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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
38static int qdisc_notify(struct net *net, struct sk_buff *oskb,
39 struct nlmsghdr *n, u32 clid,
40 struct Qdisc *old, struct Qdisc *new);
41static 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. */
126static DEFINE_RWLOCK(qdisc_mod_lock);
127
128
129/************************************************
130 * Queueing disciplines manipulation. *
131 ************************************************/
132
133
134/* The list of all installed queueing disciplines. */
135
136static struct Qdisc_ops *qdisc_base;
137
138/* Register/uregister queueing discipline */
139
140int 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;
174out:
175 write_unlock(&qdisc_mod_lock);
176 return rc;
177
178out_einval:
179 rc = -EINVAL;
180 goto out;
181}
182EXPORT_SYMBOL(register_qdisc);
183
184int 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}
201EXPORT_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
207static 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
222static 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
228void 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}
233EXPORT_SYMBOL(qdisc_list_del);
234
235struct 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);
247out:
248 return q;
249}
250
251static 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
270static 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
288static struct qdisc_rate_table *qdisc_rtab_list;
289
290struct 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}
315EXPORT_SYMBOL(qdisc_get_rtab);
316
317void 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}
334EXPORT_SYMBOL(qdisc_put_rtab);
335
336static LIST_HEAD(qdisc_stab_list);
337static DEFINE_SPINLOCK(qdisc_stab_lock);
338
339static 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
344static 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
401static void stab_kfree_rcu(struct rcu_head *head)
402{
403 kfree(container_of(head, struct qdisc_size_table, rcu));
404}
405
406void 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}
420EXPORT_SYMBOL(qdisc_put_stab);
421
422static 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
435nla_put_failure:
436 return -1;
437}
438
439void __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;
460out:
461 if (unlikely(pkt_len < 1))
462 pkt_len = 1;
463 qdisc_skb_cb(skb)->pkt_len = pkt_len;
464}
465EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
466
467void 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}
475EXPORT_SYMBOL(qdisc_warn_nonwc);
476
477static 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
488void 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}
494EXPORT_SYMBOL(qdisc_watchdog_init);
495
496void qdisc_watchdog_schedule(struct qdisc_watchdog *wd, psched_time_t expires)
497{
498 ktime_t time;
499
500 if (test_bit(__QDISC_STATE_DEACTIVATED,
501 &qdisc_root_sleeping(wd->qdisc)->state))
502 return;
503
504 qdisc_throttled(wd->qdisc);
505 time = ktime_set(0, 0);
506 time = ktime_add_ns(time, PSCHED_TICKS2NS(expires));
507 hrtimer_start(&wd->timer, time, HRTIMER_MODE_ABS);
508}
509EXPORT_SYMBOL(qdisc_watchdog_schedule);
510
511void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
512{
513 hrtimer_cancel(&wd->timer);
514 qdisc_unthrottled(wd->qdisc);
515}
516EXPORT_SYMBOL(qdisc_watchdog_cancel);
517
518static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
519{
520 unsigned int size = n * sizeof(struct hlist_head), i;
521 struct hlist_head *h;
522
523 if (size <= PAGE_SIZE)
524 h = kmalloc(size, GFP_KERNEL);
525 else
526 h = (struct hlist_head *)
527 __get_free_pages(GFP_KERNEL, get_order(size));
528
529 if (h != NULL) {
530 for (i = 0; i < n; i++)
531 INIT_HLIST_HEAD(&h[i]);
532 }
533 return h;
534}
535
536static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
537{
538 unsigned int size = n * sizeof(struct hlist_head);
539
540 if (size <= PAGE_SIZE)
541 kfree(h);
542 else
543 free_pages((unsigned long)h, get_order(size));
544}
545
546void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
547{
548 struct Qdisc_class_common *cl;
549 struct hlist_node *n, *next;
550 struct hlist_head *nhash, *ohash;
551 unsigned int nsize, nmask, osize;
552 unsigned int i, h;
553
554 /* Rehash when load factor exceeds 0.75 */
555 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
556 return;
557 nsize = clhash->hashsize * 2;
558 nmask = nsize - 1;
559 nhash = qdisc_class_hash_alloc(nsize);
560 if (nhash == NULL)
561 return;
562
563 ohash = clhash->hash;
564 osize = clhash->hashsize;
565
566 sch_tree_lock(sch);
567 for (i = 0; i < osize; i++) {
568 hlist_for_each_entry_safe(cl, n, next, &ohash[i], hnode) {
569 h = qdisc_class_hash(cl->classid, nmask);
570 hlist_add_head(&cl->hnode, &nhash[h]);
571 }
572 }
573 clhash->hash = nhash;
574 clhash->hashsize = nsize;
575 clhash->hashmask = nmask;
576 sch_tree_unlock(sch);
577
578 qdisc_class_hash_free(ohash, osize);
579}
580EXPORT_SYMBOL(qdisc_class_hash_grow);
581
582int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
583{
584 unsigned int size = 4;
585
586 clhash->hash = qdisc_class_hash_alloc(size);
587 if (clhash->hash == NULL)
588 return -ENOMEM;
589 clhash->hashsize = size;
590 clhash->hashmask = size - 1;
591 clhash->hashelems = 0;
592 return 0;
593}
594EXPORT_SYMBOL(qdisc_class_hash_init);
595
596void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
597{
598 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
599}
600EXPORT_SYMBOL(qdisc_class_hash_destroy);
601
602void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
603 struct Qdisc_class_common *cl)
604{
605 unsigned int h;
606
607 INIT_HLIST_NODE(&cl->hnode);
608 h = qdisc_class_hash(cl->classid, clhash->hashmask);
609 hlist_add_head(&cl->hnode, &clhash->hash[h]);
610 clhash->hashelems++;
611}
612EXPORT_SYMBOL(qdisc_class_hash_insert);
613
614void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
615 struct Qdisc_class_common *cl)
616{
617 hlist_del(&cl->hnode);
618 clhash->hashelems--;
619}
620EXPORT_SYMBOL(qdisc_class_hash_remove);
621
622/* Allocate an unique handle from space managed by kernel
623 * Possible range is [8000-FFFF]:0000 (0x8000 values)
624 */
625static u32 qdisc_alloc_handle(struct net_device *dev)
626{
627 int i = 0x8000;
628 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
629
630 do {
631 autohandle += TC_H_MAKE(0x10000U, 0);
632 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
633 autohandle = TC_H_MAKE(0x80000000U, 0);
634 if (!qdisc_lookup(dev, autohandle))
635 return autohandle;
636 cond_resched();
637 } while (--i > 0);
638
639 return 0;
640}
641
642void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
643{
644 const struct Qdisc_class_ops *cops;
645 unsigned long cl;
646 u32 parentid;
647
648 if (n == 0)
649 return;
650 while ((parentid = sch->parent)) {
651 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
652 return;
653
654 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
655 if (sch == NULL) {
656 WARN_ON(parentid != TC_H_ROOT);
657 return;
658 }
659 cops = sch->ops->cl_ops;
660 if (cops->qlen_notify) {
661 cl = cops->get(sch, parentid);
662 cops->qlen_notify(sch, cl);
663 cops->put(sch, cl);
664 }
665 sch->q.qlen -= n;
666 }
667}
668EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
669
670static void notify_and_destroy(struct net *net, struct sk_buff *skb,
671 struct nlmsghdr *n, u32 clid,
672 struct Qdisc *old, struct Qdisc *new)
673{
674 if (new || old)
675 qdisc_notify(net, skb, n, clid, old, new);
676
677 if (old)
678 qdisc_destroy(old);
679}
680
681/* Graft qdisc "new" to class "classid" of qdisc "parent" or
682 * to device "dev".
683 *
684 * When appropriate send a netlink notification using 'skb'
685 * and "n".
686 *
687 * On success, destroy old qdisc.
688 */
689
690static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
691 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
692 struct Qdisc *new, struct Qdisc *old)
693{
694 struct Qdisc *q = old;
695 struct net *net = dev_net(dev);
696 int err = 0;
697
698 if (parent == NULL) {
699 unsigned int i, num_q, ingress;
700
701 ingress = 0;
702 num_q = dev->num_tx_queues;
703 if ((q && q->flags & TCQ_F_INGRESS) ||
704 (new && new->flags & TCQ_F_INGRESS)) {
705 num_q = 1;
706 ingress = 1;
707 if (!dev_ingress_queue(dev))
708 return -ENOENT;
709 }
710
711 if (dev->flags & IFF_UP)
712 dev_deactivate(dev);
713
714 if (new && new->ops->attach) {
715 new->ops->attach(new);
716 num_q = 0;
717 }
718
719 for (i = 0; i < num_q; i++) {
720 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
721
722 if (!ingress)
723 dev_queue = netdev_get_tx_queue(dev, i);
724
725 old = dev_graft_qdisc(dev_queue, new);
726 if (new && i > 0)
727 atomic_inc(&new->refcnt);
728
729 if (!ingress)
730 qdisc_destroy(old);
731 }
732
733 if (!ingress) {
734 notify_and_destroy(net, skb, n, classid,
735 dev->qdisc, new);
736 if (new && !new->ops->attach)
737 atomic_inc(&new->refcnt);
738 dev->qdisc = new ? : &noop_qdisc;
739 } else {
740 notify_and_destroy(net, skb, n, classid, old, new);
741 }
742
743 if (dev->flags & IFF_UP)
744 dev_activate(dev);
745 } else {
746 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
747
748 err = -EOPNOTSUPP;
749 if (cops && cops->graft) {
750 unsigned long cl = cops->get(parent, classid);
751 if (cl) {
752 err = cops->graft(parent, cl, new, &old);
753 cops->put(parent, cl);
754 } else
755 err = -ENOENT;
756 }
757 if (!err)
758 notify_and_destroy(net, skb, n, classid, old, new);
759 }
760 return err;
761}
762
763/* lockdep annotation is needed for ingress; egress gets it only for name */
764static struct lock_class_key qdisc_tx_lock;
765static struct lock_class_key qdisc_rx_lock;
766
767/*
768 Allocate and initialize new qdisc.
769
770 Parameters are passed via opt.
771 */
772
773static struct Qdisc *
774qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
775 struct Qdisc *p, u32 parent, u32 handle,
776 struct nlattr **tca, int *errp)
777{
778 int err;
779 struct nlattr *kind = tca[TCA_KIND];
780 struct Qdisc *sch;
781 struct Qdisc_ops *ops;
782 struct qdisc_size_table *stab;
783
784 ops = qdisc_lookup_ops(kind);
785#ifdef CONFIG_MODULES
786 if (ops == NULL && kind != NULL) {
787 char name[IFNAMSIZ];
788 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
789 /* We dropped the RTNL semaphore in order to
790 * perform the module load. So, even if we
791 * succeeded in loading the module we have to
792 * tell the caller to replay the request. We
793 * indicate this using -EAGAIN.
794 * We replay the request because the device may
795 * go away in the mean time.
796 */
797 rtnl_unlock();
798 request_module("sch_%s", name);
799 rtnl_lock();
800 ops = qdisc_lookup_ops(kind);
801 if (ops != NULL) {
802 /* We will try again qdisc_lookup_ops,
803 * so don't keep a reference.
