bazarr/libs/dns/rdtypes/ANY/CSYNC.py

125 lines
4.5 KiB
Python

# Copyright (C) 2004-2007, 2009-2011, 2016 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.
import struct
import dns.exception
import dns.rdata
import dns.rdatatype
import dns.name
from dns._compat import xrange
class CSYNC(dns.rdata.Rdata):
"""CSYNC record
@ivar serial: the SOA serial number
@type serial: int
@ivar flags: the CSYNC flags
@type flags: int
@ivar windows: the windowed bitmap list
@type windows: list of (window number, string) tuples"""
__slots__ = ['serial', 'flags', 'windows']
def __init__(self, rdclass, rdtype, serial, flags, windows):
super(CSYNC, self).__init__(rdclass, rdtype)
self.serial = serial
self.flags = flags
self.windows = windows
def to_text(self, origin=None, relativize=True, **kw):
text = ''
for (window, bitmap) in self.windows:
bits = []
for i in xrange(0, len(bitmap)):
byte = bitmap[i]
for j in xrange(0, 8):
if byte & (0x80 >> j):
bits.append(dns.rdatatype.to_text(window * 256 +
i * 8 + j))
text += (' ' + ' '.join(bits))
return '%d %d%s' % (self.serial, self.flags, text)
@classmethod
def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
serial = tok.get_uint32()
flags = tok.get_uint16()
rdtypes = []
while 1:
token = tok.get().unescape()
if token.is_eol_or_eof():
break
nrdtype = dns.rdatatype.from_text(token.value)
if nrdtype == 0:
raise dns.exception.SyntaxError("CSYNC with bit 0")
if nrdtype > 65535:
raise dns.exception.SyntaxError("CSYNC with bit > 65535")
rdtypes.append(nrdtype)
rdtypes.sort()
window = 0
octets = 0
prior_rdtype = 0
bitmap = bytearray(b'\0' * 32)
windows = []
for nrdtype in rdtypes:
if nrdtype == prior_rdtype:
continue
prior_rdtype = nrdtype
new_window = nrdtype // 256
if new_window != window:
windows.append((window, bitmap[0:octets]))
bitmap = bytearray(b'\0' * 32)
window = new_window
offset = nrdtype % 256
byte = offset // 8
bit = offset % 8
octets = byte + 1
bitmap[byte] = bitmap[byte] | (0x80 >> bit)
windows.append((window, bitmap[0:octets]))
return cls(rdclass, rdtype, serial, flags, windows)
def to_wire(self, file, compress=None, origin=None):
file.write(struct.pack('!IH', self.serial, self.flags))
for (window, bitmap) in self.windows:
file.write(struct.pack('!BB', window, len(bitmap)))
file.write(bitmap)
@classmethod
def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None):
if rdlen < 6:
raise dns.exception.FormError("CSYNC too short")
(serial, flags) = struct.unpack("!IH", wire[current: current + 6])
current += 6
rdlen -= 6
windows = []
while rdlen > 0:
if rdlen < 3:
raise dns.exception.FormError("CSYNC too short")
window = wire[current]
octets = wire[current + 1]
if octets == 0 or octets > 32:
raise dns.exception.FormError("bad CSYNC octets")
current += 2
rdlen -= 2
if rdlen < octets:
raise dns.exception.FormError("bad CSYNC bitmap length")
bitmap = bytearray(wire[current: current + octets].unwrap())
current += octets
rdlen -= octets
windows.append((window, bitmap))
return cls(rdclass, rdtype, serial, flags, windows)