mac80211: mesh portal functionality support

Currently the mesh code doesn't support bridging mesh point interfaces
with wired ethernet or AP to construct an MPP or MAP. This patch adds
code to support the "6 address frame format packet" functionality to
mesh point interfaces. Now the mesh network can be used as backhaul
for end to end communication.

Signed-off-by: Li YanBo <dreamfly281@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 126 insertions, 1 deletions

diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index e4fa2905fadc..3c72557df45a 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -36,6 +36,7 @@ struct mpath_node {
 };
 
 static struct mesh_table *mesh_paths;
+static struct mesh_table *mpp_paths; /* Store paths for MPP&MAP */
 
 /* This lock will have the grow table function as writer and add / delete nodes
  * as readers. When reading the table (i.e. doing lookups) we are well protected
@@ -94,6 +95,34 @@ struct mesh_path *mesh_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
 	return NULL;
 }
 
+struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
+{
+	struct mesh_path *mpath;
+	struct hlist_node *n;
+	struct hlist_head *bucket;
+	struct mesh_table *tbl;
+	struct mpath_node *node;
+
+	tbl = rcu_dereference(mpp_paths);
+
+	bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
+	hlist_for_each_entry_rcu(node, n, bucket, list) {
+		mpath = node->mpath;
+		if (mpath->sdata == sdata &&
+		    memcmp(dst, mpath->dst, ETH_ALEN) == 0) {
+			if (MPATH_EXPIRED(mpath)) {
+				spin_lock_bh(&mpath->state_lock);
+				if (MPATH_EXPIRED(mpath))
+					mpath->flags &= ~MESH_PATH_ACTIVE;
+				spin_unlock_bh(&mpath->state_lock);
+			}
+			return mpath;
+		}
+	}
+	return NULL;
+}
+
+
 /**
  * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
  * @idx: index
@@ -226,6 +255,91 @@ err_path_alloc:
 }
 
 
+int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata)
+{
+	struct mesh_path *mpath, *new_mpath;
+	struct mpath_node *node, *new_node;
+	struct hlist_head *bucket;
+	struct hlist_node *n;
+	int grow = 0;
+	int err = 0;
+	u32 hash_idx;
+
+
+	if (memcmp(dst, sdata->dev->dev_addr, ETH_ALEN) == 0)
+		/* never add ourselves as neighbours */
+		return -ENOTSUPP;
+
+	if (is_multicast_ether_addr(dst))
+		return -ENOTSUPP;
+
+	err = -ENOMEM;
+	new_mpath = kzalloc(sizeof(struct mesh_path), GFP_KERNEL);
+	if (!new_mpath)
+		goto err_path_alloc;
+
+	new_node = kmalloc(sizeof(struct mpath_node), GFP_KERNEL);
+	if (!new_node)
+		goto err_node_alloc;
+
+	read_lock(&pathtbl_resize_lock);
+	memcpy(new_mpath->dst, dst, ETH_ALEN);
+	memcpy(new_mpath->mpp, mpp, ETH_ALEN);
+	new_mpath->sdata = sdata;
+	new_mpath->flags = 0;
+	skb_queue_head_init(&new_mpath->frame_queue);
+	new_node->mpath = new_mpath;
+	new_mpath->exp_time = jiffies;
+	spin_lock_init(&new_mpath->state_lock);
+
+	hash_idx = mesh_table_hash(dst, sdata, mpp_paths);
+	bucket = &mpp_paths->hash_buckets[hash_idx];
+
+	spin_lock(&mpp_paths->hashwlock[hash_idx]);
+
+	err = -EEXIST;
+	hlist_for_each_entry(node, n, bucket, list) {
+		mpath = node->mpath;
+		if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0)
+			goto err_exists;
+	}
+
+	hlist_add_head_rcu(&new_node->list, bucket);
+	if (atomic_inc_return(&mpp_paths->entries) >=
+		mpp_paths->mean_chain_len * (mpp_paths->hash_mask + 1))
+		grow = 1;
+
+	spin_unlock(&mpp_paths->hashwlock[hash_idx]);
+	read_unlock(&pathtbl_resize_lock);
+	if (grow) {
+		struct mesh_table *oldtbl, *newtbl;
+
+		write_lock(&pathtbl_resize_lock);
+		oldtbl = mpp_paths;
+		newtbl = mesh_table_grow(mpp_paths);
+		if (!newtbl) {
+			write_unlock(&pathtbl_resize_lock);
+			return 0;
+		}
+		rcu_assign_pointer(mpp_paths, newtbl);
+		write_unlock(&pathtbl_resize_lock);
+
+		synchronize_rcu();
+		mesh_table_free(oldtbl, false);
+	}
+	return 0;
+
+err_exists:
+	spin_unlock(&mpp_paths->hashwlock[hash_idx]);
+	read_unlock(&pathtbl_resize_lock);
+	kfree(new_node);
+err_node_alloc:
+	kfree(new_mpath);
+err_path_alloc:
+	return err;
+}
+
+
 /**
  * mesh_plink_broken - deactivates paths and sends perr when a link breaks
  *
@@ -475,11 +589,21 @@ static int mesh_path_node_copy(struct hlist_node *p, struct mesh_table *newtbl)
 int mesh_pathtbl_init(void)
 {
 	mesh_paths = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
+	if (!mesh_paths)
+		return -ENOMEM;
 	mesh_paths->free_node = &mesh_path_node_free;
 	mesh_paths->copy_node = &mesh_path_node_copy;
 	mesh_paths->mean_chain_len = MEAN_CHAIN_LEN;
-	if (!mesh_paths)
+
+	mpp_paths = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
+	if (!mpp_paths) {
+		mesh_table_free(mesh_paths, true);
 		return -ENOMEM;
+	}
+	mpp_paths->free_node = &mesh_path_node_free;
+	mpp_paths->copy_node = &mesh_path_node_copy;
+	mpp_paths->mean_chain_len = MEAN_CHAIN_LEN;
+
 	return 0;
 }
 
@@ -511,4 +635,5 @@ void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
 void mesh_pathtbl_unregister(void)
 {
 	mesh_table_free(mesh_paths, true);
+	mesh_table_free(mpp_paths, true);
 }