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iio: magnetometer: ak8974: Fix runtime PM imbalance on error
[linux/fpc-iii.git] / net / sched / sch_api.c
blob912ed9b901ac985ff2bd09d174358a2d5db3e7e9
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 #include <linux/hashtable.h>
33
34 #include <net/net_namespace.h>
35 #include <net/sock.h>
36 #include <net/netlink.h>
37 #include <net/pkt_sched.h>
38
39 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
40 struct nlmsghdr *n, u32 clid,
41 struct Qdisc *old, struct Qdisc *new);
42 static int tclass_notify(struct net *net, struct sk_buff *oskb,
43 struct nlmsghdr *n, struct Qdisc *q,
44 unsigned long cl, int event);
45
46 /*
47
48 Short review.
49 -------------
50
51 This file consists of two interrelated parts:
52
53 1. queueing disciplines manager frontend.
54 2. traffic classes manager frontend.
55
56 Generally, queueing discipline ("qdisc") is a black box,
57 which is able to enqueue packets and to dequeue them (when
58 device is ready to send something) in order and at times
59 determined by algorithm hidden in it.
60
61 qdisc's are divided to two categories:
62 - "queues", which have no internal structure visible from outside.
63 - "schedulers", which split all the packets to "traffic classes",
64 using "packet classifiers" (look at cls_api.c)
65
66 In turn, classes may have child qdiscs (as rule, queues)
67 attached to them etc. etc. etc.
68
69 The goal of the routines in this file is to translate
70 information supplied by user in the form of handles
71 to more intelligible for kernel form, to make some sanity
72 checks and part of work, which is common to all qdiscs
73 and to provide rtnetlink notifications.
74
75 All real intelligent work is done inside qdisc modules.
76
77
78
79 Every discipline has two major routines: enqueue and dequeue.
80
81 ---dequeue
82
83 dequeue usually returns a skb to send. It is allowed to return NULL,
84 but it does not mean that queue is empty, it just means that
85 discipline does not want to send anything this time.
86 Queue is really empty if q->q.qlen == 0.
87 For complicated disciplines with multiple queues q->q is not
88 real packet queue, but however q->q.qlen must be valid.
89
90 ---enqueue
91
92 enqueue returns 0, if packet was enqueued successfully.
93 If packet (this one or another one) was dropped, it returns
94 not zero error code.
95 NET_XMIT_DROP - this packet dropped
96 Expected action: do not backoff, but wait until queue will clear.
97 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
98 Expected action: backoff or ignore
99
100 Auxiliary routines:
101
102 ---peek
103
104 like dequeue but without removing a packet from the queue
105
106 ---reset
107
108 returns qdisc to initial state: purge all buffers, clear all
109 timers, counters (except for statistics) etc.
110
111 ---init
112
113 initializes newly created qdisc.
114
115 ---destroy
116
117 destroys resources allocated by init and during lifetime of qdisc.
118
119 ---change
120
121 changes qdisc parameters.
122 */
123
124 /* Protects list of registered TC modules. It is pure SMP lock. */
125 static DEFINE_RWLOCK(qdisc_mod_lock);
126
127
128 /************************************************
129 * Queueing disciplines manipulation. *
130 ************************************************/
131
132
133 /* The list of all installed queueing disciplines. */
134
135 static struct Qdisc_ops *qdisc_base;
136
137 /* Register/unregister queueing discipline */
138
139 int register_qdisc(struct Qdisc_ops *qops)
140 {
141 struct Qdisc_ops *q, **qp;
142 int rc = -EEXIST;
143
144 write_lock(&qdisc_mod_lock);
145 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
146 if (!strcmp(qops->id, q->id))
147 goto out;
148
149 if (qops->enqueue == NULL)
150 qops->enqueue = noop_qdisc_ops.enqueue;
151 if (qops->peek == NULL) {
152 if (qops->dequeue == NULL)
153 qops->peek = noop_qdisc_ops.peek;
154 else
155 goto out_einval;
156 }
157 if (qops->dequeue == NULL)
158 qops->dequeue = noop_qdisc_ops.dequeue;
159
160 if (qops->cl_ops) {
161 const struct Qdisc_class_ops *cops = qops->cl_ops;
162
163 if (!(cops->get && cops->put && cops->walk && cops->leaf))
164 goto out_einval;
165
166 if (cops->tcf_chain && !(cops->bind_tcf && cops->unbind_tcf))
167 goto out_einval;
168 }
169
170 qops->next = NULL;
171 *qp = qops;
172 rc = 0;
173 out:
174 write_unlock(&qdisc_mod_lock);
175 return rc;
176
177 out_einval:
178 rc = -EINVAL;
179 goto out;
180 }
181 EXPORT_SYMBOL(register_qdisc);
182
183 int unregister_qdisc(struct Qdisc_ops *qops)
184 {
185 struct Qdisc_ops *q, **qp;
186 int err = -ENOENT;
187
188 write_lock(&qdisc_mod_lock);
189 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
190 if (q == qops)
191 break;
192 if (q) {
193 *qp = q->next;
194 q->next = NULL;
195 err = 0;
196 }
197 write_unlock(&qdisc_mod_lock);
198 return err;
199 }
200 EXPORT_SYMBOL(unregister_qdisc);
201
202 /* Get default qdisc if not otherwise specified */
203 void qdisc_get_default(char *name, size_t len)
204 {
205 read_lock(&qdisc_mod_lock);
206 strlcpy(name, default_qdisc_ops->id, len);
207 read_unlock(&qdisc_mod_lock);
208 }
209
210 static struct Qdisc_ops *qdisc_lookup_default(const char *name)
211 {
212 struct Qdisc_ops *q = NULL;
213
214 for (q = qdisc_base; q; q = q->next) {
215 if (!strcmp(name, q->id)) {
216 if (!try_module_get(q->owner))
217 q = NULL;
218 break;
219 }
220 }
221
222 return q;
223 }
224
225 /* Set new default qdisc to use */
226 int qdisc_set_default(const char *name)
227 {
228 const struct Qdisc_ops *ops;
229
230 if (!capable(CAP_NET_ADMIN))
231 return -EPERM;
232
233 write_lock(&qdisc_mod_lock);
234 ops = qdisc_lookup_default(name);
235 if (!ops) {
236 /* Not found, drop lock and try to load module */
237 write_unlock(&qdisc_mod_lock);
238 request_module("sch_%s", name);
239 write_lock(&qdisc_mod_lock);
240
241 ops = qdisc_lookup_default(name);
242 }
243
244 if (ops) {
245 /* Set new default */
246 module_put(default_qdisc_ops->owner);
247 default_qdisc_ops = ops;
248 }
249 write_unlock(&qdisc_mod_lock);
250
251 return ops ? 0 : -ENOENT;
252 }
253
254 /* We know handle. Find qdisc among all qdisc's attached to device
255 * (root qdisc, all its children, children of children etc.)
