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51b968d3febb477be1e4183c8a94258c97fdcd18
[deliverable/linux.git] / net / sched / sch_api.c
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/uregister 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 /* We know handle. Find qdisc among all qdisc's attached to device
204 (root qdisc, all its children, children of children etc.)
205 */
206
207 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
208 {
209 struct Qdisc *q;
210
211 if (!(root->flags & TCQ_F_BUILTIN) &&
212 root->handle == handle)
213 return root;
214
215 list_for_each_entry(q, &root->list, list) {
216 if (q->handle == handle)
217 return q;
218 }
219 return NULL;
220 }
221
222 static void qdisc_list_add(struct Qdisc *q)
223 {
224 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
225 list_add_tail(&q->list, &qdisc_dev(q)->qdisc->list);
226 }
227
228 void qdisc_list_del(struct Qdisc *q)
229 {
230 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
231 list_del(&q->list);
232 }
233 EXPORT_SYMBOL(qdisc_list_del);
234
235 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
236 {
237 struct Qdisc *q;
238
239 q = qdisc_match_from_root(dev->qdisc, handle);
240 if (q)
241 goto out;
242
243 if (dev_ingress_queue(dev))
244 q = qdisc_match_from_root(
245 dev_ingress_queue(dev)->qdisc_sleeping,
246 handle);
247 out:
248 return q;
249 }
250
251 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
252 {
253 unsigned long cl;
254 struct Qdisc *leaf;
255 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
256
257 if (cops == NULL)
258 return NULL;
259 cl = cops->get(p, classid);
260
261 if (cl == 0)
262 return NULL;
263 leaf = cops->leaf(p, cl);
264 cops->put(p, cl);
265 return leaf;
266 }
267
268 /* Find queueing discipline by name */
269
270 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
271 {
272 struct Qdisc_ops *q = NULL;
273
274 if (kind) {
275 read_lock(&qdisc_mod_lock);
276 for (q = qdisc_base; q; q = q->next) {
277 if (nla_strcmp(kind, q->id) == 0) {
278 if (!try_module_get(q->owner))
279 q = NULL;
280 break;
281 }
282 }
283 read_unlock(&qdisc_mod_lock);
284 }
285 return q;
286 }
287
288 /* The linklayer setting were not transferred from iproute2, in older
289 * versions, and the rate tables lookup systems have been dropped in
290 * the kernel. To keep backward compatible with older iproute2 tc
291 * utils, we detect the linklayer setting by detecting if the rate
292 * table were modified.
293 *
294 * For linklayer ATM table entries, the rate table will be aligned to
295 * 48 bytes, thus some table entries will contain the same value. The
296 * mpu (min packet unit) is also encoded into the old rate table, thus
297 * starting from the mpu, we find low and high table entries for
298 * mapping this cell. If these entries contain the same value, when
299 * the rate tables have been modified for linklayer ATM.
300 *
301 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
302 * and then roundup to the next cell, calc the table entry one below,
303 * and compare.
304 */
305 static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
306 {
307 int low = roundup(r->mpu, 48);
308 int high = roundup(low+1, 48);
309 int cell_low = low >> r->cell_log;
310 int cell_high = (high >> r->cell_log) - 1;
311
312 /* rtab is too inaccurate at rates > 100Mbit/s */
313 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
314 pr_debug("TC linklayer: Giving up ATM detection\n");
315 return TC_LINKLAYER_ETHERNET;
316 }
317
318 if ((cell_high > cell_low) && (cell_high < 256)
319 && (rtab[cell_low] == rtab[cell_high])) {
320 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
321 cell_low, cell_high, rtab[cell_high]);
322 return TC_LINKLAYER_ATM;
323 }
324 return TC_LINKLAYER_ETHERNET;
325 }
326
327 static struct qdisc_rate_table *qdisc_rtab_list;
328
329 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct nlattr *tab)
330 {
331 struct qdisc_rate_table *rtab;
332
333 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
334 nla_len(tab) != TC_RTAB_SIZE)
335 return NULL;
336
337 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
338 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
339 !memcmp(&rtab->data, nla_data(tab), 1024)) {
340 rtab->refcnt++;
341 return rtab;
342 }
343 }
344
345 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
346 if (rtab) {
347 rtab->rate = *r;
348 rtab->refcnt = 1;
349 memcpy(rtab->data, nla_data(tab), 1024);
350 if (r->linklayer == TC_LINKLAYER_UNAWARE)
351 r->linklayer = __detect_linklayer(r, rtab->data);
352 rtab->next = qdisc_rtab_list;
353 qdisc_rtab_list = rtab;
354 }
355 return rtab;
356 }
357 EXPORT_SYMBOL(qdisc_get_rtab);
358
359 void qdisc_put_rtab(struct qdisc_rate_table *tab)
360 {
361 struct qdisc_rate_table *rtab, **rtabp;
362
363 if (!tab || --tab->refcnt)
364 return;
365
366 for (rtabp = &qdisc_rtab_list;
367 (rtab = *rtabp) != NULL;
368 rtabp = &rtab->next) {
369 if (rtab == tab) {
370 *rtabp = rtab->next;
371 kfree(rtab);
372 return;
373 }
374 }
375 }
376 EXPORT_SYMBOL(qdisc_put_rtab);
377
378 static LIST_HEAD(qdisc_stab_list);
379 static DEFINE_SPINLOCK(qdisc_stab_lock);
380
381 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
382 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
383 [TCA_STAB_DATA] = { .type = NLA_BINARY },
384 };
385
386 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
387 {
388 struct nlattr *tb[TCA_STAB_MAX + 1];
389 struct qdisc_size_table *stab;
390 struct tc_sizespec *s;
391 unsigned int tsize = 0;
392 u16 *tab = NULL;
393 int err;
394
395 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
396 if (err < 0)
