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Merge tag 'mvebu-dt-4.8-1' of git://git.infradead.org/linux-mvebu into next/dt
[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 if (wd->last_expires == expires)
611 return;
612
613 wd->last_expires = expires;
614 hrtimer_start(&wd->timer,
615 ns_to_ktime(expires),
616 HRTIMER_MODE_ABS_PINNED);
617 }
618 EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
619
620 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
621 {
622 hrtimer_cancel(&wd->timer);
623 qdisc_unthrottled(wd->qdisc);
624 }
625 EXPORT_SYMBOL(qdisc_watchdog_cancel);
626
627 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
628 {
629 unsigned int size = n * sizeof(struct hlist_head), i;
630 struct hlist_head *h;
631
632 if (size <= PAGE_SIZE)
633 h = kmalloc(size, GFP_KERNEL);
634 else
635 h = (struct hlist_head *)
636 __get_free_pages(GFP_KERNEL, get_order(size));
637
638 if (h != NULL) {
639 for (i = 0; i < n; i++)
640 INIT_HLIST_HEAD(&h[i]);
641 }
642 return h;
643 }
644
645 static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
646 {
647 unsigned int size = n * sizeof(struct hlist_head);
648
649 if (size <= PAGE_SIZE)
650 kfree(h);
651 else
652 free_pages((unsigned long)h, get_order(size));
653 }
654
655 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
656 {
657 struct Qdisc_class_common *cl;
658 struct hlist_node *next;
659 struct hlist_head *nhash, *ohash;
660 unsigned int nsize, nmask, osize;
661 unsigned int i, h;
662
663 /* Rehash when load factor exceeds 0.75 */
664 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
665 return;
666 nsize = clhash->hashsize * 2;
667 nmask = nsize - 1;
668 nhash = qdisc_class_hash_alloc(nsize);
669 if (nhash == NULL)
670 return;
671
672 ohash = clhash->hash;
673 osize = clhash->hashsize;
674
675 sch_tree_lock(sch);
676 for (i = 0; i < osize; i++) {
677 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
678 h = qdisc_class_hash(cl->classid, nmask);
679 hlist_add_head(&cl->hnode, &nhash[h]);
680 }
681 }
682 clhash->hash = nhash;
683 clhash->hashsize = nsize;
684 clhash->hashmask = nmask;
685 sch_tree_unlock(sch);
686
687 qdisc_class_hash_free(ohash, osize);
688 }
689 EXPORT_SYMBOL(qdisc_class_hash_grow);
690
691 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
692 {
693 unsigned int size = 4;
694
695 clhash->hash = qdisc_class_hash_alloc(size);
696 if (clhash->hash == NULL)
697 return -ENOMEM;
698 clhash->hashsize = size;
699 clhash->hashmask = size - 1;
700 clhash->hashelems = 0;
701 return 0;
702 }
703 EXPORT_SYMBOL(qdisc_class_hash_init);
704
705 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
706 {
707 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
708 }
709 EXPORT_SYMBOL(qdisc_class_hash_destroy);
710
711 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
712 struct Qdisc_class_common *cl)
713 {
714 unsigned int h;
715
716 INIT_HLIST_NODE(&cl->hnode);
717 h = qdisc_class_hash(cl->classid, clhash->hashmask);
718 hlist_add_head(&cl->hnode, &clhash->hash[h]);
719 clhash->hashelems++;
720 }
721 EXPORT_SYMBOL(qdisc_class_hash_insert);
722
723 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
724 struct Qdisc_class_common *cl)
725 {
726 hlist_del(&cl->hnode);
727 clhash->hashelems--;
728 }
729 EXPORT_SYMBOL(qdisc_class_hash_remove);
730
731 /* Allocate an unique handle from space managed by kernel
732 * Possible range is [8000-FFFF]:0000 (0x8000 values)
733 */
734 static u32 qdisc_alloc_handle(struct net_device *dev)
735 {
736 int i = 0x8000;
737 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
738
739 do {
740 autohandle += TC_H_MAKE(0x10000U, 0);
741 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
742 autohandle = TC_H_MAKE(0x80000000U, 0);
743 if (!qdisc_lookup(dev, autohandle))
744 return autohandle;
745 cond_resched();
746 } while (--i > 0);
747
748 return 0;
749 }
750
751 void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,
752 unsigned int len)
753 {
754 const struct Qdisc_class_ops *cops;
755 unsigned long cl;
756 u32 parentid;
757 int drops;
758
759 if (n == 0 && len == 0)
760 return;
761 drops = max_t(int, n, 0);
762 rcu_read_lock();
763 while ((parentid = sch->parent)) {
764 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
765 break;
766
767 if (sch->flags & TCQ_F_NOPARENT)
768 break;
769 /* TODO: perform the search on a per txq basis */
770 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
771 if (sch == NULL) {
772 WARN_ON_ONCE(parentid != TC_H_ROOT);
773 break;
774 }
775 cops = sch->ops->cl_ops;
776 if (cops->qlen_notify) {
777 cl = cops->get(sch, parentid);
778 cops->qlen_notify(sch, cl);
779 cops->put(sch, cl);
780 }
781 sch->q.qlen -= n;
782 sch->qstats.backlog -= len;
783 __qdisc_qstats_drop(sch, drops);
784 }
785 rcu_read_unlock();
786 }
787 EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
788
789 static void notify_and_destroy(struct net *net, struct sk_buff *skb,
790 struct nlmsghdr *n, u32 clid,
791 struct Qdisc *old, struct Qdisc *new)
792 {
793 if (new || old)
794 qdisc_notify(net, skb, n, clid, old, new);
795
796 if (old)
797 qdisc_destroy(old);
798 }
799
800 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
801 * to device "dev".
