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