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