net/netfilter/xt_rateest.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * (C) 2007 Patrick McHardy <kaber@trash.net>
   4  */
   5 #include <linux/module.h>
   6 #include <linux/skbuff.h>
   7 #include <linux/gen_stats.h>
   8
   9 #include <linux/netfilter/x_tables.h>
  10 #include <linux/netfilter/xt_rateest.h>
  11 #include <net/netfilter/xt_rateest.h>
  12
  13
  14 static bool
  15 xt_rateest_mt(const struct sk_buff *skb, struct xt_action_param *par)
  16 {
  17         const struct xt_rateest_match_info *info = par->matchinfo;
  18         struct gnet_stats_rate_est64 sample = {0};
  19         u_int32_t bps1, bps2, pps1, pps2;
  20         bool ret = true;
  21
  22         gen_estimator_read(&info->est1->rate_est, &sample);
  23
  24         if (info->flags & XT_RATEEST_MATCH_DELTA) {
  25                 bps1 = info->bps1 >= sample.bps ? info->bps1 - sample.bps : 0;
  26                 pps1 = info->pps1 >= sample.pps ? info->pps1 - sample.pps : 0;
  27         } else {
  28                 bps1 = sample.bps;
  29                 pps1 = sample.pps;
  30         }
  31
  32         if (info->flags & XT_RATEEST_MATCH_ABS) {
  33                 bps2 = info->bps2;
  34                 pps2 = info->pps2;
  35         } else {
  36                 gen_estimator_read(&info->est2->rate_est, &sample);
  37
  38                 if (info->flags & XT_RATEEST_MATCH_DELTA) {
  39                         bps2 = info->bps2 >= sample.bps ? info->bps2 - sample.bps : 0;
  40                         pps2 = info->pps2 >= sample.pps ? info->pps2 - sample.pps : 0;
  41                 } else {
  42                         bps2 = sample.bps;
  43                         pps2 = sample.pps;
  44                 }
  45         }
  46
  47         switch (info->mode) {
  48         case XT_RATEEST_MATCH_LT:
  49                 if (info->flags & XT_RATEEST_MATCH_BPS)
  50                         ret &= bps1 < bps2;
  51                 if (info->flags & XT_RATEEST_MATCH_PPS)
  52                         ret &= pps1 < pps2;
  53                 break;
  54         case XT_RATEEST_MATCH_GT:
  55                 if (info->flags & XT_RATEEST_MATCH_BPS)
  56                         ret &= bps1 > bps2;
  57                 if (info->flags & XT_RATEEST_MATCH_PPS)
  58                         ret &= pps1 > pps2;
  59                 break;
  60         case XT_RATEEST_MATCH_EQ:
  61                 if (info->flags & XT_RATEEST_MATCH_BPS)
  62                         ret &= bps1 == bps2;
  63                 if (info->flags & XT_RATEEST_MATCH_PPS)
  64                         ret &= pps1 == pps2;
  65                 break;
  66         }
  67
  68         ret ^= info->flags & XT_RATEEST_MATCH_INVERT ? true : false;
  69         return ret;
  70 }
  71
  72 static int xt_rateest_mt_checkentry(const struct xt_mtchk_param *par)
  73 {
  74         struct xt_rateest_match_info *info = par->matchinfo;
  75         struct xt_rateest *est1, *est2;
  76         int ret = -EINVAL;
  77
  78         if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS |
  79                                      XT_RATEEST_MATCH_REL)) != 1)
  80                 goto err1;
  81
  82         if (!(info->flags & (XT_RATEEST_MATCH_BPS | XT_RATEEST_MATCH_PPS)))
  83                 goto err1;
  84
  85         switch (info->mode) {
  86         case XT_RATEEST_MATCH_EQ:
  87         case XT_RATEEST_MATCH_LT:
  88         case XT_RATEEST_MATCH_GT:
  89                 break;
  90         default:
  91                 goto err1;
  92         }
  93
  94         ret  = -ENOENT;
  95         est1 = xt_rateest_lookup(par->net, info->name1);
  96         if (!est1)
  97                 goto err1;
  98
  99         est2 = NULL;
 100         if (info->flags & XT_RATEEST_MATCH_REL) {
 101                 est2 = xt_rateest_lookup(par->net, info->name2);
 102                 if (!est2)
 103                         goto err2;
 104         }
 105
 106         info->est1 = est1;
 107         info->est2 = est2;
 108         return 0;
 109
 110 err2:
 111         xt_rateest_put(par->net, est1);
 112 err1:
 113         return ret;
 114 }
 115
 116 static void xt_rateest_mt_destroy(const struct xt_mtdtor_param *par)
 117 {
 118         struct xt_rateest_match_info *info = par->matchinfo;
 119
 120         xt_rateest_put(par->net, info->est1);
 121         if (info->est2)
 122                 xt_rateest_put(par->net, info->est2);
 123 }
 124
 125 static struct xt_match xt_rateest_mt_reg __read_mostly = {
 126         .name       = "rateest",
 127         .revision   = 0,
 128         .family     = NFPROTO_UNSPEC,
 129         .match      = xt_rateest_mt,
 130         .checkentry = xt_rateest_mt_checkentry,
 131         .destroy    = xt_rateest_mt_destroy,
 132         .matchsize  = sizeof(struct xt_rateest_match_info),
 133         .usersize   = offsetof(struct xt_rateest_match_info, est1),
 134         .me         = THIS_MODULE,
 135 };
 136
 137 static int __init xt_rateest_mt_init(void)
 138 {
 139         return xt_register_match(&xt_rateest_mt_reg);
 140 }
 141
 142 static void __exit xt_rateest_mt_fini(void)
 143 {
 144         xt_unregister_match(&xt_rateest_mt_reg);
 145 }
 146
 147 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 148 MODULE_LICENSE("GPL");
 149 MODULE_DESCRIPTION("xtables rate estimator match");
 150 MODULE_ALIAS("ipt_rateest");
 151 MODULE_ALIAS("ip6t_rateest");
 152 module_init(xt_rateest_mt_init);
 153 module_exit(xt_rateest_mt_fini);