Linux Audio

Check our new training course

Loading...
v3.15
 
   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/unregister 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/* Get default qdisc if not otherwise specified */
 204void qdisc_get_default(char *name, size_t len)
 205{
 206	read_lock(&qdisc_mod_lock);
 207	strlcpy(name, default_qdisc_ops->id, len);
 208	read_unlock(&qdisc_mod_lock);
 209}
 210
 211static struct Qdisc_ops *qdisc_lookup_default(const char *name)
 212{
 213	struct Qdisc_ops *q = NULL;
 214
 215	for (q = qdisc_base; q; q = q->next) {
 216		if (!strcmp(name, q->id)) {
 217			if (!try_module_get(q->owner))
 218				q = NULL;
 219			break;
 220		}
 221	}
 222
 223	return q;
 224}
 225
 226/* Set new default qdisc to use */
 227int qdisc_set_default(const char *name)
 228{
 229	const struct Qdisc_ops *ops;
 230
 231	if (!capable(CAP_NET_ADMIN))
 232		return -EPERM;
 233
 234	write_lock(&qdisc_mod_lock);
 235	ops = qdisc_lookup_default(name);
 236	if (!ops) {
 237		/* Not found, drop lock and try to load module */
 238		write_unlock(&qdisc_mod_lock);
 239		request_module("sch_%s", name);
 240		write_lock(&qdisc_mod_lock);
 241
 242		ops = qdisc_lookup_default(name);
 243	}
 244
 245	if (ops) {
 246		/* Set new default */
 247		module_put(default_qdisc_ops->owner);
 248		default_qdisc_ops = ops;
 249	}
 250	write_unlock(&qdisc_mod_lock);
 251
 252	return ops ? 0 : -ENOENT;
 253}
 254
 
 
 
 
 
 
 
 
 
 255/* We know handle. Find qdisc among all qdisc's attached to device
 256   (root qdisc, all its children, children of children etc.)
 
 257 */
 258
 259static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
 260{
 261	struct Qdisc *q;
 262
 
 
 
 263	if (!(root->flags & TCQ_F_BUILTIN) &&
 264	    root->handle == handle)
 265		return root;
 266
 267	list_for_each_entry(q, &root->list, list) {
 
 268		if (q->handle == handle)
 269			return q;
 270	}
 271	return NULL;
 272}
 273
 274void qdisc_list_add(struct Qdisc *q)
 275{
 276	if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
 277		struct Qdisc *root = qdisc_dev(q)->qdisc;
 278
 279		WARN_ON_ONCE(root == &noop_qdisc);
 280		list_add_tail(&q->list, &root->list);
 281	}
 282}
 283EXPORT_SYMBOL(qdisc_list_add);
 284
 285void qdisc_list_del(struct Qdisc *q)
 286{
 287	if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
 288		list_del(&q->list);
 
 
 289}
 290EXPORT_SYMBOL(qdisc_list_del);
 291
 292struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
 293{
 294	struct Qdisc *q;
 295
 296	q = qdisc_match_from_root(dev->qdisc, handle);
 
 
 297	if (q)
 298		goto out;
 299
 300	if (dev_ingress_queue(dev))
 301		q = qdisc_match_from_root(
 302			dev_ingress_queue(dev)->qdisc_sleeping,
 303			handle);
 304out:
 305	return q;
 306}
 307
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 308static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
 309{
 310	unsigned long cl;
 311	struct Qdisc *leaf;
 312	const struct Qdisc_class_ops *cops = p->ops->cl_ops;
 313
 314	if (cops == NULL)
 315		return NULL;
 316	cl = cops->get(p, classid);
 317
 318	if (cl == 0)
 319		return NULL;
 320	leaf = cops->leaf(p, cl);
 321	cops->put(p, cl);
 322	return leaf;
 323}
 324
 325/* Find queueing discipline by name */
 326
 327static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
 328{
 329	struct Qdisc_ops *q = NULL;
 330
 331	if (kind) {
 332		read_lock(&qdisc_mod_lock);
 333		for (q = qdisc_base; q; q = q->next) {
 334			if (nla_strcmp(kind, q->id) == 0) {
 335				if (!try_module_get(q->owner))
 336					q = NULL;
 337				break;
 338			}
 339		}
 340		read_unlock(&qdisc_mod_lock);
 341	}
 342	return q;
 343}
 344
 345/* The linklayer setting were not transferred from iproute2, in older
 346 * versions, and the rate tables lookup systems have been dropped in
 347 * the kernel. To keep backward compatible with older iproute2 tc
 348 * utils, we detect the linklayer setting by detecting if the rate
 349 * table were modified.
 350 *
 351 * For linklayer ATM table entries, the rate table will be aligned to
 352 * 48 bytes, thus some table entries will contain the same value.  The
 353 * mpu (min packet unit) is also encoded into the old rate table, thus
 354 * starting from the mpu, we find low and high table entries for
 355 * mapping this cell.  If these entries contain the same value, when
 356 * the rate tables have been modified for linklayer ATM.
 357 *
 358 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
 359 * and then roundup to the next cell, calc the table entry one below,
 360 * and compare.
 361 */
 362static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
 363{
 364	int low       = roundup(r->mpu, 48);
 365	int high      = roundup(low+1, 48);
 366	int cell_low  = low >> r->cell_log;
 367	int cell_high = (high >> r->cell_log) - 1;
 368
 369	/* rtab is too inaccurate at rates > 100Mbit/s */
 370	if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
 371		pr_debug("TC linklayer: Giving up ATM detection\n");
 372		return TC_LINKLAYER_ETHERNET;
 373	}
 374
 375	if ((cell_high > cell_low) && (cell_high < 256)
 376	    && (rtab[cell_low] == rtab[cell_high])) {
 377		pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
 378			 cell_low, cell_high, rtab[cell_high]);
 379		return TC_LINKLAYER_ATM;
 380	}
 381	return TC_LINKLAYER_ETHERNET;
 382}
 383
 384static struct qdisc_rate_table *qdisc_rtab_list;
 385
 386struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct nlattr *tab)
 
 
 387{
 388	struct qdisc_rate_table *rtab;
 389
 390	if (tab == NULL || r->rate == 0 || r->cell_log == 0 ||
 391	    nla_len(tab) != TC_RTAB_SIZE)
 
 
 392		return NULL;
 
 393
 394	for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
 395		if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
 396		    !memcmp(&rtab->data, nla_data(tab), 1024)) {
 397			rtab->refcnt++;
 398			return rtab;
 399		}
 400	}
 401
 402	rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
 403	if (rtab) {
 404		rtab->rate = *r;
 405		rtab->refcnt = 1;
 406		memcpy(rtab->data, nla_data(tab), 1024);
 407		if (r->linklayer == TC_LINKLAYER_UNAWARE)
 408			r->linklayer = __detect_linklayer(r, rtab->data);
 409		rtab->next = qdisc_rtab_list;
 410		qdisc_rtab_list = rtab;
 
