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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/unregister 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/* Get default qdisc if not otherwise specified */
204void qdisc_get_default(char *name, size_t len)
205{
206 read_lock(&qdisc_mod_lock);
207 strlcpy(name, default_qdisc_ops->id, len);
208 read_unlock(&qdisc_mod_lock);
209}
210
211static struct Qdisc_ops *qdisc_lookup_default(const char *name)
212{
213 struct Qdisc_ops *q = NULL;
214
215 for (q = qdisc_base; q; q = q->next) {
216 if (!strcmp(name, q->id)) {
217 if (!try_module_get(q->owner))
218 q = NULL;
219 break;
220 }
221 }
222
223 return q;
224}
225
226/* Set new default qdisc to use */
227int qdisc_set_default(const char *name)
228{
229 const struct Qdisc_ops *ops;
230
231 if (!capable(CAP_NET_ADMIN))
232 return -EPERM;
233
234 write_lock(&qdisc_mod_lock);
235 ops = qdisc_lookup_default(name);
236 if (!ops) {
237 /* Not found, drop lock and try to load module */
238 write_unlock(&qdisc_mod_lock);
239 request_module("sch_%s", name);
240 write_lock(&qdisc_mod_lock);
241
242 ops = qdisc_lookup_default(name);
243 }
244
245 if (ops) {
246 /* Set new default */
247 module_put(default_qdisc_ops->owner);
248 default_qdisc_ops = ops;
249 }
250 write_unlock(&qdisc_mod_lock);
251
252 return ops ? 0 : -ENOENT;
253}
254
255/* We know handle. Find qdisc among all qdisc's attached to device
256 * (root qdisc, all its children, children of children etc.)
257 * Note: caller either uses rtnl or rcu_read_lock()
258 */
259
260static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
261{
262 struct Qdisc *q;
263
264 if (!(root->flags & TCQ_F_BUILTIN) &&
265 root->handle == handle)
266 return root;
267
268 list_for_each_entry_rcu(q, &root->list, list) {
269 if (q->handle == handle)
270 return q;
271 }
272 return NULL;
273}
274
275void qdisc_list_add(struct Qdisc *q)
276{
277 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
278 struct Qdisc *root = qdisc_dev(q)->qdisc;
279
280 WARN_ON_ONCE(root == &noop_qdisc);
281 ASSERT_RTNL();
282 list_add_tail_rcu(&q->list, &root->list);
283 }
284}
285EXPORT_SYMBOL(qdisc_list_add);
286
287void qdisc_list_del(struct Qdisc *q)
288{
289 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
290 ASSERT_RTNL();
291 list_del_rcu(&q->list);
292 }
293}
294EXPORT_SYMBOL(qdisc_list_del);
295
296struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
297{
298 struct Qdisc *q;
299
300 q = qdisc_match_from_root(dev->qdisc, handle);
301 if (q)
302 goto out;
303
304 if (dev_ingress_queue(dev))
305 q = qdisc_match_from_root(
306 dev_ingress_queue(dev)->qdisc_sleeping,
307 handle);
308out:
309 return q;
310}
311
312static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
313{
314 unsigned long cl;
315 struct Qdisc *leaf;
316 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
317
318 if (cops == NULL)
319 return NULL;
320 cl = cops->get(p, classid);
321
322 if (cl == 0)
323 return NULL;
324 leaf = cops->leaf(p, cl);
325 cops->put(p, cl);
326 return leaf;
327}
328
329/* Find queueing discipline by name */
330
331static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
332{
333 struct Qdisc_ops *q = NULL;
334
335 if (kind) {
336 read_lock(&qdisc_mod_lock);
337 for (q = qdisc_base; q; q = q->next) {
338 if (nla_strcmp(kind, q->id) == 0) {
339 if (!try_module_get(q->owner))
340 q = NULL;
341 break;
342 }
343 }
344 read_unlock(&qdisc_mod_lock);
345 }
346 return q;
347}
348
349/* The linklayer setting were not transferred from iproute2, in older
350 * versions, and the rate tables lookup systems have been dropped in
351 * the kernel. To keep backward compatible with older iproute2 tc
352 * utils, we detect the linklayer setting by detecting if the rate
353 * table were modified.
354 *
355 * For linklayer ATM table entries, the rate table will be aligned to
356 * 48 bytes, thus some table entries will contain the same value. The
357 * mpu (min packet unit) is also encoded into the old rate table, thus
358 * starting from the mpu, we find low and high table entries for
359 * mapping this cell. If these entries contain the same value, when
360 * the rate tables have been modified for linklayer ATM.
361 *
362 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
363 * and then roundup to the next cell, calc the table entry one below,
364 * and compare.
365 */
366static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
367{
368 int low = roundup(r->mpu, 48);
369 int high = roundup(low+1, 48);
370 int cell_low = low >> r->cell_log;
371 int cell_high = (high >> r->cell_log) - 1;
372
373 /* rtab is too inaccurate at rates > 100Mbit/s */
374 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
375 pr_debug("TC linklayer: Giving up ATM detection\n");
376 return TC_LINKLAYER_ETHERNET;
377 }
378
379 if ((cell_high > cell_low) && (cell_high < 256)
380 && (rtab[cell_low] == rtab[cell_high])) {
381 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
382 cell_low, cell_high, rtab[cell_high]);
383 return TC_LINKLAYER_ATM;
384 }
385 return TC_LINKLAYER_ETHERNET;
386}
387
388static struct qdisc_rate_table *qdisc_rtab_list;
389
390struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct nlattr *tab)
391{
392 struct qdisc_rate_table *rtab;
393
394 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
395 nla_len(tab) != TC_RTAB_SIZE)
396 return NULL;
397
398 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
399 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
400 !memcmp(&rtab->data, nla_data(tab), 1024)) {
401 rtab->refcnt++;
402 return rtab;
403 }
404 }
405
406 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
407 if (rtab) {
408 rtab->rate = *r;
409 rtab->refcnt = 1;
410 memcpy(rtab->data, nla_data(tab), 1024);
411 if (r->linklayer == TC_LINKLAYER_UNAWARE)
412 r->linklayer = __detect_linklayer(r, rtab->data);
413 rtab->next = qdisc_rtab_list;
414 qdisc_rtab_list = rtab;
415 }
416 return rtab;
417}
418EXPORT_SYMBOL(qdisc_get_rtab);
419
420void qdisc_put_rtab(struct qdisc_rate_table *tab)
421{
422 struct qdisc_rate_table *rtab, **rtabp;
423
424 if (!tab || --tab->refcnt)
425 return;
426
427 for (rtabp = &qdisc_rtab_list;
428 (rtab = *rtabp) != NULL;
429 rtabp = &rtab->next) {
430 if (rtab == tab) {
431 *rtabp = rtab->next;
432 kfree(rtab);
433 return;
434 }
435 }
436}
437EXPORT_SYMBOL(qdisc_put_rtab);
438
439static LIST_HEAD(qdisc_stab_list);
440static DEFINE_SPINLOCK(qdisc_stab_lock);
441
442static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
443 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
444 [TCA_STAB_DATA] = { .type = NLA_BINARY },
445};
446
447static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
448{
449 struct nlattr *tb[TCA_STAB_MAX + 1];
450 struct qdisc_size_table *stab;
451 struct tc_sizespec *s;
452 unsigned int tsize = 0;
453 u16 *tab = NULL;
454 int err;
455
456 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
457 if (err < 0)
458 return ERR_PTR(err);
459 if (!tb[TCA_STAB_BASE])
460 return ERR_PTR(-EINVAL);
461
462 s = nla_data(tb[TCA_STAB_BASE]);
463
464 if (s->tsize > 0) {
465 if (!tb[TCA_STAB_DATA])
466 return ERR_PTR(-EINVAL);
467 tab = nla_data(tb[TCA_STAB_DATA]);
468 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
469 }
470
471 if (tsize != s->tsize || (!tab && tsize > 0))
472 return ERR_PTR(-EINVAL);
473
474 spin_lock(&qdisc_stab_lock);
475
476 list_for_each_entry(stab, &qdisc_stab_list, list) {
477 if (memcmp(&stab->szopts, s, sizeof(*s)))
478 continue;
479 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
480 continue;
481 stab->refcnt++;
482 spin_unlock(&qdisc_stab_lock);
483 return stab;
484 }
485
486 spin_unlock(&qdisc_stab_lock);
487
488 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
489 if (!stab)
490 return ERR_PTR(-ENOMEM);
491
492 stab->refcnt = 1;
493 stab->szopts = *s;
494 if (tsize > 0)
495 memcpy(stab->data, tab, tsize * sizeof(u16));
496
497 spin_lock(&qdisc_stab_lock);
498 list_add_tail(&stab->list, &qdisc_stab_list);
499 spin_unlock(&qdisc_stab_lock);
500
501 return stab;
502}
503
504static void stab_kfree_rcu(struct rcu_head *head)
505{
506 kfree(container_of(head, struct qdisc_size_table, rcu));
507}
508
509void qdisc_put_stab(struct qdisc_size_table *tab)
510{
511 if (!tab)
512 return;
513
514 spin_lock(&qdisc_stab_lock);
515
516 if (--tab->refcnt == 0) {
517 list_del(&tab->list);
518 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
519 }
520
521 spin_unlock(&qdisc_stab_lock);
522}
523EXPORT_SYMBOL(qdisc_put_stab);
524
525static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
526{
527 struct nlattr *nest;
528
529 nest = nla_nest_start(skb, TCA_STAB);
530 if (nest == NULL)
531 goto nla_put_failure;
532 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
533 goto nla_put_failure;
534 nla_nest_end(skb, nest);
535
536 return skb->len;
537
538nla_put_failure:
539 return -1;
540}
541
542void __qdisc_calculate_pkt_len(struct sk_buff *skb, const struct qdisc_size_table *stab)
543{
544 int pkt_len, slot;
545
546 pkt_len = skb->len + stab->szopts.overhead;
547 if (unlikely(!stab->szopts.tsize))
548 goto out;
549
550 slot = pkt_len + stab->szopts.cell_align;
551 if (unlikely(slot < 0))
552 slot = 0;
553
554 slot >>= stab->szopts.cell_log;
555 if (likely(slot < stab->szopts.tsize))
556 pkt_len = stab->data[slot];
557 else
558 pkt_len = stab->data[stab->szopts.tsize - 1] *
559 (slot / stab->szopts.tsize) +
560 stab->data[slot % stab->szopts.tsize];
561
562 pkt_len <<= stab->szopts.size_log;
563out:
564 if (unlikely(pkt_len < 1))
565 pkt_len = 1;
566 qdisc_skb_cb(skb)->pkt_len = pkt_len;
567}
568EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
569
570void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
571{
572 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
573 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
574 txt, qdisc->ops->id, qdisc->handle >> 16);
575 qdisc->flags |= TCQ_F_WARN_NONWC;
576 }
577}
578EXPORT_SYMBOL(qdisc_warn_nonwc);
579
580static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
581{
582 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
583 timer);
584
585 rcu_read_lock();
586 qdisc_unthrottled(wd->qdisc);
587 __netif_schedule(qdisc_root(wd->qdisc));
588 rcu_read_unlock();
589
590 return HRTIMER_NORESTART;
591}
592
593void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
594{
595 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
596 wd->timer.function = qdisc_watchdog;
597 wd->qdisc = qdisc;
598}
599EXPORT_SYMBOL(qdisc_watchdog_init);
600
601void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires, bool throttle)
602{
603 if (test_bit(__QDISC_STATE_DEACTIVATED,
604 &qdisc_root_sleeping(wd->qdisc)->state))
605 return;
606
607 if (throttle)
608 qdisc_throttled(wd->qdisc);
609
610 hrtimer_start(&wd->timer,
611 ns_to_ktime(expires),
612 HRTIMER_MODE_ABS_PINNED);
613}
614EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
615
616void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
617{
618 hrtimer_cancel(&wd->timer);
619 qdisc_unthrottled(wd->qdisc);
620}
621EXPORT_SYMBOL(qdisc_watchdog_cancel);
622
623static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
624{
625 unsigned int size = n * sizeof(struct hlist_head), i;
626 struct hlist_head *h;
627
628 if (size <= PAGE_SIZE)
629 h = kmalloc(size, GFP_KERNEL);
630 else
631 h = (struct hlist_head *)
632 __get_free_pages(GFP_KERNEL, get_order(size));
633
634 if (h != NULL) {
635 for (i = 0; i < n; i++)
636 INIT_HLIST_HEAD(&h[i]);
637 }
638 return h;
639}
640
641static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
642{
643 unsigned int size = n * sizeof(struct hlist_head);
644
645 if (size <= PAGE_SIZE)
646 kfree(h);
647 else
648 free_pages((unsigned long)h, get_order(size));
649}
650
651void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
652{
653 struct Qdisc_class_common *cl;
654 struct hlist_node *next;
655 struct hlist_head *nhash, *ohash;
656 unsigned int nsize, nmask, osize;
657 unsigned int i, h;
658
659 /* Rehash when load factor exceeds 0.75 */
660 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
661 return;
662 nsize = clhash->hashsize * 2;
663 nmask = nsize - 1;
664 nhash = qdisc_class_hash_alloc(nsize);
665 if (nhash == NULL)
666 return;
667
668 ohash = clhash->hash;
669 osize = clhash->hashsize;
670
671 sch_tree_lock(sch);
672 for (i = 0; i < osize; i++) {
673 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
674 h = qdisc_class_hash(cl->classid, nmask);
675 hlist_add_head(&cl->hnode, &nhash[h]);
676 }
677 }
678 clhash->hash = nhash;
679 clhash->hashsize = nsize;
680 clhash->hashmask = nmask;
681 sch_tree_unlock(sch);
682
683 qdisc_class_hash_free(ohash, osize);
684}
685EXPORT_SYMBOL(qdisc_class_hash_grow);
686
687int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
688{
689 unsigned int size = 4;
690
691 clhash->hash = qdisc_class_hash_alloc(size);
692 if (clhash->hash == NULL)
693 return -ENOMEM;
694 clhash->hashsize = size;
695 clhash->hashmask = size - 1;
696 clhash->hashelems = 0;
697 return 0;
698}
699EXPORT_SYMBOL(qdisc_class_hash_init);
700
701void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
702{
703 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
704}
705EXPORT_SYMBOL(qdisc_class_hash_destroy);
706
707void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
708 struct Qdisc_class_common *cl)
709{
710 unsigned int h;
711
712 INIT_HLIST_NODE(&cl->hnode);
713 h = qdisc_class_hash(cl->classid, clhash->hashmask);
714 hlist_add_head(&cl->hnode, &clhash->hash[h]);
715 clhash->hashelems++;
716}
717EXPORT_SYMBOL(qdisc_class_hash_insert);
718
719void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
720 struct Qdisc_class_common *cl)
721{
722 hlist_del(&cl->hnode);
723 clhash->hashelems--;
724}
725EXPORT_SYMBOL(qdisc_class_hash_remove);
726
727/* Allocate an unique handle from space managed by kernel
728 * Possible range is [8000-FFFF]:0000 (0x8000 values)
729 */
730static u32 qdisc_alloc_handle(struct net_device *dev)
731{
732 int i = 0x8000;
733 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
734
735 do {
736 autohandle += TC_H_MAKE(0x10000U, 0);
737 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
738 autohandle = TC_H_MAKE(0x80000000U, 0);
739 if (!qdisc_lookup(dev, autohandle))
740 return autohandle;
741 cond_resched();
742 } while (--i > 0);
743
744 return 0;
745}
746
747void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,
748 unsigned int len)
749{
750 const struct Qdisc_class_ops *cops;
751 unsigned long cl;
752 u32 parentid;
753 int drops;
754
755 if (n == 0 && len == 0)
756 return;
757 drops = max_t(int, n, 0);
758 rcu_read_lock();
759 while ((parentid = sch->parent)) {
760 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
761 break;
762
763 if (sch->flags & TCQ_F_NOPARENT)
764 break;
765 /* TODO: perform the search on a per txq basis */
766 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
767 if (sch == NULL) {
768 WARN_ON_ONCE(parentid != TC_H_ROOT);
769 break;
770 }
771 cops = sch->ops->cl_ops;
772 if (cops->qlen_notify) {
773 cl = cops->get(sch, parentid);
774 cops->qlen_notify(sch, cl);
775 cops->put(sch, cl);
776 }
777 sch->q.qlen -= n;
778 sch->qstats.backlog -= len;
779 __qdisc_qstats_drop(sch, drops);
780 }
781 rcu_read_unlock();
782}
783EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
784
785static void notify_and_destroy(struct net *net, struct sk_buff *skb,
786 struct nlmsghdr *n, u32 clid,
787 struct Qdisc *old, struct Qdisc *new)
788{
789 if (new || old)
790 qdisc_notify(net, skb, n, clid, old, new);
791
792 if (old)
793 qdisc_destroy(old);
794}
795
796/* Graft qdisc "new" to class "classid" of qdisc "parent" or
797 * to device "dev".