804 */
805 module_put(ops->owner);
806 err = -EAGAIN;
807 goto err_out;
808 }
809 }
810 }
811#endif
812
813 err = -ENOENT;
814 if (ops == NULL)
815 goto err_out;
816
817 sch = qdisc_alloc(dev_queue, ops);
818 if (IS_ERR(sch)) {
819 err = PTR_ERR(sch);
820 goto err_out2;
821 }
822
823 sch->parent = parent;
824
825 if (handle == TC_H_INGRESS) {
826 sch->flags |= TCQ_F_INGRESS;
827 handle = TC_H_MAKE(TC_H_INGRESS, 0);
828 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
829 } else {
830 if (handle == 0) {
831 handle = qdisc_alloc_handle(dev);
832 err = -ENOMEM;
833 if (handle == 0)
834 goto err_out3;
835 }
836 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
837 }
838
839 sch->handle = handle;
840
841 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
842 if (tca[TCA_STAB]) {
843 stab = qdisc_get_stab(tca[TCA_STAB]);
844 if (IS_ERR(stab)) {
845 err = PTR_ERR(stab);
846 goto err_out4;
847 }
848 rcu_assign_pointer(sch->stab, stab);
849 }
850 if (tca[TCA_RATE]) {
851 spinlock_t *root_lock;
852
853 err = -EOPNOTSUPP;
854 if (sch->flags & TCQ_F_MQROOT)
855 goto err_out4;
856
857 if ((sch->parent != TC_H_ROOT) &&
858 !(sch->flags & TCQ_F_INGRESS) &&
859 (!p || !(p->flags & TCQ_F_MQROOT)))
860 root_lock = qdisc_root_sleeping_lock(sch);
861 else
862 root_lock = qdisc_lock(sch);
863
864 err = gen_new_estimator(&sch->bstats, &sch->rate_est,
865 root_lock, tca[TCA_RATE]);
866 if (err)
867 goto err_out4;
868 }
869
870 qdisc_list_add(sch);
871
872 return sch;
873 }
874err_out3:
875 dev_put(dev);
876 kfree((char *) sch - sch->padded);
877err_out2:
878 module_put(ops->owner);
879err_out:
880 *errp = err;
881 return NULL;
882
883err_out4:
884 /*
885 * Any broken qdiscs that would require a ops->reset() here?
886 * The qdisc was never in action so it shouldn't be necessary.
887 */
888 qdisc_put_stab(rtnl_dereference(sch->stab));
889 if (ops->destroy)
890 ops->destroy(sch);
891 goto err_out3;
892}
893
894static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
895{
896 struct qdisc_size_table *ostab, *stab = NULL;
897 int err = 0;
898
899 if (tca[TCA_OPTIONS]) {
900 if (sch->ops->change == NULL)
901 return -EINVAL;
902 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
903 if (err)
904 return err;
905 }
906
907 if (tca[TCA_STAB]) {
908 stab = qdisc_get_stab(tca[TCA_STAB]);
909 if (IS_ERR(stab))
910 return PTR_ERR(stab);
911 }
912
913 ostab = rtnl_dereference(sch->stab);
914 rcu_assign_pointer(sch->stab, stab);
915 qdisc_put_stab(ostab);
916
917 if (tca[TCA_RATE]) {
918 /* NB: ignores errors from replace_estimator
919 because change can't be undone. */
920 if (sch->flags & TCQ_F_MQROOT)
921 goto out;
922 gen_replace_estimator(&sch->bstats, &sch->rate_est,
923 qdisc_root_sleeping_lock(sch),
924 tca[TCA_RATE]);
925 }
926out:
927 return 0;
928}
929
930struct check_loop_arg {
931 struct qdisc_walker w;
932 struct Qdisc *p;
933 int depth;
934};
935
936static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
937
938static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
939{
940 struct check_loop_arg arg;
941
942 if (q->ops->cl_ops == NULL)
943 return 0;
944
945 arg.w.stop = arg.w.skip = arg.w.count = 0;
946 arg.w.fn = check_loop_fn;
947 arg.depth = depth;
948 arg.p = p;
949 q->ops->cl_ops->walk(q, &arg.w);
950 return arg.w.stop ? -ELOOP : 0;
951}
952
953static int
954check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
955{
956 struct Qdisc *leaf;
957 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
958 struct check_loop_arg *arg = (struct check_loop_arg *)w;
959
960 leaf = cops->leaf(q, cl);
961 if (leaf) {
962 if (leaf == arg->p || arg->depth > 7)
963 return -ELOOP;
964 return check_loop(leaf, arg->p, arg->depth + 1);
965 }
966 return 0;
967}
968
969/*
970 * Delete/get qdisc.
971 */
972
973static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
974{
975 struct net *net = sock_net(skb->sk);
976 struct tcmsg *tcm = NLMSG_DATA(n);
977 struct nlattr *tca[TCA_MAX + 1];
978 struct net_device *dev;
979 u32 clid = tcm->tcm_parent;
980 struct Qdisc *q = NULL;
981 struct Qdisc *p = NULL;
982 int err;
983
984 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
985 if (!dev)
986 return -ENODEV;
987
988 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
989 if (err < 0)
990 return err;
991
992 if (clid) {
993 if (clid != TC_H_ROOT) {
994 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
995 p = qdisc_lookup(dev, TC_H_MAJ(clid));
996 if (!p)
997 return -ENOENT;
998 q = qdisc_leaf(p, clid);
999 } else if (dev_ingress_queue(dev)) {
1000 q = dev_ingress_queue(dev)->qdisc_sleeping;
1001 }
1002 } else {
1003 q = dev->qdisc;
1004 }
1005 if (!q)
1006 return -ENOENT;
1007
1008 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1009 return -EINVAL;
1010 } else {
1011 q = qdisc_lookup(dev, tcm->tcm_handle);
1012 if (!q)
1013 return -ENOENT;
1014 }
1015
1016 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1017 return -EINVAL;
1018
1019 if (n->nlmsg_type == RTM_DELQDISC) {
1020 if (!clid)
1021 return -EINVAL;
1022 if (q->handle == 0)
1023 return -ENOENT;
1024 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1025 if (err != 0)
1026 return err;
1027 } else {
1028 qdisc_notify(net, skb, n, clid, NULL, q);
1029 }
1030 return 0;
1031}
1032
1033/*
1034 * Create/change qdisc.
1035 */
1036
1037static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1038{
1039 struct net *net = sock_net(skb->sk);
1040 struct tcmsg *tcm;
1041 struct nlattr *tca[TCA_MAX + 1];
1042 struct net_device *dev;
1043 u32 clid;
1044 struct Qdisc *q, *p;
1045 int err;
1046
1047replay:
1048 /* Reinit, just in case something touches this. */
1049 tcm = NLMSG_DATA(n);
1050 clid = tcm->tcm_parent;
1051 q = p = NULL;
1052
1053 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1054 if (!dev)
1055 return -ENODEV;
1056
1057 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1058 if (err < 0)
1059 return err;
1060
1061 if (clid) {
1062 if (clid != TC_H_ROOT) {
1063 if (clid != TC_H_INGRESS) {
1064 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1065 if (!p)
1066 return -ENOENT;
1067 q = qdisc_leaf(p, clid);
1068 } else if (dev_ingress_queue_create(dev)) {
1069 q = dev_ingress_queue(dev)->qdisc_sleeping;
1070 }
1071 } else {
1072 q = dev->qdisc;
1073 }
1074
1075 /* It may be default qdisc, ignore it */
1076 if (q && q->handle == 0)
1077 q = NULL;
1078
1079 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1080 if (tcm->tcm_handle) {
1081 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1082 return -EEXIST;
1083 if (TC_H_MIN(tcm->tcm_handle))
1084 return -EINVAL;
1085 q = qdisc_lookup(dev, tcm->tcm_handle);
1086 if (!q)
1087 goto create_n_graft;
1088 if (n->nlmsg_flags & NLM_F_EXCL)
1089 return -EEXIST;
1090 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1091 return -EINVAL;
1092 if (q == p ||
1093 (p && check_loop(q, p, 0)))
1094 return -ELOOP;
1095 atomic_inc(&q->refcnt);
1096 goto graft;
1097 } else {
1098 if (!q)
1099 goto create_n_graft;
1100
1101 /* This magic test requires explanation.
1102 *
1103 * We know, that some child q is already
1104 * attached to this parent and have choice:
1105 * either to change it or to create/graft new one.
1106 *
1107 * 1. We are allowed to create/graft only
1108 * if CREATE and REPLACE flags are set.
1109 *
1110 * 2. If EXCL is set, requestor wanted to say,
1111 * that qdisc tcm_handle is not expected
1112 * to exist, so that we choose create/graft too.
1113 *
1114 * 3. The last case is when no flags are set.
1115 * Alas, it is sort of hole in API, we
1116 * cannot decide what to do unambiguously.
1117 * For now we select create/graft, if
1118 * user gave KIND, which does not match existing.
1119 */
1120 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1121 (n->nlmsg_flags & NLM_F_REPLACE) &&
1122 ((n->nlmsg_flags & NLM_F_EXCL) ||
1123 (tca[TCA_KIND] &&
1124 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1125 goto create_n_graft;
1126 }
1127 }
1128 } else {
1129 if (!tcm->tcm_handle)
1130 return -EINVAL;
1131 q = qdisc_lookup(dev, tcm->tcm_handle);
1132 }
1133
1134 /* Change qdisc parameters */
1135 if (q == NULL)
1136 return -ENOENT;
1137 if (n->nlmsg_flags & NLM_F_EXCL)
1138 return -EEXIST;
1139 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1140 return -EINVAL;
1141 err = qdisc_change(q, tca);
1142 if (err == 0)
1143 qdisc_notify(net, skb, n, clid, NULL, q);
1144 return err;
1145
1146create_n_graft:
1147 if (!(n->nlmsg_flags & NLM_F_CREATE))
1148 return -ENOENT;
1149 if (clid == TC_H_INGRESS) {
1150 if (dev_ingress_queue(dev))
1151 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1152 tcm->tcm_parent, tcm->tcm_parent,
1153 tca, &err);
1154 else
1155 err = -ENOENT;
1156 } else {
1157 struct netdev_queue *dev_queue;
1158
1159 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1160 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1161 else if (p)
1162 dev_queue = p->dev_queue;
1163 else
1164 dev_queue = netdev_get_tx_queue(dev, 0);
1165
1166 q = qdisc_create(dev, dev_queue, p,
1167 tcm->tcm_parent, tcm->tcm_handle,
1168 tca, &err);
1169 }
1170 if (q == NULL) {
1171 if (err == -EAGAIN)
1172 goto replay;
1173 return err;
1174 }
1175
1176graft:
1177 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1178 if (err) {
1179 if (q)
1180 qdisc_destroy(q);
1181 return err;
1182 }
1183
1184 return 0;
1185}
1186
1187static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1188 u32 pid, u32 seq, u16 flags, int event)
1189{
1190 struct tcmsg *tcm;
1191 struct nlmsghdr *nlh;
1192 unsigned char *b = skb_tail_pointer(skb);
1193 struct gnet_dump d;
1194 struct qdisc_size_table *stab;
1195
1196 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1197 tcm = NLMSG_DATA(nlh);
1198 tcm->tcm_family = AF_UNSPEC;
1199 tcm->tcm__pad1 = 0;
1200 tcm->tcm__pad2 = 0;
1201 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1202 tcm->tcm_parent = clid;
1203 tcm->tcm_handle = q->handle;
1204 tcm->tcm_info = atomic_read(&q->refcnt);
1205 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1206 goto nla_put_failure;
1207 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1208 goto nla_put_failure;
1209 q->qstats.qlen = q->q.qlen;
1210
1211 stab = rtnl_dereference(q->stab);
1212 if (stab && qdisc_dump_stab(skb, stab) < 0)
1213 goto nla_put_failure;
1214
1215 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1216 qdisc_root_sleeping_lock(q), &d) < 0)
1217 goto nla_put_failure;
1218
1219 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1220 goto nla_put_failure;
1221
1222 if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
1223 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1224 gnet_stats_copy_queue(&d, &q->qstats) < 0)
1225 goto nla_put_failure;
1226