256 * Note: caller either uses rtnl or rcu_read_lock()
257 */
258
259 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
260 {
261 struct Qdisc *q;
262
263 if (!qdisc_dev(root))
264 return (root->handle == handle ? root : NULL);
265
266 if (!(root->flags & TCQ_F_BUILTIN) &&
267 root->handle == handle)
268 return root;
269
270 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle) {
271 if (q->handle == handle)
272 return q;
273 }
274 return NULL;
275 }
276
277 void qdisc_hash_add(struct Qdisc *q)
278 {
279 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
280 ASSERT_RTNL();
281 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
282 }
283 }
284 EXPORT_SYMBOL(qdisc_hash_add);
285
286 void qdisc_hash_del(struct Qdisc *q)
287 {
288 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
289 ASSERT_RTNL();
290 hash_del_rcu(&q->hash);
291 }
292 }
293 EXPORT_SYMBOL(qdisc_hash_del);
294
295 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
296 {
297 struct Qdisc *q;
298
299 if (!handle)
300 return NULL;
301 q = qdisc_match_from_root(dev->qdisc, handle);
302 if (q)
303 goto out;
304
305 if (dev_ingress_queue(dev))
306 q = qdisc_match_from_root(
307 dev_ingress_queue(dev)->qdisc_sleeping,
308 handle);
309 out:
310 return q;
311 }
312
313 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
314 {
315 unsigned long cl;
316 struct Qdisc *leaf;
317 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
318
319 if (cops == NULL)
320 return NULL;
321 cl = cops->get(p, classid);
322
323 if (cl == 0)
324 return NULL;
325 leaf = cops->leaf(p, cl);
326 cops->put(p, cl);
327 return leaf;
328 }
329
330 /* Find queueing discipline by name */
331
332 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
333 {
334 struct Qdisc_ops *q = NULL;
335
336 if (kind) {
337 read_lock(&qdisc_mod_lock);
338 for (q = qdisc_base; q; q = q->next) {
339 if (nla_strcmp(kind, q->id) == 0) {
340 if (!try_module_get(q->owner))
341 q = NULL;
342 break;
343 }
344 }
345 read_unlock(&qdisc_mod_lock);
346 }
347 return q;
348 }
349
350 /* The linklayer setting were not transferred from iproute2, in older
351 * versions, and the rate tables lookup systems have been dropped in
352 * the kernel. To keep backward compatible with older iproute2 tc
353 * utils, we detect the linklayer setting by detecting if the rate
354 * table were modified.
355 *
356 * For linklayer ATM table entries, the rate table will be aligned to
357 * 48 bytes, thus some table entries will contain the same value. The
358 * mpu (min packet unit) is also encoded into the old rate table, thus
359 * starting from the mpu, we find low and high table entries for
360 * mapping this cell. If these entries contain the same value, when
361 * the rate tables have been modified for linklayer ATM.
362 *
363 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
364 * and then roundup to the next cell, calc the table entry one below,
365 * and compare.
366 */
367 static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
368 {
369 int low = roundup(r->mpu, 48);
370 int high = roundup(low+1, 48);
371 int cell_low = low >> r->cell_log;
372 int cell_high = (high >> r->cell_log) - 1;
373
374 /* rtab is too inaccurate at rates > 100Mbit/s */
375 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
376 pr_debug("TC linklayer: Giving up ATM detection\n");
377 return TC_LINKLAYER_ETHERNET;
378 }
379
380 if ((cell_high > cell_low) && (cell_high < 256)
381 && (rtab[cell_low] == rtab[cell_high])) {
382 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
383 cell_low, cell_high, rtab[cell_high]);
384 return TC_LINKLAYER_ATM;
385 }
386 return TC_LINKLAYER_ETHERNET;
387 }
388
389 static struct qdisc_rate_table *qdisc_rtab_list;
390
391 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
392 struct nlattr *tab)
393 {
394 struct qdisc_rate_table *rtab;
395
396 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
397 nla_len(tab) != TC_RTAB_SIZE)
398 return NULL;
399
400 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
401 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
402 !memcmp(&rtab->data, nla_data(tab), 1024)) {
403 rtab->refcnt++;
404 return rtab;
405 }
406 }
407
408 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
409 if (rtab) {
410 rtab->rate = *r;
411 rtab->refcnt = 1;
412 memcpy(rtab->data, nla_data(tab), 1024);
413 if (r->linklayer == TC_LINKLAYER_UNAWARE)
414 r->linklayer = __detect_linklayer(r, rtab->data);
415 rtab->next = qdisc_rtab_list;
416 qdisc_rtab_list = rtab;
417 }
418 return rtab;
419 }
420 EXPORT_SYMBOL(qdisc_get_rtab);
421
422 void qdisc_put_rtab(struct qdisc_rate_table *tab)
423 {
424 struct qdisc_rate_table *rtab, **rtabp;
425
426 if (!tab || --tab->refcnt)
427 return;
428
429 for (rtabp = &qdisc_rtab_list;
430 (rtab = *rtabp) != NULL;
431 rtabp = &rtab->next) {
432 if (rtab == tab) {
433 *rtabp = rtab->next;
434 kfree(rtab);
435 return;
436 }
437 }
438 }
439 EXPORT_SYMBOL(qdisc_put_rtab);
440
441 static LIST_HEAD(qdisc_stab_list);
442 static DEFINE_SPINLOCK(qdisc_stab_lock);
443
444 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
445 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
446 [TCA_STAB_DATA] = { .type = NLA_BINARY },
447 };
448
449 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
450 {
451 struct nlattr *tb[TCA_STAB_MAX + 1];
452 struct qdisc_size_table *stab;
453 struct tc_sizespec *s;
454 unsigned int tsize = 0;
455 u16 *tab = NULL;
456 int err;
457
458 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
459 if (err < 0)
460 return ERR_PTR(err);
461 if (!tb[TCA_STAB_BASE])
462 return ERR_PTR(-EINVAL);
463
464 s = nla_data(tb[TCA_STAB_BASE]);
465
466 if (s->tsize > 0) {
467 if (!tb[TCA_STAB_DATA])
468 return ERR_PTR(-EINVAL);
469 tab = nla_data(tb[TCA_STAB_DATA]);
470 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
471 }
472
473 if (tsize != s->tsize || (!tab && tsize > 0))
474 return ERR_PTR(-EINVAL);
475
476 spin_lock(&qdisc_stab_lock);
477
478 list_for_each_entry(stab, &qdisc_stab_list, list) {
479 if (memcmp(&stab->szopts, s, sizeof(*s)))
480 continue;
481 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
482 continue;
483 stab->refcnt++;
484 spin_unlock(&qdisc_stab_lock);
485 return stab;
486 }
487
488 spin_unlock(&qdisc_stab_lock);
489
490 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
491 if (!stab)
492 return ERR_PTR(-ENOMEM);
493
494 stab->refcnt = 1;
495 stab->szopts = *s;
496 if (tsize > 0)
497 memcpy(stab->data, tab, tsize * sizeof(u16));
498
499 spin_lock(&qdisc_stab_lock);
500 list_add_tail(&stab->list, &qdisc_stab_list);
501 spin_unlock(&qdisc_stab_lock);
502
503 return stab;
504 }
505
506 static void stab_kfree_rcu(struct rcu_head *head)
507 {
508 kfree(container_of(head, struct qdisc_size_table, rcu));
509 }
510
511 void qdisc_put_stab(struct qdisc_size_table *tab)
512 {
513 if (!tab)
514 return;
515
516 spin_lock(&qdisc_stab_lock);
517
518 if (--tab->refcnt == 0) {
519 list_del(&tab->list);
520 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
521 }
522
523 spin_unlock(&qdisc_stab_lock);
524 }
525 EXPORT_SYMBOL(qdisc_put_stab);
526
