Release 4.11 net/sched/sch_netem.c

/*
 * net/sched/sch_netem.c        Network emulator
 *
 *              This program is free software; you can redistribute it and/or
 *              modify it under the terms of the GNU General Public License
 *              as published by the Free Software Foundation; either version
 *              2 of the License.
 *
 *              Many of the algorithms and ideas for this came from
 *              NIST Net which is not copyrighted.
 *
 * Authors:     Stephen Hemminger <shemminger@osdl.org>
 *              Catalin(ux aka Dino) BOIE <catab at umbrella dot ro>
 */

#include <linux/mm.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/vmalloc.h>
#include <linux/rtnetlink.h>
#include <linux/reciprocal_div.h>
#include <linux/rbtree.h>

#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/inet_ecn.h>


#define VERSION "1.3"

/*      Network Emulation Queuing algorithm.
        ====================================

        Sources: [1] Mark Carson, Darrin Santay, "NIST Net - A Linux-based
                 Network Emulation Tool
                 [2] Luigi Rizzo, DummyNet for FreeBSD

         ----------------------------------------------------------------

         This started out as a simple way to delay outgoing packets to
         test TCP but has grown to include most of the functionality
         of a full blown network emulator like NISTnet. It can delay
         packets and add random jitter (and correlation). The random
         distribution can be loaded from a table as well to provide
         normal, Pareto, or experimental curves. Packet loss,
         duplication, and reordering can also be emulated.

         This qdisc does not do classification that can be handled in
         layering other disciplines.  It does not need to do bandwidth
         control either since that can be handled by using token
         bucket or other rate control.

     Correlated Loss Generator models

        Added generation of correlated loss according to the
        "Gilbert-Elliot" model, a 4-state markov model.

        References:
        [1] NetemCLG Home http://netgroup.uniroma2.it/NetemCLG
        [2] S. Salsano, F. Ludovici, A. Ordine, "Definition of a general
        and intuitive loss model for packet networks and its implementation
        in the Netem module in the Linux kernel", available in [1]

        Authors: Stefano Salsano <stefano.salsano at uniroma2.it
                 Fabio Ludovici <fabio.ludovici at yahoo.it>
*/


struct netem_sched_data {
	/* internal t(ime)fifo qdisc uses t_root and sch->limit */
	
struct rb_root t_root;

	/* optional qdisc for classful handling (NULL at netem init) */
	
struct Qdisc	*qdisc;

	
struct qdisc_watchdog watchdog;

	
psched_tdiff_t latency;
	
psched_tdiff_t jitter;

	
u32 loss;
	
u32 ecn;
	
u32 limit;
	
u32 counter;
	
u32 gap;
	
u32 duplicate;
	
u32 reorder;
	
u32 corrupt;
	
u64 rate;
	
s32 packet_overhead;
	
u32 cell_size;
	
struct reciprocal_value cell_size_reciprocal;
	
s32 cell_overhead;

	
struct crndstate {
		
u32 last;
		
u32 rho;
	} 




delay_cor, loss_cor, dup_cor, reorder_cor, corrupt_cor;

	
struct disttable {
		
u32  size;
		
s16 table[0];
	} 
*delay_dist;

	enum  {
		
CLG_RANDOM,
		
CLG_4_STATES,
		
CLG_GILB_ELL,
        } 
loss_model;

	enum {
		
TX_IN_GAP_PERIOD = 1,
		
TX_IN_BURST_PERIOD,
		
LOST_IN_GAP_PERIOD,
		
LOST_IN_BURST_PERIOD,
        } 
_4_state_model;

	enum {
		
GOOD_STATE = 1,
		
BAD_STATE,
        } 
GE_state_model;

	/* Correlated Loss Generation models */
	
struct clgstate {
		/* state of the Markov chain */
		
u8 state;

		/* 4-states and Gilbert-Elliot models */
		
u32 a1;	/* p13 for 4-states or p for GE */
		
u32 a2;	/* p31 for 4-states or r for GE */
		
u32 a3;	/* p32 for 4-states or h for GE */
		
u32 a4;	/* p14 for 4-states or 1-k for GE */
		
u32 a5; /* p23 used only in 4-states */
	} 
clg;

};

/* Time stamp put into socket buffer control block
 * Only valid when skbs are in our internal t(ime)fifo queue.
 *
 * As skb->rbnode uses same storage than skb->next, skb->prev and skb->tstamp,
 * and skb->next & skb->prev are scratch space for a qdisc,
 * we save skb->tstamp value in skb->cb[] before destroying it.
 */

struct netem_skb_cb {
	
psched_time_t	time_to_send;
	
ktime_t		tstamp_save;
};




static struct sk_buff *netem_rb_to_skb(struct rb_node *rb)
{
	return rb_entry(rb, struct sk_buff, rbnode);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric Dumazet
23
95.83%
2
66.67%
Geliang Tang
1
4.17%
1
33.33%
Total
24
100.00%
3
100.00%



static inline struct netem_skb_cb *netem_skb_cb(struct sk_buff *skb)
{
	/* we assume we can use skb next/prev/tstamp as storage for rb_node */
	qdisc_cb_private_validate(skb, sizeof(struct netem_skb_cb));
	return (struct netem_skb_cb *)qdisc_skb_cb(skb)->data;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jussi Kivilinna
36
92.31%
2
50.00%
David S. Miller
2
5.13%
1
25.00%
Eric Dumazet
1
2.56%
1
25.00%
Total
39
100.00%
4
100.00%