1227 if (gnet_stats_finish_copy(&d) < 0)
1228 goto nla_put_failure;
1229
1230 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1231 return skb->len;
1232
1233nlmsg_failure:
1234nla_put_failure:
1235 nlmsg_trim(skb, b);
1236 return -1;
1237}
1238
1239static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1240{
1241 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1242}
1243
1244static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1245 struct nlmsghdr *n, u32 clid,
1246 struct Qdisc *old, struct Qdisc *new)
1247{
1248 struct sk_buff *skb;
1249 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
1250
1251 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1252 if (!skb)
1253 return -ENOBUFS;
1254
1255 if (old && !tc_qdisc_dump_ignore(old)) {
1256 if (tc_fill_qdisc(skb, old, clid, pid, n->nlmsg_seq,
1257 0, RTM_DELQDISC) < 0)
1258 goto err_out;
1259 }
1260 if (new && !tc_qdisc_dump_ignore(new)) {
1261 if (tc_fill_qdisc(skb, new, clid, pid, n->nlmsg_seq,
1262 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1263 goto err_out;
1264 }
1265
1266 if (skb->len)
1267 return rtnetlink_send(skb, net, pid, RTNLGRP_TC,
1268 n->nlmsg_flags & NLM_F_ECHO);
1269
1270err_out:
1271 kfree_skb(skb);
1272 return -EINVAL;
1273}
1274
1275static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1276 struct netlink_callback *cb,
1277 int *q_idx_p, int s_q_idx)
1278{
1279 int ret = 0, q_idx = *q_idx_p;
1280 struct Qdisc *q;
1281
1282 if (!root)
1283 return 0;
1284
1285 q = root;
1286 if (q_idx < s_q_idx) {
1287 q_idx++;
1288 } else {
1289 if (!tc_qdisc_dump_ignore(q) &&
1290 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid,
1291 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1292 goto done;
1293 q_idx++;
1294 }
1295 list_for_each_entry(q, &root->list, list) {
1296 if (q_idx < s_q_idx) {
1297 q_idx++;
1298 continue;
1299 }
1300 if (!tc_qdisc_dump_ignore(q) &&
1301 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid,
1302 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1303 goto done;
1304 q_idx++;
1305 }
1306
1307out:
1308 *q_idx_p = q_idx;
1309 return ret;
1310done:
1311 ret = -1;
1312 goto out;
1313}
1314
1315static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1316{
1317 struct net *net = sock_net(skb->sk);
1318 int idx, q_idx;
1319 int s_idx, s_q_idx;
1320 struct net_device *dev;
1321
1322 s_idx = cb->args[0];
1323 s_q_idx = q_idx = cb->args[1];
1324
1325 rcu_read_lock();
1326 idx = 0;
1327 for_each_netdev_rcu(net, dev) {
1328 struct netdev_queue *dev_queue;
1329
1330 if (idx < s_idx)
1331 goto cont;
1332 if (idx > s_idx)
1333 s_q_idx = 0;
1334 q_idx = 0;
1335
1336 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1337 goto done;
1338
1339 dev_queue = dev_ingress_queue(dev);
1340 if (dev_queue &&
1341 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1342 &q_idx, s_q_idx) < 0)
1343 goto done;
1344
1345cont:
1346 idx++;
1347 }
1348
1349done:
1350 rcu_read_unlock();
1351
1352 cb->args[0] = idx;
1353 cb->args[1] = q_idx;
1354
1355 return skb->len;
1356}
1357
1358
1359
1360/************************************************
1361 * Traffic classes manipulation. *
1362 ************************************************/
1363
1364
1365
1366static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1367{
1368 struct net *net = sock_net(skb->sk);
1369 struct tcmsg *tcm = NLMSG_DATA(n);
1370 struct nlattr *tca[TCA_MAX + 1];
1371 struct net_device *dev;
1372 struct Qdisc *q = NULL;
1373 const struct Qdisc_class_ops *cops;
1374 unsigned long cl = 0;
1375 unsigned long new_cl;
1376 u32 pid = tcm->tcm_parent;
1377 u32 clid = tcm->tcm_handle;
1378 u32 qid = TC_H_MAJ(clid);
1379 int err;
1380
1381 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1382 if (!dev)
1383 return -ENODEV;
1384
1385 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1386 if (err < 0)
1387 return err;
1388
1389 /*
1390 parent == TC_H_UNSPEC - unspecified parent.
1391 parent == TC_H_ROOT - class is root, which has no parent.
1392 parent == X:0 - parent is root class.
1393 parent == X:Y - parent is a node in hierarchy.
1394 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1395
1396 handle == 0:0 - generate handle from kernel pool.
1397 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1398 handle == X:Y - clear.
1399 handle == X:0 - root class.
1400 */
1401
1402 /* Step 1. Determine qdisc handle X:0 */
1403
1404 if (pid != TC_H_ROOT) {
1405 u32 qid1 = TC_H_MAJ(pid);
1406
1407 if (qid && qid1) {
1408 /* If both majors are known, they must be identical. */
1409 if (qid != qid1)
1410 return -EINVAL;
1411 } else if (qid1) {
1412 qid = qid1;
1413 } else if (qid == 0)
1414 qid = dev->qdisc->handle;
1415
1416 /* Now qid is genuine qdisc handle consistent
1417 * both with parent and child.
1418 *
1419 * TC_H_MAJ(pid) still may be unspecified, complete it now.
1420 */
1421 if (pid)
1422 pid = TC_H_MAKE(qid, pid);
1423 } else {
1424 if (qid == 0)
1425 qid = dev->qdisc->handle;
1426 }
1427
1428 /* OK. Locate qdisc */
1429 q = qdisc_lookup(dev, qid);
1430 if (!q)
1431 return -ENOENT;
1432
1433 /* An check that it supports classes */
1434 cops = q->ops->cl_ops;
1435 if (cops == NULL)
1436 return -EINVAL;
1437
1438 /* Now try to get class */
1439 if (clid == 0) {
1440 if (pid == TC_H_ROOT)
1441 clid = qid;
1442 } else
1443 clid = TC_H_MAKE(qid, clid);
1444
1445 if (clid)
1446 cl = cops->get(q, clid);
1447
1448 if (cl == 0) {
1449 err = -ENOENT;
1450 if (n->nlmsg_type != RTM_NEWTCLASS ||
1451 !(n->nlmsg_flags & NLM_F_CREATE))
1452 goto out;
1453 } else {
1454 switch (n->nlmsg_type) {
1455 case RTM_NEWTCLASS:
1456 err = -EEXIST;
1457 if (n->nlmsg_flags & NLM_F_EXCL)
1458 goto out;
1459 break;
1460 case RTM_DELTCLASS:
1461 err = -EOPNOTSUPP;
1462 if (cops->delete)
1463 err = cops->delete(q, cl);
1464 if (err == 0)
1465 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1466 goto out;
1467 case RTM_GETTCLASS:
1468 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1469 goto out;
1470 default:
1471 err = -EINVAL;
1472 goto out;
1473 }
1474 }
1475
1476 new_cl = cl;
1477 err = -EOPNOTSUPP;
1478 if (cops->change)
1479 err = cops->change(q, clid, pid, tca, &new_cl);
1480 if (err == 0)
1481 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1482
1483out:
1484 if (cl)
1485 cops->put(q, cl);
1486
1487 return err;
1488}
1489
1490
1491static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1492 unsigned long cl,
1493 u32 pid, u32 seq, u16 flags, int event)
1494{
1495 struct tcmsg *tcm;
1496 struct nlmsghdr *nlh;
1497 unsigned char *b = skb_tail_pointer(skb);
1498 struct gnet_dump d;
1499 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1500
1501 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1502 tcm = NLMSG_DATA(nlh);
1503 tcm->tcm_family = AF_UNSPEC;
1504 tcm->tcm__pad1 = 0;
1505 tcm->tcm__pad2 = 0;
1506 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1507 tcm->tcm_parent = q->handle;
1508 tcm->tcm_handle = q->handle;
1509 tcm->tcm_info = 0;
1510 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1511 goto nla_put_failure;
1512 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1513 goto nla_put_failure;
1514
1515 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1516 qdisc_root_sleeping_lock(q), &d) < 0)
1517 goto nla_put_failure;
1518
1519 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1520 goto nla_put_failure;
1521
1522 if (gnet_stats_finish_copy(&d) < 0)
1523 goto nla_put_failure;
1524
1525 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1526 return skb->len;
1527
1528nlmsg_failure:
1529nla_put_failure:
1530 nlmsg_trim(skb, b);
1531 return -1;
1532}
1533
1534static int tclass_notify(struct net *net, struct sk_buff *oskb,
1535 struct nlmsghdr *n, struct Qdisc *q,
1536 unsigned long cl, int event)
1537{
1538 struct sk_buff *skb;
1539 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
1540
1541 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1542 if (!skb)
1543 return -ENOBUFS;
1544
1545 if (tc_fill_tclass(skb, q, cl, pid, n->nlmsg_seq, 0, event) < 0) {
1546 kfree_skb(skb);
1547 return -EINVAL;
1548 }
1549
1550 return rtnetlink_send(skb, net, pid, RTNLGRP_TC,
1551 n->nlmsg_flags & NLM_F_ECHO);
1552}
1553
1554struct qdisc_dump_args {
1555 struct qdisc_walker w;
1556 struct sk_buff *skb;
1557 struct netlink_callback *cb;
1558};
1559
1560static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1561{
1562 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1563
1564 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).pid,
1565 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1566}
1567
1568static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1569 struct tcmsg *tcm, struct netlink_callback *cb,
1570 int *t_p, int s_t)
1571{
1572 struct qdisc_dump_args arg;
1573
1574 if (tc_qdisc_dump_ignore(q) ||
1575 *t_p < s_t || !q->ops->cl_ops ||
1576 (tcm->tcm_parent &&
1577 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1578 (*t_p)++;
1579 return 0;
1580 }
1581 if (*t_p > s_t)
1582 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1583 arg.w.fn = qdisc_class_dump;
1584 arg.skb = skb;
1585 arg.cb = cb;
1586 arg.w.stop = 0;
1587 arg.w.skip = cb->args[1];
1588 arg.w.count = 0;
1589 q->ops->cl_ops->walk(q, &arg.w);
1590 cb->args[1] = arg.w.count;
1591 if (arg.w.stop)
1592 return -1;
1593 (*t_p)++;
1594 return 0;
1595}
1596
1597static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1598 struct tcmsg *tcm, struct netlink_callback *cb,
1599 int *t_p, int s_t)
1600{
1601 struct Qdisc *q;
1602
1603 if (!root)
1604 return 0;
1605
1606 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1607 return -1;
1608
1609 list_for_each_entry(q, &root->list, list) {
1610 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1611 return -1;
1612 }
1613
1614 return 0;
1615}
1616
1617static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1618{
1619 struct tcmsg *tcm = (struct tcmsg *)NLMSG_DATA(cb->nlh);
1620 struct net *net = sock_net(skb->sk);
1621 struct netdev_queue *dev_queue;
1622 struct net_device *dev;
1623 int t, s_t;
1624
1625 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
1626 return 0;
1627 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1628 if (!dev)
1629 return 0;
1630
1631 s_t = cb->args[0];
1632 t = 0;
1633
1634 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1635 goto done;
1636
1637 dev_queue = dev_ingress_queue(dev);
1638 if (dev_queue &&
1639 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1640 &t, s_t) < 0)
1641 goto done;
1642
1643done:
1644 cb->args[0] = t;
1645
1646 dev_put(dev);
1647 return skb->len;
1648}
1649
1650/* Main classifier routine: scans classifier chain attached
1651 * to this qdisc, (optionally) tests for protocol and asks
1652 * specific classifiers.
