proc: add LSM hook checks to /proc/<tid>/timerslack_ns
[cascardo/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 #include <linux/hashtable.h>
33
34 #include <net/net_namespace.h>
35 #include <net/sock.h>
36 #include <net/netlink.h>
37 #include <net/pkt_sched.h>
38
39 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
40                         struct nlmsghdr *n, u32 clid,
41                         struct Qdisc *old, struct Qdisc *new);
42 static int tclass_notify(struct net *net, struct sk_buff *oskb,
43                          struct nlmsghdr *n, struct Qdisc *q,
44                          unsigned long cl, int event);
45
46 /*
47
48    Short review.
49    -------------
50
51    This file consists of two interrelated parts:
52
53    1. queueing disciplines manager frontend.
54    2. traffic classes manager frontend.
55
56    Generally, queueing discipline ("qdisc") is a black box,
57    which is able to enqueue packets and to dequeue them (when
58    device is ready to send something) in order and at times
59    determined by algorithm hidden in it.
60
61    qdisc's are divided to two categories:
62    - "queues", which have no internal structure visible from outside.
63    - "schedulers", which split all the packets to "traffic classes",
64      using "packet classifiers" (look at cls_api.c)
65
66    In turn, classes may have child qdiscs (as rule, queues)
67    attached to them etc. etc. etc.
68
69    The goal of the routines in this file is to translate
70    information supplied by user in the form of handles
71    to more intelligible for kernel form, to make some sanity
72    checks and part of work, which is common to all qdiscs
73    and to provide rtnetlink notifications.
74
75    All real intelligent work is done inside qdisc modules.
76
77
78
79    Every discipline has two major routines: enqueue and dequeue.
80
81    ---dequeue
82
83    dequeue usually returns a skb to send. It is allowed to return NULL,
84    but it does not mean that queue is empty, it just means that
85    discipline does not want to send anything this time.
86    Queue is really empty if q->q.qlen == 0.
87    For complicated disciplines with multiple queues q->q is not
88    real packet queue, but however q->q.qlen must be valid.
89
90    ---enqueue
91
92    enqueue returns 0, if packet was enqueued successfully.
93    If packet (this one or another one) was dropped, it returns
94    not zero error code.
95    NET_XMIT_DROP        - this packet dropped
96      Expected action: do not backoff, but wait until queue will clear.
97    NET_XMIT_CN          - probably this packet enqueued, but another one dropped.
98      Expected action: backoff or ignore
99
100    Auxiliary routines:
101
102    ---peek
103
104    like dequeue but without removing a packet from the queue
105
106    ---reset
107
108    returns qdisc to initial state: purge all buffers, clear all
109    timers, counters (except for statistics) etc.
110
111    ---init
112
113    initializes newly created qdisc.
114
115    ---destroy
116
117    destroys resources allocated by init and during lifetime of qdisc.
118
119    ---change
120
121    changes qdisc parameters.
122  */
123
124 /* Protects list of registered TC modules. It is pure SMP lock. */
125 static DEFINE_RWLOCK(qdisc_mod_lock);
126
127
128 /************************************************
129  *      Queueing disciplines manipulation.      *
130  ************************************************/
131
132
133 /* The list of all installed queueing disciplines. */
134
135 static struct Qdisc_ops *qdisc_base;
136
137 /* Register/unregister queueing discipline */
138
139 int register_qdisc(struct Qdisc_ops *qops)
140 {
141         struct Qdisc_ops *q, **qp;
142         int rc = -EEXIST;
143
144         write_lock(&qdisc_mod_lock);
145         for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
146                 if (!strcmp(qops->id, q->id))
147                         goto out;
148
149         if (qops->enqueue == NULL)
150                 qops->enqueue = noop_qdisc_ops.enqueue;
151         if (qops->peek == NULL) {
152                 if (qops->dequeue == NULL)
153                         qops->peek = noop_qdisc_ops.peek;
154                 else
155                         goto out_einval;
156         }
157         if (qops->dequeue == NULL)
158                 qops->dequeue = noop_qdisc_ops.dequeue;
159
160         if (qops->cl_ops) {
161                 const struct Qdisc_class_ops *cops = qops->cl_ops;
162
163                 if (!(cops->get && cops->put && cops->walk && cops->leaf))
164                         goto out_einval;
165
166                 if (cops->tcf_chain && !(cops->bind_tcf && cops->unbind_tcf))
167                         goto out_einval;
168         }
169
170         qops->next = NULL;
171         *qp = qops;
172         rc = 0;
173 out:
174         write_unlock(&qdisc_mod_lock);
175         return rc;
176
177 out_einval:
178         rc = -EINVAL;
179         goto out;
180 }
181 EXPORT_SYMBOL(register_qdisc);
182
183 int unregister_qdisc(struct Qdisc_ops *qops)
184 {
185         struct Qdisc_ops *q, **qp;
186         int err = -ENOENT;
187
188         write_lock(&qdisc_mod_lock);
189         for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
190                 if (q == qops)
191                         break;
192         if (q) {
193                 *qp = q->next;
194                 q->next = NULL;
195                 err = 0;
196         }
197         write_unlock(&qdisc_mod_lock);
198         return err;
199 }
200 EXPORT_SYMBOL(unregister_qdisc);
201
202 /* Get default qdisc if not otherwise specified */
203 void qdisc_get_default(char *name, size_t len)
204 {
205         read_lock(&qdisc_mod_lock);
206         strlcpy(name, default_qdisc_ops->id, len);
207         read_unlock(&qdisc_mod_lock);
208 }
209
210 static struct Qdisc_ops *qdisc_lookup_default(const char *name)
211 {
212         struct Qdisc_ops *q = NULL;
213
214         for (q = qdisc_base; q; q = q->next) {
215                 if (!strcmp(name, q->id)) {
216                         if (!try_module_get(q->owner))
217                                 q = NULL;
218                         break;
219                 }
220         }
221
222         return q;
223 }
224
225 /* Set new default qdisc to use */
226 int qdisc_set_default(const char *name)
227 {
228         const struct Qdisc_ops *ops;
229
230         if (!capable(CAP_NET_ADMIN))
231                 return -EPERM;
232
233         write_lock(&qdisc_mod_lock);
234         ops = qdisc_lookup_default(name);
235         if (!ops) {
236                 /* Not found, drop lock and try to load module */
237                 write_unlock(&qdisc_mod_lock);
238                 request_module("sch_%s", name);
239                 write_lock(&qdisc_mod_lock);
240
241                 ops = qdisc_lookup_default(name);
242         }
243
244         if (ops) {
245                 /* Set new default */
246                 module_put(default_qdisc_ops->owner);
247                 default_qdisc_ops = ops;
248         }
249         write_unlock(&qdisc_mod_lock);
250
251         return ops ? 0 : -ENOENT;
252 }
253
254 /* We know handle. Find qdisc among all qdisc's attached to device
255  * (root qdisc, all its children, children of children etc.)
