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spi/pl022: disable port when unused
[linux-2.6/btrfs-unstable.git] / net / sched / sch_netem.c
bloba2a95aabf9c22bd3b0b0bbbe558feb1c1f65430a
1 /*
2 * net/sched/sch_netem.c Network emulator
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License.
8 *
9 * Many of the algorithms and ideas for this came from
10 * NIST Net which is not copyrighted.
11 *
12 * Authors: Stephen Hemminger <shemminger@osdl.org>
13 * Catalin(ux aka Dino) BOIE <catab at umbrella dot ro>
14 */
15
16 #include <linux/mm.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/types.h>
20 #include <linux/kernel.h>
21 #include <linux/errno.h>
22 #include <linux/skbuff.h>
23 #include <linux/vmalloc.h>
24 #include <linux/rtnetlink.h>
25 #include <linux/reciprocal_div.h>
26
27 #include <net/netlink.h>
28 #include <net/pkt_sched.h>
29 #include <net/inet_ecn.h>
30
31 #define VERSION "1.3"
32
33 /* Network Emulation Queuing algorithm.
34 ====================================
35
36 Sources: [1] Mark Carson, Darrin Santay, "NIST Net - A Linux-based
37 Network Emulation Tool
38 [2] Luigi Rizzo, DummyNet for FreeBSD
39
40 ----------------------------------------------------------------
41
42 This started out as a simple way to delay outgoing packets to
43 test TCP but has grown to include most of the functionality
44 of a full blown network emulator like NISTnet. It can delay
45 packets and add random jitter (and correlation). The random
46 distribution can be loaded from a table as well to provide
47 normal, Pareto, or experimental curves. Packet loss,
48 duplication, and reordering can also be emulated.
49
50 This qdisc does not do classification that can be handled in
51 layering other disciplines. It does not need to do bandwidth
52 control either since that can be handled by using token
53 bucket or other rate control.
54
55 Correlated Loss Generator models
56
57 Added generation of correlated loss according to the
58 "Gilbert-Elliot" model, a 4-state markov model.
59
60 References:
61 [1] NetemCLG Home http://netgroup.uniroma2.it/NetemCLG
62 [2] S. Salsano, F. Ludovici, A. Ordine, "Definition of a general
63 and intuitive loss model for packet networks and its implementation
64 in the Netem module in the Linux kernel", available in [1]
65
66 Authors: Stefano Salsano <stefano.salsano at uniroma2.it
67 Fabio Ludovici <fabio.ludovici at yahoo.it>
68 */
69
70 struct netem_sched_data {
71 /* internal t(ime)fifo qdisc uses sch->q and sch->limit */
72
73 /* optional qdisc for classful handling (NULL at netem init) */
74 struct Qdisc *qdisc;
75
76 struct qdisc_watchdog watchdog;
77
78 psched_tdiff_t latency;
79 psched_tdiff_t jitter;
80
81 u32 loss;
82 u32 ecn;
83 u32 limit;
84 u32 counter;
85 u32 gap;
86 u32 duplicate;
87 u32 reorder;
88 u32 corrupt;
89 u32 rate;
90 s32 packet_overhead;
91 u32 cell_size;
92 u32 cell_size_reciprocal;
93 s32 cell_overhead;
94
95 struct crndstate {
96 u32 last;
97 u32 rho;
98 } delay_cor, loss_cor, dup_cor, reorder_cor, corrupt_cor;
99
100 struct disttable {
101 u32 size;
102 s16 table[0];
103 } *delay_dist;
104
105 enum {
106 CLG_RANDOM,
107 CLG_4_STATES,
108 CLG_GILB_ELL,
109 } loss_model;
110
111 /* Correlated Loss Generation models */
112 struct clgstate {
113 /* state of the Markov chain */
114 u8 state;
115
116 /* 4-states and Gilbert-Elliot models */
117 u32 a1; /* p13 for 4-states or p for GE */
118 u32 a2; /* p31 for 4-states or r for GE */
119 u32 a3; /* p32 for 4-states or h for GE */
120 u32 a4; /* p14 for 4-states or 1-k for GE */
121 u32 a5; /* p23 used only in 4-states */
122 } clg;
123
124 };
125
126 /* Time stamp put into socket buffer control block
127 * Only valid when skbs are in our internal t(ime)fifo queue.
