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drm/i915: Use mmio flips to change tiling mode on Baytrail
[linux-2.6/btrfs-unstable.git] / net / sched / sch_api.c
blob58bed7599db7d9f5538f01ff5057e7aa79d0a915
1 /*
2 * net/sched/sch_api.c Packet scheduler API.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 * Fixes:
12 *
13 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired.
14 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
15 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support
16 */
17
18 #include <linux/module.h>
19 #include <linux/types.h>
20 #include <linux/kernel.h>
21 #include <linux/string.h>
22 #include <linux/errno.h>
23 #include <linux/skbuff.h>
24 #include <linux/init.h>
25 #include <linux/proc_fs.h>
26 #include <linux/seq_file.h>
27 #include <linux/kmod.h>
28 #include <linux/list.h>
29 #include <linux/hrtimer.h>
30 #include <linux/lockdep.h>
31 #include <linux/slab.h>
32
33 #include <net/net_namespace.h>
34 #include <net/sock.h>
35 #include <net/netlink.h>
36 #include <net/pkt_sched.h>
37
38 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
39 struct nlmsghdr *n, u32 clid,
40 struct Qdisc *old, struct Qdisc *new);
41 static int tclass_notify(struct net *net, struct sk_buff *oskb,
42 struct nlmsghdr *n, struct Qdisc *q,
43 unsigned long cl, int event);
44
45 /*
46
47 Short review.
48 -------------
49
50 This file consists of two interrelated parts:
51
52 1. queueing disciplines manager frontend.
53 2. traffic classes manager frontend.
54
55 Generally, queueing discipline ("qdisc") is a black box,
56 which is able to enqueue packets and to dequeue them (when
57 device is ready to send something) in order and at times
58 determined by algorithm hidden in it.
59
60 qdisc's are divided to two categories:
61 - "queues", which have no internal structure visible from outside.
62 - "schedulers", which split all the packets to "traffic classes",
63 using "packet classifiers" (look at cls_api.c)
64
65 In turn, classes may have child qdiscs (as rule, queues)
66 attached to them etc. etc. etc.
67
68 The goal of the routines in this file is to translate
69 information supplied by user in the form of handles
70 to more intelligible for kernel form, to make some sanity
71 checks and part of work, which is common to all qdiscs
72 and to provide rtnetlink notifications.
73
74 All real intelligent work is done inside qdisc modules.
75
76
77
78 Every discipline has two major routines: enqueue and dequeue.
79
80 ---dequeue
81
82 dequeue usually returns a skb to send. It is allowed to return NULL,
83 but it does not mean that queue is empty, it just means that
84 discipline does not want to send anything this time.
85 Queue is really empty if q->q.qlen == 0.
86 For complicated disciplines with multiple queues q->q is not
87 real packet queue, but however q->q.qlen must be valid.
88
89 ---enqueue
90
91 enqueue returns 0, if packet was enqueued successfully.
92 If packet (this one or another one) was dropped, it returns
93 not zero error code.
94 NET_XMIT_DROP - this packet dropped
95 Expected action: do not backoff, but wait until queue will clear.
96 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
97 Expected action: backoff or ignore
98 NET_XMIT_POLICED - dropped by police.
99 Expected action: backoff or error to real-time apps.
100
101 Auxiliary routines:
102
103 ---peek
104
105 like dequeue but without removing a packet from the queue
106
107 ---reset
108
109 returns qdisc to initial state: purge all buffers, clear all
110 timers, counters (except for statistics) etc.
111
112 ---init
113
114 initializes newly created qdisc.
115
116 ---destroy
117
118 destroys resources allocated by init and during lifetime of qdisc.
119
120 ---change
121
122 changes qdisc parameters.
123 */
124
125 /* Protects list of registered TC modules. It is pure SMP lock. */
126 static DEFINE_RWLOCK(qdisc_mod_lock);
127
128
129 /************************************************
130 * Queueing disciplines manipulation. *
131 ************************************************/
132
133
134 /* The list of all installed queueing disciplines. */
135
136 static struct Qdisc_ops *qdisc_base;
137
138 /* Register/unregister queueing discipline */
139
140 int register_qdisc(struct Qdisc_ops *qops)
141 {
142 struct Qdisc_ops *q, **qp;
143 int rc = -EEXIST;
144
145 write_lock(&qdisc_mod_lock);
146 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
147 if (!strcmp(qops->id, q->id))
148 goto out;
149
150 if (qops->enqueue == NULL)
151 qops->enqueue = noop_qdisc_ops.enqueue;
152 if (qops->peek == NULL) {
153 if (qops->dequeue == NULL)
154 qops->peek = noop_qdisc_ops.peek;
155 else
156 goto out_einval;
157 }
158 if (qops->dequeue == NULL)
159 qops->dequeue = noop_qdisc_ops.dequeue;
160
161 if (qops->cl_ops) {
162 const struct Qdisc_class_ops *cops = qops->cl_ops;
163
164 if (!(cops->get && cops->put && cops->walk && cops->leaf))
165 goto out_einval;
166
167 if (cops->tcf_chain && !(cops->bind_tcf && cops->unbind_tcf))
168 goto out_einval;
169 }
170
171 qops->next = NULL;
172 *qp = qops;
173 rc = 0;
174 out:
175 write_unlock(&qdisc_mod_lock);
176 return rc;
177
178 out_einval:
179 rc = -EINVAL;
180 goto out;
181 }
182 EXPORT_SYMBOL(register_qdisc);
183
184 int unregister_qdisc(struct Qdisc_ops *qops)
185 {
186 struct Qdisc_ops *q, **qp;
187 int err = -ENOENT;
188
189 write_lock(&qdisc_mod_lock);
190 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
191 if (q == qops)
192 break;
193 if (q) {
194 *qp = q->next;
195 q->next = NULL;
196 err = 0;
197 }
198 write_unlock(&qdisc_mod_lock);
199 return err;
200 }
201 EXPORT_SYMBOL(unregister_qdisc);
202
203 /* Get default qdisc if not otherwise specified */
204 void 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
211 static 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 */
227 int 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 */
258
259 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
260 {
261 struct Qdisc *q;
262
263 if (!(root->flags & TCQ_F_BUILTIN) &&
264 root->handle == handle)
265 return root;
266
267 list_for_each_entry(q, &root->list, list) {
268 if (q->handle == handle)
269 return q;
270 }
271 return NULL;
272 }
273
274 void qdisc_list_add(struct Qdisc *q)
275 {
276 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
277 struct Qdisc *root = qdisc_dev(q)->qdisc;
278
279 WARN_ON_ONCE(root == &noop_qdisc);
280 list_add_tail(&q->list, &root->list);
281 }
282 }
283 EXPORT_SYMBOL(qdisc_list_add);
284
285 void qdisc_list_del(struct Qdisc *q)
286 {
287 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
288 list_del(&q->list);
289 }
290 EXPORT_SYMBOL(qdisc_list_del);
291
292 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
293 {
294 struct Qdisc *q;
295
296 q = qdisc_match_from_root(dev->qdisc, handle);
297 if (q)
298 goto out;
299
300 if (dev_ingress_queue(dev))
301 q = qdisc_match_from_root(
302 dev_ingress_queue(dev)->qdisc_sleeping,
303 handle);
304 out:
305 return q;
306 }
307
308 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
309 {
310 unsigned long cl;
311 struct Qdisc *leaf;
312 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
313
314 if (cops == NULL)
315 return NULL;
316 cl = cops->get(p, classid);
317
318 if (cl == 0)
319 return NULL;
320 leaf = cops->leaf(p, cl);
321 cops->put(p, cl);
322 return leaf;
323 }
324
325 /* Find queueing discipline by name */
326
327 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
328 {
329 struct Qdisc_ops *q = NULL;
330
331 if (kind) {
332 read_lock(&qdisc_mod_lock);
333 for (q = qdisc_base; q; q = q->next) {
334 if (nla_strcmp(kind, q->id) == 0) {
335 if (!try_module_get(q->owner))
336 q = NULL;
337 break;
338 }
339 }
340 read_unlock(&qdisc_mod_lock);
341 }
342 return q;
343 }
344
345 /* The linklayer setting were not transferred from iproute2, in older
346 * versions, and the rate tables lookup systems have been dropped in
347 * the kernel. To keep backward compatible with older iproute2 tc
348 * utils, we detect the linklayer setting by detecting if the rate
349 * table were modified.
