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(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 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 netdev_put(dev, &sch->dev_tracker); 1393 qdisc_free(sch); 1394 err_out2: 1395 module_put(ops->owner); 1396 err_out: 1397 *errp = err; 1398 return NULL; 1399 } 1400 1401 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca, 1402 struct netlink_ext_ack *extack) 1403 { 1404 struct qdisc_size_table *ostab, *stab = NULL; 1405 int err = 0; 1406 1407 if (tca[TCA_OPTIONS]) { 1408 if (!sch->ops->change) { 1409 NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc"); 1410 return -EINVAL; 1411 } 1412 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) { 1413 NL_SET_ERR_MSG(extack, "Change of blocks is not supported"); 1414 return -EOPNOTSUPP; 1415 } 1416 err = sch->ops->change(sch, tca[TCA_OPTIONS], extack); 1417 if (err) 1418 return err; 1419 } 1420 1421 if (tca[TCA_STAB]) { 1422 stab = qdisc_get_stab(tca[TCA_STAB], extack); 1423 if (IS_ERR(stab)) 1424 return PTR_ERR(stab); 1425 } 1426 1427 ostab = rtnl_dereference(sch->stab); 1428 rcu_assign_pointer(sch->stab, stab); 1429 qdisc_put_stab(ostab); 1430 1431 if (tca[TCA_RATE]) { 1432 /* NB: ignores errors from replace_estimator 1433 because change can't be undone. */ 1434 if (sch->flags & TCQ_F_MQROOT) 1435 goto out; 1436 gen_replace_estimator(&sch->bstats, 1437 sch->cpu_bstats, 1438 &sch->rate_est, 1439 NULL, 1440 true, 1441 tca[TCA_RATE]); 1442 } 1443 out: 1444 return 0; 1445 } 1446 1447 struct check_loop_arg { 1448 struct qdisc_walker w; 1449 struct Qdisc *p; 1450 int depth; 1451 }; 1452 1453 static int check_loop_fn(struct Qdisc *q, unsigned long cl, 1454 struct qdisc_walker *w); 1455 1456 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth) 1457 { 1458 struct check_loop_arg arg; 1459 1460 if (q->ops->cl_ops == NULL) 1461 return 0; 1462 1463 arg.w.stop = arg.w.skip = arg.w.count = 0; 1464 arg.w.fn = check_loop_fn; 1465 arg.depth = depth; 1466 arg.p = p; 1467 q->ops->cl_ops->walk(q, &arg.w); 1468 return arg.w.stop ? -ELOOP : 0; 1469 } 1470 1471 static int 1472 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w) 1473 { 1474 struct Qdisc *leaf; 1475 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 1476 struct check_loop_arg *arg = (struct check_loop_arg *)w; 1477 1478 leaf = cops->leaf(q, cl); 1479 if (leaf) { 1480 if (leaf == arg->p || arg->depth > 7) 1481 return -ELOOP; 1482 return check_loop(leaf, arg->p, arg->depth + 1); 1483 } 1484 return 0; 1485 } 1486 1487 const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = { 1488 [TCA_KIND] = { .type = NLA_STRING }, 1489 [TCA_RATE] = { .type = NLA_BINARY, 1490 .len = sizeof(struct tc_estimator) }, 1491 [TCA_STAB] = { .type = NLA_NESTED }, 1492 [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG }, 1493 [TCA_CHAIN] = { .type = NLA_U32 }, 1494 [TCA_INGRESS_BLOCK] = { .type = NLA_U32 }, 1495 [TCA_EGRESS_BLOCK] = { .type = NLA_U32 }, 1496 }; 1497 1498 /* 1499 * Delete/get qdisc. 1500 */ 1501 1502 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, 1503 struct netlink_ext_ack *extack) 1504 { 1505 struct net *net = sock_net(skb->sk); 1506 struct tcmsg *tcm = nlmsg_data(n); 1507 struct nlattr *tca[TCA_MAX + 1]; 1508 struct net_device *dev; 1509 u32 clid; 1510 struct Qdisc *q = NULL; 1511 struct Qdisc *p = NULL; 1512 int err; 1513 1514 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 1515 rtm_tca_policy, extack); 1516 if (err < 0) 1517 return err; 1518 1519 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1520 