misc: rtsx_usb: Use USB remote wakeup signaling for card insertion detection
[linux/fpc-iii.git] / net / sched / sch_api.c
blobca3b0f46de53032906e992e1759c6c912d0ba483
1 /*
2 * net/sched/sch_api.c Packet scheduler API.
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.
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
11 * Fixes:
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
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/slab.h>
31 #include <linux/hashtable.h>
33 #include <net/net_namespace.h>
34 #include <net/sock.h>
35 #include <net/netlink.h>
36 #include <net/pkt_sched.h>
37 #include <net/pkt_cls.h>
41 Short review.
42 -------------
44 This file consists of two interrelated parts:
46 1. queueing disciplines manager frontend.
47 2. traffic classes manager frontend.
49 Generally, queueing discipline ("qdisc") is a black box,
50 which is able to enqueue packets and to dequeue them (when
51 device is ready to send something) in order and at times
52 determined by algorithm hidden in it.
54 qdisc's are divided to two categories:
55 - "queues", which have no internal structure visible from outside.
56 - "schedulers", which split all the packets to "traffic classes",
57 using "packet classifiers" (look at cls_api.c)
59 In turn, classes may have child qdiscs (as rule, queues)
60 attached to them etc. etc. etc.
62 The goal of the routines in this file is to translate
63 information supplied by user in the form of handles
64 to more intelligible for kernel form, to make some sanity
65 checks and part of work, which is common to all qdiscs
66 and to provide rtnetlink notifications.
68 All real intelligent work is done inside qdisc modules.
72 Every discipline has two major routines: enqueue and dequeue.
74 ---dequeue
76 dequeue usually returns a skb to send. It is allowed to return NULL,
77 but it does not mean that queue is empty, it just means that
78 discipline does not want to send anything this time.
79 Queue is really empty if q->q.qlen == 0.
80 For complicated disciplines with multiple queues q->q is not
81 real packet queue, but however q->q.qlen must be valid.
83 ---enqueue
85 enqueue returns 0, if packet was enqueued successfully.
86 If packet (this one or another one) was dropped, it returns
87 not zero error code.
88 NET_XMIT_DROP - this packet dropped
89 Expected action: do not backoff, but wait until queue will clear.
90 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
91 Expected action: backoff or ignore
93 Auxiliary routines:
95 ---peek
97 like dequeue but without removing a packet from the queue
99 ---reset
101 returns qdisc to initial state: purge all buffers, clear all
102 timers, counters (except for statistics) etc.
104 ---init
106 initializes newly created qdisc.
108 ---destroy
110 destroys resources allocated by init and during lifetime of qdisc.
112 ---change
114 changes qdisc parameters.
117 /* Protects list of registered TC modules. It is pure SMP lock. */
118 static DEFINE_RWLOCK(qdisc_mod_lock);
121 /************************************************
122 * Queueing disciplines manipulation. *
123 ************************************************/
126 /* The list of all installed queueing disciplines. */
128 static struct Qdisc_ops *qdisc_base;
130 /* Register/unregister queueing discipline */
132 int register_qdisc(struct Qdisc_ops *qops)
134 struct Qdisc_ops *q, **qp;
135 int rc = -EEXIST;
137 write_lock(&qdisc_mod_lock);
138 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
139 if (!strcmp(qops->id, q->id))
140 goto out;
142 if (qops->enqueue == NULL)
143 qops->enqueue = noop_qdisc_ops.enqueue;
144 if (qops->peek == NULL) {
145 if (qops->dequeue == NULL)
146 qops->peek = noop_qdisc_ops.peek;
147 else
148 goto out_einval;
150 if (qops->dequeue == NULL)
151 qops->dequeue = noop_qdisc_ops.dequeue;
153 if (qops->cl_ops) {
154 const struct Qdisc_class_ops *cops = qops->cl_ops;
156 if (!(cops->find && cops->walk && cops->leaf))
157 goto out_einval;
159 if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf))
160 goto out_einval;
163 qops->next = NULL;
164 *qp = qops;
165 rc = 0;
166 out:
167 write_unlock(&qdisc_mod_lock);
168 return rc;
170 out_einval:
171 rc = -EINVAL;
172 goto out;
174 EXPORT_SYMBOL(register_qdisc);
176 int unregister_qdisc(struct Qdisc_ops *qops)
178 struct Qdisc_ops *q, **qp;
179 int err = -ENOENT;
181 write_lock(&qdisc_mod_lock);
182 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
183 if (q == qops)
184 break;
185 if (q) {
186 *qp = q->next;
187 q->next = NULL;
188 err = 0;
190 write_unlock(&qdisc_mod_lock);
191 return err;
193 EXPORT_SYMBOL(unregister_qdisc);
195 /* Get default qdisc if not otherwise specified */
196 void qdisc_get_default(char *name, size_t len)
198 read_lock(&qdisc_mod_lock);
199 strlcpy(name, default_qdisc_ops->id, len);
200 read_unlock(&qdisc_mod_lock);
203 static struct Qdisc_ops *qdisc_lookup_default(const char *name)
205 struct Qdisc_ops *q = NULL;
207 for (q = qdisc_base; q; q = q->next) {
208 if (!strcmp(name, q->id)) {
209 if (!try_module_get(q->owner))
210 q = NULL;
211 break;
215 return q;
218 /* Set new default qdisc to use */
219 int qdisc_set_default(const char *name)
221 const struct Qdisc_ops *ops;
223 if (!capable(CAP_NET_ADMIN))
224 return -EPERM;
226 write_lock(&qdisc_mod_lock);
227 ops = qdisc_lookup_default(name);
228 if (!ops) {
229 /* Not found, drop lock and try to load module */
230 write_unlock(&qdisc_mod_lock);
231 request_module("sch_%s", name);
232 write_lock(&qdisc_mod_lock);
234 ops = qdisc_lookup_default(name);
237 if (ops) {
238 /* Set new default */
239 module_put(default_qdisc_ops->owner);
240 default_qdisc_ops = ops;
242 write_unlock(&qdisc_mod_lock);
244 return ops ? 0 : -ENOENT;
247 #ifdef CONFIG_NET_SCH_DEFAULT
248 /* Set default value from kernel config */
249 static int __init sch_default_qdisc(void)
251 return qdisc_set_default(CONFIG_DEFAULT_NET_SCH);
253 late_initcall(sch_default_qdisc);
254 #endif
256 /* We know handle. Find qdisc among all qdisc's attached to device
257 * (root qdisc, all its children, children of children etc.)