397 return ERR_PTR(err);
398 if (!tb[TCA_STAB_BASE])
399 return ERR_PTR(-EINVAL);
400
401 s = nla_data(tb[TCA_STAB_BASE]);
402
403 if (s->tsize > 0) {
404 if (!tb[TCA_STAB_DATA])
405 return ERR_PTR(-EINVAL);
406 tab = nla_data(tb[TCA_STAB_DATA]);
407 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
408 }
409
410 if (tsize != s->tsize || (!tab && tsize > 0))
411 return ERR_PTR(-EINVAL);
412
413 spin_lock(&qdisc_stab_lock);
414
415 list_for_each_entry(stab, &qdisc_stab_list, list) {
416 if (memcmp(&stab->szopts, s, sizeof(*s)))
417 continue;
418 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
419 continue;
420 stab->refcnt++;
421 spin_unlock(&qdisc_stab_lock);
422 return stab;
423 }
424
425 spin_unlock(&qdisc_stab_lock);
426
427 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
428 if (!stab)
429 return ERR_PTR(-ENOMEM);
430
431 stab->refcnt = 1;
432 stab->szopts = *s;
433 if (tsize > 0)
434 memcpy(stab->data, tab, tsize * sizeof(u16));
435
436 spin_lock(&qdisc_stab_lock);
437 list_add_tail(&stab->list, &qdisc_stab_list);
438 spin_unlock(&qdisc_stab_lock);
439
440 return stab;
441 }
442
443 static void stab_kfree_rcu(struct rcu_head *head)
444 {
445 kfree(container_of(head, struct qdisc_size_table, rcu));
446 }
447
448 void qdisc_put_stab(struct qdisc_size_table *tab)
449 {
450 if (!tab)
451 return;
452
453 spin_lock(&qdisc_stab_lock);
454
455 if (--tab->refcnt == 0) {
456 list_del(&tab->list);
457 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
458 }
459
460 spin_unlock(&qdisc_stab_lock);
461 }
462 EXPORT_SYMBOL(qdisc_put_stab);
463
464 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
465 {
466 struct nlattr *nest;
467
468 nest = nla_nest_start(skb, TCA_STAB);
469 if (nest == NULL)
470 goto nla_put_failure;
471 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
472 goto nla_put_failure;
473 nla_nest_end(skb, nest);
474
475 return skb->len;
476
477 nla_put_failure:
478 return -1;
479 }
480
481 void __qdisc_calculate_pkt_len(struct sk_buff *skb, const struct qdisc_size_table *stab)
482 {
483 int pkt_len, slot;
484
485 pkt_len = skb->len + stab->szopts.overhead;
486 if (unlikely(!stab->szopts.tsize))
487 goto out;
488
489 slot = pkt_len + stab->szopts.cell_align;
490 if (unlikely(slot < 0))
491 slot = 0;
492
493 slot >>= stab->szopts.cell_log;
494 if (likely(slot < stab->szopts.tsize))
495 pkt_len = stab->data[slot];
496 else
497 pkt_len = stab->data[stab->szopts.tsize - 1] *
498 (slot / stab->szopts.tsize) +
499 stab->data[slot % stab->szopts.tsize];
500
501 pkt_len <<= stab->szopts.size_log;
502 out:
503 if (unlikely(pkt_len < 1))
504 pkt_len = 1;
505 qdisc_skb_cb(skb)->pkt_len = pkt_len;
506 }
507 EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
508
509 void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc)
510 {
511 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
512 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
513 txt, qdisc->ops->id, qdisc->handle >> 16);
514 qdisc->flags |= TCQ_F_WARN_NONWC;
515 }
516 }
517 EXPORT_SYMBOL(qdisc_warn_nonwc);
518
519 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
520 {
521 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
522 timer);
523
524 qdisc_unthrottled(wd->qdisc);
525 __netif_schedule(qdisc_root(wd->qdisc));
526
527 return HRTIMER_NORESTART;
528 }
529
530 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
531 {
532 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
533 wd->timer.function = qdisc_watchdog;
534 wd->qdisc = qdisc;
535 }
536 EXPORT_SYMBOL(qdisc_watchdog_init);
537
538 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
539 {
540 if (test_bit(__QDISC_STATE_DEACTIVATED,
541 &qdisc_root_sleeping(wd->qdisc)->state))
542 return;
543
544 qdisc_throttled(wd->qdisc);
545
546 hrtimer_start(&wd->timer,
547 ns_to_ktime(expires),
548 HRTIMER_MODE_ABS);
549 }
550 EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
551
552 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
553 {
554 hrtimer_cancel(&wd->timer);
555 qdisc_unthrottled(wd->qdisc);
556 }
557 EXPORT_SYMBOL(qdisc_watchdog_cancel);
558
559 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
560 {
561 unsigned int size = n * sizeof(struct hlist_head), i;
562 struct hlist_head *h;
563
564 if (size <= PAGE_SIZE)
565 h = kmalloc(size, GFP_KERNEL);
566 else
567 h = (struct hlist_head *)
568 __get_free_pages(GFP_KERNEL, get_order(size));
569
570 if (h != NULL) {
571 for (i = 0; i < n; i++)
572 INIT_HLIST_HEAD(&h[i]);
573 }
574 return h;
575 }
576
577 static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
578 {
579 unsigned int size = n * sizeof(struct hlist_head);
580
581 if (size <= PAGE_SIZE)
582 kfree(h);
583 else
584 free_pages((unsigned long)h, get_order(size));
585 }
586
587 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
588 {
589 struct Qdisc_class_common *cl;
590 struct hlist_node *next;
591 struct hlist_head *nhash, *ohash;
592 unsigned int nsize, nmask, osize;
593 unsigned int i, h;
594
595 /* Rehash when load factor exceeds 0.75 */
596 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
597 return;
598 nsize = clhash->hashsize * 2;
599 nmask = nsize - 1;
600 nhash = qdisc_class_hash_alloc(nsize);
601 if (nhash == NULL)
602 return;
603
604 ohash = clhash->hash;
605 osize = clhash->hashsize;
606
607 sch_tree_lock(sch);
608 for (i = 0; i < osize; i++) {
609 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
610 h = qdisc_class_hash(cl->classid, nmask);
611 hlist_add_head(&cl->hnode, &nhash[h]);
612 }
613 }
614 clhash->hash = nhash;
615 clhash->hashsize = nsize;
616 clhash->hashmask = nmask;
617 sch_tree_unlock(sch);
618
