[mirror_ubuntu-jammy-kernel.git] / net / netfilter / xt_REDIRECT.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
 * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
 *
 * Based on Rusty Russell's IPv4 REDIRECT target. Development of IPv6
 * NAT funded by Astaro.
 */

#include <linux/if.h>
#include <linux/inetdevice.h>
#include <linux/ip.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/netfilter.h>
#include <linux/types.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <linux/netfilter/x_tables.h>
#include <net/addrconf.h>
#include <net/checksum.h>
#include <net/protocol.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_redirect.h>

static unsigned int
redirect_tg6(struct sk_buff *skb, const struct xt_action_param *par)
{
	return nf_nat_redirect_ipv6(skb, par->targinfo, xt_hooknum(par));
}

static int redirect_tg6_checkentry(const struct xt_tgchk_param *par)
{
	const struct nf_nat_range2 *range = par->targinfo;

	if (range->flags & NF_NAT_RANGE_MAP_IPS)
		return -EINVAL;

	return nf_ct_netns_get(par->net, par->family);
}

static void redirect_tg_destroy(const struct xt_tgdtor_param *par)
{
	nf_ct_netns_put(par->net, par->family);
}

/* FIXME: Take multiple ranges --RR */
static int redirect_tg4_check(const struct xt_tgchk_param *par)
{
	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;

	if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) {
		pr_debug("bad MAP_IPS.\n");
		return -EINVAL;
	}
	if (mr->rangesize != 1) {
		pr_debug("bad rangesize %u.\n", mr->rangesize);
		return -EINVAL;
	}
	return nf_ct_netns_get(par->net, par->family);
}

static unsigned int
redirect_tg4(struct sk_buff *skb, const struct xt_action_param *par)
{
	return nf_nat_redirect_ipv4(skb, par->targinfo, xt_hooknum(par));
}

static struct xt_target redirect_tg_reg[] __read_mostly = {
	{
		.name       = "REDIRECT",
		.family     = NFPROTO_IPV6,
		.revision   = 0,
		.table      = "nat",
		.checkentry = redirect_tg6_checkentry,
		.destroy    = redirect_tg_destroy,
		.target     = redirect_tg6,
		.targetsize = sizeof(struct nf_nat_range),
		.hooks      = (1 << NF_INET_PRE_ROUTING) |
		              (1 << NF_INET_LOCAL_OUT),
		.me         = THIS_MODULE,
	},
	{
		.name       = "REDIRECT",
		.family     = NFPROTO_IPV4,
		.revision   = 0,
		.table      = "nat",
		.target     = redirect_tg4,
		.checkentry = redirect_tg4_check,
		.destroy    = redirect_tg_destroy,
		.targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat),
		.hooks      = (1 << NF_INET_PRE_ROUTING) |
		              (1 << NF_INET_LOCAL_OUT),
		.me         = THIS_MODULE,
	},
};

static int __init redirect_tg_init(void)
{
	return xt_register_targets(redirect_tg_reg,
				   ARRAY_SIZE(redirect_tg_reg));
}

static void __exit redirect_tg_exit(void)
{
	xt_unregister_targets(redirect_tg_reg, ARRAY_SIZE(redirect_tg_reg));
}

