mac80211: support (partial) VHT radiotap information

Add some information that we have about VHT to radiotap.
This at least lets one see the MCS and NSS information.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 42 insertions, 0 deletions

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 6e933409979..c4ed83b74e5 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -638,6 +638,8 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
         local->hw.radiotap_mcs_details = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
                                          IEEE80211_RADIOTAP_MCS_HAVE_GI |
                                          IEEE80211_RADIOTAP_MCS_HAVE_BW;
+        local->hw.radiotap_vht_details = IEEE80211_RADIOTAP_VHT_KNOWN_GI |
+                                         IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH;
         local->user_power_level = IEEE80211_UNSET_POWER_LEVEL;
         wiphy->ht_capa_mod_mask = &mac80211_ht_capa_mod_mask;
 
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 825f33cf7bb..9b13b8b2424 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -111,6 +111,11 @@ ieee80211_rx_radiotap_space(struct ieee80211_local *local,
                 len += 8;
         }
 
+        if (status->flag & RX_FLAG_VHT) {
+                len = ALIGN(len, 2);
+                len += 12;
+        }
+
         if (status->vendor_radiotap_len) {
                 if (WARN_ON_ONCE(status->vendor_radiotap_align == 0))
                         status->vendor_radiotap_align = 1;
@@ -297,6 +302,41 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
                 *pos++ = 0;
         }
 
+        if (status->flag & RX_FLAG_VHT) {
+                u16 known = local->hw.radiotap_vht_details;
+
+                rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
+                /* known field - how to handle 80+80? */
+                if (status->flag & RX_FLAG_80P80MHZ)
+                        known &= ~IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH;
+                put_unaligned_le16(known, pos);
+                pos += 2;
+                /* flags */
+                if (status->flag & RX_FLAG_SHORT_GI)
+                        *pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
+                pos++;
+                /* bandwidth */
+                if (status->flag & RX_FLAG_80MHZ)
+                        *pos++ = 4;
+                else if (status->flag & RX_FLAG_80P80MHZ)
+                        *pos++ = 0; /* marked not known above */
+                else if (status->flag & RX_FLAG_160MHZ)
+                        *pos++ = 11;
+                else if (status->flag & RX_FLAG_40MHZ)
+                        *pos++ = 1;
+                else /* 20 MHz */
+                        *pos++ = 0;
+                /* MCS/NSS */
+                *pos = (status->rate_idx << 4) | status->vht_nss;
+                pos += 4;
+                /* coding field */
+                pos++;
+                /* group ID */
+                pos++;
+                /* partial_aid */
+                pos += 2;
+        }
+
         if (status->vendor_radiotap_len) {
                 /* ensure 2 byte alignment for the vendor field as required */
                 if ((pos - (u8 *)rthdr) & 1)