619 qdisc_class_hash_free(ohash, osize);
620 }
621 EXPORT_SYMBOL(qdisc_class_hash_grow);
622
623 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
624 {
625 unsigned int size = 4;
626
627 clhash->hash = qdisc_class_hash_alloc(size);
628 if (clhash->hash == NULL)
629 return -ENOMEM;
630 clhash->hashsize = size;
631 clhash->hashmask = size - 1;
632 clhash->hashelems = 0;
633 return 0;
634 }
635 EXPORT_SYMBOL(qdisc_class_hash_init);
636
637 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
638 {
639 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
640 }
641 EXPORT_SYMBOL(qdisc_class_hash_destroy);
642
643 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
644 struct Qdisc_class_common *cl)
645 {
646 unsigned int h;
647
648 INIT_HLIST_NODE(&cl->hnode);
649 h = qdisc_class_hash(cl->classid, clhash->hashmask);
650 hlist_add_head(&cl->hnode, &clhash->hash[h]);
651 clhash->hashelems++;
652 }
653 EXPORT_SYMBOL(qdisc_class_hash_insert);
654
655 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
656 struct Qdisc_class_common *cl)
657 {
658 hlist_del(&cl->hnode);
659 clhash->hashelems--;
660 }
661 EXPORT_SYMBOL(qdisc_class_hash_remove);
662
663 /* Allocate an unique handle from space managed by kernel
664 * Possible range is [8000-FFFF]:0000 (0x8000 values)
665 */
666 static u32 qdisc_alloc_handle(struct net_device *dev)
667 {
668 int i = 0x8000;
669 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
670
671 do {
672 autohandle += TC_H_MAKE(0x10000U, 0);
673 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
674 autohandle = TC_H_MAKE(0x80000000U, 0);
675 if (!qdisc_lookup(dev, autohandle))
676 return autohandle;
677 cond_resched();
678 } while (--i > 0);
679
680 return 0;
681 }
682
683 void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
684 {
685 const struct Qdisc_class_ops *cops;
686 unsigned long cl;
687 u32 parentid;
688
689 if (n == 0)
690 return;
691 while ((parentid = sch->parent)) {
692 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
693 return;
694
695 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
696 if (sch == NULL) {
697 WARN_ON(parentid != TC_H_ROOT);
698 return;
699 }
700 cops = sch->ops->cl_ops;
701 if (cops->qlen_notify) {
702 cl = cops->get(sch, parentid);
703 cops->qlen_notify(sch, cl);
704 cops->put(sch, cl);
705 }
706 sch->q.qlen -= n;
707 }
708 }
709 EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
710
711 static void notify_and_destroy(struct net *net, struct sk_buff *skb,
712 struct nlmsghdr *n, u32 clid,
713 struct Qdisc *old, struct Qdisc *new)
714 {
715 if (new || old)
716 qdisc_notify(net, skb, n, clid, old, new);
717
718 if (old)
719 qdisc_destroy(old);
720 }
721
722 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
723 * to device "dev".
724 *
725 * When appropriate send a netlink notification using 'skb'
726 * and "n".
727 *
728 * On success, destroy old qdisc.
729 */
730
731 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
732 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
733 struct Qdisc *new, struct Qdisc *old)
734 {
735 struct Qdisc *q = old;
736 struct net *net = dev_net(dev);
737 int err = 0;
738
739 if (parent == NULL) {
740 unsigned int i, num_q, ingress;
741
742 ingress = 0;
743 num_q = dev->num_tx_queues;
744 if ((q && q->flags & TCQ_F_INGRESS) ||
745 (new && new->flags & TCQ_F_INGRESS)) {
746 num_q = 1;
747 ingress = 1;
748 if (!dev_ingress_queue(dev))
749 return -ENOENT;
750 }
751
752 if (dev->flags & IFF_UP)
753 dev_deactivate(dev);
754
755 if (new && new->ops->attach) {
756 new->ops->attach(new);
757 num_q = 0;
758 }
759
760 for (i = 0; i < num_q; i++) {
761 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
762
763 if (!ingress)
764 dev_queue = netdev_get_tx_queue(dev, i);
765
766 old = dev_graft_qdisc(dev_queue, new);
767 if (new && i > 0)
768 atomic_inc(&new->refcnt);
769
770 if (!ingress)
771 qdisc_destroy(old);
772 }
773
774 if (!ingress) {
775 notify_and_destroy(net, skb, n, classid,
776 dev->qdisc, new);
777 if (new && !new->ops->attach)
778 atomic_inc(&new->refcnt);
779 dev->qdisc = new ? : &noop_qdisc;
780 } else {
781 notify_and_destroy(net, skb, n, classid, old, new);
782 }
783
784 if (dev->flags & IFF_UP)
785 dev_activate(dev);
786 } else {
787 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
788
789 err = -EOPNOTSUPP;
790 if (cops && cops->graft) {
791 unsigned long cl = cops->get(parent, classid);
792 if (cl) {
793 err = cops->graft(parent, cl, new, &old);
794 cops->put(parent, cl);
795 } else
796 err = -ENOENT;
797 }
798 if (!err)
799 notify_and_destroy(net, skb, n, classid, old, new);
800 }
801 return err;
802 }
803
804 /* lockdep annotation is needed for ingress; egress gets it only for name */
805 static struct lock_class_key qdisc_tx_lock;
806 static struct lock_class_key qdisc_rx_lock;
807
808 /*
809 Allocate and initialize new qdisc.
810
811 Parameters are passed via opt.
812 */
813
814 static struct Qdisc *
815 qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
816 struct Qdisc *p, u32 parent, u32 handle,
817 struct nlattr **tca, int *errp)
818 {
819 int err;
820 struct nlattr *kind = tca[TCA_KIND];
821 struct Qdisc *sch;
822 struct Qdisc_ops *ops;
823 struct qdisc_size_table *stab;
824
825 ops = qdisc_lookup_ops(kind);
826 #ifdef CONFIG_MODULES
827 if (ops == NULL && kind != NULL) {
828 char name[IFNAMSIZ];
829 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
830 /* We dropped the RTNL semaphore in order to
831 * perform the module load. So, even if we
832 * succeeded in loading the module we have to
833 * tell the caller to replay the request. We
834 * indicate this using -EAGAIN.
