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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[deliverable/linux.git] / net / sched / sch_api.c
1 /*
2 * net/sched/sch_api.c Packet scheduler API.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 * Fixes:
12 *
13 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired.
14 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
15 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support
16 */
17
18 #include <linux/module.h>
19 #include <linux/types.h>
20 #include <linux/kernel.h>
21 #include <linux/string.h>
22 #include <linux/errno.h>
23 #include <linux/skbuff.h>
24 #include <linux/init.h>
25 #include <linux/proc_fs.h>
26 #include <linux/seq_file.h>
27 #include <linux/kmod.h>
28 #include <linux/list.h>
29 #include <linux/hrtimer.h>
30 #include <linux/lockdep.h>
31 #include <linux/slab.h>
32
33 #include <net/net_namespace.h>
34 #include <net/sock.h>
35 #include <net/netlink.h>
36 #include <net/pkt_sched.h>
37
38 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
39 struct nlmsghdr *n, u32 clid,
40 struct Qdisc *old, struct Qdisc *new);
41 static int tclass_notify(struct net *net, struct sk_buff *oskb,
42 struct nlmsghdr *n, struct Qdisc *q,
43 unsigned long cl, int event);
44
45 /*
46
47 Short review.
48 -------------
49
50 This file consists of two interrelated parts:
51
52 1. queueing disciplines manager frontend.
53 2. traffic classes manager frontend.
54
55 Generally, queueing discipline ("qdisc") is a black box,
56 which is able to enqueue packets and to dequeue them (when
57 device is ready to send something) in order and at times
58 determined by algorithm hidden in it.
59
60 qdisc's are divided to two categories:
61 - "queues", which have no internal structure visible from outside.
62 - "schedulers", which split all the packets to "traffic classes",
63 using "packet classifiers" (look at cls_api.c)
64
65 In turn, classes may have child qdiscs (as rule, queues)
66 attached to them etc. etc. etc.
67
68 The goal of the routines in this file is to translate
69 information supplied by user in the form of handles
70 to more intelligible for kernel form, to make some sanity
71 checks and part of work, which is common to all qdiscs
72 and to provide rtnetlink notifications.
73
74 All real intelligent work is done inside qdisc modules.
75
76
77
78 Every discipline has two major routines: enqueue and dequeue.
79
80 ---dequeue
81
82 dequeue usually returns a skb to send. It is allowed to return NULL,
83 but it does not mean that queue is empty, it just means that
84 discipline does not want to send anything this time.
85 Queue is really empty if q->q.qlen == 0.
86 For complicated disciplines with multiple queues q->q is not
87 real packet queue, but however q->q.qlen must be valid.
88
89 ---enqueue
90
91 enqueue returns 0, if packet was enqueued successfully.
92 If packet (this one or another one) was dropped, it returns
93 not zero error code.
94 NET_XMIT_DROP - this packet dropped
95 Expected action: do not backoff, but wait until queue will clear.
96 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
97 Expected action: backoff or ignore
98 NET_XMIT_POLICED - dropped by police.
99 Expected action: backoff or error to real-time apps.
100
101 Auxiliary routines:
102
103 ---peek
104
105 like dequeue but without removing a packet from the queue
106
107 ---reset
108
109 returns qdisc to initial state: purge all buffers, clear all
110 timers, counters (except for statistics) etc.
111
112 ---init
113
114 initializes newly created qdisc.
115
116 ---destroy
117
118 destroys resources allocated by init and during lifetime of qdisc.
119
120 ---change
121
122 changes qdisc parameters.
123 */
124
125 /* Protects list of registered TC modules. It is pure SMP lock. */
126 static DEFINE_RWLOCK(qdisc_mod_lock);
127
128
129 /************************************************
130 * Queueing disciplines manipulation. *
131 ************************************************/
132
133
134 /* The list of all installed queueing disciplines. */
135
136 static struct Qdisc_ops *qdisc_base;
137
138 /* Register/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 if (test_bit(__QDISC_STATE_DEACTIVATED,
499 &qdisc_root_sleeping(wd->qdisc)->state))
500 return;
501
502 qdisc_throttled(wd->qdisc);
503
504 hrtimer_start(&wd->timer,
505 ns_to_ktime(PSCHED_TICKS2NS(expires)),
506 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 * Possible range is [8000-FFFF]:0000 (0x8000 values)
623 */
624 static u32 qdisc_alloc_handle(struct net_device *dev)
625 {
626 int i = 0x8000;
627 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
628
629 do {
630 autohandle += TC_H_MAKE(0x10000U, 0);
631 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
632 autohandle = TC_H_MAKE(0x80000000U, 0);
633 if (!qdisc_lookup(dev, autohandle))
634 return autohandle;
635 cond_resched();
636 } while (--i > 0);
637
638 return 0;
639 }
640
641 void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
642 {
643 const struct Qdisc_class_ops *cops;
644 unsigned long cl;
645 u32 parentid;
646
647 if (n == 0)
648 return;
649 while ((parentid = sch->parent)) {
650 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
651 return;
652
653 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
654 if (sch == NULL) {
655 WARN_ON(parentid != TC_H_ROOT);
656 return;
657 }
658 cops = sch->ops->cl_ops;
659 if (cops->qlen_notify) {
660 cl = cops->get(sch, parentid);
661 cops->qlen_notify(sch, cl);
662 cops->put(sch, cl);
663 }
664 sch->q.qlen -= n;
665 }
666 }
667 EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
668
669 static void notify_and_destroy(struct net *net, struct sk_buff *skb,
670 struct nlmsghdr *n, u32 clid,
671 struct Qdisc *old, struct Qdisc *new)
672 {
673 if (new || old)
674 qdisc_notify(net, skb, n, clid, old, new);
675
676 if (old)
677 qdisc_destroy(old);
678 }
679
680 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
681 * to device "dev".