258 * Note: caller either uses rtnl or rcu_read_lock()
261 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
263 struct Qdisc *q;
265 if (!qdisc_dev(root))
266 return (root->handle == handle ? root : NULL);
268 if (!(root->flags & TCQ_F_BUILTIN) &&
269 root->handle == handle)
270 return root;
272 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle) {
273 if (q->handle == handle)
274 return q;
276 return NULL;
279 void qdisc_hash_add(struct Qdisc *q, bool invisible)
281 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
282 ASSERT_RTNL();
283 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
284 if (invisible)
285 q->flags |= TCQ_F_INVISIBLE;
288 EXPORT_SYMBOL(qdisc_hash_add);
290 void qdisc_hash_del(struct Qdisc *q)
292 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
293 ASSERT_RTNL();
294 hash_del_rcu(&q->hash);
297 EXPORT_SYMBOL(qdisc_hash_del);
299 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
301 struct Qdisc *q;
303 if (!handle)
304 return NULL;
305 q = qdisc_match_from_root(dev->qdisc, handle);
306 if (q)
307 goto out;
309 if (dev_ingress_queue(dev))
310 q = qdisc_match_from_root(
311 dev_ingress_queue(dev)->qdisc_sleeping,
312 handle);
313 out:
314 return q;
317 struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle)
319 struct netdev_queue *nq;
320 struct Qdisc *q;
322 if (!handle)
323 return NULL;
324 q = qdisc_match_from_root(dev->qdisc, handle);
325 if (q)
326 goto out;
328 nq = dev_ingress_queue_rcu(dev);
329 if (nq)
330 q = qdisc_match_from_root(nq->qdisc_sleeping, handle);
331 out:
332 return q;
335 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
337 unsigned long cl;
338 struct Qdisc *leaf;
339 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
341 if (cops == NULL)
342 return NULL;
343 cl = cops->find(p, classid);
345 if (cl == 0)
346 return NULL;
347 leaf = cops->leaf(p, cl);
348 return leaf;
351 /* Find queueing discipline by name */
353 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
355 struct Qdisc_ops *q = NULL;
357 if (kind) {
358 read_lock(&qdisc_mod_lock);
359 for (q = qdisc_base; q; q = q->next) {
360 if (nla_strcmp(kind, q->id) == 0) {
361 if (!try_module_get(q->owner))
362 q = NULL;
363 break;
366 read_unlock(&qdisc_mod_lock);
368 return q;
371 /* The linklayer setting were not transferred from iproute2, in older
372 * versions, and the rate tables lookup systems have been dropped in
373 * the kernel. To keep backward compatible with older iproute2 tc
374 * utils, we detect the linklayer setting by detecting if the rate
375 * table were modified.
377 * For linklayer ATM table entries, the rate table will be aligned to
378 * 48 bytes, thus some table entries will contain the same value. The
379 * mpu (min packet unit) is also encoded into the old rate table, thus
380 * starting from the mpu, we find low and high table entries for
381 * mapping this cell. If these entries contain the same value, when
382 * the rate tables have been modified for linklayer ATM.
384 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
385 * and then roundup to the next cell, calc the table entry one below,
386 * and compare.
388 static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
390 int low = roundup(r->mpu, 48);
391 int high = roundup(low+1, 48);
392 int cell_low = low >> r->cell_log;
393 int cell_high = (high >> r->cell_log) - 1;
395 /* rtab is too inaccurate at rates > 100Mbit/s */
396 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
397 pr_debug("TC linklayer: Giving up ATM detection\n");
398 return TC_LINKLAYER_ETHERNET;
401 if ((cell_high > cell_low) && (cell_high < 256)
402 && (rtab[cell_low] == rtab[cell_high])) {
403 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
404 cell_low, cell_high, rtab[cell_high]);
405 return TC_LINKLAYER_ATM;
407 return TC_LINKLAYER_ETHERNET;
410 static struct qdisc_rate_table *qdisc_rtab_list;
412 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
413 struct nlattr *tab,
414 struct netlink_ext_ack *extack)
416 struct qdisc_rate_table *rtab;
418 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
419 nla_len(tab) != TC_RTAB_SIZE) {
420 NL_SET_ERR_MSG(extack, "Invalid rate table parameters for searching");
421 return NULL;
424 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
425 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
426 !memcmp(&rtab->data, nla_data(tab), 1024)) {
427 rtab->refcnt++;
428 return rtab;
432 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
433 if (rtab) {
434 rtab->rate = *r;
435 rtab->refcnt = 1;
436 memcpy(rtab->data, nla_data(tab), 1024);
437 if (r->linklayer == TC_LINKLAYER_UNAWARE)
438 r->linklayer = __detect_linklayer(r, rtab->data);
439 rtab->next = qdisc_rtab_list;
440 qdisc_rtab_list = rtab;
441 } else {
442 NL_SET_ERR_MSG(extack, "Failed to allocate new qdisc rate table");
444 return rtab;
446 EXPORT_SYMBOL(qdisc_get_rtab);
448 void qdisc_put_rtab(struct qdisc_rate_table *tab)
450 struct qdisc_rate_table *rtab, **rtabp;
452 if (!tab || --tab->refcnt)
453 return;
455 for (rtabp = &qdisc_rtab_list;
456 (rtab = *rtabp) != NULL;
457 rtabp = &rtab->next) {
458 if (rtab == tab) {
459 *rtabp = rtab->next;
460 kfree(rtab);
461 return;
465 EXPORT_SYMBOL(qdisc_put_rtab);
467 static LIST_HEAD(qdisc_stab_list);
469 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
470 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
471 [TCA_STAB_DATA] = { .type = NLA_BINARY },
474 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt,
475 struct netlink_ext_ack *extack)
477 struct nlattr *tb[TCA_STAB_MAX + 1];
478 struct qdisc_size_table *stab;
479 struct tc_sizespec *s;
480 unsigned int tsize = 0;
481 u16 *tab = NULL;
482 int err;
484 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy, extack);
485 if (err < 0)
486 return ERR_PTR(err);
487 if (!tb[TCA_STAB_BASE]) {
488 NL_SET_ERR_MSG(extack, "Size table base attribute is missing");
489 return ERR_PTR(-EINVAL);
492 s = nla_data(tb[TCA_STAB_BASE]);
494 if (s->tsize > 0) {
495 if (!tb[TCA_STAB_DATA]) {
496 NL_SET_ERR_MSG(extack, "Size table data attribute is missing");
497 return ERR_PTR(-EINVAL);
499 tab = nla_data(tb[TCA_STAB_DATA]);
500 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
503 if (tsize != s->tsize || (!tab && tsize > 0)) {
504 NL_SET_ERR_MSG(extack, "Invalid size of size table");
505 return ERR_PTR(-EINVAL);
508 list_for_each_entry(stab, &qdisc_stab_list, list) {
509 if (memcmp(&stab->szopts, s, sizeof(*s)))
510 continue;
511 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
512 continue;
513 stab->refcnt++;
514 return stab;
517 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
518 if (!stab)
