1 /* 2 * net/sched/sch_api.c Packet scheduler API. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 10 * 11 * Fixes: 12 * 13 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired. 14 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support 15 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support 16 */ 17 18 #include <linux/module.h> 19 #include <linux/types.h> 20 #include <linux/kernel.h> 21 #include <linux/string.h> 22 #include <linux/errno.h> 23 #include <linux/skbuff.h> 24 #include <linux/init.h> 25 #include <linux/proc_fs.h> 26 #include <linux/seq_file.h> 27 #include <linux/kmod.h> 28 #include <linux/list.h> 29 #include <linux/hrtimer.h> 30 #include <linux/lockdep.h> 31 #include <linux/slab.h> 32 33 #include <net/net_namespace.h> 34 #include <net/sock.h> 35 #include <net/netlink.h> 36 #include <net/pkt_sched.h> 37 38 static int qdisc_notify(struct net *net, struct sk_buff *oskb, 39 struct nlmsghdr *n, u32 clid, 40 struct Qdisc *old, struct Qdisc *new); 41 static int tclass_notify(struct net *net, struct sk_buff *oskb, 42 struct nlmsghdr *n, struct Qdisc *q, 43 unsigned long cl, int event); 44 45 /* 46 47 Short review. 48 ------------- 49 50 This file consists of two interrelated parts: 51 52 1. queueing disciplines manager frontend. 53 2. traffic classes manager frontend. 54 55 Generally, queueing discipline ("qdisc") is a black box, 56 which is able to enqueue packets and to dequeue them (when 57 device is ready to send something) in order and at times 58 determined by algorithm hidden in it. 59 60 qdisc's are divided to two categories: 61 - "queues", which have no internal structure visible from outside. 62 - "schedulers", which split all the packets to "traffic classes", 63 using "packet classifiers" (look at cls_api.c) 64 65 In turn, classes may have child qdiscs (as rule, queues) 66 attached to them etc. etc. etc. 67 68 The goal of the routines in this file is to translate 69 information supplied by user in the form of handles 70 to more intelligible for kernel form, to make some sanity 71 checks and part of work, which is common to all qdiscs 72 and to provide rtnetlink notifications. 73 74 All real intelligent work is done inside qdisc modules. 75 76 77 78 Every discipline has two major routines: enqueue and dequeue. 79 80 ---dequeue 81 82 dequeue usually returns a skb to send. It is allowed to return NULL, 83 but it does not mean that queue is empty, it just means that 84 discipline does not want to send anything this time. 85 Queue is really empty if q->q.qlen == 0. 86 For complicated disciplines with multiple queues q->q is not 87 real packet queue, but however q->q.qlen must be valid. 88 89 ---enqueue 90 91 enqueue returns 0, if packet was enqueued successfully. 92 If packet (this one or another one) was dropped, it returns 93 not zero error code. 94 NET_XMIT_DROP - this packet dropped 95 Expected action: do not backoff, but wait until queue will clear. 96 NET_XMIT_CN - probably this packet enqueued, but another one dropped. 97 Expected action: backoff or ignore 98 NET_XMIT_POLICED - dropped by police. 99 Expected action: backoff or error to real-time apps. 100 101 Auxiliary routines: 102 103 ---peek 104 105 like dequeue but without removing a packet from the queue 106 107 ---reset 108 109 returns qdisc to initial state: purge all buffers, clear all 110 timers, counters (except for statistics) etc. 111 112 ---init 113 114 initializes newly created qdisc. 115 116 ---destroy 117 118 destroys resources allocated by init and during lifetime of qdisc. 119 120 ---change 121 122 changes qdisc parameters. 123 */ 124 125 /* Protects list of registered TC modules. It is pure SMP lock. */ 126 static DEFINE_RWLOCK(qdisc_mod_lock); 127 128 129 /************************************************ 130 * Queueing disciplines manipulation. * 131 ************************************************/ 132 133 134 /* The list of all installed queueing disciplines. */ 135 136 static struct Qdisc_ops *qdisc_base; 137 138 /* Register/unregister queueing discipline */ 139 140 int register_qdisc(struct Qdisc_ops *qops) 141 { 142 struct Qdisc_ops *q, **qp; 143 int rc = -EEXIST; 144 145 write_lock(&qdisc_mod_lock); 146 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next) 147 if (!strcmp(qops->id, q->id)) 148 goto out; 149 150 if (qops->enqueue == NULL) 151 qops->enqueue = noop_qdisc_ops.enqueue; 152 if (qops->peek == NULL) { 153 if (qops->dequeue == NULL) 154 qops->peek = noop_qdisc_ops.peek; 155 else 156 goto out_einval; 157 } 158 if (qops->dequeue == NULL) 159 qops->dequeue = noop_qdisc_ops.dequeue; 160 161 if (qops->cl_ops) { 162 const struct Qdisc_class_ops *cops = qops->cl_ops; 163 164 if (!(cops->get && cops->put && cops->walk && cops->leaf)) 165 goto out_einval; 166 167 if (cops->tcf_chain && !(cops->bind_tcf && cops->unbind_tcf)) 168 goto out_einval; 169 } 170 171 qops->next = NULL; 172 *qp = qops; 173 rc = 0; 174 out: 175 write_unlock(&qdisc_mod_lock); 176 return rc; 177 178 out_einval: 179 rc = -EINVAL; 180 goto out; 181 } 182 EXPORT_SYMBOL(register_qdisc); 183 184 int unregister_qdisc(struct Qdisc_ops *qops) 185 { 186 struct Qdisc_ops *q, **qp; 187 int err = -ENOENT; 188 189 write_lock(&qdisc_mod_lock); 190 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next) 191 if (q == qops) 192 break; 193 if (q) { 194 *qp = q->next; 195 q->next = NULL; 196 err = 0; 197 } 198 write_unlock(&qdisc_mod_lock); 199 return err; 200 } 201 EXPORT_SYMBOL(unregister_qdisc); 202 203 /* Get default qdisc if not otherwise specified */ 204 void qdisc_get_default(char *name, size_t len) 205 { 206 read_lock(&qdisc_mod_lock); 207 strlcpy(name, default_qdisc_ops->id, len); 208 read_unlock(&qdisc_mod_lock); 209 } 210 211 static struct Qdisc_ops *qdisc_lookup_default(const char *name) 212 { 213 struct Qdisc_ops *q = NULL; 214 215 for (q = qdisc_base; q; q = q->next) { 216 if (!strcmp(name, q->id)) { 217 if (!try_module_get(q->owner)) 218 q = NULL; 219 break; 220 } 221 } 222 223 return q; 224 } 225 226 /* Set new default qdisc to use */ 227 int qdisc_set_default(const char *name) 228 { 229 const struct Qdisc_ops *ops; 230 231 if (!capable(CAP_NET_ADMIN)) 232 return -EPERM; 233 234 write_lock(&qdisc_mod_lock); 235 ops = qdisc_lookup_default(name); 236 if (!ops) { 237 /* Not found, drop lock and try to load module */ 238 write_unlock(&qdisc_mod_lock); 239 request_module("sch_%s", name); 240 write_lock(&qdisc_mod_lock); 241 242 ops = qdisc_lookup_default(name); 243 } 244 245 if (ops) { 246 /* Set new default */ 247 module_put(default_qdisc_ops->owner); 248 default_qdisc_ops = ops; 249 } 250 write_unlock(&qdisc_mod_lock); 251 252 return ops ? 