1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * net/sched/sch_api.c	Packet scheduler API.
   4 *
   5 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   6 *
   7 * Fixes:
   8 *
   9 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired.
  10 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
  11 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support
  12 */
  13
  14#include <linux/module.h>
  15#include <linux/types.h>
  16#include <linux/kernel.h>
  17#include <linux/string.h>
  18#include <linux/errno.h>
  19#include <linux/skbuff.h>
  20#include <linux/init.h>
  21#include <linux/proc_fs.h>
  22#include <linux/seq_file.h>
  23#include <linux/kmod.h>
  24#include <linux/list.h>
  25#include <linux/hrtimer.h>
  26#include <linux/slab.h>
  27#include <linux/hashtable.h>
  28
  29#include <net/net_namespace.h>
  30#include <net/sock.h>
  31#include <net/netlink.h>
  32#include <net/pkt_sched.h>
  33#include <net/pkt_cls.h>
 
 
 
  34
  35/*
  36
  37   Short review.
  38   -------------
  39
  40   This file consists of two interrelated parts:
  41
  42   1. queueing disciplines manager frontend.
  43   2. traffic classes manager frontend.
  44
  45   Generally, queueing discipline ("qdisc") is a black box,
  46   which is able to enqueue packets and to dequeue them (when
  47   device is ready to send something) in order and at times
  48   determined by algorithm hidden in it.
  49
  50   qdisc's are divided to two categories:
  51   - "queues", which have no internal structure visible from outside.
  52   - "schedulers", which split all the packets to "traffic classes",
  53     using "packet classifiers" (look at cls_api.c)
  54
  55   In turn, classes may have child qdiscs (as rule, queues)
  56   attached to them etc. etc. etc.
  57
  58   The goal of the routines in this file is to translate
  59   information supplied by user in the form of handles
  60   to more intelligible for kernel form, to make some sanity
  61   checks and part of work, which is common to all qdiscs
  62   and to provide rtnetlink notifications.
  63
  64   All real intelligent work is done inside qdisc modules.
  65
  66
  67
  68   Every discipline has two major routines: enqueue and dequeue.
  69
  70   ---dequeue
  71
  72   dequeue usually returns a skb to send. It is allowed to return NULL,
  73   but it does not mean that queue is empty, it just means that
  74   discipline does not want to send anything this time.
  75   Queue is really empty if q->q.qlen == 0.
  76   For complicated disciplines with multiple queues q->q is not
  77   real packet queue, but however q->q.qlen must be valid.
  78
  79   ---enqueue
  80
  81   enqueue returns 0, if packet was enqueued successfully.
  82   If packet (this one or another one) was dropped, it returns
  83   not zero error code.
  84   NET_XMIT_DROP 	- this packet dropped
  85     Expected action: do not backoff, but wait until queue will clear.
  86   NET_XMIT_CN	 	- probably this packet enqueued, but another one dropped.
  87     Expected action: backoff or ignore
  88
  89   Auxiliary routines:
  90
  91   ---peek
  92
  93   like dequeue but without removing a packet from the queue
  94
  95   ---reset
  96
  97   returns qdisc to initial state: purge all buffers, clear all
  98   timers, counters (except for statistics) etc.
  99
 100   ---init
 101
 102   initializes newly created qdisc.
 103
 104   ---destroy
 105
 106   destroys resources allocated by init and during lifetime of qdisc.
 107
 108   ---change
 109
 110   changes qdisc parameters.
 111 */
 112
 113/* Protects list of registered TC modules. It is pure SMP lock. */
 114static DEFINE_RWLOCK(qdisc_mod_lock);
 115
 116
 117/************************************************
 118 *	Queueing disciplines manipulation.	*
 119 ************************************************/
 120
 121
 122/* The list of all installed queueing disciplines. */
 123
 124static struct Qdisc_ops *qdisc_base;
 125
 126/* Register/unregister queueing discipline */
 127
 128int register_qdisc(struct Qdisc_ops *qops)
 129{
 130	struct Qdisc_ops *q, **qp;
 131	int rc = -EEXIST;
 132
 133	write_lock(&qdisc_mod_lock);
 134	for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
 135		if (!strcmp(qops->id, q->id))
 136			goto out;
 137
 138	if (qops->enqueue == NULL)
 139		qops->enqueue = noop_qdisc_ops.enqueue;
 140	if (qops->peek == NULL) {
 141		if (qops->dequeue == NULL)
 142			qops->peek = noop_qdisc_ops.peek;
 143		else
 144			goto out_einval;
 145	}
 146	if (qops->dequeue == NULL)
 147		qops->dequeue = noop_qdisc_ops.dequeue;
 148
 149	if (qops->cl_ops) {
 150		const struct Qdisc_class_ops *cops = qops->cl_ops;
 151
 152		if (!(cops->find && cops->walk && cops->leaf))
 153			goto out_einval;
 154
 155		if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf))
 156			goto out_einval;
 157	}
 158
 159	qops->next = NULL;
 160	*qp = qops;
 161	rc = 0;
 162out:
 163	write_unlock(&qdisc_mod_lock);
 164	return rc;
 165
 166out_einval:
 167	rc = -EINVAL;
 168	goto out;
 169}
 170EXPORT_SYMBOL(register_qdisc);
 171
 172int unregister_qdisc(struct Qdisc_ops *qops)
 173{
 174	struct Qdisc_ops *q, **qp;
 175	int err = -ENOENT;
 176
 177	write_lock(&qdisc_mod_lock);
 178	for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
 179		if (q == qops)
 180			break;
 181	if (q) {
 182		*qp = q->next;
 183		q->next = NULL;
 184		err = 0;
 185	}
 186	write_unlock(&qdisc_mod_lock);
 187	return err;
 
 188}
 189EXPORT_SYMBOL(unregister_qdisc);
 190
 191/* Get default qdisc if not otherwise specified */
 192void qdisc_get_default(char *name, size_t len)
 193{
 194	read_lock(&qdisc_mod_lock);
 195	strlcpy(name, default_qdisc_ops->id, len);
 196	read_unlock(&qdisc_mod_lock);
 197}
 198
 199static struct Qdisc_ops *qdisc_lookup_default(const char *name)
 200{
 201	struct Qdisc_ops *q = NULL;
 202
 203	for (q = qdisc_base; q; q = q->next) {
 204		if (!strcmp(name, q->id)) {
 205			if (!try_module_get(q->owner))
 206				q = NULL;
 207			break;
 208		}
 209	}
 210
 211	return q;
 212}
 213
 214/* Set new default qdisc to use */
 215int qdisc_set_default(const char *name)
 216{
 217	const struct Qdisc_ops *ops;
 218
 219	if (!capable(CAP_NET_ADMIN))
 220		return -EPERM;
 221
 222	write_lock(&qdisc_mod_lock);
 223	ops = qdisc_lookup_default(name);
 224	if (!ops) {
 225		/* Not found, drop lock and try to load module */
 226		write_unlock(&qdisc_mod_lock);
 227		request_module("sch_%s", name);
 228		write_lock(&qdisc_mod_lock);
 229
 230		ops = qdisc_lookup_default(name);
 231	}
 232
 233	if (ops) {
 234		/* Set new default */
 235		module_put(default_qdisc_ops->owner);
 236		default_qdisc_ops = ops;
 237	}
 238	write_unlock(&qdisc_mod_lock);
 239
 240	return ops ? 0 : -ENOENT;
 241}
 242
 243#ifdef CONFIG_NET_SCH_DEFAULT
 244/* Set default value from kernel config */
 245static int __init sch_default_qdisc(void)
 246{
 247	return qdisc_set_default(CONFIG_DEFAULT_NET_SCH);
 248}
 249late_initcall(sch_default_qdisc);
 250#endif
 251
 252/* We know handle. Find qdisc among all qdisc's attached to device
 253 * (root qdisc, all its children, children of children etc.)
 254 * Note: caller either uses rtnl or rcu_read_lock()
 255 */
 256
 257static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
 258{
 259	struct Qdisc *q;
 260
 261	if (!qdisc_dev(root))
 262		return (root->handle == handle ? root : NULL);
 263
 264	if (!(root->flags & TCQ_F_BUILTIN) &&
 265	    root->handle == handle)
 266		return root;
 267
 268	hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle) {
 
