mac80211: keep mesh ifaces in allmulti mode

Currently a mesh node will not forward a multicast frame if it is not subscribed
to the specific multicast address. This patch addresses the issue and fixes mesh
multicast forwarding.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/main.c

@@ -245,10 +245,13 @@ static int ieee80211_open(struct net_device *dev)
 	case IEEE80211_IF_TYPE_AP:
 		sdata->bss = &sdata->u.ap;
 		break;
+	case IEEE80211_IF_TYPE_MESH_POINT:
+		/* mesh ifaces must set allmulti to forward mcast traffic */
+		atomic_inc(&local->iff_allmultis);
+		break;
 	case IEEE80211_IF_TYPE_STA:
 	case IEEE80211_IF_TYPE_MNTR:
 	case IEEE80211_IF_TYPE_IBSS:
-	case IEEE80211_IF_TYPE_MESH_POINT:
 		/* no special treatment */
 		break;
 	case IEEE80211_IF_TYPE_INVALID:
@@ -495,6 +498,9 @@ static int ieee80211_stop(struct net_device *dev)
 		netif_addr_unlock_bh(local->mdev);
 		break;
 	case IEEE80211_IF_TYPE_MESH_POINT:
+		/* allmulti is always set on mesh ifaces */
+		atomic_dec(&local->iff_allmultis);
+		/* fall through */
 	case IEEE80211_IF_TYPE_STA:
 	case IEEE80211_IF_TYPE_IBSS:
 		sdata->u.sta.state = IEEE80211_DISABLED;