835 * We replay the request because the device may
836 * go away in the mean time.
837 */
838 rtnl_unlock();
839 request_module("sch_%s", name);
840 rtnl_lock();
841 ops = qdisc_lookup_ops(kind);
842 if (ops != NULL) {
843 /* We will try again qdisc_lookup_ops,
844 * so don't keep a reference.
845 */
846 module_put(ops->owner);
847 err = -EAGAIN;
848 goto err_out;
849 }
850 }
851 }
852 #endif
853
854 err = -ENOENT;
855 if (ops == NULL)
856 goto err_out;
857
858 sch = qdisc_alloc(dev_queue, ops);
859 if (IS_ERR(sch)) {
860 err = PTR_ERR(sch);
861 goto err_out2;
862 }
863
864 sch->parent = parent;
865
866 if (handle == TC_H_INGRESS) {
867 sch->flags |= TCQ_F_INGRESS;
868 handle = TC_H_MAKE(TC_H_INGRESS, 0);
869 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
870 } else {
871 if (handle == 0) {
872 handle = qdisc_alloc_handle(dev);
873 err = -ENOMEM;
874 if (handle == 0)
875 goto err_out3;
876 }
877 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
878 if (!netif_is_multiqueue(dev))
879 sch->flags |= TCQ_F_ONETXQUEUE;
880 }
881
882 sch->handle = handle;
883
884 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
885 if (tca[TCA_STAB]) {
886 stab = qdisc_get_stab(tca[TCA_STAB]);
887 if (IS_ERR(stab)) {
888 err = PTR_ERR(stab);
889 goto err_out4;
890 }
891 rcu_assign_pointer(sch->stab, stab);
892 }
893 if (tca[TCA_RATE]) {
894 spinlock_t *root_lock;
895
896 err = -EOPNOTSUPP;
897 if (sch->flags & TCQ_F_MQROOT)
898 goto err_out4;
899
900 if ((sch->parent != TC_H_ROOT) &&
901 !(sch->flags & TCQ_F_INGRESS) &&
902 (!p || !(p->flags & TCQ_F_MQROOT)))
903 root_lock = qdisc_root_sleeping_lock(sch);
904 else
905 root_lock = qdisc_lock(sch);
906
907 err = gen_new_estimator(&sch->bstats, &sch->rate_est,
908 root_lock, tca[TCA_RATE]);
909 if (err)
910 goto err_out4;
911 }
912
913 qdisc_list_add(sch);
914
915 return sch;
916 }
917 err_out3:
918 dev_put(dev);
919 kfree((char *) sch - sch->padded);
920 err_out2:
921 module_put(ops->owner);
922 err_out:
923 *errp = err;
924 return NULL;
925
926 err_out4:
927 /*
928 * Any broken qdiscs that would require a ops->reset() here?
929 * The qdisc was never in action so it shouldn't be necessary.
930 */
931 qdisc_put_stab(rtnl_dereference(sch->stab));
932 if (ops->destroy)
933 ops->destroy(sch);
934 goto err_out3;
935 }
936
937 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
938 {
939 struct qdisc_size_table *ostab, *stab = NULL;
940 int err = 0;
941
942 if (tca[TCA_OPTIONS]) {
943 if (sch->ops->change == NULL)
944 return -EINVAL;
945 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
946 if (err)
947 return err;
948 }
949
950 if (tca[TCA_STAB]) {
951 stab = qdisc_get_stab(tca[TCA_STAB]);
952 if (IS_ERR(stab))
953 return PTR_ERR(stab);
954 }
955
956 ostab = rtnl_dereference(sch->stab);
957 rcu_assign_pointer(sch->stab, stab);
958 qdisc_put_stab(ostab);
959
960 if (tca[TCA_RATE]) {
961 /* NB: ignores errors from replace_estimator
962 because change can't be undone. */
963 if (sch->flags & TCQ_F_MQROOT)
964 goto out;
965 gen_replace_estimator(&sch->bstats, &sch->rate_est,
966 qdisc_root_sleeping_lock(sch),
967 tca[TCA_RATE]);
968 }
969 out:
970 return 0;
971 }
972
973 struct check_loop_arg {
974 struct qdisc_walker w;
975 struct Qdisc *p;
976 int depth;
977 };
978
979 static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
980
981 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
982 {
983 struct check_loop_arg arg;
984
985 if (q->ops->cl_ops == NULL)
986 return 0;
987
988 arg.w.stop = arg.w.skip = arg.w.count = 0;
989 arg.w.fn = check_loop_fn;
990 arg.depth = depth;
991 arg.p = p;
992 q->ops->cl_ops->walk(q, &arg.w);
993 return arg.w.stop ? -ELOOP : 0;
994 }
995
996 static int
997 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
998 {
999 struct Qdisc *leaf;
1000 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1001 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1002
1003 leaf = cops->leaf(q, cl);
1004 if (leaf) {
1005 if (leaf == arg->p || arg->depth > 7)
1006 return -ELOOP;
1007 return check_loop(leaf, arg->p, arg->depth + 1);
1008 }
1009 return 0;
1010 }
1011
1012 /*
1013 * Delete/get qdisc.
