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
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
|
/*
* Copyright (c) 2008-2009 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.
*
* Development of this code funded by Astaro AG (http://www.astaro.com/)
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/dst.h>
#include <net/sock.h>
#include <net/tcp_states.h> /* for TCP_TIME_WAIT */
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nft_meta.h>
void nft_meta_get_eval(const struct nft_expr *expr,
struct nft_data data[NFT_REG_MAX + 1],
const struct nft_pktinfo *pkt)
{
const struct nft_meta *priv = nft_expr_priv(expr);
const struct sk_buff *skb = pkt->skb;
const struct net_device *in = pkt->in, *out = pkt->out;
struct nft_data *dest = &data[priv->dreg];
switch (priv->key) {
case NFT_META_LEN:
dest->data[0] = skb->len;
break;
case NFT_META_PROTOCOL:
*(__be16 *)dest->data = skb->protocol;
break;
case NFT_META_NFPROTO:
dest->data[0] = pkt->ops->pf;
break;
case NFT_META_L4PROTO:
dest->data[0] = pkt->tprot;
break;
case NFT_META_PRIORITY:
dest->data[0] = skb->priority;
break;
case NFT_META_MARK:
dest->data[0] = skb->mark;
break;
case NFT_META_IIF:
if (in == NULL)
goto err;
dest->data[0] = in->ifindex;
break;
case NFT_META_OIF:
if (out == NULL)
goto err;
dest->data[0] = out->ifindex;
break;
case NFT_META_IIFNAME:
if (in == NULL)
goto err;
strncpy((char *)dest->data, in->name, sizeof(dest->data));
break;
case NFT_META_OIFNAME:
if (out == NULL)
goto err;
strncpy((char *)dest->data, out->name, sizeof(dest->data));
break;
case NFT_META_IIFTYPE:
if (in == NULL)
goto err;
*(u16 *)dest->data = in->type;
break;
case NFT_META_OIFTYPE:
if (out == NULL)
goto err;
*(u16 *)dest->data = out->type;
break;
case NFT_META_SKUID:
if (skb->sk == NULL || skb->sk->sk_state == TCP_TIME_WAIT)
goto err;
read_lock_bh(&skb->sk->sk_callback_lock);
if (skb->sk->sk_socket == NULL ||
skb->sk->sk_socket->file == NULL) {
read_unlock_bh(&skb->sk->sk_callback_lock);
goto err;
}
dest->data[0] =
from_kuid_munged(&init_user_ns,
skb->sk->sk_socket->file->f_cred->fsuid);
read_unlock_bh(&skb->sk->sk_callback_lock);
break;
case NFT_META_SKGID:
if (skb->sk == NULL || skb->sk->sk_state == TCP_TIME_WAIT)
goto err;
read_lock_bh(&skb->sk->sk_callback_lock);
if (skb->sk->sk_socket == NULL ||
skb->sk->sk_socket->file == NULL) {
read_unlock_bh(&skb->sk->sk_callback_lock);
goto err;
}
dest->data[0] =
from_kgid_munged(&init_user_ns,
skb->sk->sk_socket->file->f_cred->fsgid);
read_unlock_bh(&skb->sk->sk_callback_lock);
break;
#ifdef CONFIG_IP_ROUTE_CLASSID
case NFT_META_RTCLASSID: {
const struct dst_entry *dst = skb_dst(skb);
if (dst == NULL)
goto err;
dest->data[0] = dst->tclassid;
break;
}
#endif
#ifdef CONFIG_NETWORK_SECMARK
case NFT_META_SECMARK:
dest->data[0] = skb->secmark;
break;
#endif
default:
WARN_ON(1);
goto err;
}
return;
err:
data[NFT_REG_VERDICT].verdict = NFT_BREAK;
}
EXPORT_SYMBOL_GPL(nft_meta_get_eval);
void nft_meta_set_eval(const struct nft_expr *expr,
struct nft_data data[NFT_REG_MAX + 1],
const struct nft_pktinfo *pkt)
{
const struct nft_meta *meta = nft_expr_priv(expr);
struct sk_buff *skb = pkt->skb;
u32 value = data[meta->sreg].data[0];
switch (meta->key) {
case NFT_META_MARK:
skb->mark = value;
break;
case NFT_META_PRIORITY:
skb->priority = value;
break;
case NFT_META_NFTRACE:
skb->nf_trace = 1;
break;
default:
WARN_ON(1);
}
}
EXPORT_SYMBOL_GPL(nft_meta_set_eval);
const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = {
[NFTA_META_DREG] = { .type = NLA_U32 },
