linux/net/core/gen_estimator.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * net/sched/gen_estimator.c	Simple rate estimator.
 *
 * Authors:	Alexey Kuznetsov, <[email protected]>
 *		Eric Dumazet <[email protected]>
 *
 * Changes:
 *              Jamal Hadi Salim - moved it to net/core and reshulfed
 *              names to make it usable in general net subsystem.
 */

#include <linux/uaccess.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/seqlock.h>
#include <net/sock.h>
#include <net/gen_stats.h>

/* This code is NOT intended to be used for statistics collection,
 * its purpose is to provide a base for statistical multiplexing
 * for controlled load service.
 * If you need only statistics, run a user level daemon which
 * periodically reads byte counters.
 */

struct net_rate_estimator { … };

static void est_fetch_counters(struct net_rate_estimator *e,
			       struct gnet_stats_basic_sync *b)
{ … }

static void est_timer(struct timer_list *t)
{ … }

/**
 * gen_new_estimator - create a new rate estimator
 * @bstats: basic statistics
 * @cpu_bstats: bstats per cpu
 * @rate_est: rate estimator statistics
 * @lock: lock for statistics and control path
 * @running: true if @bstats represents a running qdisc, thus @bstats'
 *           internal values might change during basic reads. Only used
 *           if @bstats_cpu is NULL
 * @opt: rate estimator configuration TLV
 *
 * Creates a new rate estimator with &bstats as source and &rate_est
 * as destination. A new timer with the interval specified in the
 * configuration TLV is created. Upon each interval, the latest statistics
 * will be read from &bstats and the estimated rate will be stored in
 * &rate_est with the statistics lock grabbed during this period.
 *
 * Returns 0 on success or a negative error code.
 *
 */
int gen_new_estimator(struct gnet_stats_basic_sync *bstats,
		      struct gnet_stats_basic_sync __percpu *cpu_bstats,
		      struct net_rate_estimator __rcu **rate_est,
		      spinlock_t *lock,
		      bool running,
		      struct nlattr *opt)
{ … }
EXPORT_SYMBOL(…);

/**
 * gen_kill_estimator - remove a rate estimator
 * @rate_est: rate estimator
 *
 * Removes the rate estimator.
 *
 */
void gen_kill_estimator(struct net_rate_estimator __rcu **rate_est)
{ … }
EXPORT_SYMBOL(…);

/**
 * gen_replace_estimator - replace rate estimator configuration
 * @bstats: basic statistics
 * @cpu_bstats: bstats per cpu
 * @rate_est: rate estimator statistics
 * @lock: lock for statistics and control path
 * @running: true if @bstats represents a running qdisc, thus @bstats'
 *           internal values might change during basic reads. Only used
 *           if @cpu_bstats is NULL
 * @opt: rate estimator configuration TLV
 *
 * Replaces the configuration of a rate estimator by calling
 * gen_kill_estimator() and gen_new_estimator().
 *
 * Returns 0 on success or a negative error code.
 */
int gen_replace_estimator(struct gnet_stats_basic_sync *bstats,
			  struct gnet_stats_basic_sync __percpu *cpu_bstats,
			  struct net_rate_estimator __rcu **rate_est,
			  spinlock_t *lock,
			  bool running, struct nlattr *opt)
{ … }
EXPORT_SYMBOL(…);

/**
 * gen_estimator_active - test if estimator is currently in use
 * @rate_est: rate estimator
 *
 * Returns true if estimator is active, and false if not.
 */
bool gen_estimator_active(struct net_rate_estimator __rcu **rate_est)
{ … }
EXPORT_SYMBOL(…);

bool gen_estimator_read(struct net_rate_estimator __rcu **rate_est,
			struct gnet_stats_rate_est64 *sample)
{ … }
EXPORT_SYMBOL(…);