[mirror_ubuntu-eoan-kernel.git] / net / netfilter / nft_reject_inet.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2014 Patrick McHardy <kaber@trash.net>
 */

#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 <net/netfilter/ipv4/nf_reject.h>
#include <net/netfilter/ipv6/nf_reject.h>

static void nft_reject_inet_eval(const struct nft_expr *expr,
				 struct nft_regs *regs,
				 const struct nft_pktinfo *pkt)
{
	struct nft_reject *priv = nft_expr_priv(expr);

	switch (nft_pf(pkt)) {
	case NFPROTO_IPV4:
		switch (priv->type) {
		case NFT_REJECT_ICMP_UNREACH:
			nf_send_unreach(pkt->skb, priv->icmp_code,
					nft_hook(pkt));
			break;
		case NFT_REJECT_TCP_RST:
			nf_send_reset(nft_net(pkt), pkt->skb, nft_hook(pkt));
			break;
		case NFT_REJECT_ICMPX_UNREACH:
			nf_send_unreach(pkt->skb,
					nft_reject_icmp_code(priv->icmp_code),
					nft_hook(pkt));
			break;
		}
		break;
	case NFPROTO_IPV6:
		switch (priv->type) {
		case NFT_REJECT_ICMP_UNREACH:
			nf_send_unreach6(nft_net(pkt), pkt->skb,
					 priv->icmp_code, nft_hook(pkt));
			break;
		case NFT_REJECT_TCP_RST:
			nf_send_reset6(nft_net(pkt), pkt->skb, nft_hook(pkt));
			break;
		case NFT_REJECT_ICMPX_UNREACH:
			nf_send_unreach6(nft_net(pkt), pkt->skb,
					 nft_reject_icmpv6_code(priv->icmp_code),
					 nft_hook(pkt));
			break;
		}
		break;
	}

	regs->verdict.code = NF_DROP;
}

static int nft_reject_inet_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;
}

static int nft_reject_inet_dump(struct sk_buff *skb,
				const struct nft_expr *expr)
{
	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;
}

static struct nft_expr_type nft_reject_inet_type;
static const struct nft_expr_ops nft_reject_inet_ops = {
	.type		= &nft_reject_inet_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_reject)),
	.eval		= nft_reject_inet_eval,
	.init		= nft_reject_inet_init,
	.dump		= nft_reject_inet_dump,
	.validate	= nft_reject_validate,
};

static struct nft_expr_type nft_reject_inet_type __read_mostly = {
	.family		= NFPROTO_INET,
	.name		= "reject",
	.ops		= &nft_reject_inet_ops,
	.policy		= nft_reject_policy,
	.maxattr	= NFTA_REJECT_MAX,
	.owner		= THIS_MODULE,
};

static int __init nft_reject_inet_module_init(void)
{
	return nft_register_expr(&nft_reject_inet_type);
}

static void __exit nft_reject_inet_module_exit(void)
{
	nft_unregister_expr(&nft_reject_inet_type);
}