802 *
803 * When appropriate send a netlink notification using 'skb'
804 * and "n".
805 *
806 * On success, destroy old qdisc.
807 */
808
809 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
810 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
811 struct Qdisc *new, struct Qdisc *old)
812 {
813 struct Qdisc *q = old;
814 struct net *net = dev_net(dev);
815 int err = 0;
816
817 if (parent == NULL) {
818 unsigned int i, num_q, ingress;
819
820 ingress = 0;
821 num_q = dev->num_tx_queues;
822 if ((q && q->flags & TCQ_F_INGRESS) ||
823 (new && new->flags & TCQ_F_INGRESS)) {
824 num_q = 1;
825 ingress = 1;
826 if (!dev_ingress_queue(dev))
827 return -ENOENT;
828 }
829
830 if (dev->flags & IFF_UP)
831 dev_deactivate(dev);
832
833 if (new && new->ops->attach)
834 goto skip;
835
836 for (i = 0; i < num_q; i++) {
837 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
838
839 if (!ingress)
840 dev_queue = netdev_get_tx_queue(dev, i);
841
842 old = dev_graft_qdisc(dev_queue, new);
843 if (new && i > 0)
844 atomic_inc(&new->refcnt);
845
846 if (!ingress)
847 qdisc_destroy(old);
848 }
849
850 skip:
851 if (!ingress) {
852 notify_and_destroy(net, skb, n, classid,
853 dev->qdisc, new);
854 if (new && !new->ops->attach)
855 atomic_inc(&new->refcnt);
856 dev->qdisc = new ? : &noop_qdisc;
857
858 if (new && new->ops->attach)
859 new->ops->attach(new);
860 } else {
861 notify_and_destroy(net, skb, n, classid, old, new);
862 }
863
864 if (dev->flags & IFF_UP)
865 dev_activate(dev);
866 } else {
867 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
868
869 err = -EOPNOTSUPP;
870 if (cops && cops->graft) {
871 unsigned long cl = cops->get(parent, classid);
872 if (cl) {
873 err = cops->graft(parent, cl, new, &old);
874 cops->put(parent, cl);
875 } else
876 err = -ENOENT;
877 }
878 if (!err)
879 notify_and_destroy(net, skb, n, classid, old, new);
880 }
881 return err;
882 }
883
884 /* lockdep annotation is needed for ingress; egress gets it only for name */
885 static struct lock_class_key qdisc_tx_lock;
886 static struct lock_class_key qdisc_rx_lock;
887
888 /*
889 Allocate and initialize new qdisc.
890
891 Parameters are passed via opt.
892 */
893
894 static struct Qdisc *
895 qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
896 struct Qdisc *p, u32 parent, u32 handle,
897 struct nlattr **tca, int *errp)
898 {
899 int err;
900 struct nlattr *kind = tca[TCA_KIND];
901 struct Qdisc *sch;
902 struct Qdisc_ops *ops;
903 struct qdisc_size_table *stab;
904
905 ops = qdisc_lookup_ops(kind);
906 #ifdef CONFIG_MODULES
907 if (ops == NULL && kind != NULL) {
908 char name[IFNAMSIZ];
909 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
910 /* We dropped the RTNL semaphore in order to
911 * perform the module load. So, even if we
912 * succeeded in loading the module we have to
913 * tell the caller to replay the request. We
914 * indicate this using -EAGAIN.
915 * We replay the request because the device may
916 * go away in the mean time.
917 */
918 rtnl_unlock();
919 request_module("sch_%s", name);
920 rtnl_lock();
921 ops = qdisc_lookup_ops(kind);
922 if (ops != NULL) {
923 /* We will try again qdisc_lookup_ops,
924 * so don't keep a reference.
