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mm: Initialize error in shmem_file_aio_read()
[linux/fpc-iii.git] / net / sched / sch_api.c
bloba0b84e0e22deb4c9e998499b1e202ebaafda95f8
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(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) && !capable(CAP_NET_ADMIN))
1088 return -EPERM;
1089
1090 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1091 if (err < 0)
1092 return err;
1093
1094 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1095 if (!dev)
1096 return -ENODEV;
1097
1098 clid = tcm->tcm_parent;
1099 if (clid) {
1100 if (clid != TC_H_ROOT) {
1101 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1102 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1103 if (!p)
1104 return -ENOENT;
1105 q = qdisc_leaf(p, clid);
1106 } else if (dev_ingress_queue(dev)) {
1107 q = dev_ingress_queue(dev)->qdisc_sleeping;
1108 }
1109 } else {
1110 q = dev->qdisc;
1111 }
1112 if (!q)
1113 return -ENOENT;
1114
1115 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1116 return -EINVAL;
1117 } else {
1118 q = qdisc_lookup(dev, tcm->tcm_handle);
1119 if (!q)
1120 return -ENOENT;
1121 }
1122
1123 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1124 return -EINVAL;
1125
1126 if (n->nlmsg_type == RTM_DELQDISC) {
1127 if (!clid)
1128 return -EINVAL;
1129 if (q->handle == 0)
1130 return -ENOENT;
1131 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1132 if (err != 0)
1133 return err;
1134 } else {
1135 qdisc_notify(net, skb, n, clid, NULL, q);
1136 }
1137 return 0;
1138 }
1139
1140 /*
1141 * Create/change qdisc.
1142 */
1143
1144 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1145 {
1146 struct net *net = sock_net(skb->sk);
1147 struct tcmsg *tcm;
1148 struct nlattr *tca[TCA_MAX + 1];
1149 struct net_device *dev;
1150 u32 clid;
1151 struct Qdisc *q, *p;
1152 int err;
1153
1154 if (!capable(CAP_NET_ADMIN))
1155 return -EPERM;
1156
1157 replay:
1158 /* Reinit, just in case something touches this. */
1159 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1160 if (err < 0)
1161 return err;
1162
1163 tcm = nlmsg_data(n);
1164 clid = tcm->tcm_parent;
1165 q = p = NULL;
1166
1167 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1168 if (!dev)
1169 return -ENODEV;
1170
1171
1172 if (clid) {
1173 if (clid != TC_H_ROOT) {
1174 if (clid != TC_H_INGRESS) {
1175 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1176 if (!p)
1177 return -ENOENT;
1178 q = qdisc_leaf(p, clid);
1179 } else if (dev_ingress_queue_create(dev)) {
1180 q = dev_ingress_queue(dev)->qdisc_sleeping;
1181 }
1182 } else {
1183 q = dev->qdisc;
1184 }
1185
1186 /* It may be default qdisc, ignore it */
1187 if (q && q->handle == 0)
1188 q = NULL;
1189
1190 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1191 if (tcm->tcm_handle) {
1192 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1193 return -EEXIST;
1194 if (TC_H_MIN(tcm->tcm_handle))
1195 return -EINVAL;
1196 q = qdisc_lookup(dev, tcm->tcm_handle);
1197 if (!q)
1198 goto create_n_graft;
1199 if (n->nlmsg_flags & NLM_F_EXCL)
1200 return -EEXIST;
1201 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1202 return -EINVAL;
1203 if (q == p ||
1204 (p && check_loop(q, p, 0)))
1205 return -ELOOP;
1206 atomic_inc(&q->refcnt);
1207 goto graft;
1208 } else {
1209 if (!q)
1210 goto create_n_graft;
1211
1212 /* This magic test requires explanation.
1213 *
1214 * We know, that some child q is already
1215 * attached to this parent and have choice:
1216 * either to change it or to create/graft new one.
1217 *
1218 * 1. We are allowed to create/graft only
1219 * if CREATE and REPLACE flags are set.