256  * Note: caller either uses rtnl or rcu_read_lock()
257  */
258
259 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
260 {
261         struct Qdisc *q;
262
263         if (!qdisc_dev(root))
264                 return (root->handle == handle ? root : NULL);
265
266         if (!(root->flags & TCQ_F_BUILTIN) &&
267             root->handle == handle)
268                 return root;
269
270         hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle) {
271                 if (q->handle == handle)
272                         return q;
273         }
274         return NULL;
275 }
276
277 void qdisc_hash_add(struct Qdisc *q)
278 {
279         if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
280                 struct Qdisc *root = qdisc_dev(q)->qdisc;
281
282                 WARN_ON_ONCE(root == &noop_qdisc);
283                 ASSERT_RTNL();
284                 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
285         }
286 }
287 EXPORT_SYMBOL(qdisc_hash_add);
288
289 void qdisc_hash_del(struct Qdisc *q)
290 {
291         if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
292                 ASSERT_RTNL();
293                 hash_del_rcu(&q->hash);
294         }
295 }
296 EXPORT_SYMBOL(qdisc_hash_del);
297
298 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
299 {
300         struct Qdisc *q;
301
302         q = qdisc_match_from_root(dev->qdisc, handle);
303         if (q)
304                 goto out;
305
306         if (dev_ingress_queue(dev))
307                 q = qdisc_match_from_root(
308                         dev_ingress_queue(dev)->qdisc_sleeping,
309                         handle);
310 out:
311         return q;
312 }
313
314 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
315 {
316         unsigned long cl;
317         struct Qdisc *leaf;
318         const struct Qdisc_class_ops *cops = p->ops->cl_ops;
319
320         if (cops == NULL)
321                 return NULL;
322         cl = cops->get(p, classid);
323
324         if (cl == 0)
325                 return NULL;
326         leaf = cops->leaf(p, cl);
327         cops->put(p, cl);
328         return leaf;
329 }
330
331 /* Find queueing discipline by name */
332
333 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
334 {
335         struct Qdisc_ops *q = NULL;
336
337         if (kind) {
338                 read_lock(&qdisc_mod_lock);
339                 for (q = qdisc_base; q; q = q->next) {
340                         if (nla_strcmp(kind, q->id) == 0) {
341                                 if (!try_module_get(q->owner))
342                                         q = NULL;
343                                 break;
344                         }
345                 }
346                 read_unlock(&qdisc_mod_lock);
347         }
348         return q;
349 }
350
351 /* The linklayer setting were not transferred from iproute2, in older
352  * versions, and the rate tables lookup systems have been dropped in
353  * the kernel. To keep backward compatible with older iproute2 tc
354  * utils, we detect the linklayer setting by detecting if the rate
355  * table were modified.
356  *
357  * For linklayer ATM table entries, the rate table will be aligned to
358  * 48 bytes, thus some table entries will contain the same value.  The
359  * mpu (min packet unit) is also encoded into the old rate table, thus
360  * starting from the mpu, we find low and high table entries for
361  * mapping this cell.  If these entries contain the same value, when
362  * the rate tables have been modified for linklayer ATM.
363  *
364  * This is done by rounding mpu to the nearest 48 bytes cell/entry,
365  * and then roundup to the next cell, calc the table entry one below,
366  * and compare.
367  */
368 static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
369 {
370         int low       = roundup(r->mpu, 48);
371         int high      = roundup(low+1, 48);
372         int cell_low  = low >> r->cell_log;
373         int cell_high = (high >> r->cell_log) - 1;
374
375         /* rtab is too inaccurate at rates > 100Mbit/s */
376         if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
377                 pr_debug("TC linklayer: Giving up ATM detection\n");
378                 return TC_LINKLAYER_ETHERNET;
379         }
380
381         if ((cell_high > cell_low) && (cell_high < 256)
382             && (rtab[cell_low] == rtab[cell_high])) {
383                 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
384                          cell_low, cell_high, rtab[cell_high]);
385                 return TC_LINKLAYER_ATM;
386         }
387         return TC_LINKLAYER_ETHERNET;
388 }
389
390 static struct qdisc_rate_table *qdisc_rtab_list;
391
392 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
393                                         struct nlattr *tab)
394 {
395         struct qdisc_rate_table *rtab;
396
397         if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
398             nla_len(tab) != TC_RTAB_SIZE)
399                 return NULL;
400
401         for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
402                 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
403                     !memcmp(&rtab->data, nla_data(tab), 1024)) {
404                         rtab->refcnt++;
405                         return rtab;
406                 }
407         }
408
409         rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
410         if (rtab) {
411                 rtab->rate = *r;
412                 rtab->refcnt = 1;
413                 memcpy(rtab->data, nla_data(tab), 1024);
414                 if (r->linklayer == TC_LINKLAYER_UNAWARE)
415                         r->linklayer = __detect_linklayer(r, rtab->data);
416                 rtab->next = qdisc_rtab_list;
417                 qdisc_rtab_list = rtab;
418         }
419         return rtab;
420 }
421 EXPORT_SYMBOL(qdisc_get_rtab);
422
423 void qdisc_put_rtab(struct qdisc_rate_table *tab)
424 {
425         struct qdisc_rate_table *rtab, **rtabp;
426
427         if (!tab || --tab->refcnt)
428                 return;
429
430         for (rtabp = &qdisc_rtab_list;
431              (rtab = *rtabp) != NULL;
432              rtabp = &rtab->next) {
433                 if (rtab == tab) {
434                         *rtabp = rtab->next;
435                         kfree(rtab);
436                         return;
437                 }
438         }
439 }
440 EXPORT_SYMBOL(qdisc_put_rtab);
441
442 static LIST_HEAD(qdisc_stab_list);
443 static DEFINE_SPINLOCK(qdisc_stab_lock);
444
445 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
446         [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
447         [TCA_STAB_DATA] = { .type = NLA_BINARY },
448 };
449
450 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
451 {
452         struct nlattr *tb[TCA_STAB_MAX + 1];
453         struct qdisc_size_table *stab;
454         struct tc_sizespec *s;
455         unsigned int tsize = 0;
456         u16 *tab = NULL;
457         int err;
458
459         err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
460         if (err < 0)
461                 return ERR_PTR(err);
462         if (!tb[TCA_STAB_BASE])
463                 return ERR_PTR(-EINVAL);
464
465         s = nla_data(tb[TCA_STAB_BASE]);
466
467         if (s->tsize > 0) {
468                 if (!tb[TCA_STAB_DATA])
469                         return ERR_PTR(-EINVAL);
470                 tab = nla_data(tb[TCA_STAB_DATA]);
471                 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
472         }
473
474         if (tsize != s->tsize || (!tab && tsize > 0))
475                 return ERR_PTR(-EINVAL);
476
477         spin_lock(&qdisc_stab_lock);
478
479         list_for_each_entry(stab, &qdisc_stab_list, list) {
480                 if (memcmp(&stab->szopts, s, sizeof(*s)))
481                         continue;
482                 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
483                         continue;
484                 stab->refcnt++;
485                 spin_unlock(&qdisc_stab_lock);
486                 return stab;
487         }
488
489         spin_unlock(&qdisc_stab_lock);
490
491         stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
492         if (!stab)
493                 return ERR_PTR(-ENOMEM);
494
495         stab->refcnt = 1;
496         stab->szopts = *s;
497         if (tsize > 0)
498                 memcpy(stab->data, tab, tsize * sizeof(u16));
499
500         spin_lock(&qdisc_stab_lock);
501         list_add_tail(&stab->list, &qdisc_stab_list);
502         spin_unlock(&qdisc_stab_lock);
503
504         return stab;
505 }
506
507 static void stab_kfree_rcu(struct rcu_head *head)
508 {
509         kfree(container_of(head, struct qdisc_size_table, rcu));
510 }
511
512 void qdisc_put_stab(struct qdisc_size_table *tab)
513 {
514         if (!tab)
515                 return;
516
517         spin_lock(&qdisc_stab_lock);
518
519         if (--tab->refcnt == 0) {
520                 list_del(&tab->list);
521                 call_rcu_bh(&tab->rcu, stab_kfree_rcu);
522         }
523
524         spin_unlock(&qdisc_stab_lock);
525 }
526 EXPORT_SYMBOL(qdisc_put_stab);
527