if (!dev) 1521 return -ENODEV; 1522 1523 clid = tcm->tcm_parent; 1524 if (clid) { 1525 if (clid != TC_H_ROOT) { 1526 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) { 1527 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1528 if (!p) { 1529 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid"); 1530 return -ENOENT; 1531 } 1532 q = qdisc_leaf(p, clid); 1533 } else if (dev_ingress_queue(dev)) { 1534 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); 1535 } 1536 } else { 1537 q = rtnl_dereference(dev->qdisc); 1538 } 1539 if (!q) { 1540 NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device"); 1541 return -ENOENT; 1542 } 1543 1544 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) { 1545 NL_SET_ERR_MSG(extack, "Invalid handle"); 1546 return -EINVAL; 1547 } 1548 } else { 1549 q = qdisc_lookup(dev, tcm->tcm_handle); 1550 if (!q) { 1551 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle"); 1552 return -ENOENT; 1553 } 1554 } 1555 1556 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1557 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1558 return -EINVAL; 1559 } 1560 1561 if (n->nlmsg_type == RTM_DELQDISC) { 1562 if (!clid) { 1563 NL_SET_ERR_MSG(extack, "Classid cannot be zero"); 1564 return -EINVAL; 1565 } 1566 if (q->handle == 0) { 1567 NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero"); 1568 return -ENOENT; 1569 } 1570 err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack); 1571 if (err != 0) 1572 return err; 1573 } else { 1574 qdisc_get_notify(net, skb, n, clid, q, NULL); 1575 } 1576 return 0; 1577 } 1578 1579 static bool req_create_or_replace(struct nlmsghdr *n) 1580 { 1581 return (n->nlmsg_flags & NLM_F_CREATE && 1582 n->nlmsg_flags & NLM_F_REPLACE); 1583 } 1584 1585 static bool req_create_exclusive(struct nlmsghdr *n) 1586 { 1587 return (n->nlmsg_flags & NLM_F_CREATE && 1588 n->nlmsg_flags & NLM_F_EXCL); 1589 } 1590 1591 static bool req_change(struct nlmsghdr *n) 1592 { 1593 return (!(n->nlmsg_flags & NLM_F_CREATE) && 1594 !(n->nlmsg_flags & NLM_F_REPLACE) && 1595 !(n->nlmsg_flags & NLM_F_EXCL)); 1596 } 1597 1598 /* 1599 * Create/change qdisc. 1600 */ 1601 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, 1602 struct netlink_ext_ack *extack) 1603 { 1604 struct net *net = sock_net(skb->sk); 1605 struct tcmsg *tcm; 1606 struct nlattr *tca[TCA_MAX + 1]; 1607 struct net_device *dev; 1608 u32 clid; 1609 struct Qdisc *q, *p; 1610 int err; 1611 1612 replay: 1613 /* Reinit, just in case something touches this. */ 1614 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 1615 rtm_tca_policy, extack); 1616 if (err < 0) 1617 return err; 1618 1619 tcm = nlmsg_data(n); 1620 clid = tcm->tcm_parent; 1621 q = p = NULL; 1622 1623 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1624 if (!dev) 1625 return -ENODEV; 1626 1627 1628 if (clid) { 1629 if (clid != TC_H_ROOT) { 1630 if (clid != TC_H_INGRESS) { 1631 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1632 if (!p) { 1633 NL_SET_ERR_MSG(extack, "Failed to find specified qdisc"); 1634 return -ENOENT; 1635 } 1636 q = qdisc_leaf(p, clid); 1637 } else if (dev_ingress_queue_create(dev)) { 1638 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); 1639 } 1640 } else { 1641 q = rtnl_dereference(dev->qdisc); 1642 } 1643 1644 /* It may be default qdisc, ignore it */ 1645 if (q && q->handle == 0) 1646 q = NULL; 1647 1648 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) { 1649 if (tcm->tcm_handle) { 1650 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) { 1651 NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override"); 1652 return -EEXIST; 1653 } 1654 if (TC_H_MIN(tcm->tcm_handle)) { 1655 NL_SET_ERR_MSG(extack, "Invalid minor handle"); 1656 return -EINVAL; 1657 } 1658 q = qdisc_lookup(dev, tcm->tcm_handle); 1659 if (!q) 1660 goto create_n_graft; 1661 if (n->nlmsg_flags & NLM_F_EXCL) { 1662 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override"); 1663 return -EEXIST; 1664 } 1665 if (tca[TCA_KIND] && 1666 nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1667 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1668 return -EINVAL; 1669 } 1670 if (q->flags & TCQ_F_INGRESS) { 1671 NL_SET_ERR_MSG(extack, 1672 "Cannot regraft ingress or clsact Qdiscs"); 1673 return -EINVAL; 1674 } 1675 if (q == p || 1676 (p && check_loop(q, p, 0))) { 1677 NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected"); 1678 return -ELOOP; 1679 } 1680 if (clid == TC_H_INGRESS) { 1681 NL_SET_ERR_MSG(extack, "Ingress cannot graft directly"); 1682 return -EINVAL; 1683 } 1684 qdisc_refcount_inc(q); 1685 goto graft; 1686 } else { 1687 if (!q) 1688 goto create_n_graft; 1689 1690 /* This magic test requires explanation. 1691 * 1692 * We know, that some child q is already 1693 * attached to this parent and have choice: 1694 * 1) change it or 2) create/graft new one. 1695 * If the requested qdisc kind is different 1696 * than the existing one, then we choose graft. 1697 * If they are the same then this is "change" 1698 * operation - just let it fallthrough.. 1699 * 1700 * 1. We are allowed to create/graft only 1701 * if the request is explicitly stating 1702 * "please create if it doesn't exist". 1703 * 1704 * 2. If the request is to exclusive create 1705 * then the qdisc tcm_handle is not expected 1706 * to exist, so that we choose create/graft too. 1707 * 1708 * 3. The last case is when no flags are set. 1709 * This will happen when for example tc 1710 * utility issues a "change" command. 1711 * Alas, it is sort of hole in API, we 1712 * cannot decide what to do unambiguously. 1713 * For now we select create/graft. 1714 */ 1715 if (tca[TCA_KIND] && 1716 nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1717 if (req_create_or_replace(n) || 1718 req_create_exclusive(n)) 1719 goto create_n_graft; 1720 else if (req_change(n)) 1721 goto create_n_graft2; 1722 } 1723 } 1724 } 1725 } else { 1726 if (!tcm->tcm_handle) { 1727 NL_SET_ERR_MSG(extack, "Handle cannot be zero"); 1728 return -EINVAL; 1729 } 1730 q = qdisc_lookup(dev, tcm->tcm_handle); 1731 } 1732 1733 /* Change qdisc parameters */ 1734 if (!q) { 1735 NL_SET_ERR_MSG(extack, "Specified qdisc not found"); 1736 return -ENOENT; 1737 } 1738 if (n->nlmsg_flags & NLM_F_EXCL) { 1739 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify"); 1740 return -EEXIST; 1741 } 1742 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1743 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1744 return -EINVAL; 1745 } 1746 err = qdisc_change(q, tca, extack); 1747 if (err == 0) 1748 qdisc_notify(net, skb, n, clid, NULL, q, extack); 1749 return err; 1750 1751 create_n_graft: 1752 if (!