682 *
683 * When appropriate send a netlink notification using 'skb'
684 * and "n".
685 *
686 * On success, destroy old qdisc.
687 */
688
689 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
690 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
691 struct Qdisc *new, struct Qdisc *old)
692 {
693 struct Qdisc *q = old;
694 struct net *net = dev_net(dev);
695 int err = 0;
696
697 if (parent == NULL) {
698 unsigned int i, num_q, ingress;
699
700 ingress = 0;
701 num_q = dev->num_tx_queues;
702 if ((q && q->flags & TCQ_F_INGRESS) ||
703 (new && new->flags & TCQ_F_INGRESS)) {
704 num_q = 1;
705 ingress = 1;
706 if (!dev_ingress_queue(dev))
707 return -ENOENT;
708 }
709
710 if (dev->flags & IFF_UP)
711 dev_deactivate(dev);
712
713 if (new && new->ops->attach) {
714 new->ops->attach(new);
715 num_q = 0;
716 }
717
718 for (i = 0; i < num_q; i++) {
719 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
720
721 if (!ingress)
722 dev_queue = netdev_get_tx_queue(dev, i);
723
724 old = dev_graft_qdisc(dev_queue, new);
725 if (new && i > 0)
726 atomic_inc(&new->refcnt);
727
728 if (!ingress)
729 qdisc_destroy(old);
730 }
731
732 if (!ingress) {
733 notify_and_destroy(net, skb, n, classid,
734 dev->qdisc, new);
735 if (new && !new->ops->attach)
736 atomic_inc(&new->refcnt);
737 dev->qdisc = new ? : &noop_qdisc;
738 } else {
739 notify_and_destroy(net, skb, n, classid, old, new);
740 }
741
742 if (dev->flags & IFF_UP)
743 dev_activate(dev);
744 } else {
745 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
746
747 err = -EOPNOTSUPP;
748 if (cops && cops->graft) {
749 unsigned long cl = cops->get(parent, classid);
750 if (cl) {
751 err = cops->graft(parent, cl, new, &old);
752 cops->put(parent, cl);
753 } else
754 err = -ENOENT;
755 }
756 if (!err)
757 notify_and_destroy(net, skb, n, classid, old, new);
758 }
759 return err;
760 }
761
762 /* lockdep annotation is needed for ingress; egress gets it only for name */
763 static struct lock_class_key qdisc_tx_lock;
764 static struct lock_class_key qdisc_rx_lock;
765
766 /*
767 Allocate and initialize new qdisc.
768
769 Parameters are passed via opt.
770 */
771
772 static struct Qdisc *
773 qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
774 struct Qdisc *p, u32 parent, u32 handle,
775 struct nlattr **tca, int *errp)
776 {
777 int err;
778 struct nlattr *kind = tca[TCA_KIND];
779 struct Qdisc *sch;
780 struct Qdisc_ops *ops;
781 struct qdisc_size_table *stab;
782
783 ops = qdisc_lookup_ops(kind);
784 #ifdef CONFIG_MODULES
785 if (ops == NULL && kind != NULL) {
786 char name[IFNAMSIZ];
787 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
788 /* We dropped the RTNL semaphore in order to
789 * perform the module load. So, even if we
790 * succeeded in loading the module we have to
791 * tell the caller to replay the request. We
792 * indicate this using -EAGAIN.
793 * We replay the request because the device may
794 * go away in the mean time.
795 */
796 rtnl_unlock();
797 request_module("sch_%s", name);
798 rtnl_lock();
799 ops = qdisc_lookup_ops(kind);
800 if (ops != NULL) {
801 /* We will try again qdisc_lookup_ops,
802 * so don't keep a reference.