0 : -ENOENT; 253 } 254 255 /* We know handle. Find qdisc among all qdisc's attached to device 256 * (root qdisc, all its children, children of children etc.) 257 * Note: caller either uses rtnl or rcu_read_lock() 258 */ 259 260 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle) 261 { 262 struct Qdisc *q; 263 264 if (!(root->flags & TCQ_F_BUILTIN) && 265 root->handle == handle) 266 return root; 267 268 list_for_each_entry_rcu(q, &root->list, list) { 269 if (q->handle == handle) 270 return q; 271 } 272 return NULL; 273 } 274 275 void qdisc_list_add(struct Qdisc *q) 276 { 277 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) { 278 struct Qdisc *root = qdisc_dev(q)->qdisc; 279 280 WARN_ON_ONCE(root == &noop_qdisc); 281 ASSERT_RTNL(); 282 list_add_tail_rcu(&q->list, &root->list); 283 } 284 } 285 EXPORT_SYMBOL(qdisc_list_add); 286 287 void qdisc_list_del(struct Qdisc *q) 288 { 289 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) { 290 ASSERT_RTNL(); 291 list_del_rcu(&q->list); 292 } 293 } 294 EXPORT_SYMBOL(qdisc_list_del); 295 296 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle) 297 { 298 struct Qdisc *q; 299 300 q = qdisc_match_from_root(dev->qdisc, handle); 301 if (q) 302 goto out; 303 304 if (dev_ingress_queue(dev)) 305 q = qdisc_match_from_root( 306 dev_ingress_queue(dev)->qdisc_sleeping, 307 handle); 308 out: 309 return q; 310 } 311 312 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid) 313 { 314 unsigned long cl; 315 struct Qdisc *leaf; 316 const struct Qdisc_class_ops *cops = p->ops->cl_ops; 317 318 if (cops == NULL) 319 return NULL; 320 cl = cops->get(p, classid); 321 322 if (cl == 0) 323 return NULL; 324 leaf = cops->leaf(p, cl); 325 cops->put(p, cl); 326 return leaf; 327 } 328 329 /* Find queueing discipline by name */ 330 331 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind) 332 { 333 struct Qdisc_ops *q = NULL; 334 335 if (kind) { 336 read_lock(&qdisc_mod_lock); 337 for (q = qdisc_base; q; q = q->next) { 338 if (nla_strcmp(kind, q->id) == 0) { 339 if (!try_module_get(q->owner)) 340 q = NULL; 341 break; 342 } 343 } 344 read_unlock(&qdisc_mod_lock); 345 } 346 return q; 347 } 348 349 /* The linklayer setting were not transferred from iproute2, in older 350 * versions, and the rate tables lookup systems have been dropped in 351 * the kernel. To keep backward compatible with older iproute2 tc 352 * utils, we detect the linklayer setting by detecting if the rate 353 * table were modified. 354 * 355 * For linklayer ATM table entries, the rate table will be aligned to 356 * 48 bytes, thus some table entries will contain the same value. The 357 * mpu (min packet unit) is also encoded into the old rate table, thus 358 * starting from the mpu, we find low and high table entries for 359 * mapping this cell. If these entries contain the same value, when 360 * the rate tables have been modified for linklayer ATM. 361 * 362 * This is done by rounding mpu to the nearest 48 bytes cell/entry, 363 * and then roundup to the next cell, calc the table entry one below, 364 * and compare. 365 */ 366 static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab) 367 { 368 int low = roundup(r->mpu, 48); 369 int high = roundup(low+1, 48); 370 int cell_low = low >> r->cell_log; 371 int cell_high = (high >> r->cell_log) - 1; 372 373 /* rtab is too inaccurate at rates > 100Mbit/s */ 374 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) { 375 pr_debug("TC linklayer: Giving up ATM detection\n"); 376 return TC_LINKLAYER_ETHERNET; 377 } 378 379 if ((cell_high > cell_low) && (cell_high < 256) 380 && (rtab[cell_low] == rtab[cell_high])) { 381 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n", 382 cell_low, cell_high, rtab[cell_high]); 383 return TC_LINKLAYER_ATM; 384 } 385 return TC_LINKLAYER_ETHERNET; 386 } 387 388 static struct qdisc_rate_table *qdisc_rtab_list; 389 390 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct nlattr *tab) 391 { 392 struct qdisc_rate_table *rtab; 393 394 if (tab == NULL || r->rate == 0 || r->cell_log == 0 || 395 nla_len(tab) != TC_RTAB_SIZE) 396 return NULL; 397 398 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) { 399 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) && 400 !memcmp(&rtab->data, nla_data(tab), 1024)) { 401 rtab->refcnt++; 402 return rtab; 403 } 404 } 405 406 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL); 407 if (rtab) { 408 rtab->rate = *r; 409 rtab->refcnt = 1; 410 memcpy(rtab->data, nla_data(tab), 1024); 411 if (r->linklayer == TC_LINKLAYER_UNAWARE) 412 r->linklayer = __detect_linklayer(r, rtab->data); 413 rtab->next = qdisc_rtab_list; 414 qdisc_rtab_list = rtab; 415 } 416 return rtab; 417 } 418 EXPORT_SYMBOL(qdisc_get_rtab); 419 420 void qdisc_put_rtab(struct qdisc_rate_table *tab) 421 { 422 struct qdisc_rate_table *rtab, **rtabp; 423 424 if (!tab || --tab->refcnt) 425 return; 426 427 for (rtabp = &qdisc_rtab_list; 428 (rtab = *rtabp) != NULL; 429 rtabp = &rtab->next) { 430 if (rtab == tab) { 431 *rtabp = rtab->next; 432 kfree(rtab); 433 return; 434 } 435 } 436 } 437 EXPORT_SYMBOL(qdisc_put_rtab); 438 439 static LIST_HEAD(qdisc_stab_list); 440 static DEFINE_SPINLOCK(qdisc_stab_lock); 441 442 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = { 443 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) }, 444 [TCA_STAB_DATA] = { .type = NLA_BINARY }, 445 }; 446 447 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt) 448 { 449 struct nlattr *tb[TCA_STAB_MAX + 1]; 450 struct qdisc_size_table *stab; 451 struct tc_sizespec *s; 452 unsigned int tsize = 0; 453 u16 *tab = NULL; 454 int err; 455 456 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy); 457 if (err < 0) 458 return ERR_PTR(err); 459 if (!tb[TCA_STAB_BASE]) 460 return ERR_PTR(-EINVAL); 461 462 s = nla_data(tb[TCA_STAB_BASE]); 463 464 if (s->tsize > 0) { 465 if (!tb[TCA_STAB_DATA]) 466 return ERR_PTR(-EINVAL); 467 tab = nla_data(tb[TCA_STAB_DATA]); 468 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16); 469 } 470 471 if (tsize != s->tsize || (!tab && tsize > 0)) 472 return ERR_PTR(-EINVAL); 473 474 spin_lock(&qdisc_stab_lock); 475 476 list_for_each_entry(stab, &qdisc_stab_list, list) { 