1653 */
1654int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
1655 struct tcf_result *res)
1656{
1657 __be16 protocol = skb->protocol;
1658 int err;
1659
1660 for (; tp; tp = tp->next) {
1661 if (tp->protocol != protocol &&
1662 tp->protocol != htons(ETH_P_ALL))
1663 continue;
1664 err = tp->classify(skb, tp, res);
1665
1666 if (err >= 0) {
1667#ifdef CONFIG_NET_CLS_ACT
1668 if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
1669 skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
1670#endif
1671 return err;
1672 }
1673 }
1674 return -1;
1675}
1676EXPORT_SYMBOL(tc_classify_compat);
1677
1678int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1679 struct tcf_result *res)
1680{
1681 int err = 0;
1682#ifdef CONFIG_NET_CLS_ACT
1683 const struct tcf_proto *otp = tp;
1684reclassify:
1685#endif
1686
1687 err = tc_classify_compat(skb, tp, res);
1688#ifdef CONFIG_NET_CLS_ACT
1689 if (err == TC_ACT_RECLASSIFY) {
1690 u32 verd = G_TC_VERD(skb->tc_verd);
1691 tp = otp;
1692
1693 if (verd++ >= MAX_REC_LOOP) {
1694 net_notice_ratelimited("%s: packet reclassify loop rule prio %u protocol %02x\n",
1695 tp->q->ops->id,
1696 tp->prio & 0xffff,
1697 ntohs(tp->protocol));
1698 return TC_ACT_SHOT;
1699 }
1700 skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
1701 goto reclassify;
1702 }
1703#endif
1704 return err;
1705}
1706EXPORT_SYMBOL(tc_classify);
1707
1708void tcf_destroy(struct tcf_proto *tp)
1709{
1710 tp->ops->destroy(tp);
1711 module_put(tp->ops->owner);
1712 kfree(tp);
1713}
1714
1715void tcf_destroy_chain(struct tcf_proto **fl)
1716{
1717 struct tcf_proto *tp;
1718
1719 while ((tp = *fl) != NULL) {
1720 *fl = tp->next;
1721 tcf_destroy(tp);
1722 }
1723}
1724EXPORT_SYMBOL(tcf_destroy_chain);
1725
1726#ifdef CONFIG_PROC_FS
1727static int psched_show(struct seq_file *seq, void *v)
1728{
1729 struct timespec ts;
1730
1731 hrtimer_get_res(CLOCK_MONOTONIC, &ts);
1732 seq_printf(seq, "%08x %08x %08x %08x\n",
1733 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1734 1000000,
1735 (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
1736
1737 return 0;
1738}
1739
1740static int psched_open(struct inode *inode, struct file *file)
1741{
1742 return single_open(file, psched_show, NULL);
1743}
1744
1745static const struct file_operations psched_fops = {
1746 .owner = THIS_MODULE,
1747 .open = psched_open,
1748 .read = seq_read,
1749 .llseek = seq_lseek,
1750 .release = single_release,
1751};
1752
1753static int __net_init psched_net_init(struct net *net)
1754{
1755 struct proc_dir_entry *e;
1756
1757 e = proc_net_fops_create(net, "psched", 0, &psched_fops);
1758 if (e == NULL)
1759 return -ENOMEM;
1760
1761 return 0;
1762}
1763
1764static void __net_exit psched_net_exit(struct net *net)
1765{
1766 proc_net_remove(net, "psched");
1767}
1768#else
1769static int __net_init psched_net_init(struct net *net)
1770{
1771 return 0;
1772}
1773
1774static void __net_exit psched_net_exit(struct net *net)
1775{
1776}
1777#endif
1778
1779static struct pernet_operations psched_net_ops = {
1780 .init = psched_net_init,
1781 .exit = psched_net_exit,
1782};
1783
1784static int __init pktsched_init(void)
1785{
1786 int err;
1787
1788 err = register_pernet_subsys(&psched_net_ops);
1789 if (err) {
1790 pr_err("pktsched_init: "
1791 "cannot initialize per netns operations\n");
1792 return err;
1793 }
1794
1795 register_qdisc(&pfifo_qdisc_ops);
1796 register_qdisc(&bfifo_qdisc_ops);
1797 register_qdisc(&pfifo_head_drop_qdisc_ops);
1798 register_qdisc(&mq_qdisc_ops);
1799
1800 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1801 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1802 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1803 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1804 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1805 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1806
1807 return 0;
1808}
1809
1810subsys_initcall(pktsched_init);
1/*
2 * net/sched/sch_api.c Packet scheduler API.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 * Fixes:
12 *
13 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired.
14 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
15 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support
16 */
17
18#include <linux/module.h>
19#include <linux/types.h>
20#include <linux/kernel.h>
21#include <linux/string.h>
22#include <linux/errno.h>
23#include <linux/skbuff.h>
24#include <linux/init.h>
25#include <linux/proc_fs.h>
26#include <linux/seq_file.h>
27#include <linux/kmod.h>
28#include <linux/list.h>
29#include <linux/hrtimer.h>
30#include <linux/lockdep.h>
31#include <linux/slab.h>
32#include <linux/hashtable.h>
33
34#include <net/net_namespace.h>
35#include <net/sock.h>
36#include <net/netlink.h>
37#include <net/pkt_sched.h>
38
39static int qdisc_notify(struct net *net, struct sk_buff *oskb,
40 struct nlmsghdr *n, u32 clid,
41 struct Qdisc *old, struct Qdisc *new);
42static int tclass_notify(struct net *net, struct sk_buff *oskb,
43 struct nlmsghdr *n, struct Qdisc *q,
44 unsigned long cl, int event);
45
46/*
47
48 Short review.
49 -------------
50
51 This file consists of two interrelated parts:
52
53 1. queueing disciplines manager frontend.
54 2. traffic classes manager frontend.
55
56 Generally, queueing discipline ("qdisc") is a black box,
57 which is able to enqueue packets and to dequeue them (when
58 device is ready to send something) in order and at times
59 determined by algorithm hidden in it.
60
61 qdisc's are divided to two categories:
62 - "queues", which have no internal structure visible from outside.
63 - "schedulers", which split all the packets to "traffic classes",
64 using "packet classifiers" (look at cls_api.c)
65
66 In turn, classes may have child qdiscs (as rule, queues)
67 attached to them etc. etc. etc.
68
69 The goal of the routines in this file is to translate
70 information supplied by user in the form of handles
71 to more intelligible for kernel form, to make some sanity
72 checks and part of work, which is common to all qdiscs
73 and to provide rtnetlink notifications.
74
75 All real intelligent work is done inside qdisc modules.
76
77
78
79 Every discipline has two major routines: enqueue and dequeue.
80
81 ---dequeue
82
83 dequeue usually returns a skb to send. It is allowed to return NULL,
84 but it does not mean that queue is empty, it just means that
85 discipline does not want to send anything this time.
86 Queue is really empty if q->q.qlen == 0.
87 For complicated disciplines with multiple queues q->q is not
88 real packet queue, but however q->q.qlen must be valid.
89
90 ---enqueue
91
92 enqueue returns 0, if packet was enqueued successfully.
93 If packet (this one or another one) was dropped, it returns
94 not zero error code.
95 NET_XMIT_DROP - this packet dropped
96 Expected action: do not backoff, but wait until queue will clear.
97 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
98 Expected action: backoff or ignore
99
100 Auxiliary routines:
101
102 ---peek
103
104 like dequeue but without removing a packet from the queue
105
106 ---reset
107
108 returns qdisc to initial state: purge all buffers, clear all
109 timers, counters (except for statistics) etc.
110
111 ---init
112
113 initializes newly created qdisc.
114
115 ---destroy
116
117 destroys resources allocated by init and during lifetime of qdisc.
118
119 ---change
120
121 changes qdisc parameters.
122 */
123
124/* Protects list of registered TC modules. It is pure SMP lock. */
125static DEFINE_RWLOCK(qdisc_mod_lock);
126
127
128/************************************************
129 * Queueing disciplines manipulation. *
130 ************************************************/
131
132
133/* The list of all installed queueing disciplines. */
134
135static struct Qdisc_ops *qdisc_base;
136
137/* Register/unregister queueing discipline */
138
139int register_qdisc(struct Qdisc_ops *qops)
140{
141 struct Qdisc_ops *q, **qp;
142 int rc = -EEXIST;
143
144 write_lock(&qdisc_mod_lock);
145 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
146 if (!strcmp(qops->id, q->id))
147 goto out;
148
149 if (qops->enqueue == NULL)
150 qops->enqueue = noop_qdisc_ops.enqueue;
151 if (qops->peek == NULL) {
152 if (qops->dequeue == NULL)
153 qops->peek = noop_qdisc_ops.peek;
154 else
155 goto out_einval;
156 }
157 if (qops->dequeue == NULL)
158 qops->dequeue = noop_qdisc_ops.dequeue;
159
160 if (qops->cl_ops) {
161 const struct Qdisc_class_ops *cops = qops->cl_ops;
162
163 if (!(cops->get && cops->put && cops->walk && cops->leaf))
164 goto out_einval;
165
166 if (cops->tcf_chain && !(cops->bind_tcf && cops->unbind_tcf))
167 goto out_einval;
168 }
169
170 qops->next = NULL;
171 *qp = qops;
172 rc = 0;
173out:
174 write_unlock(&qdisc_mod_lock);
175 return rc;
176
177out_einval:
178 rc = -EINVAL;
179 goto out;
180}
181EXPORT_SYMBOL(register_qdisc);
182
183int unregister_qdisc(struct Qdisc_ops *qops)
184{
185 struct Qdisc_ops *q, **qp;
186 int err = -ENOENT;
187
188 write_lock(&qdisc_mod_lock);
189 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
190 if (q == qops)
191 break;
192 if (q) {
193 *qp = q->next;
194 q->next = NULL;
195 err = 0;
196 }
197 write_unlock(&qdisc_mod_lock);
198 return err;
199}
200EXPORT_SYMBOL(unregister_qdisc);
201
202/* Get default qdisc if not otherwise specified */
203void qdisc_get_default(char *name, size_t len)
204{
205 read_lock(&qdisc_mod_lock);
206 strlcpy(name, default_qdisc_ops->id, len);
207 read_unlock(&qdisc_mod_lock);
208}
209
210static struct Qdisc_ops *qdisc_lookup_default(const char *name)
211{
212 struct Qdisc_ops *q = NULL;
213
214 for (q = qdisc_base; q; q = q->next) {
215 if (!strcmp(name, q->id)) {
216 if (!try_module_get(q->owner))
217 q = NULL;
218 break;
219 }
220 }
221
222 return q;
223}
224
225/* Set new default qdisc to use */
226int qdisc_set_default(const char *name)
227{
228 const struct Qdisc_ops *ops;
229
230 if (!capable(CAP_NET_ADMIN))
231 return -EPERM;
232
233 write_lock(&qdisc_mod_lock);
234 ops = qdisc_lookup_default(name);
235 if (!ops) {
236 /* Not found, drop lock and try to load module */
237 write_unlock(&qdisc_mod_lock);
238 request_module("sch_%s", name);
239 write_lock(&qdisc_mod_lock);
240
241 ops = qdisc_lookup_default(name);
242 }
243
244 if (ops) {
245 /* Set new default */
246 module_put(default_qdisc_ops->owner);
247 default_qdisc_ops = ops;
248 }
249 write_unlock(&qdisc_mod_lock);
250
251 return ops ? 0 : -ENOENT;
252}
253
254/* We know handle. Find qdisc among all qdisc's attached to device
255 * (root qdisc, all its children, children of children etc.)
256 * Note: caller either uses rtnl or rcu_read_lock()
257 */
258
259static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
260{
261 struct Qdisc *q;
262
263 if (!qdisc_dev(root))
264 return (root->handle == handle ? root : NULL);
265
266 if (!(root->flags & TCQ_F_BUILTIN) &&
267 root->handle == handle)
268 return root;
269
270 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle) {
271 if (q->handle == handle)
272 return q;
273 }
274 return NULL;
275}
276
277void qdisc_hash_add(struct Qdisc *q)
278{
279 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
280 struct Qdisc *root = qdisc_dev(q)->qdisc;
281
282 WARN_ON_ONCE(root == &noop_qdisc);
283 ASSERT_RTNL();
284 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
285 }
286}
287EXPORT_SYMBOL(qdisc_hash_add);
288
289void qdisc_hash_del(struct Qdisc *q)
290{
291 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
292 ASSERT_RTNL();
293 hash_del_rcu(&q->hash);
294 }
295}
296EXPORT_SYMBOL(qdisc_hash_del);
297
298struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
299{
300 struct Qdisc *q;
301
302 q = qdisc_match_from_root(dev->qdisc, handle);
303 if (q)
304 goto out;
305
306 if (dev_ingress_queue(dev))
307 q = qdisc_match_from_root(
308 dev_ingress_queue(dev)->qdisc_sleeping,
309 handle);
310out:
311 return q;
312}
313
314static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
315{
316 unsigned long cl;
317 struct Qdisc *leaf;
318 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
319
320 if (cops == NULL)
321 return NULL;
322 cl = cops->get(p, classid);
323
324 if (cl == 0)
325 return NULL;
326 leaf = cops->leaf(p, cl);
327 cops->put(p, cl);
328 return leaf;
329}
330
331/* Find queueing discipline by name */
332
333static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
334{
335 struct Qdisc_ops *q = NULL;
336
337 if (kind) {
338 read_lock(&qdisc_mod_lock);
339 for (q = qdisc_base; q; q = q->next) {
340 if (nla_strcmp(kind, q->id) == 0) {
341 if (!try_module_get(q->owner))
342 q = NULL;
343 break;
344 }
345 }
346 read_unlock(&qdisc_mod_lock);
347 }
348 return q;
349}
350
351/* The linklayer setting were not transferred from iproute2, in older
352 * versions, and the rate tables lookup systems have been dropped in
353 * the kernel. To keep backward compatible with older iproute2 tc
354 * utils, we detect the linklayer setting by detecting if the rate
355 * table were modified.
