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Merge branches 'pm-cpufreq-fixes' and 'pm-cpuidle-fixes'
[linux/fpc-iii.git] / net / sched / sch_api.c
blobbcf49cd2278670197f2a7e9d4e9a62ae8d117468
1 /*
2 * net/sched/sch_api.c Packet scheduler API.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 * Fixes:
12 *
13 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired.
14 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
15 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support
16 */
17
18 #include <linux/module.h>
19 #include <linux/types.h>
20 #include <linux/kernel.h>
21 #include <linux/string.h>
22 #include <linux/errno.h>
23 #include <linux/skbuff.h>
24 #include <linux/init.h>
25 #include <linux/proc_fs.h>
26 #include <linux/seq_file.h>
27 #include <linux/kmod.h>
28 #include <linux/list.h>
29 #include <linux/hrtimer.h>
30 #include <linux/lockdep.h>
31 #include <linux/slab.h>
32 #include <linux/hashtable.h>
33
34 #include <net/net_namespace.h>
35 #include <net/sock.h>
36 #include <net/netlink.h>
37 #include <net/pkt_sched.h>
38
39 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
40 struct nlmsghdr *n, u32 clid,
41 struct Qdisc *old, struct Qdisc *new);
42 static int tclass_notify(struct net *net, struct sk_buff *oskb,
43 struct nlmsghdr *n, struct Qdisc *q,
44 unsigned long cl, int event);
45
46 /*
47
48 Short review.
49 -------------
50
51 This file consists of two interrelated parts:
52
53 1. queueing disciplines manager frontend.
54 2. traffic classes manager frontend.
55
56 Generally, queueing discipline ("qdisc") is a black box,
57 which is able to enqueue packets and to dequeue them (when
58 device is ready to send something) in order and at times
59 determined by algorithm hidden in it.
60
61 qdisc's are divided to two categories:
62 - "queues", which have no internal structure visible from outside.
63 - "schedulers", which split all the packets to "traffic classes",
64 using "packet classifiers" (look at cls_api.c)
65
66 In turn, classes may have child qdiscs (as rule, queues)
67 attached to them etc. etc. etc.
68
69 The goal of the routines in this file is to translate
70 information supplied by user in the form of handles
71 to more intelligible for kernel form, to make some sanity
72 checks and part of work, which is common to all qdiscs
73 and to provide rtnetlink notifications.
74
75 All real intelligent work is done inside qdisc modules.
76
77
78
79 Every discipline has two major routines: enqueue and dequeue.
80
81 ---dequeue
82
83 dequeue usually returns a skb to send. It is allowed to return NULL,
84 but it does not mean that queue is empty, it just means that
85 discipline does not want to send anything this time.
86 Queue is really empty if q->q.qlen == 0.
87 For complicated disciplines with multiple queues q->q is not
88 real packet queue, but however q->q.qlen must be valid.
89
90 ---enqueue
91
92 enqueue returns 0, if packet was enqueued successfully.
93 If packet (this one or another one) was dropped, it returns
94 not zero error code.
95 NET_XMIT_DROP - this packet dropped
96 Expected action: do not backoff, but wait until queue will clear.
97 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
98 Expected action: backoff or ignore
99
100 Auxiliary routines:
101
102 ---peek
103
104 like dequeue but without removing a packet from the queue
105
106 ---reset
107
108 returns qdisc to initial state: purge all buffers, clear all
109 timers, counters (except for statistics) etc.
110
111 ---init
112
113 initializes newly created qdisc.
114
115 ---destroy
116
117 destroys resources allocated by init and during lifetime of qdisc.
118
119 ---change
120
121 changes qdisc parameters.
122 */
123
124 /* Protects list of registered TC modules. It is pure SMP lock. */
125 static DEFINE_RWLOCK(qdisc_mod_lock);
126
127
128 /************************************************
129 * Queueing disciplines manipulation. *
130 ************************************************/
131
132
133 /* The list of all installed queueing disciplines. */
134
135 static struct Qdisc_ops *qdisc_base;
136
137 /* Register/unregister queueing discipline */
138
139 int register_qdisc(struct Qdisc_ops *qops)
140 {
141 struct Qdisc_ops *q, **qp;
142 int rc = -EEXIST;
143
144 write_lock(&qdisc_mod_lock);
145 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
146 if (!strcmp(qops->id, q->id))
147 goto out;
148
149 if (qops->enqueue == NULL)
150 qops->enqueue = noop_qdisc_ops.enqueue;
151 if (qops->peek == NULL) {
152 if (qops->dequeue == NULL)
153 qops->peek = noop_qdisc_ops.peek;
154 else
155 goto out_einval;
156 }
157 if (qops->dequeue == NULL)
158 qops->dequeue = noop_qdisc_ops.dequeue;
159
160 if (qops->cl_ops) {
161 const struct Qdisc_class_ops *cops = qops->cl_ops;
162
163 if (!(cops->get && cops->put && cops->walk && cops->leaf))
164 goto out_einval;
165
166 if (cops->tcf_chain && !(cops->bind_tcf && cops->unbind_tcf))
167 goto out_einval;
168 }
169
170 qops->next = NULL;
171 *qp = qops;
172 rc = 0;
173 out:
174 write_unlock(&qdisc_mod_lock);
175 return rc;
176
177 out_einval:
178 rc = -EINVAL;
179 goto out;
180 }
181 EXPORT_SYMBOL(register_qdisc);
182
183 int unregister_qdisc(struct Qdisc_ops *qops)
184 {
185 struct Qdisc_ops *q, **qp;
186 int err = -ENOENT;
187
188 write_lock(&qdisc_mod_lock);
189 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
190 if (q == qops)
191 break;
192 if (q) {
193 *qp = q->next;
194 q->next = NULL;
195 err = 0;
196 }
197 write_unlock(&qdisc_mod_lock);
198 return err;
199 }
200 EXPORT_SYMBOL(unregister_qdisc);
201
202 /* Get default qdisc if not otherwise specified */
203 void qdisc_get_default(char *name, size_t len)
204 {
205 read_lock(&qdisc_mod_lock);
206 strlcpy(name, default_qdisc_ops->id, len);
207 read_unlock(&qdisc_mod_lock);
208 }
209
210 static struct Qdisc_ops *qdisc_lookup_default(const char *name)
211 {
212 struct Qdisc_ops *q = NULL;
213
214 for (q = qdisc_base; q; q = q->next) {
215 if (!strcmp(name, q->id)) {
216 if (!try_module_get(q->owner))
217 q = NULL;
218 break;
219 }
220 }
221
222 return q;
223 }
224
225 /* Set new default qdisc to use */
226 int qdisc_set_default(const char *name)
227 {
228 const struct Qdisc_ops *ops;
229
230 if (!capable(CAP_NET_ADMIN))
231 return -EPERM;
232
233 write_lock(&qdisc_mod_lock);
234 ops = qdisc_lookup_default(name);
235 if (!ops) {
236 /* Not found, drop lock and try to load module */
237 write_unlock(&qdisc_mod_lock);
238 request_module("sch_%s", name);
239 write_lock(&qdisc_mod_lock);
240
241 ops = qdisc_lookup_default(name);
242 }
243
244 if (ops) {
245 /* Set new default */
246 module_put(default_qdisc_ops->owner);
247 default_qdisc_ops = ops;
248 }
249 write_unlock(&qdisc_mod_lock);
250
251 return ops ? 0 : -ENOENT;
252 }
253
254 /* We know handle. Find qdisc among all qdisc's attached to device
255 * (root qdisc, all its children, children of children etc.)
