[NETFILTER]: x_tables: return new table from {arp,ip,ip6}t_register_table()

Typical table module registers xt_table structure (i.e. packet_filter)
and link it to list during it. We can't use one template for it because
corresponding list_head will become corrupted. We also can't unregister
with template because it wasn't changed at all and thus doesn't know in
which list it is.

So, we duplicate template at the very first step of table registration.
Table modules will save it for use during unregistration time and actual
filtering.

Do it at once to not screw bisection.

P.S.: renaming i.e. packet_filter => __packet_filter is temporary until
      full netnsization of table modules is done.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 8 deletions

diff --git a/net/ipv4/netfilter/iptable_filter.c b/net/ipv4/netfilter/iptable_filter.c
index 29bb4f9fbda..3b43ca07a26 100644
--- a/net/ipv4/netfilter/iptable_filter.c
+++ b/net/ipv4/netfilter/iptable_filter.c
@@ -53,13 +53,14 @@ static struct
 	.term = IPT_ERROR_INIT,			/* ERROR */
 };
 
-static struct xt_table packet_filter = {
+static struct xt_table __packet_filter = {
 	.name		= "filter",
 	.valid_hooks	= FILTER_VALID_HOOKS,
 	.lock		= RW_LOCK_UNLOCKED,
 	.me		= THIS_MODULE,
 	.af		= AF_INET,
 };
+static struct xt_table *packet_filter;
 
 /* The work comes in here from netfilter.c. */
 static unsigned int
@@ -69,7 +70,7 @@ ipt_hook(unsigned int hook,
 	 const struct net_device *out,
 	 int (*okfn)(struct sk_buff *))
 {
-	return ipt_do_table(skb, hook, in, out, &packet_filter);
+	return ipt_do_table(skb, hook, in, out, packet_filter);
 }
 
 static unsigned int
@@ -88,7 +89,7 @@ ipt_local_out_hook(unsigned int hook,
 		return NF_ACCEPT;
 	}
 
-	return ipt_do_table(skb, hook, in, out, &packet_filter);
+	return ipt_do_table(skb, hook, in, out, packet_filter);
 }
 
 static struct nf_hook_ops ipt_ops[] __read_mostly = {
@@ -132,9 +133,10 @@ static int __init iptable_filter_init(void)
 	initial_table.entries[1].target.verdict = -forward - 1;
 
 	/* Register table */
-	ret = ipt_register_table(&packet_filter, &initial_table.repl);
-	if (ret < 0)
-		return ret;
+	packet_filter = ipt_register_table(&init_net, &__packet_filter,
+					   &initial_table.repl);
+	if (IS_ERR(packet_filter))
+		return PTR_ERR(packet_filter);
 
 	/* Register hooks */
 	ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
@@ -144,14 +146,14 @@ static int __init iptable_filter_init(void)
 	return ret;
 
  cleanup_table:
-	ipt_unregister_table(&packet_filter);
+	ipt_unregister_table(packet_filter);
 	return ret;
 }
 
 static void __exit iptable_filter_fini(void)
 {
 	nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
-	ipt_unregister_table(&packet_filter);
+	ipt_unregister_table(packet_filter);
 }
 
 module_init(iptable_filter_init);