Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/sched/sch_gred.c Generic Random Early Detection queue.
4 *
5 * Authors: J Hadi Salim (hadi@cyberus.ca) 1998-2002
6 *
7 * 991129: - Bug fix with grio mode
8 * - a better sing. AvgQ mode with Grio(WRED)
9 * - A finer grained VQ dequeue based on sugestion
10 * from Ren Liu
11 * - More error checks
12 *
13 * For all the glorious comments look at include/net/red.h
14 */
15
16#include <linux/slab.h>
17#include <linux/module.h>
18#include <linux/types.h>
19#include <linux/kernel.h>
20#include <linux/skbuff.h>
21#include <net/pkt_cls.h>
22#include <net/pkt_sched.h>
23#include <net/red.h>
24
25#define GRED_DEF_PRIO (MAX_DPs / 2)
26#define GRED_VQ_MASK (MAX_DPs - 1)
27
28#define GRED_VQ_RED_FLAGS (TC_RED_ECN | TC_RED_HARDDROP)
29
30struct gred_sched_data;
31struct gred_sched;
32
33struct gred_sched_data {
34 u32 limit; /* HARD maximal queue length */
35 u32 DP; /* the drop parameters */
36 u32 red_flags; /* virtualQ version of red_flags */
37 u64 bytesin; /* bytes seen on virtualQ so far*/
38 u32 packetsin; /* packets seen on virtualQ so far*/
39 u32 backlog; /* bytes on the virtualQ */
40 u8 prio; /* the prio of this vq */
41
42 struct red_parms parms;
43 struct red_vars vars;
44 struct red_stats stats;
45};
46
47enum {
48 GRED_WRED_MODE = 1,
49 GRED_RIO_MODE,
50};
51
52struct gred_sched {
53 struct gred_sched_data *tab[MAX_DPs];
54 unsigned long flags;
55 u32 red_flags;
56 u32 DPs;
57 u32 def;
58 struct red_vars wred_set;
59};
60
61static inline int gred_wred_mode(struct gred_sched *table)
62{
63 return test_bit(GRED_WRED_MODE, &table->flags);
64}
65
66static inline void gred_enable_wred_mode(struct gred_sched *table)
67{
68 __set_bit(GRED_WRED_MODE, &table->flags);
69}
70
71static inline void gred_disable_wred_mode(struct gred_sched *table)
72{
73 __clear_bit(GRED_WRED_MODE, &table->flags);
74}
75
76static inline int gred_rio_mode(struct gred_sched *table)
77{
78 return test_bit(GRED_RIO_MODE, &table->flags);
79}
80
81static inline void gred_enable_rio_mode(struct gred_sched *table)
82{
83 __set_bit(GRED_RIO_MODE, &table->flags);
84}
85
86static inline void gred_disable_rio_mode(struct gred_sched *table)
87{
88 __clear_bit(GRED_RIO_MODE, &table->flags);
89}
90
91static inline int gred_wred_mode_check(struct Qdisc *sch)
92{
93 struct gred_sched *table = qdisc_priv(sch);
94 int i;
95
96 /* Really ugly O(n^2) but shouldn't be necessary too frequent. */
97 for (i = 0; i < table->DPs; i++) {
98 struct gred_sched_data *q = table->tab[i];
99 int n;
100
101 if (q == NULL)
102 continue;
103
104 for (n = i + 1; n < table->DPs; n++)
105 if (table->tab[n] && table->tab[n]->prio == q->prio)
106 return 1;
107 }
108
109 return 0;
110}
111
112static inline unsigned int gred_backlog(struct gred_sched *table,
113 struct gred_sched_data *q,
114 struct Qdisc *sch)
115{
116 if (gred_wred_mode(table))
117 return sch->qstats.backlog;
118 else
119 return q->backlog;
120}
121
122static inline u16 tc_index_to_dp(struct sk_buff *skb)
123{
124 return skb->tc_index & GRED_VQ_MASK;
125}
126
127static inline void gred_load_wred_set(const struct gred_sched *table,
128 struct gred_sched_data *q)
129{
130 q->vars.qavg = table->wred_set.qavg;
131 q->vars.qidlestart = table->wred_set.qidlestart;
132}
133
134static inline void gred_store_wred_set(struct gred_sched *table,
135 struct gred_sched_data *q)
136{
137 table->wred_set.qavg = q->vars.qavg;
138 table->wred_set.qidlestart = q->vars.qidlestart;
139}
140
141static int gred_use_ecn(struct gred_sched_data *q)
142{
143 return q->red_flags & TC_RED_ECN;
144}
145
146static int gred_use_harddrop(struct gred_sched_data *q)
147{
148 return q->red_flags & TC_RED_HARDDROP;
149}
150
151static bool gred_per_vq_red_flags_used(struct gred_sched *table)
152{
153 unsigned int i;
154
155 /* Local per-vq flags couldn't have been set unless global are 0 */
156 if (table->red_flags)
157 return false;
158 for (i = 0; i < MAX_DPs; i++)
159 if (table->tab[i] && table->tab[i]->red_flags)
160 return true;
161 return false;
162}
163
164static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch,
165 struct sk_buff **to_free)
166{
167 struct gred_sched_data *q = NULL;
168 struct gred_sched *t = qdisc_priv(sch);
169 unsigned long qavg = 0;
170 u16 dp = tc_index_to_dp(skb);
171
172 if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
173 dp = t->def;
174
175 q = t->tab[dp];
176 if (!q) {
177 /* Pass through packets not assigned to a DP
178 * if no default DP has been configured. This
179 * allows for DP flows to be left untouched.
