[13/29] netfilter: nf_tables: select set backend flavour depending on description

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 8a8bab8d7b15..f27012098846 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -281,6 +281,23 @@  struct nft_set_estimate {
 	enum nft_set_class	space;
 };
 
+/**
+ *      struct nft_set_type - nf_tables set type
+ *
+ *      @select_ops: function to select nft_set_ops
+ *      @ops: default ops, used when no select_ops functions is present
+ *      @list: used internally
+ *      @owner: module reference
+ */
+struct nft_set_type {
+	const struct nft_set_ops	*(*select_ops)(const struct nft_ctx *,
+						       const struct nft_set_desc *desc,
+						       u32 flags);
+	const struct nft_set_ops	*ops;
+	struct list_head		list;
+	struct module			*owner;
+};
+
 struct nft_set_ext;
 struct nft_expr;
 
@@ -297,8 +314,6 @@  struct nft_expr;
  *	@privsize: function to return size of set private data
  *	@init: initialize private data of new set instance
  *	@destroy: destroy private data of set instance
- *	@list: nf_tables_set_ops list node
- *	@owner: module reference
  *	@elemsize: element private size
  *	@features: features supported by the implementation
  */
@@ -345,14 +360,13 @@  struct nft_set_ops {
 						const struct nlattr * const nla[]);
 	void				(*destroy)(const struct nft_set *set);
 
-	struct list_head		list;
-	struct module			*owner;
 	unsigned int			elemsize;
 	u32				features;
+	const struct nft_set_type	*type;
 };
 
-int nft_register_set(struct nft_set_ops *ops);
-void nft_unregister_set(struct nft_set_ops *ops);
+int nft_register_set(struct nft_set_type *type);
+void nft_unregister_set(struct nft_set_type *type);
 
 /**
  * 	struct nft_set - nf_tables set instance
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index da314be0c048..c0b2b19607e1 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2377,64 +2377,77 @@  static int nf_tables_delrule(struct net *net, struct sock *nlsk,
  * Sets
  */
 
-static LIST_HEAD(nf_tables_set_ops);
+static LIST_HEAD(nf_tables_set_types);
 
-int nft_register_set(struct nft_set_ops *ops)
+int nft_register_set(struct nft_set_type *type)
 {
 	nfnl_lock(NFNL_SUBSYS_NFTABLES);
-	list_add_tail_rcu(&ops->list, &nf_tables_set_ops);
+	list_add_tail_rcu(&type->list, &nf_tables_set_types);
 	nfnl_unlock(NFNL_SUBSYS_NFTABLES);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(nft_register_set);
 
-void nft_unregister_set(struct nft_set_ops *ops)
+void nft_unregister_set(struct nft_set_type *type)
 {
 	nfnl_lock(NFNL_SUBSYS_NFTABLES);
-	list_del_rcu(&ops->list);
+	list_del_rcu(&type->list);
 	nfnl_unlock(NFNL_SUBSYS_NFTABLES);
 }
 EXPORT_SYMBOL_GPL(nft_unregister_set);
 
+#define NFT_SET_FEATURES	(NFT_SET_INTERVAL | NFT_SET_MAP | \
+				 NFT_SET_TIMEOUT | NFT_SET_OBJECT)
+
+static bool nft_set_ops_candidate(const struct nft_set_ops *ops, u32 flags)
+{
+	return (flags & ops->features) == (flags & NFT_SET_FEATURES);
+}
+
 /*
  * Select a set implementation based on the data characteristics and the
  * given policy. The total memory use might not be known if no size is
  * given, in that case the amount of memory per element is used.
  */
 static const struct nft_set_ops *
-nft_select_set_ops(const struct nlattr * const nla[],
+nft_select_set_ops(const struct nft_ctx *ctx,
+		   const struct nlattr * const nla[],
 		   const struct nft_set_desc *desc,
 		   enum nft_set_policies policy)
 {
 	const struct nft_set_ops *ops, *bops;
 	struct nft_set_estimate est, best;
-	u32 features;
+	const struct nft_set_type *type;
+	u32 flags = 0;
 
 #ifdef CONFIG_MODULES
-	if (list_empty(&nf_tables_set_ops)) {
+	if (list_empty(&nf_tables_set_types)) {
 		nfnl_unlock(NFNL_SUBSYS_NFTABLES);
 		request_module("nft-set");
 		nfnl_lock(NFNL_SUBSYS_NFTABLES);
-		if (!list_empty(&nf_tables_set_ops))
+		if (!list_empty(&nf_tables_set_types))
 			return ERR_PTR(-EAGAIN);
 	}
 #endif
-	features = 0;
-	if (nla[NFTA_SET_FLAGS] != NULL) {
-		features = ntohl(nla_get_be32(nla[NFTA_SET_FLAGS]));
-		features &= NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_TIMEOUT |
-			    NFT_SET_OBJECT;
-	}
+	if (nla[NFTA_SET_FLAGS] != NULL)
+		flags = ntohl(nla_get_be32(nla[NFTA_SET_FLAGS]));
 
 	bops	    = NULL;
 	best.size   = ~0;
 	best.lookup = ~0;
 	best.space  = ~0;
 
-	list_for_each_entry(ops, &nf_tables_set_ops, list) {
-		if ((ops->features & features) != features)
+	list_for_each_entry(type, &nf_tables_set_types, list) {
+		if (!type->select_ops)
+			ops = type->ops;
+		else
+			ops = type->select_ops(ctx, desc, flags);
+		if (!ops)
+			continue;
+
+		if (!nft_set_ops_candidate(ops, flags))
 			continue;
-		if (!ops->estimate(desc, features, &est))
+		if (!ops->estimate(desc, flags, &est))
 			continue;
 
 		switch (policy) {
@@ -2465,10 +2478,10 @@  nft_select_set_ops(const struct nlattr * const nla[],
 			break;
 		}
 
