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