925 */
926 module_put(ops->owner);
927 err = -EAGAIN;
928 goto err_out;
929 }
930 }
931 }
932 #endif
933
934 err = -ENOENT;
935 if (ops == NULL)
936 goto err_out;
937
938 sch = qdisc_alloc(dev_queue, ops);
939 if (IS_ERR(sch)) {
940 err = PTR_ERR(sch);
941 goto err_out2;
942 }
943
944 sch->parent = parent;
945
946 if (handle == TC_H_INGRESS) {
947 sch->flags |= TCQ_F_INGRESS;
948 handle = TC_H_MAKE(TC_H_INGRESS, 0);
949 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
950 } else {
951 if (handle == 0) {
952 handle = qdisc_alloc_handle(dev);
953 err = -ENOMEM;
954 if (handle == 0)
955 goto err_out3;
956 }
957 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
958 if (!netif_is_multiqueue(dev))
959 sch->flags |= TCQ_F_ONETXQUEUE;
960 }
961
962 sch->handle = handle;
963
964 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
965 if (qdisc_is_percpu_stats(sch)) {
966 sch->cpu_bstats =
967 netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
968 if (!sch->cpu_bstats)
969 goto err_out4;
970
971 sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
972 if (!sch->cpu_qstats)
973 goto err_out4;
974 }
975
976 if (tca[TCA_STAB]) {
977 stab = qdisc_get_stab(tca[TCA_STAB]);
978 if (IS_ERR(stab)) {
979 err = PTR_ERR(stab);
980 goto err_out4;
981 }
982 rcu_assign_pointer(sch->stab, stab);
983 }
984 if (tca[TCA_RATE]) {
985 spinlock_t *root_lock;
986
987 err = -EOPNOTSUPP;
988 if (sch->flags & TCQ_F_MQROOT)
989 goto err_out4;
990
991 if ((sch->parent != TC_H_ROOT) &&
992 !(sch->flags & TCQ_F_INGRESS) &&
993 (!p || !(p->flags & TCQ_F_MQROOT)))
994 root_lock = qdisc_root_sleeping_lock(sch);
995 else
996 root_lock = qdisc_lock(sch);
997
998 err = gen_new_estimator(&sch->bstats,
999 sch->cpu_bstats,
1000 &sch->rate_est,
1001 root_lock,
1002 tca[TCA_RATE]);
1003 if (err)
1004 goto err_out4;
1005 }
1006
1007 qdisc_list_add(sch);
1008
1009 return sch;
1010 }
1011 err_out3:
1012 dev_put(dev);
1013 kfree((char *) sch - sch->padded);
1014 err_out2:
1015 module_put(ops->owner);
1016 err_out:
1017 *errp = err;
1018 return NULL;
1019
1020 err_out4:
1021 free_percpu(sch->cpu_bstats);
1022 free_percpu(sch->cpu_qstats);
1023 /*
1024 * Any broken qdiscs that would require a ops->reset() here?
1025 * The qdisc was never in action so it shouldn't be necessary.
1026 */
1027 qdisc_put_stab(rtnl_dereference(sch->stab));
1028 if (ops->destroy)
1029 ops->destroy(sch);
1030 goto err_out3;
1031 }
1032
1033 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
1034 {
1035 struct qdisc_size_table *ostab, *stab = NULL;
1036 int err = 0;
1037
1038 if (tca[TCA_OPTIONS]) {
1039 if (sch->ops->change == NULL)
1040 return -EINVAL;
1041 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
1042 if (err)
1043 return err;
1044 }
1045
1046 if (tca[TCA_STAB]) {
1047 stab = qdisc_get_stab(tca[TCA_STAB]);
1048 if (IS_ERR(stab))
1049 return PTR_ERR(stab);
1050 }
1051
1052 ostab = rtnl_dereference(sch->stab);
1053 rcu_assign_pointer(sch->stab, stab);
1054 qdisc_put_stab(ostab);
1055
1056 if (tca[TCA_RATE]) {
1057 /* NB: ignores errors from replace_estimator
1058 because change can't be undone. */
1059 if (sch->flags & TCQ_F_MQROOT)
1060 goto out;
1061 gen_replace_estimator(&sch->bstats,
1062 sch->cpu_bstats,
1063 &sch->rate_est,
1064 qdisc_root_sleeping_lock(sch),
1065 tca[TCA_RATE]);
1066 }
1067 out:
1068 return 0;
1069 }
1070
1071 struct check_loop_arg {
1072 struct qdisc_walker w;
1073 struct Qdisc *p;
1074 int depth;
1075 };
1076
1077 static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
1078
1079 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1080 {
1081 struct check_loop_arg arg;
1082
1083 if (q->ops->cl_ops == NULL)
1084 return 0;
1085
1086 arg.w.stop = arg.w.skip = arg.w.count = 0;
1087 arg.w.fn = check_loop_fn;
1088 arg.depth = depth;
1089 arg.p = p;
1090 q->ops->cl_ops->walk(q, &arg.w);
1091 return arg.w.stop ? -ELOOP : 0;
1092 }
1093
1094 static int
1095 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1096 {
1097 struct Qdisc *leaf;
1098 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1099 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1100
1101 leaf = cops->leaf(q, cl);
1102 if (leaf) {
1103 if (leaf == arg->p || arg->depth > 7)
1104 return -ELOOP;
1105 return check_loop(leaf, arg->p, arg->depth + 1);
1106 }
1107 return 0;
1108 }
1109
1110 /*
1111 * Delete/get qdisc.
