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# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
# Copyright (C) 2006, 2007, 2009-2011 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.name
import dns.ipv4
import dns.ipv6
class Gateway:
"""A helper class for the IPSECKEY gateway and AMTRELAY relay fields"""
name = ""
def __init__(self, type, gateway=None):
self.type = type
self.gateway = gateway
def _invalid_type(self):
return f"invalid {self.name} type: {self.type}"
def check(self):
if self.type == 0:
if self.gateway not in (".", None):
raise SyntaxError(f"invalid {self.name} for type 0")
self.gateway = None
elif self.type == 1:
# check that it's OK
dns.ipv4.inet_aton(self.gateway)
elif self.type == 2:
# check that it's OK
dns.ipv6.inet_aton(self.gateway)
elif self.type == 3:
if not isinstance(self.gateway, dns.name.Name):
raise SyntaxError(f"invalid {self.name}; not a name")
else:
raise SyntaxError(self._invalid_type())
def to_text(self, origin=None, relativize=True):
if self.type == 0:
return "."
elif self.type in (1, 2):
return self.gateway
elif self.type == 3:
return str(self.gateway.choose_relativity(origin, relativize))
else:
raise ValueError(self._invalid_type())
def from_text(self, tok, origin=None, relativize=True, relativize_to=None):
if self.type in (0, 1, 2):
return tok.get_string()
elif self.type == 3:
return tok.get_name(origin, relativize, relativize_to)
else:
raise dns.exception.SyntaxError(self._invalid_type())
def to_wire(self, file, compress=None, origin=None, canonicalize=False):
if self.type == 0:
pass
elif self.type == 1:
file.write(dns.ipv4.inet_aton(self.gateway))
elif self.type == 2:
file.write(dns.ipv6.inet_aton(self.gateway))
elif self.type == 3:
self.gateway.to_wire(file, None, origin, False)
else:
raise ValueError(self._invalid_type())
def from_wire_parser(self, parser, origin=None):
if self.type == 0:
return None
elif self.type == 1:
return dns.ipv4.inet_ntoa(parser.get_bytes(4))
elif self.type == 2:
return dns.ipv6.inet_ntoa(parser.get_bytes(16))
elif self.type == 3:
return parser.get_name(origin)
else:
raise dns.exception.FormError(self._invalid_type())
class Bitmap:
"""A helper class for the NSEC/NSEC3/CSYNC type bitmaps"""
type_name = ""
def __init__(self, windows=None):
self.windows = windows
def to_text(self):
text = ""
for (window, bitmap) in self.windows:
bits = []
for (i, byte) in enumerate(bitmap):
for j in range(0, 8):
if byte & (0x80 >> j):
rdtype = window * 256 + i * 8 + j
bits.append(dns.rdatatype.to_text(rdtype))
text += (' ' + ' '.join(bits))
return text
def from_text(self, tok):
rdtypes = []
for token in tok.get_remaining():
rdtype = dns.rdatatype.from_text(token.unescape().value)
if rdtype == 0:
raise dns.exception.SyntaxError(f"{self.type_name} with bit 0")
rdtypes.append(rdtype)
rdtypes.sort()
window = 0
octets = 0
prior_rdtype = 0
bitmap = bytearray(b'\0' * 32)
windows = []
for rdtype in rdtypes:
if rdtype == prior_rdtype:
continue
prior_rdtype = rdtype
new_window = rdtype // 256
if new_window != window:
if octets != 0:
windows.append((window, bitmap[0:octets]))
bitmap = bytearray(b'\0' * 32)
window = new_window
offset = rdtype % 256
byte = offset // 8
bit = offset % 8
octets = byte + 1
bitmap[byte] = bitmap[byte] | (0x80 >> bit)
if octets != 0:
windows.append((window, bitmap[0:octets]))
return windows
def to_wire(self, file):
for (window, bitmap) in self.windows:
file.write(struct.pack('!BB', window, len(bitmap)))
file.write(bitmap)
def from_wire_parser(self, parser):
windows = []
last_window = -1
while parser.remaining() > 0:
window = parser.get_uint8()
if window <= last_window:
raise dns.exception.FormError(f"bad {self.type_name} bitmap")
bitmap = parser.get_counted_bytes()
if len(bitmap) == 0 or len(bitmap) > 32:
raise dns.exception.FormError(f"bad {self.type_name} octets")
windows.append((window, bitmap))
last_window = window
return windows
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