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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / sched / sch_netem.c
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 void 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 = skb_peek_tail(list);
339
340 /* Optimize for add at tail */
341 if (likely(!skb || tnext >= netem_skb_cb(skb)->time_to_send))
342 return __skb_queue_tail(list, nskb);
343
344 skb_queue_reverse_walk(list, skb) {
345 if (tnext >= netem_skb_cb(skb)->time_to_send)
346 break;
347 }
348
349 __skb_queue_after(list, skb, nskb);
350 }
351
352 /*
353 * Insert one skb into qdisc.
354 * Note: parent depends on return value to account for queue length.
355 * NET_XMIT_DROP: queue length didn't change.
356 * NET_XMIT_SUCCESS: one skb was queued.
357 */
358 static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
359 {
360 struct netem_sched_data *q = qdisc_priv(sch);
361 /* We don't fill cb now as skb_unshare() may invalidate it */
362 struct netem_skb_cb *cb;
363 struct sk_buff *skb2;
364 int count = 1;
365
366 /* Random duplication */
367 if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor))
368 ++count;
369
370 /* Drop packet? */
371 if (loss_event(q)) {
372 if (q->ecn && INET_ECN_set_ce(skb))
373 sch->qstats.drops++; /* mark packet */
374 else
375 --count;
376 }
377 if (count == 0) {
378 sch->qstats.drops++;
379 kfree_skb(skb);
380 return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
381 }
382
383 /* If a delay is expected, orphan the skb. (orphaning usually takes
384 * place at TX completion time, so _before_ the link transit delay)
385 * Ideally, this orphaning should be done after the rate limiting
386 * module, because this breaks TCP Small Queue, and other mechanisms
387 * based on socket sk_wmem_alloc.
388 */
389 if (q->latency || q->jitter)
390 skb_orphan(skb);
391
392 /*
393 * If we need to duplicate packet, then re-insert at top of the
394 * qdisc tree, since parent queuer expects that only one
395 * skb will be queued.
396 */
397 if (count > 1 && (skb2 = skb_clone(skb, GFP_ATOMIC)) != NULL) {
398 struct Qdisc *rootq = qdisc_root(sch);
399 u32 dupsave = q->duplicate; /* prevent duplicating a dup... */
400 q->duplicate = 0;
401
402 qdisc_enqueue_root(skb2, rootq);
403 q->duplicate = dupsave;
404 }
405
406 /*
407 * Randomized packet corruption.
408 * Make copy if needed since we are modifying
409 * If packet is going to be hardware checksummed, then
410 * do it now in software before we mangle it.
411 */
412 if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) {
413 if (!(skb = skb_unshare(skb, GFP_ATOMIC)) ||
414 (skb->ip_summed == CHECKSUM_PARTIAL &&
415 skb_checksum_help(skb)))
416 return qdisc_drop(skb, sch);
417
418 skb->data[net_random() % skb_headlen(skb)] ^= 1<<(net_random() % 8);
419 }
420
421 if (unlikely(skb_queue_len(&sch->q) >= sch->limit))
422 return qdisc_reshape_fail(skb, sch);
423
424 sch->qstats.backlog += qdisc_pkt_len(skb);
425
426 cb = netem_skb_cb(skb);
427 if (q->gap == 0 || /* not doing reordering */
428 q->counter < q->gap - 1 || /* inside last reordering gap */
429 q->reorder < get_crandom(&q->reorder_cor)) {
430 psched_time_t now;
431 psched_tdiff_t delay;
432
433 delay = tabledist(q->latency, q->jitter,
434 &q->delay_cor, q->delay_dist);
435
436 now = psched_get_time();
437
438 if (q->rate) {
439 struct sk_buff_head *list = &sch->q;
440
441 if (!skb_queue_empty(list)) {
442 /*
443 * Last packet in queue is reference point (now),
444 * calculate this time bonus and subtract
445 * from delay.
