1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * net/sched/sch_api.c Packet scheduler API. 4 * 5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 6 * 7 * Fixes: 8 * 9 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired. 10 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support 11 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support 12 */ 13 14 #include <linux/module.h> 15 #include <linux/types.h> 16 #include <linux/kernel.h> 17 #include <linux/string.h> 18 #include <linux/errno.h> 19 #include <linux/skbuff.h> 20 #include <linux/init.h> 21 #include <linux/proc_fs.h> 22 #include <linux/seq_file.h> 23 #include <linux/kmod.h> 24 #include <linux/list.h> 25 #include <linux/hrtimer.h> 26 #include <linux/slab.h> 27 #include <linux/hashtable.h> 28 29 #include <net/net_namespace.h> 30 #include <net/sock.h> 31 #include <net/netlink.h> 32 #include <net/pkt_sched.h> 33 #include <net/pkt_cls.h> 34 #include <net/tc_wrapper.h> 35 36 #include <trace/events/qdisc.h> 37 38 /* 39 40 Short review. 41 ------------- 42 43 This file consists of two interrelated parts: 44 45 1. queueing disciplines manager frontend. 46 2. traffic classes manager frontend. 47 48 Generally, queueing discipline ("qdisc") is a black box, 49 which is able to enqueue packets and to dequeue them (when 50 device is ready to send something) in order and at times 51 determined by algorithm hidden in it. 52 53 qdisc's are divided to two categories: 54 - "queues", which have no internal structure visible from outside. 55 - "schedulers", which split all the packets to "traffic classes", 56 using "packet classifiers" (look at cls_api.c) 57 58 In turn, classes may have child qdiscs (as rule, queues) 59 attached to them etc. etc. etc. 60 61 The goal of the routines in this file is to translate 62 information supplied by user in the form of handles 63 to more intelligible for kernel form, to make some sanity 64 checks and part of work, which is common to all qdiscs 65 and to provide rtnetlink notifications. 66 67 All real intelligent work is done inside qdisc modules. 68 69 70 71 Every discipline has two major routines: enqueue and dequeue. 72 73 ---dequeue 74 75 dequeue usually returns a skb to send. It is allowed to return NULL, 76 but it does not mean that queue is empty, it just means that 77 discipline does not want to send anything this time. 78 Queue is really empty if q->q.qlen == 0. 79 For complicated disciplines with multiple queues q->q is not 80 real packet queue, but however q->q.qlen must be valid. 81 82 ---enqueue 83 84 enqueue returns 0, if packet was enqueued successfully. 85 If packet (this one or another one) was dropped, it returns 86 not zero error code. 87 NET_XMIT_DROP - this packet dropped 88 Expected action: do not backoff, but wait until queue will clear. 89 NET_XMIT_CN - probably this packet enqueued, but another one dropped. 90 Expected action: backoff or ignore 91 92 Auxiliary routines: 93 94 ---peek 95 96 like dequeue but without removing a packet from the queue 97 98 ---reset 99 100 returns qdisc to initial state: purge all buffers, clear all 101 timers, counters (except for statistics) etc. 102 103 ---init 104 105 initializes newly created qdisc. 106 107 ---destroy 108 109 destroys resources allocated by init and during lifetime of qdisc. 110 111 ---change 112 113 changes qdisc parameters. 114 */ 115 116 /* Protects list of registered TC modules. It is pure SMP lock. */ 117 static DEFINE_RWLOCK(qdisc_mod_lock); 118 119 120 /************************************************ 121 * Queueing disciplines manipulation. * 122 ************************************************/ 123 124 125 /* The list of all installed queueing disciplines. */ 126 127 static struct Qdisc_ops *qdisc_base; 128 129 /* Register/unregister queueing discipline */ 130 131 int register_qdisc(struct Qdisc_ops *qops) 132 { 133 struct Qdisc_ops *q, **qp; 134 int rc = -EEXIST; 135 136 write_lock(&qdisc_mod_lock); 137 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next) 138 if (!strcmp(qops->id, q->id)) 139 goto out; 140 141 if (qops->enqueue == NULL) 142 qops->enqueue = noop_qdisc_ops.enqueue; 143 if (qops->peek == NULL) { 144 if (qops->dequeue == NULL) 145 qops->peek = noop_qdisc_ops.peek; 146 else 147 goto out_einval; 148 } 149 if (qops->dequeue == NULL) 150 qops->dequeue = noop_qdisc_ops.dequeue; 151 152 if (qops->cl_ops) { 153 const struct Qdisc_class_ops *cops = qops->cl_ops; 154 155 if (!(cops->find && cops->walk && cops->leaf)) 156 goto out_einval; 157 158 if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf)) 159 goto out_einval; 160 } 161 162 qops->next = NULL; 163 *qp = qops; 164 rc = 0; 165 out: 166 write_unlock(&qdisc_mod_lock); 167 return rc; 168 169 out_einval: 170 rc = -EINVAL; 171 goto out; 172 } 173 EXPORT_SYMBOL(register_qdisc); 174 175 void unregister_qdisc(struct Qdisc_ops *qops) 176 { 177 struct Qdisc_ops *q, **qp; 178 int err = -ENOENT; 179 180 write_lock(&qdisc_mod_lock); 181 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next) 182 if (q == qops) 183 break; 184 if (q) { 185 *qp = q->next; 186 q->next = NULL; 187 err = 0; 188 } 189 write_unlock(&qdisc_mod_lock); 190 191 WARN(err, "unregister qdisc(%s) failed\n", qops->id); 192 } 193 EXPORT_SYMBOL(unregister_qdisc); 194 195 /* Get default qdisc if not otherwise specified */ 196 void qdisc_get_default(char *name, size_t len) 197 { 198 read_lock(&qdisc_mod_lock); 199 strscpy(name, default_qdisc_ops->id, len); 200 read_unlock(&qdisc_mod_lock); 201 } 202 203 static struct Qdisc_ops *qdisc_lookup_default(const char *name) 204 { 205 struct Qdisc_ops *q = NULL; 206 207 for (q = qdisc_base; q; q = q->next) { 208 if (!strcmp(name, q->id)) { 209 if (!try_module_get(q->owner)) 210 q = NULL; 211 break; 212 } 213 } 214 215 return q; 216 } 217 218 /* Set new default qdisc to use */ 219 int qdisc_set_default(const char *name) 220 { 221 const struct Qdisc_ops *ops; 222 223 if (!capable(CAP_NET_ADMIN)) 224 return -EPERM; 225 226 write_lock(&qdisc_mod_lock); 227 ops = qdisc_lookup_default(name); 228 if (!ops) { 229 /* Not found, drop lock and try to load module */ 230 write_unlock(&qdisc_mod_lock); 231 request_module("sch_%s", name); 232 write_lock(&qdisc_mod_lock); 233 234 ops = qdisc_lookup_default(name); 235 } 236 237 if (ops) { 238 /* Set new default */ 239 module_put(default_qdisc_ops->owner); 240 default_qdisc_ops = ops; 241 } 242 write_unlock(&qdisc_mod_lock); 243 244 return ops ? 