mirror of https://github.com/morpheus65535/bazarr
127 lines
4.6 KiB
Python
127 lines
4.6 KiB
Python
# Copyright (C) 2004-2007, 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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import struct
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import dns.exception
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import dns.rdata
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import dns.rdatatype
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import dns.name
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from dns._compat import xrange
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class NSEC(dns.rdata.Rdata):
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"""NSEC record
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@ivar next: the next name
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@type next: dns.name.Name object
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@ivar windows: the windowed bitmap list
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@type windows: list of (window number, string) tuples"""
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__slots__ = ['next', 'windows']
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def __init__(self, rdclass, rdtype, next, windows):
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super(NSEC, self).__init__(rdclass, rdtype)
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self.next = next
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self.windows = windows
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def to_text(self, origin=None, relativize=True, **kw):
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next = self.next.choose_relativity(origin, relativize)
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text = ''
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for (window, bitmap) in self.windows:
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bits = []
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for i in xrange(0, len(bitmap)):
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byte = bitmap[i]
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for j in xrange(0, 8):
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if byte & (0x80 >> j):
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bits.append(dns.rdatatype.to_text(window * 256 +
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i * 8 + j))
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text += (' ' + ' '.join(bits))
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return '%s%s' % (next, text)
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@classmethod
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def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
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next = tok.get_name()
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next = next.choose_relativity(origin, relativize)
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rdtypes = []
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while 1:
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token = tok.get().unescape()
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if token.is_eol_or_eof():
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break
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nrdtype = dns.rdatatype.from_text(token.value)
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if nrdtype == 0:
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raise dns.exception.SyntaxError("NSEC with bit 0")
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if nrdtype > 65535:
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raise dns.exception.SyntaxError("NSEC with bit > 65535")
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rdtypes.append(nrdtype)
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rdtypes.sort()
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window = 0
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octets = 0
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prior_rdtype = 0
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bitmap = bytearray(b'\0' * 32)
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windows = []
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for nrdtype in rdtypes:
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if nrdtype == prior_rdtype:
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continue
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prior_rdtype = nrdtype
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new_window = nrdtype // 256
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if new_window != window:
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windows.append((window, bitmap[0:octets]))
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bitmap = bytearray(b'\0' * 32)
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window = new_window
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offset = nrdtype % 256
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byte = offset // 8
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bit = offset % 8
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octets = byte + 1
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bitmap[byte] = bitmap[byte] | (0x80 >> bit)
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windows.append((window, bitmap[0:octets]))
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return cls(rdclass, rdtype, next, windows)
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def to_wire(self, file, compress=None, origin=None):
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self.next.to_wire(file, None, origin)
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for (window, bitmap) in self.windows:
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file.write(struct.pack('!BB', window, len(bitmap)))
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file.write(bitmap)
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@classmethod
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def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None):
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(next, cused) = dns.name.from_wire(wire[: current + rdlen], current)
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current += cused
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rdlen -= cused
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windows = []
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while rdlen > 0:
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if rdlen < 3:
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raise dns.exception.FormError("NSEC too short")
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window = wire[current]
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octets = wire[current + 1]
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if octets == 0 or octets > 32:
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raise dns.exception.FormError("bad NSEC octets")
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current += 2
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rdlen -= 2
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if rdlen < octets:
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raise dns.exception.FormError("bad NSEC bitmap length")
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bitmap = bytearray(wire[current: current + octets].unwrap())
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current += octets
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rdlen -= octets
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windows.append((window, bitmap))
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if origin is not None:
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next = next.relativize(origin)
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return cls(rdclass, rdtype, next, windows)
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def choose_relativity(self, origin=None, relativize=True):
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self.next = self.next.choose_relativity(origin, relativize)
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