mac80211: clean up RX key checks

Using the default key for "any key set" isn't
quite what we should do. It works, but with the
upcoming changes it makes life unnecessarily
complex, so do something better here and really
check for "any key".
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/rx.c

@@ -955,12 +955,31 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 		 * have been expected.
 		 */
 		struct ieee80211_key *key = NULL;
+		struct ieee80211_sub_if_data *sdata = rx->sdata;
+		int i;
+
 		if (ieee80211_is_mgmt(fc) &&
 		    is_multicast_ether_addr(hdr->addr1) &&
 		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 			rx->key = key;
-		else if ((key = rcu_dereference(rx->sdata->default_key)))
+		else {
+			if (rx->sta) {
+				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
+					key = rcu_dereference(rx->sta->gtk[i]);
+					if (key)
+						break;
+				}
+			}
+			if (!key) {
+				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
+					key = rcu_dereference(sdata->keys[i]);
+					if (key)
+						break;
+				}
+			}
+			if (key)
 				rx->key = key;
+		}
 		return RX_CONTINUE;
 	} else {
 		u8 keyid;