803 */
804 module_put(ops->owner);
805 err = -EAGAIN;
806 goto err_out;
807 }
808 }
809 }
810 #endif
811
812 err = -ENOENT;
813 if (ops == NULL)
814 goto err_out;
815
816 sch = qdisc_alloc(dev_queue, ops);
817 if (IS_ERR(sch)) {
818 err = PTR_ERR(sch);
819 goto err_out2;
820 }
821
822 sch->parent = parent;
823
824 if (handle == TC_H_INGRESS) {
825 sch->flags |= TCQ_F_INGRESS;
826 handle = TC_H_MAKE(TC_H_INGRESS, 0);
827 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
828 } else {
829 if (handle == 0) {
830 handle = qdisc_alloc_handle(dev);
831 err = -ENOMEM;
832 if (handle == 0)
833 goto err_out3;
834 }
835 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
836 }
837
838 sch->handle = handle;
839
840 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
841 if (tca[TCA_STAB]) {
842 stab = qdisc_get_stab(tca[TCA_STAB]);
843 if (IS_ERR(stab)) {
844 err = PTR_ERR(stab);
845 goto err_out4;
846 }
847 rcu_assign_pointer(sch->stab, stab);
848 }
849 if (tca[TCA_RATE]) {
850 spinlock_t *root_lock;
851
852 err = -EOPNOTSUPP;
853 if (sch->flags & TCQ_F_MQROOT)
854 goto err_out4;
855
856 if ((sch->parent != TC_H_ROOT) &&
857 !(sch->flags & TCQ_F_INGRESS) &&
858 (!p || !(p->flags & TCQ_F_MQROOT)))
859 root_lock = qdisc_root_sleeping_lock(sch);
860 else
861 root_lock = qdisc_lock(sch);
862
863 err = gen_new_estimator(&sch->bstats, &sch->rate_est,
864 root_lock, tca[TCA_RATE]);
865 if (err)
866 goto err_out4;
867 }
868
869 qdisc_list_add(sch);
870
871 return sch;
872 }
873 err_out3:
874 dev_put(dev);
875 kfree((char *) sch - sch->padded);
876 err_out2:
877 module_put(ops->owner);
878 err_out:
879 *errp = err;
880 return NULL;
881
882 err_out4:
883 /*
884 * Any broken qdiscs that would require a ops->reset() here?
885 * The qdisc was never in action so it shouldn't be necessary.
886 */
887 qdisc_put_stab(rtnl_dereference(sch->stab));
888 if (ops->destroy)
889 ops->destroy(sch);
890 goto err_out3;
891 }
892
893 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
894 {
895 struct qdisc_size_table *ostab, *stab = NULL;
896 int err = 0;
897
898 if (tca[TCA_OPTIONS]) {
899 if (sch->ops->change == NULL)
900 return -EINVAL;
901 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
902 if (err)
903 return err;
904 }
905
906 if (tca[TCA_STAB]) {
907 stab = qdisc_get_stab(tca[TCA_STAB]);
908 if (IS_ERR(stab))
909 return PTR_ERR(stab);
910 }
911
912 ostab = rtnl_dereference(sch->stab);
913 rcu_assign_pointer(sch->stab, stab);
914 qdisc_put_stab(ostab);
915
916 if (tca[TCA_RATE]) {
917 /* NB: ignores errors from replace_estimator
918 because change can't be undone. */
919 if (sch->flags & TCQ_F_MQROOT)
920 goto out;
921 gen_replace_estimator(&sch->bstats, &sch->rate_est,
922 qdisc_root_sleeping_lock(sch),
923 tca[TCA_RATE]);
924 }
925 out:
926 return 0;
927 }
928
929 struct check_loop_arg {
930 struct qdisc_walker w;
931 struct Qdisc *p;
932 int depth;
933 };
934
935 static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
936
937 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
938 {
939 struct check_loop_arg arg;
940
941 if (q->ops->cl_ops == NULL)
942 return 0;
943
944 arg.w.stop = arg.w.skip = arg.w.count = 0;
945 arg.w.fn = check_loop_fn;
946 arg.depth = depth;
947 arg.p = p;
948 q->ops->cl_ops->walk(q, &arg.w);
949 return arg.w.stop ? -ELOOP : 0;
950 }
951
952 static int
953 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
954 {
955 struct Qdisc *leaf;
956 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
957 struct check_loop_arg *arg = (struct check_loop_arg *)w;
958
959 leaf = cops->leaf(q, cl);
960 if (leaf) {
961 if (leaf == arg->p || arg->depth > 7)
962 return -ELOOP;
963 return check_loop(leaf, arg->p, arg->depth + 1);
964 }
965 return 0;
966 }
967
968 /*
969 * Delete/get qdisc.
