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Linux 4.8.3
[linux/fpc-iii.git] / net / sched / sch_api.c
blob12ebde84552337ec7248e56fe1a64edc0227d7ec
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
38 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
39 struct nlmsghdr *n, u32 clid,
40 struct Qdisc *old, struct Qdisc *new);
41 static 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
99 Auxiliary routines:
100
101 ---peek
102
103 like dequeue but without removing a packet from the queue
104
105 ---reset
106
107 returns qdisc to initial state: purge all buffers, clear all
108 timers, counters (except for statistics) etc.
109
110 ---init
111
112 initializes newly created qdisc.
113
114 ---destroy
115
116 destroys resources allocated by init and during lifetime of qdisc.
117
118 ---change
119
120 changes qdisc parameters.
121 */
122
123 /* Protects list of registered TC modules. It is pure SMP lock. */
124 static DEFINE_RWLOCK(qdisc_mod_lock);
125
126
127 /************************************************
128 * Queueing disciplines manipulation. *
129 ************************************************/
130
131
132 /* The list of all installed queueing disciplines. */
133
134 static struct Qdisc_ops *qdisc_base;
135
136 /* Register/unregister queueing discipline */
137
138 int register_qdisc(struct Qdisc_ops *qops)
139 {
140 struct Qdisc_ops *q, **qp;
141 int rc = -EEXIST;
142
143 write_lock(&qdisc_mod_lock);
144 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
145 if (!strcmp(qops->id, q->id))
146 goto out;
147
148 if (qops->enqueue == NULL)
149 qops->enqueue = noop_qdisc_ops.enqueue;
150 if (qops->peek == NULL) {
151 if (qops->dequeue == NULL)
152 qops->peek = noop_qdisc_ops.peek;
153 else
154 goto out_einval;
155 }
156 if (qops->dequeue == NULL)
157 qops->dequeue = noop_qdisc_ops.dequeue;
158
159 if (qops->cl_ops) {
160 const struct Qdisc_class_ops *cops = qops->cl_ops;
161
162 if (!(cops->get && cops->put && cops->walk && cops->leaf))
163 goto out_einval;
164
165 if (cops->tcf_chain && !(cops->bind_tcf && cops->unbind_tcf))
166 goto out_einval;
167 }
168
169 qops->next = NULL;
170 *qp = qops;
171 rc = 0;
172 out:
173 write_unlock(&qdisc_mod_lock);
174 return rc;
175
176 out_einval:
177 rc = -EINVAL;
178 goto out;
179 }
180 EXPORT_SYMBOL(register_qdisc);
181
182 int unregister_qdisc(struct Qdisc_ops *qops)
183 {
184 struct Qdisc_ops *q, **qp;
185 int err = -ENOENT;
186
187 write_lock(&qdisc_mod_lock);
188 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
189 if (q == qops)
190 break;
191 if (q) {
192 *qp = q->next;
193 q->next = NULL;
194 err = 0;
195 }
196 write_unlock(&qdisc_mod_lock);
197 return err;
198 }
199 EXPORT_SYMBOL(unregister_qdisc);
200
201 /* Get default qdisc if not otherwise specified */
202 void qdisc_get_default(char *name, size_t len)
203 {
204 read_lock(&qdisc_mod_lock);
205 strlcpy(name, default_qdisc_ops->id, len);
206 read_unlock(&qdisc_mod_lock);
207 }
208
209 static struct Qdisc_ops *qdisc_lookup_default(const char *name)
210 {
211 struct Qdisc_ops *q = NULL;
212
213 for (q = qdisc_base; q; q = q->next) {
214 if (!strcmp(name, q->id)) {
215 if (!try_module_get(q->owner))
216 q = NULL;
217 break;
218 }
219 }
220
221 return q;
222 }
223
224 /* Set new default qdisc to use */
225 int qdisc_set_default(const char *name)
226 {
227 const struct Qdisc_ops *ops;
228
229 if (!capable(CAP_NET_ADMIN))
230 return -EPERM;
231
232 write_lock(&qdisc_mod_lock);
233 ops = qdisc_lookup_default(name);
234 if (!ops) {
235 /* Not found, drop lock and try to load module */
236 write_unlock(&qdisc_mod_lock);
237 request_module("sch_%s", name);
238 write_lock(&qdisc_mod_lock);
239
240 ops = qdisc_lookup_default(name);
241 }
242
243 if (ops) {
244 /* Set new default */
245 module_put(default_qdisc_ops->owner);
246 default_qdisc_ops = ops;
247 }
248 write_unlock(&qdisc_mod_lock);
249
250 return ops ? 0 : -ENOENT;
251 }
252
253 /* We know handle. Find qdisc among all qdisc's attached to device
254 * (root qdisc, all its children, children of children etc.)
