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 } 596 597 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc) 598 { 599 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) { 600 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n", 601 txt, qdisc->ops->id, qdisc->handle >> 16); 602 qdisc->flags |= TCQ_F_WARN_NONWC; 603 } 604 } 605 EXPORT_SYMBOL(qdisc_warn_nonwc); 606 607 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer) 608 { 609 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog, 610 timer); 611 612 rcu_read_lock(); 613 __netif_schedule(qdisc_root(wd->qdisc)); 614 rcu_read_unlock(); 615 616 return HRTIMER_NORESTART; 617 } 618 619 void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc, 620 clockid_t clockid) 621 { 622 hrtimer_init(&wd->timer, clockid, HRTIMER_MODE_ABS_PINNED); 623 wd->timer.function = qdisc_watchdog; 624 wd->qdisc = qdisc; 625 } 626 EXPORT_SYMBOL(qdisc_watchdog_init_clockid); 627 628 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc) 629 { 630 qdisc_watchdog_init_clockid(wd, qdisc, CLOCK_MONOTONIC); 631 } 632 EXPORT_SYMBOL(qdisc_watchdog_init); 633 634 void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires, 635 u64 delta_ns) 636 { 637 bool deactivated; 638 639 rcu_read_lock(); 640 deactivated = test_bit(__QDISC_STATE_DEACTIVATED, 641 &qdisc_root_sleeping(wd->qdisc)->state); 642 rcu_read_unlock(); 643 if (deactivated) 644 return; 645 646 if (hrtimer_is_queued(&wd->timer)) { 647 u64 softexpires; 648 649 softexpires = ktime_to_ns(hrtimer_get_softexpires(&wd->timer)); 650 /* If timer is already set in [expires, expires + delta_ns], 651 * do not reprogram it. 652 */ 653 if (softexpires - expires <= delta_ns) 654 return; 655 } 656 657 hrtimer_start_range_ns(&wd->timer, 658 ns_to_ktime(expires), 659 delta_ns, 660 HRTIMER_MODE_ABS_PINNED); 661 } 662 EXPORT_SYMBOL(qdisc_watchdog_schedule_range_ns); 663 664 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd) 665 { 666 hrtimer_cancel(&wd->timer); 667 } 668 EXPORT_SYMBOL(qdisc_watchdog_cancel); 669 670 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n) 671 { 672 struct hlist_head *h; 673 unsigned int i; 674 675 h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL); 676 677 if (h != NULL) { 678 for (i = 0; i < n; i++) 679 INIT_HLIST_HEAD(&h[i]); 680 } 681 return h; 682 } 683 684 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash) 685 { 686 struct Qdisc_class_common *cl; 687 struct hlist_node *next; 688 struct hlist_head *nhash, *ohash; 689 unsigned int nsize, nmask, osize; 690 unsigned int i, h; 691 692 /* Rehash when load factor exceeds 0.75 */ 693 if (clhash->hashelems * 4 <= clhash->hashsize * 3) 694 return; 695 nsize = clhash->hashsize * 2; 696 nmask = nsize - 1; 697 nhash = qdisc_class_hash_alloc(nsize); 698 if (nhash == NULL) 699 return; 700 701 ohash = clhash->hash; 702 osize = clhash->hashsize; 703 704 sch_tree_lock(sch); 705 for (i = 0; i < osize; i++) { 706 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) { 707 h = qdisc_class_hash(cl->classid, nmask); 708 hlist_add_head(&cl->hnode, &nhash[h]); 709 } 710 } 711 clhash->hash = nhash; 712 clhash->hashsize = nsize; 713 clhash->hashmask = nmask; 714 sch_tree_unlock(sch); 715 716 kvfree(ohash); 717 } 718 EXPORT_SYMBOL(qdisc_class_hash_grow); 719 720 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash) 721 { 722 unsigned int size = 4; 723 724 clhash->hash = qdisc_class_hash_alloc(size); 725 if (!clhash->hash) 726 return -ENOMEM; 727 clhash->hashsize = size; 728 clhash->hashmask = size - 1; 729 clhash->hashelems = 0; 730 return 0; 731 } 732 EXPORT_SYMBOL(qdisc_class_hash_init); 733 734 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash) 735 { 736 kvfree(clhash->hash); 737 } 738 EXPORT_SYMBOL(qdisc_class_hash_destroy); 739 740 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash, 741 struct Qdisc_class_common *cl) 742 { 743 unsigned int h; 744 745 INIT_HLIST_NODE(&cl->hnode); 746 h = qdisc_class_hash(cl->classid, clhash->hashmask); 747 hlist_add_head(&cl->hnode, &clhash->hash[h]); 748 clhash->hashelems++; 749 } 750 EXPORT_SYMBOL(qdisc_class_hash_insert); 751 752 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash, 753 struct Qdisc_class_common *cl) 754 { 755 hlist_del(&cl->hnode); 756 clhash->hashelems--; 757 } 758 EXPORT_SYMBOL(qdisc_class_hash_remove); 759 760 /* Allocate an unique handle from space managed by kernel 761 * Possible range is [8000-FFFF]:0000 (0x8000 values) 762 */ 763 static u32 qdisc_alloc_handle(struct net_device *dev) 764 { 765 int i = 0x8000; 766 static u32 autohandle = TC_H_MAKE(0x80000000U, 0); 767 768 do { 769 autohandle += TC_H_MAKE(0x10000U, 0); 770 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0)) 771 autohandle = TC_H_MAKE(0x80000000U, 0); 772 if (!qdisc_lookup(dev, autohandle)) 773 return autohandle; 774 cond_resched(); 775 } while (--i > 0); 776 777 return 0; 778 } 779 780 void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len) 781 { 782 bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED; 783 const struct Qdisc_class_ops *cops; 784 unsigned long cl; 785 u32 parentid; 786 bool notify; 787 int drops; 788 789 if (n == 0 && len == 0) 790 return; 791 drops = max_t(int, n, 0); 792 rcu_read_lock(); 793 while ((parentid = sch->parent)) { 794 if (parentid == TC_H_ROOT) 795 break; 796 797 if (sch->flags & TCQ_F_NOPARENT) 798 break; 799 /* Notify parent qdisc only if child qdisc becomes empty. 800 * 801 * If child was empty even before update then backlog 802 * counter is screwed and we skip notification because 803 * parent class is already passive. 804 * 805 * If the original child was offloaded then it is allowed 806 * to be seem as empty, so the parent is notified anyway. 