 
 411	}
 412	return rtab;
 413}
 414EXPORT_SYMBOL(qdisc_get_rtab);
 415
 416void qdisc_put_rtab(struct qdisc_rate_table *tab)
 417{
 418	struct qdisc_rate_table *rtab, **rtabp;
 419
 420	if (!tab || --tab->refcnt)
 421		return;
 422
 423	for (rtabp = &qdisc_rtab_list;
 424	     (rtab = *rtabp) != NULL;
 425	     rtabp = &rtab->next) {
 426		if (rtab == tab) {
 427			*rtabp = rtab->next;
 428			kfree(rtab);
 429			return;
 430		}
 431	}
 432}
 433EXPORT_SYMBOL(qdisc_put_rtab);
 434
 435static LIST_HEAD(qdisc_stab_list);
 436static DEFINE_SPINLOCK(qdisc_stab_lock);
 437
 438static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
 439	[TCA_STAB_BASE]	= { .len = sizeof(struct tc_sizespec) },
 440	[TCA_STAB_DATA] = { .type = NLA_BINARY },
 441};
 442
 443static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
 
 444{
 445	struct nlattr *tb[TCA_STAB_MAX + 1];
 446	struct qdisc_size_table *stab;
 447	struct tc_sizespec *s;
 448	unsigned int tsize = 0;
 449	u16 *tab = NULL;
 450	int err;
 451
 452	err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
 
 453	if (err < 0)
 454		return ERR_PTR(err);
 455	if (!tb[TCA_STAB_BASE])
 
 456		return ERR_PTR(-EINVAL);
 
 457
 458	s = nla_data(tb[TCA_STAB_BASE]);
 459
 460	if (s->tsize > 0) {
 461		if (!tb[TCA_STAB_DATA])
 
 462			return ERR_PTR(-EINVAL);
 
 463		tab = nla_data(tb[TCA_STAB_DATA]);
 464		tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
 465	}
 466
 467	if (tsize != s->tsize || (!tab && tsize > 0))
 
 468		return ERR_PTR(-EINVAL);
 469
 470	spin_lock(&qdisc_stab_lock);
 471
 472	list_for_each_entry(stab, &qdisc_stab_list, list) {
 473		if (memcmp(&stab->szopts, s, sizeof(*s)))
 474			continue;
 475		if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
 
 476			continue;
 477		stab->refcnt++;
 478		spin_unlock(&qdisc_stab_lock);
 479		return stab;
 480	}
 481
 482	spin_unlock(&qdisc_stab_lock);
 
 
 
 
 483
 484	stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
 485	if (!stab)
 486		return ERR_PTR(-ENOMEM);
 487
 488	stab->refcnt = 1;
 489	stab->szopts = *s;
 490	if (tsize > 0)
 491		memcpy(stab->data, tab, tsize * sizeof(u16));
 492
 493	spin_lock(&qdisc_stab_lock);
 494	list_add_tail(&stab->list, &qdisc_stab_list);
 495	spin_unlock(&qdisc_stab_lock);
 496
 497	return stab;
 498}
 499
 500static void stab_kfree_rcu(struct rcu_head *head)
 501{
 502	kfree(container_of(head, struct qdisc_size_table, rcu));
 503}
 504
 505void qdisc_put_stab(struct qdisc_size_table *tab)
 506{
 507	if (!tab)
 508		return;
 509
 510	spin_lock(&qdisc_stab_lock);
 511
 512	if (--tab->refcnt == 0) {
 513		list_del(&tab->list);
 514		call_rcu_bh(&tab->rcu, stab_kfree_rcu);
 515	}
 516
 517	spin_unlock(&qdisc_stab_lock);
 518}
 519EXPORT_SYMBOL(qdisc_put_stab);
 520
 521static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
 522{
 523	struct nlattr *nest;
 524
 525	nest = nla_nest_start(skb, TCA_STAB);
 526	if (nest == NULL)
 527		goto nla_put_failure;
 528	if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
 529		goto nla_put_failure;
 530	nla_nest_end(skb, nest);
 531
 532	return skb->len;
 533
 534nla_put_failure:
 535	return -1;
 536}
 537
 538void __qdisc_calculate_pkt_len(struct sk_buff *skb, const struct qdisc_size_table *stab)
 
 539{
 540	int pkt_len, slot;
 541
 542	pkt_len = skb->len + stab->szopts.overhead;
 543	if (unlikely(!stab->szopts.tsize))
 544		goto out;
 545
 546	slot = pkt_len + stab->szopts.cell_align;
 547	if (unlikely(slot < 0))
 548		slot = 0;
 549
 550	slot >>= stab->szopts.cell_log;
 551	if (likely(slot < stab->szopts.tsize))
 552		pkt_len = stab->data[slot];
 553	else
 554		pkt_len = stab->data[stab->szopts.tsize - 1] *
 555				(slot / stab->szopts.tsize) +
 556				stab->data[slot % stab->szopts.tsize];
 557
 558	pkt_len <<= stab->szopts.size_log;
 559out:
 560	if (unlikely(pkt_len < 1))
 561		pkt_len = 1;
 562	qdisc_skb_cb(skb)->pkt_len = pkt_len;
 563}
 564EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
 565
 566void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc)
 567{
 568	if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
 569		pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
 570			txt, qdisc->ops->id, qdisc->handle >> 16);
 571		qdisc->flags |= TCQ_F_WARN_NONWC;
 572	}
 573}
 574EXPORT_SYMBOL(qdisc_warn_nonwc);
 575
 576static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
 577{
 578	struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
 579						 timer);
 580
 581	qdisc_unthrottled(wd->qdisc);
 582	__netif_schedule(qdisc_root(wd->qdisc));
 
 583
 584	return HRTIMER_NORESTART;
 585}
 586
 587void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
 
 588{
 589	hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 590	wd->timer.function = qdisc_watchdog;
 591	wd->qdisc = qdisc;
 592}
 
 
 
 
 
 
 593EXPORT_SYMBOL(qdisc_watchdog_init);
 594
 595void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires)
 
 596{
 597	if (test_bit(__QDISC_STATE_DEACTIVATED,
 598		     &qdisc_root_sleeping(wd->qdisc)->state))
 599		return;
 600
 601	qdisc_throttled(wd->qdisc);
 
 
 
 
 
 
 602
 603	hrtimer_start(&wd->timer,
 604		      ns_to_ktime(expires),
 605		      HRTIMER_MODE_ABS);
 
 
 606}
 607EXPORT_SYMBOL(qdisc_watchdog_schedule_ns);
 608
 609void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
 610{
 611	hrtimer_cancel(&wd->timer);
 612	qdisc_unthrottled(wd->qdisc);
 613}
 614EXPORT_SYMBOL(qdisc_watchdog_cancel);
 615
 616static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
 617{
 618	unsigned int size = n * sizeof(struct hlist_head), i;
 619	struct hlist_head *h;
 
