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x86/speculation/mds: Fix documentation typo
[linux/fpc-iii.git] / net / sched / sch_api.c
blob7b4270987ac16876d0adf95ff01d12ee03066be0
1 /*
2 * net/sched/sch_api.c Packet scheduler API.
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, or (at your option) any later version.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 * Fixes:
12 *
13 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired.
14 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
15 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support
16 */
17
18 #include <linux/module.h>
19 #include <linux/types.h>
20 #include <linux/kernel.h>
21 #include <linux/string.h>
22 #include <linux/errno.h>
23 #include <linux/skbuff.h>
24 #include <linux/init.h>
25 #include <linux/proc_fs.h>
26 #include <linux/seq_file.h>
27 #include <linux/kmod.h>
28 #include <linux/list.h>
29 #include <linux/hrtimer.h>
30 #include <linux/lockdep.h>
31 #include <linux/slab.h>
32 #include <linux/hashtable.h>
33
34 #include <net/net_namespace.h>
35 #include <net/sock.h>
36 #include <net/netlink.h>
37 #include <net/pkt_sched.h>
38 #include <net/pkt_cls.h>
39
40 /*
41
42 Short review.
43 -------------
44
45 This file consists of two interrelated parts:
46
47 1. queueing disciplines manager frontend.
48 2. traffic classes manager frontend.
49
50 Generally, queueing discipline ("qdisc") is a black box,
51 which is able to enqueue packets and to dequeue them (when
52 device is ready to send something) in order and at times
53 determined by algorithm hidden in it.
54
55 qdisc's are divided to two categories:
56 - "queues", which have no internal structure visible from outside.
57 - "schedulers", which split all the packets to "traffic classes",
58 using "packet classifiers" (look at cls_api.c)
59
60 In turn, classes may have child qdiscs (as rule, queues)
61 attached to them etc. etc. etc.
62
63 The goal of the routines in this file is to translate
64 information supplied by user in the form of handles
65 to more intelligible for kernel form, to make some sanity
66 checks and part of work, which is common to all qdiscs
67 and to provide rtnetlink notifications.
68
69 All real intelligent work is done inside qdisc modules.
70
71
72
73 Every discipline has two major routines: enqueue and dequeue.
74
75 ---dequeue
76
77 dequeue usually returns a skb to send. It is allowed to return NULL,
78 but it does not mean that queue is empty, it just means that
79 discipline does not want to send anything this time.
80 Queue is really empty if q->q.qlen == 0.
81 For complicated disciplines with multiple queues q->q is not
82 real packet queue, but however q->q.qlen must be valid.
83
84 ---enqueue
85
86 enqueue returns 0, if packet was enqueued successfully.
87 If packet (this one or another one) was dropped, it returns
88 not zero error code.
89 NET_XMIT_DROP - this packet dropped
90 Expected action: do not backoff, but wait until queue will clear.
91 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
92 Expected action: backoff or ignore
93
94 Auxiliary routines:
95
96 ---peek
97
98 like dequeue but without removing a packet from the queue
99
100 ---reset
101
102 returns qdisc to initial state: purge all buffers, clear all
103 timers, counters (except for statistics) etc.
104
105 ---init
106
107 initializes newly created qdisc.
108
109 ---destroy
110
111 destroys resources allocated by init and during lifetime of qdisc.
112
113 ---change
114
115 changes qdisc parameters.
116 */
117
118 /* Protects list of registered TC modules. It is pure SMP lock. */
119 static DEFINE_RWLOCK(qdisc_mod_lock);
120
121
122 /************************************************
123 * Queueing disciplines manipulation. *
124 ************************************************/
125
126
127 /* The list of all installed queueing disciplines. */
128
129 static struct Qdisc_ops *qdisc_base;
130
131 /* Register/unregister queueing discipline */
132
133 int register_qdisc(struct Qdisc_ops *qops)
134 {
135 struct Qdisc_ops *q, **qp;
136 int rc = -EEXIST;
137
138 write_lock(&qdisc_mod_lock);
139 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
140 if (!strcmp(qops->id, q->id))
141 goto out;
142
143 if (qops->enqueue == NULL)
144 qops->enqueue = noop_qdisc_ops.enqueue;
145 if (qops->peek == NULL) {
146 if (qops->dequeue == NULL)
147 qops->peek = noop_qdisc_ops.peek;
148 else
149 goto out_einval;
150 }
151 if (qops->dequeue == NULL)
152 qops->dequeue = noop_qdisc_ops.dequeue;
153
154 if (qops->cl_ops) {
155 const struct Qdisc_class_ops *cops = qops->cl_ops;
156
157 if (!(cops->find && cops->walk && cops->leaf))
158 goto out_einval;
159
160 if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf))
161 goto out_einval;
162 }
163
164 qops->next = NULL;
165 *qp = qops;
166 rc = 0;
167 out:
168 write_unlock(&qdisc_mod_lock);
169 return rc;
170
171 out_einval:
172 rc = -EINVAL;
173 goto out;
174 }
175 EXPORT_SYMBOL(register_qdisc);
176
177 int unregister_qdisc(struct Qdisc_ops *qops)
178 {
179 struct Qdisc_ops *q, **qp;
180 int err = -ENOENT;
181
182 write_lock(&qdisc_mod_lock);
183 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
184 if (q == qops)
185 break;
186 if (q) {
187 *qp = q->next;
188 q->next = NULL;
189 err = 0;
190 }
191 write_unlock(&qdisc_mod_lock);
192 return err;
193 }
194 EXPORT_SYMBOL(unregister_qdisc);
195
196 /* Get default qdisc if not otherwise specified */
197 void qdisc_get_default(char *name, size_t len)
198 {
199 read_lock(&qdisc_mod_lock);
200 strlcpy(name, default_qdisc_ops->id, len);
201 read_unlock(&qdisc_mod_lock);
202 }
203
204 static struct Qdisc_ops *qdisc_lookup_default(const char *name)
205 {
206 struct Qdisc_ops *q = NULL;
207
208 for (q = qdisc_base; q; q = q->next) {
209 if (!strcmp(name, q->id)) {
210 if (!try_module_get(q->owner))
211 q = NULL;
212 break;
213 }
214 }
215
216 return q;
217 }
218
219 /* Set new default qdisc to use */
220 int qdisc_set_default(const char *name)
221 {
222 const struct Qdisc_ops *ops;
223
224 if (!capable(CAP_NET_ADMIN))
225 return -EPERM;
226
227 write_lock(&qdisc_mod_lock);
228 ops = qdisc_lookup_default(name);
229 if (!ops) {
230 /* Not found, drop lock and try to load module */
231 write_unlock(&qdisc_mod_lock);
232 request_module("sch_%s", name);
233 write_lock(&qdisc_mod_lock);
234
235 ops = qdisc_lookup_default(name);
236 }
237
238 if (ops) {
239 /* Set new default */
240 module_put(default_qdisc_ops->owner);
241 default_qdisc_ops = ops;
242 }
243 write_unlock(&qdisc_mod_lock);
244
245 return ops ? 0 : -ENOENT;
246 }
247
248 #ifdef CONFIG_NET_SCH_DEFAULT
249 /* Set default value from kernel config */
250 static int __init sch_default_qdisc(void)
251 {
252 return qdisc_set_default(CONFIG_DEFAULT_NET_SCH);
253 }
254 late_initcall(sch_default_qdisc);
255 #endif
256
257 /* We know handle. Find qdisc among all qdisc's attached to device
258 * (root qdisc, all its children, children of children etc.)
