mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 16:29:59 +00:00
![Eric Dumazet](/assets/img/avatar_default.png)
NOTRACK makes all cpus share a cache line on nf_conntrack_untracked twice per packet. This is bad for performance. __read_mostly annotation is also a bad choice. This patch introduces IPS_UNTRACKED bit so that we can use later a per_cpu untrack structure more easily. A new helper, nf_ct_untracked_get() returns a pointer to nf_conntrack_untracked. Another one, nf_ct_untracked_status_or() is used by nf_nat_init() to add IPS_NAT_DONE_MASK bits to untracked status. nf_ct_is_untracked() prototype is changed to work on a nf_conn pointer. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
53 lines
1.3 KiB
C
53 lines
1.3 KiB
C
/* This is a module which is used for setting up fake conntracks
|
|
* on packets so that they are not seen by the conntrack/NAT code.
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/skbuff.h>
|
|
|
|
#include <linux/netfilter/x_tables.h>
|
|
#include <net/netfilter/nf_conntrack.h>
|
|
|
|
MODULE_DESCRIPTION("Xtables: Disabling connection tracking for packets");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("ipt_NOTRACK");
|
|
MODULE_ALIAS("ip6t_NOTRACK");
|
|
|
|
static unsigned int
|
|
notrack_tg(struct sk_buff *skb, const struct xt_action_param *par)
|
|
{
|
|
/* Previously seen (loopback)? Ignore. */
|
|
if (skb->nfct != NULL)
|
|
return XT_CONTINUE;
|
|
|
|
/* Attach fake conntrack entry.
|
|
If there is a real ct entry correspondig to this packet,
|
|
it'll hang aroun till timing out. We don't deal with it
|
|
for performance reasons. JK */
|
|
skb->nfct = &nf_ct_untracked_get()->ct_general;
|
|
skb->nfctinfo = IP_CT_NEW;
|
|
nf_conntrack_get(skb->nfct);
|
|
|
|
return XT_CONTINUE;
|
|
}
|
|
|
|
static struct xt_target notrack_tg_reg __read_mostly = {
|
|
.name = "NOTRACK",
|
|
.revision = 0,
|
|
.family = NFPROTO_UNSPEC,
|
|
.target = notrack_tg,
|
|
.table = "raw",
|
|
.me = THIS_MODULE,
|
|
};
|
|
|
|
static int __init notrack_tg_init(void)
|
|
{
|
|
return xt_register_target(¬rack_tg_reg);
|
|
}
|
|
|
|
static void __exit notrack_tg_exit(void)
|
|
{
|
|
xt_unregister_target(¬rack_tg_reg);
|
|
}
|
|
|
|
module_init(notrack_tg_init);
|
|
module_exit(notrack_tg_exit);
|