0 : -ENOENT; 245 } 246 247 #ifdef CONFIG_NET_SCH_DEFAULT 248 /* Set default value from kernel config */ 249 static int __init sch_default_qdisc(void) 250 { 251 return qdisc_set_default(CONFIG_DEFAULT_NET_SCH); 252 } 253 late_initcall(sch_default_qdisc); 254 #endif 255 256 /* We know handle. Find qdisc among all qdisc's attached to device 257 * (root qdisc, all its children, children of children etc.) 258 * Note: caller either uses rtnl or rcu_read_lock() 259 */ 260 261 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle) 262 { 263 struct Qdisc *q; 264 265 if (!qdisc_dev(root)) 266 return (root->handle == handle ? root : NULL); 267 268 if (!(root->flags & TCQ_F_BUILTIN) && 269 root->handle == handle) 270 return root; 271 272 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle, 273 lockdep_rtnl_is_held()) { 274 if (q->handle == handle) 275 return q; 276 } 277 return NULL; 278 } 279 280 void qdisc_hash_add(struct Qdisc *q, bool invisible) 281 { 282 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) { 283 ASSERT_RTNL(); 284 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle); 285 if (invisible) 286 q->flags |= TCQ_F_INVISIBLE; 287 } 288 } 289 EXPORT_SYMBOL(qdisc_hash_add); 290 291 void qdisc_hash_del(struct Qdisc *q) 292 { 293 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) { 294 ASSERT_RTNL(); 295 hash_del_rcu(&q->hash); 296 } 297 } 298 EXPORT_SYMBOL(qdisc_hash_del); 299 300 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle) 301 { 302 struct Qdisc *q; 303 304 if (!handle) 305 return NULL; 306 q = qdisc_match_from_root(rtnl_dereference(dev->qdisc), handle); 307 if (q) 308 goto out; 309 310 if (dev_ingress_queue(dev)) 311 q = qdisc_match_from_root( 312 rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping), 313 handle); 314 out: 315 return q; 316 } 317 318 struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle) 319 { 320 struct netdev_queue *nq; 321 struct Qdisc *q; 322 323 if (!handle) 324 return NULL; 325 q = qdisc_match_from_root(rcu_dereference(dev->qdisc), handle); 326 if (q) 327 goto out; 328 329 nq = dev_ingress_queue_rcu(dev); 330 if (nq) 331 q = qdisc_match_from_root(rcu_dereference(nq->qdisc_sleeping), 332 handle); 333 out: 334 return q; 335 } 336 337 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid) 338 { 339 unsigned long cl; 340 const struct Qdisc_class_ops *cops = p->ops->cl_ops; 341 342 if (cops == NULL) 343 return NULL; 344 cl = cops->find(p, classid); 345 346 if (cl == 0) 347 return NULL; 348 return cops->leaf(p, cl); 349 } 350 351 /* Find queueing discipline by name */ 352 353 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind) 354 { 355 struct Qdisc_ops *q = NULL; 356 357 if (kind) { 358 read_lock(&qdisc_mod_lock); 359 for (q = qdisc_base; q; q = q->next) { 360 if (nla_strcmp(kind, q->id) == 0) { 361 if (!try_module_get(q->owner)) 362 q = NULL; 363 break; 364 } 365 } 366 read_unlock(&qdisc_mod_lock); 367 } 368 return q; 369 } 370 371 /* The linklayer setting were not transferred from iproute2, in older 372 * versions, and the rate tables lookup systems have been dropped in 373 * the kernel. To keep backward compatible with older iproute2 tc 374 * utils, we detect the linklayer setting by detecting if the rate 375 * table were modified. 376 * 377 * For linklayer ATM table entries, the rate table will be aligned to 378 * 48 bytes, thus some table entries will contain the same value. The 379 * mpu (min packet unit) is also encoded into the old rate table, thus 380 * starting from the mpu, we find low and high table entries for 381 * mapping this cell. If these entries contain the same value, when 382 * the rate tables have been modified for linklayer ATM. 383 * 384 * This is done by rounding mpu to the nearest 48 bytes cell/entry, 385 * and then roundup to the next cell, calc the table entry one below, 386 * and compare. 387 */ 388 static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab) 389 { 390 int low = roundup(r->mpu, 48); 391 int high = roundup(low+1, 48); 392 int cell_low = low >> r->cell_log; 393 int cell_high = (high >> r->cell_log) - 1; 394 395 /* rtab is too inaccurate at rates > 100Mbit/s */ 396 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) { 397 pr_debug("TC linklayer: Giving up ATM detection\n"); 398 return TC_LINKLAYER_ETHERNET; 399 } 400 401 if ((cell_high > cell_low) && (cell_high < 256) 402 && (rtab[cell_low] == rtab[cell_high])) { 403 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n", 404 cell_low, cell_high, rtab[cell_high]); 405 return TC_LINKLAYER_ATM; 406 } 407 return TC_LINKLAYER_ETHERNET; 408 } 409 410 static struct qdisc_rate_table *qdisc_rtab_list; 411 412 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, 413 struct nlattr *tab, 414 struct netlink_ext_ack *extack) 415 { 416 struct qdisc_rate_table *rtab; 417 418 if (tab == NULL || r->rate == 0 || 419 r->cell_log == 0 || r->cell_log >= 32 || 420 nla_len(tab) != TC_RTAB_SIZE) { 421 NL_SET_ERR_MSG(extack, "Invalid rate table parameters for searching"); 422 return NULL; 423 } 424 425 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) { 426 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) && 427 !memcmp(&rtab->data, nla_data(tab), 1024)) { 428 rtab->refcnt++; 429 return rtab; 430 } 431 } 432 433 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL); 434 if (rtab) { 435 rtab->rate = *r; 436 rtab->refcnt = 1; 437 memcpy(rtab->data, nla_data(tab), 1024); 438 if (r->linklayer == TC_LINKLAYER_UNAWARE) 439 r->linklayer = __detect_linklayer(r, rtab->data); 440 rtab->next = qdisc_rtab_list; 441 qdisc_rtab_list = rtab; 442 } else { 443 NL_SET_ERR_MSG(extack, "Failed to allocate new qdisc rate table"); 444 } 445 return rtab; 446 } 447 EXPORT_SYMBOL(qdisc_get_rtab); 448 449 void qdisc_put_rtab(struct qdisc_rate_table *tab) 450 { 451 struct qdisc_rate_table *rtab, **rtabp; 452 453 if (!tab || --tab->refcnt) 454 return; 455 456 for (rtabp = &qdisc_rtab_list; 457 (rtab = *rtabp) != NULL; 458 rtabp = &rtab->next) { 459 if (rtab == tab) { 460 *rtabp = rtab->next; 461 kfree(rtab); 462 return; 463 } 