798 *
799 * When appropriate send a netlink notification using 'skb'
800 * and "n".
801 *
802 * On success, destroy old qdisc.
803 */
804
805static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
806 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
807 struct Qdisc *new, struct Qdisc *old)
808{
809 struct Qdisc *q = old;
810 struct net *net = dev_net(dev);
811 int err = 0;
812
813 if (parent == NULL) {
814 unsigned int i, num_q, ingress;
815
816 ingress = 0;
817 num_q = dev->num_tx_queues;
818 if ((q && q->flags & TCQ_F_INGRESS) ||
819 (new && new->flags & TCQ_F_INGRESS)) {
820 num_q = 1;
821 ingress = 1;
822 if (!dev_ingress_queue(dev))
823 return -ENOENT;
824 }
825
826 if (dev->flags & IFF_UP)
827 dev_deactivate(dev);
828
829 if (new && new->ops->attach)
830 goto skip;
831
832 for (i = 0; i < num_q; i++) {
833 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
834
835 if (!ingress)
836 dev_queue = netdev_get_tx_queue(dev, i);
837
838 old = dev_graft_qdisc(dev_queue, new);
839 if (new && i > 0)
840 atomic_inc(&new->refcnt);
841
842 if (!ingress)
843 qdisc_destroy(old);
844 }
845
846skip:
847 if (!ingress) {
848 notify_and_destroy(net, skb, n, classid,
849 dev->qdisc, new);
850 if (new && !new->ops->attach)
851 atomic_inc(&new->refcnt);
852 dev->qdisc = new ? : &noop_qdisc;
853
854 if (new && new->ops->attach)
855 new->ops->attach(new);
856 } else {
857 notify_and_destroy(net, skb, n, classid, old, new);
858 }
859
860 if (dev->flags & IFF_UP)
861 dev_activate(dev);
862 } else {
863 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
864
865 err = -EOPNOTSUPP;
866 if (cops && cops->graft) {
867 unsigned long cl = cops->get(parent, classid);
868 if (cl) {
869 err = cops->graft(parent, cl, new, &old);
870 cops->put(parent, cl);
871 } else
872 err = -ENOENT;
873 }
874 if (!err)
875 notify_and_destroy(net, skb, n, classid, old, new);
876 }
877 return err;
878}
879
880/* lockdep annotation is needed for ingress; egress gets it only for name */
881static struct lock_class_key qdisc_tx_lock;
882static struct lock_class_key qdisc_rx_lock;
883
884/*
885 Allocate and initialize new qdisc.
886
887 Parameters are passed via opt.
888 */
889
890static struct Qdisc *
891qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
892 struct Qdisc *p, u32 parent, u32 handle,
893 struct nlattr **tca, int *errp)
894{
895 int err;
896 struct nlattr *kind = tca[TCA_KIND];
897 struct Qdisc *sch;
898 struct Qdisc_ops *ops;
899 struct qdisc_size_table *stab;
900
901 ops = qdisc_lookup_ops(kind);
902#ifdef CONFIG_MODULES
903 if (ops == NULL && kind != NULL) {
904 char name[IFNAMSIZ];
905 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
906 /* We dropped the RTNL semaphore in order to
907 * perform the module load. So, even if we
908 * succeeded in loading the module we have to
909 * tell the caller to replay the request. We
910 * indicate this using -EAGAIN.
911 * We replay the request because the device may
912 * go away in the mean time.
913 */
914 rtnl_unlock();
915 request_module("sch_%s", name);
916 rtnl_lock();
917 ops = qdisc_lookup_ops(kind);
918 if (ops != NULL) {
919 /* We will try again qdisc_lookup_ops,
920 * so don't keep a reference.
921 */
922 module_put(ops->owner);
923 err = -EAGAIN;
924 goto err_out;
925 }
926 }
927 }
928#endif
929
930 err = -ENOENT;
931 if (ops == NULL)
932 goto err_out;
933
934 sch = qdisc_alloc(dev_queue, ops);
935 if (IS_ERR(sch)) {
936 err = PTR_ERR(sch);
937 goto err_out2;
938 }
939
940 sch->parent = parent;
941
942 if (handle == TC_H_INGRESS) {
943 sch->flags |= TCQ_F_INGRESS;
944 handle = TC_H_MAKE(TC_H_INGRESS, 0);
945 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
946 } else {
947 if (handle == 0) {
948 handle = qdisc_alloc_handle(dev);
949 err = -ENOMEM;
950 if (handle == 0)
951 goto err_out3;
952 }
953 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
954 if (!netif_is_multiqueue(dev))
955 sch->flags |= TCQ_F_ONETXQUEUE;
956 }
957
958 sch->handle = handle;
959
960 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
961 if (qdisc_is_percpu_stats(sch)) {
962 sch->cpu_bstats =
963 netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
964 if (!sch->cpu_bstats)
965 goto err_out4;
966
967 sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
968 if (!sch->cpu_qstats)
969 goto err_out4;
970 }
971
972 if (tca[TCA_STAB]) {
973 stab = qdisc_get_stab(tca[TCA_STAB]);
974 if (IS_ERR(stab)) {
975 err = PTR_ERR(stab);
976 goto err_out4;
977 }
978 rcu_assign_pointer(sch->stab, stab);
979 }
980 if (tca[TCA_RATE]) {
981 spinlock_t *root_lock;
982
983 err = -EOPNOTSUPP;
984 if (sch->flags & TCQ_F_MQROOT)
985 goto err_out4;
986
987 if ((sch->parent != TC_H_ROOT) &&
988 !(sch->flags & TCQ_F_INGRESS) &&
989 (!p || !(p->flags & TCQ_F_MQROOT)))
990 root_lock = qdisc_root_sleeping_lock(sch);
991 else
992 root_lock = qdisc_lock(sch);
993
994 err = gen_new_estimator(&sch->bstats,
995 sch->cpu_bstats,
996 &sch->rate_est,
997 root_lock,
998 tca[TCA_RATE]);
999 if (err)
1000 goto err_out4;
1001 }
1002
1003 qdisc_list_add(sch);
1004
1005 return sch;
1006 }
1007err_out3:
1008 dev_put(dev);
1009 kfree((char *) sch - sch->padded);
1010err_out2:
1011 module_put(ops->owner);
1012err_out:
1013 *errp = err;
1014 return NULL;
1015
1016err_out4:
1017 free_percpu(sch->cpu_bstats);
1018 free_percpu(sch->cpu_qstats);
1019 /*
1020 * Any broken qdiscs that would require a ops->reset() here?
1021 * The qdisc was never in action so it shouldn't be necessary.
1022 */
1023 qdisc_put_stab(rtnl_dereference(sch->stab));
1024 if (ops->destroy)
1025 ops->destroy(sch);
1026 goto err_out3;
1027}
1028
1029static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
1030{
1031 struct qdisc_size_table *ostab, *stab = NULL;
1032 int err = 0;
1033
1034 if (tca[TCA_OPTIONS]) {
1035 if (sch->ops->change == NULL)
1036 return -EINVAL;
1037 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
1038 if (err)
1039 return err;
1040 }
1041
1042 if (tca[TCA_STAB]) {
1043 stab = qdisc_get_stab(tca[TCA_STAB]);
1044 if (IS_ERR(stab))
1045 return PTR_ERR(stab);
1046 }
1047
1048 ostab = rtnl_dereference(sch->stab);
1049 rcu_assign_pointer(sch->stab, stab);
1050 qdisc_put_stab(ostab);
1051
1052 if (tca[TCA_RATE]) {
1053 /* NB: ignores errors from replace_estimator
1054 because change can't be undone. */
1055 if (sch->flags & TCQ_F_MQROOT)
1056 goto out;
1057 gen_replace_estimator(&sch->bstats,
1058 sch->cpu_bstats,
1059 &sch->rate_est,
1060 qdisc_root_sleeping_lock(sch),
1061 tca[TCA_RATE]);
1062 }
1063out:
1064 return 0;
1065}
1066
1067struct check_loop_arg {
1068 struct qdisc_walker w;
1069 struct Qdisc *p;
1070 int depth;
1071};
1072
1073static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
1074
1075static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1076{
1077 struct check_loop_arg arg;
1078
1079 if (q->ops->cl_ops == NULL)
1080 return 0;
1081
1082 arg.w.stop = arg.w.skip = arg.w.count = 0;
1083 arg.w.fn = check_loop_fn;
1084 arg.depth = depth;
1085 arg.p = p;
1086 q->ops->cl_ops->walk(q, &arg.w);
1087 return arg.w.stop ? -ELOOP : 0;
1088}
1089
1090static int
1091check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1092{
1093 struct Qdisc *leaf;
1094 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1095 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1096
1097 leaf = cops->leaf(q, cl);
1098 if (leaf) {
1099 if (leaf == arg->p || arg->depth > 7)
1100 return -ELOOP;
1101 return check_loop(leaf, arg->p, arg->depth + 1);
1102 }
1103 return 0;
1104}
1105
1106/*
1107 * Delete/get qdisc.
1108 */
1109
1110static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1111{
1112 struct net *net = sock_net(skb->sk);
1113 struct tcmsg *tcm = nlmsg_data(n);
1114 struct nlattr *tca[TCA_MAX + 1];
1115 struct net_device *dev;
1116 u32 clid;
1117 struct Qdisc *q = NULL;
1118 struct Qdisc *p = NULL;
1119 int err;
1120
1121 if ((n->nlmsg_type != RTM_GETQDISC) &&
1122 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1123 return -EPERM;
1124
1125 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1126 if (err < 0)
1127 return err;
1128
1129 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1130 if (!dev)
1131 return -ENODEV;
1132
1133 clid = tcm->tcm_parent;
1134 if (clid) {
1135 if (clid != TC_H_ROOT) {
1136 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1137 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1138 if (!p)
1139 return -ENOENT;
1140 q = qdisc_leaf(p, clid);
1141 } else if (dev_ingress_queue(dev)) {
1142 q = dev_ingress_queue(dev)->qdisc_sleeping;
1143 }
1144 } else {
1145 q = dev->qdisc;
1146 }
1147 if (!q)
1148 return -ENOENT;
1149
1150 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1151 return -EINVAL;
1152 } else {
1153 q = qdisc_lookup(dev, tcm->tcm_handle);
1154 if (!q)
1155 return -ENOENT;
1156 }
1157
1158 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1159 return -EINVAL;
1160
1161 if (n->nlmsg_type == RTM_DELQDISC) {
1162 if (!clid)
1163 return -EINVAL;
1164 if (q->handle == 0)
1165 return -ENOENT;
1166 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1167 if (err != 0)
1168 return err;
1169 } else {
1170 qdisc_notify(net, skb, n, clid, NULL, q);
1171 }
1172 return 0;
1173}
1174
1175/*
1176 * Create/change qdisc.
1177 */
1178
1179static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1180{
1181 struct net *net = sock_net(skb->sk);
1182 struct tcmsg *tcm;
1183 struct nlattr *tca[TCA_MAX + 1];
1184 struct net_device *dev;
1185 u32 clid;
1186 struct Qdisc *q, *p;
1187 int err;
1188
1189 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1190 return -EPERM;
1191
1192replay:
1193 /* Reinit, just in case something touches this. */
1194 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1195 if (err < 0)
1196 return err;
1197
1198 tcm = nlmsg_data(n);
1199 clid = tcm->tcm_parent;
1200 q = p = NULL;
1201
1202 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1203 if (!dev)
1204 return -ENODEV;
1205
1206
1207 if (clid) {
1208 if (clid != TC_H_ROOT) {
1209 if (clid != TC_H_INGRESS) {
1210 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1211 if (!p)
1212 return -ENOENT;
1213 q = qdisc_leaf(p, clid);
1214 } else if (dev_ingress_queue_create(dev)) {
1215 q = dev_ingress_queue(dev)->qdisc_sleeping;
1216 }
1217 } else {
1218 q = dev->qdisc;
1219 }
1220
1221 /* It may be default qdisc, ignore it */
1222 if (q && q->handle == 0)
1223 q = NULL;
1224
1225 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1226 if (tcm->tcm_handle) {
1227 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1228 return -EEXIST;
1229 if (TC_H_MIN(tcm->tcm_handle))
1230 return -EINVAL;
1231 q = qdisc_lookup(dev, tcm->tcm_handle);
1232 if (!q)
1233 goto create_n_graft;
1234 if (n->nlmsg_flags & NLM_F_EXCL)
1235 return -EEXIST;
1236 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1237 return -EINVAL;
1238 if (q == p ||
1239 (p && check_loop(q, p, 0)))
1240 return -ELOOP;
1241 atomic_inc(&q->refcnt);
1242 goto graft;
1243 } else {
1244 if (!q)
1245 goto create_n_graft;
1246
1247 /* This magic test requires explanation.
1248 *
1249 * We know, that some child q is already
1250 * attached to this parent and have choice:
1251 * either to change it or to create/graft new one.
1252 *
1253 * 1. We are allowed to create/graft only
1254 * if CREATE and REPLACE flags are set.
1255 *
1256 * 2. If EXCL is set, requestor wanted to say,
1257 * that qdisc tcm_handle is not expected
1258 * to exist, so that we choose create/graft too.
1259 *
1260 * 3. The last case is when no flags are set.
1261 * Alas, it is sort of hole in API, we
1262 * cannot decide what to do unambiguously.
1263 * For now we select create/graft, if
1264 * user gave KIND, which does not match existing.
