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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
33#include <net/net_namespace.h>
34#include <net/sock.h>
35#include <net/netlink.h>
36#include <net/pkt_sched.h>
37
38static int qdisc_notify(struct net *net, struct sk_buff *oskb,
39 struct nlmsghdr *n, u32 clid,
40 struct Qdisc *old, struct Qdisc *new);
41static int tclass_notify(struct net *net, struct sk_buff *oskb,
42 struct nlmsghdr *n, struct Qdisc *q,
43 unsigned long cl, int event);
44
45/*
46
47 Short review.
48 -------------
49
50 This file consists of two interrelated parts:
51
52 1. queueing disciplines manager frontend.
53 2. traffic classes manager frontend.
54
55 Generally, queueing discipline ("qdisc") is a black box,
56 which is able to enqueue packets and to dequeue them (when
57 device is ready to send something) in order and at times
58 determined by algorithm hidden in it.
59
60 qdisc's are divided to two categories:
61 - "queues", which have no internal structure visible from outside.
62 - "schedulers", which split all the packets to "traffic classes",
63 using "packet classifiers" (look at cls_api.c)
64
65 In turn, classes may have child qdiscs (as rule, queues)
66 attached to them etc. etc. etc.
67
68 The goal of the routines in this file is to translate
69 information supplied by user in the form of handles
70 to more intelligible for kernel form, to make some sanity
71 checks and part of work, which is common to all qdiscs
72 and to provide rtnetlink notifications.
73
74 All real intelligent work is done inside qdisc modules.
75
76
77
78 Every discipline has two major routines: enqueue and dequeue.
79
80 ---dequeue
81
82 dequeue usually returns a skb to send. It is allowed to return NULL,
83 but it does not mean that queue is empty, it just means that
84 discipline does not want to send anything this time.
85 Queue is really empty if q->q.qlen == 0.
86 For complicated disciplines with multiple queues q->q is not
87 real packet queue, but however q->q.qlen must be valid.
88
89 ---enqueue
90
91 enqueue returns 0, if packet was enqueued successfully.
92 If packet (this one or another one) was dropped, it returns
93 not zero error code.
94 NET_XMIT_DROP - this packet dropped
95 Expected action: do not backoff, but wait until queue will clear.
96 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
97 Expected action: backoff or ignore
98 NET_XMIT_POLICED - dropped by police.
99 Expected action: backoff or error to real-time apps.
100
101 Auxiliary routines:
102
103 ---peek
104
105 like dequeue but without removing a packet from the queue
106
107 ---reset
108
109 returns qdisc to initial state: purge all buffers, clear all
110 timers, counters (except for statistics) etc.
111
112 ---init
113
114 initializes newly created qdisc.
115
116 ---destroy
117
118 destroys resources allocated by init and during lifetime of qdisc.
119
120 ---change
121
122 changes qdisc parameters.
123 */
124
125/* Protects list of registered TC modules. It is pure SMP lock. */
126static DEFINE_RWLOCK(qdisc_mod_lock);
127
128
129/************************************************
130 * Queueing disciplines manipulation. *
131 ************************************************/
132
133
134/* The list of all installed queueing disciplines. */
135
136static struct Qdisc_ops *qdisc_base;
137
138/* Register/uregister queueing discipline */
139
140int register_qdisc(struct Qdisc_ops *qops)
141{
142 struct Qdisc_ops *q, **qp;
143 int rc = -EEXIST;
144
145 write_lock(&qdisc_mod_lock);
146 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
147 if (!strcmp(qops->id, q->id))
148 goto out;
149
150 if (qops->enqueue == NULL)
151 qops->enqueue = noop_qdisc_ops.enqueue;
152 if (qops->peek == NULL) {
153 if (qops->dequeue == NULL)
154 qops->peek = noop_qdisc_ops.peek;
155 else
156 goto out_einval;
157 }
158 if (qops->dequeue == NULL)
159 qops->dequeue = noop_qdisc_ops.dequeue;
160
161 if (qops->cl_ops) {
162 const struct Qdisc_class_ops *cops = qops->cl_ops;
163
164 if (!(cops->get && cops->put && cops->walk && cops->leaf))
165 goto out_einval;
166
167 if (cops->tcf_chain && !(cops->bind_tcf && cops->unbind_tcf))
168 goto out_einval;
169 }
170
171 qops->next = NULL;
172 *qp = qops;
173 rc = 0;
174out:
175 write_unlock(&qdisc_mod_lock);
176 return rc;
177
178out_einval:
179 rc = -EINVAL;
180 goto out;
181}
182EXPORT_SYMBOL(register_qdisc);
183
184int unregister_qdisc(struct Qdisc_ops *qops)
185{
186 struct Qdisc_ops *q, **qp;
187 int err = -ENOENT;
188
189 write_lock(&qdisc_mod_lock);
190 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
191 if (q == qops)
192 break;
193 if (q) {
194 *qp = q->next;
195 q->next = NULL;
196 err = 0;
197 }
198 write_unlock(&qdisc_mod_lock);
199 return err;
200}
201EXPORT_SYMBOL(unregister_qdisc);
202
203/* We know handle. Find qdisc among all qdisc's attached to device
204 (root qdisc, all its children, children of children etc.)
205 */
206
207static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
208{
209 struct Qdisc *q;
210
211 if (!(root->flags & TCQ_F_BUILTIN) &&
212 root->handle == handle)
213 return root;
214
215 list_for_each_entry(q, &root->list, list) {
216 if (q->handle == handle)
217 return q;
218 }
219 return NULL;
220}
221
222static void qdisc_list_add(struct Qdisc *q)
223{
224 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
225 list_add_tail(&q->list, &qdisc_dev(q)->qdisc->list);
226}
227
228void qdisc_list_del(struct Qdisc *q)
229{
230 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
231 list_del(&q->list);
232}
233EXPORT_SYMBOL(qdisc_list_del);
234
235struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
236{
237 struct Qdisc *q;
238
239 q = qdisc_match_from_root(dev->qdisc, handle);
240 if (q)
241 goto out;
242
243 if (dev_ingress_queue(dev))
244 q = qdisc_match_from_root(
245 dev_ingress_queue(dev)->qdisc_sleeping,
246 handle);
247out:
248 return q;
249}
250
251static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
252{
253 unsigned long cl;
254 struct Qdisc *leaf;
255 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
256
257 if (cops == NULL)
258 return NULL;
259 cl = cops->get(p, classid);
260
261 if (cl == 0)
262 return NULL;
263 leaf = cops->leaf(p, cl);
264 cops->put(p, cl);
265 return leaf;
266}
267
268/* Find queueing discipline by name */
269
270static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
271{
272 struct Qdisc_ops *q = NULL;
273
274 if (kind) {
275 read_lock(&qdisc_mod_lock);
276 for (q = qdisc_base; q; q = q->next) {
277 if (nla_strcmp(kind, q->id) == 0) {
278 if (!try_module_get(q->owner))
279 q = NULL;
280 break;
281 }
282 }
283 read_unlock(&qdisc_mod_lock);
284 }
285 return q;
286}
287
288static struct qdisc_rate_table *qdisc_rtab_list;
289
290struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct nlattr *tab)
291{
292 struct qdisc_rate_table *rtab;
293
294 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
295 if (memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) == 0) {
296 rtab->refcnt++;
297 return rtab;
298 }
299 }
300
301 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
302 nla_len(tab) != TC_RTAB_SIZE)
303 return NULL;
304
305 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
306 if (rtab) {
307 rtab->rate = *r;
308 rtab->refcnt = 1;
309 memcpy(rtab->data, nla_data(tab), 1024);
310 rtab->next = qdisc_rtab_list;
311 qdisc_rtab_list = rtab;
312 }
313 return rtab;
314}
315EXPORT_SYMBOL(qdisc_get_rtab);
316
317void qdisc_put_rtab(struct qdisc_rate_table *tab)
318{
319 struct qdisc_rate_table *rtab, **rtabp;
320
321 if (!tab || --tab->refcnt)
322 return;
323
324 for (rtabp = &qdisc_rtab_list;
325 (rtab = *rtabp) != NULL;
326 rtabp = &rtab->next) {
327 if (rtab == tab) {
328 *rtabp = rtab->next;
329 kfree(rtab);
330 return;
331 }
332 }
333}
334EXPORT_SYMBOL(qdisc_put_rtab);
335
336static LIST_HEAD(qdisc_stab_list);
337static DEFINE_SPINLOCK(qdisc_stab_lock);
338
339static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
340 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
341 [TCA_STAB_DATA] = { .type = NLA_BINARY },
342};
343
344static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
345{
346 struct nlattr *tb[TCA_STAB_MAX + 1];
347 struct qdisc_size_table *stab;
348 struct tc_sizespec *s;
349 unsigned int tsize = 0;
350 u16 *tab = NULL;
351 int err;
352
353 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
354 if (err < 0)
355 return ERR_PTR(err);
356 if (!tb[TCA_STAB_BASE])
357 return ERR_PTR(-EINVAL);
358
359 s = nla_data(tb[TCA_STAB_BASE]);
360
361 if (s->tsize > 0) {
362 if (!tb[TCA_STAB_DATA])
363 return ERR_PTR(-EINVAL);
364 tab = nla_data(tb[TCA_STAB_DATA]);
365 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
366 }
367
368 if (tsize != s->tsize || (!tab && tsize > 0))
369 return ERR_PTR(-EINVAL);
370
371 spin_lock(&qdisc_stab_lock);
372
373 list_for_each_entry(stab, &qdisc_stab_list, list) {
374 if (memcmp(&stab->szopts, s, sizeof(*s)))
375 continue;
376 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
377 continue;
378 stab->refcnt++;
379 spin_unlock(&qdisc_stab_lock);
380 return stab;
381 }
382
383 spin_unlock(&qdisc_stab_lock);
384
385 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
386 if (!stab)
387 return ERR_PTR(-ENOMEM);
388
389 stab->refcnt = 1;
390 stab->szopts = *s;
391 if (tsize > 0)
392 memcpy(stab->data, tab, tsize * sizeof(u16));
393
394 spin_lock(&qdisc_stab_lock);
395 list_add_tail(&stab->list, &qdisc_stab_list);
396 spin_unlock(&qdisc_stab_lock);
397
398 return stab;
399}
400
401static void stab_kfree_rcu(struct rcu_head *head)
402{
403 kfree(container_of(head, struct qdisc_size_table, rcu));
404}
405
406void qdisc_put_stab(struct qdisc_size_table *tab)
407{
408 if (!tab)
409 return;
410
411 spin_lock(&qdisc_stab_lock);
412
413 if (--tab->refcnt == 0) {
414 list_del(&tab->list);
415 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
416 }
417
418 spin_unlock(&qdisc_stab_lock);
419}
420EXPORT_SYMBOL(qdisc_put_stab);
421
422static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
423{
424 struct nlattr *nest;
425
426 nest = nla_nest_start(skb, TCA_STAB);
427 if (nest == NULL)
428 goto nla_put_failure;
429 NLA_PUT(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts);
430 nla_nest_end(skb, nest);
431
432 return skb->len;
433
434nla_put_failure:
435 return -1;
436}
437
438void __qdisc_calculate_pkt_len(struct sk_buff *skb, const struct qdisc_size_table *stab)
439{
440 int pkt_len, slot;
441
442 pkt_len = skb->len + stab->szopts.overhead;
443 if (unlikely(!stab->szopts.tsize))
444 goto out;
445
446 slot = pkt_len + stab->szopts.cell_align;
447 if (unlikely(slot < 0))
448 slot = 0;
449
450 slot >>= stab->szopts.cell_log;
451 if (likely(slot < stab->szopts.tsize))
452 pkt_len = stab->data[slot];
453 else
454 pkt_len = stab->data[stab->szopts.tsize - 1] *
455 (slot / stab->szopts.tsize) +
456 stab->data[slot % stab->szopts.tsize];
457
458 pkt_len <<= stab->szopts.size_log;
459out:
460 if (unlikely(pkt_len < 1))
461 pkt_len = 1;
462 qdisc_skb_cb(skb)->pkt_len = pkt_len;
463}
464EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
465
466void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc)
467{
468 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
469 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
470 txt, qdisc->ops->id, qdisc->handle >> 16);
471 qdisc->flags |= TCQ_F_WARN_NONWC;
472 }
473}
474EXPORT_SYMBOL(qdisc_warn_nonwc);
475
476static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
477{
478 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
479 timer);
480
481 qdisc_unthrottled(wd->qdisc);
482 __netif_schedule(qdisc_root(wd->qdisc));
483
484 return HRTIMER_NORESTART;
485}
486
487void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
488{
489 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
490 wd->timer.function = qdisc_watchdog;
491 wd->qdisc = qdisc;
492}
493EXPORT_SYMBOL(qdisc_watchdog_init);
494
495void qdisc_watchdog_schedule(struct qdisc_watchdog *wd, psched_time_t expires)
496{
497 ktime_t time;
498
499 if (test_bit(__QDISC_STATE_DEACTIVATED,
500 &qdisc_root_sleeping(wd->qdisc)->state))
501 return;
502
503 qdisc_throttled(wd->qdisc);
504 time = ktime_set(0, 0);
505 time = ktime_add_ns(time, PSCHED_TICKS2NS(expires));
506 hrtimer_start(&wd->timer, time, HRTIMER_MODE_ABS);
507}
508EXPORT_SYMBOL(qdisc_watchdog_schedule);
509
510void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
511{
512 hrtimer_cancel(&wd->timer);
513 qdisc_unthrottled(wd->qdisc);
514}
515EXPORT_SYMBOL(qdisc_watchdog_cancel);
516
517static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
518{
519 unsigned int size = n * sizeof(struct hlist_head), i;
520 struct hlist_head *h;
521
522 if (size <= PAGE_SIZE)
523 h = kmalloc(size, GFP_KERNEL);
524 else
525 h = (struct hlist_head *)
526 __get_free_pages(GFP_KERNEL, get_order(size));
527
528 if (h != NULL) {
529 for (i = 0; i < n; i++)
530 INIT_HLIST_HEAD(&h[i]);
531 }
532 return h;
533}
534
535static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
536{
537 unsigned int size = n * sizeof(struct hlist_head);
538
539 if (size <= PAGE_SIZE)
540 kfree(h);
541 else
542 free_pages((unsigned long)h, get_order(size));
543}
544
545void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
546{
547 struct Qdisc_class_common *cl;
548 struct hlist_node *n, *next;
549 struct hlist_head *nhash, *ohash;
550 unsigned int nsize, nmask, osize;
551 unsigned int i, h;
552
553 /* Rehash when load factor exceeds 0.75 */
554 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
555 return;
556 nsize = clhash->hashsize * 2;
557 nmask = nsize - 1;
558 nhash = qdisc_class_hash_alloc(nsize);
559 if (nhash == NULL)
560 return;
561
562 ohash = clhash->hash;
563 osize = clhash->hashsize;
564
565 sch_tree_lock(sch);
566 for (i = 0; i < osize; i++) {
567 hlist_for_each_entry_safe(cl, n, next, &ohash[i], hnode) {
568 h = qdisc_class_hash(cl->classid, nmask);
569 hlist_add_head(&cl->hnode, &nhash[h]);
570 }
571 }
572 clhash->hash = nhash;
573 clhash->hashsize = nsize;
574 clhash->hashmask = nmask;
575 sch_tree_unlock(sch);
576
577 qdisc_class_hash_free(ohash, osize);
578}
579EXPORT_SYMBOL(qdisc_class_hash_grow);
580
581int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
582{
583 unsigned int size = 4;
584
585 clhash->hash = qdisc_class_hash_alloc(size);
586 if (clhash->hash == NULL)
587 return -ENOMEM;
588 clhash->hashsize = size;
589 clhash->hashmask = size - 1;
590 clhash->hashelems = 0;
591 return 0;
592}
593EXPORT_SYMBOL(qdisc_class_hash_init);
594
595void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
596{
597 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
598}
599EXPORT_SYMBOL(qdisc_class_hash_destroy);
600
601void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
602 struct Qdisc_class_common *cl)
603{
604 unsigned int h;
605
606 INIT_HLIST_NODE(&cl->hnode);
607 h = qdisc_class_hash(cl->classid, clhash->hashmask);
608 hlist_add_head(&cl->hnode, &clhash->hash[h]);
609 clhash->hashelems++;
610}
611EXPORT_SYMBOL(qdisc_class_hash_insert);
612
613void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
614 struct Qdisc_class_common *cl)
615{
616 hlist_del(&cl->hnode);
617 clhash->hashelems--;
618}
619EXPORT_SYMBOL(qdisc_class_hash_remove);
620
621/* Allocate an unique handle from space managed by kernel */
622
623static u32 qdisc_alloc_handle(struct net_device *dev)
624{
625 int i = 0x10000;
626 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
627
628 do {
629 autohandle += TC_H_MAKE(0x10000U, 0);
630 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
631 autohandle = TC_H_MAKE(0x80000000U, 0);
632 } while (qdisc_lookup(dev, autohandle) && --i > 0);
633
634 return i > 0 ? autohandle : 0;
635}
636
637void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
638{
639 const struct Qdisc_class_ops *cops;
640 unsigned long cl;
641 u32 parentid;
642
643 if (n == 0)
644 return;
645 while ((parentid = sch->parent)) {
646 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
647 return;
648
649 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
650 if (sch == NULL) {
651 WARN_ON(parentid != TC_H_ROOT);
652 return;
653 }
654 cops = sch->ops->cl_ops;
655 if (cops->qlen_notify) {
656 cl = cops->get(sch, parentid);
657 cops->qlen_notify(sch, cl);
658 cops->put(sch, cl);
659 }
660 sch->q.qlen -= n;
661 }
662}
663EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
664
665static void notify_and_destroy(struct net *net, struct sk_buff *skb,
666 struct nlmsghdr *n, u32 clid,
667 struct Qdisc *old, struct Qdisc *new)
668{
669 if (new || old)
670 qdisc_notify(net, skb, n, clid, old, new);
671
672 if (old)
673 qdisc_destroy(old);
674}
675
676/* Graft qdisc "new" to class "classid" of qdisc "parent" or
677 * to device "dev".