446 */
447 delay -= netem_skb_cb(skb_peek_tail(list))->time_to_send - now;
448 delay = max_t(psched_tdiff_t, 0, delay);
449 now = netem_skb_cb(skb_peek_tail(list))->time_to_send;
450 }
451
452 delay += packet_len_2_sched_time(skb->len, q);
453 }
454
455 cb->time_to_send = now + delay;
456 ++q->counter;
457 tfifo_enqueue(skb, sch);
458 } else {
459 /*
460 * Do re-ordering by putting one out of N packets at the front
461 * of the queue.
462 */
463 cb->time_to_send = psched_get_time();
464 q->counter = 0;
465
466 __skb_queue_head(&sch->q, skb);
467 sch->qstats.requeues++;
468 }
469
470 return NET_XMIT_SUCCESS;
471 }
472
473 static unsigned int netem_drop(struct Qdisc *sch)
474 {
475 struct netem_sched_data *q = qdisc_priv(sch);
476 unsigned int len;
477
478 len = qdisc_queue_drop(sch);
479 if (!len && q->qdisc && q->qdisc->ops->drop)
480 len = q->qdisc->ops->drop(q->qdisc);
481 if (len)
482 sch->qstats.drops++;
483
484 return len;
485 }
486
487 static struct sk_buff *netem_dequeue(struct Qdisc *sch)
488 {
489 struct netem_sched_data *q = qdisc_priv(sch);
490 struct sk_buff *skb;
491
492 if (qdisc_is_throttled(sch))
493 return NULL;
494
495 tfifo_dequeue:
496 skb = qdisc_peek_head(sch);
497 if (skb) {
498 const struct netem_skb_cb *cb = netem_skb_cb(skb);
499
500 /* if more time remaining? */
501 if (cb->time_to_send <= psched_get_time()) {
502 __skb_unlink(skb, &sch->q);
503 sch->qstats.backlog -= qdisc_pkt_len(skb);
504
505 #ifdef CONFIG_NET_CLS_ACT
506 /*
507 * If it's at ingress let's pretend the delay is
508 * from the network (tstamp will be updated).
509 */
510 if (G_TC_FROM(skb->tc_verd) & AT_INGRESS)
511 skb->tstamp.tv64 = 0;
512 #endif
513
514 if (q->qdisc) {
515 int err = qdisc_enqueue(skb, q->qdisc);
516
517 if (unlikely(err != NET_XMIT_SUCCESS)) {
518 if (net_xmit_drop_count(err)) {
519 sch->qstats.drops++;
520 qdisc_tree_decrease_qlen(sch, 1);
521 }
522 }
523 goto tfifo_dequeue;
524 }
525 deliver:
526 qdisc_unthrottled(sch);
527 qdisc_bstats_update(sch, skb);
528 return skb;
529 }
530
531 if (q->qdisc) {
532 skb = q->qdisc->ops->dequeue(q->qdisc);
533 if (skb)
534 goto deliver;
535 }
536 qdisc_watchdog_schedule(&q->watchdog, cb->time_to_send);
537 }
538
539 if (q->qdisc) {
540 skb = q->qdisc->ops->dequeue(q->qdisc);
541 if (skb)
542 goto deliver;
543 }
544 return NULL;
545 }
546
547 static void netem_reset(struct Qdisc *sch)
548 {
549 struct netem_sched_data *q = qdisc_priv(sch);
550
551 qdisc_reset_queue(sch);
552 if (q->qdisc)
553 qdisc_reset(q->qdisc);
554 qdisc_watchdog_cancel(&q->watchdog);
555 }
556
557 static void dist_free(struct disttable *d)
558 {
559 if (d) {
560 if (is_vmalloc_addr(d))
561 vfree(d);
562 else
563 kfree(d);
564 }
565 }
566
567 /*
568 * Distribution data is a variable size payload containing
569 * signed 16 bit values.
