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>
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/lockdep.h>
32 #include <net/net_namespace.h>
34 #include <net/netlink.h>
35 #include <net/pkt_sched.h>
37 static int qdisc_notify(struct sk_buff *oskb, struct nlmsghdr *n, u32 clid,
38 struct Qdisc *old, struct Qdisc *new);
39 static int tclass_notify(struct sk_buff *oskb, struct nlmsghdr *n,
40 struct Qdisc *q, unsigned long cl, int event);
47 This file consists of two interrelated parts:
49 1. queueing disciplines manager frontend.
50 2. traffic classes manager frontend.
52 Generally, queueing discipline ("qdisc") is a black box,
53 which is able to enqueue packets and to dequeue them (when
54 device is ready to send something) in order and at times
55 determined by algorithm hidden in it.
57 qdisc's are divided to two categories:
58 - "queues", which have no internal structure visible from outside.
59 - "schedulers", which split all the packets to "traffic classes",
60 using "packet classifiers" (look at cls_api.c)
62 In turn, classes may have child qdiscs (as rule, queues)
63 attached to them etc. etc. etc.
65 The goal of the routines in this file is to translate
66 information supplied by user in the form of handles
67 to more intelligible for kernel form, to make some sanity
68 checks and part of work, which is common to all qdiscs
69 and to provide rtnetlink notifications.
71 All real intelligent work is done inside qdisc modules.
75 Every discipline has two major routines: enqueue and dequeue.
79 dequeue usually returns a skb to send. It is allowed to return NULL,
80 but it does not mean that queue is empty, it just means that
81 discipline does not want to send anything this time.
82 Queue is really empty if q->q.qlen == 0.
83 For complicated disciplines with multiple queues q->q is not
84 real packet queue, but however q->q.qlen must be valid.
88 enqueue returns 0, if packet was enqueued successfully.
89 If packet (this one or another one) was dropped, it returns
91 NET_XMIT_DROP - this packet dropped
92 Expected action: do not backoff, but wait until queue will clear.
93 NET_XMIT_CN - probably this packet enqueued, but another one dropped.
94 Expected action: backoff or ignore
95 NET_XMIT_POLICED - dropped by police.
96 Expected action: backoff or error to real-time apps.
102 like dequeue but without removing a packet from the queue
106 returns qdisc to initial state: purge all buffers, clear all
107 timers, counters (except for statistics) etc.
111 initializes newly created qdisc.
115 destroys resources allocated by init and during lifetime of qdisc.
119 changes qdisc parameters.
122 /* Protects list of registered TC modules. It is pure SMP lock. */
123 static DEFINE_RWLOCK(qdisc_mod_lock);
126 /************************************************
127 * Queueing disciplines manipulation. *
128 ************************************************/
131 /* The list of all installed queueing disciplines. */
133 static struct Qdisc_ops *qdisc_base;
135 /* Register/uregister queueing discipline */
137 int register_qdisc(struct Qdisc_ops *qops)
139 struct Qdisc_ops *q, **qp;
142 write_lock(&qdisc_mod_lock);
143 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
144 if (!strcmp(qops->id, q->id))
147 if (qops->enqueue == NULL)
148 qops->enqueue = noop_qdisc_ops.enqueue;
149 if (qops->peek == NULL) {
150 if (qops->dequeue == NULL) {
151 qops->peek = noop_qdisc_ops.peek;
157 if (qops->dequeue == NULL)
158 qops->dequeue = noop_qdisc_ops.dequeue;
164 write_unlock(&qdisc_mod_lock);
167 EXPORT_SYMBOL(register_qdisc);
169 int unregister_qdisc(struct Qdisc_ops *qops)
171 struct Qdisc_ops *q, **qp;
174 write_lock(&qdisc_mod_lock);
175 for (qp = &qdisc_base; (q=*qp)!=NULL; qp = &q->next)
183 write_unlock(&qdisc_mod_lock);
186 EXPORT_SYMBOL(unregister_qdisc);
188 /* We know handle. Find qdisc among all qdisc's attached to device
189 (root qdisc, all its children, children of children etc.)
