Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
4 *
5 * Development of this code funded by Astaro AG (http://www.astaro.com/)
6 */
7
8#include <linux/kernel.h>
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/netlink.h>
12#include <linux/netfilter.h>
13#include <linux/netfilter/nf_tables.h>
14#include <net/netfilter/nf_tables_core.h>
15#include <net/netfilter/nf_tables.h>
16#include <net/netfilter/nf_tables_offload.h>
17
18struct nft_bitwise {
19 enum nft_registers sreg:8;
20 enum nft_registers dreg:8;
21 u8 len;
22 struct nft_data mask;
23 struct nft_data xor;
24};
25
26void nft_bitwise_eval(const struct nft_expr *expr,
27 struct nft_regs *regs, const struct nft_pktinfo *pkt)
28{
29 const struct nft_bitwise *priv = nft_expr_priv(expr);
30 const u32 *src = ®s->data[priv->sreg];
31 u32 *dst = ®s->data[priv->dreg];
32 unsigned int i;
33
34 for (i = 0; i < DIV_ROUND_UP(priv->len, 4); i++)
35 dst[i] = (src[i] & priv->mask.data[i]) ^ priv->xor.data[i];
36}
37
38static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = {
39 [NFTA_BITWISE_SREG] = { .type = NLA_U32 },
40 [NFTA_BITWISE_DREG] = { .type = NLA_U32 },
41 [NFTA_BITWISE_LEN] = { .type = NLA_U32 },
42 [NFTA_BITWISE_MASK] = { .type = NLA_NESTED },
43 [NFTA_BITWISE_XOR] = { .type = NLA_NESTED },
44};
45
46static int nft_bitwise_init(const struct nft_ctx *ctx,
47 const struct nft_expr *expr,
48 const struct nlattr * const tb[])
49{
50 struct nft_bitwise *priv = nft_expr_priv(expr);
51 struct nft_data_desc d1, d2;
52 u32 len;
53 int err;
54
55 if (tb[NFTA_BITWISE_SREG] == NULL ||
56 tb[NFTA_BITWISE_DREG] == NULL ||
57 tb[NFTA_BITWISE_LEN] == NULL ||
58 tb[NFTA_BITWISE_MASK] == NULL ||
59 tb[NFTA_BITWISE_XOR] == NULL)
60 return -EINVAL;
61
62 err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
63 if (err < 0)
64 return err;
65
66 priv->len = len;
67
68 priv->sreg = nft_parse_register(tb[NFTA_BITWISE_SREG]);
69 err = nft_validate_register_load(priv->sreg, priv->len);
70 if (err < 0)
71 return err;
72
73 priv->dreg = nft_parse_register(tb[NFTA_BITWISE_DREG]);
74 err = nft_validate_register_store(ctx, priv->dreg, NULL,
75 NFT_DATA_VALUE, priv->len);
76 if (err < 0)
77 return err;
78
79 err = nft_data_init(NULL, &priv->mask, sizeof(priv->mask), &d1,
80 tb[NFTA_BITWISE_MASK]);
81 if (err < 0)
82 return err;
83 if (d1.len != priv->len) {
84 err = -EINVAL;
85 goto err1;
86 }
87
88 err = nft_data_init(NULL, &priv->xor, sizeof(priv->xor), &d2,
89 tb[NFTA_BITWISE_XOR]);
90 if (err < 0)
91 goto err1;
92 if (d2.len != priv->len) {
93 err = -EINVAL;
94 goto err2;
95 }
96
97 return 0;
98err2:
99 nft_data_release(&priv->xor, d2.type);
100err1:
101 nft_data_release(&priv->mask, d1.type);
102 return err;
103}
104
105static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr)
106{
107 const struct nft_bitwise *priv = nft_expr_priv(expr);
108
109 if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
110 goto nla_put_failure;
111 if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg))
112 goto nla_put_failure;
113 if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len)))
114 goto nla_put_failure;
115
116 if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask,
117 NFT_DATA_VALUE, priv->len) < 0)
118 goto nla_put_failure;
119
120 if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor,
121 NFT_DATA_VALUE, priv->len) < 0)
122 goto nla_put_failure;
123
124 return 0;
125
126nla_put_failure:
127 return -1;
128}
129
130static struct nft_data zero;
131
132static int nft_bitwise_offload(struct nft_offload_ctx *ctx,
133 struct nft_flow_rule *flow,
134 const struct nft_expr *expr)
135{
136 const struct nft_bitwise *priv = nft_expr_priv(expr);
137
138 if (memcmp(&priv->xor, &zero, sizeof(priv->xor)) ||
139 priv->sreg != priv->dreg)
140 return -EOPNOTSUPP;
141
142 memcpy(&ctx->regs[priv->dreg].mask, &priv->mask, sizeof(priv->mask));
143
144 return 0;
145}
146
147static const struct nft_expr_ops nft_bitwise_ops = {
148 .type = &nft_bitwise_type,
149 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)),
150 .eval = nft_bitwise_eval,
151 .init = nft_bitwise_init,
152 .dump = nft_bitwise_dump,
153 .offload = nft_bitwise_offload,
154};
155
156struct nft_expr_type nft_bitwise_type __read_mostly = {
157 .name = "bitwise",
158 .ops = &nft_bitwise_ops,
159 .policy = nft_bitwise_policy,
160 .maxattr = NFTA_BITWISE_MAX,
161 .owner = THIS_MODULE,
162};