350 *
351 * For linklayer ATM table entries, the rate table will be aligned to
352 * 48 bytes, thus some table entries will contain the same value. The
353 * mpu (min packet unit) is also encoded into the old rate table, thus
354 * starting from the mpu, we find low and high table entries for
355 * mapping this cell. If these entries contain the same value, when
356 * the rate tables have been modified for linklayer ATM.
357 *
358 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
359 * and then roundup to the next cell, calc the table entry one below,
360 * and compare.
361 */
362 static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
363 {
364 int low = roundup(r->mpu, 48);
365 int high = roundup(low+1, 48);
366 int cell_low = low >> r->cell_log;
367 int cell_high = (high >> r->cell_log) - 1;
368
369 /* rtab is too inaccurate at rates > 100Mbit/s */
370 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
371 pr_debug("TC linklayer: Giving up ATM detection\n");
372 return TC_LINKLAYER_ETHERNET;
373 }
374
375 if ((cell_high > cell_low) && (cell_high < 256)
376 && (rtab[cell_low] == rtab[cell_high])) {
377 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
378 cell_low, cell_high, rtab[cell_high]);
379 return TC_LINKLAYER_ATM;
380 }
381 return TC_LINKLAYER_ETHERNET;
382 }
383
384 static struct qdisc_rate_table *qdisc_rtab_list;
385
386 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct nlattr *tab)
387 {
388 struct qdisc_rate_table *rtab;
389
390 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
391 nla_len(tab) != TC_RTAB_SIZE)
392 return NULL;
393
394 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
395 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
396 !memcmp(&rtab->data, nla_data(tab), 1024)) {
397 rtab->refcnt++;
398 return rtab;
399 }
400 }
401
402 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
403 if (rtab) {
404 rtab->rate = *r;
405 rtab->refcnt = 1;
406 memcpy(rtab->data, nla_data(tab), 1024);
407 if (r->linklayer == TC_LINKLAYER_UNAWARE)
408 r->linklayer = __detect_linklayer(r, rtab->data);
409 rtab->next = qdisc_rtab_list;
410 qdisc_rtab_list = rtab;
411 }
412 return rtab;
413 }
414 EXPORT_SYMBOL(qdisc_get_rtab);
415
416 void qdisc_put_rtab(struct qdisc_rate_table *tab)
417 {
418 struct qdisc_rate_table *rtab, **rtabp;
419
420 if (!tab || --tab->refcnt)
421 return;
422
423 for (rtabp = &qdisc_rtab_list;
424 (rtab = *rtabp) != NULL;
425 rtabp = &rtab->next) {
426 if (rtab == tab) {
427 *rtabp = rtab->next;
428 kfree(rtab);
429 return;
430 }
431 }
432 }
433 EXPORT_SYMBOL(qdisc_put_rtab);
434
435 static LIST_HEAD(qdisc_stab_list);
436 static DEFINE_SPINLOCK(qdisc_stab_lock);
437
438 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
439 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
440 [TCA_STAB_DATA] = { .type = NLA_BINARY },
441 };
442
443 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
444 {
445 struct nlattr *tb[TCA_STAB_MAX + 1];
446 struct qdisc_size_table *stab;
447 struct tc_sizespec *s;
448 unsigned int tsize = 0;
449 u16 *tab = NULL;
450 int err;
451
452 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
453 if (err < 0)
454 return ERR_PTR(err);
455 if (!tb[TCA_STAB_BASE])
456 return ERR_PTR(-EINVAL);
457
458 s = nla_data(tb[TCA_STAB_BASE]);
459
460 if (s->tsize > 0) {
461 if (!tb[TCA_STAB_DATA])
462 return ERR_PTR(-EINVAL);
463 tab = nla_data(tb[TCA_STAB_DATA]);
464 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
465 }
466
467 if (tsize != s->tsize || (!tab && tsize > 0))
468 return ERR_PTR(-EINVAL);
469
470 spin_lock(&qdisc_stab_lock);
471
472 list_for_each_entry(stab, &qdisc_stab_list, list) {
473 if (memcmp(&stab->szopts, s, sizeof(*s)))
474 continue;
475 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
476 continue;
477 stab->refcnt++;
478 spin_unlock(&qdisc_stab_lock);
479 return stab;
480 }
481
482 spin_unlock(&qdisc_stab_lock);
483
484 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
485 if (!stab)
486 return ERR_PTR(-ENOMEM);
487
488 stab->refcnt = 1;
489 stab->szopts = *s;
490 if (tsize > 0)
491 memcpy(stab->data, tab, tsize * sizeof(u16));
492
493 spin_lock(&qdisc_stab_lock);
494 list_add_tail(&stab->list, &qdisc_stab_list);
495 spin_unlock(&qdisc_stab_lock);
496
497 return stab;
498 }
499
500 static void stab_kfree_rcu(struct rcu_head *head)
501 {
502 kfree(container_of(head, struct qdisc_size_table, rcu));
503 }
504
505 void qdisc_put_stab(struct qdisc_size_table *tab)
506 {
507 if (!tab)
508 return;
509
510 spin_lock(&qdisc_stab_lock);
511
512 if (--tab->refcnt == 0) {
513 list_del(&tab->list);
514 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
515 }
516
517 spin_unlock(&qdisc_stab_lock);
518 }
519 EXPORT_SYMBOL(qdisc_put_stab);
520
521 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
522 {
523 struct nlattr *nest;
524
525 nest = nla_nest_start(skb, TCA_STAB);
526 if (nest == NULL)
527 goto nla_put_failure;
528 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
529 goto nla_put_failure;
530 nla_nest_end(skb, nest);
531
532 return skb->len;
533
534 nla_put_failure:
535 return -1;
536 }
537
538 void __qdisc_calculate_pkt_len(struct sk_buff *skb, const struct qdisc_size_table *stab)
539 {
540 int pkt_len, slot;
541
542 pkt_len = skb->len + stab->szopts.overhead;
543 if (unlikely(!stab->szopts.tsize))
544 goto out;
545
546 slot = pkt_len + stab->szopts.cell_align;
547 if (unlikely(slot < 0))
548 slot = 0;
549
550 slot >>= stab->szopts.cell_log;
551 if (likely(slot < stab->szopts.tsize))
552 pkt_len = stab->data[slot];
553 else
554 pkt_len = stab->data[stab->szopts.tsize - 1] *
555 (slot / stab->szopts.tsize) +
556 stab->data[slot % stab->szopts.tsize];
557
558 pkt_len <<= stab->szopts.size_log;
559 out:
560 if (unlikely(pkt_len < 1))
561 pkt_len = 1;
562 qdisc_skb_cb(skb)->pkt_len = pkt_len;