528 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
529 {
530         struct nlattr *nest;
531
532         nest = nla_nest_start(skb, TCA_STAB);
533         if (nest == NULL)
534                 goto nla_put_failure;
535         if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
536                 goto nla_put_failure;
537         nla_nest_end(skb, nest);
538
539         return skb->len;
540
541 nla_put_failure:
542         return -1;
543 }
544
545 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
546                                const struct qdisc_size_table *stab)
547 {
548         int pkt_len, slot;
549
550         pkt_len = skb->len + stab->szopts.overhead;
551         if (unlikely(!stab->szopts.tsize))
552                 goto out;
553
554         slot = pkt_len + stab->szopts.cell_align;
555         if (unlikely(slot < 0))
556                 slot = 0;
557
558         slot >>= stab->szopts.cell_log;
559         if (likely(slot < stab->szopts.tsize))
560                 pkt_len = stab->data[slot];
561         else
562                 pkt_len = stab->data[stab->szopts.tsize - 1] *
563                                 (slot / stab->szopts.tsize) +
564                                 stab->data[slot % stab->szopts.tsize];
565
566         pkt_len <<= stab->szopts.size_log;
567 out:
568         if (unlikely(pkt_len < 1))
569                 pkt_len = 1;
570         qdisc_skb_cb(skb)->pkt_len = pkt_len;
571 }
572 EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
573
574 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
575 {
576         if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
577                 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
578                         txt, qdisc->ops->id, qdisc->handle >> 16);
579                 qdisc->flags |= TCQ_F_WARN_NONWC;
580         }
581 }
582 EXPORT_SYMBOL(qdisc_warn_nonwc);
583
584 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
585 {
586         struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
587                                                  timer);
588
589         rcu_read_lock();
590         __netif_schedule(qdisc_root(wd->qdisc));
591         rcu_read_unlock();
592
593         return HRTIMER_NORESTART;
594 }
595
596 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
597 {
598         hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
599         wd->timer.function = qdisc_watchdog;
600         wd->qdisc = qdisc;
601 }
602 EXPORT_SYMBOL(qdisc_watchdog_init);
603
604 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
605 {
606         if (test_bit(__QDISC_STATE_DEACTIVATED,
607                      &qdisc_root_sleeping(wd->qdisc)->state))
608                 return;
609
610         if (wd->last_expires == expires)
611                 return;
612
613         wd->last_expires = expires;
614         hrtimer_start(&wd->timer,
615                       ns_to_ktime(expires),
616                       HRTIMER_MODE_ABS_PINNED);
617 }
618 EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
619
620 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
621 {
622         hrtimer_cancel(&wd->timer);
623 }
624 EXPORT_SYMBOL(qdisc_watchdog_cancel);
625
626 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
627 {
628         unsigned int size = n * sizeof(struct hlist_head), i;
629         struct hlist_head *h;
630
631         if (size <= PAGE_SIZE)
632                 h = kmalloc(size, GFP_KERNEL);
633         else
634                 h = (struct hlist_head *)
635                         __get_free_pages(GFP_KERNEL, get_order(size));
636
637         if (h != NULL) {
638                 for (i = 0; i < n; i++)
639                         INIT_HLIST_HEAD(&h[i]);
640         }
641         return h;
642 }
643
644 static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
645 {
646         unsigned int size = n * sizeof(struct hlist_head);
647
648         if (size <= PAGE_SIZE)
649                 kfree(h);
650         else
651                 free_pages((unsigned long)h, get_order(size));
652 }
653
654 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
655 {
656         struct Qdisc_class_common *cl;
657         struct hlist_node *next;
658         struct hlist_head *nhash, *ohash;
659         unsigned int nsize, nmask, osize;
660         unsigned int i, h;
661
662         /* Rehash when load factor exceeds 0.75 */
663         if (clhash->hashelems * 4 <= clhash->hashsize * 3)
664                 return;
665         nsize = clhash->hashsize * 2;
666         nmask = nsize - 1;
667         nhash = qdisc_class_hash_alloc(nsize);
668         if (nhash == NULL)
669                 return;
670
671         ohash = clhash->hash;
672         osize = clhash->hashsize;
673
674         sch_tree_lock(sch);
675         for (i = 0; i < osize; i++) {
676                 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
677                         h = qdisc_class_hash(cl->classid, nmask);
678                         hlist_add_head(&cl->hnode, &nhash[h]);
679                 }
680         }
681         clhash->hash     = nhash;
682         clhash->hashsize = nsize;
683         clhash->hashmask = nmask;
684         sch_tree_unlock(sch);
685
686         qdisc_class_hash_free(ohash, osize);
687 }
688 EXPORT_SYMBOL(qdisc_class_hash_grow);
689
690 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
691 {
692         unsigned int size = 4;
693
694         clhash->hash = qdisc_class_hash_alloc(size);
695         if (clhash->hash == NULL)
696                 return -ENOMEM;
697         clhash->hashsize  = size;
698         clhash->hashmask  = size - 1;
699         clhash->hashelems = 0;
700         return 0;
701 }
702 EXPORT_SYMBOL(qdisc_class_hash_init);
703
704 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
705 {
706         qdisc_class_hash_free(clhash->hash, clhash->hashsize);
707 }
708 EXPORT_SYMBOL(qdisc_class_hash_destroy);
709
710 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
711                              struct Qdisc_class_common *cl)
712 {
713         unsigned int h;
714
715         INIT_HLIST_NODE(&cl->hnode);
716         h = qdisc_class_hash(cl->classid, clhash->hashmask);
717         hlist_add_head(&cl->hnode, &clhash->hash[h]);
718         clhash->hashelems++;
719 }
720 EXPORT_SYMBOL(qdisc_class_hash_insert);
721
722 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
723                              struct Qdisc_class_common *cl)
724 {
725         hlist_del(&cl->hnode);
726         clhash->hashelems--;
727 }
728 EXPORT_SYMBOL(qdisc_class_hash_remove);
729
730 /* Allocate an unique handle from space managed by kernel
731  * Possible range is [8000-FFFF]:0000 (0x8000 values)
732  */
733 static u32 qdisc_alloc_handle(struct net_device *dev)
734 {
735         int i = 0x8000;
736         static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
737
738         do {
739                 autohandle += TC_H_MAKE(0x10000U, 0);
740                 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
741                         autohandle = TC_H_MAKE(0x80000000U, 0);
742                 if (!qdisc_lookup(dev, autohandle))
743                         return autohandle;
744                 cond_resched();
745         } while (--i > 0);
746
747         return 0;
748 }
749
750 void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,
751                                unsigned int len)
752 {
753         const struct Qdisc_class_ops *cops;
754         unsigned long cl;
755         u32 parentid;
756         int drops;
757
758         if (n == 0 && len == 0)
759                 return;
760         drops = max_t(int, n, 0);
761         rcu_read_lock();
762         while ((parentid = sch->parent)) {
763                 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
764                         break;
765
766                 if (sch->flags & TCQ_F_NOPARENT)
767                         break;
768                 /* TODO: perform the search on a per txq basis */
769                 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
770                 if (sch == NULL) {
771                         WARN_ON_ONCE(parentid != TC_H_ROOT);
772                         break;
773                 }
774                 cops = sch->ops->cl_ops;
775                 if (cops->qlen_notify) {
776                         cl = cops->get(sch, parentid);
777                         cops->qlen_notify(sch, cl);
778                         cops->put(sch, cl);
779                 }
780                 sch->q.qlen -= n;
781                 sch->qstats.backlog -= len;
782                 __qdisc_qstats_drop(sch, drops);
783         }
784         rcu_read_unlock();
785 }
786 EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
787
788 static void notify_and_destroy(struct net *net, struct sk_buff *skb,
789                                struct nlmsghdr *n, u32 clid,
790                                struct Qdisc *old, struct Qdisc *new)
791 {
792         if (new || old)
793                 qdisc_notify(net, skb, n, clid, old, new);
794
795         if (old)
796                 qdisc_destroy(old);
797 }
798
799 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
800  * to device "dev".
