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#
# Copyright (c) 2018 Cisco and/or its affiliates.
# 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.
#
import struct
import collections
from enum import IntEnum
import logging
from . import vpp_format
import ipaddress
import sys
import socket
#
# Set log-level in application by doing e.g.:
# logger = logging.getLogger('vpp_serializer')
# logger.setLevel(logging.DEBUG)
#
logger = logging.getLogger(__name__)
if sys.version[0] == '2':
def check(d): type(d) is dict
else:
def check(d): type(d) is dict or type(d) is bytes
def conversion_required(data, field_type):
if check(data):
return False
try:
if type(data).__name__ in vpp_format.conversion_table[field_type]:
return True
except KeyError:
return False
def conversion_packer(data, field_type):
t = type(data).__name__
return types[field_type].pack(vpp_format.
conversion_table[field_type][t](data))
def conversion_unpacker(data, field_type):
if field_type not in vpp_format.conversion_unpacker_table:
return data
return vpp_format.conversion_unpacker_table[field_type](data)
class BaseTypes(object):
def __init__(self, type, elements=0):
base_types = {'u8': '>B',
'string': '>s',
'u16': '>H',
'u32': '>I',
'i32': '>i',
'u64': '>Q',
'f64': '>d',
'bool': '>?',
'header': '>HI'}
if elements > 0 and (type == 'u8' or type == 'string'):
self.packer = struct.Struct('>%ss' % elements)
else:
self.packer = struct.Struct(base_types[type])
self.size = self.packer.size
def pack(self, data, kwargs=None):
if not data: # Default to zero if not specified
data = 0
return self.packer.pack(data)
def unpack(self, data, offset, result=None, ntc=False):
return self.packer.unpack_from(data, offset)[0], self.packer.size
class String(object):
def __init__(self):
self.name = 'string'
self.size = 1
self.length_field_packer = BaseTypes('u32')
def pack(self, list, kwargs=None):
if not list:
return self.length_field_packer.pack(0) + b""
return self.length_field_packer.pack(len(list)) + list.encode('utf8')
def unpack(self, data, offset=0, result=None, ntc=False):
length, length_field_size = self.length_field_packer.unpack(data,
offset)
if length == 0:
return b'', 0
p = BaseTypes('u8', length)
x, size = p.unpack(data, offset + length_field_size)
x2 = x.split(b'\0', 1)[0]
return (x2.decode('utf8'), size + length_field_size)
types = {'u8': BaseTypes('u8'), 'u16': BaseTypes('u16'),
'u32': BaseTypes('u32'), 'i32': BaseTypes('i32'),
'u64': BaseTypes('u64'), 'f64': BaseTypes('f64'),
'bool': BaseTypes('bool'), 'string': String()}
def vpp_get_type(name):
try:
return types[name]
except KeyError:
return None
class VPPSerializerValueError(ValueError):
pass
class FixedList_u8(object):
def __init__(self, name, field_type, num):
self.name = name
self.num = num
self.packer = BaseTypes(field_type, num)
self.size = self.packer.size
self.field_type = field_type
def pack(self, data, kwargs=None):
"""Packs a fixed length bytestring. Left-pads with zeros
if input data is too short."""
