Set vht transmission parameters using radiotap header

[Michal Kazior]

On 18 April 2015 at 12:51, Louis Desfossez <Louis.Desfossez at ugent.be> wrote:
> Using the click modular router project we are trying to inject packets on an
> Atheros QCA988x in monitor mode. Wireless parameters (nss, mcs, channel,
> guard interval, channel width and tx power) are set in the radiotap header.
> Which parameters can currently be read by the ath10k/mac80211 driver and be
> set for transmission (ie. IEEE_RADIOTAP_DBM_TX_POWER,
> IEEE_RADIOTAP_CHANNEL)?
> Is there a possibility to handle the vht information (ie.
> IEEE80211_RADIOTAP_VHT_MCS, IEEE80211_RADIOTAP_VHT_NSS)?

By the looks of ieee80211_parse_tx_radiotap() it seems that most
radiotap is ignored on Tx path.

Anyway I hope you're aware upstream ath10k doesn't support packet injection.

Also due to firmware design there's no way to specify Tx rate for each
frame. Using per-vdev fixed rate param would require really nasty
hacks in driver. I'm not even sure if it's possible with official
firmware to change mgmt and multicast tx rate (I think CT firmware
from Ben has that). I guess using `iw wlanX set bitrates` explicitly
would be better and cleaner - but first you need to get injection to
work at all.


Michał