 620
 621	if (size <= PAGE_SIZE)
 622		h = kmalloc(size, GFP_KERNEL);
 623	else
 624		h = (struct hlist_head *)
 625			__get_free_pages(GFP_KERNEL, get_order(size));
 626
 627	if (h != NULL) {
 628		for (i = 0; i < n; i++)
 629			INIT_HLIST_HEAD(&h[i]);
 630	}
 631	return h;
 632}
 633
 634static void qdisc_class_hash_free(struct hlist_head *h, unsigned int n)
 635{
 636	unsigned int size = n * sizeof(struct hlist_head);
 637
 638	if (size <= PAGE_SIZE)
 639		kfree(h);
 640	else
 641		free_pages((unsigned long)h, get_order(size));
 642}
 643
 644void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
 645{
 646	struct Qdisc_class_common *cl;
 647	struct hlist_node *next;
 648	struct hlist_head *nhash, *ohash;
 649	unsigned int nsize, nmask, osize;
 650	unsigned int i, h;
 651
 652	/* Rehash when load factor exceeds 0.75 */
 653	if (clhash->hashelems * 4 <= clhash->hashsize * 3)
 654		return;
 655	nsize = clhash->hashsize * 2;
 656	nmask = nsize - 1;
 657	nhash = qdisc_class_hash_alloc(nsize);
 658	if (nhash == NULL)
 659		return;
 660
 661	ohash = clhash->hash;
 662	osize = clhash->hashsize;
 663
 664	sch_tree_lock(sch);
 665	for (i = 0; i < osize; i++) {
 666		hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
 667			h = qdisc_class_hash(cl->classid, nmask);
 668			hlist_add_head(&cl->hnode, &nhash[h]);
 669		}
 670	}
 671	clhash->hash     = nhash;
 672	clhash->hashsize = nsize;
 673	clhash->hashmask = nmask;
 674	sch_tree_unlock(sch);
 675
 676	qdisc_class_hash_free(ohash, osize);
 677}
 678EXPORT_SYMBOL(qdisc_class_hash_grow);
 679
 680int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
 681{
 682	unsigned int size = 4;
 683
 684	clhash->hash = qdisc_class_hash_alloc(size);
 685	if (clhash->hash == NULL)
 686		return -ENOMEM;
 687	clhash->hashsize  = size;
 688	clhash->hashmask  = size - 1;
 689	clhash->hashelems = 0;
 690	return 0;
 691}
 692EXPORT_SYMBOL(qdisc_class_hash_init);
 693
 694void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
 695{
 696	qdisc_class_hash_free(clhash->hash, clhash->hashsize);
 697}
 698EXPORT_SYMBOL(qdisc_class_hash_destroy);
 699
 700void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
 701			     struct Qdisc_class_common *cl)
 702{
 703	unsigned int h;
 704
 705	INIT_HLIST_NODE(&cl->hnode);
 706	h = qdisc_class_hash(cl->classid, clhash->hashmask);
 707	hlist_add_head(&cl->hnode, &clhash->hash[h]);
 708	clhash->hashelems++;
 709}
 710EXPORT_SYMBOL(qdisc_class_hash_insert);
 711
 712void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
 713			     struct Qdisc_class_common *cl)
 714{
 715	hlist_del(&cl->hnode);
 716	clhash->hashelems--;
 717}
 718EXPORT_SYMBOL(qdisc_class_hash_remove);
 719
 720/* Allocate an unique handle from space managed by kernel
 721 * Possible range is [8000-FFFF]:0000 (0x8000 values)
 722 */
 723static u32 qdisc_alloc_handle(struct net_device *dev)
 724{
 725	int i = 0x8000;
 726	static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
 727
 728	do {
 729		autohandle += TC_H_MAKE(0x10000U, 0);
 730		if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
 731			autohandle = TC_H_MAKE(0x80000000U, 0);
 732		if (!qdisc_lookup(dev, autohandle))
 733			return autohandle;
 734		cond_resched();
 735	} while	(--i > 0);
 736
 737	return 0;
 738}
 739
 740void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
 741{
 
 742	const struct Qdisc_class_ops *cops;
 743	unsigned long cl;
 744	u32 parentid;
 
 745	int drops;
 746
 747	if (n == 0)
 748		return;
 749	drops = max_t(int, n, 0);
 
 750	while ((parentid = sch->parent)) {
 751		if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
 752			return;
 753
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 754		sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
 755		if (sch == NULL) {
 756			WARN_ON(parentid != TC_H_ROOT);
 757			return;
 758		}
 759		cops = sch->ops->cl_ops;
 760		if (cops->qlen_notify) {
 761			cl = cops->get(sch, parentid);
 762			cops->qlen_notify(sch, cl);
 763			cops->put(sch, cl);
 764		}
 765		sch->q.qlen -= n;
 766		sch->qstats.drops += drops;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 767	}
 
 
 
 
 
 
 
 
 768}
 769EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
 770
 771static void notify_and_destroy(struct net *net, struct sk_buff *skb,
 772			       struct nlmsghdr *n, u32 clid,
 773			       struct Qdisc *old, struct Qdisc *new)
 774{
 775	if (new || old)
 776		qdisc_notify(net, skb, n, clid, old, new);
 777
 778	if (old)
 779		qdisc_destroy(old);
 
 
 
 
 
 
 
 
 
 
 
 
 
 780}
 781
 782/* Graft qdisc "new" to class "classid" of qdisc "parent" or
 783 * to device "dev".
 784 *
 785 * When appropriate send a netlink notification using 'skb'
 786 * and "n".
 787 *
 788 * On success, destroy old qdisc.
 789 */
 790
 791static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
 792		       struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
 793		       struct Qdisc *new, struct Qdisc *old)
 
 794{
 795	struct Qdisc *q = old;
 796	struct net *net = dev_net(dev);
 797	int err = 0;
 798
 799	if (parent == NULL) {
 800		unsigned int i, num_q, ingress;
 801
 802		ingress = 0;
 803		num_q = dev->num_tx_queues;
 804		if ((q && q->flags & TCQ_F_INGRESS) ||
 805		    (new && new->flags & TCQ_F_INGRESS)) {
 806			num_q = 1;
 807			ingress = 1;
 808			if (!dev_ingress_queue(dev))
 
 809				return -ENOENT;
 
 810		}
 811
 812		if (dev->flags & IFF_UP)
 813			dev_deactivate(dev);
 814
 815		if (new && new->ops->attach) {
 816			new->ops->attach(new);
 817			num_q = 0;
 818		}
 819
 820		for (i = 0; i < num_q; i++) {
 821			struct netdev_queue *dev_queue = dev_ingress_queue(dev);
 822
 823			if (!ingress)
 824				dev_queue = netdev_get_tx_queue(dev, i);
 825
 826			old = dev_graft_qdisc(dev_queue, new);
 827			if (new && i > 0)
 828				atomic_inc(&new->refcnt);
 829
 830			if (!ingress)
 831				qdisc_destroy(old);
 832		}
 833
 
 834		if (!ingress) {
 835			notify_and_destroy(net, skb, n, classid,
 836					   dev->qdisc, new);
 837			if (new && !new->ops->attach)
 838				atomic_inc(&new->refcnt);
 839			dev->qdisc = new ? : &noop_qdisc;
 
 
 
 
 
 840		} else {
 841			notify_and_destroy(net, skb, n, classid, old, new);
 842		}
 843
 844		if (dev->flags & IFF_UP)
 845			dev_activate(dev);
 846	} else {
 847		const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
 
 
 848
 849		err = -EOPNOTSUPP;
 850		if (cops && cops->graft) {
 851			unsigned long cl = cops->get(parent, classid);
 852			if (cl) {
 853				err = cops->graft(parent, cl, new, &old);
 854				cops->put(parent, cl);
 855			} else
 856				err = -ENOENT;
 
 
 
 857		}
 858		if (!err)
 859			notify_and_destroy(net, skb, n, classid, old, new);
 
 
 
 
 
 
 
