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, 20 deletions

diff --git a/net/ipv4/netfilter/iptable_raw.c b/net/ipv4/netfilter/iptable_raw.c
index d16e43777c3..62a99154f14 100644
--- a/net/ipv4/netfilter/iptable_raw.c
+++ b/net/ipv4/netfilter/iptable_raw.c
@@ -41,6 +41,7 @@ static const struct xt_table packet_raw = {
         .valid_hooks =  RAW_VALID_HOOKS,
         .me = THIS_MODULE,
         .af = NFPROTO_IPV4,
+        .priority = NF_IP_PRI_RAW,
 };
 
 /* The work comes in here from netfilter.c. */
@@ -61,23 +62,7 @@ iptable_raw_hook(unsigned int hook, struct sk_buff *skb,
         return ipt_do_table(skb, hook, in, out, net->ipv4.iptable_raw);
 }
 
-/* 'raw' is the very first table. */
-static struct nf_hook_ops ipt_ops[] __read_mostly = {
-        {
-                .hook = iptable_raw_hook,
-                .pf = NFPROTO_IPV4,
-                .hooknum = NF_INET_PRE_ROUTING,
-                .priority = NF_IP_PRI_RAW,
-                .owner = THIS_MODULE,
-        },
-        {
-                .hook = iptable_raw_hook,
-                .pf = NFPROTO_IPV4,
-                .hooknum = NF_INET_LOCAL_OUT,
-                .priority = NF_IP_PRI_RAW,
-                .owner = THIS_MODULE,
-        },
-};
+static struct nf_hook_ops *rawtable_ops __read_mostly;
 
 static int __net_init iptable_raw_net_init(struct net *net)
 {
@@ -108,9 +93,11 @@ static int __init iptable_raw_init(void)
                 return ret;
 
         /* Register hooks */
-        ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
-        if (ret < 0)
+        rawtable_ops = xt_hook_link(&packet_raw, iptable_raw_hook);
+        if (IS_ERR(rawtable_ops)) {
+                ret = PTR_ERR(rawtable_ops);
                 goto cleanup_table;
+        }
 
         return ret;
 
@@ -121,7 +108,7 @@ static int __init iptable_raw_init(void)
 
 static void __exit iptable_raw_fini(void)
 {
-        nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
+        xt_hook_unlink(&packet_raw, rawtable_ops);
         unregister_pernet_subsys(&iptable_raw_net_ops);
 }