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 /* We know handle. Find qdisc among all qdisc's attached to device 204 (root qdisc, all its children, children of children etc.) 205 */ 206 207 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle) 208 { 209 struct Qdisc *q; 210 211 if (!(root->flags & TCQ_F_BUILTIN) && 212 root->handle == handle) 213 return root; 214 215 list_for_each_entry(q, &root->list, list) { 216 if (q->handle == handle) 217 return q; 218 } 219 return NULL; 220 } 221 222 static void qdisc_list_add(struct Qdisc *q) 223 { 224 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) 225 list_add_tail(&q->list, &qdisc_dev(q)->qdisc->list); 226 } 227 228 void qdisc_list_del(struct Qdisc *q) 229 { 230 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) 231 list_del(&q->list); 232 } 233 EXPORT_SYMBOL(qdisc_list_del); 234 235 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle) 236 { 237 struct Qdisc *q; 238 239 q = qdisc_match_from_root(dev->qdisc, handle); 240 if (q) 241 goto out; 242 243 if (dev_ingress_queue(dev)) 244 q = qdisc_match_from_root( 245 dev_ingress_queue(dev)->qdisc_sleeping, 246 handle); 247 out: 248 return q; 249 } 250 251 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid) 252 { 253 unsigned long cl; 254 struct Qdisc *leaf; 255 const struct Qdisc_class_ops *cops = p->ops->cl_ops; 256 257 if (cops == NULL) 258 return NULL; 259 cl = cops->get(p, classid); 260 261 if (cl == 0) 262 return NULL; 263 leaf = cops->leaf(p, cl); 264 cops->put(p, cl); 265 return leaf; 266 } 267 268 /* Find queueing discipline by name */ 269 270 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind) 271 { 272 struct Qdisc_ops *q = NULL; 273 274 if (kind) { 275 read_lock(&qdisc_mod_lock); 276 for (q = qdisc_base; q; q = q->next) { 277 if (nla_strcmp(kind, q->id) == 0) { 278 if (!try_module_get(q->owner)) 279 q = NULL; 280 break; 281 } 282 } 283 read_unlock(&qdisc_mod_lock); 284 } 285 return q; 286 } 287 288 static struct qdisc_rate_table *qdisc_rtab_list; 289 290 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct nlattr *tab) 291 { 292 struct qdisc_rate_table *rtab; 293 294 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) { 295 if (memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) == 0) { 296 rtab->refcnt++; 297 return rtab; 298 } 299 } 300 301 if (tab == NULL || r->rate == 0 || r->cell_log == 0 || 302 nla_len(tab) != TC_RTAB_SIZE) 303 return NULL; 304 305 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL); 306 if (rtab) { 307 rtab->rate = *r; 308 rtab->refcnt = 1; 309 memcpy(rtab->data, nla_data(tab), 1024); 310 rtab->next = qdisc_rtab_list; 311 qdisc_rtab_list = rtab; 312 } 313 return rtab; 314 } 315 EXPORT_SYMBOL(qdisc_get_rtab); 316 317 void qdisc_put_rtab(struct qdisc_rate_table *tab) 318 { 319 struct qdisc_rate_table *rtab, **rtabp; 320 321 if (!tab || --tab->refcnt) 322 return; 323 324 for (rtabp = &qdisc_rtab_list; 325 (rtab = *rtabp) != NULL; 326 rtabp = &rtab->next) { 327 if (rtab == tab) { 328 *rtabp = rtab->next; 329 kfree(rtab); 330 return; 331 } 332 } 333 } 334 EXPORT_SYMBOL(qdisc_put_rtab); 335 336 static LIST_HEAD(qdisc_stab_list); 337 static DEFINE_SPINLOCK(qdisc_stab_lock); 338 339 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = { 340 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) }, 341 [TCA_STAB_DATA] = { .type = NLA_BINARY }, 342 }; 343 344 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt) 345 { 346 struct nlattr *tb[TCA_STAB_MAX + 1]; 347 struct qdisc_size_table *stab; 348 struct tc_sizespec *s; 349 unsigned int tsize = 0; 350 u16 *tab = NULL; 351 int err; 352 353 err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy); 354 if (err < 0) 355 return ERR_PTR(err); 356 if (!tb[TCA_STAB_BASE]) 357 return ERR_PTR(-EINVAL); 358 359 s = nla_data(tb[TCA_STAB_BASE]); 360 361 if (s->tsize > 0) { 362 if (!tb[TCA_STAB_DATA]) 363 return ERR_PTR(-EINVAL); 364 tab = nla_data(tb[TCA_STAB_DATA]); 365 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16); 366 } 367 368 if (tsize != s->tsize || (!tab && tsize > 0)) 369 return ERR_PTR(-EINVAL); 370 371 spin_lock(&qdisc_stab_lock); 372 373 list_for_each_entry(stab, &qdisc_stab_list, list) { 374 if (memcmp(&stab->szopts, s, sizeof(*s))) 375 continue; 376 if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16))) 377 continue; 378 stab->refcnt++; 379 spin_unlock(&qdisc_stab_lock); 380 return stab; 381 } 382 383 spin_unlock(&qdisc_stab_lock); 384 385 stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL); 386 if (!stab) 387 return ERR_PTR(-ENOMEM); 388 389 stab->refcnt = 1; 390 stab->szopts = *s; 391 if (tsize > 0) 392 memcpy(stab->data, tab, tsize * sizeof(u16)); 393 394 spin_lock(&qdisc_stab_lock); 395 list_add_tail(&stab->list, &qdisc_stab_list); 396 spin_unlock(&qdisc_stab_lock); 397 398 return stab; 399 } 400 401 static void stab_kfree_rcu(struct rcu_head *head) 402 { 403 kfree(container_of(head, struct qdisc_size_table, rcu)); 404 } 405 406 void qdisc_put_stab(struct qdisc_size_table *tab) 407 { 408 if (!tab) 409 return; 410 411 spin_lock(&qdisc_stab_lock); 412 413 if (--tab->refcnt == 0) { 414 