summaryrefslogtreecommitdiffstats
path: root/net/netfilter/xt_nat.c
blob: 61eabd171186f32730b5cf5b26497b05f3c07794 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
/*
 * (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
 * (C) 2011 Patrick McHardy <kaber@trash.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>
#include <net/netfilter/nf_nat.h>

static int xt_nat_checkentry_v0(const struct xt_tgchk_param *par)
{
	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;

	if (mr->rangesize != 1) {
		pr_info_ratelimited("multiple ranges no longer supported\n");
		return -EINVAL;
	}
	return nf_ct_netns_get(par->net, par->family);
}

static int xt_nat_checkentry(const struct xt_tgchk_param *par)
{
	return nf_ct_netns_get(par->net, par->family);
}

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

static void xt_nat_convert_range(struct nf_nat_range2 *dst,
				 const struct nf_nat_ipv4_range *src)
{
	memset(&dst->min_addr, 0, sizeof(dst->min_addr));
	memset(&dst->max_addr, 0, sizeof(dst->max_addr));
	memset(&dst->base_proto, 0, sizeof(dst->base_proto));

	dst->flags	 = src->flags;
	dst->min_addr.ip = src->min_ip;
	dst->max_addr.ip = src->max_ip;
	dst->min_proto	 = src->min;
	dst->max_proto	 = src->max;
}

static unsigned int
xt_snat_target_v0(struct sk_buff *skb, const struct xt_action_param *par)
{
	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
	struct nf_nat_range2 range;
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;

	ct = nf_ct_get(skb, &ctinfo);
	WARN_ON(!(ct != NULL &&
		 (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED ||
		  ctinfo == IP_CT_RELATED_REPLY)));

	xt_nat_convert_range(&range, &mr->range[0]);
	return nf_nat_setup_info(ct, &range, NF_NAT_MANIP_SRC);
}

static unsigned int
xt_dnat_target_v0(struct sk_buff *skb, const struct xt_action_param *par)
{
	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
	struct nf_nat_range2 range;
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;

	ct = nf_ct_get(skb, &ctinfo);
	WARN_ON(!(ct != NULL &&
		 (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED)));

	xt_nat_convert_range(&range, &mr->range[0]);
	return nf_nat_setup_info(ct, &range, NF_NAT_MANIP_DST);
}

static unsigned int
xt_snat_target_v1(struct sk_buff *skb, const struct xt_action_param *par)
{
	const struct nf_nat_range *range_v1 = par->targinfo;
	struct nf_nat_range2 range;
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;

	ct = nf_ct_get(skb, &ctinfo);
	WARN_ON(!(ct != NULL &&
		 (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED ||
		  ctinfo == IP_CT_RELATED_REPLY)));

	memcpy(&range, range_v1, sizeof(*range_v1));
	memset(&range.base_proto, 0, sizeof(range.base_proto));

	return nf_nat_setup_info(ct, &range, NF_NAT_MANIP_SRC);
}

static unsigned int
xt_dnat_target_v1(struct sk_buff *skb, const struct xt_action_param *par)
{
	const struct nf_nat_range *range_v1 = par->targinfo;
	struct nf_nat_range2 range;
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;

	ct = nf_ct_get(skb, &ctinfo);
	WARN_ON(!(ct != NULL &&
		 (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED)));

	memcpy(&range, range_v1, sizeof(*range_v1));
	memset(&range.base_proto, 0, sizeof(range.base_proto));

	return nf_nat_setup_info(ct, &range, NF_NAT_MANIP_DST);
}

static unsigned int
xt_snat_target_v2(struct sk_buff *skb, const struct xt_action_param *par)
{
	const struct nf_nat_range2 *range = par->targinfo;
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;

	ct = nf_ct_get(skb, &ctinfo);
	WARN_ON(!(ct != NULL &&
		 (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED ||
		  ctinfo == IP_CT_RELATED_REPLY)));

