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v3.1
 
   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
  38static int qdisc_notify(struct net *net, struct sk_buff *oskb,
  39			struct nlmsghdr *n, u32 clid,
  40			struct Qdisc *old, struct Qdisc *new);
  41static 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. */
 126static DEFINE_RWLOCK(qdisc_mod_lock);
 127
 128
 129/************************************************
 130 *	Queueing disciplines manipulation.	*
 131 ************************************************/
 132
 133
 134/* The list of all installed queueing disciplines. */
 135
 136static struct Qdisc_ops *qdisc_base;
 137
 138/* Register/uregister queueing discipline */
 139
 140int 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;
 174out:
 175	write_unlock(&qdisc_mod_lock);
 176	return rc;
 177
 178out_einval:
 179	rc = -EINVAL;
 180	goto out;
 181}
 182EXPORT_SYMBOL(register_qdisc);
 183
 184int 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}
 201EXPORT_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
 207static 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
 222static 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
 228void 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}
 233EXPORT_SYMBOL(qdisc_list_del);
 234
 235struct 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);
 247out:
 248	return q;
 249}
 250
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 251static 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
 270static 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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 288static struct qdisc_rate_table *qdisc_rtab_list;
 289
 290struct 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}
 315EXPORT_SYMBOL(qdisc_get_rtab);
 316
 317void 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}
 334EXPORT_SYMBOL(qdisc_put_rtab);
 335
 336static LIST_HEAD(qdisc_stab_list);
 337static DEFINE_SPINLOCK(qdisc_stab_lock);
 338
 339static 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
 344static 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
 401static void stab_kfree_rcu(struct rcu_head *head)
 402{
 403	kfree(container_of(head, struct qdisc_size_table, rcu));
 404}
 405
 406void 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}
 420EXPORT_SYMBOL(qdisc_put_stab);
 421
 422static 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	NLA_PUT(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts);
 
 430	nla_nest_end(skb, nest);
 431
 432	return skb->len;
 433
 434nla_put_failure:
 435	return -1;
 436}
 437
 438void __qdisc_calculate_pkt_len(struct sk_buff *skb, const struct qdisc_size_table *stab)
 
 439{
 440	int pkt_len, slot;
 441
 442	pkt_len = skb->len + stab->szopts.overhead;
 443	if (unlikely(!stab->szopts.tsize))
 444		goto out;
 445
 446	slot = pkt_len + stab->szopts.cell_align;
 447	if (unlikely(slot < 0))
 448		slot = 0;
 449
 450	slot >>= stab->szopts.cell_log;
 451	if (likely(slot < stab->szopts.tsize))
 452		pkt_len = stab->data[slot];
 453	else
 454		pkt_len = stab->data[stab->szopts.tsize - 1] *
 455				(slot / stab->szopts.tsize) +
 456				stab->data[slot % stab->szopts.tsize];
 457
 458	pkt_len <<= stab->szopts.size_log;
 459out:
 460	if (unlikely(pkt_len < 1))
 461		pkt_len = 1;
 462	qdisc_skb_cb(skb)->pkt_len = pkt_len;
 463}
 464EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
 465
 466void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc)
 467{
 468	if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
 469		pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
 470			txt, qdisc->ops->id, qdisc->handle >> 16);
 471		qdisc->flags |= TCQ_F_WARN_NONWC;
 472	}
 473}
 474EXPORT_SYMBOL(qdisc_warn_nonwc);
 475
 476static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
 477{
 478	struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
 479						 timer);
 480
 481	qdisc_unthrottled(wd->qdisc);
 482	__netif_schedule(qdisc_root(wd->qdisc));
 
 483
 484	return HRTIMER_NORESTART;
 485}
 486
 487void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
 
 488{
 489	hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 490	wd->timer.function = qdisc_watchdog;
 491	wd->qdisc = qdisc;
 492}
 
 
 
 
 
 
 493EXPORT_SYMBOL(qdisc_watchdog_init);
 494
 495void qdisc_watchdog_schedule(struct qdisc_watchdog *wd, psched_time_t expires)
 
 496{
 497	ktime_t time;
 498
 499	if (test_bit(__QDISC_STATE_DEACTIVATED,
 500		     &qdisc_root_sleeping(wd->qdisc)->state))
 
 
 
 501		return;
 502
 503	qdisc_throttled(wd->qdisc);
 504	time = ktime_set(0, 0);
 505	time = ktime_add_ns(time, PSCHED_TICKS2NS(expires));
 506	hrtimer_start(&wd->timer, time, HRTIMER_MODE_ABS);
 
 
 
 
 
 
 
 
 
 
 
 507}
 508EXPORT_SYMBOL(qdisc_watchdog_schedule);
 509
 510void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
 511{
 512	hrtimer_cancel(&wd->timer);
 513	qdisc_unthrottled(wd->qdisc);
 514}
 515EXPORT_SYMBOL(qdisc_watchdog_cancel);
 516
 517static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
 518{
 519	unsigned int size = n * sizeof(struct hlist_head), i;
 520	struct hlist_head *h;
 
 521
 522	if (size <= PAGE_SIZE)
 523		h = kmalloc(size, GFP_KERNEL);
 524	else
 525		h = (struct hlist_head *)
 526			__get_free_pages(GFP_KERNEL, get_order(size));
 527
 528	if (h != NULL) {
 529		for (i = 0; i < n; i++)
 530			INIT_HLIST_HEAD(&h[i]);
 531	}
 532	return h;
 533}
 534
 535static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
 536{
 537	unsigned int size = n * sizeof(struct hlist_head);
 538
 539	if (size <= PAGE_SIZE)
 540		kfree(h);
 541	else
 542		free_pages((unsigned long)h, get_order(size));
 543}
 544
 545void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
 546{
 547	struct Qdisc_class_common *cl;
 548	struct hlist_node *n, *next;
 549	struct hlist_head *nhash, *ohash;
 550	unsigned int nsize, nmask, osize;
 551	unsigned int i, h;
 552
 553	/* Rehash when load factor exceeds 0.75 */
 554	if (clhash->hashelems * 4 <= clhash->hashsize * 3)
 555		return;
 556	nsize = clhash->hashsize * 2;
 557	nmask = nsize - 1;
 558	nhash = qdisc_class_hash_alloc(nsize);
 559	if (nhash == NULL)
 560		return;
 561
 562	ohash = clhash->hash;
 563	osize = clhash->hashsize;
 564
 565	sch_tree_lock(sch);
 566	for (i = 0; i < osize; i++) {
 567		hlist_for_each_entry_safe(cl, n, next, &ohash[i], hnode) {
 568			h = qdisc_class_hash(cl->classid, nmask);
 569			hlist_add_head(&cl->hnode, &nhash[h]);
 570		}
 571	}
 572	clhash->hash     = nhash;
 573	clhash->hashsize = nsize;
 574	clhash->hashmask = nmask;
 575	sch_tree_unlock(sch);
 576
 577	qdisc_class_hash_free(ohash, osize);
 578}
 579EXPORT_SYMBOL(qdisc_class_hash_grow);
 580
 581int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
 582{
 583	unsigned int size = 4;
 584
 585	clhash->hash = qdisc_class_hash_alloc(size);
 586	if (clhash->hash == NULL)
 587		return -ENOMEM;
 588	clhash->hashsize  = size;
 589	clhash->hashmask  = size - 1;
 590	clhash->hashelems = 0;
 591	return 0;
 592}
 593EXPORT_SYMBOL(qdisc_class_hash_init);
 594
 595void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
 596{
 597	qdisc_class_hash_free(clhash->hash, clhash->hashsize);
 598}
 599EXPORT_SYMBOL(qdisc_class_hash_destroy);
 600
 601void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
 602			     struct Qdisc_class_common *cl)
 603{
 604	unsigned int h;
 605
 606	INIT_HLIST_NODE(&cl->hnode);
 607	h = qdisc_class_hash(cl->classid, clhash->hashmask);
 608	hlist_add_head(&cl->hnode, &clhash->hash[h]);
 609	clhash->hashelems++;
 610}
 611EXPORT_SYMBOL(qdisc_class_hash_insert);
 612
 613void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
 614			     struct Qdisc_class_common *cl)
 615{
 616	hlist_del(&cl->hnode);
 617	clhash->hashelems--;
 618}
 619EXPORT_SYMBOL(qdisc_class_hash_remove);
 620
 621/* Allocate an unique handle from space managed by kernel */
 622
 
 623static u32 qdisc_alloc_handle(struct net_device *dev)
 624{
 625	int i = 0x10000;
 626	static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
 627
 628	do {
 629		autohandle += TC_H_MAKE(0x10000U, 0);
 630		if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
 631			autohandle = TC_H_MAKE(0x80000000U, 0);
 632	} while	(qdisc_lookup(dev, autohandle) && --i > 0);
 
 
 
 633
 634	return i > 0 ? autohandle : 0;
 635}
 636
 637void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
 638{
 
 639	const struct Qdisc_class_ops *cops;
 640	unsigned long cl;
 641	u32 parentid;
 
 
 642
 643	if (n == 0)
 644		return;
 
 
 645	while ((parentid = sch->parent)) {
 646		if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
 647			return;
 648
 649		sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 650		if (sch == NULL) {
 651			WARN_ON(parentid != TC_H_ROOT);
 652			return;
 653		}
 654		cops = sch->ops->cl_ops;
 655		if (cops->qlen_notify) {
 656			cl = cops->get(sch, parentid);
 657			cops->qlen_notify(sch, cl);
 658			cops->put(sch, cl);
 659		}
 660		sch->q.qlen -= n;
 
 
 661	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 662}
 663EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
 664
 665static void notify_and_destroy(struct net *net, struct sk_buff *skb,
 666			       struct nlmsghdr *n, u32 clid,
 667			       struct Qdisc *old, struct Qdisc *new)
 
 668{
 669	if (new || old)
 670		qdisc_notify(net, skb, n, clid, old, new);
 671
 672	if (old)
 673		qdisc_destroy(old);
 
 
 
 
 
 
 
 
 
 
 
 
 
 674}
 675
 676/* Graft qdisc "new" to class "classid" of qdisc "parent" or
 677 * to device "dev".
 678 *
 679 * When appropriate send a netlink notification using 'skb'
 680 * and "n".
 681 *
 682 * On success, destroy old qdisc.
 683 */
 684
 685static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
 686		       struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
 687		       struct Qdisc *new, struct Qdisc *old)
 
 688{
 689	struct Qdisc *q = old;
 690	struct net *net = dev_net(dev);
 691	int err = 0;
 692
 693	if (parent == NULL) {
 694		unsigned int i, num_q, ingress;
 
 695
 696		ingress = 0;
 697		num_q = dev->num_tx_queues;
 698		if ((q && q->flags & TCQ_F_INGRESS) ||
 699		    (new && new->flags & TCQ_F_INGRESS)) {
 700			num_q = 1;
 701			ingress = 1;
 702			if (!dev_ingress_queue(dev))
 
 
 703				return -ENOENT;
 
 
 
 
 
 
 
 
 
 
 
 
 704		}
 705
 706		if (dev->flags & IFF_UP)
 707			dev_deactivate(dev);
 708
 709		if (new && new->ops->attach) {
 710			new->ops->attach(new);
 711			num_q = 0;
 712		}
 713
 714		for (i = 0; i < num_q; i++) {
 715			struct netdev_queue *dev_queue = dev_ingress_queue(dev);
 716
 717			if (!ingress)
 
 718				dev_queue = netdev_get_tx_queue(dev, i);
 
 719
 720			old = dev_graft_qdisc(dev_queue, new);
 721			if (new && i > 0)
 722				atomic_inc(&new->refcnt);
 
 
 
 723
 724			if (!ingress)
 725				qdisc_destroy(old);
 
 
 
 
 
 
 726		}
 727
 
 728		if (!ingress) {
 729			notify_and_destroy(net, skb, n, classid,
 730					   dev->qdisc, new);
 731			if (new && !new->ops->attach)
 732				atomic_inc(&new->refcnt);
 733			dev->qdisc = new ? : &noop_qdisc;
 734		} else {
 735			notify_and_destroy(net, skb, n, classid, old, new);
 
 
 
 736		}
 737
 738		if (dev->flags & IFF_UP)
 739			dev_activate(dev);
 740	} else {
 741		const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
 
 
 742
 743		err = -EOPNOTSUPP;
 744		if (cops && cops->graft) {
 745			unsigned long cl = cops->get(parent, classid);
 746			if (cl) {
 747				err = cops->graft(parent, cl, new, &old);
 748				cops->put(parent, cl);
 749			} else
 750				err = -ENOENT;
 
 
 
 751		}
 752		if (!err)
 753			notify_and_destroy(net, skb, n, classid, old, new);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 754	}
 755	return err;
 756}
 757
 758/* lockdep annotation is needed for ingress; egress gets it only for name */
 759static struct lock_class_key qdisc_tx_lock;
 760static struct lock_class_key qdisc_rx_lock;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 761
 762/*
 763   Allocate and initialize new qdisc.
 764
 765   Parameters are passed via opt.
 766 */
 767
 768static struct Qdisc *
 769qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
 770	     struct Qdisc *p, u32 parent, u32 handle,
 771	     struct nlattr **tca, int *errp)
 
 772{
 773	int err;
 774	struct nlattr *kind = tca[TCA_KIND];
 775	struct Qdisc *sch;
 776	struct Qdisc_ops *ops;
 777	struct qdisc_size_table *stab;
 778
 779	ops = qdisc_lookup_ops(kind);
 780#ifdef CONFIG_MODULES
 781	if (ops == NULL && kind != NULL) {
 782		char name[IFNAMSIZ];
 783		if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
 784			/* We dropped the RTNL semaphore in order to
 785			 * perform the module load.  So, even if we
 786			 * succeeded in loading the module we have to
 787			 * tell the caller to replay the request.  We
 788			 * indicate this using -EAGAIN.
 789			 * We replay the request because the device may
 790			 * go away in the mean time.
 791			 */
 792			rtnl_unlock();
 793			request_module("sch_%s", name);
 794			rtnl_lock();
 795			ops = qdisc_lookup_ops(kind);
 796			if (ops != NULL) {
 797				/* We will try again qdisc_lookup_ops,
 798				 * so don't keep a reference.
 799				 */
 800				module_put(ops->owner);
 801				err = -EAGAIN;
 802				goto err_out;
 803			}
 804		}
 805	}
 806#endif
 807
 808	err = -ENOENT;
 809	if (ops == NULL)
 
 810		goto err_out;
 
 811
 812	sch = qdisc_alloc(dev_queue, ops);
 813	if (IS_ERR(sch)) {
 814		err = PTR_ERR(sch);
 815		goto err_out2;
 816	}
 817
 818	sch->parent = parent;
 819
 820	if (handle == TC_H_INGRESS) {
 821		sch->flags |= TCQ_F_INGRESS;
 
 
 
 
 
 822		handle = TC_H_MAKE(TC_H_INGRESS, 0);
 823		lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
 824	} else {
 825		if (handle == 0) {
 826			handle = qdisc_alloc_handle(dev);
 827			err = -ENOMEM;
 828			if (handle == 0)
 
 829				goto err_out3;
 
 830		}
 831		lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
 
 832	}
 833
 834	sch->handle = handle;
 835
 836	if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
 837		if (tca[TCA_STAB]) {
 838			stab = qdisc_get_stab(tca[TCA_STAB]);
 839			if (IS_ERR(stab)) {
 840				err = PTR_ERR(stab);
 841				goto err_out4;
 842			}
 843			rcu_assign_pointer(sch->stab, stab);
 
