open-RESTful-API/rest_api_venv/Lib/site-packages/dns/ipv4.py

# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license

# Copyright (C) 2003-2017 Nominum, Inc.
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# provided that the above copyright notice and this permission notice
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# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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"""IPv4 helper functions."""

import struct

import dns.exception

def inet_ntoa(address):
    """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):
    """Convert an IPv4 address in text form to binary form.

    *text*, a ``str``, the IPv4 address in textual form.

    Returns a ``bytes``.
    """

    if not isinstance(text, bytes):
        text = text.encode()
    parts = text.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