96 lines
3.2 KiB
Python
96 lines
3.2 KiB
Python
# Copyright (C) 2006-2017 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.
|
|
|
|
"""TXT-like base class."""
|
|
|
|
import struct
|
|
|
|
import dns.exception
|
|
import dns.rdata
|
|
import dns.tokenizer
|
|
from dns._compat import binary_type, string_types
|
|
|
|
|
|
class TXTBase(dns.rdata.Rdata):
|
|
|
|
"""Base class for rdata that is like a TXT record
|
|
|
|
@ivar strings: the strings
|
|
@type strings: list of binary
|
|
@see: RFC 1035"""
|
|
|
|
__slots__ = ['strings']
|
|
|
|
def __init__(self, rdclass, rdtype, strings):
|
|
super(TXTBase, self).__init__(rdclass, rdtype)
|
|
if isinstance(strings, binary_type) or \
|
|
isinstance(strings, string_types):
|
|
strings = [strings]
|
|
self.strings = []
|
|
for string in strings:
|
|
if isinstance(string, string_types):
|
|
string = string.encode()
|
|
self.strings.append(string)
|
|
|
|
def to_text(self, origin=None, relativize=True, **kw):
|
|
txt = ''
|
|
prefix = ''
|
|
for s in self.strings:
|
|
txt += '%s"%s"' % (prefix, dns.rdata._escapify(s))
|
|
prefix = ' '
|
|
return txt
|
|
|
|
@classmethod
|
|
def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
|
|
strings = []
|
|
while 1:
|
|
token = tok.get().unescape()
|
|
if token.is_eol_or_eof():
|
|
break
|
|
if not (token.is_quoted_string() or token.is_identifier()):
|
|
raise dns.exception.SyntaxError("expected a string")
|
|
if len(token.value) > 255:
|
|
raise dns.exception.SyntaxError("string too long")
|
|
value = token.value
|
|
if isinstance(value, binary_type):
|
|
strings.append(value)
|
|
else:
|
|
strings.append(value.encode())
|
|
if len(strings) == 0:
|
|
raise dns.exception.UnexpectedEnd
|
|
return cls(rdclass, rdtype, strings)
|
|
|
|
def to_wire(self, file, compress=None, origin=None):
|
|
for s in self.strings:
|
|
l = len(s)
|
|
assert l < 256
|
|
file.write(struct.pack('!B', l))
|
|
file.write(s)
|
|
|
|
@classmethod
|
|
def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None):
|
|
strings = []
|
|
while rdlen > 0:
|
|
l = wire[current]
|
|
current += 1
|
|
rdlen -= 1
|
|
if l > rdlen:
|
|
raise dns.exception.FormError
|
|
s = wire[current: current + l].unwrap()
|
|
current += l
|
|
rdlen -= l
|
|
strings.append(s)
|
|
return cls(rdclass, rdtype, strings)
|