527 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
528 {
529 struct nlattr *nest;
530
531 nest = nla_nest_start(skb, TCA_STAB);
532 if (nest == NULL)
533 goto nla_put_failure;
534 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
535 goto nla_put_failure;
536 nla_nest_end(skb, nest);
537
538 return skb->len;
539
540 nla_put_failure:
541 return -1;
542 }
543
544 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
545 const struct qdisc_size_table *stab)
546 {
547 int pkt_len, slot;
548
549 pkt_len = skb->len + stab->szopts.overhead;
550 if (unlikely(!stab->szopts.tsize))
551 goto out;
552
553 slot = pkt_len + stab->szopts.cell_align;
554 if (unlikely(slot < 0))
555 slot = 0;
556
557 slot >>= stab->szopts.cell_log;
558 if (likely(slot < stab->szopts.tsize))
559 pkt_len = stab->data[slot];
560 else
561 pkt_len = stab->data[stab->szopts.tsize - 1] *
562 (slot / stab->szopts.tsize) +
563 stab->data[slot % stab->szopts.tsize];
564
565 pkt_len <<= stab->szopts.size_log;
566 out:
567 if (unlikely(pkt_len < 1))
568 pkt_len = 1;
569 qdisc_skb_cb(skb)->pkt_len = pkt_len;
570 }
571 EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
572
573 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
574 {
575 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
576 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
577 txt, qdisc->ops->id, qdisc->handle >> 16);
578 qdisc->flags |= TCQ_F_WARN_NONWC;
579 }
580 }
581 EXPORT_SYMBOL(qdisc_warn_nonwc);
582
583 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
584 {
585 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
586 timer);
587
588 rcu_read_lock();
589 __netif_schedule(qdisc_root(wd->qdisc));
590 rcu_read_unlock();
591
592 return HRTIMER_NORESTART;
593 }
594
595 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
596 {
597 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
598 wd->timer.function = qdisc_watchdog;
599 wd->qdisc = qdisc;
600 }
601 EXPORT_SYMBOL(qdisc_watchdog_init);
602
603 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
604 {
605 if (test_bit(__QDISC_STATE_DEACTIVATED,
606 &qdisc_root_sleeping(wd->qdisc)->state))
607 return;
608
609 if (wd->last_expires == expires)
610 return;
611
612 wd->last_expires = expires;
613 hrtimer_start(&wd->timer,
614 ns_to_ktime(expires),
615 HRTIMER_MODE_ABS_PINNED);
616 }
617 EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
618
619 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
620 {
621 hrtimer_cancel(&wd->timer);
622 }
623 EXPORT_SYMBOL(qdisc_watchdog_cancel);
624
625 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
626 {
627 unsigned int size = n * sizeof(struct hlist_head), i;
628 struct hlist_head *h;
629
630 if (size <= PAGE_SIZE)
631 h = kmalloc(size, GFP_KERNEL);
632 else
633 h = (struct hlist_head *)
634 __get_free_pages(GFP_KERNEL, get_order(size));
635
636 if (h != NULL) {
637 for (i = 0; i < n; i++)
638 INIT_HLIST_HEAD(&h[i]);
639 }
640 return h;
641 }
642
643 static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
644 {
645 unsigned int size = n * sizeof(struct hlist_head);
646
647 if (size <= PAGE_SIZE)
648 kfree(h);
649 else
650 free_pages((unsigned long)h, get_order(size));
651 }
652
653 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
654 {
655 struct Qdisc_class_common *cl;
656 struct hlist_node *next;
657 struct hlist_head *nhash, *ohash;
658 unsigned int nsize, nmask, osize;
659 unsigned int i, h;
660
661 /* Rehash when load factor exceeds 0.75 */
662 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
663 return;
664 nsize = clhash->hashsize * 2;
665 nmask = nsize - 1;
666 nhash = qdisc_class_hash_alloc(nsize);
667 if (nhash == NULL)
668 return;
669
670 ohash = clhash->hash;
671 osize = clhash->hashsize;
672
673 sch_tree_lock(sch);
674 for (i = 0; i < osize; i++) {
675 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
676 h = qdisc_class_hash(cl->classid, nmask);
677 hlist_add_head(&cl->hnode, &nhash[h]);
678 }
679 }
680 clhash->hash = nhash;
681 clhash->hashsize = nsize;
682 clhash->hashmask = nmask;
683 sch_tree_unlock(sch);
684
685 qdisc_class_hash_free(ohash, osize);
686 }
687 EXPORT_SYMBOL(qdisc_class_hash_grow);
688
689 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
690 {
691 unsigned int size = 4;
692
693 clhash->hash = qdisc_class_hash_alloc(size);
694 if (clhash->hash == NULL)
695 return -ENOMEM;
696 clhash->hashsize = size;
697 clhash->hashmask = size - 1;
698 clhash->hashelems = 0;
699 return 0;
700 }
701 EXPORT_SYMBOL(qdisc_class_hash_init);
702
703 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
704 {
705 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
706 }
707 EXPORT_SYMBOL(qdisc_class_hash_destroy);
708
709 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
710 struct Qdisc_class_common *cl)
711 {
712 unsigned int h;
713
714 INIT_HLIST_NODE(&cl->hnode);
715 h = qdisc_class_hash(cl->classid, clhash->hashmask);
716 hlist_add_head(&cl->hnode, &clhash->hash[h]);
717 clhash->hashelems++;
718 }
719 EXPORT_SYMBOL(qdisc_class_hash_insert);
720
721 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
722 struct Qdisc_class_common *cl)
723 {
724 hlist_del(&cl->hnode);
725 clhash->hashelems--;
726 }
727 EXPORT_SYMBOL(qdisc_class_hash_remove);
728
729 /* Allocate an unique handle from space managed by kernel
730 * Possible range is [8000-FFFF]:0000 (0x8000 values)
731 */
732 static u32 qdisc_alloc_handle(struct net_device *dev)
733 {
734 int i = 0x8000;
735 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
736
737 do {
738 autohandle += TC_H_MAKE(0x10000U, 0);
739 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
740 autohandle = TC_H_MAKE(0x80000000U, 0);
741 if (!qdisc_lookup(dev, autohandle))
742 return autohandle;
743 cond_resched();
744 } while (--i > 0);
745
746 return 0;
747 }
748
749 void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,
750 unsigned int len)
751 {
752 const struct Qdisc_class_ops *cops;
753 unsigned long cl;
754 u32 parentid;
755 int drops;
756
757 if (n == 0 && len == 0)
758 return;
759 drops = max_t(int, n, 0);
760 rcu_read_lock();
761 while ((parentid = sch->parent)) {
762 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
763 break;
764
765 if (sch->flags & TCQ_F_NOPARENT)
766 break;
767 /* TODO: perform the search on a per txq basis */
768 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
769 if (sch == NULL) {
770 WARN_ON_ONCE(parentid != TC_H_ROOT);
771 break;
772 }
773 cops = sch->ops->cl_ops;
774 if (cops->qlen_notify) {
775 cl = cops->get(sch, parentid);
776 cops->qlen_notify(sch, cl);
777 cops->put(sch, cl);
778 }
779 sch->q.qlen -= n;
780 sch->qstats.backlog -= len;
781 __qdisc_qstats_drop(sch, drops);
782 }
783 rcu_read_unlock();
784 }
785 EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
786
787 static void notify_and_destroy(struct net *net, struct sk_buff *skb,
788 struct nlmsghdr *n, u32 clid,
789 struct Qdisc *old, struct Qdisc *new)
790 {
791 if (new || old)
792 qdisc_notify(net, skb, n, clid, old, new);
793
794 if (old)
795 qdisc_destroy(old);
796 }
797
798 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
799 * to device "dev".