128 */
129 struct netem_skb_cb {
130 psched_time_t time_to_send;
131 };
132
133 static inline struct netem_skb_cb *netem_skb_cb(struct sk_buff *skb)
134 {
135 qdisc_cb_private_validate(skb, sizeof(struct netem_skb_cb));
136 return (struct netem_skb_cb *)qdisc_skb_cb(skb)->data;
137 }
138
139 /* init_crandom - initialize correlated random number generator
140 * Use entropy source for initial seed.
141 */
142 static void init_crandom(struct crndstate *state, unsigned long rho)
143 {
144 state->rho = rho;
145 state->last = net_random();
146 }
147
148 /* get_crandom - correlated random number generator
149 * Next number depends on last value.
150 * rho is scaled to avoid floating point.
151 */
152 static u32 get_crandom(struct crndstate *state)
153 {
154 u64 value, rho;
155 unsigned long answer;
156
157 if (state->rho == 0) /* no correlation */
158 return net_random();
159
160 value = net_random();
161 rho = (u64)state->rho + 1;
162 answer = (value * ((1ull<<32) - rho) + state->last * rho) >> 32;
163 state->last = answer;
164 return answer;
165 }
166
167 /* loss_4state - 4-state model loss generator
168 * Generates losses according to the 4-state Markov chain adopted in
169 * the GI (General and Intuitive) loss model.
170 */
171 static bool loss_4state(struct netem_sched_data *q)
172 {
173 struct clgstate *clg = &q->clg;
174 u32 rnd = net_random();
175
176 /*
177 * Makes a comparison between rnd and the transition
178 * probabilities outgoing from the current state, then decides the
179 * next state and if the next packet has to be transmitted or lost.
180 * The four states correspond to:
181 * 1 => successfully transmitted packets within a gap period
182 * 4 => isolated losses within a gap period
183 * 3 => lost packets within a burst period
184 * 2 => successfully transmitted packets within a burst period
185 */
186 switch (clg->state) {
187 case 1:
188 if (rnd < clg->a4) {
189 clg->state = 4;
190 return true;
191 } else if (clg->a4 < rnd && rnd < clg->a1) {
192 clg->state = 3;
193 return true;
194 } else if (clg->a1 < rnd)
195 clg->state = 1;
196
197 break;
198 case 2:
199 if (rnd < clg->a5) {
200 clg->state = 3;
201 return true;
202 } else
203 clg->state = 2;
204
205 break;
206 case 3:
207 if (rnd < clg->a3)
208 clg->state = 2;
209 else if (clg->a3 < rnd && rnd < clg->a2 + clg->a3) {
210 clg->state = 1;
211 return true;
212 } else if (clg->a2 + clg->a3 < rnd) {
213 clg->state = 3;
214 return true;
215 }
216 break;
217 case 4:
218 clg->state = 1;
219 break;
220 }
221
222 return false;
223 }
224
225 /* loss_gilb_ell - Gilbert-Elliot model loss generator
226 * Generates losses according to the Gilbert-Elliot loss model or
227 * its special cases (Gilbert or Simple Gilbert)
228 *
229 * Makes a comparison between random number and the transition
230 * probabilities outgoing from the current state, then decides the
231 * next state. A second random number is extracted and the comparison
232 * with the loss probability of the current state decides if the next
233 * packet will be transmitted or lost.
234 */
235 static bool loss_gilb_ell(struct netem_sched_data *q)
236 {
237 struct clgstate *clg = &q->clg;
238
239 switch (clg->state) {
240 case 1:
241 if (net_random() < clg->a1)
242 clg->state = 2;
243 if (net_random() < clg->a4)
244 return true;
245 case 2:
246 if (net_random() < clg->a2)
247 clg->state = 1;
248 if (clg->a3 > net_random())
249 return true;
250 }
251
252 return false;
253 }
254
255 static bool loss_event(struct netem_sched_data *q)
256 {
257 switch (q->loss_model) {
258 case CLG_RANDOM:
259 /* Random packet drop 0 => none, ~0 => all */
260 return q->loss && q->loss >= get_crandom(&q->loss_cor);
261
262 case CLG_4_STATES:
263 /* 4state loss model algorithm (used also for GI model)
264 * Extracts a value from the markov 4 state loss generator,
265 * if it is 1 drops a packet and if needed writes the event in
266 * the kernel logs
267 */
268 return loss_4state(q);
269
270 case CLG_GILB_ELL:
271 /* Gilbert-Elliot loss model algorithm
272 * Extracts a value from the Gilbert-Elliot loss generator,
273 * if it is 1 drops a packet and if needed writes the event in
274 * the kernel logs
275 */
276 return loss_gilb_ell(q);
277 }
278
279 return false; /* not reached */
280 }
281
282
283 /* tabledist - return a pseudo-randomly distributed value with mean mu and
284 * std deviation sigma. Uses table lookup to approximate the desired
285 * distribution, and a uniformly-distributed pseudo-random source.