/* init_crandom - initialize correlated random number generator
 * Use entropy source for initial seed.
 */


static void init_crandom(struct crndstate *state, unsigned long rho)
{
	state->rho = rho;
	state->last = prandom_u32();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
27
96.43%
1
50.00%
Aruna-Hewapathirane
1
3.57%
1
50.00%
Total
28
100.00%
2
100.00%

/* get_crandom - correlated random number generator
 * Next number depends on last value.
 * rho is scaled to avoid floating point.
 */


static u32 get_crandom(struct crndstate *state)
{
	u64 value, rho;
	unsigned long answer;

	if (state->rho == 0)	/* no correlation */
		return prandom_u32();

	value = prandom_u32();
	rho = (u64)state->rho + 1;
	answer = (value * ((1ull<<32) - rho) + state->last * rho) >> 32;
	state->last = answer;
	return answer;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
80
97.56%
4
80.00%
Aruna-Hewapathirane
2
2.44%
1
20.00%
Total
82
100.00%
5
100.00%

/* loss_4state - 4-state model loss generator
 * Generates losses according to the 4-state Markov chain adopted in
 * the GI (General and Intuitive) loss model.
 */


static bool loss_4state(struct netem_sched_data *q)
{
	struct clgstate *clg = &q->clg;
	u32 rnd = prandom_u32();

	/*
         * Makes a comparison between rnd and the transition
         * probabilities outgoing from the current state, then decides the
         * next state and if the next packet has to be transmitted or lost.
         * The four states correspond to:
         *   TX_IN_GAP_PERIOD => successfully transmitted packets within a gap period
         *   LOST_IN_BURST_PERIOD => isolated losses within a gap period
         *   LOST_IN_GAP_PERIOD => lost packets within a burst period
         *   TX_IN_GAP_PERIOD => successfully transmitted packets within a burst period
         */
	switch (clg->state) {
	case TX_IN_GAP_PERIOD:
		if (rnd < clg->a4) {
			clg->state = LOST_IN_BURST_PERIOD;
			return true;
		} else if (clg->a4 < rnd && rnd < clg->a1 + clg->a4) {
			clg->state = LOST_IN_GAP_PERIOD;
			return true;
		} else if (clg->a1 + clg->a4 < rnd) {
			clg->state = TX_IN_GAP_PERIOD;
		}

		break;
	case TX_IN_BURST_PERIOD:
		if (rnd < clg->a5) {
			clg->state = LOST_IN_GAP_PERIOD;
			return true;
		} else {
			clg->state = TX_IN_BURST_PERIOD;
		}

		break;
	case LOST_IN_GAP_PERIOD:
		if (rnd < clg->a3)
			clg->state = TX_IN_BURST_PERIOD;
		else if (clg->a3 < rnd && rnd < clg->a2 + clg->a3) {
			clg->state = TX_IN_GAP_PERIOD;
		} else if (clg->a2 + clg->a3 < rnd) {
			clg->state = LOST_IN_GAP_PERIOD;
			return true;
		}
		break;
	case LOST_IN_BURST_PERIOD:
		clg->state = TX_IN_GAP_PERIOD;
		break;
	}

	return false;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
205
91.52%
2
50.00%
Yang Yingliang
18
8.04%
1
25.00%
Aruna-Hewapathirane
1
0.45%
1
25.00%
Total
224
100.00%
4
100.00%

/* loss_gilb_ell - Gilbert-Elliot model loss generator
 * Generates losses according to the Gilbert-Elliot loss model or
 * its special cases  (Gilbert or Simple Gilbert)
 *
 * Makes a comparison between random number and the transition
 * probabilities outgoing from the current state, then decides the
 * next state. A second random number is extracted and the comparison
 * with the loss probability of the current state decides if the next
 * packet will be transmitted or lost.
 */


static bool loss_gilb_ell(struct netem_sched_data *q)
{
	struct clgstate *clg = &q->clg;

	switch (clg->state) {
	case GOOD_STATE:
		if (prandom_u32() < clg->a1)
			clg->state = BAD_STATE;
		if (prandom_u32() < clg->a4)
			return true;
		break;
	case BAD_STATE:
		if (prandom_u32() < clg->a2)
			clg->state = GOOD_STATE;
		if (prandom_u32() > clg->a3)
			return true;
	}

	return false;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
85
91.40%
3
60.00%
Aruna-Hewapathirane
4
4.30%
1
20.00%
Yang Yingliang
4
4.30%
1
20.00%
Total
93
100.00%
5
100.00%



static bool loss_event(struct netem_sched_data *q)
{
	switch (q->loss_model) {
	case CLG_RANDOM:
		/* Random packet drop 0 => none, ~0 => all */
		return q->loss && q->loss >= get_crandom(&q->loss_cor);

	case CLG_4_STATES:
		/* 4state loss model algorithm (used also for GI model)
                * Extracts a value from the markov 4 state loss generator,
                * if it is 1 drops a packet and if needed writes the event in
                * the kernel logs
                */
		return loss_4state(q);

	case CLG_GILB_ELL:
		/* Gilbert-Elliot loss model algorithm
                * Extracts a value from the Gilbert-Elliot loss generator,
                * if it is 1 drops a packet and if needed writes the event in
                * the kernel logs
                */
		return loss_gilb_ell(q);
	}

	return false;	/* not reached */
}


Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
64
100.00%
1
100.00%
Total
64
100.00%
1
100.00%

/* tabledist - return a pseudo-randomly distributed value with mean mu and
 * std deviation sigma.  Uses table lookup to approximate the desired
 * distribution, and a uniformly-distributed pseudo-random source.
 */


static psched_tdiff_t tabledist(psched_tdiff_t mu, psched_tdiff_t sigma,
				struct crndstate *state,
				const struct disttable *dist)
{
	psched_tdiff_t x;
	long t;
	u32 rnd;

	if (sigma == 0)
		return mu;

	rnd = get_crandom(state);