678 *
679 * When appropriate send a netlink notification using 'skb'
680 * and "n".
681 *
682 * On success, destroy old qdisc.
683 */
684
685static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
686 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
687 struct Qdisc *new, struct Qdisc *old)
688{
689 struct Qdisc *q = old;
690 struct net *net = dev_net(dev);
691 int err = 0;
692
693 if (parent == NULL) {
694 unsigned int i, num_q, ingress;
695
696 ingress = 0;
697 num_q = dev->num_tx_queues;
698 if ((q && q->flags & TCQ_F_INGRESS) ||
699 (new && new->flags & TCQ_F_INGRESS)) {
700 num_q = 1;
701 ingress = 1;
702 if (!dev_ingress_queue(dev))
703 return -ENOENT;
704 }
705
706 if (dev->flags & IFF_UP)
707 dev_deactivate(dev);
708
709 if (new && new->ops->attach) {
710 new->ops->attach(new);
711 num_q = 0;
712 }
713
714 for (i = 0; i < num_q; i++) {
715 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
716
717 if (!ingress)
718 dev_queue = netdev_get_tx_queue(dev, i);
719
720 old = dev_graft_qdisc(dev_queue, new);
721 if (new && i > 0)
722 atomic_inc(&new->refcnt);
723
724 if (!ingress)
725 qdisc_destroy(old);
726 }
727
728 if (!ingress) {
729 notify_and_destroy(net, skb, n, classid,
730 dev->qdisc, new);
731 if (new && !new->ops->attach)
732 atomic_inc(&new->refcnt);
733 dev->qdisc = new ? : &noop_qdisc;
734 } else {
735 notify_and_destroy(net, skb, n, classid, old, new);
736 }
737
738 if (dev->flags & IFF_UP)
739 dev_activate(dev);
740 } else {
741 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
742
743 err = -EOPNOTSUPP;
744 if (cops && cops->graft) {
745 unsigned long cl = cops->get(parent, classid);
746 if (cl) {
747 err = cops->graft(parent, cl, new, &old);
748 cops->put(parent, cl);
749 } else
750 err = -ENOENT;
751 }
752 if (!err)
753 notify_and_destroy(net, skb, n, classid, old, new);
754 }
755 return err;
756}
757
758/* lockdep annotation is needed for ingress; egress gets it only for name */
759static struct lock_class_key qdisc_tx_lock;
760static struct lock_class_key qdisc_rx_lock;
761
762/*
763 Allocate and initialize new qdisc.
764
765 Parameters are passed via opt.
766 */
767
768static struct Qdisc *
769qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
770 struct Qdisc *p, u32 parent, u32 handle,
771 struct nlattr **tca, int *errp)
772{
773 int err;
774 struct nlattr *kind = tca[TCA_KIND];
775 struct Qdisc *sch;
776 struct Qdisc_ops *ops;
777 struct qdisc_size_table *stab;
778
779 ops = qdisc_lookup_ops(kind);
780#ifdef CONFIG_MODULES
781 if (ops == NULL && kind != NULL) {
782 char name[IFNAMSIZ];
783 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
784 /* We dropped the RTNL semaphore in order to
785 * perform the module load. So, even if we
786 * succeeded in loading the module we have to
787 * tell the caller to replay the request. We
788 * indicate this using -EAGAIN.
789 * We replay the request because the device may
790 * go away in the mean time.
791 */
792 rtnl_unlock();
793 request_module("sch_%s", name);
794 rtnl_lock();
795 ops = qdisc_lookup_ops(kind);
796 if (ops != NULL) {
797 /* We will try again qdisc_lookup_ops,
798 * so don't keep a reference.
799 */
800 module_put(ops->owner);
801 err = -EAGAIN;
802 goto err_out;
803 }
804 }
805 }
806#endif
807
808 err = -ENOENT;
809 if (ops == NULL)
810 goto err_out;
811
812 sch = qdisc_alloc(dev_queue, ops);
813 if (IS_ERR(sch)) {
814 err = PTR_ERR(sch);
815 goto err_out2;
816 }
817
818 sch->parent = parent;
819
820 if (handle == TC_H_INGRESS) {
821 sch->flags |= TCQ_F_INGRESS;
822 handle = TC_H_MAKE(TC_H_INGRESS, 0);
823 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
824 } else {
825 if (handle == 0) {
826 handle = qdisc_alloc_handle(dev);
827 err = -ENOMEM;
828 if (handle == 0)
829 goto err_out3;
830 }
831 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
832 }
833
834 sch->handle = handle;
835
836 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
837 if (tca[TCA_STAB]) {
838 stab = qdisc_get_stab(tca[TCA_STAB]);
839 if (IS_ERR(stab)) {
840 err = PTR_ERR(stab);
841 goto err_out4;
842 }
843 rcu_assign_pointer(sch->stab, stab);
844 }
845 if (tca[TCA_RATE]) {
846 spinlock_t *root_lock;
847
848 err = -EOPNOTSUPP;
849 if (sch->flags & TCQ_F_MQROOT)
850 goto err_out4;
851
852 if ((sch->parent != TC_H_ROOT) &&
853 !(sch->flags & TCQ_F_INGRESS) &&
854 (!p || !(p->flags & TCQ_F_MQROOT)))
855 root_lock = qdisc_root_sleeping_lock(sch);
856 else
857 root_lock = qdisc_lock(sch);
858
859 err = gen_new_estimator(&sch->bstats, &sch->rate_est,
860 root_lock, tca[TCA_RATE]);
861 if (err)
862 goto err_out4;
863 }
864
865 qdisc_list_add(sch);
866
867 return sch;
868 }
869err_out3:
870 dev_put(dev);
871 kfree((char *) sch - sch->padded);
872err_out2:
873 module_put(ops->owner);
874err_out:
875 *errp = err;
876 return NULL;
877
878err_out4:
879 /*
880 * Any broken qdiscs that would require a ops->reset() here?
881 * The qdisc was never in action so it shouldn't be necessary.
882 */
883 qdisc_put_stab(rtnl_dereference(sch->stab));
884 if (ops->destroy)
885 ops->destroy(sch);
886 goto err_out3;
887}
888
889static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
890{
891 struct qdisc_size_table *ostab, *stab = NULL;
892 int err = 0;
893
894 if (tca[TCA_OPTIONS]) {
895 if (sch->ops->change == NULL)
896 return -EINVAL;
897 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
898 if (err)
899 return err;
900 }
901
902 if (tca[TCA_STAB]) {
903 stab = qdisc_get_stab(tca[TCA_STAB]);
904 if (IS_ERR(stab))
905 return PTR_ERR(stab);
906 }
907
908 ostab = rtnl_dereference(sch->stab);
909 rcu_assign_pointer(sch->stab, stab);
910 qdisc_put_stab(ostab);
911
912 if (tca[TCA_RATE]) {
913 /* NB: ignores errors from replace_estimator
914 because change can't be undone. */
915 if (sch->flags & TCQ_F_MQROOT)
916 goto out;
917 gen_replace_estimator(&sch->bstats, &sch->rate_est,
918 qdisc_root_sleeping_lock(sch),
919 tca[TCA_RATE]);
920 }
921out:
922 return 0;
923}
924
925struct check_loop_arg {
926 struct qdisc_walker w;
927 struct Qdisc *p;
928 int depth;
929};
930
931static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
932
933static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
934{
935 struct check_loop_arg arg;
936
937 if (q->ops->cl_ops == NULL)
938 return 0;
939
940 arg.w.stop = arg.w.skip = arg.w.count = 0;
941 arg.w.fn = check_loop_fn;
942 arg.depth = depth;
943 arg.p = p;
944 q->ops->cl_ops->walk(q, &arg.w);
945 return arg.w.stop ? -ELOOP : 0;
946}
947
948static int
949check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
950{
951 struct Qdisc *leaf;
952 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
953 struct check_loop_arg *arg = (struct check_loop_arg *)w;
954
955 leaf = cops->leaf(q, cl);
956 if (leaf) {
957 if (leaf == arg->p || arg->depth > 7)
958 return -ELOOP;
959 return check_loop(leaf, arg->p, arg->depth + 1);
960 }
961 return 0;
962}
963
964/*
965 * Delete/get qdisc.
966 */
967
968static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
969{
970 struct net *net = sock_net(skb->sk);
971 struct tcmsg *tcm = NLMSG_DATA(n);
972 struct nlattr *tca[TCA_MAX + 1];
973 struct net_device *dev;
974 u32 clid = tcm->tcm_parent;
975 struct Qdisc *q = NULL;
976 struct Qdisc *p = NULL;
977 int err;
978
979 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
980 if (!dev)
981 return -ENODEV;
982
983 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
984 if (err < 0)
985 return err;
986
987 if (clid) {
988 if (clid != TC_H_ROOT) {
989 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
990 p = qdisc_lookup(dev, TC_H_MAJ(clid));
991 if (!p)
992 return -ENOENT;
993 q = qdisc_leaf(p, clid);
994 } else if (dev_ingress_queue(dev)) {
995 q = dev_ingress_queue(dev)->qdisc_sleeping;
996 }
997 } else {
998 q = dev->qdisc;
999 }
1000 if (!q)
1001 return -ENOENT;
1002
1003 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1004 return -EINVAL;
1005 } else {
1006 q = qdisc_lookup(dev, tcm->tcm_handle);
1007 if (!q)
1008 return -ENOENT;
1009 }
1010
1011 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1012 return -EINVAL;
1013
1014 if (n->nlmsg_type == RTM_DELQDISC) {
1015 if (!clid)
1016 return -EINVAL;
1017 if (q->handle == 0)
1018 return -ENOENT;
1019 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1020 if (err != 0)
1021 return err;
1022 } else {
1023 qdisc_notify(net, skb, n, clid, NULL, q);
1024 }
1025 return 0;
1026}
1027
1028/*
1029 * Create/change qdisc.
1030 */
1031
1032static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1033{
1034 struct net *net = sock_net(skb->sk);
1035 struct tcmsg *tcm;
1036 struct nlattr *tca[TCA_MAX + 1];
1037 struct net_device *dev;
1038 u32 clid;
1039 struct Qdisc *q, *p;
1040 int err;
1041
1042replay:
1043 /* Reinit, just in case something touches this. */
1044 tcm = NLMSG_DATA(n);
1045 clid = tcm->tcm_parent;
1046 q = p = NULL;
1047
1048 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1049 if (!dev)
1050 return -ENODEV;
1051
1052 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1053 if (err < 0)
1054 return err;
1055
1056 if (clid) {
1057 if (clid != TC_H_ROOT) {
1058 if (clid != TC_H_INGRESS) {
1059 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1060 if (!p)
1061 return -ENOENT;
1062 q = qdisc_leaf(p, clid);
1063 } else if (dev_ingress_queue_create(dev)) {
1064 q = dev_ingress_queue(dev)->qdisc_sleeping;
1065 }
1066 } else {
1067 q = dev->qdisc;
1068 }
1069
1070 /* It may be default qdisc, ignore it */
1071 if (q && q->handle == 0)
1072 q = NULL;
1073
1074 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1075 if (tcm->tcm_handle) {
1076 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1077 return -EEXIST;
1078 if (TC_H_MIN(tcm->tcm_handle))
1079 return -EINVAL;
1080 q = qdisc_lookup(dev, tcm->tcm_handle);
1081 if (!q)
1082 goto create_n_graft;
1083 if (n->nlmsg_flags & NLM_F_EXCL)
1084 return -EEXIST;
1085 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1086 return -EINVAL;
1087 if (q == p ||
1088 (p && check_loop(q, p, 0)))
1089 return -ELOOP;
1090 atomic_inc(&q->refcnt);
1091 goto graft;
1092 } else {
1093 if (!q)
1094 goto create_n_graft;
1095
1096 /* This magic test requires explanation.