801  *
802  * When appropriate send a netlink notification using 'skb'
803  * and "n".
804  *
805  * On success, destroy old qdisc.
806  */
807
808 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
809                        struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
810                        struct Qdisc *new, struct Qdisc *old)
811 {
812         struct Qdisc *q = old;
813         struct net *net = dev_net(dev);
814         int err = 0;
815
816         if (parent == NULL) {
817                 unsigned int i, num_q, ingress;
818
819                 ingress = 0;
820                 num_q = dev->num_tx_queues;
821                 if ((q && q->flags & TCQ_F_INGRESS) ||
822                     (new && new->flags & TCQ_F_INGRESS)) {
823                         num_q = 1;
824                         ingress = 1;
825                         if (!dev_ingress_queue(dev))
826                                 return -ENOENT;
827                 }
828
829                 if (dev->flags & IFF_UP)
830                         dev_deactivate(dev);
831
832                 if (new && new->ops->attach)
833                         goto skip;
834
835                 for (i = 0; i < num_q; i++) {
836                         struct netdev_queue *dev_queue = dev_ingress_queue(dev);
837
838                         if (!ingress)
839                                 dev_queue = netdev_get_tx_queue(dev, i);
840
841                         old = dev_graft_qdisc(dev_queue, new);
842                         if (new && i > 0)
843                                 atomic_inc(&new->refcnt);
844
845                         if (!ingress)
846                                 qdisc_destroy(old);
847                 }
848
849 skip:
850                 if (!ingress) {
851                         notify_and_destroy(net, skb, n, classid,
852                                            dev->qdisc, new);
853                         if (new && !new->ops->attach)
854                                 atomic_inc(&new->refcnt);
855                         dev->qdisc = new ? : &noop_qdisc;
856
857                         if (new && new->ops->attach)
858                                 new->ops->attach(new);
859                 } else {
860                         notify_and_destroy(net, skb, n, classid, old, new);
861                 }
862
863                 if (dev->flags & IFF_UP)
864                         dev_activate(dev);
865         } else {
866                 const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
867
868                 err = -EOPNOTSUPP;
869                 if (cops && cops->graft) {
870                         unsigned long cl = cops->get(parent, classid);
871                         if (cl) {
872                                 err = cops->graft(parent, cl, new, &old);
873                                 cops->put(parent, cl);
874                         } else
875                                 err = -ENOENT;
876                 }
877                 if (!err)
878                         notify_and_destroy(net, skb, n, classid, old, new);
879         }
880         return err;
881 }
882
883 /* lockdep annotation is needed for ingress; egress gets it only for name */
884 static struct lock_class_key qdisc_tx_lock;
885 static struct lock_class_key qdisc_rx_lock;
886
887 /*
888    Allocate and initialize new qdisc.
889
890    Parameters are passed via opt.
891  */
892
893 static struct Qdisc *qdisc_create(struct net_device *dev,
894                                   struct netdev_queue *dev_queue,
895                                   struct Qdisc *p, u32 parent, u32 handle,
896                                   struct nlattr **tca, int *errp)
897 {
898         int err;
899         struct nlattr *kind = tca[TCA_KIND];
900         struct Qdisc *sch;
901         struct Qdisc_ops *ops;
902         struct qdisc_size_table *stab;
903
904         ops = qdisc_lookup_ops(kind);
905 #ifdef CONFIG_MODULES
906         if (ops == NULL && kind != NULL) {
907                 char name[IFNAMSIZ];
908                 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
909                         /* We dropped the RTNL semaphore in order to
910                          * perform the module load.  So, even if we
911                          * succeeded in loading the module we have to
912                          * tell the caller to replay the request.  We
913                          * indicate this using -EAGAIN.
914                          * We replay the request because the device may
915                          * go away in the mean time.
916                          */
917                         rtnl_unlock();
918                         request_module("sch_%s", name);
919                         rtnl_lock();
920                         ops = qdisc_lookup_ops(kind);
921                         if (ops != NULL) {
922                                 /* We will try again qdisc_lookup_ops,
923                                  * so don't keep a reference.
924                                  */
925                                 module_put(ops->owner);
926                                 err = -EAGAIN;
927                                 goto err_out;
928                         }
929                 }
930         }
931 #endif
932
933         err = -ENOENT;
934         if (ops == NULL)
935                 goto err_out;
936
937         sch = qdisc_alloc(dev_queue, ops);
938         if (IS_ERR(sch)) {
939                 err = PTR_ERR(sch);
940                 goto err_out2;
941         }
942
943         sch->parent = parent;
944
945         if (handle == TC_H_INGRESS) {
946                 sch->flags |= TCQ_F_INGRESS;
947                 handle = TC_H_MAKE(TC_H_INGRESS, 0);
948                 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
949         } else {
950                 if (handle == 0) {
951                         handle = qdisc_alloc_handle(dev);
952                         err = -ENOMEM;
953                         if (handle == 0)
954                                 goto err_out3;
955                 }
956                 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
957                 if (!netif_is_multiqueue(dev))
958                         sch->flags |= TCQ_F_ONETXQUEUE;
959         }
960
961         sch->handle = handle;
962
963         if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
964                 if (qdisc_is_percpu_stats(sch)) {
965                         sch->cpu_bstats =
966                                 netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
967                         if (!sch->cpu_bstats)
968                                 goto err_out4;
969
970                         sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
971                         if (!sch->cpu_qstats)
972                                 goto err_out4;
973                 }
974
975                 if (tca[TCA_STAB]) {
976                         stab = qdisc_get_stab(tca[TCA_STAB]);
977                         if (IS_ERR(stab)) {
978                                 err = PTR_ERR(stab);
979                                 goto err_out4;
980                         }
981                         rcu_assign_pointer(sch->stab, stab);
982                 }
983                 if (tca[TCA_RATE]) {
984                         seqcount_t *running;
985
986                         err = -EOPNOTSUPP;
987                         if (sch->flags & TCQ_F_MQROOT)
988                                 goto err_out4;
989
990                         if ((sch->parent != TC_H_ROOT) &&
991                             !(sch->flags & TCQ_F_INGRESS) &&
992                             (!p || !(p->flags & TCQ_F_MQROOT)))
993                                 running = qdisc_root_sleeping_running(sch);
994                         else
995                                 running = &sch->running;
996
997                         err = gen_new_estimator(&sch->bstats,
998                                                 sch->cpu_bstats,
999                                                 &sch->rate_est,
1000                                                 NULL,
1001                                                 running,
1002                                                 tca[TCA_RATE]);
1003                         if (err)
1004                                 goto err_out4;
1005                 }
1006
1007                 qdisc_hash_add(sch);
1008
1009                 return sch;
1010         }
1011 err_out3:
1012         dev_put(dev);
1013         kfree((char *) sch - sch->padded);
1014 err_out2:
1015         module_put(ops->owner);
1016 err_out:
1017         *errp = err;
1018         return NULL;
1019
1020 err_out4:
1021         free_percpu(sch->cpu_bstats);
1022         free_percpu(sch->cpu_qstats);
1023         /*
1024          * Any broken qdiscs that would require a ops->reset() here?