1265 */
1266 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1267 (n->nlmsg_flags & NLM_F_REPLACE) &&
1268 ((n->nlmsg_flags & NLM_F_EXCL) ||
1269 (tca[TCA_KIND] &&
1270 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1271 goto create_n_graft;
1272 }
1273 }
1274 } else {
1275 if (!tcm->tcm_handle)
1276 return -EINVAL;
1277 q = qdisc_lookup(dev, tcm->tcm_handle);
1278 }
1279
1280 /* Change qdisc parameters */
1281 if (q == NULL)
1282 return -ENOENT;
1283 if (n->nlmsg_flags & NLM_F_EXCL)
1284 return -EEXIST;
1285 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1286 return -EINVAL;
1287 err = qdisc_change(q, tca);
1288 if (err == 0)
1289 qdisc_notify(net, skb, n, clid, NULL, q);
1290 return err;
1291
1292create_n_graft:
1293 if (!(n->nlmsg_flags & NLM_F_CREATE))
1294 return -ENOENT;
1295 if (clid == TC_H_INGRESS) {
1296 if (dev_ingress_queue(dev))
1297 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1298 tcm->tcm_parent, tcm->tcm_parent,
1299 tca, &err);
1300 else
1301 err = -ENOENT;
1302 } else {
1303 struct netdev_queue *dev_queue;
1304
1305 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1306 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1307 else if (p)
1308 dev_queue = p->dev_queue;
1309 else
1310 dev_queue = netdev_get_tx_queue(dev, 0);
1311
1312 q = qdisc_create(dev, dev_queue, p,
1313 tcm->tcm_parent, tcm->tcm_handle,
1314 tca, &err);
1315 }
1316 if (q == NULL) {
1317 if (err == -EAGAIN)
1318 goto replay;
1319 return err;
1320 }
1321
1322graft:
1323 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1324 if (err) {
1325 if (q)
1326 qdisc_destroy(q);
1327 return err;
1328 }
1329
1330 return 0;
1331}
1332
1333static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1334 u32 portid, u32 seq, u16 flags, int event)
1335{
1336 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
1337 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
1338 struct tcmsg *tcm;
1339 struct nlmsghdr *nlh;
1340 unsigned char *b = skb_tail_pointer(skb);
1341 struct gnet_dump d;
1342 struct qdisc_size_table *stab;
1343 __u32 qlen;
1344
1345 cond_resched();
1346 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1347 if (!nlh)
1348 goto out_nlmsg_trim;
1349 tcm = nlmsg_data(nlh);
1350 tcm->tcm_family = AF_UNSPEC;
1351 tcm->tcm__pad1 = 0;
1352 tcm->tcm__pad2 = 0;
1353 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1354 tcm->tcm_parent = clid;
1355 tcm->tcm_handle = q->handle;
1356 tcm->tcm_info = atomic_read(&q->refcnt);
1357 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1358 goto nla_put_failure;
1359 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1360 goto nla_put_failure;
1361 qlen = q->q.qlen;
1362
1363 stab = rtnl_dereference(q->stab);
1364 if (stab && qdisc_dump_stab(skb, stab) < 0)
1365 goto nla_put_failure;
1366
1367 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1368 qdisc_root_sleeping_lock(q), &d) < 0)
1369 goto nla_put_failure;
1370
1371 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1372 goto nla_put_failure;
1373
1374 if (qdisc_is_percpu_stats(q)) {
1375 cpu_bstats = q->cpu_bstats;
1376 cpu_qstats = q->cpu_qstats;
1377 }
1378
1379 if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats) < 0 ||
1380 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1381 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
1382 goto nla_put_failure;
1383
1384 if (gnet_stats_finish_copy(&d) < 0)
1385 goto nla_put_failure;
1386
1387 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1388 return skb->len;
1389
1390out_nlmsg_trim:
1391nla_put_failure:
1392 nlmsg_trim(skb, b);
1393 return -1;
1394}
1395
1396static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1397{
1398 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1399}
1400
1401static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1402 struct nlmsghdr *n, u32 clid,
1403 struct Qdisc *old, struct Qdisc *new)
1404{
1405 struct sk_buff *skb;
1406 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1407
1408 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1409 if (!skb)
1410 return -ENOBUFS;
1411
1412 if (old && !tc_qdisc_dump_ignore(old)) {
1413 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1414 0, RTM_DELQDISC) < 0)
1415 goto err_out;
1416 }
1417 if (new && !tc_qdisc_dump_ignore(new)) {
1418 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1419 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1420 goto err_out;
1421 }
1422
1423 if (skb->len)
1424 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1425 n->nlmsg_flags & NLM_F_ECHO);
1426
1427err_out:
1428 kfree_skb(skb);
1429 return -EINVAL;
1430}
1431
1432static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1433 struct netlink_callback *cb,
1434 int *q_idx_p, int s_q_idx)
1435{
1436 int ret = 0, q_idx = *q_idx_p;
1437 struct Qdisc *q;
1438
1439 if (!root)
1440 return 0;
1441
1442 q = root;
1443 if (q_idx < s_q_idx) {
1444 q_idx++;
1445 } else {
1446 if (!tc_qdisc_dump_ignore(q) &&
1447 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1448 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1449 goto done;
1450 q_idx++;
1451 }
1452 list_for_each_entry(q, &root->list, list) {
1453 if (q_idx < s_q_idx) {
1454 q_idx++;
1455 continue;
1456 }
1457 if (!tc_qdisc_dump_ignore(q) &&
1458 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1459 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1460 goto done;
1461 q_idx++;
1462 }
1463
1464out:
1465 *q_idx_p = q_idx;
1466 return ret;
1467done:
1468 ret = -1;
1469 goto out;
1470}
1471
1472static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1473{
1474 struct net *net = sock_net(skb->sk);
1475 int idx, q_idx;
1476 int s_idx, s_q_idx;
1477 struct net_device *dev;
1478
1479 s_idx = cb->args[0];
1480 s_q_idx = q_idx = cb->args[1];
1481
1482 idx = 0;
1483 ASSERT_RTNL();
1484 for_each_netdev(net, dev) {
1485 struct netdev_queue *dev_queue;
1486
1487 if (idx < s_idx)
1488 goto cont;
1489 if (idx > s_idx)
1490 s_q_idx = 0;
1491 q_idx = 0;
1492
1493 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1494 goto done;
1495
1496 dev_queue = dev_ingress_queue(dev);
1497 if (dev_queue &&
1498 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1499 &q_idx, s_q_idx) < 0)
1500 goto done;
1501
1502cont:
1503 idx++;
1504 }
1505
1506done:
1507 cb->args[0] = idx;
1508 cb->args[1] = q_idx;
1509
1510 return skb->len;
1511}
1512
1513
1514
1515/************************************************
1516 * Traffic classes manipulation. *
1517 ************************************************/
1518
1519
1520
1521static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n)
1522{
1523 struct net *net = sock_net(skb->sk);
1524 struct tcmsg *tcm = nlmsg_data(n);
1525 struct nlattr *tca[TCA_MAX + 1];
1526 struct net_device *dev;
1527 struct Qdisc *q = NULL;
1528 const struct Qdisc_class_ops *cops;
1529 unsigned long cl = 0;
1530 unsigned long new_cl;
1531 u32 portid;
1532 u32 clid;
1533 u32 qid;
1534 int err;
1535
1536 if ((n->nlmsg_type != RTM_GETTCLASS) &&
1537 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1538 return -EPERM;
1539
1540 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1541 if (err < 0)
1542 return err;
1543
1544 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1545 if (!dev)
1546 return -ENODEV;
1547
1548 /*
1549 parent == TC_H_UNSPEC - unspecified parent.
1550 parent == TC_H_ROOT - class is root, which has no parent.
1551 parent == X:0 - parent is root class.
1552 parent == X:Y - parent is a node in hierarchy.
1553 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1554
1555 handle == 0:0 - generate handle from kernel pool.
1556 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1557 handle == X:Y - clear.
1558 handle == X:0 - root class.
1559 */
1560
1561 /* Step 1. Determine qdisc handle X:0 */
1562
1563 portid = tcm->tcm_parent;
1564 clid = tcm->tcm_handle;
1565 qid = TC_H_MAJ(clid);
1566
1567 if (portid != TC_H_ROOT) {
1568 u32 qid1 = TC_H_MAJ(portid);
1569
1570 if (qid && qid1) {
1571 /* If both majors are known, they must be identical. */
1572 if (qid != qid1)
1573 return -EINVAL;
1574 } else if (qid1) {
1575 qid = qid1;
1576 } else if (qid == 0)
1577 qid = dev->qdisc->handle;
1578
1579 /* Now qid is genuine qdisc handle consistent
1580 * both with parent and child.
1581 *
1582 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1583 */
1584 if (portid)
1585 portid = TC_H_MAKE(qid, portid);
1586 } else {
1587 if (qid == 0)
1588 qid = dev->qdisc->handle;
1589 }
1590
1591 /* OK. Locate qdisc */
1592 q = qdisc_lookup(dev, qid);
1593 if (!q)
1594 return -ENOENT;
1595
1596 /* An check that it supports classes */
1597 cops = q->ops->cl_ops;
1598 if (cops == NULL)
1599 return -EINVAL;
1600
1601 /* Now try to get class */
1602 if (clid == 0) {
1603 if (portid == TC_H_ROOT)
1604 clid = qid;
1605 } else
1606 clid = TC_H_MAKE(qid, clid);
1607
1608 if (clid)
1609 cl = cops->get(q, clid);
1610
1611 if (cl == 0) {
1612 err = -ENOENT;
1613 if (n->nlmsg_type != RTM_NEWTCLASS ||
1614 !(n->nlmsg_flags & NLM_F_CREATE))
1615 goto out;
1616 } else {
1617 switch (n->nlmsg_type) {
1618 case RTM_NEWTCLASS:
1619 err = -EEXIST;
1620 if (n->nlmsg_flags & NLM_F_EXCL)
1621 goto out;
1622 break;
1623 case RTM_DELTCLASS:
1624 err = -EOPNOTSUPP;
1625 if (cops->delete)
1626 err = cops->delete(q, cl);
1627 if (err == 0)
1628 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1629 goto out;
1630 case RTM_GETTCLASS:
1631 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1632 goto out;
1633 default:
1634 err = -EINVAL;
1635 goto out;
1636 }
1637 }
1638
1639 new_cl = cl;
1640 err = -EOPNOTSUPP;
1641 if (cops->change)
1642 err = cops->change(q, clid, portid, tca, &new_cl);
1643 if (err == 0)
1644 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1645
1646out:
1647 if (cl)
1648 cops->put(q, cl);
1649
1650 return err;
1651}
1652
1653
1654static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1655 unsigned long cl,
1656 u32 portid, u32 seq, u16 flags, int event)
1657{
1658 struct tcmsg *tcm;
1659 struct nlmsghdr *nlh;
1660 unsigned char *b = skb_tail_pointer(skb);
1661 struct gnet_dump d;
1662 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1663
1664 cond_resched();
1665 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1666 if (!nlh)
1667 goto out_nlmsg_trim;
1668 tcm = nlmsg_data(nlh);
1669 tcm->tcm_family = AF_UNSPEC;
1670 tcm->tcm__pad1 = 0;
1671 tcm->tcm__pad2 = 0;
1672 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1673 tcm->tcm_parent = q->handle;
1674 tcm->tcm_handle = q->handle;
1675 tcm->tcm_info = 0;
1676 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1677 goto nla_put_failure;
1678 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1679 goto nla_put_failure;
1680
1681 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1682 qdisc_root_sleeping_lock(q), &d) < 0)
1683 goto nla_put_failure;
1684
1685 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1686 goto nla_put_failure;
1687
1688 if (gnet_stats_finish_copy(&d) < 0)
1689 goto nla_put_failure;
1690
1691 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1692 return skb->len;
1693
1694out_nlmsg_trim:
1695nla_put_failure:
1696 nlmsg_trim(skb, b);
1697 return -1;
1698}
1699
1700static int tclass_notify(struct net *net, struct sk_buff *oskb,
1701 struct nlmsghdr *n, struct Qdisc *q,
1702 unsigned long cl, int event)
1703{
1704 struct sk_buff *skb;
1705 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1706
1707 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1708 if (!skb)
1709 return -ENOBUFS;
1710
1711 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1712 kfree_skb(skb);
1713 return -EINVAL;
1714 }
1715
1716 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1717 n->nlmsg_flags & NLM_F_ECHO);
1718}
1719
1720struct qdisc_dump_args {
1721 struct qdisc_walker w;
1722 struct sk_buff *skb;
1723 struct netlink_callback *cb;
1724};
1725
1726static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1727{
1728 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1729
1730 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1731 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1732}
1733
1734static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1735 struct tcmsg *tcm, struct netlink_callback *cb,
1736 int *t_p, int s_t)
1737{
1738 struct qdisc_dump_args arg;
1739
1740 if (tc_qdisc_dump_ignore(q) ||
1741 *t_p < s_t || !q->ops->cl_ops ||
1742 (tcm->tcm_parent &&
1743 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1744 (*t_p)++;
1745 return 0;
1746 }
1747 if (*t_p > s_t)
1748 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1749 arg.w.fn = qdisc_class_dump;
1750 arg.skb = skb;
1751 arg.cb = cb;
1752 arg.w.stop = 0;
1753 arg.w.skip = cb->args[1];
1754 arg.w.count = 0;
1755 q->ops->cl_ops->walk(q, &arg.w);
1756 cb->args[1] = arg.w.count;
1757 if (arg.w.stop)
1758 return -1;
1759 (*t_p)++;
1760 return 0;
1761}
1762
1763static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1764 struct tcmsg *tcm, struct netlink_callback *cb,
1765 int *t_p, int s_t)
1766{
1767 struct Qdisc *q;
1768
1769 if (!root)
1770 return 0;
1771
1772 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1773 return -1;
1774
1775 list_for_each_entry(q, &root->list, list) {
1776 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1777 return -1;
1778 }
1779
1780 return 0;
1781}
1782
1783static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1784{
1785 struct tcmsg *tcm = nlmsg_data(cb->nlh);
1786 struct net *net = sock_net(skb->sk);
1787 struct netdev_queue *dev_queue;
1788 struct net_device *dev;
1789 int t, s_t;
1790
1791 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1792 return 0;
1793 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1794 if (!dev)
1795 return 0;
1796
1797 s_t = cb->args[0];
1798 t = 0;
1799
1800 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1801 goto done;
1802
1803 dev_queue = dev_ingress_queue(dev);
1804 if (dev_queue &&
1805 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1806 &t, s_t) < 0)
1807 goto done;
1808
1809done:
1810 cb->args[0] = t;
1811
1812 dev_put(dev);
1813 return skb->len;
1814}
1815
1816/* Main classifier routine: scans classifier chain attached
1817 * to this qdisc, (optionally) tests for protocol and asks
1818 * specific classifiers.