 
 
 
 
 
 
 
 
 
 
 
 844		}
 845		if (tca[TCA_RATE]) {
 846			spinlock_t *root_lock;
 847
 848			err = -EOPNOTSUPP;
 849			if (sch->flags & TCQ_F_MQROOT)
 850				goto err_out4;
 
 
 851
 852			if ((sch->parent != TC_H_ROOT) &&
 853			    !(sch->flags & TCQ_F_INGRESS) &&
 854			    (!p || !(p->flags & TCQ_F_MQROOT)))
 855				root_lock = qdisc_root_sleeping_lock(sch);
 856			else
 857				root_lock = qdisc_lock(sch);
 858
 859			err = gen_new_estimator(&sch->bstats, &sch->rate_est,
 860						root_lock, tca[TCA_RATE]);
 861			if (err)
 862				goto err_out4;
 
 
 
 
 
 863		}
 
 864
 865		qdisc_list_add(sch);
 
 866
 867		return sch;
 868	}
 
 
 
 
 
 
 
 869err_out3:
 870	dev_put(dev);
 871	kfree((char *) sch - sch->padded);
 
 872err_out2:
 873	module_put(ops->owner);
 874err_out:
 875	*errp = err;
 876	return NULL;
 877
 878err_out4:
 879	/*
 880	 * Any broken qdiscs that would require a ops->reset() here?
 881	 * The qdisc was never in action so it shouldn't be necessary.
 882	 */
 883	qdisc_put_stab(rtnl_dereference(sch->stab));
 884	if (ops->destroy)
 885		ops->destroy(sch);
 886	goto err_out3;
 887}
 888
 889static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
 
 890{
 891	struct qdisc_size_table *ostab, *stab = NULL;
 892	int err = 0;
 893
 894	if (tca[TCA_OPTIONS]) {
 895		if (sch->ops->change == NULL)
 
 896			return -EINVAL;
 897		err = sch->ops->change(sch, tca[TCA_OPTIONS]);
 
 
 
 
 
 898		if (err)
 899			return err;
 900	}
 901
 902	if (tca[TCA_STAB]) {
 903		stab = qdisc_get_stab(tca[TCA_STAB]);
 904		if (IS_ERR(stab))
 905			return PTR_ERR(stab);
 906	}
 907
 908	ostab = rtnl_dereference(sch->stab);
 909	rcu_assign_pointer(sch->stab, stab);
 910	qdisc_put_stab(ostab);
 911
 912	if (tca[TCA_RATE]) {
 913		/* NB: ignores errors from replace_estimator
 914		   because change can't be undone. */
 915		if (sch->flags & TCQ_F_MQROOT)
 916			goto out;
 917		gen_replace_estimator(&sch->bstats, &sch->rate_est,
 918					    qdisc_root_sleeping_lock(sch),
 919					    tca[TCA_RATE]);
 
 
 
 920	}
 921out:
 922	return 0;
 923}
 924
 925struct check_loop_arg {
 926	struct qdisc_walker	w;
 927	struct Qdisc		*p;
 928	int			depth;
 929};
 930
 931static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
 
 932
 933static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
 934{
 935	struct check_loop_arg	arg;
 936
 937	if (q->ops->cl_ops == NULL)
 938		return 0;
 939
 940	arg.w.stop = arg.w.skip = arg.w.count = 0;
 941	arg.w.fn = check_loop_fn;
 942	arg.depth = depth;
 943	arg.p = p;
 944	q->ops->cl_ops->walk(q, &arg.w);
 945	return arg.w.stop ? -ELOOP : 0;
 946}
 947
 948static int
 949check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
 950{
 951	struct Qdisc *leaf;
 952	const struct Qdisc_class_ops *cops = q->ops->cl_ops;
 953	struct check_loop_arg *arg = (struct check_loop_arg *)w;
 954
 955	leaf = cops->leaf(q, cl);
 956	if (leaf) {
 957		if (leaf == arg->p || arg->depth > 7)
 958			return -ELOOP;
 959		return check_loop(leaf, arg->p, arg->depth + 1);
 960	}
 961	return 0;
 962}
 963
 
 
 
 
 
 
 
 
 
 
 
 964/*
 965 * Delete/get qdisc.
 966 */
 967
 968static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 
 969{
 970	struct net *net = sock_net(skb->sk);
 971	struct tcmsg *tcm = NLMSG_DATA(n);
 972	struct nlattr *tca[TCA_MAX + 1];
 973	struct net_device *dev;
 974	u32 clid = tcm->tcm_parent;
 975	struct Qdisc *q = NULL;
 976	struct Qdisc *p = NULL;
 977	int err;
 978
 
 
 
 
 
 979	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
 980	if (!dev)
 981		return -ENODEV;
 982
 983	err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
 984	if (err < 0)
 985		return err;
 986
 987	if (clid) {
 988		if (clid != TC_H_ROOT) {
 989			if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
 990				p = qdisc_lookup(dev, TC_H_MAJ(clid));
 991				if (!p)
 
 992					return -ENOENT;
 
 993				q = qdisc_leaf(p, clid);
 994			} else if (dev_ingress_queue(dev)) {
 995				q = dev_ingress_queue(dev)->qdisc_sleeping;
 996			}
 997		} else {
 998			q = dev->qdisc;
 999		}
1000		if (!q)
 
1001			return -ENOENT;
 
1002
1003		if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
 
1004			return -EINVAL;
 
1005	} else {
1006		q = qdisc_lookup(dev, tcm->tcm_handle);
1007		if (!q)
 
1008			return -ENOENT;
 
1009	}
1010
1011	if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
 
1012		return -EINVAL;
 
1013
1014	if (n->nlmsg_type == RTM_DELQDISC) {
1015		if (!clid)
 
1016			return -EINVAL;
1017		if (q->handle == 0)
 
 
1018			return -ENOENT;
1019		err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
 
1020		if (err != 0)
1021			return err;
1022	} else {
1023		qdisc_notify(net, skb, n, clid, NULL, q);
1024	}
1025	return 0;
1026}
1027
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1028/*
1029 * Create/change qdisc.
1030 */
1031
1032static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
1033{
1034	struct net *net = sock_net(skb->sk);
1035	struct tcmsg *tcm;
1036	struct nlattr *tca[TCA_MAX + 1];
1037	struct net_device *dev;
1038	u32 clid;
1039	struct Qdisc *q, *p;
1040	int err;
1041
1042replay:
1043	/* Reinit, just in case something touches this. */
1044	tcm = NLMSG_DATA(n);
 
 
 
 
 
1045	clid = tcm->tcm_parent;
1046	q = p = NULL;
1047
1048	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1049	if (!dev)
1050		return -ENODEV;
1051
1052	err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1053	if (err < 0)
1054		return err;
1055
1056	if (clid) {
1057		if (clid != TC_H_ROOT) {
1058			if (clid != TC_H_INGRESS) {
1059				p = qdisc_lookup(dev, TC_H_MAJ(clid));
1060				if (!p)
 
1061					return -ENOENT;
 
1062				q = qdisc_leaf(p, clid);
1063			} else if (dev_ingress_queue_create(dev)) {
1064				q = dev_ingress_queue(dev)->qdisc_sleeping;
1065			}
1066		} else {
1067			q = dev->qdisc;
1068		}
1069
1070		/* It may be default qdisc, ignore it */
1071		if (q && q->handle == 0)
1072			q = NULL;
1073
1074		if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1075			if (tcm->tcm_handle) {
1076				if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
 
1077					return -EEXIST;
1078				if (TC_H_MIN(tcm->tcm_handle))
 
 
1079					return -EINVAL;
 
1080				q = qdisc_lookup(dev, tcm->tcm_handle);
1081				if (!q)
1082					goto create_n_graft;
1083				if (n->nlmsg_flags & NLM_F_EXCL)
 
 
 
 
 
1084					return -EEXIST;
1085				if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
 
 
 
 
 
 
 
 
1086					return -EINVAL;
 
1087				if (q == p ||
1088				    (p && check_loop(q, p, 0)))
 
1089					return -ELOOP;
1090				atomic_inc(&q->refcnt);
 
 
 
 
 
1091				goto graft;
1092			} else {
1093				if (!q)
1094					goto create_n_graft;
1095
1096				/* This magic test requires explanation.
1097				 *
1098				 *   We know, that some child q is already
1099				 *   attached to this parent and have choice:
1100				 *   either to change it or to create/graft new one.
 
 
 
 
1101				 *
1102				 *   1. We are allowed to create/graft only
1103				 *   if CREATE and REPLACE flags are set.
 
1104				 *
1105				 *   2. If EXCL is set, requestor wanted to say,
1106				 *   that qdisc tcm_handle is not expected
1107				 *   to exist, so that we choose create/graft too.
1108				 *
1109				 *   3. The last case is when no flags are set.
 
 
1110				 *   Alas, it is sort of hole in API, we
1111				 *   cannot decide what to do unambiguously.
1112				 *   For now we select create/graft, if
1113				 *   user gave KIND, which does not match existing.
1114				 */
1115				if ((n->nlmsg_flags & NLM_F_CREATE) &&
1116				    (n->nlmsg_flags & NLM_F_REPLACE) &&
1117				    ((n->nlmsg_flags & NLM_F_EXCL) ||
1118				     (tca[TCA_KIND] &&
1119				      nla_strcmp(tca[TCA_KIND], q->ops->id))))
1120					goto create_n_graft;
 
 
1121			}
1122		}
1123	} else {
1124		if (!tcm->tcm_handle)
 
1125			return -EINVAL;
 
1126		q = qdisc_lookup(dev, tcm->tcm_handle);
1127	}
1128
1129	/* Change qdisc parameters */
1130	if (q == NULL)
 
1131		return -ENOENT;
1132	if (n->nlmsg_flags & NLM_F_EXCL)
 
 
1133		return -EEXIST;
1134	if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
 
 
1135		return -EINVAL;
1136	err = qdisc_change(q, tca);
 
1137	if (err == 0)
1138		qdisc_notify(net, skb, n, clid, NULL, q);
1139	return err;
1140
1141create_n_graft:
1142	if (!(n->nlmsg_flags & NLM_F_CREATE))
 
1143		return -ENOENT;
 
 
1144	if (clid == TC_H_INGRESS) {
1145		if (dev_ingress_queue(dev))
1146			q = qdisc_create(dev, dev_ingress_queue(dev), p,
1147					 tcm->tcm_parent, tcm->tcm_parent,
1148					 tca, &err);
1149		else
 
1150			err = -ENOENT;
 
1151	} else {
1152		struct netdev_queue *dev_queue;
1153
1154		if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1155			dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1156		else if (p)
1157			dev_queue = p->dev_queue;
1158		else
1159			dev_queue = netdev_get_tx_queue(dev, 0);
1160
1161		q = qdisc_create(dev, dev_queue, p,
1162				 tcm->tcm_parent, tcm->tcm_handle,
1163				 tca, &err);
1164	}
1165	if (q == NULL) {
1166		if (err == -EAGAIN)
1167			goto replay;
1168		return err;
1169	}
1170
1171graft:
1172	err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1173	if (err) {
1174		if (q)
1175			qdisc_destroy(q);
1176		return err;
1177	}
1178
1179	return 0;
1180}
1181
1182static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1183			 u32 pid, u32 seq, u16 flags, int event)
1184{
1185	struct tcmsg *tcm;
1186	struct nlmsghdr  *nlh;
1187	unsigned char *b = skb_tail_pointer(skb);
1188	struct gnet_dump d;
1189	struct qdisc_size_table *stab;
1190
1191	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1192	tcm = NLMSG_DATA(nlh);
1193	tcm->tcm_family = AF_UNSPEC;
1194	tcm->tcm__pad1 = 0;
1195	tcm->tcm__pad2 = 0;
1196	tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1197	tcm->tcm_parent = clid;
1198	tcm->tcm_handle = q->handle;
1199	tcm->tcm_info = atomic_read(&q->refcnt);
1200	NLA_PUT_STRING(skb, TCA_KIND, q->ops->id);
1201	if (q->ops->dump && q->ops->dump(q, skb) < 0)
1202		goto nla_put_failure;
1203	q->qstats.qlen = q->q.qlen;
1204
1205	stab = rtnl_dereference(q->stab);
1206	if (stab && qdisc_dump_stab(skb, stab) < 0)
1207		goto nla_put_failure;
1208
1209	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1210					 qdisc_root_sleeping_lock(q), &d) < 0)
1211		goto nla_put_failure;
1212
1213	if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1214		goto nla_put_failure;
1215
1216	if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
1217	    gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1218	    gnet_stats_copy_queue(&d, &q->qstats) < 0)
1219		goto nla_put_failure;
1220
1221	if (gnet_stats_finish_copy(&d) < 0)
1222		goto nla_put_failure;
1223
1224	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1225	return skb->len;
1226
1227nlmsg_failure:
1228nla_put_failure:
1229	nlmsg_trim(skb, b);
1230	return -1;
1231}
1232
1233static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1234{
1235	return (q->flags & TCQ_F_BUILTIN) ? true : false;
1236}
1237
1238static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1239			struct nlmsghdr *n, u32 clid,
1240			struct Qdisc *old, struct Qdisc *new)
1241{
1242	struct sk_buff *skb;
1243	u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
1244
1245	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1246	if (!skb)
1247		return -ENOBUFS;
1248
1249	if (old && !tc_qdisc_dump_ignore(old)) {
1250		if (tc_fill_qdisc(skb, old, clid, pid, n->nlmsg_seq,
1251				  0, RTM_DELQDISC) < 0)
1252			goto err_out;
1253	}
1254	if (new && !tc_qdisc_dump_ignore(new)) {
1255		if (tc_fill_qdisc(skb, new, clid, pid, n->nlmsg_seq,
1256				  old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1257			goto err_out;
1258	}
1259
1260	if (skb->len)
1261		return rtnetlink_send(skb, net, pid, RTNLGRP_TC,
1262				      n->nlmsg_flags & NLM_F_ECHO);
1263
1264err_out:
1265	kfree_skb(skb);
1266	return -EINVAL;
1267}
1268
1269static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1270			      struct netlink_callback *cb,
1271			      int *q_idx_p, int s_q_idx)
 
1272{
1273	int ret = 0, q_idx = *q_idx_p;
1274	struct Qdisc *q;
 
1275
1276	if (!root)
1277		return 0;
1278
1279	q = root;
1280	if (q_idx < s_q_idx) {
1281		q_idx++;
1282	} else {
1283		if (!tc_qdisc_dump_ignore(q) &&
1284		    tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid,
1285				  cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
 
1286			goto done;
1287		q_idx++;
1288	}
1289	list_for_each_entry(q, &root->list, list) {
 
 
 
 
 
 
 
 
 
 
1290		if (q_idx < s_q_idx) {
1291			q_idx++;
1292			continue;
1293		}
1294		if (!tc_qdisc_dump_ignore(q) &&
1295		    tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid,
1296				  cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
 
1297			goto done;
1298		q_idx++;
1299	}
1300
1301out:
1302	*q_idx_p = q_idx;
1303	return ret;
1304done:
1305	ret = -1;
1306	goto out;
1307}
1308
1309static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1310{
1311	struct net *net = sock_net(skb->sk);
1312	int idx, q_idx;
1313	int s_idx, s_q_idx;
1314	struct net_device *dev;
 
 
 
1315
1316	s_idx = cb->args[0];
1317	s_q_idx = q_idx = cb->args[1];
1318
1319	rcu_read_lock();
1320	idx = 0;
1321	for_each_netdev_rcu(net, dev) {
 
