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dm thin metadata: fix __udivdi3 undefined on 32-bit
[linux/fpc-iii.git] / net / sched / sch_api.c
blob6d340cd6e2a7ceef7f5140a1b87511250c677a80
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 /* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */
1008 if (ops->destroy)
1009 ops->destroy(sch);
1010 err_out3:
1011 dev_put(dev);
1012 kfree((char *) sch - sch->padded);
1013 err_out2:
1014 module_put(ops->owner);
1015 err_out:
1016 *errp = err;
1017 return NULL;
1018
1019 err_out4:
1020 free_percpu(sch->cpu_bstats);
1021 free_percpu(sch->cpu_qstats);
1022 /*
1023 * Any broken qdiscs that would require a ops->reset() here?
1024 * The qdisc was never in action so it shouldn't be necessary.
1025 */
1026 qdisc_put_stab(rtnl_dereference(sch->stab));
1027 if (ops->destroy)
1028 ops->destroy(sch);
1029 goto err_out3;
1030 }
1031
1032 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
1033 {
1034 struct qdisc_size_table *ostab, *stab = NULL;
1035 int err = 0;
1036
1037 if (tca[TCA_OPTIONS]) {
1038 if (sch->ops->change == NULL)
1039 return -EINVAL;
1040 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
1041 if (err)
1042 return err;
1043 }
1044
1045 if (tca[TCA_STAB]) {
1046 stab = qdisc_get_stab(tca[TCA_STAB]);
1047 if (IS_ERR(stab))
1048 return PTR_ERR(stab);
1049 }
1050
1051 ostab = rtnl_dereference(sch->stab);
1052 rcu_assign_pointer(sch->stab, stab);
1053 qdisc_put_stab(ostab);
1054
1055 if (tca[TCA_RATE]) {
1056 /* NB: ignores errors from replace_estimator
1057 because change can't be undone. */
1058 if (sch->flags & TCQ_F_MQROOT)
1059 goto out;
1060 gen_replace_estimator(&sch->bstats,
1061 sch->cpu_bstats,
1062 &sch->rate_est,
1063 qdisc_root_sleeping_lock(sch),
1064 tca[TCA_RATE]);
1065 }
1066 out:
1067 return 0;
1068 }
1069
1070 struct check_loop_arg {
1071 struct qdisc_walker w;
1072 struct Qdisc *p;
1073 int depth;
1074 };
1075
1076 static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
1077
1078 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1079 {
1080 struct check_loop_arg arg;
1081
1082 if (q->ops->cl_ops == NULL)
1083 return 0;
1084
1085 arg.w.stop = arg.w.skip = arg.w.count = 0;
1086 arg.w.fn = check_loop_fn;
1087 arg.depth = depth;
1088 arg.p = p;
1089 q->ops->cl_ops->walk(q, &arg.w);
1090 return arg.w.stop ? -ELOOP : 0;
1091 }
1092
1093 static int
1094 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1095 {
1096 struct Qdisc *leaf;
1097 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1098 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1099
1100 leaf = cops->leaf(q, cl);
1101 if (leaf) {
1102 if (leaf == arg->p || arg->depth > 7)
1103 return -ELOOP;
1104 return check_loop(leaf, arg->p, arg->depth + 1);
1105 }
1106 return 0;
1107 }
1108
1109 /*
1110 * Delete/get qdisc.
