netfilter: nf_tables: reduce chain type table size

text  data  bss     dec    hex filename
old: 151590  2240 1152  154982  25d66 net/netfilter/nf_tables_api.o
new: 151666  2240  416  154322  25ad2 net/netfilter/nf_tables_api.o
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_tables_api.c

@@ -387,7 +387,7 @@ static inline u64 nf_tables_alloc_handle(struct nft_table *table)
 	return ++table->hgenerator;
 }
 
-static const struct nf_chain_type *chain_type[AF_MAX][NFT_CHAIN_T_MAX];
+static const struct nf_chain_type *chain_type[NFPROTO_NUMPROTO][NFT_CHAIN_T_MAX];
 
 static const struct nf_chain_type *
 __nf_tables_chain_type_lookup(int family, const struct nlattr *nla)
@@ -870,6 +870,9 @@ int nft_register_chain_type(const struct nf_chain_type *ctype)
 {
 	int err = 0;
 
+	if (WARN_ON(ctype->family >= NFPROTO_NUMPROTO))
+		return -EINVAL;
+
 	nfnl_lock(NFNL_SUBSYS_NFTABLES);
 	if (chain_type[ctype->family][ctype->type] != NULL) {
 		err = -EBUSY;