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
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
|
/*
* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
* Copyright (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
* Copyright (c) 2012 Intel Corporation
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/string.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_core.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_nat_l3proto.h>
#include <net/ip.h>
struct nft_nat {
enum nft_registers sreg_addr_min:8;
enum nft_registers sreg_addr_max:8;
enum nft_registers sreg_proto_min:8;
enum nft_registers sreg_proto_max:8;
enum nf_nat_manip_type type:8;
u8 family;
u16 flags;
};
static void nft_nat_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_nat *priv = nft_expr_priv(expr);
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(pkt->skb, &ctinfo);
struct nf_nat_range range;
memset(&range, 0, sizeof(range));
if (priv->sreg_addr_min) {
if (priv->family == AF_INET) {
range.min_addr.ip = (__force __be32)
regs->data[priv->sreg_addr_min];
range.max_addr.ip = (__force __be32)
regs->data[priv->sreg_addr_max];
} else {
memcpy(range.min_addr.ip6,
®s->data[priv->sreg_addr_min],
sizeof(range.min_addr.ip6));
memcpy(range.max_addr.ip6,
®s->data[priv->sreg_addr_max],
sizeof(range.max_addr.ip6));
}
range.flags |= NF_NAT_RANGE_MAP_IPS;
}
if (priv->sreg_proto_min) {
range.min_proto.all =
*(__be16 *)®s->data[priv->sreg_proto_min];
range.max_proto.all =
*(__be16 *)®s->data[priv->sreg_proto_max];
range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
}
range.flags |= priv->flags;
regs->verdict.code = nf_nat_setup_info(ct, &range, priv->type);
}
static const struct nla_policy nft_nat_policy[NFTA_NAT_MAX + 1] = {
[NFTA_NAT_TYPE] = { .type = NLA_U32 },
[NFTA_NAT_FAMILY] = { .type = NLA_U32 },
[NFTA_NAT_REG_ADDR_MIN] = { .type = NLA_U32 },
[NFTA_NAT_REG_ADDR_MAX] = { .type = NLA_U32 },
[NFTA_NAT_REG_PROTO_MIN] = { .type = NLA_U32 },
[NFTA_NAT_REG_PROTO_MAX] = { .type = NLA_U32 },
[NFTA_NAT_FLAGS] = { .type = NLA_U32 },
};
static int nft_nat_validate(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nft_data **data)
{
struct nft_nat *priv = nft_expr_priv(expr);
int err;
err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
if (err < 0)
return err;
switch (priv->type) {
case NFT_NAT_SNAT:
err = nft_chain_validate_hooks(ctx->chain,
(1 << NF_INET_POST_ROUTING) |
(1 << NF_INET_LOCAL_IN));
break;
case NFT_NAT_DNAT:
err = nft_chain_validate_hooks(ctx->chain,
(1 << NF_INET_PRE_ROUTING) |
(1 << NF_INET_LOCAL_OUT));
break;
}
return err;
}
static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_nat *priv = nft_expr_priv(expr);
unsigned int alen, plen;
u32 family;
int err;
if (tb[NFTA_NAT_TYPE] == NULL ||
(tb[NFTA_NAT_REG_ADDR_MIN] == NULL &&
tb[NFTA_NAT_REG_PROTO_MIN] == NULL))
return -EINVAL;
switch (ntohl(nla_get_be32(tb[NFTA_NAT_TYPE]))) {
case NFT_NAT_SNAT:
priv->type = NF_NAT_MANIP_SRC;
break;
case NFT_NAT_DNAT:
priv->type = NF_NAT_MANIP_DST;
break;
default:
return -EINVAL;
}
err = nft_nat_validate(ctx, expr, NULL);
if (err < 0)
return err;
if (tb[NFTA_NAT_FAMILY] == NULL)
return -EINVAL;
family = ntohl(nla_get_be32(tb[NFTA_NAT_FAMILY]));
if (family != ctx->afi->family)
return -EOPNOTSUPP;
switch (family) {
