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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, | |
a55e22e9 | 29 | struct nft_regs *regs, |
96518518 PM |
30 | const struct nft_pktinfo *pkt) |
31 | { | |
32 | const struct nft_bitwise *priv = nft_expr_priv(expr); | |
49499c3e PM |
33 | const u32 *src = ®s->data[priv->sreg]; |
34 | u32 *dst = ®s->data[priv->dreg]; | |
96518518 PM |
35 | unsigned int i; |
36 | ||
fad136ea PM |
37 | for (i = 0; i < DIV_ROUND_UP(priv->len, 4); i++) |
38 | dst[i] = (src[i] & priv->mask.data[i]) ^ priv->xor.data[i]; | |
96518518 PM |
39 | } |
40 | ||
41 | static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = { | |
42 | [NFTA_BITWISE_SREG] = { .type = NLA_U32 }, | |
43 | [NFTA_BITWISE_DREG] = { .type = NLA_U32 }, | |
44 | [NFTA_BITWISE_LEN] = { .type = NLA_U32 }, | |
45 | [NFTA_BITWISE_MASK] = { .type = NLA_NESTED }, | |
46 | [NFTA_BITWISE_XOR] = { .type = NLA_NESTED }, | |
47 | }; | |
48 | ||
49 | static int nft_bitwise_init(const struct nft_ctx *ctx, | |
50 | const struct nft_expr *expr, | |
51 | const struct nlattr * const tb[]) | |
52 | { | |
53 | struct nft_bitwise *priv = nft_expr_priv(expr); | |
54 | struct nft_data_desc d1, d2; | |
36b701fa | 55 | u32 len; |
96518518 PM |
56 | int err; |
57 | ||
58 | if (tb[NFTA_BITWISE_SREG] == NULL || | |
59 | tb[NFTA_BITWISE_DREG] == NULL || | |
60 | tb[NFTA_BITWISE_LEN] == NULL || | |
61 | tb[NFTA_BITWISE_MASK] == NULL || | |
62 | tb[NFTA_BITWISE_XOR] == NULL) | |
63 | return -EINVAL; | |
64 | ||
36b701fa LGL |
65 | err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len); |
66 | if (err < 0) | |
67 | return err; | |
68 | ||
69 | priv->len = len; | |
70 | ||
b1c96ed3 | 71 | priv->sreg = nft_parse_register(tb[NFTA_BITWISE_SREG]); |
d07db988 | 72 | err = nft_validate_register_load(priv->sreg, priv->len); |
96518518 PM |
73 | if (err < 0) |
74 | return err; | |
75 | ||
b1c96ed3 | 76 | priv->dreg = nft_parse_register(tb[NFTA_BITWISE_DREG]); |
1ec10212 PM |
77 | err = nft_validate_register_store(ctx, priv->dreg, NULL, |
78 | NFT_DATA_VALUE, priv->len); | |
96518518 PM |
79 | if (err < 0) |
80 | return err; | |
81 | ||
d0a11fc3 PM |
82 | err = nft_data_init(NULL, &priv->mask, sizeof(priv->mask), &d1, |
83 | tb[NFTA_BITWISE_MASK]); | |
96518518 PM |
84 | if (err < 0) |
85 | return err; | |
86 | if (d1.len != priv->len) | |
87 | return -EINVAL; | |
88 | ||
d0a11fc3 PM |
89 | err = nft_data_init(NULL, &priv->xor, sizeof(priv->xor), &d2, |
90 | tb[NFTA_BITWISE_XOR]); | |
96518518 PM |
91 | if (err < 0) |
92 | return err; | |
93 | if (d2.len != priv->len) | |
94 | return -EINVAL; | |
95 | ||
96 | return 0; | |
97 | } | |
98 | ||
99 | static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
100 | { | |
101 | const struct nft_bitwise *priv = nft_expr_priv(expr); | |
102 | ||
b1c96ed3 | 103 | if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg)) |
96518518 | 104 | goto nla_put_failure; |
b1c96ed3 | 105 | if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg)) |
96518518 PM |
106 | goto nla_put_failure; |
107 | if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len))) | |
108 | goto nla_put_failure; | |
109 | ||
110 | if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask, | |
111 | NFT_DATA_VALUE, priv->len) < 0) | |
112 | goto nla_put_failure; | |
113 | ||
114 | if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor, | |
115 | NFT_DATA_VALUE, priv->len) < 0) | |
116 | goto nla_put_failure; | |
117 | ||
118 | return 0; | |
119 | ||
120 | nla_put_failure: | |
121 | return -1; | |
122 | } | |
123 | ||
ef1f7df9 PM |
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 | ||
4e24877e | 132 | struct nft_expr_type nft_bitwise_type __read_mostly = { |
ef1f7df9 PM |
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 | 138 | }; |