On Tue, 2015-01-27 at 12:39 +0100, Janusz Dziedzic wrote: > On 27 January 2015 at 11:24, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > > On Tue, 2015-01-27 at 09:44 +0100, Janusz Dziedzic wrote: > > > >> +u8 *ieee80211_ie_build_vht_oper(u8 *pos, struct ieee80211_sta_vht_cap *vht_cap, > >> + const struct cfg80211_chan_def *chandef) > > > >> + /* 1 stream, MCS0-7 as a min Basic VHT MCS rates */ > >> + vht_oper->basic_mcs_set = cpu_to_le16(0xfffc); > > > > Unless I'm mistaken in my reading of the spec, this will make any > > well-behaved client (i.e. not mac80211) not join this network since it > > supports VHT MCSes. > > > > We seem to do the same for HT: > > > > /* It seems that Basic MCS set and Supported MCS set > > are identical for the first 10 bytes */ > > memset(&ht_oper->basic_set, 0, 16); > > memcpy(&ht_oper->basic_set, &ht_cap->mcs, 10); > > > > but I'm not convinced it's right. It probably only works because nobody > > ever tested against a well-behaved non-HT client? Or perhaps there isn't > > even one? > > > for HT (spec, 20.3.5) - MCS0 .. MSC7 are mandatory - but this is for > all stations (not sure about ibss) > for VHT (22.5, table 22-30) - MCS0...MCS7 are mandatory for nss=1 (20,40,80) > Seems such set is secure? > > If I understand correctly case you describe with non-HT client: > non-HT client should not understand HT ies, and HT-only client should > not understand VHT ies? Yeah that's a good point, I guess older clients won't even look at this, and we don't include the HT or VHT marker in the basic rate set IE. johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