192 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
196 if (!(root->flags & TCQ_F_BUILTIN) &&
197 root->handle == handle)
200 list_for_each_entry(q, &root->list, list) {
201 if (q->handle == handle)
207 static void qdisc_list_add(struct Qdisc *q)
209 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
210 list_add_tail(&q->list, &qdisc_dev(q)->qdisc->list);
213 void qdisc_list_del(struct Qdisc *q)
215 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
218 EXPORT_SYMBOL(qdisc_list_del);
220 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
224 q = qdisc_match_from_root(dev->qdisc, handle);
228 q = qdisc_match_from_root(dev->rx_queue.qdisc_sleeping, handle);
233 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
237 const struct Qdisc_class_ops *cops = p->ops->cl_ops;
241 cl = cops->get(p, classid);
245 leaf = cops->leaf(p, cl);
250 /* Find queueing discipline by name */
252 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
254 struct Qdisc_ops *q = NULL;
257 read_lock(&qdisc_mod_lock);
258 for (q = qdisc_base; q; q = q->next) {
259 if (nla_strcmp(kind, q->id) == 0) {
260 if (!try_module_get(q->owner))
265 read_unlock(&qdisc_mod_lock);
270 static struct qdisc_rate_table *qdisc_rtab_list;
272 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct nlattr *tab)
274 struct qdisc_rate_table *rtab;
276 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
277 if (memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) == 0) {
283 if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
284 nla_len(tab) != TC_RTAB_SIZE)
287 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
291 memcpy(rtab->data, nla_data(tab), 1024);
292 rtab->next = qdisc_rtab_list;
293 qdisc_rtab_list = rtab;
297 EXPORT_SYMBOL(qdisc_get_rtab);
299 void qdisc_put_rtab(struct qdisc_rate_table *tab)
301 struct qdisc_rate_table *rtab, **rtabp;
303 if (!tab || --tab->refcnt)
306 for (rtabp = &qdisc_rtab_list; (rtab=*rtabp) != NULL; rtabp = &rtab->next) {
314 EXPORT_SYMBOL(qdisc_put_rtab);
316 static LIST_HEAD(qdisc_stab_list);
317 static DEFINE_SPINLOCK(qdisc_stab_lock);
319 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
320 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
321 [TCA_STAB_DATA] = { .type = NLA_BINARY },
324 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
326 struct nlattr *tb[TCA_STAB_MAX + 1];
327 struct qdisc_size_table *stab;
328 struct tc_sizespec *s;
329 unsigned int tsize = 0;
333 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
336 if (!tb[TCA_STAB_BASE])
337 return ERR_PTR(-EINVAL);
339 s = nla_data(tb[TCA_STAB_BASE]);
342 if (!tb[TCA_STAB_DATA])
343 return ERR_PTR(-EINVAL);
344 tab = nla_data(tb[TCA_STAB_DATA]);
345 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
348 if (!s || tsize != s->tsize || (!tab && tsize > 0))
349 return ERR_PTR(-EINVAL);
351 spin_lock(&qdisc_stab_lock);
353 list_for_each_entry(stab, &qdisc_stab_list, list) {
354 if (memcmp(&stab->szopts, s, sizeof(*s)))
356 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
359 spin_unlock(&qdisc_stab_lock);
363 spin_unlock(&qdisc_stab_lock);
365 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
367 return ERR_PTR(-ENOMEM);
372 memcpy(stab->data, tab, tsize * sizeof(u16));
374 spin_lock(&qdisc_stab_lock);
375 list_add_tail(&stab->list, &qdisc_stab_list);
376 spin_unlock(&qdisc_stab_lock);
381 void qdisc_put_stab(struct qdisc_size_table *tab)
386 spin_lock(&qdisc_stab_lock);
388 if (--tab->refcnt == 0) {
389 list_del(&tab->list);
393 spin_unlock(&qdisc_stab_lock);
395 EXPORT_SYMBOL(qdisc_put_stab);
397 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
401 nest = nla_nest_start(skb, TCA_STAB);
403 goto nla_put_failure;
404 NLA_PUT(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts);
405 nla_nest_end(skb, nest);
413 void qdisc_calculate_pkt_len(struct sk_buff *skb, struct qdisc_size_table *stab)
417 pkt_len = skb->len + stab->szopts.overhead;
418 if (unlikely(!stab->szopts.tsize))
421 slot = pkt_len + stab->szopts.cell_align;
422 if (unlikely(slot < 0))
425 slot >>= stab->szopts.cell_log;
426 if (likely(slot < stab->szopts.tsize))
427 pkt_len = stab->data[slot];
429 pkt_len = stab->data[stab->szopts.tsize - 1] *
430 (slot / stab->szopts.tsize) +
431 stab->data[slot % stab->szopts.tsize];
433 pkt_len <<= stab->szopts.size_log;
435 if (unlikely(pkt_len < 1))
437 qdisc_skb_cb(skb)->pkt_len = pkt_len;
439 EXPORT_SYMBOL(qdisc_calculate_pkt_len);
441 void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc)
443 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
445 "%s: %s qdisc %X: is non-work-conserving?\n",