1097 *
1098 * We know, that some child q is already
1099 * attached to this parent and have choice:
1100 * either to change it or to create/graft new one.
1101 *
1102 * 1. We are allowed to create/graft only
1103 * if CREATE and REPLACE flags are set.
1104 *
1105 * 2. If EXCL is set, requestor wanted to say,
1106 * that qdisc tcm_handle is not expected
1107 * to exist, so that we choose create/graft too.
1108 *
1109 * 3. The last case is when no flags are set.
1110 * Alas, it is sort of hole in API, we
1111 * cannot decide what to do unambiguously.
1112 * For now we select create/graft, if
1113 * user gave KIND, which does not match existing.
1114 */
1115 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1116 (n->nlmsg_flags & NLM_F_REPLACE) &&
1117 ((n->nlmsg_flags & NLM_F_EXCL) ||
1118 (tca[TCA_KIND] &&
1119 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1120 goto create_n_graft;
1121 }
1122 }
1123 } else {
1124 if (!tcm->tcm_handle)
1125 return -EINVAL;
1126 q = qdisc_lookup(dev, tcm->tcm_handle);
1127 }
1128
1129 /* Change qdisc parameters */
1130 if (q == NULL)
1131 return -ENOENT;
1132 if (n->nlmsg_flags & NLM_F_EXCL)
1133 return -EEXIST;
1134 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1135 return -EINVAL;
1136 err = qdisc_change(q, tca);
1137 if (err == 0)
1138 qdisc_notify(net, skb, n, clid, NULL, q);
1139 return err;
1140
1141create_n_graft:
1142 if (!(n->nlmsg_flags & NLM_F_CREATE))
1143 return -ENOENT;
1144 if (clid == TC_H_INGRESS) {
1145 if (dev_ingress_queue(dev))
1146 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1147 tcm->tcm_parent, tcm->tcm_parent,
1148 tca, &err);
1149 else
1150 err = -ENOENT;
1151 } else {
1152 struct netdev_queue *dev_queue;
1153
1154 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1155 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1156 else if (p)
1157 dev_queue = p->dev_queue;
1158 else
1159 dev_queue = netdev_get_tx_queue(dev, 0);
1160
1161 q = qdisc_create(dev, dev_queue, p,
1162 tcm->tcm_parent, tcm->tcm_handle,
1163 tca, &err);
1164 }
1165 if (q == NULL) {
1166 if (err == -EAGAIN)
1167 goto replay;
1168 return err;
1169 }
1170
1171graft:
1172 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1173 if (err) {
1174 if (q)
1175 qdisc_destroy(q);
1176 return err;
1177 }
1178
1179 return 0;
1180}
1181
1182static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1183 u32 pid, u32 seq, u16 flags, int event)
1184{
1185 struct tcmsg *tcm;
1186 struct nlmsghdr *nlh;
1187 unsigned char *b = skb_tail_pointer(skb);
1188 struct gnet_dump d;
1189 struct qdisc_size_table *stab;
1190
1191 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1192 tcm = NLMSG_DATA(nlh);
1193 tcm->tcm_family = AF_UNSPEC;
1194 tcm->tcm__pad1 = 0;
1195 tcm->tcm__pad2 = 0;
1196 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1197 tcm->tcm_parent = clid;
1198 tcm->tcm_handle = q->handle;
1199 tcm->tcm_info = atomic_read(&q->refcnt);
1200 NLA_PUT_STRING(skb, TCA_KIND, q->ops->id);
1201 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1202 goto nla_put_failure;
1203 q->qstats.qlen = q->q.qlen;
1204
1205 stab = rtnl_dereference(q->stab);
1206 if (stab && qdisc_dump_stab(skb, stab) < 0)
1207 goto nla_put_failure;
1208
1209 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1210 qdisc_root_sleeping_lock(q), &d) < 0)
1211 goto nla_put_failure;
1212
1213 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1214 goto nla_put_failure;
1215
1216 if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
1217 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1218 gnet_stats_copy_queue(&d, &q->qstats) < 0)
1219 goto nla_put_failure;
1220
1221 if (gnet_stats_finish_copy(&d) < 0)
1222 goto nla_put_failure;
1223
1224 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1225 return skb->len;
1226
1227nlmsg_failure:
1228nla_put_failure:
1229 nlmsg_trim(skb, b);
1230 return -1;
1231}
1232
1233static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1234{
1235 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1236}
1237
1238static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1239 struct nlmsghdr *n, u32 clid,
1240 struct Qdisc *old, struct Qdisc *new)
1241{
1242 struct sk_buff *skb;
1243 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
1244
1245 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1246 if (!skb)
1247 return -ENOBUFS;
1248
1249 if (old && !tc_qdisc_dump_ignore(old)) {
1250 if (tc_fill_qdisc(skb, old, clid, pid, n->nlmsg_seq,
1251 0, RTM_DELQDISC) < 0)
1252 goto err_out;
1253 }
1254 if (new && !tc_qdisc_dump_ignore(new)) {
1255 if (tc_fill_qdisc(skb, new, clid, pid, n->nlmsg_seq,
1256 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1257 goto err_out;
1258 }
1259
1260 if (skb->len)
1261 return rtnetlink_send(skb, net, pid, RTNLGRP_TC,
1262 n->nlmsg_flags & NLM_F_ECHO);
1263
1264err_out:
1265 kfree_skb(skb);
1266 return -EINVAL;
1267}
1268
1269static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1270 struct netlink_callback *cb,
1271 int *q_idx_p, int s_q_idx)
1272{
1273 int ret = 0, q_idx = *q_idx_p;
1274 struct Qdisc *q;
1275
1276 if (!root)
1277 return 0;
1278
1279 q = root;
1280 if (q_idx < s_q_idx) {
1281 q_idx++;
1282 } else {
1283 if (!tc_qdisc_dump_ignore(q) &&
1284 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid,
1285 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1286 goto done;
1287 q_idx++;
1288 }
1289 list_for_each_entry(q, &root->list, list) {
1290 if (q_idx < s_q_idx) {
1291 q_idx++;
1292 continue;
1293 }
1294 if (!tc_qdisc_dump_ignore(q) &&
1295 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid,
1296 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1297 goto done;
1298 q_idx++;
1299 }
1300
1301out:
1302 *q_idx_p = q_idx;
1303 return ret;
1304done:
1305 ret = -1;
1306 goto out;
1307}
1308
1309static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1310{
1311 struct net *net = sock_net(skb->sk);
1312 int idx, q_idx;
1313 int s_idx, s_q_idx;
1314 struct net_device *dev;
1315
1316 s_idx = cb->args[0];
1317 s_q_idx = q_idx = cb->args[1];
1318
1319 rcu_read_lock();
1320 idx = 0;
1321 for_each_netdev_rcu(net, dev) {
1322 struct netdev_queue *dev_queue;
1323
1324 if (idx < s_idx)
1325 goto cont;
1326 if (idx > s_idx)
1327 s_q_idx = 0;
1328 q_idx = 0;
1329
1330 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1331 goto done;
1332
1333 dev_queue = dev_ingress_queue(dev);
1334 if (dev_queue &&
1335 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1336 &q_idx, s_q_idx) < 0)
1337 goto done;
1338
1339cont:
1340 idx++;
1341 }
1342
1343done:
1344 rcu_read_unlock();
1345
1346 cb->args[0] = idx;
1347 cb->args[1] = q_idx;
1348
1349 return skb->len;
1350}
1351
1352
1353
1354/************************************************
1355 * Traffic classes manipulation. *
1356 ************************************************/
1357
1358
1359
1360static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1361{
1362 struct net *net = sock_net(skb->sk);
1363 struct tcmsg *tcm = NLMSG_DATA(n);
1364 struct nlattr *tca[TCA_MAX + 1];
1365 struct net_device *dev;
1366 struct Qdisc *q = NULL;
1367 const struct Qdisc_class_ops *cops;
1368 unsigned long cl = 0;
1369 unsigned long new_cl;
1370 u32 pid = tcm->tcm_parent;
1371 u32 clid = tcm->tcm_handle;
1372 u32 qid = TC_H_MAJ(clid);
1373 int err;
1374
1375 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1376 if (!dev)
1377 return -ENODEV;
1378
1379 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1380 if (err < 0)
1381 return err;
1382
1383 /*
1384 parent == TC_H_UNSPEC - unspecified parent.
1385 parent == TC_H_ROOT - class is root, which has no parent.
1386 parent == X:0 - parent is root class.
1387 parent == X:Y - parent is a node in hierarchy.
1388 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1389
1390 handle == 0:0 - generate handle from kernel pool.
1391 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1392 handle == X:Y - clear.
1393 handle == X:0 - root class.
1394 */
1395
1396 /* Step 1. Determine qdisc handle X:0 */
1397
1398 if (pid != TC_H_ROOT) {
1399 u32 qid1 = TC_H_MAJ(pid);
1400
1401 if (qid && qid1) {
1402 /* If both majors are known, they must be identical. */
1403 if (qid != qid1)
1404 return -EINVAL;
1405 } else if (qid1) {
1406 qid = qid1;
1407 } else if (qid == 0)
1408 qid = dev->qdisc->handle;
1409
1410 /* Now qid is genuine qdisc handle consistent
1411 * both with parent and child.
1412 *
1413 * TC_H_MAJ(pid) still may be unspecified, complete it now.
1414 */
1415 if (pid)
1416 pid = TC_H_MAKE(qid, pid);
1417 } else {
1418 if (qid == 0)
1419 qid = dev->qdisc->handle;
1420 }
1421
1422 /* OK. Locate qdisc */
1423 q = qdisc_lookup(dev, qid);
1424 if (!q)
1425 return -ENOENT;
1426
1427 /* An check that it supports classes */
1428 cops = q->ops->cl_ops;
1429 if (cops == NULL)
1430 return -EINVAL;
1431
1432 /* Now try to get class */
1433 if (clid == 0) {
1434 if (pid == TC_H_ROOT)
1435 clid = qid;
1436 } else
1437 clid = TC_H_MAKE(qid, clid);
1438
1439 if (clid)
1440 cl = cops->get(q, clid);
1441
1442 if (cl == 0) {
1443 err = -ENOENT;
1444 if (n->nlmsg_type != RTM_NEWTCLASS ||
1445 !(n->nlmsg_flags & NLM_F_CREATE))
1446 goto out;
1447 } else {
1448 switch (n->nlmsg_type) {
1449 case RTM_NEWTCLASS:
1450 err = -EEXIST;
1451 if (n->nlmsg_flags & NLM_F_EXCL)
1452 goto out;
1453 break;
1454 case RTM_DELTCLASS:
1455 err = -EOPNOTSUPP;
1456 if (cops->delete)
1457 err = cops->delete(q, cl);
1458 if (err == 0)
1459 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1460 goto out;
1461 case RTM_GETTCLASS:
1462 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1463 goto out;
1464 default:
1465 err = -EINVAL;
1466 goto out;
1467 }
1468 }
1469
1470 new_cl = cl;
1471 err = -EOPNOTSUPP;
1472 if (cops->change)
1473 err = cops->change(q, clid, pid, tca, &new_cl);
1474 if (err == 0)
1475 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1476
1477out:
1478 if (cl)
1479 cops->put(q, cl);
1480
1481 return err;
1482}
1483
1484
1485static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1486 unsigned long cl,
1487 u32 pid, u32 seq, u16 flags, int event)
1488{
1489 struct tcmsg *tcm;
1490 struct nlmsghdr *nlh;
1491 unsigned char *b = skb_tail_pointer(skb);
1492 struct gnet_dump d;
1493 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1494
1495 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1496 tcm = NLMSG_DATA(nlh);
1497 tcm->tcm_family = AF_UNSPEC;
1498 tcm->tcm__pad1 = 0;
1499 tcm->tcm__pad2 = 0;
1500 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1501 tcm->tcm_parent = q->handle;
1502 tcm->tcm_handle = q->handle;
1503 tcm->tcm_info = 0;
1504 NLA_PUT_STRING(skb, TCA_KIND, q->ops->id);
1505 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1506 goto nla_put_failure;
1507
1508 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1509 qdisc_root_sleeping_lock(q), &d) < 0)
1510 goto nla_put_failure;
1511
1512 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1513 goto nla_put_failure;
1514
1515 if (gnet_stats_finish_copy(&d) < 0)
1516 goto nla_put_failure;
1517
1518 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1519 return skb->len;
1520
1521nlmsg_failure:
1522nla_put_failure:
1523 nlmsg_trim(skb, b);
1524 return -1;
1525}
1526
1527static int tclass_notify(struct net *net, struct sk_buff *oskb,
1528 struct nlmsghdr *n, struct Qdisc *q,
1529 unsigned long cl, int event)
1530{
1531 struct sk_buff *skb;
1532 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
1533
1534 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1535 if (!skb)
1536 return -ENOBUFS;
1537
1538 if (tc_fill_tclass(skb, q, cl, pid, n->nlmsg_seq, 0, event) < 0) {
1539 kfree_skb(skb);
1540 return -EINVAL;
1541 }
1542
1543 return rtnetlink_send(skb, net, pid, RTNLGRP_TC,
1544 n->nlmsg_flags & NLM_F_ECHO);
1545}
1546
1547struct qdisc_dump_args {
1548 struct qdisc_walker w;
1549 struct sk_buff *skb;
1550 struct netlink_callback *cb;
1551};
1552
1553static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1554{
1555 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1556
1557 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).pid,
1558 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1559}
1560
1561static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1562 struct tcmsg *tcm, struct netlink_callback *cb,
1563 int *t_p, int s_t)
1564{
1565 struct qdisc_dump_args arg;
1566
1567 if (tc_qdisc_dump_ignore(q) ||
1568 *t_p < s_t || !q->ops->cl_ops ||
1569 (tcm->tcm_parent &&
1570 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1571 (*t_p)++;
1572 return 0;
1573 }
1574 if (*t_p > s_t)
1575 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1576 arg.w.fn = qdisc_class_dump;
1577 arg.skb = skb;
1578 arg.cb = cb;
1579 arg.w.stop = 0;
1580 arg.w.skip = cb->args[1];
1581 arg.w.count = 0;
1582 q->ops->cl_ops->walk(q, &arg.w);
1583 cb->args[1] = arg.w.count;
1584 if (arg.w.stop)
1585 return -1;
1586 (*t_p)++;
1587 return 0;
1588}
1589
1590static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1591 struct tcmsg *tcm, struct netlink_callback *cb,
1592 int *t_p, int s_t)
1593{
1594 struct Qdisc *q;
1595
1596 if (!root)
1597 return 0;
1598
1599 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1600 return -1;
1601
1602 list_for_each_entry(q, &root->list, list) {
1603 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1604 return -1;
1605 }
1606
1607 return 0;
1608}
1609
1610static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1611{
1612 struct tcmsg *tcm = (struct tcmsg *)NLMSG_DATA(cb->nlh);
1613 struct net *net = sock_net(skb->sk);
1614 struct netdev_queue *dev_queue;
1615 struct net_device *dev;
1616 int t, s_t;
1617
1618 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
1619 return 0;
1620 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1621 if (!dev)
1622 return 0;
1623
1624 s_t = cb->args[0];
1625 t = 0;
1626
1627 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1628 goto done;
1629
1630 dev_queue = dev_ingress_queue(dev);
1631 if (dev_queue &&
1632 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1633 &t, s_t) < 0)
1634 goto done;
1635
1636done:
1637 cb->args[0] = t;
1638
1639 dev_put(dev);
1640 return skb->len;
1641}
1642
1643/* Main classifier routine: scans classifier chain attached
1644 * to this qdisc, (optionally) tests for protocol and asks
1645 * specific classifiers.
