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
|
/*
* Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org>
*
* 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.
*/
#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_range_expr {
struct nft_data data_from;
struct nft_data data_to;
enum nft_registers sreg:8;
u8 len;
enum nft_range_ops op:8;
};
static void nft_range_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_range_expr *priv = nft_expr_priv(expr);
bool mismatch;
int d1, d2;
d1 = memcmp(®s->data[priv->sreg], &priv->data_from, priv->len);
d2 = memcmp(®s->data[priv->sreg], &priv->data_to, priv->len);
switch (priv->op) {
case NFT_RANGE_EQ:
mismatch = (d1 < 0 || d2 > 0);
break;
case NFT_RANGE_NEQ:
mismatch = (d1 >= 0 && d2 <= 0);
break;
}
if (mismatch)
regs->verdict.code = NFT_BREAK;
}
static const struct nla_policy nft_range_policy[NFTA_RANGE_MAX + 1] = {
[NFTA_RANGE_SREG] = { .type = NLA_U32 },
[NFTA_RANGE_OP] = { .type = NLA_U32 },
[NFTA_RANGE_FROM_DATA] = { .type = NLA_NESTED },
[NFTA_RANGE_TO_DATA] = { .type = NLA_NESTED },
};
static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_range_expr *priv = nft_expr_priv(expr);
struct nft_data_desc desc_from, desc_to;
int err;
err = nft_data_init(NULL, &priv->data_from, sizeof(priv->data_from),
&desc_from, tb[NFTA_RANGE_FROM_DATA]);
if (err < 0)
return err;
err = nft_data_init(NULL, &priv->data_to, sizeof(priv->data_to),
&desc_to, tb[NFTA_RANGE_TO_DATA]);
if (err < 0)
goto err1;
if (desc_from.len != desc_to.len) {
err = -EINVAL;
goto err2;
}
priv->sreg = nft_parse_register(tb[NFTA_RANGE_SREG]);
err = nft_validate_register_load(priv->sreg, desc_from.len);
if (err < 0)
goto err2;
priv->op = ntohl(nla_get_be32(tb[NFTA_RANGE_OP]));
priv->len = desc_from.len;
return 0;
err2:
nft_data_uninit(&priv->data_to, desc_to.type);
err1:
nft_data_uninit(&priv->data_from, desc_from.type);
return err;
}
static int nft_range_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_range_expr *priv = nft_expr_priv(expr);
if (nft_dump_register(skb, NFTA_RANGE_SREG, priv->sreg))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_RANGE_OP, htonl(priv->op)))
goto nla_put_failure;
if (nft_data_dump(skb, NFTA_RANGE_FROM_DATA, &priv->data_from,
NFT_DATA_VALUE, priv->len) < 0 ||
nft_data_dump(skb, NFTA_RANGE_TO_DATA, &priv->data_to,
NFT_DATA_VALUE, priv->len) < 0)
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static struct nft_expr_type nft_range_type;
static const struct nft_expr_ops nft_range_ops = {
.type = &nft_range_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_range_expr)),
.eval = nft_range_eval,
.init = nft_range_init,
.dump = nft_range_dump,
};
static struct nft_expr_type nft_range_type __read_mostly = {
.name = "range",
.ops = &nft_range_ops,
.policy = nft_range_policy,
.maxattr = NFTA_RANGE_MAX,
.owner = THIS_MODULE,
};
int __init nft_range_module_init(void)
{
return nft_register_expr(&nft_range_type);
}
void nft_range_module_exit(void)
{
nft_unregister_expr(&nft_range_type);
}
|
