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MIPS: Make the die_lock be raw
[linux-2.6/linux-mips.git] / net / sched / sch_api.c
blobdca6c1a576f77e70ee7cab5c187946c96a7219d2
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 NLA_PUT(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts);
430 nla_nest_end(skb, nest);
431
432 return skb->len;
433
434 nla_put_failure:
435 return -1;
436 }
437
438 void __qdisc_calculate_pkt_len(struct sk_buff *skb, const struct qdisc_size_table *stab)
439 {
440 int pkt_len, slot;
441
442 pkt_len = skb->len + stab->szopts.overhead;
443 if (unlikely(!stab->szopts.tsize))
444 goto out;
445
446 slot = pkt_len + stab->szopts.cell_align;
447 if (unlikely(slot < 0))
448 slot = 0;
449
450 slot >>= stab->szopts.cell_log;
451 if (likely(slot < stab->szopts.tsize))
452 pkt_len = stab->data[slot];
453 else
454 pkt_len = stab->data[stab->szopts.tsize - 1] *
455 (slot / stab->szopts.tsize) +
456 stab->data[slot % stab->szopts.tsize];
457
458 pkt_len <<= stab->szopts.size_log;
459 out:
460 if (unlikely(pkt_len < 1))
461 pkt_len = 1;
462 qdisc_skb_cb(skb)->pkt_len = pkt_len;
463 }
464 EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
465
466 void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc)
467 {
468 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
469 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
470 txt, qdisc->ops->id, qdisc->handle >> 16);
471 qdisc->flags |= TCQ_F_WARN_NONWC;
472 }
473 }
474 EXPORT_SYMBOL(qdisc_warn_nonwc);
475
476 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
477 {
478 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
479 timer);
480
481 qdisc_unthrottled(wd->qdisc);
482 __netif_schedule(qdisc_root(wd->qdisc));
483
484 return HRTIMER_NORESTART;
485 }
486
487 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
488 {
489 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
490 wd->timer.function = qdisc_watchdog;
491 wd->qdisc = qdisc;
492 }
493 EXPORT_SYMBOL(qdisc_watchdog_init);
494
495 void qdisc_watchdog_schedule(struct qdisc_watchdog *wd, psched_time_t expires)
496 {
497 ktime_t time;
498
499 if (test_bit(__QDISC_STATE_DEACTIVATED,
500 &qdisc_root_sleeping(wd->qdisc)->state))
501 return;
502
503 qdisc_throttled(wd->qdisc);
504 time = ktime_set(0, 0);
505 time = ktime_add_ns(time, PSCHED_TICKS2NS(expires));
506 hrtimer_start(&wd->timer, time, HRTIMER_MODE_ABS);
507 }
508 EXPORT_SYMBOL(qdisc_watchdog_schedule);
509
510 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
511 {
512 hrtimer_cancel(&wd->timer);
513 qdisc_unthrottled(wd->qdisc);
514 }
515 EXPORT_SYMBOL(qdisc_watchdog_cancel);
516
517 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
518 {
519 unsigned int size = n * sizeof(struct hlist_head), i;
520 struct hlist_head *h;
521
522 if (size <= PAGE_SIZE)
523 h = kmalloc(size, GFP_KERNEL);
524 else
525 h = (struct hlist_head *)
526 __get_free_pages(GFP_KERNEL, get_order(size));
527
528 if (h != NULL) {
529 for (i = 0; i < n; i++)
530 INIT_HLIST_HEAD(&h[i]);
531 }
532 return h;
533 }
534
535 static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
536 {
537 unsigned int size = n * sizeof(struct hlist_head);
538
539 if (size <= PAGE_SIZE)
540 kfree(h);
541 else
542 free_pages((unsigned long)h, get_order(size));
543 }
544
545 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
546 {
547 struct Qdisc_class_common *cl;
548 struct hlist_node *n, *next;
549 struct hlist_head *nhash, *ohash;
550 unsigned int nsize, nmask, osize;
551 unsigned int i, h;
552
553 /* Rehash when load factor exceeds 0.75 */
554 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
555 return;
556 nsize = clhash->hashsize * 2;
557 nmask = nsize - 1;
558 nhash = qdisc_class_hash_alloc(nsize);
559 if (nhash == NULL)
560 return;
561
562 ohash = clhash->hash;
563 osize = clhash->hashsize;
564
565 sch_tree_lock(sch);
566 for (i = 0; i < osize; i++) {
567 hlist_for_each_entry_safe(cl, n, next, &ohash[i], hnode) {
568 h = qdisc_class_hash(cl->classid, nmask);
569 hlist_add_head(&cl->hnode, &nhash[h]);
570 }
571 }
572 clhash->hash = nhash;
573 clhash->hashsize = nsize;
574 clhash->hashmask = nmask;
575 sch_tree_unlock(sch);
576
577 qdisc_class_hash_free(ohash, osize);
578 }
579 EXPORT_SYMBOL(qdisc_class_hash_grow);
580
581 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
582 {
583 unsigned int size = 4;
584
585 clhash->hash = qdisc_class_hash_alloc(size);
586 if (clhash->hash == NULL)