464 } 465 } 466 EXPORT_SYMBOL(qdisc_put_rtab); 467 468 static LIST_HEAD(qdisc_stab_list); 469 470 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = { 471 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) }, 472 [TCA_STAB_DATA] = { .type = NLA_BINARY }, 473 }; 474 475 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt, 476 struct netlink_ext_ack *extack) 477 { 478 struct nlattr *tb[TCA_STAB_MAX + 1]; 479 struct qdisc_size_table *stab; 480 struct tc_sizespec *s; 481 unsigned int tsize = 0; 482 u16 *tab = NULL; 483 int err; 484 485 err = nla_parse_nested_deprecated(tb, TCA_STAB_MAX, opt, stab_policy, 486 extack); 487 if (err < 0) 488 return ERR_PTR(err); 489 if (!tb[TCA_STAB_BASE]) { 490 NL_SET_ERR_MSG(extack, "Size table base attribute is missing"); 491 return ERR_PTR(-EINVAL); 492 } 493 494 s = nla_data(tb[TCA_STAB_BASE]); 495 496 if (s->tsize > 0) { 497 if (!tb[TCA_STAB_DATA]) { 498 NL_SET_ERR_MSG(extack, "Size table data attribute is missing"); 499 return ERR_PTR(-EINVAL); 500 } 501 tab = nla_data(tb[TCA_STAB_DATA]); 502 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16); 503 } 504 505 if (tsize != s->tsize || (!tab && tsize > 0)) { 506 NL_SET_ERR_MSG(extack, "Invalid size of size table"); 507 return ERR_PTR(-EINVAL); 508 } 509 510 list_for_each_entry(stab, &qdisc_stab_list, list) { 511 if (memcmp(&stab->szopts, s, sizeof(*s))) 512 continue; 513 if (tsize > 0 && 514 memcmp(stab->data, tab, flex_array_size(stab, data, tsize))) 515 continue; 516 stab->refcnt++; 517 return stab; 518 } 519 520 if (s->size_log > STAB_SIZE_LOG_MAX || 521 s->cell_log > STAB_SIZE_LOG_MAX) { 522 NL_SET_ERR_MSG(extack, "Invalid logarithmic size of size table"); 523 return ERR_PTR(-EINVAL); 524 } 525 526 stab = kmalloc(struct_size(stab, data, tsize), GFP_KERNEL); 527 if (!stab) 528 return ERR_PTR(-ENOMEM); 529 530 stab->refcnt = 1; 531 stab->szopts = *s; 532 if (tsize > 0) 533 memcpy(stab->data, tab, flex_array_size(stab, data, tsize)); 534 535 list_add_tail(&stab->list, &qdisc_stab_list); 536 537 return stab; 538 } 539 540 void qdisc_put_stab(struct qdisc_size_table *tab) 541 { 542 if (!tab) 543 return; 544 545 if (--tab->refcnt == 0) { 546 list_del(&tab->list); 547 kfree_rcu(tab, rcu); 548 } 549 } 550 EXPORT_SYMBOL(qdisc_put_stab); 551 552 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab) 553 { 554 struct nlattr *nest; 555 556 nest = nla_nest_start_noflag(skb, TCA_STAB); 557 if (nest == NULL) 558 goto nla_put_failure; 559 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts)) 560 goto nla_put_failure; 561 nla_nest_end(skb, nest); 562 563 return skb->len; 564 565 nla_put_failure: 566 return -1; 567 } 568 569 void __qdisc_calculate_pkt_len(struct sk_buff *skb, 570 const struct qdisc_size_table *stab) 571 { 572 int pkt_len, slot; 573 574 pkt_len = skb->len + stab->szopts.overhead; 575 if (unlikely(!stab->szopts.tsize)) 576 goto out; 577 578 slot = pkt_len + stab->szopts.cell_align; 579 if (unlikely(slot < 0)) 580 slot = 0; 581 582 slot >>= stab->szopts.cell_log; 583 if (likely(slot < stab->szopts.tsize)) 584 pkt_len = stab->data[slot]; 585 else 586 pkt_len = stab->data[stab->szopts.tsize - 1] * 587 (slot / stab->szopts.tsize) + 588 stab->data[slot % stab->szopts.tsize]; 589 590 pkt_len <<= stab->szopts.size_log; 591 out: 592 if (unlikely(pkt_len < 1)) 593 pkt_len = 1; 594 qdisc_skb_cb(skb)->pkt_len = pkt_len; 595 } 596 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_add_dev(struct Qdisc *sch, struct net_device *dev, 1213 struct netlink_ext_ack *extack) 1214 { 1215 const struct Qdisc_class_ops *cl_ops = sch->ops->cl_ops; 1216 struct tcf_block *block; 1217 int err; 1218 1219 block = cl_ops->tcf_block(sch, TC_H_MIN_INGRESS, NULL); 1220 if (block) { 1221 err = xa_insert(&block->ports, dev->ifindex, dev, GFP_KERNEL); 1222 if (err) { 1223 NL_SET_ERR_MSG(extack, 1224 "ingress block dev insert failed"); 1225 return err; 1226 } 1227 } 1228 1229 block = cl_ops->tcf_block(sch, TC_H_MIN_EGRESS, NULL); 1230 if (block) { 1231 err = xa_insert(&block->ports, dev->ifindex, dev, GFP_KERNEL); 1232 if (err) { 1233 NL_SET_ERR_MSG(extack, 1234 "Egress block dev insert failed"); 1235 goto err_out; 1236 } 1237 } 1238 1239 return 0; 1240 1241 err_out: 1242 block = cl_ops->tcf_block(sch, TC_H_MIN_INGRESS, NULL); 1243 if (block) 1244 xa_erase(&block->ports, dev->ifindex); 1245 1246 return err; 1247 } 1248 1249 static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca, 1250 struct netlink_ext_ack *extack) 1251 { 1252 u32 block_index; 1253 1254 if (tca[TCA_INGRESS_BLOCK]) { 1255 block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]); 1256 1257 if (!block_index) { 1258 NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0"); 1259 return -EINVAL; 1260 } 1261 if (!sch->ops->ingress_block_set) { 1262 NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported"); 1263 return -EOPNOTSUPP; 1264 } 1265 sch->ops->ingress_block_set(sch, block_index); 1266 } 1267 if (tca[TCA_EGRESS_BLOCK]) { 1268 block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]); 1269 1270 if (!block_index) { 1271 NL_SET_ERR_MSG(extack, "Egress block index cannot be 0"); 1272 return -EINVAL; 1273 } 1274 if (!sch->ops->egress_block_set) { 1275 NL_SET_ERR_MSG(extack, "Egress block sharing is not supported"); 1276 return -EOPNOTSUPP; 1277 } 1278 sch->ops->egress_block_set(sch, block_index); 1279 } 1280 return 0; 1281 } 1282 1283 /* 1284 Allocate and initialize new qdisc. 1285 1286 Parameters are passed via opt. 1287 */ 1288 1289 static struct Qdisc *qdisc_create(struct net_device *dev, 1290 struct netdev_queue *dev_queue, 1291 u32 parent, u32 handle, 1292 struct nlattr **tca, int *errp, 1293 struct netlink_ext_ack *extack) 1294 { 1295 int err; 1296 struct nlattr *kind = tca[TCA_KIND]; 1297 struct Qdisc *sch; 1298 struct Qdisc_ops *ops; 1299 struct qdisc_size_table *stab; 1300 1301 ops = qdisc_lookup_ops(kind); 1302 #ifdef CONFIG_MODULES 1303 if (ops == NULL && kind != NULL) { 1304 char name[IFNAMSIZ]; 1305 if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) { 1306 /* We dropped the RTNL semaphore in order to 1307 * perform the module load. So, even if we 1308 * succeeded in loading the module we have to 1309 * tell the caller to replay the request. We 1310 * indicate this using -EAGAIN. 