Current File : //lib/python3/dist-packages/netaddr/strategy/ipv6.py
#-----------------------------------------------------------------------------
# Copyright (c) 2008 by David P. D. Moss. All rights reserved.
#
# Released under the BSD license. See the LICENSE file for details.
#-----------------------------------------------------------------------------
"""
IPv6 address logic.
"""
import struct as _struct
OPT_IMPORTS = False
# Check whether we need to use fallback code or not.
try:
import socket as _socket
# These might all generate exceptions on different platforms.
if not _socket.has_ipv6:
raise Exception('IPv6 disabled')
_socket.inet_pton
_socket.AF_INET6
from _socket import (inet_pton as _inet_pton, inet_ntop as _inet_ntop,
AF_INET6)
OPT_IMPORTS = True
except Exception:
from netaddr.fbsocket import (inet_pton as _inet_pton, inet_ntop as _inet_ntop,
AF_INET6)
from netaddr.core import AddrFormatError
from netaddr.strategy import (
valid_words as _valid_words, int_to_words as _int_to_words,
words_to_int as _words_to_int, valid_bits as _valid_bits,
bits_to_int as _bits_to_int, int_to_bits as _int_to_bits,
valid_bin as _valid_bin, int_to_bin as _int_to_bin,
bin_to_int as _bin_to_int)
#: The width (in bits) of this address type.
width = 128
#: The individual word size (in bits) of this address type.
word_size = 16
#: The separator character used between each word.
word_sep = ':'
#: The AF_* constant value of this address type.
family = AF_INET6
#: A friendly string name address type.
family_name = 'IPv6'
#: The version of this address type.
version = 6
#: The number base to be used when interpreting word values as integers.
word_base = 16
#: The maximum integer value that can be represented by this address type.
max_int = 2 ** width - 1
#: The number of words in this address type.
num_words = width // word_size
#: The maximum integer value for an individual word in this address type.
max_word = 2 ** word_size - 1
#: A dictionary mapping IPv6 CIDR prefixes to the equivalent netmasks.
prefix_to_netmask = dict(
[(i, max_int ^ (2 ** (width - i) - 1)) for i in range(0, width+1)])
#: A dictionary mapping IPv6 netmasks to their equivalent CIDR prefixes.
netmask_to_prefix = dict(
[(max_int ^ (2 ** (width - i) - 1), i) for i in range(0, width+1)])
#: A dictionary mapping IPv6 CIDR prefixes to the equivalent hostmasks.
prefix_to_hostmask = dict(
[(i, (2 ** (width - i) - 1)) for i in range(0, width+1)])
#: A dictionary mapping IPv6 hostmasks to their equivalent CIDR prefixes.
hostmask_to_prefix = dict(
[((2 ** (width - i) - 1), i) for i in range(0, width+1)])
#-----------------------------------------------------------------------------
# Dialect classes.
#-----------------------------------------------------------------------------
class ipv6_compact(object):
"""An IPv6 dialect class - compact form."""
#: The format string used to converting words into string values.
word_fmt = '%x'
#: Boolean flag indicating if IPv6 compaction algorithm should be used.
compact = True
class ipv6_full(ipv6_compact):
"""An IPv6 dialect class - 'all zeroes' form."""
#: Boolean flag indicating if IPv6 compaction algorithm should be used.
compact = False
class ipv6_verbose(ipv6_compact):
"""An IPv6 dialect class - extra wide 'all zeroes' form."""
#: The format string used to converting words into string values.
word_fmt = '%.4x'
#: Boolean flag indicating if IPv6 compaction algorithm should be used.
compact = False
def valid_str(addr, flags=0):
"""
:param addr: An IPv6 address in presentation (string) format.
:param flags: decides which rules are applied to the interpretation of the
addr value. Future use - currently has no effect.
:return: ``True`` if IPv6 address is valid, ``False`` otherwise.
"""
if addr == '':
raise AddrFormatError('Empty strings are not supported!')
try:
_inet_pton(AF_INET6, addr)
except:
return False
return True
def str_to_int(addr, flags=0):
"""
:param addr: An IPv6 address in string form.
:param flags: decides which rules are applied to the interpretation of the
addr value. Future use - currently has no effect.
:return: The equivalent unsigned integer for a given IPv6 address.
"""
try:
packed_int = _inet_pton(AF_INET6, addr)
return packed_to_int(packed_int)
except Exception:
raise AddrFormatError('%r is not a valid IPv6 address string!' % (addr,))
def int_to_str(int_val, dialect=None):
"""
:param int_val: An unsigned integer.
:param dialect: (optional) a Python class defining formatting options.
:return: The IPv6 presentation (string) format address equivalent to the
unsigned integer provided.
"""
if dialect is None:
dialect = ipv6_compact
addr = None
try:
packed_int = int_to_packed(int_val)
if dialect.compact:
# Default return value.
addr = _inet_ntop(AF_INET6, packed_int)
else:
# Custom return value.
words = list(_struct.unpack('>8H', packed_int))
tokens = [dialect.word_fmt % word for word in words]
addr = word_sep.join(tokens)
except Exception:
raise ValueError('%r is not a valid 128-bit unsigned integer!' % (int_val,))
return addr
def int_to_arpa(int_val):
"""
:param int_val: An unsigned integer.
:return: The reverse DNS lookup for an IPv6 address in network byte
order integer form.
"""
addr = int_to_str(int_val, ipv6_verbose)
tokens = list(addr.replace(':', ''))
tokens.reverse()
# We won't support ip6.int here - see RFC 3152 for details.
tokens = tokens + ['ip6', 'arpa', '']
return '.'.join(tokens)
def int_to_packed(int_val):
"""
:param int_val: the integer to be packed.
:return: a packed string that is equivalent to value represented by an
unsigned integer.
"""
words = int_to_words(int_val, 4, 32)
return _struct.pack('>4I', *words)
def packed_to_int(packed_int):
"""
:param packed_int: a packed string containing an unsigned integer.
It is assumed that string is packed in network byte order.
:return: An unsigned integer equivalent to value of network address
represented by packed binary string.
"""
words = list(_struct.unpack('>4I', packed_int))
int_val = 0
for i, num in enumerate(reversed(words)):
word = num
word = word << 32 * i
int_val = int_val | word
return int_val
def valid_words(words):
return _valid_words(words, word_size, num_words)
def int_to_words(int_val, num_words=None, word_size=None):
if num_words is None:
num_words = globals()['num_words']
if word_size is None:
word_size = globals()['word_size']
return _int_to_words(int_val, word_size, num_words)
def words_to_int(words):
return _words_to_int(words, word_size, num_words)
def valid_bits(bits):
return _valid_bits(bits, width, word_sep)
def bits_to_int(bits):
return _bits_to_int(bits, width, word_sep)
def int_to_bits(int_val, word_sep=None):
if word_sep is None:
word_sep = globals()['word_sep']
return _int_to_bits(int_val, word_size, num_words, word_sep)
def valid_bin(bin_val):
return _valid_bin(bin_val, width)
def int_to_bin(int_val):
return _int_to_bin(int_val, width)
def bin_to_int(bin_val):
return _bin_to_int(bin_val, width)
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