1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * net/sched/sch_api.c Packet scheduler API. 4 * 5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 6 * 7 * Fixes: 8 * 9 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired. 10 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support 11 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support 12 */ 13 14 #include <linux/module.h> 15 #include <linux/types.h> 16 #include <linux/kernel.h> 17 #include <linux/string.h> 18 #include <linux/errno.h> 19 #include <linux/skbuff.h> 20 #include <linux/init.h> 21 #include <linux/proc_fs.h> 22 #include <linux/seq_file.h> 23 #include <linux/kmod.h> 24 #include <linux/list.h> 25 #include <linux/hrtimer.h> 26 #include <linux/slab.h> 27 #include <linux/hashtable.h> 28 29 #include <net/net_namespace.h> 30 #include <net/sock.h> 31 #include <net/netlink.h> 32 #include <net/pkt_sched.h> 33 #include <net/pkt_cls.h> 34 #include <net/tc_wrapper.h> 35 36 #include <trace/events/qdisc.h> 37 38 /* 39 40 Short review. 41 ------------- 42 43 This file consists of two interrelated parts: 44 45 1. queueing disciplines manager frontend. 46 2. traffic classes manager frontend. 47 48 Generally, queueing discipline ("qdisc") is a black box, 49 which is able to enqueue packets and to dequeue them (when 50 device is ready to send something) in order and at times 51 determined by algorithm hidden in it. 52 53 qdisc's are divided to two categories: 54 - "queues", which have no internal structure visible from outside. 55 - "schedulers", which split all the packets to "traffic classes", 56 using "packet classifiers" (look at cls_api.c) 57 58 In turn, classes may have child qdiscs (as rule, queues) 59 attached to them etc. etc. etc. 60 61 The goal of the routines in this file is to translate 62 information supplied by user in the form of handles 63 to more intelligible for kernel form, to make some sanity 64 checks and part of work, which is common to all qdiscs 65 and to provide rtnetlink notifications. 66 67 All real intelligent work is done inside qdisc modules. 68 69 70 71 Every discipline has two major routines: enqueue and dequeue. 72 73 ---dequeue 74 75 dequeue usually returns a skb to send. It is allowed to return NULL, 76 but it does not mean that queue is empty, it just means that 77 discipline does not want to send anything this time. 78 Queue is really empty if q->q.qlen == 0. 79 For complicated disciplines with multiple queues q->q is not 80 real packet queue, but however q->q.qlen must be valid. 81 82 ---enqueue 83 84 enqueue returns 0, if packet was enqueued successfully. 85 If packet (this one or another one) was dropped, it returns 86 not zero error code. 87 NET_XMIT_DROP - this packet dropped 88 Expected action: do not backoff, but wait until queue will clear. 89 NET_XMIT_CN - probably this packet enqueued, but another one dropped. 90 Expected action: backoff or ignore 91 92 Auxiliary routines: 93 94 ---peek 95 96 like dequeue but without removing a packet from the queue 97 98 ---reset 99 100 returns qdisc to initial state: purge all buffers, clear all 101 timers, counters (except for statistics) etc. 102 103 ---init 104 105 initializes newly created qdisc. 106 107 ---destroy 108 109 destroys resources allocated by init and during lifetime of qdisc. 110 111 ---change 112 113 changes qdisc parameters. 114 */ 115 116 /* Protects list of registered TC modules. It is pure SMP lock. */ 117 static DEFINE_RWLOCK(qdisc_mod_lock); 118 119 120 /************************************************ 121 * Queueing disciplines manipulation. * 122 ************************************************/ 123 124 125 /* The list of all installed queueing disciplines. */ 126 127 static struct Qdisc_ops *qdisc_base; 128 129 /* Register/unregister queueing discipline */ 130 131 int register_qdisc(struct Qdisc_ops *qops) 132 { 133 struct Qdisc_ops *q, **qp; 134 int rc = -EEXIST; 135 136 write_lock(&qdisc_mod_lock); 137 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next) 138 if (!strcmp(qops->id, q->id)) 139 goto out; 140 141 if (qops->enqueue == NULL) 142 qops->enqueue = noop_qdisc_ops.enqueue; 143 if (qops->peek == NULL) { 144 if (qops->dequeue == NULL) 145 qops->peek = noop_qdisc_ops.peek; 146 else 147 goto out_einval; 148 } 149 if (qops->dequeue == NULL) 150 qops->dequeue = noop_qdisc_ops.dequeue; 151 152 if (qops->cl_ops) { 153 const struct Qdisc_class_ops *cops = qops->cl_ops; 154 155 if (!(cops->find && cops->walk && cops->leaf)) 156 goto out_einval; 157 158 if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf)) 159 goto out_einval; 160 } 161 162 qops->next = NULL; 163 *qp = qops; 164 rc = 0; 165 out: 166 write_unlock(&qdisc_mod_lock); 167 return rc; 168 169 out_einval: 170 rc = -EINVAL; 171 goto out; 172 } 173 EXPORT_SYMBOL(register_qdisc); 174 175 void unregister_qdisc(struct Qdisc_ops *qops) 176 { 177 struct Qdisc_ops *q, **qp; 178 int err = -ENOENT; 179 180 write_lock(&qdisc_mod_lock); 181 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next) 182 if (q == qops) 183 break; 184 if (q) { 185 *qp = q->next; 186 q->next = NULL; 187 err = 0; 188 } 189 write_unlock(&qdisc_mod_lock); 190 191 WARN(err, "unregister qdisc(%s) failed\n", qops->id); 192 } 193 EXPORT_SYMBOL(unregister_qdisc); 194 195 /* Get default qdisc if not otherwise specified */ 196 void qdisc_get_default(char *name, size_t len) 197 { 198 read_lock(&qdisc_mod_lock); 199 strscpy(name, default_qdisc_ops->id, len); 200 read_unlock(&qdisc_mod_lock); 201 } 202 203 static struct Qdisc_ops *qdisc_lookup_default(const char *name) 204 { 205 struct Qdisc_ops *q = NULL; 206 207 for (q = qdisc_base; q; q = q->next) { 208 if (!strcmp(name, q->id)) { 209 if (!try_module_get(q->owner)) 210 q = NULL; 211 break; 212 } 213 } 214 215 return q; 216 } 217 218 /* Set new default qdisc to use */ 219 int qdisc_set_default(const char *name) 220 { 221 const struct Qdisc_ops *ops; 222 223 if (!capable(CAP_NET_ADMIN)) 224 return -EPERM; 225 226 write_lock(&qdisc_mod_lock); 227 ops = qdisc_lookup_default(name); 228 if (!ops) { 229 /* Not found, drop lock and try to load module */ 230 write_unlock(&qdisc_mod_lock); 231 request_module("sch_%s", name); 232 write_lock(&qdisc_mod_lock); 233 234 ops = qdisc_lookup_default(name); 235 } 236 237 if (ops) { 238 /* Set new default */ 239 module_put(default_qdisc_ops->owner); 240 default_qdisc_ops = ops; 241 } 242 write_unlock(&qdisc_mod_lock); 243 244 return ops ? 0 : -ENOENT; 245 } 246 247 #ifdef CONFIG_NET_SCH_DEFAULT 248 /* Set default value from kernel config */ 249 static int __init sch_default_qdisc(void) 250 { 251 return qdisc_set_default(CONFIG_DEFAULT_NET_SCH); 252 } 253 late_initcall(sch_default_qdisc); 254 #endif 255 256 /* We know handle. Find qdisc among all qdisc's attached to device 257 * (root qdisc, all its children, children of children etc.) 258 * Note: caller either uses rtnl or rcu_read_lock() 259 */ 260 261 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle) 262 { 263 struct Qdisc *q; 264 265 if (!qdisc_dev(root)) 266 return (root->handle == handle ? root : NULL); 267 268 if (!