net/netfilter/xt_nfacct.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * (C) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
   4  * (C) 2011 Intra2net AG <https://www.intra2net.com>
   5  */
   6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   7
   8 #include <linux/module.h>
   9 #include <linux/skbuff.h>
  10
  11 #include <linux/netfilter/x_tables.h>
  12 #include <linux/netfilter/nfnetlink_acct.h>
  13 #include <linux/netfilter/xt_nfacct.h>
  14
  15 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
  16 MODULE_DESCRIPTION("Xtables: match for the extended accounting infrastructure");
  17 MODULE_LICENSE("GPL");
  18 MODULE_ALIAS("ipt_nfacct");
  19 MODULE_ALIAS("ip6t_nfacct");
  20
  21 static bool nfacct_mt(const struct sk_buff *skb, struct xt_action_param *par)
  22 {
  23         int overquota;
  24         const struct xt_nfacct_match_info *info = par->targinfo;
  25
  26         nfnl_acct_update(skb, info->nfacct);
  27
  28         overquota = nfnl_acct_overquota(xt_net(par), info->nfacct);
  29
  30         return overquota != NFACCT_UNDERQUOTA;
  31 }
  32
  33 static int
  34 nfacct_mt_checkentry(const struct xt_mtchk_param *par)
  35 {
  36         struct xt_nfacct_match_info *info = par->matchinfo;
  37         struct nf_acct *nfacct;
  38
  39         nfacct = nfnl_acct_find_get(par->net, info->name);
  40         if (nfacct == NULL) {
  41                 pr_info_ratelimited("accounting object `%s' does not exists\n",
  42                                     info->name);
  43                 return -ENOENT;
  44         }
  45         info->nfacct = nfacct;
  46         return 0;
  47 }
  48
  49 static void
  50 nfacct_mt_destroy(const struct xt_mtdtor_param *par)
  51 {
  52         const struct xt_nfacct_match_info *info = par->matchinfo;
  53
  54         nfnl_acct_put(info->nfacct);
  55 }
  56
  57 static struct xt_match nfacct_mt_reg[] __read_mostly = {
  58         {
  59                 .name       = "nfacct",
  60                 .revision   = 0,
  61                 .family     = NFPROTO_UNSPEC,
  62                 .checkentry = nfacct_mt_checkentry,
  63                 .match      = nfacct_mt,
  64                 .destroy    = nfacct_mt_destroy,
  65                 .matchsize  = sizeof(struct xt_nfacct_match_info),
  66                 .usersize   = offsetof(struct xt_nfacct_match_info, nfacct),
  67                 .me         = THIS_MODULE,
  68         },
  69         {
  70                 .name       = "nfacct",
  71                 .revision   = 1,
  72                 .family     = NFPROTO_UNSPEC,
  73                 .checkentry = nfacct_mt_checkentry,
  74                 .match      = nfacct_mt,
  75                 .destroy    = nfacct_mt_destroy,
  76                 .matchsize  = sizeof(struct xt_nfacct_match_info_v1),
  77                 .usersize   = offsetof(struct xt_nfacct_match_info_v1, nfacct),
  78                 .me         = THIS_MODULE,
  79         },
  80 };
  81
  82 static int __init nfacct_mt_init(void)
  83 {
  84         return xt_register_matches(nfacct_mt_reg, ARRAY_SIZE(nfacct_mt_reg));
  85 }
  86
  87 static void __exit nfacct_mt_exit(void)
  88 {
  89         xt_unregister_matches(nfacct_mt_reg, ARRAY_SIZE(nfacct_mt_reg));
  90 }
  91
  92 module_init(nfacct_mt_init);
  93 module_exit(nfacct_mt_exit);