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96518518 PM |
1 | /* |
2 | * Copyright (c) 2008 Patrick McHardy <kaber@trash.net> | |
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.h> | |
18 | // FIXME: | |
19 | #include <net/ipv6.h> | |
20 | ||
21 | struct nft_exthdr { | |
22 | u8 type; | |
23 | u8 offset; | |
24 | u8 len; | |
25 | enum nft_registers dreg:8; | |
26 | }; | |
27 | ||
28 | static void nft_exthdr_eval(const struct nft_expr *expr, | |
a55e22e9 | 29 | struct nft_regs *regs, |
96518518 PM |
30 | const struct nft_pktinfo *pkt) |
31 | { | |
32 | struct nft_exthdr *priv = nft_expr_priv(expr); | |
49499c3e | 33 | u32 *dest = ®s->data[priv->dreg]; |
540436c8 | 34 | unsigned int offset = 0; |
96518518 PM |
35 | int err; |
36 | ||
37 | err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL); | |
38 | if (err < 0) | |
39 | goto err; | |
40 | offset += priv->offset; | |
41 | ||
49499c3e | 42 | dest[priv->len / NFT_REG32_SIZE] = 0; |
fad136ea | 43 | if (skb_copy_bits(pkt->skb, offset, dest, priv->len) < 0) |
96518518 PM |
44 | goto err; |
45 | return; | |
46 | err: | |
a55e22e9 | 47 | regs->verdict.code = NFT_BREAK; |
96518518 PM |
48 | } |
49 | ||
50 | static const struct nla_policy nft_exthdr_policy[NFTA_EXTHDR_MAX + 1] = { | |
51 | [NFTA_EXTHDR_DREG] = { .type = NLA_U32 }, | |
52 | [NFTA_EXTHDR_TYPE] = { .type = NLA_U8 }, | |
53 | [NFTA_EXTHDR_OFFSET] = { .type = NLA_U32 }, | |
54 | [NFTA_EXTHDR_LEN] = { .type = NLA_U32 }, | |
55 | }; | |
56 | ||
57 | static int nft_exthdr_init(const struct nft_ctx *ctx, | |
58 | const struct nft_expr *expr, | |
59 | const struct nlattr * const tb[]) | |
60 | { | |
61 | struct nft_exthdr *priv = nft_expr_priv(expr); | |
21a9e0f1 DC |
62 | u32 offset, len; |
63 | int err; | |
96518518 PM |
64 | |
65 | if (tb[NFTA_EXTHDR_DREG] == NULL || | |
66 | tb[NFTA_EXTHDR_TYPE] == NULL || | |
67 | tb[NFTA_EXTHDR_OFFSET] == NULL || | |
68 | tb[NFTA_EXTHDR_LEN] == NULL) | |
69 | return -EINVAL; | |
70 | ||
36b701fa LGL |
71 | err = nft_parse_u32_check(tb[NFTA_EXTHDR_OFFSET], U8_MAX, &offset); |
72 | if (err < 0) | |
73 | return err; | |
4da449ae | 74 | |
36b701fa LGL |
75 | err = nft_parse_u32_check(tb[NFTA_EXTHDR_LEN], U8_MAX, &len); |
76 | if (err < 0) | |
77 | return err; | |
4da449ae | 78 | |
96518518 | 79 | priv->type = nla_get_u8(tb[NFTA_EXTHDR_TYPE]); |
4da449ae LGL |
80 | priv->offset = offset; |
81 | priv->len = len; | |
b1c96ed3 | 82 | priv->dreg = nft_parse_register(tb[NFTA_EXTHDR_DREG]); |
96518518 | 83 | |
1ec10212 PM |
84 | return nft_validate_register_store(ctx, priv->dreg, NULL, |
85 | NFT_DATA_VALUE, priv->len); | |
96518518 PM |
86 | } |
87 | ||
88 | static int nft_exthdr_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
89 | { | |
90 | const struct nft_exthdr *priv = nft_expr_priv(expr); | |
91 | ||
b1c96ed3 | 92 | if (nft_dump_register(skb, NFTA_EXTHDR_DREG, priv->dreg)) |
96518518 PM |
93 | goto nla_put_failure; |
94 | if (nla_put_u8(skb, NFTA_EXTHDR_TYPE, priv->type)) | |
95 | goto nla_put_failure; | |
96 | if (nla_put_be32(skb, NFTA_EXTHDR_OFFSET, htonl(priv->offset))) | |
97 | goto nla_put_failure; | |
98 | if (nla_put_be32(skb, NFTA_EXTHDR_LEN, htonl(priv->len))) | |
99 | goto nla_put_failure; | |
100 | return 0; | |
101 | ||
102 | nla_put_failure: | |
103 | return -1; | |
104 | } | |
105 | ||
ef1f7df9 PM |
106 | static struct nft_expr_type nft_exthdr_type; |
107 | static const struct nft_expr_ops nft_exthdr_ops = { | |
108 | .type = &nft_exthdr_type, | |
96518518 | 109 | .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)), |
96518518 PM |
110 | .eval = nft_exthdr_eval, |
111 | .init = nft_exthdr_init, | |
112 | .dump = nft_exthdr_dump, | |
ef1f7df9 PM |
113 | }; |
114 | ||
115 | static struct nft_expr_type nft_exthdr_type __read_mostly = { | |
116 | .name = "exthdr", | |
117 | .ops = &nft_exthdr_ops, | |
96518518 PM |
118 | .policy = nft_exthdr_policy, |
119 | .maxattr = NFTA_EXTHDR_MAX, | |
ef1f7df9 | 120 | .owner = THIS_MODULE, |
96518518 PM |
121 | }; |
122 | ||
123 | static int __init nft_exthdr_module_init(void) | |
124 | { | |
ef1f7df9 | 125 | return nft_register_expr(&nft_exthdr_type); |
96518518 PM |
126 | } |
127 | ||
128 | static void __exit nft_exthdr_module_exit(void) | |
129 | { | |
ef1f7df9 | 130 | nft_unregister_expr(&nft_exthdr_type); |
96518518 PM |
131 | } |
132 | ||
133 | module_init(nft_exthdr_module_init); | |
134 | module_exit(nft_exthdr_module_exit); | |
135 | ||
136 | MODULE_LICENSE("GPL"); | |
137 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); | |
138 | MODULE_ALIAS_NFT_EXPR("exthdr"); |