[deliverable/linux.git] / net / netfilter / nft_reject_inet.c

/*
 * Copyright (c) 2014 Patrick McHardy <kaber@trash.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#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_data data[NFT_REG_MAX + 1],
				 const struct nft_pktinfo *pkt)
{
	struct nft_reject *priv = nft_expr_priv(expr);
	struct net *net = dev_net((pkt->in != NULL) ? pkt->in : pkt->out);

	switch (pkt->ops->pf) {
	case NFPROTO_IPV4:
		switch (priv->type) {
		case NFT_REJECT_ICMP_UNREACH:
			nf_send_unreach(pkt->skb, priv->icmp_code,
					pkt->ops->hooknum);
			break;
		case NFT_REJECT_TCP_RST:
			nf_send_reset(pkt->skb, pkt->ops->hooknum);
			break;
		case NFT_REJECT_ICMPX_UNREACH:
			nf_send_unreach(pkt->skb,
					nft_reject_icmp_code(priv->icmp_code),
					pkt->ops->hooknum);
			break;
		}
		break;
	case NFPROTO_IPV6:
		switch (priv->type) {
		case NFT_REJECT_ICMP_UNREACH:
			nf_send_unreach6(net, pkt->skb, priv->icmp_code,
					 pkt->ops->hooknum);
			break;
		case NFT_REJECT_TCP_RST:
			nf_send_reset6(net, pkt->skb, pkt->ops->hooknum);
			break;
		case NFT_REJECT_ICMPX_UNREACH:
			nf_send_unreach6(net, pkt->skb,
					 nft_reject_icmpv6_code(priv->icmp_code),
					 pkt->ops->hooknum);
			break;
		}
		break;
	}
	data[NFT_REG_VERDICT].verdict = 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;
	}

	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,
};

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
05513e9e PM	1	/*
	2	* Copyright (c) 2014 Patrick McHardy <kaber@trash.net>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	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>
51b0a5d8 PNA	17	#include <net/netfilter/ipv4/nf_reject.h>
51b0a5d8 PNA	18	#include <net/netfilter/ipv6/nf_reject.h>
05513e9e PM	19
	20	static void nft_reject_inet_eval(const struct nft_expr *expr,
	21	struct nft_data data[NFT_REG_MAX + 1],
	22	const struct nft_pktinfo *pkt)
	23	{
51b0a5d8 PNA	24	struct nft_reject *priv = nft_expr_priv(expr);
	25	struct net *net = dev_net((pkt->in != NULL) ? pkt->in : pkt->out);
	26
05513e9e PM	27	switch (pkt->ops->pf) {
05513e9e PM	28	case NFPROTO_IPV4:
51b0a5d8 PNA	29	switch (priv->type) {
51b0a5d8 PNA	30	case NFT_REJECT_ICMP_UNREACH:
ee586bbc FW	31	nf_send_unreach(pkt->skb, priv->icmp_code,
ee586bbc FW	32	pkt->ops->hooknum);
51b0a5d8 PNA	33	break;
	34	case NFT_REJECT_TCP_RST:
	35	nf_send_reset(pkt->skb, pkt->ops->hooknum);
	36	break;
	37	case NFT_REJECT_ICMPX_UNREACH:
	38	nf_send_unreach(pkt->skb,
ee586bbc FW	39	nft_reject_icmp_code(priv->icmp_code),
ee586bbc FW	40	pkt->ops->hooknum);
51b0a5d8 PNA	41	break;
	42	}
	43	break;
05513e9e	44	case NFPROTO_IPV6:
51b0a5d8 PNA	45	switch (priv->type) {
	46	case NFT_REJECT_ICMP_UNREACH:
	47	nf_send_unreach6(net, pkt->skb, priv->icmp_code,
	48	pkt->ops->hooknum);
	49	break;
	50	case NFT_REJECT_TCP_RST:
	51	nf_send_reset6(net, pkt->skb, pkt->ops->hooknum);
	52	break;
	53	case NFT_REJECT_ICMPX_UNREACH:
	54	nf_send_unreach6(net, pkt->skb,
	55	nft_reject_icmpv6_code(priv->icmp_code),
	56	pkt->ops->hooknum);
	57	break;
	58	}
	59	break;
	60	}
	61	data[NFT_REG_VERDICT].verdict = NF_DROP;
	62	}
	63
	64	static 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;
05513e9e	92	}
51b0a5d8 PNA	93	return 0;
	94	}
	95
	96	static 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	}
	111
	112	return 0;
	113
	114	nla_put_failure:
	115	return -1;
05513e9e PM	116	}
	117
	118	static struct nft_expr_type nft_reject_inet_type;
	119	static const struct nft_expr_ops nft_reject_inet_ops = {
	120	.type = &nft_reject_inet_type,
	121	.size = NFT_EXPR_SIZE(sizeof(struct nft_reject)),
	122	.eval = nft_reject_inet_eval,
51b0a5d8 PNA	123	.init = nft_reject_inet_init,
51b0a5d8 PNA	124	.dump = nft_reject_inet_dump,
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");