587 return -ENOMEM;
588 clhash->hashsize = size;
589 clhash->hashmask = size - 1;
590 clhash->hashelems = 0;
591 return 0;
592 }
593 EXPORT_SYMBOL(qdisc_class_hash_init);
594
595 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
596 {
597 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
598 }
599 EXPORT_SYMBOL(qdisc_class_hash_destroy);
600
601 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
602 struct Qdisc_class_common *cl)
603 {
604 unsigned int h;
605
606 INIT_HLIST_NODE(&cl->hnode);
607 h = qdisc_class_hash(cl->classid, clhash->hashmask);
608 hlist_add_head(&cl->hnode, &clhash->hash[h]);
609 clhash->hashelems++;
610 }
611 EXPORT_SYMBOL(qdisc_class_hash_insert);
612
613 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
614 struct Qdisc_class_common *cl)
615 {
616 hlist_del(&cl->hnode);
617 clhash->hashelems--;
618 }
619 EXPORT_SYMBOL(qdisc_class_hash_remove);
620
621 /* Allocate an unique handle from space managed by kernel */
622
623 static u32 qdisc_alloc_handle(struct net_device *dev)
624 {
625 int i = 0x10000;
626 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
627
628 do {
629 autohandle += TC_H_MAKE(0x10000U, 0);
630 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
631 autohandle = TC_H_MAKE(0x80000000U, 0);
632 } while (qdisc_lookup(dev, autohandle) && --i > 0);
633
634 return i > 0 ? autohandle : 0;
635 }
636
637 void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
638 {
639 const struct Qdisc_class_ops *cops;
640 unsigned long cl;
641 u32 parentid;
642
643 if (n == 0)
644 return;
645 while ((parentid = sch->parent)) {
646 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
647 return;
648
649 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
650 if (sch == NULL) {
651 WARN_ON(parentid != TC_H_ROOT);
652 return;
653 }
654 cops = sch->ops->cl_ops;
655 if (cops->qlen_notify) {
656 cl = cops->get(sch, parentid);
657 cops->qlen_notify(sch, cl);
658 cops->put(sch, cl);
659 }
660 sch->q.qlen -= n;
661 }
662 }
663 EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
664
665 static void notify_and_destroy(struct net *net, struct sk_buff *skb,
666 struct nlmsghdr *n, u32 clid,
667 struct Qdisc *old, struct Qdisc *new)
668 {
669 if (new || old)
670 qdisc_notify(net, skb, n, clid, old, new);
671
672 if (old)
673 qdisc_destroy(old);
674 }
675
676 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
677 * to device "dev".
678 *
679 * When appropriate send a netlink notification using 'skb'
680 * and "n".
681 *
682 * On success, destroy old qdisc.
683 */
684
685 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
686 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
687 struct Qdisc *new, struct Qdisc *old)
688 {
689 struct Qdisc *q = old;
690 struct net *net = dev_net(dev);
691 int err = 0;
692
693 if (parent == NULL) {
694 unsigned int i, num_q, ingress;
695
696 ingress = 0;
697 num_q = dev->num_tx_queues;
698 if ((q && q->flags & TCQ_F_INGRESS) ||
699 (new && new->flags & TCQ_F_INGRESS)) {
700 num_q = 1;
701 ingress = 1;
702 if (!dev_ingress_queue(dev))
703 return -ENOENT;
704 }
705
706 if (dev->flags & IFF_UP)
707 dev_deactivate(dev);
708
709 if (new && new->ops->attach) {
710 new->ops->attach(new);
711 num_q = 0;
712 }
713
714 for (i = 0; i < num_q; i++) {
715 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
716
717 if (!ingress)
718 dev_queue = netdev_get_tx_queue(dev, i);
719
720 old = dev_graft_qdisc(dev_queue, new);
721 if (new && i > 0)
722 atomic_inc(&new->refcnt);
723
724 if (!ingress)
725 qdisc_destroy(old);
726 }
727
728 if (!ingress) {
729 notify_and_destroy(net, skb, n, classid,
730 dev->qdisc, new);
731 if (new && !new->ops->attach)
732 atomic_inc(&new->refcnt);
733 dev->qdisc = new ? : &noop_qdisc;
734 } else {
735 notify_and_destroy(net, skb, n, classid, old, new);
736 }
737
738 if (dev->flags & IFF_UP)
739 dev_activate(dev);
740 } else {
741 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
742
743 err = -EOPNOTSUPP;
744 if (cops && cops->graft) {
745 unsigned long cl = cops->get(parent, classid);
746 if (cl) {
747 err = cops->graft(parent, cl, new, &old);
748 cops->put(parent, cl);
749 } else
750 err = -ENOENT;
751 }
752 if (!err)
753 notify_and_destroy(net, skb, n, classid, old, new);
754 }
755 return err;
756 }
757
758 /* lockdep annotation is needed for ingress; egress gets it only for name */
759 static struct lock_class_key qdisc_tx_lock;
760 static struct lock_class_key qdisc_rx_lock;