286 */
287 static psched_tdiff_t tabledist(psched_tdiff_t mu, psched_tdiff_t sigma,
288 struct crndstate *state,
289 const struct disttable *dist)
290 {
291 psched_tdiff_t x;
292 long t;
293 u32 rnd;
294
295 if (sigma == 0)
296 return mu;
297
298 rnd = get_crandom(state);
299
300 /* default uniform distribution */
301 if (dist == NULL)
302 return (rnd % (2*sigma)) - sigma + mu;
303
304 t = dist->table[rnd % dist->size];
305 x = (sigma % NETEM_DIST_SCALE) * t;
306 if (x >= 0)
307 x += NETEM_DIST_SCALE/2;
308 else
309 x -= NETEM_DIST_SCALE/2;
310
311 return x / NETEM_DIST_SCALE + (sigma / NETEM_DIST_SCALE) * t + mu;
312 }
313
314 static psched_time_t packet_len_2_sched_time(unsigned int len, struct netem_sched_data *q)
315 {
316 u64 ticks;
317
318 len += q->packet_overhead;
319
320 if (q->cell_size) {
321 u32 cells = reciprocal_divide(len, q->cell_size_reciprocal);
322
323 if (len > cells * q->cell_size) /* extra cell needed for remainder */
324 cells++;
325 len = cells * (q->cell_size + q->cell_overhead);
326 }
327
328 ticks = (u64)len * NSEC_PER_SEC;
329
330 do_div(ticks, q->rate);
331 return PSCHED_NS2TICKS(ticks);
332 }
333
334 static int tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch)
335 {
336 struct sk_buff_head *list = &sch->q;
337 psched_time_t tnext = netem_skb_cb(nskb)->time_to_send;
338 struct sk_buff *skb;
339
340 if (likely(skb_queue_len(list) < sch->limit)) {
341 skb = skb_peek_tail(list);
342 /* Optimize for add at tail */
343 if (likely(!skb || tnext >= netem_skb_cb(skb)->time_to_send))
344 return qdisc_enqueue_tail(nskb, sch);
345
346 skb_queue_reverse_walk(list, skb) {
347 if (tnext >= netem_skb_cb(skb)->time_to_send)
348 break;
349 }
350
351 __skb_queue_after(list, skb, nskb);
352 sch->qstats.backlog += qdisc_pkt_len(nskb);
353 return NET_XMIT_SUCCESS;
354 }
355
356 return qdisc_reshape_fail(nskb, sch);
357 }
358
359 /*
360 * Insert one skb into qdisc.
361 * Note: parent depends on return value to account for queue length.
362 * NET_XMIT_DROP: queue length didn't change.
363 * NET_XMIT_SUCCESS: one skb was queued.
364 */
365 static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
366 {
367 struct netem_sched_data *q = qdisc_priv(sch);
368 /* We don't fill cb now as skb_unshare() may invalidate it */
369 struct netem_skb_cb *cb;
370 struct sk_buff *skb2;
371 int ret;
372 int count = 1;
373
374 /* Random duplication */
375 if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor))
376 ++count;
377
378 /* Drop packet? */
379 if (loss_event(q)) {
380 if (q->ecn && INET_ECN_set_ce(skb))
381 sch->qstats.drops++; /* mark packet */
382 else
383 --count;
384 }
385 if (count == 0) {
386 sch->qstats.drops++;
387 kfree_skb(skb);
388 return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
389 }
390
391 skb_orphan(skb);
392
393 /*
394 * If we need to duplicate packet, then re-insert at top of the
395 * qdisc tree, since parent queuer expects that only one
396 * skb will be queued.