 
 
 
 
 
 
1322		struct netdev_queue *dev_queue;
1323
1324		if (idx < s_idx)
1325			goto cont;
1326		if (idx > s_idx)
1327			s_q_idx = 0;
1328		q_idx = 0;
1329
1330		if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
 
 
1331			goto done;
1332
1333		dev_queue = dev_ingress_queue(dev);
1334		if (dev_queue &&
1335		    tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1336				       &q_idx, s_q_idx) < 0)
 
1337			goto done;
1338
1339cont:
1340		idx++;
1341	}
1342
1343done:
1344	rcu_read_unlock();
1345
1346	cb->args[0] = idx;
1347	cb->args[1] = q_idx;
1348
1349	return skb->len;
1350}
1351
1352
1353
1354/************************************************
1355 *	Traffic classes manipulation.		*
1356 ************************************************/
1357
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1358
 
 
 
 
 
 
 
 
1359
1360static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 
 
 
 
 
 
 
 
 
 
1361{
1362	struct net *net = sock_net(skb->sk);
1363	struct tcmsg *tcm = NLMSG_DATA(n);
1364	struct nlattr *tca[TCA_MAX + 1];
1365	struct net_device *dev;
1366	struct Qdisc *q = NULL;
1367	const struct Qdisc_class_ops *cops;
1368	unsigned long cl = 0;
1369	unsigned long new_cl;
1370	u32 pid = tcm->tcm_parent;
1371	u32 clid = tcm->tcm_handle;
1372	u32 qid = TC_H_MAJ(clid);
1373	int err;
1374
 
 
 
 
 
1375	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1376	if (!dev)
1377		return -ENODEV;
1378
1379	err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1380	if (err < 0)
1381		return err;
1382
1383	/*
1384	   parent == TC_H_UNSPEC - unspecified parent.
1385	   parent == TC_H_ROOT   - class is root, which has no parent.
1386	   parent == X:0	 - parent is root class.
1387	   parent == X:Y	 - parent is a node in hierarchy.
1388	   parent == 0:Y	 - parent is X:Y, where X:0 is qdisc.
1389
1390	   handle == 0:0	 - generate handle from kernel pool.
1391	   handle == 0:Y	 - class is X:Y, where X:0 is qdisc.
1392	   handle == X:Y	 - clear.
1393	   handle == X:0	 - root class.
1394	 */
1395
1396	/* Step 1. Determine qdisc handle X:0 */
1397
1398	if (pid != TC_H_ROOT) {
1399		u32 qid1 = TC_H_MAJ(pid);
 
 
 
 
1400
1401		if (qid && qid1) {
1402			/* If both majors are known, they must be identical. */
1403			if (qid != qid1)
1404				return -EINVAL;
1405		} else if (qid1) {
1406			qid = qid1;
1407		} else if (qid == 0)
1408			qid = dev->qdisc->handle;
1409
1410		/* Now qid is genuine qdisc handle consistent
1411		 * both with parent and child.
1412		 *
1413		 * TC_H_MAJ(pid) still may be unspecified, complete it now.
1414		 */
1415		if (pid)
1416			pid = TC_H_MAKE(qid, pid);
1417	} else {
1418		if (qid == 0)
1419			qid = dev->qdisc->handle;
1420	}
1421
1422	/* OK. Locate qdisc */
1423	q = qdisc_lookup(dev, qid);
1424	if (!q)
1425		return -ENOENT;
1426
1427	/* An check that it supports classes */
1428	cops = q->ops->cl_ops;
1429	if (cops == NULL)
1430		return -EINVAL;
1431
1432	/* Now try to get class */
1433	if (clid == 0) {
1434		if (pid == TC_H_ROOT)
1435			clid = qid;
1436	} else
1437		clid = TC_H_MAKE(qid, clid);
1438
1439	if (clid)
1440		cl = cops->get(q, clid);
1441
1442	if (cl == 0) {
1443		err = -ENOENT;
1444		if (n->nlmsg_type != RTM_NEWTCLASS ||
1445		    !(n->nlmsg_flags & NLM_F_CREATE))
1446			goto out;
1447	} else {
1448		switch (n->nlmsg_type) {
1449		case RTM_NEWTCLASS:
1450			err = -EEXIST;
1451			if (n->nlmsg_flags & NLM_F_EXCL)
1452				goto out;
1453			break;
1454		case RTM_DELTCLASS:
1455			err = -EOPNOTSUPP;
1456			if (cops->delete)
1457				err = cops->delete(q, cl);
1458			if (err == 0)
1459				tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1460			goto out;
1461		case RTM_GETTCLASS:
1462			err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1463			goto out;
1464		default:
1465			err = -EINVAL;
1466			goto out;
1467		}
1468	}
1469
 
 
 
 
 
1470	new_cl = cl;
1471	err = -EOPNOTSUPP;
1472	if (cops->change)
1473		err = cops->change(q, clid, pid, tca, &new_cl);
1474	if (err == 0)
1475		tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1476
 
 
 
1477out:
1478	if (cl)
1479		cops->put(q, cl);
1480
1481	return err;
1482}
1483
1484
1485static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1486			  unsigned long cl,
1487			  u32 pid, u32 seq, u16 flags, int event)
1488{
1489	struct tcmsg *tcm;
1490	struct nlmsghdr  *nlh;
1491	unsigned char *b = skb_tail_pointer(skb);
1492	struct gnet_dump d;
1493	const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1494
1495	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1496	tcm = NLMSG_DATA(nlh);
1497	tcm->tcm_family = AF_UNSPEC;
1498	tcm->tcm__pad1 = 0;
1499	tcm->tcm__pad2 = 0;
1500	tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1501	tcm->tcm_parent = q->handle;
1502	tcm->tcm_handle = q->handle;
1503	tcm->tcm_info = 0;
1504	NLA_PUT_STRING(skb, TCA_KIND, q->ops->id);
1505	if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1506		goto nla_put_failure;
1507
1508	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1509					 qdisc_root_sleeping_lock(q), &d) < 0)
1510		goto nla_put_failure;
1511
1512	if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1513		goto nla_put_failure;
1514
1515	if (gnet_stats_finish_copy(&d) < 0)
1516		goto nla_put_failure;
1517
1518	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1519	return skb->len;
1520
1521nlmsg_failure:
1522nla_put_failure:
1523	nlmsg_trim(skb, b);
1524	return -1;
1525}
1526
1527static int tclass_notify(struct net *net, struct sk_buff *oskb,
1528			 struct nlmsghdr *n, struct Qdisc *q,
1529			 unsigned long cl, int event)
1530{
1531	struct sk_buff *skb;
1532	u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
1533
1534	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1535	if (!skb)
1536		return -ENOBUFS;
1537
1538	if (tc_fill_tclass(skb, q, cl, pid, n->nlmsg_seq, 0, event) < 0) {
1539		kfree_skb(skb);
1540		return -EINVAL;
1541	}
1542
1543	return rtnetlink_send(skb, net, pid, RTNLGRP_TC,
1544			      n->nlmsg_flags & NLM_F_ECHO);
1545}
1546
1547struct qdisc_dump_args {
1548	struct qdisc_walker	w;
1549	struct sk_buff		*skb;
1550	struct netlink_callback	*cb;
1551};
1552
1553static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
 
1554{
1555	struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1556
1557	return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).pid,
1558			      a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
 
1559}
1560
1561static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1562				struct tcmsg *tcm, struct netlink_callback *cb,
1563				int *t_p, int s_t)
1564{
1565	struct qdisc_dump_args arg;
1566
1567	if (tc_qdisc_dump_ignore(q) ||
1568	    *t_p < s_t || !q->ops->cl_ops ||
1569	    (tcm->tcm_parent &&
1570	     TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1571		(*t_p)++;
1572		return 0;
1573	}
1574	if (*t_p > s_t)
1575		memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1576	arg.w.fn = qdisc_class_dump;
1577	arg.skb = skb;
1578	arg.cb = cb;
1579	arg.w.stop  = 0;
1580	arg.w.skip = cb->args[1];
1581	arg.w.count = 0;
1582	q->ops->cl_ops->walk(q, &arg.w);
1583	cb->args[1] = arg.w.count;
1584	if (arg.w.stop)
1585		return -1;
1586	(*t_p)++;
1587	return 0;
1588}
1589
1590static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1591			       struct tcmsg *tcm, struct netlink_callback *cb,
1592			       int *t_p, int s_t)
1593{
1594	struct Qdisc *q;
 
1595
1596	if (!root)
1597		return 0;
1598
1599	if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1600		return -1;
1601
1602	list_for_each_entry(q, &root->list, list) {
 
 
 
 
 
 
 
 
 
 
1603		if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1604			return -1;
1605	}
1606
1607	return 0;
1608}
1609
1610static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1611{
1612	struct tcmsg *tcm = (struct tcmsg *)NLMSG_DATA(cb->nlh);
1613	struct net *net = sock_net(skb->sk);
1614	struct netdev_queue *dev_queue;
1615	struct net_device *dev;
1616	int t, s_t;
1617
1618	if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
1619		return 0;
1620	dev = dev_get_by_index(net, tcm->tcm_ifindex);
1621	if (!dev)
1622		return 0;
1623
1624	s_t = cb->args[0];
1625	t = 0;
1626
1627	if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
 
1628		goto done;
1629
1630	dev_queue = dev_ingress_queue(dev);
1631	if (dev_queue &&
1632	    tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1633				&t, s_t) < 0)
1634		goto done;
1635
1636done:
1637	cb->args[0] = t;
1638
1639	dev_put(dev);
1640	return skb->len;
1641}
1642
1643/* Main classifier routine: scans classifier chain attached
1644 * to this qdisc, (optionally) tests for protocol and asks
1645 * specific classifiers.
1646 */
1647int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
1648		       struct tcf_result *res)
1649{
1650	__be16 protocol = skb->protocol;
1651	int err;
1652
1653	for (; tp; tp = tp->next) {
1654		if (tp->protocol != protocol &&
1655		    tp->protocol != htons(ETH_P_ALL))
1656			continue;
1657		err = tp->classify(skb, tp, res);
1658
1659		if (err >= 0) {
1660#ifdef CONFIG_NET_CLS_ACT
1661			if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
1662				skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
1663#endif
1664			return err;
1665		}
1666	}
1667	return -1;
1668}
1669EXPORT_SYMBOL(tc_classify_compat);
1670
1671int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1672		struct tcf_result *res)
1673{
1674	int err = 0;
1675#ifdef CONFIG_NET_CLS_ACT
1676	const struct tcf_proto *otp = tp;
1677reclassify:
1678#endif
1679
1680	err = tc_classify_compat(skb, tp, res);
1681#ifdef CONFIG_NET_CLS_ACT
1682	if (err == TC_ACT_RECLASSIFY) {
1683		u32 verd = G_TC_VERD(skb->tc_verd);
1684		tp = otp;
1685
1686		if (verd++ >= MAX_REC_LOOP) {
1687			if (net_ratelimit())
1688				pr_notice("%s: packet reclassify loop"
1689					  " rule prio %u protocol %02x\n",
1690					  tp->q->ops->id,
1691					  tp->prio & 0xffff,
1692					  ntohs(tp->protocol));
1693			return TC_ACT_SHOT;
1694		}
1695		skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
1696		goto reclassify;
1697	}
1698#endif
1699	return err;
1700}
1701EXPORT_SYMBOL(tc_classify);
1702
1703void tcf_destroy(struct tcf_proto *tp)
1704{
1705	tp->ops->destroy(tp);
1706	module_put(tp->ops->owner);
1707	kfree(tp);
1708}
1709
1710void tcf_destroy_chain(struct tcf_proto **fl)
1711{
1712	struct tcf_proto *tp;
1713
1714	while ((tp = *fl) != NULL) {
1715		*fl = tp->next;
1716		tcf_destroy(tp);
1717	}
1718}
1719EXPORT_SYMBOL(tcf_destroy_chain);
1720
1721#ifdef CONFIG_PROC_FS
1722static int psched_show(struct seq_file *seq, void *v)
1723{
1724	struct timespec ts;
1725
1726	hrtimer_get_res(CLOCK_MONOTONIC, &ts);
1727	seq_printf(seq, "%08x %08x %08x %08x\n",
1728		   (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1729		   1000000,
1730		   (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
1731
1732	return 0;
1733}
1734
1735static int psched_open(struct inode *inode, struct file *file)
1736{
1737	return single_open(file, psched_show, NULL);
1738}
1739
1740static const struct file_operations psched_fops = {
1741	.owner = THIS_MODULE,
1742	.open = psched_open,
1743	.read  = seq_read,
1744	.llseek = seq_lseek,
1745	.release = single_release,
1746};
1747
1748static int __net_init psched_net_init(struct net *net)
1749{
1750	struct proc_dir_entry *e;
1751
1752	e = proc_net_fops_create(net, "psched", 0, &psched_fops);
1753	if (e == NULL)
1754		return -ENOMEM;
1755
1756	return 0;
1757}
1758
1759static void __net_exit psched_net_exit(struct net *net)
1760{
1761	proc_net_remove(net, "psched");
1762}
1763#else
1764static int __net_init psched_net_init(struct net *net)
1765{
1766	return 0;
1767}
1768
1769static void __net_exit psched_net_exit(struct net *net)
1770{
1771}
1772#endif
1773
1774static struct pernet_operations psched_net_ops = {
1775	.init = psched_net_init,
1776	.exit = psched_net_exit,
1777};
1778
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1779static int __init pktsched_init(void)
1780{
1781	int err;
1782
1783	err = register_pernet_subsys(&psched_net_ops);
1784	if (err) {
1785		pr_err("pktsched_init: "
1786		       "cannot initialize per netns operations\n");
1787		return err;
1788	}
1789
 
1790	register_qdisc(&pfifo_qdisc_ops);
1791	register_qdisc(&bfifo_qdisc_ops);
1792	register_qdisc(&pfifo_head_drop_qdisc_ops);
1793	register_qdisc(&mq_qdisc_ops);
 
 
 
1794
1795	rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1796	rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1797	rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1798	rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1799	rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1800	rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1801
1802	return 0;
1803}
1804
1805subsys_initcall(pktsched_init);
v6.13.7
   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#include <net/tc_wrapper.h>
  35
  36#include <trace/events/qdisc.h>
 
 
 
 
 
  37
  38/*
  39
  40   Short review.
  41   -------------
  42
  43   This file consists of two interrelated parts:
  44
  45   1. queueing disciplines manager frontend.
  46   2. traffic classes manager frontend.
  47
  48   Generally, queueing discipline ("qdisc") is a black box,
  49   which is able to enqueue packets and to dequeue them (when
  50   device is ready to send something) in order and at times
  51   determined by algorithm hidden in it.
  52
  53   qdisc's are divided to two categories:
  54   - "queues", which have no internal structure visible from outside.
  55   - "schedulers", which split all the packets to "traffic classes",
  56     using "packet classifiers" (look at cls_api.c)
  57
  58   In turn, classes may have child qdiscs (as rule, queues)
  59   attached to them etc. etc. etc.
  60
  61   The goal of the routines in this file is to translate
  62   information supplied by user in the form of handles
  63   to more intelligible for kernel form, to make some sanity
  64   checks and part of work, which is common to all qdiscs
  65   and to provide rtnetlink notifications.
  66
  67   All real intelligent work is done inside qdisc modules.
  68
  69
  70
  71   Every discipline has two major routines: enqueue and dequeue.
  72
  73   ---dequeue
  74
  75   dequeue usually returns a skb to send. It is allowed to return NULL,
  76   but it does not mean that queue is empty, it just means that
  77   discipline does not want to send anything this time.
  78   Queue is really empty if q->q.qlen == 0.
  79   For complicated disciplines with multiple queues q->q is not
  80   real packet queue, but however q->q.qlen must be valid.
  81
  82   ---enqueue
  83
  84   enqueue returns 0, if packet was enqueued successfully.
  85   If packet (this one or another one) was dropped, it returns
  86   not zero error code.
  87   NET_XMIT_DROP 	- this packet dropped
  88     Expected action: do not backoff, but wait until queue will clear.
  89   NET_XMIT_CN	 	- probably this packet enqueued, but another one dropped.
  90     Expected action: backoff or ignore
 