 
 860	}
 861	return err;
 862}
 863
 864/* lockdep annotation is needed for ingress; egress gets it only for name */
 865static struct lock_class_key qdisc_tx_lock;
 866static struct lock_class_key qdisc_rx_lock;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 867
 868/*
 869   Allocate and initialize new qdisc.
 870
 871   Parameters are passed via opt.
 872 */
 873
 874static struct Qdisc *
 875qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
 876	     struct Qdisc *p, u32 parent, u32 handle,
 877	     struct nlattr **tca, int *errp)
 
 878{
 879	int err;
 880	struct nlattr *kind = tca[TCA_KIND];
 881	struct Qdisc *sch;
 882	struct Qdisc_ops *ops;
 883	struct qdisc_size_table *stab;
 884
 885	ops = qdisc_lookup_ops(kind);
 886#ifdef CONFIG_MODULES
 887	if (ops == NULL && kind != NULL) {
 888		char name[IFNAMSIZ];
 889		if (nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
 890			/* We dropped the RTNL semaphore in order to
 891			 * perform the module load.  So, even if we
 892			 * succeeded in loading the module we have to
 893			 * tell the caller to replay the request.  We
 894			 * indicate this using -EAGAIN.
 895			 * We replay the request because the device may
 896			 * go away in the mean time.
 897			 */
 898			rtnl_unlock();
 899			request_module("sch_%s", name);
 900			rtnl_lock();
 901			ops = qdisc_lookup_ops(kind);
 902			if (ops != NULL) {
 903				/* We will try again qdisc_lookup_ops,
 904				 * so don't keep a reference.
 905				 */
 906				module_put(ops->owner);
 907				err = -EAGAIN;
 908				goto err_out;
 909			}
 910		}
 911	}
 912#endif
 913
 914	err = -ENOENT;
 915	if (ops == NULL)
 
 916		goto err_out;
 
 917
 918	sch = qdisc_alloc(dev_queue, ops);
 919	if (IS_ERR(sch)) {
 920		err = PTR_ERR(sch);
 921		goto err_out2;
 922	}
 923
 924	sch->parent = parent;
 925
 926	if (handle == TC_H_INGRESS) {
 927		sch->flags |= TCQ_F_INGRESS;
 928		handle = TC_H_MAKE(TC_H_INGRESS, 0);
 929		lockdep_set_class(qdisc_lock(sch), &qdisc_rx_lock);
 930	} else {
 931		if (handle == 0) {
 932			handle = qdisc_alloc_handle(dev);
 933			err = -ENOMEM;
 934			if (handle == 0)
 
 935				goto err_out3;
 
 936		}
 937		lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
 938		if (!netif_is_multiqueue(dev))
 939			sch->flags |= TCQ_F_ONETXQUEUE;
 940	}
 941
 942	sch->handle = handle;
 943
 944	if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
 945		if (tca[TCA_STAB]) {
 946			stab = qdisc_get_stab(tca[TCA_STAB]);
 947			if (IS_ERR(stab)) {
 948				err = PTR_ERR(stab);
 949				goto err_out4;
 950			}
 951			rcu_assign_pointer(sch->stab, stab);
 952		}
 953		if (tca[TCA_RATE]) {
 954			spinlock_t *root_lock;
 955
 956			err = -EOPNOTSUPP;
 957			if (sch->flags & TCQ_F_MQROOT)
 958				goto err_out4;
 959
 960			if ((sch->parent != TC_H_ROOT) &&
 961			    !(sch->flags & TCQ_F_INGRESS) &&
 962			    (!p || !(p->flags & TCQ_F_MQROOT)))
 963				root_lock = qdisc_root_sleeping_lock(sch);
 964			else
 965				root_lock = qdisc_lock(sch);
 966
 967			err = gen_new_estimator(&sch->bstats, &sch->rate_est,
 968						root_lock, tca[TCA_RATE]);
 969			if (err)
 970				goto err_out4;
 
 
 
 
 
 
 
 
 
 971		}
 972
 973		qdisc_list_add(sch);
 974
 975		return sch;
 
 
 
 
 
 
 
 976	}
 
 
 
 
 
 
 
 
 
 
 977err_out3:
 978	dev_put(dev);
 979	kfree((char *) sch - sch->padded);
 980err_out2:
 981	module_put(ops->owner);
 982err_out:
 983	*errp = err;
 984	return NULL;
 985
 986err_out4:
 987	/*
 988	 * Any broken qdiscs that would require a ops->reset() here?
 989	 * The qdisc was never in action so it shouldn't be necessary.
 990	 */
 991	qdisc_put_stab(rtnl_dereference(sch->stab));
 992	if (ops->destroy)
 993		ops->destroy(sch);
 994	goto err_out3;
 995}
 996
 997static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
 
 998{
 999	struct qdisc_size_table *ostab, *stab = NULL;
1000	int err = 0;
1001
1002	if (tca[TCA_OPTIONS]) {
1003		if (sch->ops->change == NULL)
 
1004			return -EINVAL;
1005		err = sch->ops->change(sch, tca[TCA_OPTIONS]);
 
 
 
 
 
1006		if (err)
1007			return err;
1008	}
1009
1010	if (tca[TCA_STAB]) {
1011		stab = qdisc_get_stab(tca[TCA_STAB]);
1012		if (IS_ERR(stab))
1013			return PTR_ERR(stab);
1014	}
1015
1016	ostab = rtnl_dereference(sch->stab);
1017	rcu_assign_pointer(sch->stab, stab);
1018	qdisc_put_stab(ostab);
1019
1020	if (tca[TCA_RATE]) {
1021		/* NB: ignores errors from replace_estimator
1022		   because change can't be undone. */
1023		if (sch->flags & TCQ_F_MQROOT)
1024			goto out;
1025		gen_replace_estimator(&sch->bstats, &sch->rate_est,
1026					    qdisc_root_sleeping_lock(sch),
1027					    tca[TCA_RATE]);
 
 
 
1028	}
1029out:
1030	return 0;
1031}
1032
1033struct check_loop_arg {
1034	struct qdisc_walker	w;
1035	struct Qdisc		*p;
1036	int			depth;
1037};
1038
1039static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w);
 
1040
1041static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1042{
1043	struct check_loop_arg	arg;
1044
1045	if (q->ops->cl_ops == NULL)
1046		return 0;
1047
1048	arg.w.stop = arg.w.skip = arg.w.count = 0;
1049	arg.w.fn = check_loop_fn;
1050	arg.depth = depth;
1051	arg.p = p;
1052	q->ops->cl_ops->walk(q, &arg.w);
1053	return arg.w.stop ? -ELOOP : 0;
1054}
1055
1056static int
1057check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1058{
1059	struct Qdisc *leaf;
1060	const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1061	struct check_loop_arg *arg = (struct check_loop_arg *)w;
1062
1063	leaf = cops->leaf(q, cl);
1064	if (leaf) {
1065		if (leaf == arg->p || arg->depth > 7)
1066			return -ELOOP;
1067		return check_loop(leaf, arg->p, arg->depth + 1);
1068	}
1069	return 0;
1070}
1071
 
 
 
 
 
 
 
 
 
 
 
1072/*
1073 * Delete/get qdisc.
1074 */
1075
1076static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
 
