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dm thin: wake worker when discard is prepared
[linux-2.6.git] / net / sched / sch_api.c
bloba18d975db59cea34eb0558490deb800f24c10d22
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/uregister 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 /* We know handle. Find qdisc among all qdisc's attached to device
204 (root qdisc, all its children, children of children etc.)
205 */
206
207 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
208 {
209 struct Qdisc *q;
210
211 if (!(root->flags & TCQ_F_BUILTIN) &&
212 root->handle == handle)
213 return root;
214
215 list_for_each_entry(q, &root->list, list) {
216 if (q->handle == handle)
217 return q;
218 }
219 return NULL;
220 }
221
222 static void qdisc_list_add(struct Qdisc *q)
223 {
224 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
225 list_add_tail(&q->list, &qdisc_dev(q)->qdisc->list);
226 }
227
228 void qdisc_list_del(struct Qdisc *q)
229 {
230 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
231 list_del(&q->list);
232 }
233 EXPORT_SYMBOL(qdisc_list_del);
234
235 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
236 {
237 struct Qdisc *q;
238
239 q = qdisc_match_from_root(dev->qdisc, handle);
240 if (q)
241 goto out;
242
243 if (dev_ingress_queue(dev))
244 q = qdisc_match_from_root(
245 dev_ingress_queue(dev)->qdisc_sleeping,
246 handle);
247 out:
248 return q;
249 }
250
251 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
252 {
253 unsigned long cl;
254 struct Qdisc *leaf;
255 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
256
257 if (cops == NULL)
258 return NULL;
259 cl = cops->get(p, classid);
260
261 if (cl == 0)
262 return NULL;
263 leaf = cops->leaf(p, cl);
264 cops->put(p, cl);
265 return leaf;
266 }
267
268 /* Find queueing discipline by name */
269
270 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
271 {
272 struct Qdisc_ops *q = NULL;
273
274 if (kind) {
275 read_lock(&qdisc_mod_lock);
276 for (q = qdisc_base; q; q = q->next) {
277 if (nla_strcmp(kind, q->id) == 0) {
278 if (!try_module_get(q->owner))
279 q = NULL;
280 break;
281 }
282 }
283 read_unlock(&qdisc_mod_lock);
284 }
285 return q;
286 }
287
288 static struct qdisc_rate_table *qdisc_rtab_list;
289
290 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct nlattr *tab)
291 {
292 struct qdisc_rate_table *rtab;
293
294 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
295 if (memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) == 0) {
296 rtab->refcnt++;
297 return rtab;
298 }
299 }
300
301 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
302 nla_len(tab) != TC_RTAB_SIZE)
303 return NULL;
304
305 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
306 if (rtab) {
307 rtab->rate = *r;
308 rtab->refcnt = 1;
309 memcpy(rtab->data, nla_data(tab), 1024);
310 rtab->next = qdisc_rtab_list;
311 qdisc_rtab_list = rtab;
312 }
313 return rtab;
314 }
315 EXPORT_SYMBOL(qdisc_get_rtab);
316
317 void qdisc_put_rtab(struct qdisc_rate_table *tab)
318 {
319 struct qdisc_rate_table *rtab, **rtabp;
320
321 if (!tab || --tab->refcnt)
322 return;
323
324 for (rtabp = &qdisc_rtab_list;
325 (rtab = *rtabp) != NULL;
326 rtabp = &rtab->next) {
327 if (rtab == tab) {
328 *rtabp = rtab->next;
329 kfree(rtab);
330 return;
331 }
332 }
333 }
334 EXPORT_SYMBOL(qdisc_put_rtab);
335
336 static LIST_HEAD(qdisc_stab_list);
337 static DEFINE_SPINLOCK(qdisc_stab_lock);
338
339 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
340 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
341 [TCA_STAB_DATA] = { .type = NLA_BINARY },
342 };
343
344 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
345 {
346 struct nlattr *tb[TCA_STAB_MAX + 1];
347 struct qdisc_size_table *stab;
348 struct tc_sizespec *s;
349 unsigned int tsize = 0;
350 u16 *tab = NULL;
351 int err;
352
353 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
354 if (err < 0)
355 return ERR_PTR(err);
356 if (!tb[TCA_STAB_BASE])
357 return ERR_PTR(-EINVAL);
358
359 s = nla_data(tb[TCA_STAB_BASE]);
360
361 if (s->tsize > 0) {
362 if (!tb[TCA_STAB_DATA])
363 return ERR_PTR(-EINVAL);
364 tab = nla_data(tb[TCA_STAB_DATA]);
365 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
366 }
367
368 if (tsize != s->tsize || (!tab && tsize > 0))
369 return ERR_PTR(-EINVAL);
370
371 spin_lock(&qdisc_stab_lock);
372
373 list_for_each_entry(stab, &qdisc_stab_list, list) {
374 if (memcmp(&stab->szopts, s, sizeof(*s)))
375 continue;
376 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
377 continue;
378 stab->refcnt++;
379 spin_unlock(&qdisc_stab_lock);
380 return stab;
381 }
382
383 spin_unlock(&qdisc_stab_lock);
384
385 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
386 if (!stab)
387 return ERR_PTR(-ENOMEM);
388
389 stab->refcnt = 1;
390 stab->szopts = *s;
391 if (tsize > 0)
392 memcpy(stab->data, tab, tsize * sizeof(u16));
393
394 spin_lock(&qdisc_stab_lock);
395 list_add_tail(&stab->list, &qdisc_stab_list);
396 spin_unlock(&qdisc_stab_lock);
397
398 return stab;
399 }
400
401 static void stab_kfree_rcu(struct rcu_head *head)
402 {