477 if (memcmp(&stab->szopts, s, sizeof(*s))) 478 continue; 479 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16))) 480 continue; 481 stab->refcnt++; 482 spin_unlock(&qdisc_stab_lock); 483 return stab; 484 } 485 486 spin_unlock(&qdisc_stab_lock); 487 488 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL); 489 if (!stab) 490 return ERR_PTR(-ENOMEM); 491 492 stab->refcnt = 1; 493 stab->szopts = *s; 494 if (tsize > 0) 495 memcpy(stab->data, tab, tsize * sizeof(u16)); 496 497 spin_lock(&qdisc_stab_lock); 498 list_add_tail(&stab->list, &qdisc_stab_list); 499 spin_unlock(&qdisc_stab_lock); 500 501 return stab; 502 } 503 504 static void stab_kfree_rcu(struct rcu_head *head) 505 { 506 kfree(container_of(head, struct qdisc_size_table, rcu)); 507 } 508 509 void qdisc_put_stab(struct qdisc_size_table *tab) 510 { 511 if (!tab) 512 return; 513 514 spin_lock(&qdisc_stab_lock); 515 516 if (--tab->refcnt == 0) { 517 list_del(&tab->list); 518 call_rcu_bh(&tab->rcu, stab_kfree_rcu); 519 } 520 521 spin_unlock(&qdisc_stab_lock); 522 } 523 EXPORT_SYMBOL(qdisc_put_stab); 524 525 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab) 526 { 527 struct nlattr *nest; 528 529 nest = nla_nest_start(skb, TCA_STAB); 530 if (nest == NULL) 531 goto nla_put_failure; 532 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts)) 533 goto nla_put_failure; 534 nla_nest_end(skb, nest); 535 536 return skb->len; 537 538 nla_put_failure: 539 return -1; 540 } 541 542 void __qdisc_calculate_pkt_len(struct sk_buff *skb, const struct qdisc_size_table *stab) 543 { 544 int pkt_len, slot; 545 546 pkt_len = skb->len + stab->szopts.overhead; 547 if (unlikely(!stab->szopts.tsize)) 548 goto out; 549 550 slot = pkt_len + stab->szopts.cell_align; 551 if (unlikely(slot < 0)) 552 slot = 0; 553 554 slot >>= stab->szopts.cell_log; 555 if (likely(slot < stab->szopts.tsize)) 556 pkt_len = stab->data[slot]; 557 else 558 pkt_len = stab->data[stab->szopts.tsize - 1] * 559 (slot / stab->szopts.tsize) + 560 stab->data[slot % stab->szopts.tsize]; 561 562 pkt_len <<= stab->szopts.size_log; 563 out: 564 if (unlikely(pkt_len < 1)) 565 pkt_len = 1; 566 qdisc_skb_cb(skb)->pkt_len = pkt_len; 567 } 568 EXPORT_SYMBOL(__qdisc_calculate_pkt_len); 569 570 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc) 571 { 572 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) { 573 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n", 574 txt, qdisc->ops->id, qdisc->handle >> 16); 575 qdisc->flags |= TCQ_F_WARN_NONWC; 576 } 577 } 578 EXPORT_SYMBOL(qdisc_warn_nonwc); 579 580 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer) 581 { 582 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog, 583 timer); 584 585 rcu_read_lock(); 586 qdisc_unthrottled(wd->qdisc); 587 __netif_schedule(qdisc_root(wd->qdisc)); 588 rcu_read_unlock(); 589 590 return HRTIMER_NORESTART; 591 } 592 593 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc) 594 { 595 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); 596 wd->timer.function = qdisc_watchdog; 597 wd->qdisc = qdisc; 598 } 599 EXPORT_SYMBOL(qdisc_watchdog_init); 600 601 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires, bool throttle) 602 { 603 if (test_bit(__QDISC_STATE_DEACTIVATED, 604 &qdisc_root_sleeping(wd->qdisc)->state)) 605 return; 606 607 if (throttle) 608 qdisc_throttled(wd->qdisc); 609 610 if (wd->last_expires == expires) 611 return; 612 613 wd->last_expires = expires; 614 hrtimer_start(&wd->timer, 615 ns_to_ktime(expires), 616 HRTIMER_MODE_ABS_PINNED); 617 } 618 EXPORT_SYMBOL(qdisc_watchdog_schedule_ns); 619 620 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd) 621 { 622 hrtimer_cancel(&wd->timer); 623 qdisc_unthrottled(wd->qdisc); 624 } 625 EXPORT_SYMBOL(qdisc_watchdog_cancel); 626 627 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n) 628 { 629 unsigned int size = n * sizeof(struct hlist_head), i; 630 struct hlist_head *h; 631 632 if (size <= PAGE_SIZE) 633 h = kmalloc(size, GFP_KERNEL); 634 else 635 h = (struct hlist_head *) 636 __get_free_pages(GFP_KERNEL, get_order(size)); 637 638 if (h != NULL) { 639 for (i = 0; i < n; i++) 640 INIT_HLIST_HEAD(&h[i]); 641 } 642 return h; 643 } 644 645 static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n) 646 { 647 unsigned int size = n * sizeof(struct hlist_head); 648 649 if (size <= PAGE_SIZE) 650 kfree(h); 651 else 652 free_pages((unsigned long)h, get_order(size)); 653 } 654 655 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash) 656 { 657 struct Qdisc_class_common *cl; 658 struct hlist_node *next; 659 struct hlist_head *nhash, *ohash; 660 unsigned int nsize, nmask, osize; 661 unsigned int i, h; 662 663 /* Rehash when load factor exceeds 0.75 */ 664 if (clhash->hashelems * 4 <= clhash->hashsize * 3) 665 return; 666 nsize = clhash->hashsize * 2; 667 nmask = nsize - 1; 668 nhash = qdisc_class_hash_alloc(nsize); 669 if (nhash == NULL) 670 return; 671 672 ohash = clhash->hash; 673 osize = clhash->hashsize; 674 675 sch_tree_lock(sch); 676 for (i = 0; i < osize; i++) { 677 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) { 678 h = qdisc_class_hash(cl->classid, nmask); 679 hlist_add_head(&cl->hnode, &nhash[h]); 680 } 681 } 682 clhash->hash = nhash; 683 clhash->hashsize = nsize; 684 clhash->hashmask = nmask; 685 sch_tree_unlock(sch); 686 687 qdisc_class_hash_free(ohash, osize); 688 } 689 EXPORT_SYMBOL(qdisc_class_hash_grow); 690 691 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash) 692 { 693 unsigned int size = 4; 694 695 clhash->hash = qdisc_class_hash_alloc(size); 696 if (clhash->hash == NULL) 697 return -ENOMEM; 698 clhash->hashsize = size; 699 clhash->hashmask = size - 1; 700 clhash->hashelems = 0; 701 return 0; 702 } 703 EXPORT_SYMBOL(qdisc_class_hash_init); 704 705 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash) 706 { 707 qdisc_class_hash_free(clhash->hash, clhash->hashsize); 708 } 709 EXPORT_SYMBOL(qdisc_class_hash_destroy); 710 711 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash, 712 struct Qdisc_class_common *cl) 713 { 714 unsigned int h; 715 716 INIT_HLIST_NODE(&cl->hnode); 717 h = qdisc_class_hash(cl->classid, clhash->hashmask); 718 hlist_add_head(&cl->hnode, &clhash->hash[h]); 719 clhash->hashelems++; 720 } 721 EXPORT_SYMBOL(qdisc_class_hash_insert); 722 723 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash, 724 struct Qdisc_class_common *cl) 725 { 726 