800 *
801 * When appropriate send a netlink notification using 'skb'
802 * and "n".
803 *
804 * On success, destroy old qdisc.
805 */
806
807 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
808 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
809 struct Qdisc *new, struct Qdisc *old)
810 {
811 struct Qdisc *q = old;
812 struct net *net = dev_net(dev);
813 int err = 0;
814
815 if (parent == NULL) {
816 unsigned int i, num_q, ingress;
817
818 ingress = 0;
819 num_q = dev->num_tx_queues;
820 if ((q && q->flags & TCQ_F_INGRESS) ||
821 (new && new->flags & TCQ_F_INGRESS)) {
822 num_q = 1;
823 ingress = 1;
824 if (!dev_ingress_queue(dev))
825 return -ENOENT;
826 }
827
828 if (dev->flags & IFF_UP)
829 dev_deactivate(dev);
830
831 if (new && new->ops->attach)
832 goto skip;
833
834 for (i = 0; i < num_q; i++) {
835 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
836
837 if (!ingress)
838 dev_queue = netdev_get_tx_queue(dev, i);
839
840 old = dev_graft_qdisc(dev_queue, new);
841 if (new && i > 0)
842 atomic_inc(&new->refcnt);
843
844 if (!ingress)
845 qdisc_destroy(old);
846 }
847
848 skip:
849 if (!ingress) {
850 notify_and_destroy(net, skb, n, classid,
851 dev->qdisc, new);
852 if (new && !new->ops->attach)
853 atomic_inc(&new->refcnt);
854 dev->qdisc = new ? : &noop_qdisc;
855
856 if (new && new->ops->attach)
857 new->ops->attach(new);
858 } else {
859 notify_and_destroy(net, skb, n, classid, old, new);
860 }
861
862 if (dev->flags & IFF_UP)
863 dev_activate(dev);
864 } else {
865 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
866
867 err = -EOPNOTSUPP;
868 if (cops && cops->graft) {
869 unsigned long cl = cops->get(parent, classid);
870 if (cl) {
871 err = cops->graft(parent, cl, new, &old);
872 cops->put(parent, cl);
873 } else
874 err = -ENOENT;
875 }
876 if (!err)
877 notify_and_destroy(net, skb, n, classid, old, new);
878 }
879 return err;
880 }
881
882 /* lockdep annotation is needed for ingress; egress gets it only for name */
883 static struct lock_class_key qdisc_tx_lock;
884 static struct lock_class_key qdisc_rx_lock;
885
886 /*
887 Allocate and initialize new qdisc.
888
889 Parameters are passed via opt.
890 */
891
892 static struct Qdisc *qdisc_create(struct net_device *dev,
893 struct netdev_queue *dev_queue,
894 struct Qdisc *p, u32 parent, u32 handle,
895 struct nlattr **tca, int *errp)
896 {
897 int err;
898 struct nlattr *kind = tca[TCA_KIND];
899 struct Qdisc *sch;
900 struct Qdisc_ops *ops;
901 struct qdisc_size_table *stab;
902
903 ops = qdisc_lookup_ops(kind);
904 #ifdef CONFIG_MODULES
905 if (ops == NULL && kind != NULL) {
906 char name[IFNAMSIZ];
907 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
908 /* We dropped the RTNL semaphore in order to
909 * perform the module load. So, even if we
910 * succeeded in loading the module we have to
911 * tell the caller to replay the request. We
912 * indicate this using -EAGAIN.
913 * We replay the request because the device may
914 * go away in the mean time.
915 */
916 rtnl_unlock();
917 request_module("sch_%s", name);
918 rtnl_lock();
919 ops = qdisc_lookup_ops(kind);
920 if (ops != NULL) {
921 /* We will try again qdisc_lookup_ops,
922 * so don't keep a reference.
923 */
924 module_put(ops->owner);
925 err = -EAGAIN;
926 goto err_out;
927 }
928 }
929 }
930 #endif
931
932 err = -ENOENT;
933 if (ops == NULL)
934 goto err_out;
935
936 sch = qdisc_alloc(dev_queue, ops);
937 if (IS_ERR(sch)) {
938 err = PTR_ERR(sch);
939 goto err_out2;
940 }
941
942 sch->parent = parent;
943
944 if (handle == TC_H_INGRESS) {
945 sch->flags |= TCQ_F_INGRESS;
946 handle = TC_H_MAKE(TC_H_INGRESS, 0);
947 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
948 } else {
949 if (handle == 0) {
950 handle = qdisc_alloc_handle(dev);
951 err = -ENOMEM;
952 if (handle == 0)
953 goto err_out3;
954 }
955 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
956 if (!netif_is_multiqueue(dev))
957 sch->flags |= TCQ_F_ONETXQUEUE;
958 }
959
960 sch->handle = handle;
961
962 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
963 if (qdisc_is_percpu_stats(sch)) {
964 sch->cpu_bstats =
965 netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
966 if (!sch->cpu_bstats)
967 goto err_out4;
968
969 sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
970 if (!sch->cpu_qstats)
971 goto err_out4;
972 }
973
974 if (tca[TCA_STAB]) {
975 stab = qdisc_get_stab(tca[TCA_STAB]);
976 if (IS_ERR(stab)) {
977 err = PTR_ERR(stab);
978 goto err_out4;
979 }
980 rcu_assign_pointer(sch->stab, stab);
981 }
982 if (tca[TCA_RATE]) {
983 seqcount_t *running;
984
985 err = -EOPNOTSUPP;
986 if (sch->flags & TCQ_F_MQROOT)
987 goto err_out4;
988
989 if ((sch->parent != TC_H_ROOT) &&
990 !(sch->flags & TCQ_F_INGRESS) &&
991 (!p || !(p->flags & TCQ_F_MQROOT)))
992 running = qdisc_root_sleeping_running(sch);
993 else
994 running = &sch->running;
995
996 err = gen_new_estimator(&sch->bstats,
997 sch->cpu_bstats,
998 &sch->rate_est,
999 NULL,
1000 running,
1001 tca[TCA_RATE]);
1002 if (err)
1003 goto err_out4;
1004 }
1005
1006 qdisc_hash_add(sch);
1007
1008 return sch;
1009 }
1010 /* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */
1011 if (ops->destroy)
1012 ops->destroy(sch);
1013 err_out3:
1014 dev_put(dev);
1015 kfree((char *) sch - sch->padded);
1016 err_out2:
1017 module_put(ops->owner);
1018 err_out:
1019 *errp = err;
1020 return NULL;
1021
1022 err_out4:
1023 free_percpu(sch->cpu_bstats);
1024 free_percpu(sch->cpu_qstats);
1025 /*
1026 * Any broken qdiscs that would require a ops->reset() here?
