mac80211: filter locally-originated multicast frames

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>

diff --git a/net/mac80211/ieee80211.c b/net/mac80211/ieee80211.c
index 4e84f24fd439852e8473d70147227e82268f4aa0..42725e1cf7d34c0b7510cdf0f4a10d103964e2b0 100644 (file)
--- a/net/mac80211/ieee80211.c
+++ b/net/mac80211/ieee80211.c
@@ -2615,9 +2615,10 @@ ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
                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 */