openstack/os-ken
Code Issues Proposed changes
7c98ab2345
os-ken/ryu/ofproto/oxm_fields.py
YAMAMOTO Takashi 72a06f6f60 Move msg_pack_into from ofproto to lib 
A motivation of this change is a better modularity.
I.e. Make packet lib independent from ofproto.

Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
2015-02-16 13:05:32 +09:00

402 lines
13 KiB
Python
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# Copyright (C) 2013-2015 Nippon Telegraph and Telephone Corporation.
# Copyright (C) 2013-2015 YAMAMOTO Takashi <yamamoto at valinux co jp>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# there are two representations of value and mask this module deal with.
#
# "user"
# (value, mask) or value. the latter means no mask.
# value and mask are strings.
#
# "internal"
# value and mask are on-wire bytes.
# mask is None if no mask.
# There are two types of OXM/NXM headers.
#
# 32-bit OXM/NXM header
# +-------------------------------+-------------+-+---------------+
# | class | field |m| length |
# +-------------------------------+-------------+-+---------------+
#
# 64-bit experimenter OXM header
# +-------------------------------+-------------+-+---------------+
# | class (OFPXMC_EXPERIMENTER) | field |m| length |
# +-------------------------------+-------------+-+---------------+
# | experimenter ID |
# +---------------------------------------------------------------+
# NOTE: EXT-256 had a variation of experimenter OXM header.
# It has been rectified since then. Currently this implementation
# supports only the old version.
#
# ONF EXT-256 (old, exp_type = 2560)
# +-------------------------------+-------------+-+---------------+
# | class (OFPXMC_EXPERIMENTER) | ????? |m| length |
# +-------------------------------+-------------+-+---------------+
# | experimenter ID (ONF_EXPERIMENTER_ID) |
# +-------------------------------+---------------+---------------+
# | exp_type (PBB_UCA=2560) | pbb_uca |
# +-------------------------------+---------------+
#
# ONF EXT-256 (new, oxm_field = 41)
# +-------------------------------+-------------+-+---------------+
# | class (OFPXMC_EXPERIMENTER) | PBB_UCA=41 |m| length |
# +-------------------------------+-------------+-+---------------+
# | experimenter ID (ONF_EXPERIMENTER_ID) |
# +-------------------------------+---------------+---------------+
# | reserved, should be zero | pbb_uca |
# +-------------------------------+---------------+
import itertools
import struct
import ofproto_common
from ryu.lib.pack_utils import msg_pack_into
from ryu.lib import type_desc
OFPXMC_NXM_0 = 0 # Nicira Extended Match (NXM_OF_)
OFPXMC_NXM_1 = 1 # Nicira Extended Match (NXM_NX_)
OFPXMC_OPENFLOW_BASIC = 0x8000
OFPXMC_PACKET_REGS = 0x8001
OFPXMC_EXPERIMENTER = 0xffff
class _OxmClass(object):
def __init__(self, name, num, type_):
self.name = name
self.oxm_type = num | (self._class << 7)
# TODO(yamamoto): Clean this up later.
# Probably when we drop EXT-256 style experimenter OXMs.
self.num = self.oxm_type
self.type = type_
class OpenFlowBasic(_OxmClass):
_class = OFPXMC_OPENFLOW_BASIC
class PacketRegs(_OxmClass):
_class = OFPXMC_PACKET_REGS
class _Experimenter(_OxmClass):
_class = OFPXMC_EXPERIMENTER
def __init__(self, name, num, type_):
super(_Experimenter, self).__init__(name, num, type_)
self.num = (self.experimenter_id, self.oxm_type)
class ONFExperimenter(_Experimenter):
experimenter_id = ofproto_common.ONF_EXPERIMENTER_ID
class OldONFExperimenter(_Experimenter):
# This class is for the old version of EXT-256
experimenter_id = ofproto_common.ONF_EXPERIMENTER_ID
def __init__(self, name, num, type_):
super(OldONFExperimenter, self).__init__(name, 0, type_)
self.num = (self.experimenter_id, num)
self.exp_type = num
class NiciraExperimenter(_Experimenter):
experimenter_id = ofproto_common.NX_EXPERIMENTER_ID
class NiciraExtended0(_OxmClass):
"""Nicira Extended Match (NXM_0)
NXM header format is same as 32-bit (non-experimenter) OXMs.
"""
_class = OFPXMC_NXM_0
class NiciraExtended1(_OxmClass):
"""Nicira Extended Match (NXM_1)
NXM header format is same as 32-bit (non-experimenter) OXMs.