570 */
571 static int get_dist_table(struct Qdisc *sch, const struct nlattr *attr)
572 {
573 struct netem_sched_data *q = qdisc_priv(sch);
574 size_t n = nla_len(attr)/sizeof(__s16);
575 const __s16 *data = nla_data(attr);
576 spinlock_t *root_lock;
577 struct disttable *d;
578 int i;
579 size_t s;
580
581 if (n > NETEM_DIST_MAX)
582 return -EINVAL;
583
584 s = sizeof(struct disttable) + n * sizeof(s16);
585 d = kmalloc(s, GFP_KERNEL | __GFP_NOWARN);
586 if (!d)
587 d = vmalloc(s);
588 if (!d)
589 return -ENOMEM;
590
591 d->size = n;
592 for (i = 0; i < n; i++)
593 d->table[i] = data[i];
594
595 root_lock = qdisc_root_sleeping_lock(sch);
596
597 spin_lock_bh(root_lock);
598 swap(q->delay_dist, d);
599 spin_unlock_bh(root_lock);
600
601 dist_free(d);
602 return 0;
603 }
604
605 static void get_correlation(struct Qdisc *sch, const struct nlattr *attr)
606 {
607 struct netem_sched_data *q = qdisc_priv(sch);
608 const struct tc_netem_corr *c = nla_data(attr);
609
610 init_crandom(&q->delay_cor, c->delay_corr);
611 init_crandom(&q->loss_cor, c->loss_corr);
612 init_crandom(&q->dup_cor, c->dup_corr);
613 }
614
615 static void get_reorder(struct Qdisc *sch, const struct nlattr *attr)
616 {
617 struct netem_sched_data *q = qdisc_priv(sch);
618 const struct tc_netem_reorder *r = nla_data(attr);
619
620 q->reorder = r->probability;
621 init_crandom(&q->reorder_cor, r->correlation);
622 }
623
624 static void get_corrupt(struct Qdisc *sch, const struct nlattr *attr)
625 {
626 struct netem_sched_data *q = qdisc_priv(sch);
627 const struct tc_netem_corrupt *r = nla_data(attr);
628
629 q->corrupt = r->probability;
630 init_crandom(&q->corrupt_cor, r->correlation);
631 }
632
633 static void get_rate(struct Qdisc *sch, const struct nlattr *attr)
634 {
635 struct netem_sched_data *q = qdisc_priv(sch);
636 const struct tc_netem_rate *r = nla_data(attr);
637
638 q->rate = r->rate;
639 q->packet_overhead = r->packet_overhead;
640 q->cell_size = r->cell_size;
641 if (q->cell_size)
642 q->cell_size_reciprocal = reciprocal_value(q->cell_size);
643 q->cell_overhead = r->cell_overhead;
644 }
645
646 static int get_loss_clg(struct Qdisc *sch, const struct nlattr *attr)
647 {
648 struct netem_sched_data *q = qdisc_priv(sch);
649 const struct nlattr *la;
650 int rem;
651
652 nla_for_each_nested(la, attr, rem) {
653 u16 type = nla_type(la);
654
655 switch(type) {
656 case NETEM_LOSS_GI: {
657 const struct tc_netem_gimodel *gi = nla_data(la);
658
659 if (nla_len(la) < sizeof(struct tc_netem_gimodel)) {