1112 */
1113
1114 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1115 {
1116 struct net *net = sock_net(skb->sk);
1117 struct tcmsg *tcm = nlmsg_data(n);
1118 struct nlattr *tca[TCA_MAX + 1];
1119 struct net_device *dev;
1120 u32 clid;
1121 struct Qdisc *q = NULL;
1122 struct Qdisc *p = NULL;
1123 int err;
1124
1125 if ((n->nlmsg_type != RTM_GETQDISC) &&
1126 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1127 return -EPERM;
1128
1129 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1130 if (err < 0)
1131 return err;
1132
1133 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1134 if (!dev)
1135 return -ENODEV;
1136
1137 clid = tcm->tcm_parent;
1138 if (clid) {
1139 if (clid != TC_H_ROOT) {
1140 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1141 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1142 if (!p)
1143 return -ENOENT;
1144 q = qdisc_leaf(p, clid);
1145 } else if (dev_ingress_queue(dev)) {
1146 q = dev_ingress_queue(dev)->qdisc_sleeping;
1147 }
1148 } else {
1149 q = dev->qdisc;
1150 }
1151 if (!q)
1152 return -ENOENT;
1153
1154 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1155 return -EINVAL;
1156 } else {
1157 q = qdisc_lookup(dev, tcm->tcm_handle);
1158 if (!q)
1159 return -ENOENT;
1160 }
1161
1162 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1163 return -EINVAL;
1164
1165 if (n->nlmsg_type == RTM_DELQDISC) {
1166 if (!clid)
1167 return -EINVAL;
1168 if (q->handle == 0)
1169 return -ENOENT;
1170 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1171 if (err != 0)
1172 return err;
1173 } else {
1174 qdisc_notify(net, skb, n, clid, NULL, q);
1175 }
1176 return 0;
1177 }
1178
1179 /*
1180 * Create/change qdisc.
1181 */
1182
1183 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1184 {
1185 struct net *net = sock_net(skb->sk);
1186 struct tcmsg *tcm;
1187 struct nlattr *tca[TCA_MAX + 1];
1188 struct net_device *dev;
1189 u32 clid;
1190 struct Qdisc *q, *p;
1191 int err;
1192
1193 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1194 return -EPERM;
1195
1196 replay:
1197 /* Reinit, just in case something touches this. */
1198 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1199 if (err < 0)
1200 return err;
1201
1202 tcm = nlmsg_data(n);
1203 clid = tcm->tcm_parent;
1204 q = p = NULL;
1205
1206 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1207 if (!dev)
1208 return -ENODEV;
1209
1210
1211 if (clid) {
1212 if (clid != TC_H_ROOT) {
1213 if (clid != TC_H_INGRESS) {
1214 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1215 if (!p)
1216 return -ENOENT;
1217 q = qdisc_leaf(p, clid);
1218 } else if (dev_ingress_queue_create(dev)) {
1219 q = dev_ingress_queue(dev)->qdisc_sleeping;
1220 }
1221 } else {
1222 q = dev->qdisc;
1223 }
1224
1225 /* It may be default qdisc, ignore it */
1226 if (q && q->handle == 0)
1227 q = NULL;
1228
1229 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1230 if (tcm->tcm_handle) {
1231 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1232 return -EEXIST;
1233 if (TC_H_MIN(tcm->tcm_handle))
1234 return -EINVAL;
1235 q = qdisc_lookup(dev, tcm->tcm_handle);
1236 if (!q)
1237 goto create_n_graft;
1238 if (n->nlmsg_flags & NLM_F_EXCL)
1239 return -EEXIST;
1240 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1241 return -EINVAL;
1242 if (q == p ||
1243 (p && check_loop(q, p, 0)))
1244 return -ELOOP;
1245 atomic_inc(&q->refcnt);
1246 goto graft;
1247 } else {
1248 if (!q)
1249 goto create_n_graft;
1250
1251 /* This magic test requires explanation.
1252 *
1253 * We know, that some child q is already
1254 * attached to this parent and have choice:
1255 * either to change it or to create/graft new one.
1256 *
1257 * 1. We are allowed to create/graft only
1258 * if CREATE and REPLACE flags are set.
1259 *
1260 * 2. If EXCL is set, requestor wanted to say,
1261 * that qdisc tcm_handle is not expected
1262 * to exist, so that we choose create/graft too.
1263 *
1264 * 3. The last case is when no flags are set.
1265 * Alas, it is sort of hole in API, we
1266 * cannot decide what to do unambiguously.
1267 * For now we select create/graft, if
1268 * user gave KIND, which does not match existing.