	/* default uniform distribution */
	if (dist == NULL)
		return (rnd % (2*sigma)) - sigma + mu;

	t = dist->table[rnd % dist->size];
	x = (sigma % NETEM_DIST_SCALE) * t;
	if (x >= 0)
		x += NETEM_DIST_SCALE/2;
	else
		x -= NETEM_DIST_SCALE/2;

	return  x / NETEM_DIST_SCALE + (sigma / NETEM_DIST_SCALE) * t + mu;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
127
100.00%
5
100.00%
Total
127
100.00%
5
100.00%



static psched_time_t packet_len_2_sched_time(unsigned int len, struct netem_sched_data *q)
{
	u64 ticks;

	len += q->packet_overhead;

	if (q->cell_size) {
		u32 cells = reciprocal_divide(len, q->cell_size_reciprocal);

		if (len > cells * q->cell_size)	/* extra cell needed for remainder */
			cells++;
		len = cells * (q->cell_size + q->cell_overhead);
	}

	ticks = (u64)len * NSEC_PER_SEC;

	do_div(ticks, q->rate);
	return PSCHED_NS2TICKS(ticks);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Hagen Paul Pfeifer
83
86.46%
2
66.67%
Eric Dumazet
13
13.54%
1
33.33%
Total
96
100.00%
3
100.00%



static void tfifo_reset(struct Qdisc *sch)
{
	struct netem_sched_data *q = qdisc_priv(sch);
	struct rb_node *p;

	while ((p = rb_first(&q->t_root))) {
		struct sk_buff *skb = netem_rb_to_skb(p);

		rb_erase(p, &q->t_root);
		rtnl_kfree_skbs(skb, skb);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
66
95.65%
1
50.00%
Eric Dumazet
3
4.35%
1
50.00%
Total
69
100.00%
2
100.00%



static void tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch)
{
	struct netem_sched_data *q = qdisc_priv(sch);
	psched_time_t tnext = netem_skb_cb(nskb)->time_to_send;
	struct rb_node **p = &q->t_root.rb_node, *parent = NULL;

	while (*p) {
		struct sk_buff *skb;

		parent = *p;
		skb = netem_rb_to_skb(parent);
		if (tnext >= netem_skb_cb(skb)->time_to_send)
			p = &parent->rb_right;
		else
			p = &parent->rb_left;
	}
	rb_link_node(&nskb->rbnode, parent, p);
	rb_insert_color(&nskb->rbnode, &q->t_root);
	sch->q.qlen++;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric Dumazet
136
100.00%
4
100.00%
Total
136
100.00%
4
100.00%

/* netem can't properly corrupt a megapacket (like we get from GSO), so instead
 * when we statistically choose to corrupt one, we instead segment it, returning
 * the first packet to be corrupted, and re-enqueue the remaining frames
 */


static struct sk_buff *netem_segment(struct sk_buff *skb, struct Qdisc *sch,
				     struct sk_buff **to_free)
{
	struct sk_buff *segs;
	netdev_features_t features = netif_skb_features(skb);

	segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);

	if (IS_ERR_OR_NULL(segs)) {
		qdisc_drop(skb, sch, to_free);
		return NULL;
	}
	consume_skb(skb);
	return segs;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Neil Horman
69
88.46%
1
33.33%
Eric Dumazet
8
10.26%
1
33.33%
Florian Westphal
1
1.28%
1
33.33%
Total
78
100.00%
3
100.00%



static void netem_enqueue_skb_head(struct qdisc_skb_head *qh, struct sk_buff *skb)
{
	skb->next = qh->head;

	if (!qh->head)
		qh->tail = skb;
	qh->head = skb;
	qh->qlen++;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Florian Westphal
48
100.00%
1
100.00%
Total
48
100.00%
1
100.00%

/*
 * Insert one skb into qdisc.
 * Note: parent depends on return value to account for queue length.
 *      NET_XMIT_DROP: queue length didn't change.
 *      NET_XMIT_SUCCESS: one skb was queued.
 */


static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch,
			 struct sk_buff **to_free)
{
	struct netem_sched_data *q = qdisc_priv(sch);
	/* We don't fill cb now as skb_unshare() may invalidate it */
	struct netem_skb_cb *cb;
	struct sk_buff *skb2;
	struct sk_buff *segs = NULL;
	unsigned int len = 0, last_len, prev_len = qdisc_pkt_len(skb);
	int nb = 0;
	int count = 1;
	int rc = NET_XMIT_SUCCESS;

	/* Random duplication */
	if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor))
		++count;

	/* Drop packet? */
	if (loss_event(q)) {
		if (q->ecn && INET_ECN_set_ce(skb))
			qdisc_qstats_drop(sch); /* mark packet */
		else
			--count;
	}
	if (count == 0) {
		qdisc_qstats_drop(sch);
		__qdisc_drop(skb, to_free);
		return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
	}

	/* If a delay is expected, orphan the skb. (orphaning usually takes
         * place at TX completion time, so _before_ the link transit delay)
         */
	if (q->latency || q->jitter)
		skb_orphan_partial(skb);

