net/netfilter/xt_nfacct.c

   1 /*
   2  * (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
   3  * (C) 2011 Intra2net AG <http://www.intra2net.com>
   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 (or any
   7  * later at your option) as published by the Free Software Foundation.
   8  */
   9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11 #include <linux/module.h>
  12 #include <linux/skbuff.h>
  13
  14 #include <linux/netfilter/x_tables.h>
  15 #include <linux/netfilter/nfnetlink_acct.h>
  16 #include <linux/netfilter/xt_nfacct.h>
  17
  18 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
  19 MODULE_DESCRIPTION("Xtables: match for the extended accounting infrastructure");
  20 MODULE_LICENSE("GPL");
  21 MODULE_ALIAS("ipt_nfacct");
  22 MODULE_ALIAS("ip6t_nfacct");
  23
  24 static bool nfacct_mt(const struct sk_buff *skb, struct xt_action_param *par)
  25 {
  26         int overquota;
  27         const struct xt_nfacct_match_info *info = par->targinfo;
  28
  29         nfnl_acct_update(skb, info->nfacct);
  30
  31         overquota = nfnl_acct_overquota(xt_net(par), info->nfacct);
  32
  33         return overquota == NFACCT_UNDERQUOTA ? false : true;
  34 }
  35
  36 static int
  37 nfacct_mt_checkentry(const struct xt_mtchk_param *par)
  38 {
  39         struct xt_nfacct_match_info *info = par->matchinfo;
  40         struct nf_acct *nfacct;
  41
  42         nfacct = nfnl_acct_find_get(par->net, info->name);
  43         if (nfacct == NULL) {
  44                 pr_info_ratelimited("accounting object `%s' does not exists\n",
  45                                     info->name);
  46                 return -ENOENT;
  47         }
  48         info->nfacct = nfacct;
  49         return 0;
  50 }
  51
  52 static void
  53 nfacct_mt_destroy(const struct xt_mtdtor_param *par)
  54 {
  55         const struct xt_nfacct_match_info *info = par->matchinfo;
  56
  57         nfnl_acct_put(info->nfacct);
  58 }
  59
  60 static struct xt_match nfacct_mt_reg __read_mostly = {
  61         .name       = "nfacct",
  62         .family     = NFPROTO_UNSPEC,
  63         .checkentry = nfacct_mt_checkentry,
  64         .match      = nfacct_mt,
  65         .destroy    = nfacct_mt_destroy,
  66         .matchsize  = sizeof(struct xt_nfacct_match_info),
  67         .usersize   = offsetof(struct xt_nfacct_match_info, nfacct),
  68         .me         = THIS_MODULE,
  69 };
  70
  71 static int __init nfacct_mt_init(void)
  72 {
  73         return xt_register_match(&nfacct_mt_reg);
  74 }
  75
  76 static void __exit nfacct_mt_exit(void)
  77 {
  78         xt_unregister_match(&nfacct_mt_reg);
  79 }
  80
  81 module_init(nfacct_mt_init);
  82 module_exit(nfacct_mt_exit);