1269 */
1270 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1271 (n->nlmsg_flags & NLM_F_REPLACE) &&
1272 ((n->nlmsg_flags & NLM_F_EXCL) ||
1273 (tca[TCA_KIND] &&
1274 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1275 goto create_n_graft;
1276 }
1277 }
1278 } else {
1279 if (!tcm->tcm_handle)
1280 return -EINVAL;
1281 q = qdisc_lookup(dev, tcm->tcm_handle);
1282 }
1283
1284 /* Change qdisc parameters */
1285 if (q == NULL)
1286 return -ENOENT;
1287 if (n->nlmsg_flags & NLM_F_EXCL)
1288 return -EEXIST;
1289 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1290 return -EINVAL;
1291 err = qdisc_change(q, tca);
1292 if (err == 0)
1293 qdisc_notify(net, skb, n, clid, NULL, q);
1294 return err;
1295
1296 create_n_graft:
1297 if (!(n->nlmsg_flags & NLM_F_CREATE))
1298 return -ENOENT;
1299 if (clid == TC_H_INGRESS) {
1300 if (dev_ingress_queue(dev))
1301 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1302 tcm->tcm_parent, tcm->tcm_parent,
1303 tca, &err);
1304 else
1305 err = -ENOENT;
1306 } else {
1307 struct netdev_queue *dev_queue;
1308
1309 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1310 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1311 else if (p)
1312 dev_queue = p->dev_queue;
1313 else
1314 dev_queue = netdev_get_tx_queue(dev, 0);
1315
1316 q = qdisc_create(dev, dev_queue, p,
1317 tcm->tcm_parent, tcm->tcm_handle,
1318 tca, &err);
1319 }
1320 if (q == NULL) {
1321 if (err == -EAGAIN)
1322 goto replay;
1323 return err;
1324 }
1325
1326 graft:
1327 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1328 if (err) {
1329 if (q)
1330 qdisc_destroy(q);
1331 return err;
1332 }
1333
1334 return 0;
1335 }
1336
1337 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1338 u32 portid, u32 seq, u16 flags, int event)
1339 {
1340 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
1341 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
1342 struct tcmsg *tcm;
1343 struct nlmsghdr *nlh;
1344 unsigned char *b = skb_tail_pointer(skb);
1345 struct gnet_dump d;
1346 struct qdisc_size_table *stab;
1347 __u32 qlen;
1348
1349 cond_resched();
1350 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1351 if (!nlh)
1352 goto out_nlmsg_trim;
1353 tcm = nlmsg_data(nlh);
1354 tcm->tcm_family = AF_UNSPEC;
1355 tcm->tcm__pad1 = 0;
1356 tcm->tcm__pad2 = 0;
1357 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1358 tcm->tcm_parent = clid;
1359 tcm->tcm_handle = q->handle;
1360 tcm->tcm_info = atomic_read(&q->refcnt);
1361 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1362 goto nla_put_failure;
1363 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1364 goto nla_put_failure;
1365 qlen = q->q.qlen;
1366
1367 stab = rtnl_dereference(q->stab);
1368 if (stab && qdisc_dump_stab(skb, stab) < 0)
1369 goto nla_put_failure;
1370
1371 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1372 qdisc_root_sleeping_lock(q), &d,
1373 TCA_PAD) < 0)
1374 goto nla_put_failure;
1375
1376 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1377 goto nla_put_failure;
1378
1379 if (qdisc_is_percpu_stats(q)) {
1380 cpu_bstats = q->cpu_bstats;
1381 cpu_qstats = q->cpu_qstats;
1382 }
1383
1384 if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats) < 0 ||
1385 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1386 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
1387 goto nla_put_failure;
1388
1389 if (gnet_stats_finish_copy(&d) < 0)
1390 goto nla_put_failure;
1391
1392 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1393 return skb->len;
1394
1395 out_nlmsg_trim:
1396 nla_put_failure:
1397 nlmsg_trim(skb, b);
1398 return -1;
1399 }
1400
1401 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1402 {
1403 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1404 }
1405
1406 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1407 struct nlmsghdr *n, u32 clid,
1408 struct Qdisc *old, struct Qdisc *new)
1409 {
1410 struct sk_buff *skb;
1411 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1412
1413 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1414 if (!skb)
1415 return -ENOBUFS;
1416
1417 if (old && !tc_qdisc_dump_ignore(old)) {