446 txt, qdisc->ops->id, qdisc->handle >> 16);
447 qdisc->flags |= TCQ_F_WARN_NONWC;
450 EXPORT_SYMBOL(qdisc_warn_nonwc);
452 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
454 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
457 wd->qdisc->flags &= ~TCQ_F_THROTTLED;
458 __netif_schedule(qdisc_root(wd->qdisc));
460 return HRTIMER_NORESTART;
463 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
465 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
466 wd->timer.function = qdisc_watchdog;
469 EXPORT_SYMBOL(qdisc_watchdog_init);
471 void qdisc_watchdog_schedule(struct qdisc_watchdog *wd, psched_time_t expires)
475 if (test_bit(__QDISC_STATE_DEACTIVATED,
476 &qdisc_root_sleeping(wd->qdisc)->state))
479 wd->qdisc->flags |= TCQ_F_THROTTLED;
480 time = ktime_set(0, 0);
481 time = ktime_add_ns(time, PSCHED_TICKS2NS(expires));
482 hrtimer_start(&wd->timer, time, HRTIMER_MODE_ABS);
484 EXPORT_SYMBOL(qdisc_watchdog_schedule);
486 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
488 hrtimer_cancel(&wd->timer);
489 wd->qdisc->flags &= ~TCQ_F_THROTTLED;
491 EXPORT_SYMBOL(qdisc_watchdog_cancel);
493 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
495 unsigned int size = n * sizeof(struct hlist_head), i;
496 struct hlist_head *h;
498 if (size <= PAGE_SIZE)
499 h = kmalloc(size, GFP_KERNEL);
501 h = (struct hlist_head *)
502 __get_free_pages(GFP_KERNEL, get_order(size));
505 for (i = 0; i < n; i++)
506 INIT_HLIST_HEAD(&h[i]);
511 static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
513 unsigned int size = n * sizeof(struct hlist_head);
515 if (size <= PAGE_SIZE)
518 free_pages((unsigned long)h, get_order(size));
521 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
523 struct Qdisc_class_common *cl;
524 struct hlist_node *n, *next;
525 struct hlist_head *nhash, *ohash;
526 unsigned int nsize, nmask, osize;
529 /* Rehash when load factor exceeds 0.75 */
530 if (clhash->hashelems * 4 <= clhash->hashsize * 3)
532 nsize = clhash->hashsize * 2;
534 nhash = qdisc_class_hash_alloc(nsize);
538 ohash = clhash->hash;
539 osize = clhash->hashsize;
542 for (i = 0; i < osize; i++) {
543 hlist_for_each_entry_safe(cl, n, next, &ohash[i], hnode) {
544 h = qdisc_class_hash(cl->classid, nmask);
545 hlist_add_head(&cl->hnode, &nhash[h]);
548 clhash->hash = nhash;
549 clhash->hashsize = nsize;
550 clhash->hashmask = nmask;
551 sch_tree_unlock(sch);
553 qdisc_class_hash_free(ohash, osize);
555 EXPORT_SYMBOL(qdisc_class_hash_grow);
557 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
559 unsigned int size = 4;
561 clhash->hash = qdisc_class_hash_alloc(size);
562 if (clhash->hash == NULL)
564 clhash->hashsize = size;
565 clhash->hashmask = size - 1;
566 clhash->hashelems = 0;
569 EXPORT_SYMBOL(qdisc_class_hash_init);
571 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
573 qdisc_class_hash_free(clhash->hash, clhash->hashsize);
575 EXPORT_SYMBOL(qdisc_class_hash_destroy);
577 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
578 struct Qdisc_class_common *cl)
582 INIT_HLIST_NODE(&cl->hnode);
583 h = qdisc_class_hash(cl->classid, clhash->hashmask);
584 hlist_add_head(&cl->hnode, &clhash->hash[h]);
587 EXPORT_SYMBOL(qdisc_class_hash_insert);
589 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
590 struct Qdisc_class_common *cl)
592 hlist_del(&cl->hnode);
595 EXPORT_SYMBOL(qdisc_class_hash_remove);
597 /* Allocate an unique handle from space managed by kernel */
599 static u32 qdisc_alloc_handle(struct net_device *dev)
602 static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
605 autohandle += TC_H_MAKE(0x10000U, 0);
606 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
607 autohandle = TC_H_MAKE(0x80000000U, 0);
608 } while (qdisc_lookup(dev, autohandle) && --i > 0);
610 return i>0 ? autohandle : 0;
613 void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
615 const struct Qdisc_class_ops *cops;
621 while ((parentid = sch->parent)) {
622 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
625 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
627 WARN_ON(parentid != TC_H_ROOT);
630 cops = sch->ops->cl_ops;
631 if (cops->qlen_notify) {
632 cl = cops->get(sch, parentid);
633 cops->qlen_notify(sch, cl);
639 EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
641 static void notify_and_destroy(struct sk_buff *skb, struct nlmsghdr *n, u32 clid,
642 struct Qdisc *old, struct Qdisc *new)
645 qdisc_notify(skb, n, clid, old, new);
651 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
654 * When appropriate send a netlink notification using 'skb'
657 * On success, destroy old qdisc.
