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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 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
430 goto nla_put_failure;
431 nla_nest_end(skb, nest);
432
433 return skb->len;
434
435nla_put_failure:
436 return -1;
437}
438
439void __qdisc_calculate_pkt_len(struct sk_buff *skb, const struct qdisc_size_table *stab)
440{
441 int pkt_len, slot;
442
443 pkt_len = skb->len + stab->szopts.overhead;
444 if (unlikely(!stab->szopts.tsize))
445 goto out;
446
447 slot = pkt_len + stab->szopts.cell_align;
448 if (unlikely(slot < 0))
449 slot = 0;
450
451 slot >>= stab->szopts.cell_log;
452 if (likely(slot < stab->szopts.tsize))
453 pkt_len = stab->data[slot];
454 else
455 pkt_len = stab->data[stab->szopts.tsize - 1] *
456 (slot / stab->szopts.tsize) +
457 stab->data[slot % stab->szopts.tsize];
458
459 pkt_len <<= stab->szopts.size_log;
460out:
461 if (unlikely(pkt_len < 1))
462 pkt_len = 1;
463 qdisc_skb_cb(skb)->pkt_len = pkt_len;
464}
465EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
466
467void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc)
468{
469 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
470 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
471 txt, qdisc->ops->id, qdisc->handle >> 16);
472 qdisc->flags |= TCQ_F_WARN_NONWC;
473 }
474}
475EXPORT_SYMBOL(qdisc_warn_nonwc);
476
477static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
478{
479 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
480 timer);
481
482 qdisc_unthrottled(wd->qdisc);
483 __netif_schedule(qdisc_root(wd->qdisc));
484
485 return HRTIMER_NORESTART;
486}
487
488void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
489{
490 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
491 wd->timer.function = qdisc_watchdog;
492 wd->qdisc = qdisc;
493}
494EXPORT_SYMBOL(qdisc_watchdog_init);
495
496void qdisc_watchdog_schedule(struct qdisc_watchdog *wd, psched_time_t expires)
497{
498 ktime_t time;
499
500 if (test_bit(__QDISC_STATE_DEACTIVATED,
501 &qdisc_root_sleeping(wd->qdisc)->state))
502 return;
503
504 qdisc_throttled(wd->qdisc);
505 time = ktime_set(0, 0);
506 time = ktime_add_ns(time, PSCHED_TICKS2NS(expires));
507 hrtimer_start(&wd->timer, time, HRTIMER_MODE_ABS);
508}
509EXPORT_SYMBOL(qdisc_watchdog_schedule);
510
511void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
512{
513 hrtimer_cancel(&wd->timer);
514 qdisc_unthrottled(wd->qdisc);
515}
516EXPORT_SYMBOL(qdisc_watchdog_cancel);
517
518static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
519{
520 unsigned int size = n * sizeof(struct hlist_head), i;
521 struct hlist_head *h;
522
523 if (size <= PAGE_SIZE)
524 h = kmalloc(size, GFP_KERNEL);
525 else
526 h = (struct hlist_head *)
527 __get_free_pages(GFP_KERNEL, get_order(size));
528
529 if (h != NULL) {
530 for (i = 0; i < n; i++)
531 INIT_HLIST_HEAD(&h[i]);
532 }
533 return h;
534}
535
536static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
537{
538 unsigned int size = n * sizeof(struct hlist_head);
539
540 if (size <= PAGE_SIZE)
541 kfree(h);
542 else
543 free_pages((unsigned long)h, get_order(size));
544}
545
546void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
547{
548 struct Qdisc_class_common *cl;
549 struct hlist_node *n, *next;
550 struct hlist_head *nhash, *ohash;
551 unsigned int nsize, nmask, osize;
552 unsigned int i, h;
553
554 /* Rehash when load factor exceeds 0.75 */
555 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
556 return;
557 nsize = clhash->hashsize * 2;
558 nmask = nsize - 1;
559 nhash = qdisc_class_hash_alloc(nsize);
560 if (nhash == NULL)
561 return;
562
563 ohash = clhash->hash;
564 osize = clhash->hashsize;
565
566 sch_tree_lock(sch);
567 for (i = 0; i < osize; i++) {
568 hlist_for_each_entry_safe(cl, n, next, &ohash[i], hnode) {
569 h = qdisc_class_hash(cl->classid, nmask);
570 hlist_add_head(&cl->hnode, &nhash[h]);
571 }
572 }
573 clhash->hash = nhash;
574 clhash->hashsize = nsize;
575 clhash->hashmask = nmask;
576 sch_tree_unlock(sch);
577
578 qdisc_class_hash_free(ohash, osize);
579}
580EXPORT_SYMBOL(qdisc_class_hash_grow);
581
582int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
583{
584 unsigned int size = 4;
585
586 clhash->hash = qdisc_class_hash_alloc(size);
587 if (clhash->hash == NULL)
588 return -ENOMEM;
589 clhash->hashsize = size;
590 clhash->hashmask = size - 1;
591 clhash->hashelems = 0;
592 return 0;
593}
594EXPORT_SYMBOL(qdisc_class_hash_init);
595
596void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
597{
598 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
599}
600EXPORT_SYMBOL(qdisc_class_hash_destroy);
601
602void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
603 struct Qdisc_class_common *cl)
604{
605 unsigned int h;
606
607 INIT_HLIST_NODE(&cl->hnode);
608 h = qdisc_class_hash(cl->classid, clhash->hashmask);
609 hlist_add_head(&cl->hnode, &clhash->hash[h]);
610 clhash->hashelems++;
611}
612EXPORT_SYMBOL(qdisc_class_hash_insert);
613
614void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
615 struct Qdisc_class_common *cl)
616{
617 hlist_del(&cl->hnode);
618 clhash->hashelems--;
619}
620EXPORT_SYMBOL(qdisc_class_hash_remove);
621
622/* Allocate an unique handle from space managed by kernel
623 * Possible range is [8000-FFFF]:0000 (0x8000 values)
624 */
625static u32 qdisc_alloc_handle(struct net_device *dev)
626{
627 int i = 0x8000;
628 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
629
630 do {
631 autohandle += TC_H_MAKE(0x10000U, 0);
632 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
633 autohandle = TC_H_MAKE(0x80000000U, 0);
634 if (!qdisc_lookup(dev, autohandle))
635 return autohandle;
636 cond_resched();
637 } while (--i > 0);
638
639 return 0;
640}
641
642void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
643{
644 const struct Qdisc_class_ops *cops;
645 unsigned long cl;
646 u32 parentid;
647
648 if (n == 0)
649 return;
650 while ((parentid = sch->parent)) {
651 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
652 return;
653
654 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
655 if (sch == NULL) {
656 WARN_ON(parentid != TC_H_ROOT);
657 return;
658 }
659 cops = sch->ops->cl_ops;
660 if (cops->qlen_notify) {
661 cl = cops->get(sch, parentid);
662 cops->qlen_notify(sch, cl);
663 cops->put(sch, cl);
664 }
665 sch->q.qlen -= n;
666 }
667}
668EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
669
670static void notify_and_destroy(struct net *net, struct sk_buff *skb,
671 struct nlmsghdr *n, u32 clid,
672 struct Qdisc *old, struct Qdisc *new)
673{
674 if (new || old)
675 qdisc_notify(net, skb, n, clid, old, new);
676
677 if (old)
678 qdisc_destroy(old);
679}
680
681/* Graft qdisc "new" to class "classid" of qdisc "parent" or
682 * to device "dev".
683 *
684 * When appropriate send a netlink notification using 'skb'
685 * and "n".
686 *
687 * On success, destroy old qdisc.
688 */
689
690static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
691 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
692 struct Qdisc *new, struct Qdisc *old)
693{
694 struct Qdisc *q = old;
695 struct net *net = dev_net(dev);
696 int err = 0;
697
698 if (parent == NULL) {
699 unsigned int i, num_q, ingress;
700
701 ingress = 0;
702 num_q = dev->num_tx_queues;
703 if ((q && q->flags & TCQ_F_INGRESS) ||
704 (new && new->flags & TCQ_F_INGRESS)) {
705 num_q = 1;
706 ingress = 1;
707 if (!dev_ingress_queue(dev))
708 return -ENOENT;
709 }
710
711 if (dev->flags & IFF_UP)
712 dev_deactivate(dev);
713
714 if (new && new->ops->attach) {
715 new->ops->attach(new);
716 num_q = 0;
717 }
718
719 for (i = 0; i < num_q; i++) {
720 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
721
722 if (!ingress)
723 dev_queue = netdev_get_tx_queue(dev, i);
724
725 old = dev_graft_qdisc(dev_queue, new);
726 if (new && i > 0)
727 atomic_inc(&new->refcnt);
728
729 if (!ingress)
730 qdisc_destroy(old);
731 }
732
733 if (!ingress) {
734 notify_and_destroy(net, skb, n, classid,
735 dev->qdisc, new);
736 if (new && !new->ops->attach)
737 atomic_inc(&new->refcnt);
738 dev->qdisc = new ? : &noop_qdisc;
739 } else {
740 notify_and_destroy(net, skb, n, classid, old, new);
741 }
742
743 if (dev->flags & IFF_UP)
744 dev_activate(dev);
745 } else {
746 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
747
748 err = -EOPNOTSUPP;
749 if (cops && cops->graft) {
750 unsigned long cl = cops->get(parent, classid);
751 if (cl) {
752 err = cops->graft(parent, cl, new, &old);
753 cops->put(parent, cl);
754 } else
755 err = -ENOENT;
756 }
757 if (!err)
758 notify_and_destroy(net, skb, n, classid, old, new);
759 }
760 return err;
761}
762
763/* lockdep annotation is needed for ingress; egress gets it only for name */
764static struct lock_class_key qdisc_tx_lock;
765static struct lock_class_key qdisc_rx_lock;
766
767/*
768 Allocate and initialize new qdisc.
769
770 Parameters are passed via opt.
771 */
772
773static struct Qdisc *
774qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
775 struct Qdisc *p, u32 parent, u32 handle,
776 struct nlattr **tca, int *errp)
777{
778 int err;
779 struct nlattr *kind = tca[TCA_KIND];
780 struct Qdisc *sch;
781 struct Qdisc_ops *ops;
782 struct qdisc_size_table *stab;
783
784 ops = qdisc_lookup_ops(kind);
785#ifdef CONFIG_MODULES
786 if (ops == NULL && kind != NULL) {
787 char name[IFNAMSIZ];
788 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
789 /* We dropped the RTNL semaphore in order to
790 * perform the module load. So, even if we
791 * succeeded in loading the module we have to
792 * tell the caller to replay the request. We
793 * indicate this using -EAGAIN.
794 * We replay the request because the device may
795 * go away in the mean time.
796 */
797 rtnl_unlock();
798 request_module("sch_%s", name);
799 rtnl_lock();
800 ops = qdisc_lookup_ops(kind);
801 if (ops != NULL) {
802 /* We will try again qdisc_lookup_ops,
803 * so don't keep a reference.
804 */
805 module_put(ops->owner);
806 err = -EAGAIN;
807 goto err_out;
808 }
809 }
810 }
811#endif
812
813 err = -ENOENT;
814 if (ops == NULL)
815 goto err_out;
816
817 sch = qdisc_alloc(dev_queue, ops);
818 if (IS_ERR(sch)) {
819 err = PTR_ERR(sch);
820 goto err_out2;
821 }
822
823 sch->parent = parent;
824
825 if (handle == TC_H_INGRESS) {
826 sch->flags |= TCQ_F_INGRESS;
827 handle = TC_H_MAKE(TC_H_INGRESS, 0);
828 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
829 } else {
830 if (handle == 0) {
831 handle = qdisc_alloc_handle(dev);
832 err = -ENOMEM;
833 if (handle == 0)
834 goto err_out3;
835 }
836 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
837 }
838
839 sch->handle = handle;
840
841 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
842 if (tca[TCA_STAB]) {
843 stab = qdisc_get_stab(tca[TCA_STAB]);
844 if (IS_ERR(stab)) {
845 err = PTR_ERR(stab);
846 goto err_out4;
847 }
848 rcu_assign_pointer(sch->stab, stab);
849 }
850 if (tca[TCA_RATE]) {
851 spinlock_t *root_lock;
852
853 err = -EOPNOTSUPP;
854 if (sch->flags & TCQ_F_MQROOT)
855 goto err_out4;
856
857 if ((sch->parent != TC_H_ROOT) &&
858 !(sch->flags & TCQ_F_INGRESS) &&
859 (!p || !(p->flags & TCQ_F_MQROOT)))
860 root_lock = qdisc_root_sleeping_lock(sch);
861 else
862 root_lock = qdisc_lock(sch);
863
864 err = gen_new_estimator(&sch->bstats, &sch->rate_est,
865 root_lock, tca[TCA_RATE]);
866 if (err)
867 goto err_out4;
868 }
869
870 qdisc_list_add(sch);
871
872 return sch;
873 }
874err_out3:
875 dev_put(dev);
876 kfree((char *) sch - sch->padded);
877err_out2:
878 module_put(ops->owner);
879err_out:
880 *errp = err;
881 return NULL;
882
883err_out4:
884 /*
885 * Any broken qdiscs that would require a ops->reset() here?