403 kfree(container_of(head, struct qdisc_size_table, rcu));
404 }
405
406 void qdisc_put_stab(struct qdisc_size_table *tab)
407 {
408 if (!tab)
409 return;
410
411 spin_lock(&qdisc_stab_lock);
412
413 if (--tab->refcnt == 0) {
414 list_del(&tab->list);
415 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
416 }
417
418 spin_unlock(&qdisc_stab_lock);
419 }
420 EXPORT_SYMBOL(qdisc_put_stab);
421
422 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
423 {
424 struct nlattr *nest;
425
426 nest = nla_nest_start(skb, TCA_STAB);
427 if (nest == NULL)
428 goto nla_put_failure;
429 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
430 goto nla_put_failure;
431 nla_nest_end(skb, nest);
432
433 return skb->len;
434
435 nla_put_failure:
436 return -1;
437 }
438
439 void __qdisc_calculate_pkt_len(struct sk_buff *skb, const struct qdisc_size_table *stab)
440 {
441 int pkt_len, slot;
442
443 pkt_len = skb->len + stab->szopts.overhead;
444 if (unlikely(!stab->szopts.tsize))
445 goto out;
446
447 slot = pkt_len + stab->szopts.cell_align;
448 if (unlikely(slot < 0))
449 slot = 0;
450
451 slot >>= stab->szopts.cell_log;
452 if (likely(slot < stab->szopts.tsize))
453 pkt_len = stab->data[slot];
454 else
455 pkt_len = stab->data[stab->szopts.tsize - 1] *
456 (slot / stab->szopts.tsize) +
457 stab->data[slot % stab->szopts.tsize];
458
459 pkt_len <<= stab->szopts.size_log;
460 out:
461 if (unlikely(pkt_len < 1))
462 pkt_len = 1;
463 qdisc_skb_cb(skb)->pkt_len = pkt_len;
464 }
465 EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
466
467 void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc)
468 {
469 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
470 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
471 txt, qdisc->ops->id, qdisc->handle >> 16);
472 qdisc->flags |= TCQ_F_WARN_NONWC;
473 }
474 }
475 EXPORT_SYMBOL(qdisc_warn_nonwc);
476
477 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
478 {
479 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
480 timer);
481
482 qdisc_unthrottled(wd->qdisc);
483 __netif_schedule(qdisc_root(wd->qdisc));
484
485 return HRTIMER_NORESTART;
486 }
487
488 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
489 {
490 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
491 wd->timer.function = qdisc_watchdog;
492 wd->qdisc = qdisc;
493 }
494 EXPORT_SYMBOL(qdisc_watchdog_init);
495
496 void qdisc_watchdog_schedule(struct qdisc_watchdog *wd, psched_time_t expires)
497 {
498 ktime_t time;
499
500 if (test_bit(__QDISC_STATE_DEACTIVATED,
501 &qdisc_root_sleeping(wd->qdisc)->state))
502 return;
503
504 qdisc_throttled(wd->qdisc);
505 time = ktime_set(0, 0);
506 time = ktime_add_ns(time, PSCHED_TICKS2NS(expires));
507 hrtimer_start(&wd->timer, time, HRTIMER_MODE_ABS);
508 }
509 EXPORT_SYMBOL(qdisc_watchdog_schedule);
510
511 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
512 {
513 hrtimer_cancel(&wd->timer);
514 qdisc_unthrottled(wd->qdisc);
515 }
516 EXPORT_SYMBOL(qdisc_watchdog_cancel);
517
518 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
519 {
520 unsigned int size = n * sizeof(struct hlist_head), i;
521 struct hlist_head *h;
522
523 if (size <= PAGE_SIZE)
524 h = kmalloc(size, GFP_KERNEL);
525 else
526 h = (struct hlist_head *)
527 __get_free_pages(GFP_KERNEL, get_order(size));
528
529 if (h != NULL) {
530 for (i = 0; i < n; i++)
531 INIT_HLIST_HEAD(&h[i]);
532 }
533 return h;
534 }
535
536 static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
537 {
538 unsigned int size = n * sizeof(struct hlist_head);
539
540 if (size <= PAGE_SIZE)
541 kfree(h);
542 else
543 free_pages((unsigned long)h, get_order(size));
544 }
545
546 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
547 {
548 struct Qdisc_class_common *cl;
549 struct hlist_node *n, *next;
550 struct hlist_head *nhash, *ohash;
551 unsigned int nsize, nmask, osize;
552 unsigned int i, h;
553
554 /* Rehash when load factor exceeds 0.75 */
555 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
556 return;
557 nsize = clhash->hashsize * 2;
558 nmask = nsize - 1;
559 nhash = qdisc_class_hash_alloc(nsize);
560 if (nhash == NULL)
561 return;
562
563 ohash = clhash->hash;
564 osize = clhash->hashsize;
565
566 sch_tree_lock(sch);
567 for (i = 0; i < osize; i++) {
568 hlist_for_each_entry_safe(cl, n, next, &ohash[i], hnode) {
569 h = qdisc_class_hash(cl->classid, nmask);
570 hlist_add_head(&cl->hnode, &nhash[h]);
571 }
572 }
573 clhash->hash = nhash;
574 clhash->hashsize = nsize;
575 clhash->hashmask = nmask;
576 sch_tree_unlock(sch);
577
578 qdisc_class_hash_free(ohash, osize);
579 }
580 EXPORT_SYMBOL(qdisc_class_hash_grow);
581
582 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
583 {
584 unsigned int size = 4;
585
586 clhash->hash = qdisc_class_hash_alloc(size);
587 if (clhash->hash == NULL)
588 return -ENOMEM;
589 clhash->hashsize = size;
590 clhash->hashmask = size - 1;
591 clhash->hashelems = 0;
592 return 0;
593 }
594 EXPORT_SYMBOL(qdisc_class_hash_init);
595
596 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
597 {
598 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
599 }
600 EXPORT_SYMBOL(qdisc_class_hash_destroy);
