mac80211: count authorized stations per BSS

Currently, each AP interface will send multicast
traffic if any interface has a station entry even
if that station entry is allocated only. With the
new station state management we can easily fix it
by adding a counter that counts each authorized
station only and send multicast traffic only when
the correct interface has at least one authorized
station.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 96fe754..9516c30 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -243,6 +243,7 @@
 	u8 tim[sizeof(unsigned long) * BITS_TO_LONGS(IEEE80211_MAX_AID + 1)];
 	struct sk_buff_head ps_bc_buf;
 	atomic_t num_sta_ps; /* number of stations in PS mode */
+	atomic_t num_sta_authorized; /* number of authorized stations */
 	int dtim_count;
 	bool dtim_bc_mc;
 };