519 return ERR_PTR(-ENOMEM);
521 stab->refcnt = 1;
522 stab->szopts = *s;
523 if (tsize > 0)
524 memcpy(stab->data, tab, tsize * sizeof(u16));
526 list_add_tail(&stab->list, &qdisc_stab_list);
528 return stab;
531 static void stab_kfree_rcu(struct rcu_head *head)
533 kfree(container_of(head, struct qdisc_size_table, rcu));
536 void qdisc_put_stab(struct qdisc_size_table *tab)
538 if (!tab)
539 return;
541 if (--tab->refcnt == 0) {
542 list_del(&tab->list);
543 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
546 EXPORT_SYMBOL(qdisc_put_stab);
548 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
550 struct nlattr *nest;
552 nest = nla_nest_start(skb, TCA_STAB);
553 if (nest == NULL)
554 goto nla_put_failure;
555 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
556 goto nla_put_failure;
557 nla_nest_end(skb, nest);
559 return skb->len;
561 nla_put_failure:
562 return -1;
565 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
566 const struct qdisc_size_table *stab)
568 int pkt_len, slot;
570 pkt_len = skb->len + stab->szopts.overhead;
571 if (unlikely(!stab->szopts.tsize))
572 goto out;
574 slot = pkt_len + stab->szopts.cell_align;
575 if (unlikely(slot < 0))
576 slot = 0;
578 slot >>= stab->szopts.cell_log;
579 if (likely(slot < stab->szopts.tsize))
580 pkt_len = stab->data[slot];
581 else
582 pkt_len = stab->data[stab->szopts.tsize - 1] *
583 (slot / stab->szopts.tsize) +
584 stab->data[slot % stab->szopts.tsize];
586 pkt_len <<= stab->szopts.size_log;
587 out:
588 if (unlikely(pkt_len < 1))
589 pkt_len = 1;
590 qdisc_skb_cb(skb)->pkt_len = pkt_len;
592 EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
594 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
596 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
597 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
598 txt, qdisc->ops->id, qdisc->handle >> 16);
599 qdisc->flags |= TCQ_F_WARN_NONWC;
602 EXPORT_SYMBOL(qdisc_warn_nonwc);
604 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
606 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
607 timer);
609 rcu_read_lock();
610 __netif_schedule(qdisc_root(wd->qdisc));
611 rcu_read_unlock();
613 return HRTIMER_NORESTART;
616 void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
617 clockid_t clockid)
619 hrtimer_init(&wd->timer, clockid, HRTIMER_MODE_ABS_PINNED);
620 wd->timer.function = qdisc_watchdog;
621 wd->qdisc = qdisc;
623 EXPORT_SYMBOL(qdisc_watchdog_init_clockid);
625 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
627 qdisc_watchdog_init_clockid(wd, qdisc, CLOCK_MONOTONIC);
629 EXPORT_SYMBOL(qdisc_watchdog_init);
631 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
633 if (test_bit(__QDISC_STATE_DEACTIVATED,
634 &qdisc_root_sleeping(wd->qdisc)->state))
635 return;
637 if (wd->last_expires == expires)
638 return;
640 wd->last_expires = expires;
641 hrtimer_start(&wd->timer,
642 ns_to_ktime(expires),
643 HRTIMER_MODE_ABS_PINNED);
645 EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
647 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
649 hrtimer_cancel(&wd->timer);
651 EXPORT_SYMBOL(qdisc_watchdog_cancel);
653 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
655 struct hlist_head *h;
656 unsigned int i;
658 h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL);
660 if (h != NULL) {
661 for (i = 0; i < n; i++)
662 INIT_HLIST_HEAD(&h[i]);
664 return h;
667 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
669 struct Qdisc_class_common *cl;
670 struct hlist_node *next;
671 struct hlist_head *nhash, *ohash;
672 unsigned int nsize, nmask, osize;
673 unsigned int i, h;
675 /* Rehash when load factor exceeds 0.75 */
676 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
677 return;
678 nsize = clhash->hashsize * 2;
679 nmask = nsize - 1;
680 nhash = qdisc_class_hash_alloc(nsize);
681 if (nhash == NULL)
682 return;
684 ohash = clhash->hash;
685 osize = clhash->hashsize;
687 sch_tree_lock(sch);
688 for (i = 0; i < osize; i++) {
689 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
690 h = qdisc_class_hash(cl->classid, nmask);
691 hlist_add_head(&cl->hnode, &nhash[h]);
694 clhash->hash = nhash;
695 clhash->hashsize = nsize;
696 clhash->hashmask = nmask;
697 sch_tree_unlock(sch);
699 kvfree(ohash);
701 EXPORT_SYMBOL(qdisc_class_hash_grow);
703 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
705 unsigned int size = 4;
707 clhash->hash = qdisc_class_hash_alloc(size);
708 if (!clhash->hash)
709 return -ENOMEM;
710 clhash->hashsize = size;
711 clhash->hashmask = size - 1;
712 clhash->hashelems = 0;
713 return 0;
715 EXPORT_SYMBOL(qdisc_class_hash_init);
717 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
719 kvfree(clhash->hash);
721 EXPORT_SYMBOL(qdisc_class_hash_destroy);
723 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
724 struct Qdisc_class_common *cl)
726 unsigned int h;
728 INIT_HLIST_NODE(&cl->hnode);
729 h = qdisc_class_hash(cl->classid, clhash->hashmask);
730 hlist_add_head(&cl->hnode, &clhash->hash[h]);
731 clhash->hashelems++;
733 EXPORT_SYMBOL(qdisc_class_hash_insert);
735 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
736 struct Qdisc_class_common *cl)
738 hlist_del(&cl->hnode);
739 clhash->hashelems--;
741 EXPORT_SYMBOL(qdisc_class_hash_remove);
743 /* Allocate an unique handle from space managed by kernel
744 * Possible range is [8000-FFFF]:0000 (0x8000 values)
746 static u32 qdisc_alloc_handle(struct net_device *dev)
748 int i = 0x8000;
749 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
751 do {
752 autohandle += TC_H_MAKE(0x10000U, 0);
753 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
754 autohandle = TC_H_MAKE(0x80000000U, 0);
755 if (!qdisc_lookup(dev, autohandle))
756 return autohandle;
757 cond_resched();
758 } while (--i > 0);
760 return 0;
763 void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,
764 unsigned int len)
766 bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED;
767 const struct Qdisc_class_ops *cops;
768 unsigned long cl;
769 u32 parentid;
770 bool notify;
771 int drops;
773 if (n == 0 && len == 0)
774 return;
775 drops = max_t(int, n, 0);
776 rcu_read_lock();
777 while ((parentid = sch->parent)) {
778 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
779 break;
781 if (sch->flags & TCQ_F_NOPARENT)
782 break;
783 /* Notify parent qdisc only if child qdisc becomes empty.
785 * If child was empty even before update then backlog
786 * counter is screwed and we skip notification because
787 * parent class is already passive.
789 * If the original child was offloaded then it is allowed
790 * to be seem as empty, so the parent is notified anyway.