1220 *
1221 * 2. If EXCL is set, requestor wanted to say,
1222 * that qdisc tcm_handle is not expected
1223 * to exist, so that we choose create/graft too.
1224 *
1225 * 3. The last case is when no flags are set.
1226 * Alas, it is sort of hole in API, we
1227 * cannot decide what to do unambiguously.
1228 * For now we select create/graft, if
1229 * user gave KIND, which does not match existing.
1230 */
1231 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1232 (n->nlmsg_flags & NLM_F_REPLACE) &&
1233 ((n->nlmsg_flags & NLM_F_EXCL) ||
1234 (tca[TCA_KIND] &&
1235 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1236 goto create_n_graft;
1237 }
1238 }
1239 } else {
1240 if (!tcm->tcm_handle)
1241 return -EINVAL;
1242 q = qdisc_lookup(dev, tcm->tcm_handle);
1243 }
1244
1245 /* Change qdisc parameters */
1246 if (q == NULL)
1247 return -ENOENT;
1248 if (n->nlmsg_flags & NLM_F_EXCL)
1249 return -EEXIST;
1250 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1251 return -EINVAL;
1252 err = qdisc_change(q, tca);
1253 if (err == 0)
1254 qdisc_notify(net, skb, n, clid, NULL, q);
1255 return err;
1256
1257 create_n_graft:
1258 if (!(n->nlmsg_flags & NLM_F_CREATE))
1259 return -ENOENT;
1260 if (clid == TC_H_INGRESS) {
1261 if (dev_ingress_queue(dev))
1262 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1263 tcm->tcm_parent, tcm->tcm_parent,
1264 tca, &err);
1265 else
1266 err = -ENOENT;
1267 } else {
1268 struct netdev_queue *dev_queue;
1269
1270 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1271 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1272 else if (p)
1273 dev_queue = p->dev_queue;
1274 else
1275 dev_queue = netdev_get_tx_queue(dev, 0);
1276
1277 q = qdisc_create(dev, dev_queue, p,
1278 tcm->tcm_parent, tcm->tcm_handle,
1279 tca, &err);
1280 }
1281 if (q == NULL) {
1282 if (err == -EAGAIN)
1283 goto replay;
1284 return err;
1285 }
1286
1287 graft:
1288 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1289 if (err) {
1290 if (q)
1291 qdisc_destroy(q);
1292 return err;
1293 }
1294
1295 return 0;
1296 }
1297
1298 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1299 u32 portid, u32 seq, u16 flags, int event)
1300 {
1301 struct tcmsg *tcm;
1302 struct nlmsghdr *nlh;
1303 unsigned char *b = skb_tail_pointer(skb);
1304 struct gnet_dump d;
1305 struct qdisc_size_table *stab;
1306
1307 cond_resched();
1308 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1309 if (!nlh)
1310 goto out_nlmsg_trim;
1311 tcm = nlmsg_data(nlh);
1312 tcm->tcm_family = AF_UNSPEC;
1313 tcm->tcm__pad1 = 0;
1314 tcm->tcm__pad2 = 0;
1315 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1316 tcm->tcm_parent = clid;
1317 tcm->tcm_handle = q->handle;
1318 tcm->tcm_info = atomic_read(&q->refcnt);
1319 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1320 goto nla_put_failure;
1321 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1322 goto nla_put_failure;
1323 q->qstats.qlen = q->q.qlen;
1324
1325 stab = rtnl_dereference(q->stab);
1326 if (stab && qdisc_dump_stab(skb, stab) < 0)
1327 goto nla_put_failure;
1328
1329 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1330 qdisc_root_sleeping_lock(q), &d) < 0)
1331 goto nla_put_failure;
1332
1333 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1334 goto nla_put_failure;
1335
1336 if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
1337 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1338 gnet_stats_copy_queue(&d, &q->qstats) < 0)
1339 goto nla_put_failure;
1340
1341 if (gnet_stats_finish_copy(&d) < 0)
1342 goto nla_put_failure;
1343
1344 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1345 return skb->len;
1346
1347 out_nlmsg_trim:
1348 nla_put_failure:
1349 nlmsg_trim(skb, b);
1350 return -1;
1351 }