(root->flags & TCQ_F_BUILTIN) && 269 root->handle == handle) 270 return root; 271 272 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle, 273 lockdep_rtnl_is_held()) { 274 if (q->handle == handle) 275 return q; 276 } 277 return NULL; 278 } 279 280 void qdisc_hash_add(struct Qdisc *q, bool invisible) 281 { 282 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) { 283 ASSERT_RTNL(); 284 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle); 285 if (invisible) 286 q->flags |= TCQ_F_INVISIBLE; 287 } 288 } 289 EXPORT_SYMBOL(qdisc_hash_add); 290 291 void qdisc_hash_del(struct Qdisc *q) 292 { 293 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) { 294 ASSERT_RTNL(); 295 hash_del_rcu(&q->hash); 296 } 297 } 298 EXPORT_SYMBOL(qdisc_hash_del); 299 300 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle) 301 { 302 struct Qdisc *q; 303 304 if (!handle) 305 return NULL; 306 q = qdisc_match_from_root(rtnl_dereference(dev->qdisc), handle); 307 if (q) 308 goto out; 309 310 if (dev_ingress_queue(dev)) 311 q = qdisc_match_from_root( 312 rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping), 313 handle); 314 out: 315 return q; 316 } 317 318 struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle) 319 { 320 struct netdev_queue *nq; 321 struct Qdisc *q; 322 323 if (!handle) 324 return NULL; 325 q = qdisc_match_from_root(rcu_dereference(dev->qdisc), handle); 326 if (q) 327 goto out; 328 329 nq = dev_ingress_queue_rcu(dev); 330 if (nq) 331 q = qdisc_match_from_root(rcu_dereference(nq->qdisc_sleeping), 332 handle); 333 out: 334 return q; 335 } 336 337 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid) 338 { 339 unsigned long cl; 340 const struct Qdisc_class_ops *cops = p->ops->cl_ops; 341 342 if (cops == NULL) 343 return NULL; 344 cl = cops->find(p, classid); 345 346 if (cl == 0) 347 return NULL; 348 return cops->leaf(p, cl); 349 } 350 351 /* Find queueing discipline by name */ 352 353 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind) 354 { 355 struct Qdisc_ops *q = NULL; 356 357 if (kind) { 358 read_lock(&qdisc_mod_lock); 359 for (q = qdisc_base; q; q = q->next) { 360 if (nla_strcmp(kind, q->id) == 0) { 361 if (!try_module_get(q->owner)) 362 q = NULL; 363 break; 364 } 365 } 366 read_unlock(&qdisc_mod_lock); 367 } 368 return q; 369 } 370 371 /* The linklayer setting were not transferred from iproute2, in older 372 * versions, and the rate tables lookup systems have been dropped in 373 * the kernel. To keep backward compatible with older iproute2 tc 374 * utils, we detect the linklayer setting by detecting if the rate 375 * table were modified. 376 * 377 * For linklayer ATM table entries, the rate table will be aligned to 378 * 48 bytes, thus some table entries will contain the same value. The 379 * mpu (min packet unit) is also encoded into the old rate table, thus 380 * starting from the mpu, we find low and high table entries for 381 * mapping this cell. If these entries contain the same value, when 382 * the rate tables have been modified for linklayer ATM. 383 * 384 * This is done by rounding mpu to the nearest 48 bytes cell/entry, 385 * and then roundup to the next cell, calc the table entry one below, 386 * and compare. 387 */ 388 static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab) 389 { 390 int low = roundup(r->mpu, 48); 391 int high = roundup(low+1, 48); 392 int cell_low = low >> r->cell_log; 393 int cell_high = (high >> r->cell_log) - 1; 394 395 /* rtab is too inaccurate at rates > 100Mbit/s */ 396 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) { 397 pr_debug("TC linklayer: Giving up ATM detection\n"); 398 return TC_LINKLAYER_ETHERNET; 399 } 400 401 if ((cell_high > cell_low) && (cell_high < 256) 402 && (rtab[cell_low] == rtab[cell_high])) { 403 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n", 404 cell_low, cell_high, rtab[cell_high]); 405 return TC_LINKLAYER_ATM; 406 } 407 return TC_LINKLAYER_ETHERNET; 408 } 409 410 static struct qdisc_rate_table *qdisc_rtab_list; 411 412 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, 413 struct nlattr *tab, 414 struct netlink_ext_ack *extack) 415 { 416 struct qdisc_rate_table *rtab; 417 418 if (tab == NULL || r->rate == 0 || 419 r->cell_log == 0 || r->cell_log >= 32 || 420 nla_len(tab) != TC_RTAB_SIZE) { 421 NL_SET_ERR_MSG(extack, "Invalid rate table parameters for searching"); 422 return NULL; 423 } 424 425 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) { 426 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) && 427 !memcmp(&rtab->data, nla_data(tab), 1024)) { 428 rtab->refcnt++; 429 return rtab; 430 } 431 } 432 433 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL); 434 if (rtab) { 435 rtab->rate = *r; 436 rtab->refcnt = 1; 437 memcpy(rtab->data, nla_data(tab), 1024); 438 if (r->linklayer == TC_LINKLAYER_UNAWARE) 439 r->linklayer = __detect_linklayer(r, rtab->data); 440 rtab->next = qdisc_rtab_list; 441 qdisc_rtab_list = rtab; 442 } else { 443 NL_SET_ERR_MSG(extack, "Failed to allocate new qdisc rate table"); 444 } 445 return rtab; 446 } 447 EXPORT_SYMBOL(qdisc_get_rtab); 448 449 void qdisc_put_rtab(struct qdisc_rate_table *tab) 450 { 451 struct qdisc_rate_table *rtab, **rtabp; 452 453 if (!tab || --tab->refcnt) 454 return; 455 456 for (rtabp = &qdisc_rtab_list; 457 (rtab = *rtabp) != NULL; 458 rtabp = &rtab->next) { 459 if (rtab == tab) { 460 *rtabp = rtab->next; 461 kfree(rtab); 462 return; 463 } 464 } 465 } 466 EXPORT_SYMBOL(qdisc_put_rtab); 467 468 static LIST_HEAD(qdisc_stab_list); 469 470 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = { 471 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) }, 472 [TCA_STAB_DATA] = { .type = NLA_BINARY }, 473 }; 474 475 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt, 476 struct netlink_ext_ack *extack) 477 { 478 struct nlattr *tb[TCA_STAB_MAX + 1]; 479 struct qdisc_size_table *stab; 480 struct tc_sizespec *s; 481 unsigned int tsize = 0; 482 u16 *tab = NULL; 483 int err; 484 485 err = nla_parse_nested_deprecated(tb, TCA_STAB_MAX, opt, stab_policy, 486 extack); 487 if (err < 0) 488 return ERR_PTR(err); 489 if (!tb[TCA_STAB_BASE]) { 490 NL_SET_ERR_MSG(extack, "Size table base attribute is missing"); 491 return ERR_PTR(-EINVAL); 492 } 493 494 s = nla_data(tb[TCA_STAB_BASE]); 495 496 if (s->tsize > 0) { 497 if (!tb[TCA_STAB_DATA]) { 498 NL_SET_ERR_MSG(extack, "Size table data attribute is missing"); 499 return ERR_PTR(-EINVAL); 500 } 501 tab = nla_data(tb[TCA_STAB_DATA]); 502 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16); 503 } 504 505 if (tsize != s->tsize || (!tab && tsize > 0)) { 506 NL_SET_ERR_MSG(extack, "Invalid size of size table"); 507 return ERR_PTR(-EINVAL); 508 } 509 510 list_for_each_entry(stab, &qdisc_stab_list, list) { 511 if (memcmp(&stab->szopts, s, sizeof(*s))) 512 continue; 513 if (tsize > 0 && 514 memcmp(stab->data, tab, flex_array_size(stab, data, tsize))) 515 continue; 516 stab->refcnt++; 517 return stab; 518 } 519 520 if (s->size_log > STAB_SIZE_LOG_MAX || 521 s->cell_log > STAB_SIZE_LOG_MAX) { 522 NL_SET_ERR_MSG(extack, "Invalid logarithmic size of size table"); 523 return ERR_PTR(-EINVAL); 524 } 525 526 stab = kmalloc(struct_size(stab, data, tsize), GFP_KERNEL); 527 if (!stab) 528 return ERR_PTR(-ENOMEM); 529 530 stab->refcnt = 1; 531 stab->szopts = *s; 532 if (tsize > 0) 533 memcpy(stab->data, tab, flex_array_size(stab, data, tsize)); 534 535 list_add_tail(&stab->list, &qdisc_stab_list); 536 537 return stab; 538 } 539 540 void qdisc_put_stab(struct qdisc_size_table *tab) 541 { 542 if (!tab) 543 return; 544 545 if (--tab->refcnt == 0) { 546 list_del(&tab->list); 547 kfree_rcu(tab, rcu); 548 } 549 } 550 EXPORT_SYMBOL(qdisc_put_stab); 551 552 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab) 553 { 554 struct nlattr *nest; 555 556 nest = nla_nest_start_noflag(skb, TCA_STAB); 557 if (nest == NULL) 558 goto nla_put_failure; 559 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts)) 560 goto nla_put_failure; 561 nla_nest_end(skb, nest); 562 563 return skb->len; 564 565 nla_put_failure: 566 return -1; 567 } 568 569 void __qdisc_calculate_pkt_len(struct sk_buff *skb, 570 const struct qdisc_size_table *stab) 571 { 572 int pkt_len, slot; 573 574 pkt_len = skb->len + stab->szopts.overhead; 575 if (unlikely(!stab->szopts.tsize)) 576 goto out; 577 578 slot = pkt_len + stab->szopts.cell_align; 579 if (unlikely(slot < 0)) 580 slot = 0; 581 582 slot >>= stab->szopts.cell_log; 583 if (likely(slot < stab->szopts.tsize)) 584 pkt_len = stab->data[slot]; 585 else 586 pkt_len = stab->data[stab->szopts.tsize - 1] * 587 (slot / stab->szopts.tsize) + 588 stab->data[slot % stab->szopts.tsize]; 589 590 pkt_len <<= stab->szopts.size_log; 591 out: 592 if (unlikely(pkt_len < 1)) 593 pkt_len = 1; 594 qdisc_skb_cb(skb)->pkt_len = pkt_len; 595 } 596 597 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc) 598 { 599 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) { 600 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n", 601 txt, qdisc->ops->id, qdisc->handle >> 16); 602 qdisc->flags |= TCQ_F_WARN_NONWC; 603 } 604 } 605 EXPORT_SYMBOL(qdisc_warn_nonwc); 606 607 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer) 