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
|
/*
* 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/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_tables.h>
struct nft_cmp_expr {
struct nft_data data;
enum nft_registers sreg:8;
u8 len;
enum nft_cmp_ops op:8;
};
static void nft_cmp_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_cmp_expr *priv = nft_expr_priv(expr);
int d;
d = memcmp(®s->data[priv->sreg], &priv->data, priv->len);
switch (priv->op) {
case NFT_CMP_EQ:
if (d != 0)
goto mismatch;
break;
case NFT_CMP_NEQ:
if (d == 0)
goto mismatch;
break;
case NFT_CMP_LT:
if (d == 0)
goto mismatch;
case NFT_CMP_LTE:
if (d > 0)
goto mismatch;
break;
case NFT_CMP_GT:
if (d == 0)
goto mismatch;
case NFT_CMP_GTE:
if (d < 0)
goto mismatch;
break;
}
return;
mismatch:
regs->verdict.code = NFT_BREAK;
}
static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = {
[NFTA_CMP_SREG] = { .type = NLA_U32 },
[NFTA_CMP_OP] = { .type = NLA_U32 },
[NFTA_CMP_DATA] = { .type = NLA_NESTED },
};
static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_cmp_expr *priv = nft_expr_priv(expr);
struct nft_data_desc desc;
int err;
err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc,
tb[NFTA_CMP_DATA]);
BUG_ON(err < 0);
priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
err = nft_validate_register_load(priv->sreg, desc.len);
if (err < 0)
return err;
priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
priv->len = desc.len;
return 0;
}
static int nft_cmp_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_cmp_expr *priv = nft_expr_priv(expr);
if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))
goto nla_put_failure;
if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
NFT_DATA_VALUE, priv->len) < 0)
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static const struct nft_expr_ops nft_cmp_ops = {
.type = &nft_cmp_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),
.eval = nft_cmp_eval,
.init = nft_cmp_init,
.dump = nft_cmp_dump,
};
static int nft_cmp_fast_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
struct nft_data_desc desc;
struct nft_data data;
u32 mask;
int err;
err = nft_data_init(NULL, &data, sizeof(data), &desc,
tb[NFTA_CMP_DATA]);
BUG_ON(err < 0);
priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
err = nft_validate_register_load(priv->sreg, desc.len);
if (err < 0)
return err;
desc.len *= BITS_PER_BYTE;
mask = nft_cmp_fast_mask(desc.len);
priv->data = data.data[0] & mask;
priv->len = desc.len;
return 0;
}
static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
struct nft_data data;
if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_CMP_OP, htonl(NFT_CMP_EQ)))
goto nla_put_failure;
data.data[0] = priv->data;
if (nft_data_dump(skb, NFTA_CMP_DATA, &data,
NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0)
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
const struct nft_expr_ops nft_cmp_fast_ops = {
.type = &nft_cmp_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),
.eval = NULL, /* inlined */
.init = nft_cmp_fast_init,
.dump = nft_cmp_fast_dump,
};
static const struct nft_expr_ops *
nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])
{
struct nft_data_desc desc;
struct nft_data data;
enum nft_cmp_ops op;
int err;
if (tb[NFTA_CMP_SREG] == NULL ||
tb[NFTA_CMP_OP] == NULL ||
tb[NFTA_CMP_DATA] == NULL)
return ERR_PTR(-EINVAL);
op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
switch (op) {
case NFT_CMP_EQ:
case NFT_CMP_NEQ:
case NFT_CMP_LT:
case NFT_CMP_LTE:
case NFT_CMP_GT:
case NFT_CMP_GTE:
break;
default:
return ERR_PTR(-EINVAL);
}
err = nft_data_init(NULL, &data, sizeof(data), &desc,
tb[NFTA_CMP_DATA]);
if (err < 0)
return ERR_PTR(err);
if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ)
return &nft_cmp_fast_ops;
else
return &nft_cmp_ops;
}
struct nft_expr_type nft_cmp_type __read_mostly = {
.name = "cmp",
.select_ops = nft_cmp_select_ops,
.policy = nft_cmp_policy,
.maxattr = NFTA_CMP_MAX,
.owner = THIS_MODULE,
};
|