1025          * The qdisc was never in action so it shouldn't be necessary.
1026          */
1027         qdisc_put_stab(rtnl_dereference(sch->stab));
1028         if (ops->destroy)
1029                 ops->destroy(sch);
1030         goto err_out3;
1031 }
1032
1033 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
1034 {
1035         struct qdisc_size_table *ostab, *stab = NULL;
1036         int err = 0;
1037
1038         if (tca[TCA_OPTIONS]) {
1039                 if (sch->ops->change == NULL)
1040                         return -EINVAL;
1041                 err = sch->ops->change(sch, tca[TCA_OPTIONS]);
1042                 if (err)
1043                         return err;
1044         }
1045
1046         if (tca[TCA_STAB]) {
1047                 stab = qdisc_get_stab(tca[TCA_STAB]);
1048                 if (IS_ERR(stab))
1049                         return PTR_ERR(stab);
1050         }
1051
1052         ostab = rtnl_dereference(sch->stab);
1053         rcu_assign_pointer(sch->stab, stab);
1054         qdisc_put_stab(ostab);
1055
1056         if (tca[TCA_RATE]) {
1057                 /* NB: ignores errors from replace_estimator
1058                    because change can't be undone. */
1059                 if (sch->flags & TCQ_F_MQROOT)
1060                         goto out;
1061                 gen_replace_estimator(&sch->bstats,
1062                                       sch->cpu_bstats,
1063                                       &sch->rate_est,
1064                                       NULL,
1065                                       qdisc_root_sleeping_running(sch),
1066                                       tca[TCA_RATE]);
1067         }
1068 out:
1069         return 0;
1070 }
1071
1072 struct check_loop_arg {
1073         struct qdisc_walker     w;
1074         struct Qdisc            *p;
1075         int                     depth;
1076 };
1077
1078 static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1079                          struct qdisc_walker *w);
1080
1081 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1082 {
1083         struct check_loop_arg   arg;
1084
1085         if (q->ops->cl_ops == NULL)
1086                 return 0;
1087
1088         arg.w.stop = arg.w.skip = arg.w.count = 0;
1089         arg.w.fn = check_loop_fn;
1090         arg.depth = depth;
1091         arg.p = p;
1092         q->ops->cl_ops->walk(q, &arg.w);
1093         return arg.w.stop ? -ELOOP : 0;
1094 }
1095
1096 static int
1097 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1098 {
1099         struct Qdisc *leaf;
1100         const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1101         struct check_loop_arg *arg = (struct check_loop_arg *)w;
1102
1103         leaf = cops->leaf(q, cl);
1104         if (leaf) {
1105                 if (leaf == arg->p || arg->depth > 7)
1106                         return -ELOOP;
1107                 return check_loop(leaf, arg->p, arg->depth + 1);
1108         }
1109         return 0;
1110 }
1111
1112 /*
1113  * Delete/get qdisc.
1114  */
1115
1116 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1117 {
1118         struct net *net = sock_net(skb->sk);
1119         struct tcmsg *tcm = nlmsg_data(n);
1120         struct nlattr *tca[TCA_MAX + 1];
1121         struct net_device *dev;
1122         u32 clid;
1123         struct Qdisc *q = NULL;
1124         struct Qdisc *p = NULL;
1125         int err;
1126
1127         if ((n->nlmsg_type != RTM_GETQDISC) &&
1128             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1129                 return -EPERM;
1130
1131         err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1132         if (err < 0)
1133                 return err;
1134
1135         dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1136         if (!dev)
1137                 return -ENODEV;
1138
1139         clid = tcm->tcm_parent;
1140         if (clid) {
1141                 if (clid != TC_H_ROOT) {
1142                         if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1143                                 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1144                                 if (!p)
1145                                         return -ENOENT;
1146                                 q = qdisc_leaf(p, clid);
1147                         } else if (dev_ingress_queue(dev)) {
1148                                 q = dev_ingress_queue(dev)->qdisc_sleeping;
1149                         }
1150                 } else {
1151                         q = dev->qdisc;
1152                 }
1153                 if (!q)
1154                         return -ENOENT;
1155
1156                 if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
1157                         return -EINVAL;
1158         } else {
1159                 q = qdisc_lookup(dev, tcm->tcm_handle);
1160                 if (!q)
1161                         return -ENOENT;
1162         }
1163
1164         if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1165                 return -EINVAL;
1166
1167         if (n->nlmsg_type == RTM_DELQDISC) {
1168                 if (!clid)
1169                         return -EINVAL;
1170                 if (q->handle == 0)
1171                         return -ENOENT;
1172                 err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
1173                 if (err != 0)
1174                         return err;
1175         } else {
1176                 qdisc_notify(net, skb, n, clid, NULL, q);
1177         }
1178         return 0;
1179 }
1180
1181 /*
1182  * Create/change qdisc.
1183  */
1184
1185 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
1186 {
1187         struct net *net = sock_net(skb->sk);
1188         struct tcmsg *tcm;
1189         struct nlattr *tca[TCA_MAX + 1];
1190         struct net_device *dev;
1191         u32 clid;
1192         struct Qdisc *q, *p;
1193         int err;
1194
1195         if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1196                 return -EPERM;
1197
1198 replay:
1199         /* Reinit, just in case something touches this. */
1200         err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1201         if (err < 0)
1202                 return err;
1203
1204         tcm = nlmsg_data(n);
1205         clid = tcm->tcm_parent;
1206         q = p = NULL;
1207
1208         dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1209         if (!dev)
1210                 return -ENODEV;
1211
1212
1213         if (clid) {
1214                 if (clid != TC_H_ROOT) {
1215                         if (clid != TC_H_INGRESS) {
1216                                 p = qdisc_lookup(dev, TC_H_MAJ(clid));
1217                                 if (!p)
1218                                         return -ENOENT;
1219                                 q = qdisc_leaf(p, clid);
1220                         } else if (dev_ingress_queue_create(dev)) {
1221                                 q = dev_ingress_queue(dev)->qdisc_sleeping;
1222                         }
1223                 } else {
1224                         q = dev->qdisc;
1225                 }
1226
1227                 /* It may be default qdisc, ignore it */
1228                 if (q && q->handle == 0)
1229                         q = NULL;
1230
1231                 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1232                         if (tcm->tcm_handle) {
1233                                 if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
1234                                         return -EEXIST;
1235                                 if (TC_H_MIN(tcm->tcm_handle))
1236                                         return -EINVAL;
1237                                 q = qdisc_lookup(dev, tcm->tcm_handle);
1238                                 if (!q)
1239                                         goto create_n_graft;
1240                                 if (n->nlmsg_flags & NLM_F_EXCL)
1241                                         return -EEXIST;
1242                                 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1243                                         return -EINVAL;
1244                                 if (q == p ||
1245                                     (p && check_loop(q, p, 0)))
1246                                         return -ELOOP;
1247                                 atomic_inc(&q->refcnt);
1248                                 goto graft;
1249                         } else {
1250                                 if (!q)
1251                                         goto create_n_graft;
1252
1253                                 /* This magic test requires explanation.
1254                                  *
1255                                  *   We know, that some child q is already
1256                                  *   attached to this parent and have choice:
1257                                  *   either to change it or to create/graft new one.
1258                                  *
1259                                  *   1. We are allowed to create/graft only
1260                                  *   if CREATE and REPLACE flags are set.
