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