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_MASQUERADE.c (3314B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/* Masquerade.  Simple mapping which alters range to a local IP address
      3   (depending on route). */
      4
      5/* (C) 1999-2001 Paul `Rusty' Russell
      6 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
      7 */
      8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
      9#include <linux/module.h>
     10#include <linux/netfilter/x_tables.h>
     11#include <net/netfilter/nf_nat.h>
     12#include <net/netfilter/nf_nat_masquerade.h>
     13
     14MODULE_LICENSE("GPL");
     15MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
     16MODULE_DESCRIPTION("Xtables: automatic-address SNAT");
     17
     18/* FIXME: Multiple targets. --RR */
     19static int masquerade_tg_check(const struct xt_tgchk_param *par)
     20{
     21	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
     22
     23	if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) {
     24		pr_debug("bad MAP_IPS.\n");
     25		return -EINVAL;
     26	}
     27	if (mr->rangesize != 1) {
     28		pr_debug("bad rangesize %u\n", mr->rangesize);
     29		return -EINVAL;
     30	}
     31	return nf_ct_netns_get(par->net, par->family);
     32}
     33
     34static unsigned int
     35masquerade_tg(struct sk_buff *skb, const struct xt_action_param *par)
     36{
     37	struct nf_nat_range2 range;
     38	const struct nf_nat_ipv4_multi_range_compat *mr;
     39
     40	mr = par->targinfo;
     41	range.flags = mr->range[0].flags;
     42	range.min_proto = mr->range[0].min;
     43	range.max_proto = mr->range[0].max;
     44
     45	return nf_nat_masquerade_ipv4(skb, xt_hooknum(par), &range,
     46				      xt_out(par));
     47}
     48
     49static void masquerade_tg_destroy(const struct xt_tgdtor_param *par)
     50{
     51	nf_ct_netns_put(par->net, par->family);
     52}
     53
     54#if IS_ENABLED(CONFIG_IPV6)
     55static unsigned int
     56masquerade_tg6(struct sk_buff *skb, const struct xt_action_param *par)
     57{
     58	return nf_nat_masquerade_ipv6(skb, par->targinfo, xt_out(par));
     59}
     60
     61static int masquerade_tg6_checkentry(const struct xt_tgchk_param *par)
     62{
     63	const struct nf_nat_range2 *range = par->targinfo;
     64
     65	if (range->flags & NF_NAT_RANGE_MAP_IPS)
     66		return -EINVAL;
     67
     68	return nf_ct_netns_get(par->net, par->family);
     69}
     70#endif
     71
     72static struct xt_target masquerade_tg_reg[] __read_mostly = {
     73	{
     74#if IS_ENABLED(CONFIG_IPV6)
     75		.name		= "MASQUERADE",
     76		.family		= NFPROTO_IPV6,
     77		.target		= masquerade_tg6,
     78		.targetsize	= sizeof(struct nf_nat_range),
     79		.table		= "nat",
     80		.hooks		= 1 << NF_INET_POST_ROUTING,
     81		.checkentry	= masquerade_tg6_checkentry,
     82		.destroy	= masquerade_tg_destroy,
     83		.me		= THIS_MODULE,
     84	}, {
     85#endif
     86		.name		= "MASQUERADE",
     87		.family		= NFPROTO_IPV4,
     88		.target		= masquerade_tg,
     89		.targetsize	= sizeof(struct nf_nat_ipv4_multi_range_compat),
     90		.table		= "nat",
     91		.hooks		= 1 << NF_INET_POST_ROUTING,
     92		.checkentry	= masquerade_tg_check,
     93		.destroy	= masquerade_tg_destroy,
     94		.me		= THIS_MODULE,
     95	}
     96};
     97
     98static int __init masquerade_tg_init(void)
     99{
    100	int ret;
    101
    102	ret = xt_register_targets(masquerade_tg_reg,
    103				  ARRAY_SIZE(masquerade_tg_reg));
    104	if (ret)
    105		return ret;
    106
    107	ret = nf_nat_masquerade_inet_register_notifiers();
    108	if (ret) {
    109		xt_unregister_targets(masquerade_tg_reg,
    110				      ARRAY_SIZE(masquerade_tg_reg));
    111		return ret;
    112	}
    113
    114	return ret;
    115}
    116
    117static void __exit masquerade_tg_exit(void)
    118{
    119	xt_unregister_targets(masquerade_tg_reg, ARRAY_SIZE(masquerade_tg_reg));
    120	nf_nat_masquerade_inet_unregister_notifiers();
    121}
    122
    123module_init(masquerade_tg_init);
    124module_exit(masquerade_tg_exit);
    125#if IS_ENABLED(CONFIG_IPV6)
    126MODULE_ALIAS("ip6t_MASQUERADE");
    127#endif
    128MODULE_ALIAS("ipt_MASQUERADE");