180 */
181 if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <=
182 sch->limit))
183 return qdisc_enqueue_tail(skb, sch);
184 else
185 goto drop;
186 }
187
188 /* fix tc_index? --could be controversial but needed for
189 requeueing */
190 skb->tc_index = (skb->tc_index & ~GRED_VQ_MASK) | dp;
191 }
192
193 /* sum up all the qaves of prios < ours to get the new qave */
194 if (!gred_wred_mode(t) && gred_rio_mode(t)) {
195 int i;
196
197 for (i = 0; i < t->DPs; i++) {
198 if (t->tab[i] && t->tab[i]->prio < q->prio &&
199 !red_is_idling(&t->tab[i]->vars))
200 qavg += t->tab[i]->vars.qavg;
201 }
202
203 }
204
205 q->packetsin++;
206 q->bytesin += qdisc_pkt_len(skb);
207
208 if (gred_wred_mode(t))
209 gred_load_wred_set(t, q);
210
211 q->vars.qavg = red_calc_qavg(&q->parms,
212 &q->vars,
213 gred_backlog(t, q, sch));
214
215 if (red_is_idling(&q->vars))
216 red_end_of_idle_period(&q->vars);
217
218 if (gred_wred_mode(t))
219 gred_store_wred_set(t, q);
220
221 switch (red_action(&q->parms, &q->vars, q->vars.qavg + qavg)) {
222 case RED_DONT_MARK:
223 break;
224
225 case RED_PROB_MARK:
226 qdisc_qstats_overlimit(sch);
227 if (!gred_use_ecn(q) || !INET_ECN_set_ce(skb)) {
228 q->stats.prob_drop++;
229 goto congestion_drop;
230 }
231
232 q->stats.prob_mark++;
233 break;
234
235 case RED_HARD_MARK:
236 qdisc_qstats_overlimit(sch);
237 if (gred_use_harddrop(q) || !gred_use_ecn(q) ||
238 !INET_ECN_set_ce(skb)) {
239 q->stats.forced_drop++;
240 goto congestion_drop;
241 }
242 q->stats.forced_mark++;
243 break;
244 }
245
246 if (gred_backlog(t, q, sch) + qdisc_pkt_len(skb) <= q->limit) {
247 q->backlog += qdisc_pkt_len(skb);
248 return qdisc_enqueue_tail(skb, sch);
249 }
250
251 q->stats.pdrop++;
252drop:
253 return qdisc_drop(skb, sch, to_free);
254
255congestion_drop:
256 qdisc_drop(skb, sch, to_free);
257 return NET_XMIT_CN;
258}
259
260static struct sk_buff *gred_dequeue(struct Qdisc *sch)
261{
262 struct sk_buff *skb;
263 struct gred_sched *t = qdisc_priv(sch);
264
265 skb = qdisc_dequeue_head(sch);
266
267 if (skb) {
268 struct gred_sched_data *q;
269 u16 dp = tc_index_to_dp(skb);
270
271 if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
272 net_warn_ratelimited("GRED: Unable to relocate VQ 0x%x after dequeue, screwing up backlog\n",
273 tc_index_to_dp(skb));
274 } else {
275 q->backlog -= qdisc_pkt_len(skb);
276
277 if (gred_wred_mode(t)) {
278 if (!sch->qstats.backlog)
279 red_start_of_idle_period(&t->wred_set);
280 } else {
281 if (!q->backlog)
282 red_start_of_idle_period(&q->vars);
283 }
284 }
285
286 return skb;
287 }
288
289 return NULL;
290}
291
292static void gred_reset(struct Qdisc *sch)
293{
294 int i;
295 struct gred_sched *t = qdisc_priv(sch);
296
297 qdisc_reset_queue(sch);
298
299 for (i = 0; i < t->DPs; i++) {
300 struct gred_sched_data *q = t->tab[i];
301
302 if (!q)
303 continue;
304
305 red_restart(&q->vars);
306 q->backlog = 0;
307 }
308}
309
310static void gred_offload(struct Qdisc *sch, enum tc_gred_command command)
311{
312 struct gred_sched *table = qdisc_priv(sch);
313 struct net_device *dev = qdisc_dev(sch);
314 struct tc_gred_qopt_offload opt = {
315 .command = command,
316 .handle = sch->handle,
317 .parent = sch->parent,
318 };
319
320 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
321 return;
322
323 if (command == TC_GRED_REPLACE) {
324 unsigned int i;
325
326 opt.set.grio_on = gred_rio_mode(table);
327 opt.set.wred_on = gred_wred_mode(table);
328 opt.set.dp_cnt = table->DPs;
329 opt.set.dp_def = table->def;
330
331 for (i = 0; i < table->DPs; i++) {
332 struct gred_sched_data *q = table->tab[i];
333
334 if (!q)
335 continue;
336 opt.set.tab[i].present = true;
337 opt.set.tab[i].limit = q->limit;
338 opt.set.tab[i].prio = q->prio;
339 opt.set.tab[i].min = q->parms.qth_min >> q->parms.Wlog;
340 opt.set.tab[i].max = q->parms.qth_max >> q->parms.Wlog;
341 opt.set.tab[i].is_ecn = gred_use_ecn(q);
342 opt.set.tab[i].is_harddrop = gred_use_harddrop(q);
343 opt.set.tab[i].probability = q->parms.max_P;
344 opt.set.tab[i].backlog = &q->backlog;
345 }
346 opt.set.qstats = &sch->qstats;
347 }
348
349 dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_GRED, &opt);
350}
351
352static int gred_offload_dump_stats(struct Qdisc *sch)
353{
354 struct gred_sched *table = qdisc_priv(sch);
355 struct tc_gred_qopt_offload *hw_stats;
356 unsigned int i;
357 int ret;
358
359 hw_stats = kzalloc(sizeof(*hw_stats), GFP_KERNEL);
360 if (!hw_stats)
361 return -ENOMEM;
362
363 hw_stats->command = TC_GRED_STATS;
364 hw_stats->handle = sch->handle;
365 hw_stats->parent = sch->parent;
366
367 for (i = 0; i < MAX_DPs; i++)
368 if (table->tab[i])
369 hw_stats->stats.xstats[i] = &table->tab[i]->stats;
370
371 ret = qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_GRED, hw_stats);
372 /* Even if driver returns failure adjust the stats - in case offload
373 * ended but driver still wants to adjust the values.
374 */
375 for (i = 0; i < MAX_DPs; i++) {
376 if (!table->tab[i])
377 continue;
378 table->tab[i]->packetsin += hw_stats->stats.bstats[i].packets;
379 table->tab[i]->bytesin += hw_stats->stats.bstats[i].bytes;
380 table->tab[i]->backlog += hw_stats->stats.qstats[i].backlog;
381
382 _bstats_update(&sch->bstats,
383 hw_stats->stats.bstats[i].bytes,
384 hw_stats->stats.bstats[i].packets);
385 sch->qstats.qlen += hw_stats->stats.qstats[i].qlen;
386 sch->qstats.backlog += hw_stats->stats.qstats[i].backlog;
387 sch->qstats.drops += hw_stats->stats.qstats[i].drops;
388 sch->qstats.requeues += hw_stats->stats.qstats[i].requeues;
389 sch->qstats.overlimits += hw_stats->stats.qstats[i].overlimits;
390 }
391
392 kfree(hw_stats);
393 return ret;
394}
395
396static inline void gred_destroy_vq(struct gred_sched_data *q)
397{
398 kfree(q);
399}
400
401static int gred_change_table_def(struct Qdisc *sch, struct nlattr *dps,
402 struct netlink_ext_ack *extack)
403{
404 struct gred_sched *table = qdisc_priv(sch);
405 struct tc_gred_sopt *sopt;
406 bool red_flags_changed;
407 int i;
408
409 if (!dps)
410 return -EINVAL;
411
412 sopt = nla_data(dps);
413
414 if (sopt->DPs > MAX_DPs) {
415 NL_SET_ERR_MSG_MOD(extack, "number of virtual queues too high");
416 return -EINVAL;
417 }
418 if (sopt->DPs == 0) {
419 NL_SET_ERR_MSG_MOD(extack,
420 "number of virtual queues can't be 0");
421 return -EINVAL;
422 }
423 if (sopt->def_DP >= sopt->DPs) {
424 NL_SET_ERR_MSG_MOD(extack, "default virtual queue above virtual queue count");
425 return -EINVAL;
426 }
427 if (sopt->flags && gred_per_vq_red_flags_used(table)) {
428 NL_SET_ERR_MSG_MOD(extack, "can't set per-Qdisc RED flags when per-virtual queue flags are used");
429 return -EINVAL;
430 }
431
432 sch_tree_lock(sch);
433 table->DPs = sopt->DPs;
434 table->def = sopt->def_DP;
435 red_flags_changed = table->red_flags != sopt->flags;
436 table->red_flags = sopt->flags;
437
438 /*
439 * Every entry point to GRED is synchronized with the above code
440 * and the DP is checked against DPs, i.e. shadowed VQs can no
441 * longer be found so we can unlock right here.