397 */
398 if (count > 1 && (skb2 = skb_clone(skb, GFP_ATOMIC)) != NULL) {
399 struct Qdisc *rootq = qdisc_root(sch);
400 u32 dupsave = q->duplicate; /* prevent duplicating a dup... */
401 q->duplicate = 0;
402
403 qdisc_enqueue_root(skb2, rootq);
404 q->duplicate = dupsave;
405 }
406
407 /*
408 * Randomized packet corruption.
409 * Make copy if needed since we are modifying
410 * If packet is going to be hardware checksummed, then
411 * do it now in software before we mangle it.
412 */
413 if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) {
414 if (!(skb = skb_unshare(skb, GFP_ATOMIC)) ||
415 (skb->ip_summed == CHECKSUM_PARTIAL &&
416 skb_checksum_help(skb)))
417 return qdisc_drop(skb, sch);
418
419 skb->data[net_random() % skb_headlen(skb)] ^= 1<<(net_random() % 8);
420 }
421
422 cb = netem_skb_cb(skb);
423 if (q->gap == 0 || /* not doing reordering */
424 q->counter < q->gap - 1 || /* inside last reordering gap */
425 q->reorder < get_crandom(&q->reorder_cor)) {
426 psched_time_t now;
427 psched_tdiff_t delay;
428
429 delay = tabledist(q->latency, q->jitter,
430 &q->delay_cor, q->delay_dist);
431
432 now = psched_get_time();
433
434 if (q->rate) {
435 struct sk_buff_head *list = &sch->q;
436
437 delay += packet_len_2_sched_time(skb->len, q);
438
439 if (!skb_queue_empty(list)) {
440 /*
441 * Last packet in queue is reference point (now).
442 * First packet in queue is already in flight,
443 * calculate this time bonus and substract
444 * from delay.
445 */
446 delay -= now - netem_skb_cb(skb_peek(list))->time_to_send;
447 now = netem_skb_cb(skb_peek_tail(list))->time_to_send;
448 }
449 }
450
451 cb->time_to_send = now + delay;
452 ++q->counter;
453 ret = tfifo_enqueue(skb, sch);
454 } else {
455 /*
456 * Do re-ordering by putting one out of N packets at the front
457 * of the queue.
458 */
459 cb->time_to_send = psched_get_time();
460 q->counter = 0;
461
462 __skb_queue_head(&sch->q, skb);
463 sch->qstats.backlog += qdisc_pkt_len(skb);
464 sch->qstats.requeues++;
465 ret = NET_XMIT_SUCCESS;
466 }
467
468 if (ret != NET_XMIT_SUCCESS) {
469 if (net_xmit_drop_count(ret)) {
470 sch->qstats.drops++;
471 return ret;
472 }
473 }
474
475 return NET_XMIT_SUCCESS;
476 }
477
478 static unsigned int netem_drop(struct Qdisc *sch)
479 {
480 struct netem_sched_data *q = qdisc_priv(sch);
481 unsigned int len;
482
483 len = qdisc_queue_drop(sch);
484 if (!len && q->qdisc && q->qdisc->ops->drop)
485 len = q->qdisc->ops->drop(q->qdisc);
486 if (len)
487 sch->qstats.drops++;
488
489 return len;
490 }
491
492 static struct sk_buff *netem_dequeue(struct Qdisc *sch)
493 {
494 struct netem_sched_data *q = qdisc_priv(sch);
495 struct sk_buff *skb;
496
497 if (qdisc_is_throttled(sch))
498 return NULL;
499
500 tfifo_dequeue:
501 skb = qdisc_peek_head(sch);
502 if (skb) {
503 const struct netem_skb_cb *cb = netem_skb_cb(skb);
504
505 /* if more time remaining? */
506 if (cb->time_to_send <= psched_get_time()) {
507 __skb_unlink(skb, &sch->q);
508 sch->qstats.backlog -= qdisc_pkt_len(skb);
509
510 #ifdef CONFIG_NET_CLS_ACT
511 /*
512 * If it's at ingress let's pretend the delay is
513 * from the network (tstamp will be updated).