660 pr_info("netem: incorrect gi model size\n");
661 return -EINVAL;
662 }
663
664 q->loss_model = CLG_4_STATES;
665
666 q->clg.state = 1;
667 q->clg.a1 = gi->p13;
668 q->clg.a2 = gi->p31;
669 q->clg.a3 = gi->p32;
670 q->clg.a4 = gi->p14;
671 q->clg.a5 = gi->p23;
672 break;
673 }
674
675 case NETEM_LOSS_GE: {
676 const struct tc_netem_gemodel *ge = nla_data(la);
677
678 if (nla_len(la) < sizeof(struct tc_netem_gemodel)) {
679 pr_info("netem: incorrect ge model size\n");
680 return -EINVAL;
681 }
682
683 q->loss_model = CLG_GILB_ELL;
684 q->clg.state = 1;
685 q->clg.a1 = ge->p;
686 q->clg.a2 = ge->r;
687 q->clg.a3 = ge->h;
688 q->clg.a4 = ge->k1;
689 break;
690 }
691
692 default:
693 pr_info("netem: unknown loss type %u\n", type);
694 return -EINVAL;
695 }
696 }
697
698 return 0;
699 }
700
701 static const struct nla_policy netem_policy[TCA_NETEM_MAX + 1] = {
702 [TCA_NETEM_CORR] = { .len = sizeof(struct tc_netem_corr) },
703 [TCA_NETEM_REORDER] = { .len = sizeof(struct tc_netem_reorder) },
704 [TCA_NETEM_CORRUPT] = { .len = sizeof(struct tc_netem_corrupt) },
705 [TCA_NETEM_RATE] = { .len = sizeof(struct tc_netem_rate) },
706 [TCA_NETEM_LOSS] = { .type = NLA_NESTED },
707 [TCA_NETEM_ECN] = { .type = NLA_U32 },
708 };
709
710 static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla,
711 const struct nla_policy *policy, int len)
712 {
713 int nested_len = nla_len(nla) - NLA_ALIGN(len);
714
715 if (nested_len < 0) {
716 pr_info("netem: invalid attributes len %d\n", nested_len);
717 return -EINVAL;
718 }
719
720 if (nested_len >= nla_attr_size(0))
721 return nla_parse(tb, maxtype, nla_data(nla) + NLA_ALIGN(len),
722 nested_len, policy);
723
724 memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
725 return 0;
726 }
727
728 /* Parse netlink message to set options */
729 static int netem_change(struct Qdisc *sch, struct nlattr *opt)
730 {
731 struct netem_sched_data *q = qdisc_priv(sch);
732 struct nlattr *tb[TCA_NETEM_MAX + 1];
733 struct tc_netem_qopt *qopt;
734 int ret;
735
736 if (opt == NULL)
737 return -EINVAL;
738
739 qopt = nla_data(opt);
740 ret = parse_attr(tb, TCA_NETEM_MAX, opt, netem_policy, sizeof(*qopt));
741 if (ret < 0)
742 return ret;
743
744 sch->limit = qopt->limit;
745
746 q->latency = qopt->latency;
747 q->jitter = qopt->jitter;
748 q->limit = qopt->limit;
749 q->gap = qopt->gap;
750 q->counter = 0;
751 q->loss = qopt->loss;
752 q->duplicate = qopt->duplicate;
753
754 /* for compatibility with earlier versions.
