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(NET_SCH_ALIAS_PREFIX "%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 EXPORT_SYMBOL(__qdisc_calculate_pkt_len); 597 598 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc) 599 { 600 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) { 601 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n", 602 txt, qdisc->ops->id, qdisc->handle >> 16); 603 qdisc->flags |= TCQ_F_WARN_NONWC; 604 } 605 } 606 EXPORT_SYMBOL(qdisc_warn_nonwc); 607 608 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer) 609 { 610 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog, 611 timer); 612 613 rcu_read_lock(); 614 __netif_schedule(qdisc_root(wd->qdisc)); 615 rcu_read_unlock(); 616 617 return HRTIMER_NORESTART; 618 } 619 620 void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc, 621 clockid_t clockid) 622 { 623 hrtimer_init(&wd->timer, clockid, HRTIMER_MODE_ABS_PINNED); 624 wd->timer.function = qdisc_watchdog; 625 wd->qdisc = qdisc; 626 } 627 EXPORT_SYMBOL(qdisc_watchdog_init_clockid); 628 629 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc) 630 { 631 qdisc_watchdog_init_clockid(wd, qdisc, CLOCK_MONOTONIC); 632 } 633 EXPORT_SYMBOL(qdisc_watchdog_init); 634 635 void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires, 636 u64 delta_ns) 637 { 638 bool deactivated; 639 640 rcu_read_lock(); 641 deactivated = test_bit(__QDISC_STATE_DEACTIVATED, 642 &qdisc_root_sleeping(wd->qdisc)->state); 643 rcu_read_unlock(); 644 if (deactivated) 645 return; 646 647 if (hrtimer_is_queued(&wd->timer)) { 648 u64 softexpires; 649 650 softexpires = ktime_to_ns(hrtimer_get_softexpires(&wd->timer)); 651 /* If timer is already set in [expires, expires + delta_ns], 652 * do not reprogram it. 653 */ 654 if (softexpires - expires <= delta_ns) 655 return; 656 } 657 658 hrtimer_start_range_ns(&wd->timer, 659 ns_to_ktime(expires), 660 delta_ns, 661 HRTIMER_MODE_ABS_PINNED); 662 } 663 EXPORT_SYMBOL(qdisc_watchdog_schedule_range_ns); 664 665 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd) 666 { 667 hrtimer_cancel(&wd->timer); 668 } 669 EXPORT_SYMBOL(qdisc_watchdog_cancel); 670 671 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n) 672 { 673 struct hlist_head *h; 674 unsigned int i; 675 676 h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL); 677 678 if (h != NULL) { 679 for (i = 0; i < n; i++) 680 INIT_HLIST_HEAD(&h[i]); 681 } 682 return h; 683 } 684 685 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash) 686 { 687 struct Qdisc_class_common *cl; 688 struct hlist_node *next; 689 struct hlist_head *nhash, *ohash; 690 unsigned int nsize, nmask, osize; 691 unsigned int i, h; 692 693 /* Rehash when load factor exceeds 0.75 */ 694 if (clhash->hashelems * 4 <= clhash->hashsize * 3) 695 return; 696 nsize = clhash->hashsize * 2; 697 nmask = nsize - 1; 698 nhash = qdisc_class_hash_alloc(nsize); 699 if (nhash == NULL) 700 return; 701 702 ohash = clhash->hash; 703 osize = clhash->hashsize; 704 705 sch_tree_lock(sch); 706 for (i = 0; i < osize; i++) { 707 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) { 708 h = qdisc_class_hash(cl->classid, nmask); 709 hlist_add_head(&cl->hnode, &nhash[h]); 710 } 711 } 712 clhash->hash = nhash; 713 clhash->hashsize = nsize; 714 clhash->hashmask = nmask; 715 sch_tree_unlock(sch); 716 717 kvfree(ohash); 718 } 719 EXPORT_SYMBOL(qdisc_class_hash_grow); 720 721 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash) 722 { 723 unsigned int size = 4; 724 725 clhash->hash = qdisc_class_hash_alloc(size); 726 if (!clhash->hash) 727 return -ENOMEM; 728 clhash->hashsize = size; 729 clhash->hashmask = size - 1; 730 clhash->hashelems = 0; 731 return 0; 732 } 733 EXPORT_SYMBOL(qdisc_class_hash_init); 734 735 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash) 736 { 737 kvfree(clhash->hash); 738 } 739 EXPORT_SYMBOL(qdisc_class_hash_destroy); 740 741 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash, 742 struct Qdisc_class_common *cl) 743 { 744 unsigned int h; 745 746 INIT_HLIST_NODE(&cl->hnode); 747 h = qdisc_class_hash(cl->classid, clhash->hashmask); 748 hlist_add_head(&cl->hnode, &clhash->hash[h]); 749 clhash->hashelems++; 750 } 751 EXPORT_SYMBOL(qdisc_class_hash_insert); 752 753 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash, 754 struct Qdisc_class_common *cl) 755 { 756 hlist_del(&cl->hnode); 757 clhash->hashelems--; 758 } 759 EXPORT_SYMBOL(qdisc_class_hash_remove); 760 761 /* Allocate an unique handle from space managed by kernel 762 * Possible range is [8000-FFFF]:0000 (0x8000 values) 763 */ 764 static u32 qdisc_alloc_handle(struct net_device *dev) 765 { 766 int i = 0x8000; 767 static u32 autohandle = TC_H_MAKE(0x80000000U, 0); 768 769 do { 770 autohandle += TC_H_MAKE(0x10000U, 0); 771 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0)) 772 autohandle = TC_H_MAKE(0x80000000U, 0); 773 if (!qdisc_lookup(dev, autohandle)) 774 return autohandle; 775 cond_resched(); 776 } while (--i > 0); 777 778 return 0; 779 } 780 781 void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len) 782 { 783 bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED; 784 const struct Qdisc_class_ops *cops; 785 unsigned long cl; 786 u32 parentid; 787 bool notify; 788 int drops; 789 790 if (n == 0 && len == 0) 791 return; 792 drops = max_t(int, n, 0); 793 rcu_read_lock(); 794 while ((parentid = sch->parent)) { 795 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS)) 796 break; 797 798 if (sch->flags & TCQ_F_NOPARENT) 799 break; 800 /* Notify parent qdisc only if child qdisc becomes empty. 801 * 802 * If child was empty even before update then backlog 803 * counter is screwed and we skip notification because 804 * parent class is already passive. 805 * 806 * If the original child was offloaded then it is allowed 807 * to be seem as empty, so the parent is notified anyway. 