761
762 /*
763 Allocate and initialize new qdisc.
764
765 Parameters are passed via opt.
766 */
767
768 static struct Qdisc *
769 qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
770 struct Qdisc *p, u32 parent, u32 handle,
771 struct nlattr **tca, int *errp)
772 {
773 int err;
774 struct nlattr *kind = tca[TCA_KIND];
775 struct Qdisc *sch;
776 struct Qdisc_ops *ops;
777 struct qdisc_size_table *stab;
778
779 ops = qdisc_lookup_ops(kind);
780 #ifdef CONFIG_MODULES
781 if (ops == NULL && kind != NULL) {
782 char name[IFNAMSIZ];
783 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
784 /* We dropped the RTNL semaphore in order to
785 * perform the module load. So, even if we
786 * succeeded in loading the module we have to
787 * tell the caller to replay the request. We
788 * indicate this using -EAGAIN.
789 * We replay the request because the device may
790 * go away in the mean time.
791 */
792 rtnl_unlock();
793 request_module("sch_%s", name);
794 rtnl_lock();
795 ops = qdisc_lookup_ops(kind);
796 if (ops != NULL) {
797 /* We will try again qdisc_lookup_ops,
798 * so don't keep a reference.
799 */
800 module_put(ops->owner);
801 err = -EAGAIN;
802 goto err_out;
803 }
804 }
805 }
806 #endif
807
808 err = -ENOENT;
809 if (ops == NULL)
810 goto err_out;
811
812 sch = qdisc_alloc(dev_queue, ops);
813 if (IS_ERR(sch)) {
814 err = PTR_ERR(sch);
815 goto err_out2;
816 }
817
818 sch->parent = parent;
819
820 if (handle == TC_H_INGRESS) {
821 sch->flags |= TCQ_F_INGRESS;
822 handle = TC_H_MAKE(TC_H_INGRESS, 0);
823 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
824 } else {
825 if (handle == 0) {
826 handle = qdisc_alloc_handle(dev);
827 err = -ENOMEM;
828 if (handle == 0)
829 goto err_out3;
830 }
831 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
832 }
833
834 sch->handle = handle;
835
836 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
837 if (tca[TCA_STAB]) {
838 stab = qdisc_get_stab(tca[TCA_STAB]);
839 if (IS_ERR(stab)) {
840 err = PTR_ERR(stab);
841 goto err_out4;
842 }
843 rcu_assign_pointer(sch->stab, stab);
844 }
845 if (tca[TCA_RATE]) {
846 spinlock_t *root_lock;
847
848 err = -EOPNOTSUPP;
849 if (sch->flags & TCQ_F_MQROOT)
850 goto err_out4;
851
852 if ((sch->parent != TC_H_ROOT) &&
853 !(sch->flags & TCQ_F_INGRESS) &&
854 (!p || !(p->flags & TCQ_F_MQROOT)))
855 root_lock = qdisc_root_sleeping_lock(sch);
856 else
857 root_lock = qdisc_lock(sch);
858
859 err = gen_new_estimator(&sch->bstats, &sch->rate_est,
860 root_lock, tca[TCA_RATE]);
861 if (err)
862 goto err_out4;
863 }
864
865 qdisc_list_add(sch);
866
867 return sch;
868 }
869 err_out3:
870 dev_put(dev);
871 kfree((char *) sch - sch->padded);
872 err_out2:
873 module_put(ops->owner);
874 err_out:
875 *errp = err;
876 return NULL;
877
878 err_out4:
879 /*
880 * Any broken qdiscs that would require a ops->reset() here?
881 * The qdisc was never in action so it shouldn't be necessary.
882 */
883 qdisc_put_stab(rtnl_dereference(sch->stab));
884 if (ops->destroy)
885 ops->destroy(sch);
886 goto err_out3;
887 }
888
889 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
890 {
891 struct qdisc_size_table *ostab, *stab = NULL;
892 int err = 0;
893
894 if (tca[TCA_OPTIONS]) {
895 if (sch->ops->change == NULL)
896 return -EINVAL;
897 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
898 if (err)
899 return err;
900 }
901
902 if (tca[TCA_STAB]) {
903 stab = qdisc_get_stab(tca[TCA_STAB]);
904 if (IS_ERR(stab))
905 return PTR_ERR(stab);
906 }
907
908 ostab = rtnl_dereference(sch->stab);
909 rcu_assign_pointer(sch->stab, stab);
910 qdisc_put_stab(ostab);
911
912 if (tca[TCA_RATE]) {
913 /* NB: ignores errors from replace_estimator
914 because change can't be undone. */
915 if (sch->flags & TCQ_F_MQROOT)
916 goto out;
917 gen_replace_estimator(&sch->bstats, &sch->rate_est,
918 qdisc_root_sleeping_lock(sch),
919 tca[TCA_RATE]);
920 }
921 out:
922 return 0;
923 }
924
925 struct check_loop_arg {
926 struct qdisc_walker w;
927 struct Qdisc *p;
928 int depth;
929 };
930
931 static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
932
933 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
934 {
935 struct check_loop_arg arg;
936
937 if (q->ops->cl_ops == NULL)
938 return 0;
939
940 arg.w.stop = arg.w.skip = arg.w.count = 0;
941 arg.w.fn = check_loop_fn;
942 arg.depth = depth;
943 arg.p = p;
944 q->ops->cl_ops->walk(q, &arg.w);
945 return arg.w.stop ? -ELOOP : 0;
946 }
947
948 static int
949 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
950 {
951 struct Qdisc *leaf;
952 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
953 struct check_loop_arg *arg = (struct check_loop_arg *)w;
954
955 leaf = cops->leaf(q, cl);
956 if (leaf) {
957 if (leaf == arg->p || arg->depth > 7)
958 return -ELOOP;
959 return check_loop(leaf, arg->p, arg->depth + 1);
960 }
961 return 0;
962 }
963
964 /*
965 * Delete/get qdisc.
