cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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xt_state.c (1867B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/* Kernel module to match connection tracking information. */
      3
      4/* (C) 1999-2001 Paul `Rusty' Russell
      5 * (C) 2002-2005 Netfilter Core Team <coreteam@netfilter.org>
      6 */
      7
      8#include <linux/module.h>
      9#include <linux/skbuff.h>
     10#include <net/netfilter/nf_conntrack.h>
     11#include <linux/netfilter/x_tables.h>
     12#include <linux/netfilter/xt_state.h>
     13
     14MODULE_LICENSE("GPL");
     15MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");
     16MODULE_DESCRIPTION("ip[6]_tables connection tracking state match module");
     17MODULE_ALIAS("ipt_state");
     18MODULE_ALIAS("ip6t_state");
     19
     20static bool
     21state_mt(const struct sk_buff *skb, struct xt_action_param *par)
     22{
     23	const struct xt_state_info *sinfo = par->matchinfo;
     24	enum ip_conntrack_info ctinfo;
     25	unsigned int statebit;
     26	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
     27
     28	if (ct)
     29		statebit = XT_STATE_BIT(ctinfo);
     30	else if (ctinfo == IP_CT_UNTRACKED)
     31		statebit = XT_STATE_UNTRACKED;
     32	else
     33		statebit = XT_STATE_INVALID;
     34
     35	return (sinfo->statemask & statebit);
     36}
     37
     38static int state_mt_check(const struct xt_mtchk_param *par)
     39{
     40	int ret;
     41
     42	ret = nf_ct_netns_get(par->net, par->family);
     43	if (ret < 0)
     44		pr_info_ratelimited("cannot load conntrack support for proto=%u\n",
     45				    par->family);
     46	return ret;
     47}
     48
     49static void state_mt_destroy(const struct xt_mtdtor_param *par)
     50{
     51	nf_ct_netns_put(par->net, par->family);
     52}
     53
     54static struct xt_match state_mt_reg __read_mostly = {
     55	.name       = "state",
     56	.family     = NFPROTO_UNSPEC,
     57	.checkentry = state_mt_check,
     58	.match      = state_mt,
     59	.destroy    = state_mt_destroy,
     60	.matchsize  = sizeof(struct xt_state_info),
     61	.me         = THIS_MODULE,
     62};
     63
     64static int __init state_mt_init(void)
     65{
     66	return xt_register_match(&state_mt_reg);
     67}
     68
     69static void __exit state_mt_exit(void)
     70{
     71	xt_unregister_match(&state_mt_reg);
     72}
     73
     74module_init(state_mt_init);
     75module_exit(state_mt_exit);