If anyone wants to play with this ... The necessary code is in the "bpf" branch of my mac80211-next and iw trees. The setup of the filter is a bit stupid right now - the test program in mac80211-next/bpf (samples/bpf/wifimon) will call iw for the nl80211 part ... I should make an ELF parser in iw, but that's not as simple as using the bpf loader in samples/bpf/ :) johannes