660 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
661 struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
662 struct Qdisc *new, struct Qdisc *old)
664 struct Qdisc *q = old;
667 if (parent == NULL) {
668 unsigned int i, num_q, ingress;
671 num_q = dev->num_tx_queues;
672 if ((q && q->flags & TCQ_F_INGRESS) ||
673 (new && new->flags & TCQ_F_INGRESS)) {
678 if (dev->flags & IFF_UP)
681 if (new && new->ops->attach) {
682 new->ops->attach(new);
686 for (i = 0; i < num_q; i++) {
687 struct netdev_queue *dev_queue = &dev->rx_queue;
690 dev_queue = netdev_get_tx_queue(dev, i);
692 old = dev_graft_qdisc(dev_queue, new);
694 atomic_inc(&new->refcnt);
701 notify_and_destroy(skb, n, classid, dev->qdisc, new);
702 if (new && !new->ops->attach)
703 atomic_inc(&new->refcnt);
704 dev->qdisc = new ? : &noop_qdisc;
706 notify_and_destroy(skb, n, classid, old, new);
709 if (dev->flags & IFF_UP)
712 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
715 if (cops && cops->graft) {
716 unsigned long cl = cops->get(parent, classid);
718 err = cops->graft(parent, cl, new, &old);
719 cops->put(parent, cl);
724 notify_and_destroy(skb, n, classid, old, new);
729 /* lockdep annotation is needed for ingress; egress gets it only for name */
730 static struct lock_class_key qdisc_tx_lock;
731 static struct lock_class_key qdisc_rx_lock;
734 Allocate and initialize new qdisc.
736 Parameters are passed via opt.
739 static struct Qdisc *
740 qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
741 struct Qdisc *p, u32 parent, u32 handle,
742 struct nlattr **tca, int *errp)
745 struct nlattr *kind = tca[TCA_KIND];
747 struct Qdisc_ops *ops;
748 struct qdisc_size_table *stab;
750 ops = qdisc_lookup_ops(kind);
751 #ifdef CONFIG_MODULES
752 if (ops == NULL && kind != NULL) {
754 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
755 /* We dropped the RTNL semaphore in order to
756 * perform the module load. So, even if we
757 * succeeded in loading the module we have to
758 * tell the caller to replay the request. We
759 * indicate this using -EAGAIN.
760 * We replay the request because the device may
761 * go away in the mean time.
764 request_module("sch_%s", name);
766 ops = qdisc_lookup_ops(kind);
768 /* We will try again qdisc_lookup_ops,
769 * so don't keep a reference.
771 module_put(ops->owner);
783 sch = qdisc_alloc(dev_queue, ops);
789 sch->parent = parent;
791 if (handle == TC_H_INGRESS) {
792 sch->flags |= TCQ_F_INGRESS;
793 handle = TC_H_MAKE(TC_H_INGRESS, 0);
794 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
797 handle = qdisc_alloc_handle(dev);
802 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
805 sch->handle = handle;
807 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
809 stab = qdisc_get_stab(tca[TCA_STAB]);
817 spinlock_t *root_lock;
820 if (sch->flags & TCQ_F_MQROOT)
823 if ((sch->parent != TC_H_ROOT) &&
824 !(sch->flags & TCQ_F_INGRESS) &&
825 (!p || !(p->flags & TCQ_F_MQROOT)))
826 root_lock = qdisc_root_sleeping_lock(sch);
828 root_lock = qdisc_lock(sch);
830 err = gen_new_estimator(&sch->bstats, &sch->rate_est,
831 root_lock, tca[TCA_RATE]);
841 qdisc_put_stab(sch->stab);
843 kfree((char *) sch - sch->padded);
845 module_put(ops->owner);
852 * Any broken qdiscs that would require a ops->reset() here?
