156 lines
4.9 KiB
Python
156 lines
4.9 KiB
Python
# mac.py - functions for handling MAC (Ethernet) addresses
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#
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# Copyright (C) 2018-2025 Arthur de Jong
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#
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# This library is free software; you can redistribute it and/or
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# modify it under the terms of the GNU Lesser General Public
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# License as published by the Free Software Foundation; either
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# version 2.1 of the License, or (at your option) any later version.
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#
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# This library is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# Lesser General Public License for more details.
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#
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# You should have received a copy of the GNU Lesser General Public
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# License along with this library; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301 USA
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"""MAC address (Media Access Control address).
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A media access control address (MAC address, sometimes Ethernet address) of a
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device is meant as a unique identifier within a network at the data link
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layer.
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More information:
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* https://en.wikipedia.org/wiki/MAC_address
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* https://en.wikipedia.org/wiki/Organizationally_unique_identifier
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* https://standards.ieee.org/faqs/regauth.html#2
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>>> validate('D0-50-99-84-A2-A0')
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'd0:50:99:84:a2:a0'
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>>> to_eui48('d0:50:99:84:a2:a0')
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'D0-50-99-84-A2-A0'
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>>> is_multicast('d0:50:99:84:a2:a0')
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False
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>>> get_manufacturer('d0:50:99:84:a2:a0')
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'ASRock Incorporation'
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>>> get_oui('d0:50:99:84:a2:a0')
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'D05099'
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>>> get_iab('d0:50:99:84:a2:a0')
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'84A2A0'
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"""
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from __future__ import annotations
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import re
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from stdnum import numdb
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from stdnum.exceptions import *
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from stdnum.util import clean
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_mac_re = re.compile('^([0-9a-f]{2}:){5}[0-9a-f]{2}$')
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def compact(number: str) -> str:
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"""Convert the MAC address to the minimal, consistent representation."""
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number = clean(number, ' ').strip().lower().replace('-', ':')
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# zero-pad single-digit elements
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return ':'.join('0' + n if len(n) == 1 else n for n in number.split(':'))
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def _lookup(number: str) -> tuple[str, str]:
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"""Look up the manufacturer in the IEEE OUI registry."""
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number = compact(number).replace(':', '').upper()
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info = numdb.get('oui').info(number)
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try:
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return (
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''.join(n[0] for n in info[:-1]),
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info[-2][1]['o'].replace('%', '"'))
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except IndexError:
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raise InvalidComponent()
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def get_manufacturer(number: str) -> str:
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"""Look up the manufacturer in the IEEE OUI registry."""
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return _lookup(number)[1]
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def get_oui(number: str) -> str:
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"""Return the OUI (organization unique ID) part of the address."""
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return _lookup(number)[0]
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def get_iab(number: str) -> str:
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"""Return the IAB (individual address block) part of the address."""
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number = compact(number).replace(':', '').upper()
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return number[len(get_oui(number)):]
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def is_unicast(number: str) -> bool:
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"""Check whether the number is a unicast address.
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Unicast addresses are received by one node in a network (LAN)."""
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number = compact(number)
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return int(number[:2], 16) & 1 == 0
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def is_multicast(number: str) -> bool:
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"""Check whether the number is a multicast address.
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Multicast addresses are meant to be received by (potentially) multiple
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nodes in a network (LAN)."""
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return not is_unicast(number)
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def is_broadcast(number: str) -> bool:
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"""Check whether the number is the broadcast address.
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Broadcast addresses are meant to be received by all nodes in a network."""
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number = compact(number)
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return number == 'ff:ff:ff:ff:ff:ff'
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def is_universally_administered(number: str) -> bool:
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"""Check if the address is supposed to be assigned by the manufacturer."""
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number = compact(number)
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return int(number[:2], 16) & 2 == 0
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def is_locally_administered(number: str) -> bool:
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"""Check if the address is meant to be configured by an administrator."""
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return not is_universally_administered(number)
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def validate(number: str, validate_manufacturer: bool | None = None) -> str:
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"""Check if the number provided is a valid MAC address.
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The existence of the manufacturer is by default only checked for
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universally administered addresses but can be explicitly set with the
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`validate_manufacturer` argument.
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"""
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number = compact(number)
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if len(number) != 17:
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raise InvalidLength()
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if not _mac_re.match(number):
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raise InvalidFormat()
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if validate_manufacturer is not False:
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if validate_manufacturer or is_universally_administered(number):
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get_manufacturer(number)
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return number
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def is_valid(number: str, validate_manufacturer: bool | None = None) -> bool:
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"""Check if the number provided is a valid IBAN."""
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try:
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return bool(validate(number, validate_manufacturer=validate_manufacturer))
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except ValidationError:
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return False
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def to_eui48(number: str) -> str:
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"""Convert the MAC address to EUI-48 format."""
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return compact(number).upper().replace(':', '-')
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