#!/bin/sh
# Copyright 2007 Roy Marples
# All rights reserved

# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.

# Setup our resolv.conf
# Vitally important that we use the domain entry in resolv.conf so we
# can setup the nameservers are for the domain ONLY in resolvconf if
# we're using a decent dns cache/forwarder like dnsmasq and NOT nscd/libc.
# nscd/libc users will get the VPN nameservers before their other ones
# and will use the first one that responds - maybe the LAN ones?
# non resolvconf users just the the VPN resolv.conf

# FIXME:- if we have >1 domain, then we have to use search :/
# We need to add a flag to resolvconf to say
# "these nameservers should only be used for the listed search domains
#  if other global nameservers are present on other interfaces"
# This however, will break compatibility with Debians resolvconf
# A possible workaround would be to just list multiple domain lines
# and try and let resolvconf handle it

PATH=$PATH:/usr/local/sbin

NS=
DOMAIN=
SEARCH=
i=1
while true; do
	eval opt=\$foreign_option_${i}
	[ -z "${opt}" ] && break
	if [ "${opt}" != "${opt#dhcp-option DOMAIN *}" ]; then
		if [ -z "${DOMAIN}" ]; then
			DOMAIN="${opt#dhcp-option DOMAIN *}"
		else
			SEARCH="${SEARCH:+ }${opt#dhcp-option DOMAIN *}"
		fi
	elif [ "${opt}" != "${opt#dhcp-option DNS *}" ]; then
		NS="${NS}nameserver ${opt#dhcp-option DNS *}\n"
	fi
	i=$((${i} + 1))
done

if [ -n "${NS}" ]; then
	DNS="# Generated by openvpn for interface ${dev}\n"
	if [ -n "${SEARCH}" ] ; then
		DNS="${DNS}search ${DOMAIN} ${SEARCH}\n"
	else
		DNS="${DNS}domain ${DOMAIN}\n"
	fi
	DNS="${DNS}${NS}"
	if type resolvconf >/dev/null 2>&1; then
		printf "${DNS}" | resolvconf -a "${dev}"
	else
		# Preserve the existing resolv.conf
		if [ -e /etc/resolv.conf ] ; then
			cp -p /etc/resolv.conf /etc/resolv.conf-"${dev}".sv
		fi
		(umask 022; printf "${DNS}" > /etc/resolv.conf)
	fi
fi

# Below section is OpenRC specific
# Quick summary - our init scripts are re-entrant and set the SVCNAME env var
# as we could have >1 openvpn service

# If we have a service specific script, run this now
[ -x "${SVCNAME}"-up.sh ] && "${SVCNAME}"-up.sh

# Re-enter the init script to start any dependant services
service=/etc/init.d/"${SVCNAME}"
[ ! -x "${service}" ] && service=/usr/local/etc/init.d/"${SVCNAME}"
if [ -x "${service}" ]; then
	if ! "${service}" --quiet status; then
		export IN_BACKGROUND=true
		"${service}" --quiet start
	fi
fi

exit 0