[NFTA_META_KEY] = { .type = NLA_U32 },
[NFTA_META_SREG] = { .type = NLA_U32 },
};
EXPORT_SYMBOL_GPL(nft_meta_policy);
int nft_meta_get_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_meta *priv = nft_expr_priv(expr);
int err;
priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
switch (priv->key) {
case NFT_META_LEN:
case NFT_META_PROTOCOL:
case NFT_META_NFPROTO:
case NFT_META_L4PROTO:
case NFT_META_PRIORITY:
case NFT_META_MARK:
case NFT_META_IIF:
case NFT_META_OIF:
case NFT_META_IIFNAME:
case NFT_META_OIFNAME:
case NFT_META_IIFTYPE:
case NFT_META_OIFTYPE:
case NFT_META_SKUID:
case NFT_META_SKGID:
#ifdef CONFIG_IP_ROUTE_CLASSID
case NFT_META_RTCLASSID:
#endif
#ifdef CONFIG_NETWORK_SECMARK
case NFT_META_SECMARK:
#endif
break;
default:
return -EOPNOTSUPP;
}
priv->dreg = ntohl(nla_get_be32(tb[NFTA_META_DREG]));
err = nft_validate_output_register(priv->dreg);
if (err < 0)
return err;
err = nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE);
if (err < 0)
return err;
return 0;
}
EXPORT_SYMBOL_GPL(nft_meta_get_init);
int nft_meta_set_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_meta *priv = nft_expr_priv(expr);
int err;
priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
switch (priv->key) {
case NFT_META_MARK:
case NFT_META_PRIORITY:
case NFT_META_NFTRACE:
break;
default:
return -EOPNOTSUPP;
}
priv->sreg = ntohl(nla_get_be32(tb[NFTA_META_SREG]));
err = nft_validate_input_register(priv->sreg);
if (err < 0)
return err;
return 0;
}
EXPORT_SYMBOL_GPL(nft_meta_set_init);
int nft_meta_get_dump(struct sk_buff *skb,
const struct nft_expr *expr)
{
const struct nft_meta *priv = nft_expr_priv(expr);
if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_META_DREG, htonl(priv->dreg)))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
EXPORT_SYMBOL_GPL(nft_meta_get_dump);
int nft_meta_set_dump(struct sk_buff *skb,
const struct nft_expr *expr)
{
const struct nft_meta *priv = nft_expr_priv(expr);
if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_META_SREG, htonl(priv->sreg)))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
EXPORT_SYMBOL_GPL(nft_meta_set_dump);
static struct nft_expr_type nft_meta_type;
static const struct nft_expr_ops nft_meta_get_ops = {
.type = &nft_meta_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
.eval = nft_meta_get_eval,
.init = nft_meta_get_init,
.dump = nft_meta_get_dump,
};
static const struct nft_expr_ops nft_meta_set_ops = {
.type = &nft_meta_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
.eval = nft_meta_set_eval,
.init = nft_meta_set_init,
.dump = nft_meta_set_dump,
};
static const struct nft_expr_ops *
nft_meta_select_ops(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
{
if (tb[NFTA_META_KEY] == NULL)
return ERR_PTR(-EINVAL);
if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG])
return ERR_PTR(-EINVAL);
if (tb[NFTA_META_DREG])
return &nft_meta_get_ops;
if (tb[NFTA_META_SREG])
return &nft_meta_set_ops;
return ERR_PTR(-EINVAL);
}
static struct nft_expr_type nft_meta_type __read_mostly = {
.name = "meta",
.select_ops = &nft_meta_select_ops,
.policy = nft_meta_policy,
.maxattr = NFTA_META_MAX,
.owner = THIS_MODULE,
};
static int __init nft_meta_module_init(void)
{
return nft_register_expr(&nft_meta_type);
}
static void __exit nft_meta_module_exit(void)
{
nft_unregister_expr(&nft_meta_type);
}
module_init(nft_meta_module_init);
module_exit(nft_meta_module_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_ALIAS_NFT_EXPR("meta");
|