442 */
443 sch_tree_unlock(sch);
444
445 if (sopt->grio) {
446 gred_enable_rio_mode(table);
447 gred_disable_wred_mode(table);
448 if (gred_wred_mode_check(sch))
449 gred_enable_wred_mode(table);
450 } else {
451 gred_disable_rio_mode(table);
452 gred_disable_wred_mode(table);
453 }
454
455 if (red_flags_changed)
456 for (i = 0; i < table->DPs; i++)
457 if (table->tab[i])
458 table->tab[i]->red_flags =
459 table->red_flags & GRED_VQ_RED_FLAGS;
460
461 for (i = table->DPs; i < MAX_DPs; i++) {
462 if (table->tab[i]) {
463 pr_warn("GRED: Warning: Destroying shadowed VQ 0x%x\n",
464 i);
465 gred_destroy_vq(table->tab[i]);
466 table->tab[i] = NULL;
467 }
468 }
469
470 gred_offload(sch, TC_GRED_REPLACE);
471 return 0;
472}
473
474static inline int gred_change_vq(struct Qdisc *sch, int dp,
475 struct tc_gred_qopt *ctl, int prio,
476 u8 *stab, u32 max_P,
477 struct gred_sched_data **prealloc,
478 struct netlink_ext_ack *extack)
479{
480 struct gred_sched *table = qdisc_priv(sch);
481 struct gred_sched_data *q = table->tab[dp];
482
483 if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog)) {
484 NL_SET_ERR_MSG_MOD(extack, "invalid RED parameters");
485 return -EINVAL;
486 }
487
488 if (!q) {
489 table->tab[dp] = q = *prealloc;
490 *prealloc = NULL;
491 if (!q)
492 return -ENOMEM;
493 q->red_flags = table->red_flags & GRED_VQ_RED_FLAGS;
494 }
495
496 q->DP = dp;
497 q->prio = prio;
498 if (ctl->limit > sch->limit)
499 q->limit = sch->limit;
500 else
501 q->limit = ctl->limit;
502
503 if (q->backlog == 0)
504 red_end_of_idle_period(&q->vars);
505
506 red_set_parms(&q->parms,
507 ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog,
508 ctl->Scell_log, stab, max_P);
509 red_set_vars(&q->vars);
510 return 0;
511}
512
513static const struct nla_policy gred_vq_policy[TCA_GRED_VQ_MAX + 1] = {
514 [TCA_GRED_VQ_DP] = { .type = NLA_U32 },
515 [TCA_GRED_VQ_FLAGS] = { .type = NLA_U32 },
516};
517
518static const struct nla_policy gred_vqe_policy[TCA_GRED_VQ_ENTRY_MAX + 1] = {
519 [TCA_GRED_VQ_ENTRY] = { .type = NLA_NESTED },
520};
521
522static const struct nla_policy gred_policy[TCA_GRED_MAX + 1] = {
523 [TCA_GRED_PARMS] = { .len = sizeof(struct tc_gred_qopt) },
524 [TCA_GRED_STAB] = { .len = 256 },
525 [TCA_GRED_DPS] = { .len = sizeof(struct tc_gred_sopt) },
526 [TCA_GRED_MAX_P] = { .type = NLA_U32 },
527 [TCA_GRED_LIMIT] = { .type = NLA_U32 },
528 [TCA_GRED_VQ_LIST] = { .type = NLA_NESTED },
529};
530
531static void gred_vq_apply(struct gred_sched *table, const struct nlattr *entry)
532{
533 struct nlattr *tb[TCA_GRED_VQ_MAX + 1];
534 u32 dp;
535
536 nla_parse_nested_deprecated(tb, TCA_GRED_VQ_MAX, entry,
537 gred_vq_policy, NULL);
538
539 dp = nla_get_u32(tb[TCA_GRED_VQ_DP]);
540
541 if (tb[TCA_GRED_VQ_FLAGS])
542 table->tab[dp]->red_flags = nla_get_u32(tb[TCA_GRED_VQ_FLAGS]);
543}
544
545static void gred_vqs_apply(struct gred_sched *table, struct nlattr *vqs)
546{
547 const struct nlattr *attr;
548 int rem;
549
550 nla_for_each_nested(attr, vqs, rem) {
551 switch (nla_type(attr)) {
552 case TCA_GRED_VQ_ENTRY:
553 gred_vq_apply(table, attr);
554 break;
555 }
556 }
557}
558
559static int gred_vq_validate(struct gred_sched *table, u32 cdp,
560 const struct nlattr *entry,
561 struct netlink_ext_ack *extack)
562{
563 struct nlattr *tb[TCA_GRED_VQ_MAX + 1];
564 int err;
565 u32 dp;
566
567 err = nla_parse_nested_deprecated(tb, TCA_GRED_VQ_MAX, entry,
568 gred_vq_policy, extack);
569 if (err < 0)
570 return err;
571
572 if (!tb[TCA_GRED_VQ_DP]) {
573 NL_SET_ERR_MSG_MOD(extack, "Virtual queue with no index specified");
574 return -EINVAL;
575 }
576 dp = nla_get_u32(tb[TCA_GRED_VQ_DP]);
577 if (dp >= table->DPs) {
578 NL_SET_ERR_MSG_MOD(extack, "Virtual queue with index out of bounds");
579 return -EINVAL;
580 }
581 if (dp != cdp && !table->tab[dp]) {
582 NL_SET_ERR_MSG_MOD(extack, "Virtual queue not yet instantiated");
583 return -EINVAL;
584 }
585
586 if (tb[TCA_GRED_VQ_FLAGS]) {
587 u32 red_flags = nla_get_u32(tb[TCA_GRED_VQ_FLAGS]);
588
589 if (table->red_flags && table->red_flags != red_flags) {
590 NL_SET_ERR_MSG_MOD(extack, "can't change per-virtual queue RED flags when per-Qdisc flags are used");
591 return -EINVAL;
592 }
593 if (red_flags & ~GRED_VQ_RED_FLAGS) {
594 NL_SET_ERR_MSG_MOD(extack,
595 "invalid RED flags specified");
596 return -EINVAL;
597 }
598 }
599
600 return 0;
601}
602
603static int gred_vqs_validate(struct gred_sched *table, u32 cdp,
604 struct nlattr *vqs, struct netlink_ext_ack *extack)
605{
606 const struct nlattr *attr;