1111 */
1112
1113 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1114 {
1115 struct net *net = sock_net(skb->sk);
1116 struct tcmsg *tcm = nlmsg_data(n);
1117 struct nlattr *tca[TCA_MAX + 1];
1118 struct net_device *dev;
1119 u32 clid;
1120 struct Qdisc *q = NULL;
1121 struct Qdisc *p = NULL;
1122 int err;
1123
1124 if ((n->nlmsg_type != RTM_GETQDISC) &&
1125 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1126 return -EPERM;
1127
1128 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1129 if (err < 0)
1130 return err;
1131
1132 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1133 if (!dev)
1134 return -ENODEV;
1135
1136 clid = tcm->tcm_parent;
1137 if (clid) {
1138 if (clid != TC_H_ROOT) {
1139 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1140 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1141 if (!p)
1142 return -ENOENT;
1143 q = qdisc_leaf(p, clid);
1144 } else if (dev_ingress_queue(dev)) {
1145 q = dev_ingress_queue(dev)->qdisc_sleeping;
1146 }
1147 } else {
1148 q = dev->qdisc;
1149 }
1150 if (!q)
1151 return -ENOENT;
1152
1153 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1154 return -EINVAL;
1155 } else {
1156 q = qdisc_lookup(dev, tcm->tcm_handle);
1157 if (!q)
1158 return -ENOENT;
1159 }
1160
1161 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1162 return -EINVAL;
1163
1164 if (n->nlmsg_type == RTM_DELQDISC) {
1165 if (!clid)
1166 return -EINVAL;
1167 if (q->handle == 0)
1168 return -ENOENT;
1169 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1170 if (err != 0)
1171 return err;
1172 } else {
1173 qdisc_notify(net, skb, n, clid, NULL, q);
1174 }
1175 return 0;
1176 }
1177
1178 /*
1179 * Create/change qdisc.
1180 */
1181
1182 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1183 {
1184 struct net *net = sock_net(skb->sk);
1185 struct tcmsg *tcm;
1186 struct nlattr *tca[TCA_MAX + 1];
1187 struct net_device *dev;
1188 u32 clid;
1189 struct Qdisc *q, *p;
1190 int err;
1191
1192 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1193 return -EPERM;
1194
1195 replay:
1196 /* Reinit, just in case something touches this. */
1197 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1198 if (err < 0)
1199 return err;
1200
1201 tcm = nlmsg_data(n);
1202 clid = tcm->tcm_parent;
1203 q = p = NULL;
1204
1205 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1206 if (!dev)
1207 return -ENODEV;
1208
1209
1210 if (clid) {
1211 if (clid != TC_H_ROOT) {
1212 if (clid != TC_H_INGRESS) {
1213 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1214 if (!p)
1215 return -ENOENT;
1216 q = qdisc_leaf(p, clid);
1217 } else if (dev_ingress_queue_create(dev)) {
1218 q = dev_ingress_queue(dev)->qdisc_sleeping;
1219 }
1220 } else {
1221 q = dev->qdisc;
1222 }
1223
1224 /* It may be default qdisc, ignore it */
1225 if (q && q->handle == 0)
1226 q = NULL;
1227
1228 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1229 if (tcm->tcm_handle) {
1230 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1231 return -EEXIST;
1232 if (TC_H_MIN(tcm->tcm_handle))
1233 return -EINVAL;
1234 q = qdisc_lookup(dev, tcm->tcm_handle);
1235 if (!q)
1236 goto create_n_graft;
1237 if (n->nlmsg_flags & NLM_F_EXCL)
1238 return -EEXIST;
1239 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1240 return -EINVAL;
1241 if (q == p ||
1242 (p && check_loop(q, p, 0)))
1243 return -ELOOP;
1244 atomic_inc(&q->refcnt);
1245 goto graft;
1246 } else {
1247 if (!q)
1248 goto create_n_graft;
1249
1250 /* This magic test requires explanation.
1251 *
1252 * We know, that some child q is already
1253 * attached to this parent and have choice:
1254 * either to change it or to create/graft new one.
1255 *
1256 * 1. We are allowed to create/graft only
1257 * if CREATE and REPLACE flags are set.
1258 *
1259 * 2. If EXCL is set, requestor wanted to say,
1260 * that qdisc tcm_handle is not expected
1261 * to exist, so that we choose create/graft too.
1262 *
1263 * 3. The last case is when no flags are set.
1264 * Alas, it is sort of hole in API, we
1265 * cannot decide what to do unambiguously.
1266 * For now we select create/graft, if
1267 * user gave KIND, which does not match existing.
