1/*
2 * Copyright (c) 2008-2009 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_core.h>
18#include <net/netfilter/nf_tables.h>
19
20struct nft_immediate_expr {
21	struct nft_data		data;
22	enum nft_registers	dreg:8;
23	u8			dlen;
24};
25
26static void nft_immediate_eval(const struct nft_expr *expr,
27			       struct nft_regs *regs,
28			       const struct nft_pktinfo *pkt)
29{
30	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
31
32	nft_data_copy(&regs->data[priv->dreg], &priv->data, priv->dlen);
33}
34
35static const struct nla_policy nft_immediate_policy[NFTA_IMMEDIATE_MAX + 1] = {
36	[NFTA_IMMEDIATE_DREG]	= { .type = NLA_U32 },
37	[NFTA_IMMEDIATE_DATA]	= { .type = NLA_NESTED },
38};
39
40static int nft_immediate_init(const struct nft_ctx *ctx,
41			      const struct nft_expr *expr,
42			      const struct nlattr * const tb[])
43{
44	struct nft_immediate_expr *priv = nft_expr_priv(expr);
45	struct nft_data_desc desc;
46	int err;
47
48	if (tb[NFTA_IMMEDIATE_DREG] == NULL ||
49	    tb[NFTA_IMMEDIATE_DATA] == NULL)
50		return -EINVAL;
51
52	err = nft_data_init(ctx, &priv->data, sizeof(priv->data), &desc,
53			    tb[NFTA_IMMEDIATE_DATA]);
54	if (err < 0)
55		return err;
56	priv->dlen = desc.len;
57
58	priv->dreg = nft_parse_register(tb[NFTA_IMMEDIATE_DREG]);
59	err = nft_validate_register_store(ctx, priv->dreg, &priv->data,
60					  desc.type, desc.len);
61	if (err < 0)
62		goto err1;
63
64	return 0;
65
66err1:
67	nft_data_uninit(&priv->data, desc.type);
68	return err;
69}
70
71static void nft_immediate_destroy(const struct nft_ctx *ctx,
72				  const struct nft_expr *expr)
73{
74	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
75	return nft_data_uninit(&priv->data, nft_dreg_to_type(priv->dreg));
76}
77
78static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr)
79{
80	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
81
82	if (nft_dump_register(skb, NFTA_IMMEDIATE_DREG, priv->dreg))
83		goto nla_put_failure;
84
85	return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data,
86			     nft_dreg_to_type(priv->dreg), priv->dlen);
87
88nla_put_failure:
89	return -1;
90}
91
92static int nft_immediate_validate(const struct nft_ctx *ctx,
93				  const struct nft_expr *expr,
94				  const struct nft_data **data)
95{
96	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
97
98	if (priv->dreg == NFT_REG_VERDICT)
99		*data = &priv->data;
100
101	return 0;
102}
103
104static struct nft_expr_type nft_imm_type;
105static const struct nft_expr_ops nft_imm_ops = {
106	.type		= &nft_imm_type,
107	.size		= NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)),
108	.eval		= nft_immediate_eval,
109	.init		= nft_immediate_init,
110	.destroy	= nft_immediate_destroy,
111	.dump		= nft_immediate_dump,
112	.validate	= nft_immediate_validate,
113};
114
115static struct nft_expr_type nft_imm_type __read_mostly = {
116	.name		= "immediate",
117	.ops		= &nft_imm_ops,
118	.policy		= nft_immediate_policy,
119	.maxattr	= NFTA_IMMEDIATE_MAX,
120	.owner		= THIS_MODULE,
121};
122
123int __init nft_immediate_module_init(void)
124{
125	return nft_register_expr(&nft_imm_type);
126}
127
128void nft_immediate_module_exit(void)
129{
130	nft_unregister_expr(&nft_imm_type);
131}
132