1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2014 Patrick McHardy <kaber@trash.net>
4 */
5
6 #include <linux/kernel.h>
7 #include <linux/init.h>
8 #include <linux/module.h>
9 #include <linux/netlink.h>
10 #include <linux/netfilter.h>
11 #include <linux/netfilter/nf_tables.h>
12 #include <net/netfilter/nf_tables.h>
13 #include <net/netfilter/nft_reject.h>
14 #include <net/netfilter/ipv4/nf_reject.h>
15 #include <net/netfilter/ipv6/nf_reject.h>
16
nft_reject_inet_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)17 static void nft_reject_inet_eval(const struct nft_expr *expr,
18 struct nft_regs *regs,
19 const struct nft_pktinfo *pkt)
20 {
21 struct nft_reject *priv = nft_expr_priv(expr);
22
23 switch (nft_pf(pkt)) {
24 case NFPROTO_IPV4:
25 switch (priv->type) {
26 case NFT_REJECT_ICMP_UNREACH:
27 nf_send_unreach(pkt->skb, priv->icmp_code,
28 nft_hook(pkt));
29 break;
30 case NFT_REJECT_TCP_RST:
31 nf_send_reset(nft_net(pkt), nft_sk(pkt),
32 pkt->skb, nft_hook(pkt));
33 break;
34 case NFT_REJECT_ICMPX_UNREACH:
35 nf_send_unreach(pkt->skb,
36 nft_reject_icmp_code(priv->icmp_code),
37 nft_hook(pkt));
38 break;
39 }
40 break;
41 case NFPROTO_IPV6:
42 switch (priv->type) {
43 case NFT_REJECT_ICMP_UNREACH:
44 nf_send_unreach6(nft_net(pkt), pkt->skb,
45 priv->icmp_code, nft_hook(pkt));
46 break;
47 case NFT_REJECT_TCP_RST:
48 nf_send_reset6(nft_net(pkt), nft_sk(pkt),
49 pkt->skb, nft_hook(pkt));
50 break;
51 case NFT_REJECT_ICMPX_UNREACH:
52 nf_send_unreach6(nft_net(pkt), pkt->skb,
53 nft_reject_icmpv6_code(priv->icmp_code),
54 nft_hook(pkt));
55 break;
56 }
57 break;
58 }
59
60 regs->verdict.code = NF_DROP;
61 }
62
nft_reject_inet_validate(const struct nft_ctx * ctx,const struct nft_expr * expr)63 static int nft_reject_inet_validate(const struct nft_ctx *ctx,
64 const struct nft_expr *expr)
65 {
66 return nft_chain_validate_hooks(ctx->chain,
67 (1 << NF_INET_LOCAL_IN) |
68 (1 << NF_INET_FORWARD) |
69 (1 << NF_INET_LOCAL_OUT) |
70 (1 << NF_INET_PRE_ROUTING) |
71 (1 << NF_INET_INGRESS));
72 }
73
74 static struct nft_expr_type nft_reject_inet_type;
75 static const struct nft_expr_ops nft_reject_inet_ops = {
76 .type = &nft_reject_inet_type,
77 .size = NFT_EXPR_SIZE(sizeof(struct nft_reject)),
78 .eval = nft_reject_inet_eval,
79 .init = nft_reject_init,
80 .dump = nft_reject_dump,
81 .validate = nft_reject_inet_validate,
82 .reduce = NFT_REDUCE_READONLY,
83 };
84
85 static struct nft_expr_type nft_reject_inet_type __read_mostly = {
86 .family = NFPROTO_INET,
87 .name = "reject",
88 .ops = &nft_reject_inet_ops,
89 .policy = nft_reject_policy,
90 .maxattr = NFTA_REJECT_MAX,
91 .owner = THIS_MODULE,
92 };
93
nft_reject_inet_module_init(void)94 static int __init nft_reject_inet_module_init(void)
95 {
96 return nft_register_expr(&nft_reject_inet_type);
97 }
98
nft_reject_inet_module_exit(void)99 static void __exit nft_reject_inet_module_exit(void)
100 {
101 nft_unregister_expr(&nft_reject_inet_type);
102 }
103
104 module_init(nft_reject_inet_module_init);
105 module_exit(nft_reject_inet_module_exit);
106
107 MODULE_LICENSE("GPL");
108 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
109 MODULE_ALIAS_NFT_AF_EXPR(1, "reject");
110 MODULE_DESCRIPTION("Netfilter nftables reject inet support");
111