(n->nlmsg_flags & NLM_F_CREATE)) { 1753 NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag"); 1754 return -ENOENT; 1755 } 1756 create_n_graft2: 1757 if (clid == TC_H_INGRESS) { 1758 if (dev_ingress_queue(dev)) { 1759 q = qdisc_create(dev, dev_ingress_queue(dev), 1760 tcm->tcm_parent, tcm->tcm_parent, 1761 tca, &err, extack); 1762 } else { 1763 NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device"); 1764 err = -ENOENT; 1765 } 1766 } else { 1767 struct netdev_queue *dev_queue; 1768 1769 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue) 1770 dev_queue = p->ops->cl_ops->select_queue(p, tcm); 1771 else if (p) 1772 dev_queue = p->dev_queue; 1773 else 1774 dev_queue = netdev_get_tx_queue(dev, 0); 1775 1776 q = qdisc_create(dev, dev_queue, 1777 tcm->tcm_parent, tcm->tcm_handle, 1778 tca, &err, extack); 1779 } 1780 if (q == NULL) { 1781 if (err == -EAGAIN) 1782 goto replay; 1783 return err; 1784 } 1785 1786 graft: 1787 err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack); 1788 if (err) { 1789 if (q) 1790 qdisc_put(q); 1791 return err; 1792 } 1793 1794 return 0; 1795 } 1796 1797 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb, 1798 struct netlink_callback *cb, 1799 int *q_idx_p, int s_q_idx, bool recur, 1800 bool dump_invisible) 1801 { 1802 int ret = 0, q_idx = *q_idx_p; 1803 struct Qdisc *q; 1804 int b; 1805 1806 if (!root) 1807 return 0; 1808 1809 q = root; 1810 if (q_idx < s_q_idx) { 1811 q_idx++; 1812 } else { 1813 if (!tc_qdisc_dump_ignore(q, dump_invisible) && 1814 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1815 cb->nlh->nlmsg_seq, NLM_F_MULTI, 1816 RTM_NEWQDISC, NULL) <= 0) 1817 goto done; 1818 q_idx++; 1819 } 1820 1821 /* If dumping singletons, there is no qdisc_dev(root) and the singleton 1822 * itself has already been dumped. 1823 * 1824 * If we've already dumped the top-level (ingress) qdisc above and the global 1825 * qdisc hashtable, we don't want to hit it again 1826 */ 1827 if (!qdisc_dev(root) || !recur) 1828 goto out; 1829 1830 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { 1831 if (q_idx < s_q_idx) { 1832 q_idx++; 1833 continue; 1834 } 1835 if (!tc_qdisc_dump_ignore(q, dump_invisible) && 1836 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1837 cb->nlh->nlmsg_seq, NLM_F_MULTI, 1838 RTM_NEWQDISC, NULL) <= 0) 1839 goto done; 1840 q_idx++; 1841 } 1842 1843 out: 1844 *q_idx_p = q_idx; 1845 return ret; 1846 done: 1847 ret = -1; 1848 goto out; 1849 } 1850 1851 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb) 1852 { 1853 struct net *net = sock_net(skb->sk); 1854 int idx, q_idx; 1855 int s_idx, s_q_idx; 1856 struct net_device *dev; 1857 const struct nlmsghdr *nlh = cb->nlh; 1858 struct nlattr *tca[TCA_MAX + 1]; 1859 int err; 1860 1861 s_idx = cb->args[0]; 1862 s_q_idx = q_idx = cb->args[1]; 1863 1864 idx = 0; 1865 ASSERT_RTNL(); 1866 1867 err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX, 1868 rtm_tca_policy, cb->extack); 1869 if (err < 0) 1870 return err; 1871 1872 for_each_netdev(net, dev) { 1873 struct netdev_queue *dev_queue; 1874 1875 if (idx < s_idx) 1876 goto cont; 1877 if (idx > s_idx) 1878 s_q_idx = 0; 1879 q_idx = 0; 1880 1881 if (tc_dump_qdisc_root(rtnl_dereference(dev->qdisc), 1882 skb, cb, &q_idx, s_q_idx, 1883 true, tca[TCA_DUMP_INVISIBLE]) < 0) 1884 goto done; 1885 1886 dev_queue = dev_ingress_queue(dev); 1887 if (dev_queue && 1888 tc_dump_qdisc_root(rtnl_dereference(dev_queue->qdisc_sleeping), 1889 skb, cb, &q_idx, s_q_idx, false, 1890 tca[TCA_DUMP_INVISIBLE]) < 0) 1891 goto done; 1892 1893 cont: 1894 idx++; 1895 } 1896 1897 done: 1898 cb->args[0] = idx; 1899 cb->args[1] = q_idx; 1900 1901 return skb->len; 1902 } 1903 1904 1905 1906 /************************************************ 1907 * Traffic classes manipulation. * 1908 ************************************************/ 1909 1910 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, 1911 unsigned long cl, u32 portid, u32 seq, u16 flags, 1912 int event, struct