#!/bin/sh
#* VPNGATEWAY             -- vpn gateway address (always present)
#* TUNDEV                 -- tunnel device (always present)
#* INTERNAL_IP4_ADDRESS   -- address (always present)
#* INTERNAL_IP4_NETMASK   -- netmask (often unset)
#* INTERNAL_IP4_DNS       -- list of dns serverss
#* INTERNAL_IP4_NBNS      -- list of wins servers
#* CISCO_DEF_DOMAIN       -- default domain name
#* CISCO_BANNER           -- banner from server

fix_ip_get_output () {
	sed 's/cache//;s/metric[0-9]\+ [0-9]\+//g' | xargs echo
}

`cat /proc/sys/kernel/modprobe` tun 2>/dev/null
if [ $? != 0 ]; then
   # all this checks fail on a self-compiled kernel 2.4, though
	( grep -q " tun_init" /proc/k*syms || test -e /sys/class/misc/tun || grep -q CONFIG_TUN=y /boot/config-`uname -r` ) 2>/dev/null || echo -e "WARNING: failed to load the tun module\n"
fi

if [ -f "$1" ]; then
config="$1"
elif [ -f "/etc/vpnc/$1.conf" ]; then
	config="/etc/vpnc/$1.conf"
elif [ -f /etc/vpnc/default.conf ]; then
	config=/etc/vpnc/default.conf
elif [ -f /etc/vpnc.conf ]; then
	config=/etc/vpnc.conf
else 
     cat <<ECHO 1>&2
Usage: $0 [config]

 <config> can either be an absolute path or the name
 of a config file located in /etc/vpnc/<config>.conf
 If no config is specified, $0 will try
 /etc/vpnc/default.conf and /etc/vpnc.conf

ECHO
exit 1
fi

if [ "$1" ] ; then shift ; fi

# fix for broken devfs in kernel 2.6.x
if [ "`readlink /dev/net/tun`" = misc/net/tun \
   -a ! -e /dev/net/misc/net/tun -a -e /dev/misc/net/tun ] ; then
   ln -sf /dev/misc/net/tun /dev/net/tun
fi

# make sure tun device exists
if [ ! -e /dev/net/tun ]; then
	mkdir -p /dev/net
	mknod /dev/net/tun c 10 200
fi

# usual blah, blah, if the command above still failed
test -e /dev/net/tun || echo -e "Warning, /dev/net/tun does not exist.\nPossible reasons:\n - tun driver not available\n - device file needs to be created (howto: cd /dev; /sbin/MAKEDEV tun) "

getvar () {
	if [ $# -ne 2 ]; then
		echo "Usage: $0 <parameter file> <variable name>" 1>&2
		return 1
	fi
	sed -n 's/^'"$2"' //p' "${config}"
	return 0
}

fix_ip_get_output () {
	sed 's/cache//;s/metric[0-9]\+ [0-9]\+//g' | xargs echo
}

defr=/var/run/vpnc/defaultroute
gateway=/var/run/vpnc/gateway
pid=/var/run/vpnc/pid
dnsdev=/var/run/vpnc/dev

if [ -z "$VPNGATEWAY" ]; then
	if [ -x "`which vpnc`" ]; then
		VPNC="`which vpnc`"
	elif [ -x /usr/local/sbin/vpnc ]; then
		VPNC=/usr/sbin/vpnc
	elif [ -x /usr/sbin/vpnc ]; then
		VPNC=/usr/sbin/vpnc
	elif [ -x $(dirname $0)/vpnc ]; then
		VPNC=$(dirname $0)/vpnc
	else
		echo No vpnc daemon found, aborting...
		exit 1
	fi
	
	for i in "$gateway" "$defr" "$pid" "$dnsdev" ; do
		mkdir -p $(dirname "$i")
	done
	
	PID="$(cat "$pid" 2> /dev/null)"
	
	if [ "$PID" ]; then
		if kill -0 "$PID" > /dev/null 2>&1; then
			echo "vpnc found running (pid: $PID, pidfile: $pid)"
			exit 1
		fi
	fi
	
	exec "$VPNC" --pid-file "$pid" --script "$0 ${config} $*" "${config}" || exit 1
fi

# started from vpnc..

if [ "$CISCO_BANNER" ] ; then echo "$CISCO_BANNER" ; fi

ifconfig $TUNDEV inet $INTERNAL_IP4_ADDRESS \
	pointopoint $INTERNAL_IP4_ADDRESS \
	netmask 255.255.255.255 mtu 1412 up

networks="$(getvar "${config}" "Target networks")"
if [ -z "$networks" ]; then
    ip route add $(ip route get $VPNGATEWAY | fix_ip_get_output)
    ip route | grep '^default' | fix_ip_get_output > "$defr"
    echo "$VPNGATEWAY" > "$gateway"
    networks=default
fi
for network in $networks; do
    ip route del $network 2>/dev/null
    ip route add $network dev $TUNDEV
done

# Debian specific resolv.conf management

if [ "$INTERNAL_IP4_DNS" ] ; then
   if test -x /sbin/resolvconf && [ "$(getvar "${config}" "DNSUpdate")" != "no" ] ; then
      ( 
      if [ "$CISCO_DEF_DOMAIN" ] ; then
         echo domain "$CISCO_DEF_DOMAIN"
         echo search "$CISCO_DEF_DOMAIN"
      fi
      for ip in "$INTERNAL_IP4_DNS" ; do
         echo nameserver $ip
      done
      ) | /sbin/resolvconf -a $TUNDEV
      echo $TUNDEV > $dnsdev
   fi
   for ip in $INTERNAL_IP4_DNS ; do
      ip route get $ip | grep -q "dev $TUNDEV" || ip route add $ip dev $TUNDEV
   done
fi

ip route flush cache
exit 0