1027 * The qdisc was never in action so it shouldn't be necessary.
1028 */
1029 qdisc_put_stab(rtnl_dereference(sch->stab));
1030 if (ops->destroy)
1031 ops->destroy(sch);
1032 goto err_out3;
1033 }
1034
1035 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
1036 {
1037 struct qdisc_size_table *ostab, *stab = NULL;
1038 int err = 0;
1039
1040 if (tca[TCA_OPTIONS]) {
1041 if (sch->ops->change == NULL)
1042 return -EINVAL;
1043 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
1044 if (err)
1045 return err;
1046 }
1047
1048 if (tca[TCA_STAB]) {
1049 stab = qdisc_get_stab(tca[TCA_STAB]);
1050 if (IS_ERR(stab))
1051 return PTR_ERR(stab);
1052 }
1053
1054 ostab = rtnl_dereference(sch->stab);
1055 rcu_assign_pointer(sch->stab, stab);
1056 qdisc_put_stab(ostab);
1057
1058 if (tca[TCA_RATE]) {
1059 /* NB: ignores errors from replace_estimator
1060 because change can't be undone. */
1061 if (sch->flags & TCQ_F_MQROOT)
1062 goto out;
1063 gen_replace_estimator(&sch->bstats,
1064 sch->cpu_bstats,
1065 &sch->rate_est,
1066 NULL,
1067 qdisc_root_sleeping_running(sch),
1068 tca[TCA_RATE]);
1069 }
1070 out:
1071 return 0;
1072 }
1073
1074 struct check_loop_arg {
1075 struct qdisc_walker w;
1076 struct Qdisc *p;
1077 int depth;
1078 };
1079
1080 static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1081 struct qdisc_walker *w);
1082
1083 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1084 {
1085 struct check_loop_arg arg;
1086
1087 if (q->ops->cl_ops == NULL)
1088 return 0;
1089
1090 arg.w.stop = arg.w.skip = arg.w.count = 0;
1091 arg.w.fn = check_loop_fn;
1092 arg.depth = depth;
1093 arg.p = p;
1094 q->ops->cl_ops->walk(q, &arg.w);
1095 return arg.w.stop ? -ELOOP : 0;
1096 }
1097
1098 static int
1099 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1100 {
1101 struct Qdisc *leaf;
1102 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1103 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1104
1105 leaf = cops->leaf(q, cl);
1106 if (leaf) {
1107 if (leaf == arg->p || arg->depth > 7)
1108 return -ELOOP;
1109 return check_loop(leaf, arg->p, arg->depth + 1);
1110 }
1111 return 0;
1112 }
1113
1114 /*
1115 * Delete/get qdisc.
1116 */
1117
1118 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1119 {
1120 struct net *net = sock_net(skb->sk);
1121 struct tcmsg *tcm = nlmsg_data(n);
1122 struct nlattr *tca[TCA_MAX + 1];
1123 struct net_device *dev;
1124 u32 clid;
1125 struct Qdisc *q = NULL;
1126 struct Qdisc *p = NULL;
1127 int err;
1128
1129 if ((n->nlmsg_type != RTM_GETQDISC) &&
1130 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1131 return -EPERM;
1132
1133 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1134 if (err < 0)
1135 return err;
1136
1137 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1138 if (!dev)
1139 return -ENODEV;
1140
1141 clid = tcm->tcm_parent;
1142 if (clid) {
1143 if (clid != TC_H_ROOT) {
1144 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1145 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1146 if (!p)
1147 return -ENOENT;
1148 q = qdisc_leaf(p, clid);
1149 } else if (dev_ingress_queue(dev)) {
1150 q = dev_ingress_queue(dev)->qdisc_sleeping;
1151 }
1152 } else {
1153 q = dev->qdisc;
1154 }
1155 if (!q)
1156 return -ENOENT;
1157
1158 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1159 return -EINVAL;
1160 } else {
1161 q = qdisc_lookup(dev, tcm->tcm_handle);
1162 if (!q)
1163 return -ENOENT;
1164 }
1165
1166 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1167 return -EINVAL;
1168
1169 if (n->nlmsg_type == RTM_DELQDISC) {
1170 if (!clid)
1171 return -EINVAL;
1172 if (q->handle == 0)
1173 return -ENOENT;
1174 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1175 if (err != 0)
1176 return err;
1177 } else {
1178 qdisc_notify(net, skb, n, clid, NULL, q);
1179 }
1180 return 0;
1181 }
1182
1183 /*
1184 * Create/change qdisc.
1185 */
1186
1187 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1188 {
1189 struct net *net = sock_net(skb->sk);
1190 struct tcmsg *tcm;
1191 struct nlattr *tca[TCA_MAX + 1];
1192 struct net_device *dev;
1193 u32 clid;
1194 struct Qdisc *q, *p;
1195 int err;
1196
1197 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1198 return -EPERM;
1199
1200 replay:
1201 /* Reinit, just in case something touches this. */
1202 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1203 if (err < 0)
1204 return err;
1205
1206 tcm = nlmsg_data(n);
1207 clid = tcm->tcm_parent;
1208 q = p = NULL;
1209
1210 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1211 if (!dev)
1212 return -ENODEV;
1213
1214
1215 if (clid) {
1216 if (clid != TC_H_ROOT) {
1217 if (clid != TC_H_INGRESS) {
1218 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1219 if (!p)
1220 return -ENOENT;
1221 q = qdisc_leaf(p, clid);
1222 } else if (dev_ingress_queue_create(dev)) {
1223 q = dev_ingress_queue(dev)->qdisc_sleeping;
1224 }
1225 } else {
1226 q = dev->qdisc;
1227 }
1228
1229 /* It may be default qdisc, ignore it */
1230 if (q && q->handle == 0)
1231 q = NULL;
1232
1233 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1234 if (tcm->tcm_handle) {
1235 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1236 return -EEXIST;
1237 if (TC_H_MIN(tcm->tcm_handle))
1238 return -EINVAL;
1239 q = qdisc_lookup(dev, tcm->tcm_handle);
1240 if (!q)
1241 goto create_n_graft;
1242 if (n->nlmsg_flags & NLM_F_EXCL)
1243 return -EEXIST;
1244 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1245 return -EINVAL;
1246 if (q == p ||
1247 (p && check_loop(q, p, 0)))
1248 return -ELOOP;
1249 atomic_inc(&q->refcnt);
1250 goto graft;
1251 } else {
1252 if (!q)
1253 goto create_n_graft;
1254
1255 /* This magic test requires explanation.