886 * The qdisc was never in action so it shouldn't be necessary.
887 */
888 qdisc_put_stab(rtnl_dereference(sch->stab));
889 if (ops->destroy)
890 ops->destroy(sch);
891 goto err_out3;
892}
893
894static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
895{
896 struct qdisc_size_table *ostab, *stab = NULL;
897 int err = 0;
898
899 if (tca[TCA_OPTIONS]) {
900 if (sch->ops->change == NULL)
901 return -EINVAL;
902 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
903 if (err)
904 return err;
905 }
906
907 if (tca[TCA_STAB]) {
908 stab = qdisc_get_stab(tca[TCA_STAB]);
909 if (IS_ERR(stab))
910 return PTR_ERR(stab);
911 }
912
913 ostab = rtnl_dereference(sch->stab);
914 rcu_assign_pointer(sch->stab, stab);
915 qdisc_put_stab(ostab);
916
917 if (tca[TCA_RATE]) {
918 /* NB: ignores errors from replace_estimator
919 because change can't be undone. */
920 if (sch->flags & TCQ_F_MQROOT)
921 goto out;
922 gen_replace_estimator(&sch->bstats, &sch->rate_est,
923 qdisc_root_sleeping_lock(sch),
924 tca[TCA_RATE]);
925 }
926out:
927 return 0;
928}
929
930struct check_loop_arg {
931 struct qdisc_walker w;
932 struct Qdisc *p;
933 int depth;
934};
935
936static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
937
938static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
939{
940 struct check_loop_arg arg;
941
942 if (q->ops->cl_ops == NULL)
943 return 0;
944
945 arg.w.stop = arg.w.skip = arg.w.count = 0;
946 arg.w.fn = check_loop_fn;
947 arg.depth = depth;
948 arg.p = p;
949 q->ops->cl_ops->walk(q, &arg.w);
950 return arg.w.stop ? -ELOOP : 0;
951}
952
953static int
954check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
955{
956 struct Qdisc *leaf;
957 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
958 struct check_loop_arg *arg = (struct check_loop_arg *)w;
959
960 leaf = cops->leaf(q, cl);
961 if (leaf) {
962 if (leaf == arg->p || arg->depth > 7)
963 return -ELOOP;
964 return check_loop(leaf, arg->p, arg->depth + 1);
965 }
966 return 0;
967}
968
969/*
970 * Delete/get qdisc.
971 */
972
973static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
974{
975 struct net *net = sock_net(skb->sk);
976 struct tcmsg *tcm = NLMSG_DATA(n);
977 struct nlattr *tca[TCA_MAX + 1];
978 struct net_device *dev;
979 u32 clid = tcm->tcm_parent;
980 struct Qdisc *q = NULL;
981 struct Qdisc *p = NULL;
982 int err;
983
984 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
985 if (!dev)
986 return -ENODEV;
987
988 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
989 if (err < 0)
990 return err;
991
992 if (clid) {
993 if (clid != TC_H_ROOT) {
994 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
995 p = qdisc_lookup(dev, TC_H_MAJ(clid));
996 if (!p)
997 return -ENOENT;
998 q = qdisc_leaf(p, clid);
999 } else if (dev_ingress_queue(dev)) {
1000 q = dev_ingress_queue(dev)->qdisc_sleeping;
1001 }
1002 } else {
1003 q = dev->qdisc;
1004 }
1005 if (!q)
1006 return -ENOENT;
1007
1008 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1009 return -EINVAL;
1010 } else {
1011 q = qdisc_lookup(dev, tcm->tcm_handle);
1012 if (!q)
1013 return -ENOENT;
1014 }
1015
1016 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1017 return -EINVAL;
1018
1019 if (n->nlmsg_type == RTM_DELQDISC) {
1020 if (!clid)
1021 return -EINVAL;
1022 if (q->handle == 0)
1023 return -ENOENT;
1024 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1025 if (err != 0)
1026 return err;
1027 } else {
1028 qdisc_notify(net, skb, n, clid, NULL, q);
1029 }
1030 return 0;
1031}
1032
1033/*
1034 * Create/change qdisc.
1035 */
1036
1037static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1038{
1039 struct net *net = sock_net(skb->sk);
1040 struct tcmsg *tcm;
1041 struct nlattr *tca[TCA_MAX + 1];
1042 struct net_device *dev;
1043 u32 clid;
1044 struct Qdisc *q, *p;
1045 int err;
1046
1047replay:
1048 /* Reinit, just in case something touches this. */
1049 tcm = NLMSG_DATA(n);
1050 clid = tcm->tcm_parent;
1051 q = p = NULL;
1052
1053 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1054 if (!dev)
1055 return -ENODEV;
1056
1057 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1058 if (err < 0)
1059 return err;
1060
1061 if (clid) {
1062 if (clid != TC_H_ROOT) {
1063 if (clid != TC_H_INGRESS) {
1064 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1065 if (!p)
1066 return -ENOENT;
1067 q = qdisc_leaf(p, clid);
1068 } else if (dev_ingress_queue_create(dev)) {
1069 q = dev_ingress_queue(dev)->qdisc_sleeping;
1070 }
1071 } else {
1072 q = dev->qdisc;
1073 }
1074
1075 /* It may be default qdisc, ignore it */
1076 if (q && q->handle == 0)
1077 q = NULL;
1078
1079 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1080 if (tcm->tcm_handle) {
1081 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1082 return -EEXIST;
1083 if (TC_H_MIN(tcm->tcm_handle))
1084 return -EINVAL;
1085 q = qdisc_lookup(dev, tcm->tcm_handle);
1086 if (!q)
1087 goto create_n_graft;
1088 if (n->nlmsg_flags & NLM_F_EXCL)
1089 return -EEXIST;
1090 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1091 return -EINVAL;
1092 if (q == p ||
1093 (p && check_loop(q, p, 0)))
1094 return -ELOOP;
1095 atomic_inc(&q->refcnt);
1096 goto graft;
1097 } else {
1098 if (!q)
1099 goto create_n_graft;
1100
1101 /* This magic test requires explanation.
1102 *
1103 * We know, that some child q is already
1104 * attached to this parent and have choice:
1105 * either to change it or to create/graft new one.
1106 *
1107 * 1. We are allowed to create/graft only
1108 * if CREATE and REPLACE flags are set.
1109 *
1110 * 2. If EXCL is set, requestor wanted to say,
1111 * that qdisc tcm_handle is not expected
1112 * to exist, so that we choose create/graft too.
1113 *
1114 * 3. The last case is when no flags are set.
1115 * Alas, it is sort of hole in API, we
1116 * cannot decide what to do unambiguously.
1117 * For now we select create/graft, if
1118 * user gave KIND, which does not match existing.
1119 */
1120 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1121 (n->nlmsg_flags & NLM_F_REPLACE) &&
1122 ((n->nlmsg_flags & NLM_F_EXCL) ||
1123 (tca[TCA_KIND] &&
1124 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1125 goto create_n_graft;
1126 }
1127 }
1128 } else {
1129 if (!tcm->tcm_handle)
1130 return -EINVAL;
1131 q = qdisc_lookup(dev, tcm->tcm_handle);
1132 }
1133
1134 /* Change qdisc parameters */
1135 if (q == NULL)
1136 return -ENOENT;
1137 if (n->nlmsg_flags & NLM_F_EXCL)
1138 return -EEXIST;
1139 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1140 return -EINVAL;
1141 err = qdisc_change(q, tca);
1142 if (err == 0)
1143 qdisc_notify(net, skb, n, clid, NULL, q);
1144 return err;
1145
1146create_n_graft:
1147 if (!(n->nlmsg_flags & NLM_F_CREATE))
1148 return -ENOENT;
1149 if (clid == TC_H_INGRESS) {
1150 if (dev_ingress_queue(dev))
1151 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1152 tcm->tcm_parent, tcm->tcm_parent,
1153 tca, &err);
1154 else
1155 err = -ENOENT;
1156 } else {
1157 struct netdev_queue *dev_queue;
1158
1159 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1160 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1161 else if (p)
1162 dev_queue = p->dev_queue;
1163 else
1164 dev_queue = netdev_get_tx_queue(dev, 0);
1165
1166 q = qdisc_create(dev, dev_queue, p,
1167 tcm->tcm_parent, tcm->tcm_handle,
1168 tca, &err);
1169 }
1170 if (q == NULL) {
1171 if (err == -EAGAIN)
1172 goto replay;
1173 return err;
1174 }
1175
1176graft:
1177 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1178 if (err) {
1179 if (q)
1180 qdisc_destroy(q);
1181 return err;
1182 }
1183
1184 return 0;
1185}
1186
1187static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1188 u32 pid, u32 seq, u16 flags, int event)
1189{
1190 struct tcmsg *tcm;
1191 struct nlmsghdr *nlh;
1192 unsigned char *b = skb_tail_pointer(skb);
1193 struct gnet_dump d;
1194 struct qdisc_size_table *stab;
1195
1196 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1197 tcm = NLMSG_DATA(nlh);
1198 tcm->tcm_family = AF_UNSPEC;
1199 tcm->tcm__pad1 = 0;
1200 tcm->tcm__pad2 = 0;
1201 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1202 tcm->tcm_parent = clid;
1203 tcm->tcm_handle = q->handle;
1204 tcm->tcm_info = atomic_read(&q->refcnt);
1205 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1206 goto nla_put_failure;
1207 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1208 goto nla_put_failure;
1209 q->qstats.qlen = q->q.qlen;
1210
1211 stab = rtnl_dereference(q->stab);
1212 if (stab && qdisc_dump_stab(skb, stab) < 0)
1213 goto nla_put_failure;
1214
1215 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1216 qdisc_root_sleeping_lock(q), &d) < 0)
1217 goto nla_put_failure;
1218
1219 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1220 goto nla_put_failure;
1221
1222 if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
1223 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1224 gnet_stats_copy_queue(&d, &q->qstats) < 0)
1225 goto nla_put_failure;
1226
1227 if (gnet_stats_finish_copy(&d) < 0)
1228 goto nla_put_failure;
1229
1230 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1231 return skb->len;
1232
1233nlmsg_failure:
1234nla_put_failure:
1235 nlmsg_trim(skb, b);
1236 return -1;
1237}
1238
1239static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1240{
1241 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1242}
1243
1244static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1245 struct nlmsghdr *n, u32 clid,
1246 struct Qdisc *old, struct Qdisc *new)
1247{
1248 struct sk_buff *skb;
1249 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
1250
1251 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1252 if (!skb)
1253 return -ENOBUFS;
1254
1255 if (old && !tc_qdisc_dump_ignore(old)) {
1256 if (tc_fill_qdisc(skb, old, clid, pid, n->nlmsg_seq,
1257 0, RTM_DELQDISC) < 0)
1258 goto err_out;
1259 }
1260 if (new && !tc_qdisc_dump_ignore(new)) {
1261 if (tc_fill_qdisc(skb, new, clid, pid, n->nlmsg_seq,
1262 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1263 goto err_out;
1264 }
1265
1266 if (skb->len)
1267 return rtnetlink_send(skb, net, pid, RTNLGRP_TC,
1268 n->nlmsg_flags & NLM_F_ECHO);
1269
1270err_out:
1271 kfree_skb(skb);
1272 return -EINVAL;
1273}
1274
1275static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1276 struct netlink_callback *cb,
1277 int *q_idx_p, int s_q_idx)
1278{
1279 int ret = 0, q_idx = *q_idx_p;
1280 struct Qdisc *q;
1281
1282 if (!root)
1283 return 0;
1284
1285 q = root;
1286 if (q_idx < s_q_idx) {
1287 q_idx++;
1288 } else {
1289 if (!tc_qdisc_dump_ignore(q) &&
1290 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid,
1291 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1292 goto done;
1293 q_idx++;
1294 }
1295 list_for_each_entry(q, &root->list, list) {
1296 if (q_idx < s_q_idx) {
1297 q_idx++;
1298 continue;
1299 }
1300 if (!tc_qdisc_dump_ignore(q) &&
1301 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid,
1302 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1303 goto done;
1304 q_idx++;
1305 }
1306
1307out:
1308 *q_idx_p = q_idx;
1309 return ret;
1310done:
1311 ret = -1;
1312 goto out;
1313}
1314
1315static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1316{
1317 struct net *net = sock_net(skb->sk);
1318 int idx, q_idx;
1319 int s_idx, s_q_idx;
1320 struct net_device *dev;
1321
1322 s_idx = cb->args[0];
1323 s_q_idx = q_idx = cb->args[1];
1324
1325 rcu_read_lock();
1326 idx = 0;
1327 for_each_netdev_rcu(net, dev) {
1328 struct netdev_queue *dev_queue;
1329
1330 if (idx < s_idx)
1331 goto cont;
1332 if (idx > s_idx)
1333 s_q_idx = 0;
1334 q_idx = 0;
1335
1336 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1337 goto done;
1338
1339 dev_queue = dev_ingress_queue(dev);
1340 if (dev_queue &&
1341 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1342 &q_idx, s_q_idx) < 0)
1343 goto done;
1344
1345cont:
1346 idx++;
1347 }
1348
1349done:
1350 rcu_read_unlock();
1351
1352 cb->args[0] = idx;
1353 cb->args[1] = q_idx;
1354
1355 return skb->len;
1356}
1357
1358
1359
1360/************************************************
1361 * Traffic classes manipulation. *
1362 ************************************************/
1363
1364
1365
1366static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1367{
1368 struct net *net = sock_net(skb->sk);
1369 struct tcmsg *tcm = NLMSG_DATA(n);
1370 struct nlattr *tca[TCA_MAX + 1];
1371 struct net_device *dev;
1372 struct Qdisc *q = NULL;
1373 const struct Qdisc_class_ops *cops;
1374 unsigned long cl = 0;
1375 unsigned long new_cl;
1376 u32 pid = tcm->tcm_parent;
1377 u32 clid = tcm->tcm_handle;
1378 u32 qid = TC_H_MAJ(clid);
1379 int err;
1380
1381 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1382 if (!dev)
1383 return -ENODEV;
1384
1385 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1386 if (err < 0)
1387 return err;
1388
1389 /*
1390 parent == TC_H_UNSPEC - unspecified parent.
