mac80211: fix use of skb->cb for mesh forwarding

Now we deal with mesh forwarding before the 802.11->802.3 conversion, thus
eliminating a few unnecessary steps. The next hop lookup is called from
ieee80211_master_start_xmit() instead of subif_start_xmit(). Until the next hop
is found, RA in the frame will be all zeroes for frames originating from the
device. For forwarded frames, RA will contain the TA of the received frame,
which will be necessary to send a path error if a next hop is not found.

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>

1 files changed, 24 insertions, 21 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 771ec68b848d..4788f7b91f49 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1301,6 +1301,7 @@ int ieee80211_master_start_xmit(struct sk_buff *skb,
 				struct net_device *dev)
 {
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 	struct net_device *odev = NULL;
 	struct ieee80211_sub_if_data *osdata;
 	int headroom;
@@ -1328,6 +1329,20 @@ int ieee80211_master_start_xmit(struct sk_buff *skb,
 
 	osdata = IEEE80211_DEV_TO_SUB_IF(odev);
 
+	if (ieee80211_vif_is_mesh(&osdata->vif) &&
+	    ieee80211_is_data(hdr->frame_control)) {
+		if (ieee80211_is_data(hdr->frame_control)) {
+			if (is_multicast_ether_addr(hdr->addr3))
+				memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
+			else
+				if (mesh_nexthop_lookup(skb, odev))
+					return  0;
+			if (memcmp(odev->dev_addr, hdr->addr4, ETH_ALEN) != 0)
+				IEEE80211_IFSTA_MESH_CTR_INC(&osdata->u.sta,
+							     fwded_frames);
+		}
+	}
+
 	may_encrypt = !skb->do_not_encrypt;
 
 	headroom = osdata->local->tx_headroom;
@@ -1472,30 +1487,17 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
 	case IEEE80211_IF_TYPE_MESH_POINT:
 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
 		/* RA TA DA SA */
-		if (is_multicast_ether_addr(skb->data))
-			memcpy(hdr.addr1, skb->data, ETH_ALEN);
-		else if (mesh_nexthop_lookup(hdr.addr1, skb, dev))
-				return 0;
+		memset(hdr.addr1, 0, ETH_ALEN);
 		memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
-		if (skb->pkt_type == PACKET_OTHERHOST) {
-			/* Forwarded frame, keep mesh ttl and seqnum */
-			struct ieee80211s_hdr *prev_meshhdr;
-			prev_meshhdr = ((struct ieee80211s_hdr *)skb->cb);
-			meshhdrlen = ieee80211_get_mesh_hdrlen(prev_meshhdr);
-			memcpy(&mesh_hdr, prev_meshhdr, meshhdrlen);
-			sdata->u.sta.mshstats.fwded_frames++;
-		} else {
-			if (!sdata->u.sta.mshcfg.dot11MeshTTL) {
-				/* Do not send frames with mesh_ttl == 0 */
-				sdata->u.sta.mshstats.dropped_frames_ttl++;
-				ret = 0;
-				goto fail;
-			}
-			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
-							       sdata);
+		if (!sdata->u.sta.mshcfg.dot11MeshTTL) {
+			/* Do not send frames with mesh_ttl == 0 */
+			sdata->u.sta.mshstats.dropped_frames_ttl++;
+			ret = 0;
+			goto fail;
 		}
+		meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr, sdata);
 		hdrlen = 30;
 		break;
 #endif
@@ -1543,7 +1545,8 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
 	 * Drop unicast frames to unauthorised stations unless they are
 	 * EAPOL frames from the local station.
 	 */
-	if (unlikely(!is_multicast_ether_addr(hdr.addr1) &&
+	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
+		unlikely(!is_multicast_ether_addr(hdr.addr1) &&
 		      !(sta_flags & WLAN_STA_AUTHORIZED) &&
 		      !(ethertype == ETH_P_PAE &&
 		       compare_ether_addr(dev->dev_addr,