1077{
1078	struct net *net = sock_net(skb->sk);
1079	struct tcmsg *tcm = nlmsg_data(n);
1080	struct nlattr *tca[TCA_MAX + 1];
1081	struct net_device *dev;
1082	u32 clid;
1083	struct Qdisc *q = NULL;
1084	struct Qdisc *p = NULL;
1085	int err;
1086
1087	if ((n->nlmsg_type != RTM_GETQDISC) && !netlink_capable(skb, CAP_NET_ADMIN))
1088		return -EPERM;
1089
1090	err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1091	if (err < 0)
1092		return err;
1093
1094	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1095	if (!dev)
1096		return -ENODEV;
1097
1098	clid = tcm->tcm_parent;
1099	if (clid) {
1100		if (clid != TC_H_ROOT) {
1101			if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1102				p = qdisc_lookup(dev, TC_H_MAJ(clid));
1103				if (!p)
 
1104					return -ENOENT;
 
1105				q = qdisc_leaf(p, clid);
1106			} else if (dev_ingress_queue(dev)) {
1107				q = dev_ingress_queue(dev)->qdisc_sleeping;
1108			}
1109		} else {
1110			q = dev->qdisc;
1111		}
1112		if (!q)
 
1113			return -ENOENT;
 
1114
1115		if (tcm->tcm_handle && q->handle != tcm->tcm_handle)
 
1116			return -EINVAL;
 
1117	} else {
1118		q = qdisc_lookup(dev, tcm->tcm_handle);
1119		if (!q)
 
1120			return -ENOENT;
 
1121	}
1122
1123	if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
 
1124		return -EINVAL;
 
1125
1126	if (n->nlmsg_type == RTM_DELQDISC) {
1127		if (!clid)
 
1128			return -EINVAL;
1129		if (q->handle == 0)
 
 
1130			return -ENOENT;
1131		err = qdisc_graft(dev, p, skb, n, clid, NULL, q);
 
1132		if (err != 0)
1133			return err;
1134	} else {
1135		qdisc_notify(net, skb, n, clid, NULL, q);
1136	}
1137	return 0;
1138}
1139
1140/*
1141 * Create/change qdisc.
1142 */
1143
1144static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
 
1145{
1146	struct net *net = sock_net(skb->sk);
1147	struct tcmsg *tcm;
1148	struct nlattr *tca[TCA_MAX + 1];
1149	struct net_device *dev;
1150	u32 clid;
1151	struct Qdisc *q, *p;
1152	int err;
1153
1154	if (!netlink_capable(skb, CAP_NET_ADMIN))
1155		return -EPERM;
1156
1157replay:
1158	/* Reinit, just in case something touches this. */
1159	err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
 
1160	if (err < 0)
1161		return err;
1162
1163	tcm = nlmsg_data(n);
1164	clid = tcm->tcm_parent;
1165	q = p = NULL;
1166
1167	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1168	if (!dev)
1169		return -ENODEV;
1170
1171
1172	if (clid) {
1173		if (clid != TC_H_ROOT) {
1174			if (clid != TC_H_INGRESS) {
1175				p = qdisc_lookup(dev, TC_H_MAJ(clid));
1176				if (!p)
 
1177					return -ENOENT;
 
1178				q = qdisc_leaf(p, clid);
1179			} else if (dev_ingress_queue_create(dev)) {
1180				q = dev_ingress_queue(dev)->qdisc_sleeping;
1181			}
1182		} else {
1183			q = dev->qdisc;
1184		}
1185
1186		/* It may be default qdisc, ignore it */
1187		if (q && q->handle == 0)
1188			q = NULL;
1189
1190		if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1191			if (tcm->tcm_handle) {
1192				if (q && !(n->nlmsg_flags & NLM_F_REPLACE))
 
1193					return -EEXIST;
1194				if (TC_H_MIN(tcm->tcm_handle))
 
 
1195					return -EINVAL;
 
1196				q = qdisc_lookup(dev, tcm->tcm_handle);
1197				if (!q)
1198					goto create_n_graft;
1199				if (n->nlmsg_flags & NLM_F_EXCL)
 
1200					return -EEXIST;
1201				if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
 
 
 
1202					return -EINVAL;
 
1203				if (q == p ||
1204				    (p && check_loop(q, p, 0)))
 
1205					return -ELOOP;
1206				atomic_inc(&q->refcnt);
 
1207				goto graft;
1208			} else {
1209				if (!q)
1210					goto create_n_graft;
1211
1212				/* This magic test requires explanation.
1213				 *
1214				 *   We know, that some child q is already
1215				 *   attached to this parent and have choice:
1216				 *   either to change it or to create/graft new one.
1217				 *
1218				 *   1. We are allowed to create/graft only
1219				 *   if CREATE and REPLACE flags are set.
1220				 *
1221				 *   2. If EXCL is set, requestor wanted to say,
1222				 *   that qdisc tcm_handle is not expected
1223				 *   to exist, so that we choose create/graft too.
1224				 *
1225				 *   3. The last case is when no flags are set.
1226				 *   Alas, it is sort of hole in API, we
1227				 *   cannot decide what to do unambiguously.
1228				 *   For now we select create/graft, if
1229				 *   user gave KIND, which does not match existing.
1230				 */
1231				if ((n->nlmsg_flags & NLM_F_CREATE) &&
1232				    (n->nlmsg_flags & NLM_F_REPLACE) &&
1233				    ((n->nlmsg_flags & NLM_F_EXCL) ||
1234				     (tca[TCA_KIND] &&
1235				      nla_strcmp(tca[TCA_KIND], q->ops->id))))
1236					goto create_n_graft;
1237			}
1238		}
1239	} else {
1240		if (!tcm->tcm_handle)
 
1241			return -EINVAL;
 
1242		q = qdisc_lookup(dev, tcm->tcm_handle);
1243	}
1244
1245	/* Change qdisc parameters */
1246	if (q == NULL)
 
1247		return -ENOENT;
1248	if (n->nlmsg_flags & NLM_F_EXCL)
 
 
1249		return -EEXIST;
1250	if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id))
 
 
1251		return -EINVAL;
1252	err = qdisc_change(q, tca);
 
1253	if (err == 0)
1254		qdisc_notify(net, skb, n, clid, NULL, q);
1255	return err;
1256
1257create_n_graft:
1258	if (!(n->nlmsg_flags & NLM_F_CREATE))
 
1259		return -ENOENT;
 
1260	if (clid == TC_H_INGRESS) {
1261		if (dev_ingress_queue(dev))
1262			q = qdisc_create(dev, dev_ingress_queue(dev), p,
1263					 tcm->tcm_parent, tcm->tcm_parent,
1264					 tca, &err);
1265		else
 
1266			err = -ENOENT;
 