1256 *
1257 * We know, that some child q is already
1258 * attached to this parent and have choice:
1259 * either to change it or to create/graft new one.
1260 *
1261 * 1. We are allowed to create/graft only
1262 * if CREATE and REPLACE flags are set.
1263 *
1264 * 2. If EXCL is set, requestor wanted to say,
1265 * that qdisc tcm_handle is not expected
1266 * to exist, so that we choose create/graft too.
1267 *
1268 * 3. The last case is when no flags are set.
1269 * Alas, it is sort of hole in API, we
1270 * cannot decide what to do unambiguously.
1271 * For now we select create/graft, if
1272 * user gave KIND, which does not match existing.
1273 */
1274 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1275 (n->nlmsg_flags & NLM_F_REPLACE) &&
1276 ((n->nlmsg_flags & NLM_F_EXCL) ||
1277 (tca[TCA_KIND] &&
1278 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1279 goto create_n_graft;
1280 }
1281 }
1282 } else {
1283 if (!tcm->tcm_handle)
1284 return -EINVAL;
1285 q = qdisc_lookup(dev, tcm->tcm_handle);
1286 }
1287
1288 /* Change qdisc parameters */
1289 if (q == NULL)
1290 return -ENOENT;
1291 if (n->nlmsg_flags & NLM_F_EXCL)
1292 return -EEXIST;
1293 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1294 return -EINVAL;
1295 err = qdisc_change(q, tca);
1296 if (err == 0)
1297 qdisc_notify(net, skb, n, clid, NULL, q);
1298 return err;
1299
1300 create_n_graft:
1301 if (!(n->nlmsg_flags & NLM_F_CREATE))
1302 return -ENOENT;
1303 if (clid == TC_H_INGRESS) {
1304 if (dev_ingress_queue(dev))
1305 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1306 tcm->tcm_parent, tcm->tcm_parent,
1307 tca, &err);
1308 else
1309 err = -ENOENT;
1310 } else {
1311 struct netdev_queue *dev_queue;
1312
1313 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1314 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1315 else if (p)
1316 dev_queue = p->dev_queue;
1317 else
1318 dev_queue = netdev_get_tx_queue(dev, 0);
1319
1320 q = qdisc_create(dev, dev_queue, p,
1321 tcm->tcm_parent, tcm->tcm_handle,
1322 tca, &err);
1323 }
1324 if (q == NULL) {
1325 if (err == -EAGAIN)
1326 goto replay;
1327 return err;
1328 }
1329
1330 graft:
1331 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1332 if (err) {
1333 if (q)
1334 qdisc_destroy(q);
1335 return err;
1336 }
1337
1338 return 0;
1339 }
1340
1341 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1342 u32 portid, u32 seq, u16 flags, int event)
1343 {
1344 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
1345 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
1346 struct tcmsg *tcm;
1347 struct nlmsghdr *nlh;
1348 unsigned char *b = skb_tail_pointer(skb);
1349 struct gnet_dump d;
1350 struct qdisc_size_table *stab;
1351 __u32 qlen;
1352
1353 cond_resched();
1354 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1355 if (!nlh)
1356 goto out_nlmsg_trim;
1357 tcm = nlmsg_data(nlh);
1358 tcm->tcm_family = AF_UNSPEC;
1359 tcm->tcm__pad1 = 0;
1360 tcm->tcm__pad2 = 0;
1361 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1362 tcm->tcm_parent = clid;
1363 tcm->tcm_handle = q->handle;
1364 tcm->tcm_info = atomic_read(&q->refcnt);
1365 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1366 goto nla_put_failure;
1367 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1368 goto nla_put_failure;
1369 qlen = q->q.qlen;
1370
1371 stab = rtnl_dereference(q->stab);
1372 if (stab && qdisc_dump_stab(skb, stab) < 0)
1373 goto nla_put_failure;
1374
1375 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1376 NULL, &d, TCA_PAD) < 0)
1377 goto nla_put_failure;
1378
1379 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1380 goto nla_put_failure;
1381
1382 if (qdisc_is_percpu_stats(q)) {
1383 cpu_bstats = q->cpu_bstats;
1384 cpu_qstats = q->cpu_qstats;
1385 }
1386
1387 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(q),
1388 &d, cpu_bstats, &q->bstats) < 0 ||
1389 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1390 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
1391 goto nla_put_failure;
1392
1393 if (gnet_stats_finish_copy(&d) < 0)
1394 goto nla_put_failure;
1395
1396 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1397 return skb->len;
1398
1399 out_nlmsg_trim:
1400 nla_put_failure:
1401 nlmsg_trim(skb, b);
1402 return -1;
1403 }
1404
1405 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1406 {
1407 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1408 }
1409
1410 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1411 struct nlmsghdr *n, u32 clid,
1412 struct Qdisc *old, struct Qdisc *new)
1413 {
1414 struct sk_buff *skb;
1415 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1416
1417 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1418 if (!skb)
1419 return -ENOBUFS;
1420
1421 if (old && !tc_qdisc_dump_ignore(old)) {
1422 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1423 0, RTM_DELQDISC) < 0)
1424 goto err_out;
1425 }
1426 if (new && !tc_qdisc_dump_ignore(new)) {
1427 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1428 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1429 goto err_out;
1430 }
1431
1432 if (skb->len)
1433 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1434 n->nlmsg_flags & NLM_F_ECHO);
1435
1436 err_out:
1437 kfree_skb(skb);
1438 return -EINVAL;
1439 }
1440
1441 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1442 struct netlink_callback *cb,
1443 int *q_idx_p, int s_q_idx, bool recur)
1444 {
1445 int ret = 0, q_idx = *q_idx_p;
1446 struct Qdisc *q;
1447 int b;
1448
1449 if (!root)
1450 return 0;
1451
1452 q = root;
1453 if (q_idx < s_q_idx) {
1454 q_idx++;
1455 } else {
1456 if (!tc_qdisc_dump_ignore(q) &&
1457 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1458 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1459 RTM_NEWQDISC) <= 0)
1460 goto done;
1461 q_idx++;
1462 }
1463
1464 /* If dumping singletons, there is no qdisc_dev(root) and the singleton
1465 * itself has already been dumped.
