[patch 13/26] mac80211: filter locally-originated multicast frames

[Greg KH <gregkh@suse.de>]

[-- Attachment #1: mac80211-filter-locally-originated-multicast-frames.patch --]
[-- Type: text/plain, Size: 1216 bytes --]

2.6.22-stable review patch.  If anyone has any objections, please let us
know.

------------------

From: John W. Linville <linville@tuxdriver.com>

patch b331615722779b078822988843ddffd4eaec9f83 in mainline.

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: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 net/mac80211/ieee80211.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/net/mac80211/ieee80211.c
+++ b/net/mac80211/ieee80211.c
@@ -2615,9 +2615,10 @@ ieee80211_rx_h_data(struct ieee80211_txr
 		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 */

--