808 */ 809 notify = !sch->q.qlen && !WARN_ON_ONCE(!n && 810 !qdisc_is_offloaded); 811 /* TODO: perform the search on a per txq basis */ 812 sch = qdisc_lookup_rcu(qdisc_dev(sch), TC_H_MAJ(parentid)); 813 if (sch == NULL) { 814 WARN_ON_ONCE(parentid != TC_H_ROOT); 815 break; 816 } 817 cops = sch->ops->cl_ops; 818 if (notify && cops->qlen_notify) { 819 cl = cops->find(sch, parentid); 820 cops->qlen_notify(sch, cl); 821 } 822 sch->q.qlen -= n; 823 sch->qstats.backlog -= len; 824 __qdisc_qstats_drop(sch, drops); 825 } 826 rcu_read_unlock(); 827 } 828 EXPORT_SYMBOL(qdisc_tree_reduce_backlog); 829 830 int qdisc_offload_dump_helper(struct Qdisc *sch, enum tc_setup_type type, 831 void *type_data) 832 { 833 struct net_device *dev = qdisc_dev(sch); 834 int err; 835 836 sch->flags &= ~TCQ_F_OFFLOADED; 837 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) 838 return 0; 839 840 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data); 841 if (err == -EOPNOTSUPP) 842 return 0; 843 844 if (!err) 845 sch->flags |= TCQ_F_OFFLOADED; 846 847 return err; 848 } 849 EXPORT_SYMBOL(qdisc_offload_dump_helper); 850 851 void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch, 852 struct Qdisc *new, struct Qdisc *old, 853 enum tc_setup_type type, void *type_data, 854 struct netlink_ext_ack *extack) 855 { 856 bool any_qdisc_is_offloaded; 857 int err; 858 859 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) 860 return; 861 862 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data); 863 864 /* Don't report error if the graft is part of destroy operation. */ 865 if (!err || !new || new == &noop_qdisc) 866 return; 867 868 /* Don't report error if the parent, the old child and the new 869 * one are not offloaded. 870 */ 871 any_qdisc_is_offloaded = new->flags & TCQ_F_OFFLOADED; 872 any_qdisc_is_offloaded |= sch && sch->flags & TCQ_F_OFFLOADED; 873 any_qdisc_is_offloaded |= old && old->flags & TCQ_F_OFFLOADED; 874 875 if (any_qdisc_is_offloaded) 876 NL_SET_ERR_MSG(extack, "Offloading graft operation failed."); 877 } 878 EXPORT_SYMBOL(qdisc_offload_graft_helper); 879 880 void qdisc_offload_query_caps(struct net_device *dev, 881 enum tc_setup_type type, 882 void *caps, size_t caps_len) 883 { 884 const struct net_device_ops *ops = dev->netdev_ops; 885 struct tc_query_caps_base base = { 886 .type = type, 887 .caps = caps, 888 }; 889 890 memset(caps, 0, caps_len); 891 892 if (ops->ndo_setup_tc) 893 ops->ndo_setup_tc(dev, TC_QUERY_CAPS, &base); 894 } 895 EXPORT_SYMBOL(qdisc_offload_query_caps); 896 897 static void qdisc_offload_graft_root(struct net_device *dev, 898 struct Qdisc *new, struct Qdisc *old, 899 struct netlink_ext_ack *extack) 900 { 901 struct tc_root_qopt_offload graft_offload = { 902 .command = TC_ROOT_GRAFT, 903 .handle = new ? new->handle : 0, 904 .ingress = (new && new->flags & TCQ_F_INGRESS) || 905 (old && old->flags & TCQ_F_INGRESS), 906 }; 907 908 qdisc_offload_graft_helper(dev, NULL, new, old, 909 TC_SETUP_ROOT_QDISC, &graft_offload, extack); 910 } 911 912 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid, 913 u32 portid, u32 seq, u16 flags, int event, 914 struct netlink_ext_ack *extack) 915 { 916 struct gnet_stats_basic_sync __percpu *cpu_bstats = NULL; 917 struct gnet_stats_queue __percpu *cpu_qstats = NULL; 918 struct tcmsg *tcm; 919 struct nlmsghdr *nlh; 920 unsigned char *b = skb_tail_pointer(skb); 921 struct gnet_dump d; 922 struct qdisc_size_table *stab; 923 u32 block_index; 924 __u32 qlen; 925 926 cond_resched(); 927 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 928 if (!nlh) 929 goto out_nlmsg_trim; 930 tcm = nlmsg_data(nlh); 931 tcm->tcm_family = AF_UNSPEC; 932 tcm->tcm__pad1 = 0; 933 tcm->tcm__pad2 = 0; 934 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 935 tcm->tcm_parent = clid; 936 tcm->tcm_handle = q->handle; 937 tcm->tcm_info = refcount_read(&q->refcnt); 938 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 939 goto nla_put_failure; 940 if (q->ops->ingress_block_get) { 941 block_index = q->ops->ingress_block_get(q); 942 if (block_index && 943 nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index)) 944 goto nla_put_failure; 945 } 946 if (q->ops->egress_block_get) { 947 block_index = q->ops->egress_block_get(q); 948 if (block_index && 949 nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index)) 950 goto nla_put_failure; 951 } 952 if (q->ops->dump && q->ops->dump(q, skb) < 0) 953 goto nla_put_failure; 954 if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED))) 955 goto nla_put_failure; 956 qlen = qdisc_qlen_sum(q); 957 958 stab = rtnl_dereference(q->stab); 959 if (stab && qdisc_dump_stab(skb, stab) < 0) 960 goto nla_put_failure; 961 962 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 963 NULL, &d, TCA_PAD) < 0) 964 goto nla_put_failure; 965 966 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0) 967 goto nla_put_failure; 968 969 if (qdisc_is_percpu_stats(q)) { 970 cpu_bstats = q->cpu_bstats; 971 cpu_qstats = q->cpu_qstats; 972 } 973 974 if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats, true) < 0 || 975 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 || 976 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0) 977 goto nla_put_failure; 978 979 if (gnet_stats_finish_copy(&d) < 0) 980 goto nla_put_failure; 981 982 if (extack && extack->_msg && 983 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg)) 984 goto out_nlmsg_trim; 985 986 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 987 988 return skb->len; 989 990 out_nlmsg_trim: 991 nla_put_failure: 992 nlmsg_trim(skb, b); 993 return -1; 994 } 995 996 static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible) 997 { 998 if (q->flags & TCQ_F_BUILTIN) 999 return true; 1000 if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible) 1001 return true; 1002 1003 return false; 1004 } 1005 1006 static int qdisc_get_notify(struct net *net, struct sk_buff *oskb, 1007 struct nlmsghdr *n, u32 clid, struct Qdisc *q, 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 (!tc_qdisc_dump_ignore(q, false)) { 1018 if (tc_fill_qdisc(skb, q, clid, portid, n->nlmsg_seq, 0, 1019 RTM_NEWQDISC, extack) < 0) 1020 goto err_out; 1021 } 1022 1023 if (skb->len) 1024 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1025 n->nlmsg_flags & NLM_F_ECHO); 1026 1027 err_out: 1028 kfree_skb(skb); 1029 return -EINVAL; 1030 } 1031 1032 static int qdisc_notify(struct net *net, struct sk_buff *oskb, 1033 struct nlmsghdr *n, u32 clid, 1034 struct Qdisc *old, struct Qdisc *new, 1035 struct netlink_ext_ack *extack) 1036 { 1037 struct sk_buff *skb; 1038 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1039 1040 if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) 1041 return 0; 1042 1043 