1391 parent == TC_H_ROOT - class is root, which has no parent.
1392 parent == X:0 - parent is root class.
1393 parent == X:Y - parent is a node in hierarchy.
1394 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1395
1396 handle == 0:0 - generate handle from kernel pool.
1397 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1398 handle == X:Y - clear.
1399 handle == X:0 - root class.
1400 */
1401
1402 /* Step 1. Determine qdisc handle X:0 */
1403
1404 if (pid != TC_H_ROOT) {
1405 u32 qid1 = TC_H_MAJ(pid);
1406
1407 if (qid && qid1) {
1408 /* If both majors are known, they must be identical. */
1409 if (qid != qid1)
1410 return -EINVAL;
1411 } else if (qid1) {
1412 qid = qid1;
1413 } else if (qid == 0)
1414 qid = dev->qdisc->handle;
1415
1416 /* Now qid is genuine qdisc handle consistent
1417 * both with parent and child.
1418 *
1419 * TC_H_MAJ(pid) still may be unspecified, complete it now.
1420 */
1421 if (pid)
1422 pid = TC_H_MAKE(qid, pid);
1423 } else {
1424 if (qid == 0)
1425 qid = dev->qdisc->handle;
1426 }
1427
1428 /* OK. Locate qdisc */
1429 q = qdisc_lookup(dev, qid);
1430 if (!q)
1431 return -ENOENT;
1432
1433 /* An check that it supports classes */
1434 cops = q->ops->cl_ops;
1435 if (cops == NULL)
1436 return -EINVAL;
1437
1438 /* Now try to get class */
1439 if (clid == 0) {
1440 if (pid == TC_H_ROOT)
1441 clid = qid;
1442 } else
1443 clid = TC_H_MAKE(qid, clid);
1444
1445 if (clid)
1446 cl = cops->get(q, clid);
1447
1448 if (cl == 0) {
1449 err = -ENOENT;
1450 if (n->nlmsg_type != RTM_NEWTCLASS ||
1451 !(n->nlmsg_flags & NLM_F_CREATE))
1452 goto out;
1453 } else {
1454 switch (n->nlmsg_type) {
1455 case RTM_NEWTCLASS:
1456 err = -EEXIST;
1457 if (n->nlmsg_flags & NLM_F_EXCL)
1458 goto out;
1459 break;
1460 case RTM_DELTCLASS:
1461 err = -EOPNOTSUPP;
1462 if (cops->delete)
1463 err = cops->delete(q, cl);
1464 if (err == 0)
1465 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1466 goto out;
1467 case RTM_GETTCLASS:
1468 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1469 goto out;
1470 default:
1471 err = -EINVAL;
1472 goto out;
1473 }
1474 }
1475
1476 new_cl = cl;
1477 err = -EOPNOTSUPP;
1478 if (cops->change)
1479 err = cops->change(q, clid, pid, tca, &new_cl);
1480 if (err == 0)
1481 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1482
1483out:
1484 if (cl)
1485 cops->put(q, cl);
1486
1487 return err;
1488}
1489
1490
1491static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1492 unsigned long cl,
1493 u32 pid, u32 seq, u16 flags, int event)
1494{
1495 struct tcmsg *tcm;
1496 struct nlmsghdr *nlh;
1497 unsigned char *b = skb_tail_pointer(skb);
1498 struct gnet_dump d;
1499 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1500
1501 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1502 tcm = NLMSG_DATA(nlh);
1503 tcm->tcm_family = AF_UNSPEC;
1504 tcm->tcm__pad1 = 0;
1505 tcm->tcm__pad2 = 0;
1506 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1507 tcm->tcm_parent = q->handle;
1508 tcm->tcm_handle = q->handle;
1509 tcm->tcm_info = 0;
1510 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1511 goto nla_put_failure;
1512 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1513 goto nla_put_failure;
1514
1515 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1516 qdisc_root_sleeping_lock(q), &d) < 0)
1517 goto nla_put_failure;
1518
1519 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1520 goto nla_put_failure;
1521
1522 if (gnet_stats_finish_copy(&d) < 0)
1523 goto nla_put_failure;
1524
1525 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1526 return skb->len;
1527
1528nlmsg_failure:
1529nla_put_failure:
1530 nlmsg_trim(skb, b);
1531 return -1;
1532}
1533
1534static int tclass_notify(struct net *net, struct sk_buff *oskb,
1535 struct nlmsghdr *n, struct Qdisc *q,
1536 unsigned long cl, int event)
1537{
1538 struct sk_buff *skb;
1539 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
1540
1541 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1542 if (!skb)
1543 return -ENOBUFS;
1544
1545 if (tc_fill_tclass(skb, q, cl, pid, n->nlmsg_seq, 0, event) < 0) {
1546 kfree_skb(skb);
1547 return -EINVAL;
1548 }
1549
1550 return rtnetlink_send(skb, net, pid, RTNLGRP_TC,
1551 n->nlmsg_flags & NLM_F_ECHO);
1552}
1553
1554struct qdisc_dump_args {
1555 struct qdisc_walker w;
1556 struct sk_buff *skb;
1557 struct netlink_callback *cb;
1558};
1559
1560static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1561{
1562 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1563
1564 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).pid,
1565 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1566}
1567
1568static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1569 struct tcmsg *tcm, struct netlink_callback *cb,
1570 int *t_p, int s_t)
1571{
1572 struct qdisc_dump_args arg;
1573
1574 if (tc_qdisc_dump_ignore(q) ||
1575 *t_p < s_t || !q->ops->cl_ops ||
1576 (tcm->tcm_parent &&
1577 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1578 (*t_p)++;
1579 return 0;
1580 }
1581 if (*t_p > s_t)
1582 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1583 arg.w.fn = qdisc_class_dump;
1584 arg.skb = skb;
1585 arg.cb = cb;
1586 arg.w.stop = 0;
1587 arg.w.skip = cb->args[1];
1588 arg.w.count = 0;
1589 q->ops->cl_ops->walk(q, &arg.w);
1590 cb->args[1] = arg.w.count;
1591 if (arg.w.stop)
1592 return -1;
1593 (*t_p)++;
1594 return 0;
1595}
1596
1597static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1598 struct tcmsg *tcm, struct netlink_callback *cb,
1599 int *t_p, int s_t)
1600{
1601 struct Qdisc *q;
1602
1603 if (!root)
1604 return 0;
1605
1606 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1607 return -1;
1608
1609 list_for_each_entry(q, &root->list, list) {
1610 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1611 return -1;
1612 }
1613
1614 return 0;
1615}
1616
1617static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1618{
1619 struct tcmsg *tcm = (struct tcmsg *)NLMSG_DATA(cb->nlh);
1620 struct net *net = sock_net(skb->sk);
1621 struct netdev_queue *dev_queue;
1622 struct net_device *dev;
1623 int t, s_t;
1624
1625 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
1626 return 0;
1627 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1628 if (!dev)
1629 return 0;
1630
1631 s_t = cb->args[0];
1632 t = 0;
1633
1634 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1635 goto done;
1636
1637 dev_queue = dev_ingress_queue(dev);
1638 if (dev_queue &&
1639 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1640 &t, s_t) < 0)
1641 goto done;
1642
1643done:
1644 cb->args[0] = t;
1645
1646 dev_put(dev);
1647 return skb->len;
1648}
1649
1650/* Main classifier routine: scans classifier chain attached
1651 * to this qdisc, (optionally) tests for protocol and asks
1652 * specific classifiers.
1653 */
1654int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
1655 struct tcf_result *res)
1656{
1657 __be16 protocol = skb->protocol;
1658 int err;
1659
1660 for (; tp; tp = tp->next) {
1661 if (tp->protocol != protocol &&
1662 tp->protocol != htons(ETH_P_ALL))
1663 continue;
1664 err = tp->classify(skb, tp, res);
1665
1666 if (err >= 0) {
1667#ifdef CONFIG_NET_CLS_ACT
1668 if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
1669 skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
1670#endif
1671 return err;
1672 }
1673 }
1674 return -1;
1675}
1676EXPORT_SYMBOL(tc_classify_compat);
1677
1678int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1679 struct tcf_result *res)
1680{
1681 int err = 0;
1682#ifdef CONFIG_NET_CLS_ACT
1683 const struct tcf_proto *otp = tp;
1684reclassify:
1685#endif
1686
1687 err = tc_classify_compat(skb, tp, res);
1688#ifdef CONFIG_NET_CLS_ACT
1689 if (err == TC_ACT_RECLASSIFY) {
1690 u32 verd = G_TC_VERD(skb->tc_verd);
1691 tp = otp;
1692
1693 if (verd++ >= MAX_REC_LOOP) {
1694 net_notice_ratelimited("%s: packet reclassify loop rule prio %u protocol %02x\n",
1695 tp->q->ops->id,
1696 tp->prio & 0xffff,
1697 ntohs(tp->protocol));
1698 return TC_ACT_SHOT;
1699 }
1700 skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
1701 goto reclassify;
1702 }
1703#endif
1704 return err;
1705}
1706EXPORT_SYMBOL(tc_classify);
1707
1708void tcf_destroy(struct tcf_proto *tp)
1709{
1710 tp->ops->destroy(tp);
1711 module_put(tp->ops->owner);
1712 kfree(tp);
1713}
1714
1715void tcf_destroy_chain(struct tcf_proto **fl)
1716{
1717 struct tcf_proto *tp;
1718
1719 while ((tp = *fl) != NULL) {
1720 *fl = tp->next;
1721 tcf_destroy(tp);
1722 }
1723}
1724EXPORT_SYMBOL(tcf_destroy_chain);
1725
1726#ifdef CONFIG_PROC_FS
1727static int psched_show(struct seq_file *seq, void *v)
1728{
1729 struct timespec ts;
1730
1731 hrtimer_get_res(CLOCK_MONOTONIC, &ts);
1732 seq_printf(seq, "%08x %08x %08x %08x\n",
1733 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1734 1000000,
1735 (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
1736
1737 return 0;
1738}
1739
1740static int psched_open(struct inode *inode, struct file *file)
1741{
1742 return single_open(file, psched_show, NULL);
1743}
1744
1745static const struct file_operations psched_fops = {
1746 .owner = THIS_MODULE,
1747 .open = psched_open,
1748 .read = seq_read,
1749 .llseek = seq_lseek,
1750 .release = single_release,
1751};
1752
1753static int __net_init psched_net_init(struct net *net)
1754{
1755 struct proc_dir_entry *e;
1756
1757 e = proc_net_fops_create(net, "psched", 0, &psched_fops);
1758 if (e == NULL)
1759 return -ENOMEM;
1760
1761 return 0;
1762}
1763
1764static void __net_exit psched_net_exit(struct net *net)
1765{
1766 proc_net_remove(net, "psched");
1767}
1768#else
1769static int __net_init psched_net_init(struct net *net)
1770{
1771 return 0;
1772}
1773
1774static void __net_exit psched_net_exit(struct net *net)
1775{
1776}
1777#endif
1778
1779static struct pernet_operations psched_net_ops = {
1780 .init = psched_net_init,
1781 .exit = psched_net_exit,
1782};
1783
1784static int __init pktsched_init(void)
1785{
1786 int err;
1787
1788 err = register_pernet_subsys(&psched_net_ops);
1789 if (err) {
1790 pr_err("pktsched_init: "
1791 "cannot initialize per netns operations\n");
1792 return err;
1793 }
1794
1795 register_qdisc(&pfifo_qdisc_ops);
1796 register_qdisc(&bfifo_qdisc_ops);
1797 register_qdisc(&pfifo_head_drop_qdisc_ops);
1798 register_qdisc(&mq_qdisc_ops);
1799
1800 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1801 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1802 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1803 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1804 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1805 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1806
1807 return 0;
1808}
1809
1810subsys_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#include <net/tc_wrapper.h>
35
36#include <trace/events/qdisc.h>
37
38/*
39
40 Short review.
41 -------------
42
43 This file consists of two interrelated parts:
44
45 1. queueing disciplines manager frontend.
