iwl4965: claim RSN IBSS support

Similar like other drivers including iwl3945, do not configure group
keys to the hardware (on Ad-Hoc mode) to make IBSS RSN work.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlegacy/4965-mac.c

@@ -5724,7 +5724,8 @@ il4965_mac_setup_register(struct il_priv *il, u32 max_probe_length)
 	    BIT(NL80211_IFTYPE_STATION) | BIT(NL80211_IFTYPE_ADHOC);
 
 	hw->wiphy->flags |=
-	    WIPHY_FLAG_CUSTOM_REGULATORY | WIPHY_FLAG_DISABLE_BEACON_HINTS;
+	    WIPHY_FLAG_CUSTOM_REGULATORY | WIPHY_FLAG_DISABLE_BEACON_HINTS |
+	    WIPHY_FLAG_IBSS_RSN;
 
 	/*
 	 * For now, disable PS by default because it affects
@@ -5873,6 +5874,16 @@ il4965_mac_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 		return -EOPNOTSUPP;
 	}
 
+	/*
+	 * To support IBSS RSN, don't program group keys in IBSS, the
+	 * hardware will then not attempt to decrypt the frames.
+	 */
+	if (vif->type == NL80211_IFTYPE_ADHOC &&
+	    !(key->flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
+		D_MAC80211("leave - ad-hoc group key\n");
+		return -EOPNOTSUPP;
+	}
+
 	sta_id = il_sta_id_or_broadcast(il, sta);
 	if (sta_id == IL_INVALID_STATION)
 		return -EINVAL;