netfilter: xtables: use xt_table for hook instantiation

The respective xt_table structures already have most of the metadata
needed for hook setup. Add a 'priority' field to struct xt_table so
that xt_hook_link() can be called with a reduced number of arguments.

So should we be having more tables in the future, it comes at no
static cost (only runtime, as before) - space saved:
6807373->6806555.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

1 files changed, 7 insertions, 26 deletions

diff --git a/net/ipv4/netfilter/iptable_filter.c b/net/ipv4/netfilter/iptable_filter.c
index 1bfeaae6f62..c14bb85db1d 100644
--- a/net/ipv4/netfilter/iptable_filter.c
+++ b/net/ipv4/netfilter/iptable_filter.c
@@ -58,6 +58,7 @@ static const struct xt_table packet_filter = {
 	.valid_hooks	= FILTER_VALID_HOOKS,
 	.me		= THIS_MODULE,
 	.af		= NFPROTO_IPV4,
+	.priority	= NF_IP_PRI_FILTER,
 };
 
 static unsigned int
@@ -77,29 +78,7 @@ iptable_filter_hook(unsigned int hook, struct sk_buff *skb,
 	return ipt_do_table(skb, hook, in, out, net->ipv4.iptable_filter);
 }
 
-static struct nf_hook_ops ipt_ops[] __read_mostly = {
-	{
-		.hook		= iptable_filter_hook,
-		.owner		= THIS_MODULE,
-		.pf		= NFPROTO_IPV4,
-		.hooknum	= NF_INET_LOCAL_IN,
-		.priority	= NF_IP_PRI_FILTER,
-	},
-	{
-		.hook		= iptable_filter_hook,
-		.owner		= THIS_MODULE,
-		.pf		= NFPROTO_IPV4,
-		.hooknum	= NF_INET_FORWARD,
-		.priority	= NF_IP_PRI_FILTER,
-	},
-	{
-		.hook		= iptable_filter_hook,
-		.owner		= THIS_MODULE,
-		.pf		= NFPROTO_IPV4,
-		.hooknum	= NF_INET_LOCAL_OUT,
-		.priority	= NF_IP_PRI_FILTER,
-	},
-};
+static struct nf_hook_ops *filter_ops __read_mostly;
 
 /* Default to forward because I got too much mail already. */
 static int forward = NF_ACCEPT;
@@ -142,9 +121,11 @@ static int __init iptable_filter_init(void)
 		return ret;
 
 	/* Register hooks */
-	ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
-	if (ret < 0)
+	filter_ops = xt_hook_link(&packet_filter, iptable_filter_hook);
+	if (IS_ERR(filter_ops)) {
+		ret = PTR_ERR(filter_ops);
 		goto cleanup_table;
+	}
 
 	return ret;
 
@@ -155,7 +136,7 @@ static int __init iptable_filter_init(void)
 
 static void __exit iptable_filter_fini(void)
 {
-	nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
+	xt_hook_unlink(&packet_filter, filter_ops);
 	unregister_pernet_subsys(&iptable_filter_net_ops);
 }