):
     type_len = 2147491588
 
     def __init__(self, value=None, value_mask=None):
@@ -4408,6 +3762,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -4417,12 +3772,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = udp_src_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147491588)
         obj.value = reader.read("!H")[0]
@@ -4435,13 +3786,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("udp_src_masked {")
         with q.group():
@@ -4455,7 +3799,9 @@
             q.breakable()
         q.text('}')
 
-class vlan_pcp(OXM):
+oxm.subtypes[2147491588] = udp_src_masked
+
+class vlan_pcp(oxm):
     type_len = 2147487233
 
     def __init__(self, value=None):
@@ -4463,6 +3809,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -4471,12 +3818,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = vlan_pcp()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147487233)
         obj.value = reader.read("!B")[0]
@@ -4487,13 +3830,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("vlan_pcp {")
         with q.group():
@@ -4504,7 +3840,9 @@
             q.breakable()
         q.text('}')
 
-class vlan_pcp_masked(OXM):
+oxm.subtypes[2147487233] = vlan_pcp
+
+class vlan_pcp_masked(oxm):
     type_len = 2147487490
 
     def __init__(self, value=None, value_mask=None):
@@ -4516,6 +3854,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -4525,12 +3864,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = vlan_pcp_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147487490)
         obj.value = reader.read("!B")[0]
@@ -4543,13 +3878,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("vlan_pcp_masked {")
         with q.group():
@@ -4563,7 +3891,9 @@
             q.breakable()
         q.text('}')
 
-class vlan_vid(OXM):
+oxm.subtypes[2147487490] = vlan_pcp_masked
+
+class vlan_vid(oxm):
     type_len = 2147486722
 
     def __init__(self, value=None):
@@ -4571,6 +3901,7 @@
             self.value = value
         else:
             self.value = 0
+        return
 
     def pack(self):
         packed = []
@@ -4579,12 +3910,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = vlan_vid()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147486722)
         obj.value = reader.read("!H")[0]
@@ -4595,13 +3922,6 @@
         if self.value != other.value: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("vlan_vid {")
         with q.group():
@@ -4612,7 +3932,9 @@
             q.breakable()
         q.text('}')
 
-class vlan_vid_masked(OXM):
+oxm.subtypes[2147486722] = vlan_vid
+
+class vlan_vid_masked(oxm):
     type_len = 2147486980
 
     def __init__(self, value=None, value_mask=None):
@@ -4624,6 +3946,7 @@
             self.value_mask = value_mask
         else:
             self.value_mask = 0
+        return
 
     def pack(self):
         packed = []
@@ -4633,12 +3956,8 @@
         return ''.join(packed)
 
     @staticmethod
-    def unpack(buf):
+    def unpack(reader):
         obj = vlan_vid_masked()
-        if type(buf) == loxi.generic_util.OFReader:
-            reader = buf
-        else:
-            reader = loxi.generic_util.OFReader(buf)
         _type_len = reader.read("!L")[0]
         assert(_type_len == 2147486980)
         obj.value = reader.read("!H")[0]
@@ -4651,13 +3970,6 @@
         if self.value_mask != other.value_mask: return False
         return True
 
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def show(self):
-        import loxi.pp
-        return loxi.pp.pp(self)
-
     def pretty_print(self, q):
         q.text("vlan_vid_masked {")
         with q.group():
@@ -4671,92 +3983,6 @@
             q.breakable()
         q.text('}')
 
