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