summaryrefslogtreecommitdiff
path: root/net/netfilter/nft_reject.c
blob: ed2e668474d677b30183f914b41f04351d62be00 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
 * Copyright (c) 2013 Eric Leblond <eric@regit.org>
 *
 * Development of this code funded by Astaro AG (http://www.astaro.com/)
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nft_reject.h>
#include <linux/icmp.h>
#include <linux/icmpv6.h>

const struct nla_policy nft_reject_policy[NFTA_REJECT_MAX + 1] = {
	[NFTA_REJECT_TYPE]		= NLA_POLICY_MAX(NLA_BE32, 255),
	[NFTA_REJECT_ICMP_CODE]		= { .type = NLA_U8 },
};
EXPORT_SYMBOL_GPL(nft_reject_policy);

int nft_reject_validate(const struct nft_ctx *ctx,
			const struct nft_expr *expr,
			const struct nft_data **data)
{
	return nft_chain_validate_hooks(ctx->chain,
					(1 << NF_INET_LOCAL_IN) |
					(1 << NF_INET_FORWARD) |
					(1 << NF_INET_LOCAL_OUT) |
					(1 << NF_INET_PRE_ROUTING));
}
EXPORT_SYMBOL_GPL(nft_reject_validate);

int nft_reject_init(const struct nft_ctx *ctx,
		    const struct nft_expr *expr,
		    const struct nlattr * const tb[])
{
	struct nft_reject *priv = nft_expr_priv(expr);
	int icmp_code;

	if (tb[NFTA_REJECT_TYPE] == NULL)
		return -EINVAL;

	priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
	switch (priv->type) {
	case NFT_REJECT_ICMP_UNREACH:
	case NFT_REJECT_ICMPX_UNREACH:
		if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
			return -EINVAL;

		icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
		if (priv->type == NFT_REJECT_ICMPX_UNREACH &&
		    icmp_code > NFT_REJECT_ICMPX_MAX)
			return -EINVAL;

		priv->icmp_code = icmp_code;
		break;
	case NFT_REJECT_TCP_RST:
		break;
	default:
		return -EINVAL;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(nft_reject_init);

int nft_reject_dump(struct sk_buff *skb,
		    const struct nft_expr *expr, bool reset)
{
	const struct nft_reject *priv = nft_expr_priv(expr);

	if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
		goto nla_put_failure;

	switch (priv->type) {
	case NFT_REJECT_ICMP_UNREACH:
	case NFT_REJECT_ICMPX_UNREACH:
		if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
			goto nla_put_failure;
		break;
	default:
		break;
	}

	return 0;

nla_put_failure:
	return -1;
}
EXPORT_SYMBOL_GPL(nft_reject_dump);

static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX + 1] = {
	[NFT_REJECT_ICMPX_NO_ROUTE]		= ICMP_NET_UNREACH,
	[NFT_REJECT_ICMPX_PORT_UNREACH]		= ICMP_PORT_UNREACH,
	[NFT_REJECT_ICMPX_HOST_UNREACH]		= ICMP_HOST_UNREACH,
	[NFT_REJECT_ICMPX_ADMIN_PROHIBITED]	= ICMP_PKT_FILTERED,
};

int nft_reject_icmp_code(u8 code)
{
	if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
		return ICMP_NET_UNREACH;

	return icmp_code_v4[code];
}

EXPORT_SYMBOL_GPL(nft_reject_icmp_code);


static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX + 1] = {
	[NFT_REJECT_ICMPX_NO_ROUTE]		= ICMPV6_NOROUTE,
	[NFT_REJECT_ICMPX_PORT_UNREACH]		= ICMPV6_PORT_UNREACH,
	[NFT_REJECT_ICMPX_HOST_UNREACH]		= ICMPV6_ADDR_UNREACH,
	[NFT_REJECT_ICMPX_ADMIN_PROHIBITED]	= ICMPV6_ADM_PROHIBITED,
};

int nft_reject_icmpv6_code(u8 code)
{
	if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
		return ICMPV6_NOROUTE;

	return icmp_code_v6[code];
}

EXPORT_SYMBOL_GPL(nft_reject_icmpv6_code);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_DESCRIPTION("Netfilter x_tables over nftables module");