259 * Note: caller either uses rtnl or rcu_read_lock()
260 */
261
262 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
263 {
264 struct Qdisc *q;
265
266 if (!qdisc_dev(root))
267 return (root->handle == handle ? root : NULL);
268
269 if (!(root->flags & TCQ_F_BUILTIN) &&
270 root->handle == handle)
271 return root;
272
273 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle) {
274 if (q->handle == handle)
275 return q;
276 }
277 return NULL;
278 }
279
280 void qdisc_hash_add(struct Qdisc *q, bool invisible)
281 {
282 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
283 ASSERT_RTNL();
284 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
285 if (invisible)
286 q->flags |= TCQ_F_INVISIBLE;
287 }
288 }
289 EXPORT_SYMBOL(qdisc_hash_add);
290
291 void qdisc_hash_del(struct Qdisc *q)
292 {
293 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
294 ASSERT_RTNL();
295 hash_del_rcu(&q->hash);
296 }
297 }
298 EXPORT_SYMBOL(qdisc_hash_del);
299
300 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
301 {
302 struct Qdisc *q;
303
304 if (!handle)
305 return NULL;
306 q = qdisc_match_from_root(dev->qdisc, handle);
307 if (q)
308 goto out;
309
310 if (dev_ingress_queue(dev))
311 q = qdisc_match_from_root(
312 dev_ingress_queue(dev)->qdisc_sleeping,
313 handle);
314 out:
315 return q;
316 }
317
318 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
319 {
320 unsigned long cl;
321 struct Qdisc *leaf;
322 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
323
324 if (cops == NULL)
325 return NULL;
326 cl = cops->find(p, classid);
327
328 if (cl == 0)
329 return NULL;
330 leaf = cops->leaf(p, cl);
331 return leaf;
332 }
333
334 /* Find queueing discipline by name */
335
336 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
337 {
338 struct Qdisc_ops *q = NULL;
339
340 if (kind) {
341 read_lock(&qdisc_mod_lock);
342 for (q = qdisc_base; q; q = q->next) {
343 if (nla_strcmp(kind, q->id) == 0) {
344 if (!try_module_get(q->owner))
345 q = NULL;
346 break;
347 }
348 }
349 read_unlock(&qdisc_mod_lock);
350 }
351 return q;
352 }
353
354 /* The linklayer setting were not transferred from iproute2, in older
355 * versions, and the rate tables lookup systems have been dropped in
356 * the kernel. To keep backward compatible with older iproute2 tc
357 * utils, we detect the linklayer setting by detecting if the rate
358 * table were modified.
359 *
360 * For linklayer ATM table entries, the rate table will be aligned to
361 * 48 bytes, thus some table entries will contain the same value. The
362 * mpu (min packet unit) is also encoded into the old rate table, thus
363 * starting from the mpu, we find low and high table entries for
364 * mapping this cell. If these entries contain the same value, when
365 * the rate tables have been modified for linklayer ATM.
366 *
367 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
368 * and then roundup to the next cell, calc the table entry one below,
369 * and compare.
370 */
371 static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
372 {
373 int low = roundup(r->mpu, 48);
374 int high = roundup(low+1, 48);
375 int cell_low = low >> r->cell_log;
376 int cell_high = (high >> r->cell_log) - 1;
377
378 /* rtab is too inaccurate at rates > 100Mbit/s */
379 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
380 pr_debug("TC linklayer: Giving up ATM detection\n");
381 return TC_LINKLAYER_ETHERNET;
382 }
383
384 if ((cell_high > cell_low) && (cell_high < 256)
385 && (rtab[cell_low] == rtab[cell_high])) {
386 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
387 cell_low, cell_high, rtab[cell_high]);
388 return TC_LINKLAYER_ATM;
389 }
390 return TC_LINKLAYER_ETHERNET;
391 }
392
393 static struct qdisc_rate_table *qdisc_rtab_list;
394
395 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
396 struct nlattr *tab)
397 {
398 struct qdisc_rate_table *rtab;
399
400 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
401 nla_len(tab) != TC_RTAB_SIZE)
402 return NULL;
403
404 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
405 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
406 !memcmp(&rtab->data, nla_data(tab), 1024)) {
407 rtab->refcnt++;
408 return rtab;
409 }
410 }
411
412 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
413 if (rtab) {
414 rtab->rate = *r;
415 rtab->refcnt = 1;
416 memcpy(rtab->data, nla_data(tab), 1024);
417 if (r->linklayer == TC_LINKLAYER_UNAWARE)
418 r->linklayer = __detect_linklayer(r, rtab->data);
419 rtab->next = qdisc_rtab_list;
420 qdisc_rtab_list = rtab;
421 }
422 return rtab;
423 }
424 EXPORT_SYMBOL(qdisc_get_rtab);
425
426 void qdisc_put_rtab(struct qdisc_rate_table *tab)
427 {
428 struct qdisc_rate_table *rtab, **rtabp;
429
430 if (!tab || --tab->refcnt)
431 return;
432
433 for (rtabp = &qdisc_rtab_list;
434 (rtab = *rtabp) != NULL;
435 rtabp = &rtab->next) {
436 if (rtab == tab) {
437 *rtabp = rtab->next;
438 kfree(rtab);
439 return;
440 }
441 }
442 }
443 EXPORT_SYMBOL(qdisc_put_rtab);
444
445 static LIST_HEAD(qdisc_stab_list);
446
447 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
448 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
449 [TCA_STAB_DATA] = { .type = NLA_BINARY },
450 };
451
452 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
453 {
454 struct nlattr *tb[TCA_STAB_MAX + 1];
455 struct qdisc_size_table *stab;
456 struct tc_sizespec *s;
457 unsigned int tsize = 0;
458 u16 *tab = NULL;
459 int err;
460
461 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy, NULL);
462 if (err < 0)
463 return ERR_PTR(err);
464 if (!tb[TCA_STAB_BASE])
465 return ERR_PTR(-EINVAL);
466
467 s = nla_data(tb[TCA_STAB_BASE]);
468
469 if (s->tsize > 0) {
470 if (!tb[TCA_STAB_DATA])
471 return ERR_PTR(-EINVAL);
472 tab = nla_data(tb[TCA_STAB_DATA]);
473 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
474 }
475
476 if (tsize != s->tsize || (!tab && tsize > 0))
477 return ERR_PTR(-EINVAL);
478
479 list_for_each_entry(stab, &qdisc_stab_list, list) {
480 if (memcmp(&stab->szopts, s, sizeof(*s)))
481 continue;
482 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
483 continue;
484 stab->refcnt++;
485 return stab;
486 }
487
488 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
489 if (!stab)
490 return ERR_PTR(-ENOMEM);
491
492 stab->refcnt = 1;
493 stab->szopts = *s;
494 if (tsize > 0)
495 memcpy(stab->data, tab, tsize * sizeof(u16));
496
497 list_add_tail(&stab->list, &qdisc_stab_list);
498
499 return stab;
500 }
