#!/bin/bash -e

VERBOSE=1
LOCAL_IF=ppp0

case "$1" in
    start)
	if [ -z "$LOCAL4" ]; then
	    [ "$LOCAL_IF" ] || LOCAL_IF=ppp0
	    LOCAL4=$(ip -o addr show $LOCAL_IF | awk '/inet/ { print $4 }')
	    if [ -z "$LOCAL4" ]; then
		echo "Cannot find the IP assigned to $LOCAL_IF"
		exit 1
	     fi
	fi
	
	LOCAL6=$(printf "%x%02x:%x%02x\n" $(echo $LOCAL4 | sed -e 's/\./ /g'))
	LOCAL6="2002:$LOCAL6::1/48"

	[ "$RELAY" ] || RELAY=192.88.99.1

	if [ "$VERBOSE" ]; then
	    echo "Local v4 address: $LOCAL4"
	    echo "Local v6 address: $LOCAL6"
	    echo "6to4 Relay address: $RELAY"
	fi

	ip link  set sit0  up
	ip addr  add $LOCAL6  dev sit0
	ip route add 2000::/3  via ::$RELAY
	;;
    stop)
	ip link  set sit0  down
	;;
    *)
	echo "Usage: $0 {start|stop}"
	exit 1
	;;
esac

exit 0