1819 */
1820int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1821 struct tcf_result *res, bool compat_mode)
1822{
1823 __be16 protocol = tc_skb_protocol(skb);
1824#ifdef CONFIG_NET_CLS_ACT
1825 const struct tcf_proto *old_tp = tp;
1826 int limit = 0;
1827
1828reclassify:
1829#endif
1830 for (; tp; tp = rcu_dereference_bh(tp->next)) {
1831 int err;
1832
1833 if (tp->protocol != protocol &&
1834 tp->protocol != htons(ETH_P_ALL))
1835 continue;
1836
1837 err = tp->classify(skb, tp, res);
1838#ifdef CONFIG_NET_CLS_ACT
1839 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode))
1840 goto reset;
1841#endif
1842 if (err >= 0)
1843 return err;
1844 }
1845
1846 return TC_ACT_UNSPEC; /* signal: continue lookup */
1847#ifdef CONFIG_NET_CLS_ACT
1848reset:
1849 if (unlikely(limit++ >= MAX_REC_LOOP)) {
1850 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n",
1851 tp->q->ops->id, tp->prio & 0xffff,
1852 ntohs(tp->protocol));
1853 return TC_ACT_SHOT;
1854 }
1855
1856 tp = old_tp;
1857 protocol = tc_skb_protocol(skb);
1858 goto reclassify;
1859#endif
1860}
1861EXPORT_SYMBOL(tc_classify);
1862
1863bool tcf_destroy(struct tcf_proto *tp, bool force)
1864{
1865 if (tp->ops->destroy(tp, force)) {
1866 module_put(tp->ops->owner);
1867 kfree_rcu(tp, rcu);
1868 return true;
1869 }
1870
1871 return false;
1872}
1873
1874void tcf_destroy_chain(struct tcf_proto __rcu **fl)
1875{
1876 struct tcf_proto *tp;
1877
1878 while ((tp = rtnl_dereference(*fl)) != NULL) {
1879 RCU_INIT_POINTER(*fl, tp->next);
1880 tcf_destroy(tp, true);
1881 }
1882}
1883EXPORT_SYMBOL(tcf_destroy_chain);
1884
1885#ifdef CONFIG_PROC_FS
1886static int psched_show(struct seq_file *seq, void *v)
1887{
1888 seq_printf(seq, "%08x %08x %08x %08x\n",
1889 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1890 1000000,
1891 (u32)NSEC_PER_SEC / hrtimer_resolution);
1892
1893 return 0;
1894}
1895
1896static int psched_open(struct inode *inode, struct file *file)
1897{
1898 return single_open(file, psched_show, NULL);
1899}
1900
1901static const struct file_operations psched_fops = {
1902 .owner = THIS_MODULE,
1903 .open = psched_open,
1904 .read = seq_read,
1905 .llseek = seq_lseek,
1906 .release = single_release,
1907};
1908
1909static int __net_init psched_net_init(struct net *net)
1910{
1911 struct proc_dir_entry *e;
1912
1913 e = proc_create("psched", 0, net->proc_net, &psched_fops);
1914 if (e == NULL)
1915 return -ENOMEM;
1916
1917 return 0;
1918}
1919
1920static void __net_exit psched_net_exit(struct net *net)
1921{
1922 remove_proc_entry("psched", net->proc_net);
1923}
1924#else
1925static int __net_init psched_net_init(struct net *net)
1926{
1927 return 0;
1928}
1929
1930static void __net_exit psched_net_exit(struct net *net)
1931{
1932}
1933#endif
1934
1935static struct pernet_operations psched_net_ops = {
1936 .init = psched_net_init,
1937 .exit = psched_net_exit,
1938};
1939
1940static int __init pktsched_init(void)
1941{
1942 int err;
1943
1944 err = register_pernet_subsys(&psched_net_ops);
1945 if (err) {
1946 pr_err("pktsched_init: "
1947 "cannot initialize per netns operations\n");
1948 return err;
1949 }
1950
1951 register_qdisc(&pfifo_fast_ops);
1952 register_qdisc(&pfifo_qdisc_ops);
1953 register_qdisc(&bfifo_qdisc_ops);
1954 register_qdisc(&pfifo_head_drop_qdisc_ops);
1955 register_qdisc(&mq_qdisc_ops);
1956 register_qdisc(&noqueue_qdisc_ops);
1957
1958 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1959 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1960 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1961 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1962 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1963 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1964
1965 return 0;
1966}
1967
1968subsys_initcall(pktsched_init);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/sched/sch_api.c Packet scheduler API.
4 *
5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6 *
7 * Fixes:
8 *
9 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired.
10 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
11 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support
12 */
13
14#include <linux/module.h>
15#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/string.h>
18#include <linux/errno.h>
19#include <linux/skbuff.h>
20#include <linux/init.h>
21#include <linux/proc_fs.h>
22#include <linux/seq_file.h>
23#include <linux/kmod.h>
24#include <linux/list.h>
25#include <linux/hrtimer.h>
26#include <linux/slab.h>
27#include <linux/hashtable.h>
28
29#include <net/net_namespace.h>
30#include <net/sock.h>
31#include <net/netlink.h>
32#include <net/pkt_sched.h>
33#include <net/pkt_cls.h>
34#include <net/tc_wrapper.h>
35
36#include <trace/events/qdisc.h>
37
38/*
39
40 Short review.
41 -------------
42
43 This file consists of two interrelated parts:
44
45 1. queueing disciplines manager frontend.
46 2. traffic classes manager frontend.
47
48 Generally, queueing discipline ("qdisc") is a black box,
49 which is able to enqueue packets and to dequeue them (when
50 device is ready to send something) in order and at times
51 determined by algorithm hidden in it.
52
53 qdisc's are divided to two categories:
54 - "queues", which have no internal structure visible from outside.
55 - "schedulers", which split all the packets to "traffic classes",
56 using "packet classifiers" (look at cls_api.c)
57
58 In turn, classes may have child qdiscs (as rule, queues)
59 attached to them etc. etc. etc.
60
61 The goal of the routines in this file is to translate
62 information supplied by user in the form of handles
63 to more intelligible for kernel form, to make some sanity
64 checks and part of work, which is common to all qdiscs
65 and to provide rtnetlink notifications.
66
67 All real intelligent work is done inside qdisc modules.
68
69
70
71 Every discipline has two major routines: enqueue and dequeue.
72
73 ---dequeue
74
75 dequeue usually returns a skb to send. It is allowed to return NULL,
76 but it does not mean that queue is empty, it just means that
77 discipline does not want to send anything this time.
78 Queue is really empty if q->q.qlen == 0.
79 For complicated disciplines with multiple queues q->q is not
80 real packet queue, but however q->q.qlen must be valid.
81
82 ---enqueue
83
84 enqueue returns 0, if packet was enqueued successfully.
85 If packet (this one or another one) was dropped, it returns
86 not zero error code.
87 NET_XMIT_DROP - this packet dropped
88 Expected action: do not backoff, but wait until queue will clear.
89 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
90 Expected action: backoff or ignore
91
92 Auxiliary routines:
93
94 ---peek
95
96 like dequeue but without removing a packet from the queue
97
98 ---reset
99
100 returns qdisc to initial state: purge all buffers, clear all
101 timers, counters (except for statistics) etc.
102
103 ---init
104
105 initializes newly created qdisc.
106
107 ---destroy
108
109 destroys resources allocated by init and during lifetime of qdisc.
110
111 ---change
112
113 changes qdisc parameters.
114 */
115
116/* Protects list of registered TC modules. It is pure SMP lock. */
117static DEFINE_RWLOCK(qdisc_mod_lock);
118
119
120/************************************************
121 * Queueing disciplines manipulation. *
122 ************************************************/
123
124
125/* The list of all installed queueing disciplines. */
126
127static struct Qdisc_ops *qdisc_base;
128
129/* Register/unregister queueing discipline */
130
131int register_qdisc(struct Qdisc_ops *qops)
132{
133 struct Qdisc_ops *q, **qp;
134 int rc = -EEXIST;
135
136 write_lock(&qdisc_mod_lock);
137 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
138 if (!strcmp(qops->id, q->id))
139 goto out;
140
141 if (qops->enqueue == NULL)
142 qops->enqueue = noop_qdisc_ops.enqueue;
143 if (qops->peek == NULL) {
144 if (qops->dequeue == NULL)
145 qops->peek = noop_qdisc_ops.peek;
146 else
147 goto out_einval;
148 }
149 if (qops->dequeue == NULL)
150 qops->dequeue = noop_qdisc_ops.dequeue;
151
152 if (qops->cl_ops) {
153 const struct Qdisc_class_ops *cops = qops->cl_ops;
154
155 if (!(cops->find && cops->walk && cops->leaf))
156 goto out_einval;
157
158 if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf))
159 goto out_einval;
160 }
161
162 qops->next = NULL;
163 *qp = qops;
164 rc = 0;
165out:
166 write_unlock(&qdisc_mod_lock);
167 return rc;
168
169out_einval:
170 rc = -EINVAL;
171 goto out;
172}
173EXPORT_SYMBOL(register_qdisc);
174
175void unregister_qdisc(struct Qdisc_ops *qops)
176{
177 struct Qdisc_ops *q, **qp;
178 int err = -ENOENT;
179
180 write_lock(&qdisc_mod_lock);
181 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
182 if (q == qops)
183 break;
184 if (q) {
185 *qp = q->next;
186 q->next = NULL;
187 err = 0;
188 }
189 write_unlock(&qdisc_mod_lock);
190
191 WARN(err, "unregister qdisc(%s) failed\n", qops->id);
192}
193EXPORT_SYMBOL(unregister_qdisc);
194
195/* Get default qdisc if not otherwise specified */
196void qdisc_get_default(char *name, size_t len)
197{
198 read_lock(&qdisc_mod_lock);
199 strscpy(name, default_qdisc_ops->id, len);
200 read_unlock(&qdisc_mod_lock);
201}
202
203static struct Qdisc_ops *qdisc_lookup_default(const char *name)
204{
205 struct Qdisc_ops *q = NULL;
206
207 for (q = qdisc_base; q; q = q->next) {
208 if (!strcmp(name, q->id)) {
209 if (!try_module_get(q->owner))
210 q = NULL;
211 break;
212 }
213 }
214
215 return q;
216}
217
218/* Set new default qdisc to use */
219int qdisc_set_default(const char *name)
220{
221 const struct Qdisc_ops *ops;
222
223 if (!capable(CAP_NET_ADMIN))
224 return -EPERM;
225
226 write_lock(&qdisc_mod_lock);
227 ops = qdisc_lookup_default(name);
228 if (!ops) {
229 /* Not found, drop lock and try to load module */
230 write_unlock(&qdisc_mod_lock);
231 request_module(NET_SCH_ALIAS_PREFIX "%s", name);
232 write_lock(&qdisc_mod_lock);
233
234 ops = qdisc_lookup_default(name);
235 }
236
237 if (ops) {
238 /* Set new default */
239 module_put(default_qdisc_ops->owner);
240 default_qdisc_ops = ops;
241 }
242 write_unlock(&qdisc_mod_lock);
243
244 return ops ? 0 : -ENOENT;
245}
246
247#ifdef CONFIG_NET_SCH_DEFAULT
248/* Set default value from kernel config */
249static int __init sch_default_qdisc(void)
250{
251 return qdisc_set_default(CONFIG_DEFAULT_NET_SCH);
252}
253late_initcall(sch_default_qdisc);
254#endif
255
256/* We know handle. Find qdisc among all qdisc's attached to device
257 * (root qdisc, all its children, children of children etc.)
258 * Note: caller either uses rtnl or rcu_read_lock()
259 */
260
261static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
262{
263 struct Qdisc *q;
264
265 if (!qdisc_dev(root))
266 return (root->handle == handle ? root : NULL);
267
268 if (!(root->flags & TCQ_F_BUILTIN) &&
269 root->handle == handle)
270 return root;
271
272 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle,
273 lockdep_rtnl_is_held()) {
274 if (q->handle == handle)
275 return q;
276 }
277 return NULL;
278}
279
280void qdisc_hash_add(struct Qdisc *q, bool invisible)
281{
282 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
283 ASSERT_RTNL();
284 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
285 if (invisible)
286 q->flags |= TCQ_F_INVISIBLE;
287 }
288}
289EXPORT_SYMBOL(qdisc_hash_add);
290
291void qdisc_hash_del(struct Qdisc *q)
292{
293 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
294 ASSERT_RTNL();
295 hash_del_rcu(&q->hash);
296 }
297}
298EXPORT_SYMBOL(qdisc_hash_del);
299
300struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
301{
302 struct Qdisc *q;
303
304 if (!handle)
305 return NULL;
306 q = qdisc_match_from_root(rtnl_dereference(dev->qdisc), handle);
307 if (q)
308 goto out;
309
310 if (dev_ingress_queue(dev))
311 q = qdisc_match_from_root(
312 rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping),
313 handle);
314out:
315 return q;
316}
317
318struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle)
319{
320 struct netdev_queue *nq;
321 struct Qdisc *q;
322
323 if (!handle)
324 return NULL;
325 q = qdisc_match_from_root(rcu_dereference(dev->qdisc), handle);
326 if (q)
327 goto out;
328
329 nq = dev_ingress_queue_rcu(dev);
330 if (nq)
331 q = qdisc_match_from_root(rcu_dereference(nq->qdisc_sleeping),
332 handle);
333out:
334 return q;
335}
336
337static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
338{
339 unsigned long cl;
340 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
341
342 if (cops == NULL)
343 return NULL;
344 cl = cops->find(p, classid);
345
346 if (cl == 0)
347 return NULL;
348 return cops->leaf(p, cl);
349}
350
351/* Find queueing discipline by name */
352
353static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
354{
355 struct Qdisc_ops *q = NULL;
356
357 if (kind) {
358 read_lock(&qdisc_mod_lock);
359 for (q = qdisc_base; q; q = q->next) {
360 if (nla_strcmp(kind, q->id) == 0) {
361 if (!try_module_get(q->owner))
362 q = NULL;
363 break;
364 }
365 }
366 read_unlock(&qdisc_mod_lock);
367 }
368 return q;
369}
370
371/* The linklayer setting were not transferred from iproute2, in older
372 * versions, and the rate tables lookup systems have been dropped in
373 * the kernel. To keep backward compatible with older iproute2 tc
374 * utils, we detect the linklayer setting by detecting if the rate
375 * table were modified.
376 *
377 * For linklayer ATM table entries, the rate table will be aligned to
378 * 48 bytes, thus some table entries will contain the same value. The
379 * mpu (min packet unit) is also encoded into the old rate table, thus
380 * starting from the mpu, we find low and high table entries for
381 * mapping this cell. If these entries contain the same value, when
382 * the rate tables have been modified for linklayer ATM.
383 *
384 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
385 * and then roundup to the next cell, calc the table entry one below,
386 * and compare.