255 * Note: caller either uses rtnl or rcu_read_lock()
256 */
257
258 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
259 {
260 struct Qdisc *q;
261
262 if (!(root->flags & TCQ_F_BUILTIN) &&
263 root->handle == handle)
264 return root;
265
266 list_for_each_entry_rcu(q, &root->list, list) {
267 if (q->handle == handle)
268 return q;
269 }
270 return NULL;
271 }
272
273 void qdisc_list_add(struct Qdisc *q)
274 {
275 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
276 struct Qdisc *root = qdisc_dev(q)->qdisc;
277
278 WARN_ON_ONCE(root == &noop_qdisc);
279 ASSERT_RTNL();
280 list_add_tail_rcu(&q->list, &root->list);
281 }
282 }
283 EXPORT_SYMBOL(qdisc_list_add);
284
285 void qdisc_list_del(struct Qdisc *q)
286 {
287 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
288 ASSERT_RTNL();
289 list_del_rcu(&q->list);
290 }
291 }
292 EXPORT_SYMBOL(qdisc_list_del);
293
294 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
295 {
296 struct Qdisc *q;
297
298 q = qdisc_match_from_root(dev->qdisc, handle);
299 if (q)
300 goto out;
301
302 if (dev_ingress_queue(dev))
303 q = qdisc_match_from_root(
304 dev_ingress_queue(dev)->qdisc_sleeping,
305 handle);
306 out:
307 return q;
308 }
309
310 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
311 {
312 unsigned long cl;
313 struct Qdisc *leaf;
314 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
315
316 if (cops == NULL)
317 return NULL;
318 cl = cops->get(p, classid);
319
320 if (cl == 0)
321 return NULL;
322 leaf = cops->leaf(p, cl);
323 cops->put(p, cl);
324 return leaf;
325 }
326
327 /* Find queueing discipline by name */
328
329 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
330 {
331 struct Qdisc_ops *q = NULL;
332
333 if (kind) {
334 read_lock(&qdisc_mod_lock);
335 for (q = qdisc_base; q; q = q->next) {
336 if (nla_strcmp(kind, q->id) == 0) {
337 if (!try_module_get(q->owner))
338 q = NULL;
339 break;
340 }
341 }
342 read_unlock(&qdisc_mod_lock);
343 }
344 return q;
345 }
346
347 /* The linklayer setting were not transferred from iproute2, in older
348 * versions, and the rate tables lookup systems have been dropped in
349 * the kernel. To keep backward compatible with older iproute2 tc
350 * utils, we detect the linklayer setting by detecting if the rate
351 * table were modified.
352 *
353 * For linklayer ATM table entries, the rate table will be aligned to
354 * 48 bytes, thus some table entries will contain the same value. The
355 * mpu (min packet unit) is also encoded into the old rate table, thus
356 * starting from the mpu, we find low and high table entries for
357 * mapping this cell. If these entries contain the same value, when
358 * the rate tables have been modified for linklayer ATM.
359 *
360 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
361 * and then roundup to the next cell, calc the table entry one below,
362 * and compare.
363 */
364 static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
365 {
366 int low = roundup(r->mpu, 48);
367 int high = roundup(low+1, 48);
368 int cell_low = low >> r->cell_log;
369 int cell_high = (high >> r->cell_log) - 1;
370
371 /* rtab is too inaccurate at rates > 100Mbit/s */
372 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
373 pr_debug("TC linklayer: Giving up ATM detection\n");
374 return TC_LINKLAYER_ETHERNET;
375 }
376
377 if ((cell_high > cell_low) && (cell_high < 256)
378 && (rtab[cell_low] == rtab[cell_high])) {
379 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
380 cell_low, cell_high, rtab[cell_high]);
381 return TC_LINKLAYER_ATM;
382 }
383 return TC_LINKLAYER_ETHERNET;
384 }
385
386 static struct qdisc_rate_table *qdisc_rtab_list;
387
388 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct nlattr *tab)
389 {
390 struct qdisc_rate_table *rtab;
391
392 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
393 nla_len(tab) != TC_RTAB_SIZE)
394 return NULL;
395
396 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
397 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
398 !memcmp(&rtab->data, nla_data(tab), 1024)) {
399 rtab->refcnt++;
400 return rtab;
401 }
402 }
403
404 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
405 if (rtab) {
406 rtab->rate = *r;
407 rtab->refcnt = 1;
408 memcpy(rtab->data, nla_data(tab), 1024);
409 if (r->linklayer == TC_LINKLAYER_UNAWARE)
410 r->linklayer = __detect_linklayer(r, rtab->data);
411 rtab->next = qdisc_rtab_list;
412 qdisc_rtab_list = rtab;
413 }
414 return rtab;
415 }
416 EXPORT_SYMBOL(qdisc_get_rtab);
417
418 void qdisc_put_rtab(struct qdisc_rate_table *tab)
419 {
420 struct qdisc_rate_table *rtab, **rtabp;
421
422 if (!tab || --tab->refcnt)
423 return;
424
425 for (rtabp = &qdisc_rtab_list;
426 (rtab = *rtabp) != NULL;
