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