1646 */
1647int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
1648 struct tcf_result *res)
1649{
1650 __be16 protocol = skb->protocol;
1651 int err;
1652
1653 for (; tp; tp = tp->next) {
1654 if (tp->protocol != protocol &&
1655 tp->protocol != htons(ETH_P_ALL))
1656 continue;
1657 err = tp->classify(skb, tp, res);
1658
1659 if (err >= 0) {
1660#ifdef CONFIG_NET_CLS_ACT
1661 if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
1662 skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
1663#endif
1664 return err;
1665 }
1666 }
1667 return -1;
1668}
1669EXPORT_SYMBOL(tc_classify_compat);
1670
1671int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1672 struct tcf_result *res)
1673{
1674 int err = 0;
1675#ifdef CONFIG_NET_CLS_ACT
1676 const struct tcf_proto *otp = tp;
1677reclassify:
1678#endif
1679
1680 err = tc_classify_compat(skb, tp, res);
1681#ifdef CONFIG_NET_CLS_ACT
1682 if (err == TC_ACT_RECLASSIFY) {
1683 u32 verd = G_TC_VERD(skb->tc_verd);
1684 tp = otp;
1685
1686 if (verd++ >= MAX_REC_LOOP) {
1687 if (net_ratelimit())
1688 pr_notice("%s: packet reclassify loop"
1689 " rule prio %u protocol %02x\n",
1690 tp->q->ops->id,
1691 tp->prio & 0xffff,
1692 ntohs(tp->protocol));
1693 return TC_ACT_SHOT;
1694 }
1695 skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
1696 goto reclassify;
1697 }
1698#endif
1699 return err;
1700}
1701EXPORT_SYMBOL(tc_classify);
1702
1703void tcf_destroy(struct tcf_proto *tp)
1704{
1705 tp->ops->destroy(tp);
1706 module_put(tp->ops->owner);
1707 kfree(tp);
1708}
1709
1710void tcf_destroy_chain(struct tcf_proto **fl)
1711{
1712 struct tcf_proto *tp;
1713
1714 while ((tp = *fl) != NULL) {
1715 *fl = tp->next;
1716 tcf_destroy(tp);
1717 }
1718}
1719EXPORT_SYMBOL(tcf_destroy_chain);
1720
1721#ifdef CONFIG_PROC_FS
1722static int psched_show(struct seq_file *seq, void *v)
1723{
1724 struct timespec ts;
1725
1726 hrtimer_get_res(CLOCK_MONOTONIC, &ts);
1727 seq_printf(seq, "%08x %08x %08x %08x\n",
1728 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1729 1000000,
1730 (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
1731
1732 return 0;
1733}
1734
1735static int psched_open(struct inode *inode, struct file *file)
1736{
1737 return single_open(file, psched_show, NULL);
1738}
1739
1740static const struct file_operations psched_fops = {
1741 .owner = THIS_MODULE,
1742 .open = psched_open,
1743 .read = seq_read,
1744 .llseek = seq_lseek,
1745 .release = single_release,
1746};
1747
1748static int __net_init psched_net_init(struct net *net)
1749{
1750 struct proc_dir_entry *e;
1751
1752 e = proc_net_fops_create(net, "psched", 0, &psched_fops);
1753 if (e == NULL)
1754 return -ENOMEM;
1755
1756 return 0;
1757}
1758
1759static void __net_exit psched_net_exit(struct net *net)
1760{
1761 proc_net_remove(net, "psched");
1762}
1763#else
1764static int __net_init psched_net_init(struct net *net)
1765{
1766 return 0;
1767}
1768
1769static void __net_exit psched_net_exit(struct net *net)
1770{
1771}
1772#endif
1773
1774static struct pernet_operations psched_net_ops = {
1775 .init = psched_net_init,
1776 .exit = psched_net_exit,
1777};
1778
1779static int __init pktsched_init(void)
1780{
1781 int err;
1782
1783 err = register_pernet_subsys(&psched_net_ops);
1784 if (err) {
1785 pr_err("pktsched_init: "
1786 "cannot initialize per netns operations\n");
1787 return err;
1788 }
1789
1790 register_qdisc(&pfifo_qdisc_ops);
1791 register_qdisc(&bfifo_qdisc_ops);
1792 register_qdisc(&pfifo_head_drop_qdisc_ops);
1793 register_qdisc(&mq_qdisc_ops);
1794
1795 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1796 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1797 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1798 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1799 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1800 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1801
1802 return 0;
1803}
1804
1805subsys_initcall(pktsched_init);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/sched/sch_api.c Packet scheduler API.
4 *
5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6 *
7 * Fixes:
8 *
9 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired.
10 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
11 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support
12 */
13
14#include <linux/module.h>
15#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/string.h>
18#include <linux/errno.h>
19#include <linux/skbuff.h>
20#include <linux/init.h>
21#include <linux/proc_fs.h>
22#include <linux/seq_file.h>
23#include <linux/kmod.h>
24#include <linux/list.h>
25#include <linux/hrtimer.h>
26#include <linux/slab.h>
27#include <linux/hashtable.h>
28
29#include <net/net_namespace.h>
30#include <net/sock.h>
31#include <net/netlink.h>
32#include <net/pkt_sched.h>
33#include <net/pkt_cls.h>
34
35#include <trace/events/qdisc.h>
36
37/*
38
39 Short review.
40 -------------
41
42 This file consists of two interrelated parts:
43
44 1. queueing disciplines manager frontend.
45 2. traffic classes manager frontend.
46
47 Generally, queueing discipline ("qdisc") is a black box,
48 which is able to enqueue packets and to dequeue them (when
49 device is ready to send something) in order and at times
50 determined by algorithm hidden in it.
51
52 qdisc's are divided to two categories:
53 - "queues", which have no internal structure visible from outside.
54 - "schedulers", which split all the packets to "traffic classes",
55 using "packet classifiers" (look at cls_api.c)
56
57 In turn, classes may have child qdiscs (as rule, queues)
58 attached to them etc. etc. etc.
59
60 The goal of the routines in this file is to translate
61 information supplied by user in the form of handles
62 to more intelligible for kernel form, to make some sanity
63 checks and part of work, which is common to all qdiscs
64 and to provide rtnetlink notifications.
65
66 All real intelligent work is done inside qdisc modules.
67
68
69
70 Every discipline has two major routines: enqueue and dequeue.
71
72 ---dequeue
73
74 dequeue usually returns a skb to send. It is allowed to return NULL,
75 but it does not mean that queue is empty, it just means that
76 discipline does not want to send anything this time.
77 Queue is really empty if q->q.qlen == 0.
78 For complicated disciplines with multiple queues q->q is not
79 real packet queue, but however q->q.qlen must be valid.
80
81 ---enqueue
82
83 enqueue returns 0, if packet was enqueued successfully.
84 If packet (this one or another one) was dropped, it returns
85 not zero error code.
86 NET_XMIT_DROP - this packet dropped
87 Expected action: do not backoff, but wait until queue will clear.
88 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
89 Expected action: backoff or ignore
90
91 Auxiliary routines:
92
93 ---peek
94
95 like dequeue but without removing a packet from the queue
96
97 ---reset
98
99 returns qdisc to initial state: purge all buffers, clear all
100 timers, counters (except for statistics) etc.
101
102 ---init
103
104 initializes newly created qdisc.
105
106 ---destroy
107
108 destroys resources allocated by init and during lifetime of qdisc.
109
110 ---change
111
112 changes qdisc parameters.
113 */
114
115/* Protects list of registered TC modules. It is pure SMP lock. */
116static DEFINE_RWLOCK(qdisc_mod_lock);
117
118
119/************************************************
120 * Queueing disciplines manipulation. *
121 ************************************************/
122
123
124/* The list of all installed queueing disciplines. */
125
126static struct Qdisc_ops *qdisc_base;
127
128/* Register/unregister queueing discipline */
129
130int register_qdisc(struct Qdisc_ops *qops)
131{
132 struct Qdisc_ops *q, **qp;
133 int rc = -EEXIST;
134
135 write_lock(&qdisc_mod_lock);
136 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
137 if (!strcmp(qops->id, q->id))
138 goto out;
139
140 if (qops->enqueue == NULL)
141 qops->enqueue = noop_qdisc_ops.enqueue;
142 if (qops->peek == NULL) {
143 if (qops->dequeue == NULL)
144 qops->peek = noop_qdisc_ops.peek;
145 else
146 goto out_einval;
147 }
148 if (qops->dequeue == NULL)
149 qops->dequeue = noop_qdisc_ops.dequeue;
150
151 if (qops->cl_ops) {
152 const struct Qdisc_class_ops *cops = qops->cl_ops;
153
154 if (!(cops->find && cops->walk && cops->leaf))
155 goto out_einval;
156
157 if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf))
158 goto out_einval;
159 }
160
161 qops->next = NULL;
162 *qp = qops;
163 rc = 0;
164out:
165 write_unlock(&qdisc_mod_lock);
166 return rc;
167
168out_einval:
169 rc = -EINVAL;
170 goto out;
171}
172EXPORT_SYMBOL(register_qdisc);
173
174int unregister_qdisc(struct Qdisc_ops *qops)
175{
176 struct Qdisc_ops *q, **qp;
177 int err = -ENOENT;
178
179 write_lock(&qdisc_mod_lock);
180 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
181 if (q == qops)
182 break;
183 if (q) {
184 *qp = q->next;
185 q->next = NULL;
186 err = 0;
187 }
188 write_unlock(&qdisc_mod_lock);
189 return err;
190}
191EXPORT_SYMBOL(unregister_qdisc);
192
193/* Get default qdisc if not otherwise specified */
194void qdisc_get_default(char *name, size_t len)
195{
196 read_lock(&qdisc_mod_lock);
197 strlcpy(name, default_qdisc_ops->id, len);
198 read_unlock(&qdisc_mod_lock);
199}
200
201static struct Qdisc_ops *qdisc_lookup_default(const char *name)
202{
203 struct Qdisc_ops *q = NULL;
204
205 for (q = qdisc_base; q; q = q->next) {
206 if (!strcmp(name, q->id)) {
207 if (!try_module_get(q->owner))
208 q = NULL;
209 break;
210 }
211 }
212
213 return q;
214}
215
216/* Set new default qdisc to use */
217int qdisc_set_default(const char *name)
218{
219 const struct Qdisc_ops *ops;
220
221 if (!capable(CAP_NET_ADMIN))
222 return -EPERM;
223
224 write_lock(&qdisc_mod_lock);
225 ops = qdisc_lookup_default(name);
226 if (!ops) {
227 /* Not found, drop lock and try to load module */
228 write_unlock(&qdisc_mod_lock);
229 request_module("sch_%s", name);
230 write_lock(&qdisc_mod_lock);
231
232 ops = qdisc_lookup_default(name);
233 }
234
235 if (ops) {
236 /* Set new default */
237 module_put(default_qdisc_ops->owner);
238 default_qdisc_ops = ops;
239 }
240 write_unlock(&qdisc_mod_lock);
241
242 return ops ? 0 : -ENOENT;
243}
244
245#ifdef CONFIG_NET_SCH_DEFAULT
246/* Set default value from kernel config */
247static int __init sch_default_qdisc(void)
248{
249 return qdisc_set_default(CONFIG_DEFAULT_NET_SCH);
250}
251late_initcall(sch_default_qdisc);
252#endif
253
254/* We know handle. Find qdisc among all qdisc's attached to device
255 * (root qdisc, all its children, children of children etc.)
256 * Note: caller either uses rtnl or rcu_read_lock()
257 */
258
259static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
260{
261 struct Qdisc *q;
262
263 if (!qdisc_dev(root))
264 return (root->handle == handle ? root : NULL);
265
266 if (!(root->flags & TCQ_F_BUILTIN) &&
267 root->handle == handle)
268 return root;
269
270 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle,
271 lockdep_rtnl_is_held()) {
272 if (q->handle == handle)
273 return q;
274 }
275 return NULL;
276}
277
278void qdisc_hash_add(struct Qdisc *q, bool invisible)
279{
280 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
281 ASSERT_RTNL();
282 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
283 if (invisible)
284 q->flags |= TCQ_F_INVISIBLE;
285 }
286}
287EXPORT_SYMBOL(qdisc_hash_add);
288
289void qdisc_hash_del(struct Qdisc *q)
290{
291 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
292 ASSERT_RTNL();
293 hash_del_rcu(&q->hash);
294 }
295}
296EXPORT_SYMBOL(qdisc_hash_del);
297
298struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
299{
300 struct Qdisc *q;
301
302 if (!handle)
303 return NULL;
304 q = qdisc_match_from_root(dev->qdisc, handle);
305 if (q)
306 goto out;
307
308 if (dev_ingress_queue(dev))
309 q = qdisc_match_from_root(
310 dev_ingress_queue(dev)->qdisc_sleeping,
311 handle);
312out:
313 return q;
314}
315
316struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle)
317{
318 struct netdev_queue *nq;
319 struct Qdisc *q;
320
321 if (!handle)
322 return NULL;
323 q = qdisc_match_from_root(dev->qdisc, handle);
324 if (q)
325 goto out;
326
327 nq = dev_ingress_queue_rcu(dev);
328 if (nq)
329 q = qdisc_match_from_root(nq->qdisc_sleeping, handle);
330out:
331 return q;
332}
333
334static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
335{
336 unsigned long cl;
337 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
338
339 if (cops == NULL)
340 return NULL;
341 cl = cops->find(p, classid);
342
343 if (cl == 0)
344 return NULL;
345 return cops->leaf(p, cl);
346}
347
348/* Find queueing discipline by name */
349
350static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
351{
352 struct Qdisc_ops *q = NULL;
353
354 if (kind) {
355 read_lock(&qdisc_mod_lock);
356 for (q = qdisc_base; q; q = q->next) {
357 if (nla_strcmp(kind, q->id) == 0) {
358 if (!try_module_get(q->owner))
359 q = NULL;
360 break;
361 }
362 }
363 read_unlock(&qdisc_mod_lock);
364 }
365 return q;
366}
367
368/* The linklayer setting were not transferred from iproute2, in older
369 * versions, and the rate tables lookup systems have been dropped in
370 * the kernel. To keep backward compatible with older iproute2 tc
371 * utils, we detect the linklayer setting by detecting if the rate
372 * table were modified.
