netfilter: nf_tables: allow set names up to 32 bytes

Currently, we support set names of up to 16 bytes, get this aligned
with the maximum length we can use in ipset to make it easier when
considering migration to nf_tables.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_tables.h

@@ -303,7 +303,7 @@ void nft_unregister_set(struct nft_set_ops *ops);
 struct nft_set {
 	struct list_head		list;
 	struct list_head		bindings;
-	char				name[IFNAMSIZ];
+	char				name[NFT_SET_MAXNAMELEN];
 	u32				ktype;
 	u32				dtype;
 	u32				size;

include/uapi/linux/netfilter/nf_tables.h

@@ -3,6 +3,7 @@
 
 #define NFT_TABLE_MAXNAMELEN	32
 #define NFT_CHAIN_MAXNAMELEN	32
+#define NFT_SET_MAXNAMELEN	32
 #define NFT_USERDATA_MAXLEN	256
 
 /**

net/netfilter/nf_tables_api.c

@@ -2317,7 +2317,7 @@ nft_select_set_ops(const struct nlattr * const nla[],
 static const struct nla_policy nft_set_policy[NFTA_SET_MAX + 1] = {
 	[NFTA_SET_TABLE]		= { .type = NLA_STRING },
 	[NFTA_SET_NAME]			= { .type = NLA_STRING,
-					    .len = IFNAMSIZ - 1 },
+					    .len = NFT_SET_MAXNAMELEN - 1 },
 	[NFTA_SET_FLAGS]		= { .type = NLA_U32 },
 	[NFTA_SET_KEY_TYPE]		= { .type = NLA_U32 },
 	[NFTA_SET_KEY_LEN]		= { .type = NLA_U32 },
@@ -2401,7 +2401,7 @@ static int nf_tables_set_alloc_name(struct nft_ctx *ctx, struct nft_set *set,
 	unsigned long *inuse;
 	unsigned int n = 0, min = 0;
 
-	p = strnchr(name, IFNAMSIZ, '%');
+	p = strnchr(name, NFT_SET_MAXNAMELEN, '%');
 	if (p != NULL) {
 		if (p[1] != 'd' || strchr(p + 2, '%'))
 			return -EINVAL;
@@ -2696,7 +2696,7 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
 	struct nft_table *table;
 	struct nft_set *set;
 	struct nft_ctx ctx;
-	char name[IFNAMSIZ];
+	char name[NFT_SET_MAXNAMELEN];
 	unsigned int size;
 	bool create;
 	u64 timeout;