Source code for jfscripts.mac_to_eui64

#! /usr/bin/env python3

import argparse
import ipaddress
import re

from jfscripts import __version__




def mac_to_eui64(mac, prefix=None):
    """
    Convert a MAC address to a EUI64 address
    or, with prefix provided, a full IPv6 address
    """
    # http://tools.ietf.org/html/rfc4291#section-2.5.1
    eui64 = re.sub(r"[.:-]", "", mac).lower()
    # 5c514fcf0a5d
    eui64 = eui64[0:6] + "fffe" + eui64[6:]
    # 5c514ffffecf0a5d
    eui64 = hex(int(eui64[0:2], 16) ^ 2)[2:].zfill(2) + eui64[2:]
    # 5e514ffffecf0a5d

    if prefix is None:
        return ":".join(re.findall(r".{4}", eui64))
    else:
        try:
            net = ipaddress.ip_network(prefix, strict=False)
            euil = int("0x{0}".format(eui64), 16)
            return str(net[euil])
        except:  # noqa: E722
            return





def get_parser():
    """The argument parser for the command line interface.

    :return: A ArgumentParser object.
    :rtype: argparse.ArgumentParser
    """
    parser = argparse.ArgumentParser(
        description="Convert mac addresses to EUI64 ipv6 addresses.",
    )

    parser.add_argument(
        "mac",
        help="The mac address.",
    )

    parser.add_argument(
        "prefix",
        help="The ipv6 /64 prefix.",
    )

    parser.add_argument(
        "-V",
        "--version",
        action="version",
        version="%(prog)s {version}".format(version=__version__),
    )

    return parser





def main():
    args = get_parser().parse_args()

    print(mac_to_eui64(args.mac, args.prefix))



if __name__ == "__main__":
    main()