1268 */
1269 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1270 (n->nlmsg_flags & NLM_F_REPLACE) &&
1271 ((n->nlmsg_flags & NLM_F_EXCL) ||
1272 (tca[TCA_KIND] &&
1273 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1274 goto create_n_graft;
1275 }
1276 }
1277 } else {
1278 if (!tcm->tcm_handle)
1279 return -EINVAL;
1280 q = qdisc_lookup(dev, tcm->tcm_handle);
1281 }
1282
1283 /* Change qdisc parameters */
1284 if (q == NULL)
1285 return -ENOENT;
1286 if (n->nlmsg_flags & NLM_F_EXCL)
1287 return -EEXIST;
1288 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1289 return -EINVAL;
1290 err = qdisc_change(q, tca);
1291 if (err == 0)
1292 qdisc_notify(net, skb, n, clid, NULL, q);
1293 return err;
1294
1295 create_n_graft:
1296 if (!(n->nlmsg_flags & NLM_F_CREATE))
1297 return -ENOENT;
1298 if (clid == TC_H_INGRESS) {
1299 if (dev_ingress_queue(dev))
1300 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1301 tcm->tcm_parent, tcm->tcm_parent,
1302 tca, &err);
1303 else
1304 err = -ENOENT;
1305 } else {
1306 struct netdev_queue *dev_queue;
1307
1308 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1309 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1310 else if (p)
1311 dev_queue = p->dev_queue;
1312 else
1313 dev_queue = netdev_get_tx_queue(dev, 0);
1314
1315 q = qdisc_create(dev, dev_queue, p,
1316 tcm->tcm_parent, tcm->tcm_handle,
1317 tca, &err);
1318 }
1319 if (q == NULL) {
1320 if (err == -EAGAIN)
1321 goto replay;
1322 return err;
1323 }
1324
1325 graft:
1326 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1327 if (err) {
1328 if (q)
1329 qdisc_destroy(q);
1330 return err;
1331 }
1332
1333 return 0;
1334 }
1335
1336 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1337 u32 portid, u32 seq, u16 flags, int event)
1338 {
1339 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
1340 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
1341 struct tcmsg *tcm;
1342 struct nlmsghdr *nlh;
1343 unsigned char *b = skb_tail_pointer(skb);
1344 struct gnet_dump d;
1345 struct qdisc_size_table *stab;
1346 __u32 qlen;
1347
1348 cond_resched();
1349 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1350 if (!nlh)
1351 goto out_nlmsg_trim;
1352 tcm = nlmsg_data(nlh);
1353 tcm->tcm_family = AF_UNSPEC;
1354 tcm->tcm__pad1 = 0;
1355 tcm->tcm__pad2 = 0;
1356 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1357 tcm->tcm_parent = clid;
1358 tcm->tcm_handle = q->handle;
1359 tcm->tcm_info = atomic_read(&q->refcnt);
1360 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1361 goto nla_put_failure;
1362 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1363 goto nla_put_failure;
1364 qlen = q->q.qlen;
1365
1366 stab = rtnl_dereference(q->stab);
1367 if (stab && qdisc_dump_stab(skb, stab) < 0)
1368 goto nla_put_failure;
1369
1370 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1371 qdisc_root_sleeping_lock(q), &d) < 0)
1372 goto nla_put_failure;
1373
1374 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1375 goto nla_put_failure;
1376
1377 if (qdisc_is_percpu_stats(q)) {
1378 cpu_bstats = q->cpu_bstats;
1379 cpu_qstats = q->cpu_qstats;
1380 }
1381
1382 if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats) < 0 ||
1383 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1384 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
1385 goto nla_put_failure;
1386
1387 if (gnet_stats_finish_copy(&d) < 0)
1388 goto nla_put_failure;
1389
1390 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1391 return skb->len;
1392
1393 out_nlmsg_trim:
1394 nla_put_failure:
1395 nlmsg_trim(skb, b);
1396 return -1;
1397 }
1398
1399 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1400 {
1401 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1402 }
