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>

include/linux/ieee80211.h

@@ -471,6 +471,11 @@ struct ieee80211s_hdr {
 	u8 eaddr3[6];
 } __attribute__ ((packed));
 
+/* Mesh flags */
+#define MESH_FLAGS_AE_A4 	0x1
+#define MESH_FLAGS_AE_A5_A6	0x2
+#define MESH_FLAGS_PS_DEEP	0x4
+
 /**
  * struct ieee80211_quiet_ie
  *