netlink_ext_ack *extack) 1913 { 1914 struct tcmsg *tcm; 1915 struct nlmsghdr *nlh; 1916 unsigned char *b = skb_tail_pointer(skb); 1917 struct gnet_dump d; 1918 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops; 1919 1920 cond_resched(); 1921 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 1922 if (!nlh) 1923 goto out_nlmsg_trim; 1924 tcm = nlmsg_data(nlh); 1925 tcm->tcm_family = AF_UNSPEC; 1926 tcm->tcm__pad1 = 0; 1927 tcm->tcm__pad2 = 0; 1928 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 1929 tcm->tcm_parent = q->handle; 1930 tcm->tcm_handle = q->handle; 1931 tcm->tcm_info = 0; 1932 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 1933 goto nla_put_failure; 1934 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0) 1935 goto nla_put_failure; 1936 1937 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 1938 NULL, &d, TCA_PAD) < 0) 1939 goto nla_put_failure; 1940 1941 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0) 1942 goto nla_put_failure; 1943 1944 if (gnet_stats_finish_copy(&d) < 0) 1945 goto nla_put_failure; 1946 1947 if (extack && extack->_msg && 1948 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg)) 1949 goto out_nlmsg_trim; 1950 1951 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 1952 1953 return skb->len; 1954 1955 out_nlmsg_trim: 1956 nla_put_failure: 1957 nlmsg_trim(skb, b); 1958 return -1; 1959 } 1960 1961 static int tclass_notify(struct net *net, struct sk_buff *oskb, 1962 struct nlmsghdr *n, struct Qdisc *q, 1963 unsigned long cl, int event, struct netlink_ext_ack *extack) 1964 { 1965 struct sk_buff *skb; 1966 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1967 1968 if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) 1969 return 0; 1970 1971 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1972 if (!skb) 1973 return -ENOBUFS; 1974 1975 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event, extack) < 0) { 1976 kfree_skb(skb); 1977 return -EINVAL; 1978 } 1979 1980 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1981 n->nlmsg_flags & NLM_F_ECHO); 1982 } 1983 1984 static int tclass_get_notify(struct net *net, struct sk_buff *oskb, 1985 struct nlmsghdr *n, struct Qdisc *q, 1986 unsigned long cl, struct netlink_ext_ack *extack) 1987 { 1988 struct sk_buff *skb; 1989 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1990 1991 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1992 if (!skb) 1993 return -ENOBUFS; 1994 1995 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, RTM_NEWTCLASS, 1996 extack) < 0) { 1997 kfree_skb(skb); 1998 return -EINVAL; 1999 } 2000 2001 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 2002 n->nlmsg_flags & NLM_F_ECHO); 2003 } 2004 2005 static int tclass_del_notify(struct net *net, 2006 const struct Qdisc_class_ops *cops, 2007 struct sk_buff *oskb, struct nlmsghdr *n, 2008 struct Qdisc *q, unsigned long cl, 2009 struct netlink_ext_ack *extack) 2010 { 2011 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 2012 struct sk_buff *skb; 2013 int err = 0; 2014 2015 if (!cops->delete) 2016 return -EOPNOTSUPP; 2017 2018 if (rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) { 2019 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2020 if (!skb) 2021 return -ENOBUFS; 2022 2023 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, 2024 RTM_DELTCLASS, extack) < 0) { 2025 kfree_skb(skb); 2026 return -EINVAL; 2027 } 2028 } else { 2029 skb = NULL; 2030 } 2031 2032 err = cops->delete(q, cl, extack); 2033 if (err) { 2034 kfree_skb(skb); 2035 return err; 2036 } 2037 2038 