608 { 609 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog, 610 timer); 611 612 rcu_read_lock(); 613 __netif_schedule(qdisc_root(wd->qdisc)); 614 rcu_read_unlock(); 615 616 return HRTIMER_NORESTART; 617 } 618 619 void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc, 620 clockid_t clockid) 621 { 622 hrtimer_init(&wd->timer, clockid, HRTIMER_MODE_ABS_PINNED); 623 wd->timer.function = qdisc_watchdog; 624 wd->qdisc = qdisc; 625 } 626 EXPORT_SYMBOL(qdisc_watchdog_init_clockid); 627 628 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc) 629 { 630 qdisc_watchdog_init_clockid(wd, qdisc, CLOCK_MONOTONIC); 631 } 632 EXPORT_SYMBOL(qdisc_watchdog_init); 633 634 void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires, 635 u64 delta_ns) 636 { 637 bool deactivated; 638 639 rcu_read_lock(); 640 deactivated = test_bit(__QDISC_STATE_DEACTIVATED, 641 &qdisc_root_sleeping(wd->qdisc)->state); 642 rcu_read_unlock(); 643 if (deactivated) 644 return; 645 646 if (hrtimer_is_queued(&wd->timer)) { 647 u64 softexpires; 648 649 softexpires = ktime_to_ns(hrtimer_get_softexpires(&wd->timer)); 650 /* If timer is already set in [expires, expires + delta_ns], 651 * do not reprogram it. 652 */ 653 if (softexpires - expires <= delta_ns) 654 return; 655 } 656 657 hrtimer_start_range_ns(&wd->timer, 658 ns_to_ktime(expires), 659 delta_ns, 660 HRTIMER_MODE_ABS_PINNED); 661 } 662 EXPORT_SYMBOL(qdisc_watchdog_schedule_range_ns); 663 664 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd) 665 { 666 hrtimer_cancel(&wd->timer); 667 } 668 EXPORT_SYMBOL(qdisc_watchdog_cancel); 669 670 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n) 671 { 672 struct hlist_head *h; 673 unsigned int i; 674 675 h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL); 676 677 if (h != NULL) { 678 for (i = 0; i < n; i++) 679 INIT_HLIST_HEAD(&h[i]); 680 } 681 return h; 682 } 683 684 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash) 685 { 686 struct Qdisc_class_common *cl; 687 struct hlist_node *next; 688 struct hlist_head *nhash, *ohash; 689 unsigned int nsize, nmask, osize; 690 unsigned int i, h; 691 692 /* Rehash when load factor exceeds 0.75 */ 693 if (clhash->hashelems * 4 <= clhash->hashsize * 3) 694 return; 695 nsize = clhash->hashsize * 2; 696 nmask = nsize - 1; 697 nhash = qdisc_class_hash_alloc(nsize); 698 if (nhash == NULL) 699 return; 700 701 ohash = clhash->hash; 702 osize = clhash->hashsize; 703 704 sch_tree_lock(sch); 705 for (i = 0; i < osize; i++) { 706 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) { 707 h = qdisc_class_hash(cl->classid, nmask); 708 hlist_add_head(&cl->hnode, &nhash[h]); 709 } 710 } 711 clhash->hash = nhash; 712 clhash->hashsize = nsize; 713 clhash->hashmask = nmask; 714 sch_tree_unlock(sch); 715 716 kvfree(ohash); 717 } 718 EXPORT_SYMBOL(qdisc_class_hash_grow); 719 720 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash) 721 { 722 unsigned int size = 4; 723 724 clhash->hash = qdisc_class_hash_alloc(size); 725 if (!clhash->hash) 726 return -ENOMEM; 727 clhash->hashsize = size; 728 clhash->hashmask = size - 1; 729 clhash->hashelems = 0; 730 return 0; 731 } 732 EXPORT_SYMBOL(qdisc_class_hash_init); 733 734 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash) 735 { 736 kvfree(clhash->hash); 737 } 738 EXPORT_SYMBOL(qdisc_class_hash_destroy); 739 740 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash, 741 struct Qdisc_class_common *cl) 742 { 743 unsigned int h; 744 745 INIT_HLIST_NODE(&cl->hnode); 746 h = qdisc_class_hash(cl->classid, clhash->hashmask); 747 hlist_add_head(&cl->hnode, &clhash->hash[h]); 748 clhash->hashelems++; 749 } 750 EXPORT_SYMBOL(qdisc_class_hash_insert); 751 752 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash, 753 struct Qdisc_class_common *cl) 754 { 755 hlist_del(&cl->hnode); 756 clhash->hashelems--; 757 } 758 EXPORT_SYMBOL(qdisc_class_hash_remove); 759 760 /* Allocate an unique handle from space managed by kernel 761 * Possible range is [8000-FFFF]:0000 (0x8000 values) 762 */ 763 static u32 qdisc_alloc_handle(struct net_device *dev) 764 { 765 int i = 0x8000; 766 static u32 autohandle = TC_H_MAKE(0x80000000U, 0); 767 768 do { 769 autohandle += TC_H_MAKE(0x10000U, 0); 770 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0)) 771 autohandle = TC_H_MAKE(0x80000000U, 0); 772 if (!qdisc_lookup(dev, autohandle)) 773 return autohandle; 774 cond_resched(); 775 } while (--i > 0); 776 777 return 0; 778 } 779 780 void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len) 781 { 782 bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED; 783 const struct Qdisc_class_ops *cops; 784 unsigned long cl; 785 u32 parentid; 786 bool notify; 787 int drops; 788 789 if (n == 0 && len == 0) 790 return; 791 drops = max_t(int, n, 0); 792 rcu_read_lock(); 793 while ((parentid = sch->parent)) { 794 if (parentid == TC_H_ROOT) 795 break; 796 797 if (sch->flags & TCQ_F_NOPARENT) 798 break; 799 /* Notify parent qdisc only if child qdisc becomes empty. 800 * 801 * If child was empty even before update then backlog 802 * counter is screwed and we skip notification because 803 * parent class is already passive. 804 * 805 * If the original child was offloaded then it is allowed 806 * to be seem as empty, so the parent is notified anyway. 807 */ 808 notify = !sch->q.qlen && !WARN_ON_ONCE(!n && 809 !qdisc_is_offloaded); 810 /* TODO: perform the search on a per txq basis */ 811 sch = qdisc_lookup_rcu(qdisc_dev(sch), TC_H_MAJ(parentid)); 812 if (sch == NULL) { 813 WARN_ON_ONCE(parentid != TC_H_ROOT); 814 break; 815 } 816 cops = sch->ops->cl_ops; 817 if (notify && cops->qlen_notify) { 818 cl = cops->find(sch, parentid); 819 cops->qlen_notify(sch, cl); 820 } 821 sch->q.qlen -= n; 822 sch->qstats.backlog -= len; 823 __qdisc_qstats_drop(sch, drops); 824 } 825 rcu_read_unlock(); 826 } 827 EXPORT_SYMBOL(qdisc_tree_reduce_backlog); 828 829 int qdisc_offload_dump_helper(struct Qdisc *sch, enum tc_setup_type type, 830 void *type_data) 831 { 832 struct net_device *dev = qdisc_dev(sch); 833 int err; 834 835 sch->flags &= ~TCQ_F_OFFLOADED; 836 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) 837 return 0; 838 839 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data); 840 if (err == -EOPNOTSUPP) 841 return 0; 842 843 if (!err) 844 sch->flags |= TCQ_F_OFFLOADED; 845 846 return err; 847 } 848 EXPORT_SYMBOL(qdisc_offload_dump_helper); 849 850 void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch, 851 struct Qdisc *new, struct Qdisc *old, 852 enum tc_setup_type type, void *type_data, 853 struct netlink_ext_ack *extack) 854 { 855 bool any_qdisc_is_offloaded; 856 int err; 857 858 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) 859 return; 860 861 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data); 862 863 /* Don't report error if the graft is part of destroy operation. */ 864 if (!err || !new || new == &noop_qdisc) 865 return; 866 867 /* Don't report error if the parent, the old child and the new 868 * one are not offloaded. 