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
17static 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
63static int nft_reject_inet_validate(const struct nft_ctx *ctx,
64				    const struct nft_expr *expr,
65				    const struct nft_data **data)
66{
67	return nft_chain_validate_hooks(ctx->chain,
68					(1 << NF_INET_LOCAL_IN) |
69					(1 << NF_INET_FORWARD) |
70					(1 << NF_INET_LOCAL_OUT) |
71					(1 << NF_INET_PRE_ROUTING) |
72					(1 << NF_INET_INGRESS));
73}
74
75static struct nft_expr_type nft_reject_inet_type;
76static const struct nft_expr_ops nft_reject_inet_ops = {
77	.type		= &nft_reject_inet_type,
78	.size		= NFT_EXPR_SIZE(sizeof(struct nft_reject)),
79	.eval		= nft_reject_inet_eval,
80	.init		= nft_reject_init,
81	.dump		= nft_reject_dump,
82	.validate	= nft_reject_inet_validate,
83	.reduce		= NFT_REDUCE_READONLY,
84};
85
86static struct nft_expr_type nft_reject_inet_type __read_mostly = {
87	.family		= NFPROTO_INET,
88	.name		= "reject",
89	.ops		= &nft_reject_inet_ops,
90	.policy		= nft_reject_policy,
91	.maxattr	= NFTA_REJECT_MAX,
92	.owner		= THIS_MODULE,
93};
94
95static int __init nft_reject_inet_module_init(void)
96{
97	return nft_register_expr(&nft_reject_inet_type);
98}
99
100static void __exit nft_reject_inet_module_exit(void)
101{
102	nft_unregister_expr(&nft_reject_inet_type);
103}
104
105module_init(nft_reject_inet_module_init);
106module_exit(nft_reject_inet_module_exit);
107
108MODULE_LICENSE("GPL");
109MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
110MODULE_ALIAS_NFT_AF_EXPR(1, "reject");
111MODULE_DESCRIPTION("Netfilter nftables reject inet support");
112