On Wednesday 12 September 2012 01:46:01 Richard Farina wrote: > On 09/11/2012 07:26 PM, Christian Lamparter wrote: > > On Wednesday 12 September 2012 00:03:40 Richard Farina wrote: > >> On 09/11/2012 05:18 PM, Christian Lamparter wrote: > >>> Several people have complained about an unusual > >>> and undocumented feature of the AR9170 hardware: > >>> > >>> In siffer mode, the hardware generates spurious > >>> ACK frames for every received frame... even > >>> broadcasts. > >>> > >>> The reason for this malfunction is unknown: > >>> <http://marc.info/?l=linux-wireless&m=134517238506033> > >>> But there's a workaround: Instead of the special > >>> sniffer mode, the hardware will be put into > >>> station mode and all rx filters are disabled. > >> I am by no means an expert here but wouldn't it be better to disable > >> ACK? Or is this not really an option? > > Oh AFAIK there's some nifty software which emulates > > some sort of accesspoint by (ab-)using monitor mode > > and injection. And in this case having a device which > > ACKs any frame destined for the semi-fake ap might be > > a "good thing". > > Are you referencing airbase-ng here? Airbase-ng assumes > the hardware does not ack in monitor mode and therefore > does it itself. Mind you, I'm not saying it wouldn't be > nice to have the hardware ack (VASTLY improved response > time for one) but a monitor mode vif is assumed to not > transmit anything at all, unless we specifically inject > it. > > An ack on/off (default off) would be awesome, but baring > that the only sane choice is off. I'm no expert either, but isn't airbase-ng more of a client attack tool suite than a useful softAP? No, it must have been a different software then. Anyway, now the hardware will only react to frames that are "directed" (DA matches either the main, or one of the 8 vif mac addresses) to it (is this now sane or not?). So, the hardware ack ability is not going to just disappear, if someone is already depending on it. (BTW: wasn't there once some sort of a "tx ack" control interface in mac80211 debugfs path? Does anybody know what happend to it?) Regards, Chr -- 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