256 * Note: caller either uses rtnl or rcu_read_lock()
257 */
258
259 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
260 {
261 struct Qdisc *q;
262
263 if (!qdisc_dev(root))
264 return (root->handle == handle ? root : NULL);
265
266 if (!(root->flags & TCQ_F_BUILTIN) &&
267 root->handle == handle)
268 return root;
269
270 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle) {
271 if (q->handle == handle)
272 return q;
273 }
274 return NULL;
275 }
276
277 void qdisc_hash_add(struct Qdisc *q)
278 {
279 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
280 struct Qdisc *root = qdisc_dev(q)->qdisc;
281
282 WARN_ON_ONCE(root == &noop_qdisc);
283 ASSERT_RTNL();
284 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
285 }
286 }
287 EXPORT_SYMBOL(qdisc_hash_add);
288
289 void qdisc_hash_del(struct Qdisc *q)
290 {
291 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
292 ASSERT_RTNL();
293 hash_del_rcu(&q->hash);
294 }
295 }
296 EXPORT_SYMBOL(qdisc_hash_del);
297
298 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
299 {
300 struct Qdisc *q;
301
302 q = qdisc_match_from_root(dev->qdisc, handle);
303 if (q)
304 goto out;
305
306 if (dev_ingress_queue(dev))
307 q = qdisc_match_from_root(
308 dev_ingress_queue(dev)->qdisc_sleeping,
309 handle);
310 out:
311 return q;
312 }
313
314 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
315 {
316 unsigned long cl;
317 struct Qdisc *leaf;
318 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
319
320 if (cops == NULL)
321 return NULL;
322 cl = cops->get(p, classid);
323
324 if (cl == 0)
325 return NULL;
326 leaf = cops->leaf(p, cl);
327 cops->put(p, cl);
328 return leaf;
329 }
330
331 /* Find queueing discipline by name */
332
333 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
334 {
335 struct Qdisc_ops *q = NULL;
336
337 if (kind) {
338 read_lock(&qdisc_mod_lock);
339 for (q = qdisc_base; q; q = q->next) {
340 if (nla_strcmp(kind, q->id) == 0) {
341 if (!try_module_get(q->owner))
342 q = NULL;
343 break;
344 }
345 }
346 read_unlock(&qdisc_mod_lock);
347 }
348 return q;
349 }
350
351 /* The linklayer setting were not transferred from iproute2, in older
352 * versions, and the rate tables lookup systems have been dropped in
353 * the kernel. To keep backward compatible with older iproute2 tc
354 * utils, we detect the linklayer setting by detecting if the rate
355 * table were modified.
356 *
357 * For linklayer ATM table entries, the rate table will be aligned to
358 * 48 bytes, thus some table entries will contain the same value. The
359 * mpu (min packet unit) is also encoded into the old rate table, thus
360 * starting from the mpu, we find low and high table entries for
361 * mapping this cell. If these entries contain the same value, when
362 * the rate tables have been modified for linklayer ATM.
363 *
364 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
365 * and then roundup to the next cell, calc the table entry one below,
366 * and compare.
367 */
368 static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
369 {
370 int low = roundup(r->mpu, 48);
371 int high = roundup(low+1, 48);
372 int cell_low = low >> r->cell_log;
373 int cell_high = (high >> r->cell_log) - 1;
374
375 /* rtab is too inaccurate at rates > 100Mbit/s */
376 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
377 pr_debug("TC linklayer: Giving up ATM detection\n");
378 return TC_LINKLAYER_ETHERNET;
379 }
380
381 if ((cell_high > cell_low) && (cell_high < 256)
382 && (rtab[cell_low] == rtab[cell_high])) {
383 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
384 cell_low, cell_high, rtab[cell_high]);
385 return TC_LINKLAYER_ATM;
386 }
387 return TC_LINKLAYER_ETHERNET;
388 }
389
390 static struct qdisc_rate_table *qdisc_rtab_list;
391
392 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
393 struct nlattr *tab)
394 {
395 struct qdisc_rate_table *rtab;
396
397 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
398 nla_len(tab) != TC_RTAB_SIZE)
399 return NULL;
400
401 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
402 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
403 !memcmp(&rtab->data, nla_data(tab), 1024)) {
404 rtab->refcnt++;
405 return rtab;
406 }
407 }
408
409 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
410 if (rtab) {
411 rtab->rate = *r;
412 rtab->refcnt = 1;
413 memcpy(rtab->data, nla_data(tab), 1024);
414 if (r->linklayer == TC_LINKLAYER_UNAWARE)
415 r->linklayer = __detect_linklayer(r, rtab->data);
416 rtab->next = qdisc_rtab_list;
417 qdisc_rtab_list = rtab;
418 }
419 return rtab;
420 }
421 EXPORT_SYMBOL(qdisc_get_rtab);
422
423 void qdisc_put_rtab(struct qdisc_rate_table *tab)
424 {
425 struct qdisc_rate_table *rtab, **rtabp;
426
427 if (!tab || --tab->refcnt)
428 return;
429
430 for (rtabp = &qdisc_rtab_list;
431 (rtab = *rtabp) != NULL;
432 rtabp = &rtab->next) {
433 if (rtab == tab) {
434 *rtabp = rtab->next;
435 kfree(rtab);
436 return;
437 }
438 }
439 }
440 EXPORT_SYMBOL(qdisc_put_rtab);
441
442 static LIST_HEAD(qdisc_stab_list);
443
444 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
445 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
446 [TCA_STAB_DATA] = { .type = NLA_BINARY },
447 };
448
449 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
450 {
451 struct nlattr *tb[TCA_STAB_MAX + 1];
452 struct qdisc_size_table *stab;
453 struct tc_sizespec *s;
454 unsigned int tsize = 0;
455 u16 *tab = NULL;
456 int err;
457
458 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
459 if (err < 0)
460 return ERR_PTR(err);
461 if (!tb[TCA_STAB_BASE])
462 return ERR_PTR(-EINVAL);
463
464 s = nla_data(tb[TCA_STAB_BASE]);
465
466 if (s->tsize > 0) {
467 if (!tb[TCA_STAB_DATA])
468 return ERR_PTR(-EINVAL);
469 tab = nla_data(tb[TCA_STAB_DATA]);
470 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
471 }
472
473 if (tsize != s->tsize || (!tab && tsize > 0))
474 return ERR_PTR(-EINVAL);
475
476 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 return stab;
483 }
484
485 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
486 if (!stab)
487 return ERR_PTR(-ENOMEM);
488
489 stab->refcnt = 1;
490 stab->szopts = *s;
491 if (tsize > 0)
492 memcpy(stab->data, tab, tsize * sizeof(u16));
493
494 list_add_tail(&stab->list, &qdisc_stab_list);
495
496 return stab;
497 }
498
499 static void stab_kfree_rcu(struct rcu_head *head)
500 {
501 kfree(container_of(head, struct qdisc_size_table, rcu));
502 }
503
504 void qdisc_put_stab(struct qdisc_size_table *tab)
505 {
506 if (!tab)
507 return;
508
509 if (--tab->refcnt == 0) {
510 list_del(&tab->list);
511 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
512 }
513 }
514 EXPORT_SYMBOL(qdisc_put_stab);
515
516 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
517 {
518 struct nlattr *nest;
519
520 nest = nla_nest_start(skb, TCA_STAB);
521 if (nest == NULL)
522 goto nla_put_failure;
523 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
