linux/net/netfilter/nft_reject.c
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   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
  44        if (tb[NFTA_REJECT_TYPE] == NULL)
  45                return -EINVAL;
  46
  47        priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
  48        switch (priv->type) {
  49        case NFT_REJECT_ICMP_UNREACH:
  50                if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
  51                        return -EINVAL;
  52                priv->icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
  53        case NFT_REJECT_TCP_RST:
  54                break;
  55        default:
  56                return -EINVAL;
  57        }
  58
  59        return 0;
  60}
  61EXPORT_SYMBOL_GPL(nft_reject_init);
  62
  63int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
  64{
  65        const struct nft_reject *priv = nft_expr_priv(expr);
  66
  67        if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
  68                goto nla_put_failure;
  69
  70        switch (priv->type) {
  71        case NFT_REJECT_ICMP_UNREACH:
  72                if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
  73                        goto nla_put_failure;
  74                break;
  75        default:
  76                break;
  77        }
  78
  79        return 0;
  80
  81nla_put_failure:
  82        return -1;
  83}
  84EXPORT_SYMBOL_GPL(nft_reject_dump);
  85
  86static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX + 1] = {
  87        [NFT_REJECT_ICMPX_NO_ROUTE]             = ICMP_NET_UNREACH,
  88        [NFT_REJECT_ICMPX_PORT_UNREACH]         = ICMP_PORT_UNREACH,
  89        [NFT_REJECT_ICMPX_HOST_UNREACH]         = ICMP_HOST_UNREACH,
  90        [NFT_REJECT_ICMPX_ADMIN_PROHIBITED]     = ICMP_PKT_FILTERED,
  91};
  92
  93int nft_reject_icmp_code(u8 code)
  94{
  95        if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
  96                return ICMP_NET_UNREACH;
  97
  98        return icmp_code_v4[code];
  99}
 100
 101EXPORT_SYMBOL_GPL(nft_reject_icmp_code);
 102
 103
 104static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX + 1] = {
 105        [NFT_REJECT_ICMPX_NO_ROUTE]             = ICMPV6_NOROUTE,
 106        [NFT_REJECT_ICMPX_PORT_UNREACH]         = ICMPV6_PORT_UNREACH,
 107        [NFT_REJECT_ICMPX_HOST_UNREACH]         = ICMPV6_ADDR_UNREACH,
 108        [NFT_REJECT_ICMPX_ADMIN_PROHIBITED]     = ICMPV6_ADM_PROHIBITED,
 109};
 110
 111int nft_reject_icmpv6_code(u8 code)
 112{
 113        if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
 114                return ICMPV6_NOROUTE;
 115
 116        return icmp_code_v6[code];
 117}
 118
 119EXPORT_SYMBOL_GPL(nft_reject_icmpv6_code);
 120
 121MODULE_LICENSE("GPL");
 122MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 123MODULE_DESCRIPTION("Netfilter x_tables over nftables module");
 124