#! /bin/bash

### BEGIN INIT INFO
# Provides:          ipv6
# Required-Start:    $local_fs $all
# Required-Stop:     $local_fs $network
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: starts the ipv6 tunnel
# Description:       ipv6 tunnel start-stop-daemon
### END INIT INFO

PATH=/usr/bin:/usr/local/bin:/usr/sbin:/usr/local/sbin:/bin:/sbin
DAEMON=/usr/local/sbin/tb_userspace
NAME=v6tun

DEV_NAME=v6tun0
TUN_SINK=66.220.18.42
TUN_SOURCE=69.12.73.93
V6_ADDRS="
2001:470:c:dad::2/64
2001:470:c:dad:dead:beef:bad:cafe/64
2001:470:f548:face:dead:beef:bad:cafe/48
2001:470:f548::9/48
"
V6_ROUTES="
"
V6_GW=2001:470:c:dad::1
V6_DEFAULT=1
PID_FILE=/tmp/$NAME.pid

if [ -r /etc/default/v6tun ]; then
        . /etc/default/v6tun
fi

test -x $DAEMON || exit 0

. /lib/init/vars.sh
. /lib/lsb/init-functions

init_device() {
        ip link set dev "$DEV_NAME" up mtu 1480 txqueuelen 256 >/dev/null 2>&1 || return 1
        return 0
}

destroy_device() {
        ip link set dev "$DEV_NAME" down >/dev/null 2>&1 || return 1
        return 0
}


add_addresses() {
        PREFERED="forever"
        for address in $V6_ADDRS; do
                ip -6 addr add "$address" dev "$DEV_NAME" scope global valid_lft forever preferred_lft "$PREFERED" >/dev/null 2>&1 || return 1
                PREFERED="0"
        done
        return 0
}

add_routes() {
        if [ $V6_DEFAULT ]; then
                ip -6 route del default >/dev/null 2>&1 || true
                ip -6 route add default via "$V6_GW" dev "$DEV_NAME" >/dev/null 2>&1 || return 1
        fi
        for route in $V6_ROUTES; do
                ip -6 route add "$route" dev "$DEV_NAME" via "$V6_GW" >/dev/null 2>&1 || return 1
        done
        return 0;
}

flush_routes() {
        ip -6 route flush dev "$DEV_NAME" >/dev/null 2>&1 || true
        return 0
}

case "$1" in
        start)
                log_daemon_msg "Starting userspace tunnel driver" "$NAME"
                setsid "$DAEMON" v6tun0 "$TUN_SINK" "$TUN_SOURCE" sit >/dev/null 2>&1 &
                PID=$!
                echo $PID > $PID_FILE
                sleep 3
                log_end_msg 0
                log_daemon_msg "Initialize virtual device"
                if ! init_device; then
                        log_end_msg 1
                        exit 1
                fi
                log_end_msg 0
                log_daemon_msg "Add assigned addresses"
                if ! add_addresses; then
                        log_end_msg 1
                        exit 1
                fi
                log_end_msg 0
                log_daemon_msg "Add routes"
                if ! add_routes; then
                        log_end_msg 1
                        exit 1
                fi
                log_end_msg 0
                ;;
        stop)
                log_daemon_msg "Flushing routes"
                flush_routes
                log_end_msg 0
                log_daemon_msg "Destroying devices"
                destroy_device
                log_end_msg 0
                log_daemon_msg "Stopping userspace tunnel driver" "$NAME"
                kill `cat $PID_FILE` >/dev/null 2>&1 || true
                rm -f `cat $PID_FILE` >/dev/null 2>&1 || true
                log_end_msg 0
                ;;
        *)
                echo "Usage: /etc/init.d/v6tun {start|stop}"
                exit 1
                ;;
esac

exit 0