514 */
515 if (G_TC_FROM(skb->tc_verd) & AT_INGRESS)
516 skb->tstamp.tv64 = 0;
517 #endif
518
519 if (q->qdisc) {
520 int err = qdisc_enqueue(skb, q->qdisc);
521
522 if (unlikely(err != NET_XMIT_SUCCESS)) {
523 if (net_xmit_drop_count(err)) {
524 sch->qstats.drops++;
525 qdisc_tree_decrease_qlen(sch, 1);
526 }
527 }
528 goto tfifo_dequeue;
529 }
530 deliver:
531 qdisc_unthrottled(sch);
532 qdisc_bstats_update(sch, skb);
533 return skb;
534 }
535
536 if (q->qdisc) {
537 skb = q->qdisc->ops->dequeue(q->qdisc);
538 if (skb)
539 goto deliver;
540 }
541 qdisc_watchdog_schedule(&q->watchdog, cb->time_to_send);
542 }
543
544 if (q->qdisc) {
545 skb = q->qdisc->ops->dequeue(q->qdisc);
546 if (skb)
547 goto deliver;
548 }
549 return NULL;
550 }
551
552 static void netem_reset(struct Qdisc *sch)
553 {
554 struct netem_sched_data *q = qdisc_priv(sch);
555
556 qdisc_reset_queue(sch);
557 if (q->qdisc)
558 qdisc_reset(q->qdisc);
559 qdisc_watchdog_cancel(&q->watchdog);
560 }
561
562 static void dist_free(struct disttable *d)
563 {
564 if (d) {
565 if (is_vmalloc_addr(d))
566 vfree(d);
567 else
568 kfree(d);
569 }
570 }
571
572 /*
573 * Distribution data is a variable size payload containing
574 * signed 16 bit values.
575 */
576 static int get_dist_table(struct Qdisc *sch, const struct nlattr *attr)
577 {
578 struct netem_sched_data *q = qdisc_priv(sch);
579 size_t n = nla_len(attr)/sizeof(__s16);
580 const __s16 *data = nla_data(attr);
581 spinlock_t *root_lock;
582 struct disttable *d;
583 int i;
584 size_t s;
585
586 if (n > NETEM_DIST_MAX)
587 return -EINVAL;
588
589 s = sizeof(struct disttable) + n * sizeof(s16);
590 d = kmalloc(s, GFP_KERNEL | __GFP_NOWARN);
591 if (!d)
592 d = vmalloc(s);
593 if (!d)
594 return -ENOMEM;
595
596 d->size = n;
597 for (i = 0; i < n; i++)
598 d->table[i] = data[i];
599
600 root_lock = qdisc_root_sleeping_lock(sch);
601
602 spin_lock_bh(root_lock);
603 swap(q->delay_dist, d);
604 spin_unlock_bh(root_lock);
605
606 dist_free(d);
607 return 0;
608 }
609
610 static void get_correlation(struct Qdisc *sch, const struct nlattr *attr)
611 {
612 struct netem_sched_data *q = qdisc_priv(sch);
613 const struct tc_netem_corr *c = nla_data(attr);
614
615 init_crandom(&q->delay_cor, c->delay_corr);
616 init_crandom(&q->loss_cor, c->loss_corr);
617 init_crandom(&q->dup_cor, c->dup_corr);
618 }
619
620 static void get_reorder(struct Qdisc *sch, const struct nlattr *attr)
621 {
622 struct netem_sched_data *q = qdisc_priv(sch);
623 const struct tc_netem_reorder *r = nla_data(attr);
624
625 q->reorder = r->probability;
626 init_crandom(&q->reorder_cor, r->correlation);
627 }
628
629 static void get_corrupt(struct Qdisc *sch, const struct nlattr *attr)
630 {
631 struct netem_sched_data *q = qdisc_priv(sch);
632 const struct tc_netem_corrupt *r = nla_data(attr);
633
634 q->corrupt = r->probability;
635 init_crandom(&q->corrupt_cor, r->correlation);
636 }
637
638 static void get_rate(struct Qdisc *sch, const struct nlattr *attr)
639 {
640 struct netem_sched_data *q = qdisc_priv(sch);
641 const struct tc_netem_rate *r = nla_data(attr);
642
643 q->rate = r->rate;