1418 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1419 0, RTM_DELQDISC) < 0)
1420 goto err_out;
1421 }
1422 if (new && !tc_qdisc_dump_ignore(new)) {
1423 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1424 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1425 goto err_out;
1426 }
1427
1428 if (skb->len)
1429 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1430 n->nlmsg_flags & NLM_F_ECHO);
1431
1432 err_out:
1433 kfree_skb(skb);
1434 return -EINVAL;
1435 }
1436
1437 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1438 struct netlink_callback *cb,
1439 int *q_idx_p, int s_q_idx)
1440 {
1441 int ret = 0, q_idx = *q_idx_p;
1442 struct Qdisc *q;
1443
1444 if (!root)
1445 return 0;
1446
1447 q = root;
1448 if (q_idx < s_q_idx) {
1449 q_idx++;
1450 } else {
1451 if (!tc_qdisc_dump_ignore(q) &&
1452 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1453 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1454 goto done;
1455 q_idx++;
1456 }
1457 list_for_each_entry(q, &root->list, list) {
1458 if (q_idx < s_q_idx) {
1459 q_idx++;
1460 continue;
1461 }
1462 if (!tc_qdisc_dump_ignore(q) &&
1463 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1464 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1465 goto done;
1466 q_idx++;
1467 }
1468
1469 out:
1470 *q_idx_p = q_idx;
1471 return ret;
1472 done:
1473 ret = -1;
1474 goto out;
1475 }
1476
1477 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1478 {
1479 struct net *net = sock_net(skb->sk);
1480 int idx, q_idx;
1481 int s_idx, s_q_idx;
1482 struct net_device *dev;
1483
1484 s_idx = cb->args[0];
1485 s_q_idx = q_idx = cb->args[1];
1486
1487 idx = 0;
1488 ASSERT_RTNL();
1489 for_each_netdev(net, dev) {
1490 struct netdev_queue *dev_queue;
1491
1492 if (idx < s_idx)
1493 goto cont;
1494 if (idx > s_idx)
1495 s_q_idx = 0;
1496 q_idx = 0;
1497
1498 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1499 goto done;
1500
1501 dev_queue = dev_ingress_queue(dev);
1502 if (dev_queue &&
1503 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1504 &q_idx, s_q_idx) < 0)
1505 goto done;
1506
1507 cont:
1508 idx++;
1509 }
1510
1511 done:
1512 cb->args[0] = idx;
1513 cb->args[1] = q_idx;
1514
1515 return skb->len;
1516 }
1517
1518
1519
1520 /************************************************
1521 * Traffic classes manipulation. *
1522 ************************************************/
1523
1524
1525
1526 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n)
1527 {
1528 struct net *net = sock_net(skb->sk);
1529 struct tcmsg *tcm = nlmsg_data(n);
1530 struct nlattr *tca[TCA_MAX + 1];
1531 struct net_device *dev;
1532 struct Qdisc *q = NULL;
1533 const struct Qdisc_class_ops *cops;
1534 unsigned long cl = 0;
1535 unsigned long new_cl;
1536 u32 portid;
1537 u32 clid;
1538 u32 qid;
1539 int err;
1540
1541 if ((n->nlmsg_type != RTM_GETTCLASS) &&
1542 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1543 return -EPERM;
1544
1545 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1546 if (err < 0)
1547 return err;
1548
1549 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1550 if (!dev)
1551 return -ENODEV;
1552
1553 /*
1554 parent == TC_H_UNSPEC - unspecified parent.
1555 parent == TC_H_ROOT - class is root, which has no parent.
1556 parent == X:0 - parent is root class.
1557 parent == X:Y - parent is a node in hierarchy.
1558 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1559
1560 handle == 0:0 - generate handle from kernel pool.
1561 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1562 handle == X:Y - clear.
1563 handle == X:0 - root class.
1564 */
1565
1566 /* Step 1. Determine qdisc handle X:0 */
1567
1568 portid = tcm->tcm_parent;
1569 clid = tcm->tcm_handle;
1570 qid = TC_H_MAJ(clid);
1571
1572 if (portid != TC_H_ROOT) {
1573 u32 qid1 = TC_H_MAJ(portid);
1574
1575 if (qid && qid1) {
1576 /* If both majors are known, they must be identical. */
1577 if (qid != qid1)
1578 return -EINVAL;
1579 } else if (qid1) {
1580 qid = qid1;
1581 } else if (qid == 0)
1582 qid = dev->qdisc->handle;
1583
1584 /* Now qid is genuine qdisc handle consistent
1585 * both with parent and child.
