Source code for Exscript.util.ipv4

#
# Copyright (C) 2010-2017 Samuel Abels
# The MIT License (MIT)
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
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#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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"""
IPv4 address calculation and conversion.
"""
from builtins import str
from builtins import range
import socket
import struct
import math
import re


def _least_bit(number):
    for i in range(0, 32):
        if number & (0x00000001 << i) != 0:
            return i
    return 32


def _highest_bit(number):
    if number == 0:
        return 0
    number -= 1
    number |= number >> 1
    number |= number >> 2
    number |= number >> 4
    number |= number >> 8
    number |= number >> 16
    number += 1
    return math.sqrt(number)


[docs]def is_ip(string): """ Returns True if the given string is an IPv4 address, False otherwise. :type string: string :param string: Any string. :rtype: bool :return: True if the string is an IP address, False otherwise. """ mo = re.match(r'(\d+)\.(\d+)\.(\d+)\.(\d+)', string) if mo is None: return False for group in mo.groups(): if int(group) not in list(range(0, 256)): return False return True
[docs]def normalize_ip(ip): """ Transform the address into a fixed-length form, such as:: 192.168.0.1 -> 192.168.000.001 :type ip: string :param ip: An IP address. :rtype: string :return: The normalized IP. """ theip = ip.split('.') if len(theip) != 4: raise ValueError('ip should be 4 tuples') return '.'.join(str(int(l)).rjust(3, '0') for l in theip)
[docs]def clean_ip(ip): """ Cleans the ip address up, useful for removing leading zeros, e.g.:: 192.168.010.001 -> 192.168.10.1 :type ip: string :param ip: An IP address. :rtype: string :return: The cleaned up IP. """ return '.'.join(str(int(i)) for i in ip.split('.'))
[docs]def ip2int(ip): """ Converts the given IP address to a 4 byte integer value. :type ip: string :param ip: An IP address. :rtype: long :return: The IP, converted to a number. """ if ip == '255.255.255.255': return 0xFFFFFFFF return struct.unpack('!L', socket.inet_aton(ip))[0]
[docs]def int2ip(number): """ Converts the given integer value to an IP address. :type number: long :param number: An IP as a number. :rtype: string :return: The IP address. """ number &= 0xFFFFFFFF return socket.inet_ntoa(struct.pack('!L', number))
[docs]def pfxlen2mask_int(pfxlen): """ Converts the given prefix length to an IP mask value. :type pfxlen: int :param pfxlen: A prefix length. :rtype: long :return: The mask, as a long value. """ return 0xFFFFFFFF << (32 - int(pfxlen))
[docs]def pfxlen2mask(pfxlen): """ Converts the given prefix length to an IP mask. :type pfxlen: int :param pfxlen: A prefix length. :rtype: string :return: The mask. """ return int2ip(pfxlen2mask_int(pfxlen))
[docs]def mask2pfxlen(mask): """ Converts the given IP mask to a prefix length. :type mask: string :param mask: An IP mask. :rtype: long :return: The mask, as a long value. """ return 32 - _least_bit(ip2int(mask))
[docs]def parse_prefix(prefix, default_length=24): """ Splits the given IP prefix into a network address and a prefix length. If the prefix does not have a length (i.e., it is a simple IP address), it is presumed to have the given default length. :type prefix: string :param prefix: An IP mask. :type default_length: long :param default_length: The default ip prefix length. :rtype: string, int :return: A tuple containing the IP address and prefix length. """ if '/' in prefix: network, pfxlen = prefix.split('/') else: network = prefix pfxlen = default_length return network, int(pfxlen)
[docs]def network(prefix, default_length=24): """ Given a prefix, this function returns the corresponding network address. :type prefix: string :param prefix: An IP prefix. :type default_length: long :param default_length: The default ip prefix length. :rtype: string :return: The IP network address. """ address, pfxlen = parse_prefix(prefix, default_length) ip = ip2int(address) return int2ip(ip & pfxlen2mask_int(pfxlen))
[docs]def broadcast(prefix, default_length=24): """ Given a prefix, this function returns the corresponding broadcast address. :type prefix: string :param prefix: An IP prefix. :type default_length: long :param default_length: The default ip prefix length. :rtype: string :return: The IP broadcast address. """ address, pfxlen = parse_prefix(prefix, default_length) ip = ip2int(address) return int2ip(ip | ~pfxlen2mask_int(pfxlen))
[docs]def remote_ip(local_ip): """ Given an IP address, this function calculates the remaining available IP address under the assumption that it is a /30 network. In other words, given one link net address, this function returns the other link net address. :type local_ip: string :param local_ip: An IP address. :rtype: string :return: The other IP address of the link address pair. """ local_ip = ip2int(local_ip) network = local_ip & pfxlen2mask_int(30) return int2ip(network + 3 - (local_ip - network))
[docs]def matches_prefix(ip, prefix): """ Returns True if the given IP address is part of the given network, returns False otherwise. :type ip: string :param ip: An IP address. :type prefix: string :param prefix: An IP prefix. :rtype: bool :return: True if the IP is in the prefix, False otherwise. """ ip_int = ip2int(ip) network, pfxlen = parse_prefix(prefix) network_int = ip2int(network) mask_int = pfxlen2mask_int(pfxlen) return ip_int&mask_int == network_int&mask_int
[docs]def is_private(ip): """ Returns True if the given IP address is private, returns False otherwise. :type ip: string :param ip: An IP address. :rtype: bool :return: True if the IP is private, False otherwise. """ if matches_prefix(ip, '10.0.0.0/8'): return True if matches_prefix(ip, '172.16.0.0/12'): return True if matches_prefix(ip, '192.168.0.0/16'): return True return False
[docs]def sort(iterable): """ Given an IP address list, this function sorts the list. :type iterable: Iterator :param iterable: An IP address list. :rtype: list :return: The sorted IP address list. """ ips = sorted(normalize_ip(ip) for ip in iterable) return [clean_ip(ip) for ip in ips]