Mine

#!/bin/sh

# Emplacement de la commande route (whereis route)
ROUTE_CMD="/sbin/route"

# Repertoire de base de PPPD
# Doit obligatoirement terminer par un /
PPPD_BASE="/"
#PPPD_BASE="/usr/local/"
#PPPD_BASE="/usr/pkg/"


### FIN DE LA SECTION EDITABLE ###

usepeerdns() {
if [ -n "$USEPEERDNS" -a -f "$PPPD_BASE"etc/ppp/resolv.conf ]; then
        rm -f "$PPPD_BASE"etc/ppp/resolv.prev
        if [ -f /etc/resolv.conf ]; then
                cp /etc/resolv.conf "$PPPD_BASE"etc/ppp/resolv.prev
                grep domain "$PPPD_BASE"etc/ppp/resolv.prev > /etc/resolv.conf
                grep search "$PPPD_BASE"etc/ppp/resolv.prev >> /etc/resolv.conf
                cat "$PPPD_BASE"etc/ppp/resolv.conf >> /etc/resolv.conf
        else
                cp "$PPPD_BASE"etc/ppp/resolv.conf /etc
        fi
fi
}

if [ "$6" = "gateway-linux" ]
then
usepeerdns
OLDGATE=`netstat -r -n -A inet | tail -n 1 | awk '{ print $2 }'`
TUNSERVER=`netstat -n -t | grep 1723 | awk '{ print $5 }' | sed s/:1723// | head -n 1`
echo OLDGATE $OLDGATE > "$PPPD_BASE"etc/ppp/gateway.prev
echo TUNSERVER $TUNSERVER >> "$PPPD_BASE"etc/ppp/gateway.prev
$ROUTE_CMD add $TUNSERVER gw $OLDGATE
$ROUTE_CMD delete default gw $OLDGATE
$ROUTE_CMD add default gw $IPREMOTE
fi

if [ "$6" = "gateway-bsd" ]
then
usepeerdns
OLDGATE=`netstat -r -n -f inet | grep default | awk '{ print $2 }'`
TUNSERVER=`netstat -n -t | grep 1723 | awk '{ print $5 }' | sed s/.1723// | head -n 1`
echo OLDGATE $OLDGWATE > "$PPPD_BASE"etc/ppp/gateway.prev
echo TUNSERVER $TUNSERVER >> "$PPPD_BASE"etc/ppp/gateway.prev
$ROUTE_CMD add $TUNSERVER $OLDGATE
$ROUTE_CMD delete default $OLDGATE
$ROUTE_CMD add default $IPREMOTE
fi