 
  91
  92   Auxiliary routines:
  93
  94   ---peek
  95
  96   like dequeue but without removing a packet from the queue
  97
  98   ---reset
  99
 100   returns qdisc to initial state: purge all buffers, clear all
 101   timers, counters (except for statistics) etc.
 102
 103   ---init
 104
 105   initializes newly created qdisc.
 106
 107   ---destroy
 108
 109   destroys resources allocated by init and during lifetime of qdisc.
 110
 111   ---change
 112
 113   changes qdisc parameters.
 114 */
 115
 116/* Protects list of registered TC modules. It is pure SMP lock. */
 117static DEFINE_RWLOCK(qdisc_mod_lock);
 118
 119
 120/************************************************
 121 *	Queueing disciplines manipulation.	*
 122 ************************************************/
 123
 124
 125/* The list of all installed queueing disciplines. */
 126
 127static struct Qdisc_ops *qdisc_base;
 128
 129/* Register/unregister queueing discipline */
 130
 131int register_qdisc(struct Qdisc_ops *qops)
 132{
 133	struct Qdisc_ops *q, **qp;
 134	int rc = -EEXIST;
 135
 136	write_lock(&qdisc_mod_lock);
 137	for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
 138		if (!strcmp(qops->id, q->id))
 139			goto out;
 140
 141	if (qops->enqueue == NULL)
 142		qops->enqueue = noop_qdisc_ops.enqueue;
 143	if (qops->peek == NULL) {
 144		if (qops->dequeue == NULL)
 145			qops->peek = noop_qdisc_ops.peek;
 146		else
 147			goto out_einval;
 148	}
 149	if (qops->dequeue == NULL)
 150		qops->dequeue = noop_qdisc_ops.dequeue;
 151
 152	if (qops->cl_ops) {
 153		const struct Qdisc_class_ops *cops = qops->cl_ops;
 154
 155		if (!(cops->find && cops->walk && cops->leaf))
 156			goto out_einval;
 157
 158		if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf))
 159			goto out_einval;
 160	}
 161
 162	qops->next = NULL;
 163	*qp = qops;
 164	rc = 0;
 165out:
 166	write_unlock(&qdisc_mod_lock);
 167	return rc;
 168
 169out_einval:
 170	rc = -EINVAL;
 171	goto out;
 172}
 173EXPORT_SYMBOL(register_qdisc);
 174
 175void unregister_qdisc(struct Qdisc_ops *qops)
 176{
 177	struct Qdisc_ops *q, **qp;
 178	int err = -ENOENT;
 179
 180	write_lock(&qdisc_mod_lock);
 181	for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next)
 182		if (q == qops)
 183			break;
 184	if (q) {
 185		*qp = q->next;
 186		q->next = NULL;
 187		err = 0;
 188	}
 189	write_unlock(&qdisc_mod_lock);
 190
 191	WARN(err, "unregister qdisc(%s) failed\n", qops->id);
 192}
 193EXPORT_SYMBOL(unregister_qdisc);
 194
 195/* Get default qdisc if not otherwise specified */
 196void qdisc_get_default(char *name, size_t len)
 197{
 198	read_lock(&qdisc_mod_lock);
 199	strscpy(name, default_qdisc_ops->id, len);
 200	read_unlock(&qdisc_mod_lock);
 201}
 202
 203static struct Qdisc_ops *qdisc_lookup_default(const char *name)
 204{
 205	struct Qdisc_ops *q = NULL;
 206
 207	for (q = qdisc_base; q; q = q->next) {
 208		if (!strcmp(name, q->id)) {
 209			if (!try_module_get(q->owner))
 210				q = NULL;
 211			break;
 212		}
 213	}
 214
 215	return q;
 216}
 217
 218/* Set new default qdisc to use */
 219int qdisc_set_default(const char *name)
 220{
 221	const struct Qdisc_ops *ops;
 222
 223	if (!capable(CAP_NET_ADMIN))
 224		return -EPERM;
 225
 226	write_lock(&qdisc_mod_lock);
 227	ops = qdisc_lookup_default(name);
 228	if (!ops) {
 229		/* Not found, drop lock and try to load module */
 230		write_unlock(&qdisc_mod_lock);
 231		request_module(NET_SCH_ALIAS_PREFIX "%s", name);
 232		write_lock(&qdisc_mod_lock);
 233
 234		ops = qdisc_lookup_default(name);
 235	}
 236
 237	if (ops) {
 238		/* Set new default */
 239		module_put(default_qdisc_ops->owner);
 240		default_qdisc_ops = ops;
 241	}
 242	write_unlock(&qdisc_mod_lock);
 243
 244	return ops ? 0 : -ENOENT;
 245}
 246
 247#ifdef CONFIG_NET_SCH_DEFAULT
 248/* Set default value from kernel config */
 249static int __init sch_default_qdisc(void)
 250{
 251	return qdisc_set_default(CONFIG_DEFAULT_NET_SCH);
 252}
 253late_initcall(sch_default_qdisc);
 254#endif
 255
 256/* We know handle. Find qdisc among all qdisc's attached to device
 257 * (root qdisc, all its children, children of children etc.)
 258 * Note: caller either uses rtnl or rcu_read_lock()
 259 */
 260
 261static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
 262{
 263	struct Qdisc *q;
 264
 265	if (!qdisc_dev(root))
 266		return (root->handle == handle ? root : NULL);
 267
 268	if (!(root->flags & TCQ_F_BUILTIN) &&
 269	    root->handle == handle)
 270		return root;
 271
 272	hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle,
 273				   lockdep_rtnl_is_held()) {
 274		if (q->handle == handle)
 275			return q;
 276	}
 277	return NULL;
 278}
 279
 280void qdisc_hash_add(struct Qdisc *q, bool invisible)
 281{
 282	if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
 283		ASSERT_RTNL();
 284		hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle);
 285		if (invisible)
 286			q->flags |= TCQ_F_INVISIBLE;
 287	}
 288}
 289EXPORT_SYMBOL(qdisc_hash_add);
 290
 291void qdisc_hash_del(struct Qdisc *q)
 292{
 293	if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
 294		ASSERT_RTNL();
 295		hash_del_rcu(&q->hash);
 296	}
 297}
 298EXPORT_SYMBOL(qdisc_hash_del);
 299
 300struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
 301{
 302	struct Qdisc *q;
 303
 304	if (!handle)
 305		return NULL;
 306	q = qdisc_match_from_root(rtnl_dereference(dev->qdisc), handle);
 307	if (q)
 308		goto out;
 309
 310	if (dev_ingress_queue(dev))
 311		q = qdisc_match_from_root(
 312			rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping),
 313			handle);
 314out:
 315	return q;
 316}
 317
 318struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle)
 319{
 320	struct netdev_queue *nq;
 321	struct Qdisc *q;
 322
 323	if (!handle)
 324		return NULL;
 325	q = qdisc_match_from_root(rcu_dereference(dev->qdisc), handle);
 326	if (q)
 327		goto out;
 328
 329	nq = dev_ingress_queue_rcu(dev);
 330	if (nq)
 331		q = qdisc_match_from_root(rcu_dereference(nq->qdisc_sleeping),
 332					  handle);
 333out:
 334	return q;
 335}
 336
 337static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
 338{
 339	unsigned long cl;
 
 340	const struct Qdisc_class_ops *cops = p->ops->cl_ops;
 341
 342	if (cops == NULL)
 343		return NULL;
 344	cl = cops->find(p, classid);
 345
 346	if (cl == 0)
 347		return NULL;
 348	return cops->leaf(p, cl);
 
 
 349}
 350
 351/* Find queueing discipline by name */
 352
 353static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
 354{
 355	struct Qdisc_ops *q = NULL;
 356
 357	if (kind) {
 358		read_lock(&qdisc_mod_lock);
 359		for (q = qdisc_base; q; q = q->next) {
 360			if (nla_strcmp(kind, q->id) == 0) {
 361				if (!try_module_get(q->owner))
 362					q = NULL;
 363				break;
 364			}
 365		}
 366		read_unlock(&qdisc_mod_lock);
 367	}
 368	return q;
 369}
 370
 371/* The linklayer setting were not transferred from iproute2, in older
 372 * versions, and the rate tables lookup systems have been dropped in
 373 * the kernel. To keep backward compatible with older iproute2 tc
 374 * utils, we detect the linklayer setting by detecting if the rate
 375 * table were modified.
 376 *
 377 * For linklayer ATM table entries, the rate table will be aligned to
 378 * 48 bytes, thus some table entries will contain the same value.  The
 379 * mpu (min packet unit) is also encoded into the old rate table, thus
 380 * starting from the mpu, we find low and high table entries for
 381 * mapping this cell.  If these entries contain the same value, when
 382 * the rate tables have been modified for linklayer ATM.
 383 *
 384 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
 385 * and then roundup to the next cell, calc the table entry one below,
 386 * and compare.
 387 */
 388static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
 389{
 390	int low       = roundup(r->mpu, 48);
 391	int high      = roundup(low+1, 48);
 392	int cell_low  = low >> r->cell_log;
 393	int cell_high = (high >> r->cell_log) - 1;
 394
 395	/* rtab is too inaccurate at rates > 100Mbit/s */
 396	if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
 397		pr_debug("TC linklayer: Giving up ATM detection\n");
 398		return TC_LINKLAYER_ETHERNET;
 399	}
 400
 401	if ((cell_high > cell_low) && (cell_high < 256)
 402	    && (rtab[cell_low] == rtab[cell_high])) {
 403		pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
 404			 cell_low, cell_high, rtab[cell_high]);
 405		return TC_LINKLAYER_ATM;
 406	}
 407	return TC_LINKLAYER_ETHERNET;
 408}
 409
 410static struct qdisc_rate_table *qdisc_rtab_list;
 411
 412struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
 413					struct nlattr *tab,
 414					struct netlink_ext_ack *extack)
 415{
 416	struct qdisc_rate_table *rtab;
 417
 418	if (tab == NULL || r->rate == 0 ||
 419	    r->cell_log == 0 || r->cell_log >= 32 ||
 420	    nla_len(tab) != TC_RTAB_SIZE) {
 421		NL_SET_ERR_MSG(extack, "Invalid rate table parameters for searching");
 422		return NULL;
 423	}
 424
 425	for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
 426		if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
 427		    !memcmp(&rtab->data, nla_data(tab), 1024)) {
 428			rtab->refcnt++;
 429			return rtab;
 430		}
 431	}
 432
 
 
 
 
 433	rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
 434	if (rtab) {
 435		rtab->rate = *r;
 436		rtab->refcnt = 1;
 437		memcpy(rtab->data, nla_data(tab), 1024);
 438		if (r->linklayer == TC_LINKLAYER_UNAWARE)
 439			r->linklayer = __detect_linklayer(r, rtab->data);
 440		rtab->next = qdisc_rtab_list;
 441		qdisc_rtab_list = rtab;
 442	} else {
 443		NL_SET_ERR_MSG(extack, "Failed to allocate new qdisc rate table");
 444	}
 445	return rtab;
 446}
 447EXPORT_SYMBOL(qdisc_get_rtab);
 448
 449void qdisc_put_rtab(struct qdisc_rate_table *tab)
 450{
 451	struct qdisc_rate_table *rtab, **rtabp;
 452
 453	if (!tab || --tab->refcnt)
 454		return;
 455
 456	for (rtabp = &qdisc_rtab_list;
 457	     (rtab = *rtabp) != NULL;
 458	     rtabp = &rtab->next) {
 459		if (rtab == tab) {
 460			*rtabp = rtab->next;
 461			kfree(rtab);
 462			return;
 463		}
 464	}
 465}
 466EXPORT_SYMBOL(qdisc_put_rtab);
 467
 468static LIST_HEAD(qdisc_stab_list);
 
 469
 470static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
 471	[TCA_STAB_BASE]	= { .len = sizeof(struct tc_sizespec) },
 472	[TCA_STAB_DATA] = { .type = NLA_BINARY },
 473};
 474
 475static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt,
 476					       struct netlink_ext_ack *extack)
 477{
 478	struct nlattr *tb[TCA_STAB_MAX + 1];
 479	struct qdisc_size_table *stab;
 480	struct tc_sizespec *s;
 481	unsigned int tsize = 0;
 482	u16 *tab = NULL;
 483	int err;
 484
 485	err = nla_parse_nested_deprecated(tb, TCA_STAB_MAX, opt, stab_policy,
 486					  extack);
 487	if (err < 0)
 488		return ERR_PTR(err);
 489	if (!tb[TCA_STAB_BASE]) {
 490		NL_SET_ERR_MSG(extack, "Size table base attribute is missing");
 491		return ERR_PTR(-EINVAL);
 492	}
 493
 494	s = nla_data(tb[TCA_STAB_BASE]);
 495
 496	if (s->tsize > 0) {
 497		if (!tb[TCA_STAB_DATA]) {
 498			NL_SET_ERR_MSG(extack, "Size table data attribute is missing");
 499			return ERR_PTR(-EINVAL);
 500		}
 501		tab = nla_data(tb[TCA_STAB_DATA]);
 502		tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
 503	}
 504
 505	if (tsize != s->tsize || (!tab && tsize > 0)) {
 506		NL_SET_ERR_MSG(extack, "Invalid size of size table");
 507		return ERR_PTR(-EINVAL);
 508	}
 
 509
 510	list_for_each_entry(stab, &qdisc_stab_list, list) {
 511		if (memcmp(&stab->szopts, s, sizeof(*s)))
 512			continue;
 513		if (tsize > 0 &&
 514		    memcmp(stab->data, tab, flex_array_size(stab, data, tsize)))
 515			continue;
 516		stab->refcnt++;
 
 517		return stab;
 518	}
 519
 520	if (s->size_log > STAB_SIZE_LOG_MAX ||
 521	    s->cell_log > STAB_SIZE_LOG_MAX) {
 522		NL_SET_ERR_MSG(extack, "Invalid logarithmic size of size table");
 523		return ERR_PTR(-EINVAL);
 524	}
 525
 526	stab = kmalloc(struct_size(stab, data, tsize), GFP_KERNEL);
 527	if (!stab)
 528		return ERR_PTR(-ENOMEM);
 529
 530	stab->refcnt = 1;
 531	stab->szopts = *s;
 532	if (tsize > 0)
 533		memcpy(stab->data, tab, flex_array_size(stab, data, tsize));
 534
 
 535	list_add_tail(&stab->list, &qdisc_stab_list);
 
 536
 537	return stab;
 538}
 539
 
 
 
 
 
 540void qdisc_put_stab(struct qdisc_size_table *tab)
 541{
 542	if (!tab)
 543		return;
 544
 
 
 545	if (--tab->refcnt == 0) {
 546		list_del(&tab->list);
 547		kfree_rcu(tab, rcu);
 548	}
 
