mac80211: don't initiate path discovery when forwarding frame with unknown DA

We used to initiate a path discovery when receiving a frame for which
there is no forwarding information. To cut down on PREQ spam, just send
a (gated) PERR in response.

Also separate path discovery logic from nexthop querying. This patch
means we no longer queue frames when forwarding, so kill the PERR TX
stuff in discard_frame().

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 92fa95741761..f842f901d179 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1899,6 +1899,7 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
         struct ieee80211_local *local = rx->local;
         struct ieee80211_sub_if_data *sdata = rx->sdata;
         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+        __le16 reason = cpu_to_le16(WLAN_REASON_MESH_PATH_NOFORWARD);
         u16 q;
 
         hdr = (struct ieee80211_hdr *) skb->data;
@@ -1985,13 +1986,14 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
                                                                 fwded_mcast);
                                 memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
                         } else {
-                                int err;
-                                err = mesh_nexthop_lookup(fwd_skb, sdata);
-                                /* Failed to immediately resolve next hop:
-                                 * fwded frame was dropped or will be added
-                                 * later to the pending skb queue.  */
-                                if (err)
+                                if (mesh_nexthop_lookup(fwd_skb, sdata)) {
+                                /* can't resolve next hop, send a PERR */
+                                        mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl,
+                                                           fwd_hdr->addr3, 0, reason,
+                                                           fwd_hdr->addr2, sdata);
+                                        sdata->u.mesh.mshstats.dropped_frames_no_route++;
                                         return RX_DROP_MONITOR;
+                                }
 
                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
                                                                 fwded_unicast);