CTRL_DEV="/dev/ttyACM1"
RFKILL=`grep -l tpacpi_wwan_sw /sys/devices/platform/thinkpad_acpi/rfkill/rfkill*/name | sed s/name\$/state/`

function wwan_up {
  echo 1 > ${RFKILL}
  /usr/sbin/chat -t 5 -v "" 'AT+CGDCONT=1,"IP","internet"' "OK" "AT*ENAP=1,1" "OK" > ${CTRL_DEV} < ${CTRL_DEV}
  sleep 3
  /usr/sbin/dhclient -v usb0
}

function wwan_down {
  /usr/sbin/dhclient -r usb0
  /usr/sbin/chat -t 5 -v "" "AT*ENAP=0" "OK" > ${CTRL_DEV} < ${CTRL_DEV}
  ifconfig usb0 down
  echo 0 > ${RFKILL}
}

function usage {
  echo "Usage: $0 up|down" >&2
  exit 1
}

case "$1" in
  "up")
    wwan_up
    ;;
  "down")
    wwan_down
    ;;
  *)
    usage
    ;;
esac