46 2. traffic classes manager frontend.
47
48 Generally, queueing discipline ("qdisc") is a black box,
49 which is able to enqueue packets and to dequeue them (when
50 device is ready to send something) in order and at times
51 determined by algorithm hidden in it.
52
53 qdisc's are divided to two categories:
54 - "queues", which have no internal structure visible from outside.
55 - "schedulers", which split all the packets to "traffic classes",
56 using "packet classifiers" (look at cls_api.c)
57
58 In turn, classes may have child qdiscs (as rule, queues)
59 attached to them etc. etc. etc.
60
61 The goal of the routines in this file is to translate
62 information supplied by user in the form of handles
63 to more intelligible for kernel form, to make some sanity
64 checks and part of work, which is common to all qdiscs
65 and to provide rtnetlink notifications.
66
67 All real intelligent work is done inside qdisc modules.
68
69
70
71 Every discipline has two major routines: enqueue and dequeue.
72
73 ---dequeue
74
75 dequeue usually returns a skb to send. It is allowed to return NULL,
76 but it does not mean that queue is empty, it just means that
77 discipline does not want to send anything this time.
78 Queue is really empty if q->q.qlen == 0.
79 For complicated disciplines with multiple queues q->q is not
80 real packet queue, but however q->q.qlen must be valid.
81
82 ---enqueue
83
84 enqueue returns 0, if packet was enqueued successfully.
85 If packet (this one or another one) was dropped, it returns
86 not zero error code.
87 NET_XMIT_DROP - this packet dropped
88 Expected action: do not backoff, but wait until queue will clear.
89 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
90 Expected action: backoff or ignore
91
92 Auxiliary routines:
93
94 ---peek
95
96 like dequeue but without removing a packet from the queue
97
98 ---reset
99
100 returns qdisc to initial state: purge all buffers, clear all
101 timers, counters (except for statistics) etc.
102
103 ---init
104
105 initializes newly created qdisc.
106
107 ---destroy
108
109 destroys resources allocated by init and during lifetime of qdisc.
110
111 ---change
112
113 changes qdisc parameters.
114 */
115
116/* Protects list of registered TC modules. It is pure SMP lock. */
117static DEFINE_RWLOCK(qdisc_mod_lock);
118
119
120/************************************************
121 * Queueing disciplines manipulation. *
122 ************************************************/
123
124
125/* The list of all installed queueing disciplines. */
126
127static struct Qdisc_ops *qdisc_base;
128
129/* Register/unregister queueing discipline */
130
131int register_qdisc(struct Qdisc_ops *qops)
132{
133 struct Qdisc_ops *q, **qp;
134 int rc = -EEXIST;
135
136 write_lock(&qdisc_mod_lock);
137 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
138 if (!strcmp(qops->id, q->id))
139 goto out;
140
141 if (qops->enqueue == NULL)
142 qops->enqueue = noop_qdisc_ops.enqueue;
143 if (qops->peek == NULL) {
144 if (qops->dequeue == NULL)
145 qops->peek = noop_qdisc_ops.peek;
146 else
147 goto out_einval;
148 }
149 if (qops->dequeue == NULL)
150 qops->dequeue = noop_qdisc_ops.dequeue;
151
152 if (qops->cl_ops) {
153 const struct Qdisc_class_ops *cops = qops->cl_ops;
154
155 if (!(cops->find && cops->walk && cops->leaf))
156 goto out_einval;
157
158 if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf))
159 goto out_einval;
160 }
161
162 qops->next = NULL;
163 *qp = qops;
164 rc = 0;
165out:
166 write_unlock(&qdisc_mod_lock);
167 return rc;
168
169out_einval:
170 rc = -EINVAL;
171 goto out;
172}
173EXPORT_SYMBOL(register_qdisc);
174
175void unregister_qdisc(struct Qdisc_ops *qops)
176{
177 struct Qdisc_ops *q, **qp;
178 int err = -ENOENT;
179
180 write_lock(&qdisc_mod_lock);
181 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
182 if (q == qops)
183 break;
184 if (q) {
185 *qp = q->next;
186 q->next = NULL;
187 err = 0;
188 }
189 write_unlock(&qdisc_mod_lock);
190
191 WARN(err, "unregister qdisc(%s) failed\n", qops->id);
192}
193EXPORT_SYMBOL(unregister_qdisc);
194
195/* Get default qdisc if not otherwise specified */
196void qdisc_get_default(char *name, size_t len)
197{
198 read_lock(&qdisc_mod_lock);
199 strscpy(name, default_qdisc_ops->id, len);
200 read_unlock(&qdisc_mod_lock);
201}
202
203static struct Qdisc_ops *qdisc_lookup_default(const char *name)
204{
205 struct Qdisc_ops *q = NULL;
206
207 for (q = qdisc_base; q; q = q->next) {
208 if (!strcmp(name, q->id)) {
209 if (!try_module_get(q->owner))
210 q = NULL;
211 break;
212 }
213 }
214
215 return q;
216}
217
218/* Set new default qdisc to use */
219int qdisc_set_default(const char *name)
220{
221 const struct Qdisc_ops *ops;
222
223 if (!capable(CAP_NET_ADMIN))
224 return -EPERM;
225
226 write_lock(&qdisc_mod_lock);
227 ops = qdisc_lookup_default(name);
228 if (!ops) {
229 /* Not found, drop lock and try to load module */
230 write_unlock(&qdisc_mod_lock);
231 request_module("sch_%s", name);
232 write_lock(&qdisc_mod_lock);
233
234 ops = qdisc_lookup_default(name);
235 }
236
237 if (ops) {
238 /* Set new default */
239 module_put(default_qdisc_ops->owner);
240 default_qdisc_ops = ops;
241 }
242 write_unlock(&qdisc_mod_lock);
243
244 return ops ? 0 : -ENOENT;
245}
246
247#ifdef CONFIG_NET_SCH_DEFAULT
248/* Set default value from kernel config */
249static int __init sch_default_qdisc(void)
250{
251 return qdisc_set_default(CONFIG_DEFAULT_NET_SCH);
252}
253late_initcall(sch_default_qdisc);
254#endif
255
256/* We know handle. Find qdisc among all qdisc's attached to device
257 * (root qdisc, all its children, children of children etc.)
258 * Note: caller either uses rtnl or rcu_read_lock()
259 */
260
261static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
262{
263 struct Qdisc *q;
264
265 if (!qdisc_dev(root))
266 return (root->handle == handle ? root : NULL);
267
268 if (!(root->flags & TCQ_F_BUILTIN) &&
269 root->handle == handle)
270 return root;
271
272 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle,
273 lockdep_rtnl_is_held()) {
274 if (q->handle == handle)
275 return q;
276 }
277 return NULL;
278}
279
280void qdisc_hash_add(struct Qdisc *q, bool invisible)
281{
282 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
283 ASSERT_RTNL();
284 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
285 if (invisible)
286 q->flags |= TCQ_F_INVISIBLE;
287 }
288}
289EXPORT_SYMBOL(qdisc_hash_add);
290
291void qdisc_hash_del(struct Qdisc *q)
292{
293 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
294 ASSERT_RTNL();
295 hash_del_rcu(&q->hash);
296 }
297}
298EXPORT_SYMBOL(qdisc_hash_del);
299
300struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
301{
302 struct Qdisc *q;
303
304 if (!handle)
305 return NULL;
306 q = qdisc_match_from_root(rtnl_dereference(dev->qdisc), handle);
307 if (q)
308 goto out;
309
310 if (dev_ingress_queue(dev))
311 q = qdisc_match_from_root(
312 dev_ingress_queue(dev)->qdisc_sleeping,
313 handle);
314out:
315 return q;
316}
317
318struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle)
319{
320 struct netdev_queue *nq;
321 struct Qdisc *q;
322
323 if (!handle)
324 return NULL;
325 q = qdisc_match_from_root(rcu_dereference(dev->qdisc), handle);
326 if (q)
327 goto out;
328
329 nq = dev_ingress_queue_rcu(dev);
330 if (nq)
331 q = qdisc_match_from_root(nq->qdisc_sleeping, handle);
332out:
333 return q;
334}
335
336static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
337{
338 unsigned long cl;
339 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
340
341 if (cops == NULL)
342 return NULL;
343 cl = cops->find(p, classid);
344
345 if (cl == 0)
346 return NULL;
347 return cops->leaf(p, cl);
348}
349
350/* Find queueing discipline by name */
351
352static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
353{
354 struct Qdisc_ops *q = NULL;
355
356 if (kind) {
357 read_lock(&qdisc_mod_lock);
358 for (q = qdisc_base; q; q = q->next) {
359 if (nla_strcmp(kind, q->id) == 0) {
360 if (!try_module_get(q->owner))
361 q = NULL;
362 break;
363 }
364 }
365 read_unlock(&qdisc_mod_lock);
366 }
367 return q;
368}
369
370/* The linklayer setting were not transferred from iproute2, in older
371 * versions, and the rate tables lookup systems have been dropped in
372 * the kernel. To keep backward compatible with older iproute2 tc
373 * utils, we detect the linklayer setting by detecting if the rate
374 * table were modified.
375 *
376 * For linklayer ATM table entries, the rate table will be aligned to
377 * 48 bytes, thus some table entries will contain the same value. The
378 * mpu (min packet unit) is also encoded into the old rate table, thus
379 * starting from the mpu, we find low and high table entries for
380 * mapping this cell. If these entries contain the same value, when
381 * the rate tables have been modified for linklayer ATM.
382 *
383 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
384 * and then roundup to the next cell, calc the table entry one below,
385 * and compare.
