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96518518 | 1 | /* |
ef1f7df9 | 2 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
96518518 PM |
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 | * Development of this code funded by Astaro AG (http://www.astaro.com/) | |
9 | */ | |
10 | ||
11 | #include <linux/kernel.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/netlink.h> | |
15 | #include <linux/netfilter.h> | |
16 | #include <linux/netfilter/nf_tables.h> | |
17 | #include <net/netfilter/nf_tables_core.h> | |
18 | #include <net/netfilter/nf_tables.h> | |
19 | ||
20 | struct nft_bitwise { | |
21 | enum nft_registers sreg:8; | |
22 | enum nft_registers dreg:8; | |
23 | u8 len; | |
24 | struct nft_data mask; | |
25 | struct nft_data xor; | |
26 | }; | |
27 | ||
28 | static void nft_bitwise_eval(const struct nft_expr *expr, | |
29 | struct nft_data data[NFT_REG_MAX + 1], | |
30 | const struct nft_pktinfo *pkt) | |
31 | { | |
32 | const struct nft_bitwise *priv = nft_expr_priv(expr); | |
33 | const struct nft_data *src = &data[priv->sreg]; | |
34 | struct nft_data *dst = &data[priv->dreg]; | |
35 | unsigned int i; | |
36 | ||
37 | for (i = 0; i < DIV_ROUND_UP(priv->len, 4); i++) { | |
38 | dst->data[i] = (src->data[i] & priv->mask.data[i]) ^ | |
39 | priv->xor.data[i]; | |
40 | } | |
41 | } | |
42 | ||
43 | static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = { | |
44 | [NFTA_BITWISE_SREG] = { .type = NLA_U32 }, | |
45 | [NFTA_BITWISE_DREG] = { .type = NLA_U32 }, | |
46 | [NFTA_BITWISE_LEN] = { .type = NLA_U32 }, | |
47 | [NFTA_BITWISE_MASK] = { .type = NLA_NESTED }, | |
48 | [NFTA_BITWISE_XOR] = { .type = NLA_NESTED }, | |
49 | }; | |
50 | ||
51 | static int nft_bitwise_init(const struct nft_ctx *ctx, | |
52 | const struct nft_expr *expr, | |
53 | const struct nlattr * const tb[]) | |
54 | { | |
55 | struct nft_bitwise *priv = nft_expr_priv(expr); | |
56 | struct nft_data_desc d1, d2; | |
57 | int err; | |
58 | ||
59 | if (tb[NFTA_BITWISE_SREG] == NULL || | |
60 | tb[NFTA_BITWISE_DREG] == NULL || | |
61 | tb[NFTA_BITWISE_LEN] == NULL || | |
62 | tb[NFTA_BITWISE_MASK] == NULL || | |
63 | tb[NFTA_BITWISE_XOR] == NULL) | |
64 | return -EINVAL; | |
65 | ||
45d9bcda PM |
66 | priv->len = ntohl(nla_get_be32(tb[NFTA_BITWISE_LEN])); |
67 | ||
96518518 PM |
68 | priv->sreg = ntohl(nla_get_be32(tb[NFTA_BITWISE_SREG])); |
69 | err = nft_validate_input_register(priv->sreg); | |
70 | if (err < 0) | |
71 | return err; | |
72 | ||
73 | priv->dreg = ntohl(nla_get_be32(tb[NFTA_BITWISE_DREG])); | |
74 | err = nft_validate_output_register(priv->dreg); | |
75 | if (err < 0) | |
76 | return err; | |
45d9bcda PM |
77 | |
78 | err = nft_validate_data_load(ctx, priv->dreg, NULL, | |
79 | NFT_DATA_VALUE, priv->len); | |
96518518 PM |
80 | if (err < 0) |
81 | return err; | |
82 | ||
96518518 PM |
83 | err = nft_data_init(NULL, &priv->mask, &d1, tb[NFTA_BITWISE_MASK]); |
84 | if (err < 0) | |
85 | return err; | |
86 | if (d1.len != priv->len) | |
87 | return -EINVAL; | |
88 | ||
89 | err = nft_data_init(NULL, &priv->xor, &d2, tb[NFTA_BITWISE_XOR]); | |
90 | if (err < 0) | |
91 | return err; | |
92 | if (d2.len != priv->len) | |
93 | return -EINVAL; | |
94 | ||
95 | return 0; | |
96 | } | |
97 | ||
98 | static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
99 | { | |
100 | const struct nft_bitwise *priv = nft_expr_priv(expr); | |
101 | ||
102 | if (nla_put_be32(skb, NFTA_BITWISE_SREG, htonl(priv->sreg))) | |
103 | goto nla_put_failure; | |
104 | if (nla_put_be32(skb, NFTA_BITWISE_DREG, htonl(priv->dreg))) | |
105 | goto nla_put_failure; | |
106 | if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len))) | |
107 | goto nla_put_failure; | |
108 | ||
109 | if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask, | |
110 | NFT_DATA_VALUE, priv->len) < 0) | |
111 | goto nla_put_failure; | |
112 | ||
113 | if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor, | |
114 | NFT_DATA_VALUE, priv->len) < 0) | |
115 | goto nla_put_failure; | |
116 | ||
117 | return 0; | |
118 | ||
119 | nla_put_failure: | |
120 | return -1; | |
121 | } | |
122 | ||
ef1f7df9 PM |
123 | static struct nft_expr_type nft_bitwise_type; |
124 | static const struct nft_expr_ops nft_bitwise_ops = { | |
125 | .type = &nft_bitwise_type, | |
96518518 | 126 | .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)), |
96518518 PM |
127 | .eval = nft_bitwise_eval, |
128 | .init = nft_bitwise_init, | |
129 | .dump = nft_bitwise_dump, | |
ef1f7df9 PM |
130 | }; |
131 | ||
132 | static struct nft_expr_type nft_bitwise_type __read_mostly = { | |
133 | .name = "bitwise", | |
134 | .ops = &nft_bitwise_ops, | |
96518518 PM |
135 | .policy = nft_bitwise_policy, |
136 | .maxattr = NFTA_BITWISE_MAX, | |
ef1f7df9 | 137 | .owner = THIS_MODULE, |
96518518 PM |
138 | }; |
139 | ||
140 | int __init nft_bitwise_module_init(void) | |
141 | { | |
ef1f7df9 | 142 | return nft_register_expr(&nft_bitwise_type); |
96518518 PM |
143 | } |
144 | ||
145 | void nft_bitwise_module_exit(void) | |
146 | { | |
ef1f7df9 | 147 | nft_unregister_expr(&nft_bitwise_type); |
96518518 | 148 | } |