601
602 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
603 struct Qdisc_class_common *cl)
604 {
605 unsigned int h;
606
607 INIT_HLIST_NODE(&cl->hnode);
608 h = qdisc_class_hash(cl->classid, clhash->hashmask);
609 hlist_add_head(&cl->hnode, &clhash->hash[h]);
610 clhash->hashelems++;
611 }
612 EXPORT_SYMBOL(qdisc_class_hash_insert);
613
614 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
615 struct Qdisc_class_common *cl)
616 {
617 hlist_del(&cl->hnode);
618 clhash->hashelems--;
619 }
620 EXPORT_SYMBOL(qdisc_class_hash_remove);
621
622 /* Allocate an unique handle from space managed by kernel
623 * Possible range is [8000-FFFF]:0000 (0x8000 values)
624 */
625 static u32 qdisc_alloc_handle(struct net_device *dev)
626 {
627 int i = 0x8000;
628 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
629
630 do {
631 autohandle += TC_H_MAKE(0x10000U, 0);
632 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
633 autohandle = TC_H_MAKE(0x80000000U, 0);
634 if (!qdisc_lookup(dev, autohandle))
635 return autohandle;
636 cond_resched();
637 } while (--i > 0);
638
639 return 0;
640 }
641
642 void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
643 {
644 const struct Qdisc_class_ops *cops;
645 unsigned long cl;
646 u32 parentid;
647
648 if (n == 0)
649 return;
650 while ((parentid = sch->parent)) {
651 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
652 return;
653
654 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
655 if (sch == NULL) {
656 WARN_ON(parentid != TC_H_ROOT);
657 return;
658 }
659 cops = sch->ops->cl_ops;
660 if (cops->qlen_notify) {
661 cl = cops->get(sch, parentid);
662 cops->qlen_notify(sch, cl);
663 cops->put(sch, cl);
664 }
665 sch->q.qlen -= n;
666 }
667 }
668 EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
669
670 static void notify_and_destroy(struct net *net, struct sk_buff *skb,
671 struct nlmsghdr *n, u32 clid,
672 struct Qdisc *old, struct Qdisc *new)
673 {
674 if (new || old)
675 qdisc_notify(net, skb, n, clid, old, new);
676
677 if (old)
678 qdisc_destroy(old);
679 }
680
681 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
682 * to device "dev".
683 *
684 * When appropriate send a netlink notification using 'skb'
685 * and "n".
686 *
687 * On success, destroy old qdisc.
688 */
689
690 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
691 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
692 struct Qdisc *new, struct Qdisc *old)
693 {
694 struct Qdisc *q = old;
695 struct net *net = dev_net(dev);
696 int err = 0;
697
698 if (parent == NULL) {
699 unsigned int i, num_q, ingress;
700
701 ingress = 0;
702 num_q = dev->num_tx_queues;
703 if ((q && q->flags & TCQ_F_INGRESS) ||
704 (new && new->flags & TCQ_F_INGRESS)) {
705 num_q = 1;
706 ingress = 1;
707 if (!dev_ingress_queue(dev))
708 return -ENOENT;
709 }
710
711 if (dev->flags & IFF_UP)
712 dev_deactivate(dev);
713
714 if (new && new->ops->attach) {
715 new->ops->attach(new);
716 num_q = 0;
717 }
718
719 for (i = 0; i < num_q; i++) {
720 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
721
722 if (!ingress)
723 dev_queue = netdev_get_tx_queue(dev, i);
724
725 old = dev_graft_qdisc(dev_queue, new);
726 if (new && i > 0)
727 atomic_inc(&new->refcnt);
728
729 if (!ingress)
730 qdisc_destroy(old);
731 }
732
733 if (!ingress) {
734 notify_and_destroy(net, skb, n, classid,
735 dev->qdisc, new);
736 if (new && !new->ops->attach)
737 atomic_inc(&new->refcnt);
738 dev->qdisc = new ? : &noop_qdisc;
739 } else {
740 notify_and_destroy(net, skb, n, classid, old, new);
741 }
742
743 if (dev->flags & IFF_UP)
744 dev_activate(dev);
745 } else {
746 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
747
748 err = -EOPNOTSUPP;
749 if (cops && cops->graft) {
750 unsigned long cl = cops->get(parent, classid);
751 if (cl) {
752 err = cops->graft(parent, cl, new, &old);
753 cops->put(parent, cl);
754 } else
755 err = -ENOENT;
756 }
757 if (!err)
758 notify_and_destroy(net, skb, n, classid, old, new);
759 }
760 return err;
761 }
762
763 /* lockdep annotation is needed for ingress; egress gets it only for name */
764 static struct lock_class_key qdisc_tx_lock;
765 static struct lock_class_key qdisc_rx_lock;
766
767 /*
768 Allocate and initialize new qdisc.
769
770 Parameters are passed via opt.
771 */
772
773 static struct Qdisc *
774 qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
775 struct Qdisc *p, u32 parent, u32 handle,
776 struct nlattr **tca, int *errp)
777 {
778 int err;
779 struct nlattr *kind = tca[TCA_KIND];
780 struct Qdisc *sch;
781 struct Qdisc_ops *ops;
782 struct qdisc_size_table *stab;
783
784 ops = qdisc_lookup_ops(kind);
785 #ifdef CONFIG_MODULES
786 if (ops == NULL && kind != NULL) {
787 char name[IFNAMSIZ];
788 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
789 /* We dropped the RTNL semaphore in order to
790 * perform the module load. So, even if we
791 * succeeded in loading the module we have to
792 * tell the caller to replay the request. We
793 * indicate this using -EAGAIN.
794 * We replay the request because the device may
795 * go away in the mean time.