387 */
388static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
389{
390 int low = roundup(r->mpu, 48);
391 int high = roundup(low+1, 48);
392 int cell_low = low >> r->cell_log;
393 int cell_high = (high >> r->cell_log) - 1;
394
395 /* rtab is too inaccurate at rates > 100Mbit/s */
396 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
397 pr_debug("TC linklayer: Giving up ATM detection\n");
398 return TC_LINKLAYER_ETHERNET;
399 }
400
401 if ((cell_high > cell_low) && (cell_high < 256)
402 && (rtab[cell_low] == rtab[cell_high])) {
403 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
404 cell_low, cell_high, rtab[cell_high]);
405 return TC_LINKLAYER_ATM;
406 }
407 return TC_LINKLAYER_ETHERNET;
408}
409
410static struct qdisc_rate_table *qdisc_rtab_list;
411
412struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
413 struct nlattr *tab,
414 struct netlink_ext_ack *extack)
415{
416 struct qdisc_rate_table *rtab;
417
418 if (tab == NULL || r->rate == 0 ||
419 r->cell_log == 0 || r->cell_log >= 32 ||
420 nla_len(tab) != TC_RTAB_SIZE) {
421 NL_SET_ERR_MSG(extack, "Invalid rate table parameters for searching");
422 return NULL;
423 }
424
425 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
426 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
427 !memcmp(&rtab->data, nla_data(tab), 1024)) {
428 rtab->refcnt++;
429 return rtab;
430 }
431 }
432
433 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
434 if (rtab) {
435 rtab->rate = *r;
436 rtab->refcnt = 1;
437 memcpy(rtab->data, nla_data(tab), 1024);
438 if (r->linklayer == TC_LINKLAYER_UNAWARE)
439 r->linklayer = __detect_linklayer(r, rtab->data);
440 rtab->next = qdisc_rtab_list;
441 qdisc_rtab_list = rtab;
442 } else {
443 NL_SET_ERR_MSG(extack, "Failed to allocate new qdisc rate table");
444 }
445 return rtab;
446}
447EXPORT_SYMBOL(qdisc_get_rtab);
448
449void qdisc_put_rtab(struct qdisc_rate_table *tab)
450{
451 struct qdisc_rate_table *rtab, **rtabp;
452
453 if (!tab || --tab->refcnt)
454 return;
455
456 for (rtabp = &qdisc_rtab_list;
457 (rtab = *rtabp) != NULL;
458 rtabp = &rtab->next) {
459 if (rtab == tab) {
460 *rtabp = rtab->next;
461 kfree(rtab);
462 return;
463 }
464 }
465}
466EXPORT_SYMBOL(qdisc_put_rtab);
467
468static LIST_HEAD(qdisc_stab_list);
469
470static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
471 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
472 [TCA_STAB_DATA] = { .type = NLA_BINARY },
473};
474
475static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt,
476 struct netlink_ext_ack *extack)
477{
478 struct nlattr *tb[TCA_STAB_MAX + 1];
479 struct qdisc_size_table *stab;
480 struct tc_sizespec *s;
481 unsigned int tsize = 0;
482 u16 *tab = NULL;
483 int err;
484
485 err = nla_parse_nested_deprecated(tb, TCA_STAB_MAX, opt, stab_policy,
486 extack);
487 if (err < 0)
488 return ERR_PTR(err);
489 if (!tb[TCA_STAB_BASE]) {
490 NL_SET_ERR_MSG(extack, "Size table base attribute is missing");
491 return ERR_PTR(-EINVAL);
492 }
493
494 s = nla_data(tb[TCA_STAB_BASE]);
495
496 if (s->tsize > 0) {
497 if (!tb[TCA_STAB_DATA]) {
498 NL_SET_ERR_MSG(extack, "Size table data attribute is missing");
499 return ERR_PTR(-EINVAL);
500 }
501 tab = nla_data(tb[TCA_STAB_DATA]);
502 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
503 }
504
505 if (tsize != s->tsize || (!tab && tsize > 0)) {
506 NL_SET_ERR_MSG(extack, "Invalid size of size table");
507 return ERR_PTR(-EINVAL);
508 }
509
510 list_for_each_entry(stab, &qdisc_stab_list, list) {
511 if (memcmp(&stab->szopts, s, sizeof(*s)))
512 continue;
513 if (tsize > 0 &&
514 memcmp(stab->data, tab, flex_array_size(stab, data, tsize)))
515 continue;
516 stab->refcnt++;
517 return stab;
518 }
519
520 if (s->size_log > STAB_SIZE_LOG_MAX ||
521 s->cell_log > STAB_SIZE_LOG_MAX) {
522 NL_SET_ERR_MSG(extack, "Invalid logarithmic size of size table");
523 return ERR_PTR(-EINVAL);
524 }
525
526 stab = kmalloc(struct_size(stab, data, tsize), GFP_KERNEL);
527 if (!stab)
528 return ERR_PTR(-ENOMEM);
529
530 stab->refcnt = 1;
531 stab->szopts = *s;
532 if (tsize > 0)
533 memcpy(stab->data, tab, flex_array_size(stab, data, tsize));
534
535 list_add_tail(&stab->list, &qdisc_stab_list);
536
537 return stab;
538}
539
540void qdisc_put_stab(struct qdisc_size_table *tab)
541{
542 if (!tab)
543 return;
544
545 if (--tab->refcnt == 0) {
546 list_del(&tab->list);
547 kfree_rcu(tab, rcu);
548 }
549}
550EXPORT_SYMBOL(qdisc_put_stab);
551
552static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
553{
554 struct nlattr *nest;
555
556 nest = nla_nest_start_noflag(skb, TCA_STAB);
557 if (nest == NULL)
558 goto nla_put_failure;
559 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
560 goto nla_put_failure;
561 nla_nest_end(skb, nest);
562
563 return skb->len;
564
565nla_put_failure:
566 return -1;
567}
568
569void __qdisc_calculate_pkt_len(struct sk_buff *skb,
570 const struct qdisc_size_table *stab)
571{
572 int pkt_len, slot;
573
574 pkt_len = skb->len + stab->szopts.overhead;
575 if (unlikely(!stab->szopts.tsize))
576 goto out;
577
578 slot = pkt_len + stab->szopts.cell_align;
579 if (unlikely(slot < 0))
580 slot = 0;
581
582 slot >>= stab->szopts.cell_log;
583 if (likely(slot < stab->szopts.tsize))
584 pkt_len = stab->data[slot];
585 else
586 pkt_len = stab->data[stab->szopts.tsize - 1] *
587 (slot / stab->szopts.tsize) +
588 stab->data[slot % stab->szopts.tsize];
589
590 pkt_len <<= stab->szopts.size_log;
591out:
592 if (unlikely(pkt_len < 1))
593 pkt_len = 1;
594 qdisc_skb_cb(skb)->pkt_len = pkt_len;
595}
596
597void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
598{
599 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
600 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
601 txt, qdisc->ops->id, qdisc->handle >> 16);
602 qdisc->flags |= TCQ_F_WARN_NONWC;
603 }
604}
605EXPORT_SYMBOL(qdisc_warn_nonwc);
606
607static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
608{
609 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
610 timer);
611
612 rcu_read_lock();
613 __netif_schedule(qdisc_root(wd->qdisc));
614 rcu_read_unlock();
615
616 return HRTIMER_NORESTART;
617}
618
619void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
620 clockid_t clockid)
621{
622 hrtimer_init(&wd->timer, clockid, HRTIMER_MODE_ABS_PINNED);
623 wd->timer.function = qdisc_watchdog;
624 wd->qdisc = qdisc;
625}
626EXPORT_SYMBOL(qdisc_watchdog_init_clockid);
627
628void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
629{
630 qdisc_watchdog_init_clockid(wd, qdisc, CLOCK_MONOTONIC);
631}
632EXPORT_SYMBOL(qdisc_watchdog_init);
633
634void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires,
635 u64 delta_ns)
636{
637 bool deactivated;
638
639 rcu_read_lock();
640 deactivated = test_bit(__QDISC_STATE_DEACTIVATED,
641 &qdisc_root_sleeping(wd->qdisc)->state);
642 rcu_read_unlock();
643 if (deactivated)
644 return;
645
646 if (hrtimer_is_queued(&wd->timer)) {
647 u64 softexpires;
648
649 softexpires = ktime_to_ns(hrtimer_get_softexpires(&wd->timer));
650 /* If timer is already set in [expires, expires + delta_ns],
651 * do not reprogram it.
652 */
653 if (softexpires - expires <= delta_ns)
654 return;
655 }
656
657 hrtimer_start_range_ns(&wd->timer,
658 ns_to_ktime(expires),
659 delta_ns,
660 HRTIMER_MODE_ABS_PINNED);
661}
662EXPORT_SYMBOL(qdisc_watchdog_schedule_range_ns);
663
664void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
665{
666 hrtimer_cancel(&wd->timer);
667}
668EXPORT_SYMBOL(qdisc_watchdog_cancel);
669
670static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
671{
672 struct hlist_head *h;
673 unsigned int i;
674
675 h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL);
676
677 if (h != NULL) {
678 for (i = 0; i < n; i++)
679 INIT_HLIST_HEAD(&h[i]);
680 }
681 return h;
682}
683
684void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
685{
686 struct Qdisc_class_common *cl;
687 struct hlist_node *next;
688 struct hlist_head *nhash, *ohash;
689 unsigned int nsize, nmask, osize;
690 unsigned int i, h;
691
692 /* Rehash when load factor exceeds 0.75 */
693 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
694 return;
695 nsize = clhash->hashsize * 2;
696 nmask = nsize - 1;
697 nhash = qdisc_class_hash_alloc(nsize);
698 if (nhash == NULL)
699 return;
700
701 ohash = clhash->hash;
702 osize = clhash->hashsize;
703
704 sch_tree_lock(sch);
705 for (i = 0; i < osize; i++) {
706 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
707 h = qdisc_class_hash(cl->classid, nmask);
708 hlist_add_head(&cl->hnode, &nhash[h]);
709 }
710 }
711 clhash->hash = nhash;
712 clhash->hashsize = nsize;
713 clhash->hashmask = nmask;
714 sch_tree_unlock(sch);
715
716 kvfree(ohash);
717}
718EXPORT_SYMBOL(qdisc_class_hash_grow);
719
720int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
721{
722 unsigned int size = 4;
723
724 clhash->hash = qdisc_class_hash_alloc(size);
725 if (!clhash->hash)
726 return -ENOMEM;
727 clhash->hashsize = size;
728 clhash->hashmask = size - 1;
729 clhash->hashelems = 0;
730 return 0;
731}
732EXPORT_SYMBOL(qdisc_class_hash_init);
733
734void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
735{
736 kvfree(clhash->hash);
737}
738EXPORT_SYMBOL(qdisc_class_hash_destroy);
739
740void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
741 struct Qdisc_class_common *cl)
742{
743 unsigned int h;
744
745 INIT_HLIST_NODE(&cl->hnode);
746 h = qdisc_class_hash(cl->classid, clhash->hashmask);
747 hlist_add_head(&cl->hnode, &clhash->hash[h]);
748 clhash->hashelems++;
749}
750EXPORT_SYMBOL(qdisc_class_hash_insert);
751
752void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
753 struct Qdisc_class_common *cl)
754{
755 hlist_del(&cl->hnode);
756 clhash->hashelems--;
757}
758EXPORT_SYMBOL(qdisc_class_hash_remove);
759
760/* Allocate an unique handle from space managed by kernel
761 * Possible range is [8000-FFFF]:0000 (0x8000 values)
762 */
763static u32 qdisc_alloc_handle(struct net_device *dev)
764{
765 int i = 0x8000;
766 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
767
768 do {
769 autohandle += TC_H_MAKE(0x10000U, 0);
770 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
771 autohandle = TC_H_MAKE(0x80000000U, 0);
772 if (!qdisc_lookup(dev, autohandle))
773 return autohandle;
774 cond_resched();
775 } while (--i > 0);
776
777 return 0;
778}
779
780void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len)
781{
782 bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED;
783 const struct Qdisc_class_ops *cops;
784 unsigned long cl;
785 u32 parentid;
786 bool notify;
787 int drops;
788
789 if (n == 0 && len == 0)
790 return;
791 drops = max_t(int, n, 0);
792 rcu_read_lock();
793 while ((parentid = sch->parent)) {
794 if (parentid == TC_H_ROOT)
795 break;
796
797 if (sch->flags & TCQ_F_NOPARENT)
798 break;
799 /* Notify parent qdisc only if child qdisc becomes empty.
800 *
801 * If child was empty even before update then backlog
802 * counter is screwed and we skip notification because
803 * parent class is already passive.
804 *
805 * If the original child was offloaded then it is allowed
806 * to be seem as empty, so the parent is notified anyway.
807 */
808 notify = !sch->q.qlen && !WARN_ON_ONCE(!n &&
809 !qdisc_is_offloaded);
810 /* TODO: perform the search on a per txq basis */
811 sch = qdisc_lookup_rcu(qdisc_dev(sch), TC_H_MAJ(parentid));
812 if (sch == NULL) {
813 WARN_ON_ONCE(parentid != TC_H_ROOT);
814 break;
815 }
816 cops = sch->ops->cl_ops;
817 if (notify && cops->qlen_notify) {
818 cl = cops->find(sch, parentid);
819 cops->qlen_notify(sch, cl);
820 }
821 sch->q.qlen -= n;
822 sch->qstats.backlog -= len;
823 __qdisc_qstats_drop(sch, drops);
824 }
825 rcu_read_unlock();
826}
827EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
828
829int qdisc_offload_dump_helper(struct Qdisc *sch, enum tc_setup_type type,
830 void *type_data)
831{
832 struct net_device *dev = qdisc_dev(sch);
833 int err;
834
835 sch->flags &= ~TCQ_F_OFFLOADED;
836 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
837 return 0;
838
839 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
840 if (err == -EOPNOTSUPP)
841 return 0;
842
843 if (!err)
844 sch->flags |= TCQ_F_OFFLOADED;
845
846 return err;
847}
848EXPORT_SYMBOL(qdisc_offload_dump_helper);
849
850void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
851 struct Qdisc *new, struct Qdisc *old,
852 enum tc_setup_type type, void *type_data,
853 struct netlink_ext_ack *extack)
854{
855 bool any_qdisc_is_offloaded;
856 int err;
857
858 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
859 return;
860
861 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
862
863 /* Don't report error if the graft is part of destroy operation. */
864 if (!err || !new || new == &noop_qdisc)
865 return;
866
867 /* Don't report error if the parent, the old child and the new
868 * one are not offloaded.