427 rtabp = &rtab->next) {
428 if (rtab == tab) {
429 *rtabp = rtab->next;
430 kfree(rtab);
431 return;
432 }
433 }
434 }
435 EXPORT_SYMBOL(qdisc_put_rtab);
436
437 static LIST_HEAD(qdisc_stab_list);
438 static DEFINE_SPINLOCK(qdisc_stab_lock);
439
440 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
441 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
442 [TCA_STAB_DATA] = { .type = NLA_BINARY },
443 };
444
445 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
446 {
447 struct nlattr *tb[TCA_STAB_MAX + 1];
448 struct qdisc_size_table *stab;
449 struct tc_sizespec *s;
450 unsigned int tsize = 0;
451 u16 *tab = NULL;
452 int err;
453
454 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
455 if (err < 0)
456 return ERR_PTR(err);
457 if (!tb[TCA_STAB_BASE])
458 return ERR_PTR(-EINVAL);
459
460 s = nla_data(tb[TCA_STAB_BASE]);
461
462 if (s->tsize > 0) {
463 if (!tb[TCA_STAB_DATA])
464 return ERR_PTR(-EINVAL);
465 tab = nla_data(tb[TCA_STAB_DATA]);
466 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
467 }
468
469 if (tsize != s->tsize || (!tab && tsize > 0))
470 return ERR_PTR(-EINVAL);
471
472 spin_lock(&qdisc_stab_lock);
473
474 list_for_each_entry(stab, &qdisc_stab_list, list) {
475 if (memcmp(&stab->szopts, s, sizeof(*s)))
476 continue;
477 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
478 continue;
479 stab->refcnt++;
480 spin_unlock(&qdisc_stab_lock);
481 return stab;
482 }
483
484 spin_unlock(&qdisc_stab_lock);
485
486 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
487 if (!stab)
488 return ERR_PTR(-ENOMEM);
489
490 stab->refcnt = 1;
491 stab->szopts = *s;
492 if (tsize > 0)
493 memcpy(stab->data, tab, tsize * sizeof(u16));
494
495 spin_lock(&qdisc_stab_lock);
496 list_add_tail(&stab->list, &qdisc_stab_list);
497 spin_unlock(&qdisc_stab_lock);
498
499 return stab;
500 }
501
502 static void stab_kfree_rcu(struct rcu_head *head)
503 {
504 kfree(container_of(head, struct qdisc_size_table, rcu));
505 }
506
507 void qdisc_put_stab(struct qdisc_size_table *tab)
508 {
509 if (!tab)
510 return;
511
512 spin_lock(&qdisc_stab_lock);
513
514 if (--tab->refcnt == 0) {
515 list_del(&tab->list);
516 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
517 }
518
519 spin_unlock(&qdisc_stab_lock);
520 }
521 EXPORT_SYMBOL(qdisc_put_stab);
522
523 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
524 {
525 struct nlattr *nest;
526
527 nest = nla_nest_start(skb, TCA_STAB);
528 if (nest == NULL)
529 goto nla_put_failure;
530 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
531 goto nla_put_failure;
532 nla_nest_end(skb, nest);
533
534 return skb->len;
535
536 nla_put_failure:
537 return -1;
538 }
539
540 void __qdisc_calculate_pkt_len(struct sk_buff *skb, const struct qdisc_size_table *stab)
541 {
542 int pkt_len, slot;
543
544 pkt_len = skb->len + stab->szopts.overhead;
545 if (unlikely(!stab->szopts.tsize))
546 goto out;
547
548 slot = pkt_len + stab->szopts.cell_align;
549 if (unlikely(slot < 0))
550 slot = 0;
551
552 slot >>= stab->szopts.cell_log;
553 if (likely(slot < stab->szopts.tsize))
554 pkt_len = stab->data[slot];
555 else
556 pkt_len = stab->data[stab->szopts.tsize - 1] *
557 (slot / stab->szopts.tsize) +
558 stab->data[slot % stab->szopts.tsize];
559
560 pkt_len <<= stab->szopts.size_log;
561 out:
562 if (unlikely(pkt_len < 1))
563 pkt_len = 1;
564 qdisc_skb_cb(skb)->pkt_len = pkt_len;
565 }
566 EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
567
568 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
569 {
570 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
571 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
572 txt, qdisc->ops->id, qdisc->handle >> 16);
573 qdisc->flags |= TCQ_F_WARN_NONWC;
574 }
575 }
576 EXPORT_SYMBOL(qdisc_warn_nonwc);
577
578 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
579 {
580 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
581 timer);
582
583 rcu_read_lock();
584 __netif_schedule(qdisc_root(wd->qdisc));
585 rcu_read_unlock();
586
587 return HRTIMER_NORESTART;
588 }
589
590 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
591 {
592 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
593 wd->timer.function = qdisc_watchdog;
594 wd->qdisc = qdisc;
595 }
596 EXPORT_SYMBOL(qdisc_watchdog_init);
597
598 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
599 {
600 if (test_bit(__QDISC_STATE_DEACTIVATED,
601 &qdisc_root_sleeping(wd->qdisc)->state))
602 return;
603
604 if (wd->last_expires == expires)
605 return;
606
607 wd->last_expires = expires;
608 hrtimer_start(&wd->timer,
609 ns_to_ktime(expires),
610 HRTIMER_MODE_ABS_PINNED);
611 }
612 EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
613
