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