netfilter: restore NF_INET_NUMHOOKS

This definition is used by the iptables legacy UAPI, restore it.

Fixes: d3519cb8 ("netfilter: nf_tables: add inet ingress support")
Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/netfilter/nf_tables.h

@@ -14,6 +14,8 @@
 #include <net/netlink.h>
 #include <net/flow_offload.h>
 
+#define NFT_MAX_HOOKS	(NF_INET_INGRESS + 1)
+
 struct module;
 
 #define NFT_JUMP_STACK_SIZE	16
@@ -979,7 +981,7 @@ struct nft_chain_type {
 	int				family;
 	struct module			*owner;
 	unsigned int			hook_mask;
-	nf_hookfn			*hooks[NF_MAX_HOOKS];
+	nf_hookfn			*hooks[NFT_MAX_HOOKS];
 	int				(*ops_register)(struct net *net, const struct nf_hook_ops *ops);
 	void				(*ops_unregister)(struct net *net, const struct nf_hook_ops *ops);
 };

include/uapi/linux/netfilter.h

@@ -45,8 +45,8 @@ enum nf_inet_hooks {
 	NF_INET_FORWARD,
 	NF_INET_LOCAL_OUT,
 	NF_INET_POST_ROUTING,
-	NF_INET_INGRESS,
-	NF_INET_NUMHOOKS
+	NF_INET_NUMHOOKS,
+	NF_INET_INGRESS = NF_INET_NUMHOOKS,
 };
 
 enum nf_dev_hooks {

net/netfilter/nf_tables_api.c

@@ -1864,7 +1864,7 @@ static int nft_chain_parse_hook(struct net *net,
 		if (IS_ERR(type))
 			return PTR_ERR(type);
 	}
-	if (hook->num > NF_MAX_HOOKS || !(type->hook_mask & (1 << hook->num)))
+	if (hook->num >= NFT_MAX_HOOKS || !(type->hook_mask & (1 << hook->num)))
 		return -EOPNOTSUPP;
 
 	if (type->type == NFT_CHAIN_T_NAT &&