1014 */
1015
1016 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1017 {
1018 struct net *net = sock_net(skb->sk);
1019 struct tcmsg *tcm = nlmsg_data(n);
1020 struct nlattr *tca[TCA_MAX + 1];
1021 struct net_device *dev;
1022 u32 clid;
1023 struct Qdisc *q = NULL;
1024 struct Qdisc *p = NULL;
1025 int err;
1026
1027 if ((n->nlmsg_type != RTM_GETQDISC) && !capable(CAP_NET_ADMIN))
1028 return -EPERM;
1029
1030 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1031 if (err < 0)
1032 return err;
1033
1034 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1035 if (!dev)
1036 return -ENODEV;
1037
1038 clid = tcm->tcm_parent;
1039 if (clid) {
1040 if (clid != TC_H_ROOT) {
1041 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1042 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1043 if (!p)
1044 return -ENOENT;
1045 q = qdisc_leaf(p, clid);
1046 } else if (dev_ingress_queue(dev)) {
1047 q = dev_ingress_queue(dev)->qdisc_sleeping;
1048 }
1049 } else {
1050 q = dev->qdisc;
1051 }
1052 if (!q)
1053 return -ENOENT;
1054
1055 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1056 return -EINVAL;
1057 } else {
1058 q = qdisc_lookup(dev, tcm->tcm_handle);
1059 if (!q)
1060 return -ENOENT;
1061 }
1062
1063 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1064 return -EINVAL;
1065
1066 if (n->nlmsg_type == RTM_DELQDISC) {
1067 if (!clid)
1068 return -EINVAL;
1069 if (q->handle == 0)
1070 return -ENOENT;
1071 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1072 if (err != 0)
1073 return err;
1074 } else {
1075 qdisc_notify(net, skb, n, clid, NULL, q);
1076 }
1077 return 0;
1078 }
1079
1080 /*
1081 * Create/change qdisc.
1082 */
1083
1084 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1085 {
1086 struct net *net = sock_net(skb->sk);
1087 struct tcmsg *tcm;
1088 struct nlattr *tca[TCA_MAX + 1];
1089 struct net_device *dev;
1090 u32 clid;
1091 struct Qdisc *q, *p;
1092 int err;
1093
1094 if (!capable(CAP_NET_ADMIN))
1095 return -EPERM;
1096
1097 replay:
1098 /* Reinit, just in case something touches this. */
1099 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1100 if (err < 0)
1101 return err;
1102
1103 tcm = nlmsg_data(n);
1104 clid = tcm->tcm_parent;
1105 q = p = NULL;
1106
1107 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1108 if (!dev)
1109 return -ENODEV;
1110
1111
1112 if (clid) {
1113 if (clid != TC_H_ROOT) {
1114 if (clid != TC_H_INGRESS) {
1115 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1116 if (!p)
1117 return -ENOENT;
1118 q = qdisc_leaf(p, clid);
1119 } else if (dev_ingress_queue_create(dev)) {
1120 q = dev_ingress_queue(dev)->qdisc_sleeping;
1121 }
1122 } else {
1123 q = dev->qdisc;
1124 }
1125
1126 /* It may be default qdisc, ignore it */
1127 if (q && q->handle == 0)
1128 q = NULL;
1129
1130 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1131 if (tcm->tcm_handle) {
1132 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1133 return -EEXIST;
1134 if (TC_H_MIN(tcm->tcm_handle))
1135 return -EINVAL;
1136 q = qdisc_lookup(dev, tcm->tcm_handle);
1137 if (!q)
1138 goto create_n_graft;
1139 if (n->nlmsg_flags & NLM_F_EXCL)
1140 return -EEXIST;
1141 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1142 return -EINVAL;
1143 if (q == p ||
1144 (p && check_loop(q, p, 0)))
1145 return -ELOOP;
1146 atomic_inc(&q->refcnt);
1147 goto graft;
1148 } else {
1149 if (!q)
1150 goto create_n_graft;
1151
1152 /* This magic test requires explanation.
1153 *
1154 * We know, that some child q is already
1155 * attached to this parent and have choice:
1156 * either to change it or to create/graft new one.
1157 *
1158 * 1. We are allowed to create/graft only
1159 * if CREATE and REPLACE flags are set.
1160 *
1161 * 2. If EXCL is set, requestor wanted to say,
1162 * that qdisc tcm_handle is not expected
1163 * to exist, so that we choose create/graft too.
1164 *
1165 * 3. The last case is when no flags are set.
1166 * Alas, it is sort of hole in API, we
1167 * cannot decide what to do unambiguously.
1168 * For now we select create/graft, if
1169 * user gave KIND, which does not match existing.