1261                                  *
1262                                  *   2. If EXCL is set, requestor wanted to say,
1263                                  *   that qdisc tcm_handle is not expected
1264                                  *   to exist, so that we choose create/graft too.
1265                                  *
1266                                  *   3. The last case is when no flags are set.
1267                                  *   Alas, it is sort of hole in API, we
1268                                  *   cannot decide what to do unambiguously.
1269                                  *   For now we select create/graft, if
1270                                  *   user gave KIND, which does not match existing.
1271                                  */
1272                                 if ((n->nlmsg_flags & NLM_F_CREATE) &&
1273                                     (n->nlmsg_flags & NLM_F_REPLACE) &&
1274                                     ((n->nlmsg_flags & NLM_F_EXCL) ||
1275                                      (tca[TCA_KIND] &&
1276                                       nla_strcmp(tca[TCA_KIND], q->ops->id))))
1277                                         goto create_n_graft;
1278                         }
1279                 }
1280         } else {
1281                 if (!tcm->tcm_handle)
1282                         return -EINVAL;
1283                 q = qdisc_lookup(dev, tcm->tcm_handle);
1284         }
1285
1286         /* Change qdisc parameters */
1287         if (q == NULL)
1288                 return -ENOENT;
1289         if (n->nlmsg_flags & NLM_F_EXCL)
1290                 return -EEXIST;
1291         if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
1292                 return -EINVAL;
1293         err = qdisc_change(q, tca);
1294         if (err == 0)
1295                 qdisc_notify(net, skb, n, clid, NULL, q);
1296         return err;
1297
1298 create_n_graft:
1299         if (!(n->nlmsg_flags & NLM_F_CREATE))
1300                 return -ENOENT;
1301         if (clid == TC_H_INGRESS) {
1302                 if (dev_ingress_queue(dev))
1303                         q = qdisc_create(dev, dev_ingress_queue(dev), p,
1304                                          tcm->tcm_parent, tcm->tcm_parent,
1305                                          tca, &err);
1306                 else
1307                         err = -ENOENT;
1308         } else {
1309                 struct netdev_queue *dev_queue;
1310
1311                 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1312                         dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1313                 else if (p)
1314                         dev_queue = p->dev_queue;
1315                 else
1316                         dev_queue = netdev_get_tx_queue(dev, 0);
1317
1318                 q = qdisc_create(dev, dev_queue, p,
1319                                  tcm->tcm_parent, tcm->tcm_handle,
1320                                  tca, &err);
1321         }
1322         if (q == NULL) {
1323                 if (err == -EAGAIN)
1324                         goto replay;
1325                 return err;
1326         }
1327
1328 graft:
1329         err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1330         if (err) {
1331                 if (q)
1332                         qdisc_destroy(q);
1333                 return err;
1334         }
1335
1336         return 0;
1337 }
1338
1339 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1340                          u32 portid, u32 seq, u16 flags, int event)
1341 {
1342         struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
1343         struct gnet_stats_queue __percpu *cpu_qstats = NULL;
1344         struct tcmsg *tcm;
1345         struct nlmsghdr  *nlh;
1346         unsigned char *b = skb_tail_pointer(skb);
1347         struct gnet_dump d;
1348         struct qdisc_size_table *stab;
1349         __u32 qlen;
1350
1351         cond_resched();
1352         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1353         if (!nlh)
1354                 goto out_nlmsg_trim;
1355         tcm = nlmsg_data(nlh);
1356         tcm->tcm_family = AF_UNSPEC;
1357         tcm->tcm__pad1 = 0;
1358         tcm->tcm__pad2 = 0;
1359         tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1360         tcm->tcm_parent = clid;
1361         tcm->tcm_handle = q->handle;
1362         tcm->tcm_info = atomic_read(&q->refcnt);
1363         if (nla_put_string(skb, TCA_KIND, q->ops->id))
1364                 goto nla_put_failure;
1365         if (q->ops->dump && q->ops->dump(q, skb) < 0)
1366                 goto nla_put_failure;
1367         qlen = q->q.qlen;
1368
1369         stab = rtnl_dereference(q->stab);
1370         if (stab && qdisc_dump_stab(skb, stab) < 0)
1371                 goto nla_put_failure;
1372
1373         if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1374                                          NULL, &d, TCA_PAD) < 0)
1375                 goto nla_put_failure;
1376
1377         if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1378                 goto nla_put_failure;
1379
1380         if (qdisc_is_percpu_stats(q)) {
1381                 cpu_bstats = q->cpu_bstats;
1382                 cpu_qstats = q->cpu_qstats;
1383         }
1384
1385         if (gnet_stats_copy_basic(qdisc_root_sleeping_running(q),
1386                                   &d, cpu_bstats, &q->bstats) < 0 ||
1387             gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1388             gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
1389                 goto nla_put_failure;
1390
1391         if (gnet_stats_finish_copy(&d) < 0)
1392                 goto nla_put_failure;
1393
1394         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1395         return skb->len;
1396
1397 out_nlmsg_trim:
1398 nla_put_failure:
1399         nlmsg_trim(skb, b);
1400         return -1;
1401 }
1402
1403 static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1404 {
1405         return (q->flags & TCQ_F_BUILTIN) ? true : false;
1406 }
1407
1408 static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1409                         struct nlmsghdr *n, u32 clid,
1410                         struct Qdisc *old, struct Qdisc *new)
1411 {
1412         struct sk_buff *skb;
1413         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1414
1415         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1416         if (!skb)
1417                 return -ENOBUFS;
1418
1419         if (old && !tc_qdisc_dump_ignore(old)) {
1420                 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1421                                   0, RTM_DELQDISC) < 0)
1422                         goto err_out;
1423         }
1424         if (new && !tc_qdisc_dump_ignore(new)) {
1425                 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1426                                   old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1427                         goto err_out;
1428         }
1429
1430         if (skb->len)
1431                 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1432                                       n->nlmsg_flags & NLM_F_ECHO);
1433
1434 err_out:
1435         kfree_skb(skb);
1436         return -EINVAL;
1437 }
1438
1439 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1440                               struct netlink_callback *cb,
1441                               int *q_idx_p, int s_q_idx, bool recur)
1442 {
1443         int ret = 0, q_idx = *q_idx_p;
1444         struct Qdisc *q;
1445         int b;
1446
1447         if (!root)
1448                 return 0;
1449
1450         q = root;
1451         if (q_idx < s_q_idx) {
1452                 q_idx++;
1453         } else {
1454                 if (!tc_qdisc_dump_ignore(q) &&
1455                     tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1456                                   cb->nlh->nlmsg_seq, NLM_F_MULTI,
1457                                   RTM_NEWQDISC) <= 0)
1458                         goto done;
1459                 q_idx++;
1460         }
1461
1462         /* If dumping singletons, there is no qdisc_dev(root) and the singleton
1463          * itself has already been dumped.