792 notify = !sch->q.qlen && !WARN_ON_ONCE(!n &&
793 !qdisc_is_offloaded);
794 /* TODO: perform the search on a per txq basis */
795 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
796 if (sch == NULL) {
797 WARN_ON_ONCE(parentid != TC_H_ROOT);
798 break;
800 cops = sch->ops->cl_ops;
801 if (notify && cops->qlen_notify) {
802 cl = cops->find(sch, parentid);
803 cops->qlen_notify(sch, cl);
805 sch->q.qlen -= n;
806 sch->qstats.backlog -= len;
807 __qdisc_qstats_drop(sch, drops);
809 rcu_read_unlock();
811 EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
813 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
814 u32 portid, u32 seq, u16 flags, int event)
816 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
817 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
818 struct tcmsg *tcm;
819 struct nlmsghdr *nlh;
820 unsigned char *b = skb_tail_pointer(skb);
821 struct gnet_dump d;
822 struct qdisc_size_table *stab;
823 u32 block_index;
824 __u32 qlen;
826 cond_resched();
827 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
828 if (!nlh)
829 goto out_nlmsg_trim;
830 tcm = nlmsg_data(nlh);
831 tcm->tcm_family = AF_UNSPEC;
832 tcm->tcm__pad1 = 0;
833 tcm->tcm__pad2 = 0;
834 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
835 tcm->tcm_parent = clid;
836 tcm->tcm_handle = q->handle;
837 tcm->tcm_info = refcount_read(&q->refcnt);
838 if (nla_put_string(skb, TCA_KIND, q->ops->id))
839 goto nla_put_failure;
840 if (q->ops->ingress_block_get) {
841 block_index = q->ops->ingress_block_get(q);
842 if (block_index &&
843 nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index))
844 goto nla_put_failure;
846 if (q->ops->egress_block_get) {
847 block_index = q->ops->egress_block_get(q);
848 if (block_index &&
849 nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index))
850 goto nla_put_failure;
852 if (q->ops->dump && q->ops->dump(q, skb) < 0)
853 goto nla_put_failure;
854 if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED)))
855 goto nla_put_failure;
856 qlen = qdisc_qlen_sum(q);
858 stab = rtnl_dereference(q->stab);
859 if (stab && qdisc_dump_stab(skb, stab) < 0)
860 goto nla_put_failure;
862 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
863 NULL, &d, TCA_PAD) < 0)
864 goto nla_put_failure;
866 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
867 goto nla_put_failure;
869 if (qdisc_is_percpu_stats(q)) {
870 cpu_bstats = q->cpu_bstats;
871 cpu_qstats = q->cpu_qstats;
874 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(q),
875 &d, cpu_bstats, &q->bstats) < 0 ||
876 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
877 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
878 goto nla_put_failure;
880 if (gnet_stats_finish_copy(&d) < 0)
881 goto nla_put_failure;
883 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
884 return skb->len;
886 out_nlmsg_trim:
887 nla_put_failure:
888 nlmsg_trim(skb, b);
889 return -1;
892 static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible)
894 if (q->flags & TCQ_F_BUILTIN)
895 return true;
896 if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible)
897 return true;
899 return false;
902 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
903 struct nlmsghdr *n, u32 clid,
904 struct Qdisc *old, struct Qdisc *new)
906 struct sk_buff *skb;
907 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
909 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
910 if (!skb)
911 return -ENOBUFS;
913 if (old && !tc_qdisc_dump_ignore(old, false)) {
914 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
915 0, RTM_DELQDISC) < 0)
916 goto err_out;
918 if (new && !tc_qdisc_dump_ignore(new, false)) {
919 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
920 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
921 goto err_out;
924 if (skb->len)
925 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
926 n->nlmsg_flags & NLM_F_ECHO);
928 err_out:
929 kfree_skb(skb);
930 return -EINVAL;
933 static void notify_and_destroy(struct net *net, struct sk_buff *skb,
934 struct nlmsghdr *n, u32 clid,
935 struct Qdisc *old, struct Qdisc *new)
937 if (new || old)
938 qdisc_notify(net, skb, n, clid, old, new);
940 if (old)
941 qdisc_put(old);
944 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
945 * to device "dev".
947 * When appropriate send a netlink notification using 'skb'
948 * and "n".
950 * On success, destroy old qdisc.
953 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
954 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
955 struct Qdisc *new, struct Qdisc *old,
956 struct netlink_ext_ack *extack)
958 struct Qdisc *q = old;
959 struct net *net = dev_net(dev);
960 int err = 0;
962 if (parent == NULL) {
963 unsigned int i, num_q, ingress;
965 ingress = 0;
966 num_q = dev->num_tx_queues;
967 if ((q && q->flags & TCQ_F_INGRESS) ||
968 (new && new->flags & TCQ_F_INGRESS)) {
969 num_q = 1;
970 ingress = 1;
971 if (!dev_ingress_queue(dev)) {
972 NL_SET_ERR_MSG(extack, "Device does not have an ingress queue");
973 return -ENOENT;
977 if (dev->flags & IFF_UP)
978 dev_deactivate(dev);
980 if (new && new->ops->attach)
981 goto skip;
983 for (i = 0; i < num_q; i++) {
984 struct netdev_queue *dev_queue = dev_ingress_queue(dev);
986 if (!ingress)
987 dev_queue = netdev_get_tx_queue(dev, i);
989 old = dev_graft_qdisc(dev_queue, new);
990 if (new && i > 0)
991 qdisc_refcount_inc(new);
993 if (!ingress)
994 qdisc_put(old);
997 skip:
998 if (!ingress) {
999 notify_and_destroy(net, skb, n, classid,
1000 dev->qdisc, new);
1001 if (new && !new->ops->attach)
1002 qdisc_refcount_inc(new);
1003 dev->qdisc = new ? : &noop_qdisc;
1005 if (new && new->ops->attach)
1006 new->ops->attach(new);
1007 } else {
1008 notify_and_destroy(net, skb, n, classid, old, new);
1011 if (dev->flags & IFF_UP)
1012 dev_activate(dev);
1013 } else {
1014 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
1016 /* Only support running class lockless if parent is lockless */
1017 if (new && (new->flags & TCQ_F_NOLOCK) &&
1018 parent && !(parent->flags & TCQ_F_NOLOCK))
1019 new->flags &= ~TCQ_F_NOLOCK;
1021 err = -EOPNOTSUPP;
1022 if (cops && cops->graft) {
1023 unsigned long cl = cops->find(parent, classid);
1025 if (cl) {
1026 err = cops->graft(parent, cl, new, &old,
1027 extack);
1028 } else {
1029 NL_SET_ERR_MSG(extack, "Specified class not found");
1030 err = -ENOENT;
1033 if (!err)
1034 notify_and_destroy(net, skb, n, classid, old, new);
1036 return err;
1039 static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca,
1040 struct netlink_ext_ack *extack)
1042 u32 block_index;
1044 if (tca[TCA_INGRESS_BLOCK]) {
1045 block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]);
1047 if (!block_index) {
1048 NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0");
1049 return -EINVAL;
1051 if (!sch->ops->ingress_block_set) {
1052 NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported");
1053 return -EOPNOTSUPP;
1055 sch->ops->ingress_block_set(sch, block_index);
1057 if (tca[TCA_EGRESS_BLOCK]) {
1058 block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]);
1060 if (!block_index) {
1061 NL_SET_ERR_MSG(extack, "Egress block index cannot be 0");
1062 return -EINVAL;
1064 if (!sch->ops->egress_block_set) {
1065 NL_SET_ERR_MSG(extack, "Egress block sharing is not supported");
1066 return -EOPNOTSUPP;
1068 sch->ops->egress_block_set(sch, block_index);
1070 return 0;
1074 Allocate and initialize new qdisc.
1076 Parameters are passed via opt.
1079 static struct Qdisc *qdisc_create(struct net_device *dev,
1080 struct netdev_queue *dev_queue,
1081 struct Qdisc *p, u32 parent, u32 handle,
1082 struct nlattr **tca, int *errp,
1083 struct netlink_ext_ack *extack)
1085 int err;
1086 struct nlattr *kind = tca[TCA_KIND];
1087 struct Qdisc *sch;
1088 struct Qdisc_ops *ops;
1089 struct qdisc_size_table *stab;
1091 ops = qdisc_lookup_ops(kind);
1092 #ifdef CONFIG_MODULES
1093 if (ops == NULL && kind != NULL) {
1094 char name[IFNAMSIZ];
1095 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
1096 /* We dropped the RTNL semaphore in order to
1097 * perform the module load. So, even if we
1098 * succeeded in loading the module we have to
1099 * tell the caller to replay the request. We
1100 * indicate this using -EAGAIN.