501
502 static void stab_kfree_rcu(struct rcu_head *head)
503 {
504 kfree(container_of(head, struct qdisc_size_table, rcu));
505 }
506
507 void qdisc_put_stab(struct qdisc_size_table *tab)
508 {
509 if (!tab)
510 return;
511
512 if (--tab->refcnt == 0) {
513 list_del(&tab->list);
514 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
515 }
516 }
517 EXPORT_SYMBOL(qdisc_put_stab);
518
519 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
520 {
521 struct nlattr *nest;
522
523 nest = nla_nest_start(skb, TCA_STAB);
524 if (nest == NULL)
525 goto nla_put_failure;
526 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
527 goto nla_put_failure;
528 nla_nest_end(skb, nest);
529
530 return skb->len;
531
532 nla_put_failure:
533 return -1;
534 }
535
536 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
537 const struct qdisc_size_table *stab)
538 {
539 int pkt_len, slot;
540
541 pkt_len = skb->len + stab->szopts.overhead;
542 if (unlikely(!stab->szopts.tsize))
543 goto out;
544
545 slot = pkt_len + stab->szopts.cell_align;
546 if (unlikely(slot < 0))
547 slot = 0;
548
549 slot >>= stab->szopts.cell_log;
550 if (likely(slot < stab->szopts.tsize))
551 pkt_len = stab->data[slot];
552 else
553 pkt_len = stab->data[stab->szopts.tsize - 1] *
554 (slot / stab->szopts.tsize) +
555 stab->data[slot % stab->szopts.tsize];
556
557 pkt_len <<= stab->szopts.size_log;
558 out:
559 if (unlikely(pkt_len < 1))
560 pkt_len = 1;
561 qdisc_skb_cb(skb)->pkt_len = pkt_len;
562 }
563 EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
564
565 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
566 {
567 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
568 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
569 txt, qdisc->ops->id, qdisc->handle >> 16);
570 qdisc->flags |= TCQ_F_WARN_NONWC;
571 }
572 }
573 EXPORT_SYMBOL(qdisc_warn_nonwc);
574
575 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
576 {
577 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
578 timer);
579
580 rcu_read_lock();
581 __netif_schedule(qdisc_root(wd->qdisc));
582 rcu_read_unlock();
583
584 return HRTIMER_NORESTART;
585 }
586
587 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
588 {
589 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
590 wd->timer.function = qdisc_watchdog;
591 wd->qdisc = qdisc;
592 }
593 EXPORT_SYMBOL(qdisc_watchdog_init);
594
595 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
596 {
597 if (test_bit(__QDISC_STATE_DEACTIVATED,
598 &qdisc_root_sleeping(wd->qdisc)->state))
599 return;
600
601 if (wd->last_expires == expires)
602 return;
603
604 wd->last_expires = expires;
605 hrtimer_start(&wd->timer,
606 ns_to_ktime(expires),
607 HRTIMER_MODE_ABS_PINNED);
608 }
609 EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
610
611 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
612 {
613 hrtimer_cancel(&wd->timer);
614 }
615 EXPORT_SYMBOL(qdisc_watchdog_cancel);
616
617 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
618 {
619 struct hlist_head *h;
620 unsigned int i;
621
622 h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL);
623
624 if (h != NULL) {
625 for (i = 0; i < n; i++)
626 INIT_HLIST_HEAD(&h[i]);
627 }
628 return h;
629 }
630
631 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
632 {
633 struct Qdisc_class_common *cl;
634 struct hlist_node *next;
635 struct hlist_head *nhash, *ohash;
636 unsigned int nsize, nmask, osize;
637 unsigned int i, h;
638
639 /* Rehash when load factor exceeds 0.75 */
640 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
641 return;
642 nsize = clhash->hashsize * 2;
643 nmask = nsize - 1;
644 nhash = qdisc_class_hash_alloc(nsize);
645 if (nhash == NULL)
646 return;
647
648 ohash = clhash->hash;
649 osize = clhash->hashsize;
650
651 sch_tree_lock(sch);
652 for (i = 0; i < osize; i++) {
653 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
654 h = qdisc_class_hash(cl->classid, nmask);
655 hlist_add_head(&cl->hnode, &nhash[h]);
656 }
657 }
658 clhash->hash = nhash;
659 clhash->hashsize = nsize;
660 clhash->hashmask = nmask;
661 sch_tree_unlock(sch);
662
663 kvfree(ohash);
664 }
665 EXPORT_SYMBOL(qdisc_class_hash_grow);
666
667 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
668 {
669 unsigned int size = 4;
670
671 clhash->hash = qdisc_class_hash_alloc(size);
672 if (clhash->hash == NULL)
673 return -ENOMEM;
674 clhash->hashsize = size;
675 clhash->hashmask = size - 1;
676 clhash->hashelems = 0;
677 return 0;
678 }
679 EXPORT_SYMBOL(qdisc_class_hash_init);
680
681 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
682 {
683 kvfree(clhash->hash);
684 }
685 EXPORT_SYMBOL(qdisc_class_hash_destroy);
686
687 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
688 struct Qdisc_class_common *cl)
689 {
690 unsigned int h;
691
692 INIT_HLIST_NODE(&cl->hnode);
693 h = qdisc_class_hash(cl->classid, clhash->hashmask);
694 hlist_add_head(&cl->hnode, &clhash->hash[h]);
695 clhash->hashelems++;
696 }
697 EXPORT_SYMBOL(qdisc_class_hash_insert);
698
699 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
700 struct Qdisc_class_common *cl)
701 {
702 hlist_del(&cl->hnode);
703 clhash->hashelems--;
704 }
705 EXPORT_SYMBOL(qdisc_class_hash_remove);
706
707 /* Allocate an unique handle from space managed by kernel
708 * Possible range is [8000-FFFF]:0000 (0x8000 values)
709 */
710 static u32 qdisc_alloc_handle(struct net_device *dev)
711 {
712 int i = 0x8000;
713 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
714
715 do {
716 autohandle += TC_H_MAKE(0x10000U, 0);
717 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
718 autohandle = TC_H_MAKE(0x80000000U, 0);
719 if (!qdisc_lookup(dev, autohandle))
720 return autohandle;
721 cond_resched();
722 } while (--i > 0);
723
724 return 0;
725 }
726
727 void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,
728 unsigned int len)
729 {
730 const struct Qdisc_class_ops *cops;
731 unsigned long cl;
732 u32 parentid;
733 bool notify;
734 int drops;
735
736 if (n == 0 && len == 0)
737 return;
738 drops = max_t(int, n, 0);
739 rcu_read_lock();
740 while ((parentid = sch->parent)) {
741 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
742 break;
743
744 if (sch->flags & TCQ_F_NOPARENT)
745 break;
746 /* Notify parent qdisc only if child qdisc becomes empty.
747 *
748 * If child was empty even before update then backlog
749 * counter is screwed and we skip notification because
750 * parent class is already passive.