1403
1404 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1405 struct nlmsghdr *n, u32 clid,
1406 struct Qdisc *old, struct Qdisc *new)
1407 {
1408 struct sk_buff *skb;
1409 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1410
1411 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1412 if (!skb)
1413 return -ENOBUFS;
1414
1415 if (old && !tc_qdisc_dump_ignore(old)) {
1416 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1417 0, RTM_DELQDISC) < 0)
1418 goto err_out;
1419 }
1420 if (new && !tc_qdisc_dump_ignore(new)) {
1421 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1422 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1423 goto err_out;
1424 }
1425
1426 if (skb->len)
1427 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1428 n->nlmsg_flags & NLM_F_ECHO);
1429
1430 err_out:
1431 kfree_skb(skb);
1432 return -EINVAL;
1433 }
1434
1435 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1436 struct netlink_callback *cb,
1437 int *q_idx_p, int s_q_idx)
1438 {
1439 int ret = 0, q_idx = *q_idx_p;
1440 struct Qdisc *q;
1441
1442 if (!root)
1443 return 0;
1444
1445 q = root;
1446 if (q_idx < s_q_idx) {
1447 q_idx++;
1448 } else {
1449 if (!tc_qdisc_dump_ignore(q) &&
1450 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1451 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1452 goto done;
1453 q_idx++;
1454 }
1455 list_for_each_entry(q, &root->list, list) {
1456 if (q_idx < s_q_idx) {
1457 q_idx++;
1458 continue;
1459 }
1460 if (!tc_qdisc_dump_ignore(q) &&
1461 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1462 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1463 goto done;
1464 q_idx++;
1465 }
1466
1467 out:
1468 *q_idx_p = q_idx;
1469 return ret;
1470 done:
1471 ret = -1;
1472 goto out;
1473 }
1474
1475 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1476 {
1477 struct net *net = sock_net(skb->sk);
1478 int idx, q_idx;
1479 int s_idx, s_q_idx;
1480 struct net_device *dev;
1481
1482 s_idx = cb->args[0];
1483 s_q_idx = q_idx = cb->args[1];
1484
1485 idx = 0;
1486 ASSERT_RTNL();
1487 for_each_netdev(net, dev) {
1488 struct netdev_queue *dev_queue;
1489
1490 if (idx < s_idx)
1491 goto cont;
1492 if (idx > s_idx)
1493 s_q_idx = 0;
1494 q_idx = 0;
1495
1496 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1497 goto done;
1498
1499 dev_queue = dev_ingress_queue(dev);
1500 if (dev_queue &&
1501 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1502 &q_idx, s_q_idx) < 0)
1503 goto done;
1504
1505 cont:
1506 idx++;
1507 }
1508
1509 done:
1510 cb->args[0] = idx;
1511 cb->args[1] = q_idx;
1512
1513 return skb->len;
1514 }
1515
1516
1517
1518 /************************************************
1519 * Traffic classes manipulation. *
1520 ************************************************/
1521
1522
1523
1524 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n)
1525 {
1526 struct net *net = sock_net(skb->sk);
1527 struct tcmsg *tcm = nlmsg_data(n);
1528 struct nlattr *tca[TCA_MAX + 1];
1529 struct net_device *dev;
1530 struct Qdisc *q = NULL;
1531 const struct Qdisc_class_ops *cops;
1532 unsigned long cl = 0;
1533 unsigned long new_cl;
1534 u32 portid;
1535 u32 clid;
1536 u32 qid;
1537 int err;
1538
1539 if ((n->nlmsg_type != RTM_GETTCLASS) &&
1540 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1541 return -EPERM;
1542
1543 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1544 if (err < 0)
1545 return err;
1546
1547 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1548 if (!dev)
1549 return -ENODEV;
1550
1551 /*
1552 parent == TC_H_UNSPEC - unspecified parent.
1553 parent == TC_H_ROOT - class is root, which has no parent.
1554 parent == X:0 - parent is root class.
1555 parent == X:Y - parent is a node in hierarchy.