373 *
374 * For linklayer ATM table entries, the rate table will be aligned to
375 * 48 bytes, thus some table entries will contain the same value. The
376 * mpu (min packet unit) is also encoded into the old rate table, thus
377 * starting from the mpu, we find low and high table entries for
378 * mapping this cell. If these entries contain the same value, when
379 * the rate tables have been modified for linklayer ATM.
380 *
381 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
382 * and then roundup to the next cell, calc the table entry one below,
383 * and compare.
384 */
385static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
386{
387 int low = roundup(r->mpu, 48);
388 int high = roundup(low+1, 48);
389 int cell_low = low >> r->cell_log;
390 int cell_high = (high >> r->cell_log) - 1;
391
392 /* rtab is too inaccurate at rates > 100Mbit/s */
393 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
394 pr_debug("TC linklayer: Giving up ATM detection\n");
395 return TC_LINKLAYER_ETHERNET;
396 }
397
398 if ((cell_high > cell_low) && (cell_high < 256)
399 && (rtab[cell_low] == rtab[cell_high])) {
400 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
401 cell_low, cell_high, rtab[cell_high]);
402 return TC_LINKLAYER_ATM;
403 }
404 return TC_LINKLAYER_ETHERNET;
405}
406
407static struct qdisc_rate_table *qdisc_rtab_list;
408
409struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
410 struct nlattr *tab,
411 struct netlink_ext_ack *extack)
412{
413 struct qdisc_rate_table *rtab;
414
415 if (tab == NULL || r->rate == 0 ||
416 r->cell_log == 0 || r->cell_log >= 32 ||
417 nla_len(tab) != TC_RTAB_SIZE) {
418 NL_SET_ERR_MSG(extack, "Invalid rate table parameters for searching");
419 return NULL;
420 }
421
422 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
423 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
424 !memcmp(&rtab->data, nla_data(tab), 1024)) {
425 rtab->refcnt++;
426 return rtab;
427 }
428 }
429
430 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
431 if (rtab) {
432 rtab->rate = *r;
433 rtab->refcnt = 1;
434 memcpy(rtab->data, nla_data(tab), 1024);
435 if (r->linklayer == TC_LINKLAYER_UNAWARE)
436 r->linklayer = __detect_linklayer(r, rtab->data);
437 rtab->next = qdisc_rtab_list;
438 qdisc_rtab_list = rtab;
439 } else {
440 NL_SET_ERR_MSG(extack, "Failed to allocate new qdisc rate table");
441 }
442 return rtab;
443}
444EXPORT_SYMBOL(qdisc_get_rtab);
445
446void qdisc_put_rtab(struct qdisc_rate_table *tab)
447{
448 struct qdisc_rate_table *rtab, **rtabp;
449
450 if (!tab || --tab->refcnt)
451 return;
452
453 for (rtabp = &qdisc_rtab_list;
454 (rtab = *rtabp) != NULL;
455 rtabp = &rtab->next) {
456 if (rtab == tab) {
457 *rtabp = rtab->next;
458 kfree(rtab);
459 return;
460 }
461 }
462}
463EXPORT_SYMBOL(qdisc_put_rtab);
464
465static LIST_HEAD(qdisc_stab_list);
466
467static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
468 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
469 [TCA_STAB_DATA] = { .type = NLA_BINARY },
470};
471
472static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt,
473 struct netlink_ext_ack *extack)
474{
475 struct nlattr *tb[TCA_STAB_MAX + 1];
476 struct qdisc_size_table *stab;
477 struct tc_sizespec *s;
478 unsigned int tsize = 0;
479 u16 *tab = NULL;
480 int err;
481
482 err = nla_parse_nested_deprecated(tb, TCA_STAB_MAX, opt, stab_policy,
483 extack);
484 if (err < 0)
485 return ERR_PTR(err);
486 if (!tb[TCA_STAB_BASE]) {
487 NL_SET_ERR_MSG(extack, "Size table base attribute is missing");
488 return ERR_PTR(-EINVAL);
489 }
490
491 s = nla_data(tb[TCA_STAB_BASE]);
492
493 if (s->tsize > 0) {
494 if (!tb[TCA_STAB_DATA]) {
495 NL_SET_ERR_MSG(extack, "Size table data attribute is missing");
496 return ERR_PTR(-EINVAL);
497 }
498 tab = nla_data(tb[TCA_STAB_DATA]);
499 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
500 }
501
502 if (tsize != s->tsize || (!tab && tsize > 0)) {
503 NL_SET_ERR_MSG(extack, "Invalid size of size table");
504 return ERR_PTR(-EINVAL);
505 }
506
507 list_for_each_entry(stab, &qdisc_stab_list, list) {
508 if (memcmp(&stab->szopts, s, sizeof(*s)))
509 continue;
510 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
511 continue;
512 stab->refcnt++;
513 return stab;
514 }
515
516 if (s->size_log > STAB_SIZE_LOG_MAX ||
517 s->cell_log > STAB_SIZE_LOG_MAX) {
518 NL_SET_ERR_MSG(extack, "Invalid logarithmic size of size table");
519 return ERR_PTR(-EINVAL);
520 }
521
522 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
523 if (!stab)
524 return ERR_PTR(-ENOMEM);
525
526 stab->refcnt = 1;
527 stab->szopts = *s;
528 if (tsize > 0)
529 memcpy(stab->data, tab, tsize * sizeof(u16));
530
531 list_add_tail(&stab->list, &qdisc_stab_list);
532
533 return stab;
534}
535
536void qdisc_put_stab(struct qdisc_size_table *tab)
537{
538 if (!tab)
539 return;
540
541 if (--tab->refcnt == 0) {
542 list_del(&tab->list);
543 kfree_rcu(tab, rcu);
544 }
545}
546EXPORT_SYMBOL(qdisc_put_stab);
547
548static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
549{
550 struct nlattr *nest;
551
552 nest = nla_nest_start_noflag(skb, TCA_STAB);
553 if (nest == NULL)
554 goto nla_put_failure;
555 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
556 goto nla_put_failure;
557 nla_nest_end(skb, nest);
558
559 return skb->len;
560
561nla_put_failure:
562 return -1;
563}
564
565void __qdisc_calculate_pkt_len(struct sk_buff *skb,
566 const struct qdisc_size_table *stab)
567{
568 int pkt_len, slot;
569
570 pkt_len = skb->len + stab->szopts.overhead;
571 if (unlikely(!stab->szopts.tsize))
572 goto out;
573
574 slot = pkt_len + stab->szopts.cell_align;
575 if (unlikely(slot < 0))
576 slot = 0;
577
578 slot >>= stab->szopts.cell_log;
579 if (likely(slot < stab->szopts.tsize))
580 pkt_len = stab->data[slot];
581 else
582 pkt_len = stab->data[stab->szopts.tsize - 1] *
583 (slot / stab->szopts.tsize) +
584 stab->data[slot % stab->szopts.tsize];
585
586 pkt_len <<= stab->szopts.size_log;
587out:
588 if (unlikely(pkt_len < 1))
589 pkt_len = 1;
590 qdisc_skb_cb(skb)->pkt_len = pkt_len;
591}
592EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
593
594void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
595{
596 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
597 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
598 txt, qdisc->ops->id, qdisc->handle >> 16);
599 qdisc->flags |= TCQ_F_WARN_NONWC;
600 }
601}
602EXPORT_SYMBOL(qdisc_warn_nonwc);
603
604static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
605{
606 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
607 timer);
608
609 rcu_read_lock();
610 __netif_schedule(qdisc_root(wd->qdisc));
611 rcu_read_unlock();
612
613 return HRTIMER_NORESTART;
614}
615
616void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
617 clockid_t clockid)
618{
619 hrtimer_init(&wd->timer, clockid, HRTIMER_MODE_ABS_PINNED);
620 wd->timer.function = qdisc_watchdog;
621 wd->qdisc = qdisc;
622}
623EXPORT_SYMBOL(qdisc_watchdog_init_clockid);
624
625void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
626{
627 qdisc_watchdog_init_clockid(wd, qdisc, CLOCK_MONOTONIC);
628}
629EXPORT_SYMBOL(qdisc_watchdog_init);
630
631void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires,
632 u64 delta_ns)
633{
634 if (test_bit(__QDISC_STATE_DEACTIVATED,
635 &qdisc_root_sleeping(wd->qdisc)->state))
636 return;
637
638 if (hrtimer_is_queued(&wd->timer)) {
639 /* If timer is already set in [expires, expires + delta_ns],
640 * do not reprogram it.
641 */
642 if (wd->last_expires - expires <= delta_ns)
643 return;
644 }
645
646 wd->last_expires = expires;
647 hrtimer_start_range_ns(&wd->timer,
648 ns_to_ktime(expires),
649 delta_ns,
650 HRTIMER_MODE_ABS_PINNED);
651}
652EXPORT_SYMBOL(qdisc_watchdog_schedule_range_ns);
653
654void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
655{
656 hrtimer_cancel(&wd->timer);
657}
658EXPORT_SYMBOL(qdisc_watchdog_cancel);
659
660static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
661{
662 struct hlist_head *h;
663 unsigned int i;
664
665 h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL);
666
667 if (h != NULL) {
668 for (i = 0; i < n; i++)
669 INIT_HLIST_HEAD(&h[i]);
670 }
671 return h;
672}
673
674void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
675{
676 struct Qdisc_class_common *cl;
677 struct hlist_node *next;
678 struct hlist_head *nhash, *ohash;
679 unsigned int nsize, nmask, osize;
680 unsigned int i, h;
681
682 /* Rehash when load factor exceeds 0.75 */
683 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
684 return;
685 nsize = clhash->hashsize * 2;
686 nmask = nsize - 1;
687 nhash = qdisc_class_hash_alloc(nsize);
688 if (nhash == NULL)
689 return;
690
691 ohash = clhash->hash;
692 osize = clhash->hashsize;
693
694 sch_tree_lock(sch);
695 for (i = 0; i < osize; i++) {
696 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
697 h = qdisc_class_hash(cl->classid, nmask);
698 hlist_add_head(&cl->hnode, &nhash[h]);
699 }
700 }
701 clhash->hash = nhash;
702 clhash->hashsize = nsize;
703 clhash->hashmask = nmask;
704 sch_tree_unlock(sch);
705
706 kvfree(ohash);
707}
708EXPORT_SYMBOL(qdisc_class_hash_grow);
709
710int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
711{
712 unsigned int size = 4;
713
714 clhash->hash = qdisc_class_hash_alloc(size);
715 if (!clhash->hash)
716 return -ENOMEM;
717 clhash->hashsize = size;
718 clhash->hashmask = size - 1;
719 clhash->hashelems = 0;
720 return 0;
721}
722EXPORT_SYMBOL(qdisc_class_hash_init);
723
724void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
725{
726 kvfree(clhash->hash);
727}
728EXPORT_SYMBOL(qdisc_class_hash_destroy);
729
730void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
731 struct Qdisc_class_common *cl)
732{
733 unsigned int h;
734
735 INIT_HLIST_NODE(&cl->hnode);
736 h = qdisc_class_hash(cl->classid, clhash->hashmask);
737 hlist_add_head(&cl->hnode, &clhash->hash[h]);
738 clhash->hashelems++;
739}
740EXPORT_SYMBOL(qdisc_class_hash_insert);
741
742void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
743 struct Qdisc_class_common *cl)
744{
745 hlist_del(&cl->hnode);
746 clhash->hashelems--;
747}
748EXPORT_SYMBOL(qdisc_class_hash_remove);
749
750/* Allocate an unique handle from space managed by kernel
751 * Possible range is [8000-FFFF]:0000 (0x8000 values)
752 */
753static u32 qdisc_alloc_handle(struct net_device *dev)
754{
755 int i = 0x8000;
756 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
757
758 do {
759 autohandle += TC_H_MAKE(0x10000U, 0);
760 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
761 autohandle = TC_H_MAKE(0x80000000U, 0);
762 if (!qdisc_lookup(dev, autohandle))
763 return autohandle;
764 cond_resched();
765 } while (--i > 0);
766
767 return 0;
768}
769
770void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len)
771{
772 bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED;
773 const struct Qdisc_class_ops *cops;
774 unsigned long cl;
775 u32 parentid;
776 bool notify;
777 int drops;
778
779 if (n == 0 && len == 0)
780 return;
781 drops = max_t(int, n, 0);
782 rcu_read_lock();
783 while ((parentid = sch->parent)) {
784 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
785 break;
786
787 if (sch->flags & TCQ_F_NOPARENT)
788 break;
789 /* Notify parent qdisc only if child qdisc becomes empty.
790 *
791 * If child was empty even before update then backlog
792 * counter is screwed and we skip notification because
793 * parent class is already passive.
794 *
795 * If the original child was offloaded then it is allowed
796 * to be seem as empty, so the parent is notified anyway.