err = rtnetlink_maybe_send(skb, net, portid, RTNLGRP_TC, 2039 n->nlmsg_flags & NLM_F_ECHO); 2040 return err; 2041 } 2042 2043 #ifdef CONFIG_NET_CLS 2044 2045 struct tcf_bind_args { 2046 struct tcf_walker w; 2047 unsigned long base; 2048 unsigned long cl; 2049 u32 classid; 2050 }; 2051 2052 static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg) 2053 { 2054 struct tcf_bind_args *a = (void *)arg; 2055 2056 if (n && tp->ops->bind_class) { 2057 struct Qdisc *q = tcf_block_q(tp->chain->block); 2058 2059 sch_tree_lock(q); 2060 tp->ops->bind_class(n, a->classid, a->cl, q, a->base); 2061 sch_tree_unlock(q); 2062 } 2063 return 0; 2064 } 2065 2066 struct tc_bind_class_args { 2067 struct qdisc_walker w; 2068 unsigned long new_cl; 2069 u32 portid; 2070 u32 clid; 2071 }; 2072 2073 static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl, 2074 struct qdisc_walker *w) 2075 { 2076 struct tc_bind_class_args *a = (struct tc_bind_class_args *)w; 2077 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 2078 struct tcf_block *block; 2079 struct tcf_chain *chain; 2080 2081 block = cops->tcf_block(q, cl, NULL); 2082 if (!block) 2083 return 0; 2084 for (chain = tcf_get_next_chain(block, NULL); 2085 chain; 2086 chain = tcf_get_next_chain(block, chain)) { 2087 struct tcf_proto *tp; 2088 2089 for (tp = tcf_get_next_proto(chain, NULL); 2090 tp; tp = tcf_get_next_proto(chain, tp)) { 2091 struct tcf_bind_args arg = {}; 2092 2093 arg.w.fn = tcf_node_bind; 2094 arg.classid = a->clid; 2095 arg.base = cl; 2096 arg.cl = a->new_cl; 2097 tp->ops->walk(tp, &arg.w, true); 2098 } 2099 } 2100 2101 return 0; 2102 } 2103 2104 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, 2105 unsigned long new_cl) 2106 { 2107 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 2108 struct tc_bind_class_args args = {}; 2109 2110 if (!cops->tcf_block) 2111 return; 2112 args.portid = portid; 2113 args.clid = clid; 2114 args.new_cl = new_cl; 2115 args.w.fn = tc_bind_class_walker; 2116 q->ops->cl_ops->walk(q, &args.w); 2117 } 2118 2119 #else 2120 2121 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, 2122 unsigned long new_cl) 2123 { 2124 } 2125 2126 #endif 2127 2128 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, 2129 struct netlink_ext_ack *extack) 2130 { 2131 struct net *net = sock_net(skb->sk); 2132 struct tcmsg *tcm = nlmsg_data(n); 2133 struct nlattr *tca[TCA_MAX + 1]; 2134 struct net_device *dev; 2135 struct Qdisc *q = NULL; 2136 const struct Qdisc_class_ops *cops; 2137 unsigned long cl = 0; 2138 unsigned long new_cl; 2139 u32 portid; 2140 u32 clid; 2141 u32 qid; 2142 int err; 2143 2144 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 2145 rtm_tca_policy, extack); 2146 if (err < 0) 2147 return err; 2148 2149 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 2150 if (!dev) 2151 return -ENODEV; 2152 2153 /* 2154 parent == TC_H_UNSPEC - unspecified parent. 2155 parent == TC_H_ROOT - class is root, which has no parent. 2156 parent == X:0 - parent is root class. 2157 parent == X:Y - parent is a node in hierarchy. 2158 parent == 0:Y - parent is X:Y, where X:0 is qdisc. 2159 2160 handle == 0:0 - generate handle from kernel pool. 2161 handle == 0:Y - class is X:Y, where X:0 is qdisc. 2162 handle == X:Y - clear. 2163 handle == X:0 - root class. 