869 */ 870 any_qdisc_is_offloaded = new->flags & TCQ_F_OFFLOADED; 871 any_qdisc_is_offloaded |= sch && sch->flags & TCQ_F_OFFLOADED; 872 any_qdisc_is_offloaded |= old && old->flags & TCQ_F_OFFLOADED; 873 874 if (any_qdisc_is_offloaded) 875 NL_SET_ERR_MSG(extack, "Offloading graft operation failed."); 876 } 877 EXPORT_SYMBOL(qdisc_offload_graft_helper); 878 879 void qdisc_offload_query_caps(struct net_device *dev, 880 enum tc_setup_type type, 881 void *caps, size_t caps_len) 882 { 883 const struct net_device_ops *ops = dev->netdev_ops; 884 struct tc_query_caps_base base = { 885 .type = type, 886 .caps = caps, 887 }; 888 889 memset(caps, 0, caps_len); 890 891 if (ops->ndo_setup_tc) 892 ops->ndo_setup_tc(dev, TC_QUERY_CAPS, &base); 893 } 894 EXPORT_SYMBOL(qdisc_offload_query_caps); 895 896 static void qdisc_offload_graft_root(struct net_device *dev, 897 struct Qdisc *new, struct Qdisc *old, 898 struct netlink_ext_ack *extack) 899 { 900 struct tc_root_qopt_offload graft_offload = { 901 .command = TC_ROOT_GRAFT, 902 .handle = new ? new->handle : 0, 903 .ingress = (new && new->flags & TCQ_F_INGRESS) || 904 (old && old->flags & TCQ_F_INGRESS), 905 }; 906 907 qdisc_offload_graft_helper(dev, NULL, new, old, 908 TC_SETUP_ROOT_QDISC, &graft_offload, extack); 909 } 910 911 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid, 912 u32 portid, u32 seq, u16 flags, int event, 913 struct netlink_ext_ack *extack) 914 { 915 struct gnet_stats_basic_sync __percpu *cpu_bstats = NULL; 916 struct gnet_stats_queue __percpu *cpu_qstats = NULL; 917 struct tcmsg *tcm; 918 struct nlmsghdr *nlh; 919 unsigned char *b = skb_tail_pointer(skb); 920 struct gnet_dump d; 921 struct qdisc_size_table *stab; 922 u32 block_index; 923 __u32 qlen; 924 925 cond_resched(); 926 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 927 if (!nlh) 928 goto out_nlmsg_trim; 929 tcm = nlmsg_data(nlh); 930 tcm->tcm_family = AF_UNSPEC; 931 tcm->tcm__pad1 = 0; 932 tcm->tcm__pad2 = 0; 933 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 934 tcm->tcm_parent = clid; 935 tcm->tcm_handle = q->handle; 936 tcm->tcm_info = refcount_read(&q->refcnt); 937 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 938 goto nla_put_failure; 939 if (q->ops->ingress_block_get) { 940 block_index = q->ops->ingress_block_get(q); 941 if (block_index && 942 nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index)) 943 goto nla_put_failure; 944 } 945 if (q->ops->egress_block_get) { 946 block_index = q->ops->egress_block_get(q); 947 if (block_index && 948 nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index)) 949 goto nla_put_failure; 950 } 951 if (q->ops->dump && q->ops->dump(q, skb) < 0) 952 goto nla_put_failure; 953 if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED))) 954 goto nla_put_failure; 955 qlen = qdisc_qlen_sum(q); 956 957 stab = rtnl_dereference(q->stab); 958 if (stab && qdisc_dump_stab(skb, stab) < 0) 959 goto nla_put_failure; 960 961 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 962 NULL, &d, TCA_PAD) < 0) 963 goto nla_put_failure; 964 965 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0) 966 goto nla_put_failure; 967 968 if (qdisc_is_percpu_stats(q)) { 969 cpu_bstats = q->cpu_bstats; 970 cpu_qstats = q->cpu_qstats; 971 } 972 973 if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats, true) < 0 || 974 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 || 975 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0) 976 goto nla_put_failure; 977 978 if (gnet_stats_finish_copy(&d) < 0) 979 goto nla_put_failure; 980 981 if (extack && extack->_msg && 982 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg)) 983 goto out_nlmsg_trim; 984 985 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 986 987 return skb->len; 988 989 out_nlmsg_trim: 990 nla_put_failure: 991 nlmsg_trim(skb, b); 992 return -1; 993 } 994 995 static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible) 996 { 997 if (q->flags & TCQ_F_BUILTIN) 998 return true; 999 if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible) 1000 return true; 1001 1002 return false; 1003 } 1004 1005 static int qdisc_notify(struct net *net, struct sk_buff *oskb, 1006 struct nlmsghdr *n, u32 clid, 1007 struct Qdisc *old, struct Qdisc *new, 1008 struct netlink_ext_ack *extack) 1009 { 1010 struct sk_buff *skb; 1011 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1012 1013 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1014 if (!skb) 1015 return -ENOBUFS; 1016 1017 if (old && !tc_qdisc_dump_ignore(old, false)) { 1018 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq, 1019 0, RTM_DELQDISC, extack) < 0) 1020 goto err_out; 1021 } 1022 if (new && !tc_qdisc_dump_ignore(new, false)) { 1023 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq, 1024 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC, extack) < 0) 1025 goto err_out; 1026 } 1027 1028 if (skb->len) 1029 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1030 n->nlmsg_flags & NLM_F_ECHO); 1031 1032 err_out: 1033 kfree_skb(skb); 1034 return -EINVAL; 1035 } 1036 1037 static void notify_and_destroy(struct net *net, struct sk_buff *skb, 1038 struct nlmsghdr *n, u32 clid, 1039 struct Qdisc *old, struct Qdisc *new, 1040 struct netlink_ext_ack *extack) 1041 { 1042 if (new || old) 1043 qdisc_notify(net, skb, n, clid, old, new, extack); 1044 1045 if (old) 1046 qdisc_put(old); 1047 } 1048 1049 static void qdisc_clear_nolock(struct Qdisc *sch) 1050 { 1051 sch->flags &= ~TCQ_F_NOLOCK; 1052 if (!(sch->flags & TCQ_F_CPUSTATS)) 1053 return; 1054 1055 free_percpu(sch->cpu_bstats); 1056 free_percpu(sch->cpu_qstats); 1057 sch->cpu_bstats = NULL; 1058 sch->cpu_qstats = NULL; 1059 sch->flags &= ~TCQ_F_CPUSTATS; 1060 } 1061 1062 /* Graft qdisc "new" to class "classid" of qdisc "parent" or 1063 * to device "dev". 1064 * 1065 * When appropriate send a netlink notification using 'skb' 1066 * and "n". 1067 * 1068 * On success, destroy old qdisc. 1069 */ 1070 1071 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent, 1072 struct sk_buff *skb, struct nlmsghdr *n, u32 classid, 1073 struct Qdisc *new, struct Qdisc *old, 1074 struct netlink_ext_ack *extack) 1075 { 1076 struct Qdisc *q = old; 1077 struct net *net = dev_net(dev); 1078 1079 if (parent == NULL) { 1080 unsigned int i, num_q, ingress; 1081 struct netdev_queue *dev_queue; 1082 1083 ingress = 0; 1084 num_q = dev->num_tx_queues; 1085 if ((q && q->flags & TCQ_F_INGRESS) || 1086 (new && new->flags & TCQ_F_INGRESS)) { 1087 ingress = 1; 1088 dev_queue = dev_ingress_queue(dev); 1089 if (!dev_queue) { 1090 NL_SET_ERR_MSG(extack, "Device does not have an ingress queue"); 1091 return -ENOENT; 1092 } 1093 1094 q = rtnl_dereference(dev_queue->qdisc_sleeping); 1095 1096 /* This is the counterpart of that qdisc_refcount_inc_nz() call in 1097 * __tcf_qdisc_find() for filter requests. 1098 */ 1099 if (!qdisc_refcount_dec_if_one(q)) { 1100 NL_SET_ERR_MSG(extack, 1101 "Current ingress or clsact Qdisc has ongoing filter requests"); 1102 return -EBUSY; 1103 } 1104 } 1105 1106 if (dev->flags & IFF_UP) 1107 dev_deactivate(dev); 1108 1109 qdisc_offload_graft_root(dev, new, old, extack); 1110 1111 if (new && new->ops->attach && !ingress) 1112 goto skip; 1113 1114 if (!ingress) { 1115 for (i = 0; i < num_q; i++) { 1116 dev_queue = netdev_get_tx_queue(dev, i); 1117 old = dev_graft_qdisc(dev_queue, new); 1118 1119 if (new && i > 0) 1120 qdisc_refcount_inc(new); 1121 qdisc_put(old); 1122 } 1123 } else { 1124 old = dev_graft_qdisc(dev_queue, NULL); 1125 1126 /* {ingress,clsact}_destroy() @old before grafting @new to avoid 1127 * unprotected concurrent accesses to net_device::miniq_{in,e}gress 1128 * pointer(s) in mini_qdisc_pair_swap(). 1129 */ 1130 qdisc_notify(net, skb, n, classid, old, new, extack); 1131 qdisc_destroy(old); 1132 1133 dev_graft_qdisc(dev_queue, new); 1134 } 1135 1136 skip: 1137 if (!ingress) { 1138 old = rtnl_dereference(dev->qdisc); 1139 if (new && !new->ops->attach) 1140 qdisc_refcount_inc(new); 1141 rcu_assign_pointer(dev->qdisc, new ? : &noop_qdisc); 1142 1143 notify_and_destroy(net, skb, n, classid, old, new, extack); 1144 1145 if (new && new->ops->attach) 1146 new->ops->attach(new); 1147 } 1148 1149 if (dev->flags & IFF_UP) 1150 dev_activate(dev); 1151 } else { 1152 const struct Qdisc_class_ops *cops = parent->ops->cl_ops; 1153 unsigned long cl; 1154 int err; 1155 1156 /* Only support running class lockless if parent is lockless */ 1157 if (new && (new->flags & TCQ_F_NOLOCK) && !(parent->flags & TCQ_F_NOLOCK)) 1158 qdisc_clear_nolock(new); 1159 1160 if (!cops || !cops->graft) 1161 return -EOPNOTSUPP; 1162 1163 cl = cops->find(parent, classid); 1164 if (!cl) { 1165 NL_SET_ERR_MSG(extack, "Specified class not found"); 1166 return -ENOENT; 1167 } 1168 1169 if (new && new->ops == &noqueue_qdisc_ops) { 1170 NL_SET_ERR_MSG(extack, "Cannot assign noqueue to a class"); 1171 return -EINVAL; 1172 } 1173 1174 if (new && 1175 !