1556 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1557
1558 handle == 0:0 - generate handle from kernel pool.
1559 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1560 handle == X:Y - clear.
1561 handle == X:0 - root class.
1562 */
1563
1564 /* Step 1. Determine qdisc handle X:0 */
1565
1566 portid = tcm->tcm_parent;
1567 clid = tcm->tcm_handle;
1568 qid = TC_H_MAJ(clid);
1569
1570 if (portid != TC_H_ROOT) {
1571 u32 qid1 = TC_H_MAJ(portid);
1572
1573 if (qid && qid1) {
1574 /* If both majors are known, they must be identical. */
1575 if (qid != qid1)
1576 return -EINVAL;
1577 } else if (qid1) {
1578 qid = qid1;
1579 } else if (qid == 0)
1580 qid = dev->qdisc->handle;
1581
1582 /* Now qid is genuine qdisc handle consistent
1583 * both with parent and child.
1584 *
1585 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1586 */
1587 if (portid)
1588 portid = TC_H_MAKE(qid, portid);
1589 } else {
1590 if (qid == 0)
1591 qid = dev->qdisc->handle;
1592 }
1593
1594 /* OK. Locate qdisc */
1595 q = qdisc_lookup(dev, qid);
1596 if (!q)
1597 return -ENOENT;
1598
1599 /* An check that it supports classes */
1600 cops = q->ops->cl_ops;
1601 if (cops == NULL)
1602 return -EINVAL;
1603
1604 /* Now try to get class */
1605 if (clid == 0) {
1606 if (portid == TC_H_ROOT)
1607 clid = qid;
1608 } else
1609 clid = TC_H_MAKE(qid, clid);
1610
1611 if (clid)
1612 cl = cops->get(q, clid);
1613
1614 if (cl == 0) {
1615 err = -ENOENT;
1616 if (n->nlmsg_type != RTM_NEWTCLASS ||
1617 !(n->nlmsg_flags & NLM_F_CREATE))
1618 goto out;
1619 } else {
1620 switch (n->nlmsg_type) {
1621 case RTM_NEWTCLASS:
1622 err = -EEXIST;
1623 if (n->nlmsg_flags & NLM_F_EXCL)
1624 goto out;
1625 break;
1626 case RTM_DELTCLASS:
1627 err = -EOPNOTSUPP;
1628 if (cops->delete)
1629 err = cops->delete(q, cl);
1630 if (err == 0)
1631 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1632 goto out;
1633 case RTM_GETTCLASS:
1634 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1635 goto out;
1636 default:
1637 err = -EINVAL;
1638 goto out;
1639 }
1640 }
1641
1642 new_cl = cl;
1643 err = -EOPNOTSUPP;
1644 if (cops->change)
1645 err = cops->change(q, clid, portid, tca, &new_cl);
1646 if (err == 0)
1647 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1648
1649 out:
1650 if (cl)
1651 cops->put(q, cl);
1652
1653 return err;
1654 }
1655
1656
1657 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1658 unsigned long cl,
1659 u32 portid, u32 seq, u16 flags, int event)
1660 {
1661 struct tcmsg *tcm;
1662 struct nlmsghdr *nlh;
1663 unsigned char *b = skb_tail_pointer(skb);
1664 struct gnet_dump d;
1665 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1666
1667 cond_resched();
1668 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1669 if (!nlh)
1670 goto out_nlmsg_trim;
1671 tcm = nlmsg_data(nlh);
1672 tcm->tcm_family = AF_UNSPEC;
1673 tcm->tcm__pad1 = 0;
1674 tcm->tcm__pad2 = 0;
1675 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1676 tcm->tcm_parent = q->handle;
1677 tcm->tcm_handle = q->handle;
1678 tcm->tcm_info = 0;
1679 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1680 goto nla_put_failure;
1681 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1682 goto nla_put_failure;
1683
1684 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1685 qdisc_root_sleeping_lock(q), &d) < 0)
1686 goto nla_put_failure;
1687
