mac80211: implement cfg80211_ops to query mesh proxy path table

Implement get_mpp and dump_mpp cfg80211_ops to export the content of the
802.11s mesh proxy path table to userspace.

Signed-off-by: Henning Rogge <henning.rogge@fkie.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index fb6a150..3a04f2e 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1516,6 +1516,57 @@
 	return 0;
 }
 
+static void mpp_set_pinfo(struct mesh_path *mpath, u8 *mpp,
+			  struct mpath_info *pinfo)
+{
+	memset(pinfo, 0, sizeof(*pinfo));
+	memcpy(mpp, mpath->mpp, ETH_ALEN);
+
+	pinfo->generation = mpp_paths_generation;
+}
+
+static int ieee80211_get_mpp(struct wiphy *wiphy, struct net_device *dev,
+			     u8 *dst, u8 *mpp, struct mpath_info *pinfo)
+
+{
+	struct ieee80211_sub_if_data *sdata;
+	struct mesh_path *mpath;
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	rcu_read_lock();
+	mpath = mpp_path_lookup(sdata, dst);
+	if (!mpath) {
+		rcu_read_unlock();
+		return -ENOENT;
+	}
+	memcpy(dst, mpath->dst, ETH_ALEN);
+	mpp_set_pinfo(mpath, mpp, pinfo);
+	rcu_read_unlock();
+	return 0;
+}
+
+static int ieee80211_dump_mpp(struct wiphy *wiphy, struct net_device *dev,
+			      int idx, u8 *dst, u8 *mpp,
+			      struct mpath_info *pinfo)
+{
+	struct ieee80211_sub_if_data *sdata;
+	struct mesh_path *mpath;
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	rcu_read_lock();
+	mpath = mpp_path_lookup_by_idx(sdata, idx);
+	if (!mpath) {
+		rcu_read_unlock();
+		return -ENOENT;
+	}
+	memcpy(dst, mpath->dst, ETH_ALEN);
+	mpp_set_pinfo(mpath, mpp, pinfo);
+	rcu_read_unlock();
+	return 0;
+}
+
 static int ieee80211_get_mesh_config(struct wiphy *wiphy,
 				struct net_device *dev,
 				struct mesh_config *conf)
@@ -3547,6 +3598,8 @@
 	.change_mpath = ieee80211_change_mpath,
 	.get_mpath = ieee80211_get_mpath,
 	.dump_mpath = ieee80211_dump_mpath,
+	.get_mpp = ieee80211_get_mpp,
+	.dump_mpp = ieee80211_dump_mpp,
 	.update_mesh_config = ieee80211_update_mesh_config,
 	.get_mesh_config = ieee80211_get_mesh_config,
 	.join_mesh = ieee80211_join_mesh,
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index f39a19f..50c8473 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -270,6 +270,8 @@
 		 const u8 *dst, const u8 *mpp);
 struct mesh_path *
 mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx);
+struct mesh_path *
+mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx);
 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
@@ -317,6 +319,7 @@
 
 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
 extern int mesh_paths_generation;
+extern int mpp_paths_generation;
 
 #ifdef CONFIG_MAC80211_MESH
 static inline
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index a6699dc..b890e22 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -44,6 +44,7 @@
 static struct mesh_table __rcu *mpp_paths; /* Store paths for MPP&MAP */
 
 int mesh_paths_generation;
+int mpp_paths_generation;
 
 /* This lock will have the grow table function as writer and add / delete nodes
  * as readers. RCU provides sufficient protection only when reading the table
@@ -410,6 +411,33 @@
 }
 
 /**
+ * mpp_path_lookup_by_idx - look up a path in the proxy path table by its index
+ * @idx: index
+ * @sdata: local subif, or NULL for all entries
+ *
+ * Returns: pointer to the proxy path structure, or NULL if not found.
+ *
+ * Locking: must be called within a read rcu section.
+ */
+struct mesh_path *
+mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
+{
+	struct mesh_table *tbl = rcu_dereference(mpp_paths);
+	struct mpath_node *node;
+	int i;
+	int j = 0;
+
+	for_each_mesh_entry(tbl, node, i) {
+		if (sdata && node->mpath->sdata != sdata)
+			continue;
+		if (j++ == idx)
+			return node->mpath;
+	}
+
+	return NULL;
+}
+
+/**
  * mesh_path_add_gate - add the given mpath to a mesh gate to our path table
  * @mpath: gate path to add to table
  */
@@ -691,6 +719,9 @@
 
 	spin_unlock(&tbl->hashwlock[hash_idx]);
 	read_unlock_bh(&pathtbl_resize_lock);
+
+	mpp_paths_generation++;
+
 	if (grow) {
 		set_bit(MESH_WORK_GROW_MPP_TABLE,  &ifmsh->wrkq_flags);
 		ieee80211_queue_work(&local->hw, &sdata->work);