356 *
357 * For linklayer ATM table entries, the rate table will be aligned to
358 * 48 bytes, thus some table entries will contain the same value. The
359 * mpu (min packet unit) is also encoded into the old rate table, thus
360 * starting from the mpu, we find low and high table entries for
361 * mapping this cell. If these entries contain the same value, when
362 * the rate tables have been modified for linklayer ATM.
363 *
364 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
365 * and then roundup to the next cell, calc the table entry one below,
366 * and compare.
367 */
368static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
369{
370 int low = roundup(r->mpu, 48);
371 int high = roundup(low+1, 48);
372 int cell_low = low >> r->cell_log;
373 int cell_high = (high >> r->cell_log) - 1;
374
375 /* rtab is too inaccurate at rates > 100Mbit/s */
376 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
377 pr_debug("TC linklayer: Giving up ATM detection\n");
378 return TC_LINKLAYER_ETHERNET;
379 }
380
381 if ((cell_high > cell_low) && (cell_high < 256)
382 && (rtab[cell_low] == rtab[cell_high])) {
383 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
384 cell_low, cell_high, rtab[cell_high]);
385 return TC_LINKLAYER_ATM;
386 }
387 return TC_LINKLAYER_ETHERNET;
388}
389
390static struct qdisc_rate_table *qdisc_rtab_list;
391
392struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
393 struct nlattr *tab)
394{
395 struct qdisc_rate_table *rtab;
396
397 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
398 nla_len(tab) != TC_RTAB_SIZE)
399 return NULL;
400
401 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
402 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
403 !memcmp(&rtab->data, nla_data(tab), 1024)) {
404 rtab->refcnt++;
405 return rtab;
406 }
407 }
408
409 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
410 if (rtab) {
411 rtab->rate = *r;
412 rtab->refcnt = 1;
413 memcpy(rtab->data, nla_data(tab), 1024);
414 if (r->linklayer == TC_LINKLAYER_UNAWARE)
415 r->linklayer = __detect_linklayer(r, rtab->data);
416 rtab->next = qdisc_rtab_list;
417 qdisc_rtab_list = rtab;
418 }
419 return rtab;
420}
421EXPORT_SYMBOL(qdisc_get_rtab);
422
423void qdisc_put_rtab(struct qdisc_rate_table *tab)
424{
425 struct qdisc_rate_table *rtab, **rtabp;
426
427 if (!tab || --tab->refcnt)
428 return;
429
430 for (rtabp = &qdisc_rtab_list;
431 (rtab = *rtabp) != NULL;
432 rtabp = &rtab->next) {
433 if (rtab == tab) {
434 *rtabp = rtab->next;
435 kfree(rtab);
436 return;
437 }
438 }
439}
440EXPORT_SYMBOL(qdisc_put_rtab);
441
442static LIST_HEAD(qdisc_stab_list);
443static DEFINE_SPINLOCK(qdisc_stab_lock);
444
445static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
446 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
447 [TCA_STAB_DATA] = { .type = NLA_BINARY },
448};
449
450static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
451{
452 struct nlattr *tb[TCA_STAB_MAX + 1];
453 struct qdisc_size_table *stab;
454 struct tc_sizespec *s;
455 unsigned int tsize = 0;
456 u16 *tab = NULL;
457 int err;
458
459 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
460 if (err < 0)
461 return ERR_PTR(err);
462 if (!tb[TCA_STAB_BASE])
463 return ERR_PTR(-EINVAL);
464
465 s = nla_data(tb[TCA_STAB_BASE]);
466
467 if (s->tsize > 0) {
468 if (!tb[TCA_STAB_DATA])
469 return ERR_PTR(-EINVAL);
470 tab = nla_data(tb[TCA_STAB_DATA]);
471 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
472 }
473
474 if (tsize != s->tsize || (!tab && tsize > 0))
475 return ERR_PTR(-EINVAL);
476
477 spin_lock(&qdisc_stab_lock);
478
479 list_for_each_entry(stab, &qdisc_stab_list, list) {
480 if (memcmp(&stab->szopts, s, sizeof(*s)))
481 continue;
482 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
483 continue;
484 stab->refcnt++;
485 spin_unlock(&qdisc_stab_lock);
486 return stab;
487 }
488
489 spin_unlock(&qdisc_stab_lock);
490
491 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
492 if (!stab)
493 return ERR_PTR(-ENOMEM);
494
495 stab->refcnt = 1;
496 stab->szopts = *s;
497 if (tsize > 0)
498 memcpy(stab->data, tab, tsize * sizeof(u16));
499
500 spin_lock(&qdisc_stab_lock);
501 list_add_tail(&stab->list, &qdisc_stab_list);
502 spin_unlock(&qdisc_stab_lock);
503
504 return stab;
505}
506
507static void stab_kfree_rcu(struct rcu_head *head)
508{
509 kfree(container_of(head, struct qdisc_size_table, rcu));
510}
511
512void qdisc_put_stab(struct qdisc_size_table *tab)
513{
514 if (!tab)
515 return;
516
517 spin_lock(&qdisc_stab_lock);
518
519 if (--tab->refcnt == 0) {
520 list_del(&tab->list);
521 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
522 }
523
524 spin_unlock(&qdisc_stab_lock);
525}
526EXPORT_SYMBOL(qdisc_put_stab);
527
528static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
529{
530 struct nlattr *nest;
531
532 nest = nla_nest_start(skb, TCA_STAB);
533 if (nest == NULL)
534 goto nla_put_failure;
535 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
536 goto nla_put_failure;
537 nla_nest_end(skb, nest);
538
539 return skb->len;
540
541nla_put_failure:
542 return -1;
543}
544
545void __qdisc_calculate_pkt_len(struct sk_buff *skb,
546 const struct qdisc_size_table *stab)
547{
548 int pkt_len, slot;
549
550 pkt_len = skb->len + stab->szopts.overhead;
551 if (unlikely(!stab->szopts.tsize))
552 goto out;
553
554 slot = pkt_len + stab->szopts.cell_align;
555 if (unlikely(slot < 0))
556 slot = 0;
557
558 slot >>= stab->szopts.cell_log;
559 if (likely(slot < stab->szopts.tsize))
560 pkt_len = stab->data[slot];
561 else
562 pkt_len = stab->data[stab->szopts.tsize - 1] *
563 (slot / stab->szopts.tsize) +
564 stab->data[slot % stab->szopts.tsize];
565
566 pkt_len <<= stab->szopts.size_log;
567out:
568 if (unlikely(pkt_len < 1))
569 pkt_len = 1;
570 qdisc_skb_cb(skb)->pkt_len = pkt_len;
571}
572EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
573
574void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
575{
576 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
577 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
578 txt, qdisc->ops->id, qdisc->handle >> 16);
579 qdisc->flags |= TCQ_F_WARN_NONWC;
580 }
581}
582EXPORT_SYMBOL(qdisc_warn_nonwc);
583
584static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
585{
586 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
587 timer);
588
589 rcu_read_lock();
590 __netif_schedule(qdisc_root(wd->qdisc));
591 rcu_read_unlock();
592
593 return HRTIMER_NORESTART;
594}
595
596void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
597{
598 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
599 wd->timer.function = qdisc_watchdog;
600 wd->qdisc = qdisc;
601}
602EXPORT_SYMBOL(qdisc_watchdog_init);
603
604void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
605{
606 if (test_bit(__QDISC_STATE_DEACTIVATED,
607 &qdisc_root_sleeping(wd->qdisc)->state))
608 return;
609
610 if (wd->last_expires == expires)
611 return;
612
613 wd->last_expires = expires;
614 hrtimer_start(&wd->timer,
615 ns_to_ktime(expires),
616 HRTIMER_MODE_ABS_PINNED);
617}
618EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
619
620void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
621{
622 hrtimer_cancel(&wd->timer);
623}
624EXPORT_SYMBOL(qdisc_watchdog_cancel);
625
626static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
627{
628 unsigned int size = n * sizeof(struct hlist_head), i;
629 struct hlist_head *h;
630
631 if (size <= PAGE_SIZE)
632 h = kmalloc(size, GFP_KERNEL);
633 else
634 h = (struct hlist_head *)
635 __get_free_pages(GFP_KERNEL, get_order(size));
636
637 if (h != NULL) {
638 for (i = 0; i < n; i++)
639 INIT_HLIST_HEAD(&h[i]);
640 }
641 return h;
642}
643
644static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
645{
646 unsigned int size = n * sizeof(struct hlist_head);
647
648 if (size <= PAGE_SIZE)
649 kfree(h);
650 else
651 free_pages((unsigned long)h, get_order(size));
652}
653
654void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
655{
656 struct Qdisc_class_common *cl;
657 struct hlist_node *next;
658 struct hlist_head *nhash, *ohash;
659 unsigned int nsize, nmask, osize;
660 unsigned int i, h;
661
662 /* Rehash when load factor exceeds 0.75 */
663 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
664 return;
665 nsize = clhash->hashsize * 2;
666 nmask = nsize - 1;
667 nhash = qdisc_class_hash_alloc(nsize);
668 if (nhash == NULL)
669 return;
670
671 ohash = clhash->hash;
672 osize = clhash->hashsize;
673
674 sch_tree_lock(sch);
675 for (i = 0; i < osize; i++) {
676 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
677 h = qdisc_class_hash(cl->classid, nmask);
678 hlist_add_head(&cl->hnode, &nhash[h]);
679 }
680 }
681 clhash->hash = nhash;
682 clhash->hashsize = nsize;
683 clhash->hashmask = nmask;
684 sch_tree_unlock(sch);
685
686 qdisc_class_hash_free(ohash, osize);
687}
688EXPORT_SYMBOL(qdisc_class_hash_grow);
689
690int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
691{
692 unsigned int size = 4;
693
694 clhash->hash = qdisc_class_hash_alloc(size);
695 if (clhash->hash == NULL)
696 return -ENOMEM;
697 clhash->hashsize = size;
698 clhash->hashmask = size - 1;
699 clhash->hashelems = 0;
700 return 0;
701}
702EXPORT_SYMBOL(qdisc_class_hash_init);
703
704void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
705{
706 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
707}
708EXPORT_SYMBOL(qdisc_class_hash_destroy);
709
710void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
711 struct Qdisc_class_common *cl)
712{
713 unsigned int h;
714
715 INIT_HLIST_NODE(&cl->hnode);
716 h = qdisc_class_hash(cl->classid, clhash->hashmask);
717 hlist_add_head(&cl->hnode, &clhash->hash[h]);
718 clhash->hashelems++;
719}
720EXPORT_SYMBOL(qdisc_class_hash_insert);
721
722void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
723 struct Qdisc_class_common *cl)
724{
725 hlist_del(&cl->hnode);
726 clhash->hashelems--;
727}
728EXPORT_SYMBOL(qdisc_class_hash_remove);
729
730/* Allocate an unique handle from space managed by kernel
731 * Possible range is [8000-FFFF]:0000 (0x8000 values)
732 */
733static u32 qdisc_alloc_handle(struct net_device *dev)
734{
735 int i = 0x8000;
736 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
737
738 do {
739 autohandle += TC_H_MAKE(0x10000U, 0);
740 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
741 autohandle = TC_H_MAKE(0x80000000U, 0);
742 if (!qdisc_lookup(dev, autohandle))
743 return autohandle;
744 cond_resched();
745 } while (--i > 0);
746
747 return 0;
748}
749
750void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,
751 unsigned int len)
752{
753 const struct Qdisc_class_ops *cops;
754 unsigned long cl;
755 u32 parentid;
756 int drops;
757
758 if (n == 0 && len == 0)
759 return;
760 drops = max_t(int, n, 0);
761 rcu_read_lock();
762 while ((parentid = sch->parent)) {
763 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
764 break;
765
766 if (sch->flags & TCQ_F_NOPARENT)
767 break;
768 /* TODO: perform the search on a per txq basis */
769 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
770 if (sch == NULL) {
771 WARN_ON_ONCE(parentid != TC_H_ROOT);
772 break;
773 }
774 cops = sch->ops->cl_ops;
775 if (cops->qlen_notify) {
776 cl = cops->get(sch, parentid);
777 cops->qlen_notify(sch, cl);
778 cops->put(sch, cl);
779 }
780 sch->q.qlen -= n;
781 sch->qstats.backlog -= len;
782 __qdisc_qstats_drop(sch, drops);
783 }
784 rcu_read_unlock();
785}
786EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
787
788static void notify_and_destroy(struct net *net, struct sk_buff *skb,
789 struct nlmsghdr *n, u32 clid,
790 struct Qdisc *old, struct Qdisc *new)
791{
792 if (new || old)
793 qdisc_notify(net, skb, n, clid, old, new);
794
795 if (old)
796 qdisc_destroy(old);
797}
798
799/* Graft qdisc "new" to class "classid" of qdisc "parent" or
800 * to device "dev".
