Add OpenFlow to OpenWrt on Raspberry Pi

Thank you very much for all this
But can you teach me how to add OpenFlow protocol to openWRT system installed on my Raspberry Pi?

Have you tried openvswitch? It supports openflow.

Yes, I tried, but I couldn't install it

See: https://openwrt.org/packages/table/start?dataflt[Name_pkg-dependencies*~]=openvswitch

Do the commands opkg update && opkg install openvswitch work?