563 }
564 EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
565
566 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
567 {
568 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
569 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
570 txt, qdisc->ops->id, qdisc->handle >> 16);
571 qdisc->flags |= TCQ_F_WARN_NONWC;
572 }
573 }
574 EXPORT_SYMBOL(qdisc_warn_nonwc);
575
576 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
577 {
578 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
579 timer);
580
581 qdisc_unthrottled(wd->qdisc);
582 __netif_schedule(qdisc_root(wd->qdisc));
583
584 return HRTIMER_NORESTART;
585 }
586
587 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
588 {
589 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
590 wd->timer.function = qdisc_watchdog;
591 wd->qdisc = qdisc;
592 }
593 EXPORT_SYMBOL(qdisc_watchdog_init);
594
595 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
596 {
597 if (test_bit(__QDISC_STATE_DEACTIVATED,
598 &qdisc_root_sleeping(wd->qdisc)->state))
599 return;
600
601 qdisc_throttled(wd->qdisc);
602
603 hrtimer_start(&wd->timer,
604 ns_to_ktime(expires),
605 HRTIMER_MODE_ABS);
606 }
607 EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
608
609 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
610 {
611 hrtimer_cancel(&wd->timer);
612 qdisc_unthrottled(wd->qdisc);
613 }
614 EXPORT_SYMBOL(qdisc_watchdog_cancel);
615
616 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
617 {
618 unsigned int size = n * sizeof(struct hlist_head), i;
619 struct hlist_head *h;
620
621 if (size <= PAGE_SIZE)
622 h = kmalloc(size, GFP_KERNEL);
623 else
624 h = (struct hlist_head *)
625 __get_free_pages(GFP_KERNEL, get_order(size));
626
627 if (h != NULL) {
628 for (i = 0; i < n; i++)
629 INIT_HLIST_HEAD(&h[i]);
630 }
631 return h;
632 }
633
634 static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
635 {
636 unsigned int size = n * sizeof(struct hlist_head);
637
638 if (size <= PAGE_SIZE)
639 kfree(h);
640 else
641 free_pages((unsigned long)h, get_order(size));
642 }
643
644 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
645 {
646 struct Qdisc_class_common *cl;
647 struct hlist_node *next;
648 struct hlist_head *nhash, *ohash;
649 unsigned int nsize, nmask, osize;
650 unsigned int i, h;
651
652 /* Rehash when load factor exceeds 0.75 */
653 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
654 return;
655 nsize = clhash->hashsize * 2;
656 nmask = nsize - 1;
657 nhash = qdisc_class_hash_alloc(nsize);
658 if (nhash == NULL)
659 return;
660
661 ohash = clhash->hash;
662 osize = clhash->hashsize;
663
664 sch_tree_lock(sch);
665 for (i = 0; i < osize; i++) {
666 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
667 h = qdisc_class_hash(cl->classid, nmask);
668 hlist_add_head(&cl->hnode, &nhash[h]);
669 }
670 }
671 clhash->hash = nhash;
672 clhash->hashsize = nsize;
673 clhash->hashmask = nmask;
674 sch_tree_unlock(sch);
675
676 qdisc_class_hash_free(ohash, osize);
677 }
678 EXPORT_SYMBOL(qdisc_class_hash_grow);
679
680 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
681 {
682 unsigned int size = 4;
683
684 clhash->hash = qdisc_class_hash_alloc(size);
685 if (clhash->hash == NULL)
686 return -ENOMEM;
687 clhash->hashsize = size;
688 clhash->hashmask = size - 1;
689 clhash->hashelems = 0;
690 return 0;
691 }
692 EXPORT_SYMBOL(qdisc_class_hash_init);
693
694 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
695 {
696 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
697 }
698 EXPORT_SYMBOL(qdisc_class_hash_destroy);
699
700 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
701 struct Qdisc_class_common *cl)
702 {
703 unsigned int h;
704
705 INIT_HLIST_NODE(&cl->hnode);
706 h = qdisc_class_hash(cl->classid, clhash->hashmask);
707 hlist_add_head(&cl->hnode, &clhash->hash[h]);
708 clhash->hashelems++;
709 }
710 EXPORT_SYMBOL(qdisc_class_hash_insert);
711
712 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
713 struct Qdisc_class_common *cl)
714 {
715 hlist_del(&cl->hnode);
716 clhash->hashelems--;
717 }
718 EXPORT_SYMBOL(qdisc_class_hash_remove);
719
720 /* Allocate an unique handle from space managed by kernel
721 * Possible range is [8000-FFFF]:0000 (0x8000 values)
722 */
723 static u32 qdisc_alloc_handle(struct net_device *dev)
724 {
725 int i = 0x8000;
726 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
727
728 do {
729 autohandle += TC_H_MAKE(0x10000U, 0);
730 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
731 autohandle = TC_H_MAKE(0x80000000U, 0);
732 if (!qdisc_lookup(dev, autohandle))
733 return autohandle;
734 cond_resched();
735 } while (--i > 0);
736
737 return 0;
738 }
739
740 void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
741 {
742 const struct Qdisc_class_ops *cops;
743 unsigned long cl;
744 u32 parentid;
745 int drops;
746
747 if (n == 0)
748 return;
749 drops = max_t(int, n, 0);
750 while ((parentid = sch->parent)) {
751 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
752 return;
753
754 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
755 if (sch == NULL) {
756 WARN_ON(parentid != TC_H_ROOT);
757 return;
758 }
759 cops = sch->ops->cl_ops;
760 if (cops->qlen_notify) {
761 cl = cops->get(sch, parentid);
762 cops->qlen_notify(sch, cl);
763 cops->put(sch, cl);
764 }
765 sch->q.qlen -= n;
766 sch->qstats.drops += drops;
767 }
768 }
769 EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
770
771 static void notify_and_destroy(struct net *net, struct sk_buff *skb,
772 struct nlmsghdr *n, u32 clid,
773 struct Qdisc *old, struct Qdisc *new)
774 {
775 if (new || old)
776 qdisc_notify(net, skb, n, clid, old, new);
777
778 if (old)
779 qdisc_destroy(old);
780 }
781
782 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
783 * to device "dev".