1466 *
1467 * If we've already dumped the top-level (ingress) qdisc above and the global
1468 * qdisc hashtable, we don't want to hit it again
1469 */
1470 if (!qdisc_dev(root) || !recur)
1471 goto out;
1472
1473 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1474 if (q_idx < s_q_idx) {
1475 q_idx++;
1476 continue;
1477 }
1478 if (!tc_qdisc_dump_ignore(q) &&
1479 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1480 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1481 RTM_NEWQDISC) <= 0)
1482 goto done;
1483 q_idx++;
1484 }
1485
1486 out:
1487 *q_idx_p = q_idx;
1488 return ret;
1489 done:
1490 ret = -1;
1491 goto out;
1492 }
1493
1494 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1495 {
1496 struct net *net = sock_net(skb->sk);
1497 int idx, q_idx;
1498 int s_idx, s_q_idx;
1499 struct net_device *dev;
1500
1501 s_idx = cb->args[0];
1502 s_q_idx = q_idx = cb->args[1];
1503
1504 idx = 0;
1505 ASSERT_RTNL();
1506 for_each_netdev(net, dev) {
1507 struct netdev_queue *dev_queue;
1508
1509 if (idx < s_idx)
1510 goto cont;
1511 if (idx > s_idx)
1512 s_q_idx = 0;
1513 q_idx = 0;
1514
1515 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx,
1516 true) < 0)
1517 goto done;
1518
1519 dev_queue = dev_ingress_queue(dev);
1520 if (dev_queue &&
1521 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1522 &q_idx, s_q_idx, false) < 0)
1523 goto done;
1524
1525 cont:
1526 idx++;
1527 }
1528
1529 done:
1530 cb->args[0] = idx;
1531 cb->args[1] = q_idx;
1532
1533 return skb->len;
1534 }
1535
1536
1537
1538 /************************************************
1539 * Traffic classes manipulation. *
1540 ************************************************/
1541
1542
1543
1544 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n)
1545 {
1546 struct net *net = sock_net(skb->sk);
1547 struct tcmsg *tcm = nlmsg_data(n);
1548 struct nlattr *tca[TCA_MAX + 1];
1549 struct net_device *dev;
1550 struct Qdisc *q = NULL;
1551 const struct Qdisc_class_ops *cops;
1552 unsigned long cl = 0;
1553 unsigned long new_cl;
1554 u32 portid;
1555 u32 clid;
1556 u32 qid;
1557 int err;
1558
1559 if ((n->nlmsg_type != RTM_GETTCLASS) &&
1560 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1561 return -EPERM;
1562
1563 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1564 if (err < 0)
1565 return err;
1566
1567 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1568 if (!dev)
1569 return -ENODEV;
1570
1571 /*
1572 parent == TC_H_UNSPEC - unspecified parent.
1573 parent == TC_H_ROOT - class is root, which has no parent.
1574 parent == X:0 - parent is root class.
1575 parent == X:Y - parent is a node in hierarchy.
1576 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1577
1578 handle == 0:0 - generate handle from kernel pool.
1579 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1580 handle == X:Y - clear.
1581 handle == X:0 - root class.
1582 */
1583
1584 /* Step 1. Determine qdisc handle X:0 */
1585
1586 portid = tcm->tcm_parent;
1587 clid = tcm->tcm_handle;
1588 qid = TC_H_MAJ(clid);
1589
1590 if (portid != TC_H_ROOT) {
1591 u32 qid1 = TC_H_MAJ(portid);
1592
1593 if (qid && qid1) {
1594 /* If both majors are known, they must be identical. */
1595 if (qid != qid1)
1596 return -EINVAL;
1597 } else if (qid1) {
1598 qid = qid1;
1599 } else if (qid == 0)
1600 qid = dev->qdisc->handle;
1601
1602 /* Now qid is genuine qdisc handle consistent
1603 * both with parent and child.
1604 *
1605 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1606 */
1607 if (portid)
1608 portid = TC_H_MAKE(qid, portid);
1609 } else {
1610 if (qid == 0)
1611 qid = dev->qdisc->handle;
1612 }
1613
1614 /* OK. Locate qdisc */
1615 q = qdisc_lookup(dev, qid);
1616 if (!q)
1617 return -ENOENT;
1618
1619 /* An check that it supports classes */
1620 cops = q->ops->cl_ops;
1621 if (cops == NULL)
1622 return -EINVAL;
1623
1624 /* Now try to get class */
1625 if (clid == 0) {
1626 if (portid == TC_H_ROOT)
1627 clid = qid;
1628 } else
1629 clid = TC_H_MAKE(qid, clid);
1630
1631 if (clid)
1632 cl = cops->get(q, clid);
1633
1634 if (cl == 0) {
1635 err = -ENOENT;
1636 if (n->nlmsg_type != RTM_NEWTCLASS ||
1637 !(n->nlmsg_flags & NLM_F_CREATE))
1638 goto out;
1639 } else {
1640 switch (n->nlmsg_type) {
1641 case RTM_NEWTCLASS:
1642 err = -EEXIST;
1643 if (n->nlmsg_flags & NLM_F_EXCL)
1644 goto out;
1645 break;
1646 case RTM_DELTCLASS:
1647 err = -EOPNOTSUPP;
1648 if (cops->delete)
1649 err = cops->delete(q, cl);
1650 if (err == 0)
1651 tclass_notify(net, skb, n, q, cl,
1652 RTM_DELTCLASS);
1653 goto out;
1654 case RTM_GETTCLASS:
1655 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1656 goto out;
1657 default:
1658 err = -EINVAL;
1659 goto out;
1660 }
1661 }
1662
1663 new_cl = cl;
1664 err = -EOPNOTSUPP;
1665 if (cops->change)
1666 err = cops->change(q, clid, portid, tca, &new_cl);
1667 if (err == 0)
1668 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1669
1670 out:
1671 if (cl)
1672 cops->put(q, cl);
1673
1674 return err;
1675 }
1676
1677
1678 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1679 unsigned long cl,
1680 u32 portid, u32 seq, u16 flags, int event)
1681 {
1682 struct tcmsg *tcm;
1683 struct nlmsghdr *nlh;
1684 unsigned char *b = skb_tail_pointer(skb);
1685 struct gnet_dump d;
1686 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1687
1688 cond_resched();
1689 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1690 if (!nlh)
1691 goto out_nlmsg_trim;
1692 tcm = nlmsg_data(nlh);
1693 tcm->tcm_family = AF_UNSPEC;
1694 tcm->tcm__pad1 = 0;
1695 tcm->tcm__pad2 = 0;
1696 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1697 tcm->tcm_parent = q->handle;
1698 tcm->tcm_handle = q->handle;
1699 tcm->tcm_info = 0;
1700 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1701 goto nla_put_failure;
1702 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1703 goto nla_put_failure;
1704
1705 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1706 NULL, &d, TCA_PAD) < 0)
1707 goto nla_put_failure;
1708
1709 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1710 goto nla_put_failure;
1711
1712 if (gnet_stats_finish_copy(&d) < 0)
1713 goto nla_put_failure;
1714
1715 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1716 return skb->len;
1717
1718 out_nlmsg_trim:
1719 nla_put_failure:
1720 nlmsg_trim(skb, b);
1721 return -1;
1722 }
1723
1724 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1725 struct nlmsghdr *n, struct Qdisc *q,
1726 unsigned long cl, int event)
1727 {
1728 struct sk_buff *skb;
1729 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1730
1731 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1732 if (!skb)
1733 return -ENOBUFS;
1734