751 */
752 notify = !sch->q.qlen && !WARN_ON_ONCE(!n);
753 /* TODO: perform the search on a per txq basis */
754 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
755 if (sch == NULL) {
756 WARN_ON_ONCE(parentid != TC_H_ROOT);
757 break;
758 }
759 cops = sch->ops->cl_ops;
760 if (notify && cops->qlen_notify) {
761 cl = cops->find(sch, parentid);
762 cops->qlen_notify(sch, cl);
763 }
764 sch->q.qlen -= n;
765 sch->qstats.backlog -= len;
766 __qdisc_qstats_drop(sch, drops);
767 }
768 rcu_read_unlock();
769 }
770 EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
771
772 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
773 u32 portid, u32 seq, u16 flags, int event)
774 {
775 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
776 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
777 struct tcmsg *tcm;
778 struct nlmsghdr *nlh;
779 unsigned char *b = skb_tail_pointer(skb);
780 struct gnet_dump d;
781 struct qdisc_size_table *stab;
782 __u32 qlen;
783
784 cond_resched();
785 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
786 if (!nlh)
787 goto out_nlmsg_trim;
788 tcm = nlmsg_data(nlh);
789 tcm->tcm_family = AF_UNSPEC;
790 tcm->tcm__pad1 = 0;
791 tcm->tcm__pad2 = 0;
792 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
793 tcm->tcm_parent = clid;
794 tcm->tcm_handle = q->handle;
795 tcm->tcm_info = refcount_read(&q->refcnt);
796 if (nla_put_string(skb, TCA_KIND, q->ops->id))
797 goto nla_put_failure;
798 if (q->ops->dump && q->ops->dump(q, skb) < 0)
799 goto nla_put_failure;
800 qlen = q->q.qlen;
801
802 stab = rtnl_dereference(q->stab);
803 if (stab && qdisc_dump_stab(skb, stab) < 0)
804 goto nla_put_failure;
805
806 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
807 NULL, &d, TCA_PAD) < 0)
808 goto nla_put_failure;
809
810 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
811 goto nla_put_failure;
812
813 if (qdisc_is_percpu_stats(q)) {
814 cpu_bstats = q->cpu_bstats;
815 cpu_qstats = q->cpu_qstats;
816 }
817
818 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(q),
819 &d, cpu_bstats, &q->bstats) < 0 ||
820 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
821 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
822 goto nla_put_failure;
823
824 if (gnet_stats_finish_copy(&d) < 0)
825 goto nla_put_failure;
826
827 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
828 return skb->len;
829
830 out_nlmsg_trim:
831 nla_put_failure:
832 nlmsg_trim(skb, b);
833 return -1;
834 }
835
836 static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible)
837 {
838 if (q->flags & TCQ_F_BUILTIN)
839 return true;
840 if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible)
841 return true;
842
843 return false;
844 }
845
846 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
847 struct nlmsghdr *n, u32 clid,
848 struct Qdisc *old, struct Qdisc *new)
849 {
850 struct sk_buff *skb;
851 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
852
853 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
854 if (!skb)
855 return -ENOBUFS;
856
857 if (old && !tc_qdisc_dump_ignore(old, false)) {
858 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
859 0, RTM_DELQDISC) < 0)
860 goto err_out;
861 }
862 if (new && !tc_qdisc_dump_ignore(new, false)) {
863 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
864 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
865 goto err_out;
866 }
867
868 if (skb->len)
869 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
870 n->nlmsg_flags & NLM_F_ECHO);
871
872 err_out:
873 kfree_skb(skb);
874 return -EINVAL;
875 }
876
877 static void notify_and_destroy(struct net *net, struct sk_buff *skb,
878 struct nlmsghdr *n, u32 clid,
879 struct Qdisc *old, struct Qdisc *new)
880 {
881 if (new || old)
882 qdisc_notify(net, skb, n, clid, old, new);
883
884 if (old)
885 qdisc_destroy(old);
886 }
887
888 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
889 * to device "dev".
890 *
891 * When appropriate send a netlink notification using 'skb'
892 * and "n".
893 *
894 * On success, destroy old qdisc.
895 */
896
897 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
898 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
899 struct Qdisc *new, struct Qdisc *old)
900 {
901 struct Qdisc *q = old;
902 struct net *net = dev_net(dev);
903 int err = 0;
904
905 if (parent == NULL) {
906 unsigned int i, num_q, ingress;
907
908 ingress = 0;
909 num_q = dev->num_tx_queues;
910 if ((q && q->flags & TCQ_F_INGRESS) ||
911 (new && new->flags & TCQ_F_INGRESS)) {
912 num_q = 1;
913 ingress = 1;
914 if (!dev_ingress_queue(dev))
915 return -ENOENT;
916 }
917
918 if (dev->flags & IFF_UP)
919 dev_deactivate(dev);
920
921 if (new && new->ops->attach)
922 goto skip;
923
924 for (i = 0; i < num_q; i++) {
925 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
926
927 if (!ingress)
928 dev_queue = netdev_get_tx_queue(dev, i);
929
930 old = dev_graft_qdisc(dev_queue, new);
931 if (new && i > 0)
932 qdisc_refcount_inc(new);
933
934 if (!ingress)
935 qdisc_destroy(old);
936 }
937
938 skip:
939 if (!ingress) {
940 notify_and_destroy(net, skb, n, classid,
941 dev->qdisc, new);
942 if (new && !new->ops->attach)
943 qdisc_refcount_inc(new);
944 dev->qdisc = new ? : &noop_qdisc;
945
946 if (new && new->ops->attach)
947 new->ops->attach(new);
948 } else {
949 notify_and_destroy(net, skb, n, classid, old, new);
950 }
951
952 if (dev->flags & IFF_UP)
953 dev_activate(dev);
954 } else {
955 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
956
957 err = -EOPNOTSUPP;
958 if (cops && cops->graft) {
959 unsigned long cl = cops->find(parent, classid);
960
961 if (cl)
962 err = cops->graft(parent, cl, new, &old);
963 else
964 err = -ENOENT;
965 }
966 if (!err)
967 notify_and_destroy(net, skb, n, classid, old, new);
968 }
969 return err;
970 }
971
972 /* lockdep annotation is needed for ingress; egress gets it only for name */
973 static struct lock_class_key qdisc_tx_lock;
974 static struct lock_class_key qdisc_rx_lock;
975
976 /*
977 Allocate and initialize new qdisc.
978
979 Parameters are passed via opt.
980 */
981
982 static struct Qdisc *qdisc_create(struct net_device *dev,
983 struct netdev_queue *dev_queue,
984 struct Qdisc *p, u32 parent, u32 handle,
985 struct nlattr **tca, int *errp)
986 {
987 int err;
988 struct nlattr *kind = tca[TCA_KIND];
989 struct Qdisc *sch;
990 struct Qdisc_ops *ops;
991 struct qdisc_size_table *stab;
992
993 ops = qdisc_lookup_ops(kind);
994 #ifdef CONFIG_MODULES
995 if (ops == NULL && kind != NULL) {
996 char name[IFNAMSIZ];
997 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
998 /* We dropped the RTNL semaphore in order to
999 * perform the module load. So, even if we
1000 * succeeded in loading the module we have to
1001 * tell the caller to replay the request. We
1002 * indicate this using -EAGAIN.
1003 * We replay the request because the device may
1004 * go away in the mean time.
1005 */
1006 rtnl_unlock();
1007 request_module("sch_%s", name);
1008 rtnl_lock();
1009 ops = qdisc_lookup_ops(kind);
1010 if (ops != NULL) {
1011 /* We will try again qdisc_lookup_ops,
1012 * so don't keep a reference.
