From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Tue, 19 Dec 2017 13:53:45 +0100
Subject: [PATCH] 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>
---

--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -969,7 +969,6 @@ 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
@@ -977,7 +976,6 @@ 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;
--- a/net/bridge/netfilter/nf_tables_bridge.c
+++ b/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,
 };
 
--- a/net/ipv4/netfilter/nf_tables_arp.c
+++ b/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,
 };
 
--- a/net/ipv4/netfilter/nf_tables_ipv4.c
+++ b/net/ipv4/netfilter/nf_tables_ipv4.c
@@ -32,7 +32,6 @@ static unsigned int nft_do_chain_ipv4(vo
 
 static struct nft_af_info nft_af_ipv4 __read_mostly = {
 	.family		= NFPROTO_IPV4,
-	.nhooks		= NF_INET_NUMHOOKS,
 	.owner		= THIS_MODULE,
 };
 
--- a/net/ipv6/netfilter/nf_tables_ipv6.c
+++ b/net/ipv6/netfilter/nf_tables_ipv6.c
@@ -30,7 +30,6 @@ static unsigned int nft_do_chain_ipv6(vo
 
 static struct nft_af_info nft_af_ipv6 __read_mostly = {
 	.family		= NFPROTO_IPV6,
-	.nhooks		= NF_INET_NUMHOOKS,
 	.owner		= THIS_MODULE,
 };
 
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1374,9 +1374,6 @@ static int nft_chain_parse_hook(struct n
 		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];
@@ -5008,7 +5005,7 @@ static int nf_tables_flowtable_parse_hoo
 		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]));
--- a/net/netfilter/nf_tables_inet.c
+++ b/net/netfilter/nf_tables_inet.c
@@ -40,7 +40,6 @@ static unsigned int nft_do_chain_inet(vo
 
 static struct nft_af_info nft_af_inet __read_mostly = {
 	.family		= NFPROTO_INET,
-	.nhooks		= NF_INET_NUMHOOKS,
 	.owner		= THIS_MODULE,
 };
 
--- a/net/netfilter/nf_tables_netdev.c
+++ b/net/netfilter/nf_tables_netdev.c
@@ -40,7 +40,6 @@ nft_do_chain_netdev(void *priv, struct s
 
 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,
 };