614 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
615 {
616 hrtimer_cancel(&wd->timer);
617 }
618 EXPORT_SYMBOL(qdisc_watchdog_cancel);
619
620 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
621 {
622 unsigned int size = n * sizeof(struct hlist_head), i;
623 struct hlist_head *h;
624
625 if (size <= PAGE_SIZE)
626 h = kmalloc(size, GFP_KERNEL);
627 else
628 h = (struct hlist_head *)
629 __get_free_pages(GFP_KERNEL, get_order(size));
630
631 if (h != NULL) {
632 for (i = 0; i < n; i++)
633 INIT_HLIST_HEAD(&h[i]);
634 }
635 return h;
636 }
637
638 static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
639 {
640 unsigned int size = n * sizeof(struct hlist_head);
641
642 if (size <= PAGE_SIZE)
643 kfree(h);
644 else
645 free_pages((unsigned long)h, get_order(size));
646 }
647
648 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
649 {
650 struct Qdisc_class_common *cl;
651 struct hlist_node *next;
652 struct hlist_head *nhash, *ohash;
653 unsigned int nsize, nmask, osize;
654 unsigned int i, h;
655
656 /* Rehash when load factor exceeds 0.75 */
657 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
658 return;
659 nsize = clhash->hashsize * 2;
660 nmask = nsize - 1;
661 nhash = qdisc_class_hash_alloc(nsize);
662 if (nhash == NULL)
663 return;
664
665 ohash = clhash->hash;
666 osize = clhash->hashsize;
667
668 sch_tree_lock(sch);
669 for (i = 0; i < osize; i++) {
670 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
671 h = qdisc_class_hash(cl->classid, nmask);
672 hlist_add_head(&cl->hnode, &nhash[h]);
673 }
674 }
675 clhash->hash = nhash;
676 clhash->hashsize = nsize;
677 clhash->hashmask = nmask;
678 sch_tree_unlock(sch);
679
680 qdisc_class_hash_free(ohash, osize);
681 }
682 EXPORT_SYMBOL(qdisc_class_hash_grow);
683
684 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
685 {
686 unsigned int size = 4;
687
688 clhash->hash = qdisc_class_hash_alloc(size);
689 if (clhash->hash == NULL)
690 return -ENOMEM;
691 clhash->hashsize = size;
692 clhash->hashmask = size - 1;
693 clhash->hashelems = 0;
694 return 0;
695 }
696 EXPORT_SYMBOL(qdisc_class_hash_init);
697
698 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
699 {
700 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
701 }
702 EXPORT_SYMBOL(qdisc_class_hash_destroy);
703
704 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
705 struct Qdisc_class_common *cl)
706 {
707 unsigned int h;
708
709 INIT_HLIST_NODE(&cl->hnode);
710 h = qdisc_class_hash(cl->classid, clhash->hashmask);
711 hlist_add_head(&cl->hnode, &clhash->hash[h]);
712 clhash->hashelems++;
713 }
714 EXPORT_SYMBOL(qdisc_class_hash_insert);
715
716 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
717 struct Qdisc_class_common *cl)
718 {
719 hlist_del(&cl->hnode);
720 clhash->hashelems--;
721 }
722 EXPORT_SYMBOL(qdisc_class_hash_remove);
723
724 /* Allocate an unique handle from space managed by kernel
725 * Possible range is [8000-FFFF]:0000 (0x8000 values)
726 */
727 static u32 qdisc_alloc_handle(struct net_device *dev)
728 {
729 int i = 0x8000;
730 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
731
732 do {
733 autohandle += TC_H_MAKE(0x10000U, 0);
734 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
735 autohandle = TC_H_MAKE(0x80000000U, 0);
736 if (!qdisc_lookup(dev, autohandle))
737 return autohandle;
738 cond_resched();
739 } while (--i > 0);
740
741 return 0;
742 }
743
744 void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,
745 unsigned int len)
746 {
747 const struct Qdisc_class_ops *cops;
748 unsigned long cl;
749 u32 parentid;
750 int drops;
751
752 if (n == 0 && len == 0)
753 return;
754 drops = max_t(int, n, 0);
755 rcu_read_lock();
756 while ((parentid = sch->parent)) {
757 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
758 break;
759
760 if (sch->flags & TCQ_F_NOPARENT)
761 break;
762 /* TODO: perform the search on a per txq basis */
763 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
764 if (sch == NULL) {
765 WARN_ON_ONCE(parentid != TC_H_ROOT);
766 break;
767 }
768 cops = sch->ops->cl_ops;
769 if (cops->qlen_notify) {
770 cl = cops->get(sch, parentid);
771 cops->qlen_notify(sch, cl);
772 cops->put(sch, cl);
773 }
774 sch->q.qlen -= n;
775 sch->qstats.backlog -= len;
776 __qdisc_qstats_drop(sch, drops);
777 }
778 rcu_read_unlock();
779 }
780 EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
781
782 static void notify_and_destroy(struct net *net, struct sk_buff *skb,
783 struct nlmsghdr *n, u32 clid,
784 struct Qdisc *old, struct Qdisc *new)
785 {
786 if (new || old)
787 qdisc_notify(net, skb, n, clid, old, new);
788
789 if (old)
790 qdisc_destroy(old);
791 }
792
793 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
794 * to device "dev".