607 int rem, err;
608
609 err = nla_validate_nested_deprecated(vqs, TCA_GRED_VQ_ENTRY_MAX,
610 gred_vqe_policy, extack);
611 if (err < 0)
612 return err;
613
614 nla_for_each_nested(attr, vqs, rem) {
615 switch (nla_type(attr)) {
616 case TCA_GRED_VQ_ENTRY:
617 err = gred_vq_validate(table, cdp, attr, extack);
618 if (err)
619 return err;
620 break;
621 default:
622 NL_SET_ERR_MSG_MOD(extack, "GRED_VQ_LIST can contain only entry attributes");
623 return -EINVAL;
624 }
625 }
626
627 if (rem > 0) {
628 NL_SET_ERR_MSG_MOD(extack, "Trailing data after parsing virtual queue list");
629 return -EINVAL;
630 }
631
632 return 0;
633}
634
635static int gred_change(struct Qdisc *sch, struct nlattr *opt,
636 struct netlink_ext_ack *extack)
637{
638 struct gred_sched *table = qdisc_priv(sch);
639 struct tc_gred_qopt *ctl;
640 struct nlattr *tb[TCA_GRED_MAX + 1];
641 int err, prio = GRED_DEF_PRIO;
642 u8 *stab;
643 u32 max_P;
644 struct gred_sched_data *prealloc;
645
646 if (opt == NULL)
647 return -EINVAL;
648
649 err = nla_parse_nested_deprecated(tb, TCA_GRED_MAX, opt, gred_policy,
650 extack);
651 if (err < 0)
652 return err;
653
654 if (tb[TCA_GRED_PARMS] == NULL && tb[TCA_GRED_STAB] == NULL) {
655 if (tb[TCA_GRED_LIMIT] != NULL)
656 sch->limit = nla_get_u32(tb[TCA_GRED_LIMIT]);
657 return gred_change_table_def(sch, tb[TCA_GRED_DPS], extack);
658 }
659
660 if (tb[TCA_GRED_PARMS] == NULL ||
661 tb[TCA_GRED_STAB] == NULL ||
662 tb[TCA_GRED_LIMIT] != NULL) {
663 NL_SET_ERR_MSG_MOD(extack, "can't configure Qdisc and virtual queue at the same time");
664 return -EINVAL;
665 }
666
667 max_P = tb[TCA_GRED_MAX_P] ? nla_get_u32(tb[TCA_GRED_MAX_P]) : 0;
668
669 ctl = nla_data(tb[TCA_GRED_PARMS]);
670 stab = nla_data(tb[TCA_GRED_STAB]);
671
672 if (ctl->DP >= table->DPs) {
673 NL_SET_ERR_MSG_MOD(extack, "virtual queue index above virtual queue count");
674 return -EINVAL;
675 }
676
677 if (tb[TCA_GRED_VQ_LIST]) {
678 err = gred_vqs_validate(table, ctl->DP, tb[TCA_GRED_VQ_LIST],
679 extack);
680 if (err)
681 return err;
682 }
683
684 if (gred_rio_mode(table)) {
685 if (ctl->prio == 0) {
686 int def_prio = GRED_DEF_PRIO;
687
688 if (table->tab[table->def])
689 def_prio = table->tab[table->def]->prio;
690
691 printk(KERN_DEBUG "GRED: DP %u does not have a prio "
692 "setting default to %d\n", ctl->DP, def_prio);
693
694 prio = def_prio;
695 } else
696 prio = ctl->prio;
697 }
698
699 prealloc = kzalloc(sizeof(*prealloc), GFP_KERNEL);
700 sch_tree_lock(sch);
701
702 err = gred_change_vq(sch, ctl->DP, ctl, prio, stab, max_P, &prealloc,
703 extack);
704 if (err < 0)
705 goto err_unlock_free;
706
707 if (tb[TCA_GRED_VQ_LIST])
708 gred_vqs_apply(table, tb[TCA_GRED_VQ_LIST]);
709
710 if (gred_rio_mode(table)) {
711 gred_disable_wred_mode(table);
712 if (gred_wred_mode_check(sch))
713 gred_enable_wred_mode(table);
714 }
715
716 sch_tree_unlock(sch);
717 kfree(prealloc);
718
719 gred_offload(sch, TC_GRED_REPLACE);
720 return 0;
721
722err_unlock_free:
723 sch_tree_unlock(sch);
724 kfree(prealloc);
725 return err;
726}
727
728static int gred_init(struct Qdisc *sch, struct nlattr *opt,
729 struct netlink_ext_ack *extack)
730{
731 struct nlattr *tb[TCA_GRED_MAX + 1];
732 int err;
733
734 if (!opt)
735 return -EINVAL;
736
737 err = nla_parse_nested_deprecated(tb, TCA_GRED_MAX, opt, gred_policy,
738 extack);
739 if (err < 0)
740 return err;
741
742 if (tb[TCA_GRED_PARMS] || tb[TCA_GRED_STAB]) {
743 NL_SET_ERR_MSG_MOD(extack,
744 "virtual queue configuration can't be specified at initialization time");
745 return -EINVAL;
746 }
747
748 if (tb[TCA_GRED_LIMIT])
749 sch->limit = nla_get_u32(tb[TCA_GRED_LIMIT]);
750 else
751 sch->limit = qdisc_dev(sch)->tx_queue_len
752 * psched_mtu(qdisc_dev(sch));
753
754 return gred_change_table_def(sch, tb[TCA_GRED_DPS], extack);
755}
756
757static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
758{
759 struct gred_sched *table = qdisc_priv(sch);
760 struct nlattr *parms, *vqs, *opts = NULL;
761 int i;
762 u32 max_p[MAX_DPs];
763 struct tc_gred_sopt sopt = {
764 .DPs = table->DPs,
765 .def_DP = table->def,
766 .grio = gred_rio_mode(table),
767 .flags = table->red_flags,
768 };
769
770 if (gred_offload_dump_stats(sch))
771 goto nla_put_failure;
772
773 opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
774 if (opts == NULL)
775 goto nla_put_failure;
776 if (nla_put(skb, TCA_GRED_DPS, sizeof(sopt), &sopt))
777 goto nla_put_failure;
778
779 for (i = 0; i < MAX_DPs; i++) {
780 struct gred_sched_data *q = table->tab[i];
781
782 max_p[i] = q ? q->parms.max_P : 0;