796 */
797 rtnl_unlock();
798 request_module("sch_%s", name);
799 rtnl_lock();
800 ops = qdisc_lookup_ops(kind);
801 if (ops != NULL) {
802 /* We will try again qdisc_lookup_ops,
803 * so don't keep a reference.
804 */
805 module_put(ops->owner);
806 err = -EAGAIN;
807 goto err_out;
808 }
809 }
810 }
811 #endif
812
813 err = -ENOENT;
814 if (ops == NULL)
815 goto err_out;
816
817 sch = qdisc_alloc(dev_queue, ops);
818 if (IS_ERR(sch)) {
819 err = PTR_ERR(sch);
820 goto err_out2;
821 }
822
823 sch->parent = parent;
824
825 if (handle == TC_H_INGRESS) {
826 sch->flags |= TCQ_F_INGRESS;
827 handle = TC_H_MAKE(TC_H_INGRESS, 0);
828 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
829 } else {
830 if (handle == 0) {
831 handle = qdisc_alloc_handle(dev);
832 err = -ENOMEM;
833 if (handle == 0)
834 goto err_out3;
835 }
836 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
837 }
838
839 sch->handle = handle;
840
841 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
842 if (tca[TCA_STAB]) {
843 stab = qdisc_get_stab(tca[TCA_STAB]);
844 if (IS_ERR(stab)) {
845 err = PTR_ERR(stab);
846 goto err_out4;
847 }
848 rcu_assign_pointer(sch->stab, stab);
849 }
850 if (tca[TCA_RATE]) {
851 spinlock_t *root_lock;
852
853 err = -EOPNOTSUPP;
854 if (sch->flags & TCQ_F_MQROOT)
855 goto err_out4;
856
857 if ((sch->parent != TC_H_ROOT) &&
858 !(sch->flags & TCQ_F_INGRESS) &&
859 (!p || !(p->flags & TCQ_F_MQROOT)))
860 root_lock = qdisc_root_sleeping_lock(sch);
861 else
862 root_lock = qdisc_lock(sch);
863
864 err = gen_new_estimator(&sch->bstats, &sch->rate_est,
865 root_lock, tca[TCA_RATE]);
866 if (err)
867 goto err_out4;
868 }
869
870 qdisc_list_add(sch);
871
872 return sch;
873 }
874 err_out3:
875 dev_put(dev);
876 kfree((char *) sch - sch->padded);
877 err_out2:
878 module_put(ops->owner);
879 err_out:
880 *errp = err;
881 return NULL;
882
883 err_out4:
884 /*
885 * Any broken qdiscs that would require a ops->reset() here?
886 * The qdisc was never in action so it shouldn't be necessary.
887 */
888 qdisc_put_stab(rtnl_dereference(sch->stab));
889 if (ops->destroy)
890 ops->destroy(sch);
891 goto err_out3;
892 }
893
894 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
895 {
896 struct qdisc_size_table *ostab, *stab = NULL;
897 int err = 0;
898
899 if (tca[TCA_OPTIONS]) {
900 if (sch->ops->change == NULL)
901 return -EINVAL;
902 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
903 if (err)
904 return err;
905 }
906
907 if (tca[TCA_STAB]) {
908 stab = qdisc_get_stab(tca[TCA_STAB]);
909 if (IS_ERR(stab))
910 return PTR_ERR(stab);
911 }
912
913 ostab = rtnl_dereference(sch->stab);
914 rcu_assign_pointer(sch->stab, stab);
915 qdisc_put_stab(ostab);
916
917 if (tca[TCA_RATE]) {
918 /* NB: ignores errors from replace_estimator
919 because change can't be undone. */
920 if (sch->flags & TCQ_F_MQROOT)
921 goto out;
922 gen_replace_estimator(&sch->bstats, &sch->rate_est,
923 qdisc_root_sleeping_lock(sch),
924 tca[TCA_RATE]);
925 }
926 out:
927 return 0;
928 }
929
930 struct check_loop_arg {
931 struct qdisc_walker w;
932 struct Qdisc *p;
933 int depth;
934 };
935
936 static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
937
938 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
939 {
940 struct check_loop_arg arg;
941
942 if (q->ops->cl_ops == NULL)
943 return 0;
944
945 arg.w.stop = arg.w.skip = arg.w.count = 0;
946 arg.w.fn = check_loop_fn;
947 arg.depth = depth;
948 arg.p = p;
949 q->ops->cl_ops->walk(q, &arg.w);
950 return arg.w.stop ? -ELOOP : 0;
951 }
952
953 static int
954 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
955 {
956 struct Qdisc *leaf;
957 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
958 struct check_loop_arg *arg = (struct check_loop_arg *)w;
959
960 leaf = cops->leaf(q, cl);
961 if (leaf) {
962 if (leaf == arg->p || arg->depth > 7)
963 return -ELOOP;
964 return check_loop(leaf, arg->p, arg->depth + 1);
965 }
966 return 0;
967 }
968
969 /*
970 * Delete/get qdisc.