1101 * We replay the request because the device may
1102 * go away in the mean time.
1104 rtnl_unlock();
1105 request_module("sch_%s", name);
1106 rtnl_lock();
1107 ops = qdisc_lookup_ops(kind);
1108 if (ops != NULL) {
1109 /* We will try again qdisc_lookup_ops,
1110 * so don't keep a reference.
1112 module_put(ops->owner);
1113 err = -EAGAIN;
1114 goto err_out;
1118 #endif
1120 err = -ENOENT;
1121 if (!ops) {
1122 NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1123 goto err_out;
1126 sch = qdisc_alloc(dev_queue, ops, extack);
1127 if (IS_ERR(sch)) {
1128 err = PTR_ERR(sch);
1129 goto err_out2;
1132 sch->parent = parent;
1134 if (handle == TC_H_INGRESS) {
1135 sch->flags |= TCQ_F_INGRESS;
1136 handle = TC_H_MAKE(TC_H_INGRESS, 0);
1137 } else {
1138 if (handle == 0) {
1139 handle = qdisc_alloc_handle(dev);
1140 err = -ENOMEM;
1141 if (handle == 0)
1142 goto err_out3;
1144 if (!netif_is_multiqueue(dev))
1145 sch->flags |= TCQ_F_ONETXQUEUE;
1148 sch->handle = handle;
1150 /* This exist to keep backward compatible with a userspace
1151 * loophole, what allowed userspace to get IFF_NO_QUEUE
1152 * facility on older kernels by setting tx_queue_len=0 (prior
1153 * to qdisc init), and then forgot to reinit tx_queue_len
1154 * before again attaching a qdisc.
1156 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) {
1157 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
1158 netdev_info(dev, "Caught tx_queue_len zero misconfig\n");
1161 err = qdisc_block_indexes_set(sch, tca, extack);
1162 if (err)
1163 goto err_out3;
1165 if (ops->init) {
1166 err = ops->init(sch, tca[TCA_OPTIONS], extack);
1167 if (err != 0)
1168 goto err_out5;
1171 if (tca[TCA_STAB]) {
1172 stab = qdisc_get_stab(tca[TCA_STAB], extack);
1173 if (IS_ERR(stab)) {
1174 err = PTR_ERR(stab);
1175 goto err_out4;
1177 rcu_assign_pointer(sch->stab, stab);
1179 if (tca[TCA_RATE]) {
1180 seqcount_t *running;
1182 err = -EOPNOTSUPP;
1183 if (sch->flags & TCQ_F_MQROOT) {
1184 NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc");
1185 goto err_out4;
1188 if (sch->parent != TC_H_ROOT &&
1189 !(sch->flags & TCQ_F_INGRESS) &&
1190 (!p || !(p->flags & TCQ_F_MQROOT)))
1191 running = qdisc_root_sleeping_running(sch);
1192 else
1193 running = &sch->running;
1195 err = gen_new_estimator(&sch->bstats,
1196 sch->cpu_bstats,
1197 &sch->rate_est,
1198 NULL,
1199 running,
1200 tca[TCA_RATE]);
1201 if (err) {
1202 NL_SET_ERR_MSG(extack, "Failed to generate new estimator");
1203 goto err_out4;
1207 qdisc_hash_add(sch, false);
1209 return sch;
1211 err_out5:
1212 /* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */
1213 if (ops->destroy)
1214 ops->destroy(sch);
1215 err_out3:
1216 dev_put(dev);
1217 qdisc_free(sch);
1218 err_out2:
1219 module_put(ops->owner);
1220 err_out:
1221 *errp = err;
1222 return NULL;
1224 err_out4:
1226 * Any broken qdiscs that would require a ops->reset() here?
1227 * The qdisc was never in action so it shouldn't be necessary.
1229 qdisc_put_stab(rtnl_dereference(sch->stab));
1230 if (ops->destroy)
1231 ops->destroy(sch);
1232 goto err_out3;
1235 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
1236 struct netlink_ext_ack *extack)
1238 struct qdisc_size_table *ostab, *stab = NULL;
1239 int err = 0;
1241 if (tca[TCA_OPTIONS]) {
1242 if (!sch->ops->change) {
1243 NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc");
1244 return -EINVAL;
1246 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
1247 NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
1248 return -EOPNOTSUPP;
1250 err = sch->ops->change(sch, tca[TCA_OPTIONS], extack);
1251 if (err)
1252 return err;
1255 if (tca[TCA_STAB]) {
1256 stab = qdisc_get_stab(tca[TCA_STAB], extack);
1257 if (IS_ERR(stab))
1258 return PTR_ERR(stab);
1261 ostab = rtnl_dereference(sch->stab);
1262 rcu_assign_pointer(sch->stab, stab);
1263 qdisc_put_stab(ostab);
1265 if (tca[TCA_RATE]) {
1266 /* NB: ignores errors from replace_estimator
1267 because change can't be undone. */
1268 if (sch->flags & TCQ_F_MQROOT)
1269 goto out;
1270 gen_replace_estimator(&sch->bstats,
1271 sch->cpu_bstats,
1272 &sch->rate_est,
1273 NULL,
1274 qdisc_root_sleeping_running(sch),
1275 tca[TCA_RATE]);
1277 out:
1278 return 0;
1281 struct check_loop_arg {
1282 struct qdisc_walker w;
1283 struct Qdisc *p;
1284 int depth;
1287 static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1288 struct qdisc_walker *w);
1290 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1292 struct check_loop_arg arg;
1294 if (q->ops->cl_ops == NULL)
1295 return 0;
1297 arg.w.stop = arg.w.skip = arg.w.count = 0;
1298 arg.w.fn = check_loop_fn;
1299 arg.depth = depth;
1300 arg.p = p;
1301 q->ops->cl_ops->walk(q, &arg.w);
1302 return arg.w.stop ? -ELOOP : 0;
1305 static int
1306 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1308 struct Qdisc *leaf;
1309 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1310 struct check_loop_arg *arg = (struct check_loop_arg *)w;
1312 leaf = cops->leaf(q, cl);
1313 if (leaf) {
1314 if (leaf == arg->p || arg->depth > 7)
1315 return -ELOOP;
1316 return check_loop(leaf, arg->p, arg->depth + 1);
1318 return 0;
1321 const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = {
1322 [TCA_KIND] = { .type = NLA_STRING },
1323 [TCA_RATE] = { .type = NLA_BINARY,
1324 .len = sizeof(struct tc_estimator) },
1325 [TCA_STAB] = { .type = NLA_NESTED },
1326 [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG },
1327 [TCA_CHAIN] = { .type = NLA_U32 },
1328 [TCA_INGRESS_BLOCK] = { .type = NLA_U32 },
1329 [TCA_EGRESS_BLOCK] = { .type = NLA_U32 },
1333 * Delete/get qdisc.