1735 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1736 kfree_skb(skb);
1737 return -EINVAL;
1738 }
1739
1740 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1741 n->nlmsg_flags & NLM_F_ECHO);
1742 }
1743
1744 struct qdisc_dump_args {
1745 struct qdisc_walker w;
1746 struct sk_buff *skb;
1747 struct netlink_callback *cb;
1748 };
1749
1750 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
1751 struct qdisc_walker *arg)
1752 {
1753 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1754
1755 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1756 a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
1757 RTM_NEWTCLASS);
1758 }
1759
1760 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1761 struct tcmsg *tcm, struct netlink_callback *cb,
1762 int *t_p, int s_t)
1763 {
1764 struct qdisc_dump_args arg;
1765
1766 if (tc_qdisc_dump_ignore(q) ||
1767 *t_p < s_t || !q->ops->cl_ops ||
1768 (tcm->tcm_parent &&
1769 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1770 (*t_p)++;
1771 return 0;
1772 }
1773 if (*t_p > s_t)
1774 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1775 arg.w.fn = qdisc_class_dump;
1776 arg.skb = skb;
1777 arg.cb = cb;
1778 arg.w.stop = 0;
1779 arg.w.skip = cb->args[1];
1780 arg.w.count = 0;
1781 q->ops->cl_ops->walk(q, &arg.w);
1782 cb->args[1] = arg.w.count;
1783 if (arg.w.stop)
1784 return -1;
1785 (*t_p)++;
1786 return 0;
1787 }
1788
1789 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1790 struct tcmsg *tcm, struct netlink_callback *cb,
1791 int *t_p, int s_t)
1792 {
1793 struct Qdisc *q;
1794 int b;
1795
1796 if (!root)
1797 return 0;
1798
1799 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1800 return -1;
1801
1802 if (!qdisc_dev(root))
1803 return 0;
1804
1805 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1806 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1807 return -1;
1808 }
1809
1810 return 0;
1811 }
1812
1813 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1814 {
1815 struct tcmsg *tcm = nlmsg_data(cb->nlh);
1816 struct net *net = sock_net(skb->sk);
1817 struct netdev_queue *dev_queue;
1818 struct net_device *dev;
1819 int t, s_t;
1820
1821 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1822 return 0;
1823 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1824 if (!dev)
1825 return 0;
1826
1827 s_t = cb->args[0];
1828 t = 0;
1829
1830 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1831 goto done;
1832
1833 dev_queue = dev_ingress_queue(dev);
1834 if (dev_queue &&
1835 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1836 &t, s_t) < 0)
1837 goto done;
1838
1839 done:
1840 cb->args[0] = t;
1841
1842 dev_put(dev);
1843 return skb->len;
1844 }
1845
1846 /* Main classifier routine: scans classifier chain attached
1847 * to this qdisc, (optionally) tests for protocol and asks
1848 * specific classifiers.
1849 */
1850 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1851 struct tcf_result *res, bool compat_mode)
1852 {
1853 #ifdef CONFIG_NET_CLS_ACT
1854 const struct tcf_proto *old_tp = tp;
1855 int limit = 0;
1856
1857 reclassify:
1858 #endif
1859 for (; tp; tp = rcu_dereference_bh(tp->next)) {
1860 __be16 protocol = tc_skb_protocol(skb);
1861 int err;
1862
1863 if (tp->protocol != protocol &&
1864 tp->protocol != htons(ETH_P_ALL))
1865 continue;
1866
1867 err = tp->classify(skb, tp, res);
1868 #ifdef CONFIG_NET_CLS_ACT
1869 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode))
1870 goto reset;
1871 #endif
1872 if (err >= 0)
1873 return err;
1874 }
1875
1876 return TC_ACT_UNSPEC; /* signal: continue lookup */
1877 #ifdef CONFIG_NET_CLS_ACT
1878 reset:
1879 if (unlikely(limit++ >= MAX_REC_LOOP)) {
1880 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n",
1881 tp->q->ops->id, tp->prio & 0xffff,
1882 ntohs(tp->protocol));
1883 return TC_ACT_SHOT;
1884 }
1885
1886 tp = old_tp;
1887 goto reclassify;
1888 #endif
1889 }
1890 EXPORT_SYMBOL(tc_classify);
1891
1892 bool tcf_destroy(struct tcf_proto *tp, bool force)
1893 {
1894 if (tp->ops->destroy(tp, force)) {
1895 module_put(tp->ops->owner);
1896 kfree_rcu(tp, rcu);
1897 return true;
1898 }
1899
1900 return false;
1901 }
1902
1903 void tcf_destroy_chain(struct tcf_proto __rcu **fl)
1904 {
1905 struct tcf_proto *tp;
1906
1907 while ((tp = rtnl_dereference(*fl)) != NULL) {
1908 RCU_INIT_POINTER(*fl, tp->next);
1909 tcf_destroy(tp, true);
1910 }
1911 }
1912 EXPORT_SYMBOL(tcf_destroy_chain);
1913
1914 #ifdef CONFIG_PROC_FS
1915 static int psched_show(struct seq_file *seq, void *v)
1916 {
1917 seq_printf(seq, "%08x %08x %08x %08x\n",
1918 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1919 1000000,
1920 (u32)NSEC_PER_SEC / hrtimer_resolution);
1921
1922 return 0;
1923 }
1924
1925 static int psched_open(struct inode *inode, struct file *file)
1926 {
1927 return single_open(file, psched_show, NULL);
1928 }
1929
1930 static const struct file_operations psched_fops = {
1931 .owner = THIS_MODULE,
1932 .open = psched_open,
1933 .read = seq_read,
1934 .llseek = seq_lseek,
1935 .release = single_release,
1936 };
1937
1938 static int __net_init psched_net_init(struct net *net)
1939 {
1940 struct proc_dir_entry *e;
1941
1942 e = proc_create("psched", 0, net->proc_net, &psched_fops);
1943 if (e == NULL)
1944 return -ENOMEM;
1945
1946 return 0;
1947 }
1948
1949 static void __net_exit psched_net_exit(struct net *net)
1950 {
1951 remove_proc_entry("psched", net->proc_net);
1952 }
1953 #else
1954 static int __net_init psched_net_init(struct net *net)
1955 {
1956 return 0;
1957 }
1958
1959 static void __net_exit psched_net_exit(struct net *net)
1960 {
1961 }
1962 #endif
1963
1964 static struct pernet_operations psched_net_ops = {
1965 .init = psched_net_init,
1966 .exit = psched_net_exit,
1967 };
1968
1969 static int __init pktsched_init(void)
1970 {
1971 int err;
1972
1973 err = register_pernet_subsys(&psched_net_ops);
1974 if (err) {
1975 pr_err("pktsched_init: "
1976 "cannot initialize per netns operations\n");
1977 return err;
1978 }
1979
1980 register_qdisc(&pfifo_fast_ops);
1981 register_qdisc(&pfifo_qdisc_ops);
1982 register_qdisc(&bfifo_qdisc_ops);
1983 register_qdisc(&pfifo_head_drop_qdisc_ops);
1984 register_qdisc(&mq_qdisc_ops);
1985 register_qdisc(&noqueue_qdisc_ops);
1986
1987 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1988 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1989 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc,
1990 NULL);
1991 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1992 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1993 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass,
1994 NULL);
1995
1996 return 0;
1997 }
1998
1999 subsys_initcall(pktsched_init);
Linux with added FPC-III support