784 *
785 * When appropriate send a netlink notification using 'skb'
786 * and "n".
787 *
788 * On success, destroy old qdisc.
789 */
790
791 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
792 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
793 struct Qdisc *new, struct Qdisc *old)
794 {
795 struct Qdisc *q = old;
796 struct net *net = dev_net(dev);
797 int err = 0;
798
799 if (parent == NULL) {
800 unsigned int i, num_q, ingress;
801
802 ingress = 0;
803 num_q = dev->num_tx_queues;
804 if ((q && q->flags & TCQ_F_INGRESS) ||
805 (new && new->flags & TCQ_F_INGRESS)) {
806 num_q = 1;
807 ingress = 1;
808 if (!dev_ingress_queue(dev))
809 return -ENOENT;
810 }
811
812 if (dev->flags & IFF_UP)
813 dev_deactivate(dev);
814
815 if (new && new->ops->attach) {
816 new->ops->attach(new);
817 num_q = 0;
818 }
819
820 for (i = 0; i < num_q; i++) {
821 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
822
823 if (!ingress)
824 dev_queue = netdev_get_tx_queue(dev, i);
825
826 old = dev_graft_qdisc(dev_queue, new);
827 if (new && i > 0)
828 atomic_inc(&new->refcnt);
829
830 if (!ingress)
831 qdisc_destroy(old);
832 }
833
834 if (!ingress) {
835 notify_and_destroy(net, skb, n, classid,
836 dev->qdisc, new);
837 if (new && !new->ops->attach)
838 atomic_inc(&new->refcnt);
839 dev->qdisc = new ? : &noop_qdisc;
840 } else {
841 notify_and_destroy(net, skb, n, classid, old, new);
842 }
843
844 if (dev->flags & IFF_UP)
845 dev_activate(dev);
846 } else {
847 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
848
849 err = -EOPNOTSUPP;
850 if (cops && cops->graft) {
851 unsigned long cl = cops->get(parent, classid);
852 if (cl) {
853 err = cops->graft(parent, cl, new, &old);
854 cops->put(parent, cl);
855 } else
856 err = -ENOENT;
857 }
858 if (!err)
859 notify_and_destroy(net, skb, n, classid, old, new);
860 }
861 return err;
862 }
863
864 /* lockdep annotation is needed for ingress; egress gets it only for name */
865 static struct lock_class_key qdisc_tx_lock;
866 static struct lock_class_key qdisc_rx_lock;
867
868 /*
869 Allocate and initialize new qdisc.
870
871 Parameters are passed via opt.
872 */
873
874 static struct Qdisc *
875 qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
876 struct Qdisc *p, u32 parent, u32 handle,
877 struct nlattr **tca, int *errp)
878 {
879 int err;
880 struct nlattr *kind = tca[TCA_KIND];
881 struct Qdisc *sch;
882 struct Qdisc_ops *ops;
883 struct qdisc_size_table *stab;
884
885 ops = qdisc_lookup_ops(kind);
886 #ifdef CONFIG_MODULES
887 if (ops == NULL && kind != NULL) {
888 char name[IFNAMSIZ];
889 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
890 /* We dropped the RTNL semaphore in order to
891 * perform the module load. So, even if we
892 * succeeded in loading the module we have to
893 * tell the caller to replay the request. We
894 * indicate this using -EAGAIN.
895 * We replay the request because the device may
896 * go away in the mean time.
897 */
898 rtnl_unlock();
899 request_module("sch_%s", name);
900 rtnl_lock();
901 ops = qdisc_lookup_ops(kind);
902 if (ops != NULL) {
903 /* We will try again qdisc_lookup_ops,
904 * so don't keep a reference.
905 */
906 module_put(ops->owner);
907 err = -EAGAIN;
908 goto err_out;
909 }
910 }
911 }
912 #endif
913
914 err = -ENOENT;
915 if (ops == NULL)
916 goto err_out;
917
918 sch = qdisc_alloc(dev_queue, ops);
919 if (IS_ERR(sch)) {
920 err = PTR_ERR(sch);
921 goto err_out2;
922 }
923
924 sch->parent = parent;
925
926 if (handle == TC_H_INGRESS) {
927 sch->flags |= TCQ_F_INGRESS;
928 handle = TC_H_MAKE(TC_H_INGRESS, 0);
929 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
930 } else {
931 if (handle == 0) {
932 handle = qdisc_alloc_handle(dev);
933 err = -ENOMEM;
934 if (handle == 0)
935 goto err_out3;
936 }
937 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
938 if (!netif_is_multiqueue(dev))
939 sch->flags |= TCQ_F_ONETXQUEUE;
940 }
941
942 sch->handle = handle;
943
944 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
945 if (tca[TCA_STAB]) {
946 stab = qdisc_get_stab(tca[TCA_STAB]);
947 if (IS_ERR(stab)) {
948 err = PTR_ERR(stab);
949 goto err_out4;
950 }
951 rcu_assign_pointer(sch->stab, stab);
952 }
953 if (tca[TCA_RATE]) {
954 spinlock_t *root_lock;
955
956 err = -EOPNOTSUPP;
957 if (sch->flags & TCQ_F_MQROOT)
958 goto err_out4;
959
960 if ((sch->parent != TC_H_ROOT) &&
961 !(sch->flags & TCQ_F_INGRESS) &&
962 (!p || !(p->flags & TCQ_F_MQROOT)))
963 root_lock = qdisc_root_sleeping_lock(sch);
964 else
965 root_lock = qdisc_lock(sch);
966
967 err = gen_new_estimator(&sch->bstats, &sch->rate_est,
968 root_lock, tca[TCA_RATE]);
969 if (err)
970 goto err_out4;
971 }
972
973 qdisc_list_add(sch);
974
975 return sch;
976 }
977 err_out3:
978 dev_put(dev);
979 kfree((char *) sch - sch->padded);
980 err_out2:
981 module_put(ops->owner);
982 err_out:
983 *errp = err;
984 return NULL;
985
986 err_out4:
987 /*
988 * Any broken qdiscs that would require a ops->reset() here?