if not data:
return b'\x00' * self.size
if len(data) > self.num:
raise VPPSerializerValueError(
'Fixed list length error for "{}", got: {}'
' expected: {}'
.format(self.name, len(data), self.num))
return self.packer.pack(data)
def unpack(self, data, offset=0, result=None, ntc=False):
if len(data[offset:]) < self.num:
raise VPPSerializerValueError(
'Invalid array length for "{}" got {}'
' expected {}'
.format(self.name, len(data[offset:]), self.num))
if self.field_type == 'string':
s = self.packer.unpack(data, offset)
s2 = s[0].split(b'\0', 1)[0]
return (s2.decode('utf-8'), self.num)
return self.packer.unpack(data, offset)
class FixedList(object):
def __init__(self, name, field_type, num):
self.num = num
self.packer = types[field_type]
self.size = self.packer.size * num
self.name = name
self.field_type = field_type
def pack(self, list, kwargs):
if len(list) != self.num:
raise VPPSerializerValueError(
'Fixed list length error, got: {} expected: {}'
.format(len(list), self.num))
b = bytes()
for e in list:
b += self.packer.pack(e)
return b
def unpack(self, data, offset=0, result=None, ntc=False):
# Return a list of arguments
result = []
total = 0
for e in range(self.num):
x, size = self.packer.unpack(data, offset, ntc=ntc)
result.append(x)
offset += size
total += size
return result, total
class VLAList(object):
def __init__(self, name, field_type, len_field_name, index):
self.name = name
self.field_type = field_type
self.index = index
self.packer = types[field_type]
self.size = self.packer.size
self.length_field = len_field_name
def pack(self, list, kwargs=None):
if not list:
return b""
if len(list) != kwargs[self.length_field]:
raise VPPSerializerValueError(
'Variable length error, got: {} expected: {}'
.format(len(list), kwargs[self.length_field]))
b = bytes()
# u8 array
if self.packer.size == 1:
return bytearray(list)
for e in list:
b += self.packer.pack(e)
return b
def unpack(self, data, offset=0, result=None, ntc=False):
# Return a list of arguments
total = 0
# u8 array
if self.packer.size == 1:
if result[self.index] == 0:
return b'', 0
p = BaseTypes('u8', result[self.index])
return p.unpack(data, offset, ntc=ntc)
r = []
for e in range(result[self.index]):
x, size = self.packer.unpack(data, offset, ntc=ntc)
r.append(x)
offset += size
total += size
return r, total
class VLAList_legacy():
def __init__(self, name, field_type):
self.packer = types[field_type]
self.size = self.packer.size
def pack(self, list, kwargs=None):
if self.packer.size == 1:
return bytes(list)
b = bytes()
for e in list:
b += self.packer.pack(e)
return b
def unpack(self, data, offset=0, result=None, ntc=False):
total = 0
# Return a list of arguments
if (len(data) - offset) % self.packer.size:
raise VPPSerializerValueError(
'Legacy Variable Length Array length mismatch.')
elements = int((len(data) - offset) / self.packer.size)
r = []
for e in range(elements):
x, size = self.packer.unpack(data, offset, ntc=ntc)
r.append(x)
offset += self.packer.size
total += size
return r, total
class VPPEnumType(object):
def __init__(self, name, msgdef):
self.size = types['u32'].size
e_hash = {}
for f in msgdef:
if type(f) is dict and 'enumtype' in f:
if f['enumtype'] != 'u32':
raise NotImplementedError
continue
ename, evalue = f
e_hash[ename] = evalue
self.enum = IntEnum(name, e_hash)
types[name] = self
def __getattr__(self, name):
return self.enum[name]
def __nonzero__(self):
return True
def pack(self, data, kwargs=None):
return types['u32'].pack(data)
def unpack(self, data, offset=0, result=None, ntc=False):
x, size = types['u32'].unpack(data, offset)
return self.enum(x), size
class VPPUnionType(object):
def __init__(self, name, msgdef):
self.name = name
self.size = 0
self.maxindex = 0
fields = []
self.packers = collections.OrderedDict()
for i, f in enumerate(msgdef):
if type(f) is dict and 'crc' in f:
self.crc = f['crc']
continue
f_type, f_name = f
if f_type not in types:
logger.debug('Unknown union type {}'.format(f_type))
raise VPPSerializerValueError(
'Unknown message type {}'.format(f_type))
fields.append(f_name)
size = types[f_type].size
self.packers[f_name] = types[f_type]
if size > self.size:
self.size = size
self.maxindex = i
types[name] = self
self.tuple = collections.namedtuple(name, fields, rename=True)