	/*
         * If we need to duplicate packet, then re-insert at top of the
         * qdisc tree, since parent queuer expects that only one
         * skb will be queued.
         */
	if (count > 1 && (skb2 = skb_clone(skb, GFP_ATOMIC)) != NULL) {
		struct Qdisc *rootq = qdisc_root(sch);
		u32 dupsave = q->duplicate; /* prevent duplicating a dup... */

		q->duplicate = 0;
		rootq->enqueue(skb2, rootq, to_free);
		q->duplicate = dupsave;
	}

	/*
         * Randomized packet corruption.
         * Make copy if needed since we are modifying
         * If packet is going to be hardware checksummed, then
         * do it now in software before we mangle it.
         */
	if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) {
		if (skb_is_gso(skb)) {
			segs = netem_segment(skb, sch, to_free);
			if (!segs)
				return NET_XMIT_DROP;
		} else {
			segs = skb;
		}

		skb = segs;
		segs = segs->next;

		skb = skb_unshare(skb, GFP_ATOMIC);
		if (unlikely(!skb)) {
			qdisc_qstats_drop(sch);
			goto finish_segs;
		}
		if (skb->ip_summed == CHECKSUM_PARTIAL &&
		    skb_checksum_help(skb)) {
			qdisc_drop(skb, sch, to_free);
			goto finish_segs;
		}

		skb->data[prandom_u32() % skb_headlen(skb)] ^=
			1<<(prandom_u32() % 8);
	}

	if (unlikely(sch->q.qlen >= sch->limit))
		return qdisc_drop(skb, sch, to_free);

	qdisc_qstats_backlog_inc(sch, skb);

	cb = netem_skb_cb(skb);
	if (q->gap == 0 ||		/* not doing reordering */
	    q->counter < q->gap - 1 ||	/* inside last reordering gap */
	    q->reorder < get_crandom(&q->reorder_cor)) {
		psched_time_t now;
		psched_tdiff_t delay;

		delay = tabledist(q->latency, q->jitter,
				  &q->delay_cor, q->delay_dist);

		now = psched_get_time();

		if (q->rate) {
			struct sk_buff *last;

			if (sch->q.qlen)
				last = sch->q.tail;
			else
				last = netem_rb_to_skb(rb_last(&q->t_root));
			if (last) {
				/*
                                 * Last packet in queue is reference point (now),
                                 * calculate this time bonus and subtract
                                 * from delay.
                                 */
				delay -= netem_skb_cb(last)->time_to_send - now;
				delay = max_t(psched_tdiff_t, 0, delay);
				now = netem_skb_cb(last)->time_to_send;
			}

			delay += packet_len_2_sched_time(qdisc_pkt_len(skb), q);
		}

		cb->time_to_send = now + delay;
		cb->tstamp_save = skb->tstamp;
		++q->counter;
		tfifo_enqueue(skb, sch);
	} else {
		/*
                 * Do re-ordering by putting one out of N packets at the front
                 * of the queue.
                 */
		cb->time_to_send = psched_get_time();
		q->counter = 0;

		netem_enqueue_skb_head(&sch->q, skb);
		sch->qstats.requeues++;
	}

finish_segs:
	if (segs) {
		while (segs) {
			skb2 = segs->next;
			segs->next = NULL;
			qdisc_skb_cb(segs)->pkt_len = segs->len;
			last_len = segs->len;
			rc = qdisc_enqueue(segs, sch, to_free);
			if (rc != NET_XMIT_SUCCESS) {
				if (net_xmit_drop_count(rc))
					qdisc_qstats_drop(sch);
			} else {
				nb++;
				len += last_len;
			}
			segs = skb2;
		}
		sch->q.qlen += nb;
		if (nb > 1)
			qdisc_tree_reduce_backlog(sch, 1 - nb, prev_len - len);
	}
	return NET_XMIT_SUCCESS;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
298
39.31%
17
34.69%
Neil Horman
192
25.33%
1
2.04%
Eric Dumazet
143
18.87%
10
20.41%
Hagen Paul Pfeifer
34
4.49%
2
4.08%
Johannes Naab
23
3.03%
1
2.04%
Jarek Poplawski
15
1.98%
2
4.08%
Patrick McHardy
11
1.45%
3
6.12%
John Fastabend
9
1.19%
1
2.04%
Florian Westphal
8
1.06%
3
6.12%
David S. Miller
7
0.92%
2
4.08%
Guillaume Chazarain
6
0.79%
1
2.04%
Yang Yingliang
3
0.40%
1
2.04%
Vijay Subramanian
2
0.26%
1
2.04%
Aruna-Hewapathirane
2
0.26%
1
2.04%
Jussi Kivilinna
2
0.26%
1
2.04%
Joe Perches
2
0.26%
1
2.04%
Hideaki Yoshifuji / 吉藤英明
1
0.13%
1
2.04%
Total
758
100.00%
49
100.00%



static struct sk_buff *netem_dequeue(struct Qdisc *sch)
{
	struct netem_sched_data *q = qdisc_priv(sch);
	struct sk_buff *skb;
	struct rb_node *p;

tfifo_dequeue:
	skb = __qdisc_dequeue_head(&sch->q);
	if (skb) {
		qdisc_qstats_backlog_dec(sch, skb);
deliver:
		qdisc_bstats_update(sch, skb);
		return skb;
	}
	p = rb_first(&q->t_root);
	if (p) {
		psched_time_t time_to_send;

		skb = netem_rb_to_skb(p);

		/* if more time remaining? */
		time_to_send = netem_skb_cb(skb)->time_to_send;
		if (time_to_send <= psched_get_time()) {
			rb_erase(p, &q->t_root);

			sch->q.qlen--;
			qdisc_qstats_backlog_dec(sch, skb);
			skb->next = NULL;
			skb->prev = NULL;
			skb->tstamp = netem_skb_cb(skb)->tstamp_save;

