mac80211: parse VHT info in injected frames

Add VHT radiotap parsing support to ieee80211_parse_tx_radiotap().
That capability has been tested using a d-link dir-860l rev b1 running
OpenWrt trunk and mt76 driver

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/Documentation/networking/mac80211-injection.txt b/Documentation/networking/mac80211-injection.txt
index ec8f934..e0efcaf 100644 (file)
--- a/Documentation/networking/mac80211-injection.txt
+++ b/Documentation/networking/mac80211-injection.txt
@@ -45,6 +45,19 @@ radiotap headers and used to control injection:
    number of retries when either IEEE80211_RADIOTAP_RATE or
    IEEE80211_RADIOTAP_MCS was used
 
+ * IEEE80211_RADIOTAP_VHT
+
+   VHT mcs and number of streams used in the transmission (only for devices
+   without own rate control). Also other fields are parsed
+
+   flags field
+   IEEE80211_RADIOTAP_VHT_FLAG_SGI: use short guard interval
+
+   bandwidth field
+   1: send using 40MHz channel width
+   4: send using 80MHz channel width
+   11: send using 160MHz channel width
+
 The injection code can also skip all other currently defined radiotap fields
 facilitating replay of captured radiotap headers directly.
 

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 62ad532..c485fc2 100644 (file)
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1692,6 +1692,8 @@ static bool ieee80211_parse_tx_radiotap(struct ieee80211_local *local,
        u8 rate_retries = 0;
        u16 rate_flags = 0;
        u8 mcs_known, mcs_flags;
+       u16 vht_known;
+       u8 vht_mcs = 0, vht_nss = 0;
        int i;
 
        info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
@@ -1772,6 +1774,32 @@ static bool ieee80211_parse_tx_radiotap(struct ieee80211_local *local,
                                rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
                        break;
 
+               case IEEE80211_RADIOTAP_VHT:
+                       vht_known = get_unaligned_le16(iterator.this_arg);
+                       rate_found = true;
+
+                       rate_flags = IEEE80211_TX_RC_VHT_MCS;
+                       if ((vht_known & IEEE80211_RADIOTAP_VHT_KNOWN_GI) &&
+                           (iterator.this_arg[2] &
+                            IEEE80211_RADIOTAP_VHT_FLAG_SGI))
+                               rate_flags |= IEEE80211_TX_RC_SHORT_GI;
+                       if (vht_known &
+                           IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH) {
+                               if (iterator.this_arg[3] == 1)
+                                       rate_flags |=
+                                               IEEE80211_TX_RC_40_MHZ_WIDTH;
+                               else if (iterator.this_arg[3] == 4)
+                                       rate_flags |=
+                                               IEEE80211_TX_RC_80_MHZ_WIDTH;
+                               else if (iterator.this_arg[3] == 11)
+                                       rate_flags |=
+                                               IEEE80211_TX_RC_160_MHZ_WIDTH;
+                       }
+
+                       vht_mcs = iterator.this_arg[4] >> 4;
+                       vht_nss = iterator.this_arg[4] & 0xF;
+                       break;
+
                /*
                 * Please update the file
                 * Documentation/networking/mac80211-injection.txt
@@ -1797,6 +1825,9 @@ static bool ieee80211_parse_tx_radiotap(struct ieee80211_local *local,
 
                if (rate_flags & IEEE80211_TX_RC_MCS) {
                        info->control.rates[0].idx = rate;
+               } else if (rate_flags & IEEE80211_TX_RC_VHT_MCS) {
+                       ieee80211_rate_set_vht(info->control.rates, vht_mcs,
+                                              vht_nss);
                } else {
                        for (i = 0; i < sband->n_bitrates; i++) {
                                if (rate * 5 != sband->bitrates[i].bitrate)