869 */
870 any_qdisc_is_offloaded = new->flags & TCQ_F_OFFLOADED;
871 any_qdisc_is_offloaded |= sch && sch->flags & TCQ_F_OFFLOADED;
872 any_qdisc_is_offloaded |= old && old->flags & TCQ_F_OFFLOADED;
873
874 if (any_qdisc_is_offloaded)
875 NL_SET_ERR_MSG(extack, "Offloading graft operation failed.");
876}
877EXPORT_SYMBOL(qdisc_offload_graft_helper);
878
879void qdisc_offload_query_caps(struct net_device *dev,
880 enum tc_setup_type type,
881 void *caps, size_t caps_len)
882{
883 const struct net_device_ops *ops = dev->netdev_ops;
884 struct tc_query_caps_base base = {
885 .type = type,
886 .caps = caps,
887 };
888
889 memset(caps, 0, caps_len);
890
891 if (ops->ndo_setup_tc)
892 ops->ndo_setup_tc(dev, TC_QUERY_CAPS, &base);
893}
894EXPORT_SYMBOL(qdisc_offload_query_caps);
895
896static void qdisc_offload_graft_root(struct net_device *dev,
897 struct Qdisc *new, struct Qdisc *old,
898 struct netlink_ext_ack *extack)
899{
900 struct tc_root_qopt_offload graft_offload = {
901 .command = TC_ROOT_GRAFT,
902 .handle = new ? new->handle : 0,
903 .ingress = (new && new->flags & TCQ_F_INGRESS) ||
904 (old && old->flags & TCQ_F_INGRESS),
905 };
906
907 qdisc_offload_graft_helper(dev, NULL, new, old,
908 TC_SETUP_ROOT_QDISC, &graft_offload, extack);
909}
910
911static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
912 u32 portid, u32 seq, u16 flags, int event,
913 struct netlink_ext_ack *extack)
914{
915 struct gnet_stats_basic_sync __percpu *cpu_bstats = NULL;
916 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
917 struct tcmsg *tcm;
918 struct nlmsghdr *nlh;
919 unsigned char *b = skb_tail_pointer(skb);
920 struct gnet_dump d;
921 struct qdisc_size_table *stab;
922 u32 block_index;
923 __u32 qlen;
924
925 cond_resched();
926 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
927 if (!nlh)
928 goto out_nlmsg_trim;
929 tcm = nlmsg_data(nlh);
930 tcm->tcm_family = AF_UNSPEC;
931 tcm->tcm__pad1 = 0;
932 tcm->tcm__pad2 = 0;
933 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
934 tcm->tcm_parent = clid;
935 tcm->tcm_handle = q->handle;
936 tcm->tcm_info = refcount_read(&q->refcnt);
937 if (nla_put_string(skb, TCA_KIND, q->ops->id))
938 goto nla_put_failure;
939 if (q->ops->ingress_block_get) {
940 block_index = q->ops->ingress_block_get(q);
941 if (block_index &&
942 nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index))
943 goto nla_put_failure;
944 }
945 if (q->ops->egress_block_get) {
946 block_index = q->ops->egress_block_get(q);
947 if (block_index &&
948 nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index))
949 goto nla_put_failure;
950 }
951 if (q->ops->dump && q->ops->dump(q, skb) < 0)
952 goto nla_put_failure;
953 if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED)))
954 goto nla_put_failure;
955 qlen = qdisc_qlen_sum(q);
956
957 stab = rtnl_dereference(q->stab);
958 if (stab && qdisc_dump_stab(skb, stab) < 0)
959 goto nla_put_failure;
960
961 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
962 NULL, &d, TCA_PAD) < 0)
963 goto nla_put_failure;
964
965 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
966 goto nla_put_failure;
967
968 if (qdisc_is_percpu_stats(q)) {
969 cpu_bstats = q->cpu_bstats;
970 cpu_qstats = q->cpu_qstats;
971 }
972
973 if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats, true) < 0 ||
974 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
975 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
976 goto nla_put_failure;
977
978 if (gnet_stats_finish_copy(&d) < 0)
979 goto nla_put_failure;
980
981 if (extack && extack->_msg &&
982 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
983 goto out_nlmsg_trim;
984
985 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
986
987 return skb->len;
988
989out_nlmsg_trim:
990nla_put_failure:
991 nlmsg_trim(skb, b);
992 return -1;
993}
994
995static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible)
996{
997 if (q->flags & TCQ_F_BUILTIN)
998 return true;
999 if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible)
1000 return true;
1001
1002 return false;
1003}
1004
1005static int qdisc_get_notify(struct net *net, struct sk_buff *oskb,
1006 struct nlmsghdr *n, u32 clid, struct Qdisc *q,
1007 struct netlink_ext_ack *extack)
1008{
1009 struct sk_buff *skb;
1010 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1011
1012 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1013 if (!skb)
1014 return -ENOBUFS;
1015
1016 if (!tc_qdisc_dump_ignore(q, false)) {
1017 if (tc_fill_qdisc(skb, q, clid, portid, n->nlmsg_seq, 0,
1018 RTM_NEWQDISC, extack) < 0)
1019 goto err_out;
1020 }
1021
1022 if (skb->len)
1023 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1024 n->nlmsg_flags & NLM_F_ECHO);
1025
1026err_out:
1027 kfree_skb(skb);
1028 return -EINVAL;
1029}
1030
1031static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1032 struct nlmsghdr *n, u32 clid,
1033 struct Qdisc *old, struct Qdisc *new,
1034 struct netlink_ext_ack *extack)
1035{
1036 struct sk_buff *skb;
1037 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1038
1039 if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
1040 return 0;
1041
1042 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1043 if (!skb)
1044 return -ENOBUFS;
1045
1046 if (old && !tc_qdisc_dump_ignore(old, false)) {
1047 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1048 0, RTM_DELQDISC, extack) < 0)
1049 goto err_out;
1050 }
1051 if (new && !tc_qdisc_dump_ignore(new, false)) {
1052 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1053 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC, extack) < 0)
1054 goto err_out;
1055 }
1056
1057 if (skb->len)
1058 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1059 n->nlmsg_flags & NLM_F_ECHO);
1060
1061err_out:
1062 kfree_skb(skb);
1063 return -EINVAL;
1064}
1065
1066static void notify_and_destroy(struct net *net, struct sk_buff *skb,
1067 struct nlmsghdr *n, u32 clid,
1068 struct Qdisc *old, struct Qdisc *new,
1069 struct netlink_ext_ack *extack)
1070{
1071 if (new || old)
1072 qdisc_notify(net, skb, n, clid, old, new, extack);
1073
1074 if (old)
1075 qdisc_put(old);
1076}
1077
1078static void qdisc_clear_nolock(struct Qdisc *sch)
1079{
1080 sch->flags &= ~TCQ_F_NOLOCK;
1081 if (!(sch->flags & TCQ_F_CPUSTATS))
1082 return;
1083
1084 free_percpu(sch->cpu_bstats);
1085 free_percpu(sch->cpu_qstats);
1086 sch->cpu_bstats = NULL;
1087 sch->cpu_qstats = NULL;
1088 sch->flags &= ~TCQ_F_CPUSTATS;
1089}
1090
1091/* Graft qdisc "new" to class "classid" of qdisc "parent" or
1092 * to device "dev".
1093 *
1094 * When appropriate send a netlink notification using 'skb'
1095 * and "n".
1096 *
1097 * On success, destroy old qdisc.
1098 */
1099
1100static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
1101 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
1102 struct Qdisc *new, struct Qdisc *old,
1103 struct netlink_ext_ack *extack)
1104{
1105 struct Qdisc *q = old;
1106 struct net *net = dev_net(dev);
1107
1108 if (parent == NULL) {
1109 unsigned int i, num_q, ingress;
1110 struct netdev_queue *dev_queue;
1111
1112 ingress = 0;
1113 num_q = dev->num_tx_queues;
1114 if ((q && q->flags & TCQ_F_INGRESS) ||
1115 (new && new->flags & TCQ_F_INGRESS)) {
1116 ingress = 1;
1117 dev_queue = dev_ingress_queue(dev);
1118 if (!dev_queue) {
1119 NL_SET_ERR_MSG(extack, "Device does not have an ingress queue");
1120 return -ENOENT;
1121 }
1122
1123 q = rtnl_dereference(dev_queue->qdisc_sleeping);
1124
1125 /* This is the counterpart of that qdisc_refcount_inc_nz() call in
1126 * __tcf_qdisc_find() for filter requests.
1127 */
1128 if (!qdisc_refcount_dec_if_one(q)) {
1129 NL_SET_ERR_MSG(extack,
1130 "Current ingress or clsact Qdisc has ongoing filter requests");
1131 return -EBUSY;
1132 }
1133 }
1134
1135 if (dev->flags & IFF_UP)
1136 dev_deactivate(dev);
1137
1138 qdisc_offload_graft_root(dev, new, old, extack);
1139
1140 if (new && new->ops->attach && !ingress)
1141 goto skip;
1142
1143 if (!ingress) {
1144 for (i = 0; i < num_q; i++) {
1145 dev_queue = netdev_get_tx_queue(dev, i);
1146 old = dev_graft_qdisc(dev_queue, new);
1147
1148 if (new && i > 0)
1149 qdisc_refcount_inc(new);
1150 qdisc_put(old);
1151 }
1152 } else {
1153 old = dev_graft_qdisc(dev_queue, NULL);
1154
1155 /* {ingress,clsact}_destroy() @old before grafting @new to avoid
1156 * unprotected concurrent accesses to net_device::miniq_{in,e}gress
1157 * pointer(s) in mini_qdisc_pair_swap().
1158 */
1159 qdisc_notify(net, skb, n, classid, old, new, extack);
1160 qdisc_destroy(old);
1161
1162 dev_graft_qdisc(dev_queue, new);
1163 }
1164
1165skip:
1166 if (!ingress) {
1167 old = rtnl_dereference(dev->qdisc);
1168 if (new && !new->ops->attach)
1169 qdisc_refcount_inc(new);
1170 rcu_assign_pointer(dev->qdisc, new ? : &noop_qdisc);
1171
1172 notify_and_destroy(net, skb, n, classid, old, new, extack);
1173
1174 if (new && new->ops->attach)
1175 new->ops->attach(new);
1176 }
1177
1178 if (dev->flags & IFF_UP)
1179 dev_activate(dev);
1180 } else {
1181 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
1182 unsigned long cl;
1183 int err;
1184
1185 /* Only support running class lockless if parent is lockless */
1186 if (new && (new->flags & TCQ_F_NOLOCK) && !(parent->flags & TCQ_F_NOLOCK))
1187 qdisc_clear_nolock(new);
1188
1189 if (!cops || !cops->graft)
1190 return -EOPNOTSUPP;
1191
1192 cl = cops->find(parent, classid);
1193 if (!cl) {
1194 NL_SET_ERR_MSG(extack, "Specified class not found");
1195 return -ENOENT;
1196 }
1197
1198 if (new && new->ops == &noqueue_qdisc_ops) {
1199 NL_SET_ERR_MSG(extack, "Cannot assign noqueue to a class");
1200 return -EINVAL;
1201 }
1202
1203 if (new &&
1204 !(parent->flags & TCQ_F_MQROOT) &&
1205 rcu_access_pointer(new->stab)) {
1206 NL_SET_ERR_MSG(extack, "STAB not supported on a non root");
1207 return -EINVAL;
1208 }
1209 err = cops->graft(parent, cl, new, &old, extack);
1210 if (err)
1211 return err;
1212 notify_and_destroy(net, skb, n, classid, old, new, extack);
1213 }
1214 return 0;
1215}
1216
1217static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca,
1218 struct netlink_ext_ack *extack)
1219{
1220 u32 block_index;
1221
1222 if (tca[TCA_INGRESS_BLOCK]) {
1223 block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]);
1224
1225 if (!block_index) {
1226 NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0");
1227 return -EINVAL;
1228 }
1229 if (!sch->ops->ingress_block_set) {
1230 NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported");
1231 return -EOPNOTSUPP;
1232 }
1233 sch->ops->ingress_block_set(sch, block_index);
1234 }
1235 if (tca[TCA_EGRESS_BLOCK]) {
1236 block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]);
1237
1238 if (!block_index) {
1239 NL_SET_ERR_MSG(extack, "Egress block index cannot be 0");
1240 return -EINVAL;
1241 }
1242 if (!sch->ops->egress_block_set) {
1243 NL_SET_ERR_MSG(extack, "Egress block sharing is not supported");
1244 return -EOPNOTSUPP;
1245 }
1246 sch->ops->egress_block_set(sch, block_index);
1247 }
1248 return 0;
1249}
1250
1251/*
1252 Allocate and initialize new qdisc.
1253
1254 Parameters are passed via opt.
1255 */
1256
1257static struct Qdisc *qdisc_create(struct net_device *dev,
1258 struct netdev_queue *dev_queue,
1259 u32 parent, u32 handle,
1260 struct nlattr **tca, int *errp,
1261 struct netlink_ext_ack *extack)
1262{
1263 int err;
1264 struct nlattr *kind = tca[TCA_KIND];
1265 struct Qdisc *sch;
1266 struct Qdisc_ops *ops;
1267 struct qdisc_size_table *stab;
1268
1269 ops = qdisc_lookup_ops(kind);
1270#ifdef CONFIG_MODULES
1271 if (ops == NULL && kind != NULL) {
1272 char name[IFNAMSIZ];
1273 if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) {
1274 /* We dropped the RTNL semaphore in order to
1275 * perform the module load. So, even if we
1276 * succeeded in loading the module we have to
1277 * tell the caller to replay the request. We
1278 * indicate this using -EAGAIN.
1279 * We replay the request because the device may
1280 * go away in the mean time.
1281 */
1282 rtnl_unlock();
1283 request_module(NET_SCH_ALIAS_PREFIX "%s", name);
1284 rtnl_lock();
1285 ops = qdisc_lookup_ops(kind);
1286 if (ops != NULL) {
1287 /* We will try again qdisc_lookup_ops,
1288 * so don't keep a reference.
1289 */
1290 module_put(ops->owner);
1291 err = -EAGAIN;
1292 goto err_out;
1293 }
1294 }
1295 }
1296#endif
1297
1298 err = -ENOENT;
1299 if (!ops) {
1300 NL_SET_ERR_MSG(extack, "Specified qdisc kind is unknown");
1301 goto err_out;
1302 }
1303
1304 sch = qdisc_alloc(dev_queue, ops, extack);
1305 if (IS_ERR(sch)) {
1306 err = PTR_ERR(sch);
1307 goto err_out2;
1308 }
1309
1310 sch->parent = parent;
1311
1312 if (handle == TC_H_INGRESS) {
1313 if (!(sch->flags & TCQ_F_INGRESS)) {
1314 NL_SET_ERR_MSG(extack,
1315 "Specified parent ID is reserved for ingress and clsact Qdiscs");
1316 err = -EINVAL;
1317 goto err_out3;
1318 }
1319 handle = TC_H_MAKE(TC_H_INGRESS, 0);
1320 } else {
1321 if (handle == 0) {
1322 handle = qdisc_alloc_handle(dev);
1323 if (handle == 0) {
1324 NL_SET_ERR_MSG(extack, "Maximum number of qdisc handles was exceeded");
1325 err = -ENOSPC;
1326 goto err_out3;
1327 }
1328 }
1329 if (!netif_is_multiqueue(dev))
1330 sch->flags |= TCQ_F_ONETXQUEUE;
1331 }
1332
1333 sch->handle = handle;
1334
1335 /* This exist to keep backward compatible with a userspace
1336 * loophole, what allowed userspace to get IFF_NO_QUEUE
1337 * facility on older kernels by setting tx_queue_len=0 (prior
1338 * to qdisc init), and then forgot to reinit tx_queue_len
1339 * before again attaching a qdisc.
1340 */
1341 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) {
1342 WRITE_ONCE(dev->tx_queue_len, DEFAULT_TX_QUEUE_LEN);
1343 netdev_info(dev, "Caught tx_queue_len zero misconfig\n");
1344 }
1345
1346 err = qdisc_block_indexes_set(sch, tca, extack);
1347 if (err)
1348 goto err_out3;
1349
1350 if (tca[TCA_STAB]) {
1351 stab = qdisc_get_stab(tca[TCA_STAB], extack);
1352 if (IS_ERR(stab)) {
1353 err = PTR_ERR(stab);
1354 goto err_out3;
1355 }
1356 rcu_assign_pointer(sch->stab, stab);
1357 }
1358
1359 if (ops->init) {
1360 err = ops->init(sch, tca[TCA_OPTIONS], extack);
1361 if (err != 0)
1362 goto err_out4;
1363 }
1364
1365 if (tca[TCA_RATE]) {
1366 err = -EOPNOTSUPP;
1367 if (sch->flags & TCQ_F_MQROOT) {
1368 NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc");
1369 goto err_out4;
1370 }
1371
1372 err = gen_new_estimator(&sch->bstats,
1373 sch->cpu_bstats,
1374 &sch->rate_est,
1375 NULL,
1376 true,
1377 tca[TCA_RATE]);
1378 if (err) {
1379 NL_SET_ERR_MSG(extack, "Failed to generate new estimator");
1380 goto err_out4;
1381 }
1382 }
1383
1384 qdisc_hash_add(sch, false);
1385 trace_qdisc_create(ops, dev, parent);
1386
1387 return sch;
1388
1389err_out4:
1390 /* Even if ops->init() failed, we call ops->destroy()
1391 * like qdisc_create_dflt().