1336 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1337 struct netlink_ext_ack *extack)
1339 struct net *net = sock_net(skb->sk);
1340 struct tcmsg *tcm = nlmsg_data(n);
1341 struct nlattr *tca[TCA_MAX + 1];
1342 struct net_device *dev;
1343 u32 clid;
1344 struct Qdisc *q = NULL;
1345 struct Qdisc *p = NULL;
1346 int err;
1348 if ((n->nlmsg_type != RTM_GETQDISC) &&
1349 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1350 return -EPERM;
1352 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, rtm_tca_policy,
1353 extack);
1354 if (err < 0)
1355 return err;
1357 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1358 if (!dev)
1359 return -ENODEV;
1361 clid = tcm->tcm_parent;
1362 if (clid) {
1363 if (clid != TC_H_ROOT) {
1364 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1365 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1366 if (!p) {
1367 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid");
1368 return -ENOENT;
1370 q = qdisc_leaf(p, clid);
1371 } else if (dev_ingress_queue(dev)) {
1372 q = dev_ingress_queue(dev)->qdisc_sleeping;
1374 } else {
1375 q = dev->qdisc;
1377 if (!q) {
1378 NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device");
1379 return -ENOENT;
1382 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) {
1383 NL_SET_ERR_MSG(extack, "Invalid handle");
1384 return -EINVAL;
1386 } else {
1387 q = qdisc_lookup(dev, tcm->tcm_handle);
1388 if (!q) {
1389 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle");
1390 return -ENOENT;
1394 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1395 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1396 return -EINVAL;
1399 if (n->nlmsg_type == RTM_DELQDISC) {
1400 if (!clid) {
1401 NL_SET_ERR_MSG(extack, "Classid cannot be zero");
1402 return -EINVAL;
1404 if (q->handle == 0) {
1405 NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero");
1406 return -ENOENT;
1408 err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack);
1409 if (err != 0)
1410 return err;
1411 } else {
1412 qdisc_notify(net, skb, n, clid, NULL, q);
1414 return 0;
1418 * Create/change qdisc.
1421 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1422 struct netlink_ext_ack *extack)
1424 struct net *net = sock_net(skb->sk);
1425 struct tcmsg *tcm;
1426 struct nlattr *tca[TCA_MAX + 1];
1427 struct net_device *dev;
1428 u32 clid;
1429 struct Qdisc *q, *p;
1430 int err;
1432 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1433 return -EPERM;
1435 replay:
1436 /* Reinit, just in case something touches this. */
1437 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, rtm_tca_policy,
1438 extack);
1439 if (err < 0)
1440 return err;
1442 tcm = nlmsg_data(n);
1443 clid = tcm->tcm_parent;
1444 q = p = NULL;
1446 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1447 if (!dev)
1448 return -ENODEV;
1451 if (clid) {
1452 if (clid != TC_H_ROOT) {
1453 if (clid != TC_H_INGRESS) {
1454 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1455 if (!p) {
1456 NL_SET_ERR_MSG(extack, "Failed to find specified qdisc");
1457 return -ENOENT;
1459 q = qdisc_leaf(p, clid);
1460 } else if (dev_ingress_queue_create(dev)) {
1461 q = dev_ingress_queue(dev)->qdisc_sleeping;
1463 } else {
1464 q = dev->qdisc;
1467 /* It may be default qdisc, ignore it */
1468 if (q && q->handle == 0)
1469 q = NULL;
1471 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1472 if (tcm->tcm_handle) {
1473 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) {
1474 NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override");
1475 return -EEXIST;
1477 if (TC_H_MIN(tcm->tcm_handle)) {
1478 NL_SET_ERR_MSG(extack, "Invalid minor handle");
1479 return -EINVAL;
1481 q = qdisc_lookup(dev, tcm->tcm_handle);
1482 if (!q)
1483 goto create_n_graft;
1484 if (n->nlmsg_flags & NLM_F_EXCL) {
1485 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override");
1486 return -EEXIST;
1488 if (tca[TCA_KIND] &&
1489 nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1490 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1491 return -EINVAL;
1493 if (q == p ||
1494 (p && check_loop(q, p, 0))) {
1495 NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected");
1496 return -ELOOP;
1498 qdisc_refcount_inc(q);
1499 goto graft;
1500 } else {
1501 if (!q)
1502 goto create_n_graft;
1504 /* This magic test requires explanation.
1506 * We know, that some child q is already
1507 * attached to this parent and have choice:
1508 * either to change it or to create/graft new one.
1510 * 1. We are allowed to create/graft only
1511 * if CREATE and REPLACE flags are set.
1513 * 2. If EXCL is set, requestor wanted to say,
1514 * that qdisc tcm_handle is not expected
1515 * to exist, so that we choose create/graft too.
1517 * 3. The last case is when no flags are set.
1518 * Alas, it is sort of hole in API, we
1519 * cannot decide what to do unambiguously.
1520 * For now we select create/graft, if
1521 * user gave KIND, which does not match existing.
1523 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1524 (n->nlmsg_flags & NLM_F_REPLACE) &&
1525 ((n->nlmsg_flags & NLM_F_EXCL) ||
1526 (tca[TCA_KIND] &&
1527 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1528 goto create_n_graft;
1531 } else {
1532 if (!tcm->tcm_handle) {
1533 NL_SET_ERR_MSG(extack, "Handle cannot be zero");
1534 return -EINVAL;
1536 q = qdisc_lookup(dev, tcm->tcm_handle);
1539 /* Change qdisc parameters */
1540 if (!q) {
1541 NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1542 return -ENOENT;
1544 if (n->nlmsg_flags & NLM_F_EXCL) {
1545 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify");
1546 return -EEXIST;
1548 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1549 NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1550 return -EINVAL;
1552 err = qdisc_change(q, tca, extack);
1553 if (err == 0)
1554 qdisc_notify(net, skb, n, clid, NULL, q);
1555 return err;
1557 create_n_graft:
1558 if (!(n->nlmsg_flags & NLM_F_CREATE)) {
1559 NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag");
1560 return -ENOENT;
1562 if (clid == TC_H_INGRESS) {
1563 if (dev_ingress_queue(dev)) {
1564 q = qdisc_create(dev, dev_ingress_queue(dev), p,
1565 tcm->tcm_parent, tcm->tcm_parent,
1566 tca, &err, extack);
1567 } else {
1568 NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device");
1569 err = -ENOENT;
1571 } else {
1572 struct netdev_queue *dev_queue;
1574 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1575 dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1576 else if (p)
1577 dev_queue = p->dev_queue;
1578 else
1579 dev_queue = netdev_get_tx_queue(dev, 0);
1581 q = qdisc_create(dev, dev_queue, p,
1582 tcm->tcm_parent, tcm->tcm_handle,
1583 tca, &err, extack);
1585 if (q == NULL) {
1586 if (err == -EAGAIN)
1587 goto replay;
1588 return err;
1591 graft:
1592 err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack);
1593 if (err) {
1594 if (q)
1595 qdisc_put(q);
1596 return err;
1599 return 0;
1602 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1603 struct netlink_callback *cb,
1604 int *q_idx_p, int s_q_idx, bool recur,
1605 bool dump_invisible)
1607 int ret = 0, q_idx = *q_idx_p;
1608 struct Qdisc *q;
1609 int b;
1611 if (!root)
1612 return 0;
1614 q = root;
1615 if (q_idx < s_q_idx) {
1616 q_idx++;
1617 } else {
1618 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1619 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1620 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1621 RTM_NEWQDISC) <= 0)
1622 goto done;
1623 q_idx++;
1626 /* If dumping singletons, there is no qdisc_dev(root) and the singleton
1627 * itself has already been dumped.
