Hostapd radius accounting and Framed-IP-Address

I can see the maintainers of hostapd have http://lists.infradead.org/pipermail/hostap/2016-January/034571.html talked about sending Framed-IP-Address in Radius messages if the origin of the data was from DHCP snooping.

I've been playing with hostapd on 18.06.0-rc2 and I can get radius information and accounting information sent to a freeradius box but Framed-IP-Address is absent from the information it sends. (checked via wireshark.)

How can I get it to send Framed-IP-Address? Is the version of hostapd in the latest openwrt capable of it and do I need to do anything to ensure it can securely get the information from DHCP?
(I was struggling to workout which branch of hostapd openwrt has taken)

Has anyone got this working?

Hi, did you solve this problem? I also needed this attribute to be sent in the accounting messages for Single-Sign-On deployment.

Kind of;
I concluded that hostapd didn't support it
I installed a local radius server on the openwrt box and wrote a 5 line bash script as a addon to the radius accounting flow on the local server to look at ARP (as we have the MAC) and put the IP in the radius accounting message for onward sending to the real radius server.
Bit of a hack, but worked for what I needed.
(I was using it so a openwrt box could simulate the kind of messages you get from a grown up enterprise wireless controller to dev against; so the script wasn't production grade...)

can you share the 5 lines of code, trying to get this working but not familiar with radius. thanks.