"""
_class = OFPXMC_NXM_1
def generate(modname):
import sys
import string
import functools
mod = sys.modules[modname]
def add_attr(k, v):
setattr(mod, k, v)
for i in mod.oxm_types:
uk = string.upper(i.name)
if isinstance(i.num, tuple):
continue
oxm_class = i.num >> 7
if oxm_class != OFPXMC_OPENFLOW_BASIC:
continue
ofpxmt = i.num & 0x3f
td = i.type
add_attr('OFPXMT_OFB_' + uk, ofpxmt)
add_attr('OXM_OF_' + uk, mod.oxm_tlv_header(ofpxmt, td.size))
add_attr('OXM_OF_' + uk + '_W', mod.oxm_tlv_header_w(ofpxmt, td.size))
name_to_field = dict((f.name, f) for f in mod.oxm_types)
num_to_field = dict((f.num, f) for f in mod.oxm_types)
add_attr('oxm_from_user', functools.partial(_from_user, name_to_field))
add_attr('oxm_from_user_header',
functools.partial(_from_user_header, name_to_field))
add_attr('oxm_to_user', functools.partial(_to_user, num_to_field))
add_attr('oxm_to_user_header',
functools.partial(_to_user_header, num_to_field))
add_attr('_oxm_field_desc', functools.partial(_field_desc, num_to_field))
add_attr('oxm_normalize_user', functools.partial(_normalize_user, mod))
add_attr('oxm_parse', functools.partial(_parse, mod))
add_attr('oxm_parse_header', functools.partial(_parse_header, mod))
add_attr('oxm_serialize', functools.partial(_serialize, mod))
add_attr('oxm_serialize_header', functools.partial(_serialize_header, mod))
add_attr('oxm_to_jsondict', _to_jsondict)
add_attr('oxm_from_jsondict', _from_jsondict)
def _get_field_info_by_name(name_to_field, name):
try:
f = name_to_field[name]
t = f.type
num = f.num
except KeyError:
t = type_desc.UnknownType
if name.startswith('field_'):
num = int(name.split('_')[1])
else:
raise KeyError('unknown match field ' + name)
return num, t
def _from_user_header(name_to_field, name):
(num, t) = _get_field_info_by_name(name_to_field, name)
return num
def _from_user(name_to_field, name, user_value):
(num, t) = _get_field_info_by_name(name_to_field, name)
# the 'list' case below is a bit hack; json.dumps silently maps
# python tuples into json lists.
if isinstance(user_value, (tuple, list)):
(value, mask) = user_value
else:
value = user_value
mask = None
if value is not None:
value = t.from_user(value)
if mask is not None:
mask = t.from_user(mask)
return num, value, mask
def _get_field_info_by_number(num_to_field, n):
try:
f = num_to_field[n]
t = f.type
name = f.name
except KeyError:
t = type_desc.UnknownType
name = 'field_%d' % (n,)
return name, t
def _to_user_header(num_to_field, n):
(name, t) = _get_field_info_by_number(num_to_field, n)
return name
def _to_user(num_to_field, n, v, m):
(name, t) = _get_field_info_by_number(num_to_field, n)
if v is not None:
if hasattr(t, 'size') and t.size != len(v):
raise Exception(
'Unexpected OXM payload length %d for %s (expected %d)'
% (len(v), name, t.size))
value = t.to_user(v)
else:
value = None
if m is None:
user_value = value
else:
user_value = (value, t.to_user(m))
return name, user_value
def _field_desc(num_to_field, n):
return num_to_field[n]
def _normalize_user(mod, k, uv):
(n, v, m) = mod.oxm_from_user(k, uv)
# apply mask
if m is not None:
v = ''.join(chr(ord(x) & ord(y)) for (x, y) in itertools.izip(v, m))
(k2, uv2) = mod.oxm_to_user(n, v, m)
assert k2 == k
return (k2, uv2)
def _parse_header_impl(mod, buf, offset):
hdr_pack_str = '!I'
(header, ) = struct.unpack_from(hdr_pack_str, buf, offset)
hdr_len = struct.calcsize(hdr_pack_str)
oxm_type = header >> 9 # class|field
oxm_hasmask = mod.oxm_tlv_header_extract_hasmask(header)
oxm_class = oxm_type >> 7
oxm_length = header & 0xff
if oxm_class == OFPXMC_EXPERIMENTER:
# Experimenter OXMs have 64-bit header. (vs 32-bit for other OXMs)
exp_hdr_pack_str = '!I' # experimenter_id
(exp_id, ) = struct.unpack_from(exp_hdr_pack_str, buf,
offset + hdr_len)
exp_hdr_len = struct.calcsize(exp_hdr_pack_str)
assert exp_hdr_len == 4
oxm_field = oxm_type & 0x7f
if exp_id == ofproto_common.ONF_EXPERIMENTER_ID and oxm_field == 0:
# XXX
# This block implements EXT-256 style experimenter OXM.
onf_exp_type_pack_str = '!H'
(exp_type, ) = struct.unpack_from(onf_exp_type_pack_str, buf,
offset + hdr_len + exp_hdr_len)
exp_hdr_len += struct.calcsize(onf_exp_type_pack_str)
assert exp_hdr_len == 4 + 2
num = (exp_id, exp_type)
else:
num = (exp_id, oxm_type)
else:
num = oxm_type
exp_hdr_len = 0
value_len = oxm_length - exp_hdr_len
if oxm_hasmask:
value_len /= 2
assert value_len > 0
field_len = hdr_len + oxm_length
total_hdr_len = hdr_len + exp_hdr_len
return num, total_hdr_len, oxm_hasmask, value_len, field_len
def _parse_header(mod, buf, offset):
(oxm_type_num, total_hdr_len, hasmask, value_len,
field_len) = _parse_header_impl(mod, buf, offset)
return oxm_type_num, field_len - value_len
def _parse(mod, buf, offset):
(oxm_type_num, total_hdr_len, hasmask, value_len,
field_len) = _parse_header_impl(mod, buf, offset)
# Note: OXM payload length (oxm_len) includes Experimenter ID (exp_hdr_len)
# for experimenter OXMs.
value_offset = offset + total_hdr_len
value_pack_str = '!%ds' % value_len
assert struct.calcsize(value_pack_str) == value_len
(value, ) = struct.unpack_from(value_pack_str, buf, value_offset)
if hasmask:
(mask, ) = struct.unpack_from(value_pack_str, buf,
value_offset + value_len)
else:
mask = None
return oxm_type_num, value, mask, field_len
def _make_exp_hdr(mod, n):
exp_hdr = bytearray()
try:
desc = mod._oxm_field_desc(n)
except KeyError:
return n, exp_hdr
if isinstance(desc, _Experimenter): # XXX
(exp_id, exp_type) = n
assert desc.experimenter_id == exp_id
if isinstance(desc, OldONFExperimenter): # XXX
# XXX
# This block implements EXT-256 style experimenter OXM.
exp_hdr_pack_str = '!IH' # experimenter_id, exp_type
msg_pack_into(exp_hdr_pack_str, exp_hdr, 0,
desc.experimenter_id, desc.exp_type)
else:
assert desc.oxm_type == exp_type
exp_hdr_pack_str = '!I' # experimenter_id
msg_pack_into(exp_hdr_pack_str, exp_hdr, 0,
desc.experimenter_id)
assert len(exp_hdr) == struct.calcsize(exp_hdr_pack_str)
n = desc.oxm_type
assert (n >> 7) == OFPXMC_EXPERIMENTER
return n, exp_hdr
def _serialize_header(mod, n, buf, offset):
try:
desc = mod._oxm_field_desc(n)
value_len = desc.type.size
except KeyError:
value_len = 0
n, exp_hdr = _make_exp_hdr(mod, n)
exp_hdr_len = len(exp_hdr)
pack_str = "!I%ds" % (exp_hdr_len,)
msg_pack_into(pack_str, buf, offset,
(n << 9) | (0 << 8) | (exp_hdr_len + value_len),
bytes(exp_hdr))
return struct.calcsize(pack_str)
def _serialize(mod, n, value, mask, buf, offset):
n, exp_hdr = _make_exp_hdr(mod, n)
exp_hdr_len = len(exp_hdr)
value_len = len(value)
if mask:
assert value_len == len(mask)
pack_str = "!I%ds%ds%ds" % (exp_hdr_len, value_len, len(mask))
msg_pack_into(pack_str, buf, offset,
(n << 9) | (1 << 8) | (exp_hdr_len + value_len * 2),
bytes(exp_hdr), value, mask)
else:
pack_str = "!I%ds%ds" % (exp_hdr_len, value_len,)
msg_pack_into(pack_str, buf, offset,
(n << 9) | (0 << 8) | (exp_hdr_len + value_len),
bytes(exp_hdr), value)
return struct.calcsize(pack_str)
def _to_jsondict(k, uv):
if isinstance(uv, tuple):
(value, mask) = uv
else:
value = uv
mask = None
return {"OXMTlv": {"field": k, "value": value, "mask": mask}}
def _from_jsondict(j):
tlv = j['OXMTlv']
field = tlv['field']
value = tlv['value']
mask = tlv.get('mask')
if mask is None:
uv = value
else:
uv = (value, mask)
return (field, uv)
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