797 */
798 notify = !sch->q.qlen && !WARN_ON_ONCE(!n &&
799 !qdisc_is_offloaded);
800 /* TODO: perform the search on a per txq basis */
801 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
802 if (sch == NULL) {
803 WARN_ON_ONCE(parentid != TC_H_ROOT);
804 break;
805 }
806 cops = sch->ops->cl_ops;
807 if (notify && cops->qlen_notify) {
808 cl = cops->find(sch, parentid);
809 cops->qlen_notify(sch, cl);
810 }
811 sch->q.qlen -= n;
812 sch->qstats.backlog -= len;
813 __qdisc_qstats_drop(sch, drops);
814 }
815 rcu_read_unlock();
816}
817EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
818
819int qdisc_offload_dump_helper(struct Qdisc *sch, enum tc_setup_type type,
820 void *type_data)
821{
822 struct net_device *dev = qdisc_dev(sch);
823 int err;
824
825 sch->flags &= ~TCQ_F_OFFLOADED;
826 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
827 return 0;
828
829 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
830 if (err == -EOPNOTSUPP)
831 return 0;
832
833 if (!err)
834 sch->flags |= TCQ_F_OFFLOADED;
835
836 return err;
837}
838EXPORT_SYMBOL(qdisc_offload_dump_helper);
839
840void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
841 struct Qdisc *new, struct Qdisc *old,
842 enum tc_setup_type type, void *type_data,
843 struct netlink_ext_ack *extack)
844{
845 bool any_qdisc_is_offloaded;
846 int err;
847
848 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
849 return;
850
851 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
852
853 /* Don't report error if the graft is part of destroy operation. */
854 if (!err || !new || new == &noop_qdisc)
855 return;
856
857 /* Don't report error if the parent, the old child and the new
858 * one are not offloaded.
859 */
860 any_qdisc_is_offloaded = new->flags & TCQ_F_OFFLOADED;
861 any_qdisc_is_offloaded |= sch && sch->flags & TCQ_F_OFFLOADED;
862 any_qdisc_is_offloaded |= old && old->flags & TCQ_F_OFFLOADED;
863
864 if (any_qdisc_is_offloaded)
865 NL_SET_ERR_MSG(extack, "Offloading graft operation failed.");
866}
867EXPORT_SYMBOL(qdisc_offload_graft_helper);
868
869static void qdisc_offload_graft_root(struct net_device *dev,
870 struct Qdisc *new, struct Qdisc *old,
871 struct netlink_ext_ack *extack)
872{
873 struct tc_root_qopt_offload graft_offload = {
874 .command = TC_ROOT_GRAFT,
875 .handle = new ? new->handle : 0,
876 .ingress = (new && new->flags & TCQ_F_INGRESS) ||
877 (old && old->flags & TCQ_F_INGRESS),
878 };
879
880 qdisc_offload_graft_helper(dev, NULL, new, old,
881 TC_SETUP_ROOT_QDISC, &graft_offload, extack);
882}
883
884static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
885 u32 portid, u32 seq, u16 flags, int event)
886{
887 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
888 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
889 struct tcmsg *tcm;
890 struct nlmsghdr *nlh;
891 unsigned char *b = skb_tail_pointer(skb);
892 struct gnet_dump d;
893 struct qdisc_size_table *stab;
894 u32 block_index;
895 __u32 qlen;
896
897 cond_resched();
898 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
899 if (!nlh)
900 goto out_nlmsg_trim;
901 tcm = nlmsg_data(nlh);
902 tcm->tcm_family = AF_UNSPEC;
903 tcm->tcm__pad1 = 0;
904 tcm->tcm__pad2 = 0;
905 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
906 tcm->tcm_parent = clid;
907 tcm->tcm_handle = q->handle;
908 tcm->tcm_info = refcount_read(&q->refcnt);
909 if (nla_put_string(skb, TCA_KIND, q->ops->id))
910 goto nla_put_failure;
911 if (q->ops->ingress_block_get) {
912 block_index = q->ops->ingress_block_get(q);
913 if (block_index &&
914 nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index))
915 goto nla_put_failure;
916 }
917 if (q->ops->egress_block_get) {
918 block_index = q->ops->egress_block_get(q);
919 if (block_index &&
920 nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index))
921 goto nla_put_failure;
922 }
923 if (q->ops->dump && q->ops->dump(q, skb) < 0)
924 goto nla_put_failure;
925 if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED)))
926 goto nla_put_failure;
927 qlen = qdisc_qlen_sum(q);
928
929 stab = rtnl_dereference(q->stab);
930 if (stab && qdisc_dump_stab(skb, stab) < 0)
931 goto nla_put_failure;
932
933 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
934 NULL, &d, TCA_PAD) < 0)
935 goto nla_put_failure;
936
937 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
938 goto nla_put_failure;
939
940 if (qdisc_is_percpu_stats(q)) {
941 cpu_bstats = q->cpu_bstats;
942 cpu_qstats = q->cpu_qstats;
943 }
944
945 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(q),
946 &d, cpu_bstats, &q->bstats) < 0 ||
947 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
948 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
949 goto nla_put_failure;
950
951 if (gnet_stats_finish_copy(&d) < 0)
952 goto nla_put_failure;
953
954 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
955 return skb->len;
956
957out_nlmsg_trim:
958nla_put_failure:
959 nlmsg_trim(skb, b);
960 return -1;
961}
962
963static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible)
964{
965 if (q->flags & TCQ_F_BUILTIN)
966 return true;
967 if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible)
968 return true;
969
970 return false;
971}
972
973static int qdisc_notify(struct net *net, struct sk_buff *oskb,
974 struct nlmsghdr *n, u32 clid,
975 struct Qdisc *old, struct Qdisc *new)
976{
977 struct sk_buff *skb;
978 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
979
980 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
981 if (!skb)
982 return -ENOBUFS;
983
984 if (old && !tc_qdisc_dump_ignore(old, false)) {
985 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
986 0, RTM_DELQDISC) < 0)
987 goto err_out;
988 }
989 if (new && !tc_qdisc_dump_ignore(new, false)) {
990 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
991 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
992 goto err_out;
993 }
994
995 if (skb->len)
996 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
997 n->nlmsg_flags & NLM_F_ECHO);
998
999err_out:
1000 kfree_skb(skb);
1001 return -EINVAL;
1002}
1003
1004static void notify_and_destroy(struct net *net, struct sk_buff *skb,
1005 struct nlmsghdr *n, u32 clid,
1006 struct Qdisc *old, struct Qdisc *new)
1007{
1008 if (new || old)
1009 qdisc_notify(net, skb, n, clid, old, new);
1010
1011 if (old)
1012 qdisc_put(old);
1013}
1014
1015static void qdisc_clear_nolock(struct Qdisc *sch)
1016{
1017 sch->flags &= ~TCQ_F_NOLOCK;
1018 if (!(sch->flags & TCQ_F_CPUSTATS))
1019 return;
1020
1021 free_percpu(sch->cpu_bstats);
1022 free_percpu(sch->cpu_qstats);
1023 sch->cpu_bstats = NULL;
1024 sch->cpu_qstats = NULL;
1025 sch->flags &= ~TCQ_F_CPUSTATS;
1026}
1027
1028/* Graft qdisc "new" to class "classid" of qdisc "parent" or
1029 * to device "dev".
1030 *
1031 * When appropriate send a netlink notification using 'skb'
1032 * and "n".
1033 *
1034 * On success, destroy old qdisc.
1035 */
1036
1037static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
1038 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
1039 struct Qdisc *new, struct Qdisc *old,
1040 struct netlink_ext_ack *extack)
1041{
1042 struct Qdisc *q = old;
1043 struct net *net = dev_net(dev);
1044
1045 if (parent == NULL) {
1046 unsigned int i, num_q, ingress;
1047
1048 ingress = 0;
1049 num_q = dev->num_tx_queues;
1050 if ((q && q->flags & TCQ_F_INGRESS) ||
1051 (new && new->flags & TCQ_F_INGRESS)) {
1052 num_q = 1;
1053 ingress = 1;
1054 if (!dev_ingress_queue(dev)) {
1055 NL_SET_ERR_MSG(extack, "Device does not have an ingress queue");
1056 return -ENOENT;
1057 }
1058 }
1059
1060 if (dev->flags & IFF_UP)
1061 dev_deactivate(dev);
1062
1063 qdisc_offload_graft_root(dev, new, old, extack);
1064
1065 if (new && new->ops->attach)
1066 goto skip;
1067
1068 for (i = 0; i < num_q; i++) {
1069 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
1070
1071 if (!ingress)
1072 dev_queue = netdev_get_tx_queue(dev, i);
1073
1074 old = dev_graft_qdisc(dev_queue, new);
1075 if (new && i > 0)
1076 qdisc_refcount_inc(new);
1077
1078 if (!ingress)
1079 qdisc_put(old);
1080 }
1081
1082skip:
1083 if (!ingress) {
1084 notify_and_destroy(net, skb, n, classid,
1085 dev->qdisc, new);
1086 if (new && !new->ops->attach)
1087 qdisc_refcount_inc(new);
1088 dev->qdisc = new ? : &noop_qdisc;
1089
1090 if (new && new->ops->attach)
1091 new->ops->attach(new);
1092 } else {
1093 notify_and_destroy(net, skb, n, classid, old, new);
1094 }
1095
1096 if (dev->flags & IFF_UP)
1097 dev_activate(dev);
1098 } else {
1099 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
1100 unsigned long cl;
1101 int err;
1102
1103 /* Only support running class lockless if parent is lockless */
1104 if (new && (new->flags & TCQ_F_NOLOCK) && !(parent->flags & TCQ_F_NOLOCK))
1105 qdisc_clear_nolock(new);
1106
1107 if (!cops || !cops->graft)
1108 return -EOPNOTSUPP;
1109
1110 cl = cops->find(parent, classid);
1111 if (!cl) {
1112 NL_SET_ERR_MSG(extack, "Specified class not found");
1113 return -ENOENT;
1114 }
1115
1116 err = cops->graft(parent, cl, new, &old, extack);
1117 if (err)
1118 return err;
1119 notify_and_destroy(net, skb, n, classid, old, new);
1120 }
1121 return 0;
1122}
1123
1124static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca,
1125 struct netlink_ext_ack *extack)
1126{
1127 u32 block_index;
1128
1129 if (tca[TCA_INGRESS_BLOCK]) {
1130 block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]);
1131
1132 if (!block_index) {
1133 NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0");
1134 return -EINVAL;
1135 }
1136 if (!sch->ops->ingress_block_set) {
1137 NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported");
1138 return -EOPNOTSUPP;
1139 }
1140 sch->ops->ingress_block_set(sch, block_index);
1141 }
1142 if (tca[TCA_EGRESS_BLOCK]) {
1143 block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]);
1144
1145 if (!block_index) {
1146 NL_SET_ERR_MSG(extack, "Egress block index cannot be 0");
1147 return -EINVAL;
1148 }
1149 if (!sch->ops->egress_block_set) {
1150 NL_SET_ERR_MSG(extack, "Egress block sharing is not supported");
1151 return -EOPNOTSUPP;
1152 }
1153 sch->ops->egress_block_set(sch, block_index);
1154 }
1155 return 0;
1156}
1157
1158/*
1159 Allocate and initialize new qdisc.
1160
1161 Parameters are passed via opt.
1162 */
1163
1164static struct Qdisc *qdisc_create(struct net_device *dev,
1165 struct netdev_queue *dev_queue,
1166 struct Qdisc *p, u32 parent, u32 handle,
1167 struct nlattr **tca, int *errp,
1168 struct netlink_ext_ack *extack)
1169{
1170 int err;
1171 struct nlattr *kind = tca[TCA_KIND];
1172 struct Qdisc *sch;
1173 struct Qdisc_ops *ops;
1174 struct qdisc_size_table *stab;
1175
1176 ops = qdisc_lookup_ops(kind);
1177#ifdef CONFIG_MODULES
1178 if (ops == NULL && kind != NULL) {
1179 char name[IFNAMSIZ];
1180 if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) {
1181 /* We dropped the RTNL semaphore in order to
1182 * perform the module load. So, even if we
1183 * succeeded in loading the module we have to
1184 * tell the caller to replay the request. We
1185 * indicate this using -EAGAIN.
1186 * We replay the request because the device may
1187 * go away in the mean time.
1188 */
1189 rtnl_unlock();
1190 request_module("sch_%s", name);
1191 rtnl_lock();
1192 ops = qdisc_lookup_ops(kind);
1193 if (ops != NULL) {
1194 /* We will try again qdisc_lookup_ops,
1195 * so don't keep a reference.
1196 */
1197 module_put(ops->owner);
1198 err = -EAGAIN;
1199 goto err_out;
1200 }
1201 }
1202 }
1203#endif
1204
1205 err = -ENOENT;
1206 if (!ops) {
1207 NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1208 goto err_out;
1209 }
1210
1211 sch = qdisc_alloc(dev_queue, ops, extack);
1212 if (IS_ERR(sch)) {
1213 err = PTR_ERR(sch);
1214 goto err_out2;
1215 }
1216
1217 sch->parent = parent;
1218
1219 if (handle == TC_H_INGRESS) {
1220 sch->flags |= TCQ_F_INGRESS;
1221 handle = TC_H_MAKE(TC_H_INGRESS, 0);
1222 } else {
1223 if (handle == 0) {
1224 handle = qdisc_alloc_handle(dev);
1225 if (handle == 0) {
1226 NL_SET_ERR_MSG(extack, "Maximum number of qdisc handles was exceeded");
1227 err = -ENOSPC;
1228 goto err_out3;
1229 }
1230 }
1231 if (!netif_is_multiqueue(dev))
1232 sch->flags |= TCQ_F_ONETXQUEUE;
1233 }
1234
1235 sch->handle = handle;
1236
1237 /* This exist to keep backward compatible with a userspace
1238 * loophole, what allowed userspace to get IFF_NO_QUEUE
1239 * facility on older kernels by setting tx_queue_len=0 (prior
1240 * to qdisc init), and then forgot to reinit tx_queue_len
1241 * before again attaching a qdisc.