801 *
802 * When appropriate send a netlink notification using 'skb'
803 * and "n".
804 *
805 * On success, destroy old qdisc.
806 */
807
808static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
809 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
810 struct Qdisc *new, struct Qdisc *old)
811{
812 struct Qdisc *q = old;
813 struct net *net = dev_net(dev);
814 int err = 0;
815
816 if (parent == NULL) {
817 unsigned int i, num_q, ingress;
818
819 ingress = 0;
820 num_q = dev->num_tx_queues;
821 if ((q && q->flags & TCQ_F_INGRESS) ||
822 (new && new->flags & TCQ_F_INGRESS)) {
823 num_q = 1;
824 ingress = 1;
825 if (!dev_ingress_queue(dev))
826 return -ENOENT;
827 }
828
829 if (dev->flags & IFF_UP)
830 dev_deactivate(dev);
831
832 if (new && new->ops->attach)
833 goto skip;
834
835 for (i = 0; i < num_q; i++) {
836 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
837
838 if (!ingress)
839 dev_queue = netdev_get_tx_queue(dev, i);
840
841 old = dev_graft_qdisc(dev_queue, new);
842 if (new && i > 0)
843 atomic_inc(&new->refcnt);
844
845 if (!ingress)
846 qdisc_destroy(old);
847 }
848
849skip:
850 if (!ingress) {
851 notify_and_destroy(net, skb, n, classid,
852 dev->qdisc, new);
853 if (new && !new->ops->attach)
854 atomic_inc(&new->refcnt);
855 dev->qdisc = new ? : &noop_qdisc;
856
857 if (new && new->ops->attach)
858 new->ops->attach(new);
859 } else {
860 notify_and_destroy(net, skb, n, classid, old, new);
861 }
862
863 if (dev->flags & IFF_UP)
864 dev_activate(dev);
865 } else {
866 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
867
868 err = -EOPNOTSUPP;
869 if (cops && cops->graft) {
870 unsigned long cl = cops->get(parent, classid);
871 if (cl) {
872 err = cops->graft(parent, cl, new, &old);
873 cops->put(parent, cl);
874 } else
875 err = -ENOENT;
876 }
877 if (!err)
878 notify_and_destroy(net, skb, n, classid, old, new);
879 }
880 return err;
881}
882
883/* lockdep annotation is needed for ingress; egress gets it only for name */
884static struct lock_class_key qdisc_tx_lock;
885static struct lock_class_key qdisc_rx_lock;
886
887/*
888 Allocate and initialize new qdisc.
889
890 Parameters are passed via opt.
891 */
892
893static struct Qdisc *qdisc_create(struct net_device *dev,
894 struct netdev_queue *dev_queue,
895 struct Qdisc *p, u32 parent, u32 handle,
896 struct nlattr **tca, int *errp)
897{
898 int err;
899 struct nlattr *kind = tca[TCA_KIND];
900 struct Qdisc *sch;
901 struct Qdisc_ops *ops;
902 struct qdisc_size_table *stab;
903
904 ops = qdisc_lookup_ops(kind);
905#ifdef CONFIG_MODULES
906 if (ops == NULL && kind != NULL) {
907 char name[IFNAMSIZ];
908 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
909 /* We dropped the RTNL semaphore in order to
910 * perform the module load. So, even if we
911 * succeeded in loading the module we have to
912 * tell the caller to replay the request. We
913 * indicate this using -EAGAIN.
914 * We replay the request because the device may
915 * go away in the mean time.
916 */
917 rtnl_unlock();
918 request_module("sch_%s", name);
919 rtnl_lock();
920 ops = qdisc_lookup_ops(kind);
921 if (ops != NULL) {
922 /* We will try again qdisc_lookup_ops,
923 * so don't keep a reference.
924 */
925 module_put(ops->owner);
926 err = -EAGAIN;
927 goto err_out;
928 }
929 }
930 }
931#endif
932
933 err = -ENOENT;
934 if (ops == NULL)
935 goto err_out;
936
937 sch = qdisc_alloc(dev_queue, ops);
938 if (IS_ERR(sch)) {
939 err = PTR_ERR(sch);
940 goto err_out2;
941 }
942
943 sch->parent = parent;
944
945 if (handle == TC_H_INGRESS) {
946 sch->flags |= TCQ_F_INGRESS;
947 handle = TC_H_MAKE(TC_H_INGRESS, 0);
948 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
949 } else {
950 if (handle == 0) {
951 handle = qdisc_alloc_handle(dev);
952 err = -ENOMEM;
953 if (handle == 0)
954 goto err_out3;
955 }
956 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
957 if (!netif_is_multiqueue(dev))
958 sch->flags |= TCQ_F_ONETXQUEUE;
959 }
960
961 sch->handle = handle;
962
963 /* This exist to keep backward compatible with a userspace
964 * loophole, what allowed userspace to get IFF_NO_QUEUE
965 * facility on older kernels by setting tx_queue_len=0 (prior
966 * to qdisc init), and then forgot to reinit tx_queue_len
967 * before again attaching a qdisc.
968 */
969 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) {
970 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
971 netdev_info(dev, "Caught tx_queue_len zero misconfig\n");
972 }
973
974 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
975 if (qdisc_is_percpu_stats(sch)) {
976 sch->cpu_bstats =
977 netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
978 if (!sch->cpu_bstats)
979 goto err_out4;
980
981 sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
982 if (!sch->cpu_qstats)
983 goto err_out4;
984 }
985
986 if (tca[TCA_STAB]) {
987 stab = qdisc_get_stab(tca[TCA_STAB]);
988 if (IS_ERR(stab)) {
989 err = PTR_ERR(stab);
990 goto err_out4;
991 }
992 rcu_assign_pointer(sch->stab, stab);
993 }
994 if (tca[TCA_RATE]) {
995 seqcount_t *running;
996
997 err = -EOPNOTSUPP;
998 if (sch->flags & TCQ_F_MQROOT)
999 goto err_out4;
1000
1001 if ((sch->parent != TC_H_ROOT) &&
1002 !(sch->flags & TCQ_F_INGRESS) &&
1003 (!p || !(p->flags & TCQ_F_MQROOT)))
1004 running = qdisc_root_sleeping_running(sch);
1005 else
1006 running = &sch->running;
1007
1008 err = gen_new_estimator(&sch->bstats,
1009 sch->cpu_bstats,
1010 &sch->rate_est,
1011 NULL,
1012 running,
1013 tca[TCA_RATE]);
1014 if (err)
1015 goto err_out4;
1016 }
1017
1018 qdisc_hash_add(sch);
1019
1020 return sch;
1021 }
1022err_out3:
1023 dev_put(dev);
1024 kfree((char *) sch - sch->padded);
1025err_out2:
1026 module_put(ops->owner);
1027err_out:
1028 *errp = err;
1029 return NULL;
1030
1031err_out4:
1032 free_percpu(sch->cpu_bstats);
1033 free_percpu(sch->cpu_qstats);
1034 /*
1035 * Any broken qdiscs that would require a ops->reset() here?
1036 * The qdisc was never in action so it shouldn't be necessary.
1037 */
1038 qdisc_put_stab(rtnl_dereference(sch->stab));
1039 if (ops->destroy)
1040 ops->destroy(sch);
1041 goto err_out3;
1042}
1043
1044static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
1045{
1046 struct qdisc_size_table *ostab, *stab = NULL;
1047 int err = 0;
1048
1049 if (tca[TCA_OPTIONS]) {
1050 if (sch->ops->change == NULL)
1051 return -EINVAL;
1052 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
1053 if (err)
1054 return err;
1055 }
1056
1057 if (tca[TCA_STAB]) {
1058 stab = qdisc_get_stab(tca[TCA_STAB]);
1059 if (IS_ERR(stab))
1060 return PTR_ERR(stab);
1061 }
1062
1063 ostab = rtnl_dereference(sch->stab);
1064 rcu_assign_pointer(sch->stab, stab);
1065 qdisc_put_stab(ostab);
1066
1067 if (tca[TCA_RATE]) {
1068 /* NB: ignores errors from replace_estimator
1069 because change can't be undone. */
1070 if (sch->flags & TCQ_F_MQROOT)
1071 goto out;
1072 gen_replace_estimator(&sch->bstats,
1073 sch->cpu_bstats,
1074 &sch->rate_est,
1075 NULL,
1076 qdisc_root_sleeping_running(sch),
1077 tca[TCA_RATE]);
1078 }
1079out:
1080 return 0;
1081}
1082
1083struct check_loop_arg {
1084 struct qdisc_walker w;
1085 struct Qdisc *p;
1086 int depth;
1087};
1088
1089static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1090 struct qdisc_walker *w);
1091
1092static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1093{
1094 struct check_loop_arg arg;
1095
1096 if (q->ops->cl_ops == NULL)
1097 return 0;
1098
1099 arg.w.stop = arg.w.skip = arg.w.count = 0;
1100 arg.w.fn = check_loop_fn;
1101 arg.depth = depth;
1102 arg.p = p;
1103 q->ops->cl_ops->walk(q, &arg.w);
1104 return arg.w.stop ? -ELOOP : 0;
1105}
1106
1107static int
1108check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1109{
1110 struct Qdisc *leaf;
1111 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1112 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1113
1114 leaf = cops->leaf(q, cl);
1115 if (leaf) {
1116 if (leaf == arg->p || arg->depth > 7)
1117 return -ELOOP;
1118 return check_loop(leaf, arg->p, arg->depth + 1);
1119 }
1120 return 0;
1121}
1122
1123/*
1124 * Delete/get qdisc.