807 */ 808 notify = !sch->q.qlen && !WARN_ON_ONCE(!n && 809 !qdisc_is_offloaded); 810 /* TODO: perform the search on a per txq basis */ 811 sch = qdisc_lookup_rcu(qdisc_dev(sch), TC_H_MAJ(parentid)); 812 if (sch == NULL) { 813 WARN_ON_ONCE(parentid != TC_H_ROOT); 814 break; 815 } 816 cops = sch->ops->cl_ops; 817 if (notify && cops->qlen_notify) { 818 cl = cops->find(sch, parentid); 819 cops->qlen_notify(sch, cl); 820 } 821 sch->q.qlen -= n; 822 sch->qstats.backlog -= len; 823 __qdisc_qstats_drop(sch, drops); 824 } 825 rcu_read_unlock(); 826 } 827 EXPORT_SYMBOL(qdisc_tree_reduce_backlog); 828 829 int qdisc_offload_dump_helper(struct Qdisc *sch, enum tc_setup_type type, 830 void *type_data) 831 { 832 struct net_device *dev = qdisc_dev(sch); 833 int err; 834 835 sch->flags &= ~TCQ_F_OFFLOADED; 836 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) 837 return 0; 838 839 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data); 840 if (err == -EOPNOTSUPP) 841 return 0; 842 843 if (!err) 844 sch->flags |= TCQ_F_OFFLOADED; 845 846 return err; 847 } 848 EXPORT_SYMBOL(qdisc_offload_dump_helper); 849 850 void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch, 851 struct Qdisc *new, struct Qdisc *old, 852 enum tc_setup_type type, void *type_data, 853 struct netlink_ext_ack *extack) 854 { 855 bool any_qdisc_is_offloaded; 856 int err; 857 858 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) 859 return; 860 861 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data); 862 863 /* Don't report error if the graft is part of destroy operation. */ 864 if (!err || !new || new == &noop_qdisc) 865 return; 866 867 /* Don't report error if the parent, the old child and the new 868 * one are not offloaded. 869 */ 870 any_qdisc_is_offloaded = new->flags & TCQ_F_OFFLOADED; 871 any_qdisc_is_offloaded |= sch && sch->flags & TCQ_F_OFFLOADED; 872 any_qdisc_is_offloaded |= old && old->flags & TCQ_F_OFFLOADED; 873 874 if (any_qdisc_is_offloaded) 875 NL_SET_ERR_MSG(extack, "Offloading graft operation failed."); 876 } 877 EXPORT_SYMBOL(qdisc_offload_graft_helper); 878 879 void qdisc_offload_query_caps(struct net_device *dev, 880 enum tc_setup_type type, 881 void *caps, size_t caps_len) 882 { 883 const struct net_device_ops *ops = dev->netdev_ops; 884 struct tc_query_caps_base base = { 885 .type = type, 886 .caps = caps, 887 }; 888 889 memset(caps, 0, caps_len); 890 891 if (ops->ndo_setup_tc) 892 ops->ndo_setup_tc(dev, TC_QUERY_CAPS, &base); 893 } 894 EXPORT_SYMBOL(qdisc_offload_query_caps); 895 896 static void qdisc_offload_graft_root(struct net_device *dev, 897 struct Qdisc *new, struct Qdisc *old, 898 struct netlink_ext_ack *extack) 899 { 900 struct tc_root_qopt_offload graft_offload = { 901 .command = TC_ROOT_GRAFT, 902 .handle = new ? new->handle : 0, 903 .ingress = (new && new->flags & TCQ_F_INGRESS) || 904 (old && old->flags & TCQ_F_INGRESS), 905 }; 906 907 qdisc_offload_graft_helper(dev, NULL, new, old, 908 TC_SETUP_ROOT_QDISC, &graft_offload, extack); 909 } 910 911 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid, 912 u32 portid, u32 seq, u16 flags, int event, 913 struct netlink_ext_ack *extack) 914 { 915 struct gnet_stats_basic_sync __percpu *cpu_bstats = NULL; 916 struct gnet_stats_queue __percpu *cpu_qstats = NULL; 917 struct tcmsg *tcm; 918 struct nlmsghdr *nlh; 919 unsigned char *b = skb_tail_pointer(skb); 920 struct gnet_dump d; 921 struct qdisc_size_table *stab; 922 u32 block_index; 923 __u32 qlen; 924 925 cond_resched(); 926 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 927 if (!nlh) 928 goto out_nlmsg_trim; 929 tcm = nlmsg_data(nlh); 930 tcm->tcm_family = AF_UNSPEC; 931 tcm->tcm__pad1 = 0; 932 tcm->tcm__pad2 = 0; 933 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 934 tcm->tcm_parent = clid; 935 tcm->tcm_handle = q->handle; 936 tcm->tcm_info = refcount_read(&q->refcnt); 937 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 938 goto nla_put_failure; 939 if (q->ops->ingress_block_get) { 940 block_index = q->ops->ingress_block_get(q); 941 if (block_index && 942 nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index)) 943 goto nla_put_failure; 944 } 945 if (q->ops->egress_block_get) { 946 block_index = q->ops->egress_block_get(q); 947 if (block_index && 948 nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index)) 949 goto nla_put_failure; 950 } 951 if (q->ops->dump && q->ops->dump(q, skb) < 0) 952 goto nla_put_failure; 953 if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED))) 954 goto nla_put_failure; 955 qlen = qdisc_qlen_sum(q); 956 957 stab = rtnl_dereference(q->stab); 958 if (stab && qdisc_dump_stab(skb, stab) < 0) 959 goto nla_put_failure; 960 961 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 962 NULL, &d, TCA_PAD) < 0) 963 goto nla_put_failure; 964 965 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0) 966 goto nla_put_failure; 967 968 if (qdisc_is_percpu_stats(q)) { 969 cpu_bstats = q->cpu_bstats; 970 cpu_qstats = q->cpu_qstats; 971 } 972 973 if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats, true) < 0 || 974 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 || 975 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0) 976 goto nla_put_failure; 977 978 if (gnet_stats_finish_copy(&d) < 0) 979 goto nla_put_failure; 980 981 if (extack && extack->_msg && 982 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg)) 983 goto out_nlmsg_trim; 984 985 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 986 987 return skb->len; 988 989 out_nlmsg_trim: 990 nla_put_failure: 991 nlmsg_trim(skb, b); 992 return -1; 993 } 994 995 static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible) 996 { 997 if (q->flags & TCQ_F_BUILTIN) 998 return true; 999 if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible) 1000 return true; 1001 1002 return false; 1003 } 1004 1005 static int qdisc_get_notify(struct net *net, struct sk_buff *oskb, 1006 struct nlmsghdr *n, u32 clid, struct Qdisc *q, 1007 struct netlink_ext_ack *extack) 1008 { 1009 struct sk_buff *skb; 1010 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1011 1012 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1013 if (!skb) 1014 return -ENOBUFS; 1015 1016 if (!tc_qdisc_dump_ignore(q, false)) { 1017 if (tc_fill_qdisc(skb, q, clid, portid, n->nlmsg_seq, 0, 1018 RTM_NEWQDISC, extack) < 0) 1019 goto err_out; 1020 } 1021 1022 if (skb->len) 1023 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1024 n->nlmsg_flags & NLM_F_ECHO); 1025 1026 err_out: 1027 kfree_skb(skb); 1028 return -EINVAL; 1029 } 1030 1031 static int qdisc_notify(struct net *net, struct sk_buff *oskb, 1032 struct nlmsghdr *n, u32 clid, 1033 struct Qdisc *old, struct Qdisc *new, 1034 struct netlink_ext_ack *extack) 1035 { 1036 struct sk_buff *skb; 1037 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1038 1039 if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) 1040 return 0; 1041 1042 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1043 if (!skb) 1044 return -ENOBUFS; 1045 1046 if (old && !tc_qdisc_dump_ignore(old, false)) { 