1586 *
1587 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1588 */
1589 if (portid)
1590 portid = TC_H_MAKE(qid, portid);
1591 } else {
1592 if (qid == 0)
1593 qid = dev->qdisc->handle;
1594 }
1595
1596 /* OK. Locate qdisc */
1597 q = qdisc_lookup(dev, qid);
1598 if (!q)
1599 return -ENOENT;
1600
1601 /* An check that it supports classes */
1602 cops = q->ops->cl_ops;
1603 if (cops == NULL)
1604 return -EINVAL;
1605
1606 /* Now try to get class */
1607 if (clid == 0) {
1608 if (portid == TC_H_ROOT)
1609 clid = qid;
1610 } else
1611 clid = TC_H_MAKE(qid, clid);
1612
1613 if (clid)
1614 cl = cops->get(q, clid);
1615
1616 if (cl == 0) {
1617 err = -ENOENT;
1618 if (n->nlmsg_type != RTM_NEWTCLASS ||
1619 !(n->nlmsg_flags & NLM_F_CREATE))
1620 goto out;
1621 } else {
1622 switch (n->nlmsg_type) {
1623 case RTM_NEWTCLASS:
1624 err = -EEXIST;
1625 if (n->nlmsg_flags & NLM_F_EXCL)
1626 goto out;
1627 break;
1628 case RTM_DELTCLASS:
1629 err = -EOPNOTSUPP;
1630 if (cops->delete)
1631 err = cops->delete(q, cl);
1632 if (err == 0)
1633 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1634 goto out;
1635 case RTM_GETTCLASS:
1636 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1637 goto out;
1638 default:
1639 err = -EINVAL;
1640 goto out;
1641 }
1642 }
1643
1644 new_cl = cl;
1645 err = -EOPNOTSUPP;
1646 if (cops->change)
1647 err = cops->change(q, clid, portid, tca, &new_cl);
1648 if (err == 0)
1649 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1650
1651 out:
1652 if (cl)
1653 cops->put(q, cl);
1654
1655 return err;
1656 }
1657
1658
1659 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1660 unsigned long cl,
1661 u32 portid, u32 seq, u16 flags, int event)
1662 {
1663 struct tcmsg *tcm;
1664 struct nlmsghdr *nlh;
1665 unsigned char *b = skb_tail_pointer(skb);
1666 struct gnet_dump d;
1667 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1668
1669 cond_resched();
1670 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1671 if (!nlh)
1672 goto out_nlmsg_trim;
1673 tcm = nlmsg_data(nlh);
1674 tcm->tcm_family = AF_UNSPEC;
1675 tcm->tcm__pad1 = 0;
1676 tcm->tcm__pad2 = 0;
1677 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1678 tcm->tcm_parent = q->handle;
1679 tcm->tcm_handle = q->handle;
1680 tcm->tcm_info = 0;
1681 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1682 goto nla_put_failure;
1683 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1684 goto nla_put_failure;
1685
1686 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1687 qdisc_root_sleeping_lock(q), &d,
1688 TCA_PAD) < 0)
1689 goto nla_put_failure;
1690
1691 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1692 goto nla_put_failure;
1693
1694 if (gnet_stats_finish_copy(&d) < 0)
1695 goto nla_put_failure;
1696
1697 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1698 return skb->len;
1699
1700 out_nlmsg_trim:
1701 nla_put_failure:
1702 nlmsg_trim(skb, b);
1703 return -1;
1704 }
1705
1706 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1707 struct nlmsghdr *n, struct Qdisc *q,
1708 unsigned long cl, int event)
1709 {
1710 struct sk_buff *skb;
1711 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1712
1713 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1714 if (!skb)
1715 return -ENOBUFS;
1716
1717 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1718 kfree_skb(skb);
1719 return -EINVAL;
1720 }
1721
1722 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1723 n->nlmsg_flags & NLM_F_ECHO);
1724 }
1725
1726 struct qdisc_dump_args {
1727 struct qdisc_walker w;
1728 struct sk_buff *skb;
1729 struct netlink_callback *cb;
1730 };
1731
1732 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1733 {
1734 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1735
1736 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1737 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1738 }
1739
1740 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1741 struct tcmsg *tcm, struct netlink_callback *cb,
1742 int *t_p, int s_t)
1743 {
1744 struct qdisc_dump_args arg;
1745
1746 if (tc_qdisc_dump_ignore(q) ||
1747 *t_p < s_t || !q->ops->cl_ops ||
1748 (tcm->tcm_parent &&
1749 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1750 (*t_p)++;
1751 return 0;
1752 }
1753 if (*t_p > s_t)
1754 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1755 arg.w.fn = qdisc_class_dump;
1756 arg.skb = skb;
1757 arg.cb = cb;
1758 arg.w.stop = 0;
1759 arg.w.skip = cb->args[1];
1760 arg.w.count = 0;
1761 q->ops->cl_ops->walk(q, &arg.w);
1762 cb->args[1] = arg.w.count;
1763 if (arg.w.stop)
1764 return -1;
1765 (*t_p)++;
1766 return 0;
1767 }
1768
1769 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1770 struct tcmsg *tcm, struct netlink_callback *cb,
1771 int *t_p, int s_t)
1772 {
1773 struct Qdisc *q;
1774
1775 if (!root)
1776 return 0;
1777
1778 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1779 return -1;
1780
1781 list_for_each_entry(q, &root->list, list) {
1782 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1783 return -1;
1784 }
1785
1786 return 0;
1787 }
1788
1789 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1790 {
1791 struct tcmsg *tcm = nlmsg_data(cb->nlh);
1792 struct net *net = sock_net(skb->sk);
1793 struct netdev_queue *dev_queue;
1794 struct net_device *dev;
1795 int t, s_t;
1796
1797 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1798 return 0;
1799 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1800 if (!dev)
1801 return 0;
1802
1803 s_t = cb->args[0];
1804 t = 0;
1805
1806 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1807 goto done;
1808
1809 dev_queue = dev_ingress_queue(dev);
1810 if (dev_queue &&
1811 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1812 &t, s_t) < 0)
1813 goto done;
1814
1815 done:
1816 cb->args[0] = t;
1817
1818 dev_put(dev);
1819 return skb->len;
1820 }
1821
1822 /* Main classifier routine: scans classifier chain attached
1823 * to this qdisc, (optionally) tests for protocol and asks
1824 * specific classifiers.
