xref: /openbmc/linux/net/netfilter/nft_immediate.c (revision b9b77222)
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 
20 static void nft_immediate_eval(const struct nft_expr *expr,
21 			       struct nft_regs *regs,
22 			       const struct nft_pktinfo *pkt)
23 {
24 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
25 
26 	nft_data_copy(&regs->data[priv->dreg], &priv->data, priv->dlen);
27 }
28 
29 static const struct nla_policy nft_immediate_policy[NFTA_IMMEDIATE_MAX + 1] = {
30 	[NFTA_IMMEDIATE_DREG]	= { .type = NLA_U32 },
31 	[NFTA_IMMEDIATE_DATA]	= { .type = NLA_NESTED },
32 };
33 
34 static int nft_immediate_init(const struct nft_ctx *ctx,
35 			      const struct nft_expr *expr,
36 			      const struct nlattr * const tb[])
37 {
38 	struct nft_immediate_expr *priv = nft_expr_priv(expr);
39 	struct nft_data_desc desc;
40 	int err;
41 
42 	if (tb[NFTA_IMMEDIATE_DREG] == NULL ||
43 	    tb[NFTA_IMMEDIATE_DATA] == NULL)
44 		return -EINVAL;
45 
46 	err = nft_data_init(ctx, &priv->data, sizeof(priv->data), &desc,
47 			    tb[NFTA_IMMEDIATE_DATA]);
48 	if (err < 0)
49 		return err;
50 
51 	priv->dlen = desc.len;
52 
53 	priv->dreg = nft_parse_register(tb[NFTA_IMMEDIATE_DREG]);
54 	err = nft_validate_register_store(ctx, priv->dreg, &priv->data,
55 					  desc.type, desc.len);
56 	if (err < 0)
57 		goto err1;
58 
59 	return 0;
60 
61 err1:
62 	nft_data_release(&priv->data, desc.type);
63 	return err;
64 }
65 
66 static void nft_immediate_activate(const struct nft_ctx *ctx,
67 				   const struct nft_expr *expr)
68 {
69 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
70 
71 	return nft_data_hold(&priv->data, nft_dreg_to_type(priv->dreg));
72 }
73 
74 static void nft_immediate_deactivate(const struct nft_ctx *ctx,
75 				     const struct nft_expr *expr)
76 {
77 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
78 
79 	return nft_data_release(&priv->data, nft_dreg_to_type(priv->dreg));
80 }
81 
82 static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr)
83 {
84 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
85 
86 	if (nft_dump_register(skb, NFTA_IMMEDIATE_DREG, priv->dreg))
87 		goto nla_put_failure;
88 
89 	return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data,
90 			     nft_dreg_to_type(priv->dreg), priv->dlen);
91 
92 nla_put_failure:
93 	return -1;
94 }
95 
96 static int nft_immediate_validate(const struct nft_ctx *ctx,
97 				  const struct nft_expr *expr,
98 				  const struct nft_data **d)
99 {
100 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
101 	struct nft_ctx *pctx = (struct nft_ctx *)ctx;
102 	const struct nft_data *data;
103 	int err;
104 
105 	if (priv->dreg != NFT_REG_VERDICT)
106 		return 0;
107 
108 	data = &priv->data;
109 
110 	switch (data->verdict.code) {
111 	case NFT_JUMP:
112 	case NFT_GOTO:
113 		pctx->level++;
114 		err = nft_chain_validate(ctx, data->verdict.chain);
115 		if (err < 0)
116 			return err;
117 		pctx->level--;
118 		break;
119 	default:
120 		break;
121 	}
122 
123 	return 0;
124 }
125 
126 static const struct nft_expr_ops nft_imm_ops = {
127 	.type		= &nft_imm_type,
128 	.size		= NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)),
129 	.eval		= nft_immediate_eval,
130 	.init		= nft_immediate_init,
131 	.activate	= nft_immediate_activate,
132 	.deactivate	= nft_immediate_deactivate,
133 	.dump		= nft_immediate_dump,
134 	.validate	= nft_immediate_validate,
135 };
136 
137 struct nft_expr_type nft_imm_type __read_mostly = {
138 	.name		= "immediate",
139 	.ops		= &nft_imm_ops,
140 	.policy		= nft_immediate_policy,
141 	.maxattr	= NFTA_IMMEDIATE_MAX,
142 	.owner		= THIS_MODULE,
143 };
144