mac80211: redesign scan RX

Scan receive is rather inefficient when there are
multiple virtual interfaces. We iterate all of the
virtual interfaces and then notify cfg80211 about
each beacon many times.

Redesign scan RX to happen before everything else.
Then we can also get rid of IEEE80211_RX_IN_SCAN
since we don't have to accept frames into the RX
handlers for scanning or scheduled scanning any
more. Overall, this simplifies the code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 8 insertions, 39 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 17a56151be7f..1d7a58098e34 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -413,29 +413,6 @@ static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 
 /* rx handlers */
 
-static ieee80211_rx_result debug_noinline
-ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
-{
-	struct ieee80211_local *local = rx->local;
-	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
-	struct sk_buff *skb = rx->skb;
-
-	if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
-		   !rcu_access_pointer(local->sched_scan_sdata)))
-		return RX_CONTINUE;
-
-	if (test_bit(SCAN_HW_SCANNING, &local->scanning) ||
-	    test_bit(SCAN_SW_SCANNING, &local->scanning) ||
-	    test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning) ||
-	    rcu_access_pointer(local->sched_scan_sdata))
-		return ieee80211_scan_rx(rx->sdata, skb);
-
-	/* scanning finished during invoking of handlers */
-	I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
-	return RX_DROP_UNUSABLE;
-}
-
-
 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
@@ -2692,7 +2669,6 @@ static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
 			goto rxh_next;  \
 	} while (0);
 
-	CALL_RXH(ieee80211_rx_h_passive_scan)
 	CALL_RXH(ieee80211_rx_h_check)
 
 	ieee80211_rx_reorder_ampdu(rx);
@@ -2762,11 +2738,8 @@ static int prepare_for_handlers(struct ieee80211_rx_data *rx,
 			return 0;
 		if (ieee80211_is_beacon(hdr->frame_control)) {
 			return 1;
-		}
-		else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
-			if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
-				return 0;
-			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
+		} else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
+			return 0;
 		} else if (!multicast &&
 			   !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
 			if (!(sdata->dev->flags & IFF_PROMISC))
@@ -2804,11 +2777,9 @@ static int prepare_for_handlers(struct ieee80211_rx_data *rx,
 			 * and location updates. Note that mac80211
 			 * itself never looks at these frames.
 			 */
-			if (!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
-			    ieee80211_is_public_action(hdr, skb->len))
+			if (ieee80211_is_public_action(hdr, skb->len))
 				return 1;
-			if (!(status->rx_flags & IEEE80211_RX_IN_SCAN) &&
-			    !ieee80211_is_beacon(hdr->frame_control))
+			if (!ieee80211_is_beacon(hdr->frame_control))
 				return 0;
 			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
 		}
@@ -2874,7 +2845,6 @@ static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 					 struct sk_buff *skb)
 {
-	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 	struct ieee80211_local *local = hw_to_local(hw);
 	struct ieee80211_sub_if_data *sdata;
 	struct ieee80211_hdr *hdr;
@@ -2892,11 +2862,6 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 	if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
 		local->dot11ReceivedFragmentCount++;
 
-	if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
-		     test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning) ||
-		     test_bit(SCAN_SW_SCANNING, &local->scanning)))
-		status->rx_flags |= IEEE80211_RX_IN_SCAN;
-
 	if (ieee80211_is_mgmt(fc))
 		err = skb_linearize(skb);
 	else
@@ -2911,6 +2876,10 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 	ieee80211_parse_qos(&rx);
 	ieee80211_verify_alignment(&rx);
 
+	if (unlikely(ieee80211_is_probe_resp(hdr->frame_control) ||
+		     ieee80211_is_beacon(hdr->frame_control)))
+		ieee80211_scan_rx(local, skb);
+
 	if (ieee80211_is_data(fc)) {
 		prev_sta = NULL;