1629 * If we've already dumped the top-level (ingress) qdisc above and the global
1630 * qdisc hashtable, we don't want to hit it again
1632 if (!qdisc_dev(root) || !recur)
1633 goto out;
1635 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1636 if (q_idx < s_q_idx) {
1637 q_idx++;
1638 continue;
1640 if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1641 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1642 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1643 RTM_NEWQDISC) <= 0)
1644 goto done;
1645 q_idx++;
1648 out:
1649 *q_idx_p = q_idx;
1650 return ret;
1651 done:
1652 ret = -1;
1653 goto out;
1656 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1658 struct net *net = sock_net(skb->sk);
1659 int idx, q_idx;
1660 int s_idx, s_q_idx;
1661 struct net_device *dev;
1662 const struct nlmsghdr *nlh = cb->nlh;
1663 struct nlattr *tca[TCA_MAX + 1];
1664 int err;
1666 s_idx = cb->args[0];
1667 s_q_idx = q_idx = cb->args[1];
1669 idx = 0;
1670 ASSERT_RTNL();
1672 err = nlmsg_parse(nlh, sizeof(struct tcmsg), tca, TCA_MAX,
1673 rtm_tca_policy, cb->extack);
1674 if (err < 0)
1675 return err;
1677 for_each_netdev(net, dev) {
1678 struct netdev_queue *dev_queue;
1680 if (idx < s_idx)
1681 goto cont;
1682 if (idx > s_idx)
1683 s_q_idx = 0;
1684 q_idx = 0;
1686 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx,
1687 true, tca[TCA_DUMP_INVISIBLE]) < 0)
1688 goto done;
1690 dev_queue = dev_ingress_queue(dev);
1691 if (dev_queue &&
1692 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1693 &q_idx, s_q_idx, false,
1694 tca[TCA_DUMP_INVISIBLE]) < 0)
1695 goto done;
1697 cont:
1698 idx++;
1701 done:
1702 cb->args[0] = idx;
1703 cb->args[1] = q_idx;
1705 return skb->len;
1710 /************************************************
1711 * Traffic classes manipulation. *
1712 ************************************************/
1714 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1715 unsigned long cl,
1716 u32 portid, u32 seq, u16 flags, int event)
1718 struct tcmsg *tcm;
1719 struct nlmsghdr *nlh;
1720 unsigned char *b = skb_tail_pointer(skb);
1721 struct gnet_dump d;
1722 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1724 cond_resched();
1725 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1726 if (!nlh)
1727 goto out_nlmsg_trim;
1728 tcm = nlmsg_data(nlh);
1729 tcm->tcm_family = AF_UNSPEC;
1730 tcm->tcm__pad1 = 0;
1731 tcm->tcm__pad2 = 0;
1732 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1733 tcm->tcm_parent = q->handle;
1734 tcm->tcm_handle = q->handle;
1735 tcm->tcm_info = 0;
1736 if (nla_put_string(skb, TCA_KIND, q->ops->id))
1737 goto nla_put_failure;
1738 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1739 goto nla_put_failure;
1741 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1742 NULL, &d, TCA_PAD) < 0)
1743 goto nla_put_failure;
1745 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1746 goto nla_put_failure;
1748 if (gnet_stats_finish_copy(&d) < 0)
1749 goto nla_put_failure;
1751 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1752 return skb->len;
1754 out_nlmsg_trim:
1755 nla_put_failure:
1756 nlmsg_trim(skb, b);
1757 return -1;
1760 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1761 struct nlmsghdr *n, struct Qdisc *q,
1762 unsigned long cl, int event)
1764 struct sk_buff *skb;
1765 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1767 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1768 if (!skb)
1769 return -ENOBUFS;
1771 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1772 kfree_skb(skb);
1773 return -EINVAL;
1776 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1777 n->nlmsg_flags & NLM_F_ECHO);
1780 static int tclass_del_notify(struct net *net,
1781 const struct Qdisc_class_ops *cops,
1782 struct sk_buff *oskb, struct nlmsghdr *n,
1783 struct Qdisc *q, unsigned long cl)
1785 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1786 struct sk_buff *skb;
1787 int err = 0;
1789 if (!cops->delete)
1790 return -EOPNOTSUPP;
1792 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1793 if (!skb)
1794 return -ENOBUFS;
1796 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0,
1797 RTM_DELTCLASS) < 0) {
1798 kfree_skb(skb);
1799 return -EINVAL;
1802 err = cops->delete(q, cl);
1803 if (err) {
1804 kfree_skb(skb);
1805 return err;
1808 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1809 n->nlmsg_flags & NLM_F_ECHO);
1812 #ifdef CONFIG_NET_CLS
1814 struct tcf_bind_args {
1815 struct tcf_walker w;
1816 u32 classid;
1817 unsigned long cl;
1820 static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
1822 struct tcf_bind_args *a = (void *)arg;
1824 if (tp->ops->bind_class) {
1825 struct Qdisc *q = tcf_block_q(tp->chain->block);
1827 sch_tree_lock(q);
1828 tp->ops->bind_class(n, a->classid, a->cl);
1829 sch_tree_unlock(q);
1831 return 0;
1834 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1835 unsigned long new_cl)
1837 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1838 struct tcf_block *block;
1839 struct tcf_chain *chain;
1840 unsigned long cl;
1842 cl = cops->find(q, portid);
1843 if (!cl)
1844 return;
1845 block = cops->tcf_block(q, cl, NULL);
1846 if (!block)
1847 return;
1848 list_for_each_entry(chain, &block->chain_list, list) {
1849 struct tcf_proto *tp;
1851 for (tp = rtnl_dereference(chain->filter_chain);
1852 tp; tp = rtnl_dereference(tp->next)) {
1853 struct tcf_bind_args arg = {};
1855 arg.w.fn = tcf_node_bind;
1856 arg.classid = clid;
1857 arg.cl = new_cl;
1858 tp->ops->walk(tp, &arg.w);
1863 #else
1865 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1866 unsigned long new_cl)
1870 #endif
1872 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
1873 struct netlink_ext_ack *extack)
1875 struct net *net = sock_net(skb->sk);
1876 struct tcmsg *tcm = nlmsg_data(n);
1877 struct nlattr *tca[TCA_MAX + 1];
1878 struct net_device *dev;
1879 struct Qdisc *q = NULL;
1880 const struct Qdisc_class_ops *cops;
1881 unsigned long cl = 0;
1882 unsigned long new_cl;
1883 u32 portid;
1884 u32 clid;
1885 u32 qid;
1886 int err;
1888 if ((n->nlmsg_type != RTM_GETTCLASS) &&
1889 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1890 return -EPERM;
1892 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, rtm_tca_policy,
1893 extack);
1894 if (err < 0)
1895 return err;
1897 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1898 if (!dev)
1899 return -ENODEV;
1902 parent == TC_H_UNSPEC - unspecified parent.
1903 parent == TC_H_ROOT - class is root, which has no parent.
1904 parent == X:0 - parent is root class.