795 *
796 * When appropriate send a netlink notification using 'skb'
797 * and "n".
798 *
799 * On success, destroy old qdisc.
800 */
801
802 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
803 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
804 struct Qdisc *new, struct Qdisc *old)
805 {
806 struct Qdisc *q = old;
807 struct net *net = dev_net(dev);
808 int err = 0;
809
810 if (parent == NULL) {
811 unsigned int i, num_q, ingress;
812
813 ingress = 0;
814 num_q = dev->num_tx_queues;
815 if ((q && q->flags & TCQ_F_INGRESS) ||
816 (new && new->flags & TCQ_F_INGRESS)) {
817 num_q = 1;
818 ingress = 1;
819 if (!dev_ingress_queue(dev))
820 return -ENOENT;
821 }
822
823 if (dev->flags & IFF_UP)
824 dev_deactivate(dev);
825
826 if (new && new->ops->attach)
827 goto skip;
828
829 for (i = 0; i < num_q; i++) {
830 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
831
832 if (!ingress)
833 dev_queue = netdev_get_tx_queue(dev, i);
834
835 old = dev_graft_qdisc(dev_queue, new);
836 if (new && i > 0)
837 atomic_inc(&new->refcnt);
838
839 if (!ingress)
840 qdisc_destroy(old);
841 }
842
843 skip:
844 if (!ingress) {
845 notify_and_destroy(net, skb, n, classid,
846 dev->qdisc, new);
847 if (new && !new->ops->attach)
848 atomic_inc(&new->refcnt);
849 dev->qdisc = new ? : &noop_qdisc;
850
851 if (new && new->ops->attach)
852 new->ops->attach(new);
853 } else {
854 notify_and_destroy(net, skb, n, classid, old, new);
855 }
856
857 if (dev->flags & IFF_UP)
858 dev_activate(dev);
859 } else {
860 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
861
862 err = -EOPNOTSUPP;
863 if (cops && cops->graft) {
864 unsigned long cl = cops->get(parent, classid);
865 if (cl) {
866 err = cops->graft(parent, cl, new, &old);
867 cops->put(parent, cl);
868 } else
869 err = -ENOENT;
870 }
871 if (!err)
872 notify_and_destroy(net, skb, n, classid, old, new);
873 }
874 return err;
875 }
876
877 /* lockdep annotation is needed for ingress; egress gets it only for name */
878 static struct lock_class_key qdisc_tx_lock;
879 static struct lock_class_key qdisc_rx_lock;
880
881 /*
882 Allocate and initialize new qdisc.
883
884 Parameters are passed via opt.
885 */
886
887 static struct Qdisc *
888 qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
889 struct Qdisc *p, u32 parent, u32 handle,
890 struct nlattr **tca, int *errp)
891 {
892 int err;
893 struct nlattr *kind = tca[TCA_KIND];
894 struct Qdisc *sch;
895 struct Qdisc_ops *ops;
896 struct qdisc_size_table *stab;
897
898 ops = qdisc_lookup_ops(kind);
899 #ifdef CONFIG_MODULES
900 if (ops == NULL && kind != NULL) {
901 char name[IFNAMSIZ];
902 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
903 /* We dropped the RTNL semaphore in order to
904 * perform the module load. So, even if we
905 * succeeded in loading the module we have to
906 * tell the caller to replay the request. We
907 * indicate this using -EAGAIN.
908 * We replay the request because the device may
909 * go away in the mean time.
910 */
911 rtnl_unlock();
912 request_module("sch_%s", name);
913 rtnl_lock();
914 ops = qdisc_lookup_ops(kind);
915 if (ops != NULL) {
916 /* We will try again qdisc_lookup_ops,
917 * so don't keep a reference.
