# 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))