 269		if (q->handle == handle)
 270			return q;
 271	}
 272	return NULL;
 273}
 274
 275void qdisc_hash_add(struct Qdisc *q, bool invisible)
 276{
 277	if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
 278		ASSERT_RTNL();
 279		hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
 280		if (invisible)
 281			q->flags |= TCQ_F_INVISIBLE;
 282	}
 283}
 284EXPORT_SYMBOL(qdisc_hash_add);
 285
 286void qdisc_hash_del(struct Qdisc *q)
 287{
 288	if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
 289		ASSERT_RTNL();
 290		hash_del_rcu(&q->hash);
 291	}
 292}
 293EXPORT_SYMBOL(qdisc_hash_del);
 294
 295struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
 296{
 297	struct Qdisc *q;
 298
 299	if (!handle)
 300		return NULL;
 301	q = qdisc_match_from_root(dev->qdisc, handle);
 302	if (q)
 303		goto out;
 304
 305	if (dev_ingress_queue(dev))
 306		q = qdisc_match_from_root(
 307			dev_ingress_queue(dev)->qdisc_sleeping,
 308			handle);
 309out:
 310	return q;
 311}
 312
 313struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle)
 314{
 315	struct netdev_queue *nq;
 316	struct Qdisc *q;
 317
 318	if (!handle)
 319		return NULL;
 320	q = qdisc_match_from_root(dev->qdisc, handle);
 321	if (q)
 322		goto out;
 323
 324	nq = dev_ingress_queue_rcu(dev);
 325	if (nq)
 326		q = qdisc_match_from_root(nq->qdisc_sleeping, handle);
 
 327out:
 328	return q;
 329}
 330
 331static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
 332{
 333	unsigned long cl;
 334	const struct Qdisc_class_ops *cops = p->ops->cl_ops;
 335
 336	if (cops == NULL)
 337		return NULL;
 338	cl = cops->find(p, classid);
 339
 340	if (cl == 0)
 341		return NULL;
 342	return cops->leaf(p, cl);
 343}
 344
 345/* Find queueing discipline by name */
 346
 347static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
 348{
 349	struct Qdisc_ops *q = NULL;
 350
 351	if (kind) {
 352		read_lock(&qdisc_mod_lock);
 353		for (q = qdisc_base; q; q = q->next) {
 354			if (nla_strcmp(kind, q->id) == 0) {
 355				if (!try_module_get(q->owner))
 356					q = NULL;
 357				break;
 358			}
 359		}
 360		read_unlock(&qdisc_mod_lock);
 361	}
 362	return q;
 363}
 364
 365/* The linklayer setting were not transferred from iproute2, in older
 366 * versions, and the rate tables lookup systems have been dropped in
 367 * the kernel. To keep backward compatible with older iproute2 tc
 368 * utils, we detect the linklayer setting by detecting if the rate
 369 * table were modified.
 370 *
 371 * For linklayer ATM table entries, the rate table will be aligned to
 372 * 48 bytes, thus some table entries will contain the same value.  The
 373 * mpu (min packet unit) is also encoded into the old rate table, thus
 374 * starting from the mpu, we find low and high table entries for
 375 * mapping this cell.  If these entries contain the same value, when
 376 * the rate tables have been modified for linklayer ATM.
 377 *
 378 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
 379 * and then roundup to the next cell, calc the table entry one below,
 380 * and compare.
 381 */
 382static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
 383{
 384	int low       = roundup(r->mpu, 48);
 385	int high      = roundup(low+1, 48);
 386	int cell_low  = low >> r->cell_log;
 387	int cell_high = (high >> r->cell_log) - 1;
 388
 389	/* rtab is too inaccurate at rates > 100Mbit/s */
 390	if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
 391		pr_debug("TC linklayer: Giving up ATM detection\n");
 392		return TC_LINKLAYER_ETHERNET;
 393	}
 394
 395	if ((cell_high > cell_low) && (cell_high < 256)
 396	    && (rtab[cell_low] == rtab[cell_high])) {
 397		pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
 398			 cell_low, cell_high, rtab[cell_high]);
 399		return TC_LINKLAYER_ATM;
 400	}
 401	return TC_LINKLAYER_ETHERNET;
 402}
 403
 404static struct qdisc_rate_table *qdisc_rtab_list;
 405
 406struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
 407					struct nlattr *tab,
 408					struct netlink_ext_ack *extack)
 409{
 410	struct qdisc_rate_table *rtab;
 411
 412	if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
 
 413	    nla_len(tab) != TC_RTAB_SIZE) {
 414		NL_SET_ERR_MSG(extack, "Invalid rate table parameters for searching");
 415		return NULL;
 416	}
 417
 418	for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
 419		if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
 420		    !memcmp(&rtab->data, nla_data(tab), 1024)) {
 421			rtab->refcnt++;
 422			return rtab;
 423		}
 424	}
 425
 426	rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
 427	if (rtab) {
 428		rtab->rate = *r;
 429		rtab->refcnt = 1;
 430		memcpy(rtab->data, nla_data(tab), 1024);
 431		if (r->linklayer == TC_LINKLAYER_UNAWARE)
 432			r->linklayer = __detect_linklayer(r, rtab->data);
 433		rtab->next = qdisc_rtab_list;
 434		qdisc_rtab_list = rtab;
 435	} else {
 436		NL_SET_ERR_MSG(extack, "Failed to allocate new qdisc rate table");
 437	}
 438	return rtab;
 439}
 440EXPORT_SYMBOL(qdisc_get_rtab);
 441
 442void qdisc_put_rtab(struct qdisc_rate_table *tab)
 443{
 444	struct qdisc_rate_table *rtab, **rtabp;
 445
 446	if (!tab || --tab->refcnt)
 447		return;
 448
 449	for (rtabp = &qdisc_rtab_list;
 450	     (rtab = *rtabp) != NULL;
 451	     rtabp = &rtab->next) {
 452		if (rtab == tab) {
 453			*rtabp = rtab->next;
 454			kfree(rtab);
 455			return;
 456		}
 457	}
 458}
 459EXPORT_SYMBOL(qdisc_put_rtab);
 460
 461static LIST_HEAD(qdisc_stab_list);
 462
 463static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
 464	[TCA_STAB_BASE]	= { .len = sizeof(struct tc_sizespec) },
 465	[TCA_STAB_DATA] = { .type = NLA_BINARY },
 466};
 467
 468static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt,
 469					       struct netlink_ext_ack *extack)
 470{
 471	struct nlattr *tb[TCA_STAB_MAX + 1];
 472	struct qdisc_size_table *stab;
 473	struct tc_sizespec *s;
 474	unsigned int tsize = 0;
 475	u16 *tab = NULL;
 476	int err;
 477
 478	err = nla_parse_nested_deprecated(tb, TCA_STAB_MAX, opt, stab_policy,
 479					  extack);
 480	if (err < 0)
 481		return ERR_PTR(err);
 482	if (!tb[TCA_STAB_BASE]) {
 483		NL_SET_ERR_MSG(extack, "Size table base attribute is missing");
 484		return ERR_PTR(-EINVAL);
 485	}
 486
 487	s = nla_data(tb[TCA_STAB_BASE]);
 488
 489	if (s->tsize > 0) {
 490		if (!tb[TCA_STAB_DATA]) {
 491			NL_SET_ERR_MSG(extack, "Size table data attribute is missing");
 492			return ERR_PTR(-EINVAL);
 493		}
 494		tab = nla_data(tb[TCA_STAB_DATA]);
 495		tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
 496	}
 497
 498	if (tsize != s->tsize || (!tab && tsize > 0)) {
 499		NL_SET_ERR_MSG(extack, "Invalid size of size table");
 500		return ERR_PTR(-EINVAL);
 501	}
 502
 503	list_for_each_entry(stab, &qdisc_stab_list, list) {
 504		if (memcmp(&stab->szopts, s, sizeof(*s)))
 505			continue;
 506		if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
 
 507			continue;
 508		stab->refcnt++;
 509		return stab;
 510	}
 511
 512	stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
 
 
 
 
 