1267	} else {
1268		struct netdev_queue *dev_queue;
1269
1270		if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1271			dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1272		else if (p)
1273			dev_queue = p->dev_queue;
1274		else
1275			dev_queue = netdev_get_tx_queue(dev, 0);
1276
1277		q = qdisc_create(dev, dev_queue, p,
1278				 tcm->tcm_parent, tcm->tcm_handle,
1279				 tca, &err);
1280	}
1281	if (q == NULL) {
1282		if (err == -EAGAIN)
1283			goto replay;
1284		return err;
1285	}
1286
1287graft:
1288	err = qdisc_graft(dev, p, skb, n, clid, q, NULL);
1289	if (err) {
1290		if (q)
1291			qdisc_destroy(q);
1292		return err;
1293	}
1294
1295	return 0;
1296}
1297
1298static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
1299			 u32 portid, u32 seq, u16 flags, int event)
1300{
1301	struct tcmsg *tcm;
1302	struct nlmsghdr  *nlh;
1303	unsigned char *b = skb_tail_pointer(skb);
1304	struct gnet_dump d;
1305	struct qdisc_size_table *stab;
1306
1307	cond_resched();
1308	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1309	if (!nlh)
1310		goto out_nlmsg_trim;
1311	tcm = nlmsg_data(nlh);
1312	tcm->tcm_family = AF_UNSPEC;
1313	tcm->tcm__pad1 = 0;
1314	tcm->tcm__pad2 = 0;
1315	tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1316	tcm->tcm_parent = clid;
1317	tcm->tcm_handle = q->handle;
1318	tcm->tcm_info = atomic_read(&q->refcnt);
1319	if (nla_put_string(skb, TCA_KIND, q->ops->id))
1320		goto nla_put_failure;
1321	if (q->ops->dump && q->ops->dump(q, skb) < 0)
1322		goto nla_put_failure;
1323	q->qstats.qlen = q->q.qlen;
1324
1325	stab = rtnl_dereference(q->stab);
1326	if (stab && qdisc_dump_stab(skb, stab) < 0)
1327		goto nla_put_failure;
1328
1329	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1330					 qdisc_root_sleeping_lock(q), &d) < 0)
1331		goto nla_put_failure;
1332
1333	if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
1334		goto nla_put_failure;
1335
1336	if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
1337	    gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
1338	    gnet_stats_copy_queue(&d, &q->qstats) < 0)
1339		goto nla_put_failure;
1340
1341	if (gnet_stats_finish_copy(&d) < 0)
1342		goto nla_put_failure;
1343
1344	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1345	return skb->len;
1346
1347out_nlmsg_trim:
1348nla_put_failure:
1349	nlmsg_trim(skb, b);
1350	return -1;
1351}
1352
1353static bool tc_qdisc_dump_ignore(struct Qdisc *q)
1354{
1355	return (q->flags & TCQ_F_BUILTIN) ? true : false;
1356}
1357
1358static int qdisc_notify(struct net *net, struct sk_buff *oskb,
1359			struct nlmsghdr *n, u32 clid,
1360			struct Qdisc *old, struct Qdisc *new)
1361{
1362	struct sk_buff *skb;
1363	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1364
1365	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1366	if (!skb)
1367		return -ENOBUFS;
1368
1369	if (old && !tc_qdisc_dump_ignore(old)) {
1370		if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1371				  0, RTM_DELQDISC) < 0)
1372			goto err_out;
1373	}
1374	if (new && !tc_qdisc_dump_ignore(new)) {
1375		if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1376				  old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1377			goto err_out;
1378	}
1379
1380	if (skb->len)
1381		return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1382				      n->nlmsg_flags & NLM_F_ECHO);
1383
1384err_out:
1385	kfree_skb(skb);
1386	return -EINVAL;
1387}
1388
1389static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1390			      struct netlink_callback *cb,
1391			      int *q_idx_p, int s_q_idx)
 
1392{
1393	int ret = 0, q_idx = *q_idx_p;
1394	struct Qdisc *q;
 
1395
1396	if (!root)
1397		return 0;
1398
1399	q = root;
1400	if (q_idx < s_q_idx) {
1401		q_idx++;
1402	} else {
1403		if (!tc_qdisc_dump_ignore(q) &&
1404		    tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1405				  cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
 
1406			goto done;
1407		q_idx++;
1408	}
1409	list_for_each_entry(q, &root->list, list) {
 
 
 
 
 
 
 
 
 
 
1410		if (q_idx < s_q_idx) {
1411			q_idx++;
1412			continue;
1413		}
1414		if (!tc_qdisc_dump_ignore(q) &&
1415		    tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1416				  cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0)
 
1417			goto done;
1418		q_idx++;
1419	}
1420
1421out:
1422	*q_idx_p = q_idx;
1423	return ret;
1424done:
1425	ret = -1;
1426	goto out;
1427}
1428
1429static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1430{
1431	struct net *net = sock_net(skb->sk);
1432	int idx, q_idx;
1433	int s_idx, s_q_idx;
1434	struct net_device *dev;
 
 
 
1435
1436	s_idx = cb->args[0];
1437	s_q_idx = q_idx = cb->args[1];
1438
1439	idx = 0;
1440	ASSERT_RTNL();
 
 
 
 
 
 
1441	for_each_netdev(net, dev) {
1442		struct netdev_queue *dev_queue;
1443
1444		if (idx < s_idx)
1445			goto cont;
1446		if (idx > s_idx)
1447			s_q_idx = 0;
1448		q_idx = 0;
1449
1450		if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
 
 
1451			goto done;
1452
1453		dev_queue = dev_ingress_queue(dev);
1454		if (dev_queue &&
1455		    tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1456				       &q_idx, s_q_idx) < 0)
 
1457			goto done;
1458
1459cont:
1460		idx++;
1461	}
1462
1463done:
1464	cb->args[0] = idx;
1465	cb->args[1] = q_idx;
1466
1467	return skb->len;
1468}
1469
1470
1471
1472/************************************************
1473 *	Traffic classes manipulation.		*
1474 ************************************************/
1475
 
 
 
 
 
 
 
 
 