(parent->flags & TCQ_F_MQROOT) && 1176 rcu_access_pointer(new->stab)) { 1177 NL_SET_ERR_MSG(extack, "STAB not supported on a non root"); 1178 return -EINVAL; 1179 } 1180 err = cops->graft(parent, cl, new, &old, extack); 1181 if (err) 1182 return err; 1183 notify_and_destroy(net, skb, n, classid, old, new, extack); 1184 } 1185 return 0; 1186 } 1187 1188 static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca, 1189 struct netlink_ext_ack *extack) 1190 { 1191 u32 block_index; 1192 1193 if (tca[TCA_INGRESS_BLOCK]) { 1194 block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]); 1195 1196 if (!block_index) { 1197 NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0"); 1198 return -EINVAL; 1199 } 1200 if (!sch->ops->ingress_block_set) { 1201 NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported"); 1202 return -EOPNOTSUPP; 1203 } 1204 sch->ops->ingress_block_set(sch, block_index); 1205 } 1206 if (tca[TCA_EGRESS_BLOCK]) { 1207 block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]); 1208 1209 if (!block_index) { 1210 NL_SET_ERR_MSG(extack, "Egress block index cannot be 0"); 1211 return -EINVAL; 1212 } 1213 if (!sch->ops->egress_block_set) { 1214 NL_SET_ERR_MSG(extack, "Egress block sharing is not supported"); 1215 return -EOPNOTSUPP; 1216 } 1217 sch->ops->egress_block_set(sch, block_index); 1218 } 1219 return 0; 1220 } 1221 1222 /* 1223 Allocate and initialize new qdisc. 1224 1225 Parameters are passed via opt. 1226 */ 1227 1228 static struct Qdisc *qdisc_create(struct net_device *dev, 1229 struct netdev_queue *dev_queue, 1230 u32 parent, u32 handle, 1231 struct nlattr **tca, int *errp, 1232 struct netlink_ext_ack *extack) 1233 { 1234 int err; 1235 struct nlattr *kind = tca[TCA_KIND]; 1236 struct Qdisc *sch; 1237 struct Qdisc_ops *ops; 1238 struct qdisc_size_table *stab; 1239 1240 ops = qdisc_lookup_ops(kind); 1241 #ifdef CONFIG_MODULES 1242 if (ops == NULL && kind != NULL) { 1243 char name[IFNAMSIZ]; 1244 if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) { 1245 /* We dropped the RTNL semaphore in order to 1246 * perform the module load. So, even if we 1247 * succeeded in loading the module we have to 1248 * tell the caller to replay the request. We 1249 * indicate this using -EAGAIN. 1250 * We replay the request because the device may 1251 * go away in the mean time. 1252 */ 1253 rtnl_unlock(); 1254 request_module("sch_%s", name); 1255 rtnl_lock(); 1256 ops = qdisc_lookup_ops(kind); 1257 if (ops != NULL) { 1258 /* We will try again qdisc_lookup_ops, 1259 * so don't keep a reference. 1260 */ 1261 module_put(ops->owner); 1262 err = -EAGAIN; 1263 goto err_out; 1264 } 1265 } 1266 } 1267 #endif 1268 1269 err = -ENOENT; 1270 if (!ops) { 1271 NL_SET_ERR_MSG(extack, "Specified qdisc kind is unknown"); 1272 goto err_out; 1273 } 1274 1275 sch = qdisc_alloc(dev_queue, ops, extack); 1276 if (IS_ERR(sch)) { 1277 err = PTR_ERR(sch); 1278 goto err_out2; 1279 } 1280 1281 sch->parent = parent; 1282 1283 if (handle == TC_H_INGRESS) { 1284 if (!(sch->flags & TCQ_F_INGRESS)) { 1285 NL_SET_ERR_MSG(extack, 1286 "Specified parent ID is reserved for ingress and clsact Qdiscs"); 1287 err = -EINVAL; 1288 goto err_out3; 1289 } 1290 handle = TC_H_MAKE(TC_H_INGRESS, 0); 1291 } else { 1292 if (handle == 0) { 1293 handle = qdisc_alloc_handle(dev); 1294 if (handle == 0) { 1295 NL_SET_ERR_MSG(extack, "Maximum number of qdisc handles was exceeded"); 1296 err = -ENOSPC; 1297 goto err_out3; 1298 } 1299 } 1300 if (!netif_is_multiqueue(dev)) 1301 sch->flags |= TCQ_F_ONETXQUEUE; 1302 } 1303 1304 sch->handle = handle; 1305 1306 /* This exist to keep backward compatible with a userspace 1307 * loophole, what allowed userspace to get IFF_NO_QUEUE 1308 * facility on older kernels by setting tx_queue_len=0 (prior 1309 * to qdisc init), and then forgot to reinit tx_queue_len 1310 * before again attaching a qdisc. 1311 */ 1312 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) { 1313 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN; 1314 netdev_info(dev, "Caught tx_queue_len zero misconfig\n"); 1315 } 1316 1317 err = qdisc_block_indexes_set(sch, tca, extack); 1318 if (err) 1319 goto err_out3; 1320 1321 if (tca[TCA_STAB]) { 1322 stab = qdisc_get_stab(tca[TCA_STAB], extack); 1323 if (IS_ERR(stab)) { 1324 err = PTR_ERR(stab); 1325 goto err_out3; 1326 } 1327 rcu_assign_pointer(sch->stab, stab); 1328 } 1329 1330 if (ops->init) { 1331 err = ops->init(sch, tca[TCA_OPTIONS], extack); 1332 if (err != 0) 1333 goto err_out4; 1334 } 1335 1336 if (tca[TCA_RATE]) { 1337 err = -EOPNOTSUPP; 1338 if (sch->flags & TCQ_F_MQROOT) { 1339 NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc"); 1340 goto err_out4; 1341 } 1342 1343 err = gen_new_estimator(&sch->bstats, 1344 sch->cpu_bstats, 1345 &sch->rate_est, 1346 NULL, 1347 true, 1348 tca[TCA_RATE]); 1349 if (err) { 1350 NL_SET_ERR_MSG(extack, "Failed to generate new estimator"); 1351 goto err_out4; 1352 } 1353 } 1354 1355 qdisc_hash_add(sch, false); 1356 trace_qdisc_create(ops, dev, parent); 1357 1358 return sch; 1359 1360 err_out4: 1361 /* Even if ops->init() failed, we call ops->destroy() 1362 * like qdisc_create_dflt(). 1363 */ 1364 if (ops->destroy) 1365 ops->destroy(sch); 1366 qdisc_put_stab(rtnl_dereference(sch->stab)); 1367 err_out3: 1368 lockdep_unregister_key(&sch->root_lock_key); 1369 netdev_put(dev, &sch->dev_tracker); 1370 qdisc_free(sch); 1371 err_out2: 1372 module_put(ops->owner); 1373 err_out: 1374 *errp = err; 1375 return NULL; 1376 } 1377 1378 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca, 1379 struct netlink_ext_ack *extack) 1380 { 1381 struct qdisc_size_table *ostab, *stab = NULL; 1382 int err = 0; 1383 1384 if (tca[TCA_OPTIONS]) { 1385 if (!sch->ops->change) { 1386 NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc"); 1387 return -EINVAL; 1388 } 1389 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) { 1390 NL_SET_ERR_MSG(extack, "Change of blocks is not supported"); 1391 return -EOPNOTSUPP; 1392 } 1393 err = sch->ops->change(sch, tca[TCA_OPTIONS], extack); 1394 if (err) 1395 return err; 1396 } 1397 1398 if (tca[TCA_STAB]) { 1399 stab = qdisc_get_stab(tca[TCA_STAB], extack); 1400 if (IS_ERR(stab)) 1401 return PTR_ERR(stab); 1402 } 1403 1404 ostab = rtnl_dereference(sch->stab); 1405 rcu_assign_pointer(sch->stab, stab); 1406 qdisc_put_stab(ostab); 1407 1408 if (tca[TCA_RATE]) { 1409 /* NB: ignores errors from replace_estimator 1410 because change can't be undone. */ 1411 if (sch->flags & TCQ_F_MQROOT) 1412 goto out; 1413 gen_replace_estimator(&sch->bstats, 1414 sch->cpu_bstats, 1415 &sch->rate_est, 1416 NULL, 1417 true, 1418 tca[TCA_RATE]); 1419 } 1420 out: 1421 return 0; 1422 } 1423 1424 struct check_loop_arg { 1425 struct qdisc_walker w; 1426 struct Qdisc *p; 1427 int depth; 1428 }; 1429 1430 static int check_loop_fn(struct Qdisc *q, unsigned long cl, 1431 struct qdisc_walker *w); 1432 1433 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth) 1434 { 1435 struct check_loop_arg arg; 1436 1437 if (q->ops->cl_ops == NULL) 1438 return 0; 1439 1440 arg.w.stop = arg.w.skip = arg.w.count = 0; 1441 arg.w.fn = check_loop_fn; 1442 arg.depth = depth; 1443 arg.p = p; 1444 q->ops->cl_ops->walk(q, &arg.w); 1445 return arg.w.stop ? -ELOOP : 0; 1446 } 1447 1448 static int 1449 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w) 1450 { 1451 struct Qdisc *leaf; 1452 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 1453 struct check_loop_arg *arg = (struct check_loop_arg *)w; 1454 1455 leaf = cops->leaf(q, cl); 1456 if (leaf) { 1457 if (leaf == arg->p || arg->depth > 7) 1458 return -ELOOP; 1459 return check_loop(leaf, arg->p, arg->depth + 1); 1460 } 1461 return 0; 1462 } 1463 1464 const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = { 1465 [TCA_KIND] = { .type = NLA_STRING }, 1466 [TCA_RATE] = { .type = NLA_BINARY, 1467 .len = sizeof(struct tc_estimator) }, 1468 [TCA_STAB] = { .type = NLA_NESTED }, 1469 [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG }, 1470 [TCA_CHAIN] = { .type = NLA_U32 }, 1471 [TCA_INGRESS_BLOCK] = { .type = NLA_U32 }, 1472 [TCA_EGRESS_BLOCK] = { .type = NLA_U32 }, 1473 }; 1474 1475 /* 1476 * Delete/get qdisc. 