netfilter: nf_tables: convert hash and rbtree to set extensions

The set implementations' private struct will only contain the elements
needed to maintain the search structure, all other elements are moved
to the set extensions.

Element allocation and initialization is performed centrally by
nf_tables_api instead of by the different set implementations'
->insert() functions. A new "elemsize" member in the set ops specifies
the amount of memory to reserve for internal usage. Destruction
will also be moved out of the set implementations by a following patch.

Except for element allocation, the patch is a simple conversion to
using data from the extension area.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 13 insertions, 43 deletions

diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
index dc96a7e94f80..15951a823d1d 100644
--- a/net/netfilter/nft_hash.c
+++ b/net/netfilter/nft_hash.c
@@ -29,8 +29,7 @@ struct nft_hash {
 
 struct nft_hash_elem {
 	struct rhash_head		node;
-	struct nft_data			key;
-	struct nft_data			data[];
+	struct nft_set_ext		ext;
 };
 
 struct nft_hash_cmp_arg {
@@ -51,7 +50,7 @@ static inline u32 nft_hash_obj(const void *data, u32 len, u32 seed)
 {
 	const struct nft_hash_elem *he = data;
 
-	return jhash(&he->key, len, seed);
+	return jhash(nft_set_ext_key(&he->ext), len, seed);
 }
 
 static inline int nft_hash_cmp(struct rhashtable_compare_arg *arg,
@@ -60,7 +59,7 @@ static inline int nft_hash_cmp(struct rhashtable_compare_arg *arg,
 	const struct nft_hash_cmp_arg *x = arg->key;
 	const struct nft_hash_elem *he = ptr;
 
-	if (nft_data_cmp(&he->key, x->key, x->set->klen))
+	if (nft_data_cmp(nft_set_ext_key(&he->ext), x->key, x->set->klen))
 		return 1;
 	return 0;
 }
@@ -78,7 +77,7 @@ static bool nft_hash_lookup(const struct nft_set *set,
 
 	he = rhashtable_lookup_fast(&priv->ht, &arg, nft_hash_params);
 	if (he && set->flags & NFT_SET_MAP)
-		nft_data_copy(data, he->data);
+		nft_data_copy(data, nft_set_ext_data(&he->ext));
 
 	return !!he;
 }
@@ -87,43 +86,22 @@ static int nft_hash_insert(const struct nft_set *set,
 			   const struct nft_set_elem *elem)
 {
 	struct nft_hash *priv = nft_set_priv(set);
-	struct nft_hash_elem *he;
+	struct nft_hash_elem *he = elem->priv;
 	struct nft_hash_cmp_arg arg = {
 		.set	 = set,
 		.key	 = &elem->key,
 	};
-	unsigned int size;
-	int err;
-
-	if (elem->flags != 0)
-		return -EINVAL;
-
-	size = sizeof(*he);
-	if (set->flags & NFT_SET_MAP)
-		size += sizeof(he->data[0]);
-
-	he = kzalloc(size, GFP_KERNEL);
-	if (he == NULL)
-		return -ENOMEM;
-
-	nft_data_copy(&he->key, &elem->key);
-	if (set->flags & NFT_SET_MAP)
-		nft_data_copy(he->data, &elem->data);
-
-	err = rhashtable_lookup_insert_key(&priv->ht, &arg, &he->node,
-					   nft_hash_params);
-	if (err)
-		kfree(he);
 
-	return err;
+	return rhashtable_lookup_insert_key(&priv->ht, &arg, &he->node,
+					    nft_hash_params);
 }
 
 static void nft_hash_elem_destroy(const struct nft_set *set,
 				  struct nft_hash_elem *he)
 {
-	nft_data_uninit(&he->key, NFT_DATA_VALUE);
+	nft_data_uninit(nft_set_ext_key(&he->ext), NFT_DATA_VALUE);
 	if (set->flags & NFT_SET_MAP)
-		nft_data_uninit(he->data, set->dtype);
+		nft_data_uninit(nft_set_ext_data(&he->ext), set->dtype);
 	kfree(he);
 }
 
@@ -150,10 +128,7 @@ static int nft_hash_get(const struct nft_set *set, struct nft_set_elem *elem)
 	if (!he)
 		return -ENOENT;
 
-	elem->cookie = he;
-	elem->flags = 0;
-	if (set->flags & NFT_SET_MAP)
-		nft_data_copy(&elem->data, he->data);
+	elem->priv = he;
 
 	return 0;
 }
@@ -162,7 +137,7 @@ static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
 			  struct nft_set_iter *iter)
 {
 	struct nft_hash *priv = nft_set_priv(set);
-	const struct nft_hash_elem *he;
+	struct nft_hash_elem *he;
 	struct rhashtable_iter hti;
 	struct nft_set_elem elem;
 	int err;
@@ -192,10 +167,7 @@ static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,
 		if (iter->count < iter->skip)
 			goto cont;
 
-		memcpy(&elem.key, &he->key, sizeof(elem.key));
-		if (set->flags & NFT_SET_MAP)
-			memcpy(&elem.data, he->data, sizeof(elem.data));
-		elem.flags = 0;
+		elem.priv = he;
 
 		iter->err = iter->fn(ctx, set, iter, &elem);
 		if (iter->err < 0)
@@ -254,9 +226,6 @@ static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
 	unsigned int esize;
 
 	esize = sizeof(struct nft_hash_elem);
-	if (features & NFT_SET_MAP)
-		esize += FIELD_SIZEOF(struct nft_hash_elem, data[0]);
-
 	if (desc->size) {
 		est->size = sizeof(struct nft_hash) +
 			    roundup_pow_of_two(desc->size * 4 / 3) *
@@ -278,6 +247,7 @@ static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
 
 static struct nft_set_ops nft_hash_ops __read_mostly = {
 	.privsize       = nft_hash_privsize,
+	.elemsize	= offsetof(struct nft_hash_elem, ext),
 	.estimate	= nft_hash_estimate,
 	.init		= nft_hash_init,
 	.destroy	= nft_hash_destroy,