524 goto nla_put_failure;
525 nla_nest_end(skb, nest);
526
527 return skb->len;
528
529 nla_put_failure:
530 return -1;
531 }
532
533 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
534 const struct qdisc_size_table *stab)
535 {
536 int pkt_len, slot;
537
538 pkt_len = skb->len + stab->szopts.overhead;
539 if (unlikely(!stab->szopts.tsize))
540 goto out;
541
542 slot = pkt_len + stab->szopts.cell_align;
543 if (unlikely(slot < 0))
544 slot = 0;
545
546 slot >>= stab->szopts.cell_log;
547 if (likely(slot < stab->szopts.tsize))
548 pkt_len = stab->data[slot];
549 else
550 pkt_len = stab->data[stab->szopts.tsize - 1] *
551 (slot / stab->szopts.tsize) +
552 stab->data[slot % stab->szopts.tsize];
553
554 pkt_len <<= stab->szopts.size_log;
555 out:
556 if (unlikely(pkt_len < 1))
557 pkt_len = 1;
558 qdisc_skb_cb(skb)->pkt_len = pkt_len;
559 }
560 EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
561
562 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
563 {
564 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
565 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
566 txt, qdisc->ops->id, qdisc->handle >> 16);
567 qdisc->flags |= TCQ_F_WARN_NONWC;
568 }
569 }
570 EXPORT_SYMBOL(qdisc_warn_nonwc);
571
572 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
573 {
574 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
575 timer);
576
577 rcu_read_lock();
578 __netif_schedule(qdisc_root(wd->qdisc));
579 rcu_read_unlock();
580
581 return HRTIMER_NORESTART;
582 }
583
584 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
585 {
586 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
587 wd->timer.function = qdisc_watchdog;
588 wd->qdisc = qdisc;
589 }
590 EXPORT_SYMBOL(qdisc_watchdog_init);
591
592 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
593 {
594 if (test_bit(__QDISC_STATE_DEACTIVATED,
595 &qdisc_root_sleeping(wd->qdisc)->state))
596 return;
597
598 if (wd->last_expires == expires)
599 return;
600
601 wd->last_expires = expires;
602 hrtimer_start(&wd->timer,
603 ns_to_ktime(expires),
604 HRTIMER_MODE_ABS_PINNED);
605 }
606 EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
607
608 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
609 {
610 hrtimer_cancel(&wd->timer);
611 }
612 EXPORT_SYMBOL(qdisc_watchdog_cancel);
613
614 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
615 {
616 unsigned int size = n * sizeof(struct hlist_head), i;
617 struct hlist_head *h;
618
619 if (size <= PAGE_SIZE)
620 h = kmalloc(size, GFP_KERNEL);
621 else
622 h = (struct hlist_head *)
623 __get_free_pages(GFP_KERNEL, get_order(size));
624
625 if (h != NULL) {
626 for (i = 0; i < n; i++)
627 INIT_HLIST_HEAD(&h[i]);
628 }
629 return h;
630 }
631
632 static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
633 {
634 unsigned int size = n * sizeof(struct hlist_head);
635
636 if (size <= PAGE_SIZE)
637 kfree(h);
638 else
639 free_pages((unsigned long)h, get_order(size));
640 }
641
642 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
643 {
644 struct Qdisc_class_common *cl;
645 struct hlist_node *next;
646 struct hlist_head *nhash, *ohash;
647 unsigned int nsize, nmask, osize;
648 unsigned int i, h;
649
650 /* Rehash when load factor exceeds 0.75 */
651 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
652 return;
653 nsize = clhash->hashsize * 2;
654 nmask = nsize - 1;
655 nhash = qdisc_class_hash_alloc(nsize);
656 if (nhash == NULL)
657 return;
658
659 ohash = clhash->hash;
660 osize = clhash->hashsize;
661
662 sch_tree_lock(sch);
663 for (i = 0; i < osize; i++) {
664 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
665 h = qdisc_class_hash(cl->classid, nmask);
666 hlist_add_head(&cl->hnode, &nhash[h]);
667 }
668 }
669 clhash->hash = nhash;
670 clhash->hashsize = nsize;
671 clhash->hashmask = nmask;
672 sch_tree_unlock(sch);
673
674 qdisc_class_hash_free(ohash, osize);
675 }
676 EXPORT_SYMBOL(qdisc_class_hash_grow);
677
678 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
679 {
680 unsigned int size = 4;
681
682 clhash->hash = qdisc_class_hash_alloc(size);
683 if (clhash->hash == NULL)
684 return -ENOMEM;
685 clhash->hashsize = size;
686 clhash->hashmask = size - 1;
687 clhash->hashelems = 0;
688 return 0;
689 }
690 EXPORT_SYMBOL(qdisc_class_hash_init);
691
692 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
693 {
694 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
695 }
696 EXPORT_SYMBOL(qdisc_class_hash_destroy);
697
698 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
699 struct Qdisc_class_common *cl)
700 {
701 unsigned int h;
702
703 INIT_HLIST_NODE(&cl->hnode);
704 h = qdisc_class_hash(cl->classid, clhash->hashmask);
705 hlist_add_head(&cl->hnode, &clhash->hash[h]);
706 clhash->hashelems++;
707 }
708 EXPORT_SYMBOL(qdisc_class_hash_insert);
709
710 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
711 struct Qdisc_class_common *cl)
712 {
713 hlist_del(&cl->hnode);
714 clhash->hashelems--;
715 }
716 EXPORT_SYMBOL(qdisc_class_hash_remove);
717
718 /* Allocate an unique handle from space managed by kernel
719 * Possible range is [8000-FFFF]:0000 (0x8000 values)
720 */
721 static u32 qdisc_alloc_handle(struct net_device *dev)
722 {
723 int i = 0x8000;
724 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
725
726 do {
727 autohandle += TC_H_MAKE(0x10000U, 0);
728 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
729 autohandle = TC_H_MAKE(0x80000000U, 0);
730 if (!qdisc_lookup(dev, autohandle))
731 return autohandle;
732 cond_resched();
733 } while (--i > 0);
734
735 return 0;
736 }
737
738 void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,
739 unsigned int len)
740 {
741 const struct Qdisc_class_ops *cops;
742 unsigned long cl;
743 u32 parentid;
744 int drops;
745
746 if (n == 0 && len == 0)
747 return;
748 drops = max_t(int, n, 0);
749 rcu_read_lock();
750 while ((parentid = sch->parent)) {
751 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
752 break;
753
754 if (sch->flags & TCQ_F_NOPARENT)
755 break;
756 /* TODO: perform the search on a per txq basis */
757 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
758 if (sch == NULL) {
759 WARN_ON_ONCE(parentid != TC_H_ROOT);
760 break;
761 }
762 cops = sch->ops->cl_ops;
763 if (cops->qlen_notify) {
764 cl = cops->get(sch, parentid);
765 cops->qlen_notify(sch, cl);
766 cops->put(sch, cl);
767 }
768 sch->q.qlen -= n;
769 sch->qstats.backlog -= len;
770 __qdisc_qstats_drop(sch, drops);
771 }
772 rcu_read_unlock();
773 }
774 EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
775
776 static void notify_and_destroy(struct net *net, struct sk_buff *skb,
777 struct nlmsghdr *n, u32 clid,
778 struct Qdisc *old, struct Qdisc *new)
779 {
780 if (new || old)
781 qdisc_notify(net, skb, n, clid, old, new);
782
783 if (old)
784 qdisc_destroy(old);
785 }
786
787 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
788 * to device "dev".