989 * The qdisc was never in action so it shouldn't be necessary.
990 */
991 qdisc_put_stab(rtnl_dereference(sch->stab));
992 if (ops->destroy)
993 ops->destroy(sch);
994 goto err_out3;
995 }
996
997 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
998 {
999 struct qdisc_size_table *ostab, *stab = NULL;
1000 int err = 0;
1001
1002 if (tca[TCA_OPTIONS]) {
1003 if (sch->ops->change == NULL)
1004 return -EINVAL;
1005 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
1006 if (err)
1007 return err;
1008 }
1009
1010 if (tca[TCA_STAB]) {
1011 stab = qdisc_get_stab(tca[TCA_STAB]);
1012 if (IS_ERR(stab))
1013 return PTR_ERR(stab);
1014 }
1015
1016 ostab = rtnl_dereference(sch->stab);
1017 rcu_assign_pointer(sch->stab, stab);
1018 qdisc_put_stab(ostab);
1019
1020 if (tca[TCA_RATE]) {
1021 /* NB: ignores errors from replace_estimator
1022 because change can't be undone. */
1023 if (sch->flags & TCQ_F_MQROOT)
1024 goto out;
1025 gen_replace_estimator(&sch->bstats, &sch->rate_est,
1026 qdisc_root_sleeping_lock(sch),
1027 tca[TCA_RATE]);
1028 }
1029 out:
1030 return 0;
1031 }
1032
1033 struct check_loop_arg {
1034 struct qdisc_walker w;
1035 struct Qdisc *p;
1036 int depth;
1037 };
1038
1039 static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
1040
1041 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1042 {
1043 struct check_loop_arg arg;
1044
1045 if (q->ops->cl_ops == NULL)
1046 return 0;
1047
1048 arg.w.stop = arg.w.skip = arg.w.count = 0;
1049 arg.w.fn = check_loop_fn;
1050 arg.depth = depth;
1051 arg.p = p;
1052 q->ops->cl_ops->walk(q, &arg.w);
1053 return arg.w.stop ? -ELOOP : 0;
1054 }
1055
1056 static int
1057 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1058 {
1059 struct Qdisc *leaf;
1060 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1061 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1062
1063 leaf = cops->leaf(q, cl);
1064 if (leaf) {
1065 if (leaf == arg->p || arg->depth > 7)
1066 return -ELOOP;
1067 return check_loop(leaf, arg->p, arg->depth + 1);
1068 }
1069 return 0;
1070 }
1071
1072 /*
1073 * Delete/get qdisc.
1074 */
1075
1076 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1077 {
1078 struct net *net = sock_net(skb->sk);
1079 struct tcmsg *tcm = nlmsg_data(n);
1080 struct nlattr *tca[TCA_MAX + 1];
1081 struct net_device *dev;
1082 u32 clid;
1083 struct Qdisc *q = NULL;
1084 struct Qdisc *p = NULL;
1085 int err;
1086
1087 if ((n->nlmsg_type != RTM_GETQDISC) &&
1088 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1089 return -EPERM;
1090
1091 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1092 if (err < 0)
1093 return err;
1094
1095 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1096 if (!dev)
1097 return -ENODEV;
1098
1099 clid = tcm->tcm_parent;
1100 if (clid) {
1101 if (clid != TC_H_ROOT) {
1102 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1103 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1104 if (!p)
1105 return -ENOENT;
1106 q = qdisc_leaf(p, clid);
1107 } else if (dev_ingress_queue(dev)) {
1108 q = dev_ingress_queue(dev)->qdisc_sleeping;
1109 }
1110 } else {
1111 q = dev->qdisc;
1112 }
1113 if (!q)
1114 return -ENOENT;
1115
1116 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1117 return -EINVAL;
1118 } else {
1119 q = qdisc_lookup(dev, tcm->tcm_handle);
1120 if (!q)
1121 return -ENOENT;
1122 }
1123
1124 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1125 return -EINVAL;
1126
1127 if (n->nlmsg_type == RTM_DELQDISC) {
1128 if (!clid)
1129 return -EINVAL;
1130 if (q->handle == 0)
1131 return -ENOENT;
1132 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1133 if (err != 0)
1134 return err;
1135 } else {
1136 qdisc_notify(net, skb, n, clid, NULL, q);
1137 }
1138 return 0;
1139 }
1140
1141 /*
1142 * Create/change qdisc.
1143 */
1144
1145 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1146 {
1147 struct net *net = sock_net(skb->sk);
1148 struct tcmsg *tcm;
1149 struct nlattr *tca[TCA_MAX + 1];
1150 struct net_device *dev;
1151 u32 clid;
1152 struct Qdisc *q, *p;
1153 int err;
1154
1155 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1156 return -EPERM;
1157
1158 replay:
1159 /* Reinit, just in case something touches this. */
1160 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1161 if (err < 0)
1162 return err;
1163
1164 tcm = nlmsg_data(n);
1165 clid = tcm->tcm_parent;
1166 q = p = NULL;
1167
1168 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1169 if (!dev)
1170 return -ENODEV;
1171
1172
1173 if (clid) {
1174 if (clid != TC_H_ROOT) {
1175 if (clid != TC_H_INGRESS) {
1176 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1177 if (!p)
1178 return -ENOENT;
1179 q = qdisc_leaf(p, clid);
1180 } else if (dev_ingress_queue_create(dev)) {
1181 q = dev_ingress_queue(dev)->qdisc_sleeping;
1182 }
1183 } else {
1184 q = dev->qdisc;
1185 }
1186
1187 /* It may be default qdisc, ignore it */
1188 if (q && q->handle == 0)
1189 q = NULL;
1190
1191 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1192 if (tcm->tcm_handle) {
1193 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1194 return -EEXIST;
1195 if (TC_H_MIN(tcm->tcm_handle))
1196 return -EINVAL;
1197 q = qdisc_lookup(dev, tcm->tcm_handle);
1198 if (!q)
1199 goto create_n_graft;
1200 if (n->nlmsg_flags & NLM_F_EXCL)
1201 return -EEXIST;
1202 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1203 return -EINVAL;
1204 if (q == p ||
1205 (p && check_loop(q, p, 0)))
1206 return -ELOOP;
1207 atomic_inc(&q->refcnt);
1208 goto graft;
1209 } else {
1210 if (!q)
1211 goto create_n_graft;
1212
1213 /* This magic test requires explanation.