971 */
972
973 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
974 {
975 struct net *net = sock_net(skb->sk);
976 struct tcmsg *tcm = nlmsg_data(n);
977 struct nlattr *tca[TCA_MAX + 1];
978 struct net_device *dev;
979 u32 clid = tcm->tcm_parent;
980 struct Qdisc *q = NULL;
981 struct Qdisc *p = NULL;
982 int err;
983
984 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
985 if (!dev)
986 return -ENODEV;
987
988 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
989 if (err < 0)
990 return err;
991
992 if (clid) {
993 if (clid != TC_H_ROOT) {
994 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
995 p = qdisc_lookup(dev, TC_H_MAJ(clid));
996 if (!p)
997 return -ENOENT;
998 q = qdisc_leaf(p, clid);
999 } else if (dev_ingress_queue(dev)) {
1000 q = dev_ingress_queue(dev)->qdisc_sleeping;
1001 }
1002 } else {
1003 q = dev->qdisc;
1004 }
1005 if (!q)
1006 return -ENOENT;
1007
1008 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1009 return -EINVAL;
1010 } else {
1011 q = qdisc_lookup(dev, tcm->tcm_handle);
1012 if (!q)
1013 return -ENOENT;
1014 }
1015
1016 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1017 return -EINVAL;
1018
1019 if (n->nlmsg_type == RTM_DELQDISC) {
1020 if (!clid)
1021 return -EINVAL;
1022 if (q->handle == 0)
1023 return -ENOENT;
1024 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1025 if (err != 0)
1026 return err;
1027 } else {
1028 qdisc_notify(net, skb, n, clid, NULL, q);
1029 }
1030 return 0;
1031 }
1032
1033 /*
1034 * Create/change qdisc.
1035 */
1036
1037 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1038 {
1039 struct net *net = sock_net(skb->sk);
1040 struct tcmsg *tcm;
1041 struct nlattr *tca[TCA_MAX + 1];
1042 struct net_device *dev;
1043 u32 clid;
1044 struct Qdisc *q, *p;
1045 int err;
1046
1047 replay:
1048 /* Reinit, just in case something touches this. */
1049 tcm = nlmsg_data(n);
1050 clid = tcm->tcm_parent;
1051 q = p = NULL;
1052
1053 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1054 if (!dev)
1055 return -ENODEV;
1056
1057 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1058 if (err < 0)
1059 return err;
1060
1061 if (clid) {
1062 if (clid != TC_H_ROOT) {
1063 if (clid != TC_H_INGRESS) {
1064 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1065 if (!p)
1066 return -ENOENT;
1067 q = qdisc_leaf(p, clid);
1068 } else if (dev_ingress_queue_create(dev)) {
1069 q = dev_ingress_queue(dev)->qdisc_sleeping;
1070 }
1071 } else {
1072 q = dev->qdisc;
1073 }
1074
1075 /* It may be default qdisc, ignore it */
1076 if (q && q->handle == 0)
1077 q = NULL;
1078
1079 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1080 if (tcm->tcm_handle) {
1081 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1082 return -EEXIST;
1083 if (TC_H_MIN(tcm->tcm_handle))
1084 return -EINVAL;
1085 q = qdisc_lookup(dev, tcm->tcm_handle);
1086 if (!q)
1087 goto create_n_graft;
1088 if (n->nlmsg_flags & NLM_F_EXCL)
1089 return -EEXIST;
1090 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1091 return -EINVAL;
1092 if (q == p ||
1093 (p && check_loop(q, p, 0)))
1094 return -ELOOP;
1095 atomic_inc(&q->refcnt);
1096 goto graft;
1097 } else {
1098 if (!q)
1099 goto create_n_graft;
1100
1101 /* This magic test requires explanation.
1102 *
1103 * We know, that some child q is already
1104 * attached to this parent and have choice:
1105 * either to change it or to create/graft new one.
1106 *
1107 * 1. We are allowed to create/graft only
1108 * if CREATE and REPLACE flags are set.
1109 *
1110 * 2. If EXCL is set, requestor wanted to say,
1111 * that qdisc tcm_handle is not expected
1112 * to exist, so that we choose create/graft too.
1113 *
1114 * 3. The last case is when no flags are set.
1115 * Alas, it is sort of hole in API, we
1116 * cannot decide what to do unambiguously.
1117 * For now we select create/graft, if
1118 * user gave KIND, which does not match existing.
1119 */
1120 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1121 (n->nlmsg_flags & NLM_F_REPLACE) &&
1122 ((n->nlmsg_flags & NLM_F_EXCL) ||
1123 (tca[TCA_KIND] &&
1124 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1125 goto create_n_graft;
1126 }
1127 }
1128 } else {
1129 if (!tcm->tcm_handle)
1130 return -EINVAL;
1131 q = qdisc_lookup(dev, tcm->tcm_handle);
1132 }
1133
1134 /* Change qdisc parameters */
1135 if (q == NULL)
1136 return -ENOENT;
1137 if (n->nlmsg_flags & NLM_F_EXCL)
1138 return -EEXIST;
1139 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1140 return -EINVAL;
1141 err = qdisc_change(q, tca);
1142 if (err == 0)
1143 qdisc_notify(net, skb, n, clid, NULL, q);
1144 return err;
1145
1146 create_n_graft:
1147 if (!(n->nlmsg_flags & NLM_F_CREATE))
1148 return -ENOENT;
1149 if (clid == TC_H_INGRESS) {
1150 if (dev_ingress_queue(dev))
1151 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1152 tcm->tcm_parent, tcm->tcm_parent,
1153 tca, &err);
1154 else
1155 err = -ENOENT;
1156 } else {
1157 struct netdev_queue *dev_queue;
1158
1159 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1160 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1161 else if (p)
1162 dev_queue = p->dev_queue;
1163 else
1164 dev_queue = netdev_get_tx_queue(dev, 0);
1165
1166 q = qdisc_create(dev, dev_queue, p,
1167 tcm->tcm_parent, tcm->tcm_handle,
1168 tca, &err);
1169 }
1170 if (q == NULL) {
1171 if (err == -EAGAIN)
1172 goto replay;
1173 return err;
1174 }
1175
1176 graft:
1177 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1178 if (err) {
1179 if (q)
1180 qdisc_destroy(q);
1181 return err;
1182 }
1183
1184 return 0;
1185 }
1186
1187 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1188 u32 portid, u32 seq, u16 flags, int event)
