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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ip6table_nat.c (3737B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
      4 *
      5 * Based on Rusty Russell's IPv4 NAT code. Development of IPv6 NAT
      6 * funded by Astaro.
      7 */
      8
      9#include <linux/module.h>
     10#include <linux/netfilter.h>
     11#include <linux/netfilter_ipv6.h>
     12#include <linux/netfilter_ipv6/ip6_tables.h>
     13#include <linux/ipv6.h>
     14#include <net/ipv6.h>
     15
     16#include <net/netfilter/nf_nat.h>
     17
     18struct ip6table_nat_pernet {
     19	struct nf_hook_ops *nf_nat_ops;
     20};
     21
     22static unsigned int ip6table_nat_net_id __read_mostly;
     23
     24static const struct xt_table nf_nat_ipv6_table = {
     25	.name		= "nat",
     26	.valid_hooks	= (1 << NF_INET_PRE_ROUTING) |
     27			  (1 << NF_INET_POST_ROUTING) |
     28			  (1 << NF_INET_LOCAL_OUT) |
     29			  (1 << NF_INET_LOCAL_IN),
     30	.me		= THIS_MODULE,
     31	.af		= NFPROTO_IPV6,
     32};
     33
     34static const struct nf_hook_ops nf_nat_ipv6_ops[] = {
     35	{
     36		.hook		= ip6t_do_table,
     37		.pf		= NFPROTO_IPV6,
     38		.hooknum	= NF_INET_PRE_ROUTING,
     39		.priority	= NF_IP6_PRI_NAT_DST,
     40	},
     41	{
     42		.hook		= ip6t_do_table,
     43		.pf		= NFPROTO_IPV6,
     44		.hooknum	= NF_INET_POST_ROUTING,
     45		.priority	= NF_IP6_PRI_NAT_SRC,
     46	},
     47	{
     48		.hook		= ip6t_do_table,
     49		.pf		= NFPROTO_IPV6,
     50		.hooknum	= NF_INET_LOCAL_OUT,
     51		.priority	= NF_IP6_PRI_NAT_DST,
     52	},
     53	{
     54		.hook		= ip6t_do_table,
     55		.pf		= NFPROTO_IPV6,
     56		.hooknum	= NF_INET_LOCAL_IN,
     57		.priority	= NF_IP6_PRI_NAT_SRC,
     58	},
     59};
     60
     61static int ip6t_nat_register_lookups(struct net *net)
     62{
     63	struct ip6table_nat_pernet *xt_nat_net;
     64	struct nf_hook_ops *ops;
     65	struct xt_table *table;
     66	int i, ret;
     67
     68	table = xt_find_table(net, NFPROTO_IPV6, "nat");
     69	if (WARN_ON_ONCE(!table))
     70		return -ENOENT;
     71
     72	xt_nat_net = net_generic(net, ip6table_nat_net_id);
     73	ops = kmemdup(nf_nat_ipv6_ops, sizeof(nf_nat_ipv6_ops), GFP_KERNEL);
     74	if (!ops)
     75		return -ENOMEM;
     76
     77	for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++) {
     78		ops[i].priv = table;
     79		ret = nf_nat_ipv6_register_fn(net, &ops[i]);
     80		if (ret) {
     81			while (i)
     82				nf_nat_ipv6_unregister_fn(net, &ops[--i]);
     83
     84			kfree(ops);
     85			return ret;
     86		}
     87	}
     88
     89	xt_nat_net->nf_nat_ops = ops;
     90	return 0;
     91}
     92
     93static void ip6t_nat_unregister_lookups(struct net *net)
     94{
     95	struct ip6table_nat_pernet *xt_nat_net = net_generic(net, ip6table_nat_net_id);
     96	struct nf_hook_ops *ops = xt_nat_net->nf_nat_ops;
     97	int i;
     98
     99	if (!ops)
    100		return;
    101
    102	for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++)
    103		nf_nat_ipv6_unregister_fn(net, &ops[i]);
    104
    105	kfree(ops);
    106}
    107
    108static int ip6table_nat_table_init(struct net *net)
    109{
    110	struct ip6t_replace *repl;
    111	int ret;
    112
    113	repl = ip6t_alloc_initial_table(&nf_nat_ipv6_table);
    114	if (repl == NULL)
    115		return -ENOMEM;
    116	ret = ip6t_register_table(net, &nf_nat_ipv6_table, repl,
    117				  NULL);
    118	if (ret < 0) {
    119		kfree(repl);
    120		return ret;
    121	}
    122
    123	ret = ip6t_nat_register_lookups(net);
    124	if (ret < 0)
    125		ip6t_unregister_table_exit(net, "nat");
    126
    127	kfree(repl);
    128	return ret;
    129}
    130
    131static void __net_exit ip6table_nat_net_pre_exit(struct net *net)
    132{
    133	ip6t_nat_unregister_lookups(net);
    134}
    135
    136static void __net_exit ip6table_nat_net_exit(struct net *net)
    137{
    138	ip6t_unregister_table_exit(net, "nat");
    139}
    140
    141static struct pernet_operations ip6table_nat_net_ops = {
    142	.pre_exit = ip6table_nat_net_pre_exit,
    143	.exit	= ip6table_nat_net_exit,
    144	.id	= &ip6table_nat_net_id,
    145	.size	= sizeof(struct ip6table_nat_pernet),
    146};
    147
    148static int __init ip6table_nat_init(void)
    149{
    150	int ret = xt_register_template(&nf_nat_ipv6_table,
    151				       ip6table_nat_table_init);
    152
    153	if (ret < 0)
    154		return ret;
    155
    156	ret = register_pernet_subsys(&ip6table_nat_net_ops);
    157	if (ret)
    158		xt_unregister_template(&nf_nat_ipv6_table);
    159
    160	return ret;
    161}
    162
    163static void __exit ip6table_nat_exit(void)
    164{
    165	unregister_pernet_subsys(&ip6table_nat_net_ops);
    166	xt_unregister_template(&nf_nat_ipv6_table);
    167}
    168
    169module_init(ip6table_nat_init);
    170module_exit(ip6table_nat_exit);
    171
    172MODULE_LICENSE("GPL");