1311 * We replay the request because the device may 1312 * go away in the mean time. 1313 */ 1314 rtnl_unlock(); 1315 request_module("sch_%s", name); 1316 rtnl_lock(); 1317 ops = qdisc_lookup_ops(kind); 1318 if (ops != NULL) { 1319 /* We will try again qdisc_lookup_ops, 1320 * so don't keep a reference. 1321 */ 1322 module_put(ops->owner); 1323 err = -EAGAIN; 1324 goto err_out; 1325 } 1326 } 1327 } 1328 #endif 1329 1330 err = -ENOENT; 1331 if (!ops) { 1332 NL_SET_ERR_MSG(extack, "Specified qdisc kind is unknown"); 1333 goto err_out; 1334 } 1335 1336 sch = qdisc_alloc(dev_queue, ops, extack); 1337 if (IS_ERR(sch)) { 1338 err = PTR_ERR(sch); 1339 goto err_out2; 1340 } 1341 1342 sch->parent = parent; 1343 1344 if (handle == TC_H_INGRESS) { 1345 if (!(sch->flags & TCQ_F_INGRESS)) { 1346 NL_SET_ERR_MSG(extack, 1347 "Specified parent ID is reserved for ingress and clsact Qdiscs"); 1348 err = -EINVAL; 1349 goto err_out3; 1350 } 1351 handle = TC_H_MAKE(TC_H_INGRESS, 0); 1352 } else { 1353 if (handle == 0) { 1354 handle = qdisc_alloc_handle(dev); 1355 if (handle == 0) { 1356 NL_SET_ERR_MSG(extack, "Maximum number of qdisc handles was exceeded"); 1357 err = -ENOSPC; 1358 goto err_out3; 1359 } 1360 } 1361 if (!netif_is_multiqueue(dev)) 1362 sch->flags |= TCQ_F_ONETXQUEUE; 1363 } 1364 1365 sch->handle = handle; 1366 1367 /* This exist to keep backward compatible with a userspace 1368 * loophole, what allowed userspace to get IFF_NO_QUEUE 1369 * facility on older kernels by setting tx_queue_len=0 (prior 1370 * to qdisc init), and then forgot to reinit tx_queue_len 1371 * before again attaching a qdisc. 1372 */ 1373 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) { 1374 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN; 1375 netdev_info(dev, "Caught tx_queue_len zero misconfig\n"); 1376 } 1377 1378 err = qdisc_block_indexes_set(sch, tca, extack); 1379 if (err) 1380 goto err_out3; 1381 1382 if (tca[TCA_STAB]) { 1383 stab = qdisc_get_stab(tca[TCA_STAB], extack); 1384 if (IS_ERR(stab)) { 1385 err = PTR_ERR(stab); 1386 goto err_out3; 1387 } 1388 rcu_assign_pointer(sch->stab, stab); 1389 } 1390 1391 if (ops->init) { 1392 err = ops->init(sch, tca[TCA_OPTIONS], extack); 1393 if (err != 0) 1394 goto err_out4; 1395 } 1396 1397 if (tca[TCA_RATE]) { 1398 err = -EOPNOTSUPP; 1399 if (sch->flags & TCQ_F_MQROOT) { 1400 NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc"); 1401 goto err_out4; 1402 } 1403 1404 err = gen_new_estimator(&sch->bstats, 1405 sch->cpu_bstats, 1406 &sch->rate_est, 1407 NULL, 1408 true, 1409 tca[TCA_RATE]); 1410 if (err) { 1411 NL_SET_ERR_MSG(extack, "Failed to generate new estimator"); 1412 goto err_out4; 1413 } 1414 } 1415 1416 qdisc_hash_add(sch, false); 1417 trace_qdisc_create(ops, dev, parent); 1418 1419 err = qdisc_block_add_dev(sch, dev, extack); 1420 if (err) 1421 goto err_out4; 1422 1423 return sch; 1424 1425 err_out4: 1426 /* Even if ops->init() failed, we call ops->destroy() 1427 * like qdisc_create_dflt(). 1428 */ 1429 if (ops->destroy) 1430 ops->destroy(sch); 1431 qdisc_put_stab(rtnl_dereference(sch->stab)); 1432 err_out3: 1433 netdev_put(dev, &sch->dev_tracker); 1434 qdisc_free(sch); 1435 err_out2: 1436 module_put(ops->owner); 1437 err_out: 1438 *errp = err; 1439 return NULL; 1440 } 1441 1442 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca, 1443 struct netlink_ext_ack *extack) 1444 { 1445 struct qdisc_size_table *ostab, *stab = NULL; 1446 int err = 0; 1447 1448 if (tca[TCA_OPTIONS]) { 1449 if (!sch->ops->change) { 1450 NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc"); 1451 return -EINVAL; 1452 } 1453 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) { 1454 NL_SET_ERR_MSG(extack, "Change of blocks is not supported"); 1455 return -EOPNOTSUPP; 1456 } 1457 err = sch->ops->change(sch, tca[TCA_OPTIONS], extack); 1458 if (err) 1459 return err; 1460 } 1461 1462 if (tca[TCA_STAB]) { 1463 stab = qdisc_get_stab(tca[TCA_STAB], extack); 1464 if (IS_ERR(stab)) 1465 return PTR_ERR(stab); 1466 } 1467 1468 ostab = rtnl_dereference(sch->stab); 1469 rcu_assign_pointer(sch->stab, stab); 1470 qdisc_put_stab(ostab); 1471 1472 if (tca[TCA_RATE]) { 1473 /* NB: ignores errors from replace_estimator 1474 because change can't be undone. */ 1475 if (sch->flags & TCQ_F_MQROOT) 1476 goto out; 1477 gen_replace_estimator(&sch->bstats, 1478 sch->cpu_bstats, 1479 &sch->rate_est, 1480 NULL, 1481 true, 1482 tca[TCA_RATE]); 1483 } 1484 out: 1485 return 0; 1486 } 1487 1488 struct check_loop_arg { 1489 struct qdisc_walker w; 1490 struct Qdisc *p; 1491 int depth; 1492 }; 1493 1494 static int check_loop_fn(struct Qdisc *q, unsigned long cl, 1495 struct qdisc_walker *w); 1496 1497 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth) 1498 { 1499 struct check_loop_arg arg; 1500 1501 if (q->ops->cl_ops == NULL) 1502 return 0; 1503 1504 arg.w.stop = arg.w.skip = arg.w.count = 0; 1505 arg.w.fn = check_loop_fn; 1506 arg.depth = depth; 1507 arg.p = p; 1508 q->ops->cl_ops->walk(q, &arg.w); 1509 return arg.w.stop ? -ELOOP : 0; 1510 } 1511 1512 static int 1513 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w) 1514 { 1515 struct Qdisc *leaf; 1516 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 1517 struct check_loop_arg *arg = (struct check_loop_arg *)w; 1518 1519 leaf = cops->leaf(q, cl); 1520 if (leaf) { 1521 if (leaf == arg->p || arg->depth > 7) 1522 return -ELOOP; 1523 return check_loop(leaf, arg->p, arg->depth + 1); 1524 } 1525 return 0; 1526 } 1527 1528 const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = { 1529 [TCA_KIND] = { .type = NLA_STRING }, 1530 [TCA_RATE] = { .type = NLA_BINARY, 1531 .len = sizeof(struct tc_estimator) }, 1532 [TCA_STAB] = { .type = NLA_NESTED }, 1533 [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG }, 1534 [TCA_CHAIN] = { .type = NLA_U32 }, 1535 [TCA_INGRESS_BLOCK] = { .type = NLA_U32 }, 1536 [TCA_EGRESS_BLOCK] = { .type = NLA_U32 }, 1537 }; 1538 1539 /* 1540 * Delete/get qdisc. 