1242 */
1243 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) {
1244 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
1245 netdev_info(dev, "Caught tx_queue_len zero misconfig\n");
1246 }
1247
1248 err = qdisc_block_indexes_set(sch, tca, extack);
1249 if (err)
1250 goto err_out3;
1251
1252 if (ops->init) {
1253 err = ops->init(sch, tca[TCA_OPTIONS], extack);
1254 if (err != 0)
1255 goto err_out5;
1256 }
1257
1258 if (tca[TCA_STAB]) {
1259 stab = qdisc_get_stab(tca[TCA_STAB], extack);
1260 if (IS_ERR(stab)) {
1261 err = PTR_ERR(stab);
1262 goto err_out4;
1263 }
1264 rcu_assign_pointer(sch->stab, stab);
1265 }
1266 if (tca[TCA_RATE]) {
1267 seqcount_t *running;
1268
1269 err = -EOPNOTSUPP;
1270 if (sch->flags & TCQ_F_MQROOT) {
1271 NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc");
1272 goto err_out4;
1273 }
1274
1275 if (sch->parent != TC_H_ROOT &&
1276 !(sch->flags & TCQ_F_INGRESS) &&
1277 (!p || !(p->flags & TCQ_F_MQROOT)))
1278 running = qdisc_root_sleeping_running(sch);
1279 else
1280 running = &sch->running;
1281
1282 err = gen_new_estimator(&sch->bstats,
1283 sch->cpu_bstats,
1284 &sch->rate_est,
1285 NULL,
1286 running,
1287 tca[TCA_RATE]);
1288 if (err) {
1289 NL_SET_ERR_MSG(extack, "Failed to generate new estimator");
1290 goto err_out4;
1291 }
1292 }
1293
1294 qdisc_hash_add(sch, false);
1295 trace_qdisc_create(ops, dev, parent);
1296
1297 return sch;
1298
1299err_out5:
1300 /* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */
1301 if (ops->destroy)
1302 ops->destroy(sch);
1303err_out3:
1304 dev_put(dev);
1305 qdisc_free(sch);
1306err_out2:
1307 module_put(ops->owner);
1308err_out:
1309 *errp = err;
1310 return NULL;
1311
1312err_out4:
1313 /*
1314 * Any broken qdiscs that would require a ops->reset() here?
1315 * The qdisc was never in action so it shouldn't be necessary.
1316 */
1317 qdisc_put_stab(rtnl_dereference(sch->stab));
1318 if (ops->destroy)
1319 ops->destroy(sch);
1320 goto err_out3;
1321}
1322
1323static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
1324 struct netlink_ext_ack *extack)
1325{
1326 struct qdisc_size_table *ostab, *stab = NULL;
1327 int err = 0;
1328
1329 if (tca[TCA_OPTIONS]) {
1330 if (!sch->ops->change) {
1331 NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc");
1332 return -EINVAL;
1333 }
1334 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
1335 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
1336 return -EOPNOTSUPP;
1337 }
1338 err = sch->ops->change(sch, tca[TCA_OPTIONS], extack);
1339 if (err)
1340 return err;
1341 }
1342
1343 if (tca[TCA_STAB]) {
1344 stab = qdisc_get_stab(tca[TCA_STAB], extack);
1345 if (IS_ERR(stab))
1346 return PTR_ERR(stab);
1347 }
1348
1349 ostab = rtnl_dereference(sch->stab);
1350 rcu_assign_pointer(sch->stab, stab);
1351 qdisc_put_stab(ostab);
1352
1353 if (tca[TCA_RATE]) {
1354 /* NB: ignores errors from replace_estimator
1355 because change can't be undone. */
1356 if (sch->flags & TCQ_F_MQROOT)
1357 goto out;
1358 gen_replace_estimator(&sch->bstats,
1359 sch->cpu_bstats,
1360 &sch->rate_est,
1361 NULL,
1362 qdisc_root_sleeping_running(sch),
1363 tca[TCA_RATE]);
1364 }
1365out:
1366 return 0;
1367}
1368
1369struct check_loop_arg {
1370 struct qdisc_walker w;
1371 struct Qdisc *p;
1372 int depth;
1373};
1374
1375static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1376 struct qdisc_walker *w);
1377
1378static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1379{
1380 struct check_loop_arg arg;
1381
1382 if (q->ops->cl_ops == NULL)
1383 return 0;
1384
1385 arg.w.stop = arg.w.skip = arg.w.count = 0;
1386 arg.w.fn = check_loop_fn;
1387 arg.depth = depth;
1388 arg.p = p;
1389 q->ops->cl_ops->walk(q, &arg.w);
1390 return arg.w.stop ? -ELOOP : 0;
1391}
1392
1393static int
1394check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1395{
1396 struct Qdisc *leaf;
1397 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1398 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1399
1400 leaf = cops->leaf(q, cl);
1401 if (leaf) {
1402 if (leaf == arg->p || arg->depth > 7)
1403 return -ELOOP;
1404 return check_loop(leaf, arg->p, arg->depth + 1);
1405 }
1406 return 0;
1407}
1408
1409const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = {
1410 [TCA_KIND] = { .type = NLA_STRING },
1411 [TCA_RATE] = { .type = NLA_BINARY,
1412 .len = sizeof(struct tc_estimator) },
1413 [TCA_STAB] = { .type = NLA_NESTED },
1414 [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG },
1415 [TCA_CHAIN] = { .type = NLA_U32 },
1416 [TCA_INGRESS_BLOCK] = { .type = NLA_U32 },
1417 [TCA_EGRESS_BLOCK] = { .type = NLA_U32 },
1418};
1419
1420/*
1421 * Delete/get qdisc.
1422 */
1423
1424static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1425 struct netlink_ext_ack *extack)
1426{
1427 struct net *net = sock_net(skb->sk);
1428 struct tcmsg *tcm = nlmsg_data(n);
1429 struct nlattr *tca[TCA_MAX + 1];
1430 struct net_device *dev;
1431 u32 clid;
1432 struct Qdisc *q = NULL;
1433 struct Qdisc *p = NULL;
1434 int err;
1435
1436 if ((n->nlmsg_type != RTM_GETQDISC) &&
1437 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1438 return -EPERM;
1439
1440 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1441 rtm_tca_policy, extack);
1442 if (err < 0)
1443 return err;
1444
1445 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1446 if (!dev)
1447 return -ENODEV;
1448
1449 clid = tcm->tcm_parent;
1450 if (clid) {
1451 if (clid != TC_H_ROOT) {
1452 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1453 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1454 if (!p) {
1455 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid");
1456 return -ENOENT;
1457 }
1458 q = qdisc_leaf(p, clid);
1459 } else if (dev_ingress_queue(dev)) {
1460 q = dev_ingress_queue(dev)->qdisc_sleeping;
1461 }
1462 } else {
1463 q = dev->qdisc;
1464 }
1465 if (!q) {
1466 NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device");
1467 return -ENOENT;
1468 }
1469
1470 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) {
1471 NL_SET_ERR_MSG(extack, "Invalid handle");
1472 return -EINVAL;
1473 }
1474 } else {
1475 q = qdisc_lookup(dev, tcm->tcm_handle);
1476 if (!q) {
1477 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle");
1478 return -ENOENT;
1479 }
1480 }
1481
1482 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1483 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1484 return -EINVAL;
1485 }
1486
1487 if (n->nlmsg_type == RTM_DELQDISC) {
1488 if (!clid) {
1489 NL_SET_ERR_MSG(extack, "Classid cannot be zero");
1490 return -EINVAL;
1491 }
1492 if (q->handle == 0) {
1493 NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero");
1494 return -ENOENT;
1495 }
1496 err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack);
1497 if (err != 0)
1498 return err;
1499 } else {
1500 qdisc_notify(net, skb, n, clid, NULL, q);
1501 }
1502 return 0;
1503}
1504
1505/*
1506 * Create/change qdisc.
1507 */
1508
1509static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1510 struct netlink_ext_ack *extack)
1511{
1512 struct net *net = sock_net(skb->sk);
1513 struct tcmsg *tcm;
1514 struct nlattr *tca[TCA_MAX + 1];
1515 struct net_device *dev;
1516 u32 clid;
1517 struct Qdisc *q, *p;
1518 int err;
1519
1520 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1521 return -EPERM;
1522
1523replay:
1524 /* Reinit, just in case something touches this. */
1525 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1526 rtm_tca_policy, extack);
1527 if (err < 0)
1528 return err;
1529
1530 tcm = nlmsg_data(n);
1531 clid = tcm->tcm_parent;
1532 q = p = NULL;
1533
1534 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1535 if (!dev)
1536 return -ENODEV;
1537
1538
1539 if (clid) {
1540 if (clid != TC_H_ROOT) {
1541 if (clid != TC_H_INGRESS) {
1542 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1543 if (!p) {
1544 NL_SET_ERR_MSG(extack, "Failed to find specified qdisc");
1545 return -ENOENT;
1546 }
1547 q = qdisc_leaf(p, clid);
1548 } else if (dev_ingress_queue_create(dev)) {
1549 q = dev_ingress_queue(dev)->qdisc_sleeping;
1550 }
1551 } else {
1552 q = dev->qdisc;
1553 }
1554
1555 /* It may be default qdisc, ignore it */
1556 if (q && q->handle == 0)
1557 q = NULL;
1558
1559 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1560 if (tcm->tcm_handle) {
1561 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) {
1562 NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override");
1563 return -EEXIST;
1564 }
1565 if (TC_H_MIN(tcm->tcm_handle)) {
1566 NL_SET_ERR_MSG(extack, "Invalid minor handle");
1567 return -EINVAL;
1568 }
1569 q = qdisc_lookup(dev, tcm->tcm_handle);
1570 if (!q)
1571 goto create_n_graft;
1572 if (n->nlmsg_flags & NLM_F_EXCL) {
1573 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override");
1574 return -EEXIST;
1575 }
1576 if (tca[TCA_KIND] &&
1577 nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1578 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1579 return -EINVAL;
1580 }
1581 if (q == p ||
1582 (p && check_loop(q, p, 0))) {
1583 NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected");
1584 return -ELOOP;
1585 }
1586 qdisc_refcount_inc(q);
1587 goto graft;
1588 } else {
1589 if (!q)
1590 goto create_n_graft;
1591
1592 /* This magic test requires explanation.
1593 *
1594 * We know, that some child q is already
1595 * attached to this parent and have choice:
1596 * either to change it or to create/graft new one.
1597 *
1598 * 1. We are allowed to create/graft only
1599 * if CREATE and REPLACE flags are set.
1600 *
1601 * 2. If EXCL is set, requestor wanted to say,
1602 * that qdisc tcm_handle is not expected
1603 * to exist, so that we choose create/graft too.
1604 *
1605 * 3. The last case is when no flags are set.
1606 * Alas, it is sort of hole in API, we
1607 * cannot decide what to do unambiguously.
1608 * For now we select create/graft, if
1609 * user gave KIND, which does not match existing.
1610 */
1611 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1612 (n->nlmsg_flags & NLM_F_REPLACE) &&
1613 ((n->nlmsg_flags & NLM_F_EXCL) ||
1614 (tca[TCA_KIND] &&
1615 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1616 goto create_n_graft;
1617 }
1618 }
1619 } else {
1620 if (!tcm->tcm_handle) {
1621 NL_SET_ERR_MSG(extack, "Handle cannot be zero");
1622 return -EINVAL;
1623 }
1624 q = qdisc_lookup(dev, tcm->tcm_handle);
1625 }
1626
1627 /* Change qdisc parameters */
1628 if (!q) {
1629 NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1630 return -ENOENT;
1631 }
1632 if (n->nlmsg_flags & NLM_F_EXCL) {
1633 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify");
1634 return -EEXIST;
1635 }
1636 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1637 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1638 return -EINVAL;
1639 }
1640 err = qdisc_change(q, tca, extack);
1641 if (err == 0)
1642 qdisc_notify(net, skb, n, clid, NULL, q);
1643 return err;
1644
1645create_n_graft:
1646 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
1647 NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag");
1648 return -ENOENT;
1649 }
1650 if (clid == TC_H_INGRESS) {
1651 if (dev_ingress_queue(dev)) {
1652 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1653 tcm->tcm_parent, tcm->tcm_parent,
1654 tca, &err, extack);
1655 } else {
1656 NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device");
1657 err = -ENOENT;
1658 }
1659 } else {
1660 struct netdev_queue *dev_queue;
1661
1662 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1663 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1664 else if (p)
1665 dev_queue = p->dev_queue;
1666 else
1667 dev_queue = netdev_get_tx_queue(dev, 0);
1668
1669 q = qdisc_create(dev, dev_queue, p,
1670 tcm->tcm_parent, tcm->tcm_handle,
1671 tca, &err, extack);
1672 }
1673 if (q == NULL) {
1674 if (err == -EAGAIN)
1675 goto replay;
1676 return err;
1677 }
1678
1679graft:
1680 err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack);
1681 if (err) {
1682 if (q)
1683 qdisc_put(q);
1684 return err;
1685 }
1686
1687 return 0;
1688}
1689
1690static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1691 struct netlink_callback *cb,
1692 int *q_idx_p, int s_q_idx, bool recur,
1693 bool dump_invisible)
1694{
1695 int ret = 0, q_idx = *q_idx_p;
1696 struct Qdisc *q;
1697 int b;
1698
1699 if (!root)
1700 return 0;
1701
1702 q = root;
1703 if (q_idx < s_q_idx) {
1704 q_idx++;
1705 } else {
1706 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1707 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1708 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1709 RTM_NEWQDISC) <= 0)
1710 goto done;
1711 q_idx++;
1712 }
1713
1714 /* If dumping singletons, there is no qdisc_dev(root) and the singleton
1715 * itself has already been dumped.