module_init(redirect_tg_init);
module_exit(redirect_tg_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_DESCRIPTION("Xtables: Connection redirection to localhost");
MODULE_ALIAS("ip6t_REDIRECT");
MODULE_ALIAS("ipt_REDIRECT");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
2cbc78a2 JE	2	/*
	3	* (C) 1999-2001 Paul `Rusty' Russell
	4	* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
	5	* Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
	6	*
2cbc78a2 JE	7	* Based on Rusty Russell's IPv4 REDIRECT target. Development of IPv6
	8	* NAT funded by Astaro.
	9	*/
	10
	11	#include <linux/if.h>
	12	#include <linux/inetdevice.h>
	13	#include <linux/ip.h>
	14	#include <linux/kernel.h>
	15	#include <linux/module.h>
	16	#include <linux/netdevice.h>
	17	#include <linux/netfilter.h>
	18	#include <linux/types.h>
	19	#include <linux/netfilter_ipv4.h>
	20	#include <linux/netfilter_ipv6.h>
	21	#include <linux/netfilter/x_tables.h>
	22	#include <net/addrconf.h>
	23	#include <net/checksum.h>
	24	#include <net/protocol.h>
	25	#include <net/netfilter/nf_nat.h>
b59eaf9e	26	#include <net/netfilter/nf_nat_redirect.h>
2cbc78a2 JE	27
	28	static unsigned int
	29	redirect_tg6(struct sk_buff skb, const struct xt_action_param par)
	30	{
613dbd95	31	return nf_nat_redirect_ipv6(skb, par->targinfo, xt_hooknum(par));
2cbc78a2 JE	32	}
	33
	34	static int redirect_tg6_checkentry(const struct xt_tgchk_param *par)
	35	{
2eb0f624	36	const struct nf_nat_range2 *range = par->targinfo;
2cbc78a2 JE	37
	38	if (range->flags & NF_NAT_RANGE_MAP_IPS)
	39	return -EINVAL;
a357b3f8 FW	40
	41	return nf_ct_netns_get(par->net, par->family);
	42	}
	43
	44	static void redirect_tg_destroy(const struct xt_tgdtor_param *par)
	45	{
	46	nf_ct_netns_put(par->net, par->family);
2cbc78a2 JE	47	}
	48
	49	/* FIXME: Take multiple ranges --RR */
	50	static int redirect_tg4_check(const struct xt_tgchk_param *par)
	51	{
	52	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
	53
	54	if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) {
	55	pr_debug("bad MAP_IPS.\n");
	56	return -EINVAL;
	57	}
	58	if (mr->rangesize != 1) {
	59	pr_debug("bad rangesize %u.\n", mr->rangesize);
	60	return -EINVAL;
	61	}
a357b3f8	62	return nf_ct_netns_get(par->net, par->family);
2cbc78a2 JE	63	}
	64
	65	static unsigned int
	66	redirect_tg4(struct sk_buff skb, const struct xt_action_param par)
	67	{
613dbd95	68	return nf_nat_redirect_ipv4(skb, par->targinfo, xt_hooknum(par));
2cbc78a2 JE	69	}
	70
	71	static struct xt_target redirect_tg_reg[] __read_mostly = {
	72	{
	73	.name = "REDIRECT",
	74	.family = NFPROTO_IPV6,
	75	.revision = 0,
	76	.table = "nat",
	77	.checkentry = redirect_tg6_checkentry,
a357b3f8	78	.destroy = redirect_tg_destroy,
2cbc78a2 JE	79	.target = redirect_tg6,
	80	.targetsize = sizeof(struct nf_nat_range),
	81	.hooks = (1 << NF_INET_PRE_ROUTING) \|
	82	(1 << NF_INET_LOCAL_OUT),
	83	.me = THIS_MODULE,
	84	},
	85	{
	86	.name = "REDIRECT",
	87	.family = NFPROTO_IPV4,
	88	.revision = 0,
	89	.table = "nat",
	90	.target = redirect_tg4,
	91	.checkentry = redirect_tg4_check,
a357b3f8	92	.destroy = redirect_tg_destroy,
2cbc78a2 JE	93	.targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat),
	94	.hooks = (1 << NF_INET_PRE_ROUTING) \|
	95	(1 << NF_INET_LOCAL_OUT),
	96	.me = THIS_MODULE,
	97	},
	98	};
	99
	100	static int __init redirect_tg_init(void)
	101	{
	102	return xt_register_targets(redirect_tg_reg,
	103	ARRAY_SIZE(redirect_tg_reg));
	104	}
	105
	106	static void __exit redirect_tg_exit(void)
	107	{
	108	xt_unregister_targets(redirect_tg_reg, ARRAY_SIZE(redirect_tg_reg));
	109	}
	110
	111	module_init(redirect_tg_init);
	112	module_exit(redirect_tg_exit);
	113
	114	MODULE_LICENSE("GPL");
	115	MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
	116	MODULE_DESCRIPTION("Xtables: Connection redirection to localhost");
	117	MODULE_ALIAS("ip6t_REDIRECT");
	118	MODULE_ALIAS("ipt_REDIRECT");