1476
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1477
1478static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1479{
1480	struct net *net = sock_net(skb->sk);
1481	struct tcmsg *tcm = nlmsg_data(n);
1482	struct nlattr *tca[TCA_MAX + 1];
1483	struct net_device *dev;
1484	struct Qdisc *q = NULL;
1485	const struct Qdisc_class_ops *cops;
1486	unsigned long cl = 0;
1487	unsigned long new_cl;
1488	u32 portid;
1489	u32 clid;
1490	u32 qid;
1491	int err;
1492
1493	if ((n->nlmsg_type != RTM_GETTCLASS) && !netlink_capable(skb, CAP_NET_ADMIN))
1494		return -EPERM;
1495
1496	err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
1497	if (err < 0)
1498		return err;
1499
1500	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1501	if (!dev)
1502		return -ENODEV;
1503
1504	/*
1505	   parent == TC_H_UNSPEC - unspecified parent.
1506	   parent == TC_H_ROOT   - class is root, which has no parent.
1507	   parent == X:0	 - parent is root class.
1508	   parent == X:Y	 - parent is a node in hierarchy.
1509	   parent == 0:Y	 - parent is X:Y, where X:0 is qdisc.
1510
1511	   handle == 0:0	 - generate handle from kernel pool.
1512	   handle == 0:Y	 - class is X:Y, where X:0 is qdisc.
1513	   handle == X:Y	 - clear.
1514	   handle == X:0	 - root class.
1515	 */
1516
1517	/* Step 1. Determine qdisc handle X:0 */
1518
1519	portid = tcm->tcm_parent;
1520	clid = tcm->tcm_handle;
1521	qid = TC_H_MAJ(clid);
1522
1523	if (portid != TC_H_ROOT) {
1524		u32 qid1 = TC_H_MAJ(portid);
1525
1526		if (qid && qid1) {
1527			/* If both majors are known, they must be identical. */
1528			if (qid != qid1)
1529				return -EINVAL;
1530		} else if (qid1) {
1531			qid = qid1;
1532		} else if (qid == 0)
1533			qid = dev->qdisc->handle;
1534
1535		/* Now qid is genuine qdisc handle consistent
1536		 * both with parent and child.
1537		 *
1538		 * TC_H_MAJ(portid) still may be unspecified, complete it now.
1539		 */
1540		if (portid)
1541			portid = TC_H_MAKE(qid, portid);
1542	} else {
1543		if (qid == 0)
1544			qid = dev->qdisc->handle;
1545	}
1546
1547	/* OK. Locate qdisc */
1548	q = qdisc_lookup(dev, qid);
1549	if (!q)
1550		return -ENOENT;
1551
1552	/* An check that it supports classes */
1553	cops = q->ops->cl_ops;
1554	if (cops == NULL)
1555		return -EINVAL;
1556
1557	/* Now try to get class */
1558	if (clid == 0) {
1559		if (portid == TC_H_ROOT)
1560			clid = qid;
1561	} else
1562		clid = TC_H_MAKE(qid, clid);
1563
1564	if (clid)
1565		cl = cops->get(q, clid);
1566
1567	if (cl == 0) {
1568		err = -ENOENT;
1569		if (n->nlmsg_type != RTM_NEWTCLASS ||
1570		    !(n->nlmsg_flags & NLM_F_CREATE))
1571			goto out;
1572	} else {
1573		switch (n->nlmsg_type) {
1574		case RTM_NEWTCLASS:
1575			err = -EEXIST;
1576			if (n->nlmsg_flags & NLM_F_EXCL)
1577				goto out;
1578			break;
1579		case RTM_DELTCLASS:
1580			err = -EOPNOTSUPP;
1581			if (cops->delete)
1582				err = cops->delete(q, cl);
1583			if (err == 0)
1584				tclass_notify(net, skb, n, q, cl, RTM_DELTCLASS);
1585			goto out;
1586		case RTM_GETTCLASS:
1587			err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
1588			goto out;
1589		default:
1590			err = -EINVAL;
1591			goto out;
1592		}
1593	}
1594
 
 
 
 
 
1595	new_cl = cl;
1596	err = -EOPNOTSUPP;
1597	if (cops->change)
1598		err = cops->change(q, clid, portid, tca, &new_cl);
1599	if (err == 0)
1600		tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
1601
 
 
 
1602out:
1603	if (cl)
1604		cops->put(q, cl);
1605
1606	return err;
1607}
1608
1609
1610static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1611			  unsigned long cl,
1612			  u32 portid, u32 seq, u16 flags, int event)
1613{
1614	struct tcmsg *tcm;
1615	struct nlmsghdr  *nlh;
1616	unsigned char *b = skb_tail_pointer(skb);
1617	struct gnet_dump d;
1618	const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1619
1620	cond_resched();
1621	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1622	if (!nlh)
1623		goto out_nlmsg_trim;
1624	tcm = nlmsg_data(nlh);
1625	tcm->tcm_family = AF_UNSPEC;
1626	tcm->tcm__pad1 = 0;
1627	tcm->tcm__pad2 = 0;
1628	tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1629	tcm->tcm_parent = q->handle;
1630	tcm->tcm_handle = q->handle;
1631	tcm->tcm_info = 0;
1632	if (nla_put_string(skb, TCA_KIND, q->ops->id))
1633		goto nla_put_failure;
1634	if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1635		goto nla_put_failure;
1636
1637	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1638					 qdisc_root_sleeping_lock(q), &d) < 0)
1639		goto nla_put_failure;
1640
1641	if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1642		goto nla_put_failure;
1643
1644	if (gnet_stats_finish_copy(&d) < 0)
1645		goto nla_put_failure;
1646
1647	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1648	return skb->len;
1649
1650out_nlmsg_trim:
1651nla_put_failure:
1652	nlmsg_trim(skb, b);
1653	return -1;
1654}
1655
1656static int tclass_notify(struct net *net, struct sk_buff *oskb,
1657			 struct nlmsghdr *n, struct Qdisc *q,
1658			 unsigned long cl, int event)
1659{
1660	struct sk_buff *skb;
1661	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1662
1663	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1664	if (!skb)
1665		return -ENOBUFS;
1666
1667	if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1668		kfree_skb(skb);
1669		return -EINVAL;
1670	}
1671
1672	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1673			      n->nlmsg_flags & NLM_F_ECHO);
1674}
1675
1676struct qdisc_dump_args {
1677	struct qdisc_walker	w;
1678	struct sk_buff		*skb;
1679	struct netlink_callback	*cb;
1680};
1681
1682static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg)
 
1683{
1684	struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
1685
1686	return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
1687			      a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS);
 
1688}
1689
1690static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
1691				struct tcmsg *tcm, struct netlink_callback *cb,
1692				int *t_p, int s_t)
1693{
1694	struct qdisc_dump_args arg;
1695
1696	if (tc_qdisc_dump_ignore(q) ||
1697	    *t_p < s_t || !q->ops->cl_ops ||
1698	    (tcm->tcm_parent &&
1699	     TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
1700		(*t_p)++;
1701		return 0;
1702	}
1703	if (*t_p > s_t)
1704		memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
1705	arg.w.fn = qdisc_class_dump;
1706	arg.skb = skb;
1707	arg.cb = cb;
1708	arg.w.stop  = 0;
1709	arg.w.skip = cb->args[1];
1710	arg.w.count = 0;
1711	q->ops->cl_ops->walk(q, &arg.w);
1712	cb->args[1] = arg.w.count;
1713	if (arg.w.stop)
1714		return -1;
1715	(*t_p)++;
1716	return 0;
1717}
1718
1719static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
1720			       struct tcmsg *tcm, struct netlink_callback *cb,
1721			       int *t_p, int s_t)
1722{
1723	struct Qdisc *q;
 
1724
1725	if (!root)
1726		return 0;
1727
1728	if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
1729		return -1;
1730
1731	list_for_each_entry(q, &root->list, list) {
 
 
 
 
 
 
 
 
 
 
1732		if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
1733			return -1;
1734	}
1735
1736	return 0;
1737}
1738
1739static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
1740{
1741	struct tcmsg *tcm = nlmsg_data(cb->nlh);
1742	struct net *net = sock_net(skb->sk);
1743	struct netdev_queue *dev_queue;
1744	struct net_device *dev;
1745	int t, s_t;
1746
1747	if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1748		return 0;
1749	dev = dev_get_by_index(net, tcm->tcm_ifindex);
1750	if (!dev)
1751		return 0;
1752
1753	s_t = cb->args[0];
1754	t = 0;
1755
1756	if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
 