 
 513	if (!stab)
 514		return ERR_PTR(-ENOMEM);
 515
 516	stab->refcnt = 1;
 517	stab->szopts = *s;
 518	if (tsize > 0)
 519		memcpy(stab->data, tab, tsize * sizeof(u16));
 520
 521	list_add_tail(&stab->list, &qdisc_stab_list);
 522
 523	return stab;
 524}
 525
 526void qdisc_put_stab(struct qdisc_size_table *tab)
 527{
 528	if (!tab)
 529		return;
 530
 531	if (--tab->refcnt == 0) {
 532		list_del(&tab->list);
 533		kfree_rcu(tab, rcu);
 534	}
 535}
 536EXPORT_SYMBOL(qdisc_put_stab);
 537
 538static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
 539{
 540	struct nlattr *nest;
 541
 542	nest = nla_nest_start_noflag(skb, TCA_STAB);
 543	if (nest == NULL)
 544		goto nla_put_failure;
 545	if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
 546		goto nla_put_failure;
 547	nla_nest_end(skb, nest);
 548
 549	return skb->len;
 550
 551nla_put_failure:
 552	return -1;
 553}
 554
 555void __qdisc_calculate_pkt_len(struct sk_buff *skb,
 556			       const struct qdisc_size_table *stab)
 557{
 558	int pkt_len, slot;
 559
 560	pkt_len = skb->len + stab->szopts.overhead;
 561	if (unlikely(!stab->szopts.tsize))
 562		goto out;
 563
 564	slot = pkt_len + stab->szopts.cell_align;
 565	if (unlikely(slot < 0))
 566		slot = 0;
 567
 568	slot >>= stab->szopts.cell_log;
 569	if (likely(slot < stab->szopts.tsize))
 570		pkt_len = stab->data[slot];
 571	else
 572		pkt_len = stab->data[stab->szopts.tsize - 1] *
 573				(slot / stab->szopts.tsize) +
 574				stab->data[slot % stab->szopts.tsize];
 575
 576	pkt_len <<= stab->szopts.size_log;
 577out:
 578	if (unlikely(pkt_len < 1))
 579		pkt_len = 1;
 580	qdisc_skb_cb(skb)->pkt_len = pkt_len;
 581}
 582EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
 583
 584void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
 585{
 586	if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
 587		pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
 588			txt, qdisc->ops->id, qdisc->handle >> 16);
 589		qdisc->flags |= TCQ_F_WARN_NONWC;
 590	}
 591}
 592EXPORT_SYMBOL(qdisc_warn_nonwc);
 593
 594static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
 595{
 596	struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
 597						 timer);
 598
 599	rcu_read_lock();
 600	__netif_schedule(qdisc_root(wd->qdisc));
 601	rcu_read_unlock();
 602
 603	return HRTIMER_NORESTART;
 604}
 605
 606void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
 607				 clockid_t clockid)
 608{
 609	hrtimer_init(&wd->timer, clockid, HRTIMER_MODE_ABS_PINNED);
 610	wd->timer.function = qdisc_watchdog;
 611	wd->qdisc = qdisc;
 612}
 613EXPORT_SYMBOL(qdisc_watchdog_init_clockid);
 614
 615void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
 616{
 617	qdisc_watchdog_init_clockid(wd, qdisc, CLOCK_MONOTONIC);
 618}
 619EXPORT_SYMBOL(qdisc_watchdog_init);
 620
 621void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
 
 622{
 623	if (test_bit(__QDISC_STATE_DEACTIVATED,
 624		     &qdisc_root_sleeping(wd->qdisc)->state))
 625		return;
 626
 627	if (wd->last_expires == expires)
 
 
 
 
 628		return;
 629
 630	wd->last_expires = expires;
 631	hrtimer_start(&wd->timer,
 632		      ns_to_ktime(expires),
 633		      HRTIMER_MODE_ABS_PINNED);
 
 
 
 
 
 
 
 
 
 
 
 634}
 635EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
 636
 637void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
 638{
 639	hrtimer_cancel(&wd->timer);
 640}
 641EXPORT_SYMBOL(qdisc_watchdog_cancel);
 642
 643static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
 644{
 645	struct hlist_head *h;
 646	unsigned int i;
 647
 648	h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL);
 649
 650	if (h != NULL) {
 651		for (i = 0; i < n; i++)
 652			INIT_HLIST_HEAD(&h[i]);
 653	}
 654	return h;
 655}
 656
 657void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
 658{
 659	struct Qdisc_class_common *cl;
 660	struct hlist_node *next;
 661	struct hlist_head *nhash, *ohash;
 662	unsigned int nsize, nmask, osize;
 663	unsigned int i, h;
 664
 665	/* Rehash when load factor exceeds 0.75 */
 666	if (clhash->hashelems * 4 <= clhash->hashsize * 3)
 667		return;
 668	nsize = clhash->hashsize * 2;
 669	nmask = nsize - 1;
 670	nhash = qdisc_class_hash_alloc(nsize);
 671	if (nhash == NULL)
 672		return;
 673
 674	ohash = clhash->hash;
 675	osize = clhash->hashsize;
 676
 677	sch_tree_lock(sch);
 678	for (i = 0; i < osize; i++) {
 679		hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
 680			h = qdisc_class_hash(cl->classid, nmask);
 681			hlist_add_head(&cl->hnode, &nhash[h]);
 682		}
 683	}
 684	clhash->hash     = nhash;
 685	clhash->hashsize = nsize;
 686	clhash->hashmask = nmask;
 687	sch_tree_unlock(sch);
 688
 689	kvfree(ohash);
 690}
 691EXPORT_SYMBOL(qdisc_class_hash_grow);
 692
 693int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
 694{
 695	unsigned int size = 4;
 696
 697	clhash->hash = qdisc_class_hash_alloc(size);
 698	if (!clhash->hash)
 699		return -ENOMEM;
 700	clhash->hashsize  = size;
 701	clhash->hashmask  = size - 1;
 702	clhash->hashelems = 0;
 703	return 0;
 704}
 705EXPORT_SYMBOL(qdisc_class_hash_init);
 706
 707void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
 708{
 709	kvfree(clhash->hash);
 710}
 711EXPORT_SYMBOL(qdisc_class_hash_destroy);
 712
 713void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
 714			     struct Qdisc_class_common *cl)
 715{
 716	unsigned int h;
 717
 718	INIT_HLIST_NODE(&cl->hnode);
 719	h = qdisc_class_hash(cl->classid, clhash->hashmask);
 720	hlist_add_head(&cl->hnode, &clhash->hash[h]);
 721	clhash->hashelems++;
 722}
 723EXPORT_SYMBOL(qdisc_class_hash_insert);
 724
 725void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
 726			     struct Qdisc_class_common *cl)
 727{
 728	hlist_del(&cl->hnode);
 729	clhash->hashelems--;
 730}
 731EXPORT_SYMBOL(qdisc_class_hash_remove);
 732
 733/* Allocate an unique handle from space managed by kernel
 734 * Possible range is [8000-FFFF]:0000 (0x8000 values)
 735 */
 736static u32 qdisc_alloc_handle(struct net_device *dev)
 737{
 738	int i = 0x8000;
 739	static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
 740
 741	do {
 742		autohandle += TC_H_MAKE(0x10000U, 0);
 743		if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
 744			autohandle = TC_H_MAKE(0x80000000U, 0);
 745		if (!qdisc_lookup(dev, autohandle))
 746			return autohandle;
 747		cond_resched();
 748	} while	(--i > 0);
 749
 750	return 0;
 751}
 752
 753void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len)
 754{
 755	bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED;
 756	const struct Qdisc_class_ops *cops;
 757	unsigned long cl;
 758	u32 parentid;
 759	bool notify;
 760	int drops;
 761
 762	if (n == 0 && len == 0)
 763		return;
 764	drops = max_t(int, n, 0);
 765	rcu_read_lock();
 766	while ((parentid = sch->parent)) {
 767		if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
 768			break;
 769
 770		if (sch->flags & TCQ_F_NOPARENT)
 771			break;
 772		/* Notify parent qdisc only if child qdisc becomes empty.
 773		 *
 774		 * If child was empty even before update then backlog
 775		 * counter is screwed and we skip notification because
 776		 * parent class is already passive.
 777		 *
 778		 * If the original child was offloaded then it is allowed
 779		 * to be seem as empty, so the parent is notified anyway.
 780		 */
 781		notify = !sch->q.qlen && !WARN_ON_ONCE(!n &&
 782						       !qdisc_is_offloaded);
 783		/* TODO: perform the search on a per txq basis */
 784		sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
 785		if (sch == NULL) {
 786			WARN_ON_ONCE(parentid != TC_H_ROOT);
 787			break;
 788		}
 789		cops = sch->ops->cl_ops;
 790		if (notify && cops->qlen_notify) {
 791			cl = cops->find(sch, parentid);
 792			cops->qlen_notify(sch, cl);
 793		}
 794		sch->q.qlen -= n;
 795		sch->qstats.backlog -= len;
 796		__qdisc_qstats_drop(sch, drops);
 797	}
 798	rcu_read_unlock();
 799}
 800EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
 801
 802int qdisc_offload_dump_helper(struct Qdisc *sch, enum tc_setup_type type,
 803			      void *type_data)
 804{
 805	struct net_device *dev = qdisc_dev(sch);
 806	int err;
 807
 808	sch->flags &= ~TCQ_F_OFFLOADED;
 809	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
 810		return 0;
 811
 812	err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
 813	if (err == -EOPNOTSUPP)
 814		return 0;
 815
 816	if (!err)
 817		sch->flags |= TCQ_F_OFFLOADED;
 818
 819	return err;
 820}
 821EXPORT_SYMBOL(qdisc_offload_dump_helper);
 822
 823void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
 824				struct Qdisc *new, struct Qdisc *old,
 825				enum tc_setup_type type, void *type_data,
 826				struct netlink_ext_ack *extack)
 827{
 828	bool any_qdisc_is_offloaded;
 829	int err;
 830
 831	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
 832		return;
 833
 834	err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
 835
 836	/* Don't report error if the graft is part of destroy operation. */
 837	if (!err || !new || new == &noop_qdisc)
 838		return;
 839
 840	/* Don't report error if the parent, the old child and the new
 841	 * one are not offloaded.
 842	 */
 843	any_qdisc_is_offloaded = new->flags & TCQ_F_OFFLOADED;
 844	any_qdisc_is_offloaded |= sch && sch->flags & TCQ_F_OFFLOADED;
 845	any_qdisc_is_offloaded |= old && old->flags & TCQ_F_OFFLOADED;
 846
 847	if (any_qdisc_is_offloaded)
 848		NL_SET_ERR_MSG(extack, "Offloading graft operation failed.");
 849}
 850EXPORT_SYMBOL(qdisc_offload_graft_helper);
 851
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 852static void qdisc_offload_graft_root(struct net_device *dev,
 853				     struct Qdisc *new, struct Qdisc *old,
 854				     struct netlink_ext_ack *extack)
 855{
 856	struct tc_root_qopt_offload graft_offload = {
 857		.command	= TC_ROOT_GRAFT,
 858		.handle		= new ? new->handle : 0,
 859		.ingress	= (new && new->flags & TCQ_F_INGRESS) ||
 860				  (old && old->flags & TCQ_F_INGRESS),
 861	};
 862
 863	qdisc_offload_graft_helper(dev, NULL, new, old,
 864				   TC_SETUP_ROOT_QDISC, &graft_offload, extack);
 865}
 866
 867static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
 868			 u32 portid, u32 seq, u16 flags, int event)
 