1541 */ 1542 1543 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, 1544 struct netlink_ext_ack *extack) 1545 { 1546 struct net *net = sock_net(skb->sk); 1547 struct tcmsg *tcm = nlmsg_data(n); 1548 struct nlattr *tca[TCA_MAX + 1]; 1549 struct net_device *dev; 1550 u32 clid; 1551 struct Qdisc *q = NULL; 1552 struct Qdisc *p = NULL; 1553 int err; 1554 1555 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 1556 rtm_tca_policy, extack); 1557 if (err < 0) 1558 return err; 1559 1560 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1561 if (!dev) 1562 return -ENODEV; 1563 1564 clid = tcm->tcm_parent; 1565 if (clid) { 1566 if (clid != TC_H_ROOT) { 1567 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) { 1568 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1569 if (!p) { 1570 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid"); 1571 return -ENOENT; 1572 } 1573 q = qdisc_leaf(p, clid); 1574 } else if (dev_ingress_queue(dev)) { 1575 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); 1576 } 1577 } else { 1578 q = rtnl_dereference(dev->qdisc); 1579 } 1580 if (!q) { 1581 NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device"); 1582 return -ENOENT; 1583 } 1584 1585 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) { 1586 NL_SET_ERR_MSG(extack, "Invalid handle"); 1587 return -EINVAL; 1588 } 1589 } else { 1590 q = qdisc_lookup(dev, tcm->tcm_handle); 1591 if (!q) { 1592 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle"); 1593 return -ENOENT; 1594 } 1595 } 1596 1597 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1598 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1599 return -EINVAL; 1600 } 1601 1602 if (n->nlmsg_type == RTM_DELQDISC) { 1603 if (!clid) { 1604 NL_SET_ERR_MSG(extack, "Classid cannot be zero"); 1605 return -EINVAL; 1606 } 1607 if (q->handle == 0) { 1608 NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero"); 1609 return -ENOENT; 1610 } 1611 err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack); 1612 if (err != 0) 1613 return err; 1614 } else { 1615 qdisc_get_notify(net, skb, n, clid, q, NULL); 1616 } 1617 return 0; 1618 } 1619 1620 static bool req_create_or_replace(struct nlmsghdr *n) 1621 { 1622 return (n->nlmsg_flags & NLM_F_CREATE && 1623 n->nlmsg_flags & NLM_F_REPLACE); 1624 } 1625 1626 static bool req_create_exclusive(struct nlmsghdr *n) 1627 { 1628 return (n->nlmsg_flags & NLM_F_CREATE && 1629 n->nlmsg_flags & NLM_F_EXCL); 1630 } 1631 1632 static bool req_change(struct nlmsghdr *n) 1633 { 1634 return (!(n->nlmsg_flags & NLM_F_CREATE) && 1635 !(n->nlmsg_flags & NLM_F_REPLACE) && 1636 !(n->nlmsg_flags & NLM_F_EXCL)); 1637 } 1638 1639 /* 1640 * Create/change qdisc. 1641 */ 1642 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, 1643 struct netlink_ext_ack *extack) 1644 { 1645 struct net *net = sock_net(skb->sk); 1646 struct tcmsg *tcm; 1647 struct nlattr *tca[TCA_MAX + 1]; 1648 struct net_device *dev; 1649 u32 clid; 1650 struct Qdisc *q, *p; 1651 int err; 1652 1653 replay: 1654 /* Reinit, just in case something touches this. */ 1655 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 1656 rtm_tca_policy, extack); 1657 if (err < 0) 1658 return err; 1659 1660 tcm = nlmsg_data(n); 1661 clid = tcm->tcm_parent; 1662 q = p = NULL; 1663 1664 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1665 if (!dev) 1666 return -ENODEV; 1667 1668 1669 if (clid) { 1670 if (clid != TC_H_ROOT) { 1671 if (clid != TC_H_INGRESS) { 1672 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1673 if (!p) { 1674 NL_SET_ERR_MSG(extack, "Failed to find specified qdisc"); 1675 return -ENOENT; 1676 } 1677 q = qdisc_leaf(p, clid); 1678 } else if (dev_ingress_queue_create(dev)) { 1679 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); 1680 } 1681 } else { 1682 q = rtnl_dereference(dev->qdisc); 1683 } 1684 1685 /* It may be default qdisc, ignore it */ 1686 if (q && q->handle == 0) 1687 q = NULL; 1688 1689 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) { 1690 if (tcm->tcm_handle) { 1691 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) { 1692 NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override"); 1693 return -EEXIST; 1694 } 1695 if (TC_H_MIN(tcm->tcm_handle)) { 1696 NL_SET_ERR_MSG(extack, "Invalid minor handle"); 1697 return -EINVAL; 1698 } 1699 q = qdisc_lookup(dev, tcm->tcm_handle); 1700 if (!q) 1701 goto create_n_graft; 1702 if (n->nlmsg_flags & NLM_F_EXCL) { 1703 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override"); 1704 return -EEXIST; 1705 } 1706 if (tca[TCA_KIND] && 1707 nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1708 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1709 return -EINVAL; 1710 } 1711 if (q->flags & TCQ_F_INGRESS) { 1712 NL_SET_ERR_MSG(extack, 1713 "Cannot regraft ingress or clsact Qdiscs"); 1714 return -EINVAL; 1715 } 1716 if (q == p || 1717 (p && check_loop(q, p, 0))) { 1718 NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected"); 1719 return -ELOOP; 1720 } 1721 if (clid == TC_H_INGRESS) { 1722 NL_SET_ERR_MSG(extack, "Ingress cannot graft directly"); 1723 return -EINVAL; 1724 } 1725 qdisc_refcount_inc(q); 1726 goto graft; 1727 } else { 1728 if (!q) 1729 goto create_n_graft; 1730 1731 /* This magic test requires explanation. 1732 * 1733 * We know, that some child q is already 1734 * attached to this parent and have choice: 1735 * 1) change it or 2) create/graft new one. 1736 * If the requested qdisc kind is different 1737 * than the existing one, then we choose graft. 1738 * If they are the same then this is "change" 1739 * operation - just let it fallthrough.. 1740 * 1741 * 1. We are allowed to create/graft only 1742 * if the request is explicitly stating 1743 * "please create if it doesn't exist". 1744 * 1745 * 2. If the request is to exclusive create 1746 * then the qdisc tcm_handle is not expected 1747 * to exist, so that we choose create/graft too. 1748 * 1749 * 3. The last case is when no flags are set. 1750 * This will happen when for example tc 1751 * utility issues a "change" command. 1752 * Alas, it is sort of hole in API, we 1753 * cannot decide what to do unambiguously. 1754 * For now we select create/graft. 