1170 */
1171 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1172 (n->nlmsg_flags & NLM_F_REPLACE) &&
1173 ((n->nlmsg_flags & NLM_F_EXCL) ||
1174 (tca[TCA_KIND] &&
1175 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1176 goto create_n_graft;
1177 }
1178 }
1179 } else {
1180 if (!tcm->tcm_handle)
1181 return -EINVAL;
1182 q = qdisc_lookup(dev, tcm->tcm_handle);
1183 }
1184
1185 /* Change qdisc parameters */
1186 if (q == NULL)
1187 return -ENOENT;
1188 if (n->nlmsg_flags & NLM_F_EXCL)
1189 return -EEXIST;
1190 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1191 return -EINVAL;
1192 err = qdisc_change(q, tca);
1193 if (err == 0)
1194 qdisc_notify(net, skb, n, clid, NULL, q);
1195 return err;
1196
1197 create_n_graft:
1198 if (!(n->nlmsg_flags & NLM_F_CREATE))
1199 return -ENOENT;
1200 if (clid == TC_H_INGRESS) {
1201 if (dev_ingress_queue(dev))
1202 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1203 tcm->tcm_parent, tcm->tcm_parent,
1204 tca, &err);
1205 else
1206 err = -ENOENT;
1207 } else {
1208 struct netdev_queue *dev_queue;
1209
1210 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1211 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1212 else if (p)
1213 dev_queue = p->dev_queue;
1214 else
1215 dev_queue = netdev_get_tx_queue(dev, 0);
1216
1217 q = qdisc_create(dev, dev_queue, p,
1218 tcm->tcm_parent, tcm->tcm_handle,
1219 tca, &err);
1220 }
1221 if (q == NULL) {
1222 if (err == -EAGAIN)
1223 goto replay;
1224 return err;
1225 }
1226
1227 graft:
1228 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1229 if (err) {
1230 if (q)
1231 qdisc_destroy(q);
1232 return err;
1233 }
1234
1235 return 0;
1236 }
1237
1238 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1239 u32 portid, u32 seq, u16 flags, int event)
1240 {
1241 struct tcmsg *tcm;
1242 struct nlmsghdr *nlh;
1243 unsigned char *b = skb_tail_pointer(skb);
1244 struct gnet_dump d;
1245 struct qdisc_size_table *stab;
1246
1247 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1248 if (!nlh)
1249 goto out_nlmsg_trim;
1250 tcm = nlmsg_data(nlh);
1251 tcm->tcm_family = AF_UNSPEC;
1252 tcm->tcm__pad1 = 0;
1253 tcm->tcm__pad2 = 0;
1254 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1255 tcm->tcm_parent = clid;
1256 tcm->tcm_handle = q->handle;
1257 tcm->tcm_info = atomic_read(&q->refcnt);
1258 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1259 goto nla_put_failure;
1260 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1261 goto nla_put_failure;
1262 q->qstats.qlen = q->q.qlen;
1263
1264 stab = rtnl_dereference(q->stab);
1265 if (stab && qdisc_dump_stab(skb, stab) < 0)
1266 goto nla_put_failure;
1267
1268 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1269 qdisc_root_sleeping_lock(q), &d) < 0)
1270 goto nla_put_failure;
1271
1272 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1273 goto nla_put_failure;
1274
1275 if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
1276 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1277 gnet_stats_copy_queue(&d, &q->qstats) < 0)
1278 goto nla_put_failure;
1279
1280 if (gnet_stats_finish_copy(&d) < 0)
1281 goto nla_put_failure;
1282
1283 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1284 return skb->len;
1285
1286 out_nlmsg_trim:
1287 nla_put_failure:
1288 nlmsg_trim(skb, b);
1289 return -1;
1290 }
1291
1292 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1293 {
1294 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1295 }
1296
1297 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1298 struct nlmsghdr *n, u32 clid,
1299 struct Qdisc *old, struct Qdisc *new)
1300 {
1301 struct sk_buff *skb;
1302 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1303
1304 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1305 if (!skb)
1306 return -ENOBUFS;
1307
1308 if (old && !tc_qdisc_dump_ignore(old)) {
1309 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1310 0, RTM_DELQDISC) < 0)
1311 goto err_out;
1312 }
1313 if (new && !tc_qdisc_dump_ignore(new)) {
1314 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1315 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1316 goto err_out;
1317 }
1318
1319 if (skb->len)
1320 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1321 n->nlmsg_flags & NLM_F_ECHO);
1322
1323 err_out:
1324 kfree_skb(skb);
1325 return -EINVAL;
1326 }
1327
1328 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1329 struct netlink_callback *cb,
1330 int *q_idx_p, int s_q_idx)
1331 {
1332 int ret = 0, q_idx = *q_idx_p;
1333 struct Qdisc *q;
1334
1335 if (!root)
1336 return 0;
1337
1338 q = root;
1339 if (q_idx < s_q_idx) {
1340 q_idx++;
1341 } else {
1342 if (!tc_qdisc_dump_ignore(q) &&
1343 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1344 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1345 goto done;
1346 q_idx++;
1347 }
1348 list_for_each_entry(q, &root->list, list) {
1349 if (q_idx < s_q_idx) {
1350 q_idx++;
1351 continue;
1352 }
1353 if (!tc_qdisc_dump_ignore(q) &&
1354 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1355 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1356 goto done;
1357 q_idx++;
1358 }
1359
1360 out:
1361 *q_idx_p = q_idx;
1362 return ret;
1363 done:
1364 ret = -1;
1365 goto out;
1366 }
1367
1368 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1369 {
1370 struct net *net = sock_net(skb->sk);
1371 int idx, q_idx;
1372 int s_idx, s_q_idx;
1373 struct net_device *dev;
1374
1375 s_idx = cb->args[0];
1376 s_q_idx = q_idx = cb->args[1];
1377
1378 rcu_read_lock();
1379 idx = 0;
1380 for_each_netdev_rcu(net, dev) {
1381 struct netdev_queue *dev_queue;
1382
1383 if (idx < s_idx)
1384 goto cont;
1385 if (idx > s_idx)
1386 s_q_idx = 0;
1387 q_idx = 0;
1388
1389 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1390 goto done;
1391
1392 dev_queue = dev_ingress_queue(dev);
1393 if (dev_queue &&
1394 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1395 &q_idx, s_q_idx) < 0)
1396 goto done;
1397
1398 cont:
1399 idx++;
1400 }
1401
1402 done:
1403 rcu_read_unlock();
1404
1405 cb->args[0] = idx;
1406 cb->args[1] = q_idx;
1407
1408 return skb->len;
1409 }
1410
1411
1412
1413 /************************************************
1414 * Traffic classes manipulation. *
1415 ************************************************/
1416
1417
1418
1419 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n)
1420 {
1421 struct net *net = sock_net(skb->sk);
1422 struct tcmsg *tcm = nlmsg_data(n);
1423 struct nlattr *tca[TCA_MAX + 1];
1424 struct net_device *dev;
1425 struct Qdisc *q = NULL;
1426 const struct Qdisc_class_ops *cops;
1427 unsigned long cl = 0;
1428 unsigned long new_cl;
1429 u32 portid;
1430 u32 clid;
1431 u32 qid;
1432 int err;
1433
1434 if ((n->nlmsg_type != RTM_GETTCLASS) && !capable(CAP_NET_ADMIN))
1435 return -EPERM;
1436
1437 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1438 if (err < 0)
1439 return err;
1440
1441 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1442 if (!dev)
1443 return -ENODEV;
1444
1445 /*
1446 parent == TC_H_UNSPEC - unspecified parent.
1447 parent == TC_H_ROOT - class is root, which has no parent.
1448 parent == X:0 - parent is root class.