1464          *
1465          * If we've already dumped the top-level (ingress) qdisc above and the global
1466          * qdisc hashtable, we don't want to hit it again
1467          */
1468         if (!qdisc_dev(root) || !recur)
1469                 goto out;
1470
1471         hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1472                 if (q_idx < s_q_idx) {
1473                         q_idx++;
1474                         continue;
1475                 }
1476                 if (!tc_qdisc_dump_ignore(q) &&
1477                     tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1478                                   cb->nlh->nlmsg_seq, NLM_F_MULTI,
1479                                   RTM_NEWQDISC) <= 0)
1480                         goto done;
1481                 q_idx++;
1482         }
1483
1484 out:
1485         *q_idx_p = q_idx;
1486         return ret;
1487 done:
1488         ret = -1;
1489         goto out;
1490 }
1491
1492 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1493 {
1494         struct net *net = sock_net(skb->sk);
1495         int idx, q_idx;
1496         int s_idx, s_q_idx;
1497         struct net_device *dev;
1498
1499         s_idx = cb->args[0];
1500         s_q_idx = q_idx = cb->args[1];
1501
1502         idx = 0;
1503         ASSERT_RTNL();
1504         for_each_netdev(net, dev) {
1505                 struct netdev_queue *dev_queue;
1506
1507                 if (idx < s_idx)
1508                         goto cont;
1509                 if (idx > s_idx)
1510                         s_q_idx = 0;
1511                 q_idx = 0;
1512
1513                 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx,
1514                                        true) < 0)
1515                         goto done;
1516
1517                 dev_queue = dev_ingress_queue(dev);
1518                 if (dev_queue &&
1519                     tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1520                                        &q_idx, s_q_idx, false) < 0)
1521                         goto done;
1522
1523 cont:
1524                 idx++;
1525         }
1526
1527 done:
1528         cb->args[0] = idx;
1529         cb->args[1] = q_idx;
1530
1531         return skb->len;
1532 }
1533
1534
1535
1536 /************************************************
1537  *      Traffic classes manipulation.           *
1538  ************************************************/
1539
1540
1541
1542 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n)
1543 {
1544         struct net *net = sock_net(skb->sk);
1545         struct tcmsg *tcm = nlmsg_data(n);
1546         struct nlattr *tca[TCA_MAX + 1];
1547         struct net_device *dev;
1548         struct Qdisc *q = NULL;
1549         const struct Qdisc_class_ops *cops;
1550         unsigned long cl = 0;
1551         unsigned long new_cl;
1552         u32 portid;
1553         u32 clid;
1554         u32 qid;
1555         int err;
1556
1557         if ((n->nlmsg_type != RTM_GETTCLASS) &&
1558             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1559                 return -EPERM;
1560
1561         err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1562         if (err < 0)
1563                 return err;
1564
1565         dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1566         if (!dev)
1567                 return -ENODEV;
1568
1569         /*
1570            parent == TC_H_UNSPEC - unspecified parent.
1571            parent == TC_H_ROOT   - class is root, which has no parent.
1572            parent == X:0         - parent is root class.
1573            parent == X:Y         - parent is a node in hierarchy.
1574            parent == 0:Y         - parent is X:Y, where X:0 is qdisc.
1575
1576            handle == 0:0         - generate handle from kernel pool.
1577            handle == 0:Y         - class is X:Y, where X:0 is qdisc.
1578            handle == X:Y         - clear.
1579            handle == X:0         - root class.
1580          */
1581
1582         /* Step 1. Determine qdisc handle X:0 */
1583
1584         portid = tcm->tcm_parent;
1585         clid = tcm->tcm_handle;
1586         qid = TC_H_MAJ(clid);
1587
1588         if (portid != TC_H_ROOT) {
1589                 u32 qid1 = TC_H_MAJ(portid);
1590
1591                 if (qid && qid1) {
1592                         /* If both majors are known, they must be identical. */
1593                         if (qid != qid1)
1594                                 return -EINVAL;
1595                 } else if (qid1) {
1596                         qid = qid1;
1597                 } else if (qid == 0)
1598                         qid = dev->qdisc->handle;
1599
1600                 /* Now qid is genuine qdisc handle consistent
1601                  * both with parent and child.
1602                  *
1603                  * TC_H_MAJ(portid) still may be unspecified, complete it now.
1604                  */
1605                 if (portid)
1606                         portid = TC_H_MAKE(qid, portid);
1607         } else {
1608                 if (qid == 0)
1609                         qid = dev->qdisc->handle;
1610         }
1611
1612         /* OK. Locate qdisc */
1613         q = qdisc_lookup(dev, qid);
1614         if (!q)
1615                 return -ENOENT;
1616
1617         /* An check that it supports classes */
1618         cops = q->ops->cl_ops;
1619         if (cops == NULL)
1620                 return -EINVAL;
1621
1622         /* Now try to get class */
1623         if (clid == 0) {
1624                 if (portid == TC_H_ROOT)
1625                         clid = qid;
1626         } else
1627                 clid = TC_H_MAKE(qid, clid);
1628
1629         if (clid)
1630                 cl = cops->get(q, clid);
1631
1632         if (cl == 0) {
1633                 err = -ENOENT;
1634                 if (n->nlmsg_type != RTM_NEWTCLASS ||
1635                     !(n->nlmsg_flags & NLM_F_CREATE))
1636                         goto out;
1637         } else {
1638                 switch (n->nlmsg_type) {
1639                 case RTM_NEWTCLASS:
1640                         err = -EEXIST;
1641                         if (n->nlmsg_flags & NLM_F_EXCL)
1642                                 goto out;
1643                         break;
1644                 case RTM_DELTCLASS:
1645                         err = -EOPNOTSUPP;
1646                         if (cops->delete)
1647                                 err = cops->delete(q, cl);
1648                         if (err == 0)
1649                                 tclass_notify(net, skb, n, q, cl,
1650                                               RTM_DELTCLASS);
1651                         goto out;
1652                 case RTM_GETTCLASS:
1653                         err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1654                         goto out;
1655                 default:
1656                         err = -EINVAL;
1657                         goto out;
1658                 }
1659         }
1660
1661         new_cl = cl;
1662         err = -EOPNOTSUPP;
1663         if (cops->change)
1664                 err = cops->change(q, clid, portid, tca, &new_cl);
1665         if (err == 0)
1666                 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1667
1668 out:
1669         if (cl)
1670                 cops->put(q, cl);
1671
1672         return err;
1673 }
1674
1675
1676 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1677                           unsigned long cl,
1678                           u32 portid, u32 seq, u16 flags, int event)
1679 {
1680         struct tcmsg *tcm;
1681         struct nlmsghdr  *nlh;
1682         unsigned char *b = skb_tail_pointer(skb);
1683         struct gnet_dump d;
1684         const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1685
1686         cond_resched();
1687         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1688         if (!nlh)
1689                 goto out_nlmsg_trim;
1690         tcm = nlmsg_data(nlh);
1691         tcm->tcm_family = AF_UNSPEC;
1692         tcm->tcm__pad1 = 0;
1693         tcm->tcm__pad2 = 0;
1694         tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1695         tcm->tcm_parent = q->handle;
1696         tcm->tcm_handle = q->handle;
1697         tcm->tcm_info = 0;
1698         if (nla_put_string(skb, TCA_KIND, q->ops->id))
1699                 goto nla_put_failure;
1700         if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1701                 goto nla_put_failure;
1702
1703         if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1704                                          NULL, &d, TCA_PAD) < 0)
1705                 goto nla_put_failure;
1706
1707         if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1708                 goto nla_put_failure;
1709
1710         if (gnet_stats_finish_copy(&d) < 0)
1711                 goto nla_put_failure;
1712
1713         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1714         return skb->len;
1715
1716 out_nlmsg_trim:
1717 nla_put_failure:
1718         nlmsg_trim(skb, b);
