mac80211: Scale down to non-HT association with TKIP/WEP as pairwise cipher

As TKIP is not updated to new security needs which arise when
TKIP is used to encrypt A-MPDU aggregated data frames, IEEE802.11n
does not allow any cipher other than CCMP (Which has new extensions
defined) as pairwise cipher between HT peers.

When such configuration (TKIP/WEP in HT) is forced, we still
associate in non-HT mode (11a/b/g).

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/wext.c b/net/mac80211/wext.c
index 7162d58..011592f 100644
--- a/net/mac80211/wext.c
+++ b/net/mac80211/wext.c
@@ -903,12 +903,22 @@
 
 	switch (data->flags & IW_AUTH_INDEX) {
 	case IW_AUTH_WPA_VERSION:
-	case IW_AUTH_CIPHER_PAIRWISE:
 	case IW_AUTH_CIPHER_GROUP:
 	case IW_AUTH_WPA_ENABLED:
 	case IW_AUTH_RX_UNENCRYPTED_EAPOL:
 	case IW_AUTH_KEY_MGMT:
 		break;
+	case IW_AUTH_CIPHER_PAIRWISE:
+		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+			if (data->value & (IW_AUTH_CIPHER_WEP40 |
+			    IW_AUTH_CIPHER_WEP104 | IW_AUTH_CIPHER_TKIP))
+				sdata->u.sta.flags |=
+					IEEE80211_STA_TKIP_WEP_USED;
+			else
+				sdata->u.sta.flags &=
+					~IEEE80211_STA_TKIP_WEP_USED;
+		}
+		break;
 	case IW_AUTH_DROP_UNENCRYPTED:
 		sdata->drop_unencrypted = !!data->value;
 		break;