mac80211: add STBC flag for radiotap

Some chips can tell us if received frame was
encoded with STBC or not. To make this information available
in user space we can use updated radiotap specification:
http://www.radiotap.org/defined-fields/MCS

This patch will set number of STBC encoded spatial streams (Nss).
The HAVE_STBC flag should be provided by driver.

Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 6e2c8c5236c4..7507f7cdd68c 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -258,6 +258,8 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
         pos += 2;
 
         if (status->flag & RX_FLAG_HT) {
+                unsigned int stbc;
+
                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
                 *pos++ = local->hw.radiotap_mcs_details;
                 *pos = 0;
@@ -267,6 +269,8 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
                         *pos |= IEEE80211_RADIOTAP_MCS_BW_40;
                 if (status->flag & RX_FLAG_HT_GF)
                         *pos |= IEEE80211_RADIOTAP_MCS_FMT_GF;
+                stbc = (status->flag & RX_FLAG_STBC_MASK) >> RX_FLAG_STBC_SHIFT;
+                *pos |= stbc << IEEE80211_RADIOTAP_MCS_STBC_SHIFT;
                 pos++;
                 *pos++ = status->rate_idx;
         }