1189 {
1190 struct tcmsg *tcm;
1191 struct nlmsghdr *nlh;
1192 unsigned char *b = skb_tail_pointer(skb);
1193 struct gnet_dump d;
1194 struct qdisc_size_table *stab;
1195
1196 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1197 if (!nlh)
1198 goto out_nlmsg_trim;
1199 tcm = nlmsg_data(nlh);
1200 tcm->tcm_family = AF_UNSPEC;
1201 tcm->tcm__pad1 = 0;
1202 tcm->tcm__pad2 = 0;
1203 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1204 tcm->tcm_parent = clid;
1205 tcm->tcm_handle = q->handle;
1206 tcm->tcm_info = atomic_read(&q->refcnt);
1207 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1208 goto nla_put_failure;
1209 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1210 goto nla_put_failure;
1211 q->qstats.qlen = q->q.qlen;
1212
1213 stab = rtnl_dereference(q->stab);
1214 if (stab && qdisc_dump_stab(skb, stab) < 0)
1215 goto nla_put_failure;
1216
1217 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1218 qdisc_root_sleeping_lock(q), &d) < 0)
1219 goto nla_put_failure;
1220
1221 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1222 goto nla_put_failure;
1223
1224 if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
1225 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1226 gnet_stats_copy_queue(&d, &q->qstats) < 0)
1227 goto nla_put_failure;
1228
1229 if (gnet_stats_finish_copy(&d) < 0)
1230 goto nla_put_failure;
1231
1232 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1233 return skb->len;
1234
1235 out_nlmsg_trim:
1236 nla_put_failure:
1237 nlmsg_trim(skb, b);
1238 return -1;
1239 }
1240
1241 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1242 {
1243 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1244 }
1245
1246 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1247 struct nlmsghdr *n, u32 clid,
1248 struct Qdisc *old, struct Qdisc *new)
1249 {
1250 struct sk_buff *skb;
1251 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1252
1253 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1254 if (!skb)
1255 return -ENOBUFS;
1256
1257 if (old && !tc_qdisc_dump_ignore(old)) {
1258 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1259 0, RTM_DELQDISC) < 0)
1260 goto err_out;
1261 }
1262 if (new && !tc_qdisc_dump_ignore(new)) {
1263 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1264 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1265 goto err_out;
1266 }
1267
1268 if (skb->len)
1269 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1270 n->nlmsg_flags & NLM_F_ECHO);
1271
1272 err_out:
1273 kfree_skb(skb);
1274 return -EINVAL;
1275 }
1276
1277 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1278 struct netlink_callback *cb,
1279 int *q_idx_p, int s_q_idx)
1280 {
1281 int ret = 0, q_idx = *q_idx_p;
1282 struct Qdisc *q;
1283
1284 if (!root)
1285 return 0;
1286
1287 q = root;
1288 if (q_idx < s_q_idx) {
1289 q_idx++;
1290 } else {
1291 if (!tc_qdisc_dump_ignore(q) &&
1292 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1293 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1294 goto done;
1295 q_idx++;
1296 }
1297 list_for_each_entry(q, &root->list, list) {
1298 if (q_idx < s_q_idx) {
1299 q_idx++;
1300 continue;
1301 }
1302 if (!tc_qdisc_dump_ignore(q) &&
1303 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1304 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1305 goto done;
1306 q_idx++;
1307 }
1308
1309 out:
1310 *q_idx_p = q_idx;
1311 return ret;
1312 done:
1313 ret = -1;
1314 goto out;
1315 }
1316
1317 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1318 {
1319 struct net *net = sock_net(skb->sk);
1320 int idx, q_idx;
1321 int s_idx, s_q_idx;
1322 struct net_device *dev;
1323
1324 s_idx = cb->args[0];
1325 s_q_idx = q_idx = cb->args[1];
1326
1327 rcu_read_lock();
1328 idx = 0;
1329 for_each_netdev_rcu(net, dev) {
1330 struct netdev_queue *dev_queue;
1331
1332 if (idx < s_idx)
1333 goto cont;
1334 if (idx > s_idx)
1335 s_q_idx = 0;
1336 q_idx = 0;
1337
1338 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1339 goto done;
1340
1341 dev_queue = dev_ingress_queue(dev);
1342 if (dev_queue &&
1343 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1344 &q_idx, s_q_idx) < 0)
1345 goto done;
1346
1347 cont:
1348 idx++;
1349 }
1350
1351 done:
1352 rcu_read_unlock();
1353
1354 cb->args[0] = idx;
1355 cb->args[1] = q_idx;
1356
1357 return skb->len;
1358 }
1359
1360
1361
1362 /************************************************
1363 * Traffic classes manipulation. *
1364 ************************************************/
1365
1366
1367
1368 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1369 {
1370 struct net *net = sock_net(skb->sk);
1371 struct tcmsg *tcm = nlmsg_data(n);
1372 struct nlattr *tca[TCA_MAX + 1];
1373 struct net_device *dev;
1374 struct Qdisc *q = NULL;
1375 const struct Qdisc_class_ops *cops;
1376 unsigned long cl = 0;
1377 unsigned long new_cl;
1378 u32 portid = tcm->tcm_parent;
1379 u32 clid = tcm->tcm_handle;
1380 u32 qid = TC_H_MAJ(clid);
1381 int err;
1382
1383 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1384 if (!dev)
1385 return -ENODEV;
1386
1387 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1388 if (err < 0)
1389 return err;
1390
1391 /*
1392 parent == TC_H_UNSPEC - unspecified parent.
1393 parent == TC_H_ROOT - class is root, which has no parent.
1394 parent == X:0 - parent is root class.
1395 parent == X:Y - parent is a node in hierarchy.
1396 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1397
1398 handle == 0:0 - generate handle from kernel pool.
1399 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1400 handle == X:Y - clear.
1401 handle == X:0 - root class.