1352
1353 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1354 {
1355 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1356 }
1357
1358 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1359 struct nlmsghdr *n, u32 clid,
1360 struct Qdisc *old, struct Qdisc *new)
1361 {
1362 struct sk_buff *skb;
1363 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1364
1365 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1366 if (!skb)
1367 return -ENOBUFS;
1368
1369 if (old && !tc_qdisc_dump_ignore(old)) {
1370 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1371 0, RTM_DELQDISC) < 0)
1372 goto err_out;
1373 }
1374 if (new && !tc_qdisc_dump_ignore(new)) {
1375 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1376 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1377 goto err_out;
1378 }
1379
1380 if (skb->len)
1381 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1382 n->nlmsg_flags & NLM_F_ECHO);
1383
1384 err_out:
1385 kfree_skb(skb);
1386 return -EINVAL;
1387 }
1388
1389 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1390 struct netlink_callback *cb,
1391 int *q_idx_p, int s_q_idx)
1392 {
1393 int ret = 0, q_idx = *q_idx_p;
1394 struct Qdisc *q;
1395
1396 if (!root)
1397 return 0;
1398
1399 q = root;
1400 if (q_idx < s_q_idx) {
1401 q_idx++;
1402 } else {
1403 if (!tc_qdisc_dump_ignore(q) &&
1404 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1405 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1406 goto done;
1407 q_idx++;
1408 }
1409 list_for_each_entry(q, &root->list, list) {
1410 if (q_idx < s_q_idx) {
1411 q_idx++;
1412 continue;
1413 }
1414 if (!tc_qdisc_dump_ignore(q) &&
1415 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1416 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1417 goto done;
1418 q_idx++;
1419 }
1420
1421 out:
1422 *q_idx_p = q_idx;
1423 return ret;
1424 done:
1425 ret = -1;
1426 goto out;
1427 }
1428
1429 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1430 {
1431 struct net *net = sock_net(skb->sk);
1432 int idx, q_idx;
1433 int s_idx, s_q_idx;
1434 struct net_device *dev;
1435
1436 s_idx = cb->args[0];
1437 s_q_idx = q_idx = cb->args[1];
1438
1439 idx = 0;
1440 ASSERT_RTNL();
1441 for_each_netdev(net, dev) {
1442 struct netdev_queue *dev_queue;
1443
1444 if (idx < s_idx)
1445 goto cont;
1446 if (idx > s_idx)
1447 s_q_idx = 0;
1448 q_idx = 0;
1449
1450 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1451 goto done;
1452
1453 dev_queue = dev_ingress_queue(dev);
1454 if (dev_queue &&
1455 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1456 &q_idx, s_q_idx) < 0)
1457 goto done;
1458
1459 cont:
1460 idx++;
1461 }
1462
1463 done:
1464 cb->args[0] = idx;
1465 cb->args[1] = q_idx;
1466
1467 return skb->len;
1468 }
1469
1470
1471
1472 /************************************************
1473 * Traffic classes manipulation. *
1474 ************************************************/
1475
1476
1477
1478 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n)
1479 {
1480 struct net *net = sock_net(skb->sk);
1481 struct tcmsg *tcm = nlmsg_data(n);
1482 struct nlattr *tca[TCA_MAX + 1];
1483 struct net_device *dev;
1484 struct Qdisc *q = NULL;
1485 const struct Qdisc_class_ops *cops;
1486 unsigned long cl = 0;
1487 unsigned long new_cl;
1488 u32 portid;
1489 u32 clid;
1490 u32 qid;
1491 int err;
1492
1493 if ((n->nlmsg_type != RTM_GETTCLASS) && !capable(CAP_NET_ADMIN))
1494 return -EPERM;
1495
1496 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1497 if (err < 0)
1498 return err;
1499
1500 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1501 if (!dev)
1502 return -ENODEV;
1503
1504 /*
1505 parent == TC_H_UNSPEC - unspecified parent.
1506 parent == TC_H_ROOT - class is root, which has no parent.