1477 */ 1478 1479 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, 1480 struct netlink_ext_ack *extack) 1481 { 1482 struct net *net = sock_net(skb->sk); 1483 struct tcmsg *tcm = nlmsg_data(n); 1484 struct nlattr *tca[TCA_MAX + 1]; 1485 struct net_device *dev; 1486 u32 clid; 1487 struct Qdisc *q = NULL; 1488 struct Qdisc *p = NULL; 1489 int err; 1490 1491 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 1492 rtm_tca_policy, extack); 1493 if (err < 0) 1494 return err; 1495 1496 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1497 if (!dev) 1498 return -ENODEV; 1499 1500 clid = tcm->tcm_parent; 1501 if (clid) { 1502 if (clid != TC_H_ROOT) { 1503 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) { 1504 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1505 if (!p) { 1506 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid"); 1507 return -ENOENT; 1508 } 1509 q = qdisc_leaf(p, clid); 1510 } else if (dev_ingress_queue(dev)) { 1511 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); 1512 } 1513 } else { 1514 q = rtnl_dereference(dev->qdisc); 1515 } 1516 if (!q) { 1517 NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device"); 1518 return -ENOENT; 1519 } 1520 1521 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) { 1522 NL_SET_ERR_MSG(extack, "Invalid handle"); 1523 return -EINVAL; 1524 } 1525 } else { 1526 q = qdisc_lookup(dev, tcm->tcm_handle); 1527 if (!q) { 1528 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle"); 1529 return -ENOENT; 1530 } 1531 } 1532 1533 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1534 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1535 return -EINVAL; 1536 } 1537 1538 if (n->nlmsg_type == RTM_DELQDISC) { 1539 if (!clid) { 1540 NL_SET_ERR_MSG(extack, "Classid cannot be zero"); 1541 return -EINVAL; 1542 } 1543 if (q->handle == 0) { 1544 NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero"); 1545 return -ENOENT; 1546 } 1547 err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack); 1548 if (err != 0) 1549 return err; 1550 } else { 1551 qdisc_notify(net, skb, n, clid, NULL, q, NULL); 1552 } 1553 return 0; 1554 } 1555 1556 static bool req_create_or_replace(struct nlmsghdr *n) 1557 { 1558 return (n->nlmsg_flags & NLM_F_CREATE && 1559 n->nlmsg_flags & NLM_F_REPLACE); 1560 } 1561 1562 static bool req_create_exclusive(struct nlmsghdr *n) 1563 { 1564 return (n->nlmsg_flags & NLM_F_CREATE && 1565 n->nlmsg_flags & NLM_F_EXCL); 1566 } 1567 1568 static bool req_change(struct nlmsghdr *n) 1569 { 1570 return (!(n->nlmsg_flags & NLM_F_CREATE) && 1571 !(n->nlmsg_flags & NLM_F_REPLACE) && 1572 !(n->nlmsg_flags & NLM_F_EXCL)); 1573 } 1574 1575 /* 1576 * Create/change qdisc. 1577 */ 1578 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, 1579 struct netlink_ext_ack *extack) 1580 { 1581 struct net *net = sock_net(skb->sk); 1582 struct tcmsg *tcm; 1583 struct nlattr *tca[TCA_MAX + 1]; 1584 struct net_device *dev; 1585 u32 clid; 1586 struct Qdisc *q, *p; 1587 int err; 1588 1589 replay: 1590 /* Reinit, just in case something touches this. */ 1591 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 1592 rtm_tca_policy, extack); 1593 if (err < 0) 1594 return err; 1595 1596 tcm = nlmsg_data(n); 1597 clid = tcm->tcm_parent; 1598 q = p = NULL; 1599 1600 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1601 if (!dev) 1602 return -ENODEV; 1603 1604 1605 if (clid) { 1606 if (clid != TC_H_ROOT) { 1607 if (clid != TC_H_INGRESS) { 1608 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1609 if (!p) { 1610 NL_SET_ERR_MSG(extack, "Failed to find specified qdisc"); 1611 return -ENOENT; 1612 } 1613 q = qdisc_leaf(p, clid); 1614 } else if (dev_ingress_queue_create(dev)) { 1615 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); 1616 } 1617 } else { 1618 q = rtnl_dereference(dev->qdisc); 1619 } 1620 1621 /* It may be default qdisc, ignore it */ 1622 if (q && q->handle == 0) 1623 q = NULL; 1624 1625 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) { 1626 if (tcm->tcm_handle) { 1627 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) { 1628 NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override"); 1629 return -EEXIST; 1630 } 1631 if (TC_H_MIN(tcm->tcm_handle)) { 1632 NL_SET_ERR_MSG(extack, "Invalid minor handle"); 1633 return -EINVAL; 1634 } 1635 q = qdisc_lookup(dev, tcm->tcm_handle); 1636 if (!q) 1637 goto create_n_graft; 1638 if (q->parent != tcm->tcm_parent) { 1639 NL_SET_ERR_MSG(extack, "Cannot move an existing qdisc to a different parent"); 1640 return -EINVAL; 1641 } 1642 if (n->nlmsg_flags & NLM_F_EXCL) { 1643 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override"); 1644 return -EEXIST; 1645 } 1646 if (tca[TCA_KIND] && 1647 nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1648 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1649 return -EINVAL; 1650 } 1651 if (q->flags & TCQ_F_INGRESS) { 1652 NL_SET_ERR_MSG(extack, 1653 "Cannot regraft ingress or clsact Qdiscs"); 1654 return -EINVAL; 1655 } 1656 if (q == p || 1657 (p && check_loop(q, p, 0))) { 1658 NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected"); 1659 return -ELOOP; 1660 } 1661 if (clid == TC_H_INGRESS) { 1662 NL_SET_ERR_MSG(extack, "Ingress cannot graft directly"); 1663 return -EINVAL; 1664 } 1665 qdisc_refcount_inc(q); 1666 goto graft; 1667 } else { 1668 if (!q) 1669 goto create_n_graft; 1670 1671 /* This magic test requires explanation. 1672 * 1673 * We know, that some child q is already 1674 * attached to this parent and have choice: 1675 * 1) change it or 2) create/graft new one. 1676 * If the requested qdisc kind is different 1677 * than the existing one, then we choose graft. 1678 * If they are the same then this is "change" 1679 * operation - just let it fallthrough.. 1680 * 1681 * 1. We are allowed to create/graft only 1682 * if the request is explicitly stating 1683 * "please create if it doesn't exist". 1684 * 1685 * 2. If the request is to exclusive create 1686 * then the qdisc tcm_handle is not expected 1687 * to exist, so that we choose create/graft too. 1688 * 1689 * 3. The last case is when no flags are set. 1690 * This will happen when for example tc 1691 * utility issues a "change" command. 1692 * Alas, it is sort of hole in API, we 1693 * cannot decide what to do unambiguously. 1694 * For now we select create/graft. 1695 */ 1696 if (tca[TCA_KIND] && 1697 nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1698 if (req_create_or_replace(n) || 1699 req_create_exclusive(n)) 1700 goto create_n_graft; 1701 else if (req_change(n)) 1702 goto create_n_graft2; 1703 } 1704 } 1705 } 1706 } else { 1707 if (!tcm->tcm_handle) { 1708 NL_SET_ERR_MSG(extack, "Handle cannot be zero"); 1709 return -EINVAL; 1710 } 1711 q = qdisc_lookup(dev, tcm->tcm_handle); 1712 } 1713 1714 /* Change qdisc parameters */ 1715 if (!q) { 1716 NL_SET_ERR_MSG(extack, "Specified qdisc not found"); 1717 return -ENOENT; 1718 } 1719 if (n->nlmsg_flags & NLM_F_EXCL) { 1720 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify"); 1721 return -EEXIST; 1722 } 1723 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1724 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1725 return -EINVAL; 1726 } 1727 err = qdisc_change(q, tca, extack); 1728 if (err == 0) 1729 qdisc_notify(net, skb, n, clid, NULL, q, extack); 1730 return err; 1731 1732 create_n_graft: 1733 if (!(n->nlmsg_flags & NLM_F_CREATE)) { 1734 NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag"); 1735 return -ENOENT; 1736 } 1737 create_n_graft2: 1738 if (clid == TC_H_INGRESS) { 1739 if (dev_ingress_queue(dev)) { 1740 q = qdisc_create(dev, dev_ingress_queue(dev), 1741 tcm->tcm_parent, tcm->tcm_parent, 1742 tca, &err, extack); 1743 } else { 1744 NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device"); 1745 err = -ENOENT; 1746 } 1747 } else { 1748 struct netdev_queue *dev_queue; 1749 1750 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue) 1751 dev_queue = p->ops->cl_ops->select_queue(p, tcm); 1752 else if (p) 1753 dev_queue = p->dev_queue; 1754 else 1755 dev_queue = netdev_get_tx_queue(dev, 0); 1756 1757 q = qdisc_create(dev, dev_queue, 1758 tcm->tcm_parent, tcm->tcm_handle, 1759 tca, &err, extack); 1760 } 1761 if (q == NULL) { 1762 if (err == -EAGAIN) 1763 goto replay; 1764 return err; 1765 } 1766 1767 graft: 1768 err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack); 1769 if (err) { 1770 if (q) 1771 qdisc_put(q); 1772 return err; 1773 } 1774 1775 return 0; 1776 } 1777 1778 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb, 1779 struct netlink_callback *cb, 1780 int *q_idx_p, int s_q_idx, bool recur, 1781 bool dump_invisible) 1782 { 1783 int ret = 0, q_idx = *q_idx_p; 1784 struct Qdisc *q; 1785 int b; 1786 1787 if (!root) 1788 return 0; 1789 1790 q = root; 1791 if (q_idx < s_q_idx) { 1792 q_idx++; 1793 } else { 1794 if (!tc_qdisc_dump_ignore(q, dump_invisible) && 1795 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1796 cb->nlh->nlmsg_seq, NLM_F_MULTI, 1797 RTM_NEWQDISC, NULL) <= 0) 1798 goto done; 1799 q_idx++; 1800 } 1801 1802 /* If dumping singletons, there is no qdisc_dev(root) and the singleton 1803 * itself has already been dumped. 