386 */
387static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
388{
389 int low = roundup(r->mpu, 48);
390 int high = roundup(low+1, 48);
391 int cell_low = low >> r->cell_log;
392 int cell_high = (high >> r->cell_log) - 1;
393
394 /* rtab is too inaccurate at rates > 100Mbit/s */
395 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
396 pr_debug("TC linklayer: Giving up ATM detection\n");
397 return TC_LINKLAYER_ETHERNET;
398 }
399
400 if ((cell_high > cell_low) && (cell_high < 256)
401 && (rtab[cell_low] == rtab[cell_high])) {
402 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
403 cell_low, cell_high, rtab[cell_high]);
404 return TC_LINKLAYER_ATM;
405 }
406 return TC_LINKLAYER_ETHERNET;
407}
408
409static struct qdisc_rate_table *qdisc_rtab_list;
410
411struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
412 struct nlattr *tab,
413 struct netlink_ext_ack *extack)
414{
415 struct qdisc_rate_table *rtab;
416
417 if (tab == NULL || r->rate == 0 ||
418 r->cell_log == 0 || r->cell_log >= 32 ||
419 nla_len(tab) != TC_RTAB_SIZE) {
420 NL_SET_ERR_MSG(extack, "Invalid rate table parameters for searching");
421 return NULL;
422 }
423
424 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
425 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
426 !memcmp(&rtab->data, nla_data(tab), 1024)) {
427 rtab->refcnt++;
428 return rtab;
429 }
430 }
431
432 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
433 if (rtab) {
434 rtab->rate = *r;
435 rtab->refcnt = 1;
436 memcpy(rtab->data, nla_data(tab), 1024);
437 if (r->linklayer == TC_LINKLAYER_UNAWARE)
438 r->linklayer = __detect_linklayer(r, rtab->data);
439 rtab->next = qdisc_rtab_list;
440 qdisc_rtab_list = rtab;
441 } else {
442 NL_SET_ERR_MSG(extack, "Failed to allocate new qdisc rate table");
443 }
444 return rtab;
445}
446EXPORT_SYMBOL(qdisc_get_rtab);
447
448void qdisc_put_rtab(struct qdisc_rate_table *tab)
449{
450 struct qdisc_rate_table *rtab, **rtabp;
451
452 if (!tab || --tab->refcnt)
453 return;
454
455 for (rtabp = &qdisc_rtab_list;
456 (rtab = *rtabp) != NULL;
457 rtabp = &rtab->next) {
458 if (rtab == tab) {
459 *rtabp = rtab->next;
460 kfree(rtab);
461 return;
462 }
463 }
464}
465EXPORT_SYMBOL(qdisc_put_rtab);
466
467static LIST_HEAD(qdisc_stab_list);
468
469static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
470 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
471 [TCA_STAB_DATA] = { .type = NLA_BINARY },
472};
473
474static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt,
475 struct netlink_ext_ack *extack)
476{
477 struct nlattr *tb[TCA_STAB_MAX + 1];
478 struct qdisc_size_table *stab;
479 struct tc_sizespec *s;
480 unsigned int tsize = 0;
481 u16 *tab = NULL;
482 int err;
483
484 err = nla_parse_nested_deprecated(tb, TCA_STAB_MAX, opt, stab_policy,
485 extack);
486 if (err < 0)
487 return ERR_PTR(err);
488 if (!tb[TCA_STAB_BASE]) {
489 NL_SET_ERR_MSG(extack, "Size table base attribute is missing");
490 return ERR_PTR(-EINVAL);
491 }
492
493 s = nla_data(tb[TCA_STAB_BASE]);
494
495 if (s->tsize > 0) {
496 if (!tb[TCA_STAB_DATA]) {
497 NL_SET_ERR_MSG(extack, "Size table data attribute is missing");
498 return ERR_PTR(-EINVAL);
499 }
500 tab = nla_data(tb[TCA_STAB_DATA]);
501 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
502 }
503
504 if (tsize != s->tsize || (!tab && tsize > 0)) {
505 NL_SET_ERR_MSG(extack, "Invalid size of size table");
506 return ERR_PTR(-EINVAL);
507 }
508
509 list_for_each_entry(stab, &qdisc_stab_list, list) {
510 if (memcmp(&stab->szopts, s, sizeof(*s)))
511 continue;
512 if (tsize > 0 &&
513 memcmp(stab->data, tab, flex_array_size(stab, data, tsize)))
514 continue;
515 stab->refcnt++;
516 return stab;
517 }
518
519 if (s->size_log > STAB_SIZE_LOG_MAX ||
520 s->cell_log > STAB_SIZE_LOG_MAX) {
521 NL_SET_ERR_MSG(extack, "Invalid logarithmic size of size table");
522 return ERR_PTR(-EINVAL);
523 }
524
525 stab = kmalloc(struct_size(stab, data, tsize), GFP_KERNEL);
526 if (!stab)
527 return ERR_PTR(-ENOMEM);
528
529 stab->refcnt = 1;
530 stab->szopts = *s;
531 if (tsize > 0)
532 memcpy(stab->data, tab, flex_array_size(stab, data, tsize));
533
534 list_add_tail(&stab->list, &qdisc_stab_list);
535
536 return stab;
537}
538
539void qdisc_put_stab(struct qdisc_size_table *tab)
540{
541 if (!tab)
542 return;
543
544 if (--tab->refcnt == 0) {
545 list_del(&tab->list);
546 kfree_rcu(tab, rcu);
547 }
548}
549EXPORT_SYMBOL(qdisc_put_stab);
550
551static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
552{
553 struct nlattr *nest;
554
555 nest = nla_nest_start_noflag(skb, TCA_STAB);
556 if (nest == NULL)
557 goto nla_put_failure;
558 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
559 goto nla_put_failure;
560 nla_nest_end(skb, nest);
561
562 return skb->len;
563
564nla_put_failure:
565 return -1;
566}
567
568void __qdisc_calculate_pkt_len(struct sk_buff *skb,
569 const struct qdisc_size_table *stab)
570{
571 int pkt_len, slot;
572
573 pkt_len = skb->len + stab->szopts.overhead;
574 if (unlikely(!stab->szopts.tsize))
575 goto out;
576
577 slot = pkt_len + stab->szopts.cell_align;
578 if (unlikely(slot < 0))
579 slot = 0;
580
581 slot >>= stab->szopts.cell_log;
582 if (likely(slot < stab->szopts.tsize))
583 pkt_len = stab->data[slot];
584 else
585 pkt_len = stab->data[stab->szopts.tsize - 1] *
586 (slot / stab->szopts.tsize) +
587 stab->data[slot % stab->szopts.tsize];
588
589 pkt_len <<= stab->szopts.size_log;
590out:
591 if (unlikely(pkt_len < 1))
592 pkt_len = 1;
593 qdisc_skb_cb(skb)->pkt_len = pkt_len;
594}
595EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
596
597void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
598{
599 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
600 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
601 txt, qdisc->ops->id, qdisc->handle >> 16);
602 qdisc->flags |= TCQ_F_WARN_NONWC;
603 }
604}
605EXPORT_SYMBOL(qdisc_warn_nonwc);
606
607static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
608{
609 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
610 timer);
611
612 rcu_read_lock();
613 __netif_schedule(qdisc_root(wd->qdisc));
614 rcu_read_unlock();
615
616 return HRTIMER_NORESTART;
617}
618
619void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
620 clockid_t clockid)
621{
622 hrtimer_init(&wd->timer, clockid, HRTIMER_MODE_ABS_PINNED);
623 wd->timer.function = qdisc_watchdog;
624 wd->qdisc = qdisc;
625}
626EXPORT_SYMBOL(qdisc_watchdog_init_clockid);
627
628void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
629{
630 qdisc_watchdog_init_clockid(wd, qdisc, CLOCK_MONOTONIC);
631}
632EXPORT_SYMBOL(qdisc_watchdog_init);
633
634void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires,
635 u64 delta_ns)
636{
637 if (test_bit(__QDISC_STATE_DEACTIVATED,
638 &qdisc_root_sleeping(wd->qdisc)->state))
639 return;
640
641 if (hrtimer_is_queued(&wd->timer)) {
642 /* If timer is already set in [expires, expires + delta_ns],
643 * do not reprogram it.
644 */
645 if (wd->last_expires - expires <= delta_ns)
646 return;
647 }
648
649 wd->last_expires = expires;
650 hrtimer_start_range_ns(&wd->timer,
651 ns_to_ktime(expires),
652 delta_ns,
653 HRTIMER_MODE_ABS_PINNED);
654}
655EXPORT_SYMBOL(qdisc_watchdog_schedule_range_ns);
656
657void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
658{
659 hrtimer_cancel(&wd->timer);
660}
661EXPORT_SYMBOL(qdisc_watchdog_cancel);
662
663static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
664{
665 struct hlist_head *h;
666 unsigned int i;
667
668 h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL);
669
670 if (h != NULL) {
671 for (i = 0; i < n; i++)
672 INIT_HLIST_HEAD(&h[i]);
673 }
674 return h;
675}
676
677void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
678{
679 struct Qdisc_class_common *cl;
680 struct hlist_node *next;
681 struct hlist_head *nhash, *ohash;
682 unsigned int nsize, nmask, osize;
683 unsigned int i, h;
684
685 /* Rehash when load factor exceeds 0.75 */
686 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
687 return;
688 nsize = clhash->hashsize * 2;
689 nmask = nsize - 1;
690 nhash = qdisc_class_hash_alloc(nsize);
691 if (nhash == NULL)
692 return;
693
694 ohash = clhash->hash;
695 osize = clhash->hashsize;
696
697 sch_tree_lock(sch);
698 for (i = 0; i < osize; i++) {
699 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
700 h = qdisc_class_hash(cl->classid, nmask);
701 hlist_add_head(&cl->hnode, &nhash[h]);
702 }
703 }
704 clhash->hash = nhash;
705 clhash->hashsize = nsize;
706 clhash->hashmask = nmask;
707 sch_tree_unlock(sch);
708
709 kvfree(ohash);
710}
711EXPORT_SYMBOL(qdisc_class_hash_grow);
712
713int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
714{
715 unsigned int size = 4;
716
717 clhash->hash = qdisc_class_hash_alloc(size);
718 if (!clhash->hash)
719 return -ENOMEM;
720 clhash->hashsize = size;
721 clhash->hashmask = size - 1;
722 clhash->hashelems = 0;
723 return 0;
724}
725EXPORT_SYMBOL(qdisc_class_hash_init);
726
727void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
728{
729 kvfree(clhash->hash);
730}
731EXPORT_SYMBOL(qdisc_class_hash_destroy);
732
733void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
734 struct Qdisc_class_common *cl)
735{
736 unsigned int h;
737
738 INIT_HLIST_NODE(&cl->hnode);
739 h = qdisc_class_hash(cl->classid, clhash->hashmask);
740 hlist_add_head(&cl->hnode, &clhash->hash[h]);
741 clhash->hashelems++;
742}
743EXPORT_SYMBOL(qdisc_class_hash_insert);
744
745void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
746 struct Qdisc_class_common *cl)
747{
748 hlist_del(&cl->hnode);
749 clhash->hashelems--;
750}
751EXPORT_SYMBOL(qdisc_class_hash_remove);
752
753/* Allocate an unique handle from space managed by kernel
754 * Possible range is [8000-FFFF]:0000 (0x8000 values)
755 */
756static u32 qdisc_alloc_handle(struct net_device *dev)
757{
758 int i = 0x8000;
759 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
760
761 do {
762 autohandle += TC_H_MAKE(0x10000U, 0);
763 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
764 autohandle = TC_H_MAKE(0x80000000U, 0);
765 if (!qdisc_lookup(dev, autohandle))
766 return autohandle;
767 cond_resched();
768 } while (--i > 0);
769
770 return 0;
771}
772
773void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len)
774{
775 bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED;
776 const struct Qdisc_class_ops *cops;
777 unsigned long cl;
778 u32 parentid;
779 bool notify;
780 int drops;
781
782 if (n == 0 && len == 0)
783 return;
784 drops = max_t(int, n, 0);
785 rcu_read_lock();
786 while ((parentid = sch->parent)) {
787 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
788 break;
789
790 if (sch->flags & TCQ_F_NOPARENT)
791 break;
792 /* Notify parent qdisc only if child qdisc becomes empty.
793 *
794 * If child was empty even before update then backlog
795 * counter is screwed and we skip notification because
796 * parent class is already passive.
797 *
798 * If the original child was offloaded then it is allowed
799 * to be seem as empty, so the parent is notified anyway.
800 */
801 notify = !sch->q.qlen && !WARN_ON_ONCE(!n &&
802 !qdisc_is_offloaded);
803 /* TODO: perform the search on a per txq basis */
804 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
805 if (sch == NULL) {
806 WARN_ON_ONCE(parentid != TC_H_ROOT);
807 break;
808 }
809 cops = sch->ops->cl_ops;
810 if (notify && cops->qlen_notify) {
811 cl = cops->find(sch, parentid);
812 cops->qlen_notify(sch, cl);
813 }
814 sch->q.qlen -= n;
815 sch->qstats.backlog -= len;
816 __qdisc_qstats_drop(sch, drops);
817 }
818 rcu_read_unlock();
819}
820EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
821
822int qdisc_offload_dump_helper(struct Qdisc *sch, enum tc_setup_type type,
823 void *type_data)
824{
825 struct net_device *dev = qdisc_dev(sch);
826 int err;
827
828 sch->flags &= ~TCQ_F_OFFLOADED;
829 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
830 return 0;
831
832 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
833 if (err == -EOPNOTSUPP)
834 return 0;
835
836 if (!err)
837 sch->flags |= TCQ_F_OFFLOADED;
838
839 return err;
840}
841EXPORT_SYMBOL(qdisc_offload_dump_helper);
842
843void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
844 struct Qdisc *new, struct Qdisc *old,
845 enum tc_setup_type type, void *type_data,
846 struct netlink_ext_ack *extack)
847{
848 bool any_qdisc_is_offloaded;
849 int err;
850
851 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
852 return;
853
854 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
855
856 /* Don't report error if the graft is part of destroy operation. */
857 if (!err || !new || new == &noop_qdisc)
858 return;
859
860 /* Don't report error if the parent, the old child and the new
861 * one are not offloaded.
