mac80211: mesh portal functionality support

Currently the mesh code doesn't support bridging mesh point interfaces
with wired ethernet or AP to construct an MPP or MAP. This patch adds
code to support the "6 address frame format packet" functionality to
mesh point interfaces. Now the mesh network can be used as backhaul
for end to end communication.

Signed-off-by: Li YanBo <dreamfly281@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 3ab9670..2efa4dd 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1107,10 +1107,6 @@
 
 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
 
-	if (ieee80211_vif_is_mesh(&sdata->vif))
-		hdrlen += ieee80211_get_mesh_hdrlen(
-				(struct ieee80211s_hdr *) (skb->data + hdrlen));
-
 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
 	 * header
 	 * IEEE 802.11 address fields:
@@ -1134,6 +1130,15 @@
 		if (unlikely(sdata->vif.type != NL80211_IFTYPE_WDS &&
 			     sdata->vif.type != NL80211_IFTYPE_MESH_POINT))
 			return -1;
+		if (ieee80211_vif_is_mesh(&sdata->vif)) {
+			struct ieee80211s_hdr *meshdr = (struct ieee80211s_hdr *)
+				(skb->data + hdrlen);
+			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
+			if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
+				memcpy(dst, meshdr->eaddr1, ETH_ALEN);
+				memcpy(src, meshdr->eaddr2, ETH_ALEN);
+			}
+		}
 		break;
 	case __constant_cpu_to_le16(IEEE80211_FCTL_FROMDS):
 		if (sdata->vif.type != NL80211_IFTYPE_STATION ||
@@ -1393,6 +1398,25 @@
 		/* illegal frame */
 		return RX_DROP_MONITOR;
 
+	if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6){
+		struct ieee80211_sub_if_data *sdata;
+		struct mesh_path *mppath;
+
+		sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
+		rcu_read_lock();
+		mppath = mpp_path_lookup(mesh_hdr->eaddr2, sdata);
+		if (!mppath) {
+			mpp_path_add(mesh_hdr->eaddr2, hdr->addr4, sdata);
+		} else {
+			spin_lock_bh(&mppath->state_lock);
+			mppath->exp_time = jiffies;
+			if (compare_ether_addr(mppath->mpp, hdr->addr4) != 0)
+				memcpy(mppath->mpp, hdr->addr4, ETH_ALEN);
+			spin_unlock_bh(&mppath->state_lock);
+		}
+		rcu_read_unlock();
+	}
+
 	if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
 		return RX_CONTINUE;