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