1402 */
1403
1404 /* Step 1. Determine qdisc handle X:0 */
1405
1406 if (portid != TC_H_ROOT) {
1407 u32 qid1 = TC_H_MAJ(portid);
1408
1409 if (qid && qid1) {
1410 /* If both majors are known, they must be identical. */
1411 if (qid != qid1)
1412 return -EINVAL;
1413 } else if (qid1) {
1414 qid = qid1;
1415 } else if (qid == 0)
1416 qid = dev->qdisc->handle;
1417
1418 /* Now qid is genuine qdisc handle consistent
1419 * both with parent and child.
1420 *
1421 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1422 */
1423 if (portid)
1424 portid = TC_H_MAKE(qid, portid);
1425 } else {
1426 if (qid == 0)
1427 qid = dev->qdisc->handle;
1428 }
1429
1430 /* OK. Locate qdisc */
1431 q = qdisc_lookup(dev, qid);
1432 if (!q)
1433 return -ENOENT;
1434
1435 /* An check that it supports classes */
1436 cops = q->ops->cl_ops;
1437 if (cops == NULL)
1438 return -EINVAL;
1439
1440 /* Now try to get class */
1441 if (clid == 0) {
1442 if (portid == TC_H_ROOT)
1443 clid = qid;
1444 } else
1445 clid = TC_H_MAKE(qid, clid);
1446
1447 if (clid)
1448 cl = cops->get(q, clid);
1449
1450 if (cl == 0) {
1451 err = -ENOENT;
1452 if (n->nlmsg_type != RTM_NEWTCLASS ||
1453 !(n->nlmsg_flags & NLM_F_CREATE))
1454 goto out;
1455 } else {
1456 switch (n->nlmsg_type) {
1457 case RTM_NEWTCLASS:
1458 err = -EEXIST;
1459 if (n->nlmsg_flags & NLM_F_EXCL)
1460 goto out;
1461 break;
1462 case RTM_DELTCLASS:
1463 err = -EOPNOTSUPP;
1464 if (cops->delete)
1465 err = cops->delete(q, cl);
1466 if (err == 0)
1467 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1468 goto out;
1469 case RTM_GETTCLASS:
1470 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1471 goto out;
1472 default:
1473 err = -EINVAL;
1474 goto out;
1475 }
1476 }
1477
1478 new_cl = cl;
1479 err = -EOPNOTSUPP;
1480 if (cops->change)
1481 err = cops->change(q, clid, portid, tca, &new_cl);
1482 if (err == 0)
1483 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1484
1485 out:
1486 if (cl)
1487 cops->put(q, cl);
1488
1489 return err;
1490 }
1491
1492
1493 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1494 unsigned long cl,
1495 u32 portid, u32 seq, u16 flags, int event)
1496 {
1497 struct tcmsg *tcm;
1498 struct nlmsghdr *nlh;
1499 unsigned char *b = skb_tail_pointer(skb);
1500 struct gnet_dump d;
1501 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1502
1503 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1504 if (!nlh)
1505 goto out_nlmsg_trim;
1506 tcm = nlmsg_data(nlh);
1507 tcm->tcm_family = AF_UNSPEC;
1508 tcm->tcm__pad1 = 0;
1509 tcm->tcm__pad2 = 0;
1510 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1511 tcm->tcm_parent = q->handle;
1512 tcm->tcm_handle = q->handle;
1513 tcm->tcm_info = 0;
1514 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1515 goto nla_put_failure;
1516 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1517 goto nla_put_failure;
1518
1519 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1520 qdisc_root_sleeping_lock(q), &d) < 0)
1521 goto nla_put_failure;
1522
1523 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1524 goto nla_put_failure;
1525
1526 if (gnet_stats_finish_copy(&d) < 0)
1527 goto nla_put_failure;
1528
1529 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1530 return skb->len;
1531
1532 out_nlmsg_trim:
1533 nla_put_failure:
1534 nlmsg_trim(skb, b);
1535 return -1;
1536 }
1537
1538 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1539 struct nlmsghdr *n, struct Qdisc *q,
1540 unsigned long cl, int event)
1541 {
1542 struct sk_buff *skb;
1543 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1544
1545 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1546 if (!skb)
1547 return -ENOBUFS;
1548
1549 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1550 kfree_skb(skb);
1551 return -EINVAL;
1552 }
1553
1554 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1555 n->nlmsg_flags & NLM_F_ECHO);
1556 }
1557
1558 struct qdisc_dump_args {
1559 struct qdisc_walker w;
1560 struct sk_buff *skb;
1561 struct netlink_callback *cb;
1562 };
1563
1564 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1565 {
1566 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1567
1568 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1569 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1570 }
1571
1572 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1573 struct tcmsg *tcm, struct netlink_callback *cb,
1574 int *t_p, int s_t)
1575 {
1576 struct qdisc_dump_args arg;
1577
1578 if (tc_qdisc_dump_ignore(q) ||
1579 *t_p < s_t || !q->ops->cl_ops ||
1580 (tcm->tcm_parent &&
1581 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1582 (*t_p)++;
1583 return 0;
1584 }
1585 if (*t_p > s_t)
1586 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1587 arg.w.fn = qdisc_class_dump;
1588 arg.skb = skb;
1589 arg.cb = cb;
1590 arg.w.stop = 0;
1591 arg.w.skip = cb->args[1];
1592 arg.w.count = 0;
1593 q->ops->cl_ops->walk(q, &arg.w);
1594 cb->args[1] = arg.w.count;
1595 if (arg.w.stop)
1596 return -1;
1597 (*t_p)++;
1598 return 0;
1599 }
1600
1601 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1602 struct tcmsg *tcm, struct netlink_callback *cb,
1603 int *t_p, int s_t)
1604 {
1605 struct Qdisc *q;
1606
1607 if (!root)
1608 return 0;
1609
1610 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1611 return -1;
1612
1613 list_for_each_entry(q, &root->list, list) {
1614 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1615 return -1;
1616 }
1617
1618 return 0;
1619 }
1620
1621 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1622 {
1623 struct tcmsg *tcm = nlmsg_data(cb->nlh);
1624 struct net *net = sock_net(skb->sk);
1625 struct netdev_queue *dev_queue;
1626 struct net_device *dev;
1627 int t, s_t;
1628
1629 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
1630 return 0;
1631 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1632 if (!dev)
1633 return 0;
1634
1635 s_t = cb->args[0];
1636 t = 0;
1637
1638 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1639 goto done;
1640
1641 dev_queue = dev_ingress_queue(dev);
1642 if (dev_queue &&
1643 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1644 &t, s_t) < 0)
1645 goto done;
1646
1647 done:
1648 cb->args[0] = t;
1649
1650 dev_put(dev);
1651 return skb->len;
1652 }
1653
1654 /* Main classifier routine: scans classifier chain attached
1655 * to this qdisc, (optionally) tests for protocol and asks
1656 * specific classifiers.