#ifdef CONFIG_NET_CLS_ACT
			/*
                         * If it's at ingress let's pretend the delay is
                         * from the network (tstamp will be updated).
                         */
			if (skb->tc_redirected && skb->tc_from_ingress)
				skb->tstamp = 0;
#endif

			if (q->qdisc) {
				unsigned int pkt_len = qdisc_pkt_len(skb);
				struct sk_buff *to_free = NULL;
				int err;

				err = qdisc_enqueue(skb, q->qdisc, &to_free);
				kfree_skb_list(to_free);
				if (err != NET_XMIT_SUCCESS &&
				    net_xmit_drop_count(err)) {
					qdisc_qstats_drop(sch);
					qdisc_tree_reduce_backlog(sch, 1,
								  pkt_len);
				}
				goto tfifo_dequeue;
			}
			goto deliver;
		}

		if (q->qdisc) {
			skb = q->qdisc->ops->dequeue(q->qdisc);
			if (skb)
				goto deliver;
		}
		qdisc_watchdog_schedule(&q->watchdog, time_to_send);
	}

	if (q->qdisc) {
		skb = q->qdisc->ops->dequeue(q->qdisc);
		if (skb)
			goto deliver;
	}
	return NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric Dumazet
227
67.56%
7
25.93%
Stephen Hemminger
62
18.45%
10
37.04%
Jarek Poplawski
21
6.25%
3
11.11%
Beshay, Joseph
9
2.68%
1
3.70%
John Fastabend
6
1.79%
1
3.70%
Willem de Bruijn
5
1.49%
1
3.70%
Américo Wang
2
0.60%
1
3.70%
Jussi Kivilinna
2
0.60%
1
3.70%
Florian Westphal
1
0.30%
1
3.70%
Patrick McHardy
1
0.30%
1
3.70%
Total
336
100.00%
27
100.00%



static void netem_reset(struct Qdisc *sch)
{
	struct netem_sched_data *q = qdisc_priv(sch);

	qdisc_reset_queue(sch);
	tfifo_reset(sch);
	if (q->qdisc)
		qdisc_reset(q->qdisc);
	qdisc_watchdog_cancel(&q->watchdog);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
39
75.00%
5
71.43%
Eric Dumazet
11
21.15%
1
14.29%
Patrick McHardy
2
3.85%
1
14.29%
Total
52
100.00%
7
100.00%



static void dist_free(struct disttable *d)
{
	kvfree(d);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
15
93.75%
1
50.00%
Américo Wang
1
6.25%
1
50.00%
Total
16
100.00%
2
100.00%

/*
 * Distribution data is a variable size payload containing
 * signed 16 bit values.
 */


static int get_dist_table(struct Qdisc *sch, const struct nlattr *attr)
{
	struct netem_sched_data *q = qdisc_priv(sch);
	size_t n = nla_len(attr)/sizeof(__s16);
	const __s16 *data = nla_data(attr);
	spinlock_t *root_lock;
	struct disttable *d;
	int i;
	size_t s;

	if (n > NETEM_DIST_MAX)
		return -EINVAL;

	s = sizeof(struct disttable) + n * sizeof(s16);
	d = kmalloc(s, GFP_KERNEL | __GFP_NOWARN);
	if (!d)
		d = vmalloc(s);
	if (!d)
		return -ENOMEM;

	d->size = n;
	for (i = 0; i < n; i++)
		d->table[i] = data[i];

	root_lock = qdisc_root_sleeping_lock(sch);

	spin_lock_bh(root_lock);
	swap(q->delay_dist, d);
	spin_unlock_bh(root_lock);

	dist_free(d);
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
159
85.03%
8
61.54%
David S. Miller
12
6.42%
1
7.69%
Eric Dumazet
10
5.35%
1
7.69%
Patrick McHardy
5
2.67%
2
15.38%
Jarek Poplawski
1
0.53%
1
7.69%
Total
187
100.00%
13
100.00%



static void get_correlation(struct netem_sched_data *q, const struct nlattr *attr)
{
	const struct tc_netem_corr *c = nla_data(attr);

	init_crandom(&q->delay_cor, c->delay_corr);
	init_crandom(&q->loss_cor, c->loss_corr);
	init_crandom(&q->dup_cor, c->dup_corr);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
60
93.75%
4
66.67%
Yang Yingliang
2
3.12%
1
16.67%
Patrick McHardy
2
3.12%
1
16.67%
Total
64
100.00%
6
100.00%



static void get_reorder(struct netem_sched_data *q, const struct nlattr *attr)
{
	const struct tc_netem_reorder *r = nla_data(attr);

	q->reorder = r->probability;
	init_crandom(&q->reorder_cor, r->correlation);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
44
91.67%
2
50.00%
Yang Yingliang
2
4.17%
1
25.00%
Patrick McHardy
2
4.17%
1
25.00%
Total
48
100.00%
4
100.00%



static void get_corrupt(struct netem_sched_data *q, const struct nlattr *attr)
{
	const struct tc_netem_corrupt *r = nla_data(attr);

	q->corrupt = r->probability;
	init_crandom(&q->corrupt_cor, r->correlation);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
44
91.67%
3
60.00%
Yang Yingliang
2
4.17%
1
20.00%
Patrick McHardy
2
4.17%
1
20.00%
Total
48
100.00%
5
100.00%



static void get_rate(struct netem_sched_data *q, const struct nlattr *attr)
{
	const struct tc_netem_rate *r = nla_data(attr);