2164 */ 2165 2166 /* Step 1. Determine qdisc handle X:0 */ 2167 2168 portid = tcm->tcm_parent; 2169 clid = tcm->tcm_handle; 2170 qid = TC_H_MAJ(clid); 2171 2172 if (portid != TC_H_ROOT) { 2173 u32 qid1 = TC_H_MAJ(portid); 2174 2175 if (qid && qid1) { 2176 /* If both majors are known, they must be identical. */ 2177 if (qid != qid1) 2178 return -EINVAL; 2179 } else if (qid1) { 2180 qid = qid1; 2181 } else if (qid == 0) 2182 qid = rtnl_dereference(dev->qdisc)->handle; 2183 2184 /* Now qid is genuine qdisc handle consistent 2185 * both with parent and child. 2186 * 2187 * TC_H_MAJ(portid) still may be unspecified, complete it now. 2188 */ 2189 if (portid) 2190 portid = TC_H_MAKE(qid, portid); 2191 } else { 2192 if (qid == 0) 2193 qid = rtnl_dereference(dev->qdisc)->handle; 2194 } 2195 2196 /* OK. Locate qdisc */ 2197 q = qdisc_lookup(dev, qid); 2198 if (!q) 2199 return -ENOENT; 2200 2201 /* An check that it supports classes */ 2202 cops = q->ops->cl_ops; 2203 if (cops == NULL) 2204 return -EINVAL; 2205 2206 /* Now try to get class */ 2207 if (clid == 0) { 2208 if (portid == TC_H_ROOT) 2209 clid = qid; 2210 } else 2211 clid = TC_H_MAKE(qid, clid); 2212 2213 if (clid) 2214 cl = cops->find(q, clid); 2215 2216 if (cl == 0) { 2217 err = -ENOENT; 2218 if (n->nlmsg_type != RTM_NEWTCLASS || 2219 !(n->nlmsg_flags & NLM_F_CREATE)) 2220 goto out; 2221 } else { 2222 switch (n->nlmsg_type) { 2223 case RTM_NEWTCLASS: 2224 err = -EEXIST; 2225 if (n->nlmsg_flags & NLM_F_EXCL) 2226 goto out; 2227 break; 2228 case RTM_DELTCLASS: 2229 err = tclass_del_notify(net, cops, skb, n, q, cl, extack); 2230 /* Unbind the class with flilters with 0 */ 2231 tc_bind_tclass(q, portid, clid, 0); 2232 goto out; 2233 case RTM_GETTCLASS: 2234 err = tclass_get_notify(net, skb, n, q, cl, extack); 2235 goto out; 2236 default: 2237 err = -EINVAL; 2238 goto out; 2239 } 2240 } 2241 2242 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) { 2243 NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes"); 2244 return -EOPNOTSUPP; 2245 } 2246 2247 new_cl = cl; 2248 err = -EOPNOTSUPP; 2249 if (cops->change) 2250 err = cops->change(q, clid, portid, tca, &new_cl, extack); 2251 if (err == 0) { 2252 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS, extack); 2253 /* We just create a new class, need to do reverse binding. */ 2254 if (cl != new_cl) 2255 tc_bind_tclass(q, portid, clid, new_cl); 2256 } 2257 out: 2258 return err; 2259 } 2260 2261 struct qdisc_dump_args { 2262 struct qdisc_walker w; 2263 struct sk_buff *skb; 2264 struct netlink_callback *cb; 2265 }; 2266 2267 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, 2268 struct qdisc_walker *arg) 2269 { 2270 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg; 2271 2272 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid, 2273 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, 2274 RTM_NEWTCLASS, NULL); 2275 } 2276 2277 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb, 2278 struct tcmsg *tcm, struct netlink_callback *cb, 2279 int *t_p, int s_t) 2280 { 2281 struct qdisc_dump_args arg; 2282 2283 if (tc_qdisc_dump_ignore(q, false) || 2284 *t_p < s_t || !q->ops->cl_ops || 2285 (tcm->tcm_parent && 2286 TC_H_MAJ(tcm->tcm_parent) != q->handle)) { 2287 (*t_p)++; 2288 return 0; 2289 } 2290 if (*t_p > s_t) 2291 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); 2292 arg.w.fn = qdisc_class_dump; 2293 arg.skb = skb; 2294 arg.cb = cb; 2295 arg.w.stop = 0; 2296 arg.w.skip = cb->args[1]; 2297 arg.w.count = 0; 2298 q->ops->cl_ops->walk(q, &arg.w); 2299 cb->args[1] = arg.w.count; 2300 if (arg.w.stop) 2301 return -1; 2302 (*t_p)++; 2303 return 0; 2304 } 2305 2306 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb, 2307 struct tcmsg *tcm, struct netlink_callback *cb, 2308 int *t_p, int s_t, bool recur) 2309 { 2310 