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165 lines
4.7 KiB
Python

5 years ago
# -*- coding: utf-8 -*-
# Copyright (c) 2019 gevent contributors. See LICENSE for details.
#
# Portions of this code taken from dnspython
# https://github.com/rthalley/dnspython
#
# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
# Copyright (C) 2003-2017 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.
"""
Private support for parsing textual addresses.
"""
from __future__ import absolute_import, division, print_function
import binascii
import re
import struct
from gevent.resolver import hostname_types
class AddressSyntaxError(ValueError):
pass
def _ipv4_inet_aton(text):
"""
Convert an IPv4 address in text form to binary struct.
*text*, a ``text``, the IPv4 address in textual form.
Returns a ``binary``.
"""
if not isinstance(text, bytes):
text = text.encode()
parts = text.split(b'.')
if len(parts) != 4:
raise AddressSyntaxError(text)
for part in parts:
if not part.isdigit():
raise AddressSyntaxError
if len(part) > 1 and part[0] == '0':
# No leading zeros
raise AddressSyntaxError(text)
try:
ints = [int(part) for part in parts]
return struct.pack('BBBB', *ints)
except:
raise AddressSyntaxError(text)
def _ipv6_inet_aton(text,
_v4_ending=re.compile(br'(.*):(\d+\.\d+\.\d+\.\d+)$'),
_colon_colon_start=re.compile(br'::.*'),
_colon_colon_end=re.compile(br'.*::$')):
"""
Convert an IPv6 address in text form to binary form.
*text*, a ``text``, the IPv6 address in textual form.
Returns a ``binary``.
"""
# pylint:disable=too-many-branches
#
# Our aim here is not something fast; we just want something that works.
#
if not isinstance(text, bytes):
text = text.encode()
if text == b'::':
text = b'0::'
#
# Get rid of the icky dot-quad syntax if we have it.
#
m = _v4_ending.match(text)
if not m is None:
b = bytearray(_ipv4_inet_aton(m.group(2)))
text = (u"{}:{:02x}{:02x}:{:02x}{:02x}".format(m.group(1).decode(),
b[0], b[1], b[2],
b[3])).encode()
#
# Try to turn '::<whatever>' into ':<whatever>'; if no match try to
# turn '<whatever>::' into '<whatever>:'
#
m = _colon_colon_start.match(text)
if not m is None:
text = text[1:]
else:
m = _colon_colon_end.match(text)
if not m is None:
text = text[:-1]
#
# Now canonicalize into 8 chunks of 4 hex digits each
#
chunks = text.split(b':')
l = len(chunks)
if l > 8:
raise SyntaxError
seen_empty = False
canonical = []
for c in chunks:
if c == b'':
if seen_empty:
raise AddressSyntaxError(text)
seen_empty = True
for _ in range(0, 8 - l + 1):
canonical.append(b'0000')
else:
lc = len(c)
if lc > 4:
raise AddressSyntaxError(text)
if lc != 4:
c = (b'0' * (4 - lc)) + c
canonical.append(c)
if l < 8 and not seen_empty:
raise AddressSyntaxError(text)
text = b''.join(canonical)
#
# Finally we can go to binary.
#
try:
return binascii.unhexlify(text)
except (binascii.Error, TypeError):
raise AddressSyntaxError(text)
def _is_addr(host, parse=_ipv4_inet_aton):
if not host or not isinstance(host, hostname_types):
return False
try:
parse(host)
except AddressSyntaxError:
return False
else:
return True
# Return True if host is a valid IPv4 address
is_ipv4_addr = _is_addr
def is_ipv6_addr(host):
# Return True if host is a valid IPv6 address
if host and isinstance(host, hostname_types):
s = '%' if isinstance(host, str) else b'%'
host = host.split(s, 1)[0]
return _is_addr(host, _ipv6_inet_aton)