1047 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq, 1048 0, RTM_DELQDISC, extack) < 0) 1049 goto err_out; 1050 } 1051 if (new && !tc_qdisc_dump_ignore(new, false)) { 1052 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq, 1053 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC, extack) < 0) 1054 goto err_out; 1055 } 1056 1057 if (skb->len) 1058 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1059 n->nlmsg_flags & NLM_F_ECHO); 1060 1061 err_out: 1062 kfree_skb(skb); 1063 return -EINVAL; 1064 } 1065 1066 static void notify_and_destroy(struct net *net, struct sk_buff *skb, 1067 struct nlmsghdr *n, u32 clid, 1068 struct Qdisc *old, struct Qdisc *new, 1069 struct netlink_ext_ack *extack) 1070 { 1071 if (new || old) 1072 qdisc_notify(net, skb, n, clid, old, new, extack); 1073 1074 if (old) 1075 qdisc_put(old); 1076 } 1077 1078 static void qdisc_clear_nolock(struct Qdisc *sch) 1079 { 1080 sch->flags &= ~TCQ_F_NOLOCK; 1081 if (!(sch->flags & TCQ_F_CPUSTATS)) 1082 return; 1083 1084 free_percpu(sch->cpu_bstats); 1085 free_percpu(sch->cpu_qstats); 1086 sch->cpu_bstats = NULL; 1087 sch->cpu_qstats = NULL; 1088 sch->flags &= ~TCQ_F_CPUSTATS; 1089 } 1090 1091 /* Graft qdisc "new" to class "classid" of qdisc "parent" or 1092 * to device "dev". 1093 * 1094 * When appropriate send a netlink notification using 'skb' 1095 * and "n". 1096 * 1097 * On success, destroy old qdisc. 1098 */ 1099 1100 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent, 1101 struct sk_buff *skb, struct nlmsghdr *n, u32 classid, 1102 struct Qdisc *new, struct Qdisc *old, 1103 struct netlink_ext_ack *extack) 1104 { 1105 struct Qdisc *q = old; 1106 struct net *net = dev_net(dev); 1107 1108 if (parent == NULL) { 1109 unsigned int i, num_q, ingress; 1110 struct netdev_queue *dev_queue; 1111 1112 ingress = 0; 1113 num_q = dev->num_tx_queues; 1114 if ((q && q->flags & TCQ_F_INGRESS) || 1115 (new && new->flags & TCQ_F_INGRESS)) { 1116 ingress = 1; 1117 dev_queue = dev_ingress_queue(dev); 1118 if (!dev_queue) { 1119 NL_SET_ERR_MSG(extack, "Device does not have an ingress queue"); 1120 return -ENOENT; 1121 } 1122 1123 q = rtnl_dereference(dev_queue->qdisc_sleeping); 1124 1125 /* This is the counterpart of that qdisc_refcount_inc_nz() call in 1126 * __tcf_qdisc_find() for filter requests. 1127 */ 1128 if (!qdisc_refcount_dec_if_one(q)) { 1129 NL_SET_ERR_MSG(extack, 1130 "Current ingress or clsact Qdisc has ongoing filter requests"); 1131 return -EBUSY; 1132 } 1133 } 1134 1135 if (dev->flags & IFF_UP) 1136 dev_deactivate(dev); 1137 1138 qdisc_offload_graft_root(dev, new, old, extack); 1139 1140 if (new && new->ops->attach && !ingress) 1141 goto skip; 1142 1143 if (!ingress) { 1144 for (i = 0; i < num_q; i++) { 1145 dev_queue = netdev_get_tx_queue(dev, i); 1146 old = dev_graft_qdisc(dev_queue, new); 1147 1148 if (new && i > 0) 1149 qdisc_refcount_inc(new); 1150 qdisc_put(old); 1151 } 1152 } else { 1153 old = dev_graft_qdisc(dev_queue, NULL); 1154 1155 /* {ingress,clsact}_destroy() @old before grafting @new to avoid 1156 * unprotected concurrent accesses to net_device::miniq_{in,e}gress 1157 * pointer(s) in mini_qdisc_pair_swap(). 1158 */ 1159 qdisc_notify(net, skb, n, classid, old, new, extack); 1160 qdisc_destroy(old); 1161 1162 dev_graft_qdisc(dev_queue, new); 1163 } 1164 1165 skip: 1166 if (!ingress) { 1167 old = rtnl_dereference(dev->qdisc); 1168 if (new && !new->ops->attach) 1169 qdisc_refcount_inc(new); 1170 rcu_assign_pointer(dev->qdisc, new ? : &noop_qdisc); 1171 1172 notify_and_destroy(net, skb, n, classid, old, new, extack); 1173 1174 if (new && new->ops->attach) 1175 new->ops->attach(new); 1176 } 1177 1178 if (dev->flags & IFF_UP) 1179 dev_activate(dev); 1180 } else { 1181 const struct Qdisc_class_ops *cops = parent->ops->cl_ops; 1182 unsigned long cl; 1183 int err; 1184 1185 /* Only support running class lockless if parent is lockless */ 1186 if (new && (new->flags & TCQ_F_NOLOCK) && !(parent->flags & TCQ_F_NOLOCK)) 1187 qdisc_clear_nolock(new); 1188 1189 if (!cops || !cops->graft) 1190 return -EOPNOTSUPP; 1191 1192 cl = cops->find(parent, classid); 1193 if (!cl) { 1194 NL_SET_ERR_MSG(extack, "Specified class not found"); 1195 return -ENOENT; 1196 } 1197 1198 if (new && new->ops == &noqueue_qdisc_ops) { 1199 NL_SET_ERR_MSG(extack, "Cannot assign noqueue to a class"); 1200 return -EINVAL; 1201 } 1202 1203 if (new && 1204 !(parent->flags & TCQ_F_MQROOT) && 1205 rcu_access_pointer(new->stab)) { 1206 NL_SET_ERR_MSG(extack, "STAB not supported on a non root"); 1207 return -EINVAL; 1208 } 1209 err = cops->graft(parent, cl, new, &old, extack); 1210 if (err) 1211 return err; 1212 notify_and_destroy(net, skb, n, classid, old, new, extack); 1213 } 1214 return 0; 1215 } 1216 1217 static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca, 1218 struct netlink_ext_ack *extack) 1219 { 1220 u32 block_index; 1221 1222 if (tca[TCA_INGRESS_BLOCK]) { 1223 block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]); 1224 1225 if (!block_index) { 1226 NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0"); 1227 return -EINVAL; 1228 } 1229 if (!sch->ops->ingress_block_set) { 1230 NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported"); 1231 return -EOPNOTSUPP; 1232 } 1233 sch->ops->ingress_block_set(sch, block_index); 1234 } 1235 if (tca[TCA_EGRESS_BLOCK]) { 1236 block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]); 1237 1238 if (!block_index) { 1239 NL_SET_ERR_MSG(extack, "Egress block index cannot be 0"); 1240 return -EINVAL; 1241 } 1242 if (!sch->ops->egress_block_set) { 1243 NL_SET_ERR_MSG(extack, "Egress block sharing is not supported"); 1244 return -EOPNOTSUPP; 1245 } 1246 sch->ops->egress_block_set(sch, block_index); 1247 } 1248 return 0; 1249 } 1250 1251 /* 1252 Allocate and initialize new qdisc. 1253 1254 Parameters are passed via opt. 1255 */ 1256 1257 static struct Qdisc *qdisc_create(struct net_device *dev, 1258 struct netdev_queue *dev_queue, 1259 u32 parent, u32 handle, 1260 struct nlattr **tca, int *errp, 1261 struct netlink_ext_ack *extack) 1262 { 1263 int err; 1264 struct nlattr *kind = tca[TCA_KIND]; 1265 struct Qdisc *sch; 1266 struct Qdisc_ops *ops; 1267 struct qdisc_size_table *stab; 1268 1269 ops = qdisc_lookup_ops(kind); 1270 #ifdef CONFIG_MODULES 1271 if (ops == NULL && kind != NULL) { 1272 char name[IFNAMSIZ]; 1273 if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) { 1274 /* We dropped the RTNL semaphore in order to 1275 * perform the module load. So, even if we 1276 * succeeded in loading the module we have to 1277 * tell the caller to replay the request. We 1278 * indicate this using -EAGAIN. 