1392 */
1393 if (ops->destroy)
1394 ops->destroy(sch);
1395 qdisc_put_stab(rtnl_dereference(sch->stab));
1396err_out3:
1397 lockdep_unregister_key(&sch->root_lock_key);
1398 netdev_put(dev, &sch->dev_tracker);
1399 qdisc_free(sch);
1400err_out2:
1401 module_put(ops->owner);
1402err_out:
1403 *errp = err;
1404 return NULL;
1405}
1406
1407static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
1408 struct netlink_ext_ack *extack)
1409{
1410 struct qdisc_size_table *ostab, *stab = NULL;
1411 int err = 0;
1412
1413 if (tca[TCA_OPTIONS]) {
1414 if (!sch->ops->change) {
1415 NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc");
1416 return -EINVAL;
1417 }
1418 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
1419 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
1420 return -EOPNOTSUPP;
1421 }
1422 err = sch->ops->change(sch, tca[TCA_OPTIONS], extack);
1423 if (err)
1424 return err;
1425 }
1426
1427 if (tca[TCA_STAB]) {
1428 stab = qdisc_get_stab(tca[TCA_STAB], extack);
1429 if (IS_ERR(stab))
1430 return PTR_ERR(stab);
1431 }
1432
1433 ostab = rtnl_dereference(sch->stab);
1434 rcu_assign_pointer(sch->stab, stab);
1435 qdisc_put_stab(ostab);
1436
1437 if (tca[TCA_RATE]) {
1438 /* NB: ignores errors from replace_estimator
1439 because change can't be undone. */
1440 if (sch->flags & TCQ_F_MQROOT)
1441 goto out;
1442 gen_replace_estimator(&sch->bstats,
1443 sch->cpu_bstats,
1444 &sch->rate_est,
1445 NULL,
1446 true,
1447 tca[TCA_RATE]);
1448 }
1449out:
1450 return 0;
1451}
1452
1453struct check_loop_arg {
1454 struct qdisc_walker w;
1455 struct Qdisc *p;
1456 int depth;
1457};
1458
1459static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1460 struct qdisc_walker *w);
1461
1462static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1463{
1464 struct check_loop_arg arg;
1465
1466 if (q->ops->cl_ops == NULL)
1467 return 0;
1468
1469 arg.w.stop = arg.w.skip = arg.w.count = 0;
1470 arg.w.fn = check_loop_fn;
1471 arg.depth = depth;
1472 arg.p = p;
1473 q->ops->cl_ops->walk(q, &arg.w);
1474 return arg.w.stop ? -ELOOP : 0;
1475}
1476
1477static int
1478check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1479{
1480 struct Qdisc *leaf;
1481 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1482 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1483
1484 leaf = cops->leaf(q, cl);
1485 if (leaf) {
1486 if (leaf == arg->p || arg->depth > 7)
1487 return -ELOOP;
1488 return check_loop(leaf, arg->p, arg->depth + 1);
1489 }
1490 return 0;
1491}
1492
1493const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = {
1494 [TCA_KIND] = { .type = NLA_STRING },
1495 [TCA_RATE] = { .type = NLA_BINARY,
1496 .len = sizeof(struct tc_estimator) },
1497 [TCA_STAB] = { .type = NLA_NESTED },
1498 [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG },
1499 [TCA_CHAIN] = { .type = NLA_U32 },
1500 [TCA_INGRESS_BLOCK] = { .type = NLA_U32 },
1501 [TCA_EGRESS_BLOCK] = { .type = NLA_U32 },
1502};
1503
1504/*
1505 * Delete/get qdisc.
1506 */
1507
1508static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1509 struct netlink_ext_ack *extack)
1510{
1511 struct net *net = sock_net(skb->sk);
1512 struct tcmsg *tcm = nlmsg_data(n);
1513 struct nlattr *tca[TCA_MAX + 1];
1514 struct net_device *dev;
1515 u32 clid;
1516 struct Qdisc *q = NULL;
1517 struct Qdisc *p = NULL;
1518 int err;
1519
1520 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1521 rtm_tca_policy, extack);
1522 if (err < 0)
1523 return err;
1524
1525 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1526 if (!dev)
1527 return -ENODEV;
1528
1529 clid = tcm->tcm_parent;
1530 if (clid) {
1531 if (clid != TC_H_ROOT) {
1532 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1533 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1534 if (!p) {
1535 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid");
1536 return -ENOENT;
1537 }
1538 q = qdisc_leaf(p, clid);
1539 } else if (dev_ingress_queue(dev)) {
1540 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping);
1541 }
1542 } else {
1543 q = rtnl_dereference(dev->qdisc);
1544 }
1545 if (!q) {
1546 NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device");
1547 return -ENOENT;
1548 }
1549
1550 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) {
1551 NL_SET_ERR_MSG(extack, "Invalid handle");
1552 return -EINVAL;
1553 }
1554 } else {
1555 q = qdisc_lookup(dev, tcm->tcm_handle);
1556 if (!q) {
1557 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle");
1558 return -ENOENT;
1559 }
1560 }
1561
1562 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1563 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1564 return -EINVAL;
1565 }
1566
1567 if (n->nlmsg_type == RTM_DELQDISC) {
1568 if (!clid) {
1569 NL_SET_ERR_MSG(extack, "Classid cannot be zero");
1570 return -EINVAL;
1571 }
1572 if (q->handle == 0) {
1573 NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero");
1574 return -ENOENT;
1575 }
1576 err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack);
1577 if (err != 0)
1578 return err;
1579 } else {
1580 qdisc_get_notify(net, skb, n, clid, q, NULL);
1581 }
1582 return 0;
1583}
1584
1585static bool req_create_or_replace(struct nlmsghdr *n)
1586{
1587 return (n->nlmsg_flags & NLM_F_CREATE &&
1588 n->nlmsg_flags & NLM_F_REPLACE);
1589}
1590
1591static bool req_create_exclusive(struct nlmsghdr *n)
1592{
1593 return (n->nlmsg_flags & NLM_F_CREATE &&
1594 n->nlmsg_flags & NLM_F_EXCL);
1595}
1596
1597static bool req_change(struct nlmsghdr *n)
1598{
1599 return (!(n->nlmsg_flags & NLM_F_CREATE) &&
1600 !(n->nlmsg_flags & NLM_F_REPLACE) &&
1601 !(n->nlmsg_flags & NLM_F_EXCL));
1602}
1603
1604/*
1605 * Create/change qdisc.
1606 */
1607static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1608 struct netlink_ext_ack *extack)
1609{
1610 struct net *net = sock_net(skb->sk);
1611 struct tcmsg *tcm;
1612 struct nlattr *tca[TCA_MAX + 1];
1613 struct net_device *dev;
1614 u32 clid;
1615 struct Qdisc *q, *p;
1616 int err;
1617
1618replay:
1619 /* Reinit, just in case something touches this. */
1620 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1621 rtm_tca_policy, extack);
1622 if (err < 0)
1623 return err;
1624
1625 tcm = nlmsg_data(n);
1626 clid = tcm->tcm_parent;
1627 q = p = NULL;
1628
1629 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1630 if (!dev)
1631 return -ENODEV;
1632
1633
1634 if (clid) {
1635 if (clid != TC_H_ROOT) {
1636 if (clid != TC_H_INGRESS) {
1637 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1638 if (!p) {
1639 NL_SET_ERR_MSG(extack, "Failed to find specified qdisc");
1640 return -ENOENT;
1641 }
1642 q = qdisc_leaf(p, clid);
1643 } else if (dev_ingress_queue_create(dev)) {
1644 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping);
1645 }
1646 } else {
1647 q = rtnl_dereference(dev->qdisc);
1648 }
1649
1650 /* It may be default qdisc, ignore it */
1651 if (q && q->handle == 0)
1652 q = NULL;
1653
1654 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1655 if (tcm->tcm_handle) {
1656 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) {
1657 NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override");
1658 return -EEXIST;
1659 }
1660 if (TC_H_MIN(tcm->tcm_handle)) {
1661 NL_SET_ERR_MSG(extack, "Invalid minor handle");
1662 return -EINVAL;
1663 }
1664 q = qdisc_lookup(dev, tcm->tcm_handle);
1665 if (!q)
1666 goto create_n_graft;
1667 if (q->parent != tcm->tcm_parent) {
1668 NL_SET_ERR_MSG(extack, "Cannot move an existing qdisc to a different parent");
1669 return -EINVAL;
1670 }
1671 if (n->nlmsg_flags & NLM_F_EXCL) {
1672 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override");
1673 return -EEXIST;
1674 }
1675 if (tca[TCA_KIND] &&
1676 nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1677 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1678 return -EINVAL;
1679 }
1680 if (q->flags & TCQ_F_INGRESS) {
1681 NL_SET_ERR_MSG(extack,
1682 "Cannot regraft ingress or clsact Qdiscs");
1683 return -EINVAL;
1684 }
1685 if (q == p ||
1686 (p && check_loop(q, p, 0))) {
1687 NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected");
1688 return -ELOOP;
1689 }
1690 if (clid == TC_H_INGRESS) {
1691 NL_SET_ERR_MSG(extack, "Ingress cannot graft directly");
1692 return -EINVAL;
1693 }
1694 qdisc_refcount_inc(q);
1695 goto graft;
1696 } else {
1697 if (!q)
1698 goto create_n_graft;
1699
1700 /* This magic test requires explanation.
1701 *
1702 * We know, that some child q is already
1703 * attached to this parent and have choice:
1704 * 1) change it or 2) create/graft new one.
1705 * If the requested qdisc kind is different
1706 * than the existing one, then we choose graft.
1707 * If they are the same then this is "change"
1708 * operation - just let it fallthrough..
1709 *
1710 * 1. We are allowed to create/graft only
1711 * if the request is explicitly stating
1712 * "please create if it doesn't exist".
1713 *
1714 * 2. If the request is to exclusive create
1715 * then the qdisc tcm_handle is not expected
1716 * to exist, so that we choose create/graft too.
1717 *
1718 * 3. The last case is when no flags are set.
1719 * This will happen when for example tc
1720 * utility issues a "change" command.
1721 * Alas, it is sort of hole in API, we
1722 * cannot decide what to do unambiguously.
1723 * For now we select create/graft.
1724 */
1725 if (tca[TCA_KIND] &&
1726 nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1727 if (req_create_or_replace(n) ||
1728 req_create_exclusive(n))
1729 goto create_n_graft;
1730 else if (req_change(n))
1731 goto create_n_graft2;
1732 }
1733 }
1734 }
1735 } else {
1736 if (!tcm->tcm_handle) {
1737 NL_SET_ERR_MSG(extack, "Handle cannot be zero");
1738 return -EINVAL;
1739 }
1740 q = qdisc_lookup(dev, tcm->tcm_handle);
1741 }
1742
1743 /* Change qdisc parameters */
1744 if (!q) {
1745 NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1746 return -ENOENT;
1747 }
1748 if (n->nlmsg_flags & NLM_F_EXCL) {
1749 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify");
1750 return -EEXIST;
1751 }
1752 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1753 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1754 return -EINVAL;
1755 }
1756 err = qdisc_change(q, tca, extack);
1757 if (err == 0)
1758 qdisc_notify(net, skb, n, clid, NULL, q, extack);
1759 return err;
1760
1761create_n_graft:
1762 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
1763 NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag");
1764 return -ENOENT;
1765 }
1766create_n_graft2:
1767 if (clid == TC_H_INGRESS) {
1768 if (dev_ingress_queue(dev)) {
1769 q = qdisc_create(dev, dev_ingress_queue(dev),
1770 tcm->tcm_parent, tcm->tcm_parent,
1771 tca, &err, extack);
1772 } else {
1773 NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device");
1774 err = -ENOENT;
1775 }
1776 } else {
1777 struct netdev_queue *dev_queue;
1778
1779 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1780 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1781 else if (p)
1782 dev_queue = p->dev_queue;
1783 else
1784 dev_queue = netdev_get_tx_queue(dev, 0);
1785
1786 q = qdisc_create(dev, dev_queue,
1787 tcm->tcm_parent, tcm->tcm_handle,
1788 tca, &err, extack);
1789 }
1790 if (q == NULL) {
1791 if (err == -EAGAIN)
1792 goto replay;
1793 return err;
1794 }
1795
1796graft:
1797 err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack);
1798 if (err) {
1799 if (q)
1800 qdisc_put(q);
1801 return err;
1802 }
1803
1804 return 0;
1805}
1806
1807static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1808 struct netlink_callback *cb,
1809 int *q_idx_p, int s_q_idx, bool recur,
1810 bool dump_invisible)
1811{
1812 int ret = 0, q_idx = *q_idx_p;
1813 struct Qdisc *q;
1814 int b;
1815
1816 if (!root)
1817 return 0;
1818
1819 q = root;
1820 if (q_idx < s_q_idx) {
1821 q_idx++;
1822 } else {
1823 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1824 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1825 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1826 RTM_NEWQDISC, NULL) <= 0)
1827 goto done;
1828 q_idx++;
1829 }
1830
1831 /* If dumping singletons, there is no qdisc_dev(root) and the singleton
1832 * itself has already been dumped.