case NFPROTO_IPV4:
alen = FIELD_SIZEOF(struct nf_nat_range, min_addr.ip);
break;
case NFPROTO_IPV6:
alen = FIELD_SIZEOF(struct nf_nat_range, min_addr.ip6);
break;
default:
return -EAFNOSUPPORT;
}
priv->family = family;
if (tb[NFTA_NAT_REG_ADDR_MIN]) {
priv->sreg_addr_min =
nft_parse_register(tb[NFTA_NAT_REG_ADDR_MIN]);
err = nft_validate_register_load(priv->sreg_addr_min, alen);
if (err < 0)
return err;
if (tb[NFTA_NAT_REG_ADDR_MAX]) {
priv->sreg_addr_max =
nft_parse_register(tb[NFTA_NAT_REG_ADDR_MAX]);
err = nft_validate_register_load(priv->sreg_addr_max,
alen);
if (err < 0)
return err;
} else {
priv->sreg_addr_max = priv->sreg_addr_min;
}
}
plen = FIELD_SIZEOF(struct nf_nat_range, min_addr.all);
if (tb[NFTA_NAT_REG_PROTO_MIN]) {
priv->sreg_proto_min =
nft_parse_register(tb[NFTA_NAT_REG_PROTO_MIN]);
err = nft_validate_register_load(priv->sreg_proto_min, plen);
if (err < 0)
return err;
if (tb[NFTA_NAT_REG_PROTO_MAX]) {
priv->sreg_proto_max =
nft_parse_register(tb[NFTA_NAT_REG_PROTO_MAX]);
err = nft_validate_register_load(priv->sreg_proto_max,
plen);
if (err < 0)
return err;
} else {
priv->sreg_proto_max = priv->sreg_proto_min;
}
}
if (tb[NFTA_NAT_FLAGS]) {
priv->flags = ntohl(nla_get_be32(tb[NFTA_NAT_FLAGS]));
if (priv->flags & ~NF_NAT_RANGE_MASK)
return -EINVAL;
}
return nf_ct_netns_get(ctx->net, family);
}
static int nft_nat_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_nat *priv = nft_expr_priv(expr);
switch (priv->type) {
case NF_NAT_MANIP_SRC:
if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_SNAT)))
goto nla_put_failure;
break;
case NF_NAT_MANIP_DST:
if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_DNAT)))
goto nla_put_failure;
break;
}
if (nla_put_be32(skb, NFTA_NAT_FAMILY, htonl(priv->family)))
goto nla_put_failure;
if (priv->sreg_addr_min) {
if (nft_dump_register(skb, NFTA_NAT_REG_ADDR_MIN,
priv->sreg_addr_min) ||
nft_dump_register(skb, NFTA_NAT_REG_ADDR_MAX,
priv->sreg_addr_max))
goto nla_put_failure;
}
if (priv->sreg_proto_min) {
if (nft_dump_register(skb, NFTA_NAT_REG_PROTO_MIN,
priv->sreg_proto_min) ||
nft_dump_register(skb, NFTA_NAT_REG_PROTO_MAX,
priv->sreg_proto_max))
goto nla_put_failure;
}
if (priv->flags != 0) {
if (nla_put_be32(skb, NFTA_NAT_FLAGS, htonl(priv->flags)))
goto nla_put_failure;
}
return 0;
nla_put_failure:
return -1;
}
static void
nft_nat_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
{
const struct nft_nat *priv = nft_expr_priv(expr);
nf_ct_netns_put(ctx->net, priv->family);
}
static struct nft_expr_type nft_nat_type;
static const struct nft_expr_ops nft_nat_ops = {
.type = &nft_nat_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
.eval = nft_nat_eval,
.init = nft_nat_init,
.destroy = nft_nat_destroy,
.dump = nft_nat_dump,
.validate = nft_nat_validate,
};
static struct nft_expr_type nft_nat_type __read_mostly = {
.name = "nat",
.ops = &nft_nat_ops,
.policy = nft_nat_policy,
.maxattr = NFTA_NAT_MAX,
.owner = THIS_MODULE,
};
static int __init nft_nat_module_init(void)
{
return nft_register_expr(&nft_nat_type);
}
static void __exit nft_nat_module_exit(void)
{
nft_unregister_expr(&nft_nat_type);
}
module_init(nft_nat_module_init);
module_exit(nft_nat_module_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>");
MODULE_ALIAS_NFT_EXPR("nat");
|