970 */
971
972 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
973 {
974 struct net *net = sock_net(skb->sk);
975 struct tcmsg *tcm = nlmsg_data(n);
976 struct nlattr *tca[TCA_MAX + 1];
977 struct net_device *dev;
978 u32 clid = tcm->tcm_parent;
979 struct Qdisc *q = NULL;
980 struct Qdisc *p = NULL;
981 int err;
982
983 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
984 if (!dev)
985 return -ENODEV;
986
987 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
988 if (err < 0)
989 return err;
990
991 if (clid) {
992 if (clid != TC_H_ROOT) {
993 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
994 p = qdisc_lookup(dev, TC_H_MAJ(clid));
995 if (!p)
996 return -ENOENT;
997 q = qdisc_leaf(p, clid);
998 } else if (dev_ingress_queue(dev)) {
999 q = dev_ingress_queue(dev)->qdisc_sleeping;
1000 }
1001 } else {
1002 q = dev->qdisc;
1003 }
1004 if (!q)
1005 return -ENOENT;
1006
1007 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1008 return -EINVAL;
1009 } else {
1010 q = qdisc_lookup(dev, tcm->tcm_handle);
1011 if (!q)
1012 return -ENOENT;
1013 }
1014
1015 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1016 return -EINVAL;
1017
1018 if (n->nlmsg_type == RTM_DELQDISC) {
1019 if (!clid)
1020 return -EINVAL;
1021 if (q->handle == 0)
1022 return -ENOENT;
1023 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1024 if (err != 0)
1025 return err;
1026 } else {
1027 qdisc_notify(net, skb, n, clid, NULL, q);
1028 }
1029 return 0;
1030 }
1031
1032 /*
1033 * Create/change qdisc.
1034 */
1035
1036 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1037 {
1038 struct net *net = sock_net(skb->sk);
1039 struct tcmsg *tcm;
1040 struct nlattr *tca[TCA_MAX + 1];
1041 struct net_device *dev;
1042 u32 clid;
1043 struct Qdisc *q, *p;
1044 int err;
1045
1046 replay:
1047 /* Reinit, just in case something touches this. */
1048 tcm = nlmsg_data(n);
1049 clid = tcm->tcm_parent;
1050 q = p = NULL;
1051
1052 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1053 if (!dev)
1054 return -ENODEV;
1055
1056 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1057 if (err < 0)
1058 return err;
1059
1060 if (clid) {
1061 if (clid != TC_H_ROOT) {
1062 if (clid != TC_H_INGRESS) {
1063 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1064 if (!p)
1065 return -ENOENT;
1066 q = qdisc_leaf(p, clid);
1067 } else if (dev_ingress_queue_create(dev)) {
1068 q = dev_ingress_queue(dev)->qdisc_sleeping;
1069 }
1070 } else {
1071 q = dev->qdisc;
1072 }
1073
1074 /* It may be default qdisc, ignore it */
1075 if (q && q->handle == 0)
1076 q = NULL;
1077
1078 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1079 if (tcm->tcm_handle) {
1080 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1081 return -EEXIST;
1082 if (TC_H_MIN(tcm->tcm_handle))
1083 return -EINVAL;
1084 q = qdisc_lookup(dev, tcm->tcm_handle);
1085 if (!q)
1086 goto create_n_graft;
1087 if (n->nlmsg_flags & NLM_F_EXCL)
1088 return -EEXIST;
1089 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1090 return -EINVAL;
1091 if (q == p ||
1092 (p && check_loop(q, p, 0)))
1093 return -ELOOP;
1094 atomic_inc(&q->refcnt);
1095 goto graft;
1096 } else {
1097 if (!q)
1098 goto create_n_graft;
1099
1100 /* This magic test requires explanation.
1101 *
1102 * We know, that some child q is already
1103 * attached to this parent and have choice:
1104 * either to change it or to create/graft new one.
1105 *
1106 * 1. We are allowed to create/graft only
1107 * if CREATE and REPLACE flags are set.
1108 *
1109 * 2. If EXCL is set, requestor wanted to say,
1110 * that qdisc tcm_handle is not expected
1111 * to exist, so that we choose create/graft too.
1112 *
1113 * 3. The last case is when no flags are set.
1114 * Alas, it is sort of hole in API, we
1115 * cannot decide what to do unambiguously.
1116 * For now we select create/graft, if
1117 * user gave KIND, which does not match existing.