1688 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1689 goto nla_put_failure;
1690
1691 if (gnet_stats_finish_copy(&d) < 0)
1692 goto nla_put_failure;
1693
1694 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1695 return skb->len;
1696
1697 out_nlmsg_trim:
1698 nla_put_failure:
1699 nlmsg_trim(skb, b);
1700 return -1;
1701 }
1702
1703 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1704 struct nlmsghdr *n, struct Qdisc *q,
1705 unsigned long cl, int event)
1706 {
1707 struct sk_buff *skb;
1708 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1709
1710 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1711 if (!skb)
1712 return -ENOBUFS;
1713
1714 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1715 kfree_skb(skb);
1716 return -EINVAL;
1717 }
1718
1719 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1720 n->nlmsg_flags & NLM_F_ECHO);
1721 }
1722
1723 struct qdisc_dump_args {
1724 struct qdisc_walker w;
1725 struct sk_buff *skb;
1726 struct netlink_callback *cb;
1727 };
1728
1729 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1730 {
1731 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1732
1733 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1734 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1735 }
1736
1737 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1738 struct tcmsg *tcm, struct netlink_callback *cb,
1739 int *t_p, int s_t)
1740 {
1741 struct qdisc_dump_args arg;
1742
1743 if (tc_qdisc_dump_ignore(q) ||
1744 *t_p < s_t || !q->ops->cl_ops ||
1745 (tcm->tcm_parent &&
1746 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1747 (*t_p)++;
1748 return 0;
1749 }
1750 if (*t_p > s_t)
1751 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1752 arg.w.fn = qdisc_class_dump;
1753 arg.skb = skb;
1754 arg.cb = cb;
1755 arg.w.stop = 0;
1756 arg.w.skip = cb->args[1];
1757 arg.w.count = 0;
1758 q->ops->cl_ops->walk(q, &arg.w);
1759 cb->args[1] = arg.w.count;
1760 if (arg.w.stop)
1761 return -1;
1762 (*t_p)++;
1763 return 0;
1764 }
1765
1766 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1767 struct tcmsg *tcm, struct netlink_callback *cb,
1768 int *t_p, int s_t)
1769 {
1770 struct Qdisc *q;
1771
1772 if (!root)
1773 return 0;
1774
1775 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1776 return -1;
1777
1778 list_for_each_entry(q, &root->list, list) {
1779 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1780 return -1;
1781 }
1782
1783 return 0;
1784 }
1785
1786 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1787 {
1788 struct tcmsg *tcm = nlmsg_data(cb->nlh);
1789 struct net *net = sock_net(skb->sk);
1790 struct netdev_queue *dev_queue;
1791 struct net_device *dev;
1792 int t, s_t;
1793
1794 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1795 return 0;
1796 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1797 if (!dev)
1798 return 0;
1799
1800 s_t = cb->args[0];
1801 t = 0;
1802
1803 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1804 goto done;
1805
1806 dev_queue = dev_ingress_queue(dev);
1807 if (dev_queue &&
1808 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1809 &t, s_t) < 0)
1810 goto done;
1811
1812 done:
1813 cb->args[0] = t;
1814
1815 dev_put(dev);
1816 return skb->len;
1817 }
1818
1819 /* Main classifier routine: scans classifier chain attached
1820 * to this qdisc, (optionally) tests for protocol and asks
1821 * specific classifiers.
