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         int err;
  46
  47         err = nft_reject_validate(ctx, expr, NULL);
  48         if (err < 0)
  49                 return err;
  50
  51         if (tb[NFTA_REJECT_TYPE] == NULL)
  52                 return -EINVAL;
  53
  54         priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
  55         switch (priv->type) {
  56         case NFT_REJECT_ICMP_UNREACH:
  57                 if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
  58                         return -EINVAL;
  59                 priv->icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
  60         case NFT_REJECT_TCP_RST:
  61                 break;
  62         default:
  63                 return -EINVAL;
  64         }
  65
  66         return 0;
  67 }
  68 EXPORT_SYMBOL_GPL(nft_reject_init);
  69
  70 int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
  71 {
  72         const struct nft_reject *priv = nft_expr_priv(expr);
  73
  74         if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
  75                 goto nla_put_failure;
  76
  77         switch (priv->type) {
  78         case NFT_REJECT_ICMP_UNREACH:
  79                 if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
  80                         goto nla_put_failure;
  81                 break;
  82         default:
  83                 break;
  84         }
  85
  86         return 0;
  87
  88 nla_put_failure:
  89         return -1;
  90 }
  91 EXPORT_SYMBOL_GPL(nft_reject_dump);
  92
  93 static u8 icmp_code_v4[NFT_REJECT_ICMPX_MAX + 1] = {
  94         [NFT_REJECT_ICMPX_NO_ROUTE]             = ICMP_NET_UNREACH,
  95         [NFT_REJECT_ICMPX_PORT_UNREACH]         = ICMP_PORT_UNREACH,
  96         [NFT_REJECT_ICMPX_HOST_UNREACH]         = ICMP_HOST_UNREACH,
  97         [NFT_REJECT_ICMPX_ADMIN_PROHIBITED]     = ICMP_PKT_FILTERED,
  98 };
  99
 100 int nft_reject_icmp_code(u8 code)
 101 {
 102         BUG_ON(code > NFT_REJECT_ICMPX_MAX);
 103
 104         return icmp_code_v4[code];
 105 }
 106
 107 EXPORT_SYMBOL_GPL(nft_reject_icmp_code);
 108
 109
 110 static u8 icmp_code_v6[NFT_REJECT_ICMPX_MAX + 1] = {
 111         [NFT_REJECT_ICMPX_NO_ROUTE]             = ICMPV6_NOROUTE,
 112         [NFT_REJECT_ICMPX_PORT_UNREACH]         = ICMPV6_PORT_UNREACH,
 113         [NFT_REJECT_ICMPX_HOST_UNREACH]         = ICMPV6_ADDR_UNREACH,
 114         [NFT_REJECT_ICMPX_ADMIN_PROHIBITED]     = ICMPV6_ADM_PROHIBITED,
 115 };
 116
 117 int nft_reject_icmpv6_code(u8 code)
 118 {
 119         BUG_ON(code > NFT_REJECT_ICMPX_MAX);
 120
 121         return icmp_code_v6[code];
 122 }
 123
 124 EXPORT_SYMBOL_GPL(nft_reject_icmpv6_code);
 125
 126 MODULE_LICENSE("GPL");
 127 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");