1716 *
1717 * If we've already dumped the top-level (ingress) qdisc above and the global
1718 * qdisc hashtable, we don't want to hit it again
1719 */
1720 if (!qdisc_dev(root) || !recur)
1721 goto out;
1722
1723 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1724 if (q_idx < s_q_idx) {
1725 q_idx++;
1726 continue;
1727 }
1728 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1729 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1730 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1731 RTM_NEWQDISC) <= 0)
1732 goto done;
1733 q_idx++;
1734 }
1735
1736out:
1737 *q_idx_p = q_idx;
1738 return ret;
1739done:
1740 ret = -1;
1741 goto out;
1742}
1743
1744static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1745{
1746 struct net *net = sock_net(skb->sk);
1747 int idx, q_idx;
1748 int s_idx, s_q_idx;
1749 struct net_device *dev;
1750 const struct nlmsghdr *nlh = cb->nlh;
1751 struct nlattr *tca[TCA_MAX + 1];
1752 int err;
1753
1754 s_idx = cb->args[0];
1755 s_q_idx = q_idx = cb->args[1];
1756
1757 idx = 0;
1758 ASSERT_RTNL();
1759
1760 err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX,
1761 rtm_tca_policy, cb->extack);
1762 if (err < 0)
1763 return err;
1764
1765 for_each_netdev(net, dev) {
1766 struct netdev_queue *dev_queue;
1767
1768 if (idx < s_idx)
1769 goto cont;
1770 if (idx > s_idx)
1771 s_q_idx = 0;
1772 q_idx = 0;
1773
1774 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx,
1775 true, tca[TCA_DUMP_INVISIBLE]) < 0)
1776 goto done;
1777
1778 dev_queue = dev_ingress_queue(dev);
1779 if (dev_queue &&
1780 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1781 &q_idx, s_q_idx, false,
1782 tca[TCA_DUMP_INVISIBLE]) < 0)
1783 goto done;
1784
1785cont:
1786 idx++;
1787 }
1788
1789done:
1790 cb->args[0] = idx;
1791 cb->args[1] = q_idx;
1792
1793 return skb->len;
1794}
1795
1796
1797
1798/************************************************
1799 * Traffic classes manipulation. *
1800 ************************************************/
1801
1802static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1803 unsigned long cl,
1804 u32 portid, u32 seq, u16 flags, int event)
1805{
1806 struct tcmsg *tcm;
1807 struct nlmsghdr *nlh;
1808 unsigned char *b = skb_tail_pointer(skb);
1809 struct gnet_dump d;
1810 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1811
1812 cond_resched();
1813 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1814 if (!nlh)
1815 goto out_nlmsg_trim;
1816 tcm = nlmsg_data(nlh);
1817 tcm->tcm_family = AF_UNSPEC;
1818 tcm->tcm__pad1 = 0;
1819 tcm->tcm__pad2 = 0;
1820 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1821 tcm->tcm_parent = q->handle;
1822 tcm->tcm_handle = q->handle;
1823 tcm->tcm_info = 0;
1824 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1825 goto nla_put_failure;
1826 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1827 goto nla_put_failure;
1828
1829 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1830 NULL, &d, TCA_PAD) < 0)
1831 goto nla_put_failure;
1832
1833 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1834 goto nla_put_failure;
1835
1836 if (gnet_stats_finish_copy(&d) < 0)
1837 goto nla_put_failure;
1838
1839 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1840 return skb->len;
1841
1842out_nlmsg_trim:
1843nla_put_failure:
1844 nlmsg_trim(skb, b);
1845 return -1;
1846}
1847
1848static int tclass_notify(struct net *net, struct sk_buff *oskb,
1849 struct nlmsghdr *n, struct Qdisc *q,
1850 unsigned long cl, int event)
1851{
1852 struct sk_buff *skb;
1853 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1854 int err = 0;
1855
1856 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1857 if (!skb)
1858 return -ENOBUFS;
1859
1860 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1861 kfree_skb(skb);
1862 return -EINVAL;
1863 }
1864
1865 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1866 n->nlmsg_flags & NLM_F_ECHO);
1867 if (err > 0)
1868 err = 0;
1869 return err;
1870}
1871
1872static int tclass_del_notify(struct net *net,
1873 const struct Qdisc_class_ops *cops,
1874 struct sk_buff *oskb, struct nlmsghdr *n,
1875 struct Qdisc *q, unsigned long cl,
1876 struct netlink_ext_ack *extack)
1877{
1878 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1879 struct sk_buff *skb;
1880 int err = 0;
1881
1882 if (!cops->delete)
1883 return -EOPNOTSUPP;
1884
1885 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1886 if (!skb)
1887 return -ENOBUFS;
1888
1889 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0,
1890 RTM_DELTCLASS) < 0) {
1891 kfree_skb(skb);
1892 return -EINVAL;
1893 }
1894
1895 err = cops->delete(q, cl, extack);
1896 if (err) {
1897 kfree_skb(skb);
1898 return err;
1899 }
1900
1901 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1902 n->nlmsg_flags & NLM_F_ECHO);
1903 if (err > 0)
1904 err = 0;
1905 return err;
1906}
1907
1908#ifdef CONFIG_NET_CLS
1909
1910struct tcf_bind_args {
1911 struct tcf_walker w;
1912 unsigned long base;
1913 unsigned long cl;
1914 u32 classid;
1915};
1916
1917static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
1918{
1919 struct tcf_bind_args *a = (void *)arg;
1920
1921 if (tp->ops->bind_class) {
1922 struct Qdisc *q = tcf_block_q(tp->chain->block);
1923
1924 sch_tree_lock(q);
1925 tp->ops->bind_class(n, a->classid, a->cl, q, a->base);
1926 sch_tree_unlock(q);
1927 }
1928 return 0;
1929}
1930
1931struct tc_bind_class_args {
1932 struct qdisc_walker w;
1933 unsigned long new_cl;
1934 u32 portid;
1935 u32 clid;
1936};
1937
1938static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl,
1939 struct qdisc_walker *w)
1940{
1941 struct tc_bind_class_args *a = (struct tc_bind_class_args *)w;
1942 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1943 struct tcf_block *block;
1944 struct tcf_chain *chain;
1945
1946 block = cops->tcf_block(q, cl, NULL);
1947 if (!block)
1948 return 0;
1949 for (chain = tcf_get_next_chain(block, NULL);
1950 chain;
1951 chain = tcf_get_next_chain(block, chain)) {
1952 struct tcf_proto *tp;
1953
1954 for (tp = tcf_get_next_proto(chain, NULL);
1955 tp; tp = tcf_get_next_proto(chain, tp)) {
1956 struct tcf_bind_args arg = {};
1957
1958 arg.w.fn = tcf_node_bind;
1959 arg.classid = a->clid;
1960 arg.base = cl;
1961 arg.cl = a->new_cl;
1962 tp->ops->walk(tp, &arg.w, true);
1963 }
1964 }
1965
1966 return 0;
1967}
1968
1969static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1970 unsigned long new_cl)
1971{
1972 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1973 struct tc_bind_class_args args = {};
1974
1975 if (!cops->tcf_block)
1976 return;
1977 args.portid = portid;
1978 args.clid = clid;
1979 args.new_cl = new_cl;
1980 args.w.fn = tc_bind_class_walker;
1981 q->ops->cl_ops->walk(q, &args.w);
1982}
1983
1984#else
1985
1986static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1987 unsigned long new_cl)
1988{
1989}
1990
1991#endif
1992
1993static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
1994 struct netlink_ext_ack *extack)
1995{
1996 struct net *net = sock_net(skb->sk);
1997 struct tcmsg *tcm = nlmsg_data(n);
1998 struct nlattr *tca[TCA_MAX + 1];
1999 struct net_device *dev;
2000 struct Qdisc *q = NULL;
2001 const struct Qdisc_class_ops *cops;
2002 unsigned long cl = 0;
2003 unsigned long new_cl;
2004 u32 portid;
2005 u32 clid;
2006 u32 qid;
2007 int err;
2008
2009 if ((n->nlmsg_type != RTM_GETTCLASS) &&
2010 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2011 return -EPERM;
2012
2013 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
2014 rtm_tca_policy, extack);
2015 if (err < 0)
2016 return err;
2017
2018 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2019 if (!dev)
2020 return -ENODEV;
2021
2022 /*
2023 parent == TC_H_UNSPEC - unspecified parent.
2024 parent == TC_H_ROOT - class is root, which has no parent.
2025 parent == X:0 - parent is root class.
2026 parent == X:Y - parent is a node in hierarchy.
2027 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
2028
2029 handle == 0:0 - generate handle from kernel pool.
2030 handle == 0:Y - class is X:Y, where X:0 is qdisc.
2031 handle == X:Y - clear.
2032 handle == X:0 - root class.
2033 */
2034
2035 /* Step 1. Determine qdisc handle X:0 */
2036
2037 portid = tcm->tcm_parent;
2038 clid = tcm->tcm_handle;
2039 qid = TC_H_MAJ(clid);
2040
2041 if (portid != TC_H_ROOT) {
2042 u32 qid1 = TC_H_MAJ(portid);
2043
2044 if (qid && qid1) {
2045 /* If both majors are known, they must be identical. */
2046 if (qid != qid1)
2047 return -EINVAL;
2048 } else if (qid1) {
2049 qid = qid1;
2050 } else if (qid == 0)
2051 qid = dev->qdisc->handle;
2052
2053 /* Now qid is genuine qdisc handle consistent
2054 * both with parent and child.
2055 *
2056 * TC_H_MAJ(portid) still may be unspecified, complete it now.
2057 */
2058 if (portid)
2059 portid = TC_H_MAKE(qid, portid);
2060 } else {
2061 if (qid == 0)
2062 qid = dev->qdisc->handle;
2063 }
2064
2065 /* OK. Locate qdisc */
2066 q = qdisc_lookup(dev, qid);
2067 if (!q)
2068 return -ENOENT;
2069
2070 /* An check that it supports classes */
2071 cops = q->ops->cl_ops;
2072 if (cops == NULL)
2073 return -EINVAL;
2074
2075 /* Now try to get class */
2076 if (clid == 0) {
2077 if (portid == TC_H_ROOT)
2078 clid = qid;
2079 } else
2080 clid = TC_H_MAKE(qid, clid);
2081
2082 if (clid)
2083 cl = cops->find(q, clid);
2084
2085 if (cl == 0) {
2086 err = -ENOENT;
2087 if (n->nlmsg_type != RTM_NEWTCLASS ||
2088 !(n->nlmsg_flags & NLM_F_CREATE))
2089 goto out;
2090 } else {
2091 switch (n->nlmsg_type) {
2092 case RTM_NEWTCLASS:
2093 err = -EEXIST;
2094 if (n->nlmsg_flags & NLM_F_EXCL)
2095 goto out;
2096 break;
2097 case RTM_DELTCLASS:
2098 err = tclass_del_notify(net, cops, skb, n, q, cl, extack);
2099 /* Unbind the class with flilters with 0 */
2100 tc_bind_tclass(q, portid, clid, 0);
2101 goto out;
2102 case RTM_GETTCLASS:
2103 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
2104 goto out;
2105 default:
2106 err = -EINVAL;
2107 goto out;
2108 }
2109 }
2110
2111 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
2112 NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes");
2113 return -EOPNOTSUPP;
2114 }
2115
2116 new_cl = cl;
2117 err = -EOPNOTSUPP;
2118 if (cops->change)
2119 err = cops->change(q, clid, portid, tca, &new_cl, extack);
2120 if (err == 0) {
2121 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
2122 /* We just create a new class, need to do reverse binding. */
2123 if (cl != new_cl)
2124 tc_bind_tclass(q, portid, clid, new_cl);
2125 }
2126out:
2127 return err;
2128}
2129
2130struct qdisc_dump_args {
2131 struct qdisc_walker w;
2132 struct sk_buff *skb;
2133 struct netlink_callback *cb;
2134};
2135
2136static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
2137 struct qdisc_walker *arg)
2138{
2139 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
2140
2141 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
2142 a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2143 RTM_NEWTCLASS);
2144}
2145
2146static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
2147 struct tcmsg *tcm, struct netlink_callback *cb,
2148 int *t_p, int s_t)
2149{
2150 struct qdisc_dump_args arg;
2151
2152 if (tc_qdisc_dump_ignore(q, false) ||
2153 *t_p < s_t || !q->ops->cl_ops ||
2154 (tcm->tcm_parent &&
2155 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
2156 (*t_p)++;
2157 return 0;
2158 }
2159 if (*t_p > s_t)
2160 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
2161 arg.w.fn = qdisc_class_dump;
2162 arg.skb = skb;
2163 arg.cb = cb;
2164 arg.w.stop = 0;
2165 arg.w.skip = cb->args[1];
2166 arg.w.count = 0;
2167 q->ops->cl_ops->walk(q, &arg.w);
2168 cb->args[1] = arg.w.count;
2169 if (arg.w.stop)
2170 return -1;
2171 (*t_p)++;
2172 return 0;
2173}
2174
2175static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
2176 struct tcmsg *tcm, struct netlink_callback *cb,
2177 int *t_p, int s_t, bool recur)
2178{
2179 struct Qdisc *q;
2180 int b;
2181
2182 if (!root)
2183 return 0;
2184
2185 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
2186 return -1;
2187
2188 if (!qdisc_dev(root) || !recur)
2189 return 0;
2190
2191 if (tcm->tcm_parent) {
2192 q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent));
2193 if (q && q != root &&
2194 tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2195 return -1;
2196 return 0;
2197 }
2198 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
2199 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2200 return -1;
2201 }
2202
2203 return 0;
2204}
2205
2206static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
2207{
2208 struct tcmsg *tcm = nlmsg_data(cb->nlh);
2209 struct net *net = sock_net(skb->sk);
2210 struct netdev_queue *dev_queue;
2211 struct net_device *dev;
2212 int t, s_t;
2213
2214 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2215 return 0;
2216 dev = dev_get_by_index(net, tcm->tcm_ifindex);
2217 if (!dev)
2218 return 0;
2219
2220 s_t = cb->args[0];
2221 t = 0;
2222
2223 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t, true) < 0)
2224 goto done;
2225
2226 dev_queue = dev_ingress_queue(dev);
2227 if (dev_queue &&
2228 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
2229 &t, s_t, false) < 0)
2230 goto done;
2231
2232done:
2233 cb->args[0] = t;
2234
2235 dev_put(dev);
2236 return skb->len;
2237}
2238
2239#ifdef CONFIG_PROC_FS
2240static int psched_show(struct seq_file *seq, void *v)
2241{
2242 seq_printf(seq, "%08x %08x %08x %08x\n",
2243 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
2244 1000000,
2245 (u32)NSEC_PER_SEC / hrtimer_resolution);
2246
2247 return 0;
2248}
2249
2250static int __net_init psched_net_init(struct net *net)
2251{
2252 struct proc_dir_entry *e;
2253
2254 e = proc_create_single("psched", 0, net->proc_net, psched_show);
2255 if (e == NULL)
2256 return -ENOMEM;
2257
2258 return 0;
2259}
2260
2261static void __net_exit psched_net_exit(struct net *net)
2262{
2263 remove_proc_entry("psched", net->proc_net);
2264}
2265#else
2266static int __net_init psched_net_init(struct net *net)
2267{
2268 return 0;
2269}
2270
2271static void __net_exit psched_net_exit(struct net *net)
2272{
2273}
2274#endif
2275
2276static struct pernet_operations psched_net_ops = {
2277 .init = psched_net_init,
2278 .exit = psched_net_exit,
2279};
2280
2281static int __init pktsched_init(void)
2282{
2283 int err;
2284
2285 err = register_pernet_subsys(&psched_net_ops);
2286 if (err) {
2287 pr_err("pktsched_init: "
2288 "cannot initialize per netns operations\n");
2289 return err;
2290 }
2291
2292 register_qdisc(&pfifo_fast_ops);
2293 register_qdisc(&pfifo_qdisc_ops);
2294 register_qdisc(&bfifo_qdisc_ops);
2295 register_qdisc(&pfifo_head_drop_qdisc_ops);
2296 register_qdisc(&mq_qdisc_ops);
2297 register_qdisc(&noqueue_qdisc_ops);
2298
2299 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, 0);
2300 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, 0);
2301 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc,
2302 0);
2303 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, 0);
2304 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, 0);
2305 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass,
2306 0);
2307
2308 return 0;
2309}
2310
2311subsys_initcall(pktsched_init);