nl80211: add Guard Interval support for set_bitrate_mask

Allow to force SGI, LGI.
Mainly for test purpose.

Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -1776,6 +1776,7 @@ struct cfg80211_bitrate_mask {
 		u32 legacy;
 		u8 ht_mcs[IEEE80211_HT_MCS_MASK_LEN];
 		u16 vht_mcs[NL80211_VHT_NSS_MAX];
+		enum nl80211_txrate_gi gi;
 	} control[IEEE80211_NUM_BANDS];
 };
 /**

include/uapi/linux/nl80211.h

@@ -3156,6 +3156,7 @@ enum nl80211_key_attributes {
  *	in an array of MCS numbers.
  * @NL80211_TXRATE_VHT: VHT rates allowed for TX rate selection,
  *	see &struct nl80211_txrate_vht
+ * @NL80211_TXRATE_GI: configure GI, see &enum nl80211_txrate_gi
  * @__NL80211_TXRATE_AFTER_LAST: internal
  * @NL80211_TXRATE_MAX: highest TX rate attribute
  */
@@ -3164,6 +3165,7 @@ enum nl80211_tx_rate_attributes {
 	NL80211_TXRATE_LEGACY,
 	NL80211_TXRATE_HT,
 	NL80211_TXRATE_VHT,
+	NL80211_TXRATE_GI,
 
 	/* keep last */
 	__NL80211_TXRATE_AFTER_LAST,
@@ -3181,6 +3183,12 @@ struct nl80211_txrate_vht {
 	__u16 mcs[NL80211_VHT_NSS_MAX];
 };
 
+enum nl80211_txrate_gi {
+	NL80211_TXRATE_DEFAULT_GI,
+	NL80211_TXRATE_FORCE_SGI,
+	NL80211_TXRATE_FORCE_LGI,
+};
+
 /**
  * enum nl80211_band - Frequency band
  * @NL80211_BAND_2GHZ: 2.4 GHz ISM band

net/wireless/nl80211.c

@@ -7447,6 +7447,7 @@ static const struct nla_policy nl80211_txattr_policy[NL80211_TXRATE_MAX + 1] = {
 	[NL80211_TXRATE_HT] = { .type = NLA_BINARY,
 				.len = NL80211_MAX_SUPP_HT_RATES },
 	[NL80211_TXRATE_VHT] = { .len = sizeof(struct nl80211_txrate_vht)},
+	[NL80211_TXRATE_GI] = { .type = NLA_U8 },
 };
 
 static int nl80211_set_tx_bitrate_mask(struct sk_buff *skb,
@@ -7527,6 +7528,12 @@ static int nl80211_set_tx_bitrate_mask(struct sk_buff *skb,
 					mask.control[band].vht_mcs))
 				return -EINVAL;
 		}
+		if (tb[NL80211_TXRATE_GI]) {
+			mask.control[band].gi =
+				nla_get_u8(tb[NL80211_TXRATE_GI]);
+			if (mask.control[band].gi > NL80211_TXRATE_FORCE_LGI)
+				return -EINVAL;
+		}
 
 		if (mask.control[band].legacy == 0) {
 			/* don't allow empty legacy rates if HT or VHT