# Union of variable length?
def pack(self, data, kwargs=None):
if not data:
return b'\x00' * self.size
for k, v in data.items():
logger.debug("Key: {} Value: {}".format(k, v))
b = self.packers[k].pack(v, kwargs)
break
r = bytearray(self.size)
r[:len(b)] = b
return r
def unpack(self, data, offset=0, result=None, ntc=False):
r = []
maxsize = 0
for k, p in self.packers.items():
x, size = p.unpack(data, offset, ntc=ntc)
if size > maxsize:
maxsize = size
r.append(x)
return self.tuple._make(r), maxsize
class VPPTypeAlias(object):
def __init__(self, name, msgdef):
self.name = name
t = vpp_get_type(msgdef['type'])
if not t:
raise ValueError()
if 'length' in msgdef:
if msgdef['length'] == 0:
raise ValueError()
if msgdef['type'] == 'u8':
self.packer = FixedList_u8(name, msgdef['type'],
msgdef['length'])
self.size = self.packer.size
else:
self.packer = FixedList(name, msgdef['type'], msgdef['length'])
else:
self.packer = t
self.size = t.size
types[name] = self
def pack(self, data, kwargs=None):
if data and conversion_required(data, self.name):
try:
return conversion_packer(data, self.name)
# Python 2 and 3 raises different exceptions from inet_pton
except(OSError, socket.error, TypeError):
pass
return self.packer.pack(data, kwargs)
def unpack(self, data, offset=0, result=None, ntc=False):
t, size = self.packer.unpack(data, offset, result, ntc=ntc)
if not ntc:
return conversion_unpacker(t, self.name), size
return t, size
class VPPType(object):
# Set everything up to be able to pack / unpack
def __init__(self, name, msgdef):
self.name = name
self.msgdef = msgdef
self.packers = []
self.fields = []
self.fieldtypes = []
self.field_by_name = {}
size = 0
for i, f in enumerate(msgdef):
if type(f) is dict and 'crc' in f:
self.crc = f['crc']
continue
f_type, f_name = f[:2]
self.fields.append(f_name)
self.field_by_name[f_name] = None
self.fieldtypes.append(f_type)
if f_type not in types:
logger.debug('Unknown type {}'.format(f_type))
raise VPPSerializerValueError(
'Unknown message type {}'.format(f_type))
if len(f) == 3: # list
list_elements = f[2]
if list_elements == 0:
p = VLAList_legacy(f_name, f_type)
self.packers.append(p)
elif f_type == 'u8' or f_type == 'string':
p = FixedList_u8(f_name, f_type, list_elements)
self.packers.append(p)
size += p.size
else:
p = FixedList(f_name, f_type, list_elements)
self.packers.append(p)
size += p.size
elif len(f) == 4: # Variable length list
length_index = self.fields.index(f[3])
p = VLAList(f_name, f_type, f[3], length_index)
self.packers.append(p)
else:
self.packers.append(types[f_type])
size += types[f_type].size
self.size = size
self.tuple = collections.namedtuple(name, self.fields, rename=True)
types[name] = self
def pack(self, data, kwargs=None):
if not kwargs:
kwargs = data
b = bytes()
# Try one of the format functions
if data and conversion_required(data, self.name):
return conversion_packer(data, self.name)
for i, a in enumerate(self.fields):
if data and type(data) is not dict and a not in data:
raise VPPSerializerValueError(
"Invalid argument: {} expected {}.{}".
format(data, self.name, a))
# Defaulting to zero.
if not data or a not in data: # Default to 0
arg = None
kwarg = None # No default for VLA
else:
arg = data[a]
kwarg = kwargs[a] if a in kwargs else None
if isinstance(self.packers[i], VPPType):
b += self.packers[i].pack(arg, kwarg)
else:
b += self.packers[i].pack(arg, kwargs)
return b
def unpack(self, data, offset=0, result=None, ntc=False):
# Return a list of arguments
result = []
total = 0
for p in self.packers:
x, size = p.unpack(data, offset, result, ntc)
if type(x) is tuple and len(x) == 1:
x = x[0]
result.append(x)
offset += size
total += size
t = self.tuple._make(result)
if not ntc:
t = conversion_unpacker(t, self.name)
return t, total
class VPPMessage(VPPType):
pass