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>

4 files changed, 71 insertions, 0 deletions

diff --git a/include/net/ieee80211_radiotap.h b/include/net/ieee80211_radiotap.h
index 7f0df133d11..c3999632e61 100644
--- a/include/net/ieee80211_radiotap.h
+++ b/include/net/ieee80211_radiotap.h
@@ -186,6 +186,10 @@ struct ieee80211_radiotap_header {
  * IEEE80211_RADIOTAP_AMPDU_STATUS      u32, u16, u8, u8        unitless
  *
  *      Contains the AMPDU information for the subframe.
+ *
+ * IEEE80211_RADIOTAP_VHT       u16, u8, u8, u8[4], u8, u8, u16
+ *
+ *      Contains VHT information about this frame.
  */
 enum ieee80211_radiotap_type {
         IEEE80211_RADIOTAP_TSFT = 0,
@@ -209,6 +213,7 @@ enum ieee80211_radiotap_type {
 
         IEEE80211_RADIOTAP_MCS = 19,
         IEEE80211_RADIOTAP_AMPDU_STATUS = 20,
+        IEEE80211_RADIOTAP_VHT = 21,
 
         /* valid in every it_present bitmap, even vendor namespaces */
         IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE = 29,
@@ -282,6 +287,25 @@ enum ieee80211_radiotap_type {
 #define IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_ERR          0x0010
 #define IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_KNOWN        0x0020
 
+/* For IEEE80211_RADIOTAP_VHT */
+#define IEEE80211_RADIOTAP_VHT_KNOWN_STBC                       0x0001
+#define IEEE80211_RADIOTAP_VHT_KNOWN_TXOP_PS_NA                 0x0002
+#define IEEE80211_RADIOTAP_VHT_KNOWN_GI                         0x0004
+#define IEEE80211_RADIOTAP_VHT_KNOWN_SGI_NSYM_DIS               0x0008
+#define IEEE80211_RADIOTAP_VHT_KNOWN_LDPC_EXTRA_OFDM_SYM        0x0010
+#define IEEE80211_RADIOTAP_VHT_KNOWN_BEAMFORMED                 0x0020
+#define IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH                  0x0040
+#define IEEE80211_RADIOTAP_VHT_KNOWN_GROUP_ID                   0x0080
+#define IEEE80211_RADIOTAP_VHT_KNOWN_PARTIAL_AID                0x0100
+
+#define IEEE80211_RADIOTAP_VHT_FLAG_STBC                        0x01
+#define IEEE80211_RADIOTAP_VHT_FLAG_TXOP_PS_NA                  0x02
+#define IEEE80211_RADIOTAP_VHT_FLAG_SGI                         0x04
+#define IEEE80211_RADIOTAP_VHT_FLAG_SGI_NSYM_M10_9              0x08
+#define IEEE80211_RADIOTAP_VHT_FLAG_LDPC_EXTRA_OFDM_SYM         0x10
+#define IEEE80211_RADIOTAP_VHT_FLAG_BEAMFORMED                  0x20
+
+
 /* helpers */
 static inline int ieee80211_get_radiotap_len(unsigned char *data)
 {
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index db7680acd0d..e806f1d81f6 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1473,6 +1473,10 @@ enum ieee80211_hw_flags {
  *      include _FMT. Use %IEEE80211_RADIOTAP_MCS_HAVE_* values, only
  *      adding _BW is supported today.
  *
+ * @radiotap_vht_details: lists which VHT MCS information the HW reports,
+ *      the default is _GI | _BANDWIDTH.
+ *      Use the %IEEE80211_RADIOTAP_VHT_KNOWN_* values.
+ *
  * @netdev_features: netdev features to be set in each netdev created
  *      from this HW. Note only HW checksum features are currently
  *      compatible with mac80211. Other feature bits will be rejected.
@@ -1499,6 +1503,7 @@ struct ieee80211_hw {
         u8 max_tx_aggregation_subframes;
         u8 offchannel_tx_hw_queue;
         u8 radiotap_mcs_details;
+        u16 radiotap_vht_details;
         netdev_features_t netdev_features;
 };
 
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)