783 }
784 if (nla_put(skb, TCA_GRED_MAX_P, sizeof(max_p), max_p))
785 goto nla_put_failure;
786
787 if (nla_put_u32(skb, TCA_GRED_LIMIT, sch->limit))
788 goto nla_put_failure;
789
790 /* Old style all-in-one dump of VQs */
791 parms = nla_nest_start_noflag(skb, TCA_GRED_PARMS);
792 if (parms == NULL)
793 goto nla_put_failure;
794
795 for (i = 0; i < MAX_DPs; i++) {
796 struct gred_sched_data *q = table->tab[i];
797 struct tc_gred_qopt opt;
798 unsigned long qavg;
799
800 memset(&opt, 0, sizeof(opt));
801
802 if (!q) {
803 /* hack -- fix at some point with proper message
804 This is how we indicate to tc that there is no VQ
805 at this DP */
806
807 opt.DP = MAX_DPs + i;
808 goto append_opt;
809 }
810
811 opt.limit = q->limit;
812 opt.DP = q->DP;
813 opt.backlog = gred_backlog(table, q, sch);
814 opt.prio = q->prio;
815 opt.qth_min = q->parms.qth_min >> q->parms.Wlog;
816 opt.qth_max = q->parms.qth_max >> q->parms.Wlog;
817 opt.Wlog = q->parms.Wlog;
818 opt.Plog = q->parms.Plog;
819 opt.Scell_log = q->parms.Scell_log;
820 opt.other = q->stats.other;
821 opt.early = q->stats.prob_drop;
822 opt.forced = q->stats.forced_drop;
823 opt.pdrop = q->stats.pdrop;
824 opt.packets = q->packetsin;
825 opt.bytesin = q->bytesin;
826
827 if (gred_wred_mode(table))
828 gred_load_wred_set(table, q);
829
830 qavg = red_calc_qavg(&q->parms, &q->vars,
831 q->vars.qavg >> q->parms.Wlog);
832 opt.qave = qavg >> q->parms.Wlog;
833
834append_opt:
835 if (nla_append(skb, sizeof(opt), &opt) < 0)
836 goto nla_put_failure;
837 }
838
839 nla_nest_end(skb, parms);
840
841 /* Dump the VQs again, in more structured way */
842 vqs = nla_nest_start_noflag(skb, TCA_GRED_VQ_LIST);
843 if (!vqs)
844 goto nla_put_failure;
845
846 for (i = 0; i < MAX_DPs; i++) {
847 struct gred_sched_data *q = table->tab[i];
848 struct nlattr *vq;
849
850 if (!q)
851 continue;
852
853 vq = nla_nest_start_noflag(skb, TCA_GRED_VQ_ENTRY);
854 if (!vq)
855 goto nla_put_failure;
856
857 if (nla_put_u32(skb, TCA_GRED_VQ_DP, q->DP))
858 goto nla_put_failure;
859
860 if (nla_put_u32(skb, TCA_GRED_VQ_FLAGS, q->red_flags))
861 goto nla_put_failure;
862
863 /* Stats */
864 if (nla_put_u64_64bit(skb, TCA_GRED_VQ_STAT_BYTES, q->bytesin,
865 TCA_GRED_VQ_PAD))
866 goto nla_put_failure;
867 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PACKETS, q->packetsin))
868 goto nla_put_failure;
869 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_BACKLOG,
870 gred_backlog(table, q, sch)))
871 goto nla_put_failure;
872 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PROB_DROP,
873 q->stats.prob_drop))
874 goto nla_put_failure;
875 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PROB_MARK,
876 q->stats.prob_mark))
877 goto nla_put_failure;
878 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_FORCED_DROP,
879 q->stats.forced_drop))
880 goto nla_put_failure;
881 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_FORCED_MARK,
882 q->stats.forced_mark))
883 goto nla_put_failure;
884 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PDROP, q->stats.pdrop))
885 goto nla_put_failure;
886 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_OTHER, q->stats.other))
887 goto nla_put_failure;
888
889 nla_nest_end(skb, vq);
890 }
891 nla_nest_end(skb, vqs);
892
893 return nla_nest_end(skb, opts);
894
895nla_put_failure:
896 nla_nest_cancel(skb, opts);
897 return -EMSGSIZE;
898}
899
900static void gred_destroy(struct Qdisc *sch)
901{
902 struct gred_sched *table = qdisc_priv(sch);
903 int i;
904
905 for (i = 0; i < table->DPs; i++) {
906 if (table->tab[i])
907 gred_destroy_vq(table->tab[i]);
908 }
909 gred_offload(sch, TC_GRED_DESTROY);
910}
911
912static struct Qdisc_ops gred_qdisc_ops __read_mostly = {
913 .id = "gred",
914 .priv_size = sizeof(struct gred_sched),
915 .enqueue = gred_enqueue,
916 .dequeue = gred_dequeue,
917 .peek = qdisc_peek_head,
918 .init = gred_init,
919 .reset = gred_reset,
920 .destroy = gred_destroy,
921 .change = gred_change,
922 .dump = gred_dump,
923 .owner = THIS_MODULE,
924};
925
926static int __init gred_module_init(void)
927{
928 return register_qdisc(&gred_qdisc_ops);
929}
930
931static void __exit gred_module_exit(void)
932{
933 unregister_qdisc(&gred_qdisc_ops);
934}
935
936module_init(gred_module_init)
937module_exit(gred_module_exit)
938
939MODULE_LICENSE("GPL");
1/*
2 * net/sched/sch_gred.c Generic Random Early Detection queue.
3 *
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version
8 * 2 of the License, or (at your option) any later version.