module_init(nft_reject_inet_module_init);
module_exit(nft_reject_inet_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_ALIAS_NFT_AF_EXPR(1, "reject");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
05513e9e PM	2	/*
05513e9e PM	3	* Copyright (c) 2014 Patrick McHardy <kaber@trash.net>
05513e9e PM	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>
51b0a5d8 PNA	14	#include <net/netfilter/ipv4/nf_reject.h>
51b0a5d8 PNA	15	#include <net/netfilter/ipv6/nf_reject.h>
05513e9e PM	16
05513e9e PM	17	static void nft_reject_inet_eval(const struct nft_expr *expr,
a55e22e9	18	struct nft_regs *regs,
05513e9e PM	19	const struct nft_pktinfo *pkt)
05513e9e PM	20	{
51b0a5d8	21	struct nft_reject *priv = nft_expr_priv(expr);
51b0a5d8	22
0e5a1c7e	23	switch (nft_pf(pkt)) {
05513e9e	24	case NFPROTO_IPV4:
51b0a5d8 PNA	25	switch (priv->type) {
51b0a5d8 PNA	26	case NFT_REJECT_ICMP_UNREACH:
ee586bbc	27	nf_send_unreach(pkt->skb, priv->icmp_code,
0e5a1c7e	28	nft_hook(pkt));
51b0a5d8 PNA	29	break;
51b0a5d8 PNA	30	case NFT_REJECT_TCP_RST:
0e5a1c7e	31	nf_send_reset(nft_net(pkt), pkt->skb, nft_hook(pkt));
51b0a5d8 PNA	32	break;
	33	case NFT_REJECT_ICMPX_UNREACH:
	34	nf_send_unreach(pkt->skb,
ee586bbc	35	nft_reject_icmp_code(priv->icmp_code),
0e5a1c7e	36	nft_hook(pkt));
51b0a5d8 PNA	37	break;
	38	}
	39	break;
05513e9e	40	case NFPROTO_IPV6:
51b0a5d8 PNA	41	switch (priv->type) {
51b0a5d8 PNA	42	case NFT_REJECT_ICMP_UNREACH:
0e5a1c7e PNA	43	nf_send_unreach6(nft_net(pkt), pkt->skb,
0e5a1c7e PNA	44	priv->icmp_code, nft_hook(pkt));
51b0a5d8 PNA	45	break;
51b0a5d8 PNA	46	case NFT_REJECT_TCP_RST:
0e5a1c7e	47	nf_send_reset6(nft_net(pkt), pkt->skb, nft_hook(pkt));
51b0a5d8 PNA	48	break;
51b0a5d8 PNA	49	case NFT_REJECT_ICMPX_UNREACH:
0e5a1c7e	50	nf_send_unreach6(nft_net(pkt), pkt->skb,
51b0a5d8	51	nft_reject_icmpv6_code(priv->icmp_code),
0e5a1c7e	52	nft_hook(pkt));
51b0a5d8 PNA	53	break;
	54	}
	55	break;
	56	}
a55e22e9 PM	57
a55e22e9 PM	58	regs->verdict.code = NF_DROP;
51b0a5d8 PNA	59	}
	60
	61	static int nft_reject_inet_init(const struct nft_ctx *ctx,
	62	const struct nft_expr *expr,
	63	const struct nlattr * const tb[])
	64	{
	65	struct nft_reject *priv = nft_expr_priv(expr);
c56e3956	66	int icmp_code;
51b0a5d8 PNA	67
	68	if (tb[NFTA_REJECT_TYPE] == NULL)
	69	return -EINVAL;
	70
	71	priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
	72	switch (priv->type) {
	73	case NFT_REJECT_ICMP_UNREACH:
	74	case NFT_REJECT_ICMPX_UNREACH:
	75	if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
	76	return -EINVAL;
	77
	78	icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
	79	if (priv->type == NFT_REJECT_ICMPX_UNREACH &&
	80	icmp_code > NFT_REJECT_ICMPX_MAX)
	81	return -EINVAL;
	82
	83	priv->icmp_code = icmp_code;
	84	break;
	85	case NFT_REJECT_TCP_RST:
	86	break;
	87	default:
	88	return -EINVAL;
05513e9e	89	}
51b0a5d8 PNA	90	return 0;
	91	}
	92
	93	static int nft_reject_inet_dump(struct sk_buff *skb,
	94	const struct nft_expr *expr)
	95	{
	96	const struct nft_reject *priv = nft_expr_priv(expr);
	97
	98	if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
	99	goto nla_put_failure;
	100
	101	switch (priv->type) {
	102	case NFT_REJECT_ICMP_UNREACH:
	103	case NFT_REJECT_ICMPX_UNREACH:
	104	if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
	105	goto nla_put_failure;
	106	break;
129d23a5 DM	107	default:
129d23a5 DM	108	break;
51b0a5d8 PNA	109	}
	110
	111	return 0;
	112
	113	nla_put_failure:
	114	return -1;
05513e9e PM	115	}
	116
	117	static struct nft_expr_type nft_reject_inet_type;
	118	static const struct nft_expr_ops nft_reject_inet_ops = {
	119	.type = &nft_reject_inet_type,
	120	.size = NFT_EXPR_SIZE(sizeof(struct nft_reject)),
	121	.eval = nft_reject_inet_eval,
51b0a5d8 PNA	122	.init = nft_reject_inet_init,
51b0a5d8 PNA	123	.dump = nft_reject_inet_dump,
89e1f6d2	124	.validate = nft_reject_validate,
05513e9e PM	125	};
	126
	127	static struct nft_expr_type nft_reject_inet_type __read_mostly = {
	128	.family = NFPROTO_INET,
	129	.name = "reject",
	130	.ops = &nft_reject_inet_ops,
	131	.policy = nft_reject_policy,
	132	.maxattr = NFTA_REJECT_MAX,
	133	.owner = THIS_MODULE,
	134	};
	135
	136	static int __init nft_reject_inet_module_init(void)
	137	{
	138	return nft_register_expr(&nft_reject_inet_type);
	139	}
	140
	141	static void __exit nft_reject_inet_module_exit(void)
	142	{
	143	nft_unregister_expr(&nft_reject_inet_type);
	144	}
	145
	146	module_init(nft_reject_inet_module_init);
	147	module_exit(nft_reject_inet_module_exit);
	148
	149	MODULE_LICENSE("GPL");
	150	MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
	151	MODULE_ALIAS_NFT_AF_EXPR(1, "reject");