#!/bin/sh

ARP=arp
MACTODEV=mac-to-devinfo

usage() {
    echo "Usage: $0 [-i interface] [-x port] IP-address"
}

if [ "$1" == "-i" ]; then
    INTERFACE="$2"
    if [ -z "$INTERFACE" ]; then
	echo "-i without interface"
	usage
	exit 1
    fi
    shift
    shift
fi

if [ "$1" == "-x" ]; then
    PORT="-x $2"
    if [ -z "$PORT" ]; then
	echo "-x without the port"
	usage
	exit 1
    fi
    shift
    shift
fi

IP="$1"
shift

if [ -z "$IP" ]; then
	echo "Must specify IP address"
	usage
	exit 1
fi


if [ ! -x "$(which $ARP)" ]; then
    do_arp() {
	cat /proc/net/arp
    }
    ARPMACFIELD=4
else
    do_arp() {
	$ARP -n
    }
    ARPMACFIELD=3
fi

if [ -z "$INTERFACE" ]; then
    ping -q -c 2 $IP >/dev/null
    MAC=$(do_arp|grep "$IP "|tr -s \  | cut -f$ARPMACFIELD -d\  )
else
    MAC=$(arping -f -c 5 -I $INTERFACE $IP | grep 'Unicast reply from' | cut -f2 -d \[ | cut -f1 -d\])
fi

$MACTODEV $PORT $MAC