mac80211: Use 3-address format for mesh broadcast frames.

The 11s task group recently changed the frame mesh multicast/broadcast frame
format to use 3-address.  This was done to avoid interactions with widely
deployed lazy-WDS access points.

This patch changes the format of group addressed frames, both mesh-originated
and proxied, to use the data format defined in draft D2.08 and forward.  The
address fields used for group addressed frames is:

In 802.11 header
 ToDS:0  FromDS:1
 addr1: DA  (broadcast/multicast address)
 addr2: TA
 addr3: Mesh SA

In address extension header:
 addr4: SA  (only present if frame was proxied)

Note that this change breaks backward compatibility with earlier mesh stack
versions.

Signed-off-by: Andrey Yurovsky <andrey@cozybit.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/net/wireless/util.c b/net/wireless/util.c
index ba387d85dcfd..693275a16a26 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -274,11 +274,11 @@ static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
         switch (ae) {
         case 0:
                 return 6;
-        case 1:
+        case MESH_FLAGS_AE_A4:
                 return 12;
-        case 2:
+        case MESH_FLAGS_AE_A5_A6:
                 return 18;
-        case 3:
+        case (MESH_FLAGS_AE_A4 | MESH_FLAGS_AE_A5_A6):
                 return 24;
         default:
                 return 6;
@@ -333,10 +333,18 @@ int ieee80211_data_to_8023(struct sk_buff *skb, u8 *addr,
                 }
                 break;
         case cpu_to_le16(IEEE80211_FCTL_FROMDS):
-                if (iftype != NL80211_IFTYPE_STATION ||
+                if ((iftype != NL80211_IFTYPE_STATION &&
+                    iftype != NL80211_IFTYPE_MESH_POINT) ||
                     (is_multicast_ether_addr(dst) &&
                      !compare_ether_addr(src, addr)))
                         return -1;
+                if (iftype == NL80211_IFTYPE_MESH_POINT) {
+                        struct ieee80211s_hdr *meshdr =
+                                (struct ieee80211s_hdr *) (skb->data + hdrlen);
+                        hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
+                        if (meshdr->flags & MESH_FLAGS_AE_A4)
+                                memcpy(src, meshdr->eaddr1, ETH_ALEN);
+                }
                 break;
         case cpu_to_le16(0):
                 if (iftype != NL80211_IFTYPE_ADHOC)