From ef246a1480cc484cd2aeda75737cb0848616ddf3 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 20 Sep 2023 21:25:26 +0300 Subject: wifi: mac80211: support antenna control in injection Support antenna control for injection by parsing the antenna radiotap field (which may be presented multiple times) and telling the driver about the resulting antenna bitmap. Of course there's no guarantee the driver will actually honour this, just like any other injection control. If misconfigured, i.e. the injected HT/VHT MCS needs more chains than antennas are configured, the bitmap is reset to zero, indicating no selection. For now this is only set up for two anntenas so we keep more free bits, but that can be trivially extended if any driver implements support for it that can deal with hardware with more antennas. Signed-off-by: Johannes Berg Signed-off-by: Gregory Greenman Link: https://lore.kernel.org/r/20230920211508.f71001aa4da9.I00ccb762a806ea62bc3d728fa3a0d29f4f285eeb@changeid Signed-off-by: Johannes Berg --- net/mac80211/tx.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'net/mac80211/tx.c') diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 932516f8cc13..a984fc54644e 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -2162,6 +2162,11 @@ bool ieee80211_parse_tx_radiotap(struct sk_buff *skb, rate_found = true; break; + case IEEE80211_RADIOTAP_ANTENNA: + /* this can appear multiple times, keep a bitmap */ + info->control.antennas |= BIT(*iterator.this_arg); + break; + case IEEE80211_RADIOTAP_DATA_RETRIES: rate_retries = *iterator.this_arg; break; @@ -2256,8 +2261,17 @@ bool ieee80211_parse_tx_radiotap(struct sk_buff *skb, } if (rate_flags & IEEE80211_TX_RC_MCS) { + /* reset antennas if not enough */ + if (IEEE80211_HT_MCS_CHAINS(rate) > + hweight8(info->control.antennas)) + info->control.antennas = 0; + info->control.rates[0].idx = rate; } else if (rate_flags & IEEE80211_TX_RC_VHT_MCS) { + /* reset antennas if not enough */ + if (vht_nss > hweight8(info->control.antennas)) + info->control.antennas = 0; + ieee80211_rate_set_vht(info->control.rates, vht_mcs, vht_nss); } else if (sband) { -- cgit v1.2.3-58-ga151