1279 * We replay the request because the device may 1280 * go away in the mean time. 1281 */ 1282 rtnl_unlock(); 1283 request_module(NET_SCH_ALIAS_PREFIX "%s", name); 1284 rtnl_lock(); 1285 ops = qdisc_lookup_ops(kind); 1286 if (ops != NULL) { 1287 /* We will try again qdisc_lookup_ops, 1288 * so don't keep a reference. 1289 */ 1290 module_put(ops->owner); 1291 err = -EAGAIN; 1292 goto err_out; 1293 } 1294 } 1295 } 1296 #endif 1297 1298 err = -ENOENT; 1299 if (!ops) { 1300 NL_SET_ERR_MSG(extack, "Specified qdisc kind is unknown"); 1301 goto err_out; 1302 } 1303 1304 sch = qdisc_alloc(dev_queue, ops, extack); 1305 if (IS_ERR(sch)) { 1306 err = PTR_ERR(sch); 1307 goto err_out2; 1308 } 1309 1310 sch->parent = parent; 1311 1312 if (handle == TC_H_INGRESS) { 1313 if (!(sch->flags & TCQ_F_INGRESS)) { 1314 NL_SET_ERR_MSG(extack, 1315 "Specified parent ID is reserved for ingress and clsact Qdiscs"); 1316 err = -EINVAL; 1317 goto err_out3; 1318 } 1319 handle = TC_H_MAKE(TC_H_INGRESS, 0); 1320 } else { 1321 if (handle == 0) { 1322 handle = qdisc_alloc_handle(dev); 1323 if (handle == 0) { 1324 NL_SET_ERR_MSG(extack, "Maximum number of qdisc handles was exceeded"); 1325 err = -ENOSPC; 1326 goto err_out3; 1327 } 1328 } 1329 if (!netif_is_multiqueue(dev)) 1330 sch->flags |= TCQ_F_ONETXQUEUE; 1331 } 1332 1333 sch->handle = handle; 1334 1335 /* This exist to keep backward compatible with a userspace 1336 * loophole, what allowed userspace to get IFF_NO_QUEUE 1337 * facility on older kernels by setting tx_queue_len=0 (prior 1338 * to qdisc init), and then forgot to reinit tx_queue_len 1339 * before again attaching a qdisc. 1340 */ 1341 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) { 1342 WRITE_ONCE(dev->tx_queue_len, DEFAULT_TX_QUEUE_LEN); 1343 netdev_info(dev, "Caught tx_queue_len zero misconfig\n"); 1344 } 1345 1346 err = qdisc_block_indexes_set(sch, tca, extack); 1347 if (err) 1348 goto err_out3; 1349 1350 if (tca[TCA_STAB]) { 1351 stab = qdisc_get_stab(tca[TCA_STAB], extack); 1352 if (IS_ERR(stab)) { 1353 err = PTR_ERR(stab); 1354 goto err_out3; 1355 } 1356 rcu_assign_pointer(sch->stab, stab); 1357 } 1358 1359 if (ops->init) { 1360 err = ops->init(sch, tca[TCA_OPTIONS], extack); 1361 if (err != 0) 1362 goto err_out4; 1363 } 1364 1365 if (tca[TCA_RATE]) { 1366 err = -EOPNOTSUPP; 1367 if (sch->flags & TCQ_F_MQROOT) { 1368 NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc"); 1369 goto err_out4; 1370 } 1371 1372 err = gen_new_estimator(&sch->bstats, 1373 sch->cpu_bstats, 1374 &sch->rate_est, 1375 NULL, 1376 true, 1377 tca[TCA_RATE]); 1378 if (err) { 1379 NL_SET_ERR_MSG(extack, "Failed to generate new estimator"); 1380 goto err_out4; 1381 } 1382 } 1383 1384 qdisc_hash_add(sch, false); 1385 trace_qdisc_create(ops, dev, parent); 1386 1387 return sch; 1388 1389 err_out4: 1390 /* Even if ops->init() failed, we call ops->destroy() 1391 * like qdisc_create_dflt(). 1392 */ 1393 if (ops->destroy) 1394 ops->destroy(sch); 1395 qdisc_put_stab(rtnl_dereference(sch->stab)); 1396 err_out3: 1397 lockdep_unregister_key(&sch->root_lock_key); 1398 netdev_put(dev, &sch->dev_tracker); 1399 qdisc_free(sch); 1400 err_out2: 1401 module_put(ops->owner); 1402 err_out: 1403 *errp = err; 1404 return NULL; 1405 } 1406 1407 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca, 1408 struct netlink_ext_ack *extack) 1409 { 1410 struct qdisc_size_table *ostab, *stab = NULL; 1411 int err = 0; 1412 1413 if (tca[TCA_OPTIONS]) { 1414 if (!sch->ops->change) { 1415 NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc"); 1416 return -EINVAL; 1417 } 1418 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) { 1419 NL_SET_ERR_MSG(extack, "Change of blocks is not supported"); 1420 return -EOPNOTSUPP; 1421 } 1422 err = sch->ops->change(sch, tca[TCA_OPTIONS], extack); 1423 if (err) 1424 return err; 1425 } 1426 1427 if (tca[TCA_STAB]) { 1428 stab = qdisc_get_stab(tca[TCA_STAB], extack); 1429 if (IS_ERR(stab)) 1430 return PTR_ERR(stab); 1431 } 1432 1433 ostab = rtnl_dereference(sch->stab); 1434 rcu_assign_pointer(sch->stab, stab); 1435 qdisc_put_stab(ostab); 1436 1437 if (tca[TCA_RATE]) { 1438 /* NB: ignores errors from replace_estimator 1439 because change can't be undone. */ 1440 if (sch->flags & TCQ_F_MQROOT) 1441 goto out; 1442 gen_replace_estimator(&sch->bstats, 1443 sch->cpu_bstats, 1444 &sch->rate_est, 1445 NULL, 1446 true, 1447 tca[TCA_RATE]); 1448 } 1449 out: 1450 return 0; 1451 } 1452 1453 struct check_loop_arg { 1454 struct qdisc_walker w; 1455 struct Qdisc *p; 1456 int depth; 1457 }; 1458 1459 static int check_loop_fn(struct Qdisc *q, unsigned long cl, 1460 struct qdisc_walker *w); 1461 1462 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth) 1463 { 1464 struct check_loop_arg arg; 1465 1466 if (q->ops->cl_ops == NULL) 1467 return 0; 1468 1469 arg.w.stop = arg.w.skip = arg.w.count = 0; 1470 arg.w.fn = check_loop_fn; 1471 arg.depth = depth; 1472 arg.p = p; 1473 q->ops->cl_ops->walk(q, &arg.w); 1474 return arg.w.stop ? -ELOOP : 0; 1475 } 1476 1477 static int 1478 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w) 1479 { 1480 struct Qdisc *leaf; 1481 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 1482 struct check_loop_arg *arg = (struct check_loop_arg *)w; 1483 1484 leaf = cops->leaf(q, cl); 1485 if (leaf) { 1486 if (leaf == arg->p || arg->depth > 7) 1487 return -ELOOP; 1488 return check_loop(leaf, arg->p, arg->depth + 1); 1489 } 1490 return 0; 1491 } 1492 1493 const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = { 1494 [TCA_KIND] = { .type = NLA_STRING }, 1495 [TCA_RATE] = { .type = NLA_BINARY, 1496 .len = sizeof(struct tc_estimator) }, 1497 [TCA_STAB] = { .type = NLA_NESTED }, 1498 [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG }, 1499 [TCA_CHAIN] = { .type = NLA_U32 }, 1500 [TCA_INGRESS_BLOCK] = { .type = NLA_U32 }, 1501 [TCA_EGRESS_BLOCK] = { .type = NLA_U32 }, 1502 }; 1503 1504 /* 1505 * Delete/get qdisc. 