1755 */ 1756 if (tca[TCA_KIND] && 1757 nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1758 if (req_create_or_replace(n) || 1759 req_create_exclusive(n)) 1760 goto create_n_graft; 1761 else if (req_change(n)) 1762 goto create_n_graft2; 1763 } 1764 } 1765 } 1766 } else { 1767 if (!tcm->tcm_handle) { 1768 NL_SET_ERR_MSG(extack, "Handle cannot be zero"); 1769 return -EINVAL; 1770 } 1771 q = qdisc_lookup(dev, tcm->tcm_handle); 1772 } 1773 1774 /* Change qdisc parameters */ 1775 if (!q) { 1776 NL_SET_ERR_MSG(extack, "Specified qdisc not found"); 1777 return -ENOENT; 1778 } 1779 if (n->nlmsg_flags & NLM_F_EXCL) { 1780 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify"); 1781 return -EEXIST; 1782 } 1783 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1784 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1785 return -EINVAL; 1786 } 1787 err = qdisc_change(q, tca, extack); 1788 if (err == 0) 1789 qdisc_notify(net, skb, n, clid, NULL, q, extack); 1790 return err; 1791 1792 create_n_graft: 1793 if (!(n->nlmsg_flags & NLM_F_CREATE)) { 1794 NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag"); 1795 return -ENOENT; 1796 } 1797 create_n_graft2: 1798 if (clid == TC_H_INGRESS) { 1799 if (dev_ingress_queue(dev)) { 1800 q = qdisc_create(dev, dev_ingress_queue(dev), 1801 tcm->tcm_parent, tcm->tcm_parent, 1802 tca, &err, extack); 1803 } else { 1804 NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device"); 1805 err = -ENOENT; 1806 } 1807 } else { 1808 struct netdev_queue *dev_queue; 1809 1810 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue) 1811 dev_queue = p->ops->cl_ops->select_queue(p, tcm); 1812 else if (p) 1813 dev_queue = p->dev_queue; 1814 else 1815 dev_queue = netdev_get_tx_queue(dev, 0); 1816 1817 q = qdisc_create(dev, dev_queue, 1818 tcm->tcm_parent, tcm->tcm_handle, 1819 tca, &err, extack); 1820 } 1821 if (q == NULL) { 1822 if (err == -EAGAIN) 1823 goto replay; 1824 return err; 1825 } 1826 1827 graft: 1828 err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack); 1829 if (err) { 1830 if (q) 1831 qdisc_put(q); 1832 return err; 1833 } 1834 1835 return 0; 1836 } 1837 1838 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb, 1839 struct netlink_callback *cb, 1840 int *q_idx_p, int s_q_idx, bool recur, 1841 bool dump_invisible) 1842 { 1843 int ret = 0, q_idx = *q_idx_p; 1844 struct Qdisc *q; 1845 int b; 1846 1847 if (!root) 1848 return 0; 1849 1850 q = root; 1851 if (q_idx < s_q_idx) { 1852 q_idx++; 1853 } else { 1854 if (!tc_qdisc_dump_ignore(q, dump_invisible) && 1855 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1856 cb->nlh->nlmsg_seq, NLM_F_MULTI, 1857 RTM_NEWQDISC, NULL) <= 0) 1858 goto done; 1859 q_idx++; 1860 } 1861 1862 /* If dumping singletons, there is no qdisc_dev(root) and the singleton 1863 * itself has already been dumped. 1864 * 1865 * If we've already dumped the top-level (ingress) qdisc above and the global 1866 * qdisc hashtable, we don't want to hit it again 1867 */ 1868 if (!qdisc_dev(root) || !recur) 1869 goto out; 1870 1871 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { 1872 if (q_idx < s_q_idx) { 1873 q_idx++; 1874 continue; 1875 } 1876 if (!tc_qdisc_dump_ignore(q, dump_invisible) && 1877 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1878 cb->nlh->nlmsg_seq, NLM_F_MULTI, 1879 RTM_NEWQDISC, NULL) <= 0) 1880 goto done; 1881 q_idx++; 1882 } 1883 1884 out: 1885 *q_idx_p = q_idx; 1886 return ret; 1887 done: 1888 ret = -1; 1889 goto out; 1890 } 1891 1892 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb) 1893 { 1894 struct net *net = sock_net(skb->sk); 1895 int idx, q_idx; 1896 int s_idx, s_q_idx; 1897 struct net_device *dev; 1898 const struct nlmsghdr *nlh = cb->nlh; 1899 struct nlattr *tca[TCA_MAX + 1]; 1900 int err; 1901 1902 s_idx = cb->args[0]; 1903 s_q_idx = q_idx = cb->args[1]; 1904 1905 idx = 0; 1906 ASSERT_RTNL(); 1907 1908 err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX, 1909 rtm_tca_policy, cb->extack); 1910 if (err < 0) 1911 return err; 1912 1913 for_each_netdev(net, dev) { 1914 struct netdev_queue *dev_queue; 1915 1916 if (idx < s_idx) 1917 goto cont; 1918 if (idx > s_idx) 1919 s_q_idx = 0; 1920 q_idx = 0; 1921 1922 if (tc_dump_qdisc_root(rtnl_dereference(dev->qdisc), 1923 skb, cb, &q_idx, s_q_idx, 1924 true, tca[TCA_DUMP_INVISIBLE]) < 0) 1925 goto done; 1926 1927 dev_queue = dev_ingress_queue(dev); 1928 if (dev_queue && 1929 tc_dump_qdisc_root(rtnl_dereference(dev_queue->qdisc_sleeping), 1930 skb, cb, &q_idx, s_q_idx, false, 1931 tca[TCA_DUMP_INVISIBLE]) < 0) 1932 goto done; 1933 1934 cont: 1935 idx++; 1936 } 1937 1938 done: 1939 cb->args[0] = idx; 1940 cb->args[1] = q_idx; 1941 1942 return skb->len; 1943 } 1944 1945 1946 1947 /************************************************ 1948 * Traffic classes manipulation. * 1949 ************************************************/ 1950 1951 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, 1952 unsigned long cl, u32 portid, u32 seq, u16 flags, 1953 int event, struct netlink_ext_ack *extack) 1954 { 1955 struct tcmsg *tcm; 1956 struct nlmsghdr *nlh; 1957 unsigned char *b = skb_tail_pointer(skb); 1958 struct gnet_dump d; 1959 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops; 1960 1961 cond_resched(); 1962 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 1963 if (!nlh) 1964 goto out_nlmsg_trim; 1965 tcm = nlmsg_data(nlh); 1966 tcm->tcm_family = AF_UNSPEC; 1967 tcm->tcm__pad1 = 0; 1968 tcm->tcm__pad2 = 0; 1969 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 1970 tcm->tcm_parent = q->handle; 1971 tcm->tcm_handle = q->handle; 1972 tcm->tcm_info = 0; 1973 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 1974 goto nla_put_failure; 1975 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0) 1976 goto nla_put_failure; 1977 1978 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 1979 NULL, &d, TCA_PAD) < 0) 1980 goto nla_put_failure; 1981 1982 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0) 1983 goto nla_put_failure; 1984 1985 if (gnet_stats_finish_copy(&d) < 0) 1986 goto nla_put_failure; 1987 1988 if (extack && extack->_msg && 1989 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg)) 1990 goto out_nlmsg_trim; 1991 1992 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 1993 1994 return skb->len; 1995 1996 out_nlmsg_trim: 1997 nla_put_failure: 1998 nlmsg_trim(skb, b); 1999 return -1; 2000 } 2001 2002 static int tclass_notify(struct net *net, struct sk_buff *oskb, 2003 struct nlmsghdr *n, struct Qdisc *q, 2004 unsigned long cl, int event, struct netlink_ext_ack *extack) 2005 { 2006 struct sk_buff *skb; 2007 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 