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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 <net/netfilter/ipv4/nf_reject.h>
18#include <net/netfilter/ipv6/nf_reject.h>
19
20static void nft_reject_inet_eval(const struct nft_expr *expr,
21 struct nft_regs *regs,
22 const struct nft_pktinfo *pkt)
23{
24 struct nft_reject *priv = nft_expr_priv(expr);
25
26 switch (nft_pf(pkt)) {
27 case NFPROTO_IPV4:
28 switch (priv->type) {
29 case NFT_REJECT_ICMP_UNREACH:
30 nf_send_unreach(pkt->skb, priv->icmp_code,
31 nft_hook(pkt));
32 break;
33 case NFT_REJECT_TCP_RST:
34 nf_send_reset(nft_net(pkt), pkt->skb, nft_hook(pkt));
35 break;
36 case NFT_REJECT_ICMPX_UNREACH:
37 nf_send_unreach(pkt->skb,
38 nft_reject_icmp_code(priv->icmp_code),
39 nft_hook(pkt));
40 break;
41 }
42 break;
43 case NFPROTO_IPV6:
44 switch (priv->type) {
45 case NFT_REJECT_ICMP_UNREACH:
46 nf_send_unreach6(nft_net(pkt), pkt->skb,
47 priv->icmp_code, nft_hook(pkt));
48 break;
49 case NFT_REJECT_TCP_RST:
50 nf_send_reset6(nft_net(pkt), pkt->skb, nft_hook(pkt));
51 break;
52 case NFT_REJECT_ICMPX_UNREACH:
53 nf_send_unreach6(nft_net(pkt), pkt->skb,
54 nft_reject_icmpv6_code(priv->icmp_code),
55 nft_hook(pkt));
56 break;
57 }
58 break;
59 }
60
61 regs->verdict.code = NF_DROP;
62}
63
64static int nft_reject_inet_init(const struct nft_ctx *ctx,
65 const struct nft_expr *expr,
66 const struct nlattr * const tb[])
67{
68 struct nft_reject *priv = nft_expr_priv(expr);
69 int icmp_code;
70
71 if (tb[NFTA_REJECT_TYPE] == NULL)
72 return -EINVAL;
73
74 priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
75 switch (priv->type) {
76 case NFT_REJECT_ICMP_UNREACH:
77 case NFT_REJECT_ICMPX_UNREACH:
78 if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
79 return -EINVAL;
80
81 icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
82 if (priv->type == NFT_REJECT_ICMPX_UNREACH &&
83 icmp_code > NFT_REJECT_ICMPX_MAX)
84 return -EINVAL;
85
86 priv->icmp_code = icmp_code;
87 break;
88 case NFT_REJECT_TCP_RST:
89 break;
90 default:
91 return -EINVAL;
92 }
93 return 0;
94}
95
96static int nft_reject_inet_dump(struct sk_buff *skb,
97 const struct nft_expr *expr)
98{
99 const struct nft_reject *priv = nft_expr_priv(expr);
100
101 if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
102 goto nla_put_failure;
103
104 switch (priv->type) {
105 case NFT_REJECT_ICMP_UNREACH:
106 case NFT_REJECT_ICMPX_UNREACH:
107 if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
108 goto nla_put_failure;
109 break;
110 default:
111 break;
112 }
113
114 return 0;
115
116nla_put_failure:
117 return -1;
118}
119
120static struct nft_expr_type nft_reject_inet_type;
121static const struct nft_expr_ops nft_reject_inet_ops = {
122 .type = &nft_reject_inet_type,
123 .size = NFT_EXPR_SIZE(sizeof(struct nft_reject)),
124 .eval = nft_reject_inet_eval,
125 .init = nft_reject_inet_init,
126 .dump = nft_reject_inet_dump,
127 .validate = nft_reject_validate,
128};
129
130static struct nft_expr_type nft_reject_inet_type __read_mostly = {
131 .family = NFPROTO_INET,
132 .name = "reject",
133 .ops = &nft_reject_inet_ops,
134 .policy = nft_reject_policy,
135 .maxattr = NFTA_REJECT_MAX,
136 .owner = THIS_MODULE,
137};
138
139static int __init nft_reject_inet_module_init(void)
140{
141 return nft_register_expr(&nft_reject_inet_type);
142}
143
144static void __exit nft_reject_inet_module_exit(void)
145{
146 nft_unregister_expr(&nft_reject_inet_type);
147}
148
149module_init(nft_reject_inet_module_init);
150module_exit(nft_reject_inet_module_exit);
151
152MODULE_LICENSE("GPL");
153MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
154MODULE_ALIAS_NFT_AF_EXPR(1, "reject");
155
