/usr/share/pyshared/dns/edns.py is in python-dnspython 1.9.4-0ubuntu3.
This file is owned by root:root, with mode 0o644.
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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 | # Copyright (C) 2009 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.
"""EDNS Options"""
NSID = 3
class Option(object):
"""Base class for all EDNS option types.
"""
def __init__(self, otype):
"""Initialize an option.
@param rdtype: The rdata type
@type rdtype: int
"""
self.otype = otype
def to_wire(self, file):
"""Convert an option to wire format.
"""
raise NotImplementedError
def from_wire(cls, otype, wire, current, olen):
"""Build an EDNS option object from wire format
@param otype: The option type
@type otype: int
@param wire: The wire-format message
@type wire: string
@param current: The offet in wire of the beginning of the rdata.
@type current: int
@param olen: The length of the wire-format option data
@type olen: int
@rtype: dns.ends.Option instance"""
raise NotImplementedError
from_wire = classmethod(from_wire)
def _cmp(self, other):
"""Compare an ENDS option with another option of the same type.
Return < 0 if self < other, 0 if self == other, and > 0 if self > other.
"""
raise NotImplementedError
def __eq__(self, other):
if not isinstance(other, Option):
return False
if self.otype != other.otype:
return False
return self._cmp(other) == 0
def __ne__(self, other):
if not isinstance(other, Option):
return False
if self.otype != other.otype:
return False
return self._cmp(other) != 0
def __lt__(self, other):
if not isinstance(other, Option) or \
self.otype != other.otype:
return NotImplemented
return self._cmp(other) < 0
def __le__(self, other):
if not isinstance(other, Option) or \
self.otype != other.otype:
return NotImplemented
return self._cmp(other) <= 0
def __ge__(self, other):
if not isinstance(other, Option) or \
self.otype != other.otype:
return NotImplemented
return self._cmp(other) >= 0
def __gt__(self, other):
if not isinstance(other, Option) or \
self.otype != other.otype:
return NotImplemented
return self._cmp(other) > 0
class GenericOption(Option):
"""Generate Rdata Class
This class is used for EDNS option types for which we have no better
implementation.
"""
def __init__(self, otype, data):
super(GenericOption, self).__init__(otype)
self.data = data
def to_wire(self, file):
file.write(self.data)
def from_wire(cls, otype, wire, current, olen):
return cls(otype, wire[current : current + olen])
from_wire = classmethod(from_wire)
def _cmp(self, other):
return cmp(self.data, other.data)
_type_to_class = {
}
def get_option_class(otype):
cls = _type_to_class.get(otype)
if cls is None:
cls = GenericOption
return cls
def option_from_wire(otype, wire, current, olen):
"""Build an EDNS option object from wire format
@param otype: The option type
@type otype: int
@param wire: The wire-format message
@type wire: string
@param current: The offet in wire of the beginning of the rdata.
@type current: int
@param olen: The length of the wire-format option data
@type olen: int
@rtype: dns.ends.Option instance"""
cls = get_option_class(otype)
return cls.from_wire(otype, wire, current, olen)
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