 869{
 870	struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
 871	struct gnet_stats_queue __percpu *cpu_qstats = NULL;
 872	struct tcmsg *tcm;
 873	struct nlmsghdr  *nlh;
 874	unsigned char *b = skb_tail_pointer(skb);
 875	struct gnet_dump d;
 876	struct qdisc_size_table *stab;
 877	u32 block_index;
 878	__u32 qlen;
 879
 880	cond_resched();
 881	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 882	if (!nlh)
 883		goto out_nlmsg_trim;
 884	tcm = nlmsg_data(nlh);
 885	tcm->tcm_family = AF_UNSPEC;
 886	tcm->tcm__pad1 = 0;
 887	tcm->tcm__pad2 = 0;
 888	tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
 889	tcm->tcm_parent = clid;
 890	tcm->tcm_handle = q->handle;
 891	tcm->tcm_info = refcount_read(&q->refcnt);
 892	if (nla_put_string(skb, TCA_KIND, q->ops->id))
 893		goto nla_put_failure;
 894	if (q->ops->ingress_block_get) {
 895		block_index = q->ops->ingress_block_get(q);
 896		if (block_index &&
 897		    nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index))
 898			goto nla_put_failure;
 899	}
 900	if (q->ops->egress_block_get) {
 901		block_index = q->ops->egress_block_get(q);
 902		if (block_index &&
 903		    nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index))
 904			goto nla_put_failure;
 905	}
 906	if (q->ops->dump && q->ops->dump(q, skb) < 0)
 907		goto nla_put_failure;
 908	if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED)))
 909		goto nla_put_failure;
 910	qlen = qdisc_qlen_sum(q);
 911
 912	stab = rtnl_dereference(q->stab);
 913	if (stab && qdisc_dump_stab(skb, stab) < 0)
 914		goto nla_put_failure;
 915
 916	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
 917					 NULL, &d, TCA_PAD) < 0)
 918		goto nla_put_failure;
 919
 920	if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
 921		goto nla_put_failure;
 922
 923	if (qdisc_is_percpu_stats(q)) {
 924		cpu_bstats = q->cpu_bstats;
 925		cpu_qstats = q->cpu_qstats;
 926	}
 927
 928	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(q),
 929				  &d, cpu_bstats, &q->bstats) < 0 ||
 930	    gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
 931	    gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
 932		goto nla_put_failure;
 933
 934	if (gnet_stats_finish_copy(&d) < 0)
 935		goto nla_put_failure;
 936
 
 
 
 
 937	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 
 938	return skb->len;
 939
 940out_nlmsg_trim:
 941nla_put_failure:
 942	nlmsg_trim(skb, b);
 943	return -1;
 944}
 945
 946static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible)
 947{
 948	if (q->flags & TCQ_F_BUILTIN)
 949		return true;
 950	if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible)
 951		return true;
 952
 953	return false;
 954}
 955
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 956static int qdisc_notify(struct net *net, struct sk_buff *oskb,
 957			struct nlmsghdr *n, u32 clid,
 958			struct Qdisc *old, struct Qdisc *new)
 
 959{
 960	struct sk_buff *skb;
 961	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 962
 
 
 
 963	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 964	if (!skb)
 965		return -ENOBUFS;
 966
 967	if (old && !tc_qdisc_dump_ignore(old, false)) {
 968		if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
 969				  0, RTM_DELQDISC) < 0)
 970			goto err_out;
 971	}
 972	if (new && !tc_qdisc_dump_ignore(new, false)) {
 973		if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
 974				  old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
 975			goto err_out;
 976	}
 977
 978	if (skb->len)
 979		return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 980				      n->nlmsg_flags & NLM_F_ECHO);
 981
 982err_out:
 983	kfree_skb(skb);
 984	return -EINVAL;
 985}
 986
 987static void notify_and_destroy(struct net *net, struct sk_buff *skb,
 988			       struct nlmsghdr *n, u32 clid,
 989			       struct Qdisc *old, struct Qdisc *new)
 
 990{
 991	if (new || old)
 992		qdisc_notify(net, skb, n, clid, old, new);
 993
 994	if (old)
 995		qdisc_put(old);
 996}
 997
 998static void qdisc_clear_nolock(struct Qdisc *sch)
 999{
1000	sch->flags &= ~TCQ_F_NOLOCK;
1001	if (!(sch->flags & TCQ_F_CPUSTATS))
1002		return;
1003
1004	free_percpu(sch->cpu_bstats);
1005	free_percpu(sch->cpu_qstats);
1006	sch->cpu_bstats = NULL;
1007	sch->cpu_qstats = NULL;
1008	sch->flags &= ~TCQ_F_CPUSTATS;
1009}
1010
1011/* Graft qdisc "new" to class "classid" of qdisc "parent" or
1012 * to device "dev".
1013 *
1014 * When appropriate send a netlink notification using 'skb'
1015 * and "n".
1016 *
1017 * On success, destroy old qdisc.
1018 */
1019
1020static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
1021		       struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
1022		       struct Qdisc *new, struct Qdisc *old,
1023		       struct netlink_ext_ack *extack)
1024{
1025	struct Qdisc *q = old;
1026	struct net *net = dev_net(dev);
1027
1028	if (parent == NULL) {
1029		unsigned int i, num_q, ingress;
 
1030
1031		ingress = 0;
1032		num_q = dev->num_tx_queues;
1033		if ((q && q->flags & TCQ_F_INGRESS) ||
1034		    (new && new->flags & TCQ_F_INGRESS)) {
1035			num_q = 1;
1036			ingress = 1;
1037			if (!dev_ingress_queue(dev)) {
 
1038				NL_SET_ERR_MSG(extack, "Device does not have an ingress queue");
1039				return -ENOENT;
1040			}
 
 
 
 
 
 
 
 
 
 
 
1041		}
1042
1043		if (dev->flags & IFF_UP)
1044			dev_deactivate(dev);
1045
1046		qdisc_offload_graft_root(dev, new, old, extack);
1047
1048		if (new && new->ops->attach)
1049			goto skip;
1050
1051		for (i = 0; i < num_q; i++) {
1052			struct netdev_queue *dev_queue = dev_ingress_queue(dev);
1053
1054			if (!ingress)
1055				dev_queue = netdev_get_tx_queue(dev, i);
 
1056
1057			old = dev_graft_qdisc(dev_queue, new);
1058			if (new && i > 0)
1059				qdisc_refcount_inc(new);
1060
1061			if (!ingress)
1062				qdisc_put(old);
 
 
 
 
 
 
 
 
 
 
 
 
1063		}
1064
1065skip:
1066		if (!ingress) {
1067			notify_and_destroy(net, skb, n, classid,
1068					   dev->qdisc, new);
1069			if (new && !new->ops->attach)
1070				qdisc_refcount_inc(new);
1071			dev->qdisc = new ? : &noop_qdisc;
 
 
1072
1073			if (new && new->ops->attach)
1074				new->ops->attach(new);
1075		} else {
1076			notify_and_destroy(net, skb, n, classid, old, new);
1077		}
1078
1079		if (dev->flags & IFF_UP)
1080			dev_activate(dev);
1081	} else {
1082		const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
1083		unsigned long cl;
1084		int err;
1085
1086		/* Only support running class lockless if parent is lockless */
1087		if (new && (new->flags & TCQ_F_NOLOCK) &&
1088		    parent && !(parent->flags & TCQ_F_NOLOCK))
1089			qdisc_clear_nolock(new);
1090
1091		if (!cops || !cops->graft)
1092			return -EOPNOTSUPP;
1093
1094		cl = cops->find(parent, classid);
1095		if (!cl) {
1096			NL_SET_ERR_MSG(extack, "Specified class not found");
1097			return -ENOENT;
1098		}
1099
 
 
 
 
 