1507 parent == X:0 - parent is root class.
1508 parent == X:Y - parent is a node in hierarchy.
1509 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1510
1511 handle == 0:0 - generate handle from kernel pool.
1512 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1513 handle == X:Y - clear.
1514 handle == X:0 - root class.
1515 */
1516
1517 /* Step 1. Determine qdisc handle X:0 */
1518
1519 portid = tcm->tcm_parent;
1520 clid = tcm->tcm_handle;
1521 qid = TC_H_MAJ(clid);
1522
1523 if (portid != TC_H_ROOT) {
1524 u32 qid1 = TC_H_MAJ(portid);
1525
1526 if (qid && qid1) {
1527 /* If both majors are known, they must be identical. */
1528 if (qid != qid1)
1529 return -EINVAL;
1530 } else if (qid1) {
1531 qid = qid1;
1532 } else if (qid == 0)
1533 qid = dev->qdisc->handle;
1534
1535 /* Now qid is genuine qdisc handle consistent
1536 * both with parent and child.
1537 *
1538 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1539 */
1540 if (portid)
1541 portid = TC_H_MAKE(qid, portid);
1542 } else {
1543 if (qid == 0)
1544 qid = dev->qdisc->handle;
1545 }
1546
1547 /* OK. Locate qdisc */
1548 q = qdisc_lookup(dev, qid);
1549 if (!q)
1550 return -ENOENT;
1551
1552 /* An check that it supports classes */
1553 cops = q->ops->cl_ops;
1554 if (cops == NULL)
1555 return -EINVAL;
1556
1557 /* Now try to get class */
1558 if (clid == 0) {
1559 if (portid == TC_H_ROOT)
1560 clid = qid;
1561 } else
1562 clid = TC_H_MAKE(qid, clid);
1563
1564 if (clid)
1565 cl = cops->get(q, clid);
1566
1567 if (cl == 0) {
1568 err = -ENOENT;
1569 if (n->nlmsg_type != RTM_NEWTCLASS ||
1570 !(n->nlmsg_flags & NLM_F_CREATE))
1571 goto out;
1572 } else {
1573 switch (n->nlmsg_type) {
1574 case RTM_NEWTCLASS:
1575 err = -EEXIST;
1576 if (n->nlmsg_flags & NLM_F_EXCL)
1577 goto out;
1578 break;
1579 case RTM_DELTCLASS:
1580 err = -EOPNOTSUPP;
1581 if (cops->delete)
1582 err = cops->delete(q, cl);
1583 if (err == 0)
1584 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1585 goto out;
1586 case RTM_GETTCLASS:
1587 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1588 goto out;
1589 default:
1590 err = -EINVAL;
1591 goto out;
1592 }
1593 }
1594
1595 new_cl = cl;
1596 err = -EOPNOTSUPP;
1597 if (cops->change)
1598 err = cops->change(q, clid, portid, tca, &new_cl);
1599 if (err == 0)
1600 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1601
1602 out:
1603 if (cl)
1604 cops->put(q, cl);
1605
1606 return err;
1607 }
1608
1609
1610 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1611 unsigned long cl,
1612 u32 portid, u32 seq, u16 flags, int event)
1613 {
1614 struct tcmsg *tcm;
1615 struct nlmsghdr *nlh;
1616 unsigned char *b = skb_tail_pointer(skb);
1617 struct gnet_dump d;
1618 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1619
1620 cond_resched();
1621 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1622 if (!nlh)
1623 goto out_nlmsg_trim;
1624 tcm = nlmsg_data(nlh);
1625 tcm->tcm_family = AF_UNSPEC;
1626 tcm->tcm__pad1 = 0;
1627 tcm->tcm__pad2 = 0;
1628 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1629 tcm->tcm_parent = q->handle;
1630 tcm->tcm_handle = q->handle;
1631 tcm->tcm_info = 0;
1632 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1633 goto nla_put_failure;
1634 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1635 goto nla_put_failure;
1636
1637 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1638 qdisc_root_sleeping_lock(q), &d) < 0)