1804 * 1805 * If we've already dumped the top-level (ingress) qdisc above and the global 1806 * qdisc hashtable, we don't want to hit it again 1807 */ 1808 if (!qdisc_dev(root) || !recur) 1809 goto out; 1810 1811 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { 1812 if (q_idx < s_q_idx) { 1813 q_idx++; 1814 continue; 1815 } 1816 if (!tc_qdisc_dump_ignore(q, dump_invisible) && 1817 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1818 cb->nlh->nlmsg_seq, NLM_F_MULTI, 1819 RTM_NEWQDISC, NULL) <= 0) 1820 goto done; 1821 q_idx++; 1822 } 1823 1824 out: 1825 *q_idx_p = q_idx; 1826 return ret; 1827 done: 1828 ret = -1; 1829 goto out; 1830 } 1831 1832 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb) 1833 { 1834 struct net *net = sock_net(skb->sk); 1835 int idx, q_idx; 1836 int s_idx, s_q_idx; 1837 struct net_device *dev; 1838 const struct nlmsghdr *nlh = cb->nlh; 1839 struct nlattr *tca[TCA_MAX + 1]; 1840 int err; 1841 1842 s_idx = cb->args[0]; 1843 s_q_idx = q_idx = cb->args[1]; 1844 1845 idx = 0; 1846 ASSERT_RTNL(); 1847 1848 err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX, 1849 rtm_tca_policy, cb->extack); 1850 if (err < 0) 1851 return err; 1852 1853 for_each_netdev(net, dev) { 1854 struct netdev_queue *dev_queue; 1855 1856 if (idx < s_idx) 1857 goto cont; 1858 if (idx > s_idx) 1859 s_q_idx = 0; 1860 q_idx = 0; 1861 1862 if (tc_dump_qdisc_root(rtnl_dereference(dev->qdisc), 1863 skb, cb, &q_idx, s_q_idx, 1864 true, tca[TCA_DUMP_INVISIBLE]) < 0) 1865 goto done; 1866 1867 dev_queue = dev_ingress_queue(dev); 1868 if (dev_queue && 1869 tc_dump_qdisc_root(rtnl_dereference(dev_queue->qdisc_sleeping), 1870 skb, cb, &q_idx, s_q_idx, false, 1871 tca[TCA_DUMP_INVISIBLE]) < 0) 1872 goto done; 1873 1874 cont: 1875 idx++; 1876 } 1877 1878 done: 1879 cb->args[0] = idx; 1880 cb->args[1] = q_idx; 1881 1882 return skb->len; 1883 } 1884 1885 1886 1887 /************************************************ 1888 * Traffic classes manipulation. * 1889 ************************************************/ 1890 1891 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, 1892 unsigned long cl, u32 portid, u32 seq, u16 flags, 1893 int event, struct netlink_ext_ack *extack) 1894 { 1895 struct tcmsg *tcm; 1896 struct nlmsghdr *nlh; 1897 unsigned char *b = skb_tail_pointer(skb); 1898 struct gnet_dump d; 1899 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops; 1900 1901 cond_resched(); 1902 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 1903 if (!nlh) 1904 goto out_nlmsg_trim; 1905 tcm = nlmsg_data(nlh); 1906 tcm->tcm_family = AF_UNSPEC; 1907 tcm->tcm__pad1 = 0; 1908 tcm->tcm__pad2 = 0; 1909 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 1910 tcm->tcm_parent = q->handle; 1911 tcm->tcm_handle = q->handle; 1912 tcm->tcm_info = 0; 1913 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 1914 goto nla_put_failure; 1915 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0) 1916 goto nla_put_failure; 1917 1918 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 1919 NULL, &d, TCA_PAD) < 0) 1920 goto nla_put_failure; 1921 1922 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0) 1923 goto nla_put_failure; 1924 1925 if (gnet_stats_finish_copy(&d) < 0) 1926 goto nla_put_failure; 1927 1928 if (extack && extack->_msg && 1929 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg)) 1930 goto out_nlmsg_trim; 1931 1932 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 1933 1934 return skb->len; 1935 1936 out_nlmsg_trim: 1937 nla_put_failure: 1938 nlmsg_trim(skb, b); 1939 return -1; 1940 } 1941 1942 static int tclass_notify(struct net *net, struct sk_buff *oskb, 1943 struct nlmsghdr *n, struct Qdisc *q, 1944 unsigned long cl, int event, struct netlink_ext_ack *extack) 1945 { 1946 struct sk_buff *skb; 1947 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1948 1949 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1950 if (!skb) 1951 return -ENOBUFS; 1952 1953 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event, extack) < 0) { 1954 kfree_skb(skb); 1955 return -EINVAL; 1956 } 1957 1958 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1959 n->nlmsg_flags & NLM_F_ECHO); 1960 } 1961 1962 static int tclass_del_notify(struct net *net, 1963 const struct Qdisc_class_ops *cops, 1964 struct sk_buff *oskb, struct nlmsghdr *n, 1965 struct Qdisc *q, unsigned long cl, 1966 struct netlink_ext_ack *extack) 1967 { 1968 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1969 struct sk_buff *skb; 1970 int err = 0; 1971 1972 if (!cops->delete) 1973 return -EOPNOTSUPP; 1974 1975 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1976 if (!skb) 1977 return -ENOBUFS; 1978 1979 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, 1980 RTM_DELTCLASS, extack) < 0) { 1981 kfree_skb(skb); 1982 return -EINVAL; 1983 } 1984 1985 err = cops->delete(q, cl, extack); 1986 if (err) { 1987 kfree_skb(skb); 1988 return err; 1989 } 1990 1991 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1992 n->nlmsg_flags & NLM_F_ECHO); 1993 return err; 1994 } 1995 1996 #ifdef CONFIG_NET_CLS 1997 1998 struct tcf_bind_args { 1999 struct tcf_walker w; 2000 unsigned long base; 2001 unsigned long cl; 2002 u32 classid; 2003 }; 2004 2005 static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg) 2006 { 2007 struct tcf_bind_args *a = (void *)arg; 2008 2009 if (n && tp->ops->bind_class) { 2010 struct Qdisc *q = tcf_block_q(tp->chain->block); 2011 2012 sch_tree_lock(q); 2013 tp->ops->bind_class(n, a->classid, a->cl, q, a->base); 2014 sch_tree_unlock(q); 2015 } 2016 return 0; 2017 } 2018 2019 struct tc_bind_class_args { 2020 struct qdisc_walker w; 2021 unsigned long new_cl; 2022 u32 portid; 2023 u32 clid; 2024 }; 2025 2026 static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl, 2027 struct qdisc_walker *w) 2028 { 2029 struct tc_bind_class_args *a = (struct tc_bind_class_args *)w; 2030 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 2031 struct tcf_block *block; 2032 struct tcf_chain *chain; 2033 2034 block = cops->tcf_block(q, cl, NULL); 2035 if (!block) 2036 return 0; 2037 for (chain = tcf_get_next_chain(block, NULL); 2038 chain; 2039 chain = tcf_get_next_chain(block, chain)) { 2040 struct tcf_proto *tp; 2041 2042 for (tp = tcf_get_next_proto(chain, NULL); 2043 tp; tp = tcf_get_next_proto(chain, tp)) { 2044 struct tcf_bind_args arg = {}; 2045 2046 arg.w.fn = tcf_node_bind; 2047 arg.classid = a->clid; 2048 arg.base = cl; 2049 arg.cl = a->new_cl; 2050 tp->ops->walk(tp, &arg.w, true); 2051 } 2052 } 2053 2054 return 0; 2055 } 2056 2057 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, 2058 unsigned long new_cl) 2059 { 2060 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 2061 struct tc_bind_class_args args = {}; 2062 2063 if (!cops->tcf_block) 2064 return; 2065 args.portid = portid; 2066 args.clid = clid; 2067 args.new_cl = new_cl; 2068 args.w.fn = tc_bind_class_walker; 2069 q->ops->cl_ops->walk(q, &args.w); 2070 } 2071 2072 #else 2073 2074 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, 2075 unsigned long new_cl) 2076 { 2077 } 2078 2079 #endif 2080 2081 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, 2082 struct netlink_ext_ack *extack) 2083 { 2084 struct net *net = sock_net(skb->sk); 2085 struct tcmsg *tcm = nlmsg_data(n); 2086 struct nlattr *tca[TCA_MAX + 1]; 2087 struct net_device *dev; 2088 struct Qdisc *q = NULL; 2089 const struct Qdisc_class_ops *cops; 2090 unsigned long cl = 0; 2091 unsigned long new_cl; 2092 u32 portid; 2093 u32 clid; 2094 u32 qid; 2095 int err; 2096 2097 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 2098 rtm_tca_policy, extack); 2099 if (err < 0) 2100 return err; 2101 2102 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 2103 if (!dev) 2104 return -ENODEV; 2105 2106 /* 2107 parent == TC_H_UNSPEC - unspecified parent. 