966 */
967
968 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
969 {
970 struct net *net = sock_net(skb->sk);
971 struct tcmsg *tcm = NLMSG_DATA(n);
972 struct nlattr *tca[TCA_MAX + 1];
973 struct net_device *dev;
974 u32 clid = tcm->tcm_parent;
975 struct Qdisc *q = NULL;
976 struct Qdisc *p = NULL;
977 int err;
978
979 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
980 if (!dev)
981 return -ENODEV;
982
983 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
984 if (err < 0)
985 return err;
986
987 if (clid) {
988 if (clid != TC_H_ROOT) {
989 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
990 p = qdisc_lookup(dev, TC_H_MAJ(clid));
991 if (!p)
992 return -ENOENT;
993 q = qdisc_leaf(p, clid);
994 } else if (dev_ingress_queue(dev)) {
995 q = dev_ingress_queue(dev)->qdisc_sleeping;
996 }
997 } else {
998 q = dev->qdisc;
999 }
1000 if (!q)
1001 return -ENOENT;
1002
1003 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1004 return -EINVAL;
1005 } else {
1006 q = qdisc_lookup(dev, tcm->tcm_handle);
1007 if (!q)
1008 return -ENOENT;
1009 }
1010
1011 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1012 return -EINVAL;
1013
1014 if (n->nlmsg_type == RTM_DELQDISC) {
1015 if (!clid)
1016 return -EINVAL;
1017 if (q->handle == 0)
1018 return -ENOENT;
1019 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1020 if (err != 0)
1021 return err;
1022 } else {
1023 qdisc_notify(net, skb, n, clid, NULL, q);
1024 }
1025 return 0;
1026 }
1027
1028 /*
1029 * Create/change qdisc.
1030 */
1031
1032 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1033 {
1034 struct net *net = sock_net(skb->sk);
1035 struct tcmsg *tcm;
1036 struct nlattr *tca[TCA_MAX + 1];
1037 struct net_device *dev;
1038 u32 clid;
1039 struct Qdisc *q, *p;
1040 int err;
1041
1042 replay:
1043 /* Reinit, just in case something touches this. */
1044 tcm = NLMSG_DATA(n);
1045 clid = tcm->tcm_parent;
1046 q = p = NULL;
1047
1048 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1049 if (!dev)
1050 return -ENODEV;
1051
1052 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1053 if (err < 0)
1054 return err;
1055
1056 if (clid) {
1057 if (clid != TC_H_ROOT) {
1058 if (clid != TC_H_INGRESS) {
1059 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1060 if (!p)
1061 return -ENOENT;
1062 q = qdisc_leaf(p, clid);
1063 } else if (dev_ingress_queue_create(dev)) {
1064 q = dev_ingress_queue(dev)->qdisc_sleeping;
1065 }
1066 } else {
1067 q = dev->qdisc;
1068 }
1069
1070 /* It may be default qdisc, ignore it */
1071 if (q && q->handle == 0)
1072 q = NULL;
1073
1074 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1075 if (tcm->tcm_handle) {
1076 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1077 return -EEXIST;
1078 if (TC_H_MIN(tcm->tcm_handle))
1079 return -EINVAL;
1080 q = qdisc_lookup(dev, tcm->tcm_handle);
1081 if (!q)
1082 goto create_n_graft;
1083 if (n->nlmsg_flags & NLM_F_EXCL)
1084 return -EEXIST;
1085 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1086 return -EINVAL;
1087 if (q == p ||
1088 (p && check_loop(q, p, 0)))
1089 return -ELOOP;
1090 atomic_inc(&q->refcnt);
1091 goto graft;
1092 } else {
1093 if (!q)
1094 goto create_n_graft;
1095
1096 /* This magic test requires explanation.
1097 *
1098 * We know, that some child q is already
1099 * attached to this parent and have choice:
1100 * either to change it or to create/graft new one.
1101 *
1102 * 1. We are allowed to create/graft only
1103 * if CREATE and REPLACE flags are set.
1104 *
1105 * 2. If EXCL is set, requestor wanted to say,
1106 * that qdisc tcm_handle is not expected
1107 * to exist, so that we choose create/graft too.
1108 *
1109 * 3. The last case is when no flags are set.