1118 */
1119 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1120 (n->nlmsg_flags & NLM_F_REPLACE) &&
1121 ((n->nlmsg_flags & NLM_F_EXCL) ||
1122 (tca[TCA_KIND] &&
1123 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1124 goto create_n_graft;
1125 }
1126 }
1127 } else {
1128 if (!tcm->tcm_handle)
1129 return -EINVAL;
1130 q = qdisc_lookup(dev, tcm->tcm_handle);
1131 }
1132
1133 /* Change qdisc parameters */
1134 if (q == NULL)
1135 return -ENOENT;
1136 if (n->nlmsg_flags & NLM_F_EXCL)
1137 return -EEXIST;
1138 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1139 return -EINVAL;
1140 err = qdisc_change(q, tca);
1141 if (err == 0)
1142 qdisc_notify(net, skb, n, clid, NULL, q);
1143 return err;
1144
1145 create_n_graft:
1146 if (!(n->nlmsg_flags & NLM_F_CREATE))
1147 return -ENOENT;
1148 if (clid == TC_H_INGRESS) {
1149 if (dev_ingress_queue(dev))
1150 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1151 tcm->tcm_parent, tcm->tcm_parent,
1152 tca, &err);
1153 else
1154 err = -ENOENT;
1155 } else {
1156 struct netdev_queue *dev_queue;
1157
1158 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1159 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1160 else if (p)
1161 dev_queue = p->dev_queue;
1162 else
1163 dev_queue = netdev_get_tx_queue(dev, 0);
1164
1165 q = qdisc_create(dev, dev_queue, p,
1166 tcm->tcm_parent, tcm->tcm_handle,
1167 tca, &err);
1168 }
1169 if (q == NULL) {
1170 if (err == -EAGAIN)
1171 goto replay;
1172 return err;
1173 }
1174
1175 graft:
1176 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1177 if (err) {
1178 if (q)
1179 qdisc_destroy(q);
1180 return err;
1181 }
1182
1183 return 0;
1184 }
1185
1186 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1187 u32 portid, u32 seq, u16 flags, int event)
1188 {
1189 struct tcmsg *tcm;
1190 struct nlmsghdr *nlh;
1191 unsigned char *b = skb_tail_pointer(skb);
1192 struct gnet_dump d;
1193 struct qdisc_size_table *stab;
1194
1195 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1196 if (!nlh)
1197 goto out_nlmsg_trim;
1198 tcm = nlmsg_data(nlh);
1199 tcm->tcm_family = AF_UNSPEC;
1200 tcm->tcm__pad1 = 0;
1201 tcm->tcm__pad2 = 0;
1202 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1203 tcm->tcm_parent = clid;
1204 tcm->tcm_handle = q->handle;
1205 tcm->tcm_info = atomic_read(&q->refcnt);
1206 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1207 goto nla_put_failure;
1208 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1209 goto nla_put_failure;
1210 q->qstats.qlen = q->q.qlen;
1211
1212 stab = rtnl_dereference(q->stab);
1213 if (stab && qdisc_dump_stab(skb, stab) < 0)
1214 goto nla_put_failure;
1215
1216 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1217 qdisc_root_sleeping_lock(q), &d) < 0)
1218 goto nla_put_failure;
1219
1220 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1221 goto nla_put_failure;
1222
1223 if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
1224 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1225 gnet_stats_copy_queue(&d, &q->qstats) < 0)
1226 goto nla_put_failure;
1227
1228 if (gnet_stats_finish_copy(&d) < 0)
1229 goto nla_put_failure;
1230
1231 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1232 return skb->len;
1233
1234 out_nlmsg_trim:
1235 nla_put_failure:
1236 nlmsg_trim(skb, b);
1237 return -1;
1238 }
1239
1240 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1241 {
1242 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1243 }
1244
1245 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1246 struct nlmsghdr *n, u32 clid,
1247 struct Qdisc *old, struct Qdisc *new)
1248 {
1249 struct sk_buff *skb;
1250 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1251
1252 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1253 if (!skb)
1254 return -ENOBUFS;
1255
1256 if (old && !tc_qdisc_dump_ignore(old)) {
1257 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1258 0, RTM_DELQDISC) < 0)
1259 goto err_out;
1260 }
1261 if (new && !tc_qdisc_dump_ignore(new)) {
1262 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1263 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1264 goto err_out;
1265 }
1266
1267 if (skb->len)
1268 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1269 n->nlmsg_flags & NLM_F_ECHO);
1270
1271 err_out:
1272 kfree_skb(skb);
1273 return -EINVAL;
1274 }
1275
1276 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1277 struct netlink_callback *cb,
1278 int *q_idx_p, int s_q_idx)
1279 {
1280 int ret = 0, q_idx = *q_idx_p;
1281 struct Qdisc *q;
1282
1283 if (!root)
1284 return 0;
1285
1286 q = root;
1287 if (q_idx < s_q_idx) {
