func_ipup()
{
wan0_ifname_t=$(nvram get wan0_ifname_t)
ipaddr=$(nvram get lan_ipaddr)
ex_ipaddr="${ipaddr:0:10}254/32"
case "$wan0_ifname_t" in
  "eth2.2")
    echo "当前不需要修改iptables"
    ;;
  "usb0")
	iptables -I FORWARD -o usb0 -d 0.0.0.0/0 -j DROP
	iptables -I FORWARD -d "$ex_ipaddr" -s 20.0.0.1/32 -j DROP
	iptables -I FORWARD -o usb0 -d 123.163.55.203/32 -j ACCEPT
	iptables -I FORWARD -o usb0 -d 111.6.51.100/32 -j ACCEPT

    ;;
  *)
      echo "????"
    ;;
esac
   return 0
}