1013 */
1014 module_put(ops->owner);
1015 err = -EAGAIN;
1016 goto err_out;
1017 }
1018 }
1019 }
1020 #endif
1021
1022 err = -ENOENT;
1023 if (ops == NULL)
1024 goto err_out;
1025
1026 sch = qdisc_alloc(dev_queue, ops);
1027 if (IS_ERR(sch)) {
1028 err = PTR_ERR(sch);
1029 goto err_out2;
1030 }
1031
1032 sch->parent = parent;
1033
1034 if (handle == TC_H_INGRESS) {
1035 sch->flags |= TCQ_F_INGRESS;
1036 handle = TC_H_MAKE(TC_H_INGRESS, 0);
1037 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
1038 } else {
1039 if (handle == 0) {
1040 handle = qdisc_alloc_handle(dev);
1041 err = -ENOMEM;
1042 if (handle == 0)
1043 goto err_out3;
1044 }
1045 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
1046 if (!netif_is_multiqueue(dev))
1047 sch->flags |= TCQ_F_ONETXQUEUE;
1048 }
1049
1050 sch->handle = handle;
1051
1052 /* This exist to keep backward compatible with a userspace
1053 * loophole, what allowed userspace to get IFF_NO_QUEUE
1054 * facility on older kernels by setting tx_queue_len=0 (prior
1055 * to qdisc init), and then forgot to reinit tx_queue_len
1056 * before again attaching a qdisc.
1057 */
1058 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) {
1059 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
1060 netdev_info(dev, "Caught tx_queue_len zero misconfig\n");
1061 }
1062
1063 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
1064 if (qdisc_is_percpu_stats(sch)) {
1065 sch->cpu_bstats =
1066 netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
1067 if (!sch->cpu_bstats)
1068 goto err_out4;
1069
1070 sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
1071 if (!sch->cpu_qstats)
1072 goto err_out4;
1073 }
1074
1075 if (tca[TCA_STAB]) {
1076 stab = qdisc_get_stab(tca[TCA_STAB]);
1077 if (IS_ERR(stab)) {
1078 err = PTR_ERR(stab);
1079 goto err_out4;
1080 }
1081 rcu_assign_pointer(sch->stab, stab);
1082 }
1083 if (tca[TCA_RATE]) {
1084 seqcount_t *running;
1085
1086 err = -EOPNOTSUPP;
1087 if (sch->flags & TCQ_F_MQROOT)
1088 goto err_out4;
1089
1090 if ((sch->parent != TC_H_ROOT) &&
1091 !(sch->flags & TCQ_F_INGRESS) &&
1092 (!p || !(p->flags & TCQ_F_MQROOT)))
1093 running = qdisc_root_sleeping_running(sch);
1094 else
1095 running = &sch->running;
1096
1097 err = gen_new_estimator(&sch->bstats,
1098 sch->cpu_bstats,
1099 &sch->rate_est,
1100 NULL,
1101 running,
1102 tca[TCA_RATE]);
1103 if (err)
1104 goto err_out4;
1105 }
1106
1107 qdisc_hash_add(sch, false);
1108
1109 return sch;
1110 }
1111 /* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */
1112 if (ops->destroy)
1113 ops->destroy(sch);
1114 err_out3:
1115 dev_put(dev);
1116 kfree((char *) sch - sch->padded);
1117 err_out2:
1118 module_put(ops->owner);
1119 err_out:
1120 *errp = err;
1121 return NULL;
1122
1123 err_out4:
1124 free_percpu(sch->cpu_bstats);
1125 free_percpu(sch->cpu_qstats);
1126 /*
1127 * Any broken qdiscs that would require a ops->reset() here?
1128 * The qdisc was never in action so it shouldn't be necessary.
1129 */
1130 qdisc_put_stab(rtnl_dereference(sch->stab));
1131 if (ops->destroy)
1132 ops->destroy(sch);
1133 goto err_out3;
1134 }
1135
1136 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
1137 {
1138 struct qdisc_size_table *ostab, *stab = NULL;
1139 int err = 0;
1140
1141 if (tca[TCA_OPTIONS]) {
1142 if (sch->ops->change == NULL)
1143 return -EINVAL;
1144 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
1145 if (err)
1146 return err;
1147 }
1148
1149 if (tca[TCA_STAB]) {
1150 stab = qdisc_get_stab(tca[TCA_STAB]);
1151 if (IS_ERR(stab))
1152 return PTR_ERR(stab);
1153 }
1154
1155 ostab = rtnl_dereference(sch->stab);
1156 rcu_assign_pointer(sch->stab, stab);
1157 qdisc_put_stab(ostab);
1158
1159 if (tca[TCA_RATE]) {
1160 /* NB: ignores errors from replace_estimator
1161 because change can't be undone. */
1162 if (sch->flags & TCQ_F_MQROOT)
1163 goto out;
1164 gen_replace_estimator(&sch->bstats,
1165 sch->cpu_bstats,
1166 &sch->rate_est,
1167 NULL,
1168 qdisc_root_sleeping_running(sch),
1169 tca[TCA_RATE]);
1170 }
1171 out:
1172 return 0;
1173 }
1174
1175 struct check_loop_arg {
1176 struct qdisc_walker w;
1177 struct Qdisc *p;
1178 int depth;
1179 };
1180
1181 static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1182 struct qdisc_walker *w);
1183
1184 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1185 {
1186 struct check_loop_arg arg;
1187
1188 if (q->ops->cl_ops == NULL)
1189 return 0;
1190
1191 arg.w.stop = arg.w.skip = arg.w.count = 0;
1192 arg.w.fn = check_loop_fn;
1193 arg.depth = depth;
1194 arg.p = p;
1195 q->ops->cl_ops->walk(q, &arg.w);
1196 return arg.w.stop ? -ELOOP : 0;
1197 }
1198
1199 static int
1200 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1201 {
1202 struct Qdisc *leaf;
1203 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1204 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1205
1206 leaf = cops->leaf(q, cl);
1207 if (leaf) {
1208 if (leaf == arg->p || arg->depth > 7)
1209 return -ELOOP;
1210 return check_loop(leaf, arg->p, arg->depth + 1);
1211 }
1212 return 0;
1213 }
1214
1215 /*
1216 * Delete/get qdisc.
1217 */
1218
1219 const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = {
1220 [TCA_KIND] = { .type = NLA_STRING },
1221 [TCA_RATE] = { .type = NLA_BINARY,
1222 .len = sizeof(struct tc_estimator) },
1223 [TCA_STAB] = { .type = NLA_NESTED },
1224 [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG },
1225 [TCA_CHAIN] = { .type = NLA_U32 },
1226 };
1227
1228 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1229 struct netlink_ext_ack *extack)
1230 {
1231 struct net *net = sock_net(skb->sk);
1232 struct tcmsg *tcm = nlmsg_data(n);
1233 struct nlattr *tca[TCA_MAX + 1];
1234 struct net_device *dev;
1235 u32 clid;
1236 struct Qdisc *q = NULL;
1237 struct Qdisc *p = NULL;
1238 int err;
1239
1240 if ((n->nlmsg_type != RTM_GETQDISC) &&
1241 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1242 return -EPERM;
1243
1244 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, rtm_tca_policy,
1245 extack);
1246 if (err < 0)
1247 return err;
1248
1249 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1250 if (!dev)
1251 return -ENODEV;
1252
1253 clid = tcm->tcm_parent;
1254 if (clid) {
1255 if (clid != TC_H_ROOT) {
1256 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1257 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1258 if (!p)
1259 return -ENOENT;
1260 q = qdisc_leaf(p, clid);
1261 } else if (dev_ingress_queue(dev)) {
1262 q = dev_ingress_queue(dev)->qdisc_sleeping;
1263 }
1264 } else {
1265 q = dev->qdisc;
1266 }
1267 if (!q)
1268 return -ENOENT;
1269
1270 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1271 return -EINVAL;
1272 } else {
1273 q = qdisc_lookup(dev, tcm->tcm_handle);
1274 if (!q)
1275 return -ENOENT;
1276 }
1277
1278 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1279 return -EINVAL;
1280
1281 if (n->nlmsg_type == RTM_DELQDISC) {
1282 if (!clid)
1283 return -EINVAL;
1284 if (q->handle == 0)
1285 return -ENOENT;
1286 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1287 if (err != 0)
1288 return err;
1289 } else {
1290 qdisc_notify(net, skb, n, clid, NULL, q);
1291 }
1292 return 0;
1293 }
1294
1295 /*
1296 * Create/change qdisc.