 
 549}
 550EXPORT_SYMBOL(qdisc_put_stab);
 551
 552static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
 553{
 554	struct nlattr *nest;
 555
 556	nest = nla_nest_start_noflag(skb, TCA_STAB);
 557	if (nest == NULL)
 558		goto nla_put_failure;
 559	if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
 560		goto nla_put_failure;
 561	nla_nest_end(skb, nest);
 562
 563	return skb->len;
 564
 565nla_put_failure:
 566	return -1;
 567}
 568
 569void __qdisc_calculate_pkt_len(struct sk_buff *skb,
 570			       const struct qdisc_size_table *stab)
 571{
 572	int pkt_len, slot;
 573
 574	pkt_len = skb->len + stab->szopts.overhead;
 575	if (unlikely(!stab->szopts.tsize))
 576		goto out;
 577
 578	slot = pkt_len + stab->szopts.cell_align;
 579	if (unlikely(slot < 0))
 580		slot = 0;
 581
 582	slot >>= stab->szopts.cell_log;
 583	if (likely(slot < stab->szopts.tsize))
 584		pkt_len = stab->data[slot];
 585	else
 586		pkt_len = stab->data[stab->szopts.tsize - 1] *
 587				(slot / stab->szopts.tsize) +
 588				stab->data[slot % stab->szopts.tsize];
 589
 590	pkt_len <<= stab->szopts.size_log;
 591out:
 592	if (unlikely(pkt_len < 1))
 593		pkt_len = 1;
 594	qdisc_skb_cb(skb)->pkt_len = pkt_len;
 595}
 
 596
 597void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
 598{
 599	if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
 600		pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
 601			txt, qdisc->ops->id, qdisc->handle >> 16);
 602		qdisc->flags |= TCQ_F_WARN_NONWC;
 603	}
 604}
 605EXPORT_SYMBOL(qdisc_warn_nonwc);
 606
 607static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
 608{
 609	struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
 610						 timer);
 611
 612	rcu_read_lock();
 613	__netif_schedule(qdisc_root(wd->qdisc));
 614	rcu_read_unlock();
 615
 616	return HRTIMER_NORESTART;
 617}
 618
 619void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
 620				 clockid_t clockid)
 621{
 622	hrtimer_init(&wd->timer, clockid, HRTIMER_MODE_ABS_PINNED);
 623	wd->timer.function = qdisc_watchdog;
 624	wd->qdisc = qdisc;
 625}
 626EXPORT_SYMBOL(qdisc_watchdog_init_clockid);
 627
 628void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
 629{
 630	qdisc_watchdog_init_clockid(wd, qdisc, CLOCK_MONOTONIC);
 631}
 632EXPORT_SYMBOL(qdisc_watchdog_init);
 633
 634void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires,
 635				      u64 delta_ns)
 636{
 637	bool deactivated;
 638
 639	rcu_read_lock();
 640	deactivated = test_bit(__QDISC_STATE_DEACTIVATED,
 641			       &qdisc_root_sleeping(wd->qdisc)->state);
 642	rcu_read_unlock();
 643	if (deactivated)
 644		return;
 645
 646	if (hrtimer_is_queued(&wd->timer)) {
 647		u64 softexpires;
 648
 649		softexpires = ktime_to_ns(hrtimer_get_softexpires(&wd->timer));
 650		/* If timer is already set in [expires, expires + delta_ns],
 651		 * do not reprogram it.
 652		 */
 653		if (softexpires - expires <= delta_ns)
 654			return;
 655	}
 656
 657	hrtimer_start_range_ns(&wd->timer,
 658			       ns_to_ktime(expires),
 659			       delta_ns,
 660			       HRTIMER_MODE_ABS_PINNED);
 661}
 662EXPORT_SYMBOL(qdisc_watchdog_schedule_range_ns);
 663
 664void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
 665{
 666	hrtimer_cancel(&wd->timer);
 
 667}
 668EXPORT_SYMBOL(qdisc_watchdog_cancel);
 669
 670static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
 671{
 
 672	struct hlist_head *h;
 673	unsigned int i;
 674
 675	h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL);
 
 
 
 
 676
 677	if (h != NULL) {
 678		for (i = 0; i < n; i++)
 679			INIT_HLIST_HEAD(&h[i]);
 680	}
 681	return h;
 682}
 683
 
 
 
 
 
 
 
 
 
 
 684void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
 685{
 686	struct Qdisc_class_common *cl;
 687	struct hlist_node *next;
 688	struct hlist_head *nhash, *ohash;
 689	unsigned int nsize, nmask, osize;
 690	unsigned int i, h;
 691
 692	/* Rehash when load factor exceeds 0.75 */
 693	if (clhash->hashelems * 4 <= clhash->hashsize * 3)
 694		return;
 695	nsize = clhash->hashsize * 2;
 696	nmask = nsize - 1;
 697	nhash = qdisc_class_hash_alloc(nsize);
 698	if (nhash == NULL)
 699		return;
 700
 701	ohash = clhash->hash;
 702	osize = clhash->hashsize;
 703
 704	sch_tree_lock(sch);
 705	for (i = 0; i < osize; i++) {
 706		hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
 707			h = qdisc_class_hash(cl->classid, nmask);
 708			hlist_add_head(&cl->hnode, &nhash[h]);
 709		}
 710	}
 711	clhash->hash     = nhash;
 712	clhash->hashsize = nsize;
 713	clhash->hashmask = nmask;
 714	sch_tree_unlock(sch);
 715
 716	kvfree(ohash);
 717}
 718EXPORT_SYMBOL(qdisc_class_hash_grow);
 719
 720int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
 721{
 722	unsigned int size = 4;
 723
 724	clhash->hash = qdisc_class_hash_alloc(size);
 725	if (!clhash->hash)
 726		return -ENOMEM;
 727	clhash->hashsize  = size;
 728	clhash->hashmask  = size - 1;
 729	clhash->hashelems = 0;
 730	return 0;
 731}
 732EXPORT_SYMBOL(qdisc_class_hash_init);
 733
 734void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
 735{
 736	kvfree(clhash->hash);
 737}
 738EXPORT_SYMBOL(qdisc_class_hash_destroy);
 739
 740void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
 741			     struct Qdisc_class_common *cl)
 742{
 743	unsigned int h;
 744
 745	INIT_HLIST_NODE(&cl->hnode);
 746	h = qdisc_class_hash(cl->classid, clhash->hashmask);
 747	hlist_add_head(&cl->hnode, &clhash->hash[h]);
 748	clhash->hashelems++;
 749}
 750EXPORT_SYMBOL(qdisc_class_hash_insert);
 751
 752void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
 753			     struct Qdisc_class_common *cl)
 754{
 755	hlist_del(&cl->hnode);
 756	clhash->hashelems--;
 757}
 758EXPORT_SYMBOL(qdisc_class_hash_remove);
 759
 760/* Allocate an unique handle from space managed by kernel
 761 * Possible range is [8000-FFFF]:0000 (0x8000 values)
 762 */
 763static u32 qdisc_alloc_handle(struct net_device *dev)
 764{
 765	int i = 0x8000;
 766	static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
 767
 768	do {
 769		autohandle += TC_H_MAKE(0x10000U, 0);
 770		if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
 771			autohandle = TC_H_MAKE(0x80000000U, 0);
 772		if (!qdisc_lookup(dev, autohandle))
 773			return autohandle;
 774		cond_resched();
 775	} while	(--i > 0);
 776
 777	return 0;
 778}
 779
 780void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len)
 781{
 782	bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED;
 783	const struct Qdisc_class_ops *cops;
 784	unsigned long cl;
 785	u32 parentid;
 786	bool notify;
 787	int drops;
 788
 789	if (n == 0 && len == 0)
 790		return;
 791	drops = max_t(int, n, 0);
 792	rcu_read_lock();
 793	while ((parentid = sch->parent)) {
 794		if (parentid == TC_H_ROOT)
 795			break;
 796
 797		if (sch->flags & TCQ_F_NOPARENT)
 798			break;
 799		/* Notify parent qdisc only if child qdisc becomes empty.
 800		 *
 801		 * If child was empty even before update then backlog
 802		 * counter is screwed and we skip notification because
 803		 * parent class is already passive.
 804		 *
 805		 * If the original child was offloaded then it is allowed
 806		 * to be seem as empty, so the parent is notified anyway.
 807		 */
 808		notify = !sch->q.qlen && !WARN_ON_ONCE(!n &&
 809						       !qdisc_is_offloaded);
 810		/* TODO: perform the search on a per txq basis */
 811		sch = qdisc_lookup_rcu(qdisc_dev(sch), TC_H_MAJ(parentid));
 812		if (sch == NULL) {
 813			WARN_ON_ONCE(parentid != TC_H_ROOT);
 814			break;
 815		}
 816		cops = sch->ops->cl_ops;
 817		if (notify && cops->qlen_notify) {
 818			cl = cops->find(sch, parentid);
 819			cops->qlen_notify(sch, cl);
 
 820		}
 821		sch->q.qlen -= n;
 822		sch->qstats.backlog -= len;
 823		__qdisc_qstats_drop(sch, drops);
 824	}
 825	rcu_read_unlock();
 826}
 827EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
 828
 829int qdisc_offload_dump_helper(struct Qdisc *sch, enum tc_setup_type type,
 830			      void *type_data)
 831{
 832	struct net_device *dev = qdisc_dev(sch);
 833	int err;
 834
 835	sch->flags &= ~TCQ_F_OFFLOADED;
 836	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
 837		return 0;
 838
 839	err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
 840	if (err == -EOPNOTSUPP)
 841		return 0;
 842
 843	if (!err)
 844		sch->flags |= TCQ_F_OFFLOADED;
 845
 846	return err;
 847}
 848EXPORT_SYMBOL(qdisc_offload_dump_helper);
 849
 850void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
 851				struct Qdisc *new, struct Qdisc *old,
 852				enum tc_setup_type type, void *type_data,
 853				struct netlink_ext_ack *extack)
 854{
 855	bool any_qdisc_is_offloaded;
 856	int err;
 857
 858	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
 859		return;
 860
 861	err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
 862
 863	/* Don't report error if the graft is part of destroy operation. */
 864	if (!err || !new || new == &noop_qdisc)
 865		return;
 866
 867	/* Don't report error if the parent, the old child and the new
 868	 * one are not offloaded.
 869	 */
 870	any_qdisc_is_offloaded = new->flags & TCQ_F_OFFLOADED;
 871	any_qdisc_is_offloaded |= sch && sch->flags & TCQ_F_OFFLOADED;
 872	any_qdisc_is_offloaded |= old && old->flags & TCQ_F_OFFLOADED;
 873
 874	if (any_qdisc_is_offloaded)
 875		NL_SET_ERR_MSG(extack, "Offloading graft operation failed.");
 876}
 877EXPORT_SYMBOL(qdisc_offload_graft_helper);
 878
 879void qdisc_offload_query_caps(struct net_device *dev,
 880			      enum tc_setup_type type,
 881			      void *caps, size_t caps_len)
 882{
 883	const struct net_device_ops *ops = dev->netdev_ops;
 884	struct tc_query_caps_base base = {
 885		.type = type,
 886		.caps = caps,
 887	};
 888
 889	memset(caps, 0, caps_len);
 890
 891	if (ops->ndo_setup_tc)
 892		ops->ndo_setup_tc(dev, TC_QUERY_CAPS, &base);
 893}
 894EXPORT_SYMBOL(qdisc_offload_query_caps);
 895
 896static void qdisc_offload_graft_root(struct net_device *dev,
 897				     struct Qdisc *new, struct Qdisc *old,
 898				     struct netlink_ext_ack *extack)
 899{
 900	struct tc_root_qopt_offload graft_offload = {
 901		.command	= TC_ROOT_GRAFT,
 902		.handle		= new ? new->handle : 0,
 903		.ingress	= (new && new->flags & TCQ_F_INGRESS) ||
 904				  (old && old->flags & TCQ_F_INGRESS),
 905	};
 906
 907	qdisc_offload_graft_helper(dev, NULL, new, old,
 908				   TC_SETUP_ROOT_QDISC, &graft_offload, extack);
 909}
 910
 911static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
 912			 u32 portid, u32 seq, u16 flags, int event,
 913			 struct netlink_ext_ack *extack)
 914{
 915	struct gnet_stats_basic_sync __percpu *cpu_bstats = NULL;
 916	struct gnet_stats_queue __percpu *cpu_qstats = NULL;
 917	struct tcmsg *tcm;
 918	struct nlmsghdr  *nlh;
 919	unsigned char *b = skb_tail_pointer(skb);
 920	struct gnet_dump d;
 921	struct qdisc_size_table *stab;
 922	u32 block_index;
 923	__u32 qlen;
 924
 925	cond_resched();
 926	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 927	if (!nlh)
 928		goto out_nlmsg_trim;
 929	tcm = nlmsg_data(nlh);
 930	tcm->tcm_family = AF_UNSPEC;
 931	tcm->tcm__pad1 = 0;
 932	tcm->tcm__pad2 = 0;
 933	tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
 934	tcm->tcm_parent = clid;
 935	tcm->tcm_handle = q->handle;
 936	tcm->tcm_info = refcount_read(&q->refcnt);
 937	if (nla_put_string(skb, TCA_KIND, q->ops->id))
 938		goto nla_put_failure;
 939	if (q->ops->ingress_block_get) {
 940		block_index = q->ops->ingress_block_get(q);
 941		if (block_index &&
 942		    nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index))
 943			goto nla_put_failure;
 944	}
 945	if (q->ops->egress_block_get) {
 946		block_index = q->ops->egress_block_get(q);
 947		if (block_index &&
 948		    nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index))
 949			goto nla_put_failure;
 950	}
 951	if (q->ops->dump && q->ops->dump(q, skb) < 0)
 952		goto nla_put_failure;
 953	if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED)))
 954		goto nla_put_failure;
 955	qlen = qdisc_qlen_sum(q);
 956
 957	stab = rtnl_dereference(q->stab);
 958	if (stab && qdisc_dump_stab(skb, stab) < 0)
 959		goto nla_put_failure;
 960
 961	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
 962					 NULL, &d, TCA_PAD) < 0)
 963		goto nla_put_failure;
 964
 965	if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
 966		goto nla_put_failure;
 967
 968	if (qdisc_is_percpu_stats(q)) {
 969		cpu_bstats = q->cpu_bstats;
 970		cpu_qstats = q->cpu_qstats;
 971	}
 972
 973	if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats, true) < 0 ||
 974	    gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
 975	    gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
 976		goto nla_put_failure;
 977
 978	if (gnet_stats_finish_copy(&d) < 0)
 979		goto nla_put_failure;
 980
 981	if (extack && extack->_msg &&
 982	    nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
 983		goto out_nlmsg_trim;
 984
 985	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 986
 987	return skb->len;
 988
 989out_nlmsg_trim:
 990nla_put_failure:
 991	nlmsg_trim(skb, b);
 992	return -1;
 993}
 994
 995static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible)
 996{
 997	if (q->flags & TCQ_F_BUILTIN)
 998		return true;
 999	if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible)
1000		return true;
1001
1002	return false;
1003}
1004
1005static int qdisc_get_notify(struct net *net, struct sk_buff *oskb,
1006			    struct nlmsghdr *n, u32 clid, struct Qdisc *q,
1007			    struct netlink_ext_ack *extack)
1008{
1009	struct sk_buff *skb;
1010	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1011
1012	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1013	if (!skb)
1014		return -ENOBUFS;
1015
1016	if (!tc_qdisc_dump_ignore(q, false)) {
1017		if (tc_fill_qdisc(skb, q, clid, portid, n->nlmsg_seq, 0,
1018				  RTM_NEWQDISC, extack) < 0)
1019			goto err_out;
1020	}
1021
1022	if (skb->len)
1023		return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1024				      n->nlmsg_flags & NLM_F_ECHO);
1025
1026err_out:
1027	kfree_skb(skb);
1028	return -EINVAL;
1029}
1030
1031static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1032			struct nlmsghdr *n, u32 clid,
1033			struct Qdisc *old, struct Qdisc *new,
1034			struct netlink_ext_ack *extack)
1035{
1036	struct sk_buff *skb;
1037	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1038
1039	if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
1040		return 0;
1041
1042	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1043	if (!skb)
1044		return -ENOBUFS;
1045
1046	if (old && !tc_qdisc_dump_ignore(old, false)) {
1047		if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1048				  0, RTM_DELQDISC, extack) < 0)
1049			goto err_out;
1050	}
1051	if (new && !tc_qdisc_dump_ignore(new, false)) {
1052		if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1053				  old ? NLM_F_REPLACE : 0, RTM_NEWQDISC, extack) < 0)
1054			goto err_out;
1055	}
1056
1057	if (skb->len)
1058		return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1059				      n->nlmsg_flags & NLM_F_ECHO);
1060
1061err_out:
1062	kfree_skb(skb);
1063	return -EINVAL;
1064}
 
