|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
"""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"): |
|
|
|
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. |
|
""" |
|
|
|
|
|
return dns.ipv4.inet_ntoa(dns.ipv4.inet_aton(text)) |
|
|