1214 *
1215 * We know, that some child q is already
1216 * attached to this parent and have choice:
1217 * either to change it or to create/graft new one.
1218 *
1219 * 1. We are allowed to create/graft only
1220 * if CREATE and REPLACE flags are set.
1221 *
1222 * 2. If EXCL is set, requestor wanted to say,
1223 * that qdisc tcm_handle is not expected
1224 * to exist, so that we choose create/graft too.
1225 *
1226 * 3. The last case is when no flags are set.
1227 * Alas, it is sort of hole in API, we
1228 * cannot decide what to do unambiguously.
1229 * For now we select create/graft, if
1230 * user gave KIND, which does not match existing.
1231 */
1232 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1233 (n->nlmsg_flags & NLM_F_REPLACE) &&
1234 ((n->nlmsg_flags & NLM_F_EXCL) ||
1235 (tca[TCA_KIND] &&
1236 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1237 goto create_n_graft;
1238 }
1239 }
1240 } else {
1241 if (!tcm->tcm_handle)
1242 return -EINVAL;
1243 q = qdisc_lookup(dev, tcm->tcm_handle);
1244 }
1245
1246 /* Change qdisc parameters */
1247 if (q == NULL)
1248 return -ENOENT;
1249 if (n->nlmsg_flags & NLM_F_EXCL)
1250 return -EEXIST;
1251 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1252 return -EINVAL;
1253 err = qdisc_change(q, tca);
1254 if (err == 0)
1255 qdisc_notify(net, skb, n, clid, NULL, q);
1256 return err;
1257
1258 create_n_graft:
1259 if (!(n->nlmsg_flags & NLM_F_CREATE))
1260 return -ENOENT;
1261 if (clid == TC_H_INGRESS) {
1262 if (dev_ingress_queue(dev))
1263 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1264 tcm->tcm_parent, tcm->tcm_parent,
1265 tca, &err);
1266 else
1267 err = -ENOENT;
1268 } else {
1269 struct netdev_queue *dev_queue;
1270
1271 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1272 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1273 else if (p)
1274 dev_queue = p->dev_queue;
1275 else
1276 dev_queue = netdev_get_tx_queue(dev, 0);
1277
1278 q = qdisc_create(dev, dev_queue, p,
1279 tcm->tcm_parent, tcm->tcm_handle,
1280 tca, &err);
1281 }
1282 if (q == NULL) {
1283 if (err == -EAGAIN)
1284 goto replay;
1285 return err;
1286 }
1287
1288 graft:
1289 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1290 if (err) {
1291 if (q)
1292 qdisc_destroy(q);
1293 return err;
1294 }
1295
1296 return 0;
1297 }
1298
1299 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1300 u32 portid, u32 seq, u16 flags, int event)
1301 {
1302 struct tcmsg *tcm;
1303 struct nlmsghdr *nlh;
1304 unsigned char *b = skb_tail_pointer(skb);
1305 struct gnet_dump d;
1306 struct qdisc_size_table *stab;
1307
1308 cond_resched();
1309 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1310 if (!nlh)
1311 goto out_nlmsg_trim;
1312 tcm = nlmsg_data(nlh);
1313 tcm->tcm_family = AF_UNSPEC;
1314 tcm->tcm__pad1 = 0;
1315 tcm->tcm__pad2 = 0;
1316 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1317 tcm->tcm_parent = clid;
1318 tcm->tcm_handle = q->handle;
1319 tcm->tcm_info = atomic_read(&q->refcnt);
1320 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1321 goto nla_put_failure;
1322 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1323 goto nla_put_failure;
1324 q->qstats.qlen = q->q.qlen;
1325
1326 stab = rtnl_dereference(q->stab);
1327 if (stab && qdisc_dump_stab(skb, stab) < 0)
1328 goto nla_put_failure;
1329
1330 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1331 qdisc_root_sleeping_lock(q), &d) < 0)
1332 goto nla_put_failure;
1333
1334 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1335 goto nla_put_failure;
1336
1337 if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
1338 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1339 gnet_stats_copy_queue(&d, &q->qstats) < 0)
1340 goto nla_put_failure;
1341
1342 if (gnet_stats_finish_copy(&d) < 0)
1343 goto nla_put_failure;
1344
1345 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1346 return skb->len;
1347
1348 out_nlmsg_trim:
1349 nla_put_failure:
1350 nlmsg_trim(skb, b);
1351 return -1;
1352 }
1353
1354 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1355 {
1356 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1357 }
1358
1359 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1360 struct nlmsghdr *n, u32 clid,
1361 struct Qdisc *old, struct Qdisc *new)
1362 {
1363 struct sk_buff *skb;
1364 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1365
1366 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1367 if (!skb)
1368 return -ENOBUFS;
1369
1370 if (old && !tc_qdisc_dump_ignore(old)) {
1371 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1372 0, RTM_DELQDISC) < 0)
1373 goto err_out;
1374 }
1375 if (new && !tc_qdisc_dump_ignore(new)) {
1376 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1377 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1378 goto err_out;
1379 }
1380
1381 if (skb->len)
1382 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1383 n->nlmsg_flags & NLM_F_ECHO);
1384
1385 err_out:
1386 kfree_skb(skb);
1387 return -EINVAL;
1388 }
1389
1390 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1391 struct netlink_callback *cb,
1392 int *q_idx_p, int s_q_idx)
1393 {
1394 int ret = 0, q_idx = *q_idx_p;
1395 struct Qdisc *q;
1396
1397 if (!root)
1398 return 0;
1399
1400 q = root;
1401 if (q_idx < s_q_idx) {
1402 q_idx++;
1403 } else {
1404 if (!tc_qdisc_dump_ignore(q) &&
1405 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1406 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1407 goto done;
1408 q_idx++;
1409 }
1410 list_for_each_entry(q, &root->list, list) {
1411 if (q_idx < s_q_idx) {
1412 q_idx++;
1413 continue;
1414 }
1415 if (!tc_qdisc_dump_ignore(q) &&
1416 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1417 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1418 goto done;
1419 q_idx++;
1420 }
1421
1422 out:
1423 *q_idx_p = q_idx;
1424 return ret;
1425 done:
1426 ret = -1;
1427 goto out;
1428 }
1429
1430 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1431 {
1432 struct net *net = sock_net(skb->sk);
1433 int idx, q_idx;
1434 int s_idx, s_q_idx;
1435 struct net_device *dev;
1436
1437 s_idx = cb->args[0];
1438 s_q_idx = q_idx = cb->args[1];
1439
1440 idx = 0;
1441 ASSERT_RTNL();
1442 for_each_netdev(net, dev) {
1443 struct netdev_queue *dev_queue;
1444
1445 if (idx < s_idx)
1446 goto cont;
1447 if (idx > s_idx)
1448 s_q_idx = 0;
1449 q_idx = 0;
1450
1451 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1452 goto done;
1453
1454 dev_queue = dev_ingress_queue(dev);
1455 if (dev_queue &&
1456 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1457 &q_idx, s_q_idx) < 0)
1458 goto done;
1459
1460 cont:
1461 idx++;
1462 }
1463
1464 done:
1465 cb->args[0] = idx;
1466 cb->args[1] = q_idx;
1467
1468 return skb->len;
1469 }
1470
1471
1472
1473 /************************************************
1474 * Traffic classes manipulation. *
1475 ************************************************/
1476
1477
1478
1479 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n)
1480 {
1481 struct net *net = sock_net(skb->sk);
1482 struct tcmsg *tcm = nlmsg_data(n);
1483 struct nlattr *tca[TCA_MAX + 1];
1484 struct net_device *dev;
1485 struct Qdisc *q = NULL;
1486 const struct Qdisc_class_ops *cops;
1487 unsigned long cl = 0;
1488 unsigned long new_cl;
1489 u32 portid;
1490 u32 clid;
1491 u32 qid;
1492 int err;
1493
1494 if ((n->nlmsg_type != RTM_GETTCLASS) &&
1495 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1496 return -EPERM;
1497
1498 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1499 if (err < 0)
1500 return err;
1501
1502 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1503 if (!dev)
1504 return -ENODEV;
1505
1506 /*
1507 parent == TC_H_UNSPEC - unspecified parent.