	return nf_nat_setup_info(ct, range, NF_NAT_MANIP_SRC);
}

static unsigned int
xt_dnat_target_v2(struct sk_buff *skb, const struct xt_action_param *par)
{
	const struct nf_nat_range2 *range = par->targinfo;
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;

	ct = nf_ct_get(skb, &ctinfo);
	WARN_ON(!(ct != NULL &&
		 (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED)));

	return nf_nat_setup_info(ct, range, NF_NAT_MANIP_DST);
}

static struct xt_target xt_nat_target_reg[] __read_mostly = {
	{
		.name		= "SNAT",
		.revision	= 0,
		.checkentry	= xt_nat_checkentry_v0,
		.destroy	= xt_nat_destroy,
		.target		= xt_snat_target_v0,
		.targetsize	= sizeof(struct nf_nat_ipv4_multi_range_compat),
		.family		= NFPROTO_IPV4,
		.table		= "nat",
		.hooks		= (1 << NF_INET_POST_ROUTING) |
				  (1 << NF_INET_LOCAL_IN),
		.me		= THIS_MODULE,
	},
	{
		.name		= "DNAT",
		.revision	= 0,
		.checkentry	= xt_nat_checkentry_v0,
		.destroy	= xt_nat_destroy,
		.target		= xt_dnat_target_v0,
		.targetsize	= sizeof(struct nf_nat_ipv4_multi_range_compat),
		.family		= NFPROTO_IPV4,
		.table		= "nat",
		.hooks		= (1 << NF_INET_PRE_ROUTING) |
				  (1 << NF_INET_LOCAL_OUT),
		.me		= THIS_MODULE,
	},
	{
		.name		= "SNAT",
		.revision	= 1,
		.checkentry	= xt_nat_checkentry,
		.destroy	= xt_nat_destroy,
		.target		= xt_snat_target_v1,
		.targetsize	= sizeof(struct nf_nat_range),
		.table		= "nat",
		.hooks		= (1 << NF_INET_POST_ROUTING) |
				  (1 << NF_INET_LOCAL_IN),
		.me		= THIS_MODULE,
	},
	{
		.name		= "DNAT",
		.revision	= 1,
		.checkentry	= xt_nat_checkentry,
		.destroy	= xt_nat_destroy,
		.target		= xt_dnat_target_v1,
		.targetsize	= sizeof(struct nf_nat_range),
		.table		= "nat",
		.hooks		= (1 << NF_INET_PRE_ROUTING) |
				  (1 << NF_INET_LOCAL_OUT),
		.me		= THIS_MODULE,
	},
	{
		.name		= "SNAT",
		.revision	= 2,
		.checkentry	= xt_nat_checkentry,
		.destroy	= xt_nat_destroy,
		.target		= xt_snat_target_v2,
		.targetsize	= sizeof(struct nf_nat_range2),
		.table		= "nat",
		.hooks		= (1 << NF_INET_POST_ROUTING) |
				  (1 << NF_INET_LOCAL_IN),
		.me		= THIS_MODULE,
	},
	{
		.name		= "DNAT",
		.revision	= 2,
		.checkentry	= xt_nat_checkentry,
		.destroy	= xt_nat_destroy,
		.target		= xt_dnat_target_v2,
		.targetsize	= sizeof(struct nf_nat_range2),
		.table		= "nat",
		.hooks		= (1 << NF_INET_PRE_ROUTING) |
				  (1 << NF_INET_LOCAL_OUT),
		.me		= THIS_MODULE,
	},
};

static int __init xt_nat_init(void)
{
	return xt_register_targets(xt_nat_target_reg,
				   ARRAY_SIZE(xt_nat_target_reg));
}

static void __exit xt_nat_exit(void)
{
	xt_unregister_targets(xt_nat_target_reg, ARRAY_SIZE(xt_nat_target_reg));
}

module_init(xt_nat_init);
module_exit(xt_nat_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_ALIAS("ipt_SNAT");
MODULE_ALIAS("ipt_DNAT");
MODULE_ALIAS("ip6t_SNAT");
MODULE_ALIAS("ip6t_DNAT");