1639 goto nla_put_failure;
1640
1641 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1642 goto nla_put_failure;
1643
1644 if (gnet_stats_finish_copy(&d) < 0)
1645 goto nla_put_failure;
1646
1647 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1648 return skb->len;
1649
1650 out_nlmsg_trim:
1651 nla_put_failure:
1652 nlmsg_trim(skb, b);
1653 return -1;
1654 }
1655
1656 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1657 struct nlmsghdr *n, struct Qdisc *q,
1658 unsigned long cl, int event)
1659 {
1660 struct sk_buff *skb;
1661 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1662
1663 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1664 if (!skb)
1665 return -ENOBUFS;
1666
1667 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1668 kfree_skb(skb);
1669 return -EINVAL;
1670 }
1671
1672 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1673 n->nlmsg_flags & NLM_F_ECHO);
1674 }
1675
1676 struct qdisc_dump_args {
1677 struct qdisc_walker w;
1678 struct sk_buff *skb;
1679 struct netlink_callback *cb;
1680 };
1681
1682 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1683 {
1684 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1685
1686 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1687 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1688 }
1689
1690 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1691 struct tcmsg *tcm, struct netlink_callback *cb,
1692 int *t_p, int s_t)
1693 {
1694 struct qdisc_dump_args arg;
1695
1696 if (tc_qdisc_dump_ignore(q) ||
1697 *t_p < s_t || !q->ops->cl_ops ||
1698 (tcm->tcm_parent &&
1699 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1700 (*t_p)++;
1701 return 0;
1702 }
1703 if (*t_p > s_t)
1704 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1705 arg.w.fn = qdisc_class_dump;
1706 arg.skb = skb;
1707 arg.cb = cb;
1708 arg.w.stop = 0;
1709 arg.w.skip = cb->args[1];
1710 arg.w.count = 0;
1711 q->ops->cl_ops->walk(q, &arg.w);
1712 cb->args[1] = arg.w.count;
1713 if (arg.w.stop)
1714 return -1;
1715 (*t_p)++;
1716 return 0;
1717 }
1718
1719 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1720 struct tcmsg *tcm, struct netlink_callback *cb,
1721 int *t_p, int s_t)
1722 {
1723 struct Qdisc *q;
1724
1725 if (!root)
1726 return 0;
1727
1728 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1729 return -1;
1730
1731 list_for_each_entry(q, &root->list, list) {
1732 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1733 return -1;
1734 }
1735
1736 return 0;
1737 }
1738
1739 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1740 {
1741 struct tcmsg *tcm = nlmsg_data(cb->nlh);
1742 struct net *net = sock_net(skb->sk);
1743 struct netdev_queue *dev_queue;
1744 struct net_device *dev;
1745 int t, s_t;
1746
1747 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1748 return 0;
1749 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1750 if (!dev)
1751 return 0;
1752
1753 s_t = cb->args[0];
1754 t = 0;
1755
1756 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1757 goto done;
1758
1759 dev_queue = dev_ingress_queue(dev);
1760 if (dev_queue &&
1761 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1762 &t, s_t) < 0)
1763 goto done;
1764
1765 done:
1766 cb->args[0] = t;
1767
1768 dev_put(dev);
1769 return skb->len;
1770 }
1771
1772 /* Main classifier routine: scans classifier chain attached
1773 * to this qdisc, (optionally) tests for protocol and asks
1774 * specific classifiers.