1288 q_idx++;
1289 } else {
1290 if (!tc_qdisc_dump_ignore(q) &&
1291 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1292 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1293 goto done;
1294 q_idx++;
1295 }
1296 list_for_each_entry(q, &root->list, list) {
1297 if (q_idx < s_q_idx) {
1298 q_idx++;
1299 continue;
1300 }
1301 if (!tc_qdisc_dump_ignore(q) &&
1302 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1303 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1304 goto done;
1305 q_idx++;
1306 }
1307
1308 out:
1309 *q_idx_p = q_idx;
1310 return ret;
1311 done:
1312 ret = -1;
1313 goto out;
1314 }
1315
1316 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1317 {
1318 struct net *net = sock_net(skb->sk);
1319 int idx, q_idx;
1320 int s_idx, s_q_idx;
1321 struct net_device *dev;
1322
1323 s_idx = cb->args[0];
1324 s_q_idx = q_idx = cb->args[1];
1325
1326 rcu_read_lock();
1327 idx = 0;
1328 for_each_netdev_rcu(net, dev) {
1329 struct netdev_queue *dev_queue;
1330
1331 if (idx < s_idx)
1332 goto cont;
1333 if (idx > s_idx)
1334 s_q_idx = 0;
1335 q_idx = 0;
1336
1337 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1338 goto done;
1339
1340 dev_queue = dev_ingress_queue(dev);
1341 if (dev_queue &&
1342 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1343 &q_idx, s_q_idx) < 0)
1344 goto done;
1345
1346 cont:
1347 idx++;
1348 }
1349
1350 done:
1351 rcu_read_unlock();
1352
1353 cb->args[0] = idx;
1354 cb->args[1] = q_idx;
1355
1356 return skb->len;
1357 }
1358
1359
1360
1361 /************************************************
1362 * Traffic classes manipulation. *
1363 ************************************************/
1364
1365
1366
1367 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1368 {
1369 struct net *net = sock_net(skb->sk);
1370 struct tcmsg *tcm = nlmsg_data(n);
1371 struct nlattr *tca[TCA_MAX + 1];
1372 struct net_device *dev;
1373 struct Qdisc *q = NULL;
1374 const struct Qdisc_class_ops *cops;
1375 unsigned long cl = 0;
1376 unsigned long new_cl;
1377 u32 portid = tcm->tcm_parent;
1378 u32 clid = tcm->tcm_handle;
1379 u32 qid = TC_H_MAJ(clid);
1380 int err;
1381
1382 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1383 if (!dev)
1384 return -ENODEV;
1385
1386 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1387 if (err < 0)
1388 return err;
1389
1390 /*
1391 parent == TC_H_UNSPEC - unspecified parent.
1392 parent == TC_H_ROOT - class is root, which has no parent.
1393 parent == X:0 - parent is root class.
1394 parent == X:Y - parent is a node in hierarchy.
1395 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1396
1397 handle == 0:0 - generate handle from kernel pool.
1398 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1399 handle == X:Y - clear.
1400 handle == X:0 - root class.
1401 */
1402
1403 /* Step 1. Determine qdisc handle X:0 */
1404
1405 if (portid != TC_H_ROOT) {
1406 u32 qid1 = TC_H_MAJ(portid);
1407
1408 if (qid && qid1) {
1409 /* If both majors are known, they must be identical. */
1410 if (qid != qid1)
1411 return -EINVAL;
1412 } else if (qid1) {
1413 qid = qid1;
1414 } else if (qid == 0)
1415 qid = dev->qdisc->handle;
1416
1417 /* Now qid is genuine qdisc handle consistent
1418 * both with parent and child.
1419 *
1420 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1421 */
1422 if (portid)
1423 portid = TC_H_MAKE(qid, portid);
1424 } else {
1425 if (qid == 0)
1426 qid = dev->qdisc->handle;
1427 }
1428
1429 /* OK. Locate qdisc */
1430 q = qdisc_lookup(dev, qid);
1431 if (!q)
1432 return -ENOENT;
1433
1434 /* An check that it supports classes */
1435 cops = q->ops->cl_ops;
1436 if (cops == NULL)
1437 return -EINVAL;
1438
1439 /* Now try to get class */
1440 if (clid == 0) {
1441 if (portid == TC_H_ROOT)
1442 clid = qid;
1443 } else
1444 clid = TC_H_MAKE(qid, clid);
1445
1446 if (clid)
1447 cl = cops->get(q, clid);
1448
1449 if (cl == 0) {
1450 err = -ENOENT;
1451 if (n->nlmsg_type != RTM_NEWTCLASS ||
1452 !(n->nlmsg_flags & NLM_F_CREATE))
1453 goto out;
1454 } else {
1455 switch (n->nlmsg_type) {
1456 case RTM_NEWTCLASS:
1457 err = -EEXIST;
1458 if (n->nlmsg_flags & NLM_F_EXCL)
1459 goto out;
1460 break;
1461 case RTM_DELTCLASS:
1462 err = -EOPNOTSUPP;
1463 if (cops->delete)
1464 err = cops->delete(q, cl);
1465 if (err == 0)
1466 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1467 goto out;
1468 case RTM_GETTCLASS:
1469 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1470 goto out;
1471 default:
1472 err = -EINVAL;
1473 goto out;
1474 }
1475 }
1476
1477 new_cl = cl;
1478 err = -EOPNOTSUPP;
1479 if (cops->change)
