// SPDX-License-Identifier: GPL-2.0-only
|
/* Kernel module to match connection tracking information. */
|
|
/* (C) 1999-2001 Paul `Rusty' Russell
|
* (C) 2002-2005 Netfilter Core Team <coreteam@netfilter.org>
|
*/
|
|
#include <linux/module.h>
|
#include <linux/skbuff.h>
|
#include <net/netfilter/nf_conntrack.h>
|
#include <linux/netfilter/x_tables.h>
|
#include <linux/netfilter/xt_state.h>
|
|
MODULE_LICENSE("GPL");
|
MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");
|
MODULE_DESCRIPTION("ip[6]_tables connection tracking state match module");
|
MODULE_ALIAS("ipt_state");
|
MODULE_ALIAS("ip6t_state");
|
|
static bool
|
state_mt(const struct sk_buff *skb, struct xt_action_param *par)
|
{
|
const struct xt_state_info *sinfo = par->matchinfo;
|
enum ip_conntrack_info ctinfo;
|
unsigned int statebit;
|
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
|
|
if (ct)
|
statebit = XT_STATE_BIT(ctinfo);
|
else if (ctinfo == IP_CT_UNTRACKED)
|
statebit = XT_STATE_UNTRACKED;
|
else
|
statebit = XT_STATE_INVALID;
|
|
return (sinfo->statemask & statebit);
|
}
|
|
static int state_mt_check(const struct xt_mtchk_param *par)
|
{
|
int ret;
|
|
ret = nf_ct_netns_get(par->net, par->family);
|
if (ret < 0)
|
pr_info_ratelimited("cannot load conntrack support for proto=%u\n",
|
par->family);
|
return ret;
|
}
|
|
static void state_mt_destroy(const struct xt_mtdtor_param *par)
|
{
|
nf_ct_netns_put(par->net, par->family);
|
}
|
|
static struct xt_match state_mt_reg __read_mostly = {
|
.name = "state",
|
.family = NFPROTO_UNSPEC,
|
.checkentry = state_mt_check,
|
.match = state_mt,
|
.destroy = state_mt_destroy,
|
.matchsize = sizeof(struct xt_state_info),
|
.me = THIS_MODULE,
|
};
|
|
static int __init state_mt_init(void)
|
{
|
return xt_register_match(&state_mt_reg);
|
}
|
|
static void __exit state_mt_exit(void)
|
{
|
xt_unregister_match(&state_mt_reg);
|
}
|
|
module_init(state_mt_init);
|
module_exit(state_mt_exit);
|