862 */
863 any_qdisc_is_offloaded = new->flags & TCQ_F_OFFLOADED;
864 any_qdisc_is_offloaded |= sch && sch->flags & TCQ_F_OFFLOADED;
865 any_qdisc_is_offloaded |= old && old->flags & TCQ_F_OFFLOADED;
866
867 if (any_qdisc_is_offloaded)
868 NL_SET_ERR_MSG(extack, "Offloading graft operation failed.");
869}
870EXPORT_SYMBOL(qdisc_offload_graft_helper);
871
872void qdisc_offload_query_caps(struct net_device *dev,
873 enum tc_setup_type type,
874 void *caps, size_t caps_len)
875{
876 const struct net_device_ops *ops = dev->netdev_ops;
877 struct tc_query_caps_base base = {
878 .type = type,
879 .caps = caps,
880 };
881
882 memset(caps, 0, caps_len);
883
884 if (ops->ndo_setup_tc)
885 ops->ndo_setup_tc(dev, TC_QUERY_CAPS, &base);
886}
887EXPORT_SYMBOL(qdisc_offload_query_caps);
888
889static void qdisc_offload_graft_root(struct net_device *dev,
890 struct Qdisc *new, struct Qdisc *old,
891 struct netlink_ext_ack *extack)
892{
893 struct tc_root_qopt_offload graft_offload = {
894 .command = TC_ROOT_GRAFT,
895 .handle = new ? new->handle : 0,
896 .ingress = (new && new->flags & TCQ_F_INGRESS) ||
897 (old && old->flags & TCQ_F_INGRESS),
898 };
899
900 qdisc_offload_graft_helper(dev, NULL, new, old,
901 TC_SETUP_ROOT_QDISC, &graft_offload, extack);
902}
903
904static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
905 u32 portid, u32 seq, u16 flags, int event)
906{
907 struct gnet_stats_basic_sync __percpu *cpu_bstats = NULL;
908 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
909 struct tcmsg *tcm;
910 struct nlmsghdr *nlh;
911 unsigned char *b = skb_tail_pointer(skb);
912 struct gnet_dump d;
913 struct qdisc_size_table *stab;
914 u32 block_index;
915 __u32 qlen;
916
917 cond_resched();
918 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
919 if (!nlh)
920 goto out_nlmsg_trim;
921 tcm = nlmsg_data(nlh);
922 tcm->tcm_family = AF_UNSPEC;
923 tcm->tcm__pad1 = 0;
924 tcm->tcm__pad2 = 0;
925 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
926 tcm->tcm_parent = clid;
927 tcm->tcm_handle = q->handle;
928 tcm->tcm_info = refcount_read(&q->refcnt);
929 if (nla_put_string(skb, TCA_KIND, q->ops->id))
930 goto nla_put_failure;
931 if (q->ops->ingress_block_get) {
932 block_index = q->ops->ingress_block_get(q);
933 if (block_index &&
934 nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index))
935 goto nla_put_failure;
936 }
937 if (q->ops->egress_block_get) {
938 block_index = q->ops->egress_block_get(q);
939 if (block_index &&
940 nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index))
941 goto nla_put_failure;
942 }
943 if (q->ops->dump && q->ops->dump(q, skb) < 0)
944 goto nla_put_failure;
945 if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED)))
946 goto nla_put_failure;
947 qlen = qdisc_qlen_sum(q);
948
949 stab = rtnl_dereference(q->stab);
950 if (stab && qdisc_dump_stab(skb, stab) < 0)
951 goto nla_put_failure;
952
953 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
954 NULL, &d, TCA_PAD) < 0)
955 goto nla_put_failure;
956
957 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
958 goto nla_put_failure;
959
960 if (qdisc_is_percpu_stats(q)) {
961 cpu_bstats = q->cpu_bstats;
962 cpu_qstats = q->cpu_qstats;
963 }
964
965 if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats, true) < 0 ||
966 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
967 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
968 goto nla_put_failure;
969
970 if (gnet_stats_finish_copy(&d) < 0)
971 goto nla_put_failure;
972
973 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
974 return skb->len;
975
976out_nlmsg_trim:
977nla_put_failure:
978 nlmsg_trim(skb, b);
979 return -1;
980}
981
982static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible)
983{
984 if (q->flags & TCQ_F_BUILTIN)
985 return true;
986 if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible)
987 return true;
988
989 return false;
990}
991
992static int qdisc_notify(struct net *net, struct sk_buff *oskb,
993 struct nlmsghdr *n, u32 clid,
994 struct Qdisc *old, struct Qdisc *new)
995{
996 struct sk_buff *skb;
997 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
998
999 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1000 if (!skb)
1001 return -ENOBUFS;
1002
1003 if (old && !tc_qdisc_dump_ignore(old, false)) {
1004 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1005 0, RTM_DELQDISC) < 0)
1006 goto err_out;
1007 }
1008 if (new && !tc_qdisc_dump_ignore(new, false)) {
1009 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1010 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1011 goto err_out;
1012 }
1013
1014 if (skb->len)
1015 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1016 n->nlmsg_flags & NLM_F_ECHO);
1017
1018err_out:
1019 kfree_skb(skb);
1020 return -EINVAL;
1021}
1022
1023static void notify_and_destroy(struct net *net, struct sk_buff *skb,
1024 struct nlmsghdr *n, u32 clid,
1025 struct Qdisc *old, struct Qdisc *new)
1026{
1027 if (new || old)
1028 qdisc_notify(net, skb, n, clid, old, new);
1029
1030 if (old)
1031 qdisc_put(old);
1032}
1033
1034static void qdisc_clear_nolock(struct Qdisc *sch)
1035{
1036 sch->flags &= ~TCQ_F_NOLOCK;
1037 if (!(sch->flags & TCQ_F_CPUSTATS))
1038 return;
1039
1040 free_percpu(sch->cpu_bstats);
1041 free_percpu(sch->cpu_qstats);
1042 sch->cpu_bstats = NULL;
1043 sch->cpu_qstats = NULL;
1044 sch->flags &= ~TCQ_F_CPUSTATS;
1045}
1046
1047/* Graft qdisc "new" to class "classid" of qdisc "parent" or
1048 * to device "dev".
1049 *
1050 * When appropriate send a netlink notification using 'skb'
1051 * and "n".
1052 *
1053 * On success, destroy old qdisc.
1054 */
1055
1056static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
1057 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
1058 struct Qdisc *new, struct Qdisc *old,
1059 struct netlink_ext_ack *extack)
1060{
1061 struct Qdisc *q = old;
1062 struct net *net = dev_net(dev);
1063
1064 if (parent == NULL) {
1065 unsigned int i, num_q, ingress;
1066
1067 ingress = 0;
1068 num_q = dev->num_tx_queues;
1069 if ((q && q->flags & TCQ_F_INGRESS) ||
1070 (new && new->flags & TCQ_F_INGRESS)) {
1071 num_q = 1;
1072 ingress = 1;
1073 if (!dev_ingress_queue(dev)) {
1074 NL_SET_ERR_MSG(extack, "Device does not have an ingress queue");
1075 return -ENOENT;
1076 }
1077 }
1078
1079 if (dev->flags & IFF_UP)
1080 dev_deactivate(dev);
1081
1082 qdisc_offload_graft_root(dev, new, old, extack);
1083
1084 if (new && new->ops->attach && !ingress)
1085 goto skip;
1086
1087 for (i = 0; i < num_q; i++) {
1088 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
1089
1090 if (!ingress)
1091 dev_queue = netdev_get_tx_queue(dev, i);
1092
1093 old = dev_graft_qdisc(dev_queue, new);
1094 if (new && i > 0)
1095 qdisc_refcount_inc(new);
1096
1097 if (!ingress)
1098 qdisc_put(old);
1099 }
1100
1101skip:
1102 if (!ingress) {
1103 old = rtnl_dereference(dev->qdisc);
1104 if (new && !new->ops->attach)
1105 qdisc_refcount_inc(new);
1106 rcu_assign_pointer(dev->qdisc, new ? : &noop_qdisc);
1107
1108 notify_and_destroy(net, skb, n, classid, old, new);
1109
1110 if (new && new->ops->attach)
1111 new->ops->attach(new);
1112 } else {
1113 notify_and_destroy(net, skb, n, classid, old, new);
1114 }
1115
1116 if (dev->flags & IFF_UP)
1117 dev_activate(dev);
1118 } else {
1119 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
1120 unsigned long cl;
1121 int err;
1122
1123 /* Only support running class lockless if parent is lockless */
1124 if (new && (new->flags & TCQ_F_NOLOCK) && !(parent->flags & TCQ_F_NOLOCK))
1125 qdisc_clear_nolock(new);
1126
1127 if (!cops || !cops->graft)
1128 return -EOPNOTSUPP;
1129
1130 cl = cops->find(parent, classid);
1131 if (!cl) {
1132 NL_SET_ERR_MSG(extack, "Specified class not found");
1133 return -ENOENT;
1134 }
1135
1136 if (new && new->ops == &noqueue_qdisc_ops) {
1137 NL_SET_ERR_MSG(extack, "Cannot assign noqueue to a class");
1138 return -EINVAL;
1139 }
1140
1141 err = cops->graft(parent, cl, new, &old, extack);
1142 if (err)
1143 return err;
1144 notify_and_destroy(net, skb, n, classid, old, new);
1145 }
1146 return 0;
1147}
1148
1149static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca,
1150 struct netlink_ext_ack *extack)
1151{
1152 u32 block_index;
1153
1154 if (tca[TCA_INGRESS_BLOCK]) {
1155 block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]);
1156
1157 if (!block_index) {
1158 NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0");
1159 return -EINVAL;
1160 }
1161 if (!sch->ops->ingress_block_set) {
1162 NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported");
1163 return -EOPNOTSUPP;
1164 }
1165 sch->ops->ingress_block_set(sch, block_index);
1166 }
1167 if (tca[TCA_EGRESS_BLOCK]) {
1168 block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]);
1169
1170 if (!block_index) {
1171 NL_SET_ERR_MSG(extack, "Egress block index cannot be 0");
1172 return -EINVAL;
1173 }
1174 if (!sch->ops->egress_block_set) {
1175 NL_SET_ERR_MSG(extack, "Egress block sharing is not supported");
1176 return -EOPNOTSUPP;
1177 }
1178 sch->ops->egress_block_set(sch, block_index);
1179 }
1180 return 0;
1181}
1182
1183/*
1184 Allocate and initialize new qdisc.
1185
1186 Parameters are passed via opt.
1187 */
1188
1189static struct Qdisc *qdisc_create(struct net_device *dev,
1190 struct netdev_queue *dev_queue,
1191 u32 parent, u32 handle,
1192 struct nlattr **tca, int *errp,
1193 struct netlink_ext_ack *extack)
1194{
1195 int err;
1196 struct nlattr *kind = tca[TCA_KIND];
1197 struct Qdisc *sch;
1198 struct Qdisc_ops *ops;
1199 struct qdisc_size_table *stab;
1200
1201 ops = qdisc_lookup_ops(kind);
1202#ifdef CONFIG_MODULES
1203 if (ops == NULL && kind != NULL) {
1204 char name[IFNAMSIZ];
1205 if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) {
1206 /* We dropped the RTNL semaphore in order to
1207 * perform the module load. So, even if we
1208 * succeeded in loading the module we have to
1209 * tell the caller to replay the request. We
1210 * indicate this using -EAGAIN.
1211 * We replay the request because the device may
1212 * go away in the mean time.
1213 */
1214 rtnl_unlock();
1215 request_module("sch_%s", name);
1216 rtnl_lock();
1217 ops = qdisc_lookup_ops(kind);
1218 if (ops != NULL) {
1219 /* We will try again qdisc_lookup_ops,
1220 * so don't keep a reference.
