Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9#include <linux/kernel.h>
10#include <linux/init.h>
11#include <linux/module.h>
12#include <linux/netlink.h>
13#include <linux/netfilter.h>
14#include <linux/netfilter/nf_tables.h>
15#include <net/netfilter/nf_tables_core.h>
16#include <net/netfilter/nf_tables.h>
17
18struct nft_range_expr {
19 struct nft_data data_from;
20 struct nft_data data_to;
21 enum nft_registers sreg:8;
22 u8 len;
23 enum nft_range_ops op:8;
24};
25
26static void nft_range_eval(const struct nft_expr *expr,
27 struct nft_regs *regs,
28 const struct nft_pktinfo *pkt)
29{
30 const struct nft_range_expr *priv = nft_expr_priv(expr);
31 int d1, d2;
32
33 d1 = memcmp(®s->data[priv->sreg], &priv->data_from, priv->len);
34 d2 = memcmp(®s->data[priv->sreg], &priv->data_to, priv->len);
35 switch (priv->op) {
36 case NFT_RANGE_EQ:
37 if (d1 < 0 || d2 > 0)
38 regs->verdict.code = NFT_BREAK;
39 break;
40 case NFT_RANGE_NEQ:
41 if (d1 >= 0 && d2 <= 0)
42 regs->verdict.code = NFT_BREAK;
43 break;
44 }
45}
46
47static const struct nla_policy nft_range_policy[NFTA_RANGE_MAX + 1] = {
48 [NFTA_RANGE_SREG] = { .type = NLA_U32 },
49 [NFTA_RANGE_OP] = { .type = NLA_U32 },
50 [NFTA_RANGE_FROM_DATA] = { .type = NLA_NESTED },
51 [NFTA_RANGE_TO_DATA] = { .type = NLA_NESTED },
52};
53
54static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
55 const struct nlattr * const tb[])
56{
57 struct nft_range_expr *priv = nft_expr_priv(expr);
58 struct nft_data_desc desc_from, desc_to;
59 int err;
60 u32 op;
61
62 err = nft_data_init(NULL, &priv->data_from, sizeof(priv->data_from),
63 &desc_from, tb[NFTA_RANGE_FROM_DATA]);
64 if (err < 0)
65 return err;
66
67 err = nft_data_init(NULL, &priv->data_to, sizeof(priv->data_to),
68 &desc_to, tb[NFTA_RANGE_TO_DATA]);
69 if (err < 0)
70 goto err1;
71
72 if (desc_from.len != desc_to.len) {
73 err = -EINVAL;
74 goto err2;
75 }
76
77 priv->sreg = nft_parse_register(tb[NFTA_RANGE_SREG]);
78 err = nft_validate_register_load(priv->sreg, desc_from.len);
79 if (err < 0)
80 goto err2;
81
82 err = nft_parse_u32_check(tb[NFTA_RANGE_OP], U8_MAX, &op);
83 if (err < 0)
84 goto err2;
85
86 switch (op) {
87 case NFT_RANGE_EQ:
88 case NFT_RANGE_NEQ:
89 break;
90 default:
91 err = -EINVAL;
92 goto err2;
93 }
94
95 priv->op = op;
96 priv->len = desc_from.len;
97 return 0;
98err2:
99 nft_data_uninit(&priv->data_to, desc_to.type);
100err1:
101 nft_data_uninit(&priv->data_from, desc_from.type);
102 return err;
103}
104
105static int nft_range_dump(struct sk_buff *skb, const struct nft_expr *expr)
106{
107 const struct nft_range_expr *priv = nft_expr_priv(expr);
108
109 if (nft_dump_register(skb, NFTA_RANGE_SREG, priv->sreg))
110 goto nla_put_failure;
111 if (nla_put_be32(skb, NFTA_RANGE_OP, htonl(priv->op)))
112 goto nla_put_failure;
113
114 if (nft_data_dump(skb, NFTA_RANGE_FROM_DATA, &priv->data_from,
115 NFT_DATA_VALUE, priv->len) < 0 ||
116 nft_data_dump(skb, NFTA_RANGE_TO_DATA, &priv->data_to,
117 NFT_DATA_VALUE, priv->len) < 0)
118 goto nla_put_failure;
119 return 0;
120
121nla_put_failure:
122 return -1;
123}
124
125static struct nft_expr_type nft_range_type;
126static const struct nft_expr_ops nft_range_ops = {
127 .type = &nft_range_type,
128 .size = NFT_EXPR_SIZE(sizeof(struct nft_range_expr)),
129 .eval = nft_range_eval,
130 .init = nft_range_init,
131 .dump = nft_range_dump,
132};
133
134static struct nft_expr_type nft_range_type __read_mostly = {
135 .name = "range",
136 .ops = &nft_range_ops,
137 .policy = nft_range_policy,
138 .maxattr = NFTA_RANGE_MAX,
139 .owner = THIS_MODULE,
140};
141
142int __init nft_range_module_init(void)
143{
144 return nft_register_expr(&nft_range_type);
145}
146
147void nft_range_module_exit(void)
148{
149 nft_unregister_expr(&nft_range_type);
150}