789 *
790 * When appropriate send a netlink notification using 'skb'
791 * and "n".
792 *
793 * On success, destroy old qdisc.
794 */
795
796 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
797 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
798 struct Qdisc *new, struct Qdisc *old)
799 {
800 struct Qdisc *q = old;
801 struct net *net = dev_net(dev);
802 int err = 0;
803
804 if (parent == NULL) {
805 unsigned int i, num_q, ingress;
806
807 ingress = 0;
808 num_q = dev->num_tx_queues;
809 if ((q && q->flags & TCQ_F_INGRESS) ||
810 (new && new->flags & TCQ_F_INGRESS)) {
811 num_q = 1;
812 ingress = 1;
813 if (!dev_ingress_queue(dev))
814 return -ENOENT;
815 }
816
817 if (dev->flags & IFF_UP)
818 dev_deactivate(dev);
819
820 if (new && new->ops->attach)
821 goto skip;
822
823 for (i = 0; i < num_q; i++) {
824 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
825
826 if (!ingress)
827 dev_queue = netdev_get_tx_queue(dev, i);
828
829 old = dev_graft_qdisc(dev_queue, new);
830 if (new && i > 0)
831 atomic_inc(&new->refcnt);
832
833 if (!ingress)
834 qdisc_destroy(old);
835 }
836
837 skip:
838 if (!ingress) {
839 notify_and_destroy(net, skb, n, classid,
840 dev->qdisc, new);
841 if (new && !new->ops->attach)
842 atomic_inc(&new->refcnt);
843 dev->qdisc = new ? : &noop_qdisc;
844
845 if (new && new->ops->attach)
846 new->ops->attach(new);
847 } else {
848 notify_and_destroy(net, skb, n, classid, old, new);
849 }
850
851 if (dev->flags & IFF_UP)
852 dev_activate(dev);
853 } else {
854 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
855
856 err = -EOPNOTSUPP;
857 if (cops && cops->graft) {
858 unsigned long cl = cops->get(parent, classid);
859 if (cl) {
860 err = cops->graft(parent, cl, new, &old);
861 cops->put(parent, cl);
862 } else
863 err = -ENOENT;
864 }
865 if (!err)
866 notify_and_destroy(net, skb, n, classid, old, new);
867 }
868 return err;
869 }
870
871 /* lockdep annotation is needed for ingress; egress gets it only for name */
872 static struct lock_class_key qdisc_tx_lock;
873 static struct lock_class_key qdisc_rx_lock;
874
875 /*
876 Allocate and initialize new qdisc.
877
878 Parameters are passed via opt.
879 */
880
881 static struct Qdisc *qdisc_create(struct net_device *dev,
882 struct netdev_queue *dev_queue,
883 struct Qdisc *p, u32 parent, u32 handle,
884 struct nlattr **tca, int *errp)
885 {
886 int err;
887 struct nlattr *kind = tca[TCA_KIND];
888 struct Qdisc *sch;
889 struct Qdisc_ops *ops;
890 struct qdisc_size_table *stab;
891
892 ops = qdisc_lookup_ops(kind);
893 #ifdef CONFIG_MODULES
894 if (ops == NULL && kind != NULL) {
895 char name[IFNAMSIZ];
896 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
897 /* We dropped the RTNL semaphore in order to
898 * perform the module load. So, even if we
899 * succeeded in loading the module we have to
900 * tell the caller to replay the request. We
901 * indicate this using -EAGAIN.
902 * We replay the request because the device may
903 * go away in the mean time.
904 */
905 rtnl_unlock();
906 request_module("sch_%s", name);
907 rtnl_lock();
908 ops = qdisc_lookup_ops(kind);
909 if (ops != NULL) {
910 /* We will try again qdisc_lookup_ops,
911 * so don't keep a reference.
912 */
913 module_put(ops->owner);
914 err = -EAGAIN;
915 goto err_out;
916 }
917 }
918 }
919 #endif
920
921 err = -ENOENT;
922 if (ops == NULL)
923 goto err_out;
924
925 sch = qdisc_alloc(dev_queue, ops);
926 if (IS_ERR(sch)) {
927 err = PTR_ERR(sch);
928 goto err_out2;
929 }
930
931 sch->parent = parent;
932
933 if (handle == TC_H_INGRESS) {
934 sch->flags |= TCQ_F_INGRESS;
935 handle = TC_H_MAKE(TC_H_INGRESS, 0);
936 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
937 } else {
938 if (handle == 0) {
939 handle = qdisc_alloc_handle(dev);
940 err = -ENOMEM;
941 if (handle == 0)
942 goto err_out3;
943 }
944 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
945 if (!netif_is_multiqueue(dev))
946 sch->flags |= TCQ_F_ONETXQUEUE;
947 }
948
949 sch->handle = handle;
950
951 /* This exist to keep backward compatible with a userspace
952 * loophole, what allowed userspace to get IFF_NO_QUEUE
953 * facility on older kernels by setting tx_queue_len=0 (prior
954 * to qdisc init), and then forgot to reinit tx_queue_len
955 * before again attaching a qdisc.