2008 2009 if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) 2010 return 0; 2011 2012 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2013 if (!skb) 2014 return -ENOBUFS; 2015 2016 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event, extack) < 0) { 2017 kfree_skb(skb); 2018 return -EINVAL; 2019 } 2020 2021 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 2022 n->nlmsg_flags & NLM_F_ECHO); 2023 } 2024 2025 static int tclass_get_notify(struct net *net, struct sk_buff *oskb, 2026 struct nlmsghdr *n, struct Qdisc *q, 2027 unsigned long cl, struct netlink_ext_ack *extack) 2028 { 2029 struct sk_buff *skb; 2030 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 2031 2032 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2033 if (!skb) 2034 return -ENOBUFS; 2035 2036 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, RTM_NEWTCLASS, 2037 extack) < 0) { 2038 kfree_skb(skb); 2039 return -EINVAL; 2040 } 2041 2042 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 2043 n->nlmsg_flags & NLM_F_ECHO); 2044 } 2045 2046 static int tclass_del_notify(struct net *net, 2047 const struct Qdisc_class_ops *cops, 2048 struct sk_buff *oskb, struct nlmsghdr *n, 2049 struct Qdisc *q, unsigned long cl, 2050 struct netlink_ext_ack *extack) 2051 { 2052 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 2053 struct sk_buff *skb; 2054 int err = 0; 2055 2056 if (!cops->delete) 2057 return -EOPNOTSUPP; 2058 2059 if (rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) { 2060 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2061 if (!skb) 2062 return -ENOBUFS; 2063 2064 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, 2065 RTM_DELTCLASS, extack) < 0) { 2066 kfree_skb(skb); 2067 return -EINVAL; 2068 } 2069 } else { 2070 skb = NULL; 2071 } 2072 2073 err = cops->delete(q, cl, extack); 2074 if (err) { 2075 kfree_skb(skb); 2076 return err; 2077 } 2078 2079 err = rtnetlink_maybe_send(skb, net, portid, RTNLGRP_TC, 2080 n->nlmsg_flags & NLM_F_ECHO); 2081 return err; 2082 } 2083 2084 #ifdef CONFIG_NET_CLS 2085 2086 struct tcf_bind_args { 2087 struct tcf_walker w; 2088 unsigned long base; 2089 unsigned long cl; 2090 u32 classid; 2091 }; 2092 2093 static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg) 2094 { 2095 struct tcf_bind_args *a = (void *)arg; 2096 2097 if (n && tp->ops->bind_class) { 2098 struct Qdisc *q = tcf_block_q(tp->chain->block); 2099 2100 sch_tree_lock(q); 2101 tp->ops->bind_class(n, a->classid, a->cl, q, a->base); 2102 sch_tree_unlock(q); 2103 } 2104 return 0; 2105 } 2106 2107 struct tc_bind_class_args { 2108 struct qdisc_walker w; 2109 unsigned long new_cl; 2110 u32 portid; 2111 u32 clid; 2112 }; 2113 2114 static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl, 2115 struct qdisc_walker *w) 2116 { 2117 struct tc_bind_class_args *a = (struct tc_bind_class_args *)w; 2118 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 2119 struct tcf_block *block; 2120 struct tcf_chain *chain; 2121 2122 block = cops->tcf_block(q, cl, NULL); 2123 if (!block) 2124 return 0; 2125 for (chain = tcf_get_next_chain(block, NULL); 2126 chain; 2127 chain = tcf_get_next_chain(block, chain)) { 2128 struct tcf_proto *tp; 2129 2130 for (tp = tcf_get_next_proto(chain, NULL); 2131 tp; tp = tcf_get_next_proto(chain, tp)) { 2132 struct tcf_bind_args arg = {}; 2133 2134 arg.w.fn = tcf_node_bind; 2135 arg.classid = a->clid; 2136 arg.base = cl; 2137 arg.cl = a->new_cl; 2138 tp->ops->walk(tp, &arg.w, true); 2139 } 2140 } 2141 2142 return 0; 2143 } 2144 2145 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, 2146 unsigned long new_cl) 2147 { 2148 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 2149 struct tc_bind_class_args args = {}; 2150 2151 if (!cops->tcf_block) 2152 return; 2153 args.portid = portid; 2154 args.clid = clid; 2155 args.new_cl = new_cl; 2156 args.w.fn = tc_bind_class_walker; 2157 q->ops->cl_ops->walk(q, &args.w); 2158 } 2159 2160 #else 2161 2162 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, 2163 unsigned long new_cl) 2164 { 2165 } 2166 2167 #endif 2168 2169 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, 2170 struct netlink_ext_ack *extack) 2171 { 2172 struct net *net = sock_net(skb->sk); 2173 struct tcmsg *tcm = nlmsg_data(n); 2174 struct nlattr *tca[TCA_MAX + 1]; 2175 struct net_device *dev; 2176 struct Qdisc *q = NULL; 2177 const struct Qdisc_class_ops *cops; 2178 unsigned long cl = 0; 2179 unsigned long new_cl; 2180 u32 portid; 2181 u32 clid; 2182 u32 qid; 2183 int err; 2184 2185 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 2186 rtm_tca_policy, extack); 2187 if (err < 0) 2188 return err; 2189 2190 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 2191 if (!dev) 2192 return -ENODEV; 2193 2194 /* 2195 parent == TC_H_UNSPEC - unspecified parent. 2196 parent == TC_H_ROOT - class is root, which has no parent. 2197 parent == X:0 - parent is root class. 2198 parent == X:Y - parent is a node in hierarchy. 2199 parent == 0:Y - parent is X:Y, where X:0 is qdisc. 2200 2201 handle == 0:0 - generate handle from kernel pool. 2202 handle == 0:Y - class is X:Y, where X:0 is qdisc. 2203 handle == X:Y - clear. 2204 handle == X:0 - root class. 2205 */ 2206 2207 /* Step 1. Determine qdisc handle X:0 */ 2208 2209 portid = tcm->tcm_parent; 2210 clid = tcm->tcm_handle; 2211 qid = TC_H_MAJ(clid); 2212 2213 if (portid != TC_H_ROOT) { 2214 u32 qid1 = TC_H_MAJ(portid); 2215 2216 if (qid && qid1) { 2217 /* If both majors are known, they must be identical. */ 2218 if (qid != qid1) 2219 return -EINVAL; 2220 } else if (qid1) { 2221 qid = qid1; 2222 } else if (qid == 0) 2223 qid = rtnl_dereference(dev->qdisc)->handle; 2224 2225 /* Now qid is genuine qdisc handle consistent 2226 * both with parent and child. 2227 * 2228 * TC_H_MAJ(portid) still may be unspecified, complete it now. 2229 */ 2230 if (portid) 2231 portid = TC_H_MAKE(qid, portid); 2232 } else { 2233 if (qid == 0) 2234 qid = rtnl_dereference(dev->qdisc)->handle; 2235 } 2236 2237 /* OK. Locate qdisc */ 2238 q = qdisc_lookup(dev, qid); 2239 if (!q) 2240 return -ENOENT; 2241 2242 /* An check that it supports classes */ 2243 cops = q->ops->cl_ops; 2244 if (cops == NULL) 2245 return -EINVAL; 2246 2247 /* Now try to get class */ 2248 if (clid == 0) { 2249 if (portid == TC_H_ROOT) 2250 clid = qid; 2251 } else 2252 clid = TC_H_MAKE(qid, clid); 2253 2254 if (clid) 2255 cl = cops->find(q, clid); 2256 2257 if (cl == 0) { 2258 err = -ENOENT; 2259 if (n->nlmsg_type != RTM_NEWTCLASS || 2260 !