9 *
10 * Authors: J Hadi Salim (hadi@cyberus.ca) 1998-2002
11 *
12 * 991129: - Bug fix with grio mode
13 * - a better sing. AvgQ mode with Grio(WRED)
14 * - A finer grained VQ dequeue based on sugestion
15 * from Ren Liu
16 * - More error checks
17 *
18 * For all the glorious comments look at include/net/red.h
19 */
20
21#include <linux/slab.h>
22#include <linux/module.h>
23#include <linux/types.h>
24#include <linux/kernel.h>
25#include <linux/skbuff.h>
26#include <net/pkt_sched.h>
27#include <net/red.h>
28
29#define GRED_DEF_PRIO (MAX_DPs / 2)
30#define GRED_VQ_MASK (MAX_DPs - 1)
31
32struct gred_sched_data;
33struct gred_sched;
34
35struct gred_sched_data {
36 u32 limit; /* HARD maximal queue length */
37 u32 DP; /* the drop parameters */
38 u32 bytesin; /* bytes seen on virtualQ so far*/
39 u32 packetsin; /* packets seen on virtualQ so far*/
40 u32 backlog; /* bytes on the virtualQ */
41 u8 prio; /* the prio of this vq */
42
43 struct red_parms parms;
44 struct red_vars vars;
45 struct red_stats stats;
46};
47
48enum {
49 GRED_WRED_MODE = 1,
50 GRED_RIO_MODE,
51};
52
53struct gred_sched {
54 struct gred_sched_data *tab[MAX_DPs];
55 unsigned long flags;
56 u32 red_flags;
57 u32 DPs;
58 u32 def;
59 struct red_vars wred_set;
60};
61
62static inline int gred_wred_mode(struct gred_sched *table)
63{
64 return test_bit(GRED_WRED_MODE, &table->flags);
65}
66
67static inline void gred_enable_wred_mode(struct gred_sched *table)
68{
69 __set_bit(GRED_WRED_MODE, &table->flags);
70}
71
72static inline void gred_disable_wred_mode(struct gred_sched *table)
73{
74 __clear_bit(GRED_WRED_MODE, &table->flags);
75}
76
77static inline int gred_rio_mode(struct gred_sched *table)
78{
79 return test_bit(GRED_RIO_MODE, &table->flags);
80}
81
82static inline void gred_enable_rio_mode(struct gred_sched *table)
83{
84 __set_bit(GRED_RIO_MODE, &table->flags);
85}
86
87static inline void gred_disable_rio_mode(struct gred_sched *table)
88{
89 __clear_bit(GRED_RIO_MODE, &table->flags);
90}
91
92static inline int gred_wred_mode_check(struct Qdisc *sch)
93{
94 struct gred_sched *table = qdisc_priv(sch);
95 int i;
96
97 /* Really ugly O(n^2) but shouldn't be necessary too frequent. */
98 for (i = 0; i < table->DPs; i++) {
99 struct gred_sched_data *q = table->tab[i];
100 int n;
101
102 if (q == NULL)
103 continue;
104
105 for (n = i + 1; n < table->DPs; n++)
106 if (table->tab[n] && table->tab[n]->prio == q->prio)
107 return 1;
108 }
109
110 return 0;
111}
112
113static inline unsigned int gred_backlog(struct gred_sched *table,
114 struct gred_sched_data *q,
115 struct Qdisc *sch)
116{
117 if (gred_wred_mode(table))
118 return sch->qstats.backlog;
119 else
120 return q->backlog;
121}
122
123static inline u16 tc_index_to_dp(struct sk_buff *skb)
124{
125 return skb->tc_index & GRED_VQ_MASK;
126}
127
128static inline void gred_load_wred_set(const struct gred_sched *table,
129 struct gred_sched_data *q)
130{
131 q->vars.qavg = table->wred_set.qavg;
132 q->vars.qidlestart = table->wred_set.qidlestart;
133}
134
135static inline void gred_store_wred_set(struct gred_sched *table,
136 struct gred_sched_data *q)
137{
138 table->wred_set.qavg = q->vars.qavg;
139 table->wred_set.qidlestart = q->vars.qidlestart;
140}
141
142static inline int gred_use_ecn(struct gred_sched *t)
143{
144 return t->red_flags & TC_RED_ECN;
145}
146
147static inline int gred_use_harddrop(struct gred_sched *t)
148{
149 return t->red_flags & TC_RED_HARDDROP;
150}
151
152static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch)
153{
154 struct gred_sched_data *q = NULL;
155 struct gred_sched *t = qdisc_priv(sch);
156 unsigned long qavg = 0;
157 u16 dp = tc_index_to_dp(skb);
158
159 if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
160 dp = t->def;
161
162 q = t->tab[dp];
163 if (!q) {
164 /* Pass through packets not assigned to a DP
165 * if no default DP has been configured. This
166 * allows for DP flows to be left untouched.
167 */
168 if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <=
169 sch->limit))
170 return qdisc_enqueue_tail(skb, sch);
171 else
172 goto drop;
173 }
174
175 /* fix tc_index? --could be controversial but needed for
176 requeueing */
177 skb->tc_index = (skb->tc_index & ~GRED_VQ_MASK) | dp;
178 }
179
180 /* sum up all the qaves of prios < ours to get the new qave */
181 if (!gred_wred_mode(t) && gred_rio_mode(t)) {
182 int i;
183
184 for (i = 0; i < t->DPs; i++) {
185 if (t->tab[i] && t->tab[i]->prio < q->prio &&
186 !red_is_idling(&t->tab[i]->vars))
187 qavg += t->tab[i]->vars.qavg;
188 }
189
190 }
191
192 q->packetsin++;
193 q->bytesin += qdisc_pkt_len(skb);
194
195 if (gred_wred_mode(t))
196 gred_load_wred_set(t, q);
197
198 q->vars.qavg = red_calc_qavg(&q->parms,
199 &q->vars,
200 gred_backlog(t, q, sch));
201
202 if (red_is_idling(&q->vars))
203 red_end_of_idle_period(&q->vars);
204
205 if (gred_wred_mode(t))
206 gred_store_wred_set(t, q);
207
208 switch (red_action(&q->parms, &q->vars, q->vars.qavg + qavg)) {
209 case RED_DONT_MARK:
210 break;
211
212 case RED_PROB_MARK:
213 qdisc_qstats_overlimit(sch);
214 if (!gred_use_ecn(t) || !INET_ECN_set_ce(skb)) {
215 q->stats.prob_drop++;
216 goto congestion_drop;
217 }
218
219 q->stats.prob_mark++;
