David,
The script that uses ipset is not posted; it is a slight variation of the one on the Wiki. I'm adding it now (and attached it directly to you for your convenience).
On OpenWrt, install:
- diffutils; and -ipset
Also, don't put a space between these two lines:
ipset -N ipipfilter hash:ip 2>/dev/null if [ $? -eq 0 ]
73,
- Lynwood KB3VWG