net/netfilter/nft_reject.c

   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
  20 const 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 };
  24 EXPORT_SYMBOL_GPL(nft_reject_policy);
  25
  26 int 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 }
  35 EXPORT_SYMBOL_GPL(nft_reject_validate);
  36
  37 int nft_reject_init(const struct nft_ctx *ctx,
  38                     const struct nft_expr *expr,
  39                     const struct nlattr * const tb[])
  40 {
  41         struct nft_reject *priv = nft_expr_priv(expr);
  42
  43         if (tb[NFTA_REJECT_TYPE] == NULL)
  44                 return -EINVAL;
  45
  46         priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
  47         switch (priv->type) {
  48         case NFT_REJECT_ICMP_UNREACH:
  49                 if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
  50                         return -EINVAL;
  51                 priv->icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
  52         case NFT_REJECT_TCP_RST:
  53                 break;
  54         default:
  55                 return -EINVAL;
  56         }
  57
  58         return 0;
  59 }
  60 EXPORT_SYMBOL_GPL(nft_reject_init);
  61
  62 int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
  63 {
  64         const struct nft_reject *priv = nft_expr_priv(expr);
  65
  66         if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
  67                 goto nla_put_failure;
  68
  69         switch (priv->type) {
  70         case NFT_REJECT_ICMP_UNREACH:
  71                 if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
  72                         goto nla_put_failure;
  73                 break;
  74         default:
  75                 break;
  76         }
  77
  78         return 0;
  79
  80 nla_put_failure:
  81         return -1;
  82 }
  83 EXPORT_SYMBOL_GPL(nft_reject_dump);
  84
  85 static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX + 1] = {
  86         [NFT_REJECT_ICMPX_NO_ROUTE]             = ICMP_NET_UNREACH,
  87         [NFT_REJECT_ICMPX_PORT_UNREACH]         = ICMP_PORT_UNREACH,
  88         [NFT_REJECT_ICMPX_HOST_UNREACH]         = ICMP_HOST_UNREACH,
  89         [NFT_REJECT_ICMPX_ADMIN_PROHIBITED]     = ICMP_PKT_FILTERED,
  90 };
  91
  92 int nft_reject_icmp_code(u8 code)
  93 {
  94         if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
  95                 return ICMP_NET_UNREACH;
  96
  97         return icmp_code_v4[code];
  98 }
  99
 100 EXPORT_SYMBOL_GPL(nft_reject_icmp_code);
 101
 102
 103 static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX + 1] = {
 104         [NFT_REJECT_ICMPX_NO_ROUTE]             = ICMPV6_NOROUTE,
 105         [NFT_REJECT_ICMPX_PORT_UNREACH]         = ICMPV6_PORT_UNREACH,
 106         [NFT_REJECT_ICMPX_HOST_UNREACH]         = ICMPV6_ADDR_UNREACH,
 107         [NFT_REJECT_ICMPX_ADMIN_PROHIBITED]     = ICMPV6_ADM_PROHIBITED,
 108 };
 109
 110 int nft_reject_icmpv6_code(u8 code)
 111 {
 112         if (WARN_ON_ONCE(code > NFT_REJECT_ICMPX_MAX))
 113                 return ICMPV6_NOROUTE;
 114
 115         return icmp_code_v6[code];
 116 }
 117
 118 EXPORT_SYMBOL_GPL(nft_reject_icmpv6_code);
 119
 120 MODULE_LICENSE("GPL");
 121 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 122 MODULE_DESCRIPTION("Netfilter x_tables over nftables module");