#!/bin/sh

#
# mac-lookup
#
# This takes a given list of MAC addresses or a list of OUIs
# and returns the manufacturer or owner of each OUI.
# The list may be give as arguments or it may be piped through stdin.
# The MAC format may be the same as the examples below.
# Octet separators may be ':' or '-' or nothing.
#
#     $ echo "00:25:00:ff:ec:01 00-1a-11-ff-ff-01 002304a63f01" | mac-lookup
#     002500     (base 16)            Apple, Inc
#     001A11     (base 16)            Google Inc.
#     002304     (base 16)            Cisco Systems
#
# This is the equivalent:
#
#     $ mac-lookup 00:25:00:fe:cc:78 00-1a-11-ff-ff-01 002304a63f01
#     002500     (base 16)            Apple, Inc
#     001A11     (base 16)            Google Inc.
#     002304     (base 16)            Cisco Systems
#
# If an OUI is not found in the oui cache or if the cache does not exist then
# this script will attempt to download a fresh copy from the IEEE. It will not
# attempt to update the cache more than once per hour even if an OUI is not
# found in the current cache.
#
# FILES
#
#     /var/tmp/oui.txt
#
# AUTHOR
#
#     Noah Spurrier <noah@noah.org>
#
# LICENSE
#
#     This license is OSI and FSF approved as GPL-compatible.
#     This license identical to the ISC License and is registered with and
#     approved by the Open Source Initiative. For more information vist:
#         http://opensource.org/licenses/isc-license.txt
#
#     Copyright (c) 2010, Noah Spurrier <noah@noah.org>
#
#     Permission to use, copy, modify, and/or distribute this software for any
#     purpose with or without fee is hereby granted, provided that the above
#     copyright notice and this permission notice appear in all copies.
#
#     THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
#     WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
#     MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
#     ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
#     WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
#     ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
#     OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#
# VERSION
#
#     Version 1
#

if [ $# -eq 0 ]; then
	MAC_LIST=$(cat)
else
	MAC_LIST=$@
fi

# Do a little clean-up of the input argument.
# This can be improved. This is done in two steps as a way to implement
# greedy matching. We want to match first a full 6-octet MAC address.
# If not matched then try just a 3-octet OUI.
TARGET_MAC=$(echo ${MAC_LIST} | grep -E --only-matching --max-count=1 -e "([[:xdigit:]]{2}){6}" -e "([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}" -e "([[:xdigit:]]{1,2}-){5}[[:xdigit:]]{1,2}" | sed -e 's/[-:]//g' -e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/')
TARGET_OUI=$( for m in ${TARGET_MAC}; do echo $m | cut -c -6; done)
if [ -z "${TARGET_OUI}" ]; then
	TARGET_OUI=$(echo ${MAC_LIST} | grep -E --only-matching --max-count=1 -e "([[:xdigit:]]{2}){3}" -e "([[:xdigit:]]{1,2}:){2}[[:xdigit:]]{1,2}" -e "([[:xdigit:]]{1,2}-){2}[[:xdigit:]]{1,2}" | sed -e 's/[-:]//g' -e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/')
fi

#OUI_CACHE_DIR_LIST="/var/cache/ /var/tmp/ /tmp/"
#OUI_CACHE_FILENAME="oui.txt"
#OUI_CACHE="/var/cache/oui.txt"
# Many applications install their own copies. We save some time by checking
# these sources first. If they don't pan out then we search IEEE_URL.
#LOCAL_OUI_PATHS="/etc/ntop/oui.txt /etc/arpalert/oui.txt /usr/share/btscanner/oui.txt /usr/share/arp-scan/ieee-oui.txt" # /usr/share/arpwatch/ethercodes.dat"

OUI_CACHE="/var/tmp/oui.txt"
MIN_CACHE_AGE_SECONDS=3600
# This is the official system of record for OUI assignments.
#IEEE_URL="http://standards.ieee.org/regauth/oui/oui.txt"
#IEEE_URL="http://standards.ieee.org/develop/regauth/oui/oui.txt"
IEEE_URL="http://standards-oui.ieee.org/oui.txt"

refresh_oui_cache () {
	cache_age=$(stat -c %Y ${OUI_CACHE})
	age=$(date "+%s" -d "-${cache_age:-0} seconds")
	if [ ${age:-0} -lt ${MIN_CACHE_AGE_SECONDS} ]; then
		return
	fi
	rm ${OUI_CACHE}
	(umask 000; date +"# %s%n# %F %T%z" > ${OUI_CACHE})
	# Note that I do want APPEND because the previous command
	# initialized the file with a specific umask and a date comment.
	curl -s ${IEEE_URL} >> ${OUI_CACHE}
}

for OUI in ${TARGET_OUI}; do
	if ! grep ${OUI} ${OUI_CACHE}; then
		refresh_oui_cache
		grep ${OUI} ${OUI_CACHE}
#		grep -A 5 ${OUI} ${OUI_CACHE}
	fi
done

# vim:set sr et ts=4 sw=4 ft=sh: // See Vim, :help 'modeline'