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"""Defines flow statistics structures and related items."""
# System imports
# Third-party imports
# Local source tree imports
from pyof.foundation.base import GenericBitMask, GenericStruct
from pyof.foundation.basic_types import (
HWAddress, IPAddress, Pad, UBInt8, UBInt16, UBInt32)
__all__ = ('Match', 'FlowWildCards')
class FlowWildCards(GenericBitMask):
"""Wildcards used to identify flows.
``OFPFW_NW_SRC_*``: IP source address wildcard bit count. 0 is exact match,
1 ignores the LSB, 2 ignores the 2 least-significant bits, ..., 32 and
higher wildcard the entire field. This is the *opposite* of the usual
convention where e.g. /24 indicates that 8 bits (not 24 bits) are
wildcarded.
``OFPFW_NW_DST_*``: IP destination address wildcard bit count. Same format
as source.
"""
#: Switch input port.
OFPFW_IN_PORT = 1 << 0
#: VLAN id.
OFPFW_DL_VLAN = 1 << 1
#: Ethernet source address.
OFPFW_DL_SRC = 1 << 2
#: Ethernet destination address.
OFPFW_DL_DST = 1 << 3
#: Ethernet frame type.
OFPFW_DL_TYPE = 1 << 4
#: IP protocol.
OFPFW_NW_PROTO = 1 << 5
#: TCP/UDP source port.
OFPFW_TP_SRC = 1 << 6
#: TCP/UDP destination port.
OFPFW_TP_DST = 1 << 7
# See class docstring
OFPFW_NW_SRC_SHIFT = 8
OFPFW_NW_SRC_BITS = 6
OFPFW_NW_SRC_MASK = ((1 << OFPFW_NW_SRC_BITS) - 1) << OFPFW_NW_SRC_SHIFT
OFPFW_NW_SRC_ALL = 32 << OFPFW_NW_SRC_SHIFT
# See class docstring
OFPFW_NW_DST_SHIFT = 14
OFPFW_NW_DST_BITS = 6
OFPFW_NW_DST_MASK = ((1 << OFPFW_NW_DST_BITS) - 1) << OFPFW_NW_DST_SHIFT
OFPFW_NW_DST_ALL = 32 << OFPFW_NW_DST_SHIFT
OFPFW_DL_VLAN_PCP = 1 << 20
OFPFW_NW_TOS = 1 << 21
#: Wildcard all fields.
OFPFW_ALL = ((1 << 22) - 1)
# Classes
class Match(GenericStruct):
"""Describes a flow entry. Fields to match against flows."""
#: Wildcards fields.
wildcards = UBInt32(value=FlowWildCards.OFPFW_ALL, enum_ref=FlowWildCards)
#: Input switch port.
in_port = UBInt16(0)
#: Ethernet source address. (default: '00:00:00:00:00:00')
dl_src = HWAddress()
#: Ethernet destination address. (default: '00:00:00:00:00:00')
dl_dst = HWAddress()
#: Input VLAN id. (default: 0)
dl_vlan = UBInt16(0)
#: Input VLAN priority. (default: 0)
dl_vlan_pcp = UBInt8(0)
#: Align to 64-bits.
pad1 = Pad(1)
#: Ethernet frame type. (default: 0)
dl_type = UBInt16(0)
#: IP ToS (actually DSCP field, 6 bits). (default: 0)
nw_tos = UBInt8(0)
#: IP protocol or lower 8 bits of ARP opcode. (default: 0)
nw_proto = UBInt8(0)
#: Align to 64-bits.
pad2 = Pad(2)
#: IP source address. (default: '0.0.0.0/0')
nw_src = IPAddress('0.0.0.0/0')
#: IP destination address. (default: '0.0.0.0/0')
nw_dst = IPAddress('0.0.0.0/0')
#: TCP/UDP source port. (default: 0)
tp_src = UBInt16(0)
#: TCP/UDP destination port. (default: 0)
tp_dst = UBInt16(0)
def __init__(self, **kwargs):
"""All the constructor parameters below are optional.