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1044 if (!skb) 1045 return -ENOBUFS; 1046 1047 if (old && !tc_qdisc_dump_ignore(old, false)) { 1048 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq, 1049 0, RTM_DELQDISC, extack) < 0) 1050 goto err_out; 1051 } 1052 if (new && !tc_qdisc_dump_ignore(new, false)) { 1053 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq, 1054 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC, extack) < 0) 1055 goto err_out; 1056 } 1057 1058 if (skb->len) 1059 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1060 n->nlmsg_flags & NLM_F_ECHO); 1061 1062 err_out: 1063 kfree_skb(skb); 1064 return -EINVAL; 1065 } 1066 1067 static void notify_and_destroy(struct net *net, struct sk_buff *skb, 1068 struct nlmsghdr *n, u32 clid, 1069 struct Qdisc *old, struct Qdisc *new, 1070 struct netlink_ext_ack *extack) 1071 { 1072 if (new || old) 1073 qdisc_notify(net, skb, n, clid, old, new, extack); 1074 1075 if (old) 1076 qdisc_put(old); 1077 } 1078 1079 static void qdisc_clear_nolock(struct Qdisc *sch) 1080 { 1081 sch->flags &= ~TCQ_F_NOLOCK; 1082 if (!(sch->flags & TCQ_F_CPUSTATS)) 1083 return; 1084 1085 free_percpu(sch->cpu_bstats); 1086 free_percpu(sch->cpu_qstats); 1087 sch->cpu_bstats = NULL; 1088 sch->cpu_qstats = NULL; 1089 sch->flags &= ~TCQ_F_CPUSTATS; 1090 } 1091 1092 /* Graft qdisc "new" to class "classid" of qdisc "parent" or 1093 * to device "dev". 1094 * 1095 * When appropriate send a netlink notification using 'skb' 1096 * and "n". 1097 * 1098 * On success, destroy old qdisc. 1099 */ 1100 1101 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent, 1102 struct sk_buff *skb, struct nlmsghdr *n, u32 classid, 1103 struct Qdisc *new, struct Qdisc *old, 1104 struct netlink_ext_ack *extack) 1105 { 1106 struct Qdisc *q = old; 1107 struct net *net = dev_net(dev); 1108 1109 if (parent == NULL) { 1110 unsigned int i, num_q, ingress; 1111 struct netdev_queue *dev_queue; 1112 1113 ingress = 0; 1114 num_q = dev->num_tx_queues; 1115 if ((q && q->flags & TCQ_F_INGRESS) || 1116 (new && new->flags & TCQ_F_INGRESS)) { 1117 ingress = 1; 1118 dev_queue = dev_ingress_queue(dev); 1119 if (!dev_queue) { 1120 NL_SET_ERR_MSG(extack, "Device does not have an ingress queue"); 1121 return -ENOENT; 1122 } 1123 1124 q = rtnl_dereference(dev_queue->qdisc_sleeping); 1125 1126 /* This is the counterpart of that qdisc_refcount_inc_nz() call in 1127 * __tcf_qdisc_find() for filter requests. 1128 */ 1129 if (!qdisc_refcount_dec_if_one(q)) { 1130 NL_SET_ERR_MSG(extack, 1131 "Current ingress or clsact Qdisc has ongoing filter requests"); 1132 return -EBUSY; 1133 } 1134 } 1135 1136 if (dev->flags & IFF_UP) 1137 dev_deactivate(dev); 1138 1139 qdisc_offload_graft_root(dev, new, old, extack); 1140 1141 if (new && new->ops->attach && !ingress) 1142 goto skip; 1143 1144 if (!ingress) { 1145 for (i = 0; i < num_q; i++) { 1146 dev_queue = netdev_get_tx_queue(dev, i); 1147 old = dev_graft_qdisc(dev_queue, new); 1148 1149 if (new && i > 0) 1150 qdisc_refcount_inc(new); 1151 qdisc_put(old); 1152 } 1153 } else { 1154 old = dev_graft_qdisc(dev_queue, NULL); 1155 1156 /* {ingress,clsact}_destroy() @old before grafting @new to avoid 1157 * unprotected concurrent accesses to net_device::miniq_{in,e}gress 1158 * pointer(s) in mini_qdisc_pair_swap(). 1159 */ 1160 qdisc_notify(net, skb, n, classid, old, new, extack); 1161 qdisc_destroy(old); 1162 1163 dev_graft_qdisc(dev_queue, new); 1164 } 1165 1166 skip: 1167 if (!ingress) { 1168 old = rtnl_dereference(dev->qdisc); 1169 if (new && !new->ops->attach) 1170 qdisc_refcount_inc(new); 1171 rcu_assign_pointer(dev->qdisc, new ? : &noop_qdisc); 1172 1173 notify_and_destroy(net, skb, n, classid, old, new, extack); 1174 1175 if (new && new->ops->attach) 1176 new->ops->attach(new); 1177 } 1178 1179 if (dev->flags & IFF_UP) 1180 dev_activate(dev); 1181 } else { 1182 const struct Qdisc_class_ops *cops = parent->ops->cl_ops; 1183 unsigned long cl; 1184 int err; 1185 1186 /* Only support running class lockless if parent is lockless */ 1187 if (new && (new->flags & TCQ_F_NOLOCK) && !(parent->flags & TCQ_F_NOLOCK)) 1188 qdisc_clear_nolock(new); 1189 1190 if (!cops || !cops->graft) 1191 return -EOPNOTSUPP; 1192 1193 cl = cops->find(parent, classid); 1194 if (!cl) { 1195 NL_SET_ERR_MSG(extack, "Specified class not found"); 1196 return -ENOENT; 1197 } 1198 1199 if (new && new->ops == &noqueue_qdisc_ops) { 1200 NL_SET_ERR_MSG(extack, "Cannot assign noqueue to a class"); 1201 return -EINVAL; 1202 } 1203 1204 err = cops->graft(parent, cl, new, &old, extack); 1205 if (err) 1206 return err; 1207 notify_and_destroy(net, skb, n, classid, old, new, extack); 1208 } 1209 return 0; 1210 } 1211 1212 static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca, 1213 struct netlink_ext_ack *extack) 1214 { 1215 u32 block_index; 1216 1217 if (tca[TCA_INGRESS_BLOCK]) { 1218 block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]); 1219 1220 if (!block_index) { 1221 NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0"); 1222 return -EINVAL; 1223 } 1224 if (!sch->ops->ingress_block_set) { 1225 NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported"); 1226 return -EOPNOTSUPP; 1227 } 1228 sch->ops->ingress_block_set(sch, block_index); 1229 } 1230 if (tca[TCA_EGRESS_BLOCK]) { 1231 block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]); 1232 1233 if (!block_index) { 1234 NL_SET_ERR_MSG(extack, "Egress block index cannot be 0"); 1235 return -EINVAL; 1236 } 1237 if (!sch->ops->egress_block_set) { 1238 NL_SET_ERR_MSG(extack, "Egress block sharing is not supported"); 1239 return -EOPNOTSUPP; 1240 } 1241 sch->ops->egress_block_set(sch, block_index); 1242 } 1243 return 0; 1244 } 1245 1246 /* 1247 Allocate and initialize new qdisc. 1248 1249 Parameters are passed via opt. 1250 */ 1251 1252 static struct Qdisc *qdisc_create(struct net_device *dev, 1253 struct netdev_queue *dev_queue, 1254 u32 parent, u32 handle, 1255 struct nlattr **tca, int *errp, 1256 struct netlink_ext_ack *extack) 1257 { 1258 int err; 1259 struct nlattr *kind = tca[TCA_KIND]; 1260 struct Qdisc *sch; 1261 struct Qdisc_ops *ops; 1262 struct qdisc_size_table *stab; 1263 1264 ops = qdisc_lookup_ops(kind); 1265 #ifdef CONFIG_MODULES 1266 if (ops == NULL && kind != NULL) { 1267 char name[IFNAMSIZ]; 1268 if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) { 1269 /* We dropped the RTNL semaphore in order to 1270 * perform the module load. So, even if we 1271 * succeeded in loading the module we have to 1272 * tell the caller to replay the request. We 1273 * indicate this using -EAGAIN. 