1833 *
1834 * If we've already dumped the top-level (ingress) qdisc above and the global
1835 * qdisc hashtable, we don't want to hit it again
1836 */
1837 if (!qdisc_dev(root) || !recur)
1838 goto out;
1839
1840 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1841 if (q_idx < s_q_idx) {
1842 q_idx++;
1843 continue;
1844 }
1845 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1846 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1847 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1848 RTM_NEWQDISC, NULL) <= 0)
1849 goto done;
1850 q_idx++;
1851 }
1852
1853out:
1854 *q_idx_p = q_idx;
1855 return ret;
1856done:
1857 ret = -1;
1858 goto out;
1859}
1860
1861static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1862{
1863 struct net *net = sock_net(skb->sk);
1864 int idx, q_idx;
1865 int s_idx, s_q_idx;
1866 struct net_device *dev;
1867 const struct nlmsghdr *nlh = cb->nlh;
1868 struct nlattr *tca[TCA_MAX + 1];
1869 int err;
1870
1871 s_idx = cb->args[0];
1872 s_q_idx = q_idx = cb->args[1];
1873
1874 idx = 0;
1875 ASSERT_RTNL();
1876
1877 err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX,
1878 rtm_tca_policy, cb->extack);
1879 if (err < 0)
1880 return err;
1881
1882 for_each_netdev(net, dev) {
1883 struct netdev_queue *dev_queue;
1884
1885 if (idx < s_idx)
1886 goto cont;
1887 if (idx > s_idx)
1888 s_q_idx = 0;
1889 q_idx = 0;
1890
1891 if (tc_dump_qdisc_root(rtnl_dereference(dev->qdisc),
1892 skb, cb, &q_idx, s_q_idx,
1893 true, tca[TCA_DUMP_INVISIBLE]) < 0)
1894 goto done;
1895
1896 dev_queue = dev_ingress_queue(dev);
1897 if (dev_queue &&
1898 tc_dump_qdisc_root(rtnl_dereference(dev_queue->qdisc_sleeping),
1899 skb, cb, &q_idx, s_q_idx, false,
1900 tca[TCA_DUMP_INVISIBLE]) < 0)
1901 goto done;
1902
1903cont:
1904 idx++;
1905 }
1906
1907done:
1908 cb->args[0] = idx;
1909 cb->args[1] = q_idx;
1910
1911 return skb->len;
1912}
1913
1914
1915
1916/************************************************
1917 * Traffic classes manipulation. *
1918 ************************************************/
1919
1920static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1921 unsigned long cl, u32 portid, u32 seq, u16 flags,
1922 int event, struct netlink_ext_ack *extack)
1923{
1924 struct tcmsg *tcm;
1925 struct nlmsghdr *nlh;
1926 unsigned char *b = skb_tail_pointer(skb);
1927 struct gnet_dump d;
1928 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1929
1930 cond_resched();
1931 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1932 if (!nlh)
1933 goto out_nlmsg_trim;
1934 tcm = nlmsg_data(nlh);
1935 tcm->tcm_family = AF_UNSPEC;
1936 tcm->tcm__pad1 = 0;
1937 tcm->tcm__pad2 = 0;
1938 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1939 tcm->tcm_parent = q->handle;
1940 tcm->tcm_handle = q->handle;
1941 tcm->tcm_info = 0;
1942 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1943 goto nla_put_failure;
1944 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1945 goto nla_put_failure;
1946
1947 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1948 NULL, &d, TCA_PAD) < 0)
1949 goto nla_put_failure;
1950
1951 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1952 goto nla_put_failure;
1953
1954 if (gnet_stats_finish_copy(&d) < 0)
1955 goto nla_put_failure;
1956
1957 if (extack && extack->_msg &&
1958 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
1959 goto out_nlmsg_trim;
1960
1961 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1962
1963 return skb->len;
1964
1965out_nlmsg_trim:
1966nla_put_failure:
1967 nlmsg_trim(skb, b);
1968 return -1;
1969}
1970
1971static int tclass_notify(struct net *net, struct sk_buff *oskb,
1972 struct nlmsghdr *n, struct Qdisc *q,
1973 unsigned long cl, int event, struct netlink_ext_ack *extack)
1974{
1975 struct sk_buff *skb;
1976 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1977
1978 if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
1979 return 0;
1980
1981 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1982 if (!skb)
1983 return -ENOBUFS;
1984
1985 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event, extack) < 0) {
1986 kfree_skb(skb);
1987 return -EINVAL;
1988 }
1989
1990 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1991 n->nlmsg_flags & NLM_F_ECHO);
1992}
1993
1994static int tclass_get_notify(struct net *net, struct sk_buff *oskb,
1995 struct nlmsghdr *n, struct Qdisc *q,
1996 unsigned long cl, struct netlink_ext_ack *extack)
1997{
1998 struct sk_buff *skb;
1999 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2000
2001 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2002 if (!skb)
2003 return -ENOBUFS;
2004
2005 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, RTM_NEWTCLASS,
2006 extack) < 0) {
2007 kfree_skb(skb);
2008 return -EINVAL;
2009 }
2010
2011 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2012 n->nlmsg_flags & NLM_F_ECHO);
2013}
2014
2015static int tclass_del_notify(struct net *net,
2016 const struct Qdisc_class_ops *cops,
2017 struct sk_buff *oskb, struct nlmsghdr *n,
2018 struct Qdisc *q, unsigned long cl,
2019 struct netlink_ext_ack *extack)
2020{
2021 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2022 struct sk_buff *skb;
2023 int err = 0;
2024
2025 if (!cops->delete)
2026 return -EOPNOTSUPP;
2027
2028 if (rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) {
2029 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2030 if (!skb)
2031 return -ENOBUFS;
2032
2033 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0,
2034 RTM_DELTCLASS, extack) < 0) {
2035 kfree_skb(skb);
2036 return -EINVAL;
2037 }
2038 } else {
2039 skb = NULL;
2040 }
2041
2042 err = cops->delete(q, cl, extack);
2043 if (err) {
2044 kfree_skb(skb);
2045 return err;
2046 }
2047
2048 err = rtnetlink_maybe_send(skb, net, portid, RTNLGRP_TC,
2049 n->nlmsg_flags & NLM_F_ECHO);
2050 return err;
2051}
2052
2053#ifdef CONFIG_NET_CLS
2054
2055struct tcf_bind_args {
2056 struct tcf_walker w;
2057 unsigned long base;
2058 unsigned long cl;
2059 u32 classid;
2060};
2061
2062static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2063{
2064 struct tcf_bind_args *a = (void *)arg;
2065
2066 if (n && tp->ops->bind_class) {
2067 struct Qdisc *q = tcf_block_q(tp->chain->block);
2068
2069 sch_tree_lock(q);
2070 tp->ops->bind_class(n, a->classid, a->cl, q, a->base);
2071 sch_tree_unlock(q);
2072 }
2073 return 0;
2074}
2075
2076struct tc_bind_class_args {
2077 struct qdisc_walker w;
2078 unsigned long new_cl;
2079 u32 portid;
2080 u32 clid;
2081};
2082
2083static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl,
2084 struct qdisc_walker *w)
2085{
2086 struct tc_bind_class_args *a = (struct tc_bind_class_args *)w;
2087 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
2088 struct tcf_block *block;
2089 struct tcf_chain *chain;
2090
2091 block = cops->tcf_block(q, cl, NULL);
2092 if (!block)
2093 return 0;
2094 for (chain = tcf_get_next_chain(block, NULL);
2095 chain;
2096 chain = tcf_get_next_chain(block, chain)) {
2097 struct tcf_proto *tp;
2098
2099 for (tp = tcf_get_next_proto(chain, NULL);
2100 tp; tp = tcf_get_next_proto(chain, tp)) {
2101 struct tcf_bind_args arg = {};
2102
2103 arg.w.fn = tcf_node_bind;
2104 arg.classid = a->clid;
2105 arg.base = cl;
2106 arg.cl = a->new_cl;
2107 tp->ops->walk(tp, &arg.w, true);
2108 }
2109 }
2110
2111 return 0;
2112}
2113
2114static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
2115 unsigned long new_cl)
2116{
2117 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
2118 struct tc_bind_class_args args = {};
2119
2120 if (!cops->tcf_block)
2121 return;
2122 args.portid = portid;
2123 args.clid = clid;
2124 args.new_cl = new_cl;
2125 args.w.fn = tc_bind_class_walker;
2126 q->ops->cl_ops->walk(q, &args.w);
2127}
2128
2129#else
2130
2131static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
2132 unsigned long new_cl)
2133{
2134}
2135
2136#endif
2137
2138static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
2139 struct netlink_ext_ack *extack)
2140{
2141 struct net *net = sock_net(skb->sk);
2142 struct tcmsg *tcm = nlmsg_data(n);
2143 struct nlattr *tca[TCA_MAX + 1];
2144 struct net_device *dev;
2145 struct Qdisc *q = NULL;
2146 const struct Qdisc_class_ops *cops;
2147 unsigned long cl = 0;
2148 unsigned long new_cl;
2149 u32 portid;
2150 u32 clid;
2151 u32 qid;
2152 int err;
2153
2154 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
2155 rtm_tca_policy, extack);
2156 if (err < 0)
2157 return err;
2158
2159 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2160 if (!dev)
2161 return -ENODEV;
2162
2163 /*
2164 parent == TC_H_UNSPEC - unspecified parent.
2165 parent == TC_H_ROOT - class is root, which has no parent.
2166 parent == X:0 - parent is root class.
2167 parent == X:Y - parent is a node in hierarchy.
2168 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
2169
2170 handle == 0:0 - generate handle from kernel pool.
2171 handle == 0:Y - class is X:Y, where X:0 is qdisc.
2172 handle == X:Y - clear.
2173 handle == X:0 - root class.
2174 */
2175
2176 /* Step 1. Determine qdisc handle X:0 */
2177
2178 portid = tcm->tcm_parent;
2179 clid = tcm->tcm_handle;
2180 qid = TC_H_MAJ(clid);
2181
2182 if (portid != TC_H_ROOT) {
2183 u32 qid1 = TC_H_MAJ(portid);
2184
2185 if (qid && qid1) {
2186 /* If both majors are known, they must be identical. */
2187 if (qid != qid1)
2188 return -EINVAL;
2189 } else if (qid1) {
2190 qid = qid1;
2191 } else if (qid == 0)
2192 qid = rtnl_dereference(dev->qdisc)->handle;
2193
2194 /* Now qid is genuine qdisc handle consistent
2195 * both with parent and child.
2196 *
2197 * TC_H_MAJ(portid) still may be unspecified, complete it now.
2198 */
2199 if (portid)
2200 portid = TC_H_MAKE(qid, portid);
2201 } else {
2202 if (qid == 0)
2203 qid = rtnl_dereference(dev->qdisc)->handle;
2204 }
2205
2206 /* OK. Locate qdisc */
2207 q = qdisc_lookup(dev, qid);
2208 if (!q)
2209 return -ENOENT;
2210
2211 /* An check that it supports classes */
2212 cops = q->ops->cl_ops;
2213 if (cops == NULL)
2214 return -EINVAL;
2215
2216 /* Now try to get class */
2217 if (clid == 0) {
2218 if (portid == TC_H_ROOT)
2219 clid = qid;
2220 } else
2221 clid = TC_H_MAKE(qid, clid);
2222
2223 if (clid)
2224 cl = cops->find(q, clid);
2225
2226 if (cl == 0) {
2227 err = -ENOENT;
2228 if (n->nlmsg_type != RTM_NEWTCLASS ||
2229 !(n->nlmsg_flags & NLM_F_CREATE))
2230 goto out;
2231 } else {
2232 switch (n->nlmsg_type) {
2233 case RTM_NEWTCLASS:
2234 err = -EEXIST;
2235 if (n->nlmsg_flags & NLM_F_EXCL)
2236 goto out;
2237 break;
2238 case RTM_DELTCLASS:
2239 err = tclass_del_notify(net, cops, skb, n, q, cl, extack);
2240 /* Unbind the class with flilters with 0 */
2241 tc_bind_tclass(q, portid, clid, 0);
2242 goto out;
2243 case RTM_GETTCLASS:
2244 err = tclass_get_notify(net, skb, n, q, cl, extack);
2245 goto out;
2246 default:
2247 err = -EINVAL;
2248 goto out;
2249 }
2250 }
2251
2252 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
2253 NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes");
2254 return -EOPNOTSUPP;
2255 }
2256
2257 new_cl = cl;
2258 err = -EOPNOTSUPP;
2259 if (cops->change)
2260 err = cops->change(q, clid, portid, tca, &new_cl, extack);
2261 if (err == 0) {
2262 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS, extack);
2263 /* We just create a new class, need to do reverse binding. */
2264 if (cl != new_cl)
2265 tc_bind_tclass(q, portid, clid, new_cl);
2266 }
2267out:
2268 return err;
2269}
2270
2271struct qdisc_dump_args {
2272 struct qdisc_walker w;
2273 struct sk_buff *skb;
2274 struct netlink_callback *cb;
2275};
2276
2277static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
2278 struct qdisc_walker *arg)
2279{
2280 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
2281
2282 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
2283 a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2284 RTM_NEWTCLASS, NULL);
2285}
2286
2287static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
2288 struct tcmsg *tcm, struct netlink_callback *cb,
2289 int *t_p, int s_t)
2290{
2291 struct qdisc_dump_args arg;
2292
2293 if (tc_qdisc_dump_ignore(q, false) ||
2294 *t_p < s_t || !q->ops->cl_ops ||
2295 (tcm->tcm_parent &&
2296 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
2297 (*t_p)++;
2298 return 0;
2299 }
2300 if (*t_p > s_t)
2301 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
2302 arg.w.fn = qdisc_class_dump;
2303 arg.skb = skb;
2304 arg.cb = cb;
2305 arg.w.stop = 0;
2306 arg.w.skip = cb->args[1];
2307 arg.w.count = 0;
2308 q->ops->cl_ops->walk(q, &arg.w);
2309 cb->args[1] = arg.w.count;
2310 if (arg.w.stop)
2311 return -1;
2312 (*t_p)++;
2313 return 0;
2314}
2315
2316static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
2317 struct tcmsg *tcm, struct netlink_callback *cb,
2318 int *t_p, int s_t, bool recur)
2319{
2320 struct Qdisc *q;
2321 int b;
2322
2323 if (!root)
2324 return 0;
2325
2326 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
2327 return -1;
2328
2329 if (!qdisc_dev(root) || !recur)
2330 return 0;
2331
2332 if (tcm->tcm_parent) {
2333 q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent));
2334 if (q && q != root &&
2335 tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2336 return -1;
2337 return 0;
2338 }
2339 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
2340 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2341 return -1;
2342 }
2343
2344 return 0;
2345}
2346
2347static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
2348{
2349 struct tcmsg *tcm = nlmsg_data(cb->nlh);
2350 struct net *net = sock_net(skb->sk);
2351 struct netdev_queue *dev_queue;
2352 struct net_device *dev;
2353 int t, s_t;
2354
2355 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2356 return 0;
2357 dev = dev_get_by_index(net, tcm->tcm_ifindex);
2358 if (!dev)
2359 return 0;
2360
2361 s_t = cb->args[0];
2362 t = 0;
2363
2364 if (tc_dump_tclass_root(rtnl_dereference(dev->qdisc),
2365 skb, tcm, cb, &t, s_t, true) < 0)
2366 goto done;
2367
2368 dev_queue = dev_ingress_queue(dev);
2369 if (dev_queue &&
2370 tc_dump_tclass_root(rtnl_dereference(dev_queue->qdisc_sleeping),
2371 skb, tcm, cb, &t, s_t, false) < 0)
2372 goto done;
2373
2374done:
2375 cb->args[0] = t;
2376
2377 dev_put(dev);
2378 return skb->len;
2379}
2380
2381#ifdef CONFIG_PROC_FS
2382static int psched_show(struct seq_file *seq, void *v)
2383{
2384 seq_printf(seq, "%08x %08x %08x %08x\n",
2385 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
2386 1000000,
2387 (u32)NSEC_PER_SEC / hrtimer_resolution);
2388
2389 return 0;
2390}
2391
2392static int __net_init psched_net_init(struct net *net)
2393{
2394 struct proc_dir_entry *e;
2395
2396 e = proc_create_single("psched", 0, net->proc_net, psched_show);
2397 if (e == NULL)
2398 return -ENOMEM;
2399
2400 return 0;
2401}
2402
2403static void __net_exit psched_net_exit(struct net *net)
2404{
2405 remove_proc_entry("psched", net->proc_net);
2406}
2407#else
2408static int __net_init psched_net_init(struct net *net)
2409{
2410 return 0;
2411}
2412
2413static void __net_exit psched_net_exit(struct net *net)
2414{
2415}
2416#endif
2417
2418static struct pernet_operations psched_net_ops = {
2419 .init = psched_net_init,
2420 .exit = psched_net_exit,
2421};
2422
2423#if IS_ENABLED(CONFIG_MITIGATION_RETPOLINE)
2424DEFINE_STATIC_KEY_FALSE(tc_skip_wrapper);
2425#endif
2426
2427static const struct rtnl_msg_handler psched_rtnl_msg_handlers[] __initconst = {
2428 {.msgtype = RTM_NEWQDISC, .doit = tc_modify_qdisc},
2429 {.msgtype = RTM_DELQDISC, .doit = tc_get_qdisc},
2430 {.msgtype = RTM_GETQDISC, .doit = tc_get_qdisc,
2431 .dumpit = tc_dump_qdisc},
2432 {.msgtype = RTM_NEWTCLASS, .doit = tc_ctl_tclass},
2433 {.msgtype = RTM_DELTCLASS, .doit = tc_ctl_tclass},
2434 {.msgtype = RTM_GETTCLASS, .doit = tc_ctl_tclass,
2435 .dumpit = tc_dump_tclass},
2436};
2437
2438static int __init pktsched_init(void)
2439{
2440 int err;
2441
2442 err = register_pernet_subsys(&psched_net_ops);
2443 if (err) {
2444 pr_err("pktsched_init: "
2445 "cannot initialize per netns operations\n");
2446 return err;
2447 }
2448
2449 register_qdisc(&pfifo_fast_ops);
2450 register_qdisc(&pfifo_qdisc_ops);
2451 register_qdisc(&bfifo_qdisc_ops);
2452 register_qdisc(&pfifo_head_drop_qdisc_ops);
2453 register_qdisc(&mq_qdisc_ops);
2454 register_qdisc(&noqueue_qdisc_ops);
2455
2456 rtnl_register_many(psched_rtnl_msg_handlers);
2457
2458 tc_wrapper_init();
2459
2460 return 0;
2461}
2462
2463subsys_initcall(pktsched_init);