	q->rate = r->rate;
	q->packet_overhead = r->packet_overhead;
	q->cell_size = r->cell_size;
	q->cell_overhead = r->cell_overhead;
	if (q->cell_size)
		q->cell_size_reciprocal = reciprocal_value(q->cell_size);
	else
		q->cell_size_reciprocal = (struct reciprocal_value) { 0 };
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Hagen Paul Pfeifer
71
78.89%
2
50.00%
Hannes Frederic Sowa
17
18.89%
1
25.00%
Yang Yingliang
2
2.22%
1
25.00%
Total
90
100.00%
4
100.00%



static int get_loss_clg(struct netem_sched_data *q, const struct nlattr *attr)
{
	const struct nlattr *la;
	int rem;

	nla_for_each_nested(la, attr, rem) {
		u16 type = nla_type(la);

		switch (type) {
		case NETEM_LOSS_GI: {
			const struct tc_netem_gimodel *gi = nla_data(la);

			if (nla_len(la) < sizeof(struct tc_netem_gimodel)) {
				pr_info("netem: incorrect gi model size\n");
				return -EINVAL;
			}

			q->loss_model = CLG_4_STATES;

			q->clg.state = TX_IN_GAP_PERIOD;
			q->clg.a1 = gi->p13;
			q->clg.a2 = gi->p31;
			q->clg.a3 = gi->p32;
			q->clg.a4 = gi->p14;
			q->clg.a5 = gi->p23;
			break;
		}

		case NETEM_LOSS_GE: {
			const struct tc_netem_gemodel *ge = nla_data(la);

			if (nla_len(la) < sizeof(struct tc_netem_gemodel)) {
				pr_info("netem: incorrect ge model size\n");
				return -EINVAL;
			}

			q->loss_model = CLG_GILB_ELL;
			q->clg.state = GOOD_STATE;
			q->clg.a1 = ge->p;
			q->clg.a2 = ge->r;
			q->clg.a3 = ge->h;
			q->clg.a4 = ge->k1;
			break;
		}

		default:
			pr_info("netem: unknown loss type %u\n", type);
			return -EINVAL;
		}
	}

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
261
98.49%
3
60.00%
Yang Yingliang
4
1.51%
2
40.00%
Total
265
100.00%
5
100.00%


static const struct nla_policy netem_policy[TCA_NETEM_MAX + 1] = {
	[TCA_NETEM_CORR]	= { .len = sizeof(struct tc_netem_corr) },
	[TCA_NETEM_REORDER]	= { .len = sizeof(struct tc_netem_reorder) },
	[TCA_NETEM_CORRUPT]	= { .len = sizeof(struct tc_netem_corrupt) },
	[TCA_NETEM_RATE]	= { .len = sizeof(struct tc_netem_rate) },
	[TCA_NETEM_LOSS]	= { .type = NLA_NESTED },
	[TCA_NETEM_ECN]		= { .type = NLA_U32 },
	[TCA_NETEM_RATE64]	= { .type = NLA_U64 },
};



static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla,
		      const struct nla_policy *policy, int len)
{
	int nested_len = nla_len(nla) - NLA_ALIGN(len);

	if (nested_len < 0) {
		pr_info("netem: invalid attributes len %d\n", nested_len);
		return -EINVAL;
	}

	if (nested_len >= nla_attr_size(0))
		return nla_parse(tb, maxtype, nla_data(nla) + NLA_ALIGN(len),
				 nested_len, policy);

	memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Thomas Graf
106
92.17%
1
50.00%
Stephen Hemminger
9
7.83%
1
50.00%
Total
115
100.00%
2
100.00%

/* Parse netlink message to set options */


static int netem_change(struct Qdisc *sch, struct nlattr *opt)
{
	struct netem_sched_data *q = qdisc_priv(sch);
	struct nlattr *tb[TCA_NETEM_MAX + 1];
	struct tc_netem_qopt *qopt;
	struct clgstate old_clg;
	int old_loss_model = CLG_RANDOM;
	int ret;

	if (opt == NULL)
		return -EINVAL;

	qopt = nla_data(opt);
	ret = parse_attr(tb, TCA_NETEM_MAX, opt, netem_policy, sizeof(*qopt));
	if (ret < 0)
		return ret;

	/* backup q->clg and q->loss_model */
	old_clg = q->clg;
	old_loss_model = q->loss_model;

	if (tb[TCA_NETEM_LOSS]) {
		ret = get_loss_clg(q, tb[TCA_NETEM_LOSS]);
		if (ret) {
			q->loss_model = old_loss_model;
			return ret;
		}
	} else {
		q->loss_model = CLG_RANDOM;
	}

	if (tb[TCA_NETEM_DELAY_DIST]) {
		ret = get_dist_table(sch, tb[TCA_NETEM_DELAY_DIST]);
		if (ret) {
			/* recover clg and loss_model, in case of
                         * q->clg and q->loss_model were modified
                         * in get_loss_clg()
                         */
			q->clg = old_clg;
			q->loss_model = old_loss_model;
			return ret;
		}
	}

	sch->limit = qopt->limit;

	q->latency = qopt->latency;
	q->jitter = qopt->jitter;
	q->limit = qopt->limit;
	q->gap = qopt->gap;
	q->counter = 0;
	q->loss = qopt->loss;
	q->duplicate = qopt->duplicate;