644 q->packet_overhead = r->packet_overhead;
645 q->cell_size = r->cell_size;
646 if (q->cell_size)
647 q->cell_size_reciprocal = reciprocal_value(q->cell_size);
648 q->cell_overhead = r->cell_overhead;
649 }
650
651 static int get_loss_clg(struct Qdisc *sch, const struct nlattr *attr)
652 {
653 struct netem_sched_data *q = qdisc_priv(sch);
654 const struct nlattr *la;
655 int rem;
656
657 nla_for_each_nested(la, attr, rem) {
658 u16 type = nla_type(la);
659
660 switch(type) {
661 case NETEM_LOSS_GI: {
662 const struct tc_netem_gimodel *gi = nla_data(la);
663
664 if (nla_len(la) < sizeof(struct tc_netem_gimodel)) {
665 pr_info("netem: incorrect gi model size\n");
666 return -EINVAL;
667 }
668
669 q->loss_model = CLG_4_STATES;
670
671 q->clg.state = 1;
672 q->clg.a1 = gi->p13;
673 q->clg.a2 = gi->p31;
674 q->clg.a3 = gi->p32;
675 q->clg.a4 = gi->p14;
676 q->clg.a5 = gi->p23;
677 break;
678 }
679
680 case NETEM_LOSS_GE: {
681 const struct tc_netem_gemodel *ge = nla_data(la);
682
683 if (nla_len(la) < sizeof(struct tc_netem_gemodel)) {
684 pr_info("netem: incorrect ge model size\n");
685 return -EINVAL;
686 }
687
688 q->loss_model = CLG_GILB_ELL;
689 q->clg.state = 1;
690 q->clg.a1 = ge->p;
691 q->clg.a2 = ge->r;
692 q->clg.a3 = ge->h;
693 q->clg.a4 = ge->k1;
694 break;
695 }
696
697 default:
698 pr_info("netem: unknown loss type %u\n", type);
699 return -EINVAL;
700 }
701 }
702
703 return 0;
704 }
705
706 static const struct nla_policy netem_policy[TCA_NETEM_MAX + 1] = {
707 [TCA_NETEM_CORR] = { .len = sizeof(struct tc_netem_corr) },
708 [TCA_NETEM_REORDER] = { .len = sizeof(struct tc_netem_reorder) },
709 [TCA_NETEM_CORRUPT] = { .len = sizeof(struct tc_netem_corrupt) },
710 [TCA_NETEM_RATE] = { .len = sizeof(struct tc_netem_rate) },
711 [TCA_NETEM_LOSS] = { .type = NLA_NESTED },
712 [TCA_NETEM_ECN] = { .type = NLA_U32 },
713 };
714
715 static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla,
716 const struct nla_policy *policy, int len)
717 {
718 int nested_len = nla_len(nla) - NLA_ALIGN(len);
719
720 if (nested_len < 0) {
721 pr_info("netem: invalid attributes len %d\n", nested_len);
722 return -EINVAL;
723 }
724
725 if (nested_len >= nla_attr_size(0))
726 return nla_parse(tb, maxtype, nla_data(nla) + NLA_ALIGN(len),
727 nested_len, policy);
728
729 memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
730 return 0;
731 }
732
733 /* Parse netlink message to set options */
734 static int netem_change(struct Qdisc *sch, struct nlattr *opt)
735 {
736 struct netem_sched_data *q = qdisc_priv(sch);
737 struct nlattr *tb[TCA_NETEM_MAX + 1];
738 struct tc_netem_qopt *qopt;
739 int ret;
740
741 if (opt == NULL)
742 return -EINVAL;
743
744 qopt = nla_data(opt);
745 ret = parse_attr(tb, TCA_NETEM_MAX, opt, netem_policy, sizeof(*qopt));
746 if (ret < 0)
747 return ret;
748
749 sch->limit = qopt->limit;
750
751 q->latency = qopt->latency;
752 q->jitter = qopt->jitter;
753 q->limit = qopt->limit;
754 q->gap = qopt->gap;
755 q->counter = 0;
756 q->loss = qopt->loss;
757 q->duplicate = qopt->duplicate;
758
759 /* for compatibility with earlier versions.