956 */
957 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) {
958 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
959 netdev_info(dev, "Caught tx_queue_len zero misconfig\n");
960 }
961
962 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
963 if (qdisc_is_percpu_stats(sch)) {
964 sch->cpu_bstats =
965 netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
966 if (!sch->cpu_bstats)
967 goto err_out4;
968
969 sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
970 if (!sch->cpu_qstats)
971 goto err_out4;
972 }
973
974 if (tca[TCA_STAB]) {
975 stab = qdisc_get_stab(tca[TCA_STAB]);
976 if (IS_ERR(stab)) {
977 err = PTR_ERR(stab);
978 goto err_out4;
979 }
980 rcu_assign_pointer(sch->stab, stab);
981 }
982 if (tca[TCA_RATE]) {
983 seqcount_t *running;
984
985 err = -EOPNOTSUPP;
986 if (sch->flags & TCQ_F_MQROOT)
987 goto err_out4;
988
989 if ((sch->parent != TC_H_ROOT) &&
990 !(sch->flags & TCQ_F_INGRESS) &&
991 (!p || !(p->flags & TCQ_F_MQROOT)))
992 running = qdisc_root_sleeping_running(sch);
993 else
994 running = &sch->running;
995
996 err = gen_new_estimator(&sch->bstats,
997 sch->cpu_bstats,
998 &sch->rate_est,
999 NULL,
1000 running,
1001 tca[TCA_RATE]);
1002 if (err)
1003 goto err_out4;
1004 }
1005
1006 qdisc_hash_add(sch);
1007
1008 return sch;
1009 }
1010 /* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */
1011 ops->destroy(sch);
1012 err_out3:
1013 dev_put(dev);
1014 kfree((char *) sch - sch->padded);
1015 err_out2:
1016 module_put(ops->owner);
1017 err_out:
1018 *errp = err;
1019 return NULL;
1020
1021 err_out4:
1022 free_percpu(sch->cpu_bstats);
1023 free_percpu(sch->cpu_qstats);
1024 /*
1025 * Any broken qdiscs that would require a ops->reset() here?
1026 * The qdisc was never in action so it shouldn't be necessary.
1027 */
1028 qdisc_put_stab(rtnl_dereference(sch->stab));
1029 if (ops->destroy)
1030 ops->destroy(sch);
1031 goto err_out3;
1032 }
1033
1034 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
1035 {
1036 struct qdisc_size_table *ostab, *stab = NULL;
1037 int err = 0;
1038
1039 if (tca[TCA_OPTIONS]) {
1040 if (sch->ops->change == NULL)
1041 return -EINVAL;
1042 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
1043 if (err)
1044 return err;
1045 }
1046
1047 if (tca[TCA_STAB]) {
1048 stab = qdisc_get_stab(tca[TCA_STAB]);
1049 if (IS_ERR(stab))
1050 return PTR_ERR(stab);
1051 }
1052
1053 ostab = rtnl_dereference(sch->stab);
1054 rcu_assign_pointer(sch->stab, stab);
1055 qdisc_put_stab(ostab);
1056
1057 if (tca[TCA_RATE]) {
1058 /* NB: ignores errors from replace_estimator
1059 because change can't be undone. */
1060 if (sch->flags & TCQ_F_MQROOT)
1061 goto out;
1062 gen_replace_estimator(&sch->bstats,
1063 sch->cpu_bstats,
1064 &sch->rate_est,
1065 NULL,
1066 qdisc_root_sleeping_running(sch),
1067 tca[TCA_RATE]);
1068 }
1069 out:
1070 return 0;
1071 }
1072
1073 struct check_loop_arg {
1074 struct qdisc_walker w;
1075 struct Qdisc *p;
1076 int depth;
1077 };
1078
1079 static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1080 struct qdisc_walker *w);
1081
1082 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1083 {
1084 struct check_loop_arg arg;
1085
1086 if (q->ops->cl_ops == NULL)
1087 return 0;
1088
1089 arg.w.stop = arg.w.skip = arg.w.count = 0;
1090 arg.w.fn = check_loop_fn;
1091 arg.depth = depth;
1092 arg.p = p;
1093 q->ops->cl_ops->walk(q, &arg.w);
1094 return arg.w.stop ? -ELOOP : 0;
1095 }
1096
1097 static int
1098 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1099 {
1100 struct Qdisc *leaf;
1101 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1102 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1103
1104 leaf = cops->leaf(q, cl);
1105 if (leaf) {
1106 if (leaf == arg->p || arg->depth > 7)
1107 return -ELOOP;
1108 return check_loop(leaf, arg->p, arg->depth + 1);
1109 }
1110 return 0;
1111 }
1112
1113 /*
1114 * Delete/get qdisc.
1115 */
1116
1117 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1118 {
1119 struct net *net = sock_net(skb->sk);
1120 struct tcmsg *tcm = nlmsg_data(n);
1121 struct nlattr *tca[TCA_MAX + 1];
1122 struct net_device *dev;
1123 u32 clid;
1124 struct Qdisc *q = NULL;
1125 struct Qdisc *p = NULL;
1126 int err;
1127
1128 if ((n->nlmsg_type != RTM_GETQDISC) &&
1129 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1130 return -EPERM;
1131
1132 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1133 if (err < 0)
1134 return err;
1135
1136 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1137 if (!dev)
1138 return -ENODEV;
1139
1140 clid = tcm->tcm_parent;
1141 if (clid) {
1142 if (clid != TC_H_ROOT) {
1143 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1144 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1145 if (!p)
1146 return -ENOENT;
1147 q = qdisc_leaf(p, clid);
1148 } else if (dev_ingress_queue(dev)) {
1149 q = dev_ingress_queue(dev)->qdisc_sleeping;
1150 }
1151 } else {
1152 q = dev->qdisc;
1153 }
1154 if (!q)
1155 return -ENOENT;
1156
1157 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1158 return -EINVAL;
1159 } else {
1160 q = qdisc_lookup(dev, tcm->tcm_handle);
1161 if (!q)
1162 return -ENOENT;
1163 }
1164
1165 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1166 return -EINVAL;
1167
1168 if (n->nlmsg_type == RTM_DELQDISC) {
1169 if (!clid)
1170 return -EINVAL;
1171 if (q->handle == 0)
1172 return -ENOENT;
1173 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1174 if (err != 0)
1175 return err;
1176 } else {
1177 qdisc_notify(net, skb, n, clid, NULL, q);
1178 }
1179 return 0;
1180 }
1181
1182 /*
1183 * Create/change qdisc.
1184 */
1185
1186 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1187 {
1188 struct net *net = sock_net(skb->sk);
1189 struct tcmsg *tcm;
1190 struct nlattr *tca[TCA_MAX + 1];
1191 struct net_device *dev;
1192 u32 clid;
1193 struct Qdisc *q, *p;
1194 int err;
1195
1196 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1197 return -EPERM;
1198
1199 replay:
1200 /* Reinit, just in case something touches this. */
1201 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1202 if (err < 0)
1203 return err;
1204
1205 tcm = nlmsg_data(n);
1206 clid = tcm->tcm_parent;
1207 q = p = NULL;
1208
1209 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1210 if (!dev)
1211 return -ENODEV;
1212
1213
1214 if (clid) {
1215 if (clid != TC_H_ROOT) {
1216 if (clid != TC_H_INGRESS) {
1217 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1218 if (!p)
1219 return -ENOENT;
1220 q = qdisc_leaf(p, clid);
1221 } else if (dev_ingress_queue_create(dev)) {
1222 q = dev_ingress_queue(dev)->qdisc_sleeping;
1223 }
1224 } else {
1225 q = dev->qdisc;
1226 }
1227
1228 /* It may be default qdisc, ignore it */
1229 if (q && q->handle == 0)
1230 q = NULL;
1231
1232 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1233 if (tcm->tcm_handle) {
1234 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1235 return -EEXIST;
1236 if (TC_H_MIN(tcm->tcm_handle))
1237 return -EINVAL;
1238 q = qdisc_lookup(dev, tcm->tcm_handle);
1239 if (!q)
1240 goto create_n_graft;
1241 if (n->nlmsg_flags & NLM_F_EXCL)
1242 return -EEXIST;
1243 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1244 return -EINVAL;
1245 if (q == p ||
1246 (p && check_loop(q, p, 0)))
1247 return -ELOOP;
1248 atomic_inc(&q->refcnt);
1249 goto graft;
1250 } else {
1251 if (!q)
1252 goto create_n_graft;
1253
1254 /* This magic test requires explanation.
