2 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
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.
8 * Development of this code funded by Astaro AG (http://www.astaro.com/)
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>
25 enum nft_registers dreg:8;
28 static void nft_exthdr_eval(const struct nft_expr *expr,
29 struct nft_regs *regs,
30 const struct nft_pktinfo *pkt)
32 struct nft_exthdr *priv = nft_expr_priv(expr);
33 u32 *dest = ®s->data[priv->dreg];
34 unsigned int offset = 0;
37 err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL);
40 offset += priv->offset;
42 dest[priv->len / NFT_REG32_SIZE] = 0;
43 if (skb_copy_bits(pkt->skb, offset, dest, priv->len) < 0)
47 regs->verdict.code = NFT_BREAK;
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 },
57 static int nft_exthdr_init(const struct nft_ctx *ctx,
58 const struct nft_expr *expr,
59 const struct nlattr * const tb[])
61 struct nft_exthdr *priv = nft_expr_priv(expr);
64 if (tb[NFTA_EXTHDR_DREG] == NULL ||
65 tb[NFTA_EXTHDR_TYPE] == NULL ||
66 tb[NFTA_EXTHDR_OFFSET] == NULL ||
67 tb[NFTA_EXTHDR_LEN] == NULL)
70 err = nft_parse_u32_check(tb[NFTA_EXTHDR_OFFSET], U8_MAX, &offset);
74 err = nft_parse_u32_check(tb[NFTA_EXTHDR_LEN], U8_MAX, &len);
78 priv->type = nla_get_u8(tb[NFTA_EXTHDR_TYPE]);
79 priv->offset = offset;
81 priv->dreg = nft_parse_register(tb[NFTA_EXTHDR_DREG]);
83 return nft_validate_register_store(ctx, priv->dreg, NULL,
84 NFT_DATA_VALUE, priv->len);
87 static int nft_exthdr_dump(struct sk_buff *skb, const struct nft_expr *expr)
89 const struct nft_exthdr *priv = nft_expr_priv(expr);
91 if (nft_dump_register(skb, NFTA_EXTHDR_DREG, priv->dreg))
93 if (nla_put_u8(skb, NFTA_EXTHDR_TYPE, priv->type))
95 if (nla_put_be32(skb, NFTA_EXTHDR_OFFSET, htonl(priv->offset)))
97 if (nla_put_be32(skb, NFTA_EXTHDR_LEN, htonl(priv->len)))
105 static struct nft_expr_type nft_exthdr_type;
106 static const struct nft_expr_ops nft_exthdr_ops = {
107 .type = &nft_exthdr_type,
108 .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
109 .eval = nft_exthdr_eval,
110 .init = nft_exthdr_init,
111 .dump = nft_exthdr_dump,
114 static struct nft_expr_type nft_exthdr_type __read_mostly = {
116 .ops = &nft_exthdr_ops,
117 .policy = nft_exthdr_policy,
118 .maxattr = NFTA_EXTHDR_MAX,
119 .owner = THIS_MODULE,
122 static int __init nft_exthdr_module_init(void)
124 return nft_register_expr(&nft_exthdr_type);
127 static void __exit nft_exthdr_module_exit(void)
129 nft_unregister_expr(&nft_exthdr_type);
132 module_init(nft_exthdr_module_init);
133 module_exit(nft_exthdr_module_exit);
135 MODULE_LICENSE("GPL");
136 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
137 MODULE_ALIAS_NFT_EXPR("exthdr");