#!/bin/sh
#
# $OpenBSD: dhclient-script,v 1.22 2011/04/09 19:53:00 krw Exp $
#
# Copyright (c) 2003 Kenneth R Westerback <krw@openbsd.org>
#
# Permission to use, copy, modify, and 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.
#

#
# Helper functions that implement common actions.
#

delete_old_address() {
	if [ -n "$old_ip_address" ]; then
		ifconfig $interface inet $old_ip_address delete
		route -q $rdomain delete "$old_ip_address" 127.0.0.1
	fi
}

ip6_delete_old_address() {
	if [ -n "$old_ip6_address" ]; then
		ifconfig $interface inet6 $old_ip6_address delete
	fi
}

add_new_address() {
	ifconfig $interface \
		inet $new_ip_address \
		netmask $new_subnet_mask \
		broadcast $new_broadcast_address

	# XXX Original TIMEOUT code did not do this unless $new_routers was set?
	route -q $rdomain add $new_ip_address 127.0.0.1
}

ip6_add_new_address() {
	ifconfig $interface \
		inet6 $new_ip6_address \
		prefixlen $new_ip6_prefixlen
}

delete_old_routes() {
	# Delete existing default route. We only allow one, so no need to
	# process $old_routers list.
	route -q $rdomain -n flush -inet -iface $interface
	arp -dan
}

add_new_routes() {
	route -q $rdomain -n flush -inet -iface $interface
	for router in $new_routers; do
		if [ "$new_ip_address" = "$router" ]; then
			route -q $rdomain add default -iface $router
		else
			route -q $rdomain add default $router
		fi
		# 2nd and subsequent default routers error out, so explicitly
		# stop processing the list after the first one.
		break
	done
}

add_new_resolv_conf() {
	# Create resolv.conf when either $new_domain_name_servers or
	# $new_domain_name are provided. As reported in PR#3135, some ISPs
	# provide only $new_domain_name_servers.

	rm -f /etc/resolv.conf.std

	if [ -n "$new_domain_name" ]; then
		echo "search $new_domain_name" >>/etc/resolv.conf.std
	fi

	if [ -n "$new_domain_name_servers" ]; then
		for nameserver in $new_domain_name_servers; do
			echo "nameserver $nameserver" >>/etc/resolv.conf.std
		done
	fi

	if [ -f /etc/resolv.conf.std ]; then
		if [ -f /etc/resolv.conf.tail ]; then
			cat /etc/resolv.conf.tail >>/etc/resolv.conf.std
		fi

		# In case (e.g. during OpenBSD installs) /etc/resolv.conf
		# is a symbolic link, take care to preserve the link and write
		# the new data in the correct location.

		if [ -f /etc/resolv.conf ]; then
			cat /etc/resolv.conf > /etc/resolv.conf.save
		fi
		cat /etc/resolv.conf.std > /etc/resolv.conf
		rm -f /etc/resolv.conf.std

		# Try to ensure correct ownership and permissions.
		chown -RL root:wheel /etc/resolv.conf
		chmod -RL 644 /etc/resolv.conf

		return 0
	fi

	return 1
}

ip6_add_new_resolv_conf() {
	# Create resolv.conf when either $new_dhcp6_name_servers or
	# $new_dhcp6_domain_search are provided.

	rm -f /etc/resolv.conf.std6

	if [ -n "$new_dhcp6_domain_search" ]; then
		echo "search $new_dhcp6_domain_search" >>/etc/resolv.conf.std6
	fi

	if [ -n "$new_dhcp6_name_servers" ]; then
		for nameserver in $new_dhcp6_name_servers; do
			echo "nameserver $nameserver" >>/etc/resolv.conf.std6
		done
	fi

	if [ -f /etc/resolv.conf.std6 ]; then
		if [ -f /etc/resolv.conf.tail ]; then
			cat /etc/resolv.conf.tail >>/etc/resolv.conf.std6
		fi

		# In case (e.g. during OpenBSD installs) /etc/resolv.conf
		# is a symbolic link, take care to preserve the link and write
		# the new data in the correct location.

		if [ -f /etc/resolv.conf ]; then
			cat /etc/resolv.conf > /etc/resolv.conf.save
		fi
		cat /etc/resolv.conf.std6 > /etc/resolv.conf
		rm -f /etc/resolv.conf.std6

		# Try to ensure correct ownership and permissions.
		chown -RL root:wheel /etc/resolv.conf
		chmod -RL 644 /etc/resolv.conf

		return 0
	fi

	return 1
}

#
# Start of active code.
#

case $reason in
MEDIUM)
	# Not called by OpenBSD dhclient(8).
	;;

PREINIT)
	# Not called by OpenBSD dhclient(8).
	;;

PREINIT6)
	# Not called by OpenBSD dhclient(8).
	;;

ARPSEND)
	# Not called by OpenBSD dhclient(8).
	# Always fail. i.e. don't wait for ARP packet here.
	exit 1
	;;

ARPCHECK)
	# Not called by OpenBSD dhclient(8).
	# Always succeed. i.e. accept lease.
	;;

BOUND|RENEW|REBIND|REBOOT)
	if [ -n "$old_ip_address" ]; then
		if [ "$old_ip_address" != "$new_ip_address" ]; then
			delete_old_address
			delete_old_routes
		fi
	fi
	if [ "$reason" = BOUND ] ||
	   [ "$reason" = REBOOT ] ||
	   [ -z "$old_ip_address" ] ||
	   [ "$old_ip_address" != "$new_ip_address" ]; then
		add_new_address
		add_new_routes
	fi
	add_new_resolv_conf
	;;

BOUND6|RENEW6|REBIND6)
	if [ -n "$old_ip6_address" ]; then
		if [ "$old_ip6_address" != "$new_ip6_address" ]; then
			ip6_delete_old_address
		fi
	fi
	if [ "$reason" = BOUND6 ] ||
	   [ -z "$old_ip6_address" ] ||
	   [ "$old_ip6_address" != "$new_ip6_address" ]; then
		ip6_add_new_address
	fi
	ip6_add_new_resolv_conf
	;;

EXPIRE|FAIL)
	if [ -n "$old_ip_address" ]; then
		delete_old_address
		delete_old_routes
	fi
	if [ -f /etc/resolv.conf.save ]; then
		cat /etc/resolv.conf.save > /etc/resolv.conf
	fi
	;;

EXPIRE6|RELEASE6|STOP6)
	if [ -n "$old_ip6_address" ]; then
		ip6_delete_old_address
	fi
	;;

TIMEOUT)
	add_new_address
	sleep 1
	if [ -n "$new_routers" ]; then
		set "$new_routers"
		if ping -q -c 1 -w 1 "$1"; then
			add_new_routes
			if add_new_resolv_conf; then
				exit 0
			fi
		fi
	fi
	ifconfig $interface inet $new_ip_address delete
	# XXX Why not a delete_old_address as before all other invocations of
	#     delete_old_routes?
	delete_old_routes
	exit 1
	;;
esac

exit 0