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