1508 parent == TC_H_ROOT - class is root, which has no parent.
1509 parent == X:0 - parent is root class.
1510 parent == X:Y - parent is a node in hierarchy.
1511 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1512
1513 handle == 0:0 - generate handle from kernel pool.
1514 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1515 handle == X:Y - clear.
1516 handle == X:0 - root class.
1517 */
1518
1519 /* Step 1. Determine qdisc handle X:0 */
1520
1521 portid = tcm->tcm_parent;
1522 clid = tcm->tcm_handle;
1523 qid = TC_H_MAJ(clid);
1524
1525 if (portid != TC_H_ROOT) {
1526 u32 qid1 = TC_H_MAJ(portid);
1527
1528 if (qid && qid1) {
1529 /* If both majors are known, they must be identical. */
1530 if (qid != qid1)
1531 return -EINVAL;
1532 } else if (qid1) {
1533 qid = qid1;
1534 } else if (qid == 0)
1535 qid = dev->qdisc->handle;
1536
1537 /* Now qid is genuine qdisc handle consistent
1538 * both with parent and child.
1539 *
1540 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1541 */
1542 if (portid)
1543 portid = TC_H_MAKE(qid, portid);
1544 } else {
1545 if (qid == 0)
1546 qid = dev->qdisc->handle;
1547 }
1548
1549 /* OK. Locate qdisc */
1550 q = qdisc_lookup(dev, qid);
1551 if (!q)
1552 return -ENOENT;
1553
1554 /* An check that it supports classes */
1555 cops = q->ops->cl_ops;
1556 if (cops == NULL)
1557 return -EINVAL;
1558
1559 /* Now try to get class */
1560 if (clid == 0) {
1561 if (portid == TC_H_ROOT)
1562 clid = qid;
1563 } else
1564 clid = TC_H_MAKE(qid, clid);
1565
1566 if (clid)
1567 cl = cops->get(q, clid);
1568
1569 if (cl == 0) {
1570 err = -ENOENT;
1571 if (n->nlmsg_type != RTM_NEWTCLASS ||
1572 !(n->nlmsg_flags & NLM_F_CREATE))
1573 goto out;
1574 } else {
1575 switch (n->nlmsg_type) {
1576 case RTM_NEWTCLASS:
1577 err = -EEXIST;
1578 if (n->nlmsg_flags & NLM_F_EXCL)
1579 goto out;
1580 break;
1581 case RTM_DELTCLASS:
1582 err = -EOPNOTSUPP;
1583 if (cops->delete)
1584 err = cops->delete(q, cl);
1585 if (err == 0)
1586 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1587 goto out;
1588 case RTM_GETTCLASS:
1589 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1590 goto out;
1591 default:
1592 err = -EINVAL;
1593 goto out;
1594 }
1595 }
1596
1597 new_cl = cl;
1598 err = -EOPNOTSUPP;
1599 if (cops->change)
1600 err = cops->change(q, clid, portid, tca, &new_cl);
1601 if (err == 0)
1602 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1603
1604 out:
1605 if (cl)
1606 cops->put(q, cl);
1607
1608 return err;
1609 }
1610
1611
1612 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1613 unsigned long cl,
1614 u32 portid, u32 seq, u16 flags, int event)
1615 {
1616 struct tcmsg *tcm;
1617 struct nlmsghdr *nlh;
1618 unsigned char *b = skb_tail_pointer(skb);
1619 struct gnet_dump d;
1620 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1621
1622 cond_resched();
1623 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1624 if (!nlh)
1625 goto out_nlmsg_trim;
1626 tcm = nlmsg_data(nlh);
1627 tcm->tcm_family = AF_UNSPEC;
1628 tcm->tcm__pad1 = 0;
1629 tcm->tcm__pad2 = 0;
1630 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1631 tcm->tcm_parent = q->handle;
1632 tcm->tcm_handle = q->handle;
1633 tcm->tcm_info = 0;
1634 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1635 goto nla_put_failure;
1636 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1637 goto nla_put_failure;
1638
1639 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1640 qdisc_root_sleeping_lock(q), &d) < 0)
1641 goto nla_put_failure;
1642
1643 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1644 goto nla_put_failure;
1645
1646 if (gnet_stats_finish_copy(&d) < 0)
1647 goto nla_put_failure;
1648
1649 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1650 return skb->len;
1651
1652 out_nlmsg_trim:
1653 nla_put_failure:
1654 nlmsg_trim(skb, b);
1655 return -1;
1656 }
1657
1658 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1659 struct nlmsghdr *n, struct Qdisc *q,
1660 unsigned long cl, int event)
1661 {
1662 struct sk_buff *skb;
1663 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1664
1665 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1666 if (!skb)
1667 return -ENOBUFS;
1668
1669 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1670 kfree_skb(skb);
1671 return -EINVAL;
1672 }
1673
1674 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1675 n->nlmsg_flags & NLM_F_ECHO);
1676 }
1677
1678 struct qdisc_dump_args {
1679 struct qdisc_walker w;
1680 struct sk_buff *skb;
1681 struct netlink_callback *cb;
1682 };
1683
1684 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1685 {
1686 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1687
1688 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1689 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1690 }
1691
1692 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1693 struct tcmsg *tcm, struct netlink_callback *cb,
1694 int *t_p, int s_t)
1695 {
1696 struct qdisc_dump_args arg;
1697
1698 if (tc_qdisc_dump_ignore(q) ||
1699 *t_p < s_t || !q->ops->cl_ops ||
1700 (tcm->tcm_parent &&
1701 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1702 (*t_p)++;
1703 return 0;
1704 }
1705 if (*t_p > s_t)
1706 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1707 arg.w.fn = qdisc_class_dump;
1708 arg.skb = skb;
1709 arg.cb = cb;
1710 arg.w.stop = 0;
1711 arg.w.skip = cb->args[1];
1712 arg.w.count = 0;
1713 q->ops->cl_ops->walk(q, &arg.w);
1714 cb->args[1] = arg.w.count;
1715 if (arg.w.stop)
1716 return -1;
