# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
# Copyright (C) 2003-2007, 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 socket
import struct
import dns.immutable
import dns.ipv4
import dns.rdata
try:
_proto_tcp = socket.getprotobyname("tcp")
_proto_udp = socket.getprotobyname("udp")
except OSError:
# Fall back to defaults in case /etc/protocols is unavailable.
_proto_tcp = 6
_proto_udp = 17
@dns.immutable.immutable
class WKS(dns.rdata.Rdata):
"""WKS record"""
# see: RFC 1035
__slots__ = ["address", "protocol", "bitmap"]
def __init__(self, rdclass, rdtype, address, protocol, bitmap):
super().__init__(rdclass, rdtype)
self.address = self._as_ipv4_address(address)
self.protocol = self._as_uint8(protocol)
self.bitmap = self._as_bytes(bitmap)
def to_text(self, origin=None, relativize=True, **kw):
bits = []
for i, byte in enumerate(self.bitmap):
for j in range(0, 8):
if byte & (0x80 >> j):
bits.append(str(i * 8 + j))
text = " ".join(bits)
return "%s %d %s" % (self.address, self.protocol, text)
@classmethod
def from_text(
cls, rdclass, rdtype, tok, origin=None, relativize=True, relativize_to=None
):
address = tok.get_string()
protocol = tok.get_string()
if protocol.isdigit():
protocol = int(protocol)
else:
protocol = socket.getprotobyname(protocol)
bitmap = bytearray()
for token in tok.get_remaining():
value = token.unescape().value
if value.isdigit():
serv = int(value)
else:
if protocol != _proto_udp and protocol != _proto_tcp:
raise NotImplementedError("protocol must be TCP or UDP")
if protocol == _proto_udp:
protocol_text = "udp"
else:
protocol_text = "tcp"
serv = socket.getservbyname(value, protocol_text)
i = serv // 8
l = len(bitmap)
if l < i + 1:
for _ in range(l, i + 1):
bitmap.append(0)
bitmap[i] = bitmap[i] | (0x80 >> (serv % 8))
bitmap = dns.rdata._truncate_bitmap(bitmap)
return cls(rdclass, rdtype, address, protocol, bitmap)
def _to_wire(self, file, compress=None, origin=None, canonicalize=False):
file.write(dns.ipv4.inet_aton(self.address))
protocol = struct.pack("!B", self.protocol)
file.write(protocol)
file.write(self.bitmap)
@classmethod
def from_wire_parser(cls, rdclass, rdtype, parser, origin=None):
address = parser.get_bytes(4)
protocol = parser.get_uint8()
bitmap = parser.get_remaining()
return cls(rdclass, rdtype, address, protocol, bitmap)
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