knipknap/exscript

#
# 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,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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from Exscript.util import ipv4
from Exscript.stdlib.util import secure_function


@secure_function
def in_network(scope, prefixes, destination, default_pfxlen=[24]):
    """
    Returns True if the given destination is in the network range that is
    defined by the given prefix (e.g. 10.0.0.1/22). If the given prefix
    does not have a prefix length specified, the given default prefix length
    is applied. If no such prefix length is given, the default length is
    /24.

    If a list of prefixes is passed, this function returns True only if
    the given destination is in ANY of the given prefixes.

    :type  prefixes: string
    :param prefixes: A prefix, or a list of IP prefixes.
    :type  destination: string
    :param destination: An IP address.
    :type  default_pfxlen: int
    :param default_pfxlen: The default prefix length.
    :rtype:  True
    :return: Whether the given destination is in the given network.
    """
    needle = ipv4.ip2int(destination[0])
    for prefix in prefixes:
        network, pfxlen = ipv4.parse_prefix(prefix, default_pfxlen[0])
        mask = ipv4.pfxlen2mask_int(pfxlen)
        if needle & mask == ipv4.ip2int(network) & mask:
            return [True]
    return [False]


@secure_function
def mask(scope, ips, mask):
    """
    Applies the given IP mask (e.g. 255.255.255.0) to the given IP address
    (or list of IP addresses) and returns it.

    :type  ips: string
    :param ips: A prefix, or a list of IP prefixes.
    :type  mask: string
    :param mask: An IP mask.
    :rtype:  string
    :return: The network(s) that result(s) from applying the mask.
    """
    mask = ipv4.ip2int(mask[0])
    return [ipv4.int2ip(ipv4.ip2int(ip) & mask) for ip in ips]


@secure_function
def mask2pfxlen(scope, masks):
    """
    Converts the given IP mask(s) (e.g. 255.255.255.0) to prefix length(s).

    :type  masks: string
    :param masks: An IP mask, or a list of masks.
    :rtype:  string
    :return: The prefix length(s) that result(s) from converting the mask.
    """
    return [ipv4.mask2pfxlen(mask) for mask in masks]


@secure_function
def pfxlen2mask(scope, pfxlen):
    """
    Converts the given prefix length(s) (e.g. 30) to IP mask(s).

    :type  pfxlen: int
    :param pfxlen: An IP prefix length.
    :rtype:  string
    :return: The mask(s) that result(s) from converting the prefix length.
    """
    return [ipv4.pfxlen2mask(pfx) for pfx in pfxlen]


@secure_function
def network(scope, prefixes):
    """
    Given a prefix, this function returns the corresponding network address.

    :type  prefixes: string
    :param prefixes: An IP prefix.
    :rtype:  string
    :return: The network address(es) of the prefix length(s).
    """
    return [ipv4.network(pfx) for pfx in prefixes]


@secure_function
def broadcast(scope, prefixes):
    """
    Given a prefix, this function returns the corresponding broadcast address.

    :type  prefixes: string
    :param prefixes: An IP prefix.
    :rtype:  string
    :return: The broadcast address(es) of the prefix length(s).
    """
    return [ipv4.broadcast(pfx) for pfx in prefixes]


@secure_function
def pfxmask(scope, ips, pfxlen):
    """
    Applies the given prefix length to the given ips, resulting in a
    (list of) IP network addresses.

    :type  ips: string
    :param ips: An IP address, or a list of IP addresses.
    :type  pfxlen: int
    :param pfxlen: An IP prefix length.
    :rtype:  string
    :return: The mask(s) that result(s) from converting the prefix length.
    """
    mask = ipv4.pfxlen2mask_int(pfxlen[0])
    return [ipv4.int2ip(ipv4.ip2int(ip) & mask) for ip in ips]


@secure_function
def remote_ip(scope, local_ips):
    """
    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_ips: string
    :param local_ips: An IP address, or a list of IP addresses.
    :rtype:  string
    :return: The other IP address of the link address pair.
    """
    return [ipv4.remote_ip(ip) for ip in local_ips]