1274 * We replay the request because the device may 1275 * go away in the mean time. 1276 */ 1277 rtnl_unlock(); 1278 request_module(NET_SCH_ALIAS_PREFIX "%s", name); 1279 rtnl_lock(); 1280 ops = qdisc_lookup_ops(kind); 1281 if (ops != NULL) { 1282 /* We will try again qdisc_lookup_ops, 1283 * so don't keep a reference. 1284 */ 1285 module_put(ops->owner); 1286 err = -EAGAIN; 1287 goto err_out; 1288 } 1289 } 1290 } 1291 #endif 1292 1293 err = -ENOENT; 1294 if (!ops) { 1295 NL_SET_ERR_MSG(extack, "Specified qdisc kind is unknown"); 1296 goto err_out; 1297 } 1298 1299 sch = qdisc_alloc(dev_queue, ops, extack); 1300 if (IS_ERR(sch)) { 1301 err = PTR_ERR(sch); 1302 goto err_out2; 1303 } 1304 1305 sch->parent = parent; 1306 1307 if (handle == TC_H_INGRESS) { 1308 if (!(sch->flags & TCQ_F_INGRESS)) { 1309 NL_SET_ERR_MSG(extack, 1310 "Specified parent ID is reserved for ingress and clsact Qdiscs"); 1311 err = -EINVAL; 1312 goto err_out3; 1313 } 1314 handle = TC_H_MAKE(TC_H_INGRESS, 0); 1315 } else { 1316 if (handle == 0) { 1317 handle = qdisc_alloc_handle(dev); 1318 if (handle == 0) { 1319 NL_SET_ERR_MSG(extack, "Maximum number of qdisc handles was exceeded"); 1320 err = -ENOSPC; 1321 goto err_out3; 1322 } 1323 } 1324 if (!netif_is_multiqueue(dev)) 1325 sch->flags |= TCQ_F_ONETXQUEUE; 1326 } 1327 1328 sch->handle = handle; 1329 1330 /* This exist to keep backward compatible with a userspace 1331 * loophole, what allowed userspace to get IFF_NO_QUEUE 1332 * facility on older kernels by setting tx_queue_len=0 (prior 1333 * to qdisc init), and then forgot to reinit tx_queue_len 1334 * before again attaching a qdisc. 1335 */ 1336 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) { 1337 WRITE_ONCE(dev->tx_queue_len, DEFAULT_TX_QUEUE_LEN); 1338 netdev_info(dev, "Caught tx_queue_len zero misconfig\n"); 1339 } 1340 1341 err = qdisc_block_indexes_set(sch, tca, extack); 1342 if (err) 1343 goto err_out3; 1344 1345 if (tca[TCA_STAB]) { 1346 stab = qdisc_get_stab(tca[TCA_STAB], extack); 1347 if (IS_ERR(stab)) { 1348 err = PTR_ERR(stab); 1349 goto err_out3; 1350 } 1351 rcu_assign_pointer(sch->stab, stab); 1352 } 1353 1354 if (ops->init) { 1355 err = ops->init(sch, tca[TCA_OPTIONS], extack); 1356 if (err != 0) 1357 goto err_out4; 1358 } 1359 1360 if (tca[TCA_RATE]) { 1361 err = -EOPNOTSUPP; 1362 if (sch->flags & TCQ_F_MQROOT) { 1363 NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc"); 1364 goto err_out4; 1365 } 1366 1367 err = gen_new_estimator(&sch->bstats, 1368 sch->cpu_bstats, 1369 &sch->rate_est, 1370 NULL, 1371 true, 1372 tca[TCA_RATE]); 1373 if (err) { 1374 NL_SET_ERR_MSG(extack, "Failed to generate new estimator"); 1375 goto err_out4; 1376 } 1377 } 1378 1379 qdisc_hash_add(sch, false); 1380 trace_qdisc_create(ops, dev, parent); 1381 1382 return sch; 1383 1384 err_out4: 1385 /* Even if ops->init() failed, we call ops->destroy() 1386 * like qdisc_create_dflt(). 1387 */ 1388 if (ops->destroy) 1389 ops->destroy(sch); 1390 qdisc_put_stab(rtnl_dereference(sch->stab)); 1391 err_out3: 1392 lockdep_unregister_key(&sch->root_lock_key); 1393 netdev_put(dev, &sch->dev_tracker); 1394 qdisc_free(sch); 1395 err_out2: 1396 module_put(ops->owner); 1397 err_out: 1398 *errp = err; 1399 return NULL; 1400 } 1401 1402 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca, 1403 struct netlink_ext_ack *extack) 1404 { 1405 struct qdisc_size_table *ostab, *stab = NULL; 1406 int err = 0; 1407 1408 if (tca[TCA_OPTIONS]) { 1409 if (!sch->ops->change) { 1410 NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc"); 1411 return -EINVAL; 1412 } 1413 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) { 1414 NL_SET_ERR_MSG(extack, "Change of blocks is not supported"); 1415 return -EOPNOTSUPP; 1416 } 1417 err = sch->ops->change(sch, tca[TCA_OPTIONS], extack); 1418 if (err) 1419 return err; 1420 } 1421 1422 if (tca[TCA_STAB]) { 1423 stab = qdisc_get_stab(tca[TCA_STAB], extack); 1424 if (IS_ERR(stab)) 1425 return PTR_ERR(stab); 1426 } 1427 1428 ostab = rtnl_dereference(sch->stab); 1429 rcu_assign_pointer(sch->stab, stab); 1430 qdisc_put_stab(ostab); 1431 1432 if (tca[TCA_RATE]) { 1433 /* NB: ignores errors from replace_estimator 1434 because change can't be undone. */ 1435 if (sch->flags & TCQ_F_MQROOT) 1436 goto out; 1437 gen_replace_estimator(&sch->bstats, 1438 sch->cpu_bstats, 1439 &sch->rate_est, 1440 NULL, 1441 true, 1442 tca[TCA_RATE]); 1443 } 1444 out: 1445 return 0; 1446 } 1447 1448 struct check_loop_arg { 1449 struct qdisc_walker w; 1450 struct Qdisc *p; 1451 int depth; 1452 }; 1453 1454 static int check_loop_fn(struct Qdisc *q, unsigned long cl, 1455 struct qdisc_walker *w); 1456 1457 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth) 1458 { 1459 struct check_loop_arg arg; 1460 1461 if (q->ops->cl_ops == NULL) 1462 return 0; 1463 1464 arg.w.stop = arg.w.skip = arg.w.count = 0; 1465 arg.w.fn = check_loop_fn; 1466 arg.depth = depth; 1467 arg.p = p; 1468 q->ops->cl_ops->walk(q, &arg.w); 1469 return arg.w.stop ? -ELOOP : 0; 1470 } 1471 1472 static int 1473 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w) 1474 { 1475 struct Qdisc *leaf; 1476 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 1477 struct check_loop_arg *arg = (struct check_loop_arg *)w; 1478 1479 leaf = cops->leaf(q, cl); 1480 if (leaf) { 1481 if (leaf == arg->p || arg->depth > 7) 1482 return -ELOOP; 1483 return check_loop(leaf, arg->p, arg->depth + 1); 1484 } 1485 return 0; 1486 } 1487 1488 const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = { 1489 [TCA_KIND] = { .type = NLA_STRING }, 1490 [TCA_RATE] = { .type = NLA_BINARY, 1491 .len = sizeof(struct tc_estimator) }, 1492 [TCA_STAB] = { .type = NLA_NESTED }, 1493 [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG }, 1494 [TCA_CHAIN] = { .type = NLA_U32 }, 1495 [TCA_INGRESS_BLOCK] = { .type = NLA_U32 }, 1496 [TCA_EGRESS_BLOCK] = { .type = NLA_U32 }, 1497 }; 1498 1499 /* 1500 * Delete/get qdisc. 