918 */
919 module_put(ops->owner);
920 err = -EAGAIN;
921 goto err_out;
922 }
923 }
924 }
925 #endif
926
927 err = -ENOENT;
928 if (ops == NULL)
929 goto err_out;
930
931 sch = qdisc_alloc(dev_queue, ops);
932 if (IS_ERR(sch)) {
933 err = PTR_ERR(sch);
934 goto err_out2;
935 }
936
937 sch->parent = parent;
938
939 if (handle == TC_H_INGRESS) {
940 sch->flags |= TCQ_F_INGRESS;
941 handle = TC_H_MAKE(TC_H_INGRESS, 0);
942 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
943 } else {
944 if (handle == 0) {
945 handle = qdisc_alloc_handle(dev);
946 err = -ENOMEM;
947 if (handle == 0)
948 goto err_out3;
949 }
950 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
951 if (!netif_is_multiqueue(dev))
952 sch->flags |= TCQ_F_ONETXQUEUE;
953 }
954
955 sch->handle = handle;
956
957 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
958 if (qdisc_is_percpu_stats(sch)) {
959 sch->cpu_bstats =
960 netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
961 if (!sch->cpu_bstats)
962 goto err_out4;
963
964 sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
965 if (!sch->cpu_qstats)
966 goto err_out4;
967 }
968
969 if (tca[TCA_STAB]) {
970 stab = qdisc_get_stab(tca[TCA_STAB]);
971 if (IS_ERR(stab)) {
972 err = PTR_ERR(stab);
973 goto err_out4;
974 }
975 rcu_assign_pointer(sch->stab, stab);
976 }
977 if (tca[TCA_RATE]) {
978 seqcount_t *running;
979
980 err = -EOPNOTSUPP;
981 if (sch->flags & TCQ_F_MQROOT)
982 goto err_out4;
983
984 if ((sch->parent != TC_H_ROOT) &&
985 !(sch->flags & TCQ_F_INGRESS) &&
986 (!p || !(p->flags & TCQ_F_MQROOT)))
987 running = qdisc_root_sleeping_running(sch);
988 else
989 running = &sch->running;
990
991 err = gen_new_estimator(&sch->bstats,
992 sch->cpu_bstats,
993 &sch->rate_est,
994 NULL,
995 running,
996 tca[TCA_RATE]);
997 if (err)
998 goto err_out4;
999 }
1000
1001 qdisc_list_add(sch);
1002
1003 return sch;
1004 }
1005 err_out3:
1006 dev_put(dev);
1007 kfree((char *) sch - sch->padded);
1008 err_out2:
1009 module_put(ops->owner);
1010 err_out:
1011 *errp = err;
1012 return NULL;
1013
1014 err_out4:
1015 free_percpu(sch->cpu_bstats);
1016 free_percpu(sch->cpu_qstats);
1017 /*
1018 * Any broken qdiscs that would require a ops->reset() here?
1019 * The qdisc was never in action so it shouldn't be necessary.
1020 */
1021 qdisc_put_stab(rtnl_dereference(sch->stab));
1022 if (ops->destroy)
1023 ops->destroy(sch);
1024 goto err_out3;
1025 }
1026
1027 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
1028 {
1029 struct qdisc_size_table *ostab, *stab = NULL;
1030 int err = 0;
1031
1032 if (tca[TCA_OPTIONS]) {
1033 if (sch->ops->change == NULL)
1034 return -EINVAL;
1035 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
1036 if (err)
1037 return err;
1038 }
1039
1040 if (tca[TCA_STAB]) {
1041 stab = qdisc_get_stab(tca[TCA_STAB]);
1042 if (IS_ERR(stab))
1043 return PTR_ERR(stab);
1044 }
1045
1046 ostab = rtnl_dereference(sch->stab);
1047 rcu_assign_pointer(sch->stab, stab);
1048 qdisc_put_stab(ostab);
1049
1050 if (tca[TCA_RATE]) {
1051 /* NB: ignores errors from replace_estimator
1052 because change can't be undone. */
1053 if (sch->flags & TCQ_F_MQROOT)
1054 goto out;
1055 gen_replace_estimator(&sch->bstats,
1056 sch->cpu_bstats,
1057 &sch->rate_est,
1058 NULL,
1059 qdisc_root_sleeping_running(sch),
1060 tca[TCA_RATE]);
1061 }
1062 out:
1063 return 0;
1064 }
1065
1066 struct check_loop_arg {
1067 struct qdisc_walker w;
1068 struct Qdisc *p;
1069 int depth;
1070 };
1071
1072 static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
1073
1074 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1075 {
1076 struct check_loop_arg arg;
1077
1078 if (q->ops->cl_ops == NULL)
1079 return 0;
1080
1081 arg.w.stop = arg.w.skip = arg.w.count = 0;
1082 arg.w.fn = check_loop_fn;
1083 arg.depth = depth;
1084 arg.p = p;
1085 q->ops->cl_ops->walk(q, &arg.w);
1086 return arg.w.stop ? -ELOOP : 0;
1087 }
1088
1089 static int
1090 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1091 {
1092 struct Qdisc *leaf;
1093 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1094 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1095
1096 leaf = cops->leaf(q, cl);
1097 if (leaf) {
1098 if (leaf == arg->p || arg->depth > 7)
1099 return -ELOOP;
1100 return check_loop(leaf, arg->p, arg->depth + 1);
1101 }
1102 return 0;
1103 }
1104
1105 /*
1106 * Delete/get qdisc.