1506 */ 1507 1508 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, 1509 struct netlink_ext_ack *extack) 1510 { 1511 struct net *net = sock_net(skb->sk); 1512 struct tcmsg *tcm = nlmsg_data(n); 1513 struct nlattr *tca[TCA_MAX + 1]; 1514 struct net_device *dev; 1515 u32 clid; 1516 struct Qdisc *q = NULL; 1517 struct Qdisc *p = NULL; 1518 int err; 1519 1520 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 1521 rtm_tca_policy, extack); 1522 if (err < 0) 1523 return err; 1524 1525 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1526 if (!dev) 1527 return -ENODEV; 1528 1529 clid = tcm->tcm_parent; 1530 if (clid) { 1531 if (clid != TC_H_ROOT) { 1532 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) { 1533 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1534 if (!p) { 1535 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid"); 1536 return -ENOENT; 1537 } 1538 q = qdisc_leaf(p, clid); 1539 } else if (dev_ingress_queue(dev)) { 1540 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); 1541 } 1542 } else { 1543 q = rtnl_dereference(dev->qdisc); 1544 } 1545 if (!q) { 1546 NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device"); 1547 return -ENOENT; 1548 } 1549 1550 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) { 1551 NL_SET_ERR_MSG(extack, "Invalid handle"); 1552 return -EINVAL; 1553 } 1554 } else { 1555 q = qdisc_lookup(dev, tcm->tcm_handle); 1556 if (!q) { 1557 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle"); 1558 return -ENOENT; 1559 } 1560 } 1561 1562 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1563 NL_SET_ERR_MSG(extack, "Invalid qdisc name: must match existing qdisc"); 1564 return -EINVAL; 1565 } 1566 1567 if (n->nlmsg_type == RTM_DELQDISC) { 1568 if (!clid) { 1569 NL_SET_ERR_MSG(extack, "Classid cannot be zero"); 1570 return -EINVAL; 1571 } 1572 if (q->handle == 0) { 1573 NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero"); 1574 return -ENOENT; 1575 } 1576 err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack); 1577 if (err != 0) 1578 return err; 1579 } else { 1580 qdisc_get_notify(net, skb, n, clid, q, NULL); 1581 } 1582 return 0; 1583 } 1584 1585 static bool req_create_or_replace(struct nlmsghdr *n) 1586 { 1587 return (n->nlmsg_flags & NLM_F_CREATE && 1588 n->nlmsg_flags & NLM_F_REPLACE); 1589 } 1590 1591 static bool req_create_exclusive(struct nlmsghdr *n) 1592 { 1593 return (n->nlmsg_flags & NLM_F_CREATE && 1594 n->nlmsg_flags & NLM_F_EXCL); 1595 } 1596 1597 static bool req_change(struct nlmsghdr *n) 1598 { 1599 return (!(n->nlmsg_flags & NLM_F_CREATE) && 1600 !(n->nlmsg_flags & NLM_F_REPLACE) && 1601 !(n->nlmsg_flags & NLM_F_EXCL)); 1602 } 1603 1604 /* 1605 * Create/change qdisc. 1606 */ 1607 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, 1608 struct netlink_ext_ack *extack) 1609 { 1610 struct net *net = sock_net(skb->sk); 1611 struct tcmsg *tcm; 1612 struct nlattr *tca[TCA_MAX + 1]; 1613 struct net_device *dev; 1614 u32 clid; 1615 struct Qdisc *q, *p; 1616 int err; 1617 1618 replay: 1619 /* Reinit, just in case something touches this. */ 1620 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 1621 rtm_tca_policy, extack); 1622 if (err < 0) 1623 return err; 1624 1625 tcm = nlmsg_data(n); 1626 clid = tcm->tcm_parent; 1627 q = p = NULL; 1628 1629 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1630 if (!dev) 1631 return -ENODEV; 1632 1633 1634 if (clid) { 1635 if (clid != TC_H_ROOT) { 1636 if (clid != TC_H_INGRESS) { 1637 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1638 if (!p) { 1639 NL_SET_ERR_MSG(extack, "Failed to find specified qdisc"); 1640 return -ENOENT; 1641 } 1642 q = qdisc_leaf(p, clid); 1643 } else if (dev_ingress_queue_create(dev)) { 1644 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); 1645 } 1646 } else { 1647 q = rtnl_dereference(dev->qdisc); 1648 } 1649 1650 /* It may be default qdisc, ignore it */ 1651 if (q && q->handle == 0) 1652 q = NULL; 1653 1654 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) { 1655 if (tcm->tcm_handle) { 1656 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) { 1657 NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override"); 1658 return -EEXIST; 1659 } 1660 if (TC_H_MIN(tcm->tcm_handle)) { 1661 NL_SET_ERR_MSG(extack, "Invalid minor handle"); 1662 return -EINVAL; 1663 } 1664 q = qdisc_lookup(dev, tcm->tcm_handle); 1665 if (!q) 1666 goto create_n_graft; 1667 if (q->parent != tcm->tcm_parent) { 1668 NL_SET_ERR_MSG(extack, "Cannot move an existing qdisc to a different parent"); 1669 return -EINVAL; 1670 } 1671 if (n->nlmsg_flags & NLM_F_EXCL) { 1672 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override"); 1673 return -EEXIST; 1674 } 1675 if (tca[TCA_KIND] && 1676 nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1677 NL_SET_ERR_MSG(extack, "Invalid qdisc name: must match existing qdisc"); 1678 return -EINVAL; 1679 } 1680 if (q->flags & TCQ_F_INGRESS) { 1681 NL_SET_ERR_MSG(extack, 1682 "Cannot regraft ingress or clsact Qdiscs"); 1683 return -EINVAL; 1684 } 1685 if (q == p || 1686 (p && check_loop(q, p, 0))) { 1687 NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected"); 1688 return -ELOOP; 1689 } 1690 if (clid == TC_H_INGRESS) { 1691 NL_SET_ERR_MSG(extack, "Ingress cannot graft directly"); 1692 return -EINVAL; 1693 } 1694 qdisc_refcount_inc(q); 1695 goto graft; 1696 } else { 1697 if (!q) 1698 goto create_n_graft; 1699 1700 /* This magic test requires explanation. 1701 * 1702 * We know, that some child q is already 1703 * attached to this parent and have choice: 1704 * 1) change it or 2) create/graft new one. 1705 * If the requested qdisc kind is different 1706 * than the existing one, then we choose graft. 1707 * If they are the same then this is "change" 1708 * operation - just let it fallthrough.. 1709 * 1710 * 1. We are allowed to create/graft only 1711 * if the request is explicitly stating 1712 * "please create if it doesn't exist". 1713 * 1714 * 2. If the request is to exclusive create 1715 * then the qdisc tcm_handle is not expected 1716 * to exist, so that we choose create/graft too. 1717 * 1718 * 3. The last case is when no flags are set. 1719 * This will happen when for example tc 1720 * utility issues a "change" command. 1721 * Alas, it is sort of hole in API, we 1722 * cannot decide what to do unambiguously. 1723 * For now we select create/graft. 