(n->nlmsg_flags & NLM_F_CREATE)) 2261 goto out; 2262 } else { 2263 switch (n->nlmsg_type) { 2264 case RTM_NEWTCLASS: 2265 err = -EEXIST; 2266 if (n->nlmsg_flags & NLM_F_EXCL) 2267 goto out; 2268 break; 2269 case RTM_DELTCLASS: 2270 err = tclass_del_notify(net, cops, skb, n, q, cl, extack); 2271 /* Unbind the class with flilters with 0 */ 2272 tc_bind_tclass(q, portid, clid, 0); 2273 goto out; 2274 case RTM_GETTCLASS: 2275 err = tclass_get_notify(net, skb, n, q, cl, extack); 2276 goto out; 2277 default: 2278 err = -EINVAL; 2279 goto out; 2280 } 2281 } 2282 2283 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) { 2284 NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes"); 2285 return -EOPNOTSUPP; 2286 } 2287 2288 new_cl = cl; 2289 err = -EOPNOTSUPP; 2290 if (cops->change) 2291 err = cops->change(q, clid, portid, tca, &new_cl, extack); 2292 if (err == 0) { 2293 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS, extack); 2294 /* We just create a new class, need to do reverse binding. */ 2295 if (cl != new_cl) 2296 tc_bind_tclass(q, portid, clid, new_cl); 2297 } 2298 out: 2299 return err; 2300 } 2301 2302 struct qdisc_dump_args { 2303 struct qdisc_walker w; 2304 struct sk_buff *skb; 2305 struct netlink_callback *cb; 2306 }; 2307 2308 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, 2309 struct qdisc_walker *arg) 2310 { 2311 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg; 2312 2313 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid, 2314 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, 2315 RTM_NEWTCLASS, NULL); 2316 } 2317 2318 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb, 2319 struct tcmsg *tcm, struct netlink_callback *cb, 2320 int *t_p, int s_t) 2321 { 2322 struct qdisc_dump_args arg; 2323 2324 if (tc_qdisc_dump_ignore(q, false) || 2325 *t_p < s_t || !q->ops->cl_ops || 2326 (tcm->tcm_parent && 2327 TC_H_MAJ(tcm->tcm_parent) != q->handle)) { 2328 (*t_p)++; 2329 return 0; 2330 } 2331 if (*t_p > s_t) 2332 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); 2333 arg.w.fn = qdisc_class_dump; 2334 arg.skb = skb; 2335 arg.cb = cb; 2336 arg.w.stop = 0; 2337 arg.w.skip = cb->args[1]; 2338 arg.w.count = 0; 2339 q->ops->cl_ops->walk(q, &arg.w); 2340 cb->args[1] = arg.w.count; 2341 if (arg.w.stop) 2342 return -1; 2343 (*t_p)++; 2344 return 0; 2345 } 2346 2347 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb, 2348 struct tcmsg *tcm, struct netlink_callback *cb, 2349 int *t_p, int s_t, bool recur) 2350 { 2351 struct Qdisc *q; 2352 int b; 2353 2354 if (!root) 2355 return 0; 2356 2357 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0) 2358 return -1; 2359 2360 if (!qdisc_dev(root) || !recur) 2361 return 0; 2362 2363 if (tcm->tcm_parent) { 2364 q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent)); 2365 if (q && q != root && 2366 tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 2367 return -1; 2368 return 0; 2369 } 2370 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { 2371 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 2372 return -1; 2373 } 2374 2375 return 0; 2376 } 2377 2378 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb) 2379 { 2380 struct tcmsg *tcm = nlmsg_data(cb->nlh); 2381 struct net *net = sock_net(skb->sk); 2382 struct netdev_queue *dev_queue; 2383 struct net_device *dev; 2384 int t, s_t; 2385 2386 if (nlmsg_len(cb->nlh) < sizeof(*tcm)) 2387 return 0; 2388 dev = dev_get_by_index(net, tcm->tcm_ifindex); 2389 if (!dev) 2390 return 0; 2391 2392 s_t = cb->args[0]; 2393 t = 0; 2394 2395 if (tc_dump_tclass_root(rtnl_dereference(dev->qdisc), 2396 skb, tcm, cb, &t, s_t, true) < 0) 2397 goto done; 2398 2399 dev_queue = dev_ingress_queue(dev); 2400 if (dev_queue && 2401 tc_dump_tclass_root(rtnl_dereference(dev_queue->qdisc_sleeping), 2402 skb, tcm, cb, &t, s_t, false) < 0) 2403 goto done; 2404 2405 done: 2406 cb->args[0] = t; 2407 2408 dev_put(dev); 2409 return skb->len; 2410 } 2411 2412 #ifdef CONFIG_PROC_FS 2413 static int psched_show(struct seq_file *seq, void *v) 2414 { 2415 seq_printf(seq, "%08x %08x %08x %08x\n", 2416 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1), 2417 1000000, 2418 (u32)NSEC_PER_SEC / hrtimer_resolution); 2419 2420 return 0; 2421 } 2422 2423 static int __net_init psched_net_init(struct net *net) 2424 { 2425 struct proc_dir_entry *e; 2426 2427 e = proc_create_single("psched", 0, net->proc_net, psched_show); 2428 if (e == NULL) 2429 return -ENOMEM; 2430 2431 return 0; 2432 } 2433 2434 static void __net_exit psched_net_exit(struct net *net) 2435 { 2436 remove_proc_entry("psched", net->proc_net); 2437 } 2438 #else 2439 static int __net_init psched_net_init(struct net *net) 2440 { 2441 return 0; 2442 } 2443 2444 static void __net_exit psched_net_exit(struct net *net) 2445 { 2446 } 2447 #endif 2448 2449 static struct pernet_operations psched_net_ops = { 2450 .init = psched_net_init, 2451 .exit = psched_net_exit, 2452 }; 2453 2454 #if IS_ENABLED(CONFIG_RETPOLINE) 2455 DEFINE_STATIC_KEY_FALSE(tc_skip_wrapper); 2456 #endif 2457 2458 static int __init pktsched_init(void) 2459 { 2460 int err; 2461 2462 err = register_pernet_subsys(&psched_net_ops); 2463 if (err) { 2464 pr_err("pktsched_init: " 2465 "cannot initialize per netns operations\n"); 2466 return err; 2467 } 2468 2469 register_qdisc(&pfifo_fast_ops); 2470 register_qdisc(&pfifo_qdisc_ops); 2471 register_qdisc(&bfifo_qdisc_ops); 2472 register_qdisc(&pfifo_head_drop_qdisc_ops); 2473 register_qdisc(&mq_qdisc_ops); 2474 register_qdisc(&noqueue_qdisc_ops); 2475 2476 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, 0); 2477 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, 0); 2478 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, 2479 0); 2480 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, 0); 2481 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, 0); 2482 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, 2483 0); 2484 2485 tc_wrapper_init(); 2486 2487 return 0; 2488 } 2489 2490 subsys_initcall(pktsched_init); 2491