#!/bin/sh
# PUMP Script
# $1 Calling circumstance (up, renewal, down)
# $2 interface
# $3 ip

# Exit early, if we're not being called for the initial lease
[ "$1" != "up" ] && exit 0

# See if we're needed at all, only run when booted with dhcphostname
for i in $(cat /proc/cmdline)
do
	if [ "$i" = "dhcphostname" ]
	then
		# dhcphostname is set, get the PTR for the ip
		hostname=$(host $3 | awk '{ print substr($5, 0, length($5)-1) }')
		if [ -n "$hostname" ]
		then
			echo $hostname > /etc/hostname
		fi
	fi
done