list_del(&tab->list); 415 call_rcu_bh(&tab->rcu, stab_kfree_rcu); 416 } 417 418 spin_unlock(&qdisc_stab_lock); 419 } 420 EXPORT_SYMBOL(qdisc_put_stab); 421 422 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab) 423 { 424 struct nlattr *nest; 425 426 nest = nla_nest_start(skb, TCA_STAB); 427 if (nest == NULL) 428 goto nla_put_failure; 429 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts)) 430 goto nla_put_failure; 431 nla_nest_end(skb, nest); 432 433 return skb->len; 434 435 nla_put_failure: 436 return -1; 437 } 438 439 void __qdisc_calculate_pkt_len(struct sk_buff *skb, const struct qdisc_size_table *stab) 440 { 441 int pkt_len, slot; 442 443 pkt_len = skb->len + stab->szopts.overhead; 444 if (unlikely(!stab->szopts.tsize)) 445 goto out; 446 447 slot = pkt_len + stab->szopts.cell_align; 448 if (unlikely(slot < 0)) 449 slot = 0; 450 451 slot >>= stab->szopts.cell_log; 452 if (likely(slot < stab->szopts.tsize)) 453 pkt_len = stab->data[slot]; 454 else 455 pkt_len = stab->data[stab->szopts.tsize - 1] * 456 (slot / stab->szopts.tsize) + 457 stab->data[slot % stab->szopts.tsize]; 458 459 pkt_len <<= stab->szopts.size_log; 460 out: 461 if (unlikely(pkt_len < 1)) 462 pkt_len = 1; 463 qdisc_skb_cb(skb)->pkt_len = pkt_len; 464 } 465 EXPORT_SYMBOL(__qdisc_calculate_pkt_len); 466 467 void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc) 468 { 469 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) { 470 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n", 471 txt, qdisc->ops->id, qdisc->handle >> 16); 472 qdisc->flags |= TCQ_F_WARN_NONWC; 473 } 474 } 475 EXPORT_SYMBOL(qdisc_warn_nonwc); 476 477 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer) 478 { 479 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog, 480 timer); 481 482 qdisc_unthrottled(wd->qdisc); 483 __netif_schedule(qdisc_root(wd->qdisc)); 484 485 return HRTIMER_NORESTART; 486 } 487 488 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc) 489 { 490 hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); 491 wd->timer.function = qdisc_watchdog; 492 wd->qdisc = qdisc; 493 } 494 EXPORT_SYMBOL(qdisc_watchdog_init); 495 496 void qdisc_watchdog_schedule(struct qdisc_watchdog *wd, psched_time_t expires) 497 { 498 ktime_t time; 499 500 if (test_bit(__QDISC_STATE_DEACTIVATED, 501 &qdisc_root_sleeping(wd->qdisc)->state)) 502 return; 503 504 qdisc_throttled(wd->qdisc); 505 time = ktime_set(0, 0); 506 time = ktime_add_ns(time, PSCHED_TICKS2NS(expires)); 507 hrtimer_start(&wd->timer, time, HRTIMER_MODE_ABS); 508 } 509 EXPORT_SYMBOL(qdisc_watchdog_schedule); 510 511 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd) 512 { 513 hrtimer_cancel(&wd->timer); 514 qdisc_unthrottled(wd->qdisc); 515 } 516 EXPORT_SYMBOL(qdisc_watchdog_cancel); 517 518 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n) 519 { 520 unsigned int size = n * sizeof(struct hlist_head), i; 521 struct hlist_head *h; 522 523 if (size <= PAGE_SIZE) 524 h = kmalloc(size, GFP_KERNEL); 525 else 526 h = (struct hlist_head *) 527 __get_free_pages(GFP_KERNEL, get_order(size)); 528 529 if (h != NULL) { 530 for (i = 0; i < n; i++) 531 INIT_HLIST_HEAD(&h[i]); 532 } 533 return h; 534 } 535 536 static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n) 537 { 538 unsigned int size = n * sizeof(struct hlist_head); 539 540 if (size <= PAGE_SIZE) 541 kfree(h); 542 else 543 free_pages((unsigned long)h, get_order(size)); 544 } 545 546 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash) 547 { 548 struct Qdisc_class_common *cl; 549 struct hlist_node *n, *next; 550 struct hlist_head *nhash, *ohash; 551 unsigned int nsize, nmask, osize; 552 unsigned int i, h; 553 554 /* Rehash when load factor exceeds 0.75 */ 555 if (clhash->hashelems * 4 <= clhash->hashsize * 3) 556 return; 557 nsize = clhash->hashsize * 2; 558 nmask = nsize - 1; 559 nhash = qdisc_class_hash_alloc(nsize); 560 if (nhash == NULL) 561 return; 562 563 ohash = clhash->hash; 564 osize = clhash->hashsize; 565 566 sch_tree_lock(sch); 567 for (i = 0; i < osize; i++) { 568 hlist_for_each_entry_safe(cl, n, next, &ohash[i], hnode) { 569 h = qdisc_class_hash(cl->classid, nmask); 570 hlist_add_head(&cl->hnode, &nhash[h]); 571 } 572 } 573 clhash->hash = nhash; 574 clhash->hashsize = nsize; 575 clhash->hashmask = nmask; 576 sch_tree_unlock(sch); 577 578 qdisc_class_hash_free(ohash, osize); 579 } 580 EXPORT_SYMBOL(qdisc_class_hash_grow); 581 582 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash) 583 { 584 unsigned int size = 4; 585 586 clhash->hash = qdisc_class_hash_alloc(size); 587 if (clhash->hash == NULL) 588 return -ENOMEM; 589 clhash->hashsize = size; 590 clhash->hashmask = size - 1; 591 clhash->hashelems = 0; 592 return 0; 593 } 594 EXPORT_SYMBOL(qdisc_class_hash_init); 595 596 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash) 597 { 598 qdisc_class_hash_free(clhash->hash, clhash->hashsize); 599 } 600 EXPORT_SYMBOL(qdisc_class_hash_destroy); 601 602 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash, 603 struct Qdisc_class_common *cl) 604 { 605 unsigned int h; 606 607 INIT_HLIST_NODE(&cl->hnode); 608 h = qdisc_class_hash(cl->classid, clhash->hashmask); 609 hlist_add_head(&cl->hnode, &clhash->hash[h]); 610 clhash->hashelems++; 611 } 612 EXPORT_SYMBOL(qdisc_class_hash_insert); 613 614 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash, 615 struct Qdisc_class_common *cl) 616 { 617 hlist_del(&cl->hnode); 618 clhash->hashelems--; 619 } 620 EXPORT_SYMBOL(qdisc_class_hash_remove); 621 622 /* Allocate an unique handle from space managed by kernel 623 * Possible range is [8000-FFFF]:0000 (0x8000 values) 624 */ 625 static u32 qdisc_alloc_handle(struct net_device *dev) 626 { 627 int i = 0x8000; 628 static u32 autohandle = TC_H_MAKE(0x80000000U, 0); 629 630 do { 631 autohandle += TC_H_MAKE(0x10000U, 0); 632 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0)) 633 autohandle = TC_H_MAKE(0x80000000U, 0); 634 if (!qdisc_lookup(dev, autohandle)) 635 return autohandle; 636 cond_resched(); 637 } while (--i > 0); 638 639 return 0; 640 } 641 642 void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n) 643 { 644 const struct Qdisc_class_ops *cops; 645 unsigned long cl; 646 u32 parentid; 647 648 if (n == 0) 649 return; 650 while ((parentid = sch->parent)) { 651 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS)) 652 return; 653 654 sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid)); 655 if (sch == NULL) { 656 WARN_ON(parentid != TC_H_ROOT); 657 return; 658 } 659 cops = sch->ops->cl_ops; 660 if (cops->qlen_notify) { 661 cl = cops->get(sch, parentid); 662 cops->qlen_notify(sch, cl); 663 cops->put(sch, cl); 664 } 665 sch->q.qlen -= n; 666 } 667 } 668 EXPORT_SYMBOL(qdisc_tree_decrease_qlen); 669 670 static void notify_and_destroy(struct net *net, struct sk_buff *skb, 671 struct nlmsghdr *n, u32 clid, 672 struct Qdisc *old, struct Qdisc *new) 673 { 674 if (new || old) 675 qdisc_notify(net, skb, n, clid, old, new); 676 677 if (old) 678 qdisc_destroy(old); 679 } 680 681 /* Graft qdisc "new" to class "classid" of qdisc "parent" or 682 * to device "dev". 683 * 684 * When appropriate send a netlink notification using 'skb' 685 * and "n". 686 * 687 * On success, destroy old qdisc. 688 */ 689 690 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent, 691 struct sk_buff *skb, struct nlmsghdr *n, u32 classid, 692 struct Qdisc *new, struct Qdisc *old) 693 { 694 struct Qdisc *q = old; 695 struct net *net = dev_net(dev); 696 int err = 0; 697 698 if (parent == NULL) { 699 unsigned int i, num_q, ingress; 700 701 ingress = 0; 702 num_q = dev->num_tx_queues; 703 if ((q && q->flags & TCQ_F_INGRESS) || 704 (new && new->flags & TCQ_F_INGRESS)) { 705 num_q = 1; 706 ingress = 1; 707 if (!dev_ingress_queue(dev)) 708 return -ENOENT; 709 } 710 711 if (dev->flags & IFF_UP) 712 dev_deactivate(dev); 713 714 if (new && new->ops->attach) { 715 new->ops->attach(new); 716 num_q = 0; 717 } 718 719 for (i = 0; i < num_q; i++) { 720 struct netdev_queue *dev_queue = dev_ingress_queue(dev); 721 722 if (!ingress) 723 dev_queue = netdev_get_tx_queue(dev, i); 724 725 old = dev_graft_qdisc(dev_queue, new); 726 if (new && i > 0) 727 atomic_inc(&new->refcnt); 728 729 if (!ingress) 730 qdisc_destroy(old); 731 } 732 733 if (!ingress) { 734 notify_and_destroy(net, skb, n, classid, 735 dev->qdisc, new); 736 if (new && !new->ops->attach) 737 atomic_inc(&new->refcnt); 738 dev->qdisc = new ? : &noop_qdisc; 739 } else { 740 notify_and_destroy(net, skb, n, classid, old, new); 741 } 742 743 if (dev->flags & IFF_UP) 744 dev_activate(dev); 745 } else { 746 const struct Qdisc_class_ops *cops = parent->ops->cl_ops; 747 748 err = -EOPNOTSUPP; 749 if (cops && cops->graft) { 750 unsigned long cl = cops->get(parent, classid); 751 if (cl) { 752 err = cops->graft(parent, cl, new, &old); 753 cops->put(parent, cl); 754 } else 755 err = -ENOENT; 756 } 757 if (!err) 758 notify_and_destroy(net, skb, n, classid, old, new); 759 } 760 return err; 761 } 762 763 /* lockdep annotation is needed for ingress; egress gets it only for name */ 764 static struct lock_class_key qdisc_tx_lock; 765 static struct lock_class_key qdisc_rx_lock; 766 767 /* 768 Allocate and initialize new qdisc. 769 770 Parameters are passed via opt. 771 */ 772 773 static struct Qdisc * 774 qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue, 775 struct Qdisc *p, u32 parent, u32 handle, 776 struct nlattr **tca, int *errp) 777 { 778 int err; 779 struct nlattr *kind = tca[TCA_KIND]; 780 struct Qdisc *sch; 781 struct Qdisc_ops *ops; 782 struct qdisc_size_table *stab; 783 784 ops = qdisc_lookup_ops(kind); 785 #ifdef CONFIG_MODULES 786 if (ops == NULL && kind != NULL) { 787 char name[IFNAMSIZ]; 788 if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) { 789 /* We dropped the RTNL semaphore in order to 790 * perform the module load. So, even if we 791 * succeeded in loading the module we have to 792 * tell the caller to replay the request. We 793 * indicate this using -EAGAIN. 794 * We replay the request because the device may 795 * go away in the mean time. 796 */ 797 rtnl_unlock(); 798 request_module("sch_%s", name); 799 rtnl_lock(); 800 ops = qdisc_lookup_ops(kind); 801 if (ops != NULL) { 802 /* We will try again qdisc_lookup_ops, 803 * so don't keep a reference. 