1255 *
1256 * We know, that some child q is already
1257 * attached to this parent and have choice:
1258 * either to change it or to create/graft new one.
1259 *
1260 * 1. We are allowed to create/graft only
1261 * if CREATE and REPLACE flags are set.
1262 *
1263 * 2. If EXCL is set, requestor wanted to say,
1264 * that qdisc tcm_handle is not expected
1265 * to exist, so that we choose create/graft too.
1266 *
1267 * 3. The last case is when no flags are set.
1268 * Alas, it is sort of hole in API, we
1269 * cannot decide what to do unambiguously.
1270 * For now we select create/graft, if
1271 * user gave KIND, which does not match existing.
1272 */
1273 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1274 (n->nlmsg_flags & NLM_F_REPLACE) &&
1275 ((n->nlmsg_flags & NLM_F_EXCL) ||
1276 (tca[TCA_KIND] &&
1277 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1278 goto create_n_graft;
1279 }
1280 }
1281 } else {
1282 if (!tcm->tcm_handle)
1283 return -EINVAL;
1284 q = qdisc_lookup(dev, tcm->tcm_handle);
1285 }
1286
1287 /* Change qdisc parameters */
1288 if (q == NULL)
1289 return -ENOENT;
1290 if (n->nlmsg_flags & NLM_F_EXCL)
1291 return -EEXIST;
1292 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1293 return -EINVAL;
1294 err = qdisc_change(q, tca);
1295 if (err == 0)
1296 qdisc_notify(net, skb, n, clid, NULL, q);
1297 return err;
1298
1299 create_n_graft:
1300 if (!(n->nlmsg_flags & NLM_F_CREATE))
1301 return -ENOENT;
1302 if (clid == TC_H_INGRESS) {
1303 if (dev_ingress_queue(dev))
1304 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1305 tcm->tcm_parent, tcm->tcm_parent,
1306 tca, &err);
1307 else
1308 err = -ENOENT;
1309 } else {
1310 struct netdev_queue *dev_queue;
1311
1312 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1313 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1314 else if (p)
1315 dev_queue = p->dev_queue;
1316 else
1317 dev_queue = netdev_get_tx_queue(dev, 0);
1318
1319 q = qdisc_create(dev, dev_queue, p,
1320 tcm->tcm_parent, tcm->tcm_handle,
1321 tca, &err);
1322 }
1323 if (q == NULL) {
1324 if (err == -EAGAIN)
1325 goto replay;
1326 return err;
1327 }
1328
1329 graft:
1330 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1331 if (err) {
1332 if (q)
1333 qdisc_destroy(q);
1334 return err;
1335 }
1336
1337 return 0;
1338 }
1339
1340 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1341 u32 portid, u32 seq, u16 flags, int event)
1342 {
1343 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
1344 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
1345 struct tcmsg *tcm;
1346 struct nlmsghdr *nlh;
1347 unsigned char *b = skb_tail_pointer(skb);
1348 struct gnet_dump d;
1349 struct qdisc_size_table *stab;
1350 __u32 qlen;
1351
1352 cond_resched();
1353 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1354 if (!nlh)
1355 goto out_nlmsg_trim;
1356 tcm = nlmsg_data(nlh);
1357 tcm->tcm_family = AF_UNSPEC;
1358 tcm->tcm__pad1 = 0;
1359 tcm->tcm__pad2 = 0;
1360 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1361 tcm->tcm_parent = clid;
1362 tcm->tcm_handle = q->handle;
1363 tcm->tcm_info = atomic_read(&q->refcnt);
1364 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1365 goto nla_put_failure;
1366 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1367 goto nla_put_failure;
1368 qlen = q->q.qlen;
1369
1370 stab = rtnl_dereference(q->stab);
1371 if (stab && qdisc_dump_stab(skb, stab) < 0)
1372 goto nla_put_failure;
1373
1374 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1375 NULL, &d, TCA_PAD) < 0)
1376 goto nla_put_failure;
1377
1378 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1379 goto nla_put_failure;
1380
1381 if (qdisc_is_percpu_stats(q)) {
1382 cpu_bstats = q->cpu_bstats;
1383 cpu_qstats = q->cpu_qstats;
1384 }
1385
1386 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(q),
1387 &d, cpu_bstats, &q->bstats) < 0 ||
1388 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
1389 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
1390 goto nla_put_failure;
1391
1392 if (gnet_stats_finish_copy(&d) < 0)
1393 goto nla_put_failure;
1394
1395 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1396 return skb->len;
1397
1398 out_nlmsg_trim:
1399 nla_put_failure:
1400 nlmsg_trim(skb, b);
1401 return -1;
1402 }
1403
1404 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1405 {
1406 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1407 }
1408
1409 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1410 struct nlmsghdr *n, u32 clid,
1411 struct Qdisc *old, struct Qdisc *new)
1412 {
1413 struct sk_buff *skb;
1414 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1415
1416 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1417 if (!skb)
1418 return -ENOBUFS;
1419
1420 if (old && !tc_qdisc_dump_ignore(old)) {
1421 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1422 0, RTM_DELQDISC) < 0)
1423 goto err_out;
1424 }
1425 if (new && !tc_qdisc_dump_ignore(new)) {
1426 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1427 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1428 goto err_out;
1429 }
1430
1431 if (skb->len)
1432 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1433 n->nlmsg_flags & NLM_F_ECHO);
1434
1435 err_out:
1436 kfree_skb(skb);
1437 return -EINVAL;
1438 }
1439
1440 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1441 struct netlink_callback *cb,
1442 int *q_idx_p, int s_q_idx, bool recur)
1443 {
1444 int ret = 0, q_idx = *q_idx_p;
1445 struct Qdisc *q;
1446 int b;
1447
1448 if (!root)
1449 return 0;
1450
1451 q = root;
1452 if (q_idx < s_q_idx) {
1453 q_idx++;
1454 } else {
1455 if (!tc_qdisc_dump_ignore(q) &&
1456 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1457 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1458 RTM_NEWQDISC) <= 0)
1459 goto done;
1460 q_idx++;
1461 }
1462
1463 /* If dumping singletons, there is no qdisc_dev(root) and the singleton
1464 * itself has already been dumped.
