#!/bin/bash

# sics_dev.sh - a script for setting up an ipv6 tunnel to ipv6.sics.se
# Requires at least the iproute package.

# More information about the tunnel at http://www.ipv6.sics.se/

# Antti Laiti <laiti (at) iki.fi>

# environment
PATH=/bin:/sbin
set -e

# Your prefix
PREFIX=126

# The device name for the tunnel
DEV="sics"

# Parameters for device
TTL=255
MTU=1280

# The device that connects to the ipv4 internet
DEV_IP4="eth0"

# The tunnel endpoint at sics.se
ENDPOINT="193.10.66.219"

# The ip addresses you want the tunnel device have - sics.se requires at least
# the address 3ffe:200:1:$PREFIX::2

IP6_ADDRS="3ffe:200:1:$PREFIX::2 3ffe:200:$PREFIX::1:1"

# The /48 allocation that sics gives to you from 6bone address space.
LOCALNET="3ffe:200:$PREFIX::/48"

# The whole ipv6 internet
INTERNET="2000::/3"

# This tries to obtain your ip address automatically - set to your ip address if it seems to fail
OWN_IP4="`ifconfig $DEV_IP4|grep 'inet addr'|sed -e 's/.*inet addr:\([0-9\.]\+\).*/\1/'`"

# Bring up the ipv6 module - remove this if it is compiled statically to your kernel
#modprobe ipv6

case $1 in

start)

  if [ OWN_IP4 ];
    then 
      echo -n "Setting up inet6 device: ";
    else
      echo "No ipv4 address, exiting." && exit 0;
    exit 0
  fi

  # Check if the device is already running
  ip tunnel | grep $DEV > /dev/null && echo "Device $DEV already running, exiting." && exit 1

  # Bring the device up
  ip tunnel add $DEV mode sit remote $ENDPOINT local $OWN_IP4 ttl $TTL
  ip link set $DEV up mtu $MTU

  # Add the addresses to the device
  for I in $IP6_ADDRS
  do
    ip addr add $I dev $DEV
  done

  # Set the routes
  ip route add $INTERNET dev $DEV
  echo "$DEV."
;;

stop)
  echo -n "Stopping inet6 device: "
  
  # Delete the routes and device
  ip route del $INTERNET dev $DEV
  ip tunnel del $DEV
  
  # Remove the ipv6 module
  #modprobe -r ipv6
  echo "sics."
;;

restart|force-reload)
  $0 stop
  sleep 1
  $0 start
;;

*)
  echo "Usage: $0 {start|stop|restart|force-reload}" >&2
  exit 1
;;

esac

exit 0