1125 */
1126
1127static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1128{
1129 struct net *net = sock_net(skb->sk);
1130 struct tcmsg *tcm = nlmsg_data(n);
1131 struct nlattr *tca[TCA_MAX + 1];
1132 struct net_device *dev;
1133 u32 clid;
1134 struct Qdisc *q = NULL;
1135 struct Qdisc *p = NULL;
1136 int err;
1137
1138 if ((n->nlmsg_type != RTM_GETQDISC) &&
1139 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1140 return -EPERM;
1141
1142 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1143 if (err < 0)
1144 return err;
1145
1146 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1147 if (!dev)
1148 return -ENODEV;
1149
1150 clid = tcm->tcm_parent;
1151 if (clid) {
1152 if (clid != TC_H_ROOT) {
1153 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1154 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1155 if (!p)
1156 return -ENOENT;
1157 q = qdisc_leaf(p, clid);
1158 } else if (dev_ingress_queue(dev)) {
1159 q = dev_ingress_queue(dev)->qdisc_sleeping;
1160 }
1161 } else {
1162 q = dev->qdisc;
1163 }
1164 if (!q)
1165 return -ENOENT;
1166
1167 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1168 return -EINVAL;
1169 } else {
1170 q = qdisc_lookup(dev, tcm->tcm_handle);
1171 if (!q)
1172 return -ENOENT;
1173 }
1174
1175 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1176 return -EINVAL;
1177
1178 if (n->nlmsg_type == RTM_DELQDISC) {
1179 if (!clid)
1180 return -EINVAL;
1181 if (q->handle == 0)
1182 return -ENOENT;
1183 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1184 if (err != 0)
1185 return err;
1186 } else {
1187 qdisc_notify(net, skb, n, clid, NULL, q);
1188 }
1189 return 0;
1190}
1191
1192/*
1193 * Create/change qdisc.
1194 */
1195
1196static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1197{
1198 struct net *net = sock_net(skb->sk);
1199 struct tcmsg *tcm;
1200 struct nlattr *tca[TCA_MAX + 1];
1201 struct net_device *dev;
1202 u32 clid;
1203 struct Qdisc *q, *p;
1204 int err;
1205
1206 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1207 return -EPERM;
1208
1209replay:
1210 /* Reinit, just in case something touches this. */
1211 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1212 if (err < 0)
1213 return err;
1214
1215 tcm = nlmsg_data(n);
1216 clid = tcm->tcm_parent;
1217 q = p = NULL;
1218
1219 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1220 if (!dev)
1221 return -ENODEV;
1222
1223
1224 if (clid) {
1225 if (clid != TC_H_ROOT) {
1226 if (clid != TC_H_INGRESS) {
1227 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1228 if (!p)
1229 return -ENOENT;
1230 q = qdisc_leaf(p, clid);
1231 } else if (dev_ingress_queue_create(dev)) {
1232 q = dev_ingress_queue(dev)->qdisc_sleeping;
1233 }
1234 } else {
1235 q = dev->qdisc;
1236 }
1237
1238 /* It may be default qdisc, ignore it */
1239 if (q && q->handle == 0)
1240 q = NULL;
1241
1242 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1243 if (tcm->tcm_handle) {
1244 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1245 return -EEXIST;
1246 if (TC_H_MIN(tcm->tcm_handle))
1247 return -EINVAL;
1248 q = qdisc_lookup(dev, tcm->tcm_handle);
1249 if (!q)
1250 goto create_n_graft;
1251 if (n->nlmsg_flags & NLM_F_EXCL)
1252 return -EEXIST;
1253 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1254 return -EINVAL;
1255 if (q == p ||
1256 (p && check_loop(q, p, 0)))
1257 return -ELOOP;
1258 atomic_inc(&q->refcnt);
1259 goto graft;
1260 } else {
1261 if (!q)
1262 goto create_n_graft;
1263
1264 /* This magic test requires explanation.
1265 *
1266 * We know, that some child q is already
1267 * attached to this parent and have choice:
1268 * either to change it or to create/graft new one.
1269 *
1270 * 1. We are allowed to create/graft only
1271 * if CREATE and REPLACE flags are set.
1272 *
1273 * 2. If EXCL is set, requestor wanted to say,
1274 * that qdisc tcm_handle is not expected
1275 * to exist, so that we choose create/graft too.
1276 *
1277 * 3. The last case is when no flags are set.
1278 * Alas, it is sort of hole in API, we
1279 * cannot decide what to do unambiguously.
1280 * For now we select create/graft, if
1281 * user gave KIND, which does not match existing.
1282 */
1283 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1284 (n->nlmsg_flags & NLM_F_REPLACE) &&
1285 ((n->nlmsg_flags & NLM_F_EXCL) ||
1286 (tca[TCA_KIND] &&
1287 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1288 goto create_n_graft;
1289 }
1290 }
1291 } else {
1292 if (!tcm->tcm_handle)
1293 return -EINVAL;
1294 q = qdisc_lookup(dev, tcm->tcm_handle);
1295 }
1296
1297 /* Change qdisc parameters */
1298 if (q == NULL)
1299 return -ENOENT;
1300 if (n->nlmsg_flags & NLM_F_EXCL)
1301 return -EEXIST;
1302 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1303 return -EINVAL;
1304 err = qdisc_change(q, tca);
1305 if (err == 0)
1306 qdisc_notify(net, skb, n, clid, NULL, q);
1307 return err;
1308
1309create_n_graft:
1310 if (!(n->nlmsg_flags & NLM_F_CREATE))
1311 return -ENOENT;
1312 if (clid == TC_H_INGRESS) {
1313 if (dev_ingress_queue(dev))
1314 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1315 tcm->tcm_parent, tcm->tcm_parent,
1316 tca, &err);
1317 else
1318 err = -ENOENT;
1319 } else {
1320 struct netdev_queue *dev_queue;
1321
1322 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1323 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1324 else if (p)
1325 dev_queue = p->dev_queue;
1326 else
1327 dev_queue = netdev_get_tx_queue(dev, 0);
1328
1329 q = qdisc_create(dev, dev_queue, p,
1330 tcm->tcm_parent, tcm->tcm_handle,
1331 tca, &err);
1332 }
1333 if (q == NULL) {
1334 if (err == -EAGAIN)
1335 goto replay;
1336 return err;
1337 }
1338
1339graft:
1340 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1341 if (err) {
1342 if (q)
1343 qdisc_destroy(q);
1344 return err;
1345 }
1346
1347 return 0;
1348}
1349
1350static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1351 u32 portid, u32 seq, u16 flags, int event)
1352{
1353 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
1354 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
1355 struct tcmsg *tcm;
1356 struct nlmsghdr *nlh;
1357 unsigned char *b = skb_tail_pointer(skb);
1358 struct gnet_dump d;
1359 struct qdisc_size_table *stab;
1360 __u32 qlen;
1361
1362 cond_resched();
1363 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1364 if (!nlh)
1365 goto out_nlmsg_trim;
1366 tcm = nlmsg_data(nlh);
1367 tcm->tcm_family = AF_UNSPEC;
1368 tcm->tcm__pad1 = 0;
1369 tcm->tcm__pad2 = 0;
1370 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1371 tcm->tcm_parent = clid;
1372 tcm->tcm_handle = q->handle;
1373 tcm->tcm_info = atomic_read(&q->refcnt);
1374 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1375 goto nla_put_failure;
1376 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1377 goto nla_put_failure;
1378 qlen = q->q.qlen;
1379
1380 stab = rtnl_dereference(q->stab);
1381 if (stab && qdisc_dump_stab(skb, stab) < 0)
1382 goto nla_put_failure;
1383
1384 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1385 NULL, &d, TCA_PAD) < 0)
1386 goto nla_put_failure;
1387
1388 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1389 goto nla_put_failure;
1390
1391 if (qdisc_is_percpu_stats(q)) {
1392 cpu_bstats = q->cpu_bstats;
1393 cpu_qstats = q->cpu_qstats;
1394 }
1395
1396 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(q),
1397 &d, cpu_bstats, &q->bstats) < 0 ||
1398 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
1399 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
1400 goto nla_put_failure;
1401
1402 if (gnet_stats_finish_copy(&d) < 0)
1403 goto nla_put_failure;
1404
1405 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1406 return skb->len;
1407
1408out_nlmsg_trim:
1409nla_put_failure:
1410 nlmsg_trim(skb, b);
1411 return -1;
1412}
1413
1414static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1415{
1416 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1417}
1418
1419static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1420 struct nlmsghdr *n, u32 clid,
1421 struct Qdisc *old, struct Qdisc *new)
1422{
1423 struct sk_buff *skb;
1424 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1425
1426 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1427 if (!skb)
1428 return -ENOBUFS;
1429
1430 if (old && !tc_qdisc_dump_ignore(old)) {
1431 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1432 0, RTM_DELQDISC) < 0)
1433 goto err_out;
1434 }
1435 if (new && !tc_qdisc_dump_ignore(new)) {
1436 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1437 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1438 goto err_out;
1439 }
1440
1441 if (skb->len)
1442 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1443 n->nlmsg_flags & NLM_F_ECHO);
1444
1445err_out:
1446 kfree_skb(skb);
1447 return -EINVAL;
1448}
1449
1450static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1451 struct netlink_callback *cb,
1452 int *q_idx_p, int s_q_idx, bool recur)
1453{
1454 int ret = 0, q_idx = *q_idx_p;
1455 struct Qdisc *q;
1456 int b;
1457
1458 if (!root)
1459 return 0;
1460
1461 q = root;
1462 if (q_idx < s_q_idx) {
1463 q_idx++;
1464 } else {
1465 if (!tc_qdisc_dump_ignore(q) &&
1466 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1467 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1468 RTM_NEWQDISC) <= 0)
1469 goto done;
1470 q_idx++;
1471 }
1472
1473 /* If dumping singletons, there is no qdisc_dev(root) and the singleton
1474 * itself has already been dumped.
1475 *
1476 * If we've already dumped the top-level (ingress) qdisc above and the global
1477 * qdisc hashtable, we don't want to hit it again
1478 */
1479 if (!qdisc_dev(root) || !recur)
1480 goto out;
1481
1482 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1483 if (q_idx < s_q_idx) {
1484 q_idx++;
1485 continue;
1486 }
1487 if (!tc_qdisc_dump_ignore(q) &&
1488 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1489 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1490 RTM_NEWQDISC) <= 0)
1491 goto done;
1492 q_idx++;
1493 }
1494
1495out:
1496 *q_idx_p = q_idx;
1497 return ret;
1498done:
1499 ret = -1;
1500 goto out;
1501}
1502
1503static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1504{
1505 struct net *net = sock_net(skb->sk);
1506 int idx, q_idx;
1507 int s_idx, s_q_idx;
1508 struct net_device *dev;
1509
1510 s_idx = cb->args[0];
1511 s_q_idx = q_idx = cb->args[1];
1512
1513 idx = 0;
1514 ASSERT_RTNL();
1515 for_each_netdev(net, dev) {
1516 struct netdev_queue *dev_queue;
1517
1518 if (idx < s_idx)
1519 goto cont;
1520 if (idx > s_idx)
1521 s_q_idx = 0;
1522 q_idx = 0;
1523
1524 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx,
1525 true) < 0)
1526 goto done;
1527
1528 dev_queue = dev_ingress_queue(dev);
1529 if (dev_queue &&
1530 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1531 &q_idx, s_q_idx, false) < 0)
1532 goto done;
1533
1534cont:
1535 idx++;
1536 }
1537
1538done:
1539 cb->args[0] = idx;
1540 cb->args[1] = q_idx;
1541
1542 return skb->len;
1543}
1544
1545
1546
1547/************************************************
1548 * Traffic classes manipulation. *
1549 ************************************************/
1550
1551
1552
1553static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n)
1554{
1555 struct net *net = sock_net(skb->sk);
1556 struct tcmsg *tcm = nlmsg_data(n);
1557 struct nlattr *tca[TCA_MAX + 1];
1558 struct net_device *dev;
1559 struct Qdisc *q = NULL;
1560 const struct Qdisc_class_ops *cops;
1561 unsigned long cl = 0;
1562 unsigned long new_cl;
1563 u32 portid;
1564 u32 clid;
1565 u32 qid;
1566 int err;
1567
1568 if ((n->nlmsg_type != RTM_GETTCLASS) &&
1569 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1570 return -EPERM;
1571
1572 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1573 if (err < 0)
1574 return err;
1575
1576 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1577 if (!dev)
1578 return -ENODEV;
1579
1580 /*
1581 parent == TC_H_UNSPEC - unspecified parent.