1100		err = cops->graft(parent, cl, new, &old, extack);
1101		if (err)
1102			return err;
1103		notify_and_destroy(net, skb, n, classid, old, new);
1104	}
1105	return 0;
1106}
1107
1108static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca,
1109				   struct netlink_ext_ack *extack)
1110{
1111	u32 block_index;
1112
1113	if (tca[TCA_INGRESS_BLOCK]) {
1114		block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]);
1115
1116		if (!block_index) {
1117			NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0");
1118			return -EINVAL;
1119		}
1120		if (!sch->ops->ingress_block_set) {
1121			NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported");
1122			return -EOPNOTSUPP;
1123		}
1124		sch->ops->ingress_block_set(sch, block_index);
1125	}
1126	if (tca[TCA_EGRESS_BLOCK]) {
1127		block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]);
1128
1129		if (!block_index) {
1130			NL_SET_ERR_MSG(extack, "Egress block index cannot be 0");
1131			return -EINVAL;
1132		}
1133		if (!sch->ops->egress_block_set) {
1134			NL_SET_ERR_MSG(extack, "Egress block sharing is not supported");
1135			return -EOPNOTSUPP;
1136		}
1137		sch->ops->egress_block_set(sch, block_index);
1138	}
1139	return 0;
1140}
1141
1142/*
1143   Allocate and initialize new qdisc.
1144
1145   Parameters are passed via opt.
1146 */
1147
1148static struct Qdisc *qdisc_create(struct net_device *dev,
1149				  struct netdev_queue *dev_queue,
1150				  struct Qdisc *p, u32 parent, u32 handle,
1151				  struct nlattr **tca, int *errp,
1152				  struct netlink_ext_ack *extack)
1153{
1154	int err;
1155	struct nlattr *kind = tca[TCA_KIND];
1156	struct Qdisc *sch;
1157	struct Qdisc_ops *ops;
1158	struct qdisc_size_table *stab;
1159
1160	ops = qdisc_lookup_ops(kind);
1161#ifdef CONFIG_MODULES
1162	if (ops == NULL && kind != NULL) {
1163		char name[IFNAMSIZ];
1164		if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
1165			/* We dropped the RTNL semaphore in order to
1166			 * perform the module load.  So, even if we
1167			 * succeeded in loading the module we have to
1168			 * tell the caller to replay the request.  We
1169			 * indicate this using -EAGAIN.
1170			 * We replay the request because the device may
1171			 * go away in the mean time.
1172			 */
1173			rtnl_unlock();
1174			request_module("sch_%s", name);
1175			rtnl_lock();
1176			ops = qdisc_lookup_ops(kind);
1177			if (ops != NULL) {
1178				/* We will try again qdisc_lookup_ops,
1179				 * so don't keep a reference.
1180				 */
1181				module_put(ops->owner);
1182				err = -EAGAIN;
1183				goto err_out;
1184			}
1185		}
1186	}
1187#endif
1188
1189	err = -ENOENT;
1190	if (!ops) {
1191		NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1192		goto err_out;
1193	}
1194
1195	sch = qdisc_alloc(dev_queue, ops, extack);
1196	if (IS_ERR(sch)) {
1197		err = PTR_ERR(sch);
1198		goto err_out2;
1199	}
1200
1201	sch->parent = parent;
1202
1203	if (handle == TC_H_INGRESS) {
1204		sch->flags |= TCQ_F_INGRESS;
 
 
 
 
 
1205		handle = TC_H_MAKE(TC_H_INGRESS, 0);
1206	} else {
1207		if (handle == 0) {
1208			handle = qdisc_alloc_handle(dev);
1209			if (handle == 0) {
1210				NL_SET_ERR_MSG(extack, "Maximum number of qdisc handles was exceeded");
1211				err = -ENOSPC;
1212				goto err_out3;
1213			}
1214		}
1215		if (!netif_is_multiqueue(dev))
1216			sch->flags |= TCQ_F_ONETXQUEUE;
1217	}
1218
1219	sch->handle = handle;
1220
1221	/* This exist to keep backward compatible with a userspace
1222	 * loophole, what allowed userspace to get IFF_NO_QUEUE
1223	 * facility on older kernels by setting tx_queue_len=0 (prior
1224	 * to qdisc init), and then forgot to reinit tx_queue_len
1225	 * before again attaching a qdisc.
1226	 */
1227	if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) {
1228		dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
1229		netdev_info(dev, "Caught tx_queue_len zero misconfig\n");
1230	}
1231
1232	err = qdisc_block_indexes_set(sch, tca, extack);
1233	if (err)
1234		goto err_out3;
1235
1236	if (ops->init) {
1237		err = ops->init(sch, tca[TCA_OPTIONS], extack);
1238		if (err != 0)
1239			goto err_out5;
1240	}
1241
1242	if (tca[TCA_STAB]) {
1243		stab = qdisc_get_stab(tca[TCA_STAB], extack);
1244		if (IS_ERR(stab)) {
1245			err = PTR_ERR(stab);
1246			goto err_out4;
1247		}
1248		rcu_assign_pointer(sch->stab, stab);
1249	}
1250	if (tca[TCA_RATE]) {
1251		seqcount_t *running;
1252
 
 
 
 
 
 
 
1253		err = -EOPNOTSUPP;
1254		if (sch->flags & TCQ_F_MQROOT) {
1255			NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc");
1256			goto err_out4;
1257		}
1258
1259		if (sch->parent != TC_H_ROOT &&
1260		    !(sch->flags & TCQ_F_INGRESS) &&
1261		    (!p || !(p->flags & TCQ_F_MQROOT)))
1262			running = qdisc_root_sleeping_running(sch);
1263		else
1264			running = &sch->running;
1265
1266		err = gen_new_estimator(&sch->bstats,
1267					sch->cpu_bstats,
1268					&sch->rate_est,
1269					NULL,
1270					running,
1271					tca[TCA_RATE]);
1272		if (err) {
1273			NL_SET_ERR_MSG(extack, "Failed to generate new estimator");
1274			goto err_out4;
1275		}
1276	}
1277
1278	qdisc_hash_add(sch, false);
 
1279
1280	return sch;
1281
1282err_out5:
1283	/* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */
 
 
1284	if (ops->destroy)
1285		ops->destroy(sch);
 