1501 */ 1502 1503 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, 1504 struct netlink_ext_ack *extack) 1505 { 1506 struct net *net = sock_net(skb->sk); 1507 struct tcmsg *tcm = nlmsg_data(n); 1508 struct nlattr *tca[TCA_MAX + 1]; 1509 struct net_device *dev; 1510 u32 clid; 1511 struct Qdisc *q = NULL; 1512 struct Qdisc *p = NULL; 1513 int err; 1514 1515 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 1516 rtm_tca_policy, extack); 1517 if (err < 0) 1518 return err; 1519 1520 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1521 if (!dev) 1522 return -ENODEV; 1523 1524 clid = tcm->tcm_parent; 1525 if (clid) { 1526 if (clid != TC_H_ROOT) { 1527 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) { 1528 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1529 if (!p) { 1530 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid"); 1531 return -ENOENT; 1532 } 1533 q = qdisc_leaf(p, clid); 1534 } else if (dev_ingress_queue(dev)) { 1535 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); 1536 } 1537 } else { 1538 q = rtnl_dereference(dev->qdisc); 1539 } 1540 if (!q) { 1541 NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device"); 1542 return -ENOENT; 1543 } 1544 1545 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) { 1546 NL_SET_ERR_MSG(extack, "Invalid handle"); 1547 return -EINVAL; 1548 } 1549 } else { 1550 q = qdisc_lookup(dev, tcm->tcm_handle); 1551 if (!q) { 1552 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle"); 1553 return -ENOENT; 1554 } 1555 } 1556 1557 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1558 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1559 return -EINVAL; 1560 } 1561 1562 if (n->nlmsg_type == RTM_DELQDISC) { 1563 if (!clid) { 1564 NL_SET_ERR_MSG(extack, "Classid cannot be zero"); 1565 return -EINVAL; 1566 } 1567 if (q->handle == 0) { 1568 NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero"); 1569 return -ENOENT; 1570 } 1571 err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack); 1572 if (err != 0) 1573 return err; 1574 } else { 1575 qdisc_get_notify(net, skb, n, clid, q, NULL); 1576 } 1577 return 0; 1578 } 1579 1580 static bool req_create_or_replace(struct nlmsghdr *n) 1581 { 1582 return (n->nlmsg_flags & NLM_F_CREATE && 1583 n->nlmsg_flags & NLM_F_REPLACE); 1584 } 1585 1586 static bool req_create_exclusive(struct nlmsghdr *n) 1587 { 1588 return (n->nlmsg_flags & NLM_F_CREATE && 1589 n->nlmsg_flags & NLM_F_EXCL); 1590 } 1591 1592 static bool req_change(struct nlmsghdr *n) 1593 { 1594 return (!(n->nlmsg_flags & NLM_F_CREATE) && 1595 !(n->nlmsg_flags & NLM_F_REPLACE) && 1596 !(n->nlmsg_flags & NLM_F_EXCL)); 1597 } 1598 1599 /* 1600 * Create/change qdisc. 1601 */ 1602 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, 1603 struct netlink_ext_ack *extack) 1604 { 1605 struct net *net = sock_net(skb->sk); 1606 struct tcmsg *tcm; 1607 struct nlattr *tca[TCA_MAX + 1]; 1608 struct net_device *dev; 1609 u32 clid; 1610 struct Qdisc *q, *p; 1611 int err; 1612 1613 replay: 1614 /* Reinit, just in case something touches this. */ 1615 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 1616 rtm_tca_policy, extack); 1617 if (err < 0) 1618 return err; 1619 1620 tcm = nlmsg_data(n); 1621 clid = tcm->tcm_parent; 1622 q = p = NULL; 1623 1624 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1625 if (!dev) 1626 return -ENODEV; 1627 1628 1629 if (clid) { 1630 if (clid != TC_H_ROOT) { 1631 if (clid != TC_H_INGRESS) { 1632 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1633 if (!p) { 1634 NL_SET_ERR_MSG(extack, "Failed to find specified qdisc"); 1635 return -ENOENT; 1636 } 1637 q = qdisc_leaf(p, clid); 1638 } else if (dev_ingress_queue_create(dev)) { 1639 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); 1640 } 1641 } else { 1642 q = rtnl_dereference(dev->qdisc); 1643 } 1644 1645 /* It may be default qdisc, ignore it */ 1646 if (q && q->handle == 0) 1647 q = NULL; 1648 1649 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) { 1650 if (tcm->tcm_handle) { 1651 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) { 1652 NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override"); 1653 return -EEXIST; 1654 } 1655 if (TC_H_MIN(tcm->tcm_handle)) { 1656 NL_SET_ERR_MSG(extack, "Invalid minor handle"); 1657 return -EINVAL; 1658 } 1659 q = qdisc_lookup(dev, tcm->tcm_handle); 1660 if (!q) 1661 goto create_n_graft; 1662 if (n->nlmsg_flags & NLM_F_EXCL) { 1663 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override"); 1664 return -EEXIST; 1665 } 1666 if (tca[TCA_KIND] && 1667 nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1668 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1669 return -EINVAL; 1670 } 1671 if (q->flags & TCQ_F_INGRESS) { 1672 NL_SET_ERR_MSG(extack, 1673 "Cannot regraft ingress or clsact Qdiscs"); 1674 return -EINVAL; 1675 } 1676 if (q == p || 1677 (p && check_loop(q, p, 0))) { 1678 NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected"); 1679 return -ELOOP; 1680 } 1681 if (clid == TC_H_INGRESS) { 1682 NL_SET_ERR_MSG(extack, "Ingress cannot graft directly"); 1683 return -EINVAL; 1684 } 1685 qdisc_refcount_inc(q); 1686 goto graft; 1687 } else { 1688 if (!q) 1689 goto create_n_graft; 1690 1691 /* This magic test requires explanation. 1692 * 1693 * We know, that some child q is already 1694 * attached to this parent and have choice: 1695 * 1) change it or 2) create/graft new one. 1696 * If the requested qdisc kind is different 1697 * than the existing one, then we choose graft. 1698 * If they are the same then this is "change" 1699 * operation - just let it fallthrough.. 1700 * 1701 * 1. We are allowed to create/graft only 1702 * if the request is explicitly stating 1703 * "please create if it doesn't exist". 1704 * 1705 * 2. If the request is to exclusive create 1706 * then the qdisc tcm_handle is not expected 1707 * to exist, so that we choose create/graft too. 1708 * 1709 * 3. The last case is when no flags are set. 1710 * This will happen when for example tc 1711 * utility issues a "change" command. 1712 * Alas, it is sort of hole in API, we 1713 * cannot decide what to do unambiguously. 1714 * For now we select create/graft. 