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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# Copyright (c) 2017 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 copy
import enum
import logging
import pickle
import traceback
import uuid
from types import GeneratorType
from netmodel.network.flow import Flow
from netmodel.network.prefix import Prefix as Prefix_
from netmodel.model.attribute import Attribute
from netmodel.model.type import String
from netmodel.model.query import Query
from netmodel.model.filter import Filter as Filter_
from netmodel.model.field_names import FieldNames as FieldNames_
from netmodel.model.object import Object
log = logging.getLogger(__name__)
class NetmodelException(Exception):
pass
#------------------------------------------------------------------------------
NETMODEL_TLV_TYPELEN_STR = '!H'
NETMODEL_TLV_SIZE = 2
NETMODEL_TLV_TYPE_MASK = 0xfe00
NETMODEL_TLV_TYPE_SHIFT = 9
NETMODEL_TLV_LENGTH_MASK = 0x01ff
NETMODEL_TLV_OBJECT_NAME = 1
NETMODEL_TLV_FIELD = 2
NETMODEL_TLV_FIELDS = 3
NETMODEL_TLV_PREDICATE = 4
NETMODEL_TLV_FILTER = 5
NETMODEL_TLV_SRC = 6
NETMODEL_TLV_DST = 7
NETMODEL_TLV_PROTOCOL = 8
NETMODEL_TLV_FLAGS = 9
NETMODEL_TLV_PAYLOAD = 10
NETMODEL_TLV_PACKET = 11
SUCCESS = 0
WARNING = 1
ERROR = 2
FLAG_LAST = 1 << 0
FLAG_REPLY = 1 << 1
#------------------------------------------------------------------------------
class PacketProtocol(enum.Enum):
Query = 'query'
Error = 'error'
#------------------------------------------------------------------------------
class VICNTLV:
_LEN_MIN = 0
_LEN_MAX = 511
tlv_type = None
_tlv_parsers = {} # Attributes...
tlvs = []
def decode(self, buf):
(self.typelen, ) = struct.unpack(
NETMODEL_TLV_TYPELEN_STR, buf[:NETMODEL_TLV_SIZE])
tlv_type = \
(self.typelen & NETMODEL_TLV_TYPE_MASK) >> NETMODEL_TLV_TYPE_SHIFT
assert self.tlv_type == tlv_type
self.len = self.typelen & NETMODEL_TLV_LENGTH_MASK
assert len(buf) >= self.len + NETMODEL_TLV_SIZE
self.tlv_info = buf[NETMODEL_TLV_SIZE:]
self.tlv_info = self.tlv_info[:self.len]
#--------------------------------------------------------------------------
# Descriptor protocol
#--------------------------------------------------------------------------
@classmethod
def _get_tlv_parsers(cls):
if not cls._tlv_parsers:
cls._tlv_parsers = None
return cls._tlv_parsers
@staticmethod
def get_type(buf):
(typelen, ) = struct.unpack(NETMODEL_TLV_TYPELEN_STR,
buf[:NETMODEL_TLV_SIZE])
return (typelen & NETMODEL_TLV_TYPE_MASK) >> NETMODEL_TLV_TYPE_SHIFT
def _len_valid(self):
return self._LEN_MIN <= self.len and self.len <= self._LEN_MAX
#--------------------------------------------------------------------------
@classmethod
def _parser(cls, buf):
tlvs = []
while buf:
tlv_type = VICNTLV.get_type(buf)
tlv = cls._tlv_parsers[tlv_type](buf)
tlvs.append(tlv)
offset = NETMODEL_TLV_SIZE + tlv.len
buf = buf[offset:]
if tlv.tlv_type == NETMODEL_TLV_END:
break
assert len(buf) > 0
pkt = cls(tlvs)
assert pkt._tlvs_len_valid()
assert pkt._tlvs_valid()
return pkt, None, buf
@classmethod
def parser(cls, buf):
try:
return cls._parser(buf)
except:
return None, None, buf
def serialize(self, payload, prev):
data = bytearray()
for tlv in self.tlvs:
data += tlv.serialize()
return data
@classmethod
def set_type(cls, tlv_cls):
cls._tlv_parsers[tlv_cls.tlv_type] = tlv_cls
@classmethod
def get_type(cls, tlv_type):
return cls._tlv_parsers[tlv_type]
@classmethod
def set_tlv_type(cls, tlv_type):
def _set_type(tlv_cls):
tlv_cls.tlv_type = tlv_type
#cls.set_type(tlv_cls)
return tlv_cls
return _set_type
def __len__(self):
return sum(NETMODEL_TLV_SIZE + tlv.len for tlv in self.tlvs)
#------------------------------------------------------------------------------
@VICNTLV.set_tlv_type(NETMODEL_TLV_OBJECT_NAME)
class ObjectName(VICNTLV): pass
@VICNTLV.set_tlv_type(NETMODEL_TLV_FIELD)
class Field(VICNTLV):
"""Field == STR
"""
@VICNTLV.set_tlv_type(NETMODEL_TLV_PREDICATE)
class Predicate(VICNTLV):
"""Predicate == key, op, value
"""
@VICNTLV.set_tlv_type(NETMODEL_TLV_FILTER)
class Filter(Filter_, VICNTLV):
"""Filter == Array<Predicates>
"""
@VICNTLV.set_tlv_type(NETMODEL_TLV_FIELDS)
class FieldNames(FieldNames_, VICNTLV):
"""Fields == Array<Field>
"""
class Prefix(Object, Prefix_, VICNTLV):
object_name = ObjectName()
filter = Filter()
field_names = FieldNames()
def __init__(self, *args, **kwargs):
Object.__init__(self)
Prefix_.__init__(self, *args, **kwargs)
VICNTLV.__init__(self)
def get_tuple(self):
return (self.object_name, self.filter, self.field_names)
def __eq__(self, other):
return self.get_tuple() == other.get_tuple()
def __hash__(self):
return hash(self.get_tuple())
@VICNTLV.set_tlv_type(NETMODEL_TLV_SRC)
class Source(Prefix):
"""Source address
"""
@VICNTLV.set_tlv_type(NETMODEL_TLV_DST)
class Destination(Prefix):
"""Destination address
"""
@VICNTLV.set_tlv_type(NETMODEL_TLV_PROTOCOL)
class Protocol(Attribute, VICNTLV):
"""Protocol
"""
@VICNTLV.set_tlv_type(NETMODEL_TLV_FLAGS)
class Flags(Attribute, VICNTLV):
"""Flags: last, ...