hlist_del(&cl->hnode); 727 clhash->hashelems--; 728 } 729 EXPORT_SYMBOL(qdisc_class_hash_remove); 730 731 /* Allocate an unique handle from space managed by kernel 732 * Possible range is [8000-FFFF]:0000 (0x8000 values) 733 */ 734 static u32 qdisc_alloc_handle(struct net_device *dev) 735 { 736 int i = 0x8000; 737 static u32 autohandle = TC_H_MAKE(0x80000000U, 0); 738 739 do { 740 autohandle += TC_H_MAKE(0x10000U, 0); 741 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0)) 742 autohandle = TC_H_MAKE(0x80000000U, 0); 743 if (!qdisc_lookup(dev, autohandle)) 744 return autohandle; 745 cond_resched(); 746 } while (--i > 0); 747 748 return 0; 749 } 750 751 void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n, 752 unsigned int len) 753 { 754 const struct Qdisc_class_ops *cops; 755 unsigned long cl; 756 u32 parentid; 757 int drops; 758 759 if (n == 0 && len == 0) 760 return; 761 drops = max_t(int, n, 0); 762 rcu_read_lock(); 763 while ((parentid = sch->parent)) { 764 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS)) 765 break; 766 767 if (sch->flags & TCQ_F_NOPARENT) 768 break; 769 /* TODO: perform the search on a per txq basis */ 770 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid)); 771 if (sch == NULL) { 772 WARN_ON_ONCE(parentid != TC_H_ROOT); 773 break; 774 } 775 cops = sch->ops->cl_ops; 776 if (cops->qlen_notify) { 777 cl = cops->get(sch, parentid); 778 cops->qlen_notify(sch, cl); 779 cops->put(sch, cl); 780 } 781 sch->q.qlen -= n; 782 sch->qstats.backlog -= len; 783 __qdisc_qstats_drop(sch, drops); 784 } 785 rcu_read_unlock(); 786 } 787 EXPORT_SYMBOL(qdisc_tree_reduce_backlog); 788 789 static void notify_and_destroy(struct net *net, struct sk_buff *skb, 790 struct nlmsghdr *n, u32 clid, 791 struct Qdisc *old, struct Qdisc *new) 792 { 793 if (new || old) 794 qdisc_notify(net, skb, n, clid, old, new); 795 796 if (old) 797 qdisc_destroy(old); 798 } 799 800 /* Graft qdisc "new" to class "classid" of qdisc "parent" or 801 * to device "dev". 802 * 803 * When appropriate send a netlink notification using 'skb' 804 * and "n". 805 * 806 * On success, destroy old qdisc. 807 */ 808 809 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent, 810 struct sk_buff *skb, struct nlmsghdr *n, u32 classid, 811 struct Qdisc *new, struct Qdisc *old) 812 { 813 struct Qdisc *q = old; 814 struct net *net = dev_net(dev); 815 int err = 0; 816 817 if (parent == NULL) { 818 unsigned int i, num_q, ingress; 819 820 ingress = 0; 821 num_q = dev->num_tx_queues; 822 if ((q && q->flags & TCQ_F_INGRESS) || 823 (new && new->flags & TCQ_F_INGRESS)) { 824 num_q = 1; 825 ingress = 1; 826 if (!dev_ingress_queue(dev)) 827 return -ENOENT; 828 } 829 830 if (dev->flags & IFF_UP) 831 dev_deactivate(dev); 832 833 if (new && new->ops->attach) 834 goto skip; 835 836 for (i = 0; i < num_q; i++) { 837 struct netdev_queue *dev_queue = dev_ingress_queue(dev); 838 839 if (!ingress) 840 dev_queue = netdev_get_tx_queue(dev, i); 841 842 old = dev_graft_qdisc(dev_queue, new); 843 if (new && i > 0) 844 atomic_inc(&new->refcnt); 845 846 if (!ingress) 847 qdisc_destroy(old); 848 } 849 850 skip: 851 if (!ingress) { 852 notify_and_destroy(net, skb, n, classid, 853 dev->qdisc, new); 854 if (new && !new->ops->attach) 855 atomic_inc(&new->refcnt); 856 dev->qdisc = new ? : &noop_qdisc; 857 858 if (new && new->ops->attach) 859 new->ops->attach(new); 860 } else { 861 notify_and_destroy(net, skb, n, classid, old, new); 862 } 863 864 if (dev->flags & IFF_UP) 865 dev_activate(dev); 866 } else { 867 const struct Qdisc_class_ops *cops = parent->ops->cl_ops; 868 869 err = -EOPNOTSUPP; 870 if (cops && cops->graft) { 871 unsigned long cl = cops->get(parent, classid); 872 if (cl) { 873 err = cops->graft(parent, cl, new, &old); 874 cops->put(parent, cl); 875 } else 876 err = -ENOENT; 877 } 878 if (!err) 879 notify_and_destroy(net, skb, n, classid, old, new); 880 } 881 return err; 882 } 883 884 /* lockdep annotation is needed for ingress; egress gets it only for name */ 885 static struct lock_class_key qdisc_tx_lock; 886 static struct lock_class_key qdisc_rx_lock; 887 888 /* 889 Allocate and initialize new qdisc. 890 891 Parameters are passed via opt. 892 */ 893 894 static struct Qdisc * 895 qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue, 896 struct Qdisc *p, u32 parent, u32 handle, 897 struct nlattr **tca, int *errp) 898 { 899 int err; 900 struct nlattr *kind = tca[TCA_KIND]; 901 struct Qdisc *sch; 902 struct Qdisc_ops *ops; 903 struct qdisc_size_table *stab; 904 905 ops = qdisc_lookup_ops(kind); 906 #ifdef CONFIG_MODULES 907 if (ops == NULL && kind != NULL) { 908 char name[IFNAMSIZ]; 909 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) { 910 /* We dropped the RTNL semaphore in order to 911 * perform the module load. So, even if we 912 * succeeded in loading the module we have to 913 * tell the caller to replay the request. We 914 * indicate this using -EAGAIN. 915 * We replay the request because the device may 916 * go away in the mean time. 917 */ 918 rtnl_unlock(); 919 request_module("sch_%s", name); 920 rtnl_lock(); 921 ops = qdisc_lookup_ops(kind); 922 if (ops != NULL) { 923 /* We will try again qdisc_lookup_ops, 924 * so don't keep a reference. 925 */ 926 module_put(ops->owner); 927 err = -EAGAIN; 928 goto err_out; 929 } 930 } 931 } 932 #endif 933 934 err = -ENOENT; 935 if (ops == NULL) 936 goto err_out; 937 938 sch = qdisc_alloc(dev_queue, ops); 939 if (IS_ERR(sch)) { 940 err = PTR_ERR(sch); 941 goto err_out2; 942 } 943 944 sch->parent = parent; 945 946 if (handle == TC_H_INGRESS) { 947 sch->flags |= TCQ_F_INGRESS; 948 handle = TC_H_MAKE(TC_H_INGRESS, 0); 949 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock); 950 } else { 951 if (handle == 0) { 952 handle = qdisc_alloc_handle(dev); 953 err = -ENOMEM; 954 if (handle == 0) 955 goto err_out3; 956 } 957 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock); 958 if (!netif_is_multiqueue(dev)) 959 sch->flags |= TCQ_F_ONETXQUEUE; 960 } 961 962 sch->handle = handle; 963 964 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) { 965 if (qdisc_is_percpu_stats(sch)) { 966 sch->cpu_bstats = 967 netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu); 968 if (!sch->cpu_bstats) 969 goto err_out4; 970 971 sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue); 972 if (!sch->cpu_qstats) 973 goto err_out4; 974 } 975 976 if (tca[TCA_STAB]) { 977 stab = qdisc_get_stab(tca[TCA_STAB]); 978 if (IS_ERR(stab)) { 979 err = PTR_ERR(stab); 980 goto err_out4; 981 } 982 rcu_assign_pointer(sch->stab, stab); 983 } 984 if (tca[TCA_RATE]) { 985 spinlock_t *root_lock; 986 987 err = -EOPNOTSUPP; 988 if (sch->flags & TCQ_F_MQROOT) 989 goto err_out4; 990 991 if ((sch->parent != TC_H_ROOT) && 992 !