1717 (*t_p)++;
1718 return 0;
1719 }
1720
1721 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1722 struct tcmsg *tcm, struct netlink_callback *cb,
1723 int *t_p, int s_t)
1724 {
1725 struct Qdisc *q;
1726
1727 if (!root)
1728 return 0;
1729
1730 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1731 return -1;
1732
1733 list_for_each_entry(q, &root->list, list) {
1734 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1735 return -1;
1736 }
1737
1738 return 0;
1739 }
1740
1741 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1742 {
1743 struct tcmsg *tcm = nlmsg_data(cb->nlh);
1744 struct net *net = sock_net(skb->sk);
1745 struct netdev_queue *dev_queue;
1746 struct net_device *dev;
1747 int t, s_t;
1748
1749 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1750 return 0;
1751 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1752 if (!dev)
1753 return 0;
1754
1755 s_t = cb->args[0];
1756 t = 0;
1757
1758 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1759 goto done;
1760
1761 dev_queue = dev_ingress_queue(dev);
1762 if (dev_queue &&
1763 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1764 &t, s_t) < 0)
1765 goto done;
1766
1767 done:
1768 cb->args[0] = t;
1769
1770 dev_put(dev);
1771 return skb->len;
1772 }
1773
1774 /* Main classifier routine: scans classifier chain attached
1775 * to this qdisc, (optionally) tests for protocol and asks
1776 * specific classifiers.
1777 */
1778 int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
1779 struct tcf_result *res)
1780 {
1781 __be16 protocol = skb->protocol;
1782 int err;
1783
1784 for (; tp; tp = tp->next) {
1785 if (tp->protocol != protocol &&
1786 tp->protocol != htons(ETH_P_ALL))
1787 continue;
1788 err = tp->classify(skb, tp, res);
1789
1790 if (err >= 0) {
1791 #ifdef CONFIG_NET_CLS_ACT
1792 if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
1793 skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
1794 #endif
1795 return err;
1796 }
1797 }
1798 return -1;
1799 }
1800 EXPORT_SYMBOL(tc_classify_compat);
1801
1802 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1803 struct tcf_result *res)
1804 {
1805 int err = 0;
1806 #ifdef CONFIG_NET_CLS_ACT
1807 const struct tcf_proto *otp = tp;
1808 reclassify:
1809 #endif
1810
1811 err = tc_classify_compat(skb, tp, res);
1812 #ifdef CONFIG_NET_CLS_ACT
1813 if (err == TC_ACT_RECLASSIFY) {
1814 u32 verd = G_TC_VERD(skb->tc_verd);
1815 tp = otp;
1816
1817 if (verd++ >= MAX_REC_LOOP) {
1818 net_notice_ratelimited("%s: packet reclassify loop rule prio %u protocol %02x\n",
1819 tp->q->ops->id,
1820 tp->prio & 0xffff,
1821 ntohs(tp->protocol));
1822 return TC_ACT_SHOT;
1823 }
1824 skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
1825 goto reclassify;
1826 }
1827 #endif
1828 return err;
1829 }
1830 EXPORT_SYMBOL(tc_classify);
1831
1832 void tcf_destroy(struct tcf_proto *tp)
1833 {
1834 tp->ops->destroy(tp);
1835 module_put(tp->ops->owner);
1836 kfree(tp);
1837 }
1838
1839 void tcf_destroy_chain(struct tcf_proto **fl)
1840 {
1841 struct tcf_proto *tp;
1842
1843 while ((tp = *fl) != NULL) {
1844 *fl = tp->next;
1845 tcf_destroy(tp);
1846 }
1847 }
1848 EXPORT_SYMBOL(tcf_destroy_chain);
1849
1850 #ifdef CONFIG_PROC_FS
1851 static int psched_show(struct seq_file *seq, void *v)
1852 {
1853 struct timespec ts;
1854
1855 hrtimer_get_res(CLOCK_MONOTONIC, &ts);
1856 seq_printf(seq, "%08x %08x %08x %08x\n",
1857 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1858 1000000,
1859 (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
1860
1861 return 0;
1862 }
1863
1864 static int psched_open(struct inode *inode, struct file *file)
1865 {
1866 return single_open(file, psched_show, NULL);
1867 }
1868
1869 static const struct file_operations psched_fops = {
1870 .owner = THIS_MODULE,
1871 .open = psched_open,
1872 .read = seq_read,
1873 .llseek = seq_lseek,
1874 .release = single_release,
1875 };
1876
1877 static int __net_init psched_net_init(struct net *net)
1878 {
1879 struct proc_dir_entry *e;
1880
1881 e = proc_create("psched", 0, net->proc_net, &psched_fops);
1882 if (e == NULL)
1883 return -ENOMEM;
1884
1885 return 0;
1886 }
1887
1888 static void __net_exit psched_net_exit(struct net *net)
1889 {
1890 remove_proc_entry("psched", net->proc_net);
1891 }
1892 #else
1893 static int __net_init psched_net_init(struct net *net)
1894 {
1895 return 0;
1896 }
1897
1898 static void __net_exit psched_net_exit(struct net *net)
1899 {
1900 }
1901 #endif
1902
1903 static struct pernet_operations psched_net_ops = {
1904 .init = psched_net_init,
1905 .exit = psched_net_exit,
1906 };
1907
1908 static int __init pktsched_init(void)
1909 {
1910 int err;
1911
1912 err = register_pernet_subsys(&psched_net_ops);
1913 if (err) {
1914 pr_err("pktsched_init: "
1915 "cannot initialize per netns operations\n");
1916 return err;
1917 }
1918
1919 register_qdisc(&pfifo_fast_ops);
1920 register_qdisc(&pfifo_qdisc_ops);
1921 register_qdisc(&bfifo_qdisc_ops);
1922 register_qdisc(&pfifo_head_drop_qdisc_ops);
1923 register_qdisc(&mq_qdisc_ops);
1924
1925 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1926 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1927 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1928 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1929 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1930 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1931
1932 return 0;
1933 }
1934
1935 subsys_initcall(pktsched_init);
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