853 * The qdisc was never in action so it shouldn't be necessary.
860 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
862 struct qdisc_size_table *stab = NULL;
865 if (tca[TCA_OPTIONS]) {
866 if (sch->ops->change == NULL)
868 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
874 stab = qdisc_get_stab(tca[TCA_STAB]);
876 return PTR_ERR(stab);
879 qdisc_put_stab(sch->stab);
883 /* NB: ignores errors from replace_estimator
884 because change can't be undone. */
885 if (sch->flags & TCQ_F_MQROOT)
887 gen_replace_estimator(&sch->bstats, &sch->rate_est,
888 qdisc_root_sleeping_lock(sch),
895 struct check_loop_arg
897 struct qdisc_walker w;
902 static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
904 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
906 struct check_loop_arg arg;
908 if (q->ops->cl_ops == NULL)
911 arg.w.stop = arg.w.skip = arg.w.count = 0;
912 arg.w.fn = check_loop_fn;
915 q->ops->cl_ops->walk(q, &arg.w);
916 return arg.w.stop ? -ELOOP : 0;
920 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
923 const struct Qdisc_class_ops *cops = q->ops->cl_ops;
924 struct check_loop_arg *arg = (struct check_loop_arg *)w;
926 leaf = cops->leaf(q, cl);
928 if (leaf == arg->p || arg->depth > 7)
930 return check_loop(leaf, arg->p, arg->depth + 1);
939 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
941 struct net *net = sock_net(skb->sk);
942 struct tcmsg *tcm = NLMSG_DATA(n);
943 struct nlattr *tca[TCA_MAX + 1];
944 struct net_device *dev;
945 u32 clid = tcm->tcm_parent;
946 struct Qdisc *q = NULL;
947 struct Qdisc *p = NULL;
950 if (net != &init_net)
953 if ((dev = __dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL)
956 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
961 if (clid != TC_H_ROOT) {
962 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
963 if ((p = qdisc_lookup(dev, TC_H_MAJ(clid))) == NULL)
965 q = qdisc_leaf(p, clid);
966 } else { /* ingress */
967 q = dev->rx_queue.qdisc_sleeping;
975 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
978 if ((q = qdisc_lookup(dev, tcm->tcm_handle)) == NULL)
982 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
985 if (n->nlmsg_type == RTM_DELQDISC) {
990 if ((err = qdisc_graft(dev, p, skb, n, clid, NULL, q)) != 0)
993 qdisc_notify(skb, n, clid, NULL, q);
1002 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1004 struct net *net = sock_net(skb->sk);
1006 struct nlattr *tca[TCA_MAX + 1];
1007 struct net_device *dev;
1009 struct Qdisc *q, *p;
1012 if (net != &init_net)
1016 /* Reinit, just in case something touches this. */
1017 tcm = NLMSG_DATA(n);
1018 clid = tcm->tcm_parent;
1021 if ((dev = __dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL)
1024 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1029 if (clid != TC_H_ROOT) {
1030 if (clid != TC_H_INGRESS) {
1031 if ((p = qdisc_lookup(dev, TC_H_MAJ(clid))) == NULL)
1033 q = qdisc_leaf(p, clid);
1034 } else { /*ingress */
1035 q = dev->rx_queue.qdisc_sleeping;
1041 /* It may be default qdisc, ignore it */
1042 if (q && q->handle == 0)
1045 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1046 if (tcm->tcm_handle) {
1047 if (q && !(n->nlmsg_flags&NLM_F_REPLACE))
1049 if (TC_H_MIN(tcm->tcm_handle))
1051 if ((q = qdisc_lookup(dev, tcm->tcm_handle)) == NULL)
1052 goto create_n_graft;
1053 if (n->nlmsg_flags&NLM_F_EXCL)
1055 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1058 (p && check_loop(q, p, 0)))
1060 atomic_inc(&q->refcnt);
1064 goto create_n_graft;
1066 /* This magic test requires explanation.