1221 */
1222 module_put(ops->owner);
1223 err = -EAGAIN;
1224 goto err_out;
1225 }
1226 }
1227 }
1228#endif
1229
1230 err = -ENOENT;
1231 if (!ops) {
1232 NL_SET_ERR_MSG(extack, "Specified qdisc kind is unknown");
1233 goto err_out;
1234 }
1235
1236 sch = qdisc_alloc(dev_queue, ops, extack);
1237 if (IS_ERR(sch)) {
1238 err = PTR_ERR(sch);
1239 goto err_out2;
1240 }
1241
1242 sch->parent = parent;
1243
1244 if (handle == TC_H_INGRESS) {
1245 sch->flags |= TCQ_F_INGRESS;
1246 handle = TC_H_MAKE(TC_H_INGRESS, 0);
1247 } else {
1248 if (handle == 0) {
1249 handle = qdisc_alloc_handle(dev);
1250 if (handle == 0) {
1251 NL_SET_ERR_MSG(extack, "Maximum number of qdisc handles was exceeded");
1252 err = -ENOSPC;
1253 goto err_out3;
1254 }
1255 }
1256 if (!netif_is_multiqueue(dev))
1257 sch->flags |= TCQ_F_ONETXQUEUE;
1258 }
1259
1260 sch->handle = handle;
1261
1262 /* This exist to keep backward compatible with a userspace
1263 * loophole, what allowed userspace to get IFF_NO_QUEUE
1264 * facility on older kernels by setting tx_queue_len=0 (prior
1265 * to qdisc init), and then forgot to reinit tx_queue_len
1266 * before again attaching a qdisc.
1267 */
1268 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) {
1269 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
1270 netdev_info(dev, "Caught tx_queue_len zero misconfig\n");
1271 }
1272
1273 err = qdisc_block_indexes_set(sch, tca, extack);
1274 if (err)
1275 goto err_out3;
1276
1277 if (ops->init) {
1278 err = ops->init(sch, tca[TCA_OPTIONS], extack);
1279 if (err != 0)
1280 goto err_out5;
1281 }
1282
1283 if (tca[TCA_STAB]) {
1284 stab = qdisc_get_stab(tca[TCA_STAB], extack);
1285 if (IS_ERR(stab)) {
1286 err = PTR_ERR(stab);
1287 goto err_out4;
1288 }
1289 rcu_assign_pointer(sch->stab, stab);
1290 }
1291 if (tca[TCA_RATE]) {
1292 err = -EOPNOTSUPP;
1293 if (sch->flags & TCQ_F_MQROOT) {
1294 NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc");
1295 goto err_out4;
1296 }
1297
1298 err = gen_new_estimator(&sch->bstats,
1299 sch->cpu_bstats,
1300 &sch->rate_est,
1301 NULL,
1302 true,
1303 tca[TCA_RATE]);
1304 if (err) {
1305 NL_SET_ERR_MSG(extack, "Failed to generate new estimator");
1306 goto err_out4;
1307 }
1308 }
1309
1310 qdisc_hash_add(sch, false);
1311 trace_qdisc_create(ops, dev, parent);
1312
1313 return sch;
1314
1315err_out5:
1316 /* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */
1317 if (ops->destroy)
1318 ops->destroy(sch);
1319err_out3:
1320 netdev_put(dev, &sch->dev_tracker);
1321 qdisc_free(sch);
1322err_out2:
1323 module_put(ops->owner);
1324err_out:
1325 *errp = err;
1326 return NULL;
1327
1328err_out4:
1329 /*
1330 * Any broken qdiscs that would require a ops->reset() here?
1331 * The qdisc was never in action so it shouldn't be necessary.
1332 */
1333 qdisc_put_stab(rtnl_dereference(sch->stab));
1334 if (ops->destroy)
1335 ops->destroy(sch);
1336 goto err_out3;
1337}
1338
1339static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
1340 struct netlink_ext_ack *extack)
1341{
1342 struct qdisc_size_table *ostab, *stab = NULL;
1343 int err = 0;
1344
1345 if (tca[TCA_OPTIONS]) {
1346 if (!sch->ops->change) {
1347 NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc");
1348 return -EINVAL;
1349 }
1350 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
1351 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
1352 return -EOPNOTSUPP;
1353 }
1354 err = sch->ops->change(sch, tca[TCA_OPTIONS], extack);
1355 if (err)
1356 return err;
1357 }
1358
1359 if (tca[TCA_STAB]) {
1360 stab = qdisc_get_stab(tca[TCA_STAB], extack);
1361 if (IS_ERR(stab))
1362 return PTR_ERR(stab);
1363 }
1364
1365 ostab = rtnl_dereference(sch->stab);
1366 rcu_assign_pointer(sch->stab, stab);
1367 qdisc_put_stab(ostab);
1368
1369 if (tca[TCA_RATE]) {
1370 /* NB: ignores errors from replace_estimator
1371 because change can't be undone. */
1372 if (sch->flags & TCQ_F_MQROOT)
1373 goto out;
1374 gen_replace_estimator(&sch->bstats,
1375 sch->cpu_bstats,
1376 &sch->rate_est,
1377 NULL,
1378 true,
1379 tca[TCA_RATE]);
1380 }
1381out:
1382 return 0;
1383}
1384
1385struct check_loop_arg {
1386 struct qdisc_walker w;
1387 struct Qdisc *p;
1388 int depth;
1389};
1390
1391static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1392 struct qdisc_walker *w);
1393
1394static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1395{
1396 struct check_loop_arg arg;
1397
1398 if (q->ops->cl_ops == NULL)
1399 return 0;
1400
1401 arg.w.stop = arg.w.skip = arg.w.count = 0;
1402 arg.w.fn = check_loop_fn;
1403 arg.depth = depth;
1404 arg.p = p;
1405 q->ops->cl_ops->walk(q, &arg.w);
1406 return arg.w.stop ? -ELOOP : 0;
1407}
1408
1409static int
1410check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1411{
1412 struct Qdisc *leaf;
1413 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1414 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1415
1416 leaf = cops->leaf(q, cl);
1417 if (leaf) {
1418 if (leaf == arg->p || arg->depth > 7)
1419 return -ELOOP;
1420 return check_loop(leaf, arg->p, arg->depth + 1);
1421 }
1422 return 0;
1423}
1424
1425const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = {
1426 [TCA_KIND] = { .type = NLA_STRING },
1427 [TCA_RATE] = { .type = NLA_BINARY,
1428 .len = sizeof(struct tc_estimator) },
1429 [TCA_STAB] = { .type = NLA_NESTED },
1430 [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG },
1431 [TCA_CHAIN] = { .type = NLA_U32 },
1432 [TCA_INGRESS_BLOCK] = { .type = NLA_U32 },
1433 [TCA_EGRESS_BLOCK] = { .type = NLA_U32 },
1434};
1435
1436/*
1437 * Delete/get qdisc.
1438 */
1439
1440static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1441 struct netlink_ext_ack *extack)
1442{
1443 struct net *net = sock_net(skb->sk);
1444 struct tcmsg *tcm = nlmsg_data(n);
1445 struct nlattr *tca[TCA_MAX + 1];
1446 struct net_device *dev;
1447 u32 clid;
1448 struct Qdisc *q = NULL;
1449 struct Qdisc *p = NULL;
1450 int err;
1451
1452 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1453 rtm_tca_policy, extack);
1454 if (err < 0)
1455 return err;
1456
1457 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1458 if (!dev)
1459 return -ENODEV;
1460
1461 clid = tcm->tcm_parent;
1462 if (clid) {
1463 if (clid != TC_H_ROOT) {
1464 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1465 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1466 if (!p) {
1467 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid");
1468 return -ENOENT;
1469 }
1470 q = qdisc_leaf(p, clid);
1471 } else if (dev_ingress_queue(dev)) {
1472 q = dev_ingress_queue(dev)->qdisc_sleeping;
1473 }
1474 } else {
1475 q = rtnl_dereference(dev->qdisc);
1476 }
1477 if (!q) {
1478 NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device");
1479 return -ENOENT;
1480 }
1481
1482 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) {
1483 NL_SET_ERR_MSG(extack, "Invalid handle");
1484 return -EINVAL;
1485 }
1486 } else {
1487 q = qdisc_lookup(dev, tcm->tcm_handle);
1488 if (!q) {
1489 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle");
1490 return -ENOENT;
1491 }
1492 }
1493
1494 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1495 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1496 return -EINVAL;
1497 }
1498
1499 if (n->nlmsg_type == RTM_DELQDISC) {
1500 if (!clid) {
1501 NL_SET_ERR_MSG(extack, "Classid cannot be zero");
1502 return -EINVAL;
1503 }
1504 if (q->handle == 0) {
1505 NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero");
1506 return -ENOENT;
1507 }
1508 err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack);
1509 if (err != 0)
1510 return err;
1511 } else {
1512 qdisc_notify(net, skb, n, clid, NULL, q);
1513 }
1514 return 0;
1515}
1516
1517/*
1518 * Create/change qdisc.
1519 */
1520
1521static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1522 struct netlink_ext_ack *extack)
1523{
1524 struct net *net = sock_net(skb->sk);
1525 struct tcmsg *tcm;
1526 struct nlattr *tca[TCA_MAX + 1];
1527 struct net_device *dev;
1528 u32 clid;
1529 struct Qdisc *q, *p;
1530 int err;
1531
1532replay:
1533 /* Reinit, just in case something touches this. */
1534 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1535 rtm_tca_policy, extack);
1536 if (err < 0)
1537 return err;
1538
1539 tcm = nlmsg_data(n);
1540 clid = tcm->tcm_parent;
1541 q = p = NULL;
1542
1543 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1544 if (!dev)
1545 return -ENODEV;
1546
1547
1548 if (clid) {
1549 if (clid != TC_H_ROOT) {
1550 if (clid != TC_H_INGRESS) {
1551 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1552 if (!p) {
1553 NL_SET_ERR_MSG(extack, "Failed to find specified qdisc");
1554 return -ENOENT;
1555 }
1556 q = qdisc_leaf(p, clid);
1557 } else if (dev_ingress_queue_create(dev)) {
1558 q = dev_ingress_queue(dev)->qdisc_sleeping;
1559 }
1560 } else {
1561 q = rtnl_dereference(dev->qdisc);
1562 }
1563
1564 /* It may be default qdisc, ignore it */
1565 if (q && q->handle == 0)
1566 q = NULL;
1567
1568 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1569 if (tcm->tcm_handle) {
1570 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) {
1571 NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override");
1572 return -EEXIST;
1573 }
1574 if (TC_H_MIN(tcm->tcm_handle)) {
1575 NL_SET_ERR_MSG(extack, "Invalid minor handle");
1576 return -EINVAL;
1577 }
1578 q = qdisc_lookup(dev, tcm->tcm_handle);
1579 if (!q)
1580 goto create_n_graft;
1581 if (n->nlmsg_flags & NLM_F_EXCL) {
1582 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override");
1583 return -EEXIST;
1584 }
1585 if (tca[TCA_KIND] &&
1586 nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1587 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1588 return -EINVAL;
1589 }
1590 if (q == p ||
1591 (p && check_loop(q, p, 0))) {
1592 NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected");
1593 return -ELOOP;
1594 }
1595 qdisc_refcount_inc(q);
1596 goto graft;
1597 } else {
1598 if (!q)
1599 goto create_n_graft;
1600
1601 /* This magic test requires explanation.
1602 *
1603 * We know, that some child q is already
1604 * attached to this parent and have choice:
1605 * either to change it or to create/graft new one.
1606 *
1607 * 1. We are allowed to create/graft only
1608 * if CREATE and REPLACE flags are set.
1609 *
1610 * 2. If EXCL is set, requestor wanted to say,
1611 * that qdisc tcm_handle is not expected
1612 * to exist, so that we choose create/graft too.
1613 *
1614 * 3. The last case is when no flags are set.
1615 * Alas, it is sort of hole in API, we
1616 * cannot decide what to do unambiguously.
1617 * For now we select create/graft, if
1618 * user gave KIND, which does not match existing.