1110 * Alas, it is sort of hole in API, we
1111 * cannot decide what to do unambiguously.
1112 * For now we select create/graft, if
1113 * user gave KIND, which does not match existing.
1114 */
1115 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1116 (n->nlmsg_flags & NLM_F_REPLACE) &&
1117 ((n->nlmsg_flags & NLM_F_EXCL) ||
1118 (tca[TCA_KIND] &&
1119 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1120 goto create_n_graft;
1121 }
1122 }
1123 } else {
1124 if (!tcm->tcm_handle)
1125 return -EINVAL;
1126 q = qdisc_lookup(dev, tcm->tcm_handle);
1127 }
1128
1129 /* Change qdisc parameters */
1130 if (q == NULL)
1131 return -ENOENT;
1132 if (n->nlmsg_flags & NLM_F_EXCL)
1133 return -EEXIST;
1134 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1135 return -EINVAL;
1136 err = qdisc_change(q, tca);
1137 if (err == 0)
1138 qdisc_notify(net, skb, n, clid, NULL, q);
1139 return err;
1140
1141 create_n_graft:
1142 if (!(n->nlmsg_flags & NLM_F_CREATE))
1143 return -ENOENT;
1144 if (clid == TC_H_INGRESS) {
1145 if (dev_ingress_queue(dev))
1146 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1147 tcm->tcm_parent, tcm->tcm_parent,
1148 tca, &err);
1149 else
1150 err = -ENOENT;
1151 } else {
1152 struct netdev_queue *dev_queue;
1153
1154 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1155 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1156 else if (p)
1157 dev_queue = p->dev_queue;
1158 else
1159 dev_queue = netdev_get_tx_queue(dev, 0);
1160
1161 q = qdisc_create(dev, dev_queue, p,
1162 tcm->tcm_parent, tcm->tcm_handle,
1163 tca, &err);
1164 }
1165 if (q == NULL) {
1166 if (err == -EAGAIN)
1167 goto replay;
1168 return err;
1169 }
1170
1171 graft:
1172 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1173 if (err) {
1174 if (q)
1175 qdisc_destroy(q);
1176 return err;
1177 }
1178
1179 return 0;
1180 }
1181
1182 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1183 u32 pid, u32 seq, u16 flags, int event)
1184 {
1185 struct tcmsg *tcm;
1186 struct nlmsghdr *nlh;
1187 unsigned char *b = skb_tail_pointer(skb);
1188 struct gnet_dump d;
1189 struct qdisc_size_table *stab;
1190
1191 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1192 tcm = NLMSG_DATA(nlh);
1193 tcm->tcm_family = AF_UNSPEC;
1194 tcm->tcm__pad1 = 0;
1195 tcm->tcm__pad2 = 0;
1196 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1197 tcm->tcm_parent = clid;
1198 tcm->tcm_handle = q->handle;
1199 tcm->tcm_info = atomic_read(&q->refcnt);
1200 NLA_PUT_STRING(skb, TCA_KIND, q->ops->id);
1201 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1202 goto nla_put_failure;
1203 q->qstats.qlen = q->q.qlen;
1204
1205 stab = rtnl_dereference(q->stab);
1206 if (stab && qdisc_dump_stab(skb, stab) < 0)
1207 goto nla_put_failure;
1208
1209 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1210 qdisc_root_sleeping_lock(q), &d) < 0)
1211 goto nla_put_failure;
1212
1213 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1214 goto nla_put_failure;
1215
1216 if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
1217 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1218 gnet_stats_copy_queue(&d, &q->qstats) < 0)
1219 goto nla_put_failure;
1220
1221 if (gnet_stats_finish_copy(&d) < 0)
1222 goto nla_put_failure;
1223
1224 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1225 return skb->len;
1226
1227 nlmsg_failure:
1228 nla_put_failure:
1229 nlmsg_trim(skb, b);
1230 return -1;
1231 }
1232
1233 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1234 {
1235 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1236 }
1237
1238 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1239 struct nlmsghdr *n, u32 clid,
1240 struct Qdisc *old, struct Qdisc *new)
1241 {
1242 struct sk_buff *skb;
1243 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
1244
1245 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1246 if (!skb)
1247 return -ENOBUFS;
1248
1249 if (old && !tc_qdisc_dump_ignore(old)) {
1250 if (tc_fill_qdisc(skb, old, clid, pid, n->nlmsg_seq,