1286err_out3:
1287	dev_put(dev);
1288	qdisc_free(sch);
1289err_out2:
1290	module_put(ops->owner);
1291err_out:
1292	*errp = err;
1293	return NULL;
1294
1295err_out4:
1296	/*
1297	 * Any broken qdiscs that would require a ops->reset() here?
1298	 * The qdisc was never in action so it shouldn't be necessary.
1299	 */
1300	qdisc_put_stab(rtnl_dereference(sch->stab));
1301	if (ops->destroy)
1302		ops->destroy(sch);
1303	goto err_out3;
1304}
1305
1306static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
1307			struct netlink_ext_ack *extack)
1308{
1309	struct qdisc_size_table *ostab, *stab = NULL;
1310	int err = 0;
1311
1312	if (tca[TCA_OPTIONS]) {
1313		if (!sch->ops->change) {
1314			NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc");
1315			return -EINVAL;
1316		}
1317		if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
1318			NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
1319			return -EOPNOTSUPP;
1320		}
1321		err = sch->ops->change(sch, tca[TCA_OPTIONS], extack);
1322		if (err)
1323			return err;
1324	}
1325
1326	if (tca[TCA_STAB]) {
1327		stab = qdisc_get_stab(tca[TCA_STAB], extack);
1328		if (IS_ERR(stab))
1329			return PTR_ERR(stab);
1330	}
1331
1332	ostab = rtnl_dereference(sch->stab);
1333	rcu_assign_pointer(sch->stab, stab);
1334	qdisc_put_stab(ostab);
1335
1336	if (tca[TCA_RATE]) {
1337		/* NB: ignores errors from replace_estimator
1338		   because change can't be undone. */
1339		if (sch->flags & TCQ_F_MQROOT)
1340			goto out;
1341		gen_replace_estimator(&sch->bstats,
1342				      sch->cpu_bstats,
1343				      &sch->rate_est,
1344				      NULL,
1345				      qdisc_root_sleeping_running(sch),
1346				      tca[TCA_RATE]);
1347	}
1348out:
1349	return 0;
1350}
1351
1352struct check_loop_arg {
1353	struct qdisc_walker	w;
1354	struct Qdisc		*p;
1355	int			depth;
1356};
1357
1358static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1359			 struct qdisc_walker *w);
1360
1361static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1362{
1363	struct check_loop_arg	arg;
1364
1365	if (q->ops->cl_ops == NULL)
1366		return 0;
1367
1368	arg.w.stop = arg.w.skip = arg.w.count = 0;
1369	arg.w.fn = check_loop_fn;
1370	arg.depth = depth;
1371	arg.p = p;
1372	q->ops->cl_ops->walk(q, &arg.w);
1373	return arg.w.stop ? -ELOOP : 0;
1374}
1375
1376static int
1377check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1378{
1379	struct Qdisc *leaf;
1380	const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1381	struct check_loop_arg *arg = (struct check_loop_arg *)w;
1382
1383	leaf = cops->leaf(q, cl);
1384	if (leaf) {
1385		if (leaf == arg->p || arg->depth > 7)
1386			return -ELOOP;
1387		return check_loop(leaf, arg->p, arg->depth + 1);
1388	}
1389	return 0;
1390}
1391
1392const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = {
1393	[TCA_KIND]		= { .type = NLA_STRING },
1394	[TCA_RATE]		= { .type = NLA_BINARY,
1395				    .len = sizeof(struct tc_estimator) },
1396	[TCA_STAB]		= { .type = NLA_NESTED },
1397	[TCA_DUMP_INVISIBLE]	= { .type = NLA_FLAG },
1398	[TCA_CHAIN]		= { .type = NLA_U32 },
1399	[TCA_INGRESS_BLOCK]	= { .type = NLA_U32 },
1400	[TCA_EGRESS_BLOCK]	= { .type = NLA_U32 },
1401};
1402
1403/*
1404 * Delete/get qdisc.
1405 */
1406
1407static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1408			struct netlink_ext_ack *extack)
1409{
1410	struct net *net = sock_net(skb->sk);
1411	struct tcmsg *tcm = nlmsg_data(n);
1412	struct nlattr *tca[TCA_MAX + 1];
1413	struct net_device *dev;
1414	u32 clid;
1415	struct Qdisc *q = NULL;
1416	struct Qdisc *p = NULL;
1417	int err;
1418
1419	if ((n->nlmsg_type != RTM_GETQDISC) &&
1420	    !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1421		return -EPERM;
1422
1423	err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1424				     rtm_tca_policy, extack);
1425	if (err < 0)
1426		return err;
1427
1428	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1429	if (!dev)
1430		return -ENODEV;
1431
1432	clid = tcm->tcm_parent;
1433	if (clid) {
1434		if (clid != TC_H_ROOT) {
1435			if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1436				p = qdisc_lookup(dev, TC_H_MAJ(clid));
1437				if (!p) {
1438					NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid");
1439					return -ENOENT;
1440				}
1441				q = qdisc_leaf(p, clid);
1442			} else if (dev_ingress_queue(dev)) {
1443				q = dev_ingress_queue(dev)->qdisc_sleeping;
1444			}
1445		} else {
1446			q = dev->qdisc;
1447		}
1448		if (!q) {
1449			NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device");
1450			return -ENOENT;
1451		}
1452
1453		if (tcm->tcm_handle && q->handle != tcm->tcm_handle) {
1454			NL_SET_ERR_MSG(extack, "Invalid handle");
1455			return -EINVAL;
1456		}
1457	} else {
1458		q = qdisc_lookup(dev, tcm->tcm_handle);
1459		if (!q) {
1460			NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle");
1461			return -ENOENT;
1462		}
1463	}
1464
1465	if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1466		NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1467		return -EINVAL;
1468	}
1469
1470	if (n->nlmsg_type == RTM_DELQDISC) {
1471		if (!clid) {
1472			NL_SET_ERR_MSG(extack, "Classid cannot be zero");
1473			return -EINVAL;
1474		}
1475		if (q->handle == 0) {
1476			NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero");
1477			return -ENOENT;
1478		}
1479		err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack);
1480		if (err != 0)
1481			return err;
1482	} else {
1483		qdisc_notify(net, skb, n, clid, NULL, q);
1484	}
1485	return 0;
1486}
1487
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1488/*
1489 * Create/change qdisc.
1490 */
1491
1492static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1493			   struct netlink_ext_ack *extack)
1494{
1495	struct net *net = sock_net(skb->sk);
1496	struct tcmsg *tcm;
1497	struct nlattr *tca[TCA_MAX + 1];
1498	struct net_device *dev;
1499	u32 clid;
1500	struct Qdisc *q, *p;
1501	int err;
1502
1503	if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1504		return -EPERM;
1505
1506replay:
1507	/* Reinit, just in case something touches this. */
1508	err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1509				     rtm_tca_policy, extack);
1510	if (err < 0)
1511		return err;
1512
1513	tcm = nlmsg_data(n);
1514	clid = tcm->tcm_parent;
1515	q = p = NULL;
1516
1517	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1518	if (!dev)
1519		return -ENODEV;
1520
1521
1522	if (clid) {
1523		if (clid != TC_H_ROOT) {
1524			if (clid != TC_H_INGRESS) {
1525				p = qdisc_lookup(dev, TC_H_MAJ(clid));
1526				if (!p) {
1527					NL_SET_ERR_MSG(extack, "Failed to find specified qdisc");
1528					return -ENOENT;
1529				}
1530				q = qdisc_leaf(p, clid);
1531			} else if (dev_ingress_queue_create(dev)) {
1532				q = dev_ingress_queue(dev)->qdisc_sleeping;
1533			}
1534		} else {
1535			q = dev->qdisc;
1536		}
1537
1538		/* It may be default qdisc, ignore it */
1539		if (q && q->handle == 0)
1540			q = NULL;
1541
1542		if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1543			if (tcm->tcm_handle) {
1544				if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) {
1545					NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override");
1546					return -EEXIST;
1547				}
1548				if (TC_H_MIN(tcm->tcm_handle)) {
1549					NL_SET_ERR_MSG(extack, "Invalid minor handle");
1550					return -EINVAL;
1551				}
1552				q = qdisc_lookup(dev, tcm->tcm_handle);
1553				if (!q)
1554					goto create_n_graft;
1555				if (n->nlmsg_flags & NLM_F_EXCL) {
1556					NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override");
1557					return -EEXIST;
1558				}
1559				if (tca[TCA_KIND] &&
1560				    nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1561					NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1562					return -EINVAL;
1563				}
 
 
 
 
 
1564				if (q == p ||
1565				    (p && check_loop(q, p, 0))) {
1566					NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected");
1567					return -ELOOP;
1568				}
 
 
 
 
1569				qdisc_refcount_inc(q);
1570				goto graft;
1571			} else {
1572				if (!q)
1573					goto create_n_graft;
1574
1575				/* This magic test requires explanation.
1576				 *
1577				 *   We know, that some child q is already
1578				 *   attached to this parent and have choice:
1579				 *   either to change it or to create/graft new one.
 
 
 
 
1580				 *
1581				 *   1. We are allowed to create/graft only
1582				 *   if CREATE and REPLACE flags are set.
 
1583				 *
1584				 *   2. If EXCL is set, requestor wanted to say,
1585				 *   that qdisc tcm_handle is not expected
1586				 *   to exist, so that we choose create/graft too.
1587				 *
1588				 *   3. The last case is when no flags are set.
 
 
1589				 *   Alas, it is sort of hole in API, we
1590				 *   cannot decide what to do unambiguously.
1591				 *   For now we select create/graft, if
1592				 *   user gave KIND, which does not match existing.
1593				 */
1594				if ((n->nlmsg_flags & NLM_F_CREATE) &&
1595				    (n->nlmsg_flags & NLM_F_REPLACE) &&
1596				    ((n->nlmsg_flags & NLM_F_EXCL) ||
1597				     (tca[TCA_KIND] &&
1598				      nla_strcmp(tca[TCA_KIND], q->ops->id))))
1599					goto create_n_graft;
 
 
1600			}
1601		}
1602	} else {
1603		if (!tcm->tcm_handle) {
1604			NL_SET_ERR_MSG(extack, "Handle cannot be zero");
1605			return -EINVAL;
1606		}
1607		q = qdisc_lookup(dev, tcm->tcm_handle);
1608	}
1609
1610	/* Change qdisc parameters */
1611	if (!q) {
1612		NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1613		return -ENOENT;
1614	}
1615	if (n->nlmsg_flags & NLM_F_EXCL) {
1616		NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify");
1617		return -EEXIST;
1618	}
1619	if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1620		NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1621		return -EINVAL;
1622	}
1623	err = qdisc_change(q, tca, extack);
1624	if (err == 0)
1625		qdisc_notify(net, skb, n, clid, NULL, q);
1626	return err;
1627
1628create_n_graft:
1629	if (!(n->nlmsg_flags & NLM_F_CREATE)) {
1630		NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag");
1631		return -ENOENT;
1632	}
 