1065
1066static void notify_and_destroy(struct net *net, struct sk_buff *skb,
1067			       struct nlmsghdr *n, u32 clid,
1068			       struct Qdisc *old, struct Qdisc *new,
1069			       struct netlink_ext_ack *extack)
1070{
1071	if (new || old)
1072		qdisc_notify(net, skb, n, clid, old, new, extack);
1073
1074	if (old)
1075		qdisc_put(old);
1076}
1077
1078static void qdisc_clear_nolock(struct Qdisc *sch)
1079{
1080	sch->flags &= ~TCQ_F_NOLOCK;
1081	if (!(sch->flags & TCQ_F_CPUSTATS))
1082		return;
1083
1084	free_percpu(sch->cpu_bstats);
1085	free_percpu(sch->cpu_qstats);
1086	sch->cpu_bstats = NULL;
1087	sch->cpu_qstats = NULL;
1088	sch->flags &= ~TCQ_F_CPUSTATS;
1089}
1090
1091/* Graft qdisc "new" to class "classid" of qdisc "parent" or
1092 * to device "dev".
1093 *
1094 * When appropriate send a netlink notification using 'skb'
1095 * and "n".
1096 *
1097 * On success, destroy old qdisc.
1098 */
1099
1100static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
1101		       struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
1102		       struct Qdisc *new, struct Qdisc *old,
1103		       struct netlink_ext_ack *extack)
1104{
1105	struct Qdisc *q = old;
1106	struct net *net = dev_net(dev);
 
1107
1108	if (parent == NULL) {
1109		unsigned int i, num_q, ingress;
1110		struct netdev_queue *dev_queue;
1111
1112		ingress = 0;
1113		num_q = dev->num_tx_queues;
1114		if ((q && q->flags & TCQ_F_INGRESS) ||
1115		    (new && new->flags & TCQ_F_INGRESS)) {
 
1116			ingress = 1;
1117			dev_queue = dev_ingress_queue(dev);
1118			if (!dev_queue) {
1119				NL_SET_ERR_MSG(extack, "Device does not have an ingress queue");
1120				return -ENOENT;
1121			}
1122
1123			q = rtnl_dereference(dev_queue->qdisc_sleeping);
1124
1125			/* This is the counterpart of that qdisc_refcount_inc_nz() call in
1126			 * __tcf_qdisc_find() for filter requests.
1127			 */
1128			if (!qdisc_refcount_dec_if_one(q)) {
1129				NL_SET_ERR_MSG(extack,
1130					       "Current ingress or clsact Qdisc has ongoing filter requests");
1131				return -EBUSY;
1132			}
1133		}
1134
1135		if (dev->flags & IFF_UP)
1136			dev_deactivate(dev);
1137
1138		qdisc_offload_graft_root(dev, new, old, extack);
 
 
 
1139
1140		if (new && new->ops->attach && !ingress)
1141			goto skip;
1142
1143		if (!ingress) {
1144			for (i = 0; i < num_q; i++) {
1145				dev_queue = netdev_get_tx_queue(dev, i);
1146				old = dev_graft_qdisc(dev_queue, new);
1147
1148				if (new && i > 0)
1149					qdisc_refcount_inc(new);
1150				qdisc_put(old);
1151			}
1152		} else {
1153			old = dev_graft_qdisc(dev_queue, NULL);
1154
1155			/* {ingress,clsact}_destroy() @old before grafting @new to avoid
1156			 * unprotected concurrent accesses to net_device::miniq_{in,e}gress
1157			 * pointer(s) in mini_qdisc_pair_swap().
1158			 */
1159			qdisc_notify(net, skb, n, classid, old, new, extack);
1160			qdisc_destroy(old);
1161
1162			dev_graft_qdisc(dev_queue, new);
1163		}
1164
1165skip:
1166		if (!ingress) {
1167			old = rtnl_dereference(dev->qdisc);
 
1168			if (new && !new->ops->attach)
1169				qdisc_refcount_inc(new);
1170			rcu_assign_pointer(dev->qdisc, new ? : &noop_qdisc);
1171
1172			notify_and_destroy(net, skb, n, classid, old, new, extack);
1173
1174			if (new && new->ops->attach)
1175				new->ops->attach(new);
1176		}
1177
1178		if (dev->flags & IFF_UP)
1179			dev_activate(dev);
1180	} else {
1181		const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
1182		unsigned long cl;
1183		int err;
1184
1185		/* Only support running class lockless if parent is lockless */
1186		if (new && (new->flags & TCQ_F_NOLOCK) && !(parent->flags & TCQ_F_NOLOCK))
1187			qdisc_clear_nolock(new);
1188
1189		if (!cops || !cops->graft)
1190			return -EOPNOTSUPP;
1191
1192		cl = cops->find(parent, classid);
1193		if (!cl) {
1194			NL_SET_ERR_MSG(extack, "Specified class not found");
1195			return -ENOENT;
1196		}
1197
1198		if (new && new->ops == &noqueue_qdisc_ops) {
1199			NL_SET_ERR_MSG(extack, "Cannot assign noqueue to a class");
1200			return -EINVAL;
1201		}
1202
1203		if (new &&
1204		    !(parent->flags & TCQ_F_MQROOT) &&
1205		    rcu_access_pointer(new->stab)) {
1206			NL_SET_ERR_MSG(extack, "STAB not supported on a non root");
1207			return -EINVAL;
1208		}
1209		err = cops->graft(parent, cl, new, &old, extack);
1210		if (err)
1211			return err;
1212		notify_and_destroy(net, skb, n, classid, old, new, extack);
1213	}
1214	return 0;
1215}
1216
1217static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca,
1218				   struct netlink_ext_ack *extack)
1219{
1220	u32 block_index;
1221
1222	if (tca[TCA_INGRESS_BLOCK]) {
1223		block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]);
1224
1225		if (!block_index) {
1226			NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0");
1227			return -EINVAL;
1228		}
1229		if (!sch->ops->ingress_block_set) {
1230			NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported");
1231			return -EOPNOTSUPP;
1232		}
1233		sch->ops->ingress_block_set(sch, block_index);
1234	}
1235	if (tca[TCA_EGRESS_BLOCK]) {
1236		block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]);
1237
1238		if (!block_index) {
1239			NL_SET_ERR_MSG(extack, "Egress block index cannot be 0");
1240			return -EINVAL;
1241		}
1242		if (!sch->ops->egress_block_set) {
1243			NL_SET_ERR_MSG(extack, "Egress block sharing is not supported");
1244			return -EOPNOTSUPP;
1245		}
1246		sch->ops->egress_block_set(sch, block_index);
1247	}
1248	return 0;
1249}
1250
1251/*
1252   Allocate and initialize new qdisc.
1253
1254   Parameters are passed via opt.
1255 */
1256
1257static struct Qdisc *qdisc_create(struct net_device *dev,
1258				  struct netdev_queue *dev_queue,
1259				  u32 parent, u32 handle,
1260				  struct nlattr **tca, int *errp,
1261				  struct netlink_ext_ack *extack)
1262{
1263	int err;
1264	struct nlattr *kind = tca[TCA_KIND];
1265	struct Qdisc *sch;
1266	struct Qdisc_ops *ops;
1267	struct qdisc_size_table *stab;
1268
1269	ops = qdisc_lookup_ops(kind);
1270#ifdef CONFIG_MODULES
1271	if (ops == NULL && kind != NULL) {
1272		char name[IFNAMSIZ];
1273		if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) {
1274			/* We dropped the RTNL semaphore in order to
1275			 * perform the module load.  So, even if we
1276			 * succeeded in loading the module we have to
1277			 * tell the caller to replay the request.  We
1278			 * indicate this using -EAGAIN.
1279			 * We replay the request because the device may
1280			 * go away in the mean time.
1281			 */
1282			rtnl_unlock();
1283			request_module(NET_SCH_ALIAS_PREFIX "%s", name);
1284			rtnl_lock();
1285			ops = qdisc_lookup_ops(kind);
1286			if (ops != NULL) {
1287				/* We will try again qdisc_lookup_ops,
1288				 * so don't keep a reference.
1289				 */
1290				module_put(ops->owner);
1291				err = -EAGAIN;
1292				goto err_out;
1293			}
1294		}
1295	}
1296#endif
1297
1298	err = -ENOENT;
1299	if (!ops) {
1300		NL_SET_ERR_MSG(extack, "Specified qdisc kind is unknown");
1301		goto err_out;
1302	}
1303
1304	sch = qdisc_alloc(dev_queue, ops, extack);
1305	if (IS_ERR(sch)) {
1306		err = PTR_ERR(sch);
1307		goto err_out2;
1308	}
1309
1310	sch->parent = parent;
1311
1312	if (handle == TC_H_INGRESS) {
1313		if (!(sch->flags & TCQ_F_INGRESS)) {
1314			NL_SET_ERR_MSG(extack,
1315				       "Specified parent ID is reserved for ingress and clsact Qdiscs");
1316			err = -EINVAL;
1317			goto err_out3;
1318		}
1319		handle = TC_H_MAKE(TC_H_INGRESS, 0);
 
1320	} else {
1321		if (handle == 0) {
1322			handle = qdisc_alloc_handle(dev);
1323			if (handle == 0) {
1324				NL_SET_ERR_MSG(extack, "Maximum number of qdisc handles was exceeded");
1325				err = -ENOSPC;
1326				goto err_out3;
1327			}
1328		}
1329		if (!netif_is_multiqueue(dev))
1330			sch->flags |= TCQ_F_ONETXQUEUE;
1331	}
1332
1333	sch->handle = handle;
1334
1335	/* This exist to keep backward compatible with a userspace
1336	 * loophole, what allowed userspace to get IFF_NO_QUEUE
1337	 * facility on older kernels by setting tx_queue_len=0 (prior
1338	 * to qdisc init), and then forgot to reinit tx_queue_len
1339	 * before again attaching a qdisc.
1340	 */
1341	if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) {
1342		WRITE_ONCE(dev->tx_queue_len, DEFAULT_TX_QUEUE_LEN);
1343		netdev_info(dev, "Caught tx_queue_len zero misconfig\n");
1344	}
1345
1346	err = qdisc_block_indexes_set(sch, tca, extack);
1347	if (err)
1348		goto err_out3;
1349
1350	if (tca[TCA_STAB]) {
1351		stab = qdisc_get_stab(tca[TCA_STAB], extack);
1352		if (IS_ERR(stab)) {
1353			err = PTR_ERR(stab);
1354			goto err_out3;
1355		}
1356		rcu_assign_pointer(sch->stab, stab);
1357	}
1358
1359	if (ops->init) {
1360		err = ops->init(sch, tca[TCA_OPTIONS], extack);
1361		if (err != 0)
1362			goto err_out4;
1363	}
1364
1365	if (tca[TCA_RATE]) {
1366		err = -EOPNOTSUPP;
1367		if (sch->flags & TCQ_F_MQROOT) {
1368			NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc");
1369			goto err_out4;
1370		}
1371
1372		err = gen_new_estimator(&sch->bstats,
1373					sch->cpu_bstats,
1374					&sch->rate_est,
1375					NULL,
1376					true,
1377					tca[TCA_RATE]);
1378		if (err) {
1379			NL_SET_ERR_MSG(extack, "Failed to generate new estimator");
1380			goto err_out4;
1381		}
1382	}
1383
1384	qdisc_hash_add(sch, false);
1385	trace_qdisc_create(ops, dev, parent);
1386
1387	return sch;
1388
1389err_out4:
1390	/* Even if ops->init() failed, we call ops->destroy()
1391	 * like qdisc_create_dflt().
1392	 */
1393	if (ops->destroy)
1394		ops->destroy(sch);
1395	qdisc_put_stab(rtnl_dereference(sch->stab));
1396err_out3:
1397	lockdep_unregister_key(&sch->root_lock_key);
1398	netdev_put(dev, &sch->dev_tracker);
1399	qdisc_free(sch);
1400err_out2:
1401	module_put(ops->owner);
1402err_out:
1403	*errp = err;
1404	return NULL;
 
 
 
 
 
 
 
 
 
 
1405}
1406
1407static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
1408			struct netlink_ext_ack *extack)
1409{
1410	struct qdisc_size_table *ostab, *stab = NULL;
1411	int err = 0;
1412
1413	if (tca[TCA_OPTIONS]) {
1414		if (!sch->ops->change) {
1415			NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc");
1416			return -EINVAL;
1417		}
1418		if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
1419			NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
1420			return -EOPNOTSUPP;
1421		}
1422		err = sch->ops->change(sch, tca[TCA_OPTIONS], extack);
1423		if (err)
1424			return err;
1425	}
1426
1427	if (tca[TCA_STAB]) {
1428		stab = qdisc_get_stab(tca[TCA_STAB], extack);
1429		if (IS_ERR(stab))
1430			return PTR_ERR(stab);
1431	}
1432
1433	ostab = rtnl_dereference(sch->stab);
1434	rcu_assign_pointer(sch->stab, stab);
1435	qdisc_put_stab(ostab);
1436
1437	if (tca[TCA_RATE]) {
1438		/* NB: ignores errors from replace_estimator
1439		   because change can't be undone. */
1440		if (sch->flags & TCQ_F_MQROOT)
1441			goto out;
1442		gen_replace_estimator(&sch->bstats,
1443				      sch->cpu_bstats,
1444				      &sch->rate_est,
1445				      NULL,
1446				      true,
1447				      tca[TCA_RATE]);
1448	}
1449out:
1450	return 0;
1451}
1452
1453struct check_loop_arg {
1454	struct qdisc_walker	w;
1455	struct Qdisc		*p;
1456	int			depth;
1457};
1458
1459static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1460			 struct qdisc_walker *w);
1461
1462static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1463{
1464	struct check_loop_arg	arg;
1465
1466	if (q->ops->cl_ops == NULL)
1467		return 0;
1468
1469	arg.w.stop = arg.w.skip = arg.w.count = 0;
1470	arg.w.fn = check_loop_fn;
1471	arg.depth = depth;
1472	arg.p = p;
1473	q->ops->cl_ops->walk(q, &arg.w);
1474	return arg.w.stop ? -ELOOP : 0;
1475}
1476
1477static int
1478check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1479{
1480	struct Qdisc *leaf;
1481	const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1482	struct check_loop_arg *arg = (struct check_loop_arg *)w;
1483
1484	leaf = cops->leaf(q, cl);
1485	if (leaf) {
1486		if (leaf == arg->p || arg->depth > 7)
1487			return -ELOOP;
1488		return check_loop(leaf, arg->p, arg->depth + 1);
1489	}
1490	return 0;
1491}
1492
1493const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = {
1494	[TCA_KIND]		= { .type = NLA_STRING },
1495	[TCA_RATE]		= { .type = NLA_BINARY,
1496				    .len = sizeof(struct tc_estimator) },
1497	[TCA_STAB]		= { .type = NLA_NESTED },
1498	[TCA_DUMP_INVISIBLE]	= { .type = NLA_FLAG },
1499	[TCA_CHAIN]		= { .type = NLA_U32 },
1500	[TCA_INGRESS_BLOCK]	= { .type = NLA_U32 },
1501	[TCA_EGRESS_BLOCK]	= { .type = NLA_U32 },
1502};
1503
1504/*
1505 * Delete/get qdisc.
1506 */
1507
1508static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1509			struct netlink_ext_ack *extack)
1510{
1511	struct net *net = sock_net(skb->sk);
1512	struct tcmsg *tcm = nlmsg_data(n);
1513	struct nlattr *tca[TCA_MAX + 1];
1514	struct net_device *dev;
1515	u32 clid;
1516	struct Qdisc *q = NULL;
1517	struct Qdisc *p = NULL;
1518	int err;
1519
1520	err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1521				     rtm_tca_policy, extack);
1522	if (err < 0)
1523		return err;
1524
1525	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1526	if (!dev)
1527		return -ENODEV;
1528
1529	clid = tcm->tcm_parent;
 