1825 */
1826 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1827 struct tcf_result *res, bool compat_mode)
1828 {
1829 __be16 protocol = tc_skb_protocol(skb);
1830 #ifdef CONFIG_NET_CLS_ACT
1831 const struct tcf_proto *old_tp = tp;
1832 int limit = 0;
1833
1834 reclassify:
1835 #endif
1836 for (; tp; tp = rcu_dereference_bh(tp->next)) {
1837 int err;
1838
1839 if (tp->protocol != protocol &&
1840 tp->protocol != htons(ETH_P_ALL))
1841 continue;
1842
1843 err = tp->classify(skb, tp, res);
1844 #ifdef CONFIG_NET_CLS_ACT
1845 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode))
1846 goto reset;
1847 #endif
1848 if (err >= 0)
1849 return err;
1850 }
1851
1852 return TC_ACT_UNSPEC; /* signal: continue lookup */
1853 #ifdef CONFIG_NET_CLS_ACT
1854 reset:
1855 if (unlikely(limit++ >= MAX_REC_LOOP)) {
1856 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n",
1857 tp->q->ops->id, tp->prio & 0xffff,
1858 ntohs(tp->protocol));
1859 return TC_ACT_SHOT;
1860 }
1861
1862 tp = old_tp;
1863 protocol = tc_skb_protocol(skb);
1864 goto reclassify;
1865 #endif
1866 }
1867 EXPORT_SYMBOL(tc_classify);
1868
1869 bool tcf_destroy(struct tcf_proto *tp, bool force)
1870 {
1871 if (tp->ops->destroy(tp, force)) {
1872 module_put(tp->ops->owner);
1873 kfree_rcu(tp, rcu);
1874 return true;
1875 }
1876
1877 return false;
1878 }
1879
1880 void tcf_destroy_chain(struct tcf_proto __rcu **fl)
1881 {
1882 struct tcf_proto *tp;
1883
1884 while ((tp = rtnl_dereference(*fl)) != NULL) {
1885 RCU_INIT_POINTER(*fl, tp->next);
1886 tcf_destroy(tp, true);
1887 }
1888 }
1889 EXPORT_SYMBOL(tcf_destroy_chain);
1890
1891 #ifdef CONFIG_PROC_FS
1892 static int psched_show(struct seq_file *seq, void *v)
1893 {
1894 seq_printf(seq, "%08x %08x %08x %08x\n",
1895 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1896 1000000,
1897 (u32)NSEC_PER_SEC / hrtimer_resolution);
1898
1899 return 0;
1900 }
1901
1902 static int psched_open(struct inode *inode, struct file *file)
1903 {
1904 return single_open(file, psched_show, NULL);
1905 }
1906
1907 static const struct file_operations psched_fops = {
1908 .owner = THIS_MODULE,
1909 .open = psched_open,
1910 .read = seq_read,
1911 .llseek = seq_lseek,
1912 .release = single_release,
1913 };
1914
1915 static int __net_init psched_net_init(struct net *net)
1916 {
1917 struct proc_dir_entry *e;
1918
1919 e = proc_create("psched", 0, net->proc_net, &psched_fops);
1920 if (e == NULL)
1921 return -ENOMEM;
1922
1923 return 0;
1924 }
1925
1926 static void __net_exit psched_net_exit(struct net *net)
1927 {
1928 remove_proc_entry("psched", net->proc_net);
1929 }
1930 #else
1931 static int __net_init psched_net_init(struct net *net)
1932 {
1933 return 0;
1934 }
1935
1936 static void __net_exit psched_net_exit(struct net *net)
1937 {
1938 }
1939 #endif
1940
1941 static struct pernet_operations psched_net_ops = {
1942 .init = psched_net_init,
1943 .exit = psched_net_exit,
1944 };
1945
1946 static int __init pktsched_init(void)
1947 {
1948 int err;
1949
1950 err = register_pernet_subsys(&psched_net_ops);
1951 if (err) {
1952 pr_err("pktsched_init: "
1953 "cannot initialize per netns operations\n");
1954 return err;
1955 }
1956
1957 register_qdisc(&pfifo_fast_ops);
1958 register_qdisc(&pfifo_qdisc_ops);
1959 register_qdisc(&bfifo_qdisc_ops);
1960 register_qdisc(&pfifo_head_drop_qdisc_ops);
1961 register_qdisc(&mq_qdisc_ops);
1962 register_qdisc(&noqueue_qdisc_ops);
1963
1964 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1965 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1966 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1967 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1968 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1969 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1970
1971 return 0;
1972 }
1973
1974 subsys_initcall(pktsched_init);
Linux kernel - Deliverables
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