buildroot/package/busybox/udhcpc.script

#!/bin/sh

# udhcpc script edited by Tim Riker <Tim@Rikers.org>

[ -z "$1" ] && echo "Error: should be called from udhcpc" && exit 1

ACTION="$1"
RESOLV_CONF="/etc/resolv.conf"
[ -e $RESOLV_CONF ] || touch $RESOLV_CONF
[ -n "$broadcast" ] && BROADCAST="broadcast $broadcast"
[ -n "$subnet" ] && NETMASK="netmask $subnet"
# Handle stateful DHCPv6 like DHCPv4
[ -n "$ipv6" ] && ip="$ipv6/128"

if [ -z "${IF_WAIT_DELAY}" ]; then
	IF_WAIT_DELAY=10
fi

wait_for_ipv6_default_route() {
	printf "Waiting for IPv6 default route to appear"
	while [ $IF_WAIT_DELAY -gt 0 ]; do
		if ip -6 route list | grep -q default; then
			printf "\n"
			return
		fi
		sleep 1
		printf "."
		: $((IF_WAIT_DELAY -= 1))
	done
	printf " timeout!\n"
}

case "$ACTION" in
	deconfig)
		/sbin/ifconfig $interface up
		/sbin/ifconfig $interface 0.0.0.0

		# drop info from this interface
		# resolv.conf may be a symlink to /tmp/, so take care
		TMPFILE=$(mktemp)
		grep -vE "# $interface\$" $RESOLV_CONF > $TMPFILE
		cat $TMPFILE > $RESOLV_CONF
		rm -f $TMPFILE

		if [ -x /usr/sbin/avahi-autoipd ]; then
			/usr/sbin/avahi-autoipd -c $interface && /usr/sbin/avahi-autoipd -k $interface
		fi
		;;

	leasefail|nak)
		if [ -x /usr/sbin/avahi-autoipd ]; then
			/usr/sbin/avahi-autoipd -c $interface || /usr/sbin/avahi-autoipd -wD $interface --no-chroot
		fi
		;;

	renew|bound)
		if [ -x /usr/sbin/avahi-autoipd ]; then
			/usr/sbin/avahi-autoipd -c $interface && /usr/sbin/avahi-autoipd -k $interface
		fi
		/sbin/ifconfig $interface $ip $BROADCAST $NETMASK
		if [ -n "$ipv6" ] ; then
			wait_for_ipv6_default_route
		fi

		# RFC3442: If the DHCP server returns both a Classless
		# Static Routes option and a Router option, the DHCP
		# client MUST ignore the Router option.
		if [ -n "$staticroutes" ]; then
			echo "deleting routers"
			route -n | while read dest gw mask flags metric ref use iface; do
				[ "$iface" != "$interface" -o "$gw" = "0.0.0.0" ] || \
					route del -net "$dest" netmask "$mask" gw "$gw" dev "$interface"
			done

			# format: dest1/mask gw1 ... destn/mask gwn
			set -- $staticroutes
			while [ -n "$1" -a -n "$2" ]; do
				route add -net "$1" gw "$2" dev "$interface"
				shift 2
			done
		elif [ -n "$router" ] ; then
			echo "deleting routers"
			while route del default gw 0.0.0.0 dev $interface 2> /dev/null; do
				:
			done

			for i in $router ; do
				route add default gw $i dev $interface
			done
		fi

		# drop info from this interface
		# resolv.conf may be a symlink to /tmp/, so take care
		TMPFILE=$(mktemp)
		grep -vE "# $interface\$" $RESOLV_CONF > $TMPFILE
		cat $TMPFILE > $RESOLV_CONF
		rm -f $TMPFILE

		# prefer rfc3397 domain search list (option 119) if available
		if [ -n "$search" ]; then
			search_list=$search
		elif [ -n "$domain" ]; then
			search_list=$domain
		fi

		[ -n "$search_list" ] &&
			echo "search $search_list # $interface" >> $RESOLV_CONF

		for i in $dns ; do
			echo adding dns $i
			echo "nameserver $i # $interface" >> $RESOLV_CONF
		done
		;;
esac

HOOK_DIR="$0.d"
for hook in "${HOOK_DIR}/"*; do
    [ -f "${hook}" -a -x "${hook}" ] || continue
    "${hook}" "$ACTION"
done

exit 0