1251 0, RTM_DELQDISC) < 0)
1252 goto err_out;
1253 }
1254 if (new && !tc_qdisc_dump_ignore(new)) {
1255 if (tc_fill_qdisc(skb, new, clid, pid, n->nlmsg_seq,
1256 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1257 goto err_out;
1258 }
1259
1260 if (skb->len)
1261 return rtnetlink_send(skb, net, pid, RTNLGRP_TC,
1262 n->nlmsg_flags & NLM_F_ECHO);
1263
1264 err_out:
1265 kfree_skb(skb);
1266 return -EINVAL;
1267 }
1268
1269 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1270 struct netlink_callback *cb,
1271 int *q_idx_p, int s_q_idx)
1272 {
1273 int ret = 0, q_idx = *q_idx_p;
1274 struct Qdisc *q;
1275
1276 if (!root)
1277 return 0;
1278
1279 q = root;
1280 if (q_idx < s_q_idx) {
1281 q_idx++;
1282 } else {
1283 if (!tc_qdisc_dump_ignore(q) &&
1284 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid,
1285 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1286 goto done;
1287 q_idx++;
1288 }
1289 list_for_each_entry(q, &root->list, list) {
1290 if (q_idx < s_q_idx) {
1291 q_idx++;
1292 continue;
1293 }
1294 if (!tc_qdisc_dump_ignore(q) &&
1295 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid,
1296 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1297 goto done;
1298 q_idx++;
1299 }
1300
1301 out:
1302 *q_idx_p = q_idx;
1303 return ret;
1304 done:
1305 ret = -1;
1306 goto out;
1307 }
1308
1309 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1310 {
1311 struct net *net = sock_net(skb->sk);
1312 int idx, q_idx;
1313 int s_idx, s_q_idx;
1314 struct net_device *dev;
1315
1316 s_idx = cb->args[0];
1317 s_q_idx = q_idx = cb->args[1];
1318
1319 rcu_read_lock();
1320 idx = 0;
1321 for_each_netdev_rcu(net, dev) {
1322 struct netdev_queue *dev_queue;
1323
1324 if (idx < s_idx)
1325 goto cont;
1326 if (idx > s_idx)
1327 s_q_idx = 0;
1328 q_idx = 0;
1329
1330 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1331 goto done;
1332
1333 dev_queue = dev_ingress_queue(dev);
1334 if (dev_queue &&
1335 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1336 &q_idx, s_q_idx) < 0)
1337 goto done;
1338
1339 cont:
1340 idx++;
1341 }
1342
1343 done:
1344 rcu_read_unlock();
1345
1346 cb->args[0] = idx;
1347 cb->args[1] = q_idx;
1348
1349 return skb->len;
1350 }
1351
1352
1353
1354 /************************************************
1355 * Traffic classes manipulation. *
1356 ************************************************/
1357
1358
1359
1360 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1361 {
1362 struct net *net = sock_net(skb->sk);
1363 struct tcmsg *tcm = NLMSG_DATA(n);
1364 struct nlattr *tca[TCA_MAX + 1];
1365 struct net_device *dev;
1366 struct Qdisc *q = NULL;
1367 const struct Qdisc_class_ops *cops;
1368 unsigned long cl = 0;
1369 unsigned long new_cl;
1370 u32 pid = tcm->tcm_parent;
1371 u32 clid = tcm->tcm_handle;
1372 u32 qid = TC_H_MAJ(clid);
1373 int err;
1374
1375 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1376 if (!dev)
1377 return -ENODEV;
1378
1379 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1380 if (err < 0)
1381 return err;
1382
1383 /*
1384 parent == TC_H_UNSPEC - unspecified parent.
1385 parent == TC_H_ROOT - class is root, which has no parent.
1386 parent == X:0 - parent is root class.
1387 parent == X:Y - parent is a node in hierarchy.
1388 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1389
1390 handle == 0:0 - generate handle from kernel pool.
1391 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1392 handle == X:Y - clear.
1393 handle == X:0 - root class.
1394 */
1395
1396 /* Step 1. Determine qdisc handle X:0 */
1397
1398 if (pid != TC_H_ROOT) {
1399 u32 qid1 = TC_H_MAJ(pid);
1400
1401 if (qid && qid1) {
1402 /* If both majors are known, they must be identical. */
1403 if (qid != qid1)
1404 return -EINVAL;
1405 } else if (qid1) {
1406 qid = qid1;
1407 } else if (qid == 0)
1408 qid = dev->qdisc->handle;
1409
1410 /* Now qid is genuine qdisc handle consistent
1411 * both with parent and child.
1412 *
1413 * TC_H_MAJ(pid) still may be unspecified, complete it now.
