mac80211: fix vlan and optimise RX

When receiving data frames, we can send them only to
the interface they belong to based on transmitting
station (this doesn't work for probe requests). Also,
don't try to handle other frames for AP_VLAN at all
since those interface should only receive data.

Additionally, the transmit side must check that the
station we're sending a frame to is actually on the
interface we're transmitting on, and not transmit
packets to functions that live on other interfaces,
so validate that as well.

Another bug fix is needed in sta_info.c where in the
VLAN case when adding/removing stations we overwrite
the sdata variable we still need.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/rx.c

@@ -2164,11 +2164,17 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 
 	skb = rx.skb;
 
-	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+	if (rx.sdata && ieee80211_is_data(hdr->frame_control)) {
+		rx.flags |= IEEE80211_RX_RA_MATCH;
+		prepares = prepare_for_handlers(rx.sdata, &rx, hdr);
+		if (prepares)
+			prev = rx.sdata;
+	} else list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 		if (!netif_running(sdata->dev))
 			continue;
 
-		if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
+		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
+		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 			continue;
 
 		rx.flags |= IEEE80211_RX_RA_MATCH;

net/mac80211/sta_info.c

@@ -361,6 +361,7 @@ int sta_info_insert(struct sta_info *sta)
 					     u.ap);
 
 		drv_sta_notify(local, &sdata->vif, STA_NOTIFY_ADD, &sta->sta);
+		sdata = sta->sdata;
 	}
 
 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
@@ -496,6 +497,7 @@ static void __sta_info_unlink(struct sta_info **sta)
 
 		drv_sta_notify(local, &sdata->vif, STA_NOTIFY_REMOVE,
 			       &(*sta)->sta);
+		sdata = (*sta)->sdata;
 	}
 
 	if (ieee80211_vif_is_mesh(&sdata->vif)) {

net/mac80211/tx.c

@@ -1704,7 +1704,8 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 	if (!is_multicast_ether_addr(hdr.addr1)) {
 		rcu_read_lock();
 		sta = sta_info_get(local, hdr.addr1);
-		if (sta)
+		/* XXX: in the future, use sdata to look up the sta */
+		if (sta && sta->sdata == sdata)
 			sta_flags = get_sta_flags(sta);
 		rcu_read_unlock();
 	}