1297 */
1298
1299 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1300 struct netlink_ext_ack *extack)
1301 {
1302 struct net *net = sock_net(skb->sk);
1303 struct tcmsg *tcm;
1304 struct nlattr *tca[TCA_MAX + 1];
1305 struct net_device *dev;
1306 u32 clid;
1307 struct Qdisc *q, *p;
1308 int err;
1309
1310 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1311 return -EPERM;
1312
1313 replay:
1314 /* Reinit, just in case something touches this. */
1315 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, rtm_tca_policy,
1316 extack);
1317 if (err < 0)
1318 return err;
1319
1320 tcm = nlmsg_data(n);
1321 clid = tcm->tcm_parent;
1322 q = p = NULL;
1323
1324 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1325 if (!dev)
1326 return -ENODEV;
1327
1328
1329 if (clid) {
1330 if (clid != TC_H_ROOT) {
1331 if (clid != TC_H_INGRESS) {
1332 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1333 if (!p)
1334 return -ENOENT;
1335 q = qdisc_leaf(p, clid);
1336 } else if (dev_ingress_queue_create(dev)) {
1337 q = dev_ingress_queue(dev)->qdisc_sleeping;
1338 }
1339 } else {
1340 q = dev->qdisc;
1341 }
1342
1343 /* It may be default qdisc, ignore it */
1344 if (q && q->handle == 0)
1345 q = NULL;
1346
1347 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1348 if (tcm->tcm_handle) {
1349 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1350 return -EEXIST;
1351 if (TC_H_MIN(tcm->tcm_handle))
1352 return -EINVAL;
1353 q = qdisc_lookup(dev, tcm->tcm_handle);
1354 if (!q)
1355 goto create_n_graft;
1356 if (n->nlmsg_flags & NLM_F_EXCL)
1357 return -EEXIST;
1358 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1359 return -EINVAL;
1360 if (q == p ||
1361 (p && check_loop(q, p, 0)))
1362 return -ELOOP;
1363 qdisc_refcount_inc(q);
1364 goto graft;
1365 } else {
1366 if (!q)
1367 goto create_n_graft;
1368
1369 /* This magic test requires explanation.
1370 *
1371 * We know, that some child q is already
1372 * attached to this parent and have choice:
1373 * either to change it or to create/graft new one.
1374 *
1375 * 1. We are allowed to create/graft only
1376 * if CREATE and REPLACE flags are set.
1377 *
1378 * 2. If EXCL is set, requestor wanted to say,
1379 * that qdisc tcm_handle is not expected
1380 * to exist, so that we choose create/graft too.
1381 *
1382 * 3. The last case is when no flags are set.
1383 * Alas, it is sort of hole in API, we
1384 * cannot decide what to do unambiguously.
1385 * For now we select create/graft, if
1386 * user gave KIND, which does not match existing.
1387 */
1388 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1389 (n->nlmsg_flags & NLM_F_REPLACE) &&
1390 ((n->nlmsg_flags & NLM_F_EXCL) ||
1391 (tca[TCA_KIND] &&
1392 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1393 goto create_n_graft;
1394 }
1395 }
1396 } else {
1397 if (!tcm->tcm_handle)
1398 return -EINVAL;
1399 q = qdisc_lookup(dev, tcm->tcm_handle);
1400 }
1401
1402 /* Change qdisc parameters */
1403 if (q == NULL)
1404 return -ENOENT;
1405 if (n->nlmsg_flags & NLM_F_EXCL)
1406 return -EEXIST;
1407 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1408 return -EINVAL;
1409 err = qdisc_change(q, tca);
1410 if (err == 0)
1411 qdisc_notify(net, skb, n, clid, NULL, q);
1412 return err;
1413
1414 create_n_graft:
1415 if (!(n->nlmsg_flags & NLM_F_CREATE))
1416 return -ENOENT;
1417 if (clid == TC_H_INGRESS) {
1418 if (dev_ingress_queue(dev))
1419 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1420 tcm->tcm_parent, tcm->tcm_parent,
1421 tca, &err);
1422 else
1423 err = -ENOENT;
1424 } else {
1425 struct netdev_queue *dev_queue;
1426
1427 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1428 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1429 else if (p)
1430 dev_queue = p->dev_queue;
1431 else
1432 dev_queue = netdev_get_tx_queue(dev, 0);
1433
1434 q = qdisc_create(dev, dev_queue, p,
1435 tcm->tcm_parent, tcm->tcm_handle,
1436 tca, &err);
1437 }
1438 if (q == NULL) {
1439 if (err == -EAGAIN)
1440 goto replay;
1441 return err;
1442 }
1443
1444 graft:
1445 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1446 if (err) {
1447 if (q)
1448 qdisc_destroy(q);
1449 return err;
1450 }
1451
1452 return 0;
1453 }
1454
1455 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1456 struct netlink_callback *cb,
1457 int *q_idx_p, int s_q_idx, bool recur,
1458 bool dump_invisible)
1459 {
1460 int ret = 0, q_idx = *q_idx_p;
1461 struct Qdisc *q;
1462 int b;
1463
1464 if (!root)
1465 return 0;
1466
1467 q = root;
1468 if (q_idx < s_q_idx) {
1469 q_idx++;
1470 } else {
1471 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1472 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1473 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1474 RTM_NEWQDISC) <= 0)
1475 goto done;
1476 q_idx++;
1477 }
1478
1479 /* If dumping singletons, there is no qdisc_dev(root) and the singleton
1480 * itself has already been dumped.