804 */ 805 module_put(ops->owner); 806 err = -EAGAIN; 807 goto err_out; 808 } 809 } 810 } 811 #endif 812 813 err = -ENOENT; 814 if (ops == NULL) 815 goto err_out; 816 817 sch = qdisc_alloc(dev_queue, ops); 818 if (IS_ERR(sch)) { 819 err = PTR_ERR(sch); 820 goto err_out2; 821 } 822 823 sch->parent = parent; 824 825 if (handle == TC_H_INGRESS) { 826 sch->flags |= TCQ_F_INGRESS; 827 handle = TC_H_MAKE(TC_H_INGRESS, 0); 828 lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock); 829 } else { 830 if (handle == 0) { 831 handle = qdisc_alloc_handle(dev); 832 err = -ENOMEM; 833 if (handle == 0) 834 goto err_out3; 835 } 836 lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock); 837 } 838 839 sch->handle = handle; 840 841 if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) { 842 if (tca[TCA_STAB]) { 843 stab = qdisc_get_stab(tca[TCA_STAB]); 844 if (IS_ERR(stab)) { 845 err = PTR_ERR(stab); 846 goto err_out4; 847 } 848 rcu_assign_pointer(sch->stab, stab); 849 } 850 if (tca[TCA_RATE]) { 851 spinlock_t *root_lock; 852 853 err = -EOPNOTSUPP; 854 if (sch->flags & TCQ_F_MQROOT) 855 goto err_out4; 856 857 if ((sch->parent != TC_H_ROOT) && 858 !(sch->flags & TCQ_F_INGRESS) && 859 (!p || !(p->flags & TCQ_F_MQROOT))) 860 root_lock = qdisc_root_sleeping_lock(sch); 861 else 862 root_lock = qdisc_lock(sch); 863 864 err = gen_new_estimator(&sch->bstats, &sch->rate_est, 865 root_lock, tca[TCA_RATE]); 866 if (err) 867 goto err_out4; 868 } 869 870 qdisc_list_add(sch); 871 872 return sch; 873 } 874 err_out3: 875 dev_put(dev); 876 kfree((char *) sch - sch->padded); 877 err_out2: 878 module_put(ops->owner); 879 err_out: 880 *errp = err; 881 return NULL; 882 883 err_out4: 884 /* 885 * Any broken qdiscs that would require a ops->reset() here? 886 * The qdisc was never in action so it shouldn't be necessary. 887 */ 888 qdisc_put_stab(rtnl_dereference(sch->stab)); 889 if (ops->destroy) 890 ops->destroy(sch); 891 goto err_out3; 892 } 893 894 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca) 895 { 896 struct qdisc_size_table *ostab, *stab = NULL; 897 int err = 0; 898 899 if (tca[TCA_OPTIONS]) { 900 if (sch->ops->change == NULL) 901 return -EINVAL; 902 err = sch->ops->change(sch, tca[TCA_OPTIONS]); 903 if (err) 904 return err; 905 } 906 907 if (tca[TCA_STAB]) { 908 stab = qdisc_get_stab(tca[TCA_STAB]); 909 if (IS_ERR(stab)) 910 return PTR_ERR(stab); 911 } 912 913 ostab = rtnl_dereference(sch->stab); 914 rcu_assign_pointer(sch->stab, stab); 915 qdisc_put_stab(ostab); 916 917 if (tca[TCA_RATE]) { 918 /* NB: ignores errors from replace_estimator 919 because change can't be undone. */ 920 if (sch->flags & TCQ_F_MQROOT) 921 goto out; 922 gen_replace_estimator(&sch->bstats, &sch->rate_est, 923 qdisc_root_sleeping_lock(sch), 924 tca[TCA_RATE]); 925 } 926 out: 927 return 0; 928 } 929 930 struct check_loop_arg { 931 struct qdisc_walker w; 932 struct Qdisc *p; 933 int depth; 934 }; 935 936 static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w); 937 938 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth) 939 { 940 struct check_loop_arg arg; 941 942 if (q->ops->cl_ops == NULL) 943 return 0; 944 945 arg.w.stop = arg.w.skip = arg.w.count = 0; 946 arg.w.fn = check_loop_fn; 947 arg.depth = depth; 948 arg.p = p; 949 q->ops->cl_ops->walk(q, &arg.w); 950 return arg.w.stop ? -ELOOP : 0; 951 } 952 953 static int 954 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w) 955 { 956 struct Qdisc *leaf; 957 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 958 struct check_loop_arg *arg = (struct check_loop_arg *)w; 959 960 leaf = cops->leaf(q, cl); 961 if (leaf) { 962 if (leaf == arg->p || arg->depth > 7) 963 return -ELOOP; 964 return check_loop(leaf, arg->p, arg->depth + 1); 965 } 966 return 0; 967 } 968 969 /* 970 * Delete/get qdisc. 971 */ 972 973 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg) 974 { 975 struct net *net = sock_net(skb->sk); 976 struct tcmsg *tcm = NLMSG_DATA(n); 977 struct nlattr *tca[TCA_MAX + 1]; 978 struct net_device *dev; 979 u32 clid = tcm->tcm_parent; 980 struct Qdisc *q = NULL; 981 struct Qdisc *p = NULL; 982 int err; 983 984 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 985 if (!dev) 986 return -ENODEV; 987 988 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL); 989 if (err < 0) 990 return err; 991 992 if (clid) { 993 if (clid != TC_H_ROOT) { 994 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) { 995 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 996 if (!p) 997 return -ENOENT; 998 q = qdisc_leaf(p, clid); 999 } else if (dev_ingress_queue(dev)) { 1000 q = dev_ingress_queue(dev)->qdisc_sleeping; 1001 } 1002 } else { 1003 q = dev->qdisc; 1004 } 1005 if (!q) 1006 return -ENOENT; 1007 1008 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) 1009 return -EINVAL; 1010 } else { 1011 q = qdisc_lookup(dev, tcm->tcm_handle); 1012 if (!q) 1013 return -ENOENT; 1014 } 1015 1016 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) 1017 return -EINVAL; 1018 1019 if (n->nlmsg_type == RTM_DELQDISC) { 1020 if (!clid) 1021 return -EINVAL; 1022 if (q->handle == 0) 1023 return -ENOENT; 1024 err = qdisc_graft(dev, p, skb, n, clid, NULL, q); 1025 if (err != 0) 1026 return err; 1027 } else { 1028 qdisc_notify(net, skb, n, clid, NULL, q); 1029 } 1030 return 0; 1031 } 1032 1033 /* 1034 * Create/change qdisc. 