1633	if (clid == TC_H_INGRESS) {
1634		if (dev_ingress_queue(dev)) {
1635			q = qdisc_create(dev, dev_ingress_queue(dev), p,
1636					 tcm->tcm_parent, tcm->tcm_parent,
1637					 tca, &err, extack);
1638		} else {
1639			NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device");
1640			err = -ENOENT;
1641		}
1642	} else {
1643		struct netdev_queue *dev_queue;
1644
1645		if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1646			dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1647		else if (p)
1648			dev_queue = p->dev_queue;
1649		else
1650			dev_queue = netdev_get_tx_queue(dev, 0);
1651
1652		q = qdisc_create(dev, dev_queue, p,
1653				 tcm->tcm_parent, tcm->tcm_handle,
1654				 tca, &err, extack);
1655	}
1656	if (q == NULL) {
1657		if (err == -EAGAIN)
1658			goto replay;
1659		return err;
1660	}
1661
1662graft:
1663	err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack);
1664	if (err) {
1665		if (q)
1666			qdisc_put(q);
1667		return err;
1668	}
1669
1670	return 0;
1671}
1672
1673static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1674			      struct netlink_callback *cb,
1675			      int *q_idx_p, int s_q_idx, bool recur,
1676			      bool dump_invisible)
1677{
1678	int ret = 0, q_idx = *q_idx_p;
1679	struct Qdisc *q;
1680	int b;
1681
1682	if (!root)
1683		return 0;
1684
1685	q = root;
1686	if (q_idx < s_q_idx) {
1687		q_idx++;
1688	} else {
1689		if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1690		    tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1691				  cb->nlh->nlmsg_seq, NLM_F_MULTI,
1692				  RTM_NEWQDISC) <= 0)
1693			goto done;
1694		q_idx++;
1695	}
1696
1697	/* If dumping singletons, there is no qdisc_dev(root) and the singleton
1698	 * itself has already been dumped.
1699	 *
1700	 * If we've already dumped the top-level (ingress) qdisc above and the global
1701	 * qdisc hashtable, we don't want to hit it again
1702	 */
1703	if (!qdisc_dev(root) || !recur)
1704		goto out;
1705
1706	hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1707		if (q_idx < s_q_idx) {
1708			q_idx++;
1709			continue;
1710		}
1711		if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1712		    tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1713				  cb->nlh->nlmsg_seq, NLM_F_MULTI,
1714				  RTM_NEWQDISC) <= 0)
1715			goto done;
1716		q_idx++;
1717	}
1718
1719out:
1720	*q_idx_p = q_idx;
1721	return ret;
1722done:
1723	ret = -1;
1724	goto out;
1725}
1726
1727static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1728{
1729	struct net *net = sock_net(skb->sk);
1730	int idx, q_idx;
1731	int s_idx, s_q_idx;
1732	struct net_device *dev;
1733	const struct nlmsghdr *nlh = cb->nlh;
1734	struct nlattr *tca[TCA_MAX + 1];
1735	int err;
1736
1737	s_idx = cb->args[0];
1738	s_q_idx = q_idx = cb->args[1];
1739
1740	idx = 0;
1741	ASSERT_RTNL();
1742
1743	err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX,
1744				     rtm_tca_policy, cb->extack);
1745	if (err < 0)
1746		return err;
1747
1748	for_each_netdev(net, dev) {
1749		struct netdev_queue *dev_queue;
1750
1751		if (idx < s_idx)
1752			goto cont;
1753		if (idx > s_idx)
1754			s_q_idx = 0;
1755		q_idx = 0;
1756
1757		if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx,
 
1758				       true, tca[TCA_DUMP_INVISIBLE]) < 0)
1759			goto done;
1760
1761		dev_queue = dev_ingress_queue(dev);
1762		if (dev_queue &&
1763		    tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1764				       &q_idx, s_q_idx, false,
1765				       tca[TCA_DUMP_INVISIBLE]) < 0)
1766			goto done;
1767
1768cont:
1769		idx++;
1770	}
1771
1772done:
1773	cb->args[0] = idx;
1774	cb->args[1] = q_idx;
1775
1776	return skb->len;
1777}
1778
1779
1780
1781/************************************************
1782 *	Traffic classes manipulation.		*
1783 ************************************************/
1784
1785static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1786			  unsigned long cl,
1787			  u32 portid, u32 seq, u16 flags, int event)
1788{
1789	struct tcmsg *tcm;
1790	struct nlmsghdr  *nlh;
1791	unsigned char *b = skb_tail_pointer(skb);
1792	struct gnet_dump d;
1793	const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1794
1795	cond_resched();
1796	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1797	if (!nlh)
1798		goto out_nlmsg_trim;
1799	tcm = nlmsg_data(nlh);
1800	tcm->tcm_family = AF_UNSPEC;
1801	tcm->tcm__pad1 = 0;
1802	tcm->tcm__pad2 = 0;
1803	tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1804	tcm->tcm_parent = q->handle;
1805	tcm->tcm_handle = q->handle;
1806	tcm->tcm_info = 0;
1807	if (nla_put_string(skb, TCA_KIND, q->ops->id))
1808		goto nla_put_failure;
1809	if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1810		goto nla_put_failure;
1811
1812	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1813					 NULL, &d, TCA_PAD) < 0)
1814		goto nla_put_failure;
1815
1816	if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1817		goto nla_put_failure;
1818
1819	if (gnet_stats_finish_copy(&d) < 0)
1820		goto nla_put_failure;
1821
 
 
 
 
1822	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 
1823	return skb->len;
1824
1825out_nlmsg_trim:
1826nla_put_failure:
1827	nlmsg_trim(skb, b);
1828	return -1;
1829}
1830
1831static int tclass_notify(struct net *net, struct sk_buff *oskb,
1832			 struct nlmsghdr *n, struct Qdisc *q,
1833			 unsigned long cl, int event)
1834{
1835	struct sk_buff *skb;
1836	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1837	int err = 0;
 
 
1838
1839	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1840	if (!skb)
1841		return -ENOBUFS;
1842
1843	if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1844		kfree_skb(skb);
1845		return -EINVAL;
1846	}
1847
1848	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1849			     n->nlmsg_flags & NLM_F_ECHO);
1850	if (err > 0)
1851		err = 0;
1852	return err;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1853}
1854
1855static int tclass_del_notify(struct net *net,
1856			     const struct Qdisc_class_ops *cops,
1857			     struct sk_buff *oskb, struct nlmsghdr *n,
1858			     struct Qdisc *q, unsigned long cl)
 
1859{
1860	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1861	struct sk_buff *skb;
1862	int err = 0;
1863
1864	if (!cops->delete)
1865		return -EOPNOTSUPP;
1866
1867	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1868	if (!skb)
1869		return -ENOBUFS;
1870
1871	if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0,
1872			   RTM_DELTCLASS) < 0) {
1873		kfree_skb(skb);
1874		return -EINVAL;
 
 
 
 
1875	}
1876
1877	err = cops->delete(q, cl);
1878	if (err) {
1879		kfree_skb(skb);
1880		return err;
1881	}
1882
1883	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1884			     n->nlmsg_flags & NLM_F_ECHO);
1885	if (err > 0)
1886		err = 0;
1887	return err;
1888}
1889
1890#ifdef CONFIG_NET_CLS
1891
1892struct tcf_bind_args {
1893	struct tcf_walker w;
1894	u32 classid;
1895	unsigned long cl;
 
1896};
1897
1898static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
1899{
1900	struct tcf_bind_args *a = (void *)arg;
1901
1902	if (tp->ops->bind_class) {
1903		struct Qdisc *q = tcf_block_q(tp->chain->block);
1904
1905		sch_tree_lock(q);
1906		tp->ops->bind_class(n, a->classid, a->cl);
1907		sch_tree_unlock(q);
1908	}
1909	return 0;
1910}
1911
1912static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1913			   unsigned long new_cl)
 
 
 
 
 
 
 
1914{
 
1915	const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1916	struct tcf_block *block;
1917	struct tcf_chain *chain;
1918	unsigned long cl;
1919
1920	cl = cops->find(q, portid);
1921	if (!cl)
1922		return;
1923	if (!cops->tcf_block)
1924		return;
1925	block = cops->tcf_block(q, cl, NULL);
1926	if (!block)
1927		return;
1928	for (chain = tcf_get_next_chain(block, NULL);
1929	     chain;
1930	     chain = tcf_get_next_chain(block, chain)) {
1931		struct tcf_proto *tp;
1932
1933		for (tp = tcf_get_next_proto(chain, NULL, true);
1934		     tp; tp = tcf_get_next_proto(chain, tp, true)) {
1935			struct tcf_bind_args arg = {};
1936
1937			arg.w.fn = tcf_node_bind;
1938			arg.classid = clid;
1939			arg.cl = new_cl;
 
