mac80211: let unused MPP table entries timeout

Remember the last time when a mpp table entry is used for
rx or tx and remove them after MESH_PATH_EXPIRE time.

Acked-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Henning Rogge <henning.rogge@fkie.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mesh_pathtbl.c

@@ -940,6 +940,46 @@ enddel:
 	return err;
 }
 
+/**
+ * mpp_path_del - delete a mesh proxy path from the table
+ *
+ * @addr: addr address (ETH_ALEN length)
+ * @sdata: local subif
+ *
+ * Returns: 0 if successful
+ */
+static int mpp_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr)
+{
+	struct mesh_table *tbl;
+	struct mesh_path *mpath;
+	struct mpath_node *node;
+	struct hlist_head *bucket;
+	int hash_idx;
+	int err = 0;
+
+	read_lock_bh(&pathtbl_resize_lock);
+	tbl = resize_dereference_mpp_paths();
+	hash_idx = mesh_table_hash(addr, sdata, tbl);
+	bucket = &tbl->hash_buckets[hash_idx];
+
+	spin_lock(&tbl->hashwlock[hash_idx]);
+	hlist_for_each_entry(node, bucket, list) {
+		mpath = node->mpath;
+		if (mpath->sdata == sdata &&
+		    ether_addr_equal(addr, mpath->dst)) {
+			__mesh_path_del(tbl, node);
+			goto enddel;
+		}
+	}
+
+	err = -ENXIO;
+enddel:
+	mesh_paths_generation++;
+	spin_unlock(&tbl->hashwlock[hash_idx]);
+	read_unlock_bh(&pathtbl_resize_lock);
+	return err;
+}
+
 /**
  * mesh_path_tx_pending - sends pending frames in a mesh path queue
  *
@@ -1154,6 +1194,17 @@ void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
 		     time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
 			mesh_path_del(mpath->sdata, mpath->dst);
 	}
+
+	tbl = rcu_dereference(mpp_paths);
+	for_each_mesh_entry(tbl, node, i) {
+		if (node->mpath->sdata != sdata)
+			continue;
+		mpath = node->mpath;
+		if ((!(mpath->flags & MESH_PATH_FIXED)) &&
+		    time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
+			mpp_path_del(mpath->sdata, mpath->dst);
+	}
+
 	rcu_read_unlock();
 }
 

net/mac80211/rx.c

@@ -2311,6 +2311,7 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
 			spin_lock_bh(&mppath->state_lock);
 			if (!ether_addr_equal(mppath->mpp, mpp_addr))
 				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
+			mppath->exp_time = jiffies;
 			spin_unlock_bh(&mppath->state_lock);
 		}
 		rcu_read_unlock();

net/mac80211/tx.c

@@ -2173,8 +2173,11 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
 					mpp_lookup = true;
 			}
 
-			if (mpp_lookup)
+			if (mpp_lookup) {
 				mppath = mpp_path_lookup(sdata, skb->data);
+				if (mppath)
+					mppath->exp_time = jiffies;
+			}
 
 			if (mppath && mpath)
 				mesh_path_del(mpath->sdata, mpath->dst);