-		if (!try_module_get(ops->owner))
+		if (!try_module_get(type->owner))
 			continue;
 		if (bops != NULL)
-			module_put(bops->owner);
+			module_put(bops->type->owner);
 
 		bops = ops;
 		best = est;
@@ -3029,7 +3042,7 @@  static int nf_tables_newset(struct net *net, struct sock *nlsk,
 	if (!(nlh->nlmsg_flags & NLM_F_CREATE))
 		return -ENOENT;
 
-	ops = nft_select_set_ops(nla, &desc, policy);
+	ops = nft_select_set_ops(&ctx, nla, &desc, policy);
 	if (IS_ERR(ops))
 		return PTR_ERR(ops);
 
@@ -3089,14 +3102,14 @@  static int nf_tables_newset(struct net *net, struct sock *nlsk,
 err2:
 	kfree(set);
 err1:
-	module_put(ops->owner);
+	module_put(ops->type->owner);
 	return err;
 }
 
 static void nft_set_destroy(struct nft_set *set)
 {
 	set->ops->destroy(set);
-	module_put(set->ops->owner);
+	module_put(set->ops->type->owner);
 	kfree(set);
 }
 
diff --git a/net/netfilter/nft_set_bitmap.c b/net/netfilter/nft_set_bitmap.c
index b988162b5b15..87d17691278f 100644
--- a/net/netfilter/nft_set_bitmap.c
+++ b/net/netfilter/nft_set_bitmap.c
@@ -278,7 +278,9 @@  static bool nft_bitmap_estimate(const struct nft_set_desc *desc, u32 features,
 	return true;
 }
 
+static struct nft_set_type nft_bitmap_type;
 static struct nft_set_ops nft_bitmap_ops __read_mostly = {
+	.type		= &nft_bitmap_type,
 	.privsize	= nft_bitmap_privsize,
 	.elemsize	= offsetof(struct nft_bitmap_elem, ext),
 	.estimate	= nft_bitmap_estimate,
@@ -291,17 +293,21 @@  static struct nft_set_ops nft_bitmap_ops __read_mostly = {
 	.activate	= nft_bitmap_activate,
 	.lookup		= nft_bitmap_lookup,
 	.walk		= nft_bitmap_walk,
+};
+
+static struct nft_set_type nft_bitmap_type __read_mostly = {
+	.ops		= &nft_bitmap_ops,
 	.owner		= THIS_MODULE,
 };
 
 static int __init nft_bitmap_module_init(void)
 {
-	return nft_register_set(&nft_bitmap_ops);
+	return nft_register_set(&nft_bitmap_type);
 }
 
 static void __exit nft_bitmap_module_exit(void)
 {
-	nft_unregister_set(&nft_bitmap_ops);
+	nft_unregister_set(&nft_bitmap_type);
 }
 
 module_init(nft_bitmap_module_init);
diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index 7c21e3da0d88..4ba0717408d9 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -379,7 +379,9 @@  static bool nft_rhash_estimate(const struct nft_set_desc *desc, u32 features,
 	return true;
 }
 
+static struct nft_set_type nft_hash_type;
 static struct nft_set_ops nft_rhash_ops __read_mostly = {
+	.type		= &nft_hash_type,
 	.privsize       = nft_rhash_privsize,
 	.elemsize	= offsetof(struct nft_rhash_elem, ext),
 	.estimate	= nft_rhash_estimate,
@@ -394,17 +396,21 @@  static struct nft_set_ops nft_rhash_ops __read_mostly = {
 	.update		= nft_rhash_update,
 	.walk		= nft_rhash_walk,
 	.features	= NFT_SET_MAP | NFT_SET_OBJECT | NFT_SET_TIMEOUT,
+};
+
+static struct nft_set_type nft_hash_type __read_mostly = {
+	.ops		= &nft_rhash_ops,
 	.owner		= THIS_MODULE,
 };
 
 static int __init nft_hash_module_init(void)
 {
-	return nft_register_set(&nft_rhash_ops);
+	return nft_register_set(&nft_hash_type);
 }
 
 static void __exit nft_hash_module_exit(void)
 {
-	nft_unregister_set(&nft_rhash_ops);
+	nft_unregister_set(&nft_hash_type);
 }
 
 module_init(nft_hash_module_init);
diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index fbfb3cbb3916..29d41d378339 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -295,7 +295,9 @@  static bool nft_rbtree_estimate(const struct nft_set_desc *desc, u32 features,
 	return true;
 }
 
+static struct nft_set_type nft_rbtree_type;
 static struct nft_set_ops nft_rbtree_ops __read_mostly = {
+	.type		= &nft_rbtree_type,
 	.privsize	= nft_rbtree_privsize,
 	.elemsize	= offsetof(struct nft_rbtree_elem, ext),
 	.estimate	= nft_rbtree_estimate,
@@ -309,17 +311,21 @@  static struct nft_set_ops nft_rbtree_ops __read_mostly = {
 	.lookup		= nft_rbtree_lookup,
 	.walk		= nft_rbtree_walk,
 	.features	= NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT,
+};
+
+static struct nft_set_type nft_rbtree_type __read_mostly = {
+	.ops		= &nft_rbtree_ops,
 	.owner		= THIS_MODULE,
 };
 
 static int __init nft_rbtree_module_init(void)
 {
-	return nft_register_set(&nft_rbtree_ops);
+	return nft_register_set(&nft_rbtree_type);
 }
 
 static void __exit nft_rbtree_module_exit(void)
 {
-	nft_unregister_set(&nft_rbtree_ops);
+	nft_unregister_set(&nft_rbtree_type);
 }
 
 module_init(nft_rbtree_module_init);