netfilter: nf_tables: place all set backends in one single module

This patch disallows rbtree with single elements, which is causing
problems with the recent timeout support. Before this patch, you
could opt out individual set representations per module, which is
just adding extra complexity.

Fixes: 8d8540c4f5e0("netfilter: nft_set_rbtree: add timeout support")
Reported-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_tables_core.h

@@ -65,4 +65,10 @@ extern const struct nft_expr_ops nft_payload_fast_ops;
 extern struct static_key_false nft_counters_enabled;
 extern struct static_key_false nft_trace_enabled;
 
+extern struct nft_set_type nft_set_rhash_type;
+extern struct nft_set_type nft_set_hash_type;
+extern struct nft_set_type nft_set_hash_fast_type;
+extern struct nft_set_type nft_set_rbtree_type;
+extern struct nft_set_type nft_set_bitmap_type;
+
 #endif /* _NET_NF_TABLES_CORE_H */

net/netfilter/Kconfig

@@ -460,6 +460,13 @@ config NF_TABLES
 
 if NF_TABLES
 
+config NF_TABLES_SET
+	tristate "Netfilter nf_tables set infrastructure"
+	help
+	  This option enables the nf_tables set infrastructure that allows to
+	  look up for elements in a set and to build one-way mappings between
+	  matchings and actions.
+
 config NF_TABLES_INET
 	depends on IPV6
 	select NF_TABLES_IPV4
@@ -493,24 +500,6 @@ config NFT_FLOW_OFFLOAD
 	  This option adds the "flow_offload" expression that you can use to
 	  choose what flows are placed into the hardware.
 
-config NFT_SET_RBTREE
-	tristate "Netfilter nf_tables rbtree set module"
-	help
-	  This option adds the "rbtree" set type (Red Black tree) that is used
-	  to build interval-based sets.
-
-config NFT_SET_HASH
-	tristate "Netfilter nf_tables hash set module"
-	help
-	  This option adds the "hash" set type that is used to build one-way
-	  mappings between matchings and actions.
-
-config NFT_SET_BITMAP
-	tristate "Netfilter nf_tables bitmap set module"
-	help
-	  This option adds the "bitmap" set type that is used to build sets
-	  whose keys are smaller or equal to 16 bits.
-
 config NFT_COUNTER
 	tristate "Netfilter nf_tables counter module"
 	help

net/netfilter/Makefile

@@ -78,7 +78,11 @@ nf_tables-objs := nf_tables_core.o nf_tables_api.o nft_chain_filter.o \
 		  nft_bitwise.o nft_byteorder.o nft_payload.o nft_lookup.o \
 		  nft_dynset.o nft_meta.o nft_rt.o nft_exthdr.o
 
+nf_tables_set-objs := nf_tables_set_core.o \
+		      nft_set_hash.o nft_set_bitmap.o nft_set_rbtree.o
+
 obj-$(CONFIG_NF_TABLES)		+= nf_tables.o
+obj-$(CONFIG_NF_TABLES_SET)	+= nf_tables_set.o
 obj-$(CONFIG_NFT_COMPAT)	+= nft_compat.o
 obj-$(CONFIG_NFT_CONNLIMIT)	+= nft_connlimit.o
 obj-$(CONFIG_NFT_NUMGEN)	+= nft_numgen.o
@@ -91,9 +95,6 @@ obj-$(CONFIG_NFT_QUEUE)		+= nft_queue.o
 obj-$(CONFIG_NFT_QUOTA)		+= nft_quota.o
 obj-$(CONFIG_NFT_REJECT) 	+= nft_reject.o
 obj-$(CONFIG_NFT_REJECT_INET)	+= nft_reject_inet.o
-obj-$(CONFIG_NFT_SET_RBTREE)	+= nft_set_rbtree.o
-obj-$(CONFIG_NFT_SET_HASH)	+= nft_set_hash.o
-obj-$(CONFIG_NFT_SET_BITMAP)	+= nft_set_bitmap.o
 obj-$(CONFIG_NFT_COUNTER)	+= nft_counter.o
 obj-$(CONFIG_NFT_LOG)		+= nft_log.o
 obj-$(CONFIG_NFT_MASQ)		+= nft_masq.o

net/netfilter/nf_tables_set_core.c

@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <net/netfilter/nf_tables_core.h>
+
+static int __init nf_tables_set_module_init(void)
+{
+	nft_register_set(&nft_set_hash_fast_type);
+	nft_register_set(&nft_set_hash_type);
+	nft_register_set(&nft_set_rhash_type);
+	nft_register_set(&nft_set_bitmap_type);
+	nft_register_set(&nft_set_rbtree_type);
+
+	return 0;
+}
+
+static void __exit nf_tables_set_module_exit(void)
+{
+	nft_unregister_set(&nft_set_rbtree_type);
+	nft_unregister_set(&nft_set_bitmap_type);
+	nft_unregister_set(&nft_set_rhash_type);
+	nft_unregister_set(&nft_set_hash_type);
+	nft_unregister_set(&nft_set_hash_fast_type);
+}
+
+module_init(nf_tables_set_module_init);
+module_exit(nf_tables_set_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NFT_SET();

net/netfilter/nft_set_bitmap.c

@@ -296,7 +296,7 @@ static bool nft_bitmap_estimate(const struct nft_set_desc *desc, u32 features,
 	return true;
 }
 
