|
1
|
|
|
"""Base classes for Match Fields.""" |
|
2
|
|
|
|
|
3
|
1 |
|
from abc import ABC, abstractmethod |
|
4
|
|
|
|
|
5
|
|
|
|
|
6
|
1 |
|
class MatchField(ABC): |
|
7
|
|
|
"""Base class for match fields. Abstract OXM TLVs of python-openflow. |
|
8
|
|
|
|
|
9
|
|
|
Just extend this class and you will be forced to define the required |
|
10
|
|
|
low-level attributes and methods below: |
|
11
|
|
|
|
|
12
|
|
|
* "name" attribute (field name to be displayed in JSON); |
|
13
|
|
|
* "oxm_field" attribute (``OxmOfbMatchField`` enum); |
|
14
|
|
|
* Method to return a pyof OxmTLV; |
|
15
|
|
|
* Method to create an instance from an OxmTLV. |
|
16
|
|
|
""" |
|
17
|
|
|
|
|
18
|
1 |
|
def __init__(self, value): |
|
19
|
|
|
"""Define match field value.""" |
|
20
|
1 |
|
self.value = value |
|
21
|
|
|
|
|
22
|
1 |
|
@property |
|
23
|
1 |
|
@classmethod |
|
24
|
1 |
|
@abstractmethod |
|
25
|
|
|
def name(cls): |
|
26
|
|
|
"""Define a name to be displayed in JSON. |
|
27
|
|
|
|
|
28
|
|
|
It can be overriden just by a class attibute. |
|
29
|
|
|
""" |
|
30
|
|
|
|
|
31
|
1 |
|
@property |
|
32
|
1 |
|
@classmethod |
|
33
|
1 |
|
@abstractmethod |
|
34
|
|
|
def oxm_field(cls): |
|
35
|
|
|
"""Define this subclass ``OxmOfbMatchField`` value. |
|
36
|
|
|
|
|
37
|
|
|
It can be overriden just by as a class attibute. |
|
38
|
|
|
""" |
|
39
|
|
|
|
|
40
|
1 |
|
@abstractmethod |
|
41
|
|
|
def as_of_tlv(self): |
|
42
|
|
|
"""Return a pyof OXM TLV instance.""" |
|
43
|
|
|
|
|
44
|
1 |
|
@classmethod |
|
45
|
1 |
|
@abstractmethod |
|
46
|
|
|
def from_of_tlv(cls, tlv): |
|
47
|
|
|
"""Return an instance from a pyof OXM TLV.""" |
|
48
|
|
|
|
|
49
|
1 |
|
def __eq__(self, other): |
|
50
|
|
|
"""Two objects are equal if their values are the same. |
|
51
|
|
|
|
|
52
|
|
|
The oxm_field equality is checked indirectly when comparing whether |
|
53
|
|
|
the objects are instances of the same class. |
|
54
|
|
|
""" |
|
55
|
|
|
return isinstance(other, self.__class__) and other.value == self.value |
|
56
|
|
|
|
|
57
|
|
|
|
|
58
|
1 |
|
class MatchFieldFactory(ABC): |
|
59
|
|
|
"""Create the correct MatchField subclass instance. |
|
60
|
|
|
|
|
61
|
|
|
As OF 1.3 has many match fields and there are many ways to (un)pack their |
|
62
|
|
|
OxmTLV.oxm_value, this class does all the work of finding the correct |
|
63
|
|
|
MatchField class and instantiating the corresponding object. |
|
64
|
|
|
""" |
|
65
|
|
|
|
|
66
|
1 |
|
__classes = {} |
|
67
|
|
|
|
|
68
|
1 |
|
@classmethod |
|
69
|
|
|
def from_name(cls, name, value): |
|
70
|
|
|
"""Return the proper object from name and value.""" |
|
71
|
1 |
|
field_class = cls._get_class(name) |
|
72
|
1 |
|
if field_class: |
|
73
|
1 |
|
return field_class(value) |
|
74
|
|
|
return None |
|
75
|
|
|
|
|
76
|
1 |
|
@classmethod |
|
77
|
|
|
def from_of_tlv(cls, tlv): |
|
78
|
|
|
"""Return the proper object from a pyof OXM TLV.""" |
|
79
|
|
|
field_class = cls._get_class(tlv.oxm_field) |
|
80
|
|
|
if field_class: |
|
81
|
|
|
return field_class.from_of_tlv(tlv) |
|
82
|
|
|
return None |
|
83
|
|
|
|
|
84
|
1 |
|
@classmethod |
|
85
|
|
|
def _get_class(cls, name_or_field): |
|
86
|
|
|
"""Return the proper object from field name or OxmTLV.oxm_field.""" |
|
87
|
1 |
|
if not cls.__classes: |
|
88
|
1 |
|
cls._index_classes() |
|
89
|
1 |
|
return cls.__classes.get(name_or_field) |
|
90
|
|
|
|
|
91
|
1 |
|
@classmethod |
|
92
|
|
|
def _index_classes(cls): |
|
93
|
1 |
|
for subclass in MatchField.__subclasses__(): |
|
94
|
1 |
|
cls.__classes[subclass.name] = subclass |
|
95
|
|
|
cls.__classes[subclass.oxm_field] = subclass |
|
96
|
|
|
|
kytos /
of_core
