netfilter: xtables: generate initial table on-demand
The static initial tables are pretty large, and after the net
namespace has been instantiated, they just hang around for nothing.
This commit removes them and creates tables on-demand at runtime when
needed.
Size shrinks by 7735 bytes (x86_64).
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/net/ipv6/netfilter/ip6table_filter.c b/net/ipv6/netfilter/ip6table_filter.c
index 6e95d06..36b72ca 100644
--- a/net/ipv6/netfilter/ip6table_filter.c
+++ b/net/ipv6/netfilter/ip6table_filter.c
@@ -21,36 +21,6 @@
(1 << NF_INET_FORWARD) | \
(1 << NF_INET_LOCAL_OUT))
-static struct
-{
- struct ip6t_replace repl;
- struct ip6t_standard entries[3];
- struct ip6t_error term;
-} initial_table __net_initdata = {
- .repl = {
- .name = "filter",
- .valid_hooks = FILTER_VALID_HOOKS,
- .num_entries = 4,
- .size = sizeof(struct ip6t_standard) * 3 + sizeof(struct ip6t_error),
- .hook_entry = {
- [NF_INET_LOCAL_IN] = 0,
- [NF_INET_FORWARD] = sizeof(struct ip6t_standard),
- [NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
- },
- .underflow = {
- [NF_INET_LOCAL_IN] = 0,
- [NF_INET_FORWARD] = sizeof(struct ip6t_standard),
- [NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
- },
- },
- .entries = {
- IP6T_STANDARD_INIT(NF_ACCEPT), /* LOCAL_IN */
- IP6T_STANDARD_INIT(NF_ACCEPT), /* FORWARD */
- IP6T_STANDARD_INIT(NF_ACCEPT), /* LOCAL_OUT */
- },
- .term = IP6T_ERROR_INIT, /* ERROR */
-};
-
static const struct xt_table packet_filter = {
.name = "filter",
.valid_hooks = FILTER_VALID_HOOKS,
@@ -78,9 +48,18 @@
static int __net_init ip6table_filter_net_init(struct net *net)
{
- /* Register table */
+ struct ip6t_replace *repl;
+
+ repl = ip6t_alloc_initial_table(&packet_filter);
+ if (repl == NULL)
+ return -ENOMEM;
+ /* Entry 1 is the FORWARD hook */
+ ((struct ip6t_standard *)repl->entries)[1].target.verdict =
+ -forward - 1;
+
net->ipv6.ip6table_filter =
- ip6t_register_table(net, &packet_filter, &initial_table.repl);
+ ip6t_register_table(net, &packet_filter, repl);
+ kfree(repl);
if (IS_ERR(net->ipv6.ip6table_filter))
return PTR_ERR(net->ipv6.ip6table_filter);
return 0;
@@ -105,9 +84,6 @@
return -EINVAL;
}
- /* Entry 1 is the FORWARD hook */
- initial_table.entries[1].target.verdict = -forward - 1;
-
ret = register_pernet_subsys(&ip6table_filter_net_ops);
if (ret < 0)
return ret;