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| # 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)) | |