1724 */ 1725 if (tca[TCA_KIND] && 1726 nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1727 if (req_create_or_replace(n) || 1728 req_create_exclusive(n)) 1729 goto create_n_graft; 1730 else if (req_change(n)) 1731 goto create_n_graft2; 1732 } 1733 } 1734 } 1735 } else { 1736 if (!tcm->tcm_handle) { 1737 NL_SET_ERR_MSG(extack, "Handle cannot be zero"); 1738 return -EINVAL; 1739 } 1740 q = qdisc_lookup(dev, tcm->tcm_handle); 1741 } 1742 1743 /* Change qdisc parameters */ 1744 if (!q) { 1745 NL_SET_ERR_MSG(extack, "Specified qdisc not found"); 1746 return -ENOENT; 1747 } 1748 if (n->nlmsg_flags & NLM_F_EXCL) { 1749 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify"); 1750 return -EEXIST; 1751 } 1752 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1753 NL_SET_ERR_MSG(extack, "Invalid qdisc name: must match existing qdisc"); 1754 return -EINVAL; 1755 } 1756 err = qdisc_change(q, tca, extack); 1757 if (err == 0) 1758 qdisc_notify(net, skb, n, clid, NULL, q, extack); 1759 return err; 1760 1761 create_n_graft: 1762 if (!(n->nlmsg_flags & NLM_F_CREATE)) { 1763 NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag"); 1764 return -ENOENT; 1765 } 1766 create_n_graft2: 1767 if (clid == TC_H_INGRESS) { 1768 if (dev_ingress_queue(dev)) { 1769 q = qdisc_create(dev, dev_ingress_queue(dev), 1770 tcm->tcm_parent, tcm->tcm_parent, 1771 tca, &err, extack); 1772 } else { 1773 NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device"); 1774 err = -ENOENT; 1775 } 1776 } else { 1777 struct netdev_queue *dev_queue; 1778 1779 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue) 1780 dev_queue = p->ops->cl_ops->select_queue(p, tcm); 1781 else if (p) 1782 dev_queue = p->dev_queue; 1783 else 1784 dev_queue = netdev_get_tx_queue(dev, 0); 1785 1786 q = qdisc_create(dev, dev_queue, 1787 tcm->tcm_parent, tcm->tcm_handle, 1788 tca, &err, extack); 1789 } 1790 if (q == NULL) { 1791 if (err == -EAGAIN) 1792 goto replay; 1793 return err; 1794 } 1795 1796 graft: 1797 err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack); 1798 if (err) { 1799 if (q) 1800 qdisc_put(q); 1801 return err; 1802 } 1803 1804 return 0; 1805 } 1806 1807 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb, 1808 struct netlink_callback *cb, 1809 int *q_idx_p, int s_q_idx, bool recur, 1810 bool dump_invisible) 1811 { 1812 int ret = 0, q_idx = *q_idx_p; 1813 struct Qdisc *q; 1814 int b; 1815 1816 if (!root) 1817 return 0; 1818 1819 q = root; 1820 if (q_idx < s_q_idx) { 1821 q_idx++; 1822 } else { 1823 if (!tc_qdisc_dump_ignore(q, dump_invisible) && 1824 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1825 cb->nlh->nlmsg_seq, NLM_F_MULTI, 1826 RTM_NEWQDISC, NULL) <= 0) 1827 goto done; 1828 q_idx++; 1829 } 1830 1831 /* If dumping singletons, there is no qdisc_dev(root) and the singleton 1832 * itself has already been dumped. 1833 * 1834 * If we've already dumped the top-level (ingress) qdisc above and the global 1835 * qdisc hashtable, we don't want to hit it again 1836 */ 1837 if (!qdisc_dev(root) || !recur) 1838 goto out; 1839 1840 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { 1841 if (q_idx < s_q_idx) { 1842 q_idx++; 1843 continue; 1844 } 1845 if (!tc_qdisc_dump_ignore(q, dump_invisible) && 1846 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1847 cb->nlh->nlmsg_seq, NLM_F_MULTI, 1848 RTM_NEWQDISC, NULL) <= 0) 1849 goto done; 1850 q_idx++; 1851 } 1852 1853 out: 1854 *q_idx_p = q_idx; 1855 return ret; 1856 done: 1857 ret = -1; 1858 goto out; 1859 } 1860 1861 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb) 1862 { 1863 struct net *net = sock_net(skb->sk); 1864 int idx, q_idx; 1865 int s_idx, s_q_idx; 1866 struct net_device *dev; 1867 const struct nlmsghdr *nlh = cb->nlh; 1868 struct nlattr *tca[TCA_MAX + 1]; 1869 int err; 1870 1871 s_idx = cb->args[0]; 1872 s_q_idx = q_idx = cb->args[1]; 1873 1874 idx = 0; 1875 ASSERT_RTNL(); 1876 1877 err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX, 1878 rtm_tca_policy, cb->extack); 1879 if (err < 0) 1880 return err; 1881 1882 for_each_netdev(net, dev) { 1883 struct netdev_queue *dev_queue; 1884 1885 if (idx < s_idx) 1886 goto cont; 1887 if (idx > s_idx) 1888 s_q_idx = 0; 1889 q_idx = 0; 1890 1891 if (tc_dump_qdisc_root(rtnl_dereference(dev->qdisc), 1892 skb, cb, &q_idx, s_q_idx, 1893 true, tca[TCA_DUMP_INVISIBLE]) < 0) 1894 goto done; 1895 1896 dev_queue = dev_ingress_queue(dev); 1897 if (dev_queue && 1898 tc_dump_qdisc_root(rtnl_dereference(dev_queue->qdisc_sleeping), 1899 skb, cb, &q_idx, s_q_idx, false, 1900 tca[TCA_DUMP_INVISIBLE]) < 0) 1901 goto done; 1902 1903 cont: 1904 idx++; 1905 } 1906 1907 done: 1908 cb->args[0] = idx; 1909 cb->args[1] = q_idx; 1910 1911 return skb->len; 1912 } 1913 1914 1915 1916 /************************************************ 1917 * Traffic classes manipulation. * 1918 ************************************************/ 1919 1920 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, 1921 unsigned long cl, u32 portid, u32 seq, u16 flags, 1922 int event, struct netlink_ext_ack *extack) 1923 { 1924 struct tcmsg *tcm; 1925 struct nlmsghdr *nlh; 1926 unsigned char *b = skb_tail_pointer(skb); 1927 struct gnet_dump d; 1928 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops; 1929 1930 cond_resched(); 1931 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 1932 if (!nlh) 1933 goto out_nlmsg_trim; 1934 tcm = nlmsg_data(nlh); 1935 tcm->tcm_family = AF_UNSPEC; 1936 tcm->tcm__pad1 = 0; 1937 tcm->tcm__pad2 = 0; 1938 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 1939 tcm->tcm_parent = q->handle; 1940 tcm->tcm_handle = q->handle; 1941 tcm->tcm_info = 0; 1942 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 1943 goto nla_put_failure; 1944 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0) 1945 goto nla_put_failure; 1946 1947 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 1948 NULL, &d, TCA_PAD) < 0) 1949 goto nla_put_failure; 1950 1951 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0) 1952 goto nla_put_failure; 1953 1954 if (gnet_stats_finish_copy(&d) < 0) 1955 goto nla_put_failure; 1956 1957 if (extack && extack->_msg && 1958 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg)) 1959 goto out_nlmsg_trim; 1960 1961 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 1962 1963 return skb->len; 1964 1965 out_nlmsg_trim: 1966 nla_put_failure: 1967 nlmsg_trim(skb, b); 1968 return -1; 1969 } 1970 1971 static int tclass_notify(struct net *net, struct sk_buff *oskb, 1972 struct nlmsghdr *n, struct Qdisc *q, 1973 unsigned long cl, int event, struct netlink_ext_ack *extack) 1974 { 