nl80211: prevent additions to old station flags API

We don't really want/need to maintain the old
station flags API any more, so refuse changes
to new (not yet defined) flags from the old
flags API.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index f296a64..a6959f7 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -1594,6 +1594,8 @@
 	NL80211_STA_FLAG_MAX = __NL80211_STA_FLAG_AFTER_LAST - 1
 };
 
+#define NL80211_STA_FLAG_MAX_OLD_API	NL80211_STA_FLAG_TDLS_PEER
+
 /**
  * struct nl80211_sta_flag_update - station flags mask/set
  * @mask: mask of station flags to set
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index b67b111..f1b0774 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -2410,10 +2410,16 @@
 		return -EINVAL;
 	}
 
-	for (flag = 1; flag <= NL80211_STA_FLAG_MAX; flag++)
-		if (flags[flag])
+	for (flag = 1; flag <= NL80211_STA_FLAG_MAX; flag++) {
+		if (flags[flag]) {
 			params->sta_flags_set |= (1<<flag);
 
+			/* no longer support new API additions in old API */
+			if (flag > NL80211_STA_FLAG_MAX_OLD_API)
+				return -EINVAL;
+		}
+	}
+
 	return 0;
 }