1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
# Copyright (C) 2001-2017 Nominum, Inc.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose with or without fee is hereby granted,
# provided that the above copyright notice and this permission notice
# appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
"""DNS Opcodes."""
import dns.enum
import dns.exception
class Opcode(dns.enum.IntEnum):
#: Query
QUERY = 0
#: Inverse Query (historical)
IQUERY = 1
#: Server Status (unspecified and unimplemented anywhere)
STATUS = 2
#: Notify
NOTIFY = 4
#: Dynamic Update
UPDATE = 5
@classmethod
def _maximum(cls):
return 15
@classmethod
def _unknown_exception_class(cls):
return UnknownOpcode
# pylint: disable=C0413,W0401,W0614
from dns.constants._opcode_opcode import * # noqa
# pylint: enable=C0413,W0401,W0614
class UnknownOpcode(dns.exception.DNSException):
"""An DNS opcode is unknown."""
def from_text(text):
"""Convert text into an opcode.
*text*, a ``str``, the textual opcode
Raises ``dns.opcode.UnknownOpcode`` if the opcode is unknown.
Returns an ``int``.
"""
return Opcode.from_text(text)
def from_flags(flags):
"""Extract an opcode from DNS message flags.
*flags*, an ``int``, the DNS flags.
Returns an ``int``.
"""
return (flags & 0x7800) >> 11
def to_flags(value):
"""Convert an opcode to a value suitable for ORing into DNS message
flags.
*value*, an ``int``, the DNS opcode value.
Returns an ``int``.
"""
return (value << 11) & 0x7800
def to_text(value):
"""Convert an opcode to text.
*value*, an ``int`` the opcode value,
Raises ``dns.opcode.UnknownOpcode`` if the opcode is unknown.
Returns a ``str``.
"""
return Opcode.to_text(value)
def is_update(flags):
"""Is the opcode in flags UPDATE?
*flags*, an ``int``, the DNS message flags.
Returns a ``bool``.
"""
return from_flags(flags) == Opcode.UPDATE
|
