netfilter: nft_set: remove one argument from lookup and update functions

Return the extension pointer instead of passing it as a function
argument to be filled in by the callee.

As-is, whenever false is returned, the extension pointer is not used.

For all set types, when true is returned, the extension pointer was set
to the matching element.

Only exception: nft_set_bitmap doesn't support extensions.
Return a pointer to a static const empty element extension container.

return false -> return NULL
return true -> return the elements' extension pointer.

This saves one function argument.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 31 insertions, 26 deletions

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index b092e57d3c75..5b6725475906 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -459,19 +459,17 @@ struct nft_set_ext;
  *	control plane functions.
  */
 struct nft_set_ops {
-	bool				(*lookup)(const struct net *net,
+	const struct nft_set_ext *	(*lookup)(const struct net *net,
 						  const struct nft_set *set,
-						  const u32 *key,
-						  const struct nft_set_ext **ext);
-	bool				(*update)(struct nft_set *set,
+						  const u32 *key);
+	const struct nft_set_ext *	(*update)(struct nft_set *set,
 						  const u32 *key,
 						  struct nft_elem_priv *
 							(*new)(struct nft_set *,
 							       const struct nft_expr *,
 							       struct nft_regs *),
 						  const struct nft_expr *expr,
-						  struct nft_regs *regs,
-						  const struct nft_set_ext **ext);
+						  struct nft_regs *regs);
 	bool				(*delete)(const struct nft_set *set,
 						  const u32 *key);
 
diff --git a/include/net/netfilter/nf_tables_core.h b/include/net/netfilter/nf_tables_core.h
index 03b6165756fc..6a52fb97b844 100644
--- a/include/net/netfilter/nf_tables_core.h
+++ b/include/net/netfilter/nf_tables_core.h
@@ -94,34 +94,41 @@ extern const struct nft_set_type nft_set_pipapo_type;
 extern const struct nft_set_type nft_set_pipapo_avx2_type;
 
 #ifdef CONFIG_MITIGATION_RETPOLINE
-bool nft_rhash_lookup(const struct net *net, const struct nft_set *set,
-		      const u32 *key, const struct nft_set_ext **ext);
-bool nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
-		       const u32 *key, const struct nft_set_ext **ext);
-bool nft_bitmap_lookup(const struct net *net, const struct nft_set *set,
-		       const u32 *key, const struct nft_set_ext **ext);
-bool nft_hash_lookup_fast(const struct net *net,
-			  const struct nft_set *set,
-			  const u32 *key, const struct nft_set_ext **ext);
-bool nft_hash_lookup(const struct net *net, const struct nft_set *set,
-		     const u32 *key, const struct nft_set_ext **ext);
-bool nft_set_do_lookup(const struct net *net, const struct nft_set *set,
-		       const u32 *key, const struct nft_set_ext **ext);
+const struct nft_set_ext *
+nft_rhash_lookup(const struct net *net, const struct nft_set *set,
+		 const u32 *key);
+const struct nft_set_ext *
+nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
+		  const u32 *key);
+const struct nft_set_ext *
+nft_bitmap_lookup(const struct net *net, const struct nft_set *set,
+		  const u32 *key);
+const struct nft_set_ext *
+nft_hash_lookup_fast(const struct net *net, const struct nft_set *set,
+		     const u32 *key);
+const struct nft_set_ext *
+nft_hash_lookup(const struct net *net, const struct nft_set *set,
+		const u32 *key);
+const struct nft_set_ext *
+nft_set_do_lookup(const struct net *net, const struct nft_set *set,
+		  const u32 *key);
 #else
-static inline bool
+static inline const struct nft_set_ext *
 nft_set_do_lookup(const struct net *net, const struct nft_set *set,
-		  const u32 *key, const struct nft_set_ext **ext)
+		  const u32 *key)
 {
-	return set->ops->lookup(net, set, key, ext);
+	return set->ops->lookup(net, set, key);
 }
 #endif
 
 /* called from nft_pipapo_avx2.c */
-bool nft_pipapo_lookup(const struct net *net, const struct nft_set *set,
-		       const u32 *key, const struct nft_set_ext **ext);
+const struct nft_set_ext *
+nft_pipapo_lookup(const struct net *net, const struct nft_set *set,
+		  const u32 *key);
 /* called from nft_set_pipapo.c */
-bool nft_pipapo_avx2_lookup(const struct net *net, const struct nft_set *set,
-			    const u32 *key, const struct nft_set_ext **ext);
+const struct nft_set_ext *
+nft_pipapo_avx2_lookup(const struct net *net, const struct nft_set *set,
+			const u32 *key);
 
 void nft_counter_init_seqcount(void);