1/*
2 * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
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#include <linux/kernel.h>
10#include <linux/init.h>
11#include <linux/module.h>
12#include <linux/netlink.h>
13#include <linux/netfilter.h>
14#include <linux/netfilter/nf_tables.h>
15#include <net/netfilter/nf_nat.h>
16#include <net/netfilter/nf_tables.h>
17#include <net/netfilter/nft_redir.h>
18
19const struct nla_policy nft_redir_policy[NFTA_REDIR_MAX + 1] = {
20	[NFTA_REDIR_REG_PROTO_MIN]	= { .type = NLA_U32 },
21	[NFTA_REDIR_REG_PROTO_MAX]	= { .type = NLA_U32 },
22	[NFTA_REDIR_FLAGS]		= { .type = NLA_U32 },
23};
24EXPORT_SYMBOL_GPL(nft_redir_policy);
25
26int nft_redir_validate(const struct nft_ctx *ctx,
27		       const struct nft_expr *expr,
28		       const struct nft_data **data)
29{
30	int err;
31
32	err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
33	if (err < 0)
34		return err;
35
36	return nft_chain_validate_hooks(ctx->chain,
37					(1 << NF_INET_PRE_ROUTING) |
38					(1 << NF_INET_LOCAL_OUT));
39}
40EXPORT_SYMBOL_GPL(nft_redir_validate);
41
42int nft_redir_init(const struct nft_ctx *ctx,
43		   const struct nft_expr *expr,
44		   const struct nlattr * const tb[])
45{
46	struct nft_redir *priv = nft_expr_priv(expr);
47	unsigned int plen;
48	int err;
49
50	err = nft_redir_validate(ctx, expr, NULL);
51	if (err < 0)
52		return err;
53
54	plen = FIELD_SIZEOF(struct nf_nat_range, min_addr.all);
55	if (tb[NFTA_REDIR_REG_PROTO_MIN]) {
56		priv->sreg_proto_min =
57			nft_parse_register(tb[NFTA_REDIR_REG_PROTO_MIN]);
58
59		err = nft_validate_register_load(priv->sreg_proto_min, plen);
60		if (err < 0)
61			return err;
62
63		if (tb[NFTA_REDIR_REG_PROTO_MAX]) {
64			priv->sreg_proto_max =
65				nft_parse_register(tb[NFTA_REDIR_REG_PROTO_MAX]);
66
67			err = nft_validate_register_load(priv->sreg_proto_max,
68							 plen);
69			if (err < 0)
70				return err;
71		} else {
72			priv->sreg_proto_max = priv->sreg_proto_min;
73		}
74	}
75
76	if (tb[NFTA_REDIR_FLAGS]) {
77		priv->flags = ntohl(nla_get_be32(tb[NFTA_REDIR_FLAGS]));
78		if (priv->flags & ~NF_NAT_RANGE_MASK)
79			return -EINVAL;
80	}
81
82	return 0;
83}
84EXPORT_SYMBOL_GPL(nft_redir_init);
85
86int nft_redir_dump(struct sk_buff *skb, const struct nft_expr *expr)
87{
88	const struct nft_redir *priv = nft_expr_priv(expr);
89
90	if (priv->sreg_proto_min) {
91		if (nft_dump_register(skb, NFTA_REDIR_REG_PROTO_MIN,
92				      priv->sreg_proto_min))
93			goto nla_put_failure;
94		if (nft_dump_register(skb, NFTA_REDIR_REG_PROTO_MAX,
95				      priv->sreg_proto_max))
96			goto nla_put_failure;
97	}
98
99	if (priv->flags != 0 &&
100	    nla_put_be32(skb, NFTA_REDIR_FLAGS, htonl(priv->flags)))
101			goto nla_put_failure;
102
103	return 0;
104
105nla_put_failure:
106	return -1;
107}
108EXPORT_SYMBOL_GPL(nft_redir_dump);
109
110MODULE_LICENSE("GPL");
111MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");
112