mac80211: make station management completely depend on vif

The station management currently uses the virtual
interface, but you cannot add the same station to
multiple virtual interfaces if you're communicating
with it in multiple ways.

This restriction should be lifted so that in the
future we can, for instance, support bluetooth 3
with an access point that mac80211 is already
associated to.

We can do that by requiring all sta_info_get users
to provide the virtual interface and making the RX
code aware that an address may match more than one
station struct. Thanks to the previous patches this
one isn't all that large and except for the RX and
TX status paths changes has low complexity.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index b4810f6..c820823 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -403,9 +403,34 @@
 #define STA_INFO_CLEANUP_INTERVAL (10 * HZ)
 
 /*
- * Get a STA info, must have be under RCU read lock.
+ * Get a STA info, must be under RCU read lock.
  */
-struct sta_info *sta_info_get(struct ieee80211_local *local, const u8 *addr);
+struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
+			      const u8 *addr);
+
+static inline
+void for_each_sta_info_type_check(struct ieee80211_local *local,
+				  const u8 *addr,
+				  struct sta_info *sta,
+				  struct sta_info *nxt)
+{
+}
+
+#define for_each_sta_info(local, _addr, sta, nxt) 			\
+	for (	/* initialise loop */					\
+		sta = rcu_dereference(local->sta_hash[STA_HASH(_addr)]),\
+		nxt = sta ? rcu_dereference(sta->hnext) : NULL;		\
+		/* typecheck */						\
+		for_each_sta_info_type_check(local, (_addr), sta, nxt),	\
+		/* continue condition */				\
+		sta;							\
+		/* advance loop */					\
+		sta = nxt,						\
+		nxt = sta ? rcu_dereference(sta->hnext) : NULL		\
+	     )								\
+	/* compare address and run code only if it matches */		\
+	if (memcmp(sta->sta.addr, (_addr), ETH_ALEN) == 0)
+
 /*
  * Get STA info by index, BROKEN!
  */