+oxm.subtypes[2147486980] = vlan_vid_masked
 
-parsers = {
-    196640 : bsn_in_ports_128.unpack,
-    196896 : bsn_in_ports_128_masked.unpack,
-    197124 : bsn_lag_id.unpack,
-    197380 : bsn_lag_id_masked.unpack,
-    197636 : bsn_vrf.unpack,
-    197892 : bsn_vrf_masked.unpack,
-    198145 : bsn_global_vrf_allowed.unpack,
-    198401 : bsn_global_vrf_allowed_masked.unpack,
-    198660 : bsn_l3_interface_class_id.unpack,
-    198916 : bsn_l3_interface_class_id_masked.unpack,
-    199172 : bsn_l3_src_class_id.unpack,
-    199428 : bsn_l3_src_class_id_masked.unpack,
-    199684 : bsn_l3_dst_class_id.unpack,
-    199940 : bsn_l3_dst_class_id_masked.unpack,
-    2147483652 : in_port.unpack,
-    2147483912 : in_port_masked.unpack,
-    2147484164 : in_phy_port.unpack,
-    2147484424 : in_phy_port_masked.unpack,
-    2147484680 : metadata.unpack,
-    2147484944 : metadata_masked.unpack,
-    2147485190 : eth_dst.unpack,
-    2147485452 : eth_dst_masked.unpack,
-    2147485702 : eth_src.unpack,
-    2147485964 : eth_src_masked.unpack,
-    2147486210 : eth_type.unpack,
-    2147486468 : eth_type_masked.unpack,
-    2147486722 : vlan_vid.unpack,
-    2147486980 : vlan_vid_masked.unpack,
-    2147487233 : vlan_pcp.unpack,
-    2147487490 : vlan_pcp_masked.unpack,
-    2147487745 : ip_dscp.unpack,
-    2147488002 : ip_dscp_masked.unpack,
-    2147488257 : ip_ecn.unpack,
-    2147488514 : ip_ecn_masked.unpack,
-    2147488769 : ip_proto.unpack,
-    2147489026 : ip_proto_masked.unpack,
-    2147489284 : ipv4_src.unpack,
-    2147489544 : ipv4_src_masked.unpack,
-    2147489796 : ipv4_dst.unpack,
-    2147490056 : ipv4_dst_masked.unpack,
-    2147490306 : tcp_src.unpack,
-    2147490564 : tcp_src_masked.unpack,
-    2147490818 : tcp_dst.unpack,
-    2147491076 : tcp_dst_masked.unpack,
-    2147491330 : udp_src.unpack,
-    2147491588 : udp_src_masked.unpack,
-    2147491842 : udp_dst.unpack,
-    2147492100 : udp_dst_masked.unpack,
-    2147492354 : sctp_src.unpack,
-    2147492612 : sctp_src_masked.unpack,
-    2147492866 : sctp_dst.unpack,
-    2147493124 : sctp_dst_masked.unpack,
-    2147493377 : icmpv4_type.unpack,
-    2147493634 : icmpv4_type_masked.unpack,
-    2147493889 : icmpv4_code.unpack,
-    2147494146 : icmpv4_code_masked.unpack,
-    2147494402 : arp_op.unpack,
-    2147494660 : arp_op_masked.unpack,
-    2147494916 : arp_spa.unpack,
-    2147495176 : arp_spa_masked.unpack,
-    2147495428 : arp_tpa.unpack,
-    2147495688 : arp_tpa_masked.unpack,
-    2147495942 : arp_sha.unpack,
-    2147496204 : arp_sha_masked.unpack,
-    2147496454 : arp_tha.unpack,
-    2147496716 : arp_tha_masked.unpack,
-    2147496976 : ipv6_src.unpack,
-    2147497248 : ipv6_src_masked.unpack,
-    2147497488 : ipv6_dst.unpack,
-    2147497760 : ipv6_dst_masked.unpack,
-    2147497988 : ipv6_flabel.unpack,
-    2147498248 : ipv6_flabel_masked.unpack,
-    2147498497 : icmpv6_type.unpack,
-    2147498754 : icmpv6_type_masked.unpack,
-    2147499009 : icmpv6_code.unpack,
-    2147499266 : icmpv6_code_masked.unpack,
-    2147499536 : ipv6_nd_target.unpack,
-    2147499808 : ipv6_nd_target_masked.unpack,
-    2147500038 : ipv6_nd_sll.unpack,
-    2147500300 : ipv6_nd_sll_masked.unpack,
-    2147500550 : ipv6_nd_tll.unpack,
-    2147500812 : ipv6_nd_tll_masked.unpack,
-    2147501060 : mpls_label.unpack,
-    2147501320 : mpls_label_masked.unpack,
-    2147501569 : mpls_tc.unpack,
-    2147501826 : mpls_tc_masked.unpack,
-}
+
diff --git a/src/python/loxi/of12/util.py b/src/python/loxi/of12/util.py
index b908451..59be12e 100644
--- a/src/python/loxi/of12/util.py
+++ b/src/python/loxi/of12/util.py
@@ -5,9 +5,13 @@
 # Automatically generated by LOXI from template util.py
 # Do not modify
 
+import struct
 import loxi
 import const
-import struct
+import common
+import action
+import instruction
+import oxm
 
 def pretty_mac(mac):
     return ':'.join(["%02x" % x for x in mac])
@@ -66,9 +70,6 @@
 def unpack_match_bmap(reader):
     return reader.read("!Q")[0]
 
-def pack_list(values):
-    return "".join([x.pack() for x in values])
-
 MASK64 = (1 << 64) - 1
 
 def pack_bitmap_128(value):
@@ -88,3 +89,13 @@
         i += 1
         x >>= 1
     return value
+
+def unpack_list_hello_elem(reader):
+    def deserializer(reader):
+        typ, length, = reader.peek('!HH')
+        reader = reader.slice(length)
+        try:
+            return common.hello_elem.unpack(reader)
+        except loxi.ProtocolError:
+            return None
+    return [x for x in loxi.generic_util.unpack_list(reader, deserializer) if x != None]