1715 */ 1716 if (tca[TCA_KIND] && 1717 nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1718 if (req_create_or_replace(n) || 1719 req_create_exclusive(n)) 1720 goto create_n_graft; 1721 else if (req_change(n)) 1722 goto create_n_graft2; 1723 } 1724 } 1725 } 1726 } else { 1727 if (!tcm->tcm_handle) { 1728 NL_SET_ERR_MSG(extack, "Handle cannot be zero"); 1729 return -EINVAL; 1730 } 1731 q = qdisc_lookup(dev, tcm->tcm_handle); 1732 } 1733 1734 /* Change qdisc parameters */ 1735 if (!q) { 1736 NL_SET_ERR_MSG(extack, "Specified qdisc not found"); 1737 return -ENOENT; 1738 } 1739 if (n->nlmsg_flags & NLM_F_EXCL) { 1740 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify"); 1741 return -EEXIST; 1742 } 1743 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1744 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1745 return -EINVAL; 1746 } 1747 err = qdisc_change(q, tca, extack); 1748 if (err == 0) 1749 qdisc_notify(net, skb, n, clid, NULL, q, extack); 1750 return err; 1751 1752 create_n_graft: 1753 if (!(n->nlmsg_flags & NLM_F_CREATE)) { 1754 NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag"); 1755 return -ENOENT; 1756 } 1757 create_n_graft2: 1758 if (clid == TC_H_INGRESS) { 1759 if (dev_ingress_queue(dev)) { 1760 q = qdisc_create(dev, dev_ingress_queue(dev), 1761 tcm->tcm_parent, tcm->tcm_parent, 1762 tca, &err, extack); 1763 } else { 1764 NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device"); 1765 err = -ENOENT; 1766 } 1767 } else { 1768 struct netdev_queue *dev_queue; 1769 1770 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue) 1771 dev_queue = p->ops->cl_ops->select_queue(p, tcm); 1772 else if (p) 1773 dev_queue = p->dev_queue; 1774 else 1775 dev_queue = netdev_get_tx_queue(dev, 0); 1776 1777 q = qdisc_create(dev, dev_queue, 1778 tcm->tcm_parent, tcm->tcm_handle, 1779 tca, &err, extack); 1780 } 1781 if (q == NULL) { 1782 if (err == -EAGAIN) 1783 goto replay; 1784 return err; 1785 } 1786 1787 graft: 1788 err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack); 1789 if (err) { 1790 if (q) 1791 qdisc_put(q); 1792 return err; 1793 } 1794 1795 return 0; 1796 } 1797 1798 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb, 1799 struct netlink_callback *cb, 1800 int *q_idx_p, int s_q_idx, bool recur, 1801 bool dump_invisible) 1802 { 1803 int ret = 0, q_idx = *q_idx_p; 1804 struct Qdisc *q; 1805 int b; 1806 1807 if (!root) 1808 return 0; 1809 1810 q = root; 1811 if (q_idx < s_q_idx) { 1812 q_idx++; 1813 } else { 1814 if (!tc_qdisc_dump_ignore(q, dump_invisible) && 1815 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1816 cb->nlh->nlmsg_seq, NLM_F_MULTI, 1817 RTM_NEWQDISC, NULL) <= 0) 1818 goto done; 1819 q_idx++; 1820 } 1821 1822 /* If dumping singletons, there is no qdisc_dev(root) and the singleton 1823 * itself has already been dumped. 1824 * 1825 * If we've already dumped the top-level (ingress) qdisc above and the global 1826 * qdisc hashtable, we don't want to hit it again 1827 */ 1828 if (!qdisc_dev(root) || !recur) 1829 goto out; 1830 1831 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { 1832 if (q_idx < s_q_idx) { 1833 q_idx++; 1834 continue; 1835 } 1836 if (!tc_qdisc_dump_ignore(q, dump_invisible) && 1837 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1838 cb->nlh->nlmsg_seq, NLM_F_MULTI, 1839 RTM_NEWQDISC, NULL) <= 0) 1840 goto done; 1841 q_idx++; 1842 } 1843 1844 out: 1845 *q_idx_p = q_idx; 1846 return ret; 1847 done: 1848 ret = -1; 1849 goto out; 1850 } 1851 1852 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb) 1853 { 1854 struct net *net = sock_net(skb->sk); 1855 int idx, q_idx; 1856 int s_idx, s_q_idx; 1857 struct net_device *dev; 1858 const struct nlmsghdr *nlh = cb->nlh; 1859 struct nlattr *tca[TCA_MAX + 1]; 1860 int err; 1861 1862 s_idx = cb->args[0]; 1863 s_q_idx = q_idx = cb->args[1]; 1864 1865 idx = 0; 1866 ASSERT_RTNL(); 1867 1868 err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX, 1869 rtm_tca_policy, cb->extack); 1870 if (err < 0) 1871 return err; 1872 1873 for_each_netdev(net, dev) { 1874 struct netdev_queue *dev_queue; 1875 1876 if (idx < s_idx) 1877 goto cont; 1878 if (idx > s_idx) 1879 s_q_idx = 0; 1880 q_idx = 0; 1881 1882 if (tc_dump_qdisc_root(rtnl_dereference(dev->qdisc), 1883 skb, cb, &q_idx, s_q_idx, 1884 true, tca[TCA_DUMP_INVISIBLE]) < 0) 1885 goto done; 1886 1887 dev_queue = dev_ingress_queue(dev); 1888 if (dev_queue && 1889 tc_dump_qdisc_root(rtnl_dereference(dev_queue->qdisc_sleeping), 1890 skb, cb, &q_idx, s_q_idx, false, 1891 tca[TCA_DUMP_INVISIBLE]) < 0) 1892 goto done; 1893 1894 cont: 1895 idx++; 1896 } 1897 1898 done: 1899 cb->args[0] = idx; 1900 cb->args[1] = q_idx; 1901 1902 return skb->len; 1903 } 1904 1905 1906 1907 /************************************************ 1908 * Traffic classes manipulation. * 1909 ************************************************/ 1910 1911 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, 1912 unsigned long cl, u32 portid, u32 seq, u16 flags, 1913 int event, struct netlink_ext_ack *extack) 1914 { 1915 struct tcmsg *tcm; 1916 struct nlmsghdr *nlh; 1917 unsigned char *b = skb_tail_pointer(skb); 1918 struct gnet_dump d; 1919 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops; 1920 1921 cond_resched(); 1922 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 1923 if (!nlh) 1924 goto out_nlmsg_trim; 1925 tcm = nlmsg_data(nlh); 1926 tcm->tcm_family = AF_UNSPEC; 1927 tcm->tcm__pad1 = 0; 1928 tcm->tcm__pad2 = 0; 1929 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 1930 tcm->tcm_parent = q->handle; 1931 tcm->tcm_handle = q->handle; 1932 tcm->tcm_info = 0; 1933 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 1934 goto nla_put_failure; 1935 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0) 1936 goto nla_put_failure; 1937 1938 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 1939 NULL, &d, TCA_PAD) < 0) 1940 goto nla_put_failure; 1941 1942 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0) 1943 goto nla_put_failure; 1944 1945 if (gnet_stats_finish_copy(&d) < 0) 1946 goto nla_put_failure; 1947 1948 if (extack && extack->_msg && 1949 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg)) 1950 goto out_nlmsg_trim; 1951 1952 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 1953 1954 return skb->len; 1955 1956 out_nlmsg_trim: 1957 nla_put_failure: 1958 nlmsg_trim(skb, b); 1959 return -1; 1960 } 1961 1962 static int tclass_notify(struct net *net, struct sk_buff *oskb, 1963 struct nlmsghdr *n, struct Qdisc *q, 1964 unsigned long cl, int event, struct netlink_ext_ack *extack) 1965 { 1966 struct sk_buff *skb; 1967 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1968 1969 if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) 1970 return 0; 1971 1972 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1973 if (!skb) 1974 return -ENOBUFS; 1975 1976 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event, extack) < 0) { 1977 kfree_skb(skb); 1978 return -EINVAL; 1979 } 1980 1981 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1982 n->nlmsg_flags & NLM_F_ECHO); 1983 } 1984 1985 static int tclass_get_notify(struct net *net, struct sk_buff *oskb, 1986 struct nlmsghdr *n, struct Qdisc *q, 1987 unsigned long cl, struct netlink_ext_ack *extack) 1988 { 1989 struct sk_buff *skb; 1990 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1991 1992 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1993 if (!skb) 1994 return -ENOBUFS; 1995 1996 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, RTM_NEWTCLASS, 1997 extack) < 0) { 1998 kfree_skb(skb); 1999 return -EINVAL; 2000 } 2001 2002 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 2003 n->nlmsg_flags & NLM_F_ECHO); 2004 } 2005 2006 static int tclass_del_notify(struct net *net, 2007 const struct Qdisc_class_ops *cops, 2008 struct sk_buff *oskb, struct nlmsghdr *n, 2009 struct Qdisc *q, unsigned long cl, 2010 struct netlink_ext_ack *extack) 2011 { 2012 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 2013 struct sk_buff *skb; 2014 int err = 0; 2015 2016 if (!cops->delete) 2017 return -EOPNOTSUPP; 2018 2019 if (rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) { 2020 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2021 if (!skb) 2022 return -ENOBUFS; 2023 2024 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, 2025 RTM_DELTCLASS, extack) < 0) { 2026 kfree_skb(skb); 2027 return -EINVAL; 2028 } 2029 } else { 2030 skb = NULL; 2031 } 2032 2033 err = cops->delete(q, cl, extack); 2034 if (err) { 2035 kfree_skb(skb); 2036 return err; 2037 } 2038 2039 err = rtnetlink_maybe_send(skb, net, portid, RTNLGRP_TC, 2040 n->nlmsg_flags & NLM_F_ECHO); 2041 return err; 2042 } 2043 2044 #ifdef CONFIG_NET_CLS 2045 2046 struct tcf_bind_args { 2047 struct tcf_walker w; 2048 unsigned long base; 2049 unsigned long cl; 2050 u32 classid; 2051 }; 2052 2053 static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg) 2054 { 2055 struct tcf_bind_args *a = (void *)arg; 2056 2057 if (n && tp->ops->bind_class) { 2058 struct Qdisc *q = tcf_block_q(tp->chain->block); 2059 2060 sch_tree_lock(q); 2061 tp->ops->bind_class(n, a->classid, a->cl, q, a->base); 2062 sch_tree_unlock(q); 2063 } 2064 return 0; 2065 } 2066 2067 struct tc_bind_class_args { 2068 struct qdisc_walker w; 2069 unsigned long new_cl; 2070 u32 portid; 2071 u32 clid; 2072 }; 2073 2074 static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl, 2075 struct qdisc_walker *w) 2076 { 2077 struct tc_bind_class_args *a = (struct tc_bind_class_args *)w; 2078 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 2079 struct tcf_block *block; 2080 struct tcf_chain *chain; 2081 2082 block = cops->tcf_block(q, cl, NULL); 2083 if (!block) 2084 return 0; 2085 for (chain = tcf_get_next_chain(block, NULL); 2086 chain; 2087 chain = tcf_get_next_chain(block, chain)) { 2088 struct tcf_proto *tp; 2089 2090 for (tp = tcf_get_next_proto(chain, NULL); 2091 tp; tp = tcf_get_next_proto(chain, tp)) { 2092 struct tcf_bind_args arg = {}; 2093 2094 arg.w.fn = tcf_node_bind; 2095 arg.classid = a->clid; 2096 arg.base = cl; 2097 arg.cl = a->new_cl; 2098 tp->ops->walk(tp, &arg.w, true); 2099 } 2100 } 2101 2102 return 0; 2103 } 2104 2105 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, 2106 unsigned long new_cl) 2107 { 2108 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 2109 struct tc_bind_class_args args = {}; 2110 2111 if (!cops->tcf_block) 2112 return; 2113 args.portid = portid; 2114 args.clid = clid; 2115 args.new_cl = new_cl; 2116 args.w.fn = tc_bind_class_walker; 2117 q->ops->cl_ops->walk(q, &args.w); 2118 } 2119 2120 #else 2121 2122 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, 2123 unsigned long new_cl) 2124 { 2125 } 2126 2127 #endif 2128 2129 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, 2130 struct netlink_ext_ack *extack) 2131 { 2132 struct net *net = sock_net(skb->sk); 2133 struct tcmsg *tcm = nlmsg_data(n); 2134 struct nlattr *tca[TCA_MAX + 1]; 2135 struct net_device *dev; 2136 struct Qdisc *q = NULL; 2137 const struct Qdisc_class_ops *cops; 2138 unsigned long cl = 0; 2139 unsigned long new_cl; 2140 u32 portid; 2141 u32 clid; 2142 u32 qid; 2143 int err; 2144 2145 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 2146 rtm_tca_policy, extack); 2147 if (err < 0) 2148 return err; 2149 2150 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 2151 if (!dev) 2152 return -ENODEV; 2153 2154 /* 2155 parent == TC_H_UNSPEC - unspecified parent. 2156 parent == TC_H_ROOT - class is root, which has no parent. 2157 parent == X:0 - parent is root class. 2158 parent == X:Y - parent is a node in hierarchy. 2159 parent == 0:Y - parent is X:Y, where X:0 is qdisc. 2160 2161 handle == 0:0 - generate handle from kernel pool. 2162 handle == 0:Y - class is X:Y, where X:0 is qdisc. 2163 handle == X:Y - clear. 2164 handle == X:0 - root class. 2165 */ 2166 2167 /* Step 1. Determine qdisc handle X:0 */ 2168 2169 portid = tcm->tcm_parent; 2170 clid = tcm->tcm_handle; 2171 qid = TC_H_MAJ(clid); 2172 2173 if (portid != TC_H_ROOT) { 2174 u32 qid1 = TC_H_MAJ(portid); 2175 2176 if (qid && qid1) { 2177 /* If both majors are known, they must be identical. */ 2178 if (qid != qid1) 2179 return -EINVAL; 2180 } else if (qid1) { 2181 qid = qid1; 2182 } else if (qid == 0) 2183 qid = rtnl_dereference(dev->qdisc)->handle; 2184 2185 /* Now qid is genuine qdisc handle consistent 2186 * both with parent and child. 2187 * 2188 * TC_H_MAJ(portid) still may be unspecified, complete it now. 2189 */ 2190 if (portid) 2191 portid = TC_H_MAKE(qid, portid); 2192 } else { 2193 if (qid == 0) 2194 qid = rtnl_dereference(dev->qdisc)->handle; 2195 } 2196 2197 /* OK. Locate qdisc */ 2198 q = qdisc_lookup(dev, qid); 2199 if (!q) 2200 return -ENOENT; 2201 2202 /* An check that it supports classes */ 2203 cops = q->ops->cl_ops; 2204 if (cops == NULL) 2205 return -EINVAL; 2206 2207 /* Now try to get class */ 2208 if (clid == 0) { 2209 if (portid == TC_H_ROOT) 2210 clid = qid; 2211 } else 2212 clid = TC_H_MAKE(qid, clid); 2213 2214 if (clid) 2215 cl = cops->find(q, clid); 2216 2217 if (cl == 0) { 2218 err = -ENOENT; 2219 if (n->nlmsg_type != RTM_NEWTCLASS || 2220 !