1975 struct sk_buff *skb; 1976 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1977 1978 if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) 1979 return 0; 1980 1981 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1982 if (!skb) 1983 return -ENOBUFS; 1984 1985 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event, extack) < 0) { 1986 kfree_skb(skb); 1987 return -EINVAL; 1988 } 1989 1990 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1991 n->nlmsg_flags & NLM_F_ECHO); 1992 } 1993 1994 static int tclass_get_notify(struct net *net, struct sk_buff *oskb, 1995 struct nlmsghdr *n, struct Qdisc *q, 1996 unsigned long cl, struct netlink_ext_ack *extack) 1997 { 1998 struct sk_buff *skb; 1999 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 2000 2001 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2002 if (!skb) 2003 return -ENOBUFS; 2004 2005 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, RTM_NEWTCLASS, 2006 extack) < 0) { 2007 kfree_skb(skb); 2008 return -EINVAL; 2009 } 2010 2011 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 2012 n->nlmsg_flags & NLM_F_ECHO); 2013 } 2014 2015 static int tclass_del_notify(struct net *net, 2016 const struct Qdisc_class_ops *cops, 2017 struct sk_buff *oskb, struct nlmsghdr *n, 2018 struct Qdisc *q, unsigned long cl, 2019 struct netlink_ext_ack *extack) 2020 { 2021 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 2022 struct sk_buff *skb; 2023 int err = 0; 2024 2025 if (!cops->delete) 2026 return -EOPNOTSUPP; 2027 2028 if (rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) { 2029 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2030 if (!skb) 2031 return -ENOBUFS; 2032 2033 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, 2034 RTM_DELTCLASS, extack) < 0) { 2035 kfree_skb(skb); 2036 return -EINVAL; 2037 } 2038 } else { 2039 skb = NULL; 2040 } 2041 2042 err = cops->delete(q, cl, extack); 2043 if (err) { 2044 kfree_skb(skb); 2045 return err; 2046 } 2047 2048 err = rtnetlink_maybe_send(skb, net, portid, RTNLGRP_TC, 2049 n->nlmsg_flags & NLM_F_ECHO); 2050 return err; 2051 } 2052 2053 #ifdef CONFIG_NET_CLS 2054 2055 struct tcf_bind_args { 2056 struct tcf_walker w; 2057 unsigned long base; 2058 unsigned long cl; 2059 u32 classid; 2060 }; 2061 2062 static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg) 2063 { 2064 struct tcf_bind_args *a = (void *)arg; 2065 2066 if (n && tp->ops->bind_class) { 2067 struct Qdisc *q = tcf_block_q(tp->chain->block); 2068 2069 sch_tree_lock(q); 2070 tp->ops->bind_class(n, a->classid, a->cl, q, a->base); 2071 sch_tree_unlock(q); 2072 } 2073 return 0; 2074 } 2075 2076 struct tc_bind_class_args { 2077 struct qdisc_walker w; 2078 unsigned long new_cl; 2079 u32 portid; 2080 u32 clid; 2081 }; 2082 2083 static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl, 2084 struct qdisc_walker *w) 2085 { 2086 struct tc_bind_class_args *a = (struct tc_bind_class_args *)w; 2087 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 2088 struct tcf_block *block; 2089 struct tcf_chain *chain; 2090 2091 block = cops->tcf_block(q, cl, NULL); 2092 if (!block) 2093 return 0; 2094 for (chain = tcf_get_next_chain(block, NULL); 2095 chain; 2096 chain = tcf_get_next_chain(block, chain)) { 2097 struct tcf_proto *tp; 2098 2099 for (tp = tcf_get_next_proto(chain, NULL); 2100 tp; tp = tcf_get_next_proto(chain, tp)) { 2101 struct tcf_bind_args arg = {}; 2102 2103 arg.w.fn = tcf_node_bind; 2104 arg.classid = a->clid; 2105 arg.base = cl; 2106 arg.cl = a->new_cl; 2107 tp->ops->walk(tp, &arg.w, true); 2108 } 2109 } 2110 2111 return 0; 2112 } 2113 2114 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, 2115 unsigned long new_cl) 2116 { 2117 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 2118 struct tc_bind_class_args args = {}; 2119 2120 if (!cops->tcf_block) 2121 return; 2122 args.portid = portid; 2123 args.clid = clid; 2124 args.new_cl = new_cl; 2125 args.w.fn = tc_bind_class_walker; 2126 q->ops->cl_ops->walk(q, &args.w); 2127 } 2128 2129 #else 2130 2131 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, 2132 unsigned long new_cl) 2133 { 2134 } 2135 2136 #endif 2137 2138 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, 2139 struct netlink_ext_ack *extack) 2140 { 2141 struct net *net = sock_net(skb->sk); 2142 struct tcmsg *tcm = nlmsg_data(n); 2143 struct nlattr *tca[TCA_MAX + 1]; 2144 struct net_device *dev; 2145 struct Qdisc *q = NULL; 2146 const struct Qdisc_class_ops *cops; 2147 unsigned long cl = 0; 2148 unsigned long new_cl; 2149 u32 portid; 2150 u32 clid; 2151 u32 qid; 2152 int err; 2153 2154 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 2155 rtm_tca_policy, extack); 2156 if (err < 0) 2157 return err; 2158 2159 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 2160 if (!dev) 2161 return -ENODEV; 2162 2163 /* 2164 parent == TC_H_UNSPEC - unspecified parent. 2165 parent == TC_H_ROOT - class is root, which has no parent. 2166 parent == X:0 - parent is root class. 2167 parent == X:Y - parent is a node in hierarchy. 2168 parent == 0:Y - parent is X:Y, where X:0 is qdisc. 2169 2170 handle == 0:0 - generate handle from kernel pool. 2171 handle == 0:Y - class is X:Y, where X:0 is qdisc. 2172 handle == X:Y - clear. 2173 handle == X:0 - root class. 2174 */ 2175 2176 /* Step 1. Determine qdisc handle X:0 */ 2177 2178 portid = tcm->tcm_parent; 2179 clid = tcm->tcm_handle; 2180 qid = TC_H_MAJ(clid); 2181 2182 if (portid != TC_H_ROOT) { 2183 u32 qid1 = TC_H_MAJ(portid); 2184 2185 if (qid && qid1) { 2186 /* If both majors are known, they must be identical. */ 2187 if (qid != qid1) 2188 return -EINVAL; 2189 } else if (qid1) { 2190 qid = qid1; 2191 } else if (qid == 0) 2192 qid = rtnl_dereference(dev->qdisc)->handle; 2193 2194 /* Now qid is genuine qdisc handle consistent 2195 * both with parent and child. 2196 * 2197 * TC_H_MAJ(portid) still may be unspecified, complete it now. 2198 */ 2199 if (portid) 2200 portid = TC_H_MAKE(qid, portid); 2201 } else { 2202 if (qid == 0) 2203 qid = rtnl_dereference(dev->qdisc)->handle; 2204 } 2205 2206 /* OK. Locate qdisc */ 2207 q = qdisc_lookup(dev, qid); 2208 if (!q) 2209 return -ENOENT; 2210 2211 /* An check that it supports classes */ 2212 cops = q->ops->cl_ops; 2213 if (cops == NULL) 2214 return -EINVAL; 2215 2216 /* Now try to get class */ 2217 if (clid == 0) { 2218 if (portid == TC_H_ROOT) 2219 clid = qid; 2220 } else 2221 clid = TC_H_MAKE(qid, clid); 2222 2223 if (clid) 2224 cl = cops->find(q, clid); 2225 2226 if (cl == 0) { 2227 err = -ENOENT; 2228 if (n->nlmsg_type != RTM_NEWTCLASS || 2229 !