1465 *
1466 * If we've already dumped the top-level (ingress) qdisc above and the global
1467 * qdisc hashtable, we don't want to hit it again
1468 */
1469 if (!qdisc_dev(root) || !recur)
1470 goto out;
1471
1472 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1473 if (q_idx < s_q_idx) {
1474 q_idx++;
1475 continue;
1476 }
1477 if (!tc_qdisc_dump_ignore(q) &&
1478 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1479 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1480 RTM_NEWQDISC) <= 0)
1481 goto done;
1482 q_idx++;
1483 }
1484
1485 out:
1486 *q_idx_p = q_idx;
1487 return ret;
1488 done:
1489 ret = -1;
1490 goto out;
1491 }
1492
1493 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1494 {
1495 struct net *net = sock_net(skb->sk);
1496 int idx, q_idx;
1497 int s_idx, s_q_idx;
1498 struct net_device *dev;
1499
1500 s_idx = cb->args[0];
1501 s_q_idx = q_idx = cb->args[1];
1502
1503 idx = 0;
1504 ASSERT_RTNL();
1505 for_each_netdev(net, dev) {
1506 struct netdev_queue *dev_queue;
1507
1508 if (idx < s_idx)
1509 goto cont;
1510 if (idx > s_idx)
1511 s_q_idx = 0;
1512 q_idx = 0;
1513
1514 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx,
1515 true) < 0)
1516 goto done;
1517
1518 dev_queue = dev_ingress_queue(dev);
1519 if (dev_queue &&
1520 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1521 &q_idx, s_q_idx, false) < 0)
1522 goto done;
1523
1524 cont:
1525 idx++;
1526 }
1527
1528 done:
1529 cb->args[0] = idx;
1530 cb->args[1] = q_idx;
1531
1532 return skb->len;
1533 }
1534
1535
1536
1537 /************************************************
1538 * Traffic classes manipulation. *
1539 ************************************************/
1540
1541
1542
1543 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n)
1544 {
1545 struct net *net = sock_net(skb->sk);
1546 struct tcmsg *tcm = nlmsg_data(n);
1547 struct nlattr *tca[TCA_MAX + 1];
1548 struct net_device *dev;
1549 struct Qdisc *q = NULL;
1550 const struct Qdisc_class_ops *cops;
1551 unsigned long cl = 0;
1552 unsigned long new_cl;
1553 u32 portid;
1554 u32 clid;
1555 u32 qid;
1556 int err;
1557
1558 if ((n->nlmsg_type != RTM_GETTCLASS) &&
1559 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1560 return -EPERM;
1561
1562 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1563 if (err < 0)
1564 return err;
1565
1566 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1567 if (!dev)
1568 return -ENODEV;
1569
1570 /*
1571 parent == TC_H_UNSPEC - unspecified parent.
1572 parent == TC_H_ROOT - class is root, which has no parent.
1573 parent == X:0 - parent is root class.
1574 parent == X:Y - parent is a node in hierarchy.
1575 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1576
1577 handle == 0:0 - generate handle from kernel pool.
1578 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1579 handle == X:Y - clear.
1580 handle == X:0 - root class.
1581 */
1582
1583 /* Step 1. Determine qdisc handle X:0 */
1584
1585 portid = tcm->tcm_parent;
1586 clid = tcm->tcm_handle;
1587 qid = TC_H_MAJ(clid);
1588
1589 if (portid != TC_H_ROOT) {
1590 u32 qid1 = TC_H_MAJ(portid);
1591
1592 if (qid && qid1) {
1593 /* If both majors are known, they must be identical. */
1594 if (qid != qid1)
1595 return -EINVAL;
1596 } else if (qid1) {
1597 qid = qid1;
1598 } else if (qid == 0)
1599 qid = dev->qdisc->handle;
1600
1601 /* Now qid is genuine qdisc handle consistent
1602 * both with parent and child.
1603 *
1604 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1605 */
1606 if (portid)
1607 portid = TC_H_MAKE(qid, portid);
1608 } else {
1609 if (qid == 0)
1610 qid = dev->qdisc->handle;
1611 }
1612
1613 /* OK. Locate qdisc */
1614 q = qdisc_lookup(dev, qid);
1615 if (!q)
1616 return -ENOENT;
1617
1618 /* An check that it supports classes */
1619 cops = q->ops->cl_ops;
1620 if (cops == NULL)
1621 return -EINVAL;
1622
1623 /* Now try to get class */
1624 if (clid == 0) {
1625 if (portid == TC_H_ROOT)
1626 clid = qid;
1627 } else
1628 clid = TC_H_MAKE(qid, clid);
1629
1630 if (clid)
1631 cl = cops->get(q, clid);
1632
1633 if (cl == 0) {
1634 err = -ENOENT;
1635 if (n->nlmsg_type != RTM_NEWTCLASS ||
1636 !(n->nlmsg_flags & NLM_F_CREATE))
1637 goto out;
1638 } else {
1639 switch (n->nlmsg_type) {
1640 case RTM_NEWTCLASS:
1641 err = -EEXIST;
1642 if (n->nlmsg_flags & NLM_F_EXCL)
1643 goto out;
1644 break;
1645 case RTM_DELTCLASS:
1646 err = -EOPNOTSUPP;
1647 if (cops->delete)
1648 err = cops->delete(q, cl);
1649 if (err == 0)
1650 tclass_notify(net, skb, n, q, cl,
1651 RTM_DELTCLASS);
1652 goto out;
1653 case RTM_GETTCLASS:
1654 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1655 goto out;
1656 default:
1657 err = -EINVAL;
1658 goto out;
1659 }
1660 }
1661
1662 new_cl = cl;
1663 err = -EOPNOTSUPP;
1664 if (cops->change)
1665 err = cops->change(q, clid, portid, tca, &new_cl);
1666 if (err == 0)
1667 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1668
1669 out:
1670 if (cl)
1671 cops->put(q, cl);
1672
1673 return err;
1674 }
1675
1676
1677 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1678 unsigned long cl,
1679 u32 portid, u32 seq, u16 flags, int event)
1680 {
1681 struct tcmsg *tcm;
1682 struct nlmsghdr *nlh;
1683 unsigned char *b = skb_tail_pointer(skb);
1684 struct gnet_dump d;
1685 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1686
1687 cond_resched();
1688 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1689 if (!nlh)
1690 goto out_nlmsg_trim;
1691 tcm = nlmsg_data(nlh);
1692 tcm->tcm_family = AF_UNSPEC;
1693 tcm->tcm__pad1 = 0;
1694 tcm->tcm__pad2 = 0;
1695 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1696 tcm->tcm_parent = q->handle;
1697 tcm->tcm_handle = q->handle;
1698 tcm->tcm_info = 0;
1699 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1700 goto nla_put_failure;
1701 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1702 goto nla_put_failure;
1703
1704 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1705 NULL, &d, TCA_PAD) < 0)
1706 goto nla_put_failure;
1707
1708 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1709 goto nla_put_failure;
1710
1711 if (gnet_stats_finish_copy(&d) < 0)
1712 goto nla_put_failure;
1713
1714 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1715 return skb->len;
1716
1717 out_nlmsg_trim:
1718 nla_put_failure:
1719 nlmsg_trim(skb, b);
1720 return -1;
1721 }
1722
1723 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1724 struct nlmsghdr *n, struct Qdisc *q,
1725 unsigned long cl, int event)
1726 {