1107 */
1108
1109 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1110 {
1111 struct net *net = sock_net(skb->sk);
1112 struct tcmsg *tcm = nlmsg_data(n);
1113 struct nlattr *tca[TCA_MAX + 1];
1114 struct net_device *dev;
1115 u32 clid;
1116 struct Qdisc *q = NULL;
1117 struct Qdisc *p = NULL;
1118 int err;
1119
1120 if ((n->nlmsg_type != RTM_GETQDISC) &&
1121 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1122 return -EPERM;
1123
1124 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1125 if (err < 0)
1126 return err;
1127
1128 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1129 if (!dev)
1130 return -ENODEV;
1131
1132 clid = tcm->tcm_parent;
1133 if (clid) {
1134 if (clid != TC_H_ROOT) {
1135 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1136 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1137 if (!p)
1138 return -ENOENT;
1139 q = qdisc_leaf(p, clid);
1140 } else if (dev_ingress_queue(dev)) {
1141 q = dev_ingress_queue(dev)->qdisc_sleeping;
1142 }
1143 } else {
1144 q = dev->qdisc;
1145 }
1146 if (!q)
1147 return -ENOENT;
1148
1149 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1150 return -EINVAL;
1151 } else {
1152 q = qdisc_lookup(dev, tcm->tcm_handle);
1153 if (!q)
1154 return -ENOENT;
1155 }
1156
1157 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1158 return -EINVAL;
1159
1160 if (n->nlmsg_type == RTM_DELQDISC) {
1161 if (!clid)
1162 return -EINVAL;
1163 if (q->handle == 0)
1164 return -ENOENT;
1165 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1166 if (err != 0)
1167 return err;
1168 } else {
1169 qdisc_notify(net, skb, n, clid, NULL, q);
1170 }
1171 return 0;
1172 }
1173
1174 /*
1175 * Create/change qdisc.
1176 */
1177
1178 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1179 {
1180 struct net *net = sock_net(skb->sk);
1181 struct tcmsg *tcm;
1182 struct nlattr *tca[TCA_MAX + 1];
1183 struct net_device *dev;
1184 u32 clid;
1185 struct Qdisc *q, *p;
1186 int err;
1187
1188 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1189 return -EPERM;
1190
1191 replay:
1192 /* Reinit, just in case something touches this. */
1193 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1194 if (err < 0)
1195 return err;
1196
1197 tcm = nlmsg_data(n);
1198 clid = tcm->tcm_parent;
1199 q = p = NULL;
1200
1201 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1202 if (!dev)
1203 return -ENODEV;
1204
1205
1206 if (clid) {
1207 if (clid != TC_H_ROOT) {
1208 if (clid != TC_H_INGRESS) {
1209 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1210 if (!p)
1211 return -ENOENT;
1212 q = qdisc_leaf(p, clid);
1213 } else if (dev_ingress_queue_create(dev)) {
1214 q = dev_ingress_queue(dev)->qdisc_sleeping;
1215 }
1216 } else {
1217 q = dev->qdisc;
1218 }
1219
1220 /* It may be default qdisc, ignore it */
1221 if (q && q->handle == 0)
1222 q = NULL;
1223
1224 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1225 if (tcm->tcm_handle) {
1226 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1227 return -EEXIST;
1228 if (TC_H_MIN(tcm->tcm_handle))
1229 return -EINVAL;
1230 q = qdisc_lookup(dev, tcm->tcm_handle);
1231 if (!q)
1232 goto create_n_graft;
1233 if (n->nlmsg_flags & NLM_F_EXCL)
1234 return -EEXIST;
1235 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1236 return -EINVAL;
1237 if (q == p ||
1238 (p && check_loop(q, p, 0)))
1239 return -ELOOP;
1240 atomic_inc(&q->refcnt);
1241 goto graft;
1242 } else {
1243 if (!q)
1244 goto create_n_graft;
1245
1246 /* This magic test requires explanation.
1247 *
1248 * We know, that some child q is already
1249 * attached to this parent and have choice:
1250 * either to change it or to create/graft new one.
1251 *
1252 * 1. We are allowed to create/graft only
1253 * if CREATE and REPLACE flags are set.
1254 *
1255 * 2. If EXCL is set, requestor wanted to say,
1256 * that qdisc tcm_handle is not expected
1257 * to exist, so that we choose create/graft too.
1258 *
1259 * 3. The last case is when no flags are set.
1260 * Alas, it is sort of hole in API, we
1261 * cannot decide what to do unambiguously.
1262 * For now we select create/graft, if
1263 * user gave KIND, which does not match existing.
