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_validate(const struct nft_ctx *ctx,
  30                         const struct nft_expr *expr,
  31                         const struct nft_data **data)
  32 {
  33         return nft_chain_validate_hooks(ctx->chain,
  34                                         (1 << NF_INET_LOCAL_IN) |
  35                                         (1 << NF_INET_FORWARD) |
  36                                         (1 << NF_INET_LOCAL_OUT));
  37 }
  38 EXPORT_SYMBOL_GPL(nft_reject_validate);
  39
  40 int nft_reject_init(const struct nft_ctx *ctx,
  41                     const struct nft_expr *expr,
  42                     const struct nlattr * const tb[])
  43 {
  44         struct nft_reject *priv = nft_expr_priv(expr);
  45
  46         if (tb[NFTA_REJECT_TYPE] == NULL)
  47                 return -EINVAL;
  48
  49         priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
  50         switch (priv->type) {
  51         case NFT_REJECT_ICMP_UNREACH:
  52                 if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
  53                         return -EINVAL;
  54                 priv->icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
  55         case NFT_REJECT_TCP_RST:
  56                 break;
  57         default:
  58                 return -EINVAL;
  59         }
  60
  61         return 0;
  62 }
  63 EXPORT_SYMBOL_GPL(nft_reject_init);
  64
  65 int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
  66 {
  67         const struct nft_reject *priv = nft_expr_priv(expr);
  68
  69         if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
  70                 goto nla_put_failure;
  71
  72         switch (priv->type) {
  73         case NFT_REJECT_ICMP_UNREACH:
  74                 if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
  75                         goto nla_put_failure;
  76                 break;
  77         default:
  78                 break;
  79         }
  80
  81         return 0;
  82
  83 nla_put_failure:
  84         return -1;
  85 }
  86 EXPORT_SYMBOL_GPL(nft_reject_dump);
  87
  88 static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX + 1] = {
  89         [NFT_REJECT_ICMPX_NO_ROUTE]             = ICMP_NET_UNREACH,
  90         [NFT_REJECT_ICMPX_PORT_UNREACH]         = ICMP_PORT_UNREACH,
  91         [NFT_REJECT_ICMPX_HOST_UNREACH]         = ICMP_HOST_UNREACH,
  92         [NFT_REJECT_ICMPX_ADMIN_PROHIBITED]     = ICMP_PKT_FILTERED,
  93 };
  94
  95 int nft_reject_icmp_code(u8 code)
  96 {
  97         BUG_ON(code > NFT_REJECT_ICMPX_MAX);
  98
  99         return icmp_code_v4[code];
 100 }
 101
 102 EXPORT_SYMBOL_GPL(nft_reject_icmp_code);
 103
 104
 105 static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX + 1] = {
 106         [NFT_REJECT_ICMPX_NO_ROUTE]             = ICMPV6_NOROUTE,
 107         [NFT_REJECT_ICMPX_PORT_UNREACH]         = ICMPV6_PORT_UNREACH,
 108         [NFT_REJECT_ICMPX_HOST_UNREACH]         = ICMPV6_ADDR_UNREACH,
 109         [NFT_REJECT_ICMPX_ADMIN_PROHIBITED]     = ICMPV6_ADM_PROHIBITED,
 110 };
 111
 112 int nft_reject_icmpv6_code(u8 code)
 113 {
 114         BUG_ON(code > NFT_REJECT_ICMPX_MAX);
 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>");