755 * if gap is set, need to assume 100% probability
756 */
757 if (q->gap)
758 q->reorder = ~0;
759
760 if (tb[TCA_NETEM_CORR])
761 get_correlation(sch, tb[TCA_NETEM_CORR]);
762
763 if (tb[TCA_NETEM_DELAY_DIST]) {
764 ret = get_dist_table(sch, tb[TCA_NETEM_DELAY_DIST]);
765 if (ret)
766 return ret;
767 }
768
769 if (tb[TCA_NETEM_REORDER])
770 get_reorder(sch, tb[TCA_NETEM_REORDER]);
771
772 if (tb[TCA_NETEM_CORRUPT])
773 get_corrupt(sch, tb[TCA_NETEM_CORRUPT]);
774
775 if (tb[TCA_NETEM_RATE])
776 get_rate(sch, tb[TCA_NETEM_RATE]);
777
778 if (tb[TCA_NETEM_ECN])
779 q->ecn = nla_get_u32(tb[TCA_NETEM_ECN]);
780
781 q->loss_model = CLG_RANDOM;
782 if (tb[TCA_NETEM_LOSS])
783 ret = get_loss_clg(sch, tb[TCA_NETEM_LOSS]);
784
785 return ret;
786 }
787
788 static int netem_init(struct Qdisc *sch, struct nlattr *opt)
789 {
790 struct netem_sched_data *q = qdisc_priv(sch);
791 int ret;
792
793 if (!opt)
794 return -EINVAL;
795
796 qdisc_watchdog_init(&q->watchdog, sch);
797
798 q->loss_model = CLG_RANDOM;
799 ret = netem_change(sch, opt);
800 if (ret)
801 pr_info("netem: change failed\n");
802 return ret;
803 }
804
805 static void netem_destroy(struct Qdisc *sch)
806 {
807 struct netem_sched_data *q = qdisc_priv(sch);
808
809 qdisc_watchdog_cancel(&q->watchdog);
810 if (q->qdisc)
811 qdisc_destroy(q->qdisc);
812 dist_free(q->delay_dist);
813 }
814
815 static int dump_loss_model(const struct netem_sched_data *q,
816 struct sk_buff *skb)
817 {
818 struct nlattr *nest;
819
820 nest = nla_nest_start(skb, TCA_NETEM_LOSS);
821 if (nest == NULL)
822 goto nla_put_failure;
823
824 switch (q->loss_model) {
825 case CLG_RANDOM:
826 /* legacy loss model */
827 nla_nest_cancel(skb, nest);
828 return 0; /* no data */
829
830 case CLG_4_STATES: {
831 struct tc_netem_gimodel gi = {
832 .p13 = q->clg.a1,
833 .p31 = q->clg.a2,
834 .p32 = q->clg.a3,
835 .p14 = q->clg.a4,
836 .p23 = q->clg.a5,
837 };
838
839 if (nla_put(skb, NETEM_LOSS_GI, sizeof(gi), &gi))
840 goto nla_put_failure;
841 break;
842 }
843 case CLG_GILB_ELL: {
844 struct tc_netem_gemodel ge = {
845 .p = q->clg.a1,
846 .r = q->clg.a2,
847 .h = q->clg.a3,
848 .k1 = q->clg.a4,
849 };
850
851 if (nla_put(skb, NETEM_LOSS_GE, sizeof(ge), &ge))
852 goto nla_put_failure;
853 break;
854 }
855 }
856
857 nla_nest_end(skb, nest);
858 return 0;
859
860 nla_put_failure:
861 nla_nest_cancel(skb, nest);
862 return -1;
863 }
864
865 static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
866 {
867 const struct netem_sched_data *q = qdisc_priv(sch);
868 struct nlattr *nla = (struct nlattr *) skb_tail_pointer(skb);
869 struct tc_netem_qopt qopt;
870 struct tc_netem_corr cor;
871 struct tc_netem_reorder reorder;
872 struct tc_netem_corrupt corrupt;
873 struct tc_netem_rate rate;
874
875 qopt.latency = q->latency;
876 qopt.jitter = q->jitter;
877 qopt.limit = q->limit;
878 qopt.loss = q->loss;
879 qopt.gap = q->gap;
880 qopt.duplicate = q->duplicate;
881 if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
882 goto nla_put_failure;
883
884 cor.delay_corr = q->delay_cor.rho;
885 cor.loss_corr = q->loss_cor.rho;
886 cor.dup_corr = q->dup_cor.rho;
887 if (nla_put(skb, TCA_NETEM_CORR, sizeof(cor), &cor))
888 goto nla_put_failure;
889
890 reorder.probability = q->reorder;