1414 */
1415 if (pid)
1416 pid = TC_H_MAKE(qid, pid);
1417 } else {
1418 if (qid == 0)
1419 qid = dev->qdisc->handle;
1420 }
1421
1422 /* OK. Locate qdisc */
1423 q = qdisc_lookup(dev, qid);
1424 if (!q)
1425 return -ENOENT;
1426
1427 /* An check that it supports classes */
1428 cops = q->ops->cl_ops;
1429 if (cops == NULL)
1430 return -EINVAL;
1431
1432 /* Now try to get class */
1433 if (clid == 0) {
1434 if (pid == TC_H_ROOT)
1435 clid = qid;
1436 } else
1437 clid = TC_H_MAKE(qid, clid);
1438
1439 if (clid)
1440 cl = cops->get(q, clid);
1441
1442 if (cl == 0) {
1443 err = -ENOENT;
1444 if (n->nlmsg_type != RTM_NEWTCLASS ||
1445 !(n->nlmsg_flags & NLM_F_CREATE))
1446 goto out;
1447 } else {
1448 switch (n->nlmsg_type) {
1449 case RTM_NEWTCLASS:
1450 err = -EEXIST;
1451 if (n->nlmsg_flags & NLM_F_EXCL)
1452 goto out;
1453 break;
1454 case RTM_DELTCLASS:
1455 err = -EOPNOTSUPP;
1456 if (cops->delete)
1457 err = cops->delete(q, cl);
1458 if (err == 0)
1459 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1460 goto out;
1461 case RTM_GETTCLASS:
1462 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1463 goto out;
1464 default:
1465 err = -EINVAL;
1466 goto out;
1467 }
1468 }
1469
1470 new_cl = cl;
1471 err = -EOPNOTSUPP;
1472 if (cops->change)
1473 err = cops->change(q, clid, pid, tca, &new_cl);
1474 if (err == 0)
1475 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1476
1477 out:
1478 if (cl)
1479 cops->put(q, cl);
1480
1481 return err;
1482 }
1483
1484
1485 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1486 unsigned long cl,
1487 u32 pid, u32 seq, u16 flags, int event)
1488 {
1489 struct tcmsg *tcm;
1490 struct nlmsghdr *nlh;
1491 unsigned char *b = skb_tail_pointer(skb);
1492 struct gnet_dump d;
1493 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1494
1495 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1496 tcm = NLMSG_DATA(nlh);
1497 tcm->tcm_family = AF_UNSPEC;
1498 tcm->tcm__pad1 = 0;
1499 tcm->tcm__pad2 = 0;
1500 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1501 tcm->tcm_parent = q->handle;
1502 tcm->tcm_handle = q->handle;
1503 tcm->tcm_info = 0;
1504 NLA_PUT_STRING(skb, TCA_KIND, q->ops->id);
1505 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1506 goto nla_put_failure;
1507
1508 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1509 qdisc_root_sleeping_lock(q), &d) < 0)
1510 goto nla_put_failure;
1511
1512 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1513 goto nla_put_failure;
1514
1515 if (gnet_stats_finish_copy(&d) < 0)
1516 goto nla_put_failure;
1517
1518 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1519 return skb->len;
1520
1521 nlmsg_failure:
1522 nla_put_failure:
1523 nlmsg_trim(skb, b);
1524 return -1;
1525 }
1526
1527 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1528 struct nlmsghdr *n, struct Qdisc *q,
1529 unsigned long cl, int event)
1530 {
1531 struct sk_buff *skb;
1532 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
1533
1534 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1535 if (!skb)
1536 return -ENOBUFS;
1537
1538 if (tc_fill_tclass(skb, q, cl, pid, n->nlmsg_seq, 0, event) < 0) {
1539 kfree_skb(skb);
1540 return -EINVAL;
1541 }
1542
1543 return rtnetlink_send(skb, net, pid, RTNLGRP_TC,
1544 n->nlmsg_flags & NLM_F_ECHO);
1545 }
1546
1547 struct qdisc_dump_args {
1548 struct qdisc_walker w;
1549 struct sk_buff *skb;
1550 struct netlink_callback *cb;
1551 };
1552
1553 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1554 {
1555 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1556
1557 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).pid,
1558 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1559 }
1560
1561 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1562 struct tcmsg *tcm, struct netlink_callback *cb,
1563 int *t_p, int s_t)
1564 {
1565 struct qdisc_dump_args arg;
1566
1567 if (tc_qdisc_dump_ignore(q) ||
1568 *t_p < s_t || !q->ops->cl_ops ||
1569 (tcm->tcm_parent &&
1570 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1571 (*t_p)++;
1572 return 0;
1573 }
1574 if (*t_p > s_t)
1575 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1576 arg.w.fn = qdisc_class_dump;
1577 arg.skb = skb;
1578 arg.cb = cb;
1579 arg.w.stop = 0;
1580 arg.w.skip = cb->args[1];
1581 arg.w.count = 0;
1582 q->ops->cl_ops->walk(q, &arg.w);
1583 cb->args[1] = arg.w.count;
1584 if (arg.w.stop)
1585 return -1;
1586 (*t_p)++;
1587 return 0;
1588 }
1589
1590 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1591 struct tcmsg *tcm, struct netlink_callback *cb,
1592 int *t_p, int s_t)
1593 {
1594 struct Qdisc *q;
1595
1596 if (!root)
1597 return 0;
1598
1599 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1600 return -1;
1601
1602 list_for_each_entry(q, &root->list, list) {
1603 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1604 return -1;
1605 }
1606
1607 return 0;
1608 }
1609
1610 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1611 {
1612 struct tcmsg *tcm = (struct tcmsg *)NLMSG_DATA(cb->nlh);
1613 struct net *net = sock_net(skb->sk);
1614 struct netdev_queue *dev_queue;
1615 struct net_device *dev;
1616 int t, s_t;
1617
1618 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
1619 return 0;
1620 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1621 if (!dev)
1622 return 0;
1623
1624 s_t = cb->args[0];
1625 t = 0;
1626
1627 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1628 goto done;
1629
1630 dev_queue = dev_ingress_queue(dev);
1631 if (dev_queue &&
1632 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1633 &t, s_t) < 0)
1634 goto done;
1635
1636 done:
1637 cb->args[0] = t;
1638
1639 dev_put(dev);
1640 return skb->len;
1641 }
1642
1643 /* Main classifier routine: scans classifier chain attached
1644 * to this qdisc, (optionally) tests for protocol and asks
1645 * specific classifiers.