1940			tp->ops->walk(tp, &arg.w, true);
1941		}
1942	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1943}
1944
1945#else
1946
1947static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1948			   unsigned long new_cl)
1949{
1950}
1951
1952#endif
1953
1954static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
1955			 struct netlink_ext_ack *extack)
1956{
1957	struct net *net = sock_net(skb->sk);
1958	struct tcmsg *tcm = nlmsg_data(n);
1959	struct nlattr *tca[TCA_MAX + 1];
1960	struct net_device *dev;
1961	struct Qdisc *q = NULL;
1962	const struct Qdisc_class_ops *cops;
1963	unsigned long cl = 0;
1964	unsigned long new_cl;
1965	u32 portid;
1966	u32 clid;
1967	u32 qid;
1968	int err;
1969
1970	if ((n->nlmsg_type != RTM_GETTCLASS) &&
1971	    !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
1972		return -EPERM;
1973
1974	err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1975				     rtm_tca_policy, extack);
1976	if (err < 0)
1977		return err;
1978
1979	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1980	if (!dev)
1981		return -ENODEV;
1982
1983	/*
1984	   parent == TC_H_UNSPEC - unspecified parent.
1985	   parent == TC_H_ROOT   - class is root, which has no parent.
1986	   parent == X:0	 - parent is root class.
1987	   parent == X:Y	 - parent is a node in hierarchy.
1988	   parent == 0:Y	 - parent is X:Y, where X:0 is qdisc.
1989
1990	   handle == 0:0	 - generate handle from kernel pool.
1991	   handle == 0:Y	 - class is X:Y, where X:0 is qdisc.
1992	   handle == X:Y	 - clear.
1993	   handle == X:0	 - root class.
1994	 */
1995
1996	/* Step 1. Determine qdisc handle X:0 */
1997
1998	portid = tcm->tcm_parent;
1999	clid = tcm->tcm_handle;
2000	qid = TC_H_MAJ(clid);
2001
2002	if (portid != TC_H_ROOT) {
2003		u32 qid1 = TC_H_MAJ(portid);
2004
2005		if (qid && qid1) {
2006			/* If both majors are known, they must be identical. */
2007			if (qid != qid1)
2008				return -EINVAL;
2009		} else if (qid1) {
2010			qid = qid1;
2011		} else if (qid == 0)
2012			qid = dev->qdisc->handle;
2013
2014		/* Now qid is genuine qdisc handle consistent
2015		 * both with parent and child.
2016		 *
2017		 * TC_H_MAJ(portid) still may be unspecified, complete it now.
2018		 */
2019		if (portid)
2020			portid = TC_H_MAKE(qid, portid);
2021	} else {
2022		if (qid == 0)
2023			qid = dev->qdisc->handle;
2024	}
2025
2026	/* OK. Locate qdisc */
2027	q = qdisc_lookup(dev, qid);
2028	if (!q)
2029		return -ENOENT;
2030
2031	/* An check that it supports classes */
2032	cops = q->ops->cl_ops;
2033	if (cops == NULL)
2034		return -EINVAL;
2035
2036	/* Now try to get class */
2037	if (clid == 0) {
2038		if (portid == TC_H_ROOT)
2039			clid = qid;
2040	} else
2041		clid = TC_H_MAKE(qid, clid);
2042
2043	if (clid)
2044		cl = cops->find(q, clid);
2045
2046	if (cl == 0) {
2047		err = -ENOENT;
2048		if (n->nlmsg_type != RTM_NEWTCLASS ||
2049		    !(n->nlmsg_flags & NLM_F_CREATE))
2050			goto out;
2051	} else {
2052		switch (n->nlmsg_type) {
2053		case RTM_NEWTCLASS:
2054			err = -EEXIST;
2055			if (n->nlmsg_flags & NLM_F_EXCL)
2056				goto out;
2057			break;
2058		case RTM_DELTCLASS:
2059			err = tclass_del_notify(net, cops, skb, n, q, cl);
2060			/* Unbind the class with flilters with 0 */
2061			tc_bind_tclass(q, portid, clid, 0);
2062			goto out;
2063		case RTM_GETTCLASS:
2064			err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
2065			goto out;
2066		default:
2067			err = -EINVAL;
2068			goto out;
2069		}
2070	}
2071
2072	if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
2073		NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes");
2074		return -EOPNOTSUPP;
2075	}
2076
2077	new_cl = cl;
2078	err = -EOPNOTSUPP;
2079	if (cops->change)
2080		err = cops->change(q, clid, portid, tca, &new_cl, extack);
2081	if (err == 0) {
2082		tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
2083		/* We just create a new class, need to do reverse binding. */
2084		if (cl != new_cl)
2085			tc_bind_tclass(q, portid, clid, new_cl);
2086	}
2087out:
2088	return err;
2089}
2090
2091struct qdisc_dump_args {
2092	struct qdisc_walker	w;
2093	struct sk_buff		*skb;
2094	struct netlink_callback	*cb;
2095};
2096
2097static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
2098			    struct qdisc_walker *arg)
2099{
2100	struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
2101
2102	return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
2103			      a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2104			      RTM_NEWTCLASS);
2105}
2106
2107static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
2108				struct tcmsg *tcm, struct netlink_callback *cb,
2109				int *t_p, int s_t)
2110{
2111	struct qdisc_dump_args arg;
2112
2113	if (tc_qdisc_dump_ignore(q, false) ||
2114	    *t_p < s_t || !q->ops->cl_ops ||
2115	    (tcm->tcm_parent &&
2116	     TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
2117		(*t_p)++;
2118		return 0;
2119	}
2120	if (*t_p > s_t)
2121		memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
2122	arg.w.fn = qdisc_class_dump;
2123	arg.skb = skb;
2124	arg.cb = cb;
2125	arg.w.stop  = 0;
2126	arg.w.skip = cb->args[1];
2127	arg.w.count = 0;
2128	q->ops->cl_ops->walk(q, &arg.w);
2129	cb->args[1] = arg.w.count;
2130	if (arg.w.stop)
2131		return -1;
2132	(*t_p)++;
2133	return 0;
2134}
2135
2136static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
2137			       struct tcmsg *tcm, struct netlink_callback *cb,
2138			       int *t_p, int s_t)
2139{
2140	struct Qdisc *q;
2141	int b;
2142
2143	if (!root)
2144		return 0;
2145
2146	if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
2147		return -1;
2148
2149	if (!qdisc_dev(root))
2150		return 0;
2151
2152	if (tcm->tcm_parent) {
2153		q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent));
2154		if (q && q != root &&
2155		    tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2156			return -1;
2157		return 0;
2158	}
2159	hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
2160		if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2161			return -1;
2162	}
2163
2164	return 0;
2165}
2166
2167static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
2168{
2169	struct tcmsg *tcm = nlmsg_data(cb->nlh);
2170	struct net *net = sock_net(skb->sk);
2171	struct netdev_queue *dev_queue;
2172	struct net_device *dev;
2173	int t, s_t;
2174
2175	if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2176		return 0;
2177	dev = dev_get_by_index(net, tcm->tcm_ifindex);
2178	if (!dev)
2179		return 0;
2180
2181	s_t = cb->args[0];
2182	t = 0;
2183
2184	if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
 
2185		goto done;
2186
2187	dev_queue = dev_ingress_queue(dev);
2188	if (dev_queue &&
2189	    tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
2190				&t, s_t) < 0)
2191		goto done;
2192
2193done:
2194	cb->args[0] = t;
2195
2196	dev_put(dev);
2197	return skb->len;
2198}
2199
2200#ifdef CONFIG_PROC_FS
2201static int psched_show(struct seq_file *seq, void *v)
2202{
2203	seq_printf(seq, "%08x %08x %08x %08x\n",
2204		   (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
2205		   1000000,
2206		   (u32)NSEC_PER_SEC / hrtimer_resolution);
2207
2208	return 0;
2209}
2210
2211static int __net_init psched_net_init(struct net *net)
2212{
2213	struct proc_dir_entry *e;
2214
2215	e = proc_create_single("psched", 0, net->proc_net, psched_show);
2216	if (e == NULL)
2217		return -ENOMEM;
2218
2219	return 0;
2220}
2221
2222static void __net_exit psched_net_exit(struct net *net)
2223{
2224	remove_proc_entry("psched", net->proc_net);
2225}
2226#else
2227static int __net_init psched_net_init(struct net *net)
2228{
2229	return 0;
2230}
2231
2232static void __net_exit psched_net_exit(struct net *net)
2233{
2234}
2235#endif
2236
2237static struct pernet_operations psched_net_ops = {
2238	.init = psched_net_init,
2239	.exit = psched_net_exit,
2240};
2241
 
 
 
 
2242static int __init pktsched_init(void)
2243{
2244	int err;
2245
2246	err = register_pernet_subsys(&psched_net_ops);
2247	if (err) {
2248		pr_err("pktsched_init: "
2249		       "cannot initialize per netns operations\n");
2250		return err;
2251	}
2252
2253	register_qdisc(&pfifo_fast_ops);
2254	register_qdisc(&pfifo_qdisc_ops);
2255	register_qdisc(&bfifo_qdisc_ops);
2256	register_qdisc(&pfifo_head_drop_qdisc_ops);
2257	register_qdisc(&mq_qdisc_ops);
2258	register_qdisc(&noqueue_qdisc_ops);
2259
2260	rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, 0);
2261	rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, 0);
2262	rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc,
2263		      0);
2264	rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, 0);
2265	rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, 0);
2266	rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass,
2267		      0);
 
 
2268
2269	return 0;
2270}
2271
2272subsys_initcall(pktsched_init);