1775 */
1776 int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
1777 struct tcf_result *res)
1778 {
1779 __be16 protocol = skb->protocol;
1780 int err;
1781
1782 for (; tp; tp = tp->next) {
1783 if (tp->protocol != protocol &&
1784 tp->protocol != htons(ETH_P_ALL))
1785 continue;
1786 err = tp->classify(skb, tp, res);
1787
1788 if (err >= 0) {
1789 #ifdef CONFIG_NET_CLS_ACT
1790 if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
1791 skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
1792 #endif
1793 return err;
1794 }
1795 }
1796 return -1;
1797 }
1798 EXPORT_SYMBOL(tc_classify_compat);
1799
1800 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1801 struct tcf_result *res)
1802 {
1803 int err = 0;
1804 #ifdef CONFIG_NET_CLS_ACT
1805 const struct tcf_proto *otp = tp;
1806 reclassify:
1807 #endif
1808
1809 err = tc_classify_compat(skb, tp, res);
1810 #ifdef CONFIG_NET_CLS_ACT
1811 if (err == TC_ACT_RECLASSIFY) {
1812 u32 verd = G_TC_VERD(skb->tc_verd);
1813 tp = otp;
1814
1815 if (verd++ >= MAX_REC_LOOP) {
1816 net_notice_ratelimited("%s: packet reclassify loop rule prio %u protocol %02x\n",
1817 tp->q->ops->id,
1818 tp->prio & 0xffff,
1819 ntohs(tp->protocol));
1820 return TC_ACT_SHOT;
1821 }
1822 skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
1823 goto reclassify;
1824 }
1825 #endif
1826 return err;
1827 }
1828 EXPORT_SYMBOL(tc_classify);
1829
1830 void tcf_destroy(struct tcf_proto *tp)
1831 {
1832 tp->ops->destroy(tp);
1833 module_put(tp->ops->owner);
1834 kfree(tp);
1835 }
1836
1837 void tcf_destroy_chain(struct tcf_proto **fl)
1838 {
1839 struct tcf_proto *tp;
1840
1841 while ((tp = *fl) != NULL) {
1842 *fl = tp->next;
1843 tcf_destroy(tp);
1844 }
1845 }
1846 EXPORT_SYMBOL(tcf_destroy_chain);
1847
1848 #ifdef CONFIG_PROC_FS
1849 static int psched_show(struct seq_file *seq, void *v)
1850 {
1851 struct timespec ts;
1852
1853 hrtimer_get_res(CLOCK_MONOTONIC, &ts);
1854 seq_printf(seq, "%08x %08x %08x %08x\n",
1855 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1856 1000000,
1857 (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
1858
1859 return 0;
1860 }
1861
1862 static int psched_open(struct inode *inode, struct file *file)
1863 {
1864 return single_open(file, psched_show, NULL);
1865 }
1866
1867 static const struct file_operations psched_fops = {
1868 .owner = THIS_MODULE,
1869 .open = psched_open,
1870 .read = seq_read,
1871 .llseek = seq_lseek,
1872 .release = single_release,
1873 };
1874
1875 static int __net_init psched_net_init(struct net *net)
1876 {
1877 struct proc_dir_entry *e;
1878
1879 e = proc_create("psched", 0, net->proc_net, &psched_fops);
1880 if (e == NULL)
1881 return -ENOMEM;
1882
1883 return 0;
1884 }
1885
1886 static void __net_exit psched_net_exit(struct net *net)
1887 {
1888 remove_proc_entry("psched", net->proc_net);
1889 }
1890 #else
1891 static int __net_init psched_net_init(struct net *net)
1892 {
1893 return 0;
1894 }
1895
1896 static void __net_exit psched_net_exit(struct net *net)
1897 {
1898 }
1899 #endif
1900
1901 static struct pernet_operations psched_net_ops = {
1902 .init = psched_net_init,
1903 .exit = psched_net_exit,
1904 };
1905
1906 static int __init pktsched_init(void)
1907 {
1908 int err;
1909
1910 err = register_pernet_subsys(&psched_net_ops);
1911 if (err) {
1912 pr_err("pktsched_init: "
1913 "cannot initialize per netns operations\n");
1914 return err;
1915 }
1916
1917 register_qdisc(&pfifo_fast_ops);
1918 register_qdisc(&pfifo_qdisc_ops);
1919 register_qdisc(&bfifo_qdisc_ops);
1920 register_qdisc(&pfifo_head_drop_qdisc_ops);
1921 register_qdisc(&mq_qdisc_ops);
1922
1923 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1924 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1925 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1926 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1927 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1928 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1929
1930 return 0;
1931 }
1932
1933 subsys_initcall(pktsched_init);
Linux with added FPC-III support