1035 */ 1036 1037 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg) 1038 { 1039 struct net *net = sock_net(skb->sk); 1040 struct tcmsg *tcm; 1041 struct nlattr *tca[TCA_MAX + 1]; 1042 struct net_device *dev; 1043 u32 clid; 1044 struct Qdisc *q, *p; 1045 int err; 1046 1047 replay: 1048 /* Reinit, just in case something touches this. */ 1049 tcm = NLMSG_DATA(n); 1050 clid = tcm->tcm_parent; 1051 q = p = NULL; 1052 1053 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1054 if (!dev) 1055 return -ENODEV; 1056 1057 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL); 1058 if (err < 0) 1059 return err; 1060 1061 if (clid) { 1062 if (clid != TC_H_ROOT) { 1063 if (clid != TC_H_INGRESS) { 1064 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1065 if (!p) 1066 return -ENOENT; 1067 q = qdisc_leaf(p, clid); 1068 } else if (dev_ingress_queue_create(dev)) { 1069 q = dev_ingress_queue(dev)->qdisc_sleeping; 1070 } 1071 } else { 1072 q = dev->qdisc; 1073 } 1074 1075 /* It may be default qdisc, ignore it */ 1076 if (q && q->handle == 0) 1077 q = NULL; 1078 1079 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) { 1080 if (tcm->tcm_handle) { 1081 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) 1082 return -EEXIST; 1083 if (TC_H_MIN(tcm->tcm_handle)) 1084 return -EINVAL; 1085 q = qdisc_lookup(dev, tcm->tcm_handle); 1086 if (!q) 1087 goto create_n_graft; 1088 if (n->nlmsg_flags & NLM_F_EXCL) 1089 return -EEXIST; 1090 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) 1091 return -EINVAL; 1092 if (q == p || 1093 (p && check_loop(q, p, 0))) 1094 return -ELOOP; 1095 atomic_inc(&q->refcnt); 1096 goto graft; 1097 } else { 1098 if (!q) 1099 goto create_n_graft; 1100 1101 /* This magic test requires explanation. 1102 * 1103 * We know, that some child q is already 1104 * attached to this parent and have choice: 1105 * either to change it or to create/graft new one. 1106 * 1107 * 1. We are allowed to create/graft only 1108 * if CREATE and REPLACE flags are set. 1109 * 1110 * 2. If EXCL is set, requestor wanted to say, 1111 * that qdisc tcm_handle is not expected 1112 * to exist, so that we choose create/graft too. 1113 * 1114 * 3. The last case is when no flags are set. 1115 * Alas, it is sort of hole in API, we 1116 * cannot decide what to do unambiguously. 1117 * For now we select create/graft, if 1118 * user gave KIND, which does not match existing. 1119 */ 1120 if ((n->nlmsg_flags & NLM_F_CREATE) && 1121 (n->nlmsg_flags & NLM_F_REPLACE) && 1122 ((n->nlmsg_flags & NLM_F_EXCL) || 1123 (tca[TCA_KIND] && 1124 nla_strcmp(tca[TCA_KIND], q->ops->id)))) 1125 goto create_n_graft; 1126 } 1127 } 1128 } else { 1129 if (!tcm->tcm_handle) 1130 return -EINVAL; 1131 q = qdisc_lookup(dev, tcm->tcm_handle); 1132 } 1133 1134 /* Change qdisc parameters */ 1135 if (q == NULL) 1136 return -ENOENT; 1137 if (n->nlmsg_flags & NLM_F_EXCL) 1138 return -EEXIST; 1139 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) 1140 return -EINVAL; 1141 err = qdisc_change(q, tca); 1142 if (err == 0) 1143 qdisc_notify(net, skb, n, clid, NULL, q); 1144 return err; 1145 1146 create_n_graft: 1147 if (!(n->nlmsg_flags & NLM_F_CREATE)) 1148 return -ENOENT; 1149 if (clid == TC_H_INGRESS) { 1150 if (dev_ingress_queue(dev)) 1151 q = qdisc_create(dev, dev_ingress_queue(dev), p, 1152 tcm->tcm_parent, tcm->tcm_parent, 1153 tca, &err); 1154 else 1155 err = -ENOENT; 1156 } else { 1157 struct netdev_queue *dev_queue; 1158 1159 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue) 1160 dev_queue = p->ops->cl_ops->select_queue(p, tcm); 1161 else if (p) 1162 dev_queue = p->dev_queue; 1163 else 1164 dev_queue = netdev_get_tx_queue(dev, 0); 1165 1166 q = qdisc_create(dev, dev_queue, p, 1167 tcm->tcm_parent, tcm->tcm_handle, 1168 tca, &err); 1169 } 1170 if (q == NULL) { 1171 if (err == -EAGAIN) 1172 goto replay; 1173 return err; 1174 } 1175 1176 graft: 1177 err = qdisc_graft(dev, p, skb, n, clid, q, NULL); 1178 if (err) { 1179 if (q) 1180 qdisc_destroy(q); 1181 return err; 1182 } 1183 1184 return 0; 1185 } 1186 1187 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid, 1188 u32 pid, u32 seq, u16 flags, int event) 1189 { 1190 struct tcmsg *tcm; 1191 struct nlmsghdr *nlh; 1192 unsigned char *b = skb_tail_pointer(skb); 1193 struct gnet_dump d; 1194 struct qdisc_size_table *stab; 1195 1196 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags); 1197 tcm = NLMSG_DATA(nlh); 1198 tcm->tcm_family = AF_UNSPEC; 1199 tcm->tcm__pad1 = 0; 1200 tcm->tcm__pad2 = 0; 1201 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 1202 tcm->tcm_parent = clid; 1203 tcm->tcm_handle = q->handle; 1204 tcm->tcm_info = atomic_read(&q->refcnt); 1205 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 1206 goto nla_put_failure; 1207 if (q->ops->dump && q->ops->dump(q, skb) < 0) 1208 goto nla_put_failure; 1209 q->qstats.qlen = q->q.qlen; 1210 1211 stab = rtnl_dereference(q->stab); 1212 if (stab && qdisc_dump_stab(skb, stab) < 0) 1213 goto nla_put_failure; 1214 1215 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 1216 qdisc_root_sleeping_lock(q), &d) < 0) 1217 goto nla_put_failure; 1218 1219 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0) 1220 goto nla_put_failure; 1221 1222 if (gnet_stats_copy_basic(&d, &q->bstats) < 0 || 1223 gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 || 1224 gnet_stats_copy_queue(&d, &q->qstats) < 0) 1225 goto nla_put_failure; 1226 1227 if (gnet_stats_finish_copy(&d) < 0) 1228 goto nla_put_failure; 1229 1230 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 1231 return skb->len; 1232 1233 nlmsg_failure: 1234 nla_put_failure: 1235 nlmsg_trim(skb, b); 1236 return -1; 1237 } 1238 1239 static bool tc_qdisc_dump_ignore(struct Qdisc *q) 1240 { 1241 return (q->flags & TCQ_F_BUILTIN) ? true : false; 1242 } 1243 1244 static int qdisc_notify(struct net *net, struct sk_buff *oskb, 1245 struct nlmsghdr *n, u32 clid, 1246 struct Qdisc *old, struct Qdisc *new) 1247 { 1248 struct sk_buff *skb; 1249 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0; 1250 1251 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1252 if (!skb) 1253 return -ENOBUFS; 1254 1255 if (old && !tc_qdisc_dump_ignore(old)) { 1256 if (tc_fill_qdisc(skb, old, clid, pid, n->nlmsg_seq, 1257 0, RTM_DELQDISC) < 0) 1258 goto err_out; 1259 } 1260 if (new && !tc_qdisc_dump_ignore(new)) { 1261 if (tc_fill_qdisc(skb, new, clid, pid, n->nlmsg_seq, 1262 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0) 1263 goto err_out; 1264 } 1265 1266 if (skb->len) 1267 return rtnetlink_send(skb, net, pid, RTNLGRP_TC, 1268 n->nlmsg_flags & NLM_F_ECHO); 1269 1270 err_out: 1271 kfree_skb(skb); 1272 return -EINVAL; 1273 } 1274 1275 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb, 1276 struct netlink_callback *cb, 1277 int *q_idx_p, int s_q_idx) 1278 { 1279 int ret = 0, q_idx = *q_idx_p; 1280 struct Qdisc *q; 1281 1282 if (!root) 1283 return 0; 1284 1285 q = root; 1286 if (q_idx < s_q_idx) { 1287 q_idx++; 1288 } else { 1289 if (!tc_qdisc_dump_ignore(q) && 1290 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid, 1291 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0) 1292 goto done; 1293 q_idx++; 1294 } 1295 list_for_each_entry(q, &root->list, list) { 1296 if (q_idx < s_q_idx) { 1297 q_idx++; 1298 continue; 1299 } 1300 if (!tc_qdisc_dump_ignore(q) && 1301 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid, 1302 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0) 1303 goto done; 1304 q_idx++; 1305 } 1306 1307 out: 1308 *q_idx_p = q_idx; 1309 return ret; 1310 done: 1311 ret = -1; 1312 goto out; 1313 } 1314 1315 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb) 1316 { 1317 struct net *net = sock_net(skb->sk); 1318 int idx, q_idx; 1319 int s_idx, s_q_idx; 1320 struct net_device *dev; 1321 1322 s_idx = cb->args[0]; 1323 s_q_idx = q_idx = cb->args[1]; 1324 1325 rcu_read_lock(); 1326 idx = 0; 1327 for_each_netdev_rcu(net, dev) { 1328 struct netdev_queue *dev_queue; 1329 1330 if (idx < s_idx) 1331 goto cont; 1332 if (idx > s_idx) 1333 s_q_idx = 0; 1334 q_idx = 0; 1335 1336 if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0) 1337 goto done; 1338 1339 dev_queue = dev_ingress_queue(dev); 1340 if (dev_queue && 1341 tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb, 1342 &q_idx, s_q_idx) < 0) 1343 goto done; 1344 1345 cont: 1346 idx++; 1347 } 1348 1349 done: 1350 rcu_read_unlock(); 1351 1352 cb->args[0] = idx; 1353 cb->args[1] = q_idx; 1354 1355 return skb->len; 1356 } 1357 1358 1359 1360 /************************************************ 1361 * Traffic classes manipulation. * 1362 ************************************************/ 1363 1364 1365 1366 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg) 1367 { 1368 struct net *net = sock_net(skb->sk); 1369 struct tcmsg *tcm = NLMSG_DATA(n); 1370 struct nlattr *tca[TCA_MAX + 1]; 1371 struct net_device *dev; 1372 struct Qdisc *q = NULL; 1373 const struct Qdisc_class_ops *cops; 1374 unsigned long cl = 0; 1375 unsigned long new_cl; 1376 u32 pid = tcm->tcm_parent; 1377 u32 clid = tcm->tcm_handle; 1378 u32 qid = TC_H_MAJ(clid); 1379 int err; 1380 1381 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1382 if (!dev) 1383 return -ENODEV; 1384 1385 err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL); 1386 if (err < 0) 1387 return err; 1388 1389 /* 1390 parent == TC_H_UNSPEC - unspecified parent. 1391 parent == TC_H_ROOT - class is root, which has no parent. 1392 parent == X:0 - parent is root class. 1393 parent == X:Y - parent is a node in hierarchy. 1394 parent == 0:Y - parent is X:Y, where X:0 is qdisc. 1395 1396 handle == 0:0 - generate handle from kernel pool. 1397 handle == 0:Y - class is X:Y, where X:0 is qdisc. 1398 handle == X:Y - clear. 1399 handle == X:0 - root class. 1400 */ 1401 1402 /* Step 1. Determine qdisc handle X:0 */ 1403 1404 if (pid != TC_H_ROOT) { 1405 u32 qid1 = TC_H_MAJ(pid); 1406 1407 if (qid && qid1) { 1408 /* If both majors are known, they must be identical. */ 1409 if (qid != qid1) 1410 return -EINVAL; 1411 } else if (qid1) { 1412 qid = qid1; 1413 } else if (qid == 0) 1414 qid = dev->qdisc->handle; 1415 1416 /* Now qid is genuine qdisc handle consistent 1417 * both with parent and child. 