net/netfilter/xt_rateest.c

   1 /*
   2  * (C) 2007 Patrick McHardy <kaber@trash.net>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8 #include <linux/module.h>
   9 #include <linux/skbuff.h>
  10 #include <linux/gen_stats.h>
  11
  12 #include <linux/netfilter/x_tables.h>
  13 #include <linux/netfilter/xt_rateest.h>
  14 #include <net/netfilter/xt_rateest.h>
  15
  16
  17 static bool
  18 xt_rateest_mt(const struct sk_buff *skb, struct xt_action_param *par)
  19 {
  20         const struct xt_rateest_match_info *info = par->matchinfo;
  21         struct gnet_stats_rate_est64 sample = {0};
  22         u_int32_t bps1, bps2, pps1, pps2;
  23         bool ret = true;
  24
  25         gen_estimator_read(&info->est1->rate_est, &sample);
  26
  27         if (info->flags & XT_RATEEST_MATCH_DELTA) {
  28                 bps1 = info->bps1 >= sample.bps ? info->bps1 - sample.bps : 0;
  29                 pps1 = info->pps1 >= sample.pps ? info->pps1 - sample.pps : 0;
  30         } else {
  31                 bps1 = sample.bps;
  32                 pps1 = sample.pps;
  33         }
  34
  35         if (info->flags & XT_RATEEST_MATCH_ABS) {
  36                 bps2 = info->bps2;
  37                 pps2 = info->pps2;
  38         } else {
  39                 gen_estimator_read(&info->est2->rate_est, &sample);
  40
  41                 if (info->flags & XT_RATEEST_MATCH_DELTA) {
  42                         bps2 = info->bps2 >= sample.bps ? info->bps2 - sample.bps : 0;
  43                         pps2 = info->pps2 >= sample.pps ? info->pps2 - sample.pps : 0;
  44                 } else {
  45                         bps2 = sample.bps;
  46                         pps2 = sample.pps;
  47                 }
  48         }
  49
  50         switch (info->mode) {
  51         case XT_RATEEST_MATCH_LT:
  52                 if (info->flags & XT_RATEEST_MATCH_BPS)
  53                         ret &= bps1 < bps2;
  54                 if (info->flags & XT_RATEEST_MATCH_PPS)
  55                         ret &= pps1 < pps2;
  56                 break;
  57         case XT_RATEEST_MATCH_GT:
  58                 if (info->flags & XT_RATEEST_MATCH_BPS)
  59                         ret &= bps1 > bps2;
  60                 if (info->flags & XT_RATEEST_MATCH_PPS)
  61                         ret &= pps1 > pps2;
  62                 break;
  63         case XT_RATEEST_MATCH_EQ:
  64                 if (info->flags & XT_RATEEST_MATCH_BPS)
  65                         ret &= bps1 == bps2;
  66                 if (info->flags & XT_RATEEST_MATCH_PPS)
  67                         ret &= pps1 == pps2;
  68                 break;
  69         }
  70
  71         ret ^= info->flags & XT_RATEEST_MATCH_INVERT ? true : false;
  72         return ret;
  73 }
  74
  75 static int xt_rateest_mt_checkentry(const struct xt_mtchk_param *par)
  76 {
  77         struct xt_rateest_match_info *info = par->matchinfo;
  78         struct xt_rateest *est1, *est2;
  79         int ret = -EINVAL;
  80
  81         if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS |
  82                                      XT_RATEEST_MATCH_REL)) != 1)
  83                 goto err1;
  84
  85         if (!(info->flags & (XT_RATEEST_MATCH_BPS | XT_RATEEST_MATCH_PPS)))
  86                 goto err1;
  87
  88         switch (info->mode) {
  89         case XT_RATEEST_MATCH_EQ:
  90         case XT_RATEEST_MATCH_LT:
  91         case XT_RATEEST_MATCH_GT:
  92                 break;
  93         default:
  94                 goto err1;
  95         }
  96
  97         ret  = -ENOENT;
  98         est1 = xt_rateest_lookup(info->name1);
  99         if (!est1)
 100                 goto err1;
 101
 102         est2 = NULL;
 103         if (info->flags & XT_RATEEST_MATCH_REL) {
 104                 est2 = xt_rateest_lookup(info->name2);
 105                 if (!est2)
 106                         goto err2;
 107         }
 108
 109         info->est1 = est1;
 110         info->est2 = est2;
 111         return 0;
 112
 113 err2:
 114         xt_rateest_put(est1);
 115 err1:
 116         return ret;
 117 }
 118
 119 static void xt_rateest_mt_destroy(const struct xt_mtdtor_param *par)
 120 {
 121         struct xt_rateest_match_info *info = par->matchinfo;
 122
 123         xt_rateest_put(info->est1);
 124         if (info->est2)
 125                 xt_rateest_put(info->est2);
 126 }
 127
 128 static struct xt_match xt_rateest_mt_reg __read_mostly = {
 129         .name       = "rateest",
 130         .revision   = 0,
 131         .family     = NFPROTO_UNSPEC,
 132         .match      = xt_rateest_mt,
 133         .checkentry = xt_rateest_mt_checkentry,
 134         .destroy    = xt_rateest_mt_destroy,
 135         .matchsize  = sizeof(struct xt_rateest_match_info),
 136         .me         = THIS_MODULE,
 137 };
 138
 139 static int __init xt_rateest_mt_init(void)
 140 {
 141         return xt_register_match(&xt_rateest_mt_reg);
 142 }
 143
 144 static void __exit xt_rateest_mt_fini(void)
 145 {
 146         xt_unregister_match(&xt_rateest_mt_reg);
 147 }
 148
 149 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 150 MODULE_LICENSE("GPL");
 151 MODULE_DESCRIPTION("xtables rate estimator match");
 152 MODULE_ALIAS("ipt_rateest");
 153 MODULE_ALIAS("ip6t_rateest");
 154 module_init(xt_rateest_mt_init);
 155 module_exit(xt_rateest_mt_fini);