Args:
wildcards (FlowWildCards): Wildcards fields. (Default: OFPFW_ALL)
in_port (int): Input switch port. (default: 0)
dl_src (HWAddress): Ethernet source address.
(default: '00:00:00:00:00:00')
dl_dst (HWAddress): Ethernet destination address.
(default: '00:00:00:00:00:00')
dl_vlan (int): Input VLAN id. (default: 0)
dl_vlan_pcp (int): Input VLAN priority. (default: 0)
dl_type (int): Ethernet frame type. (default: 0)
nw_tos (int): IP ToS (actually DSCP field, 6 bits). (default: 0)
nw_proto (int): IP protocol or lower 8 bits of ARP opcode.
(default: 0)
nw_src (IPAddress): IP source address. (default: '0.0.0.0/0')
nw_dst (IPAddress): IP destination address. (default: '0.0.0.0/0')
tp_src (int): TCP/UDP source port. (default: 0)
tp_dst (int): TCP/UDP destination port. (default: 0)
"""
super().__init__()
for field, value in kwargs.items():
setattr(self, field, value)
def __setattr__(self, name, value):
# converts string ip_address to IPAddress
if isinstance(getattr(Match, name), IPAddress) and \
not isinstance(value, IPAddress):
if isinstance(value, list):
value = ".".join(str(x) for x in value)
value = IPAddress(value) # noqa
# convertstring or list of hwaddress to HWAddress
elif isinstance(getattr(Match, name), HWAddress) and \
not isinstance(value, HWAddress):
if isinstance(value, list):
values = ["{0:0{1}x}".format(x, 2) for x in value]
value = ":".join(values)
value = HWAddress(value)
super().__setattr__(name, value)
self.fill_wildcards(name, value)
def unpack(self, buff, offset=0):
"""Unpack *buff* into this object.
Do nothing, since the _length is already defined and it is just a Pad.
Keep buff and offset just for compability with other unpack methods.
Args:
buff (bytes): Binary buffer.
offset (int): Where to begin unpacking.
Raises:
:exc:`~.exceptions.UnpackException`: If unpack fails.
"""
super().unpack(buff, offset)
self.wildcards = UBInt32(value=FlowWildCards.OFPFW_ALL,
enum_ref=FlowWildCards)
self.wildcards.unpack(buff, offset)
def fill_wildcards(self, field=None, value=0):
"""Update wildcards attribute.
This method update a wildcards considering the attributes of the
current instance.
Args:
field (str): Name of the updated field.
value (GenericType): New value used in the field.
"""
if field in [None, 'wildcards'] or isinstance(value, Pad):
return
default_value = getattr(Match, field)
if isinstance(default_value, IPAddress):
if field == 'nw_dst':
shift = FlowWildCards.OFPFW_NW_DST_SHIFT
base_mask = FlowWildCards.OFPFW_NW_DST_MASK
else:
shift = FlowWildCards.OFPFW_NW_SRC_SHIFT
base_mask = FlowWildCards.OFPFW_NW_SRC_MASK
# First we clear the nw_dst/nw_src mask related bits on the current
# wildcard by setting 0 on all of them while we keep all other bits
# as they are.
self.wildcards &= FlowWildCards.OFPFW_ALL ^ base_mask
# nw_dst and nw_src wildcard fields have 6 bits each.
# "base_mask" is the 'all ones' for those 6 bits.
# Once we know the netmask, we can calculate the these 6 bits
# wildcard value and reverse them in order to insert them at the
# correct position in self.wildcards
wildcard = (value.max_prefix - value.netmask) << shift
self.wildcards |= wildcard
else:
wildcard_field = "OFPFW_{}".format(field.upper())
wildcard = getattr(FlowWildCards, wildcard_field)
if value == default_value and not (self.wildcards & wildcard) or \
value != default_value and (self.wildcards & wildcard):
self.wildcards ^= wildcard
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