1657 */
1658 int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
1659 struct tcf_result *res)
1660 {
1661 __be16 protocol = skb->protocol;
1662 int err;
1663
1664 for (; tp; tp = tp->next) {
1665 if (tp->protocol != protocol &&
1666 tp->protocol != htons(ETH_P_ALL))
1667 continue;
1668 err = tp->classify(skb, tp, res);
1669
1670 if (err >= 0) {
1671 #ifdef CONFIG_NET_CLS_ACT
1672 if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
1673 skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
1674 #endif
1675 return err;
1676 }
1677 }
1678 return -1;
1679 }
1680 EXPORT_SYMBOL(tc_classify_compat);
1681
1682 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1683 struct tcf_result *res)
1684 {
1685 int err = 0;
1686 #ifdef CONFIG_NET_CLS_ACT
1687 const struct tcf_proto *otp = tp;
1688 reclassify:
1689 #endif
1690
1691 err = tc_classify_compat(skb, tp, res);
1692 #ifdef CONFIG_NET_CLS_ACT
1693 if (err == TC_ACT_RECLASSIFY) {
1694 u32 verd = G_TC_VERD(skb->tc_verd);
1695 tp = otp;
1696
1697 if (verd++ >= MAX_REC_LOOP) {
1698 net_notice_ratelimited("%s: packet reclassify loop rule prio %u protocol %02x\n",
1699 tp->q->ops->id,
1700 tp->prio & 0xffff,
1701 ntohs(tp->protocol));
1702 return TC_ACT_SHOT;
1703 }
1704 skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
1705 goto reclassify;
1706 }
1707 #endif
1708 return err;
1709 }
1710 EXPORT_SYMBOL(tc_classify);
1711
1712 void tcf_destroy(struct tcf_proto *tp)
1713 {
1714 tp->ops->destroy(tp);
1715 module_put(tp->ops->owner);
1716 kfree(tp);
1717 }
1718
1719 void tcf_destroy_chain(struct tcf_proto **fl)
1720 {
1721 struct tcf_proto *tp;
1722
1723 while ((tp = *fl) != NULL) {
1724 *fl = tp->next;
1725 tcf_destroy(tp);
1726 }
1727 }
1728 EXPORT_SYMBOL(tcf_destroy_chain);
1729
1730 #ifdef CONFIG_PROC_FS
1731 static int psched_show(struct seq_file *seq, void *v)
1732 {
1733 struct timespec ts;
1734
1735 hrtimer_get_res(CLOCK_MONOTONIC, &ts);
1736 seq_printf(seq, "%08x %08x %08x %08x\n",
1737 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1738 1000000,
1739 (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
1740
1741 return 0;
1742 }
1743
1744 static int psched_open(struct inode *inode, struct file *file)
1745 {
1746 return single_open(file, psched_show, NULL);
1747 }
1748
1749 static const struct file_operations psched_fops = {
1750 .owner = THIS_MODULE,
1751 .open = psched_open,
1752 .read = seq_read,
1753 .llseek = seq_lseek,
1754 .release = single_release,
1755 };
1756
1757 static int __net_init psched_net_init(struct net *net)
1758 {
1759 struct proc_dir_entry *e;
1760
1761 e = proc_net_fops_create(net, "psched", 0, &psched_fops);
1762 if (e == NULL)
1763 return -ENOMEM;
1764
1765 return 0;
1766 }
1767
1768 static void __net_exit psched_net_exit(struct net *net)
1769 {
1770 proc_net_remove(net, "psched");
1771 }
1772 #else
1773 static int __net_init psched_net_init(struct net *net)
1774 {
1775 return 0;
1776 }
1777
1778 static void __net_exit psched_net_exit(struct net *net)
1779 {
1780 }
1781 #endif
1782
1783 static struct pernet_operations psched_net_ops = {
1784 .init = psched_net_init,
1785 .exit = psched_net_exit,
1786 };
1787
1788 static int __init pktsched_init(void)
1789 {
1790 int err;
1791
1792 err = register_pernet_subsys(&psched_net_ops);
1793 if (err) {
1794 pr_err("pktsched_init: "
1795 "cannot initialize per netns operations\n");
1796 return err;
1797 }
1798
1799 register_qdisc(&pfifo_qdisc_ops);
1800 register_qdisc(&bfifo_qdisc_ops);
1801 register_qdisc(&pfifo_head_drop_qdisc_ops);
1802 register_qdisc(&mq_qdisc_ops);
1803
1804 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1805 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1806 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1807 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1808 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1809 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1810
1811 return 0;
1812 }
1813
1814 subsys_initcall(pktsched_init);
Linus' kernel tree