(sch->flags & TCQ_F_INGRESS) && 993 (!p || !(p->flags & TCQ_F_MQROOT))) 994 root_lock = qdisc_root_sleeping_lock(sch); 995 else 996 root_lock = qdisc_lock(sch); 997 998 err = gen_new_estimator(&sch->bstats, 999 sch->cpu_bstats, 1000 &sch->rate_est, 1001 root_lock, 1002 tca[TCA_RATE]); 1003 if (err) 1004 goto err_out4; 1005 } 1006 1007 qdisc_list_add(sch); 1008 1009 return sch; 1010 } 1011 err_out3: 1012 dev_put(dev); 1013 kfree((char *) sch - sch->padded); 1014 err_out2: 1015 module_put(ops->owner); 1016 err_out: 1017 *errp = err; 1018 return NULL; 1019 1020 err_out4: 1021 free_percpu(sch->cpu_bstats); 1022 free_percpu(sch->cpu_qstats); 1023 /* 1024 * Any broken qdiscs that would require a ops->reset() here? 1025 * The qdisc was never in action so it shouldn't be necessary. 1026 */ 1027 qdisc_put_stab(rtnl_dereference(sch->stab)); 1028 if (ops->destroy) 1029 ops->destroy(sch); 1030 goto err_out3; 1031 } 1032 1033 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca) 1034 { 1035 struct qdisc_size_table *ostab, *stab = NULL; 1036 int err = 0; 1037 1038 if (tca[TCA_OPTIONS]) { 1039 if (sch->ops->change == NULL) 1040 return -EINVAL; 1041 err = sch->ops->change(sch, tca[TCA_OPTIONS]); 1042 if (err) 1043 return err; 1044 } 1045 1046 if (tca[TCA_STAB]) { 1047 stab = qdisc_get_stab(tca[TCA_STAB]); 1048 if (IS_ERR(stab)) 1049 return PTR_ERR(stab); 1050 } 1051 1052 ostab = rtnl_dereference(sch->stab); 1053 rcu_assign_pointer(sch->stab, stab); 1054 qdisc_put_stab(ostab); 1055 1056 if (tca[TCA_RATE]) { 1057 /* NB: ignores errors from replace_estimator 1058 because change can't be undone. */ 1059 if (sch->flags & TCQ_F_MQROOT) 1060 goto out; 1061 gen_replace_estimator(&sch->bstats, 1062 sch->cpu_bstats, 1063 &sch->rate_est, 1064 qdisc_root_sleeping_lock(sch), 1065 tca[TCA_RATE]); 1066 } 1067 out: 1068 return 0; 1069 } 1070 1071 struct check_loop_arg { 1072 struct qdisc_walker w; 1073 struct Qdisc *p; 1074 int depth; 1075 }; 1076 1077 static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w); 1078 1079 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth) 1080 { 1081 struct check_loop_arg arg; 1082 1083 if (q->ops->cl_ops == NULL) 1084 return 0; 1085 1086 arg.w.stop = arg.w.skip = arg.w.count = 0; 1087 arg.w.fn = check_loop_fn; 1088 arg.depth = depth; 1089 arg.p = p; 1090 q->ops->cl_ops->walk(q, &arg.w); 1091 return arg.w.stop ? -ELOOP : 0; 1092 } 1093 1094 static int 1095 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w) 1096 { 1097 struct Qdisc *leaf; 1098 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 1099 struct check_loop_arg *arg = (struct check_loop_arg *)w; 1100 1101 leaf = cops->leaf(q, cl); 1102 if (leaf) { 1103 if (leaf == arg->p || arg->depth > 7) 1104 return -ELOOP; 1105 return check_loop(leaf, arg->p, arg->depth + 1); 1106 } 1107 return 0; 1108 } 1109 1110 /* 1111 * Delete/get qdisc. 1112 */ 1113 1114 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n) 1115 { 1116 struct net *net = sock_net(skb->sk); 1117 struct tcmsg *tcm = nlmsg_data(n); 1118 struct nlattr *tca[TCA_MAX + 1]; 1119 struct net_device *dev; 1120 u32 clid; 1121 struct Qdisc *q = NULL; 1122 struct Qdisc *p = NULL; 1123 int err; 1124 1125 if ((n->nlmsg_type != RTM_GETQDISC) && 1126 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) 1127 return -EPERM; 1128 1129 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL); 1130 if (err < 0) 1131 return err; 1132 1133 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1134 if (!dev) 1135 return -ENODEV; 1136 1137 clid = tcm->tcm_parent; 1138 if (clid) { 1139 if (clid != TC_H_ROOT) { 1140 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) { 1141 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1142 if (!p) 1143 return -ENOENT; 1144 q = qdisc_leaf(p, clid); 1145 } else if (dev_ingress_queue(dev)) { 1146 q = dev_ingress_queue(dev)->qdisc_sleeping; 1147 } 1148 } else { 1149 q = dev->qdisc; 1150 } 1151 if (!q) 1152 return -ENOENT; 1153 1154 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) 1155 return -EINVAL; 1156 } else { 1157 q = qdisc_lookup(dev, tcm->tcm_handle); 1158 if (!q) 1159 return -ENOENT; 1160 } 1161 1162 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) 1163 return -EINVAL; 1164 1165 if (n->nlmsg_type == RTM_DELQDISC) { 1166 if (!clid) 1167 return -EINVAL; 1168 if (q->handle == 0) 1169 return -ENOENT; 1170 err = qdisc_graft(dev, p, skb, n, clid, NULL, q); 1171 if (err != 0) 1172 return err; 1173 } else { 1174 qdisc_notify(net, skb, n, clid, NULL, q); 1175 } 1176 return 0; 1177 } 1178 1179 /* 1180 * Create/change qdisc. 1181 */ 1182 1183 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n) 1184 { 1185 struct net *net = sock_net(skb->sk); 1186 struct tcmsg *tcm; 1187 struct nlattr *tca[TCA_MAX + 1]; 1188 struct net_device *dev; 1189 u32 clid; 1190 struct Qdisc *q, *p; 1191 int err; 1192 1193 if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) 1194 return -EPERM; 1195 1196 replay: 1197 /* Reinit, just in case something touches this. */ 1198 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL); 1199 if (err < 0) 1200 return err; 1201 1202 tcm = nlmsg_data(n); 1203 clid = tcm->tcm_parent; 1204 q = p = NULL; 1205 1206 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1207 if (!dev) 1208 return -ENODEV; 1209 1210 1211 if (clid) { 1212 if (clid != TC_H_ROOT) { 1213 if (clid != TC_H_INGRESS) { 1214 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1215 if (!p) 1216 return -ENOENT; 1217 q = qdisc_leaf(p, clid); 1218 } else if (dev_ingress_queue_create(dev)) { 1219 q = dev_ingress_queue(dev)->qdisc_sleeping; 1220 } 1221 } else { 1222 q = dev->qdisc; 1223 } 1224 1225 /* It may be default qdisc, ignore it */ 1226 if (q && q->handle == 0) 1227 q = NULL; 1228 1229 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) { 1230 if (tcm->tcm_handle) { 1231 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) 1232 return -EEXIST; 1233 if (TC_H_MIN(tcm->tcm_handle)) 1234 return -EINVAL; 1235 q = qdisc_lookup(dev, tcm->tcm_handle); 1236 if (!q) 1237 goto create_n_graft; 1238 if (n->nlmsg_flags & NLM_F_EXCL) 1239 return -EEXIST; 1240 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) 1241 return -EINVAL; 1242 if (q == p || 1243 (p && check_loop(q, p, 0))) 1244 return -ELOOP; 1245 atomic_inc(&q->refcnt); 1246 goto graft; 1247 } else { 1248 if (!q) 1249 goto create_n_graft; 1250 1251 /* This magic test requires explanation. 