mac80211: 802.11w - Add driver capability flag for MFP

This allows user space to determine whether a driver supports MFP and
behave properly without having to ask user to configure this in
MFP-optional mode.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/net/mac80211.h

@@ -865,6 +865,9 @@ enum ieee80211_tkip_key_type {
  *
  * @IEEE80211_HW_SUPPORTS_DYNAMIC_PS:
  *	Hardware has support for dynamic PS.
+ *
+ * @IEEE80211_HW_MFP_CAPABLE:
+ *	Hardware supports management frame protection (MFP, IEEE 802.11w).
  */
 enum ieee80211_hw_flags {
 	IEEE80211_HW_RX_INCLUDES_FCS			= 1<<1,
@@ -880,6 +883,7 @@ enum ieee80211_hw_flags {
 	IEEE80211_HW_SUPPORTS_PS			= 1<<11,
 	IEEE80211_HW_PS_NULLFUNC_STACK			= 1<<12,
 	IEEE80211_HW_SUPPORTS_DYNAMIC_PS		= 1<<13,
+	IEEE80211_HW_MFP_CAPABLE			= 1<<14,
 };
 
 /**

net/mac80211/wext.c

@@ -976,6 +976,10 @@ static int ieee80211_ioctl_siwauth(struct net_device *dev,
 			ret = -EOPNOTSUPP;
 		break;
 	case IW_AUTH_MFP:
+		if (!(sdata->local->hw.flags & IEEE80211_HW_MFP_CAPABLE)) {
+			ret = -EOPNOTSUPP;
+			break;
+		}
 		if (sdata->vif.type == NL80211_IFTYPE_STATION ||
 		    sdata->vif.type == NL80211_IFTYPE_ADHOC)
 			sdata->u.sta.mfp = data->value;