class ActionSetField(ActionHeader):
"""Action structure for OFPAT_SET_FIELD."""
field = OxmTLV()
_allowed_types = (ActionType.OFPAT_SET_FIELD, )
def __init__(self, field=None):
"""Create a ActionSetField with the optional parameters below.
Args:
length (int): length padded to 64 bits, followed by exactly
oxm_len bytes containing a single OXM TLV, then
exactly ((oxm_len + 4) + 7)/8*8 - (oxm_len + 4)
(between 0 and 7) bytes of all-zero bytes
field (:class:`OxmTLV`): OXM field and value.
"""
super().__init__(action_type=ActionType.OFPAT_SET_FIELD)
self.field = OxmTLV() if field is None else field
def __repr__(self):
return (f"{type(self).__name__}({self.field.oxm_field!s}, "
f"{self.field.oxm_value})")
def pack(self, value=None):
"""Pack this structure updating the length and padding it."""
self._update_length()
packet = super().pack()
return self._complete_last_byte(packet)
def _update_length(self):
"""Update the length field of the struct."""
action_length = 4 + len(self.field.pack())
overflow = action_length % 8
self.length = action_length
if overflow:
self.length = action_length + 8 - overflow
def _complete_last_byte(self, packet):
"""Pad until the packet length is a multiple of 8 (bytes)."""
padded_size = self.length
padding_bytes = padded_size - len(packet)
if padding_bytes > 0:
packet += Pad(padding_bytes).pack()
return packet
class ActionSetField(ActionHeader):
"""Action structure for OFPAT_SET_FIELD."""
field = OxmTLV()
_allowed_types = ActionType.OFPAT_SET_FIELD,
def __init__(self, field=None):
"""Create a ActionSetField with the optional parameters below.
Args:
length (int): length padded to 64 bits, followed by exactly
oxm_len bytes containing a single OXM TLV, then
exactly ((oxm_len + 4) + 7)/8*8 - (oxm_len + 4)
(between 0 and 7) bytes of all-zero bytes
field (:class:`OxmTLV`): OXM field and value.
"""
super().__init__(action_type=ActionType.OFPAT_SET_FIELD)
self.field = OxmTLV() if field is None else field
def pack(self, value=None):
"""Pack this structure updating the length and padding it."""
self._update_length()
packet = super().pack()
return self._complete_last_byte(packet)
def _update_length(self):
"""Update the length field of the struct."""
action_length = 4 + len(self.field.pack())
overflow = action_length % 8
self.length = action_length
if overflow:
self.length = action_length + 8 - overflow
def _complete_last_byte(self, packet):
"""Pad until the packet length is a multiple of 8 (bytes)."""
padded_size = self.length
padding_bytes = padded_size - len(packet)
if padding_bytes > 0:
packet += Pad(padding_bytes).pack()
return packet
class TestOxmTLV(TestCase):
"""Test OXM TLV pack and unpack."""
def setUp(self):
"""Instantiate an OXM TLV struct."""
self.tlv = OxmTLV(oxm_class=OxmClass.OFPXMC_OPENFLOW_BASIC,
oxm_field=OxmOfbMatchField.OFPXMT_OFB_IN_PHY_PORT,
oxm_hasmask=False,
oxm_value=b'')
def test_different_class_types(self):
"""Pack, unpack the result and assert the values are equal."""
for oxm_class in (OxmClass.OFPXMC_OPENFLOW_BASIC,
OxmClass.OFPXMC_EXPERIMENTER):
self.tlv.oxm_class = oxm_class
unpacked = self._create_from_pack()
self.assertEqual(oxm_class, unpacked.oxm_class)
def test_different_fields(self):
"""Pack, unpack the result and assert the values are equal."""
for oxm_field in (OxmOfbMatchField.OFPXMT_OFB_IN_PORT,
OxmOfbMatchField.OFPXMT_OFB_IPV6_EXTHDR):
self.tlv.oxm_field = oxm_field
unpacked = self._create_from_pack()
self.assertEqual(oxm_field, unpacked.oxm_field)
def test_hasmask_bit(self):
"""Pack, unpack the result and assert the values are equal."""
for oxm_hasmask in True, False:
self.tlv.oxm_hasmask = oxm_hasmask
unpacked = self._create_from_pack()
self.assertEqual(oxm_hasmask, unpacked.oxm_hasmask)
def test_different_values(self):
"""Pack, unpack the result and assert the values are equal."""
for oxm_value in b'', b'abc':
self.tlv.oxm_value = oxm_value
unpacked = self._create_from_pack()
self.assertEqual(oxm_value, unpacked.oxm_value)
def _create_from_pack(self):
"""Return a new instance by unpacking self.tlv.pack()."""
unpacked = OxmTLV()
unpacked.unpack(self.tlv.pack())
return unpacked
def test_pack_overflowed_field(self):
"""Raise PackException if field is bigger than 7 bit."""
self.tlv.oxm_class = OxmClass.OFPXMC_EXPERIMENTER
self.tlv.oxm_field = 2**7
with self.assertRaises(PackException):
self.tlv.pack()
def test_pack_invalid_field(self):
"""Raise PackException if field is invalid for a class.
