# 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.
"""IPv4 helper functions."""
import struct
from typing import Union
import dns.exception
def inet_ntoa(address: bytes) -> str:
"""Convert an IPv4 address in binary form to text form.
*address*, a ``bytes``, the IPv4 address in binary form.
Returns a ``str``.
"""
if len(address) != 4:
raise dns.exception.SyntaxError
return "%u.%u.%u.%u" % (address[0], address[1], address[2], address[3])
def inet_aton(text: Union[str, bytes]) -> bytes:
"""Convert an IPv4 address in text form to binary form.
*text*, a ``str`` or ``bytes``, the IPv4 address in textual form.
Returns a ``bytes``.
"""
if not isinstance(text, bytes):
btext = text.encode()
else:
btext = text
parts = btext.split(b".")
if len(parts) != 4:
raise dns.exception.SyntaxError
for part in parts:
if not part.isdigit():
raise dns.exception.SyntaxError
if len(part) > 1 and part[0] == ord("0"):
# No leading zeros
raise dns.exception.SyntaxError
try:
b = [int(part) for part in parts]
return struct.pack("BBBB", *b)
except Exception:
raise dns.exception.SyntaxError
def canonicalize(text: Union[str, bytes]) -> str:
"""Verify that *address* is a valid text form IPv4 address and return its
canonical text form.
*text*, a ``str`` or ``bytes``, the IPv4 address in textual form.
Raises ``dns.exception.SyntaxError`` if the text is not valid.
"""
# Note that inet_aton() only accepts canonial form, but we still run through
# inet_ntoa() to ensure the output is a str.
return dns.ipv4.inet_ntoa(dns.ipv4.inet_aton(text))
|