2108 parent == TC_H_ROOT - class is root, which has no parent. 2109 parent == X:0 - parent is root class. 2110 parent == X:Y - parent is a node in hierarchy. 2111 parent == 0:Y - parent is X:Y, where X:0 is qdisc. 2112 2113 handle == 0:0 - generate handle from kernel pool. 2114 handle == 0:Y - class is X:Y, where X:0 is qdisc. 2115 handle == X:Y - clear. 2116 handle == X:0 - root class. 2117 */ 2118 2119 /* Step 1. Determine qdisc handle X:0 */ 2120 2121 portid = tcm->tcm_parent; 2122 clid = tcm->tcm_handle; 2123 qid = TC_H_MAJ(clid); 2124 2125 if (portid != TC_H_ROOT) { 2126 u32 qid1 = TC_H_MAJ(portid); 2127 2128 if (qid && qid1) { 2129 /* If both majors are known, they must be identical. */ 2130 if (qid != qid1) 2131 return -EINVAL; 2132 } else if (qid1) { 2133 qid = qid1; 2134 } else if (qid == 0) 2135 qid = rtnl_dereference(dev->qdisc)->handle; 2136 2137 /* Now qid is genuine qdisc handle consistent 2138 * both with parent and child. 2139 * 2140 * TC_H_MAJ(portid) still may be unspecified, complete it now. 2141 */ 2142 if (portid) 2143 portid = TC_H_MAKE(qid, portid); 2144 } else { 2145 if (qid == 0) 2146 qid = rtnl_dereference(dev->qdisc)->handle; 2147 } 2148 2149 /* OK. Locate qdisc */ 2150 q = qdisc_lookup(dev, qid); 2151 if (!q) 2152 return -ENOENT; 2153 2154 /* An check that it supports classes */ 2155 cops = q->ops->cl_ops; 2156 if (cops == NULL) 2157 return -EINVAL; 2158 2159 /* Now try to get class */ 2160 if (clid == 0) { 2161 if (portid == TC_H_ROOT) 2162 clid = qid; 2163 } else 2164 clid = TC_H_MAKE(qid, clid); 2165 2166 if (clid) 2167 cl = cops->find(q, clid); 2168 2169 if (cl == 0) { 2170 err = -ENOENT; 2171 if (n->nlmsg_type != RTM_NEWTCLASS || 2172 !(n->nlmsg_flags & NLM_F_CREATE)) 2173 goto out; 2174 } else { 2175 switch (n->nlmsg_type) { 2176 case RTM_NEWTCLASS: 2177 err = -EEXIST; 2178 if (n->nlmsg_flags & NLM_F_EXCL) 2179 goto out; 2180 break; 2181 case RTM_DELTCLASS: 2182 err = tclass_del_notify(net, cops, skb, n, q, cl, extack); 2183 /* Unbind the class with flilters with 0 */ 2184 tc_bind_tclass(q, portid, clid, 0); 2185 goto out; 2186 case RTM_GETTCLASS: 2187 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS, extack); 2188 goto out; 2189 default: 2190 err = -EINVAL; 2191 goto out; 2192 } 2193 } 2194 2195 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) { 2196 NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes"); 2197 return -EOPNOTSUPP; 2198 } 2199 2200 new_cl = cl; 2201 err = -EOPNOTSUPP; 2202 if (cops->change) 2203 err = cops->change(q, clid, portid, tca, &new_cl, extack); 2204 if (err == 0) { 2205 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS, extack); 2206 /* We just create a new class, need to do reverse binding. */ 2207 if (cl != new_cl) 2208 tc_bind_tclass(q, portid, clid, new_cl); 2209 } 2210 out: 2211 return err; 2212 } 2213 2214 struct qdisc_dump_args { 2215 struct qdisc_walker w; 2216 struct sk_buff *skb; 2217 struct netlink_callback *cb; 2218 }; 2219 2220 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, 2221 struct qdisc_walker *arg) 2222 { 2223 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg; 2224 2225 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid, 2226 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, 2227 RTM_NEWTCLASS, NULL); 2228 } 2229 2230 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb, 2231 struct tcmsg *tcm, struct netlink_callback *cb, 2232 int *t_p, int s_t) 2233 { 2234 struct qdisc_dump_args arg; 2235 2236 if (tc_qdisc_dump_ignore(q, false) || 2237 *t_p < s_t || !q->ops->cl_ops || 2238 (tcm->tcm_parent && 2239 TC_H_MAJ(tcm->tcm_parent) != q->handle)) { 2240 (*t_p)++; 2241 return 0; 2242 } 2243 if (*t_p > s_t) 2244 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); 2245 arg.w.fn = qdisc_class_dump; 2246 arg.skb = skb; 2247 arg.cb = cb; 2248 arg.w.stop = 0; 2249 arg.w.skip = cb->args[1]; 2250 arg.w.count = 0; 2251 q->ops->cl_ops->walk(q, &arg.w); 2252 cb->args[1] = arg.w.count; 2253 if (arg.w.stop) 2254 return -1; 2255 (*t_p)++; 2256 return 0; 2257 } 2258 2259 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb, 2260 struct tcmsg *tcm, struct netlink_callback *cb, 2261 int *t_p, int s_t, bool recur) 2262 { 2263 struct Qdisc *q; 2264 int b; 2265 2266 if (!root) 2267 return 0; 2268 2269 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0) 2270 return -1; 2271 2272 if (!qdisc_dev(root) || !recur) 2273 return 0; 2274 2275 if (tcm->tcm_parent) { 2276 q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent)); 2277 if (q && q != root && 2278 tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 2279 return -1; 2280 return 0; 2281 } 2282 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { 2283 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 2284 return -1; 2285 } 2286 2287 return 0; 2288 } 2289 2290 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb) 2291 { 2292 struct tcmsg *tcm = nlmsg_data(cb->nlh); 2293 struct net *net = sock_net(skb->sk); 2294 struct netdev_queue *dev_queue; 2295 struct net_device *dev; 2296 int t, s_t; 2297 2298 if (nlmsg_len(cb->nlh) < sizeof(*tcm)) 2299 return 0; 2300 dev = dev_get_by_index(net, tcm->tcm_ifindex); 2301 if (!dev) 2302 return 0; 2303 2304 s_t = cb->args[0]; 2305 t = 0; 2306 2307 if (tc_dump_tclass_root(rtnl_dereference(dev->qdisc), 2308 skb, tcm, cb, &t, s_t, true) < 0) 2309 goto done; 2310 2311 dev_queue = dev_ingress_queue(dev); 2312 if (dev_queue && 2313 tc_dump_tclass_root(rtnl_dereference(dev_queue->qdisc_sleeping), 2314 skb, tcm, cb, &t, s_t, false) < 0) 2315 goto done; 2316 2317 done: 2318 cb->args[0] = t; 2319 2320 dev_put(dev); 2321 return skb->len; 2322 } 2323 2324 #ifdef CONFIG_PROC_FS 2325 static int psched_show(struct seq_file *seq, void *v) 2326 { 2327 seq_printf(seq, "%08x %08x %08x %08x\n", 2328 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1), 2329 1000000, 2330 (u32)NSEC_PER_SEC / hrtimer_resolution); 2331 2332 return 0; 2333 } 2334 2335 static int __net_init psched_net_init(struct net *net) 2336 { 2337 struct proc_dir_entry *e; 2338 2339 e = proc_create_single("psched", 0, net->proc_net, psched_show); 2340 if (e == NULL) 2341 return -ENOMEM; 2342 2343 return 0; 2344 } 2345 2346 static void __net_exit psched_net_exit(struct net *net) 2347 { 2348 remove_proc_entry("psched", net->proc_net); 2349 } 2350 #else 2351 static int __net_init psched_net_init(struct net *net) 2352 { 2353 return 0; 2354 } 2355 2356 static void __net_exit psched_net_exit(struct net *net) 2357 { 2358 } 2359 #endif 2360 2361 static struct pernet_operations psched_net_ops = { 2362 .init = psched_net_init, 2363 .exit = psched_net_exit, 2364 }; 2365 2366 #if IS_ENABLED(CONFIG_RETPOLINE) 2367 DEFINE_STATIC_KEY_FALSE(tc_skip_wrapper); 2368 #endif 2369 2370 static int __init pktsched_init(void) 2371 { 2372 int err; 2373 2374 err = register_pernet_subsys(&psched_net_ops); 2375 if (err) { 2376 pr_err("pktsched_init: " 2377 "cannot initialize per netns operations\n"); 2378 return err; 2379 } 2380 2381 register_qdisc(&pfifo_fast_ops); 2382 register_qdisc(&pfifo_qdisc_ops); 2383 register_qdisc(&bfifo_qdisc_ops); 2384 register_qdisc(&pfifo_head_drop_qdisc_ops); 2385 register_qdisc(&mq_qdisc_ops); 2386 register_qdisc(&noqueue_qdisc_ops); 2387 2388 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, 0); 2389 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, 0); 2390 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, 2391 0); 2392 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, 0); 2393 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, 0); 2394 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, 2395 0); 2396 2397 tc_wrapper_init(); 2398 2399 return 0; 2400 } 2401 2402 subsys_initcall(pktsched_init); 2403