LXR linux/net/netfilter/xt

   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
  14static bool
  15xt_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
  72static 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
 110err2:
 111        xt_rateest_put(par->net, est1);
 112err1:
 113        return ret;
 114}
 115
 116static 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
 125static 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
 137static int __init xt_rateest_mt_init(void)
 138{
 139        return xt_register_match(&xt_rateest_mt_reg);
 140}
 141
 142static void __exit xt_rateest_mt_fini(void)
 143{
 144        xt_unregister_match(&xt_rateest_mt_reg);
 145}
 146
 147MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 148MODULE_LICENSE("GPL");
 149MODULE_DESCRIPTION("xtables rate estimator match");
 150MODULE_ALIAS("ipt_rateest");
 151MODULE_ALIAS("ip6t_rateest");
 152module_init(xt_rateest_mt_init);
 153module_exit(xt_rateest_mt_fini);
 154