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
|
/*
* 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_bitwise {
enum nft_registers sreg:8;
enum nft_registers dreg:8;
u8 len;
struct nft_data mask;
struct nft_data xor;
};
void nft_bitwise_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt)
{
const struct nft_bitwise *priv = nft_expr_priv(expr);
const u32 *src = ®s->data[priv->sreg];
u32 *dst = ®s->data[priv->dreg];
unsigned int i;
for (i = 0; i < DIV_ROUND_UP(priv->len, 4); i++)
dst[i] = (src[i] & priv->mask.data[i]) ^ priv->xor.data[i];
}
static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = {
[NFTA_BITWISE_SREG] = { .type = NLA_U32 },
[NFTA_BITWISE_DREG] = { .type = NLA_U32 },
[NFTA_BITWISE_LEN] = { .type = NLA_U32 },
[NFTA_BITWISE_MASK] = { .type = NLA_NESTED },
[NFTA_BITWISE_XOR] = { .type = NLA_NESTED },
};
static int nft_bitwise_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_bitwise *priv = nft_expr_priv(expr);
struct nft_data_desc d1, d2;
u32 len;
int err;
if (tb[NFTA_BITWISE_SREG] == NULL ||
tb[NFTA_BITWISE_DREG] == NULL ||
tb[NFTA_BITWISE_LEN] == NULL ||
tb[NFTA_BITWISE_MASK] == NULL ||
tb[NFTA_BITWISE_XOR] == NULL)
return -EINVAL;
err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
if (err < 0)
return err;
priv->len = len;
priv->sreg = nft_parse_register(tb[NFTA_BITWISE_SREG]);
err = nft_validate_register_load(priv->sreg, priv->len);
if (err < 0)
return err;
priv->dreg = nft_parse_register(tb[NFTA_BITWISE_DREG]);
err = nft_validate_register_store(ctx, priv->dreg, NULL,
NFT_DATA_VALUE, priv->len);
if (err < 0)
return err;
err = nft_data_init(NULL, &priv->mask, sizeof(priv->mask), &d1,
tb[NFTA_BITWISE_MASK]);
if (err < 0)
return err;
if (d1.len != priv->len) {
err = -EINVAL;
goto err1;
}
err = nft_data_init(NULL, &priv->xor, sizeof(priv->xor), &d2,
tb[NFTA_BITWISE_XOR]);
if (err < 0)
goto err1;
if (d2.len != priv->len) {
err = -EINVAL;
goto err2;
}
return 0;
err2:
nft_data_release(&priv->xor, d2.type);
err1:
nft_data_release(&priv->mask, d1.type);
return err;
}
static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_bitwise *priv = nft_expr_priv(expr);
if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
goto nla_put_failure;
if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len)))
goto nla_put_failure;
if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask,
NFT_DATA_VALUE, priv->len) < 0)
goto nla_put_failure;
if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor,
NFT_DATA_VALUE, priv->len) < 0)
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static const struct nft_expr_ops nft_bitwise_ops = {
.type = &nft_bitwise_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)),
.eval = nft_bitwise_eval,
.init = nft_bitwise_init,
.dump = nft_bitwise_dump,
};
struct nft_expr_type nft_bitwise_type __read_mostly = {
.name = "bitwise",
.ops = &nft_bitwise_ops,
.policy = nft_bitwise_policy,
.maxattr = NFTA_BITWISE_MAX,
.owner = THIS_MODULE,
};
|
