#!/bin/bash
#
# priority: 950
#
# Start local DNS server to provide minimal DNS forward resolution for
# ourselves and our nodes.
#
# Mark Huang <mlhuang@cs.princeton.edu>
# Copyright (C) 2006 The Trustees of Princeton University
#

# Source function library and configuration
. /etc/plc.d/functions
. /etc/planetlab/plc_config

SIGNATURE="; generated by /etc/plc.d/dns --- DO NOT REMOVE THIS TEXT"

# Be verbose
set -x

case "$1" in
    start)
	if [ $PLC_DNS_ENABLED -eq 1 ] ; then
	    MESSAGE="Starting DNS server"
	    dialog "$MESSAGE"

	    dns-config
	    check
	fi

	# Set up nameservers
	if [ -n "$PLC_NET_DNS1" -o -n "$PLC_NET_DNS2" ] ; then
	    MESSAGE="Configuring resolv.conf"
	    dialog "$MESSAGE"

	    rfile=$(mktemp)
	    (
		echo $SIGNATURE
		[ -n "$PLC_NET_DNS1" ] && echo "nameserver $PLC_NET_DNS1"
		[ -n "$PLC_NET_DNS2" -a "$PLC_NET_DNS1" != "$PLC_NET_DNS2" ] && echo "nameserver $PLC_NET_DNS2"
	    ) > $rfile
	    
	    if [ $PLC_DNS_ENABLED -eq 1 ] ; then
		ourfile=$(grep "$SIGNATURE" /etc/resolv.conf| wc -l)
		if [ $ourfile -eq 0 ] ; then
		    cp /etc/resolv.conf /etc/plc_resolv.conf
		fi
	    else
		cp /etc/resolv.conf /etc/resolv_plc.backup
	    fi
	    mv -f $rfile /etc/resolv.conf
	    chmod 444 /etc/resolv.conf
	fi

	if [ $PLC_DNS_ENABLED -eq 1 ] ; then
	    plc_daemon dnsmasq
	    check
	fi

	result "$MESSAGE"
	;;

    stop)
	if [ $PLC_DNS_ENABLED -eq 1 ] ; then
	    MESSAGE=$"Reverting /etc/resolv.conf"
	    dialog "$MESSAGE"
	    if [ -f "/etc/plc_resolv.conf" ] ; then
		ourfile=$(grep "$SIGNATURE" /etc/plc_resolv.conf| wc -l)
		if [ $ourfile -ne 0 ] ; then 
		    dialog "WARNING: original /etc/resolv.conf was generated by etc/plc.d/dns"		
		fi
		mv -f /etc/plc_resolv.conf /etc/resolv.conf
	    fi
	    check
	    result ""
	    MESSAGE=$"Removing /etc/plc_hosts"
	    dialog "$MESSAGE"
	    [ -f "/etc/plc_hosts" ] && rm -f /etc/plc_hosts
	    result ""
	fi
	if [ $PLC_DNS_ENABLED -eq 0 -a -f "/etc/resolv_plc.backup" ] ; then
	    MESSAGE="Restoring /etc/resolv.conf"
	    dialog "$MESSAGE"
	    mv -f /etc/resolv_plc.backup /etc/resolv.conf
	    result ""
	fi

	if [ $PLC_DNS_ENABLED -eq 1 ] ; then
	    MESSAGE="Stopping DNS server"
	    dialog "$MESSAGE"
	    killproc plc_dnsmasq
	    check
	    result ""
	fi

	;;
esac

exit $ERRORS