1480 err = cops->change(q, clid, portid, tca, &new_cl);
1481 if (err == 0)
1482 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1483
1484 out:
1485 if (cl)
1486 cops->put(q, cl);
1487
1488 return err;
1489 }
1490
1491
1492 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1493 unsigned long cl,
1494 u32 portid, u32 seq, u16 flags, int event)
1495 {
1496 struct tcmsg *tcm;
1497 struct nlmsghdr *nlh;
1498 unsigned char *b = skb_tail_pointer(skb);
1499 struct gnet_dump d;
1500 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1501
1502 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1503 if (!nlh)
1504 goto out_nlmsg_trim;
1505 tcm = nlmsg_data(nlh);
1506 tcm->tcm_family = AF_UNSPEC;
1507 tcm->tcm__pad1 = 0;
1508 tcm->tcm__pad2 = 0;
1509 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1510 tcm->tcm_parent = q->handle;
1511 tcm->tcm_handle = q->handle;
1512 tcm->tcm_info = 0;
1513 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1514 goto nla_put_failure;
1515 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1516 goto nla_put_failure;
1517
1518 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1519 qdisc_root_sleeping_lock(q), &d) < 0)
1520 goto nla_put_failure;
1521
1522 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1523 goto nla_put_failure;
1524
1525 if (gnet_stats_finish_copy(&d) < 0)
1526 goto nla_put_failure;
1527
1528 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1529 return skb->len;
1530
1531 out_nlmsg_trim:
1532 nla_put_failure:
1533 nlmsg_trim(skb, b);
1534 return -1;
1535 }
1536
1537 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1538 struct nlmsghdr *n, struct Qdisc *q,
1539 unsigned long cl, int event)
1540 {
1541 struct sk_buff *skb;
1542 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1543
1544 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1545 if (!skb)
1546 return -ENOBUFS;
1547
1548 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1549 kfree_skb(skb);
1550 return -EINVAL;
1551 }
1552
1553 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1554 n->nlmsg_flags & NLM_F_ECHO);
1555 }
1556
1557 struct qdisc_dump_args {
1558 struct qdisc_walker w;
1559 struct sk_buff *skb;
1560 struct netlink_callback *cb;
1561 };
1562
1563 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1564 {
1565 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1566
1567 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1568 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1569 }
1570
1571 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1572 struct tcmsg *tcm, struct netlink_callback *cb,
1573 int *t_p, int s_t)
1574 {
1575 struct qdisc_dump_args arg;
1576
1577 if (tc_qdisc_dump_ignore(q) ||
1578 *t_p < s_t || !q->ops->cl_ops ||
1579 (tcm->tcm_parent &&
1580 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1581 (*t_p)++;
1582 return 0;
1583 }
1584 if (*t_p > s_t)
1585 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1586 arg.w.fn = qdisc_class_dump;
1587 arg.skb = skb;
1588 arg.cb = cb;
1589 arg.w.stop = 0;
1590 arg.w.skip = cb->args[1];
1591 arg.w.count = 0;
1592 q->ops->cl_ops->walk(q, &arg.w);
1593 cb->args[1] = arg.w.count;
1594 if (arg.w.stop)
1595 return -1;
1596 (*t_p)++;
1597 return 0;
1598 }
1599
1600 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1601 struct tcmsg *tcm, struct netlink_callback *cb,
1602 int *t_p, int s_t)
1603 {
1604 struct Qdisc *q;
1605
1606 if (!root)
1607 return 0;
1608
1609 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1610 return -1;
1611
1612 list_for_each_entry(q, &root->list, list) {
1613 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1614 return -1;
1615 }
1616
1617 return 0;
1618 }
1619
1620 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1621 {
1622 struct tcmsg *tcm = nlmsg_data(cb->nlh);
1623 struct net *net = sock_net(skb->sk);
1624 struct netdev_queue *dev_queue;
1625 struct net_device *dev;
1626 int t, s_t;
1627
1628 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
1629 return 0;
1630 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1631 if (!dev)
1632 return 0;
1633
1634 s_t = cb->args[0];
1635 t = 0;
1636
1637 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1638 goto done;
1639
1640 dev_queue = dev_ingress_queue(dev);
1641 if (dev_queue &&
1642 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1643 &t, s_t) < 0)
1644 goto done;
1645
1646 done:
1647 cb->args[0] = t;
1648
1649 dev_put(dev);
1650 return skb->len;
1651 }
1652
1653 /* Main classifier routine: scans classifier chain attached
1654 * to this qdisc, (optionally) tests for protocol and asks
1655 * specific classifiers.