"""
@VICNTLV.set_tlv_type(NETMODEL_TLV_PAYLOAD)
class Payload(Attribute, VICNTLV):
"""Payload
"""
@VICNTLV.set_tlv_type(NETMODEL_TLV_PACKET)
class Packet(Object, VICNTLV):
"""Base packet class
"""
source = Source()
destination = Destination(Prefix)
protocol = Protocol(String, default = 'query')
flags = Flags()
payload = Payload()
# This should be dispatched across L3 L4 L7
def __init__(self, source = None, destination = None, protocol = None,
flags = 0, payload = None):
self.source = source
self.destination = destination
self.protocol = protocol
self.flags = flags
self.payload = payload
def get_flow(self):
return Flow(self.source, self.destination)
@staticmethod
def from_query(query, src_query = None, reply = False):
packet = Packet()
if src_query:
address = Prefix(
object_name = src_query.object_name,
filter = src_query.filter,
field_names = src_query.field_names,
aggregate = src_query.aggregate)
if reply:
packet.destination = address
else:
packet.source = address
if query:
address = Prefix(
object_name = query.object_name,
filter = query.filter,
field_names = query.field_names,
aggregate = query.aggregate)
if reply:
packet.source = address
else:
packet.destination = address
packet.payload = (query.action, query.params)
packet.protocol = 'sync'
packet.last = not query or query.last
packet.reply = reply
return packet
def to_query(self):
action, params = self.payload
address = self.source if self.reply else self.destination
object_name = address.object_name
filter = address.filter
field_names = address.field_names
aggregate = address.aggregate
return Query(action, object_name, filter, params, field_names,
aggregate = aggregate, last = self.last, reply = self.reply)
@property
def last(self):
return self.flags & FLAG_LAST
@last.setter
def last(self, last):
if last:
self.flags |= FLAG_LAST
else:
self.flags &= ~FLAG_LAST
@property
def reply(self):
return self.flags & FLAG_REPLY
@reply.setter
def reply(self, reply):
if reply:
self.flags |= FLAG_REPLY
else:
self.flags &= ~FLAG_REPLY
class ErrorPacket(Packet):
"""
Analog with ICMP errors packets in IP networks
"""
#--------------------------------------------------------------------------
# Constructor
#--------------------------------------------------------------------------
def __init__(self, type = ERROR, code = ERROR, message = None,
traceback = None, **kwargs):
assert not traceback or isinstance(traceback, str)
Packet.__init__(self, **kwargs)
self.protocol = PacketProtocol.Error
self.last = True
self._type = type
self._code = code
self._message = message
self._traceback = traceback
#--------------------------------------------------------------------------
# Static methods
#--------------------------------------------------------------------------
@staticmethod
def from_exception(packet, e):
if isinstance(e, NetmodelException):
error_packet = ErrorPacket(
type = e.TYPE, # eg. ERROR
code = e.CODE, # eg. BADARGS
message = str(e), #e.message,
traceback = traceback.format_exc(),
last = True
)
else:
error_packet = ErrorPacket(
type = ERROR,
code = UNHANDLED_EXCEPTION,
message = str(e),
traceback = traceback.format_exc(),
last = True
)
error_packet.set_source(packet.get_destination())
error_packet.set_destination(packet.get_source())
return error_packet
def get_message(self):
"""
Returns:
The error message related to this ErrorPacket.
"""
return self._message
def get_traceback(self):
"""
Returns:
The traceback related to this ErrorPacket.
"""
return self._traceback
def get_origin(self):
"""
Returns:
A value among {code::CORE, code::GATEWAY}
identifying who is the origin of this ErrorPacket.
"""
return self._origin
def get_code(self):
"""
Returns:
The error code of the Error carried by this ErrorPacket.
"""
return self._code
def get_type(self):
"""
Returns:
The error type of the Error carried by this ErrorPacket.
"""
return self._type
def __repr__(self):
"""
Returns:
The '%r' representation of this ERROR Packet.
"""
return "<Packet.%s: %s>" % (
Packet.get_protocol_name(self.get_protocol()),
self.get_message()
)
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