1727 struct sk_buff *skb;
1728 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1729
1730 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1731 if (!skb)
1732 return -ENOBUFS;
1733
1734 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1735 kfree_skb(skb);
1736 return -EINVAL;
1737 }
1738
1739 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1740 n->nlmsg_flags & NLM_F_ECHO);
1741 }
1742
1743 struct qdisc_dump_args {
1744 struct qdisc_walker w;
1745 struct sk_buff *skb;
1746 struct netlink_callback *cb;
1747 };
1748
1749 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
1750 struct qdisc_walker *arg)
1751 {
1752 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1753
1754 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1755 a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
1756 RTM_NEWTCLASS);
1757 }
1758
1759 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1760 struct tcmsg *tcm, struct netlink_callback *cb,
1761 int *t_p, int s_t)
1762 {
1763 struct qdisc_dump_args arg;
1764
1765 if (tc_qdisc_dump_ignore(q) ||
1766 *t_p < s_t || !q->ops->cl_ops ||
1767 (tcm->tcm_parent &&
1768 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1769 (*t_p)++;
1770 return 0;
1771 }
1772 if (*t_p > s_t)
1773 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1774 arg.w.fn = qdisc_class_dump;
1775 arg.skb = skb;
1776 arg.cb = cb;
1777 arg.w.stop = 0;
1778 arg.w.skip = cb->args[1];
1779 arg.w.count = 0;
1780 q->ops->cl_ops->walk(q, &arg.w);
1781 cb->args[1] = arg.w.count;
1782 if (arg.w.stop)
1783 return -1;
1784 (*t_p)++;
1785 return 0;
1786 }
1787
1788 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1789 struct tcmsg *tcm, struct netlink_callback *cb,
1790 int *t_p, int s_t)
1791 {
1792 struct Qdisc *q;
1793 int b;
1794
1795 if (!root)
1796 return 0;
1797
1798 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1799 return -1;
1800
1801 if (!qdisc_dev(root))
1802 return 0;
1803
1804 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1805 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1806 return -1;
1807 }
1808
1809 return 0;
1810 }
1811
1812 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1813 {
1814 struct tcmsg *tcm = nlmsg_data(cb->nlh);
1815 struct net *net = sock_net(skb->sk);
1816 struct netdev_queue *dev_queue;
1817 struct net_device *dev;
1818 int t, s_t;
1819
1820 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1821 return 0;
1822 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1823 if (!dev)
1824 return 0;
1825
1826 s_t = cb->args[0];
1827 t = 0;
1828
1829 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1830 goto done;
1831
1832 dev_queue = dev_ingress_queue(dev);
1833 if (dev_queue &&
1834 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1835 &t, s_t) < 0)
1836 goto done;
1837
1838 done:
1839 cb->args[0] = t;
1840
1841 dev_put(dev);
1842 return skb->len;
1843 }
1844
1845 /* Main classifier routine: scans classifier chain attached
1846 * to this qdisc, (optionally) tests for protocol and asks
1847 * specific classifiers.
1848 */
1849 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1850 struct tcf_result *res, bool compat_mode)
1851 {
1852 __be16 protocol = tc_skb_protocol(skb);
1853 #ifdef CONFIG_NET_CLS_ACT
1854 const int max_reclassify_loop = 4;
1855 const struct tcf_proto *old_tp = tp;
1856 int limit = 0;
1857
1858 reclassify:
1859 #endif
1860 for (; tp; tp = rcu_dereference_bh(tp->next)) {
1861 int err;
1862
1863 if (tp->protocol != protocol &&
1864 tp->protocol != htons(ETH_P_ALL))
1865 continue;
1866
1867 err = tp->classify(skb, tp, res);
1868 #ifdef CONFIG_NET_CLS_ACT
1869 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode))
1870 goto reset;
1871 #endif
1872 if (err >= 0)
1873 return err;
1874 }
1875
1876 return TC_ACT_UNSPEC; /* signal: continue lookup */
1877 #ifdef CONFIG_NET_CLS_ACT
1878 reset:
1879 if (unlikely(limit++ >= max_reclassify_loop)) {
1880 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n",
1881 tp->q->ops->id, tp->prio & 0xffff,
1882 ntohs(tp->protocol));
1883 return TC_ACT_SHOT;
1884 }
1885
1886 tp = old_tp;
1887 protocol = tc_skb_protocol(skb);
1888 goto reclassify;
1889 #endif
1890 }
1891 EXPORT_SYMBOL(tc_classify);
1892
1893 #ifdef CONFIG_PROC_FS
1894 static int psched_show(struct seq_file *seq, void *v)
1895 {
1896 seq_printf(seq, "%08x %08x %08x %08x\n",
1897 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1898 1000000,
1899 (u32)NSEC_PER_SEC / hrtimer_resolution);
1900
1901 return 0;
1902 }
1903
1904 static int psched_open(struct inode *inode, struct file *file)
1905 {
1906 return single_open(file, psched_show, NULL);
1907 }
1908
1909 static const struct file_operations psched_fops = {
1910 .owner = THIS_MODULE,
1911 .open = psched_open,
1912 .read = seq_read,
1913 .llseek = seq_lseek,
1914 .release = single_release,
1915 };
1916
1917 static int __net_init psched_net_init(struct net *net)
1918 {
1919 struct proc_dir_entry *e;
1920
1921 e = proc_create("psched", 0, net->proc_net, &psched_fops);
1922 if (e == NULL)
1923 return -ENOMEM;
1924
1925 return 0;
1926 }
1927
1928 static void __net_exit psched_net_exit(struct net *net)
1929 {
1930 remove_proc_entry("psched", net->proc_net);
1931 }
1932 #else
1933 static int __net_init psched_net_init(struct net *net)
1934 {
1935 return 0;
1936 }
1937
1938 static void __net_exit psched_net_exit(struct net *net)
1939 {
1940 }
1941 #endif
1942
1943 static struct pernet_operations psched_net_ops = {
1944 .init = psched_net_init,
1945 .exit = psched_net_exit,
1946 };
1947
1948 static int __init pktsched_init(void)
1949 {
1950 int err;
1951
1952 err = register_pernet_subsys(&psched_net_ops);
1953 if (err) {
1954 pr_err("pktsched_init: "
1955 "cannot initialize per netns operations\n");
1956 return err;
1957 }
1958
1959 register_qdisc(&pfifo_fast_ops);
1960 register_qdisc(&pfifo_qdisc_ops);
1961 register_qdisc(&bfifo_qdisc_ops);
1962 register_qdisc(&pfifo_head_drop_qdisc_ops);
1963 register_qdisc(&mq_qdisc_ops);
1964 register_qdisc(&noqueue_qdisc_ops);
1965
1966 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1967 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1968 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc,
1969 NULL);
1970 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1971 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1972 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass,
1973 NULL);
1974
1975 return 0;
1976 }
1977
1978 subsys_initcall(pktsched_init);
Linux with added FPC-III support