1068 * We know, that some child q is already
1069 * attached to this parent and have choice:
1070 * either to change it or to create/graft new one.
1072 * 1. We are allowed to create/graft only
1073 * if CREATE and REPLACE flags are set.
1075 * 2. If EXCL is set, requestor wanted to say,
1076 * that qdisc tcm_handle is not expected
1077 * to exist, so that we choose create/graft too.
1079 * 3. The last case is when no flags are set.
1080 * Alas, it is sort of hole in API, we
1081 * cannot decide what to do unambiguously.
1082 * For now we select create/graft, if
1083 * user gave KIND, which does not match existing.
1085 if ((n->nlmsg_flags&NLM_F_CREATE) &&
1086 (n->nlmsg_flags&NLM_F_REPLACE) &&
1087 ((n->nlmsg_flags&NLM_F_EXCL) ||
1089 nla_strcmp(tca[TCA_KIND], q->ops->id))))
1090 goto create_n_graft;
1094 if (!tcm->tcm_handle)
1096 q = qdisc_lookup(dev, tcm->tcm_handle);
1099 /* Change qdisc parameters */
1102 if (n->nlmsg_flags&NLM_F_EXCL)
1104 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1106 err = qdisc_change(q, tca);
1108 qdisc_notify(skb, n, clid, NULL, q);
1112 if (!(n->nlmsg_flags&NLM_F_CREATE))
1114 if (clid == TC_H_INGRESS)
1115 q = qdisc_create(dev, &dev->rx_queue, p,
1116 tcm->tcm_parent, tcm->tcm_parent,
1119 unsigned int ntx = 0;
1121 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1122 ntx = p->ops->cl_ops->select_queue(p, tcm);
1124 q = qdisc_create(dev, netdev_get_tx_queue(dev, ntx), p,
1125 tcm->tcm_parent, tcm->tcm_handle,
1135 err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1145 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1146 u32 pid, u32 seq, u16 flags, int event)
1149 struct nlmsghdr *nlh;
1150 unsigned char *b = skb_tail_pointer(skb);
1153 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1154 tcm = NLMSG_DATA(nlh);
1155 tcm->tcm_family = AF_UNSPEC;
1158 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1159 tcm->tcm_parent = clid;
1160 tcm->tcm_handle = q->handle;
1161 tcm->tcm_info = atomic_read(&q->refcnt);
1162 NLA_PUT_STRING(skb, TCA_KIND, q->ops->id);
1163 if (q->ops->dump && q->ops->dump(q, skb) < 0)
1164 goto nla_put_failure;
1165 q->qstats.qlen = q->q.qlen;
1167 if (q->stab && qdisc_dump_stab(skb, q->stab) < 0)
1168 goto nla_put_failure;
1170 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1171 qdisc_root_sleeping_lock(q), &d) < 0)
1172 goto nla_put_failure;
1174 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1175 goto nla_put_failure;
1177 if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
1178 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
1179 gnet_stats_copy_queue(&d, &q->qstats) < 0)
1180 goto nla_put_failure;
1182 if (gnet_stats_finish_copy(&d) < 0)
1183 goto nla_put_failure;
1185 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1194 static int qdisc_notify(struct sk_buff *oskb, struct nlmsghdr *n,
1195 u32 clid, struct Qdisc *old, struct Qdisc *new)
1197 struct sk_buff *skb;
1198 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
1200 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1204 if (old && old->handle) {
1205 if (tc_fill_qdisc(skb, old, clid, pid, n->nlmsg_seq, 0, RTM_DELQDISC) < 0)
1209 if (tc_fill_qdisc(skb, new, clid, pid, n->nlmsg_seq, old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1214 return rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
1221 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1223 return (q->flags & TCQ_F_BUILTIN) ? true : false;
1226 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1227 struct netlink_callback *cb,
1228 int *q_idx_p, int s_q_idx)
1230 int ret = 0, q_idx = *q_idx_p;
1237 if (q_idx < s_q_idx) {
1240 if (!tc_qdisc_dump_ignore(q) &&
1241 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid,
1242 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1246 list_for_each_entry(q, &root->list, list) {
1247 if (q_idx < s_q_idx) {
1251 if (!tc_qdisc_dump_ignore(q) &&
1252 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid,
1253 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
1266 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1268 struct net *net = sock_net(skb->sk);
1271 struct net_device *dev;
1273 if (net != &init_net)
1276 s_idx = cb->args[0];
1277 s_q_idx = q_idx = cb->args[1];
1278 read_lock(&dev_base_lock);
1280 for_each_netdev(&init_net, dev) {
1281 struct netdev_queue *dev_queue;
1289 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
1292 dev_queue = &dev->rx_queue;
1293 if (tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb, &q_idx, s_q_idx) < 0)
1301 read_unlock(&dev_base_lock);
1304 cb->args[1] = q_idx;
1311 /************************************************
1312 * Traffic classes manipulation. *
1313 ************************************************/
1317 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1319 struct net *net = sock_net(skb->sk);
1320 struct tcmsg *tcm = NLMSG_DATA(n);
1321 struct nlattr *tca[TCA_MAX + 1];
1322 struct net_device *dev;
1323 struct Qdisc *q = NULL;
1324 const struct Qdisc_class_ops *cops;
1325 unsigned long cl = 0;
1326 unsigned long new_cl;
1327 u32 pid = tcm->tcm_parent;
1328 u32 clid = tcm->tcm_handle;
1329 u32 qid = TC_H_MAJ(clid);
1332 if (net != &init_net)
1335 if ((dev = __dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL)
1338 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1343 parent == TC_H_UNSPEC - unspecified parent.