-static struct nft_set_type nft_bitmap_type __read_mostly = {
+struct nft_set_type nft_set_bitmap_type __read_mostly = {
 	.owner		= THIS_MODULE,
 	.ops		= {
 		.privsize	= nft_bitmap_privsize,
@@ -314,20 +314,3 @@ static struct nft_set_type nft_bitmap_type __read_mostly = {
 		.get		= nft_bitmap_get,
 	},
 };
-
-static int __init nft_bitmap_module_init(void)
-{
-	return nft_register_set(&nft_bitmap_type);
-}
-
-static void __exit nft_bitmap_module_exit(void)
-{
-	nft_unregister_set(&nft_bitmap_type);
-}
-
-module_init(nft_bitmap_module_init);
-module_exit(nft_bitmap_module_exit);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
-MODULE_ALIAS_NFT_SET();

net/netfilter/nft_set_hash.c

@@ -654,7 +654,7 @@ static bool nft_hash_fast_estimate(const struct nft_set_desc *desc, u32 features
 	return true;
 }
 
-static struct nft_set_type nft_rhash_type __read_mostly = {
+struct nft_set_type nft_set_rhash_type __read_mostly = {
 	.owner		= THIS_MODULE,
 	.features	= NFT_SET_MAP | NFT_SET_OBJECT |
 			  NFT_SET_TIMEOUT | NFT_SET_EVAL,
@@ -677,7 +677,7 @@ static struct nft_set_type nft_rhash_type __read_mostly = {
 	},
 };
 
-static struct nft_set_type nft_hash_type __read_mostly = {
+struct nft_set_type nft_set_hash_type __read_mostly = {
 	.owner		= THIS_MODULE,
 	.features	= NFT_SET_MAP | NFT_SET_OBJECT,
 	.ops		= {
@@ -697,7 +697,7 @@ static struct nft_set_type nft_hash_type __read_mostly = {
 	},
 };
 
-static struct nft_set_type nft_hash_fast_type __read_mostly = {
+struct nft_set_type nft_set_hash_fast_type __read_mostly = {
 	.owner		= THIS_MODULE,
 	.features	= NFT_SET_MAP | NFT_SET_OBJECT,
 	.ops		= {
@@ -716,26 +716,3 @@ static struct nft_set_type nft_hash_fast_type __read_mostly = {
 		.get		= nft_hash_get,
 	},
 };
-
-static int __init nft_hash_module_init(void)
-{
-	if (nft_register_set(&nft_hash_fast_type) ||
-	    nft_register_set(&nft_hash_type) ||
-	    nft_register_set(&nft_rhash_type))
-		return 1;
-	return 0;
-}
-
-static void __exit nft_hash_module_exit(void)
-{
-	nft_unregister_set(&nft_rhash_type);
-	nft_unregister_set(&nft_hash_type);
-	nft_unregister_set(&nft_hash_fast_type);
-}
-
-module_init(nft_hash_module_init);
-module_exit(nft_hash_module_exit);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
-MODULE_ALIAS_NFT_SET();

net/netfilter/nft_set_rbtree.c

@@ -462,7 +462,7 @@ static bool nft_rbtree_estimate(const struct nft_set_desc *desc, u32 features,
 	return true;
 }
 
-static struct nft_set_type nft_rbtree_type __read_mostly = {
+struct nft_set_type nft_set_rbtree_type __read_mostly = {
 	.owner		= THIS_MODULE,
 	.features	= NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT | NFT_SET_TIMEOUT,
 	.ops		= {
@@ -481,20 +481,3 @@ static struct nft_set_type nft_rbtree_type __read_mostly = {
 		.get		= nft_rbtree_get,
 	},
 };
-
-static int __init nft_rbtree_module_init(void)
-{
-	return nft_register_set(&nft_rbtree_type);
-}
-
-static void __exit nft_rbtree_module_exit(void)
-{
-	nft_unregister_set(&nft_rbtree_type);
-}
-
-module_init(nft_rbtree_module_init);
-module_exit(nft_rbtree_module_exit);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
-MODULE_ALIAS_NFT_SET();