struct Qdisc *q; 2311 int b; 2312 2313 if (!root) 2314 return 0; 2315 2316 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0) 2317 return -1; 2318 2319 if (!qdisc_dev(root) || !recur) 2320 return 0; 2321 2322 if (tcm->tcm_parent) { 2323 q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent)); 2324 if (q && q != root && 2325 tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 2326 return -1; 2327 return 0; 2328 } 2329 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { 2330 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 2331 return -1; 2332 } 2333 2334 return 0; 2335 } 2336 2337 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb) 2338 { 2339 struct tcmsg *tcm = nlmsg_data(cb->nlh); 2340 struct net *net = sock_net(skb->sk); 2341 struct netdev_queue *dev_queue; 2342 struct net_device *dev; 2343 int t, s_t; 2344 2345 if (nlmsg_len(cb->nlh) < sizeof(*tcm)) 2346 return 0; 2347 dev = dev_get_by_index(net, tcm->tcm_ifindex); 2348 if (!dev) 2349 return 0; 2350 2351 s_t = cb->args[0]; 2352 t = 0; 2353 2354 if (tc_dump_tclass_root(rtnl_dereference(dev->qdisc), 2355 skb, tcm, cb, &t, s_t, true) < 0) 2356 goto done; 2357 2358 dev_queue = dev_ingress_queue(dev); 2359 if (dev_queue && 2360 tc_dump_tclass_root(rtnl_dereference(dev_queue->qdisc_sleeping), 2361 skb, tcm, cb, &t, s_t, false) < 0) 2362 goto done; 2363 2364 done: 2365 cb->args[0] = t; 2366 2367 dev_put(dev); 2368 return skb->len; 2369 } 2370 2371 #ifdef CONFIG_PROC_FS 2372 static int psched_show(struct seq_file *seq, void *v) 2373 { 2374 seq_printf(seq, "%08x %08x %08x %08x\n", 2375 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1), 2376 1000000, 2377 (u32)NSEC_PER_SEC / hrtimer_resolution); 2378 2379 return 0; 2380 } 2381 2382 static int __net_init psched_net_init(struct net *net) 2383 { 2384 struct proc_dir_entry *e; 2385 2386 e = proc_create_single("psched", 0, net->proc_net, psched_show); 2387 if (e == NULL) 2388 return -ENOMEM; 2389 2390 return 0; 2391 } 2392 2393 static void __net_exit psched_net_exit(struct net *net) 2394 { 2395 remove_proc_entry("psched", net->proc_net); 2396 } 2397 #else 2398 static int __net_init psched_net_init(struct net *net) 2399 { 2400 return 0; 2401 } 2402 2403 static void __net_exit psched_net_exit(struct net *net) 2404 { 2405 } 2406 #endif 2407 2408 static struct pernet_operations psched_net_ops = { 2409 .init = psched_net_init, 2410 .exit = psched_net_exit, 2411 }; 2412 2413 #if IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) 2414 DEFINE_STATIC_KEY_FALSE(tc_skip_wrapper); 2415 #endif 2416 2417 static int __init pktsched_init(void) 2418 { 2419 int err; 2420 2421 err = register_pernet_subsys(&psched_net_ops); 2422 if (err) { 2423 pr_err("pktsched_init: " 2424 "cannot initialize per netns operations\n"); 2425 return err; 2426 } 2427 2428 register_qdisc(&pfifo_fast_ops); 2429 register_qdisc(&pfifo_qdisc_ops); 2430 register_qdisc(&bfifo_qdisc_ops); 2431 register_qdisc(&pfifo_head_drop_qdisc_ops); 2432 register_qdisc(&mq_qdisc_ops); 2433 register_qdisc(&noqueue_qdisc_ops); 2434 2435 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, 0); 2436 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, 0); 2437 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, 2438 0); 2439 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, 0); 2440 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, 0); 2441 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, 2442 0); 2443 2444 tc_wrapper_init(); 2445 2446 return 0; 2447 } 2448 2449 subsys_initcall(pktsched_init); 2450