1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
  4 * Copyright (c) 2013 Eric Leblond <eric@regit.org>
  5 *
  6 * Development of this code funded by Astaro AG (http://www.astaro.com/)
  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>
 17#include <linux/icmp.h>
 18#include <linux/icmpv6.h>
 19
 20const struct nla_policy nft_reject_policy[NFTA_REJECT_MAX + 1] = {
 21	[NFTA_REJECT_TYPE]		= { .type = NLA_U32 },
 22	[NFTA_REJECT_ICMP_CODE]		= { .type = NLA_U8 },
 23};
 24EXPORT_SYMBOL_GPL(nft_reject_policy);
 25
 26int nft_reject_validate(const struct nft_ctx *ctx,
 27			const struct nft_expr *expr,
 28			const struct nft_data **data)
 29{
 30	return nft_chain_validate_hooks(ctx->chain,
 31					(1 << NF_INET_LOCAL_IN) |
 32					(1 << NF_INET_FORWARD) |
 33					(1 << NF_INET_LOCAL_OUT) |
 34					(1 << NF_INET_PRE_ROUTING));
 35}
 36EXPORT_SYMBOL_GPL(nft_reject_validate);
 37
 38int nft_reject_init(const struct nft_ctx *ctx,
 39		    const struct nft_expr *expr,
 40		    const struct nlattr * const tb[])
 41{
 42	struct nft_reject *priv = nft_expr_priv(expr);
 43	int icmp_code;
 44
 45	if (tb[NFTA_REJECT_TYPE] == NULL)
 46		return -EINVAL;
 47
 48	priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
 49	switch (priv->type) {
 50	case NFT_REJECT_ICMP_UNREACH:
 51	case NFT_REJECT_ICMPX_UNREACH:
 52		if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
 53			return -EINVAL;
 54
 55		icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
 56		if (priv->type == NFT_REJECT_ICMPX_UNREACH &&
 57		    icmp_code > NFT_REJECT_ICMPX_MAX)
 58			return -EINVAL;
 59
 60		priv->icmp_code = icmp_code;
 61		break;
 62	case NFT_REJECT_TCP_RST:
 63		break;
 64	default:
 65		return -EINVAL;
 66	}
 67
 68	return 0;
 69}
 70EXPORT_SYMBOL_GPL(nft_reject_init);
 71
 72int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
 73{
 74	const struct nft_reject *priv = nft_expr_priv(expr);
 75
 76	if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
 77		goto nla_put_failure;
 78
 79	switch (priv->type) {
 80	case NFT_REJECT_ICMP_UNREACH:
 81	case NFT_REJECT_ICMPX_UNREACH:
 82		if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
 83			goto nla_put_failure;
 84		break;
 85	default:
 86		break;
 87	}
 88
 89	return 0;
 90
 91nla_put_failure:
 92	return -1;
 93}
 94EXPORT_SYMBOL_GPL(nft_reject_dump);
 95
 96static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX + 1] = {
 97	[NFT_REJECT_ICMPX_NO_ROUTE]		= ICMP_NET_UNREACH,
 98	[NFT_REJECT_ICMPX_PORT_UNREACH]		= ICMP_PORT_UNREACH,
 99	[NFT_REJECT_ICMPX_HOST_UNREACH]		= ICMP_HOST_UNREACH,
100	[NFT_REJECT_ICMPX_ADMIN_PROHIBITED]	= ICMP_PKT_FILTERED,
101};
102
103int nft_reject_icmp_code(u8 code)
104{
105	if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
106		return ICMP_NET_UNREACH;
107
108	return icmp_code_v4[code];
109}
110
111EXPORT_SYMBOL_GPL(nft_reject_icmp_code);
112
113
114static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX + 1] = {
115	[NFT_REJECT_ICMPX_NO_ROUTE]		= ICMPV6_NOROUTE,
116	[NFT_REJECT_ICMPX_PORT_UNREACH]		= ICMPV6_PORT_UNREACH,
117	[NFT_REJECT_ICMPX_HOST_UNREACH]		= ICMPV6_ADDR_UNREACH,
118	[NFT_REJECT_ICMPX_ADMIN_PROHIBITED]	= ICMPV6_ADM_PROHIBITED,
119};
120
121int nft_reject_icmpv6_code(u8 code)
122{
123	if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
124		return ICMPV6_NOROUTE;
125
126	return icmp_code_v6[code];
127}
128
129EXPORT_SYMBOL_GPL(nft_reject_icmpv6_code);
130
131MODULE_LICENSE("GPL");
132MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
133MODULE_DESCRIPTION("Netfilter x_tables over nftables module");