1646 */
1647 int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
1648 struct tcf_result *res)
1649 {
1650 __be16 protocol = skb->protocol;
1651 int err;
1652
1653 for (; tp; tp = tp->next) {
1654 if (tp->protocol != protocol &&
1655 tp->protocol != htons(ETH_P_ALL))
1656 continue;
1657 err = tp->classify(skb, tp, res);
1658
1659 if (err >= 0) {
1660 #ifdef CONFIG_NET_CLS_ACT
1661 if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
1662 skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
1663 #endif
1664 return err;
1665 }
1666 }
1667 return -1;
1668 }
1669 EXPORT_SYMBOL(tc_classify_compat);
1670
1671 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1672 struct tcf_result *res)
1673 {
1674 int err = 0;
1675 #ifdef CONFIG_NET_CLS_ACT
1676 const struct tcf_proto *otp = tp;
1677 reclassify:
1678 #endif
1679
1680 err = tc_classify_compat(skb, tp, res);
1681 #ifdef CONFIG_NET_CLS_ACT
1682 if (err == TC_ACT_RECLASSIFY) {
1683 u32 verd = G_TC_VERD(skb->tc_verd);
1684 tp = otp;
1685
1686 if (verd++ >= MAX_REC_LOOP) {
1687 if (net_ratelimit())
1688 pr_notice("%s: packet reclassify loop"
1689 " rule prio %u protocol %02x\n",
1690 tp->q->ops->id,
1691 tp->prio & 0xffff,
1692 ntohs(tp->protocol));
1693 return TC_ACT_SHOT;
1694 }
1695 skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
1696 goto reclassify;
1697 }
1698 #endif
1699 return err;
1700 }
1701 EXPORT_SYMBOL(tc_classify);
1702
1703 void tcf_destroy(struct tcf_proto *tp)
1704 {
1705 tp->ops->destroy(tp);
1706 module_put(tp->ops->owner);
1707 kfree(tp);
1708 }
1709
1710 void tcf_destroy_chain(struct tcf_proto **fl)
1711 {
1712 struct tcf_proto *tp;
1713
1714 while ((tp = *fl) != NULL) {
1715 *fl = tp->next;
1716 tcf_destroy(tp);
1717 }
1718 }
1719 EXPORT_SYMBOL(tcf_destroy_chain);
1720
1721 #ifdef CONFIG_PROC_FS
1722 static int psched_show(struct seq_file *seq, void *v)
1723 {
1724 struct timespec ts;
1725
1726 hrtimer_get_res(CLOCK_MONOTONIC, &ts);
1727 seq_printf(seq, "%08x %08x %08x %08x\n",
1728 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1729 1000000,
1730 (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
1731
1732 return 0;
1733 }
1734
1735 static int psched_open(struct inode *inode, struct file *file)
1736 {
1737 return single_open(file, psched_show, NULL);
1738 }
1739
1740 static const struct file_operations psched_fops = {
1741 .owner = THIS_MODULE,
1742 .open = psched_open,
1743 .read = seq_read,
1744 .llseek = seq_lseek,
1745 .release = single_release,
1746 };
1747
1748 static int __net_init psched_net_init(struct net *net)
1749 {
1750 struct proc_dir_entry *e;
1751
1752 e = proc_net_fops_create(net, "psched", 0, &psched_fops);
1753 if (e == NULL)
1754 return -ENOMEM;
1755
1756 return 0;
1757 }
1758
1759 static void __net_exit psched_net_exit(struct net *net)
1760 {
1761 proc_net_remove(net, "psched");
1762 }
1763 #else
1764 static int __net_init psched_net_init(struct net *net)
1765 {
1766 return 0;
1767 }
1768
1769 static void __net_exit psched_net_exit(struct net *net)
1770 {
1771 }
1772 #endif
1773
1774 static struct pernet_operations psched_net_ops = {
1775 .init = psched_net_init,
1776 .exit = psched_net_exit,
1777 };
1778
1779 static int __init pktsched_init(void)
1780 {
1781 int err;
1782
1783 err = register_pernet_subsys(&psched_net_ops);
1784 if (err) {
1785 pr_err("pktsched_init: "
1786 "cannot initialize per netns operations\n");
1787 return err;
1788 }
1789
1790 register_qdisc(&pfifo_qdisc_ops);
1791 register_qdisc(&bfifo_qdisc_ops);
1792 register_qdisc(&pfifo_head_drop_qdisc_ops);
1793 register_qdisc(&mq_qdisc_ops);
1794
1795 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1796 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1797 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1798 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1799 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1800 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1801
1802 return 0;
1803 }
1804
1805 subsys_initcall(pktsched_init);
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