	/* for compatibility with earlier versions.
         * if gap is set, need to assume 100% probability
         */
	if (q->gap)
		q->reorder = ~0;

	if (tb[TCA_NETEM_CORR])
		get_correlation(q, tb[TCA_NETEM_CORR]);

	if (tb[TCA_NETEM_REORDER])
		get_reorder(q, tb[TCA_NETEM_REORDER]);

	if (tb[TCA_NETEM_CORRUPT])
		get_corrupt(q, tb[TCA_NETEM_CORRUPT]);

	if (tb[TCA_NETEM_RATE])
		get_rate(q, tb[TCA_NETEM_RATE]);

	if (tb[TCA_NETEM_RATE64])
		q->rate = max_t(u64, q->rate,
				nla_get_u64(tb[TCA_NETEM_RATE64]));

	if (tb[TCA_NETEM_ECN])
		q->ecn = nla_get_u32(tb[TCA_NETEM_ECN]);

	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
158
40.20%
8
44.44%
Yang Yingliang
142
36.13%
3
16.67%
Eric Dumazet
51
12.98%
2
11.11%
Patrick McHardy
33
8.40%
3
16.67%
Thomas Graf
8
2.04%
1
5.56%
David S. Miller
1
0.25%
1
5.56%
Total
393
100.00%
18
100.00%



static int netem_init(struct Qdisc *sch, struct nlattr *opt)
{
	struct netem_sched_data *q = qdisc_priv(sch);
	int ret;

	if (!opt)
		return -EINVAL;

	qdisc_watchdog_init(&q->watchdog, sch);

	q->loss_model = CLG_RANDOM;
	ret = netem_change(sch, opt);
	if (ret)
		pr_info("netem: change failed\n");
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
70
93.33%
6
75.00%
Patrick McHardy
5
6.67%
2
25.00%
Total
75
100.00%
8
100.00%



static void netem_destroy(struct Qdisc *sch)
{
	struct netem_sched_data *q = qdisc_priv(sch);

	qdisc_watchdog_cancel(&q->watchdog);
	if (q->qdisc)
		qdisc_destroy(q->qdisc);
	dist_free(q->delay_dist);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
41
83.67%
6
75.00%
Eric Dumazet
6
12.24%
1
12.50%
Patrick McHardy
2
4.08%
1
12.50%
Total
49
100.00%
8
100.00%



static int dump_loss_model(const struct netem_sched_data *q,
			   struct sk_buff *skb)
{
	struct nlattr *nest;

	nest = nla_nest_start(skb, TCA_NETEM_LOSS);
	if (nest == NULL)
		goto nla_put_failure;

	switch (q->loss_model) {
	case CLG_RANDOM:
		/* legacy loss model */
		nla_nest_cancel(skb, nest);
		return 0;	/* no data */

	case CLG_4_STATES: {
		struct tc_netem_gimodel gi = {
			.p13 = q->clg.a1,
			.p31 = q->clg.a2,
			.p32 = q->clg.a3,
			.p14 = q->clg.a4,
			.p23 = q->clg.a5,
                };

		if (nla_put(skb, NETEM_LOSS_GI, sizeof(gi), &gi))
			goto nla_put_failure;
		break;
	}
	case CLG_GILB_ELL: {
		struct tc_netem_gemodel ge = {
			.p = q->clg.a1,
			.r = q->clg.a2,
			.h = q->clg.a3,
			.k1 = q->clg.a4,
                };

		if (nla_put(skb, NETEM_LOSS_GE, sizeof(ge), &ge))
			goto nla_put_failure;
		break;
	}
	}

	nla_nest_end(skb, nest);
	return 0;

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -1;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
217
93.94%
1
50.00%
David S. Miller
14
6.06%
1
50.00%
Total
231
100.00%
2
100.00%



static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	const struct netem_sched_data *q = qdisc_priv(sch);
	struct nlattr *nla = (struct nlattr *) skb_tail_pointer(skb);
	struct tc_netem_qopt qopt;
	struct tc_netem_corr cor;
	struct tc_netem_reorder reorder;
	struct tc_netem_corrupt corrupt;
	struct tc_netem_rate rate;

	qopt.latency = q->latency;
	qopt.jitter = q->jitter;
	qopt.limit = q->limit;
	qopt.loss = q->loss;
	qopt.gap = q->gap;
	qopt.duplicate = q->duplicate;
	if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
		goto nla_put_failure;

	cor.delay_corr = q->delay_cor.rho;
	cor.loss_corr = q->loss_cor.rho;
	cor.dup_corr = q->dup_cor.rho;
	if (nla_put(skb, TCA_NETEM_CORR, sizeof(cor), &cor))
		goto nla_put_failure;

	reorder.probability = q->reorder;
	reorder.correlation = q->reorder_cor.rho;
	if (nla_put(skb, TCA_NETEM_REORDER, sizeof(reorder), &reorder))
		goto nla_put_failure;

	corrupt.probability = q->corrupt;
	corrupt.correlation = q->corrupt_cor.rho;
	if (nla_put(skb, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt))
		goto nla_put_failure;

	if (q->rate >= (1ULL << 32)) {
		if (nla_put_u64_64bit(skb, TCA_NETEM_RATE64, q->rate,
				      TCA_NETEM_PAD))
			goto nla_put_failure;
		rate.rate = ~0U;
	} else {
		rate.rate = q->rate;
	}
	rate.packet_overhead = q->packet_overhead;
	rate.cell_size = q->cell_size;
	rate.cell_overhead = q->cell_overhead;
	if (nla_put(skb, TCA_NETEM_RATE, sizeof(rate), &rate))
		goto nla_put_failure;

	if (q->ecn && nla_put_u32(skb, TCA_NETEM_ECN, q->ecn))
		goto nla_put_failure;

	if (dump_loss_model(q, skb) != 0)
		goto nla_put_failure;

	return nla_nest_end(skb, nla);