1481 *
1482 * If we've already dumped the top-level (ingress) qdisc above and the global
1483 * qdisc hashtable, we don't want to hit it again
1484 */
1485 if (!qdisc_dev(root) || !recur)
1486 goto out;
1487
1488 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1489 if (q_idx < s_q_idx) {
1490 q_idx++;
1491 continue;
1492 }
1493 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1494 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1495 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1496 RTM_NEWQDISC) <= 0)
1497 goto done;
1498 q_idx++;
1499 }
1500
1501 out:
1502 *q_idx_p = q_idx;
1503 return ret;
1504 done:
1505 ret = -1;
1506 goto out;
1507 }
1508
1509 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1510 {
1511 struct net *net = sock_net(skb->sk);
1512 int idx, q_idx;
1513 int s_idx, s_q_idx;
1514 struct net_device *dev;
1515 const struct nlmsghdr *nlh = cb->nlh;
1516 struct tcmsg *tcm = nlmsg_data(nlh);
1517 struct nlattr *tca[TCA_MAX + 1];
1518 int err;
1519
1520 s_idx = cb->args[0];
1521 s_q_idx = q_idx = cb->args[1];
1522
1523 idx = 0;
1524 ASSERT_RTNL();
1525
1526 err = nlmsg_parse(nlh, sizeof(*tcm), tca, TCA_MAX,
1527 rtm_tca_policy, NULL);
1528 if (err < 0)
1529 return err;
1530
1531 for_each_netdev(net, dev) {
1532 struct netdev_queue *dev_queue;
1533
1534 if (idx < s_idx)
1535 goto cont;
1536 if (idx > s_idx)
1537 s_q_idx = 0;
1538 q_idx = 0;
1539
1540 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx,
1541 true, tca[TCA_DUMP_INVISIBLE]) < 0)
1542 goto done;
1543
1544 dev_queue = dev_ingress_queue(dev);
1545 if (dev_queue &&
1546 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1547 &q_idx, s_q_idx, false,
1548 tca[TCA_DUMP_INVISIBLE]) < 0)
1549 goto done;
1550
1551 cont:
1552 idx++;
1553 }
1554
1555 done:
1556 cb->args[0] = idx;
1557 cb->args[1] = q_idx;
1558
1559 return skb->len;
1560 }
1561
1562
1563
1564 /************************************************
1565 * Traffic classes manipulation. *
1566 ************************************************/
1567
1568 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1569 unsigned long cl,
1570 u32 portid, u32 seq, u16 flags, int event)
1571 {
1572 struct tcmsg *tcm;
1573 struct nlmsghdr *nlh;
1574 unsigned char *b = skb_tail_pointer(skb);
1575 struct gnet_dump d;
1576 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1577
1578 cond_resched();
1579 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1580 if (!nlh)
1581 goto out_nlmsg_trim;
1582 tcm = nlmsg_data(nlh);
1583 tcm->tcm_family = AF_UNSPEC;
1584 tcm->tcm__pad1 = 0;
1585 tcm->tcm__pad2 = 0;
1586 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1587 tcm->tcm_parent = q->handle;
1588 tcm->tcm_handle = q->handle;
1589 tcm->tcm_info = 0;
1590 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1591 goto nla_put_failure;
1592 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1593 goto nla_put_failure;
1594
1595 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1596 NULL, &d, TCA_PAD) < 0)
1597 goto nla_put_failure;
1598
1599 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1600 goto nla_put_failure;
1601
1602 if (gnet_stats_finish_copy(&d) < 0)
1603 goto nla_put_failure;
1604
1605 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1606 return skb->len;
1607
1608 out_nlmsg_trim:
1609 nla_put_failure:
1610 nlmsg_trim(skb, b);
1611 return -1;
1612 }
1613
1614 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1615 struct nlmsghdr *n, struct Qdisc *q,
1616 unsigned long cl, int event)
1617 {
1618 struct sk_buff *skb;
1619 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1620
1621 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1622 if (!skb)
1623 return -ENOBUFS;
1624
1625 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1626 kfree_skb(skb);
1627 return -EINVAL;
1628 }
1629
1630 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1631 n->nlmsg_flags & NLM_F_ECHO);
1632 }
1633
1634 static int tclass_del_notify(struct net *net,
1635 const struct Qdisc_class_ops *cops,
1636 struct sk_buff *oskb, struct nlmsghdr *n,
1637 struct Qdisc *q, unsigned long cl)
1638 {
1639 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1640 struct sk_buff *skb;
1641 int err = 0;
1642
1643 if (!cops->delete)
1644 return -EOPNOTSUPP;
1645
1646 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1647 if (!skb)
1648 return -ENOBUFS;
1649
1650 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0,
1651 RTM_DELTCLASS) < 0) {
1652 kfree_skb(skb);
1653 return -EINVAL;
1654 }
1655
1656 err = cops->delete(q, cl);
1657 if (err) {
1658 kfree_skb(skb);
1659 return err;
1660 }
1661
1662 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1663 n->nlmsg_flags & NLM_F_ECHO);
1664 }
1665
1666 #ifdef CONFIG_NET_CLS
1667
1668 struct tcf_bind_args {
1669 struct tcf_walker w;
1670 u32 classid;
1671 unsigned long cl;
1672 };
1673
1674 static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
1675 {
1676 struct tcf_bind_args *a = (void *)arg;
1677
1678 if (tp->ops->bind_class) {
1679 tcf_tree_lock(tp);
1680 tp->ops->bind_class(n, a->classid, a->cl);
1681 tcf_tree_unlock(tp);
1682 }
1683 return 0;
1684 }
1685
1686 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1687 unsigned long new_cl)
1688 {
1689 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1690 struct tcf_block *block;
1691 struct tcf_chain *chain;
1692 unsigned long cl;
1693
1694 cl = cops->find(q, portid);
1695 if (!cl)
1696 return;
1697 block = cops->tcf_block(q, cl);
1698 if (!block)
1699 return;
1700 list_for_each_entry(chain, &block->chain_list, list) {
1701 struct tcf_proto *tp;
1702
1703 for (tp = rtnl_dereference(chain->filter_chain);
1704 tp; tp = rtnl_dereference(tp->next)) {
1705 struct tcf_bind_args arg = {};
1706
1707 arg.w.fn = tcf_node_bind;
1708 arg.classid = clid;
1709 arg.cl = new_cl;
1710 tp->ops->walk(tp, &arg.w);
1711 }
1712 }
1713 }
1714
1715 #else
1716
1717 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1718 unsigned long new_cl)
1719 {
1720 }
1721
1722 #endif
1723
1724 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
1725 struct netlink_ext_ack *extack)
1726 {
1727 struct net *net = sock_net(skb->sk);
1728 struct tcmsg *tcm = nlmsg_data(n);
1729 struct nlattr *tca[TCA_MAX + 1];
1730 struct net_device *dev;
1731 struct Qdisc *q = NULL;
1732 const struct Qdisc_class_ops *cops;
1733 unsigned long cl = 0;
1734 unsigned long new_cl;
1735 u32 portid;
1736 u32 clid;
1737 u32 qid;
1738 int err;
1739
1740 if ((n->nlmsg_type != RTM_GETTCLASS) &&
1741 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1742 return -EPERM;
1743
1744 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, rtm_tca_policy,
1745 extack);
1746 if (err < 0)
1747 return err;
1748
1749 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1750 if (!dev)
1751 return -ENODEV;
1752
1753 /*
1754 parent == TC_H_UNSPEC - unspecified parent.
1755 parent == TC_H_ROOT - class is root, which has no parent.
1756 parent == X:0 - parent is root class.
1757 parent == X:Y - parent is a node in hierarchy.
1758 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1759
1760 handle == 0:0 - generate handle from kernel pool.
1761 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1762 handle == X:Y - clear.
1763 handle == X:0 - root class.
1764 */
1765
1766 /* Step 1. Determine qdisc handle X:0 */
1767
1768 portid = tcm->tcm_parent;
1769 clid = tcm->tcm_handle;
1770 qid = TC_H_MAJ(clid);
1771
1772 if (portid != TC_H_ROOT) {
1773 u32 qid1 = TC_H_MAJ(portid);
1774
1775 if (qid && qid1) {
1776 /* If both majors are known, they must be identical. */
1777 if (qid != qid1)
1778 return -EINVAL;
1779 } else if (qid1) {
1780 qid = qid1;
1781 } else if (qid == 0)
1782 qid = dev->qdisc->handle;
1783
1784 /* Now qid is genuine qdisc handle consistent
1785 * both with parent and child.