891 reorder.correlation = q->reorder_cor.rho;
892 if (nla_put(skb, TCA_NETEM_REORDER, sizeof(reorder), &reorder))
893 goto nla_put_failure;
894
895 corrupt.probability = q->corrupt;
896 corrupt.correlation = q->corrupt_cor.rho;
897 if (nla_put(skb, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt))
898 goto nla_put_failure;
899
900 rate.rate = q->rate;
901 rate.packet_overhead = q->packet_overhead;
902 rate.cell_size = q->cell_size;
903 rate.cell_overhead = q->cell_overhead;
904 if (nla_put(skb, TCA_NETEM_RATE, sizeof(rate), &rate))
905 goto nla_put_failure;
906
907 if (q->ecn && nla_put_u32(skb, TCA_NETEM_ECN, q->ecn))
908 goto nla_put_failure;
909
910 if (dump_loss_model(q, skb) != 0)
911 goto nla_put_failure;
912
913 return nla_nest_end(skb, nla);
914
915 nla_put_failure:
916 nlmsg_trim(skb, nla);
917 return -1;
918 }
919
920 static int netem_dump_class(struct Qdisc *sch, unsigned long cl,
921 struct sk_buff *skb, struct tcmsg *tcm)
922 {
923 struct netem_sched_data *q = qdisc_priv(sch);
924
925 if (cl != 1 || !q->qdisc) /* only one class */
926 return -ENOENT;
927
928 tcm->tcm_handle |= TC_H_MIN(1);
929 tcm->tcm_info = q->qdisc->handle;
930
931 return 0;
932 }
933
934 static int netem_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
935 struct Qdisc **old)
936 {
937 struct netem_sched_data *q = qdisc_priv(sch);
938
939 sch_tree_lock(sch);
940 *old = q->qdisc;
941 q->qdisc = new;
942 if (*old) {
943 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
944 qdisc_reset(*old);
945 }
946 sch_tree_unlock(sch);
947
948 return 0;
949 }
950
951 static struct Qdisc *netem_leaf(struct Qdisc *sch, unsigned long arg)
952 {
953 struct netem_sched_data *q = qdisc_priv(sch);
954 return q->qdisc;
955 }
956
957 static unsigned long netem_get(struct Qdisc *sch, u32 classid)
958 {
959 return 1;
960 }
961
962 static void netem_put(struct Qdisc *sch, unsigned long arg)
963 {
964 }
965
966 static void netem_walk(struct Qdisc *sch, struct qdisc_walker *walker)
967 {
968 if (!walker->stop) {
969 if (walker->count >= walker->skip)
970 if (walker->fn(sch, 1, walker) < 0) {
971 walker->stop = 1;
972 return;
973 }
974 walker->count++;
975 }
976 }
977
978 static const struct Qdisc_class_ops netem_class_ops = {
979 .graft = netem_graft,
980 .leaf = netem_leaf,
981 .get = netem_get,
982 .put = netem_put,
983 .walk = netem_walk,
984 .dump = netem_dump_class,
985 };
986
987 static struct Qdisc_ops netem_qdisc_ops __read_mostly = {
988 .id = "netem",
989 .cl_ops = &netem_class_ops,
990 .priv_size = sizeof(struct netem_sched_data),
991 .enqueue = netem_enqueue,
992 .dequeue = netem_dequeue,
993 .peek = qdisc_peek_dequeued,
994 .drop = netem_drop,
995 .init = netem_init,
996 .reset = netem_reset,
997 .destroy = netem_destroy,
998 .change = netem_change,
999 .dump = netem_dump,
1000 .owner = THIS_MODULE,
1001 };
1002
1003
1004 static int __init netem_module_init(void)
1005 {
1006 pr_info("netem: version " VERSION "\n");
1007 return register_qdisc(&netem_qdisc_ops);
1008 }
1009 static void __exit netem_module_exit(void)
1010 {
1011 unregister_qdisc(&netem_qdisc_ops);
1012 }
1013 module_init(netem_module_init)
1014 module_exit(netem_module_exit)
1015 MODULE_LICENSE("GPL");
kernel source for telekom puls (alcatel/mediatek)