1449 parent == X:Y - parent is a node in hierarchy.
1450 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1451
1452 handle == 0:0 - generate handle from kernel pool.
1453 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1454 handle == X:Y - clear.
1455 handle == X:0 - root class.
1456 */
1457
1458 /* Step 1. Determine qdisc handle X:0 */
1459
1460 portid = tcm->tcm_parent;
1461 clid = tcm->tcm_handle;
1462 qid = TC_H_MAJ(clid);
1463
1464 if (portid != TC_H_ROOT) {
1465 u32 qid1 = TC_H_MAJ(portid);
1466
1467 if (qid && qid1) {
1468 /* If both majors are known, they must be identical. */
1469 if (qid != qid1)
1470 return -EINVAL;
1471 } else if (qid1) {
1472 qid = qid1;
1473 } else if (qid == 0)
1474 qid = dev->qdisc->handle;
1475
1476 /* Now qid is genuine qdisc handle consistent
1477 * both with parent and child.
1478 *
1479 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1480 */
1481 if (portid)
1482 portid = TC_H_MAKE(qid, portid);
1483 } else {
1484 if (qid == 0)
1485 qid = dev->qdisc->handle;
1486 }
1487
1488 /* OK. Locate qdisc */
1489 q = qdisc_lookup(dev, qid);
1490 if (!q)
1491 return -ENOENT;
1492
1493 /* An check that it supports classes */
1494 cops = q->ops->cl_ops;
1495 if (cops == NULL)
1496 return -EINVAL;
1497
1498 /* Now try to get class */
1499 if (clid == 0) {
1500 if (portid == TC_H_ROOT)
1501 clid = qid;
1502 } else
1503 clid = TC_H_MAKE(qid, clid);
1504
1505 if (clid)
1506 cl = cops->get(q, clid);
1507
1508 if (cl == 0) {
1509 err = -ENOENT;
1510 if (n->nlmsg_type != RTM_NEWTCLASS ||
1511 !(n->nlmsg_flags & NLM_F_CREATE))
1512 goto out;
1513 } else {
1514 switch (n->nlmsg_type) {
1515 case RTM_NEWTCLASS:
1516 err = -EEXIST;
1517 if (n->nlmsg_flags & NLM_F_EXCL)
1518 goto out;
1519 break;
1520 case RTM_DELTCLASS:
1521 err = -EOPNOTSUPP;
1522 if (cops->delete)
1523 err = cops->delete(q, cl);
1524 if (err == 0)
1525 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1526 goto out;
1527 case RTM_GETTCLASS:
1528 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1529 goto out;
1530 default:
1531 err = -EINVAL;
1532 goto out;
1533 }
1534 }
1535
1536 new_cl = cl;
1537 err = -EOPNOTSUPP;
1538 if (cops->change)
1539 err = cops->change(q, clid, portid, tca, &new_cl);
1540 if (err == 0)
1541 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1542
1543 out:
1544 if (cl)
1545 cops->put(q, cl);
1546
1547 return err;
1548 }
1549
1550
1551 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1552 unsigned long cl,
1553 u32 portid, u32 seq, u16 flags, int event)
1554 {
1555 struct tcmsg *tcm;
1556 struct nlmsghdr *nlh;
1557 unsigned char *b = skb_tail_pointer(skb);
1558 struct gnet_dump d;
1559 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1560
1561 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1562 if (!nlh)
1563 goto out_nlmsg_trim;
1564 tcm = nlmsg_data(nlh);
1565 tcm->tcm_family = AF_UNSPEC;
1566 tcm->tcm__pad1 = 0;
1567 tcm->tcm__pad2 = 0;
1568 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1569 tcm->tcm_parent = q->handle;
1570 tcm->tcm_handle = q->handle;
1571 tcm->tcm_info = 0;
1572 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1573 goto nla_put_failure;
1574 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1575 goto nla_put_failure;
1576
1577 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1578 qdisc_root_sleeping_lock(q), &d) < 0)
1579 goto nla_put_failure;
1580
1581 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1582 goto nla_put_failure;
1583
1584 if (gnet_stats_finish_copy(&d) < 0)
1585 goto nla_put_failure;
1586
1587 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1588 return skb->len;
1589
1590 out_nlmsg_trim:
1591 nla_put_failure:
1592 nlmsg_trim(skb, b);
1593 return -1;
1594 }
1595
1596 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1597 struct nlmsghdr *n, struct Qdisc *q,
1598 unsigned long cl, int event)
1599 {
1600 struct sk_buff *skb;
1601 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1602
1603 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1604 if (!skb)
1605 return -ENOBUFS;
1606
1607 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1608 kfree_skb(skb);
1609 return -EINVAL;
1610 }
1611
1612 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1613 n->nlmsg_flags & NLM_F_ECHO);
1614 }
1615
1616 struct qdisc_dump_args {
1617 struct qdisc_walker w;
1618 struct sk_buff *skb;
1619 struct netlink_callback *cb;
1620 };
1621
1622 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1623 {
1624 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1625
1626 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1627 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1628 }
1629
1630 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1631 struct tcmsg *tcm, struct netlink_callback *cb,
1632 int *t_p, int s_t)
1633 {
1634 struct qdisc_dump_args arg;
1635
1636 if (tc_qdisc_dump_ignore(q) ||
1637 *t_p < s_t || !q->ops->cl_ops ||
1638 (tcm->tcm_parent &&
1639 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1640 (*t_p)++;
1641 return 0;
1642 }
1643 if (*t_p > s_t)
1644 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1645 arg.w.fn = qdisc_class_dump;
1646 arg.skb = skb;
1647 arg.cb = cb;
1648 arg.w.stop = 0;
1649 arg.w.skip = cb->args[1];
1650 arg.w.count = 0;
1651 q->ops->cl_ops->walk(q, &arg.w);
1652 cb->args[1] = arg.w.count;
1653 if (arg.w.stop)
1654 return -1;
1655 (*t_p)++;
1656 return 0;
1657 }
1658
1659 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1660 struct tcmsg *tcm, struct netlink_callback *cb,
1661 int *t_p, int s_t)
1662 {
1663 struct Qdisc *q;
1664
1665 if (!root)
1666 return 0;
1667
1668 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1669 return -1;
1670
1671 list_for_each_entry(q, &root->list, list) {
1672 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1673 return -1;
1674 }
1675
1676 return 0;
1677 }
1678
1679 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1680 {
1681 struct tcmsg *tcm = nlmsg_data(cb->nlh);
1682 struct net *net = sock_net(skb->sk);
1683 struct netdev_queue *dev_queue;
1684 struct net_device *dev;
1685 int t, s_t;
1686
1687 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1688 return 0;
1689 dev = dev_get_by_index(net, tcm->tcm_ifindex);
1690 if (!dev)
1691 return 0;
1692
1693 s_t = cb->args[0];
1694 t = 0;
1695
1696 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1697 goto done;
1698
1699 dev_queue = dev_ingress_queue(dev);
1700 if (dev_queue &&
1701 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1702 &t, s_t) < 0)
1703 goto done;
1704
1705 done:
1706 cb->args[0] = t;
1707
1708 dev_put(dev);
1709 return skb->len;
1710 }
1711
1712 /* Main classifier routine: scans classifier chain attached
1713 * to this qdisc, (optionally) tests for protocol and asks
1714 * specific classifiers.
