mirror of https://github.com/morpheus65535/bazarr
102 lines
3.6 KiB
Python
102 lines
3.6 KiB
Python
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# Copyright (C) 2003-2007, 2009-2011 Nominum, Inc.
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#
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# Permission to use, copy, modify, and distribute this software and its
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# documentation for any purpose with or without fee is hereby granted,
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# provided that the above copyright notice and this permission notice
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# appear in all copies.
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#
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# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
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# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
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# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
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# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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"""MX-like base classes."""
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from io import BytesIO
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import struct
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import dns.exception
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import dns.rdata
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import dns.name
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class MXBase(dns.rdata.Rdata):
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"""Base class for rdata that is like an MX record.
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@ivar preference: the preference value
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@type preference: int
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@ivar exchange: the exchange name
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@type exchange: dns.name.Name object"""
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__slots__ = ['preference', 'exchange']
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def __init__(self, rdclass, rdtype, preference, exchange):
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super(MXBase, self).__init__(rdclass, rdtype)
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self.preference = preference
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self.exchange = exchange
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def to_text(self, origin=None, relativize=True, **kw):
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exchange = self.exchange.choose_relativity(origin, relativize)
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return '%d %s' % (self.preference, exchange)
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@classmethod
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def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
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preference = tok.get_uint16()
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exchange = tok.get_name()
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exchange = exchange.choose_relativity(origin, relativize)
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tok.get_eol()
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return cls(rdclass, rdtype, preference, exchange)
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def to_wire(self, file, compress=None, origin=None):
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pref = struct.pack("!H", self.preference)
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file.write(pref)
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self.exchange.to_wire(file, compress, origin)
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def to_digestable(self, origin=None):
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return struct.pack("!H", self.preference) + \
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self.exchange.to_digestable(origin)
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@classmethod
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def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None):
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(preference, ) = struct.unpack('!H', wire[current: current + 2])
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current += 2
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rdlen -= 2
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(exchange, cused) = dns.name.from_wire(wire[: current + rdlen],
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current)
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if cused != rdlen:
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raise dns.exception.FormError
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if origin is not None:
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exchange = exchange.relativize(origin)
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return cls(rdclass, rdtype, preference, exchange)
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def choose_relativity(self, origin=None, relativize=True):
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self.exchange = self.exchange.choose_relativity(origin, relativize)
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class UncompressedMX(MXBase):
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"""Base class for rdata that is like an MX record, but whose name
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is not compressed when converted to DNS wire format, and whose
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digestable form is not downcased."""
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def to_wire(self, file, compress=None, origin=None):
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super(UncompressedMX, self).to_wire(file, None, origin)
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def to_digestable(self, origin=None):
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f = BytesIO()
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self.to_wire(f, None, origin)
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return f.getvalue()
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class UncompressedDowncasingMX(MXBase):
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"""Base class for rdata that is like an MX record, but whose name
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is not compressed when convert to DNS wire format."""
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def to_wire(self, file, compress=None, origin=None):
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super(UncompressedDowncasingMX, self).to_wire(file, None, origin)
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