1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
4 * Copyright (c) 2013 Eric Leblond <eric@regit.org>
5 *
6 * Development of this code funded by Astaro AG (http://www.astaro.com/)
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_tables.h>
16 #include <net/netfilter/nft_reject.h>
17 #include <linux/icmp.h>
18 #include <linux/icmpv6.h>
19
20 const struct nla_policy nft_reject_policy[NFTA_REJECT_MAX + 1] = {
21 [NFTA_REJECT_TYPE] = NLA_POLICY_MAX(NLA_BE32, 255),
22 [NFTA_REJECT_ICMP_CODE] = { .type = NLA_U8 },
23 };
24 EXPORT_SYMBOL_GPL(nft_reject_policy);
25
nft_reject_validate(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nft_data ** data)26 int nft_reject_validate(const struct nft_ctx *ctx,
27 const struct nft_expr *expr,
28 const struct nft_data **data)
29 {
30 return nft_chain_validate_hooks(ctx->chain,
31 (1 << NF_INET_LOCAL_IN) |
32 (1 << NF_INET_FORWARD) |
33 (1 << NF_INET_LOCAL_OUT) |
34 (1 << NF_INET_PRE_ROUTING));
35 }
36 EXPORT_SYMBOL_GPL(nft_reject_validate);
37
nft_reject_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])38 int nft_reject_init(const struct nft_ctx *ctx,
39 const struct nft_expr *expr,
40 const struct nlattr * const tb[])
41 {
42 struct nft_reject *priv = nft_expr_priv(expr);
43 int icmp_code;
44
45 if (tb[NFTA_REJECT_TYPE] == NULL)
46 return -EINVAL;
47
48 priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
49 switch (priv->type) {
50 case NFT_REJECT_ICMP_UNREACH:
51 case NFT_REJECT_ICMPX_UNREACH:
52 if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
53 return -EINVAL;
54
55 icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
56 if (priv->type == NFT_REJECT_ICMPX_UNREACH &&
57 icmp_code > NFT_REJECT_ICMPX_MAX)
58 return -EINVAL;
59
60 priv->icmp_code = icmp_code;
61 break;
62 case NFT_REJECT_TCP_RST:
63 break;
64 default:
65 return -EINVAL;
66 }
67
68 return 0;
69 }
70 EXPORT_SYMBOL_GPL(nft_reject_init);
71
nft_reject_dump(struct sk_buff * skb,const struct nft_expr * expr,bool reset)72 int nft_reject_dump(struct sk_buff *skb,
73 const struct nft_expr *expr, bool reset)
74 {
75 const struct nft_reject *priv = nft_expr_priv(expr);
76
77 if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
78 goto nla_put_failure;
79
80 switch (priv->type) {
81 case NFT_REJECT_ICMP_UNREACH:
82 case NFT_REJECT_ICMPX_UNREACH:
83 if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
84 goto nla_put_failure;
85 break;
86 default:
87 break;
88 }
89
90 return 0;
91
92 nla_put_failure:
93 return -1;
94 }
95 EXPORT_SYMBOL_GPL(nft_reject_dump);
96
97 static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX + 1] = {
98 [NFT_REJECT_ICMPX_NO_ROUTE] = ICMP_NET_UNREACH,
99 [NFT_REJECT_ICMPX_PORT_UNREACH] = ICMP_PORT_UNREACH,
100 [NFT_REJECT_ICMPX_HOST_UNREACH] = ICMP_HOST_UNREACH,
101 [NFT_REJECT_ICMPX_ADMIN_PROHIBITED] = ICMP_PKT_FILTERED,
102 };
103
nft_reject_icmp_code(u8 code)104 int nft_reject_icmp_code(u8 code)
105 {
106 if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
107 return ICMP_NET_UNREACH;
108
109 return icmp_code_v4[code];
110 }
111
112 EXPORT_SYMBOL_GPL(nft_reject_icmp_code);
113
114
115 static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX + 1] = {
116 [NFT_REJECT_ICMPX_NO_ROUTE] = ICMPV6_NOROUTE,
117 [NFT_REJECT_ICMPX_PORT_UNREACH] = ICMPV6_PORT_UNREACH,
118 [NFT_REJECT_ICMPX_HOST_UNREACH] = ICMPV6_ADDR_UNREACH,
119 [NFT_REJECT_ICMPX_ADMIN_PROHIBITED] = ICMPV6_ADM_PROHIBITED,
120 };
121
nft_reject_icmpv6_code(u8 code)122 int nft_reject_icmpv6_code(u8 code)
123 {
124 if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
125 return ICMPV6_NOROUTE;
126
127 return icmp_code_v6[code];
128 }
129
130 EXPORT_SYMBOL_GPL(nft_reject_icmpv6_code);
131
132 MODULE_LICENSE("GPL");
133 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
134 MODULE_DESCRIPTION("Netfilter x_tables over nftables module");
135