760 * if gap is set, need to assume 100% probability
761 */
762 if (q->gap)
763 q->reorder = ~0;
764
765 if (tb[TCA_NETEM_CORR])
766 get_correlation(sch, tb[TCA_NETEM_CORR]);
767
768 if (tb[TCA_NETEM_DELAY_DIST]) {
769 ret = get_dist_table(sch, tb[TCA_NETEM_DELAY_DIST]);
770 if (ret)
771 return ret;
772 }
773
774 if (tb[TCA_NETEM_REORDER])
775 get_reorder(sch, tb[TCA_NETEM_REORDER]);
776
777 if (tb[TCA_NETEM_CORRUPT])
778 get_corrupt(sch, tb[TCA_NETEM_CORRUPT]);
779
780 if (tb[TCA_NETEM_RATE])
781 get_rate(sch, tb[TCA_NETEM_RATE]);
782
783 if (tb[TCA_NETEM_ECN])
784 q->ecn = nla_get_u32(tb[TCA_NETEM_ECN]);
785
786 q->loss_model = CLG_RANDOM;
787 if (tb[TCA_NETEM_LOSS])
788 ret = get_loss_clg(sch, tb[TCA_NETEM_LOSS]);
789
790 return ret;
791 }
792
793 static int netem_init(struct Qdisc *sch, struct nlattr *opt)
794 {
795 struct netem_sched_data *q = qdisc_priv(sch);
796 int ret;
797
798 if (!opt)
799 return -EINVAL;
800
801 qdisc_watchdog_init(&q->watchdog, sch);
802
803 q->loss_model = CLG_RANDOM;
804 ret = netem_change(sch, opt);
805 if (ret)
806 pr_info("netem: change failed\n");
807 return ret;
808 }
809
810 static void netem_destroy(struct Qdisc *sch)
811 {
812 struct netem_sched_data *q = qdisc_priv(sch);
813
814 qdisc_watchdog_cancel(&q->watchdog);
815 if (q->qdisc)
816 qdisc_destroy(q->qdisc);
817 dist_free(q->delay_dist);
818 }
819
820 static int dump_loss_model(const struct netem_sched_data *q,
821 struct sk_buff *skb)
822 {
823 struct nlattr *nest;
824
825 nest = nla_nest_start(skb, TCA_NETEM_LOSS);
826 if (nest == NULL)
827 goto nla_put_failure;
828
829 switch (q->loss_model) {
830 case CLG_RANDOM:
831 /* legacy loss model */
832 nla_nest_cancel(skb, nest);
833 return 0; /* no data */
834
835 case CLG_4_STATES: {
836 struct tc_netem_gimodel gi = {
837 .p13 = q->clg.a1,
838 .p31 = q->clg.a2,
839 .p32 = q->clg.a3,
840 .p14 = q->clg.a4,
841 .p23 = q->clg.a5,
842 };
843
844 if (nla_put(skb, NETEM_LOSS_GI, sizeof(gi), &gi))
845 goto nla_put_failure;
846 break;
847 }
848 case CLG_GILB_ELL: {
849 struct tc_netem_gemodel ge = {
850 .p = q->clg.a1,
851 .r = q->clg.a2,
852 .h = q->clg.a3,
853 .k1 = q->clg.a4,
854 };
855
856 if (nla_put(skb, NETEM_LOSS_GE, sizeof(ge), &ge))
857 goto nla_put_failure;
858 break;
859 }
860 }
861
862 nla_nest_end(skb, nest);
863 return 0;
864
865 nla_put_failure:
866 nla_nest_cancel(skb, nest);
867 return -1;
868 }
869
870 static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
871 {
872 const struct netem_sched_data *q = qdisc_priv(sch);
873 struct nlattr *nla = (struct nlattr *) skb_tail_pointer(skb);
874 struct tc_netem_qopt qopt;
875 struct tc_netem_corr cor;
876 struct tc_netem_reorder reorder;
877 struct tc_netem_corrupt corrupt;
878 struct tc_netem_rate rate;
879
880 qopt.latency = q->latency;
881 qopt.jitter = q->jitter;
882 qopt.limit = q->limit;
883 qopt.loss = q->loss;
884 qopt.gap = q->gap;
885 qopt.duplicate = q->duplicate;
886 if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
887 goto nla_put_failure;
888
889 cor.delay_corr = q->delay_cor.rho;
890 cor.loss_corr = q->loss_cor.rho;
891 cor.dup_corr = q->dup_cor.rho;
892 if (nla_put(skb, TCA_NETEM_CORR, sizeof(cor), &cor))
893 goto nla_put_failure;
894
895 reorder.probability = q->reorder;