1786 *
1787 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1788 */
1789 if (portid)
1790 portid = TC_H_MAKE(qid, portid);
1791 } else {
1792 if (qid == 0)
1793 qid = dev->qdisc->handle;
1794 }
1795
1796 /* OK. Locate qdisc */
1797 q = qdisc_lookup(dev, qid);
1798 if (!q)
1799 return -ENOENT;
1800
1801 /* An check that it supports classes */
1802 cops = q->ops->cl_ops;
1803 if (cops == NULL)
1804 return -EINVAL;
1805
1806 /* Now try to get class */
1807 if (clid == 0) {
1808 if (portid == TC_H_ROOT)
1809 clid = qid;
1810 } else
1811 clid = TC_H_MAKE(qid, clid);
1812
1813 if (clid)
1814 cl = cops->find(q, clid);
1815
1816 if (cl == 0) {
1817 err = -ENOENT;
1818 if (n->nlmsg_type != RTM_NEWTCLASS ||
1819 !(n->nlmsg_flags & NLM_F_CREATE))
1820 goto out;
1821 } else {
1822 switch (n->nlmsg_type) {
1823 case RTM_NEWTCLASS:
1824 err = -EEXIST;
1825 if (n->nlmsg_flags & NLM_F_EXCL)
1826 goto out;
1827 break;
1828 case RTM_DELTCLASS:
1829 err = tclass_del_notify(net, cops, skb, n, q, cl);
1830 /* Unbind the class with flilters with 0 */
1831 tc_bind_tclass(q, portid, clid, 0);
1832 goto out;
1833 case RTM_GETTCLASS:
1834 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1835 goto out;
1836 default:
1837 err = -EINVAL;
1838 goto out;
1839 }
1840 }
1841
1842 new_cl = cl;
1843 err = -EOPNOTSUPP;
1844 if (cops->change)
1845 err = cops->change(q, clid, portid, tca, &new_cl);
1846 if (err == 0) {
1847 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1848 /* We just create a new class, need to do reverse binding. */
1849 if (cl != new_cl)
1850 tc_bind_tclass(q, portid, clid, new_cl);
1851 }
1852 out:
1853 return err;
1854 }
1855
1856 struct qdisc_dump_args {
1857 struct qdisc_walker w;
1858 struct sk_buff *skb;
1859 struct netlink_callback *cb;
1860 };
1861
1862 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
1863 struct qdisc_walker *arg)
1864 {
1865 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1866
1867 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1868 a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
1869 RTM_NEWTCLASS);
1870 }
1871
1872 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1873 struct tcmsg *tcm, struct netlink_callback *cb,
1874 int *t_p, int s_t)
1875 {
1876 struct qdisc_dump_args arg;
1877
1878 if (tc_qdisc_dump_ignore(q, false) ||
1879 *t_p < s_t || !q->ops->cl_ops ||
1880 (tcm->tcm_parent &&
1881 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1882 (*t_p)++;
1883 return 0;
1884 }
1885 if (*t_p > s_t)
1886 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1887 arg.w.fn = qdisc_class_dump;
1888 arg.skb = skb;
1889 arg.cb = cb;
1890 arg.w.stop = 0;
1891 arg.w.skip = cb->args[1];
1892 arg.w.count = 0;
1893 q->ops->cl_ops->walk(q, &arg.w);
1894 cb->args[1] = arg.w.count;
1895 if (arg.w.stop)
1896 return -1;
1897 (*t_p)++;
1898 return 0;
1899 }
1900
1901 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1902 struct tcmsg *tcm, struct netlink_callback *cb,
1903 int *t_p, int s_t)
1904 {
1905 struct Qdisc *q;
1906 int b;
1907
1908 if (!root)
1909 return 0;
1910
1911 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1912 return -1;
1913
1914 if (!qdisc_dev(root))
1915 return 0;
1916
1917 if (tcm->tcm_parent) {
1918 q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent));
1919 if (q && q != root &&
1920 tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1921 return -1;
1922 return 0;
1923 }
1924 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1925 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1926 return -1;
1927 }
1928
1929 return 0;
1930 }
1931
1932 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1933 {
1934 struct tcmsg *tcm = nlmsg_data(cb->nlh);
1935 struct net *net = sock_net(skb->sk);
1936 struct netdev_queue *dev_queue;
1937 struct net_device *dev;
1938 int t, s_t;
1939
1940 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1941 return 0;
1942 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1943 if (!dev)
1944 return 0;
1945
1946 s_t = cb->args[0];
1947 t = 0;
1948
1949 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1950 goto done;
1951
1952 dev_queue = dev_ingress_queue(dev);
1953 if (dev_queue &&
1954 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1955 &t, s_t) < 0)
1956 goto done;
1957
1958 done:
1959 cb->args[0] = t;
1960
1961 dev_put(dev);
1962 return skb->len;
1963 }
1964
1965 #ifdef CONFIG_PROC_FS
1966 static int psched_show(struct seq_file *seq, void *v)
1967 {
1968 seq_printf(seq, "%08x %08x %08x %08x\n",
1969 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1970 1000000,
1971 (u32)NSEC_PER_SEC / hrtimer_resolution);
1972
1973 return 0;
1974 }
1975
1976 static int psched_open(struct inode *inode, struct file *file)
1977 {
1978 return single_open(file, psched_show, NULL);
1979 }
1980
1981 static const struct file_operations psched_fops = {
1982 .owner = THIS_MODULE,
1983 .open = psched_open,
1984 .read = seq_read,
1985 .llseek = seq_lseek,
1986 .release = single_release,
1987 };
1988
1989 static int __net_init psched_net_init(struct net *net)
1990 {
1991 struct proc_dir_entry *e;
1992
1993 e = proc_create("psched", 0, net->proc_net, &psched_fops);
1994 if (e == NULL)
1995 return -ENOMEM;
1996
1997 return 0;
1998 }
1999
2000 static void __net_exit psched_net_exit(struct net *net)
2001 {
2002 remove_proc_entry("psched", net->proc_net);
2003 }
2004 #else
2005 static int __net_init psched_net_init(struct net *net)
2006 {
2007 return 0;
2008 }
2009
2010 static void __net_exit psched_net_exit(struct net *net)
2011 {
2012 }
2013 #endif
2014
2015 static struct pernet_operations psched_net_ops = {
2016 .init = psched_net_init,
2017 .exit = psched_net_exit,
2018 };
2019
2020 static int __init pktsched_init(void)
2021 {
2022 int err;
2023
2024 err = register_pernet_subsys(&psched_net_ops);
2025 if (err) {
2026 pr_err("pktsched_init: "
2027 "cannot initialize per netns operations\n");
2028 return err;
2029 }
2030
2031 register_qdisc(&pfifo_fast_ops);
2032 register_qdisc(&pfifo_qdisc_ops);
2033 register_qdisc(&bfifo_qdisc_ops);
2034 register_qdisc(&pfifo_head_drop_qdisc_ops);
2035 register_qdisc(&mq_qdisc_ops);
2036 register_qdisc(&noqueue_qdisc_ops);
2037
2038 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, 0);
2039 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, 0);
2040 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc,
2041 0);
2042 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, 0);
2043 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, 0);
2044 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass,
2045 0);
2046
2047 return 0;
2048 }
2049
2050 subsys_initcall(pktsched_init);
Linux with added FPC-III support