1582 parent == TC_H_ROOT - class is root, which has no parent.
1583 parent == X:0 - parent is root class.
1584 parent == X:Y - parent is a node in hierarchy.
1585 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1586
1587 handle == 0:0 - generate handle from kernel pool.
1588 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1589 handle == X:Y - clear.
1590 handle == X:0 - root class.
1591 */
1592
1593 /* Step 1. Determine qdisc handle X:0 */
1594
1595 portid = tcm->tcm_parent;
1596 clid = tcm->tcm_handle;
1597 qid = TC_H_MAJ(clid);
1598
1599 if (portid != TC_H_ROOT) {
1600 u32 qid1 = TC_H_MAJ(portid);
1601
1602 if (qid && qid1) {
1603 /* If both majors are known, they must be identical. */
1604 if (qid != qid1)
1605 return -EINVAL;
1606 } else if (qid1) {
1607 qid = qid1;
1608 } else if (qid == 0)
1609 qid = dev->qdisc->handle;
1610
1611 /* Now qid is genuine qdisc handle consistent
1612 * both with parent and child.
1613 *
1614 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1615 */
1616 if (portid)
1617 portid = TC_H_MAKE(qid, portid);
1618 } else {
1619 if (qid == 0)
1620 qid = dev->qdisc->handle;
1621 }
1622
1623 /* OK. Locate qdisc */
1624 q = qdisc_lookup(dev, qid);
1625 if (!q)
1626 return -ENOENT;
1627
1628 /* An check that it supports classes */
1629 cops = q->ops->cl_ops;
1630 if (cops == NULL)
1631 return -EINVAL;
1632
1633 /* Now try to get class */
1634 if (clid == 0) {
1635 if (portid == TC_H_ROOT)
1636 clid = qid;
1637 } else
1638 clid = TC_H_MAKE(qid, clid);
1639
1640 if (clid)
1641 cl = cops->get(q, clid);
1642
1643 if (cl == 0) {
1644 err = -ENOENT;
1645 if (n->nlmsg_type != RTM_NEWTCLASS ||
1646 !(n->nlmsg_flags & NLM_F_CREATE))
1647 goto out;
1648 } else {
1649 switch (n->nlmsg_type) {
1650 case RTM_NEWTCLASS:
1651 err = -EEXIST;
1652 if (n->nlmsg_flags & NLM_F_EXCL)
1653 goto out;
1654 break;
1655 case RTM_DELTCLASS:
1656 err = -EOPNOTSUPP;
1657 if (cops->delete)
1658 err = cops->delete(q, cl);
1659 if (err == 0)
1660 tclass_notify(net, skb, n, q, cl,
1661 RTM_DELTCLASS);
1662 goto out;
1663 case RTM_GETTCLASS:
1664 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1665 goto out;
1666 default:
1667 err = -EINVAL;
1668 goto out;
1669 }
1670 }
1671
1672 new_cl = cl;
1673 err = -EOPNOTSUPP;
1674 if (cops->change)
1675 err = cops->change(q, clid, portid, tca, &new_cl);
1676 if (err == 0)
1677 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1678
1679out:
1680 if (cl)
1681 cops->put(q, cl);
1682
1683 return err;
1684}
1685
1686
1687static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1688 unsigned long cl,
1689 u32 portid, u32 seq, u16 flags, int event)
1690{
1691 struct tcmsg *tcm;
1692 struct nlmsghdr *nlh;
1693 unsigned char *b = skb_tail_pointer(skb);
1694 struct gnet_dump d;
1695 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1696
1697 cond_resched();
1698 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1699 if (!nlh)
1700 goto out_nlmsg_trim;
1701 tcm = nlmsg_data(nlh);
1702 tcm->tcm_family = AF_UNSPEC;
1703 tcm->tcm__pad1 = 0;
1704 tcm->tcm__pad2 = 0;
1705 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1706 tcm->tcm_parent = q->handle;
1707 tcm->tcm_handle = q->handle;
1708 tcm->tcm_info = 0;
1709 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1710 goto nla_put_failure;
1711 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1712 goto nla_put_failure;
1713
1714 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1715 NULL, &d, TCA_PAD) < 0)
1716 goto nla_put_failure;
1717
1718 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1719 goto nla_put_failure;
1720
1721 if (gnet_stats_finish_copy(&d) < 0)
1722 goto nla_put_failure;
1723
1724 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1725 return skb->len;
1726
1727out_nlmsg_trim:
1728nla_put_failure:
1729 nlmsg_trim(skb, b);
1730 return -1;
1731}
1732
1733static int tclass_notify(struct net *net, struct sk_buff *oskb,
1734 struct nlmsghdr *n, struct Qdisc *q,
1735 unsigned long cl, int event)
1736{
1737 struct sk_buff *skb;
1738 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1739
1740 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1741 if (!skb)
1742 return -ENOBUFS;
1743
1744 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1745 kfree_skb(skb);
1746 return -EINVAL;
1747 }
1748
1749 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1750 n->nlmsg_flags & NLM_F_ECHO);
1751}
1752
1753struct qdisc_dump_args {
1754 struct qdisc_walker w;
1755 struct sk_buff *skb;
1756 struct netlink_callback *cb;
1757};
1758
1759static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
1760 struct qdisc_walker *arg)
1761{
1762 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1763
1764 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1765 a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
1766 RTM_NEWTCLASS);
1767}
1768
1769static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1770 struct tcmsg *tcm, struct netlink_callback *cb,
1771 int *t_p, int s_t)
1772{
1773 struct qdisc_dump_args arg;
1774
1775 if (tc_qdisc_dump_ignore(q) ||
1776 *t_p < s_t || !q->ops->cl_ops ||
1777 (tcm->tcm_parent &&
1778 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1779 (*t_p)++;
1780 return 0;
1781 }
1782 if (*t_p > s_t)
1783 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1784 arg.w.fn = qdisc_class_dump;
1785 arg.skb = skb;
1786 arg.cb = cb;
1787 arg.w.stop = 0;
1788 arg.w.skip = cb->args[1];
1789 arg.w.count = 0;
1790 q->ops->cl_ops->walk(q, &arg.w);
1791 cb->args[1] = arg.w.count;
1792 if (arg.w.stop)
1793 return -1;
1794 (*t_p)++;
1795 return 0;
1796}
1797
1798static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1799 struct tcmsg *tcm, struct netlink_callback *cb,
1800 int *t_p, int s_t)
1801{
1802 struct Qdisc *q;
1803 int b;
1804
1805 if (!root)
1806 return 0;
1807
1808 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1809 return -1;
1810
1811 if (!qdisc_dev(root))
1812 return 0;
1813
1814 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1815 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1816 return -1;
1817 }
1818
1819 return 0;
1820}
1821
1822static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1823{
1824 struct tcmsg *tcm = nlmsg_data(cb->nlh);
1825 struct net *net = sock_net(skb->sk);
1826 struct netdev_queue *dev_queue;
1827 struct net_device *dev;
1828 int t, s_t;
1829
1830 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1831 return 0;
1832 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1833 if (!dev)
1834 return 0;
1835
1836 s_t = cb->args[0];
1837 t = 0;
1838
1839 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1840 goto done;
1841
1842 dev_queue = dev_ingress_queue(dev);
1843 if (dev_queue &&
1844 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1845 &t, s_t) < 0)
1846 goto done;
1847
1848done:
1849 cb->args[0] = t;
1850
1851 dev_put(dev);
1852 return skb->len;
1853}
1854
1855/* Main classifier routine: scans classifier chain attached
1856 * to this qdisc, (optionally) tests for protocol and asks
1857 * specific classifiers.
1858 */
1859int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1860 struct tcf_result *res, bool compat_mode)
1861{
1862 __be16 protocol = tc_skb_protocol(skb);
1863#ifdef CONFIG_NET_CLS_ACT
1864 const struct tcf_proto *old_tp = tp;
1865 int limit = 0;
1866
1867reclassify:
1868#endif
1869 for (; tp; tp = rcu_dereference_bh(tp->next)) {
1870 int err;
1871
1872 if (tp->protocol != protocol &&
1873 tp->protocol != htons(ETH_P_ALL))
1874 continue;
1875
1876 err = tp->classify(skb, tp, res);
1877#ifdef CONFIG_NET_CLS_ACT
1878 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode))
1879 goto reset;
1880#endif
1881 if (err >= 0)
1882 return err;
1883 }
1884
1885 return TC_ACT_UNSPEC; /* signal: continue lookup */
1886#ifdef CONFIG_NET_CLS_ACT
1887reset:
1888 if (unlikely(limit++ >= MAX_REC_LOOP)) {
1889 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n",
1890 tp->q->ops->id, tp->prio & 0xffff,
1891 ntohs(tp->protocol));
1892 return TC_ACT_SHOT;
1893 }
1894
1895 tp = old_tp;
1896 protocol = tc_skb_protocol(skb);
1897 goto reclassify;
1898#endif
1899}
1900EXPORT_SYMBOL(tc_classify);
1901
1902bool tcf_destroy(struct tcf_proto *tp, bool force)
1903{
1904 if (tp->ops->destroy(tp, force)) {
1905 module_put(tp->ops->owner);
1906 kfree_rcu(tp, rcu);
1907 return true;
1908 }
1909
1910 return false;
1911}
1912
1913void tcf_destroy_chain(struct tcf_proto __rcu **fl)
1914{
1915 struct tcf_proto *tp;
1916
1917 while ((tp = rtnl_dereference(*fl)) != NULL) {
1918 RCU_INIT_POINTER(*fl, tp->next);
1919 tcf_destroy(tp, true);
1920 }
1921}
1922EXPORT_SYMBOL(tcf_destroy_chain);
1923
1924#ifdef CONFIG_PROC_FS
1925static int psched_show(struct seq_file *seq, void *v)
1926{
1927 seq_printf(seq, "%08x %08x %08x %08x\n",
1928 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1929 1000000,
1930 (u32)NSEC_PER_SEC / hrtimer_resolution);
1931
1932 return 0;
1933}
1934
1935static int psched_open(struct inode *inode, struct file *file)
1936{
1937 return single_open(file, psched_show, NULL);
1938}
1939
1940static const struct file_operations psched_fops = {
1941 .owner = THIS_MODULE,
1942 .open = psched_open,
1943 .read = seq_read,
1944 .llseek = seq_lseek,
1945 .release = single_release,
1946};
1947
1948static int __net_init psched_net_init(struct net *net)
1949{
1950 struct proc_dir_entry *e;
1951
1952 e = proc_create("psched", 0, net->proc_net, &psched_fops);
1953 if (e == NULL)
1954 return -ENOMEM;
1955
1956 return 0;
1957}
1958
1959static void __net_exit psched_net_exit(struct net *net)
1960{
1961 remove_proc_entry("psched", net->proc_net);
1962}
1963#else
1964static int __net_init psched_net_init(struct net *net)
1965{
1966 return 0;
1967}
1968
1969static void __net_exit psched_net_exit(struct net *net)
1970{
1971}
1972#endif
1973
1974static struct pernet_operations psched_net_ops = {
1975 .init = psched_net_init,
1976 .exit = psched_net_exit,
1977};
1978
1979static int __init pktsched_init(void)
1980{
1981 int err;
1982
1983 err = register_pernet_subsys(&psched_net_ops);
1984 if (err) {
1985 pr_err("pktsched_init: "
1986 "cannot initialize per netns operations\n");
1987 return err;
1988 }
1989
1990 register_qdisc(&pfifo_fast_ops);
1991 register_qdisc(&pfifo_qdisc_ops);
1992 register_qdisc(&bfifo_qdisc_ops);
1993 register_qdisc(&pfifo_head_drop_qdisc_ops);
1994 register_qdisc(&mq_qdisc_ops);
1995 register_qdisc(&noqueue_qdisc_ops);
1996
1997 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1998 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1999 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc,
2000 NULL);
2001 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
2002 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
2003 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass,
2004 NULL);
2005
2006 return 0;
2007}
2008
2009subsys_initcall(pktsched_init);