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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
# We assume that AF_INET and AF_INET6 are always defined. We keep
# these here for the benefit of any old code (unlikely though that
# is!).
AF_INET = socket.AF_INET
AF_INET6 = socket.AF_INET6
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 ``str``, the textual address.
Raises ``NotImplementedError`` if the address family specified is not
implemented.
Returns a ``bytes``.
"""
if family == AF_INET:
return dns.ipv4.inet_aton(text)
elif family == AF_INET6:
return dns.ipv6.inet_aton(text, True)
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 ``bytes``, the network address in binary form.
Raises ``NotImplementedError`` if the address family specified is not
implemented.
Returns a ``str``.
"""
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 ``str``, 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, True)
return AF_INET6
except Exception:
raise ValueError
def is_multicast(text):
"""Is the textual-form network address a multicast address?
*text*, a ``str``, the textual address.
Raises ``ValueError`` if the address family cannot be determined
from the input.
Returns a ``bool``.
"""
try:
first = dns.ipv4.inet_aton(text)[0]
return first >= 224 and first <= 239
except Exception:
try:
first = dns.ipv6.inet_aton(text, True)[0]
return first == 255
except Exception:
raise ValueError
def is_address(text):
"""Is the specified string an IPv4 or IPv6 address?
*text*, a ``str``, the textual address.
Returns a ``bool``.
"""
try:
dns.ipv4.inet_aton(text)
return True
except Exception:
try:
dns.ipv6.inet_aton(text, True)
return True
except Exception:
return False
def low_level_address_tuple(high_tuple, af=None):
"""Given a "high-level" address tuple, i.e.
an (address, port) return the appropriate "low-level" address tuple
suitable for use in socket calls.
If an *af* other than ``None`` is provided, it is assumed the
address in the high-level tuple is valid and has that af. If af
is ``None``, then af_for_address will be called.
"""
address, port = high_tuple
if af is None:
af = af_for_address(address)
if af == AF_INET:
return (address, port)
elif af == AF_INET6:
i = address.find('%')
if i < 0:
# no scope, shortcut!
return (address, port, 0, 0)
# try to avoid getaddrinfo()
addrpart = address[:i]
scope = address[i + 1:]
if scope.isdigit():
return (addrpart, port, 0, int(scope))
try:
return (addrpart, port, 0, socket.if_nametoindex(scope))
except AttributeError: # pragma: no cover (we can't really test this)
ai_flags = socket.AI_NUMERICHOST
((*_, tup), *_) = socket.getaddrinfo(address, port, flags=ai_flags)
return tup
else:
raise NotImplementedError(f'unknown address family {af}')
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