1619 */
1620 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1621 (n->nlmsg_flags & NLM_F_REPLACE) &&
1622 ((n->nlmsg_flags & NLM_F_EXCL) ||
1623 (tca[TCA_KIND] &&
1624 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1625 goto create_n_graft;
1626 }
1627 }
1628 } else {
1629 if (!tcm->tcm_handle) {
1630 NL_SET_ERR_MSG(extack, "Handle cannot be zero");
1631 return -EINVAL;
1632 }
1633 q = qdisc_lookup(dev, tcm->tcm_handle);
1634 }
1635
1636 /* Change qdisc parameters */
1637 if (!q) {
1638 NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1639 return -ENOENT;
1640 }
1641 if (n->nlmsg_flags & NLM_F_EXCL) {
1642 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify");
1643 return -EEXIST;
1644 }
1645 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1646 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1647 return -EINVAL;
1648 }
1649 err = qdisc_change(q, tca, extack);
1650 if (err == 0)
1651 qdisc_notify(net, skb, n, clid, NULL, q);
1652 return err;
1653
1654create_n_graft:
1655 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
1656 NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag");
1657 return -ENOENT;
1658 }
1659 if (clid == TC_H_INGRESS) {
1660 if (dev_ingress_queue(dev)) {
1661 q = qdisc_create(dev, dev_ingress_queue(dev),
1662 tcm->tcm_parent, tcm->tcm_parent,
1663 tca, &err, extack);
1664 } else {
1665 NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device");
1666 err = -ENOENT;
1667 }
1668 } else {
1669 struct netdev_queue *dev_queue;
1670
1671 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1672 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1673 else if (p)
1674 dev_queue = p->dev_queue;
1675 else
1676 dev_queue = netdev_get_tx_queue(dev, 0);
1677
1678 q = qdisc_create(dev, dev_queue,
1679 tcm->tcm_parent, tcm->tcm_handle,
1680 tca, &err, extack);
1681 }
1682 if (q == NULL) {
1683 if (err == -EAGAIN)
1684 goto replay;
1685 return err;
1686 }
1687
1688graft:
1689 err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack);
1690 if (err) {
1691 if (q)
1692 qdisc_put(q);
1693 return err;
1694 }
1695
1696 return 0;
1697}
1698
1699static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1700 struct netlink_callback *cb,
1701 int *q_idx_p, int s_q_idx, bool recur,
1702 bool dump_invisible)
1703{
1704 int ret = 0, q_idx = *q_idx_p;
1705 struct Qdisc *q;
1706 int b;
1707
1708 if (!root)
1709 return 0;
1710
1711 q = root;
1712 if (q_idx < s_q_idx) {
1713 q_idx++;
1714 } else {
1715 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1716 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1717 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1718 RTM_NEWQDISC) <= 0)
1719 goto done;
1720 q_idx++;
1721 }
1722
1723 /* If dumping singletons, there is no qdisc_dev(root) and the singleton
1724 * itself has already been dumped.
1725 *
1726 * If we've already dumped the top-level (ingress) qdisc above and the global
1727 * qdisc hashtable, we don't want to hit it again
1728 */
1729 if (!qdisc_dev(root) || !recur)
1730 goto out;
1731
1732 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1733 if (q_idx < s_q_idx) {
1734 q_idx++;
1735 continue;
1736 }
1737 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1738 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1739 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1740 RTM_NEWQDISC) <= 0)
1741 goto done;
1742 q_idx++;
1743 }
1744
1745out:
1746 *q_idx_p = q_idx;
1747 return ret;
1748done:
1749 ret = -1;
1750 goto out;
1751}
1752
1753static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1754{
1755 struct net *net = sock_net(skb->sk);
1756 int idx, q_idx;
1757 int s_idx, s_q_idx;
1758 struct net_device *dev;
1759 const struct nlmsghdr *nlh = cb->nlh;
1760 struct nlattr *tca[TCA_MAX + 1];
1761 int err;
1762
1763 s_idx = cb->args[0];
1764 s_q_idx = q_idx = cb->args[1];
1765
1766 idx = 0;
1767 ASSERT_RTNL();
1768
1769 err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX,
1770 rtm_tca_policy, cb->extack);
1771 if (err < 0)
1772 return err;
1773
1774 for_each_netdev(net, dev) {
1775 struct netdev_queue *dev_queue;
1776
1777 if (idx < s_idx)
1778 goto cont;
1779 if (idx > s_idx)
1780 s_q_idx = 0;
1781 q_idx = 0;
1782
1783 if (tc_dump_qdisc_root(rtnl_dereference(dev->qdisc),
1784 skb, cb, &q_idx, s_q_idx,
1785 true, tca[TCA_DUMP_INVISIBLE]) < 0)
1786 goto done;
1787
1788 dev_queue = dev_ingress_queue(dev);
1789 if (dev_queue &&
1790 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1791 &q_idx, s_q_idx, false,
1792 tca[TCA_DUMP_INVISIBLE]) < 0)
1793 goto done;
1794
1795cont:
1796 idx++;
1797 }
1798
1799done:
1800 cb->args[0] = idx;
1801 cb->args[1] = q_idx;
1802
1803 return skb->len;
1804}
1805
1806
1807
1808/************************************************
1809 * Traffic classes manipulation. *
1810 ************************************************/
1811
1812static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1813 unsigned long cl,
1814 u32 portid, u32 seq, u16 flags, int event)
1815{
1816 struct tcmsg *tcm;
1817 struct nlmsghdr *nlh;
1818 unsigned char *b = skb_tail_pointer(skb);
1819 struct gnet_dump d;
1820 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1821
1822 cond_resched();
1823 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1824 if (!nlh)
1825 goto out_nlmsg_trim;
1826 tcm = nlmsg_data(nlh);
1827 tcm->tcm_family = AF_UNSPEC;
1828 tcm->tcm__pad1 = 0;
1829 tcm->tcm__pad2 = 0;
1830 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1831 tcm->tcm_parent = q->handle;
1832 tcm->tcm_handle = q->handle;
1833 tcm->tcm_info = 0;
1834 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1835 goto nla_put_failure;
1836 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1837 goto nla_put_failure;
1838
1839 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1840 NULL, &d, TCA_PAD) < 0)
1841 goto nla_put_failure;
1842
1843 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1844 goto nla_put_failure;
1845
1846 if (gnet_stats_finish_copy(&d) < 0)
1847 goto nla_put_failure;
1848
1849 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1850 return skb->len;
1851
1852out_nlmsg_trim:
1853nla_put_failure:
1854 nlmsg_trim(skb, b);
1855 return -1;
1856}
1857
1858static int tclass_notify(struct net *net, struct sk_buff *oskb,
1859 struct nlmsghdr *n, struct Qdisc *q,
1860 unsigned long cl, int event)
1861{
1862 struct sk_buff *skb;
1863 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1864
1865 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1866 if (!skb)
1867 return -ENOBUFS;
1868
1869 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1870 kfree_skb(skb);
1871 return -EINVAL;
1872 }
1873
1874 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1875 n->nlmsg_flags & NLM_F_ECHO);
1876}
1877
1878static int tclass_del_notify(struct net *net,
1879 const struct Qdisc_class_ops *cops,
1880 struct sk_buff *oskb, struct nlmsghdr *n,
1881 struct Qdisc *q, unsigned long cl,
1882 struct netlink_ext_ack *extack)
1883{
1884 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1885 struct sk_buff *skb;
1886 int err = 0;
1887
1888 if (!cops->delete)
1889 return -EOPNOTSUPP;
1890
1891 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1892 if (!skb)
1893 return -ENOBUFS;
1894
1895 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0,
1896 RTM_DELTCLASS) < 0) {
1897 kfree_skb(skb);
1898 return -EINVAL;
1899 }
1900
1901 err = cops->delete(q, cl, extack);
1902 if (err) {
1903 kfree_skb(skb);
1904 return err;
1905 }
1906
1907 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1908 n->nlmsg_flags & NLM_F_ECHO);
1909 return err;
1910}
1911
1912#ifdef CONFIG_NET_CLS
1913
1914struct tcf_bind_args {
1915 struct tcf_walker w;
1916 unsigned long base;
1917 unsigned long cl;
1918 u32 classid;
1919};
1920
1921static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
1922{
1923 struct tcf_bind_args *a = (void *)arg;
1924
1925 if (n && tp->ops->bind_class) {
1926 struct Qdisc *q = tcf_block_q(tp->chain->block);
1927
1928 sch_tree_lock(q);
1929 tp->ops->bind_class(n, a->classid, a->cl, q, a->base);
1930 sch_tree_unlock(q);
1931 }
1932 return 0;
1933}
1934
1935struct tc_bind_class_args {
1936 struct qdisc_walker w;
1937 unsigned long new_cl;
1938 u32 portid;
1939 u32 clid;
1940};
1941
1942static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl,
1943 struct qdisc_walker *w)
1944{
1945 struct tc_bind_class_args *a = (struct tc_bind_class_args *)w;
1946 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1947 struct tcf_block *block;
1948 struct tcf_chain *chain;
1949
1950 block = cops->tcf_block(q, cl, NULL);
1951 if (!block)
1952 return 0;
1953 for (chain = tcf_get_next_chain(block, NULL);
1954 chain;
1955 chain = tcf_get_next_chain(block, chain)) {
1956 struct tcf_proto *tp;
1957
1958 for (tp = tcf_get_next_proto(chain, NULL);
1959 tp; tp = tcf_get_next_proto(chain, tp)) {
1960 struct tcf_bind_args arg = {};
1961
1962 arg.w.fn = tcf_node_bind;
1963 arg.classid = a->clid;
1964 arg.base = cl;
1965 arg.cl = a->new_cl;
1966 tp->ops->walk(tp, &arg.w, true);
1967 }
1968 }
1969
1970 return 0;
1971}
1972
1973static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1974 unsigned long new_cl)
1975{
1976 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1977 struct tc_bind_class_args args = {};
1978
1979 if (!cops->tcf_block)
1980 return;
1981 args.portid = portid;
1982 args.clid = clid;
1983 args.new_cl = new_cl;
1984 args.w.fn = tc_bind_class_walker;
1985 q->ops->cl_ops->walk(q, &args.w);
1986}
1987
1988#else
1989
1990static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1991 unsigned long new_cl)
1992{
1993}
1994
1995#endif
1996
1997static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
1998 struct netlink_ext_ack *extack)
1999{
2000 struct net *net = sock_net(skb->sk);
2001 struct tcmsg *tcm = nlmsg_data(n);
2002 struct nlattr *tca[TCA_MAX + 1];
2003 struct net_device *dev;
2004 struct Qdisc *q = NULL;
2005 const struct Qdisc_class_ops *cops;
2006 unsigned long cl = 0;
2007 unsigned long new_cl;
2008 u32 portid;
2009 u32 clid;
2010 u32 qid;
2011 int err;
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 = rtnl_dereference(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 = rtnl_dereference(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(rtnl_dereference(dev->qdisc),
2224 skb, tcm, cb, &t, s_t, true) < 0)
2225 goto done;
2226
2227 dev_queue = dev_ingress_queue(dev);
2228 if (dev_queue &&
2229 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
2230 &t, s_t, false) < 0)
2231 goto done;
2232
2233done:
2234 cb->args[0] = t;
2235
2236 dev_put(dev);
2237 return skb->len;
2238}
2239
2240#ifdef CONFIG_PROC_FS
2241static int psched_show(struct seq_file *seq, void *v)
2242{
2243 seq_printf(seq, "%08x %08x %08x %08x\n",
2244 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
2245 1000000,
2246 (u32)NSEC_PER_SEC / hrtimer_resolution);
2247
2248 return 0;
2249}
2250
2251static int __net_init psched_net_init(struct net *net)
2252{
2253 struct proc_dir_entry *e;
2254
2255 e = proc_create_single("psched", 0, net->proc_net, psched_show);
2256 if (e == NULL)
2257 return -ENOMEM;
2258
2259 return 0;
2260}
2261
2262static void __net_exit psched_net_exit(struct net *net)
2263{
2264 remove_proc_entry("psched", net->proc_net);
2265}
2266#else
2267static int __net_init psched_net_init(struct net *net)
2268{
2269 return 0;
2270}
2271
2272static void __net_exit psched_net_exit(struct net *net)
2273{
2274}
2275#endif
2276
2277static struct pernet_operations psched_net_ops = {
2278 .init = psched_net_init,
2279 .exit = psched_net_exit,
2280};
2281
2282DEFINE_STATIC_KEY_FALSE(tc_skip_wrapper);
2283
2284static int __init pktsched_init(void)
2285{
2286 int err;
2287
2288 err = register_pernet_subsys(&psched_net_ops);
2289 if (err) {
2290 pr_err("pktsched_init: "
2291 "cannot initialize per netns operations\n");
2292 return err;
2293 }
2294
2295 register_qdisc(&pfifo_fast_ops);
2296 register_qdisc(&pfifo_qdisc_ops);
2297 register_qdisc(&bfifo_qdisc_ops);
2298 register_qdisc(&pfifo_head_drop_qdisc_ops);
2299 register_qdisc(&mq_qdisc_ops);
2300 register_qdisc(&noqueue_qdisc_ops);
2301
2302 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, 0);
2303 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, 0);
2304 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc,
2305 0);
2306 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, 0);
2307 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, 0);
2308 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass,
2309 0);
2310
2311 tc_wrapper_init();
2312
2313 return 0;
2314}
2315
2316subsys_initcall(pktsched_init);