commit b331615722779b078822988843ddffd4eaec9f83
author John W. Linville <linville@tuxdriver.com> Tue Aug 28 17:01:55 2007 -0400
committer David S. Miller <davem@sunset.davemloft.net> Wed Oct 10 16:48:56 2007 -0700
tree 81f9dd70c82e7fab1502aa7d79e971c004b0532d
parent 3c3b00caf98e5fdaa0184026a68f0008a5bf393e

[MAC80211]: filter locally-originated multicast frames

In STA mode, the AP will echo our traffic.  This includes multicast
traffic.

Receiving these frames confuses some protocols and applications,
notably IPv6 Duplicate Address Detection.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mac80211/rx.c

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index e2c6f5c..969be3a 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -988,9 +988,10 @@
 		memcpy(dst, hdr->addr1, ETH_ALEN);
 		memcpy(src, hdr->addr3, ETH_ALEN);
 
-		if (sdata->type != IEEE80211_IF_TYPE_STA) {
+		if (sdata->type != IEEE80211_IF_TYPE_STA ||
+		    (is_multicast_ether_addr(dst) &&
+		     !compare_ether_addr(src, dev->dev_addr)))
 			return TXRX_DROP;
-		}
 		break;
 	case 0:
 		/* DA SA BSSID */