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); 83