// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2014 Patrick McHardy <kaber@trash.net>
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/nf_tables.h>
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#include <net/netfilter/nf_tables.h>
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#include <net/netfilter/nft_reject.h>
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#include <net/netfilter/ipv4/nf_reject.h>
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#include <net/netfilter/ipv6/nf_reject.h>
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static void nft_reject_inet_eval(const struct nft_expr *expr,
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struct nft_regs *regs,
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const struct nft_pktinfo *pkt)
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{
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struct nft_reject *priv = nft_expr_priv(expr);
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switch (nft_pf(pkt)) {
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case NFPROTO_IPV4:
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switch (priv->type) {
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case NFT_REJECT_ICMP_UNREACH:
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nf_send_unreach(pkt->skb, priv->icmp_code,
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nft_hook(pkt));
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break;
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case NFT_REJECT_TCP_RST:
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nf_send_reset(nft_net(pkt), pkt->skb, nft_hook(pkt));
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break;
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case NFT_REJECT_ICMPX_UNREACH:
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nf_send_unreach(pkt->skb,
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nft_reject_icmp_code(priv->icmp_code),
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nft_hook(pkt));
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break;
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}
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break;
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case NFPROTO_IPV6:
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switch (priv->type) {
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case NFT_REJECT_ICMP_UNREACH:
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nf_send_unreach6(nft_net(pkt), pkt->skb,
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priv->icmp_code, nft_hook(pkt));
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break;
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case NFT_REJECT_TCP_RST:
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nf_send_reset6(nft_net(pkt), pkt->skb, nft_hook(pkt));
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break;
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case NFT_REJECT_ICMPX_UNREACH:
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nf_send_unreach6(nft_net(pkt), pkt->skb,
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nft_reject_icmpv6_code(priv->icmp_code),
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nft_hook(pkt));
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break;
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}
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break;
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}
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regs->verdict.code = NF_DROP;
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}
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static int nft_reject_inet_init(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_reject *priv = nft_expr_priv(expr);
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int icmp_code;
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if (tb[NFTA_REJECT_TYPE] == NULL)
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return -EINVAL;
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priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
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switch (priv->type) {
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case NFT_REJECT_ICMP_UNREACH:
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case NFT_REJECT_ICMPX_UNREACH:
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if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
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return -EINVAL;
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icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
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if (priv->type == NFT_REJECT_ICMPX_UNREACH &&
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icmp_code > NFT_REJECT_ICMPX_MAX)
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return -EINVAL;
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priv->icmp_code = icmp_code;
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break;
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case NFT_REJECT_TCP_RST:
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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static int nft_reject_inet_dump(struct sk_buff *skb,
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const struct nft_expr *expr)
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{
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const struct nft_reject *priv = nft_expr_priv(expr);
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if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
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goto nla_put_failure;
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switch (priv->type) {
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case NFT_REJECT_ICMP_UNREACH:
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case NFT_REJECT_ICMPX_UNREACH:
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if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
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goto nla_put_failure;
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break;
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default:
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break;
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}
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return 0;
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nla_put_failure:
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return -1;
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}
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static struct nft_expr_type nft_reject_inet_type;
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static const struct nft_expr_ops nft_reject_inet_ops = {
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.type = &nft_reject_inet_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_reject)),
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.eval = nft_reject_inet_eval,
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.init = nft_reject_inet_init,
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.dump = nft_reject_inet_dump,
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.validate = nft_reject_validate,
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};
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static struct nft_expr_type nft_reject_inet_type __read_mostly = {
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.family = NFPROTO_INET,
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.name = "reject",
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.ops = &nft_reject_inet_ops,
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.policy = nft_reject_policy,
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.maxattr = NFTA_REJECT_MAX,
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.owner = THIS_MODULE,
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};
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static int __init nft_reject_inet_module_init(void)
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{
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return nft_register_expr(&nft_reject_inet_type);
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}
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static void __exit nft_reject_inet_module_exit(void)
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{
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nft_unregister_expr(&nft_reject_inet_type);
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}
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module_init(nft_reject_inet_module_init);
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module_exit(nft_reject_inet_module_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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MODULE_ALIAS_NFT_AF_EXPR(1, "reject");
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MODULE_DESCRIPTION("Netfilter nftables reject inet support");
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