(n->nlmsg_flags & NLM_F_CREATE)) 2230 goto out; 2231 } else { 2232 switch (n->nlmsg_type) { 2233 case RTM_NEWTCLASS: 2234 err = -EEXIST; 2235 if (n->nlmsg_flags & NLM_F_EXCL) 2236 goto out; 2237 break; 2238 case RTM_DELTCLASS: 2239 err = tclass_del_notify(net, cops, skb, n, q, cl, extack); 2240 /* Unbind the class with flilters with 0 */ 2241 tc_bind_tclass(q, portid, clid, 0); 2242 goto out; 2243 case RTM_GETTCLASS: 2244 err = tclass_get_notify(net, skb, n, q, cl, extack); 2245 goto out; 2246 default: 2247 err = -EINVAL; 2248 goto out; 2249 } 2250 } 2251 2252 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) { 2253 NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes"); 2254 return -EOPNOTSUPP; 2255 } 2256 2257 new_cl = cl; 2258 err = -EOPNOTSUPP; 2259 if (cops->change) 2260 err = cops->change(q, clid, portid, tca, &new_cl, extack); 2261 if (err == 0) { 2262 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS, extack); 2263 /* We just create a new class, need to do reverse binding. */ 2264 if (cl != new_cl) 2265 tc_bind_tclass(q, portid, clid, new_cl); 2266 } 2267 out: 2268 return err; 2269 } 2270 2271 struct qdisc_dump_args { 2272 struct qdisc_walker w; 2273 struct sk_buff *skb; 2274 struct netlink_callback *cb; 2275 }; 2276 2277 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, 2278 struct qdisc_walker *arg) 2279 { 2280 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg; 2281 2282 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid, 2283 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, 2284 RTM_NEWTCLASS, NULL); 2285 } 2286 2287 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb, 2288 struct tcmsg *tcm, struct netlink_callback *cb, 2289 int *t_p, int s_t) 2290 { 2291 struct qdisc_dump_args arg; 2292 2293 if (tc_qdisc_dump_ignore(q, false) || 2294 *t_p < s_t || !q->ops->cl_ops || 2295 (tcm->tcm_parent && 2296 TC_H_MAJ(tcm->tcm_parent) != q->handle)) { 2297 (*t_p)++; 2298 return 0; 2299 } 2300 if (*t_p > s_t) 2301 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); 2302 arg.w.fn = qdisc_class_dump; 2303 arg.skb = skb; 2304 arg.cb = cb; 2305 arg.w.stop = 0; 2306 arg.w.skip = cb->args[1]; 2307 arg.w.count = 0; 2308 q->ops->cl_ops->walk(q, &arg.w); 2309 cb->args[1] = arg.w.count; 2310 if (arg.w.stop) 2311 return -1; 2312 (*t_p)++; 2313 return 0; 2314 } 2315 2316 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb, 2317 struct tcmsg *tcm, struct netlink_callback *cb, 2318 int *t_p, int s_t, bool recur) 2319 { 2320 struct Qdisc *q; 2321 int b; 2322 2323 if (!root) 2324 return 0; 2325 2326 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0) 2327 return -1; 2328 2329 if (!qdisc_dev(root) || !recur) 2330 return 0; 2331 2332 if (tcm->tcm_parent) { 2333 q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent)); 2334 if (q && q != root && 2335 tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 2336 return -1; 2337 return 0; 2338 } 2339 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { 2340 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 2341 return -1; 2342 } 2343 2344 return 0; 2345 } 2346 2347 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb) 2348 { 2349 struct tcmsg *tcm = nlmsg_data(cb->nlh); 2350 struct net *net = sock_net(skb->sk); 2351 struct netdev_queue *dev_queue; 2352 struct net_device *dev; 2353 int t, s_t; 2354 2355 if (nlmsg_len(cb->nlh) < sizeof(*tcm)) 2356 return 0; 2357 dev = dev_get_by_index(net, tcm->tcm_ifindex); 2358 if (!dev) 2359 return 0; 2360 2361 s_t = cb->args[0]; 2362 t = 0; 2363 2364 if (tc_dump_tclass_root(rtnl_dereference(dev->qdisc), 2365 skb, tcm, cb, &t, s_t, true) < 0) 2366 goto done; 2367 2368 dev_queue = dev_ingress_queue(dev); 2369 if (dev_queue && 2370 tc_dump_tclass_root(rtnl_dereference(dev_queue->qdisc_sleeping), 2371 skb, tcm, cb, &t, s_t, false) < 0) 2372 goto done; 2373 2374 done: 2375 cb->args[0] = t; 2376 2377 dev_put(dev); 2378 return skb->len; 2379 } 2380 2381 #ifdef CONFIG_PROC_FS 2382 static int psched_show(struct seq_file *seq, void *v) 2383 { 2384 seq_printf(seq, "%08x %08x %08x %08x\n", 2385 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1), 2386 1000000, 2387 (u32)NSEC_PER_SEC / hrtimer_resolution); 2388 2389 return 0; 2390 } 2391 2392 static int __net_init psched_net_init(struct net *net) 2393 { 2394 struct proc_dir_entry *e; 2395 2396 e = proc_create_single("psched", 0, net->proc_net, psched_show); 2397 if (e == NULL) 2398 return -ENOMEM; 2399 2400 return 0; 2401 } 2402 2403 static void __net_exit psched_net_exit(struct net *net) 2404 { 2405 remove_proc_entry("psched", net->proc_net); 2406 } 2407 #else 2408 static int __net_init psched_net_init(struct net *net) 2409 { 2410 return 0; 2411 } 2412 2413 static void __net_exit psched_net_exit(struct net *net) 2414 { 2415 } 2416 #endif 2417 2418 static struct pernet_operations psched_net_ops = { 2419 .init = psched_net_init, 2420 .exit = psched_net_exit, 2421 }; 2422 2423 #if IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) 2424 DEFINE_STATIC_KEY_FALSE(tc_skip_wrapper); 2425 #endif 2426 2427 static const struct rtnl_msg_handler psched_rtnl_msg_handlers[] __initconst = { 2428 {.msgtype = RTM_NEWQDISC, .doit = tc_modify_qdisc}, 2429 {.msgtype = RTM_DELQDISC, .doit = tc_get_qdisc}, 2430 {.msgtype = RTM_GETQDISC, .doit = tc_get_qdisc, 2431 .dumpit = tc_dump_qdisc}, 2432 {.msgtype = RTM_NEWTCLASS, .doit = tc_ctl_tclass}, 2433 {.msgtype = RTM_DELTCLASS, .doit = tc_ctl_tclass}, 2434 {.msgtype = RTM_GETTCLASS, .doit = tc_ctl_tclass, 2435 .dumpit = tc_dump_tclass}, 2436 }; 2437 2438 static int __init pktsched_init(void) 2439 { 2440 int err; 2441 2442 err = register_pernet_subsys(&psched_net_ops); 2443 if (err) { 2444 pr_err("pktsched_init: " 2445 "cannot initialize per netns operations\n"); 2446 return err; 2447 } 2448 2449 register_qdisc(&pfifo_fast_ops); 2450 register_qdisc(&pfifo_qdisc_ops); 2451 register_qdisc(&bfifo_qdisc_ops); 2452 register_qdisc(&pfifo_head_drop_qdisc_ops); 2453 register_qdisc(&mq_qdisc_ops); 2454 register_qdisc(&noqueue_qdisc_ops); 2455 2456 rtnl_register_many(psched_rtnl_msg_handlers); 2457 2458 tc_wrapper_init(); 2459 2460 return 0; 2461 } 2462 2463 subsys_initcall(pktsched_init); 2464