1252 * 1253 * We know, that some child q is already 1254 * attached to this parent and have choice: 1255 * either to change it or to create/graft new one. 1256 * 1257 * 1. We are allowed to create/graft only 1258 * if CREATE and REPLACE flags are set. 1259 * 1260 * 2. If EXCL is set, requestor wanted to say, 1261 * that qdisc tcm_handle is not expected 1262 * to exist, so that we choose create/graft too. 1263 * 1264 * 3. The last case is when no flags are set. 1265 * Alas, it is sort of hole in API, we 1266 * cannot decide what to do unambiguously. 1267 * For now we select create/graft, if 1268 * user gave KIND, which does not match existing. 1269 */ 1270 if ((n->nlmsg_flags & NLM_F_CREATE) && 1271 (n->nlmsg_flags & NLM_F_REPLACE) && 1272 ((n->nlmsg_flags & NLM_F_EXCL) || 1273 (tca[TCA_KIND] && 1274 nla_strcmp(tca[TCA_KIND], q->ops->id)))) 1275 goto create_n_graft; 1276 } 1277 } 1278 } else { 1279 if (!tcm->tcm_handle) 1280 return -EINVAL; 1281 q = qdisc_lookup(dev, tcm->tcm_handle); 1282 } 1283 1284 /* Change qdisc parameters */ 1285 if (q == NULL) 1286 return -ENOENT; 1287 if (n->nlmsg_flags & NLM_F_EXCL) 1288 return -EEXIST; 1289 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) 1290 return -EINVAL; 1291 err = qdisc_change(q, tca); 1292 if (err == 0) 1293 qdisc_notify(net, skb, n, clid, NULL, q); 1294 return err; 1295 1296 create_n_graft: 1297 if (!(n->nlmsg_flags & NLM_F_CREATE)) 1298 return -ENOENT; 1299 if (clid == TC_H_INGRESS) { 1300 if (dev_ingress_queue(dev)) 1301 q = qdisc_create(dev, dev_ingress_queue(dev), p, 1302 tcm->tcm_parent, tcm->tcm_parent, 1303 tca, &err); 1304 else 1305 err = -ENOENT; 1306 } else { 1307 struct netdev_queue *dev_queue; 1308 1309 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue) 1310 dev_queue = p->ops->cl_ops->select_queue(p, tcm); 1311 else if (p) 1312 dev_queue = p->dev_queue; 1313 else 1314 dev_queue = netdev_get_tx_queue(dev, 0); 1315 1316 q = qdisc_create(dev, dev_queue, p, 1317 tcm->tcm_parent, tcm->tcm_handle, 1318 tca, &err); 1319 } 1320 if (q == NULL) { 1321 if (err == -EAGAIN) 1322 goto replay; 1323 return err; 1324 } 1325 1326 graft: 1327 err = qdisc_graft(dev, p, skb, n, clid, q, NULL); 1328 if (err) { 1329 if (q) 1330 qdisc_destroy(q); 1331 return err; 1332 } 1333 1334 return 0; 1335 } 1336 1337 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid, 1338 u32 portid, u32 seq, u16 flags, int event) 1339 { 1340 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL; 1341 struct gnet_stats_queue __percpu *cpu_qstats = NULL; 1342 struct tcmsg *tcm; 1343 struct nlmsghdr *nlh; 1344 unsigned char *b = skb_tail_pointer(skb); 1345 struct gnet_dump d; 1346 struct qdisc_size_table *stab; 1347 __u32 qlen; 1348 1349 cond_resched(); 1350 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 1351 if (!nlh) 1352 goto out_nlmsg_trim; 1353 tcm = nlmsg_data(nlh); 1354 tcm->tcm_family = AF_UNSPEC; 1355 tcm->tcm__pad1 = 0; 1356 tcm->tcm__pad2 = 0; 1357 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 1358 tcm->tcm_parent = clid; 1359 tcm->tcm_handle = q->handle; 1360 tcm->tcm_info = atomic_read(&q->refcnt); 1361 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 1362 goto nla_put_failure; 1363 if (q->ops->dump && q->ops->dump(q, skb) < 0) 1364 goto nla_put_failure; 1365 qlen = q->q.qlen; 1366 1367 stab = rtnl_dereference(q->stab); 1368 if (stab && qdisc_dump_stab(skb, stab) < 0) 1369 goto nla_put_failure; 1370 1371 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 1372 qdisc_root_sleeping_lock(q), &d, 1373 TCA_PAD) < 0) 1374 goto nla_put_failure; 1375 1376 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0) 1377 goto nla_put_failure; 1378 1379 if (qdisc_is_percpu_stats(q)) { 1380 cpu_bstats = q->cpu_bstats; 1381 cpu_qstats = q->cpu_qstats; 1382 } 1383 1384 if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats) < 0 || 1385 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 || 1386 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0) 1387 goto nla_put_failure; 1388 1389 if (gnet_stats_finish_copy(&d) < 0) 1390 goto nla_put_failure; 1391 1392 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 1393 return skb->len; 1394 1395 out_nlmsg_trim: 1396 nla_put_failure: 1397 nlmsg_trim(skb, b); 1398 return -1; 1399 } 1400 1401 static bool tc_qdisc_dump_ignore(struct Qdisc *q) 1402 { 1403 return (q->flags & TCQ_F_BUILTIN) ? true : false; 1404 } 1405 1406 static int qdisc_notify(struct net *net, struct sk_buff *oskb, 1407 struct nlmsghdr *n, u32 clid, 1408 struct Qdisc *old, struct Qdisc *new) 1409 { 1410 struct sk_buff *skb; 1411 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1412 1413 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1414 if (!skb) 1415 return -ENOBUFS; 1416 1417 if (old && !tc_qdisc_dump_ignore(old)) { 1418 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq, 1419 0, RTM_DELQDISC) < 0) 1420 goto err_out; 1421 } 1422 if (new && !tc_qdisc_dump_ignore(new)) { 1423 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq, 1424 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0) 1425 goto err_out; 1426 } 1427 1428 if (skb->len) 1429 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1430 n->nlmsg_flags & NLM_F_ECHO); 1431 1432 err_out: 1433 kfree_skb(skb); 1434 return -EINVAL; 1435 } 1436 1437 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb, 1438 struct netlink_callback *cb, 1439 int *q_idx_p, int s_q_idx) 1440 { 1441 int ret = 0, q_idx = *q_idx_p; 1442 struct Qdisc *q; 1443 1444 if (!root) 1445 return 0; 1446 1447 q = root; 1448 if (q_idx < s_q_idx) { 1449 q_idx++; 1450 } else { 1451 if (!tc_qdisc_dump_ignore(q) && 1452 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1453 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0) 1454 goto done; 1455 q_idx++; 1456 } 1457 list_for_each_entry(q, &root->list, list) { 1458 if (q_idx < s_q_idx) { 1459 q_idx++; 1460 continue; 1461 } 1462 if (!tc_qdisc_dump_ignore(q) && 1463 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1464 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0) 1465 goto done; 1466 q_idx++; 