1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org> |
4 | */ |
5 | |
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 | |
15 | struct nft_range_expr { |
16 | struct nft_data data_from; |
17 | struct nft_data data_to; |
18 | u8 sreg; |
19 | u8 len; |
20 | enum nft_range_ops op:8; |
21 | }; |
22 | |
23 | void 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(p: ®s->data[priv->sreg], q: &priv->data_from, size: priv->len); |
30 | d2 = memcmp(p: ®s->data[priv->sreg], q: &priv->data_to, size: 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 | |
43 | static const struct nla_policy nft_range_policy[NFTA_RANGE_MAX + 1] = { |
44 | [NFTA_RANGE_SREG] = { .type = NLA_U32 }, |
45 | [NFTA_RANGE_OP] = NLA_POLICY_MAX(NLA_BE32, 255), |
46 | [NFTA_RANGE_FROM_DATA] = { .type = NLA_NESTED }, |
47 | [NFTA_RANGE_TO_DATA] = { .type = NLA_NESTED }, |
48 | }; |
49 | |
50 | static 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 = { |
55 | .type = NFT_DATA_VALUE, |
56 | .size = sizeof(priv->data_from), |
57 | }; |
58 | struct nft_data_desc desc_to = { |
59 | .type = NFT_DATA_VALUE, |
60 | .size = sizeof(priv->data_to), |
61 | }; |
62 | int err; |
63 | u32 op; |
64 | |
65 | if (!tb[NFTA_RANGE_SREG] || |
66 | !tb[NFTA_RANGE_OP] || |
67 | !tb[NFTA_RANGE_FROM_DATA] || |
68 | !tb[NFTA_RANGE_TO_DATA]) |
69 | return -EINVAL; |
70 | |
71 | err = nft_data_init(NULL, data: &priv->data_from, desc: &desc_from, |
72 | nla: tb[NFTA_RANGE_FROM_DATA]); |
73 | if (err < 0) |
74 | return err; |
75 | |
76 | err = nft_data_init(NULL, data: &priv->data_to, desc: &desc_to, |
77 | nla: tb[NFTA_RANGE_TO_DATA]); |
78 | if (err < 0) |
79 | goto err1; |
80 | |
81 | if (desc_from.len != desc_to.len) { |
82 | err = -EINVAL; |
83 | goto err2; |
84 | } |
85 | |
86 | err = nft_parse_register_load(attr: tb[NFTA_RANGE_SREG], sreg: &priv->sreg, |
87 | len: desc_from.len); |
88 | if (err < 0) |
89 | goto err2; |
90 | |
91 | err = nft_parse_u32_check(attr: tb[NFTA_RANGE_OP], U8_MAX, dest: &op); |
92 | if (err < 0) |
93 | goto err2; |
94 | |
95 | switch (op) { |
96 | case NFT_RANGE_EQ: |
97 | case NFT_RANGE_NEQ: |
98 | break; |
99 | default: |
100 | err = -EINVAL; |
101 | goto err2; |
102 | } |
103 | |
104 | priv->op = op; |
105 | priv->len = desc_from.len; |
106 | return 0; |
107 | err2: |
108 | nft_data_release(data: &priv->data_to, type: desc_to.type); |
109 | err1: |
110 | nft_data_release(data: &priv->data_from, type: desc_from.type); |
111 | return err; |
112 | } |
113 | |
114 | static int nft_range_dump(struct sk_buff *skb, |
115 | const struct nft_expr *expr, bool reset) |
116 | { |
117 | const struct nft_range_expr *priv = nft_expr_priv(expr); |
118 | |
119 | if (nft_dump_register(skb, attr: NFTA_RANGE_SREG, reg: priv->sreg)) |
120 | goto nla_put_failure; |
121 | if (nla_put_be32(skb, attrtype: NFTA_RANGE_OP, htonl(priv->op))) |
122 | goto nla_put_failure; |
123 | |
124 | if (nft_data_dump(skb, attr: NFTA_RANGE_FROM_DATA, data: &priv->data_from, |
125 | type: NFT_DATA_VALUE, len: priv->len) < 0 || |
126 | nft_data_dump(skb, attr: NFTA_RANGE_TO_DATA, data: &priv->data_to, |
127 | type: NFT_DATA_VALUE, len: priv->len) < 0) |
128 | goto nla_put_failure; |
129 | return 0; |
130 | |
131 | nla_put_failure: |
132 | return -1; |
133 | } |
134 | |
135 | static const struct nft_expr_ops nft_range_ops = { |
136 | .type = &nft_range_type, |
137 | .size = NFT_EXPR_SIZE(sizeof(struct nft_range_expr)), |
138 | .eval = nft_range_eval, |
139 | .init = nft_range_init, |
140 | .dump = nft_range_dump, |
141 | .reduce = NFT_REDUCE_READONLY, |
142 | }; |
143 | |
144 | struct nft_expr_type nft_range_type __read_mostly = { |
145 | .name = "range" , |
146 | .ops = &nft_range_ops, |
147 | .policy = nft_range_policy, |
148 | .maxattr = NFTA_RANGE_MAX, |
149 | .owner = THIS_MODULE, |
150 | }; |
151 | |