On 3/3/20 10:59 PM, Steve deRosier wrote: > On Tue, Mar 3, 2020 at 1:28 PM Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: >> On Tue, 2020-03-03 at 12:50 +0100, Markus Theil wrote: >>> Back in 2007 "mac80211: don't allow scanning in monitor mode" >>> (f27b62d3e7ec) disabled scanning in monitor mode, because hw >>> controlled by the zd1211rw driver got confused during this operation. >>> >>> Nevertheless, it can be useful to scan in monitor mode, e.g. >>> when building a tool which processes scans, channel surveys and >>> monitors the channel passively in monitor mode. >> Hmm. I'm not really sure that this makes sense. >> >> You're in monitor mode, so you won't get any scan processing as such >> (you will not be able to use nl80211 to retrieve the results!), and >> there will be a lot of confusion over sending probe requests (the code >> now looks like it would in fact attempt to do so ... but how?). >> > Additionally, I don't see what this solves for sure. At least on an > ath10k device I've been using, I can have two interfaces on one phy > (phy0), wlan0 and mon0, and I can issue a `iw wlan0 scan` and it works > famously and then capture fine on mon0. Granted, I haven't tried doing > a scan while at the same time am actively capturing, but I wonder of > the meaning of that anyway as the capturing radio would have to then > go off channel and issue probe requests etc., sort of screwing up my > capture for that time period. But anyway, can you not do this on your > radio? > > - Steve I was not able to use this combination of interfaces, when only interested in monitoring networks. The STA VIF can only scan when its put up, but then I cannot choose the operating frequency of the monitor interface freely. Sure, I can build workarounds, like changing the interface type when I need an active scan and chaning it back to monitor mode afterwards, but this also seems not very clean. Markus