220 break;
221
222 case RED_HARD_MARK:
223 qdisc_qstats_overlimit(sch);
224 if (gred_use_harddrop(t) || !gred_use_ecn(t) ||
225 !INET_ECN_set_ce(skb)) {
226 q->stats.forced_drop++;
227 goto congestion_drop;
228 }
229 q->stats.forced_mark++;
230 break;
231 }
232
233 if (gred_backlog(t, q, sch) + qdisc_pkt_len(skb) <= q->limit) {
234 q->backlog += qdisc_pkt_len(skb);
235 return qdisc_enqueue_tail(skb, sch);
236 }
237
238 q->stats.pdrop++;
239drop:
240 return qdisc_drop(skb, sch);
241
242congestion_drop:
243 qdisc_drop(skb, sch);
244 return NET_XMIT_CN;
245}
246
247static struct sk_buff *gred_dequeue(struct Qdisc *sch)
248{
249 struct sk_buff *skb;
250 struct gred_sched *t = qdisc_priv(sch);
251
252 skb = qdisc_dequeue_head(sch);
253
254 if (skb) {
255 struct gred_sched_data *q;
256 u16 dp = tc_index_to_dp(skb);
257
258 if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
259 net_warn_ratelimited("GRED: Unable to relocate VQ 0x%x after dequeue, screwing up backlog\n",
260 tc_index_to_dp(skb));
261 } else {
262 q->backlog -= qdisc_pkt_len(skb);
263
264 if (gred_wred_mode(t)) {
265 if (!sch->qstats.backlog)
266 red_start_of_idle_period(&t->wred_set);
267 } else {
268 if (!q->backlog)
269 red_start_of_idle_period(&q->vars);
270 }
271 }
272
273 return skb;
274 }
275
276 return NULL;
277}
278
279static unsigned int gred_drop(struct Qdisc *sch)
280{
281 struct sk_buff *skb;
282 struct gred_sched *t = qdisc_priv(sch);
283
284 skb = qdisc_dequeue_tail(sch);
285 if (skb) {
286 unsigned int len = qdisc_pkt_len(skb);
287 struct gred_sched_data *q;
288 u16 dp = tc_index_to_dp(skb);
289
290 if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
291 net_warn_ratelimited("GRED: Unable to relocate VQ 0x%x while dropping, screwing up backlog\n",
292 tc_index_to_dp(skb));
293 } else {
294 q->backlog -= len;
295 q->stats.other++;
296
297 if (gred_wred_mode(t)) {
298 if (!sch->qstats.backlog)
299 red_start_of_idle_period(&t->wred_set);
300 } else {
301 if (!q->backlog)
302 red_start_of_idle_period(&q->vars);
303 }
304 }
305
306 qdisc_drop(skb, sch);
307 return len;
308 }
309
310 return 0;
311}
312
313static void gred_reset(struct Qdisc *sch)
314{
315 int i;
316 struct gred_sched *t = qdisc_priv(sch);
317
318 qdisc_reset_queue(sch);
319
320 for (i = 0; i < t->DPs; i++) {
321 struct gred_sched_data *q = t->tab[i];
322
323 if (!q)
324 continue;
325
326 red_restart(&q->vars);
327 q->backlog = 0;
328 }
329}
330
331static inline void gred_destroy_vq(struct gred_sched_data *q)
332{
333 kfree(q);
334}
335
336static inline int gred_change_table_def(struct Qdisc *sch, struct nlattr *dps)
337{
338 struct gred_sched *table = qdisc_priv(sch);
339 struct tc_gred_sopt *sopt;
340 int i;
341
342 if (dps == NULL)
343 return -EINVAL;
344
345 sopt = nla_data(dps);
346
347 if (sopt->DPs > MAX_DPs || sopt->DPs == 0 || sopt->def_DP >= sopt->DPs)
348 return -EINVAL;
349
350 sch_tree_lock(sch);
351 table->DPs = sopt->DPs;
352 table->def = sopt->def_DP;
353 table->red_flags = sopt->flags;
354
355 /*
356 * Every entry point to GRED is synchronized with the above code
357 * and the DP is checked against DPs, i.e. shadowed VQs can no
358 * longer be found so we can unlock right here.
359 */
360 sch_tree_unlock(sch);
361
362 if (sopt->grio) {
363 gred_enable_rio_mode(table);
364 gred_disable_wred_mode(table);
365 if (gred_wred_mode_check(sch))
366 gred_enable_wred_mode(table);
367 } else {
368 gred_disable_rio_mode(table);
369 gred_disable_wred_mode(table);
370 }
371
372 for (i = table->DPs; i < MAX_DPs; i++) {
373 if (table->tab[i]) {
374 pr_warn("GRED: Warning: Destroying shadowed VQ 0x%x\n",
375 i);
376 gred_destroy_vq(table->tab[i]);
377 table->tab[i] = NULL;
378 }
379 }
380
381 return 0;
382}
383
384static inline int gred_change_vq(struct Qdisc *sch, int dp,
385 struct tc_gred_qopt *ctl, int prio,
386 u8 *stab, u32 max_P,
387 struct gred_sched_data **prealloc)
388{
389 struct gred_sched *table = qdisc_priv(sch);
390 struct gred_sched_data *q = table->tab[dp];
391
392 if (!q) {
393 table->tab[dp] = q = *prealloc;
394 *prealloc = NULL;
395 if (!q)
396 return -ENOMEM;
397 }
398
399 q->DP = dp;
400 q->prio = prio;
401 if (ctl->limit > sch->limit)
402 q->limit = sch->limit;
403 else
404 q->limit = ctl->limit;
405
406 if (q->backlog == 0)
407 red_end_of_idle_period(&q->vars);
408
409 red_set_parms(&q->parms,
410 ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog,
411 ctl->Scell_log, stab, max_P);
412 red_set_vars(&q->vars);
413 return 0;
414}
415
416static const struct nla_policy gred_policy[TCA_GRED_MAX + 1] = {
417 [TCA_GRED_PARMS] = { .len = sizeof(struct tc_gred_qopt) },
418 [TCA_GRED_STAB] = { .len = 256 },
419 [TCA_GRED_DPS] = { .len = sizeof(struct tc_gred_sopt) },
420 [TCA_GRED_MAX_P] = { .type = NLA_U32 },
421 [TCA_GRED_LIMIT] = { .type = NLA_U32 },
422};
423
424static int gred_change(struct Qdisc *sch, struct nlattr *opt)
425{
426 struct gred_sched *table = qdisc_priv(sch);
427 struct tc_gred_qopt *ctl;
428 struct nlattr *tb[TCA_GRED_MAX + 1];
429 int err, prio = GRED_DEF_PRIO;
430 u8 *stab;
431 u32 max_P;
432 struct gred_sched_data *prealloc;
433
434 if (opt == NULL)
435 return -EINVAL;
436
437 err = nla_parse_nested(tb, TCA_GRED_MAX, opt, gred_policy);