1264 */
1265 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1266 (n->nlmsg_flags & NLM_F_REPLACE) &&
1267 ((n->nlmsg_flags & NLM_F_EXCL) ||
1268 (tca[TCA_KIND] &&
1269 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1270 goto create_n_graft;
1271 }
1272 }
1273 } else {
1274 if (!tcm->tcm_handle)
1275 return -EINVAL;
1276 q = qdisc_lookup(dev, tcm->tcm_handle);
1277 }
1278
1279 /* Change qdisc parameters */
1280 if (q == NULL)
1281 return -ENOENT;
1282 if (n->nlmsg_flags & NLM_F_EXCL)
1283 return -EEXIST;
1284 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1285 return -EINVAL;
1286 err = qdisc_change(q, tca);
1287 if (err == 0)
1288 qdisc_notify(net, skb, n, clid, NULL, q);
1289 return err;
1290
1291 create_n_graft:
1292 if (!(n->nlmsg_flags & NLM_F_CREATE))
1293 return -ENOENT;
1294 if (clid == TC_H_INGRESS) {
1295 if (dev_ingress_queue(dev))
1296 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1297 tcm->tcm_parent, tcm->tcm_parent,
1298 tca, &err);
1299 else
1300 err = -ENOENT;
1301 } else {
1302 struct netdev_queue *dev_queue;
1303
1304 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1305 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1306 else if (p)
1307 dev_queue = p->dev_queue;
1308 else
1309 dev_queue = netdev_get_tx_queue(dev, 0);
1310
1311 q = qdisc_create(dev, dev_queue, p,
1312 tcm->tcm_parent, tcm->tcm_handle,
1313 tca, &err);
1314 }
1315 if (q == NULL) {
1316 if (err == -EAGAIN)
1317 goto replay;
1318 return err;
1319 }
1320
1321 graft:
1322 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1323 if (err) {
1324 if (q)
1325 qdisc_destroy(q);
1326 return err;
1327 }
1328
1329 return 0;
1330 }
1331
1332 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1333 u32 portid, u32 seq, u16 flags, int event)
1334 {
1335 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
1336 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
1337 struct tcmsg *tcm;
1338 struct nlmsghdr *nlh;
1339 unsigned char *b = skb_tail_pointer(skb);
1340 struct gnet_dump d;
1341 struct qdisc_size_table *stab;
1342 __u32 qlen;
1343
1344 cond_resched();
1345 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1346 if (!nlh)
1347 goto out_nlmsg_trim;
1348 tcm = nlmsg_data(nlh);
1349 tcm->tcm_family = AF_UNSPEC;
1350 tcm->tcm__pad1 = 0;
1351 tcm->tcm__pad2 = 0;
1352 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1353 tcm->tcm_parent = clid;
1354 tcm->tcm_handle = q->handle;
1355 tcm->tcm_info = atomic_read(&q->refcnt);
1356 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1357 goto nla_put_failure;
1358 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1359 goto nla_put_failure;
1360 qlen = q->q.qlen;
1361
1362 stab = rtnl_dereference(q->stab);
1363 if (stab && qdisc_dump_stab(skb, stab) < 0)
1364 goto nla_put_failure;
1365
1366 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1367 NULL, &d, TCA_PAD) < 0)
1368 goto nla_put_failure;
1369
1370 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1371 goto nla_put_failure;
1372
1373 if (qdisc_is_percpu_stats(q)) {
1374 cpu_bstats = q->cpu_bstats;
1375 cpu_qstats = q->cpu_qstats;
1376 }
1377
1378 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(q),
1379 &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
1390 out_nlmsg_trim:
1391 nla_put_failure:
1392 nlmsg_trim(skb, b);
1393 return -1;
1394 }
1395
1396 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1397 {
1398 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1399 }
1400
1401 static 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
1427 err_out:
1428 kfree_skb(skb);
1429 return -EINVAL;
1430 }
1431
1432 static 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
1464 out:
1465 *q_idx_p = q_idx;
1466 return ret;
1467 done:
1468 ret = -1;
1469 goto out;
1470 }
1471
1472 static 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
1502 cont:
1503 idx++;
1504 }
1505
1506 done:
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
1521 static 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
1646 out:
1647 if (cl)
1648 cops->put(q, cl);
1649
1650 return err;
1651 }
1652
1653
1654 static 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 NULL, &d, TCA_PAD) < 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
1694 out_nlmsg_trim:
1695 nla_put_failure:
1696 nlmsg_trim(skb, b);
1697 return -1;
1698 }
1699
1700 static 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
1720 struct qdisc_dump_args {
1721 struct qdisc_walker w;
1722 struct sk_buff *skb;
1723 struct netlink_callback *cb;
1724 };
1725
1726 static 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
1734 static 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
1763 static 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
1783 static 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
1809 done:
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 */
1820 int 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
1828 reclassify:
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
1848 reset:
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 }
1861 EXPORT_SYMBOL(tc_classify);
1862
1863 bool 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
1874 void 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 }
1883 EXPORT_SYMBOL(tcf_destroy_chain);
1884
1885 #ifdef CONFIG_PROC_FS
1886 static 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
1896 static int psched_open(struct inode *inode, struct file *file)
1897 {
1898 return single_open(file, psched_show, NULL);
1899 }
1900
1901 static 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
1909 static 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
1920 static void __net_exit psched_net_exit(struct net *net)
1921 {
1922 remove_proc_entry("psched", net->proc_net);
1923 }
1924 #else
1925 static int __net_init psched_net_init(struct net *net)
1926 {
1927 return 0;
1928 }
1929
1930 static void __net_exit psched_net_exit(struct net *net)
1931 {
1932 }
1933 #endif
1934
1935 static struct pernet_operations psched_net_ops = {
1936 .init = psched_net_init,
1937 .exit = psched_net_exit,
1938 };
1939
1940 static 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
1968 subsys_initcall(pktsched_init);
Linux with added FPC-III support