netfilter: nf_tables: remove nhooks field from struct nft_af_info

We already validate the hook through bitmask, so this check is
superfluous. When removing this, this patch is also fixing a bug in the
new flowtable codebase, since ctx->afi points to the table family
instead of the netdev family which is where the flowtable is really
hooked in.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_tables.h

@@ -973,7 +973,6 @@ enum nft_af_flags {
  *
  *	@list: used internally
  *	@family: address family
- *	@nhooks: number of hooks in this family
  *	@owner: module owner
  *	@tables: used internally
  *	@flags: family flags
@@ -981,7 +980,6 @@ enum nft_af_flags {
 struct nft_af_info {
 	struct list_head		list;
 	int				family;
-	unsigned int			nhooks;
 	struct module			*owner;
 	struct list_head		tables;
 	u32				flags;

net/bridge/netfilter/nf_tables_bridge.c

@@ -44,7 +44,6 @@ nft_do_chain_bridge(void *priv,
 
 static struct nft_af_info nft_af_bridge __read_mostly = {
 	.family		= NFPROTO_BRIDGE,
-	.nhooks		= NF_BR_NUMHOOKS,
 	.owner		= THIS_MODULE,
 };
 

net/ipv4/netfilter/nf_tables_arp.c

@@ -29,7 +29,6 @@ nft_do_chain_arp(void *priv,
 
 static struct nft_af_info nft_af_arp __read_mostly = {
 	.family		= NFPROTO_ARP,
-	.nhooks		= NF_ARP_NUMHOOKS,
 	.owner		= THIS_MODULE,
 };
 

net/ipv4/netfilter/nf_tables_ipv4.c

@@ -32,7 +32,6 @@ static unsigned int nft_do_chain_ipv4(void *priv,
 
 static struct nft_af_info nft_af_ipv4 __read_mostly = {
 	.family		= NFPROTO_IPV4,
-	.nhooks		= NF_INET_NUMHOOKS,
 	.owner		= THIS_MODULE,
 };
 

net/ipv6/netfilter/nf_tables_ipv6.c

@@ -30,7 +30,6 @@ static unsigned int nft_do_chain_ipv6(void *priv,
 
 static struct nft_af_info nft_af_ipv6 __read_mostly = {
 	.family		= NFPROTO_IPV6,
-	.nhooks		= NF_INET_NUMHOOKS,
 	.owner		= THIS_MODULE,
 };
 

net/netfilter/nf_tables_api.c

@@ -1328,9 +1328,6 @@ static int nft_chain_parse_hook(struct net *net,
 		return -EINVAL;
 
 	hook->num = ntohl(nla_get_be32(ha[NFTA_HOOK_HOOKNUM]));
-	if (hook->num >= afi->nhooks)
-		return -EINVAL;
-
 	hook->priority = ntohl(nla_get_be32(ha[NFTA_HOOK_PRIORITY]));
 
 	type = chain_type[afi->family][NFT_CHAIN_T_DEFAULT];
@@ -4993,7 +4990,7 @@ static int nf_tables_flowtable_parse_hook(const struct nft_ctx *ctx,
 		return -EINVAL;
 
 	hooknum = ntohl(nla_get_be32(tb[NFTA_FLOWTABLE_HOOK_NUM]));
-	if (hooknum >= ctx->afi->nhooks)
+	if (hooknum != NF_NETDEV_INGRESS)
 		return -EINVAL;
 
 	priority = ntohl(nla_get_be32(tb[NFTA_FLOWTABLE_HOOK_PRIORITY]));

net/netfilter/nf_tables_inet.c

@@ -40,7 +40,6 @@ static unsigned int nft_do_chain_inet(void *priv, struct sk_buff *skb,
 
 static struct nft_af_info nft_af_inet __read_mostly = {
 	.family		= NFPROTO_INET,
-	.nhooks		= NF_INET_NUMHOOKS,
 	.owner		= THIS_MODULE,
 };
 

net/netfilter/nf_tables_netdev.c

@@ -40,7 +40,6 @@ nft_do_chain_netdev(void *priv, struct sk_buff *skb,
 
 static struct nft_af_info nft_af_netdev __read_mostly = {
 	.family		= NFPROTO_NETDEV,
-	.nhooks		= NF_NETDEV_NUMHOOKS,
 	.owner		= THIS_MODULE,
 	.flags		= NFT_AF_NEEDS_DEV,
 };