896 reorder.correlation = q->reorder_cor.rho;
897 if (nla_put(skb, TCA_NETEM_REORDER, sizeof(reorder), &reorder))
898 goto nla_put_failure;
899
900 corrupt.probability = q->corrupt;
901 corrupt.correlation = q->corrupt_cor.rho;
902 if (nla_put(skb, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt))
903 goto nla_put_failure;
904
905 rate.rate = q->rate;
906 rate.packet_overhead = q->packet_overhead;
907 rate.cell_size = q->cell_size;
908 rate.cell_overhead = q->cell_overhead;
909 if (nla_put(skb, TCA_NETEM_RATE, sizeof(rate), &rate))
910 goto nla_put_failure;
911
912 if (q->ecn && nla_put_u32(skb, TCA_NETEM_ECN, q->ecn))
913 goto nla_put_failure;
914
915 if (dump_loss_model(q, skb) != 0)
916 goto nla_put_failure;
917
918 return nla_nest_end(skb, nla);
919
920 nla_put_failure:
921 nlmsg_trim(skb, nla);
922 return -1;
923 }
924
925 static int netem_dump_class(struct Qdisc *sch, unsigned long cl,
926 struct sk_buff *skb, struct tcmsg *tcm)
927 {
928 struct netem_sched_data *q = qdisc_priv(sch);
929
930 if (cl != 1 || !q->qdisc) /* only one class */
931 return -ENOENT;
932
933 tcm->tcm_handle |= TC_H_MIN(1);
934 tcm->tcm_info = q->qdisc->handle;
935
936 return 0;
937 }
938
939 static int netem_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
940 struct Qdisc **old)
941 {
942 struct netem_sched_data *q = qdisc_priv(sch);
943
944 sch_tree_lock(sch);
945 *old = q->qdisc;
946 q->qdisc = new;
947 if (*old) {
948 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
949 qdisc_reset(*old);
950 }
951 sch_tree_unlock(sch);
952
953 return 0;
954 }
955
956 static struct Qdisc *netem_leaf(struct Qdisc *sch, unsigned long arg)
957 {
958 struct netem_sched_data *q = qdisc_priv(sch);
959 return q->qdisc;
960 }
961
962 static unsigned long netem_get(struct Qdisc *sch, u32 classid)
963 {
964 return 1;
965 }
966
967 static void netem_put(struct Qdisc *sch, unsigned long arg)
968 {
969 }
970
971 static void netem_walk(struct Qdisc *sch, struct qdisc_walker *walker)
972 {
973 if (!walker->stop) {
974 if (walker->count >= walker->skip)
975 if (walker->fn(sch, 1, walker) < 0) {
976 walker->stop = 1;
977 return;
978 }
979 walker->count++;
980 }
981 }
982
983 static const struct Qdisc_class_ops netem_class_ops = {
984 .graft = netem_graft,
985 .leaf = netem_leaf,
986 .get = netem_get,
987 .put = netem_put,
988 .walk = netem_walk,
989 .dump = netem_dump_class,
990 };
991
992 static struct Qdisc_ops netem_qdisc_ops __read_mostly = {
993 .id = "netem",
994 .cl_ops = &netem_class_ops,
995 .priv_size = sizeof(struct netem_sched_data),
996 .enqueue = netem_enqueue,
997 .dequeue = netem_dequeue,
998 .peek = qdisc_peek_dequeued,
999 .drop = netem_drop,
1000 .init = netem_init,
1001 .reset = netem_reset,
1002 .destroy = netem_destroy,
1003 .change = netem_change,
1004 .dump = netem_dump,
1005 .owner = THIS_MODULE,
1006 };
1007
1008
1009 static int __init netem_module_init(void)
1010 {
1011 pr_info("netem: version " VERSION "\n");
1012 return register_qdisc(&netem_qdisc_ops);
1013 }
1014 static void __exit netem_module_exit(void)
1015 {
1016 unregister_qdisc(&netem_qdisc_ops);
1017 }
1018 module_init(netem_module_init)
1019 module_exit(netem_module_exit)
1020 MODULE_LICENSE("GPL");
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