xt_NOTRACK.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);