 
 
1530	if (clid) {
1531		if (clid != TC_H_ROOT) {
1532			if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1533				p = qdisc_lookup(dev, TC_H_MAJ(clid));
1534				if (!p) {
1535					NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid");
1536					return -ENOENT;
1537				}
1538				q = qdisc_leaf(p, clid);
1539			} else if (dev_ingress_queue(dev)) {
1540				q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping);
1541			}
1542		} else {
1543			q = rtnl_dereference(dev->qdisc);
1544		}
1545		if (!q) {
1546			NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device");
1547			return -ENOENT;
1548		}
1549
1550		if (tcm->tcm_handle && q->handle != tcm->tcm_handle) {
1551			NL_SET_ERR_MSG(extack, "Invalid handle");
1552			return -EINVAL;
1553		}
1554	} else {
1555		q = qdisc_lookup(dev, tcm->tcm_handle);
1556		if (!q) {
1557			NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle");
1558			return -ENOENT;
1559		}
1560	}
1561
1562	if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1563		NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1564		return -EINVAL;
1565	}
1566
1567	if (n->nlmsg_type == RTM_DELQDISC) {
1568		if (!clid) {
1569			NL_SET_ERR_MSG(extack, "Classid cannot be zero");
1570			return -EINVAL;
1571		}
1572		if (q->handle == 0) {
1573			NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero");
1574			return -ENOENT;
1575		}
1576		err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack);
1577		if (err != 0)
1578			return err;
1579	} else {
1580		qdisc_get_notify(net, skb, n, clid, q, NULL);
1581	}
1582	return 0;
1583}
1584
1585static bool req_create_or_replace(struct nlmsghdr *n)
1586{
1587	return (n->nlmsg_flags & NLM_F_CREATE &&
1588		n->nlmsg_flags & NLM_F_REPLACE);
1589}
1590
1591static bool req_create_exclusive(struct nlmsghdr *n)
1592{
1593	return (n->nlmsg_flags & NLM_F_CREATE &&
1594		n->nlmsg_flags & NLM_F_EXCL);
1595}
1596
1597static bool req_change(struct nlmsghdr *n)
1598{
1599	return (!(n->nlmsg_flags & NLM_F_CREATE) &&
1600		!(n->nlmsg_flags & NLM_F_REPLACE) &&
1601		!(n->nlmsg_flags & NLM_F_EXCL));
1602}
1603
1604/*
1605 * Create/change qdisc.
1606 */
1607static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1608			   struct netlink_ext_ack *extack)
1609{
1610	struct net *net = sock_net(skb->sk);
1611	struct tcmsg *tcm;
1612	struct nlattr *tca[TCA_MAX + 1];
1613	struct net_device *dev;
1614	u32 clid;
1615	struct Qdisc *q, *p;
1616	int err;
1617
1618replay:
1619	/* Reinit, just in case something touches this. */
1620	err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1621				     rtm_tca_policy, extack);
1622	if (err < 0)
1623		return err;
1624
1625	tcm = nlmsg_data(n);
1626	clid = tcm->tcm_parent;
1627	q = p = NULL;
1628
1629	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1630	if (!dev)
1631		return -ENODEV;
1632
 
 
 
1633
1634	if (clid) {
1635		if (clid != TC_H_ROOT) {
1636			if (clid != TC_H_INGRESS) {
1637				p = qdisc_lookup(dev, TC_H_MAJ(clid));
1638				if (!p) {
1639					NL_SET_ERR_MSG(extack, "Failed to find specified qdisc");
1640					return -ENOENT;
1641				}
1642				q = qdisc_leaf(p, clid);
1643			} else if (dev_ingress_queue_create(dev)) {
1644				q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping);
1645			}
1646		} else {
1647			q = rtnl_dereference(dev->qdisc);
1648		}
1649
1650		/* It may be default qdisc, ignore it */
1651		if (q && q->handle == 0)
1652			q = NULL;
1653
1654		if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1655			if (tcm->tcm_handle) {
1656				if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) {
1657					NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override");
1658					return -EEXIST;
1659				}
1660				if (TC_H_MIN(tcm->tcm_handle)) {
1661					NL_SET_ERR_MSG(extack, "Invalid minor handle");
1662					return -EINVAL;
1663				}
1664				q = qdisc_lookup(dev, tcm->tcm_handle);
1665				if (!q)
1666					goto create_n_graft;
1667				if (q->parent != tcm->tcm_parent) {
1668					NL_SET_ERR_MSG(extack, "Cannot move an existing qdisc to a different parent");
1669					return -EINVAL;
1670				}
1671				if (n->nlmsg_flags & NLM_F_EXCL) {
1672					NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override");
1673					return -EEXIST;
1674				}
1675				if (tca[TCA_KIND] &&
1676				    nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1677					NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1678					return -EINVAL;
1679				}
1680				if (q->flags & TCQ_F_INGRESS) {
1681					NL_SET_ERR_MSG(extack,
1682						       "Cannot regraft ingress or clsact Qdiscs");
1683					return -EINVAL;
1684				}
1685				if (q == p ||
1686				    (p && check_loop(q, p, 0))) {
1687					NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected");
1688					return -ELOOP;
1689				}
1690				if (clid == TC_H_INGRESS) {
1691					NL_SET_ERR_MSG(extack, "Ingress cannot graft directly");
1692					return -EINVAL;
1693				}
1694				qdisc_refcount_inc(q);
1695				goto graft;
1696			} else {
1697				if (!q)
1698					goto create_n_graft;
1699
1700				/* This magic test requires explanation.
1701				 *
1702				 *   We know, that some child q is already
1703				 *   attached to this parent and have choice:
1704				 *   1) change it or 2) create/graft new one.
1705				 *   If the requested qdisc kind is different
1706				 *   than the existing one, then we choose graft.
1707				 *   If they are the same then this is "change"
1708				 *   operation - just let it fallthrough..
1709				 *
1710				 *   1. We are allowed to create/graft only
1711				 *   if the request is explicitly stating
1712				 *   "please create if it doesn't exist".
1713				 *
1714				 *   2. If the request is to exclusive create
1715				 *   then the qdisc tcm_handle is not expected
1716				 *   to exist, so that we choose create/graft too.
1717				 *
1718				 *   3. The last case is when no flags are set.
1719				 *   This will happen when for example tc
1720				 *   utility issues a "change" command.
1721				 *   Alas, it is sort of hole in API, we
1722				 *   cannot decide what to do unambiguously.
1723				 *   For now we select create/graft.
 
1724				 */
1725				if (tca[TCA_KIND] &&
1726				    nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1727					if (req_create_or_replace(n) ||
1728					    req_create_exclusive(n))
1729						goto create_n_graft;
1730					else if (req_change(n))
1731						goto create_n_graft2;
1732				}
1733			}
1734		}
1735	} else {
1736		if (!tcm->tcm_handle) {
1737			NL_SET_ERR_MSG(extack, "Handle cannot be zero");
1738			return -EINVAL;
1739		}
1740		q = qdisc_lookup(dev, tcm->tcm_handle);
1741	}
1742
1743	/* Change qdisc parameters */
1744	if (!q) {
1745		NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1746		return -ENOENT;
1747	}
1748	if (n->nlmsg_flags & NLM_F_EXCL) {
1749		NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify");
1750		return -EEXIST;
1751	}
1752	if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1753		NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1754		return -EINVAL;
1755	}
1756	err = qdisc_change(q, tca, extack);
1757	if (err == 0)
1758		qdisc_notify(net, skb, n, clid, NULL, q, extack);
1759	return err;
1760
1761create_n_graft:
1762	if (!(n->nlmsg_flags & NLM_F_CREATE)) {
1763		NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag");
1764		return -ENOENT;
1765	}
1766create_n_graft2:
1767	if (clid == TC_H_INGRESS) {
1768		if (dev_ingress_queue(dev)) {
1769			q = qdisc_create(dev, dev_ingress_queue(dev),
1770					 tcm->tcm_parent, tcm->tcm_parent,
1771					 tca, &err, extack);
1772		} else {
1773			NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device");
1774			err = -ENOENT;
1775		}
1776	} else {
1777		struct netdev_queue *dev_queue;
1778
1779		if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1780			dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1781		else if (p)
1782			dev_queue = p->dev_queue;
1783		else
1784			dev_queue = netdev_get_tx_queue(dev, 0);
1785
1786		q = qdisc_create(dev, dev_queue,
1787				 tcm->tcm_parent, tcm->tcm_handle,
1788				 tca, &err, extack);
1789	}
1790	if (q == NULL) {
1791		if (err == -EAGAIN)
1792			goto replay;
1793		return err;
1794	}
1795
1796graft:
1797	err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack);
1798	if (err) {
1799		if (q)
1800			qdisc_put(q);
1801		return err;
1802	}
1803
1804	return 0;
1805}
1806
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1807static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1808			      struct netlink_callback *cb,
1809			      int *q_idx_p, int s_q_idx, bool recur,
1810			      bool dump_invisible)
1811{
1812	int ret = 0, q_idx = *q_idx_p;
1813	struct Qdisc *q;
1814	int b;
1815
1816	if (!root)
1817		return 0;
1818
1819	q = root;
1820	if (q_idx < s_q_idx) {
1821		q_idx++;
1822	} else {
1823		if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1824		    tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1825				  cb->nlh->nlmsg_seq, NLM_F_MULTI,
1826				  RTM_NEWQDISC, NULL) <= 0)
1827			goto done;
1828		q_idx++;
1829	}
1830
1831	/* If dumping singletons, there is no qdisc_dev(root) and the singleton
1832	 * itself has already been dumped.
1833	 *
1834	 * If we've already dumped the top-level (ingress) qdisc above and the global
1835	 * qdisc hashtable, we don't want to hit it again
1836	 */
1837	if (!qdisc_dev(root) || !recur)
1838		goto out;
1839
1840	hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1841		if (q_idx < s_q_idx) {
1842			q_idx++;
1843			continue;
1844		}
1845		if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1846		    tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1847				  cb->nlh->nlmsg_seq, NLM_F_MULTI,
1848				  RTM_NEWQDISC, NULL) <= 0)
1849			goto done;
1850		q_idx++;
1851	}
1852
1853out:
1854	*q_idx_p = q_idx;
1855	return ret;
1856done:
1857	ret = -1;
1858	goto out;
1859}
1860
1861static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1862{
1863	struct net *net = sock_net(skb->sk);
1864	int idx, q_idx;
1865	int s_idx, s_q_idx;
1866	struct net_device *dev;
1867	const struct nlmsghdr *nlh = cb->nlh;
1868	struct nlattr *tca[TCA_MAX + 1];
1869	int err;
1870
1871	s_idx = cb->args[0];
1872	s_q_idx = q_idx = cb->args[1];
1873
 
1874	idx = 0;
1875	ASSERT_RTNL();
1876
1877	err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX,
1878				     rtm_tca_policy, cb->extack);
1879	if (err < 0)
1880		return err;
1881
1882	for_each_netdev(net, dev) {
1883		struct netdev_queue *dev_queue;
1884
1885		if (idx < s_idx)
1886			goto cont;
1887		if (idx > s_idx)
1888			s_q_idx = 0;
1889		q_idx = 0;
1890
1891		if (tc_dump_qdisc_root(rtnl_dereference(dev->qdisc),
1892				       skb, cb, &q_idx, s_q_idx,
1893				       true, tca[TCA_DUMP_INVISIBLE]) < 0)
1894			goto done;
1895
1896		dev_queue = dev_ingress_queue(dev);
1897		if (dev_queue &&
1898		    tc_dump_qdisc_root(rtnl_dereference(dev_queue->qdisc_sleeping),
1899				       skb, cb, &q_idx, s_q_idx, false,
1900				       tca[TCA_DUMP_INVISIBLE]) < 0)
1901			goto done;
1902
1903cont:
1904		idx++;
1905	}
1906
1907done:
 