1822 */
1823 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1824 struct tcf_result *res, bool compat_mode)
1825 {
1826 __be16 protocol = tc_skb_protocol(skb);
1827 #ifdef CONFIG_NET_CLS_ACT
1828 const struct tcf_proto *old_tp = tp;
1829 int limit = 0;
1830
1831 reclassify:
1832 #endif
1833 for (; tp; tp = rcu_dereference_bh(tp->next)) {
1834 int err;
1835
1836 if (tp->protocol != protocol &&
1837 tp->protocol != htons(ETH_P_ALL))
1838 continue;
1839
1840 err = tp->classify(skb, tp, res);
1841 #ifdef CONFIG_NET_CLS_ACT
1842 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode))
1843 goto reset;
1844 #endif
1845 if (err >= 0)
1846 return err;
1847 }
1848
1849 return -1;
1850 #ifdef CONFIG_NET_CLS_ACT
1851 reset:
1852 if (unlikely(limit++ >= MAX_REC_LOOP)) {
1853 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n",
1854 tp->q->ops->id, tp->prio & 0xffff,
1855 ntohs(tp->protocol));
1856 return TC_ACT_SHOT;
1857 }
1858
1859 tp = old_tp;
1860 protocol = tc_skb_protocol(skb);
1861 goto reclassify;
1862 #endif
1863 }
1864 EXPORT_SYMBOL(tc_classify);
1865
1866 bool tcf_destroy(struct tcf_proto *tp, bool force)
1867 {
1868 if (tp->ops->destroy(tp, force)) {
1869 module_put(tp->ops->owner);
1870 kfree_rcu(tp, rcu);
1871 return true;
1872 }
1873
1874 return false;
1875 }
1876
1877 void tcf_destroy_chain(struct tcf_proto __rcu **fl)
1878 {
1879 struct tcf_proto *tp;
1880
1881 while ((tp = rtnl_dereference(*fl)) != NULL) {
1882 RCU_INIT_POINTER(*fl, tp->next);
1883 tcf_destroy(tp, true);
1884 }
1885 }
1886 EXPORT_SYMBOL(tcf_destroy_chain);
1887
1888 #ifdef CONFIG_PROC_FS
1889 static int psched_show(struct seq_file *seq, void *v)
1890 {
1891 seq_printf(seq, "%08x %08x %08x %08x\n",
1892 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1893 1000000,
1894 (u32)NSEC_PER_SEC / hrtimer_resolution);
1895
1896 return 0;
1897 }
1898
1899 static int psched_open(struct inode *inode, struct file *file)
1900 {
1901 return single_open(file, psched_show, NULL);
1902 }
1903
1904 static const struct file_operations psched_fops = {
1905 .owner = THIS_MODULE,
1906 .open = psched_open,
1907 .read = seq_read,
1908 .llseek = seq_lseek,
1909 .release = single_release,
1910 };
1911
1912 static int __net_init psched_net_init(struct net *net)
1913 {
1914 struct proc_dir_entry *e;
1915
1916 e = proc_create("psched", 0, net->proc_net, &psched_fops);
1917 if (e == NULL)
1918 return -ENOMEM;
1919
1920 return 0;
1921 }
1922
1923 static void __net_exit psched_net_exit(struct net *net)
1924 {
1925 remove_proc_entry("psched", net->proc_net);
1926 }
1927 #else
1928 static int __net_init psched_net_init(struct net *net)
1929 {
1930 return 0;
1931 }
1932
1933 static void __net_exit psched_net_exit(struct net *net)
1934 {
1935 }
1936 #endif
1937
1938 static struct pernet_operations psched_net_ops = {
1939 .init = psched_net_init,
1940 .exit = psched_net_exit,
1941 };
1942
1943 static int __init pktsched_init(void)
1944 {
1945 int err;
1946
1947 err = register_pernet_subsys(&psched_net_ops);
1948 if (err) {
1949 pr_err("pktsched_init: "
1950 "cannot initialize per netns operations\n");
1951 return err;
1952 }
1953
1954 register_qdisc(&pfifo_fast_ops);
1955 register_qdisc(&pfifo_qdisc_ops);
1956 register_qdisc(&bfifo_qdisc_ops);
1957 register_qdisc(&pfifo_head_drop_qdisc_ops);
1958 register_qdisc(&mq_qdisc_ops);
1959 register_qdisc(&noqueue_qdisc_ops);
1960
1961 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1962 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1963 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1964 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1965 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1966 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1967
1968 return 0;
1969 }
1970
1971 subsys_initcall(pktsched_init);
Linux with added FPC-III support