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/*
* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
* Copyright (c) 2013 Eric Leblond <eric@regit.org>
*
* 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.
*
* Development of this code funded by Astaro AG (http://www.astaro.com/)
*/
#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/icmp.h>
#include <net/netfilter/ipv4/nf_reject.h>
#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
#include <net/netfilter/ipv6/nf_reject.h>
#endif
struct nft_reject {
enum nft_reject_types type:8;
u8 icmp_code;
u8 family;
};
static void nft_reject_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);
#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
struct net *net = dev_net((pkt->in != NULL) ? pkt->in : pkt->out);
#endif
switch (priv->type) {
case NFT_REJECT_ICMP_UNREACH:
if (priv->family == NFPROTO_IPV4)
nf_send_unreach(pkt->skb, priv->icmp_code);
#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
else if (priv->family == NFPROTO_IPV6)
nf_send_unreach6(net, pkt->skb, priv->icmp_code,
pkt->ops->hooknum);
#endif
break;
case NFT_REJECT_TCP_RST:
if (priv->family == NFPROTO_IPV4)
nf_send_reset(pkt->skb, pkt->ops->hooknum);
#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
else if (priv->family == NFPROTO_IPV6)
nf_send_reset6(net, pkt->skb, pkt->ops->hooknum);
#endif
break;
}
data[NFT_REG_VERDICT].verdict = NF_DROP;
}
static const struct nla_policy nft_reject_policy[NFTA_REJECT_MAX + 1] = {
[NFTA_REJECT_TYPE] = { .type = NLA_U32 },
[NFTA_REJECT_ICMP_CODE] = { .type = NLA_U8 },
};
static int nft_reject_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_reject *priv = nft_expr_priv(expr);
if (tb[NFTA_REJECT_TYPE] == NULL)
return -EINVAL;
priv->family = ctx->afi->family;
priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
switch (priv->type) {
case NFT_REJECT_ICMP_UNREACH:
if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
return -EINVAL;
priv->icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
case NFT_REJECT_TCP_RST:
break;
default:
return -EINVAL;
}
return 0;
}
static int nft_reject_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:
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_type;
static const struct nft_expr_ops nft_reject_ops = {
.type = &nft_reject_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_reject)),
.eval = nft_reject_eval,
.init = nft_reject_init,
.dump = nft_reject_dump,
};
static struct nft_expr_type nft_reject_type __read_mostly = {
.name = "reject",
.ops = &nft_reject_ops,
.policy = nft_reject_policy,
.maxattr = NFTA_REJECT_MAX,
.owner = THIS_MODULE,
};
static int __init nft_reject_module_init(void)
{
return nft_register_expr(&nft_reject_type);
}
static void __exit nft_reject_module_exit(void)
{
nft_unregister_expr(&nft_reject_type);
}
module_init(nft_reject_module_init);
module_exit(nft_reject_module_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_ALIAS_NFT_EXPR("reject");
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