nla_put_failure:
	nlmsg_trim(skb, nla);
	return -1;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
252
62.22%
11
55.00%
Hagen Paul Pfeifer
49
12.10%
2
10.00%
Yang Yingliang
39
9.63%
1
5.00%
David S. Miller
35
8.64%
1
5.00%
Eric Dumazet
20
4.94%
1
5.00%
Patrick McHardy
4
0.99%
1
5.00%
Arnaldo Carvalho de Melo
3
0.74%
2
10.00%
Nicolas Dichtel
3
0.74%
1
5.00%
Total
405
100.00%
20
100.00%



static int netem_dump_class(struct Qdisc *sch, unsigned long cl,
			  struct sk_buff *skb, struct tcmsg *tcm)
{
	struct netem_sched_data *q = qdisc_priv(sch);

	if (cl != 1 || !q->qdisc) 	/* only one class */
		return -ENOENT;

	tcm->tcm_handle |= TC_H_MIN(1);
	tcm->tcm_info = q->qdisc->handle;

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
68
93.15%
1
50.00%
Eric Dumazet
5
6.85%
1
50.00%
Total
73
100.00%
2
100.00%



static int netem_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
		     struct Qdisc **old)
{
	struct netem_sched_data *q = qdisc_priv(sch);

	*old = qdisc_replace(sch, new, &q->qdisc);
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
47
87.04%
1
50.00%
Américo Wang
7
12.96%
1
50.00%
Total
54
100.00%
2
100.00%



static struct Qdisc *netem_leaf(struct Qdisc *sch, unsigned long arg)
{
	struct netem_sched_data *q = qdisc_priv(sch);
	return q->qdisc;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
32
100.00%
1
100.00%
Total
32
100.00%
1
100.00%



static unsigned long netem_get(struct Qdisc *sch, u32 classid)
{
	return 1;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
18
100.00%
1
100.00%
Total
18
100.00%
1
100.00%



static void netem_put(struct Qdisc *sch, unsigned long arg)
{
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
14
100.00%
1
100.00%
Total
14
100.00%
1
100.00%



static void netem_walk(struct Qdisc *sch, struct qdisc_walker *walker)
{
	if (!walker->stop) {
		if (walker->count >= walker->skip)
			if (walker->fn(sch, 1, walker) < 0) {
				walker->stop = 1;
				return;
			}
		walker->count++;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
64
100.00%
1
100.00%
Total
64
100.00%
1
100.00%


static const struct Qdisc_class_ops netem_class_ops = {
	.graft		=	netem_graft,
	.leaf		=	netem_leaf,
	.get		=	netem_get,
	.put		=	netem_put,
	.walk		=	netem_walk,
	.dump		=	netem_dump_class,
};


static struct Qdisc_ops netem_qdisc_ops __read_mostly = {
	.id		=	"netem",
	.cl_ops		=	&netem_class_ops,
	.priv_size	=	sizeof(struct netem_sched_data),
	.enqueue	=	netem_enqueue,
	.dequeue	=	netem_dequeue,
	.peek		=	qdisc_peek_dequeued,
	.init		=	netem_init,
	.reset		=	netem_reset,
	.destroy	=	netem_destroy,
	.change		=	netem_change,
	.dump		=	netem_dump,
	.owner		=	THIS_MODULE,
};




static int __init netem_module_init(void)
{
	pr_info("netem: version " VERSION "\n");
	return register_qdisc(&netem_qdisc_ops);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
23
100.00%
3
100.00%
Total
23
100.00%
3
100.00%



static void __exit netem_module_exit(void)
{
	unregister_qdisc(&netem_qdisc_ops);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
15
100.00%
2
100.00%
Total
15
100.00%
2
100.00%

module_init(netem_module_init)
module_exit(netem_module_exit)
MODULE_LICENSE("GPL");
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Stephen Hemminger
2951
59.02%
40
33.90%
Eric Dumazet
688
13.76%
19
16.10%
Hagen Paul Pfeifer
268
5.36%
3
2.54%
Neil Horman
262
5.24%
1
0.85%
Yang Yingliang
254
5.08%
7
5.93%
Patrick McHardy
129
2.58%
9
7.63%
Thomas Graf
114
2.28%
1
0.85%
David S. Miller
74
1.48%
6
5.08%
Florian Westphal
58
1.16%
4
3.39%
Jarek Poplawski
42
0.84%
6
5.08%
Jussi Kivilinna
40
0.80%
2
1.69%
Johannes Naab
23
0.46%
1
0.85%
Hannes Frederic Sowa
19
0.38%
1
0.85%
John Fastabend
15
0.30%
1
0.85%
Américo Wang
10
0.20%
3
2.54%
Aruna-Hewapathirane
10
0.20%
1
0.85%
Beshay, Joseph
9
0.18%
1
0.85%
Guillaume Chazarain
6
0.12%
1
0.85%
Arnaldo Carvalho de Melo
6
0.12%
2
1.69%
Willem de Bruijn
5
0.10%
1
0.85%
Nicolas Dichtel
3
0.06%
1
0.85%
Tejun Heo
3
0.06%
1
0.85%
Alexey Dobriyan
3
0.06%
1
0.85%
Joe Perches
2
0.04%
1
0.85%
Vijay Subramanian
2
0.04%
1
0.85%
Hideaki Yoshifuji / 吉藤英明
2
0.04%
1
0.85%
Geliang Tang
1
0.02%
1
0.85%
Lucas De Marchi
1
0.02%
1
0.85%
Total
5000
100.00%
118
100.00%
Directory: net/sched

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.