1715 */
1716 int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
1717 struct tcf_result *res)
1718 {
1719 __be16 protocol = skb->protocol;
1720 int err;
1721
1722 for (; tp; tp = tp->next) {
1723 if (tp->protocol != protocol &&
1724 tp->protocol != htons(ETH_P_ALL))
1725 continue;
1726 err = tp->classify(skb, tp, res);
1727
1728 if (err >= 0) {
1729 #ifdef CONFIG_NET_CLS_ACT
1730 if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
1731 skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
1732 #endif
1733 return err;
1734 }
1735 }
1736 return -1;
1737 }
1738 EXPORT_SYMBOL(tc_classify_compat);
1739
1740 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1741 struct tcf_result *res)
1742 {
1743 int err = 0;
1744 #ifdef CONFIG_NET_CLS_ACT
1745 const struct tcf_proto *otp = tp;
1746 reclassify:
1747 #endif
1748
1749 err = tc_classify_compat(skb, tp, res);
1750 #ifdef CONFIG_NET_CLS_ACT
1751 if (err == TC_ACT_RECLASSIFY) {
1752 u32 verd = G_TC_VERD(skb->tc_verd);
1753 tp = otp;
1754
1755 if (verd++ >= MAX_REC_LOOP) {
1756 net_notice_ratelimited("%s: packet reclassify loop rule prio %u protocol %02x\n",
1757 tp->q->ops->id,
1758 tp->prio & 0xffff,
1759 ntohs(tp->protocol));
1760 return TC_ACT_SHOT;
1761 }
1762 skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
1763 goto reclassify;
1764 }
1765 #endif
1766 return err;
1767 }
1768 EXPORT_SYMBOL(tc_classify);
1769
1770 void tcf_destroy(struct tcf_proto *tp)
1771 {
1772 tp->ops->destroy(tp);
1773 module_put(tp->ops->owner);
1774 kfree(tp);
1775 }
1776
1777 void tcf_destroy_chain(struct tcf_proto **fl)
1778 {
1779 struct tcf_proto *tp;
1780
1781 while ((tp = *fl) != NULL) {
1782 *fl = tp->next;
1783 tcf_destroy(tp);
1784 }
1785 }
1786 EXPORT_SYMBOL(tcf_destroy_chain);
1787
1788 #ifdef CONFIG_PROC_FS
1789 static int psched_show(struct seq_file *seq, void *v)
1790 {
1791 struct timespec ts;
1792
1793 hrtimer_get_res(CLOCK_MONOTONIC, &ts);
1794 seq_printf(seq, "%08x %08x %08x %08x\n",
1795 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1796 1000000,
1797 (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
1798
1799 return 0;
1800 }
1801
1802 static int psched_open(struct inode *inode, struct file *file)
1803 {
1804 return single_open(file, psched_show, NULL);
1805 }
1806
1807 static const struct file_operations psched_fops = {
1808 .owner = THIS_MODULE,
1809 .open = psched_open,
1810 .read = seq_read,
1811 .llseek = seq_lseek,
1812 .release = single_release,
1813 };
1814
1815 static int __net_init psched_net_init(struct net *net)
1816 {
1817 struct proc_dir_entry *e;
1818
1819 e = proc_create("psched", 0, net->proc_net, &psched_fops);
1820 if (e == NULL)
1821 return -ENOMEM;
1822
1823 return 0;
1824 }
1825
1826 static void __net_exit psched_net_exit(struct net *net)
1827 {
1828 remove_proc_entry("psched", net->proc_net);
1829 }
1830 #else
1831 static int __net_init psched_net_init(struct net *net)
1832 {
1833 return 0;
1834 }
1835
1836 static void __net_exit psched_net_exit(struct net *net)
1837 {
1838 }
1839 #endif
1840
1841 static struct pernet_operations psched_net_ops = {
1842 .init = psched_net_init,
1843 .exit = psched_net_exit,
1844 };
1845
1846 static int __init pktsched_init(void)
1847 {
1848 int err;
1849
1850 err = register_pernet_subsys(&psched_net_ops);
1851 if (err) {
1852 pr_err("pktsched_init: "
1853 "cannot initialize per netns operations\n");
1854 return err;
1855 }
1856
1857 register_qdisc(&pfifo_qdisc_ops);
1858 register_qdisc(&bfifo_qdisc_ops);
1859 register_qdisc(&pfifo_head_drop_qdisc_ops);
1860 register_qdisc(&mq_qdisc_ops);
1861
1862 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1863 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1864 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1865 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1866 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1867 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1868
1869 return 0;
1870 }
1871
1872 subsys_initcall(pktsched_init);
Linux kernel - Deliverables
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