 
1908	cb->args[0] = idx;
1909	cb->args[1] = q_idx;
1910
1911	return skb->len;
1912}
1913
1914
1915
1916/************************************************
1917 *	Traffic classes manipulation.		*
1918 ************************************************/
1919
1920static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1921			  unsigned long cl, u32 portid, u32 seq, u16 flags,
1922			  int event, struct netlink_ext_ack *extack)
1923{
1924	struct tcmsg *tcm;
1925	struct nlmsghdr  *nlh;
1926	unsigned char *b = skb_tail_pointer(skb);
1927	struct gnet_dump d;
1928	const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1929
1930	cond_resched();
1931	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1932	if (!nlh)
1933		goto out_nlmsg_trim;
1934	tcm = nlmsg_data(nlh);
1935	tcm->tcm_family = AF_UNSPEC;
1936	tcm->tcm__pad1 = 0;
1937	tcm->tcm__pad2 = 0;
1938	tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1939	tcm->tcm_parent = q->handle;
1940	tcm->tcm_handle = q->handle;
1941	tcm->tcm_info = 0;
1942	if (nla_put_string(skb, TCA_KIND, q->ops->id))
1943		goto nla_put_failure;
1944	if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1945		goto nla_put_failure;
1946
1947	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1948					 NULL, &d, TCA_PAD) < 0)
1949		goto nla_put_failure;
1950
1951	if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1952		goto nla_put_failure;
1953
1954	if (gnet_stats_finish_copy(&d) < 0)
1955		goto nla_put_failure;
1956
1957	if (extack && extack->_msg &&
1958	    nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
1959		goto out_nlmsg_trim;
1960
1961	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1962
1963	return skb->len;
1964
1965out_nlmsg_trim:
1966nla_put_failure:
1967	nlmsg_trim(skb, b);
1968	return -1;
1969}
1970
1971static int tclass_notify(struct net *net, struct sk_buff *oskb,
1972			 struct nlmsghdr *n, struct Qdisc *q,
1973			 unsigned long cl, int event, struct netlink_ext_ack *extack)
1974{
1975	struct sk_buff *skb;
1976	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1977
1978	if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC))
1979		return 0;
1980
1981	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1982	if (!skb)
1983		return -ENOBUFS;
1984
1985	if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event, extack) < 0) {
1986		kfree_skb(skb);
1987		return -EINVAL;
1988	}
1989
1990	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1991			      n->nlmsg_flags & NLM_F_ECHO);
1992}
1993
1994static int tclass_get_notify(struct net *net, struct sk_buff *oskb,
1995			     struct nlmsghdr *n, struct Qdisc *q,
1996			     unsigned long cl, struct netlink_ext_ack *extack)
1997{
1998	struct sk_buff *skb;
1999	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2000
2001	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2002	if (!skb)
2003		return -ENOBUFS;
2004
2005	if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, RTM_NEWTCLASS,
2006			   extack) < 0) {
2007		kfree_skb(skb);
2008		return -EINVAL;
2009	}
2010
2011	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2012			      n->nlmsg_flags & NLM_F_ECHO);
2013}
2014
2015static int tclass_del_notify(struct net *net,
2016			     const struct Qdisc_class_ops *cops,
2017			     struct sk_buff *oskb, struct nlmsghdr *n,
2018			     struct Qdisc *q, unsigned long cl,
2019			     struct netlink_ext_ack *extack)
2020{
2021	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2022	struct sk_buff *skb;
2023	int err = 0;
2024
2025	if (!cops->delete)
2026		return -EOPNOTSUPP;
2027
2028	if (rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) {
2029		skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2030		if (!skb)
2031			return -ENOBUFS;
2032
2033		if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0,
2034				   RTM_DELTCLASS, extack) < 0) {
2035			kfree_skb(skb);
2036			return -EINVAL;
2037		}
2038	} else {
2039		skb = NULL;
2040	}
2041
2042	err = cops->delete(q, cl, extack);
2043	if (err) {
2044		kfree_skb(skb);
2045		return err;
2046	}
2047
2048	err = rtnetlink_maybe_send(skb, net, portid, RTNLGRP_TC,
2049				   n->nlmsg_flags & NLM_F_ECHO);
2050	return err;
2051}
2052
2053#ifdef CONFIG_NET_CLS
2054
2055struct tcf_bind_args {
2056	struct tcf_walker w;
2057	unsigned long base;
2058	unsigned long cl;
2059	u32 classid;
2060};
2061
2062static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2063{
2064	struct tcf_bind_args *a = (void *)arg;
2065
2066	if (n && tp->ops->bind_class) {
2067		struct Qdisc *q = tcf_block_q(tp->chain->block);
2068
2069		sch_tree_lock(q);
2070		tp->ops->bind_class(n, a->classid, a->cl, q, a->base);
2071		sch_tree_unlock(q);
2072	}
2073	return 0;
2074}
2075
2076struct tc_bind_class_args {
2077	struct qdisc_walker w;
2078	unsigned long new_cl;
2079	u32 portid;
2080	u32 clid;
2081};
2082
2083static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl,
2084				struct qdisc_walker *w)
2085{
2086	struct tc_bind_class_args *a = (struct tc_bind_class_args *)w;
2087	const struct Qdisc_class_ops *cops = q->ops->cl_ops;
2088	struct tcf_block *block;
2089	struct tcf_chain *chain;
2090
2091	block = cops->tcf_block(q, cl, NULL);
2092	if (!block)
2093		return 0;
2094	for (chain = tcf_get_next_chain(block, NULL);
2095	     chain;
2096	     chain = tcf_get_next_chain(block, chain)) {
2097		struct tcf_proto *tp;
2098
2099		for (tp = tcf_get_next_proto(chain, NULL);
2100		     tp; tp = tcf_get_next_proto(chain, tp)) {
2101			struct tcf_bind_args arg = {};
2102
2103			arg.w.fn = tcf_node_bind;
2104			arg.classid = a->clid;
2105			arg.base = cl;
2106			arg.cl = a->new_cl;
2107			tp->ops->walk(tp, &arg.w, true);
2108		}
2109	}
2110
2111	return 0;
2112}
2113
2114static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
2115			   unsigned long new_cl)
2116{
2117	const struct Qdisc_class_ops *cops = q->ops->cl_ops;
2118	struct tc_bind_class_args args = {};
2119
2120	if (!cops->tcf_block)
2121		return;
2122	args.portid = portid;
2123	args.clid = clid;
2124	args.new_cl = new_cl;
2125	args.w.fn = tc_bind_class_walker;
2126	q->ops->cl_ops->walk(q, &args.w);
2127}
2128
2129#else
2130
2131static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
2132			   unsigned long new_cl)
2133{
2134}
2135
2136#endif
2137
2138static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
2139			 struct netlink_ext_ack *extack)
2140{
2141	struct net *net = sock_net(skb->sk);
2142	struct tcmsg *tcm = nlmsg_data(n);
2143	struct nlattr *tca[TCA_MAX + 1];
2144	struct net_device *dev;
2145	struct Qdisc *q = NULL;
2146	const struct Qdisc_class_ops *cops;
2147	unsigned long cl = 0;
2148	unsigned long new_cl;
2149	u32 portid;
2150	u32 clid;
2151	u32 qid;
2152	int err;
2153
2154	err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
2155				     rtm_tca_policy, extack);
2156	if (err < 0)
2157		return err;
2158
2159	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2160	if (!dev)
2161		return -ENODEV;
2162
 
 
 
 
2163	/*
2164	   parent == TC_H_UNSPEC - unspecified parent.
2165	   parent == TC_H_ROOT   - class is root, which has no parent.
2166	   parent == X:0	 - parent is root class.
2167	   parent == X:Y	 - parent is a node in hierarchy.
2168	   parent == 0:Y	 - parent is X:Y, where X:0 is qdisc.
2169
2170	   handle == 0:0	 - generate handle from kernel pool.
2171	   handle == 0:Y	 - class is X:Y, where X:0 is qdisc.
2172	   handle == X:Y	 - clear.
2173	   handle == X:0	 - root class.
2174	 */
2175
2176	/* Step 1. Determine qdisc handle X:0 */
2177
2178	portid = tcm->tcm_parent;
2179	clid = tcm->tcm_handle;
2180	qid = TC_H_MAJ(clid);
2181
2182	if (portid != TC_H_ROOT) {
2183		u32 qid1 = TC_H_MAJ(portid);
2184
2185		if (qid && qid1) {
2186			/* If both majors are known, they must be identical. */
2187			if (qid != qid1)
2188				return -EINVAL;
2189		} else if (qid1) {
2190			qid = qid1;
2191		} else if (qid == 0)
2192			qid = rtnl_dereference(dev->qdisc)->handle;
2193
2194		/* Now qid is genuine qdisc handle consistent
2195		 * both with parent and child.
2196		 *
2197		 * TC_H_MAJ(portid) still may be unspecified, complete it now.
2198		 */
2199		if (portid)
2200			portid = TC_H_MAKE(qid, portid);
2201	} else {
2202		if (qid == 0)
2203			qid = rtnl_dereference(dev->qdisc)->handle;
2204	}
2205
2206	/* OK. Locate qdisc */
2207	q = qdisc_lookup(dev, qid);
2208	if (!q)
2209		return -ENOENT;
2210
2211	/* An check that it supports classes */
2212	cops = q->ops->cl_ops;
2213	if (cops == NULL)
2214		return -EINVAL;
2215
2216	/* Now try to get class */
2217	if (clid == 0) {
2218		if (portid == TC_H_ROOT)
2219			clid = qid;
2220	} else
2221		clid = TC_H_MAKE(qid, clid);
2222
2223	if (clid)
2224		cl = cops->find(q, clid);
2225
2226	if (cl == 0) {
2227		err = -ENOENT;
2228		if (n->nlmsg_type != RTM_NEWTCLASS ||
2229		    !(n->nlmsg_flags & NLM_F_CREATE))
2230			goto out;
2231	} else {
2232		switch (n->nlmsg_type) {
2233		case RTM_NEWTCLASS:
2234			err = -EEXIST;
2235			if (n->nlmsg_flags & NLM_F_EXCL)
2236				goto out;
2237			break;
2238		case RTM_DELTCLASS:
2239			err = tclass_del_notify(net, cops, skb, n, q, cl, extack);
2240			/* Unbind the class with flilters with 0 */
2241			tc_bind_tclass(q, portid, clid, 0);
 
 
2242			goto out;
2243		case RTM_GETTCLASS:
2244			err = tclass_get_notify(net, skb, n, q, cl, extack);
2245			goto out;
2246		default:
2247			err = -EINVAL;
2248			goto out;
2249		}
2250	}
2251
2252	if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
2253		NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes");
2254		return -EOPNOTSUPP;
2255	}
2256
2257	new_cl = cl;
2258	err = -EOPNOTSUPP;
2259	if (cops->change)
2260		err = cops->change(q, clid, portid, tca, &new_cl, extack);
2261	if (err == 0) {
2262		tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS, extack);
2263		/* We just create a new class, need to do reverse binding. */
2264		if (cl != new_cl)
2265			tc_bind_tclass(q, portid, clid, new_cl);
2266	}
2267out:
 
 
 
2268	return err;
2269}
2270
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2271struct qdisc_dump_args {
2272	struct qdisc_walker	w;
2273	struct sk_buff		*skb;
2274	struct netlink_callback	*cb;
2275};
2276
2277static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
2278			    struct qdisc_walker *arg)
2279{
2280	struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
2281
2282	return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
2283			      a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2284			      RTM_NEWTCLASS, NULL);
2285}
2286
2287static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
2288				struct tcmsg *tcm, struct netlink_callback *cb,
2289				int *t_p, int s_t)
2290{
2291	struct qdisc_dump_args arg;
2292
2293	if (tc_qdisc_dump_ignore(q, false) ||
2294	    *t_p < s_t || !q->ops->cl_ops ||
2295	    (tcm->tcm_parent &&
2296	     TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
2297		(*t_p)++;
2298		return 0;
2299	}
2300	if (*t_p > s_t)
2301		memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
2302	arg.w.fn = qdisc_class_dump;
2303	arg.skb = skb;
2304	arg.cb = cb;
2305	arg.w.stop  = 0;
2306	arg.w.skip = cb->args[1];
2307	arg.w.count = 0;
2308	q->ops->cl_ops->walk(q, &arg.w);
2309	cb->args[1] = arg.w.count;
2310	if (arg.w.stop)
2311		return -1;
2312	(*t_p)++;
2313	return 0;
2314}
2315
2316static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
2317			       struct tcmsg *tcm, struct netlink_callback *cb,
2318			       int *t_p, int s_t, bool recur)
2319{
2320	struct Qdisc *q;
2321	int b;
2322
2323	if (!root)
2324		return 0;
2325
2326	if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
2327		return -1;
2328
2329	if (!qdisc_dev(root) || !recur)
2330		return 0;
2331
2332	if (tcm->tcm_parent) {
2333		q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent));
2334		if (q && q != root &&
2335		    tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2336			return -1;
2337		return 0;
2338	}
2339	hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
2340		if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2341			return -1;
2342	}
2343
2344	return 0;
2345}
2346
2347static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
2348{
2349	struct tcmsg *tcm = nlmsg_data(cb->nlh);
2350	struct net *net = sock_net(skb->sk);
2351	struct netdev_queue *dev_queue;
2352	struct net_device *dev;
2353	int t, s_t;
2354
2355	if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2356		return 0;
2357	dev = dev_get_by_index(net, tcm->tcm_ifindex);
2358	if (!dev)
2359		return 0;
2360
2361	s_t = cb->args[0];
2362	t = 0;
2363
2364	if (tc_dump_tclass_root(rtnl_dereference(dev->qdisc),
2365				skb, tcm, cb, &t, s_t, true) < 0)
2366		goto done;
2367
2368	dev_queue = dev_ingress_queue(dev);
2369	if (dev_queue &&
2370	    tc_dump_tclass_root(rtnl_dereference(dev_queue->qdisc_sleeping),
2371				skb, tcm, cb, &t, s_t, false) < 0)
2372		goto done;
2373
2374done:
2375	cb->args[0] = t;
2376
2377	dev_put(dev);
2378	return skb->len;
2379}
2380
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2381#ifdef CONFIG_PROC_FS
2382static int psched_show(struct seq_file *seq, void *v)
2383{
 
 
 
2384	seq_printf(seq, "%08x %08x %08x %08x\n",
2385		   (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
2386		   1000000,
2387		   (u32)NSEC_PER_SEC / hrtimer_resolution);
2388
2389	return 0;
2390}
2391
 
 
 
 
 
 
 
 
 
 
 
 
 
2392static int __net_init psched_net_init(struct net *net)
2393{
2394	struct proc_dir_entry *e;
2395
2396	e = proc_create_single("psched", 0, net->proc_net, psched_show);
2397	if (e == NULL)
2398		return -ENOMEM;
2399
2400	return 0;
2401}
2402
2403static void __net_exit psched_net_exit(struct net *net)
2404{
2405	remove_proc_entry("psched", net->proc_net);
2406}
2407#else
2408static int __net_init psched_net_init(struct net *net)
2409{
2410	return 0;
2411}
2412
2413static void __net_exit psched_net_exit(struct net *net)
2414{
2415}
2416#endif
2417
2418static struct pernet_operations psched_net_ops = {
2419	.init = psched_net_init,
2420	.exit = psched_net_exit,
2421};
2422
2423#if IS_ENABLED(CONFIG_MITIGATION_RETPOLINE)
2424DEFINE_STATIC_KEY_FALSE(tc_skip_wrapper);
2425#endif
2426
2427static const struct rtnl_msg_handler psched_rtnl_msg_handlers[] __initconst = {
2428	{.msgtype = RTM_NEWQDISC, .doit = tc_modify_qdisc},
2429	{.msgtype = RTM_DELQDISC, .doit = tc_get_qdisc},
2430	{.msgtype = RTM_GETQDISC, .doit = tc_get_qdisc,
2431	 .dumpit = tc_dump_qdisc},
2432	{.msgtype = RTM_NEWTCLASS, .doit = tc_ctl_tclass},
2433	{.msgtype = RTM_DELTCLASS, .doit = tc_ctl_tclass},
2434	{.msgtype = RTM_GETTCLASS, .doit = tc_ctl_tclass,
2435	 .dumpit = tc_dump_tclass},
2436};
2437
2438static int __init pktsched_init(void)
2439{
2440	int err;
2441
2442	err = register_pernet_subsys(&psched_net_ops);
2443	if (err) {
2444		pr_err("pktsched_init: "
2445		       "cannot initialize per netns operations\n");
2446		return err;
2447	}
2448
2449	register_qdisc(&pfifo_fast_ops);
2450	register_qdisc(&pfifo_qdisc_ops);
2451	register_qdisc(&bfifo_qdisc_ops);
2452	register_qdisc(&pfifo_head_drop_qdisc_ops);
2453	register_qdisc(&mq_qdisc_ops);
2454	register_qdisc(&noqueue_qdisc_ops);
2455
2456	rtnl_register_many(psched_rtnl_msg_handlers);
2457
2458	tc_wrapper_init();
 
 
 
 
 
2459
2460	return 0;
2461}
2462
2463subsys_initcall(pktsched_init);