1656 */
1657 int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
1658 struct tcf_result *res)
1659 {
1660 __be16 protocol = skb->protocol;
1661 int err;
1662
1663 for (; tp; tp = tp->next) {
1664 if (tp->protocol != protocol &&
1665 tp->protocol != htons(ETH_P_ALL))
1666 continue;
1667 err = tp->classify(skb, tp, res);
1668
1669 if (err >= 0) {
1670 #ifdef CONFIG_NET_CLS_ACT
1671 if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
1672 skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
1673 #endif
1674 return err;
1675 }
1676 }
1677 return -1;
1678 }
1679 EXPORT_SYMBOL(tc_classify_compat);
1680
1681 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1682 struct tcf_result *res)
1683 {
1684 int err = 0;
1685 #ifdef CONFIG_NET_CLS_ACT
1686 const struct tcf_proto *otp = tp;
1687 reclassify:
1688 #endif
1689
1690 err = tc_classify_compat(skb, tp, res);
1691 #ifdef CONFIG_NET_CLS_ACT
1692 if (err == TC_ACT_RECLASSIFY) {
1693 u32 verd = G_TC_VERD(skb->tc_verd);
1694 tp = otp;
1695
1696 if (verd++ >= MAX_REC_LOOP) {
1697 net_notice_ratelimited("%s: packet reclassify loop rule prio %u protocol %02x\n",
1698 tp->q->ops->id,
1699 tp->prio & 0xffff,
1700 ntohs(tp->protocol));
1701 return TC_ACT_SHOT;
1702 }
1703 skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
1704 goto reclassify;
1705 }
1706 #endif
1707 return err;
1708 }
1709 EXPORT_SYMBOL(tc_classify);
1710
1711 void tcf_destroy(struct tcf_proto *tp)
1712 {
1713 tp->ops->destroy(tp);
1714 module_put(tp->ops->owner);
1715 kfree(tp);
1716 }
1717
1718 void tcf_destroy_chain(struct tcf_proto **fl)
1719 {
1720 struct tcf_proto *tp;
1721
1722 while ((tp = *fl) != NULL) {
1723 *fl = tp->next;
1724 tcf_destroy(tp);
1725 }
1726 }
1727 EXPORT_SYMBOL(tcf_destroy_chain);
1728
1729 #ifdef CONFIG_PROC_FS
1730 static int psched_show(struct seq_file *seq, void *v)
1731 {
1732 struct timespec ts;
1733
1734 hrtimer_get_res(CLOCK_MONOTONIC, &ts);
1735 seq_printf(seq, "%08x %08x %08x %08x\n",
1736 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1737 1000000,
1738 (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
1739
1740 return 0;
1741 }
1742
1743 static int psched_open(struct inode *inode, struct file *file)
1744 {
1745 return single_open(file, psched_show, NULL);
1746 }
1747
1748 static const struct file_operations psched_fops = {
1749 .owner = THIS_MODULE,
1750 .open = psched_open,
1751 .read = seq_read,
1752 .llseek = seq_lseek,
1753 .release = single_release,
1754 };
1755
1756 static int __net_init psched_net_init(struct net *net)
1757 {
1758 struct proc_dir_entry *e;
1759
1760 e = proc_net_fops_create(net, "psched", 0, &psched_fops);
1761 if (e == NULL)
1762 return -ENOMEM;
1763
1764 return 0;
1765 }
1766
1767 static void __net_exit psched_net_exit(struct net *net)
1768 {
1769 proc_net_remove(net, "psched");
1770 }
1771 #else
1772 static int __net_init psched_net_init(struct net *net)
1773 {
1774 return 0;
1775 }
1776
1777 static void __net_exit psched_net_exit(struct net *net)
1778 {
1779 }
1780 #endif
1781
1782 static struct pernet_operations psched_net_ops = {
1783 .init = psched_net_init,
1784 .exit = psched_net_exit,
1785 };
1786
1787 static int __init pktsched_init(void)
1788 {
1789 int err;
1790
1791 err = register_pernet_subsys(&psched_net_ops);
1792 if (err) {
1793 pr_err("pktsched_init: "
1794 "cannot initialize per netns operations\n");
1795 return err;
1796 }
1797
1798 register_qdisc(&pfifo_qdisc_ops);
1799 register_qdisc(&bfifo_qdisc_ops);
1800 register_qdisc(&pfifo_head_drop_qdisc_ops);
1801 register_qdisc(&mq_qdisc_ops);
1802
1803 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1804 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1805 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1806 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1807 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1808 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1809
1810 return 0;
1811 }
1812
1813 subsys_initcall(pktsched_init);
Linux kernel - Deliverables
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