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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.
"""Generic Internet address helper functions."""
import socket
import dns.ipv4
import dns.ipv6
from ._compat import maybe_ord
# We assume that AF_INET is always defined.
AF_INET = socket.AF_INET
# AF_INET6 might not be defined in the socket module, but we need it.
# We'll try to use the socket module's value, and if it doesn't work,
# we'll use our own value.
try:
AF_INET6 = socket.AF_INET6
except AttributeError:
AF_INET6 = 9999
def inet_pton(family, text):
"""Convert the textual form of a network address into its binary form.
*family* is an ``int``, the address family.
*text* is a ``text``, the textual address.
Raises ``NotImplementedError`` if the address family specified is not
implemented.
Returns a ``binary``.
"""
if family == AF_INET:
return dns.ipv4.inet_aton(text)
elif family == AF_INET6:
return dns.ipv6.inet_aton(text)
else:
raise NotImplementedError
def inet_ntop(family, address):
"""Convert the binary form of a network address into its textual form.
*family* is an ``int``, the address family.
*address* is a ``binary``, the network address in binary form.
Raises ``NotImplementedError`` if the address family specified is not
implemented.
Returns a ``text``.
"""
if family == AF_INET:
return dns.ipv4.inet_ntoa(address)
elif family == AF_INET6:
return dns.ipv6.inet_ntoa(address)
else:
raise NotImplementedError
def af_for_address(text):
"""Determine the address family of a textual-form network address.
*text*, a ``text``, the textual address.
Raises ``ValueError`` if the address family cannot be determined
from the input.
Returns an ``int``.
"""
try:
dns.ipv4.inet_aton(text)
return AF_INET
except Exception:
try:
dns.ipv6.inet_aton(text)
return AF_INET6
except:
raise ValueError
def is_multicast(text):
"""Is the textual-form network address a multicast address?
*text*, a ``text``, the textual address.
Raises ``ValueError`` if the address family cannot be determined
from the input.
Returns a ``bool``.
"""
try:
first = maybe_ord(dns.ipv4.inet_aton(text)[0])
return first >= 224 and first <= 239
except Exception:
try:
first = maybe_ord(dns.ipv6.inet_aton(text)[0])
return first == 255
except Exception:
raise ValueError