Example: field 42 is invalid for oxm_class OFPXMC_OPENFLOW_BASIC.
"""
self.tlv.oxm_class = OxmClass.OFPXMC_OPENFLOW_BASIC
self.tlv.oxm_field = 42
with self.assertRaises(PackException):
self.tlv.pack()
def test_unpack_invalid_field(self):
"""Raise UnpackException if field is invalid for a class.
Example: field 42 is invalid for oxm_class OFPXMC_OPENFLOW_BASIC.
"""
field42 = b'\x80\x00T\x00'
tlv = OxmTLV()
with self.assertRaises(UnpackException):
tlv.unpack(field42)
def test_max_field_value(self):
"""Use all bits of oxm_field."""
self.tlv.oxm_class = OxmClass.OFPXMC_EXPERIMENTER
self.tlv.oxm_field = 127
unpacked = OxmTLV()
unpacked.unpack(self.tlv.pack())
self.assertEqual(self.tlv, unpacked)
class TestOxmTLV(TestCase):
"""Test OXM TLV pack and unpack."""
def setUp(self):
"""Instantiate an OXM TLV struct."""
self.tlv = OxmTLV(oxm_class=OxmClass.OFPXMC_OPENFLOW_BASIC,
oxm_field=OxmOfbMatchField.OFPXMT_OFB_IN_PHY_PORT,
oxm_hasmask=False, oxm_value=b'')
def test_different_class_types(self):
"""Pack, unpack the result and assert the values are equal."""
for oxm_class in (OxmClass.OFPXMC_OPENFLOW_BASIC,
OxmClass.OFPXMC_EXPERIMENTER):
self.tlv.oxm_class = oxm_class
unpacked = self._create_from_pack()
self.assertEqual(oxm_class, unpacked.oxm_class)
def test_different_fields(self):
"""Pack, unpack the result and assert the values are equal."""
for oxm_field in (OxmOfbMatchField.OFPXMT_OFB_IN_PORT,
OxmOfbMatchField.OFPXMT_OFB_IPV6_EXTHDR):
self.tlv.oxm_field = oxm_field
unpacked = self._create_from_pack()
self.assertEqual(oxm_field, unpacked.oxm_field)
def test_hasmask_bit(self):
"""Pack, unpack the result and assert the values are equal."""
for oxm_hasmask in True, False:
self.tlv.oxm_hasmask = oxm_hasmask
unpacked = self._create_from_pack()
self.assertEqual(oxm_hasmask, unpacked.oxm_hasmask)
def test_different_values(self):
"""Pack, unpack the result and assert the values are equal."""
for oxm_value in b'', b'abc':
self.tlv.oxm_value = oxm_value
unpacked = self._create_from_pack()
self.assertEqual(oxm_value, unpacked.oxm_value)
def _create_from_pack(self):
"""Return a new instance by unpacking self.tlv.pack()."""
unpacked = OxmTLV()
unpacked.unpack(self.tlv.pack())
return unpacked
def test_pack_overflowed_field(self):
"""Raise PackException if field is bigger than 7 bit."""
self.tlv.oxm_class = OxmClass.OFPXMC_EXPERIMENTER
self.tlv.oxm_field = 2**7
with self.assertRaises(PackException):
self.tlv.pack()
def test_pack_invalid_field(self):
"""Raise PackException if field is invalid for a class.
Example: field 42 is invalid for oxm_class OFPXMC_OPENFLOW_BASIC.
"""
self.tlv.oxm_class = OxmClass.OFPXMC_OPENFLOW_BASIC
self.tlv.oxm_field = 42
with self.assertRaises(PackException):
self.tlv.pack()
def test_unpack_invalid_field(self):
"""Raise UnpackException if field is invalid for a class.
Example: field 42 is invalid for oxm_class OFPXMC_OPENFLOW_BASIC.
"""
field42 = b'\x80\x00T\x00'
tlv = OxmTLV()
with self.assertRaises(UnpackException):
tlv.unpack(field42)
def test_max_field_value(self):
"""Use all bits of oxm_field."""
self.tlv.oxm_class = OxmClass.OFPXMC_EXPERIMENTER
self.tlv.oxm_field = 127
unpacked = OxmTLV()
unpacked.unpack(self.tlv.pack())
self.assertEqual(self.tlv, unpacked)