(n->nlmsg_flags & NLM_F_CREATE)) 2221 goto out; 2222 } else { 2223 switch (n->nlmsg_type) { 2224 case RTM_NEWTCLASS: 2225 err = -EEXIST; 2226 if (n->nlmsg_flags & NLM_F_EXCL) 2227 goto out; 2228 break; 2229 case RTM_DELTCLASS: 2230 err = tclass_del_notify(net, cops, skb, n, q, cl, extack); 2231 /* Unbind the class with flilters with 0 */ 2232 tc_bind_tclass(q, portid, clid, 0); 2233 goto out; 2234 case RTM_GETTCLASS: 2235 err = tclass_get_notify(net, skb, n, q, cl, extack); 2236 goto out; 2237 default: 2238 err = -EINVAL; 2239 goto out; 2240 } 2241 } 2242 2243 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) { 2244 NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes"); 2245 return -EOPNOTSUPP; 2246 } 2247 2248 new_cl = cl; 2249 err = -EOPNOTSUPP; 2250 if (cops->change) 2251 err = cops->change(q, clid, portid, tca, &new_cl, extack); 2252 if (err == 0) { 2253 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS, extack); 2254 /* We just create a new class, need to do reverse binding. */ 2255 if (cl != new_cl) 2256 tc_bind_tclass(q, portid, clid, new_cl); 2257 } 2258 out: 2259 return err; 2260 } 2261 2262 struct qdisc_dump_args { 2263 struct qdisc_walker w; 2264 struct sk_buff *skb; 2265 struct netlink_callback *cb; 2266 }; 2267 2268 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, 2269 struct qdisc_walker *arg) 2270 { 2271 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg; 2272 2273 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid, 2274 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, 2275 RTM_NEWTCLASS, NULL); 2276 } 2277 2278 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb, 2279 struct tcmsg *tcm, struct netlink_callback *cb, 2280 int *t_p, int s_t) 2281 { 2282 struct qdisc_dump_args arg; 2283 2284 if (tc_qdisc_dump_ignore(q, false) || 2285 *t_p < s_t || !q->ops->cl_ops || 2286 (tcm->tcm_parent && 2287 TC_H_MAJ(tcm->tcm_parent) != q->handle)) { 2288 (*t_p)++; 2289 return 0; 2290 } 2291 if (*t_p > s_t) 2292 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); 2293 arg.w.fn = qdisc_class_dump; 2294 arg.skb = skb; 2295 arg.cb = cb; 2296 arg.w.stop = 0; 2297 arg.w.skip = cb->args[1]; 2298 arg.w.count = 0; 2299 q->ops->cl_ops->walk(q, &arg.w); 2300 cb->args[1] = arg.w.count; 2301 if (arg.w.stop) 2302 return -1; 2303 (*t_p)++; 2304 return 0; 2305 } 2306 2307 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb, 2308 struct tcmsg *tcm, struct netlink_callback *cb, 2309 int *t_p, int s_t, bool recur) 2310 { 2311 struct Qdisc *q; 2312 int b; 2313 2314 if (!root) 2315 return 0; 2316 2317 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0) 2318 return -1; 2319 2320 if (!qdisc_dev(root) || !recur) 2321 return 0; 2322 2323 if (tcm->tcm_parent) { 2324 q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent)); 2325 if (q && q != root && 2326 tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 2327 return -1; 2328 return 0; 2329 } 2330 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { 2331 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 2332 return -1; 2333 } 2334 2335 return 0; 2336 } 2337 2338 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb) 2339 { 2340 struct tcmsg *tcm = nlmsg_data(cb->nlh); 2341 struct net *net = sock_net(skb->sk); 2342 struct netdev_queue *dev_queue; 2343 struct net_device *dev; 2344 int t, s_t; 2345 2346 if (nlmsg_len(cb->nlh) < sizeof(*tcm)) 2347 return 0; 2348 dev = dev_get_by_index(net, tcm->tcm_ifindex); 2349 if (!dev) 2350 return 0; 2351 2352 s_t = cb->args[0]; 2353 t = 0; 2354 2355 if (tc_dump_tclass_root(rtnl_dereference(dev->qdisc), 2356 skb, tcm, cb, &t, s_t, true) < 0) 2357 goto done; 2358 2359 dev_queue = dev_ingress_queue(dev); 2360 if (dev_queue && 2361 tc_dump_tclass_root(rtnl_dereference(dev_queue->qdisc_sleeping), 2362 skb, tcm, cb, &t, s_t, false) < 0) 2363 goto done; 2364 2365 done: 2366 cb->args[0] = t; 2367 2368 dev_put(dev); 2369 return skb->len; 2370 } 2371 2372 #ifdef CONFIG_PROC_FS 2373 static int psched_show(struct seq_file *seq, void *v) 2374 { 2375 seq_printf(seq, "%08x %08x %08x %08x\n", 2376 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1), 2377 1000000, 2378 (u32)NSEC_PER_SEC / hrtimer_resolution); 2379 2380 return 0; 2381 } 2382 2383 static int __net_init psched_net_init(struct net *net) 2384 { 2385 struct proc_dir_entry *e; 2386 2387 e = proc_create_single("psched", 0, net->proc_net, psched_show); 2388 if (e == NULL) 2389 return -ENOMEM; 2390 2391 return 0; 2392 } 2393 2394 static void __net_exit psched_net_exit(struct net *net) 2395 { 2396 remove_proc_entry("psched", net->proc_net); 2397 } 2398 #else 2399 static int __net_init psched_net_init(struct net *net) 2400 { 2401 return 0; 2402 } 2403 2404 static void __net_exit psched_net_exit(struct net *net) 2405 { 2406 } 2407 #endif 2408 2409 static struct pernet_operations psched_net_ops = { 2410 .init = psched_net_init, 2411 .exit = psched_net_exit, 2412 }; 2413 2414 #if IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) 2415 DEFINE_STATIC_KEY_FALSE(tc_skip_wrapper); 2416 #endif 2417 2418 static int __init pktsched_init(void) 2419 { 2420 int err; 2421 2422 err = register_pernet_subsys(&psched_net_ops); 2423 if (err) { 2424 pr_err("pktsched_init: " 2425 "cannot initialize per netns operations\n"); 2426 return err; 2427 } 2428 2429 register_qdisc(&pfifo_fast_ops); 2430 register_qdisc(&pfifo_qdisc_ops); 2431 register_qdisc(&bfifo_qdisc_ops); 2432 register_qdisc(&pfifo_head_drop_qdisc_ops); 2433 register_qdisc(&mq_qdisc_ops); 2434 register_qdisc(&noqueue_qdisc_ops); 2435 2436 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, 0); 2437 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, 0); 2438 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, 2439 0); 2440 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, 0); 2441 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, 0); 2442 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, 2443 0); 2444 2445 tc_wrapper_init(); 2446 2447 return 0; 2448 } 2449 2450 subsys_initcall(pktsched_init); 2451