mac80211: TDLS: add proper HT-oper IE

When 11n peers performs a TDLS connection on a legacy BSS, the HT
operation IE must be specified according to IEEE802.11-2012 section
9.23.3.2. Otherwise HT-protection is compromised and the medium becomes
noisy for both the TDLS and the BSS links.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index d38daf0..8802aa4 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2292,7 +2292,7 @@
 
 u8 *ieee80211_ie_build_ht_oper(u8 *pos, struct ieee80211_sta_ht_cap *ht_cap,
 			       const struct cfg80211_chan_def *chandef,
-			       u16 prot_mode)
+			       u16 prot_mode, bool rifs_mode)
 {
 	struct ieee80211_ht_operation *ht_oper;
 	/* Build HT Information */
@@ -2320,6 +2320,9 @@
 	    chandef->width != NL80211_CHAN_WIDTH_20)
 		ht_oper->ht_param |= IEEE80211_HT_PARAM_CHAN_WIDTH_ANY;
 
+	if (rifs_mode)
+		ht_oper->ht_param |= IEEE80211_HT_PARAM_RIFS_MODE;
+
 	ht_oper->operation_mode = cpu_to_le16(prot_mode);
 	ht_oper->stbc_param = 0x0000;