1344 parent == TC_H_ROOT - class is root, which has no parent.
1345 parent == X:0 - parent is root class.
1346 parent == X:Y - parent is a node in hierarchy.
1347 parent == 0:Y - parent is X:Y, where X:0 is qdisc.
1349 handle == 0:0 - generate handle from kernel pool.
1350 handle == 0:Y - class is X:Y, where X:0 is qdisc.
1351 handle == X:Y - clear.
1352 handle == X:0 - root class.
1355 /* Step 1. Determine qdisc handle X:0 */
1357 if (pid != TC_H_ROOT) {
1358 u32 qid1 = TC_H_MAJ(pid);
1361 /* If both majors are known, they must be identical. */
1366 } else if (qid == 0)
1367 qid = dev->qdisc->handle;
1369 /* Now qid is genuine qdisc handle consistent
1370 both with parent and child.
1372 TC_H_MAJ(pid) still may be unspecified, complete it now.
1375 pid = TC_H_MAKE(qid, pid);
1378 qid = dev->qdisc->handle;
1381 /* OK. Locate qdisc */
1382 if ((q = qdisc_lookup(dev, qid)) == NULL)
1385 /* An check that it supports classes */
1386 cops = q->ops->cl_ops;
1390 /* Now try to get class */
1392 if (pid == TC_H_ROOT)
1395 clid = TC_H_MAKE(qid, clid);
1398 cl = cops->get(q, clid);
1402 if (n->nlmsg_type != RTM_NEWTCLASS || !(n->nlmsg_flags&NLM_F_CREATE))
1405 switch (n->nlmsg_type) {
1408 if (n->nlmsg_flags&NLM_F_EXCL)
1414 err = cops->delete(q, cl);
1416 tclass_notify(skb, n, q, cl, RTM_DELTCLASS);
1419 err = tclass_notify(skb, n, q, cl, RTM_NEWTCLASS);
1430 err = cops->change(q, clid, pid, tca, &new_cl);
1432 tclass_notify(skb, n, q, new_cl, RTM_NEWTCLASS);
1442 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1444 u32 pid, u32 seq, u16 flags, int event)
1447 struct nlmsghdr *nlh;
1448 unsigned char *b = skb_tail_pointer(skb);
1450 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1452 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1453 tcm = NLMSG_DATA(nlh);
1454 tcm->tcm_family = AF_UNSPEC;
1457 tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1458 tcm->tcm_parent = q->handle;
1459 tcm->tcm_handle = q->handle;
1461 NLA_PUT_STRING(skb, TCA_KIND, q->ops->id);
1462 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1463 goto nla_put_failure;
1465 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1466 qdisc_root_sleeping_lock(q), &d) < 0)
1467 goto nla_put_failure;
1469 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1470 goto nla_put_failure;
1472 if (gnet_stats_finish_copy(&d) < 0)
1473 goto nla_put_failure;
1475 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1484 static int tclass_notify(struct sk_buff *oskb, struct nlmsghdr *n,
1485 struct Qdisc *q, unsigned long cl, int event)
1487 struct sk_buff *skb;
1488 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
1490 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1494 if (tc_fill_tclass(skb, q, cl, pid, n->nlmsg_seq, 0, event) < 0) {
1499 return rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
1502 struct qdisc_dump_args
1504 struct qdisc_walker w;
1505 struct sk_buff *skb;
1506 struct netlink_callback *cb;
1509 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
1511 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1513 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).pid,
1514 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
1517 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1518 struct tcmsg *tcm, struct netlink_callback *cb,
1521 struct qdisc_dump_args arg;
1523 if (tc_qdisc_dump_ignore(q) ||
1524 *t_p < s_t || !q->ops->cl_ops ||
1526 TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1531 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1532 arg.w.fn = qdisc_class_dump;
1536 arg.w.skip = cb->args[1];