1905 parent == X:Y - parent is a node in hierarchy.
1906 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1908 handle == 0:0 - generate handle from kernel pool.
1909 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1910 handle == X:Y - clear.
1911 handle == X:0 - root class.
1914 /* Step 1. Determine qdisc handle X:0 */
1916 portid = tcm->tcm_parent;
1917 clid = tcm->tcm_handle;
1918 qid = TC_H_MAJ(clid);
1920 if (portid != TC_H_ROOT) {
1921 u32 qid1 = TC_H_MAJ(portid);
1923 if (qid && qid1) {
1924 /* If both majors are known, they must be identical. */
1925 if (qid != qid1)
1926 return -EINVAL;
1927 } else if (qid1) {
1928 qid = qid1;
1929 } else if (qid == 0)
1930 qid = dev->qdisc->handle;
1932 /* Now qid is genuine qdisc handle consistent
1933 * both with parent and child.
1935 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1937 if (portid)
1938 portid = TC_H_MAKE(qid, portid);
1939 } else {
1940 if (qid == 0)
1941 qid = dev->qdisc->handle;
1944 /* OK. Locate qdisc */
1945 q = qdisc_lookup(dev, qid);
1946 if (!q)
1947 return -ENOENT;
1949 /* An check that it supports classes */
1950 cops = q->ops->cl_ops;
1951 if (cops == NULL)
1952 return -EINVAL;
1954 /* Now try to get class */
1955 if (clid == 0) {
1956 if (portid == TC_H_ROOT)
1957 clid = qid;
1958 } else
1959 clid = TC_H_MAKE(qid, clid);
1961 if (clid)
1962 cl = cops->find(q, clid);
1964 if (cl == 0) {
1965 err = -ENOENT;
1966 if (n->nlmsg_type != RTM_NEWTCLASS ||
1967 !(n->nlmsg_flags & NLM_F_CREATE))
1968 goto out;
1969 } else {
1970 switch (n->nlmsg_type) {
1971 case RTM_NEWTCLASS:
1972 err = -EEXIST;
1973 if (n->nlmsg_flags & NLM_F_EXCL)
1974 goto out;
1975 break;
1976 case RTM_DELTCLASS:
1977 err = tclass_del_notify(net, cops, skb, n, q, cl);
1978 /* Unbind the class with flilters with 0 */
1979 tc_bind_tclass(q, portid, clid, 0);
1980 goto out;
1981 case RTM_GETTCLASS:
1982 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1983 goto out;
1984 default:
1985 err = -EINVAL;
1986 goto out;
1990 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
1991 NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes");
1992 return -EOPNOTSUPP;
1995 new_cl = cl;
1996 err = -EOPNOTSUPP;
1997 if (cops->change)
1998 err = cops->change(q, clid, portid, tca, &new_cl, extack);
1999 if (err == 0) {
2000 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
2001 /* We just create a new class, need to do reverse binding. */
2002 if (cl != new_cl)
2003 tc_bind_tclass(q, portid, clid, new_cl);
2005 out:
2006 return err;
2009 struct qdisc_dump_args {
2010 struct qdisc_walker w;
2011 struct sk_buff *skb;
2012 struct netlink_callback *cb;
2015 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
2016 struct qdisc_walker *arg)
2018 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
2020 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
2021 a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2022 RTM_NEWTCLASS);
2025 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
2026 struct tcmsg *tcm, struct netlink_callback *cb,
2027 int *t_p, int s_t)
2029 struct qdisc_dump_args arg;
2031 if (tc_qdisc_dump_ignore(q, false) ||
2032 *t_p < s_t || !q->ops->cl_ops ||
2033 (tcm->tcm_parent &&
2034 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
2035 (*t_p)++;
2036 return 0;
2038 if (*t_p > s_t)
2039 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
2040 arg.w.fn = qdisc_class_dump;
2041 arg.skb = skb;
2042 arg.cb = cb;
2043 arg.w.stop = 0;
2044 arg.w.skip = cb->args[1];
2045 arg.w.count = 0;
2046 q->ops->cl_ops->walk(q, &arg.w);
2047 cb->args[1] = arg.w.count;
2048 if (arg.w.stop)
2049 return -1;
2050 (*t_p)++;
2051 return 0;
2054 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
2055 struct tcmsg *tcm, struct netlink_callback *cb,
2056 int *t_p, int s_t)
2058 struct Qdisc *q;
2059 int b;
2061 if (!root)
2062 return 0;
2064 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
2065 return -1;
2067 if (!qdisc_dev(root))
2068 return 0;
2070 if (tcm->tcm_parent) {
2071 q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent));
2072 if (q && q != root &&
2073 tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2074 return -1;
2075 return 0;
2077 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
2078 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2079 return -1;
2082 return 0;
2085 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
2087 struct tcmsg *tcm = nlmsg_data(cb->nlh);
2088 struct net *net = sock_net(skb->sk);
2089 struct netdev_queue *dev_queue;
2090 struct net_device *dev;
2091 int t, s_t;
2093 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2094 return 0;
2095 dev = dev_get_by_index(net, tcm->tcm_ifindex);
2096 if (!dev)
2097 return 0;
2099 s_t = cb->args[0];
2100 t = 0;
2102 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
2103 goto done;
2105 dev_queue = dev_ingress_queue(dev);
2106 if (dev_queue &&
2107 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
2108 &t, s_t) < 0)
2109 goto done;
2111 done:
2112 cb->args[0] = t;
2114 dev_put(dev);
2115 return skb->len;
2118 #ifdef CONFIG_PROC_FS
2119 static int psched_show(struct seq_file *seq, void *v)
2121 seq_printf(seq, "%08x %08x %08x %08x\n",
2122 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
2123 1000000,
2124 (u32)NSEC_PER_SEC / hrtimer_resolution);
2126 return 0;
2129 static int __net_init psched_net_init(struct net *net)
2131 struct proc_dir_entry *e;
2133 e = proc_create_single("psched", 0, net->proc_net, psched_show);
2134 if (e == NULL)
2135 return -ENOMEM;
2137 return 0;
2140 static void __net_exit psched_net_exit(struct net *net)
2142 remove_proc_entry("psched", net->proc_net);
2144 #else
2145 static int __net_init psched_net_init(struct net *net)
2147 return 0;
2150 static void __net_exit psched_net_exit(struct net *net)
2153 #endif
2155 static struct pernet_operations psched_net_ops = {
2156 .init = psched_net_init,
2157 .exit = psched_net_exit,
2160 static int __init pktsched_init(void)
2162 int err;
2164 err = register_pernet_subsys(&psched_net_ops);
2165 if (err) {
2166 pr_err("pktsched_init: "
2167 "cannot initialize per netns operations\n");
2168 return err;
2171 register_qdisc(&pfifo_fast_ops);
2172 register_qdisc(&pfifo_qdisc_ops);
2173 register_qdisc(&bfifo_qdisc_ops);
2174 register_qdisc(&pfifo_head_drop_qdisc_ops);
2175 register_qdisc(&mq_qdisc_ops);
2176 register_qdisc(&noqueue_qdisc_ops);
2178 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, 0);
2179 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, 0);
2180 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc,
2182 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, 0);
2183 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, 0);
2184 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass,
2187 return 0;
2190 subsys_initcall(pktsched_init);