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![Eric Dumazet](/assets/img/avatar_default.png)
1) Old code was hard to maintain, due to complex lock chains. (We probably will be able to remove some kfree_rcu() in callers) 2) Using a single timer to update all estimators does not scale. 3) Code was buggy on 32bit kernel (WRITE_ONCE() on 64bit quantity is not supposed to work well) In this rewrite : - I removed the RB tree that had to be scanned in gen_estimator_active(). qdisc dumps should be much faster. - Each estimator has its own timer. - Estimations are maintained in net_rate_estimator structure, instead of dirtying the qdisc. Minor, but part of the simplification. - Reading the estimator uses RCU and a seqcount to provide proper support for 32bit kernels. - We reduce memory need when estimators are not used, since we store a pointer, instead of the bytes/packets counters. - xt_rateest_mt() no longer has to grab a spinlock. (In the future, xt_rateest_tg() could be switched to per cpu counters) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
155 lines
3.7 KiB
C
155 lines
3.7 KiB
C
/*
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* (C) 2007 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/gen_stats.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_rateest.h>
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#include <net/netfilter/xt_rateest.h>
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static bool
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xt_rateest_mt(const struct sk_buff *skb, struct xt_action_param *par)
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{
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const struct xt_rateest_match_info *info = par->matchinfo;
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struct gnet_stats_rate_est64 sample = {0};
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u_int32_t bps1, bps2, pps1, pps2;
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bool ret = true;
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gen_estimator_read(&info->est1->rate_est, &sample);
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if (info->flags & XT_RATEEST_MATCH_DELTA) {
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bps1 = info->bps1 >= sample.bps ? info->bps1 - sample.bps : 0;
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pps1 = info->pps1 >= sample.pps ? info->pps1 - sample.pps : 0;
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} else {
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bps1 = sample.bps;
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pps1 = sample.pps;
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}
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if (info->flags & XT_RATEEST_MATCH_ABS) {
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bps2 = info->bps2;
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pps2 = info->pps2;
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} else {
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gen_estimator_read(&info->est2->rate_est, &sample);
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if (info->flags & XT_RATEEST_MATCH_DELTA) {
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bps2 = info->bps2 >= sample.bps ? info->bps2 - sample.bps : 0;
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pps2 = info->pps2 >= sample.pps ? info->pps2 - sample.pps : 0;
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} else {
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bps2 = sample.bps;
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pps2 = sample.pps;
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}
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}
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switch (info->mode) {
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case XT_RATEEST_MATCH_LT:
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if (info->flags & XT_RATEEST_MATCH_BPS)
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ret &= bps1 < bps2;
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if (info->flags & XT_RATEEST_MATCH_PPS)
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ret &= pps1 < pps2;
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break;
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case XT_RATEEST_MATCH_GT:
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if (info->flags & XT_RATEEST_MATCH_BPS)
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ret &= bps1 > bps2;
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if (info->flags & XT_RATEEST_MATCH_PPS)
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ret &= pps1 > pps2;
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break;
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case XT_RATEEST_MATCH_EQ:
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if (info->flags & XT_RATEEST_MATCH_BPS)
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ret &= bps1 == bps2;
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if (info->flags & XT_RATEEST_MATCH_PPS)
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ret &= pps1 == pps2;
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break;
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}
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ret ^= info->flags & XT_RATEEST_MATCH_INVERT ? true : false;
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return ret;
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}
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static int xt_rateest_mt_checkentry(const struct xt_mtchk_param *par)
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{
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struct xt_rateest_match_info *info = par->matchinfo;
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struct xt_rateest *est1, *est2;
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int ret = -EINVAL;
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if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS |
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XT_RATEEST_MATCH_REL)) != 1)
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goto err1;
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if (!(info->flags & (XT_RATEEST_MATCH_BPS | XT_RATEEST_MATCH_PPS)))
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goto err1;
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switch (info->mode) {
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case XT_RATEEST_MATCH_EQ:
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case XT_RATEEST_MATCH_LT:
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case XT_RATEEST_MATCH_GT:
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break;
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default:
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goto err1;
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}
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ret = -ENOENT;
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est1 = xt_rateest_lookup(info->name1);
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if (!est1)
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goto err1;
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est2 = NULL;
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if (info->flags & XT_RATEEST_MATCH_REL) {
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est2 = xt_rateest_lookup(info->name2);
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if (!est2)
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goto err2;
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}
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info->est1 = est1;
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info->est2 = est2;
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return 0;
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err2:
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xt_rateest_put(est1);
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err1:
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return ret;
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}
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static void xt_rateest_mt_destroy(const struct xt_mtdtor_param *par)
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{
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struct xt_rateest_match_info *info = par->matchinfo;
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xt_rateest_put(info->est1);
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if (info->est2)
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xt_rateest_put(info->est2);
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}
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static struct xt_match xt_rateest_mt_reg __read_mostly = {
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.name = "rateest",
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.revision = 0,
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.family = NFPROTO_UNSPEC,
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.match = xt_rateest_mt,
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.checkentry = xt_rateest_mt_checkentry,
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.destroy = xt_rateest_mt_destroy,
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.matchsize = sizeof(struct xt_rateest_match_info),
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.me = THIS_MODULE,
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};
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static int __init xt_rateest_mt_init(void)
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{
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return xt_register_match(&xt_rateest_mt_reg);
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}
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static void __exit xt_rateest_mt_fini(void)
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{
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xt_unregister_match(&xt_rateest_mt_reg);
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}
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MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("xtables rate estimator match");
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MODULE_ALIAS("ipt_rateest");
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MODULE_ALIAS("ip6t_rateest");
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module_init(xt_rateest_mt_init);
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module_exit(xt_rateest_mt_fini);
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