1467 } 1468 1469 out: 1470 *q_idx_p = q_idx; 1471 return ret; 1472 done: 1473 ret = -1; 1474 goto out; 1475 } 1476 1477 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb) 1478 { 1479 struct net *net = sock_net(skb->sk); 1480 int idx, q_idx; 1481 int s_idx, s_q_idx; 1482 struct net_device *dev; 1483 1484 s_idx = cb->args[0]; 1485 s_q_idx = q_idx = cb->args[1]; 1486 1487 idx = 0; 1488 ASSERT_RTNL(); 1489 for_each_netdev(net, dev) { 1490 struct netdev_queue *dev_queue; 1491 1492 if (idx < s_idx) 1493 goto cont; 1494 if (idx > s_idx) 1495 s_q_idx = 0; 1496 q_idx = 0; 1497 1498 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0) 1499 goto done; 1500 1501 dev_queue = dev_ingress_queue(dev); 1502 if (dev_queue && 1503 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb, 1504 &q_idx, s_q_idx) < 0) 1505 goto done; 1506 1507 cont: 1508 idx++; 1509 } 1510 1511 done: 1512 cb->args[0] = idx; 1513 cb->args[1] = q_idx; 1514 1515 return skb->len; 1516 } 1517 1518 1519 1520 /************************************************ 1521 * Traffic classes manipulation. * 1522 ************************************************/ 1523 1524 1525 1526 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n) 1527 { 1528 struct net *net = sock_net(skb->sk); 1529 struct tcmsg *tcm = nlmsg_data(n); 1530 struct nlattr *tca[TCA_MAX + 1]; 1531 struct net_device *dev; 1532 struct Qdisc *q = NULL; 1533 const struct Qdisc_class_ops *cops; 1534 unsigned long cl = 0; 1535 unsigned long new_cl; 1536 u32 portid; 1537 u32 clid; 1538 u32 qid; 1539 int err; 1540 1541 if ((n->nlmsg_type != RTM_GETTCLASS) && 1542 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) 1543 return -EPERM; 1544 1545 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL); 1546 if (err < 0) 1547 return err; 1548 1549 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1550 if (!dev) 1551 return -ENODEV; 1552 1553 /* 1554 parent == TC_H_UNSPEC - unspecified parent. 1555 parent == TC_H_ROOT - class is root, which has no parent. 1556 parent == X:0 - parent is root class. 1557 parent == X:Y - parent is a node in hierarchy. 1558 parent == 0:Y - parent is X:Y, where X:0 is qdisc. 1559 1560 handle == 0:0 - generate handle from kernel pool. 1561 handle == 0:Y - class is X:Y, where X:0 is qdisc. 1562 handle == X:Y - clear. 1563 handle == X:0 - root class. 1564 */ 1565 1566 /* Step 1. Determine qdisc handle X:0 */ 1567 1568 portid = tcm->tcm_parent; 1569 clid = tcm->tcm_handle; 1570 qid = TC_H_MAJ(clid); 1571 1572 if (portid != TC_H_ROOT) { 1573 u32 qid1 = TC_H_MAJ(portid); 1574 1575 if (qid && qid1) { 1576 /* If both majors are known, they must be identical. */ 1577 if (qid != qid1) 1578 return -EINVAL; 1579 } else if (qid1) { 1580 qid = qid1; 1581 } else if (qid == 0) 1582 qid = dev->qdisc->handle; 1583 1584 /* Now qid is genuine qdisc handle consistent 1585 * both with parent and child. 1586 * 1587 * TC_H_MAJ(portid) still may be unspecified, complete it now. 1588 */ 1589 if (portid) 1590 portid = TC_H_MAKE(qid, portid); 1591 } else { 1592 if (qid == 0) 1593 qid = dev->qdisc->handle; 1594 } 1595 1596 /* OK. Locate qdisc */ 1597 q = qdisc_lookup(dev, qid); 1598 if (!q) 1599 return -ENOENT; 1600 1601 /* An check that it supports classes */ 1602 cops = q->ops->cl_ops; 1603 if (cops == NULL) 1604 return -EINVAL; 1605 1606 /* Now try to get class */ 1607 if (clid == 0) { 1608 if (portid == TC_H_ROOT) 1609 clid = qid; 1610 } else 1611 clid = TC_H_MAKE(qid, clid); 1612 1613 if (clid) 1614 cl = cops->get(q, clid); 1615 1616 if (cl == 0) { 1617 err = -ENOENT; 1618 if (n->nlmsg_type != RTM_NEWTCLASS || 1619 !(n->nlmsg_flags & NLM_F_CREATE)) 1620 goto out; 1621 } else { 1622 switch (n->nlmsg_type) { 1623 case RTM_NEWTCLASS: 1624 err = -EEXIST; 1625 if (n->nlmsg_flags & NLM_F_EXCL) 1626 goto out; 1627 break; 1628 case RTM_DELTCLASS: 1629 err = -EOPNOTSUPP; 1630 if (cops->delete) 1631 err = cops->delete(q, cl); 1632 if (err == 0) 1633 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS); 1634 goto out; 1635 case RTM_GETTCLASS: 1636 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS); 1637 goto out; 1638 default: 1639 err = -EINVAL; 1640 goto out; 1641 } 1642 } 1643 1644 new_cl = cl; 1645 err = -EOPNOTSUPP; 1646 if (cops->change) 1647 err = cops->change(q, clid, portid, tca, &new_cl); 1648 if (err == 0) 1649 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS); 1650 1651 out: 1652 if (cl) 1653 cops->put(q, cl); 1654 1655 return err; 1656 } 1657 1658 1659 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, 1660 unsigned long cl, 1661 u32 portid, u32 seq, u16 flags, int event) 1662 { 1663 struct tcmsg *tcm; 1664 struct nlmsghdr *nlh; 1665 unsigned char *b = skb_tail_pointer(skb); 1666 struct gnet_dump d; 1667 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops; 1668 1669 cond_resched(); 1670 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 1671 if (!nlh) 1672 goto out_nlmsg_trim; 1673 tcm = nlmsg_data(nlh); 1674 tcm->tcm_family = AF_UNSPEC; 1675 tcm->tcm__pad1 = 0; 1676 tcm->tcm__pad2 = 0; 1677 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 1678 tcm->tcm_parent = q->handle; 1679 tcm->tcm_handle = q->handle; 1680 tcm->tcm_info = 0; 1681 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 1682 goto nla_put_failure; 1683 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0) 1684 goto nla_put_failure; 1685 1686 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 1687 qdisc_root_sleeping_lock(q), &d, 1688 TCA_PAD) < 0) 1689 goto nla_put_failure; 1690 1691 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0) 1692 goto nla_put_failure; 1693 1694 if (gnet_stats_finish_copy(&d) < 0) 1695 goto nla_put_failure; 1696 1697 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 1698 return skb->len; 1699 1700 out_nlmsg_trim: 1701 nla_put_failure: 1702 nlmsg_trim(skb, b); 1703 return -1; 1704 } 1705 1706 static int tclass_notify(struct net *net, struct sk_buff *oskb, 1707 struct nlmsghdr *n, struct Qdisc *q, 1708 unsigned long cl, int event) 1709 { 1710 struct sk_buff *skb; 1711 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1712 1713 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1714 if (!skb) 1715 return -ENOBUFS; 1716 1717 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) { 1718 kfree_skb(skb); 1719 return -EINVAL; 1720 } 1721 1722 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1723 n->nlmsg_flags & NLM_F_ECHO); 1724 } 1725 1726 struct qdisc_dump_args { 1727 struct qdisc_walker w; 1728 struct sk_buff *skb; 1729 struct netlink_callback *cb; 1730 }; 1731 1732 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg) 1733 { 1734 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg; 1735 1736 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid, 1737 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS); 1738 } 1739 1740 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb, 1741 struct tcmsg *tcm, struct netlink_callback *cb, 1742 int *t_p, int s_t) 1743 { 1744 struct qdisc_dump_args arg; 1745 1746 if (tc_qdisc_dump_ignore(q) || 1747 *t_p < s_t || !q->ops->cl_ops || 1748 (tcm->tcm_parent && 1749 TC_H_MAJ(tcm->tcm_parent) != q->handle)) { 1750 (*t_p)++; 1751 return 0; 1752 } 1753 if (*t_p > s_t) 1754 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); 1755 arg.w.fn = qdisc_class_dump; 1756 arg.skb = skb; 1757 arg.cb = cb; 1758 arg.w.stop = 0; 1759 arg.w.skip = cb->args[1]; 1760 arg.w.count = 0; 1761 q->ops->cl_ops->walk(q, &arg.w); 1762 cb->args[1] = arg.w.count; 1763 if (arg.w.stop) 1764 return -1; 1765 (*t_p)++; 1766 return 0; 1767 } 1768 1769 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb, 1770 struct tcmsg *tcm, struct netlink_callback *cb, 1771 int *t_p, int s_t) 1772 { 1773 struct Qdisc *q; 1774 1775 if (!root) 1776 return 0; 1777 1778 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0) 1779 return -1; 1780 1781 list_for_each_entry(q, &root->list, list) { 1782 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 1783 return -1; 1784 } 1785 1786 return 0; 1787 } 1788 1789 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb) 1790 { 1791 struct tcmsg *tcm = nlmsg_data(cb->nlh); 1792 struct net *net = sock_net(skb->sk); 1793 struct netdev_queue *dev_queue; 1794 struct net_device *dev; 1795 int t, s_t; 1796 1797 if (nlmsg_len(cb->nlh) < sizeof(*tcm)) 1798 return 0; 1799 dev = dev_get_by_index(net, tcm->tcm_ifindex); 1800 if (!dev) 1801 return 0; 1802 1803 s_t = cb->args[0]; 1804 t = 0; 1805 1806 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0) 1807 goto done; 1808 1809 dev_queue = dev_ingress_queue(dev); 1810 if (dev_queue && 1811 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb, 1812 &t, s_t) < 0) 1813 goto done; 1814 1815 done: 1816 cb->args[0] = t; 1817 1818 dev_put(dev); 1819 return skb->len; 1820 } 1821 1822 /* Main classifier routine: scans classifier chain attached 1823 * to this qdisc, (optionally) tests for protocol and asks 1824 * specific classifiers. 1825 */ 1826 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp, 1827 struct tcf_result *res, bool compat_mode) 1828 { 1829 __be16 protocol = tc_skb_protocol(skb); 1830 #ifdef CONFIG_NET_CLS_ACT 1831 const struct tcf_proto *old_tp = tp; 1832 int limit = 0; 1833 1834 reclassify: 1835 #endif 1836 for (; tp; tp = rcu_dereference_bh(tp->next)) { 1837 int err; 1838 1839 if (tp->protocol != protocol && 1840 tp->protocol != htons(ETH_P_ALL)) 1841 continue; 1842 1843 err = tp->classify(skb, tp, res); 1844 #ifdef CONFIG_NET_CLS_ACT 1845 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) 1846 goto reset; 1847 #endif 1848 if (err >= 0) 1849 return err; 1850 } 1851 1852 return TC_ACT_UNSPEC; /* signal: continue lookup */ 1853 #ifdef CONFIG_NET_CLS_ACT 1854 reset: 1855 if (unlikely(limit++ >= MAX_REC_LOOP)) { 1856 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n", 1857 tp->q->ops->id, tp->prio & 0xffff, 1858 ntohs(tp->protocol)); 1859 return TC_ACT_SHOT; 1860 } 1861 1862 tp = old_tp; 1863 protocol = tc_skb_protocol(skb); 1864 goto reclassify; 1865 #endif 1866 } 1867 EXPORT_SYMBOL(tc_classify); 1868 1869 bool tcf_destroy(struct tcf_proto *tp, bool force) 1870 { 1871 if (tp->ops->destroy(tp, force)) { 1872 module_put(tp->ops->owner); 1873 kfree_rcu(tp, rcu); 1874 return true; 1875 } 1876 1877 return false; 1878 } 1879 1880 void tcf_destroy_chain(struct tcf_proto __rcu **fl) 1881 { 1882 struct tcf_proto *tp; 1883 1884 while ((tp = rtnl_dereference(*fl)) != NULL) { 1885 RCU_INIT_POINTER(*fl, tp->next); 1886 tcf_destroy(tp, true); 1887 } 1888 } 1889 EXPORT_SYMBOL(tcf_destroy_chain); 1890 1891 #ifdef CONFIG_PROC_FS 1892 static int psched_show(struct seq_file *seq, void *v) 1893 { 1894 seq_printf(seq, "%08x %08x %08x %08x\n", 1895 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1), 1896 1000000, 1897 (u32)NSEC_PER_SEC / hrtimer_resolution); 1898 1899 return 0; 1900 } 1901 1902 static int psched_open(struct inode *inode, struct file *file) 1903 { 1904 return single_open(file, psched_show, NULL); 1905 } 1906 1907 static const struct file_operations psched_fops = { 1908 .owner = THIS_MODULE, 1909 .open = psched_open, 1910 .read = seq_read, 1911 .llseek = seq_lseek, 1912 .release = single_release, 1913 }; 1914 1915 static int __net_init psched_net_init(struct net *net) 1916 { 1917 struct proc_dir_entry *e; 1918 1919 e = proc_create("psched", 0, net->proc_net, &psched_fops); 1920 if (e == NULL) 1921 return -ENOMEM; 1922 1923 return 0; 1924 } 1925 1926 static void __net_exit psched_net_exit(struct net *net) 1927 { 1928 remove_proc_entry("psched", net->proc_net); 1929 } 1930 #else 1931 static int __net_init psched_net_init(struct net *net) 1932 { 1933 return 0; 1934 } 1935 1936 static void __net_exit psched_net_exit(struct net *net) 1937 { 1938 } 1939 #endif 1940 1941 static struct pernet_operations psched_net_ops = { 1942 .init = psched_net_init, 1943 .exit = psched_net_exit, 1944 }; 1945 1946 static int __init pktsched_init(void) 1947 { 1948 int err; 1949 1950 err = register_pernet_subsys(&psched_net_ops); 1951 if (err) { 1952 pr_err("pktsched_init: " 1953 "cannot initialize per netns operations\n"); 1954 return err; 1955 } 1956 1957 register_qdisc(&pfifo_fast_ops); 1958 register_qdisc(&pfifo_qdisc_ops); 1959 register_qdisc(&bfifo_qdisc_ops); 1960 register_qdisc(&pfifo_head_drop_qdisc_ops); 1961 register_qdisc(&mq_qdisc_ops); 1962 register_qdisc(&noqueue_qdisc_ops); 1963 1964 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL); 1965 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL); 1966 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL); 1967 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL); 1968 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL); 1969 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL); 1970 1971 return 0; 1972 } 1973 1974 subsys_initcall(pktsched_init); 1975