On Mon, Oct 24, 2011 at 14:15, Jouni Malinen <j@xxxxx> wrote: > On Mon, Oct 24, 2011 at 01:59:45PM +0200, Arik Nemtsov wrote: >> Note that the sta-rates are not really required before second addition >> (which also sets them). Initially the STA is not authorized for direct >> Tx (as determined by the WLAN_STA_TDLS_PEER_AUTH bit). >> We don't expect direct frames during link setup. > > OK.. Though, there can still be some direct frames like TDLS Discovery > Response. You have a point there - this one is not related to link setup. At this point we really have no idea about peer supported rates (and no STA entry). I just tested this with hwsim and it seems to work. The rate chosen is the the smallest non-basic rate (haven't looked at why that happens). With cards that use HW rate control (like wl12xx), this will of course be implementation defined. > >> The STA is added to let us know we should drop all non-setup packets >> between TDLS peers currently in link setup. We could have used a >> different indication, but the STA entry is make the most sense here >> since it is automatically cleaned up when we are disconnected from the >> AP (as all TDLS state should be). > > When you say "drop", I hope you mean "buffer for later delivery" and > when you say "non-setup packets", I hope you mean "non-setup Data > frames" ;-). No I mean "drop". Initially a buffer was planned, but in reality the setup process is extremely fast. I setup iperf between two regular stations (about 15mb/s) and proceeded to setup TDLS. I managed to lose only about 3-4 frames each time. Of course there may be anomalies (bad link quality etc.), but IMHO for real-world situations the extra complexity of a buffering mechanism is not warranted. Also higher level protocols (like TCP) will generally make up for any loss. I'll change the second one to "non-setup Data frames" :) > >> How about this one instead (tested hwsim with it): >> Subject: [RFC] mac80211: init rate-control for TDLS sta when supp-rates are >> known >> >> Initialize rate control algorithms only when supported rates are known >> for a TDLS peer sta. Direct Tx between peers is not allowed before the >> link is enabled. In turn, this only occurs after a change_station() >> call that sets supported rates. > > I guess this could be fine, too, assuming TDLS is the only use case for > this type of changing of STA supported rates. Currently it is - we even check this explicitly higher up in nl80211_set_station(). Arik -- 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
