#!/usr/bin/env mksh
# Script by Ypnose - http://ywstd.fr

M_SYMB="0123456789ABCDEF"

if [[ -z $1 || $1 = "-h" ]]; then
	print "usage: ${0##*/} [INTERFACE]"
	exit
fi

if ! ip link show "$1" >/dev/null 2>&1; then
	print -u2 -- "$1 does not exist"
	exit 1
fi

if (( USER_ID != 0 )); then
	print -u2 "${0##*/} must be run as root"
	exit 1
fi

i=0
while (( i < 10 )); do
	R="$(( RANDOM % 16 ))"
	S[$i]="${M_SYMB:${R}:1}"
	(( i++ ))
done

M_ADDR="00:${S[0]}${S[1]}:${S[2]}${S[3]}:${S[4]}${S[5]}:${S[6]}${S[7]}:\
${S[8]}${S[9]}"

ip link set dev "$1" down
ip link set dev "$1" addr "$M_ADDR" 

exit