root/net/netfilter/xt_NOTRACK.c

DEFINITIONS

1. notrack_tg
2. notrack_tg_init
3. notrack_tg_exit

/* 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_target_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_conntrack_untracked.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(&notrack_tg_reg);
}

static void __exit notrack_tg_exit(void)
{
        xt_unregister_target(&notrack_tg_reg);
}

module_init(notrack_tg_init);
module_exit(notrack_tg_exit);