1719         return -1;
1720 }
1721
1722 static int tclass_notify(struct net *net, struct sk_buff *oskb,
1723                          struct nlmsghdr *n, struct Qdisc *q,
1724                          unsigned long cl, int event)
1725 {
1726         struct sk_buff *skb;
1727         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1728
1729         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1730         if (!skb)
1731                 return -ENOBUFS;
1732
1733         if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1734                 kfree_skb(skb);
1735                 return -EINVAL;
1736         }
1737
1738         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1739                               n->nlmsg_flags & NLM_F_ECHO);
1740 }
1741
1742 struct qdisc_dump_args {
1743         struct qdisc_walker     w;
1744         struct sk_buff          *skb;
1745         struct netlink_callback *cb;
1746 };
1747
1748 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
1749                             struct qdisc_walker *arg)
1750 {
1751         struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1752
1753         return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1754                               a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
1755                               RTM_NEWTCLASS);
1756 }
1757
1758 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1759                                 struct tcmsg *tcm, struct netlink_callback *cb,
1760                                 int *t_p, int s_t)
1761 {
1762         struct qdisc_dump_args arg;
1763
1764         if (tc_qdisc_dump_ignore(q) ||
1765             *t_p < s_t || !q->ops->cl_ops ||
1766             (tcm->tcm_parent &&
1767              TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1768                 (*t_p)++;
1769                 return 0;
1770         }
1771         if (*t_p > s_t)
1772                 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1773         arg.w.fn = qdisc_class_dump;
1774         arg.skb = skb;
1775         arg.cb = cb;
1776         arg.w.stop  = 0;
1777         arg.w.skip = cb->args[1];
1778         arg.w.count = 0;
1779         q->ops->cl_ops->walk(q, &arg.w);
1780         cb->args[1] = arg.w.count;
1781         if (arg.w.stop)
1782                 return -1;
1783         (*t_p)++;
1784         return 0;
1785 }
1786
1787 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1788                                struct tcmsg *tcm, struct netlink_callback *cb,
1789                                int *t_p, int s_t)
1790 {
1791         struct Qdisc *q;
1792         int b;
1793
1794         if (!root)
1795                 return 0;
1796
1797         if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1798                 return -1;
1799
1800         if (!qdisc_dev(root))
1801                 return 0;
1802
1803         hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1804                 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1805                         return -1;
1806         }
1807
1808         return 0;
1809 }
1810
1811 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1812 {
1813         struct tcmsg *tcm = nlmsg_data(cb->nlh);
1814         struct net *net = sock_net(skb->sk);
1815         struct netdev_queue *dev_queue;
1816         struct net_device *dev;
1817         int t, s_t;
1818
1819         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1820                 return 0;
1821         dev = dev_get_by_index(net, tcm->tcm_ifindex);
1822         if (!dev)
1823                 return 0;
1824
1825         s_t = cb->args[0];
1826         t = 0;
1827
1828         if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
1829                 goto done;
1830
1831         dev_queue = dev_ingress_queue(dev);
1832         if (dev_queue &&
1833             tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1834                                 &t, s_t) < 0)
1835                 goto done;
1836
1837 done:
1838         cb->args[0] = t;
1839
1840         dev_put(dev);
1841         return skb->len;
1842 }
1843
1844 /* Main classifier routine: scans classifier chain attached
1845  * to this qdisc, (optionally) tests for protocol and asks
1846  * specific classifiers.
1847  */
1848 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1849                 struct tcf_result *res, bool compat_mode)
1850 {
1851         __be16 protocol = tc_skb_protocol(skb);
1852 #ifdef CONFIG_NET_CLS_ACT
1853         const struct tcf_proto *old_tp = tp;
1854         int limit = 0;
1855
1856 reclassify:
1857 #endif
1858         for (; tp; tp = rcu_dereference_bh(tp->next)) {
1859                 int err;
1860
1861                 if (tp->protocol != protocol &&
1862                     tp->protocol != htons(ETH_P_ALL))
1863                         continue;
1864
1865                 err = tp->classify(skb, tp, res);
1866 #ifdef CONFIG_NET_CLS_ACT
1867                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode))
1868                         goto reset;
1869 #endif
1870                 if (err >= 0)
1871                         return err;
1872         }
1873
1874         return TC_ACT_UNSPEC; /* signal: continue lookup */
1875 #ifdef CONFIG_NET_CLS_ACT
1876 reset:
1877         if (unlikely(limit++ >= MAX_REC_LOOP)) {
1878                 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n",
1879                                        tp->q->ops->id, tp->prio & 0xffff,
1880                                        ntohs(tp->protocol));
1881                 return TC_ACT_SHOT;
1882         }
1883
1884         tp = old_tp;
1885         protocol = tc_skb_protocol(skb);
1886         goto reclassify;
1887 #endif
1888 }
1889 EXPORT_SYMBOL(tc_classify);
1890
1891 bool tcf_destroy(struct tcf_proto *tp, bool force)
1892 {
1893         if (tp->ops->destroy(tp, force)) {
1894                 module_put(tp->ops->owner);
1895                 kfree_rcu(tp, rcu);
1896                 return true;
1897         }
1898
1899         return false;
1900 }
1901
1902 void tcf_destroy_chain(struct tcf_proto __rcu **fl)
1903 {
1904         struct tcf_proto *tp;
1905
1906         while ((tp = rtnl_dereference(*fl)) != NULL) {
1907                 RCU_INIT_POINTER(*fl, tp->next);
1908                 tcf_destroy(tp, true);
1909         }
1910 }
1911 EXPORT_SYMBOL(tcf_destroy_chain);
1912
1913 #ifdef CONFIG_PROC_FS
1914 static int psched_show(struct seq_file *seq, void *v)
1915 {
1916         seq_printf(seq, "%08x %08x %08x %08x\n",
1917                    (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1918                    1000000,
1919                    (u32)NSEC_PER_SEC / hrtimer_resolution);
1920
1921         return 0;
1922 }
1923
1924 static int psched_open(struct inode *inode, struct file *file)
1925 {
1926         return single_open(file, psched_show, NULL);
1927 }
1928
1929 static const struct file_operations psched_fops = {
1930         .owner = THIS_MODULE,
1931         .open = psched_open,
1932         .read  = seq_read,
1933         .llseek = seq_lseek,
1934         .release = single_release,
1935 };
1936
1937 static int __net_init psched_net_init(struct net *net)
1938 {
1939         struct proc_dir_entry *e;
1940
1941         e = proc_create("psched", 0, net->proc_net, &psched_fops);
1942         if (e == NULL)
1943                 return -ENOMEM;
1944
1945         return 0;
1946 }
1947
1948 static void __net_exit psched_net_exit(struct net *net)
1949 {
1950         remove_proc_entry("psched", net->proc_net);
1951 }
1952 #else
1953 static int __net_init psched_net_init(struct net *net)
1954 {
1955         return 0;
1956 }
1957
1958 static void __net_exit psched_net_exit(struct net *net)
1959 {
1960 }
1961 #endif
1962
1963 static struct pernet_operations psched_net_ops = {
1964         .init = psched_net_init,
1965         .exit = psched_net_exit,
1966 };
1967
1968 static int __init pktsched_init(void)
1969 {
1970         int err;
1971
1972         err = register_pernet_subsys(&psched_net_ops);
1973         if (err) {
1974                 pr_err("pktsched_init: "
1975                        "cannot initialize per netns operations\n");
1976                 return err;
1977         }
1978
1979         register_qdisc(&pfifo_fast_ops);
1980         register_qdisc(&pfifo_qdisc_ops);
1981         register_qdisc(&bfifo_qdisc_ops);
1982         register_qdisc(&pfifo_head_drop_qdisc_ops);
1983         register_qdisc(&mq_qdisc_ops);
1984         register_qdisc(&noqueue_qdisc_ops);
1985
1986         rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1987         rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1988         rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc,
1989                       NULL);
1990         rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1991         rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1992         rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass,
1993                       NULL);
1994
1995         return 0;
1996 }
1997
1998 subsys_initcall(pktsched_init);