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