438 if (err < 0)
439 return err;
440
441 if (tb[TCA_GRED_PARMS] == NULL && tb[TCA_GRED_STAB] == NULL) {
442 if (tb[TCA_GRED_LIMIT] != NULL)
443 sch->limit = nla_get_u32(tb[TCA_GRED_LIMIT]);
444 return gred_change_table_def(sch, opt);
445 }
446
447 if (tb[TCA_GRED_PARMS] == NULL ||
448 tb[TCA_GRED_STAB] == NULL ||
449 tb[TCA_GRED_LIMIT] != NULL)
450 return -EINVAL;
451
452 max_P = tb[TCA_GRED_MAX_P] ? nla_get_u32(tb[TCA_GRED_MAX_P]) : 0;
453
454 err = -EINVAL;
455 ctl = nla_data(tb[TCA_GRED_PARMS]);
456 stab = nla_data(tb[TCA_GRED_STAB]);
457
458 if (ctl->DP >= table->DPs)
459 goto errout;
460
461 if (gred_rio_mode(table)) {
462 if (ctl->prio == 0) {
463 int def_prio = GRED_DEF_PRIO;
464
465 if (table->tab[table->def])
466 def_prio = table->tab[table->def]->prio;
467
468 printk(KERN_DEBUG "GRED: DP %u does not have a prio "
469 "setting default to %d\n", ctl->DP, def_prio);
470
471 prio = def_prio;
472 } else
473 prio = ctl->prio;
474 }
475
476 prealloc = kzalloc(sizeof(*prealloc), GFP_KERNEL);
477 sch_tree_lock(sch);
478
479 err = gred_change_vq(sch, ctl->DP, ctl, prio, stab, max_P, &prealloc);
480 if (err < 0)
481 goto errout_locked;
482
483 if (gred_rio_mode(table)) {
484 gred_disable_wred_mode(table);
485 if (gred_wred_mode_check(sch))
486 gred_enable_wred_mode(table);
487 }
488
489 err = 0;
490
491errout_locked:
492 sch_tree_unlock(sch);
493 kfree(prealloc);
494errout:
495 return err;
496}
497
498static int gred_init(struct Qdisc *sch, struct nlattr *opt)
499{
500 struct nlattr *tb[TCA_GRED_MAX + 1];
501 int err;
502
503 if (opt == NULL)
504 return -EINVAL;
505
506 err = nla_parse_nested(tb, TCA_GRED_MAX, opt, gred_policy);
507 if (err < 0)
508 return err;
509
510 if (tb[TCA_GRED_PARMS] || tb[TCA_GRED_STAB])
511 return -EINVAL;
512
513 if (tb[TCA_GRED_LIMIT])
514 sch->limit = nla_get_u32(tb[TCA_GRED_LIMIT]);
515 else
516 sch->limit = qdisc_dev(sch)->tx_queue_len
517 * psched_mtu(qdisc_dev(sch));
518
519 return gred_change_table_def(sch, tb[TCA_GRED_DPS]);
520}
521
522static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
523{
524 struct gred_sched *table = qdisc_priv(sch);
525 struct nlattr *parms, *opts = NULL;
526 int i;
527 u32 max_p[MAX_DPs];
528 struct tc_gred_sopt sopt = {
529 .DPs = table->DPs,
530 .def_DP = table->def,
531 .grio = gred_rio_mode(table),
532 .flags = table->red_flags,
533 };
534
535 opts = nla_nest_start(skb, TCA_OPTIONS);
536 if (opts == NULL)
537 goto nla_put_failure;
538 if (nla_put(skb, TCA_GRED_DPS, sizeof(sopt), &sopt))
539 goto nla_put_failure;
540
541 for (i = 0; i < MAX_DPs; i++) {
542 struct gred_sched_data *q = table->tab[i];
543
544 max_p[i] = q ? q->parms.max_P : 0;
545 }
546 if (nla_put(skb, TCA_GRED_MAX_P, sizeof(max_p), max_p))
547 goto nla_put_failure;
548
549 if (nla_put_u32(skb, TCA_GRED_LIMIT, sch->limit))
550 goto nla_put_failure;
551
552 parms = nla_nest_start(skb, TCA_GRED_PARMS);
553 if (parms == NULL)
554 goto nla_put_failure;
555
556 for (i = 0; i < MAX_DPs; i++) {
557 struct gred_sched_data *q = table->tab[i];
558 struct tc_gred_qopt opt;
559 unsigned long qavg;
560
561 memset(&opt, 0, sizeof(opt));
562
563 if (!q) {
564 /* hack -- fix at some point with proper message
565 This is how we indicate to tc that there is no VQ
566 at this DP */
567
568 opt.DP = MAX_DPs + i;
569 goto append_opt;
570 }
571
572 opt.limit = q->limit;
573 opt.DP = q->DP;
574 opt.backlog = gred_backlog(table, q, sch);
575 opt.prio = q->prio;
576 opt.qth_min = q->parms.qth_min >> q->parms.Wlog;
577 opt.qth_max = q->parms.qth_max >> q->parms.Wlog;
578 opt.Wlog = q->parms.Wlog;
579 opt.Plog = q->parms.Plog;
580 opt.Scell_log = q->parms.Scell_log;
581 opt.other = q->stats.other;
582 opt.early = q->stats.prob_drop;
583 opt.forced = q->stats.forced_drop;
584 opt.pdrop = q->stats.pdrop;
585 opt.packets = q->packetsin;
586 opt.bytesin = q->bytesin;
587
588 if (gred_wred_mode(table))
589 gred_load_wred_set(table, q);
590
591 qavg = red_calc_qavg(&q->parms, &q->vars,
592 q->vars.qavg >> q->parms.Wlog);
593 opt.qave = qavg >> q->parms.Wlog;
594
595append_opt:
596 if (nla_append(skb, sizeof(opt), &opt) < 0)
597 goto nla_put_failure;
598 }
599
600 nla_nest_end(skb, parms);
601
602 return nla_nest_end(skb, opts);
603
604nla_put_failure:
605 nla_nest_cancel(skb, opts);
606 return -EMSGSIZE;
607}
608
609static void gred_destroy(struct Qdisc *sch)
610{
611 struct gred_sched *table = qdisc_priv(sch);
612 int i;
613
614 for (i = 0; i < table->DPs; i++) {
615 if (table->tab[i])
616 gred_destroy_vq(table->tab[i]);
617 }
618}
619
620static struct Qdisc_ops gred_qdisc_ops __read_mostly = {
621 .id = "gred",
622 .priv_size = sizeof(struct gred_sched),
623 .enqueue = gred_enqueue,
624 .dequeue = gred_dequeue,
625 .peek = qdisc_peek_head,
626 .drop = gred_drop,
627 .init = gred_init,
628 .reset = gred_reset,
629 .destroy = gred_destroy,
630 .change = gred_change,
631 .dump = gred_dump,
632 .owner = THIS_MODULE,
633};
634
635static int __init gred_module_init(void)
636{
637 return register_qdisc(&gred_qdisc_ops);
638}
639
640static void __exit gred_module_exit(void)
641{
642 unregister_qdisc(&gred_qdisc_ops);
643}
644
645module_init(gred_module_init)
646module_exit(gred_module_exit)
647
648MODULE_LICENSE("GPL");