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                                         (1 << NF_INET_PRE_ROUTING));
  35 }
  36 EXPORT_SYMBOL_GPL(nft_reject_validate);
  37
  38 int 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 }
  61 EXPORT_SYMBOL_GPL(nft_reject_init);
  62
  63 int 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
  81 nla_put_failure:
  82         return -1;
  83 }
  84 EXPORT_SYMBOL_GPL(nft_reject_dump);
  85
  86 static 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
  93 int 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
 101 EXPORT_SYMBOL_GPL(nft_reject_icmp_code);
 102
 103
 104 static 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
 111 int 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
 119 EXPORT_SYMBOL_GPL(nft_reject_icmpv6_code);
 120
 121 MODULE_LICENSE("GPL");
 122 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 123 MODULE_DESCRIPTION("Netfilter x_tables over nftables module");