kernel/net/netfilter/nft_reject.c

   1 /*
   2  * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
   3  * Copyright (c) 2013 Eric Leblond <eric@regit.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Development of this code funded by Astaro AG (http://www.astaro.com/)
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/module.h>
  15 #include <linux/netlink.h>
  16 #include <linux/netfilter.h>
  17 #include <linux/netfilter/nf_tables.h>
  18 #include <net/netfilter/nf_tables.h>
  19 #include <net/netfilter/nft_reject.h>
  20 #include <linux/icmp.h>
  21 #include <linux/icmpv6.h>
  22
  23 const struct nla_policy nft_reject_policy[NFTA_REJECT_MAX + 1] = {
  24         [NFTA_REJECT_TYPE]              = { .type = NLA_U32 },
  25         [NFTA_REJECT_ICMP_CODE]         = { .type = NLA_U8 },
  26 };
  27 EXPORT_SYMBOL_GPL(nft_reject_policy);
  28
  29 int nft_reject_init(const struct nft_ctx *ctx,
  30                     const struct nft_expr *expr,
  31                     const struct nlattr * const tb[])
  32 {
  33         struct nft_reject *priv = nft_expr_priv(expr);
  34
  35         if (tb[NFTA_REJECT_TYPE] == NULL)
  36                 return -EINVAL;
  37
  38         priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
  39         switch (priv->type) {
  40         case NFT_REJECT_ICMP_UNREACH:
  41                 if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
  42                         return -EINVAL;
  43                 priv->icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
  44         case NFT_REJECT_TCP_RST:
  45                 break;
  46         default:
  47                 return -EINVAL;
  48         }
  49
  50         return 0;
  51 }
  52 EXPORT_SYMBOL_GPL(nft_reject_init);
  53
  54 int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
  55 {
  56         const struct nft_reject *priv = nft_expr_priv(expr);
  57
  58         if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
  59                 goto nla_put_failure;
  60
  61         switch (priv->type) {
  62         case NFT_REJECT_ICMP_UNREACH:
  63                 if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
  64                         goto nla_put_failure;
  65                 break;
  66         default:
  67                 break;
  68         }
  69
  70         return 0;
  71
  72 nla_put_failure:
  73         return -1;
  74 }
  75 EXPORT_SYMBOL_GPL(nft_reject_dump);
  76
  77 static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX + 1] = {
  78         [NFT_REJECT_ICMPX_NO_ROUTE]             = ICMP_NET_UNREACH,
  79         [NFT_REJECT_ICMPX_PORT_UNREACH]         = ICMP_PORT_UNREACH,
  80         [NFT_REJECT_ICMPX_HOST_UNREACH]         = ICMP_HOST_UNREACH,
  81         [NFT_REJECT_ICMPX_ADMIN_PROHIBITED]     = ICMP_PKT_FILTERED,
  82 };
  83
  84 int nft_reject_icmp_code(u8 code)
  85 {
  86         BUG_ON(code > NFT_REJECT_ICMPX_MAX);
  87
  88         return icmp_code_v4[code];
  89 }
  90
  91 EXPORT_SYMBOL_GPL(nft_reject_icmp_code);
  92
  93
  94 static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX + 1] = {
  95         [NFT_REJECT_ICMPX_NO_ROUTE]             = ICMPV6_NOROUTE,
  96         [NFT_REJECT_ICMPX_PORT_UNREACH]         = ICMPV6_PORT_UNREACH,
  97         [NFT_REJECT_ICMPX_HOST_UNREACH]         = ICMPV6_ADDR_UNREACH,
  98         [NFT_REJECT_ICMPX_ADMIN_PROHIBITED]     = ICMPV6_ADM_PROHIBITED,
  99 };
 100
 101 int nft_reject_icmpv6_code(u8 code)
 102 {
 103         BUG_ON(code > NFT_REJECT_ICMPX_MAX);
 104
 105         return icmp_code_v6[code];
 106 }
 107
 108 EXPORT_SYMBOL_GPL(nft_reject_icmpv6_code);
 109
 110 MODULE_LICENSE("GPL");
 111 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");