1538 q->ops->cl_ops->walk(q, &arg.w);
1539 cb->args[1] = arg.w.count;
1546 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1547 struct tcmsg *tcm, struct netlink_callback *cb,
1555 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1558 list_for_each_entry(q, &root->list, list) {
1559 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1566 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1568 struct tcmsg *tcm = (struct tcmsg*)NLMSG_DATA(cb->nlh);
1569 struct net *net = sock_net(skb->sk);
1570 struct netdev_queue *dev_queue;
1571 struct net_device *dev;
1574 if (net != &init_net)
1577 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
1579 if ((dev = dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL)
1585 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1588 dev_queue = &dev->rx_queue;
1589 if (tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb, &t, s_t) < 0)
1599 /* Main classifier routine: scans classifier chain attached
1600 to this qdisc, (optionally) tests for protocol and asks
1601 specific classifiers.
1603 int tc_classify_compat(struct sk_buff *skb, struct tcf_proto *tp,
1604 struct tcf_result *res)
1606 __be16 protocol = skb->protocol;
1609 for (; tp; tp = tp->next) {
1610 if ((tp->protocol == protocol ||
1611 tp->protocol == htons(ETH_P_ALL)) &&
1612 (err = tp->classify(skb, tp, res)) >= 0) {
1613 #ifdef CONFIG_NET_CLS_ACT
1614 if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
1615 skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
1622 EXPORT_SYMBOL(tc_classify_compat);
1624 int tc_classify(struct sk_buff *skb, struct tcf_proto *tp,
1625 struct tcf_result *res)
1629 #ifdef CONFIG_NET_CLS_ACT
1630 struct tcf_proto *otp = tp;
1633 protocol = skb->protocol;
1635 err = tc_classify_compat(skb, tp, res);
1636 #ifdef CONFIG_NET_CLS_ACT
1637 if (err == TC_ACT_RECLASSIFY) {
1638 u32 verd = G_TC_VERD(skb->tc_verd);
1641 if (verd++ >= MAX_REC_LOOP) {
1642 printk("rule prio %u protocol %02x reclassify loop, "
1644 tp->prio&0xffff, ntohs(tp->protocol));
1647 skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
1653 EXPORT_SYMBOL(tc_classify);
1655 void tcf_destroy(struct tcf_proto *tp)
1657 tp->ops->destroy(tp);
1658 module_put(tp->ops->owner);
1662 void tcf_destroy_chain(struct tcf_proto **fl)
1664 struct tcf_proto *tp;
1666 while ((tp = *fl) != NULL) {
1671 EXPORT_SYMBOL(tcf_destroy_chain);
1673 #ifdef CONFIG_PROC_FS
1674 static int psched_show(struct seq_file *seq, void *v)
1678 hrtimer_get_res(CLOCK_MONOTONIC, &ts);
1679 seq_printf(seq, "%08x %08x %08x %08x\n",
1680 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1682 (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
1687 static int psched_open(struct inode *inode, struct file *file)
1689 return single_open(file, psched_show, PDE(inode)->data);
1692 static const struct file_operations psched_fops = {
1693 .owner = THIS_MODULE,
1694 .open = psched_open,
1696 .llseek = seq_lseek,
1697 .release = single_release,
1701 static int __init pktsched_init(void)
1703 register_qdisc(&pfifo_qdisc_ops);
1704 register_qdisc(&bfifo_qdisc_ops);
1705 register_qdisc(&mq_qdisc_ops);
1706 proc_net_fops_create(&init_net, "psched", 0, &psched_fops);
1708 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL);
1709 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL);
1710 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc);
1711 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL);
1712 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL);
1713 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass);
1718 subsys_initcall(pktsched_init);