1418 * 1419 * TC_H_MAJ(pid) still may be unspecified, complete it now. 1420 */ 1421 if (pid) 1422 pid = TC_H_MAKE(qid, pid); 1423 } else { 1424 if (qid == 0) 1425 qid = dev->qdisc->handle; 1426 } 1427 1428 /* OK. Locate qdisc */ 1429 q = qdisc_lookup(dev, qid); 1430 if (!q) 1431 return -ENOENT; 1432 1433 /* An check that it supports classes */ 1434 cops = q->ops->cl_ops; 1435 if (cops == NULL) 1436 return -EINVAL; 1437 1438 /* Now try to get class */ 1439 if (clid == 0) { 1440 if (pid == TC_H_ROOT) 1441 clid = qid; 1442 } else 1443 clid = TC_H_MAKE(qid, clid); 1444 1445 if (clid) 1446 cl = cops->get(q, clid); 1447 1448 if (cl == 0) { 1449 err = -ENOENT; 1450 if (n->nlmsg_type != RTM_NEWTCLASS || 1451 !(n->nlmsg_flags & NLM_F_CREATE)) 1452 goto out; 1453 } else { 1454 switch (n->nlmsg_type) { 1455 case RTM_NEWTCLASS: 1456 err = -EEXIST; 1457 if (n->nlmsg_flags & NLM_F_EXCL) 1458 goto out; 1459 break; 1460 case RTM_DELTCLASS: 1461 err = -EOPNOTSUPP; 1462 if (cops->delete) 1463 err = cops->delete(q, cl); 1464 if (err == 0) 1465 tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS); 1466 goto out; 1467 case RTM_GETTCLASS: 1468 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS); 1469 goto out; 1470 default: 1471 err = -EINVAL; 1472 goto out; 1473 } 1474 } 1475 1476 new_cl = cl; 1477 err = -EOPNOTSUPP; 1478 if (cops->change) 1479 err = cops->change(q, clid, pid, tca, &new_cl); 1480 if (err == 0) 1481 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS); 1482 1483 out: 1484 if (cl) 1485 cops->put(q, cl); 1486 1487 return err; 1488 } 1489 1490 1491 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, 1492 unsigned long cl, 1493 u32 pid, u32 seq, u16 flags, int event) 1494 { 1495 struct tcmsg *tcm; 1496 struct nlmsghdr *nlh; 1497 unsigned char *b = skb_tail_pointer(skb); 1498 struct gnet_dump d; 1499 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops; 1500 1501 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags); 1502 tcm = NLMSG_DATA(nlh); 1503 tcm->tcm_family = AF_UNSPEC; 1504 tcm->tcm__pad1 = 0; 1505 tcm->tcm__pad2 = 0; 1506 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 1507 tcm->tcm_parent = q->handle; 1508 tcm->tcm_handle = q->handle; 1509 tcm->tcm_info = 0; 1510 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 1511 goto nla_put_failure; 1512 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0) 1513 goto nla_put_failure; 1514 1515 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 1516 qdisc_root_sleeping_lock(q), &d) < 0) 1517 goto nla_put_failure; 1518 1519 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0) 1520 goto nla_put_failure; 1521 1522 if (gnet_stats_finish_copy(&d) < 0) 1523 goto nla_put_failure; 1524 1525 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 1526 return skb->len; 1527 1528 nlmsg_failure: 1529 nla_put_failure: 1530 nlmsg_trim(skb, b); 1531 return -1; 1532 } 1533 1534 static int tclass_notify(struct net *net, struct sk_buff *oskb, 1535 struct nlmsghdr *n, struct Qdisc *q, 1536 unsigned long cl, int event) 1537 { 1538 struct sk_buff *skb; 1539 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0; 1540 1541 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1542 if (!skb) 1543 return -ENOBUFS; 1544 1545 if (tc_fill_tclass(skb, q, cl, pid, n->nlmsg_seq, 0, event) < 0) { 1546 kfree_skb(skb); 1547 return -EINVAL; 1548 } 1549 1550 return rtnetlink_send(skb, net, pid, RTNLGRP_TC, 1551 n->nlmsg_flags & NLM_F_ECHO); 1552 } 1553 1554 struct qdisc_dump_args { 1555 struct qdisc_walker w; 1556 struct sk_buff *skb; 1557 struct netlink_callback *cb; 1558 }; 1559 1560 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg) 1561 { 1562 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg; 1563 1564 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).pid, 1565 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS); 1566 } 1567 1568 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb, 1569 struct tcmsg *tcm, struct netlink_callback *cb, 1570 int *t_p, int s_t) 1571 { 1572 struct qdisc_dump_args arg; 1573 1574 if (tc_qdisc_dump_ignore(q) || 1575 *t_p < s_t || !q->ops->cl_ops || 1576 (tcm->tcm_parent && 1577 TC_H_MAJ(tcm->tcm_parent) != q->handle)) { 1578 (*t_p)++; 1579 return 0; 1580 } 1581 if (*t_p > s_t) 1582 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); 1583 arg.w.fn = qdisc_class_dump; 1584 arg.skb = skb; 1585 arg.cb = cb; 1586 arg.w.stop = 0; 1587 arg.w.skip = cb->args[1]; 1588 arg.w.count = 0; 1589 q->ops->cl_ops->walk(q, &arg.w); 1590 cb->args[1] = arg.w.count; 1591 if (arg.w.stop) 1592 return -1; 1593 (*t_p)++; 1594 return 0; 1595 } 1596 1597 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb, 1598 struct tcmsg *tcm, struct netlink_callback *cb, 1599 int *t_p, int s_t) 1600 { 1601 struct Qdisc *q; 1602 1603 if (!root) 1604 return 0; 1605 1606 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0) 1607 return -1; 1608 1609 list_for_each_entry(q, &root->list, list) { 