1/*
2 * Copyright (c) 2014 Intel Corporation
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 */
9
10#include <linux/kernel.h>
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/netlink.h>
14#include <linux/netfilter.h>
15#include <linux/netfilter/nf_tables.h>
16#include <net/netfilter/nf_tables.h>
17#include <net/netfilter/nft_meta.h>
18
19#include "../br_private.h"
20
21static void nft_meta_bridge_get_eval(const struct nft_expr *expr,
22				     struct nft_data data[NFT_REG_MAX + 1],
23				     const struct nft_pktinfo *pkt)
24{
25	const struct nft_meta *priv = nft_expr_priv(expr);
26	const struct net_device *in = pkt->in, *out = pkt->out;
27	struct nft_data *dest = &data[priv->dreg];
28	const struct net_bridge_port *p;
29
30	switch (priv->key) {
31	case NFT_META_BRI_IIFNAME:
32		if (in == NULL || (p = br_port_get_rcu(in)) == NULL)
33			goto err;
34		break;
35	case NFT_META_BRI_OIFNAME:
36		if (out == NULL || (p = br_port_get_rcu(out)) == NULL)
37			goto err;
38		break;
39	default:
40		goto out;
41	}
42
43	strncpy((char *)dest->data, p->br->dev->name, sizeof(dest->data));
44	return;
45out:
46	return nft_meta_get_eval(expr, data, pkt);
47err:
48	data[NFT_REG_VERDICT].verdict = NFT_BREAK;
49}
50
51static int nft_meta_bridge_get_init(const struct nft_ctx *ctx,
52				    const struct nft_expr *expr,
53				    const struct nlattr * const tb[])
54{
55	struct nft_meta *priv = nft_expr_priv(expr);
56	int err;
57
58	priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
59	switch (priv->key) {
60	case NFT_META_BRI_IIFNAME:
61	case NFT_META_BRI_OIFNAME:
62		break;
63	default:
64		return nft_meta_get_init(ctx, expr, tb);
65	}
66
67	priv->dreg = ntohl(nla_get_be32(tb[NFTA_META_DREG]));
68	err = nft_validate_output_register(priv->dreg);
69	if (err < 0)
70		return err;
71
72	err = nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE);
73	if (err < 0)
74		return err;
75
76	return 0;
77}
78
79static struct nft_expr_type nft_meta_bridge_type;
80static const struct nft_expr_ops nft_meta_bridge_get_ops = {
81	.type		= &nft_meta_bridge_type,
82	.size		= NFT_EXPR_SIZE(sizeof(struct nft_meta)),
83	.eval		= nft_meta_bridge_get_eval,
84	.init		= nft_meta_bridge_get_init,
85	.dump		= nft_meta_get_dump,
86};
87
88static const struct nft_expr_ops nft_meta_bridge_set_ops = {
89	.type		= &nft_meta_bridge_type,
90	.size		= NFT_EXPR_SIZE(sizeof(struct nft_meta)),
91	.eval		= nft_meta_set_eval,
92	.init		= nft_meta_set_init,
93	.dump		= nft_meta_set_dump,
94};
95
96static const struct nft_expr_ops *
97nft_meta_bridge_select_ops(const struct nft_ctx *ctx,
98			   const struct nlattr * const tb[])
99{
100	if (tb[NFTA_META_KEY] == NULL)
101		return ERR_PTR(-EINVAL);
102
103	if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG])
104		return ERR_PTR(-EINVAL);
105
106	if (tb[NFTA_META_DREG])
107		return &nft_meta_bridge_get_ops;
108
109	if (tb[NFTA_META_SREG])
110		return &nft_meta_bridge_set_ops;
111
112	return ERR_PTR(-EINVAL);
113}
114
115static struct nft_expr_type nft_meta_bridge_type __read_mostly = {
116	.family         = NFPROTO_BRIDGE,
117	.name           = "meta",
118	.select_ops     = &nft_meta_bridge_select_ops,
119	.policy         = nft_meta_policy,
120	.maxattr        = NFTA_META_MAX,
121	.owner          = THIS_MODULE,
122};
123
124static int __init nft_meta_bridge_module_init(void)
125{
126	return nft_register_expr(&nft_meta_bridge_type);
127}
128
129static void __exit nft_meta_bridge_module_exit(void)
130{
131	nft_unregister_expr(&nft_meta_bridge_type);
132}
133
134module_init(nft_meta_bridge_module_init);
135module_exit(nft_meta_bridge_module_exit);
136
137MODULE_LICENSE("GPL");
138MODULE_AUTHOR("Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>");
139MODULE_ALIAS_NFT_AF_EXPR(AF_BRIDGE, "meta");
140