[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, 8 insertions, 7 deletions

diff --git a/net/ipv4/netfilter/arptable_filter.c b/net/ipv4/netfilter/arptable_filter.c
index 7201511d54d2d..b00321506a92e 100644
--- a/net/ipv4/netfilter/arptable_filter.c
+++ b/net/ipv4/netfilter/arptable_filter.c
@@ -45,7 +45,7 @@ static struct
 	.term = ARPT_ERROR_INIT,
 };
 
-static struct arpt_table packet_filter = {
+static struct arpt_table __packet_filter = {
 	.name		= "filter",
 	.valid_hooks	= FILTER_VALID_HOOKS,
 	.lock		= RW_LOCK_UNLOCKED,
@@ -53,6 +53,7 @@ static struct arpt_table packet_filter = {
 	.me		= THIS_MODULE,
 	.af		= NF_ARP,
 };
+static struct arpt_table *packet_filter;
 
 /* The work comes in here from netfilter.c */
 static unsigned int arpt_hook(unsigned int hook,
@@ -61,7 +62,7 @@ static unsigned int arpt_hook(unsigned int hook,
 			      const struct net_device *out,
 			      int (*okfn)(struct sk_buff *))
 {
-	return arpt_do_table(skb, hook, in, out, &packet_filter);
+	return arpt_do_table(skb, hook, in, out, packet_filter);
 }
 
 static struct nf_hook_ops arpt_ops[] __read_mostly = {
@@ -90,9 +91,9 @@ static int __init arptable_filter_init(void)
 	int ret;
 
 	/* Register table */
-	ret = arpt_register_table(&packet_filter, &initial_table.repl);
-	if (ret < 0)
-		return ret;
+	packet_filter = arpt_register_table(&__packet_filter, &initial_table.repl);
+	if (IS_ERR(packet_filter))
+		return PTR_ERR(packet_filter);
 
 	ret = nf_register_hooks(arpt_ops, ARRAY_SIZE(arpt_ops));
 	if (ret < 0)
@@ -100,14 +101,14 @@ static int __init arptable_filter_init(void)
 	return ret;
 
 cleanup_table:
-	arpt_unregister_table(&packet_filter);
+	arpt_unregister_table(packet_filter);
 	return ret;
 }
 
 static void __exit arptable_filter_fini(void)
 {
 	nf_unregister_hooks(arpt_ops, ARRAY_SIZE(arpt_ops));
-	arpt_unregister_table(&packet_filter);
+	arpt_unregister_table(packet_filter);
 }
 
 module_init(arptable_filter_init);