1610 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 1611 return -1; 1612 } 1613 1614 return 0; 1615 } 1616 1617 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb) 1618 { 1619 struct tcmsg *tcm = (struct tcmsg *)NLMSG_DATA(cb->nlh); 1620 struct net *net = sock_net(skb->sk); 1621 struct netdev_queue *dev_queue; 1622 struct net_device *dev; 1623 int t, s_t; 1624 1625 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm))) 1626 return 0; 1627 dev = dev_get_by_index(net, tcm->tcm_ifindex); 1628 if (!dev) 1629 return 0; 1630 1631 s_t = cb->args[0]; 1632 t = 0; 1633 1634 if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0) 1635 goto done; 1636 1637 dev_queue = dev_ingress_queue(dev); 1638 if (dev_queue && 1639 tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb, 1640 &t, s_t) < 0) 1641 goto done; 1642 1643 done: 1644 cb->args[0] = t; 1645 1646 dev_put(dev); 1647 return skb->len; 1648 } 1649 1650 /* Main classifier routine: scans classifier chain attached 1651 * to this qdisc, (optionally) tests for protocol and asks 1652 * specific classifiers. 1653 */ 1654 int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp, 1655 struct tcf_result *res) 1656 { 1657 __be16 protocol = skb->protocol; 1658 int err; 1659 1660 for (; tp; tp = tp->next) { 1661 if (tp->protocol != protocol && 1662 tp->protocol != htons(ETH_P_ALL)) 1663 continue; 1664 err = tp->classify(skb, tp, res); 1665 1666 if (err >= 0) { 1667 #ifdef CONFIG_NET_CLS_ACT 1668 if (err != TC_ACT_RECLASSIFY && skb->tc_verd) 1669 skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0); 1670 #endif 1671 return err; 1672 } 1673 } 1674 return -1; 1675 } 1676 EXPORT_SYMBOL(tc_classify_compat); 1677 1678 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp, 1679 struct tcf_result *res) 1680 { 1681 int err = 0; 1682 #ifdef CONFIG_NET_CLS_ACT 1683 const struct tcf_proto *otp = tp; 1684 reclassify: 1685 #endif 1686 1687 err = tc_classify_compat(skb, tp, res); 1688 #ifdef CONFIG_NET_CLS_ACT 1689 if (err == TC_ACT_RECLASSIFY) { 1690 u32 verd = G_TC_VERD(skb->tc_verd); 1691 tp = otp; 1692 1693 if (verd++ >= MAX_REC_LOOP) { 1694 net_notice_ratelimited("%s: packet reclassify loop rule prio %u protocol %02x\n", 1695 tp->q->ops->id, 1696 tp->prio & 0xffff, 1697 ntohs(tp->protocol)); 1698 return TC_ACT_SHOT; 1699 } 1700 skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd); 1701 goto reclassify; 1702 } 1703 #endif 1704 return err; 1705 } 1706 EXPORT_SYMBOL(tc_classify); 1707 1708 void tcf_destroy(struct tcf_proto *tp) 1709 { 1710 tp->ops->destroy(tp); 1711 module_put(tp->ops->owner); 1712 kfree(tp); 1713 } 1714 1715 void tcf_destroy_chain(struct tcf_proto **fl) 1716 { 1717 struct tcf_proto *tp; 1718 1719 while ((tp = *fl) != NULL) { 1720 *fl = tp->next; 1721 tcf_destroy(tp); 1722 } 1723 } 1724 EXPORT_SYMBOL(tcf_destroy_chain); 1725 1726 #ifdef CONFIG_PROC_FS 1727 static int psched_show(struct seq_file *seq, void *v) 1728 { 1729 struct timespec ts; 1730 1731 hrtimer_get_res(CLOCK_MONOTONIC, &ts); 1732 seq_printf(seq, "%08x %08x %08x %08x\n", 1733 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1), 1734 1000000, 1735 (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts))); 1736 1737 return 0; 1738 } 1739 1740 static int psched_open(struct inode *inode, struct file *file) 1741 { 1742 return single_open(file, psched_show, NULL); 1743 } 1744 1745 static const struct file_operations psched_fops = { 1746 .owner = THIS_MODULE, 1747 .open = psched_open, 1748 .read = seq_read, 1749 .llseek = seq_lseek, 1750 .release = single_release, 1751 }; 1752 1753 static int __net_init psched_net_init(struct net *net) 1754 { 1755 struct proc_dir_entry *e; 1756 1757 e = proc_net_fops_create(net, "psched", 0, &psched_fops); 1758 if (e == NULL) 1759 return -ENOMEM; 1760 1761 return 0; 1762 } 1763 1764 static void __net_exit psched_net_exit(struct net *net) 1765 { 1766 proc_net_remove(net, "psched"); 1767 } 1768 #else 1769 static int __net_init psched_net_init(struct net *net) 1770 { 1771 return 0; 1772 } 1773 1774 static void __net_exit psched_net_exit(struct net *net) 1775 { 1776 } 1777 #endif 1778 1779 static struct pernet_operations psched_net_ops = { 1780 .init = psched_net_init, 1781 .exit = psched_net_exit, 1782 }; 1783 1784 static int __init pktsched_init(void) 1785 { 1786 int err; 1787 1788 err = register_pernet_subsys(&psched_net_ops); 1789 if (err) { 1790 pr_err("pktsched_init: " 1791 "cannot initialize per netns operations\n"); 1792 return err; 1793 } 1794 1795 register_qdisc(&pfifo_qdisc_ops); 1796 register_qdisc(&bfifo_qdisc_ops); 1797 register_qdisc(&pfifo_head_drop_qdisc_ops); 1798 register_qdisc(&mq_qdisc_ops); 1799 1800 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL); 1801 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL); 1802 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL); 1803 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL); 1804 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL); 1805 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL); 1806 1807 return 0; 1808 } 1809 1810 subsys_initcall(pktsched_init); 1811