1757		goto done;
1758
1759	dev_queue = dev_ingress_queue(dev);
1760	if (dev_queue &&
1761	    tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
1762				&t, s_t) < 0)
1763		goto done;
1764
1765done:
1766	cb->args[0] = t;
1767
1768	dev_put(dev);
1769	return skb->len;
1770}
1771
1772/* Main classifier routine: scans classifier chain attached
1773 * to this qdisc, (optionally) tests for protocol and asks
1774 * specific classifiers.
1775 */
1776int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
1777		       struct tcf_result *res)
1778{
1779	__be16 protocol = skb->protocol;
1780	int err;
1781
1782	for (; tp; tp = tp->next) {
1783		if (tp->protocol != protocol &&
1784		    tp->protocol != htons(ETH_P_ALL))
1785			continue;
1786		err = tp->classify(skb, tp, res);
1787
1788		if (err >= 0) {
1789#ifdef CONFIG_NET_CLS_ACT
1790			if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
1791				skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
1792#endif
1793			return err;
1794		}
1795	}
1796	return -1;
1797}
1798EXPORT_SYMBOL(tc_classify_compat);
1799
1800int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1801		struct tcf_result *res)
1802{
1803	int err = 0;
1804#ifdef CONFIG_NET_CLS_ACT
1805	const struct tcf_proto *otp = tp;
1806reclassify:
1807#endif
1808
1809	err = tc_classify_compat(skb, tp, res);
1810#ifdef CONFIG_NET_CLS_ACT
1811	if (err == TC_ACT_RECLASSIFY) {
1812		u32 verd = G_TC_VERD(skb->tc_verd);
1813		tp = otp;
1814
1815		if (verd++ >= MAX_REC_LOOP) {
1816			net_notice_ratelimited("%s: packet reclassify loop rule prio %u protocol %02x\n",
1817					       tp->q->ops->id,
1818					       tp->prio & 0xffff,
1819					       ntohs(tp->protocol));
1820			return TC_ACT_SHOT;
1821		}
1822		skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
1823		goto reclassify;
1824	}
1825#endif
1826	return err;
1827}
1828EXPORT_SYMBOL(tc_classify);
1829
1830void tcf_destroy(struct tcf_proto *tp)
1831{
1832	tp->ops->destroy(tp);
1833	module_put(tp->ops->owner);
1834	kfree(tp);
1835}
1836
1837void tcf_destroy_chain(struct tcf_proto **fl)
1838{
1839	struct tcf_proto *tp;
1840
1841	while ((tp = *fl) != NULL) {
1842		*fl = tp->next;
1843		tcf_destroy(tp);
1844	}
1845}
1846EXPORT_SYMBOL(tcf_destroy_chain);
1847
1848#ifdef CONFIG_PROC_FS
1849static int psched_show(struct seq_file *seq, void *v)
1850{
1851	struct timespec ts;
1852
1853	hrtimer_get_res(CLOCK_MONOTONIC, &ts);
1854	seq_printf(seq, "%08x %08x %08x %08x\n",
1855		   (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
1856		   1000000,
1857		   (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
1858
1859	return 0;
1860}
1861
1862static int psched_open(struct inode *inode, struct file *file)
1863{
1864	return single_open(file, psched_show, NULL);
1865}
1866
1867static const struct file_operations psched_fops = {
1868	.owner = THIS_MODULE,
1869	.open = psched_open,
1870	.read  = seq_read,
1871	.llseek = seq_lseek,
1872	.release = single_release,
1873};
1874
1875static int __net_init psched_net_init(struct net *net)
1876{
1877	struct proc_dir_entry *e;
1878
1879	e = proc_create("psched", 0, net->proc_net, &psched_fops);
1880	if (e == NULL)
1881		return -ENOMEM;
1882
1883	return 0;
1884}
1885
1886static void __net_exit psched_net_exit(struct net *net)
1887{
1888	remove_proc_entry("psched", net->proc_net);
1889}
1890#else
1891static int __net_init psched_net_init(struct net *net)
1892{
1893	return 0;
1894}
1895
1896static void __net_exit psched_net_exit(struct net *net)
1897{
1898}
1899#endif
1900
1901static struct pernet_operations psched_net_ops = {
1902	.init = psched_net_init,
1903	.exit = psched_net_exit,
1904};
1905
 
 
1906static int __init pktsched_init(void)
1907{
1908	int err;
1909
1910	err = register_pernet_subsys(&psched_net_ops);
1911	if (err) {
1912		pr_err("pktsched_init: "
1913		       "cannot initialize per netns operations\n");
1914		return err;
1915	}
1916
1917	register_qdisc(&pfifo_fast_ops);
1918	register_qdisc(&pfifo_qdisc_ops);
1919	register_qdisc(&bfifo_qdisc_ops);
1920	register_qdisc(&pfifo_head_drop_qdisc_ops);
1921	register_qdisc(&mq_qdisc_ops);
 
 
 
 
 
 
 
 
 
 
1922
1923	rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
1924	rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
1925	rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
1926	rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
1927	rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
1928	rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
1929
1930	return 0;
1931}
1932
1933subsys_initcall(pktsched_init);
v6.2
   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("sch_%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			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(nq->qdisc_sleeping, handle);
 332out:
 333	return q;
 334}
 335
 336static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
 337{
 338	unsigned long cl;
 
 339	const struct Qdisc_class_ops *cops = p->ops->cl_ops;
 340
 341	if (cops == NULL)
 342		return NULL;
 343	cl = cops->find(p, classid);
 344
 345	if (cl == 0)
 346		return NULL;
 347	return cops->leaf(p, cl);
 
 
 348}
 349
 350/* Find queueing discipline by name */
 351
 352static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind)
 353{
 354	struct Qdisc_ops *q = NULL;
 355
 356	if (kind) {
 357		read_lock(&qdisc_mod_lock);
 358		for (q = qdisc_base; q; q = q->next) {
 359			if (nla_strcmp(kind, q->id) == 0) {
 360				if (!try_module_get(q->owner))
 361					q = NULL;
 362				break;
 363			}
 364		}
 365		read_unlock(&qdisc_mod_lock);
 366	}
 367	return q;
 368}
 369
 370/* The linklayer setting were not transferred from iproute2, in older
 371 * versions, and the rate tables lookup systems have been dropped in
 372 * the kernel. To keep backward compatible with older iproute2 tc
 373 * utils, we detect the linklayer setting by detecting if the rate
 374 * table were modified.
 375 *
 376 * For linklayer ATM table entries, the rate table will be aligned to
 377 * 48 bytes, thus some table entries will contain the same value.  The
 378 * mpu (min packet unit) is also encoded into the old rate table, thus
 379 * starting from the mpu, we find low and high table entries for
 380 * mapping this cell.  If these entries contain the same value, when
 381 * the rate tables have been modified for linklayer ATM.
 382 *
 383 * This is done by rounding mpu to the nearest 48 bytes cell/entry,
 384 * and then roundup to the next cell, calc the table entry one below,
 385 * and compare.
 386 */
 387static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab)
 388{
 389	int low       = roundup(r->mpu, 48);
 390	int high      = roundup(low+1, 48);
 391	int cell_low  = low >> r->cell_log;
 392	int cell_high = (high >> r->cell_log) - 1;
 393
 394	/* rtab is too inaccurate at rates > 100Mbit/s */
 395	if ((r->rate > (100000000/8)) || (rtab[0] == 0)) {
 396		pr_debug("TC linklayer: Giving up ATM detection\n");
 397		return TC_LINKLAYER_ETHERNET;
 398	}
 399
 400	if ((cell_high > cell_low) && (cell_high < 256)
 401	    && (rtab[cell_low] == rtab[cell_high])) {
 402		pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n",
 403			 cell_low, cell_high, rtab[cell_high]);
 404		return TC_LINKLAYER_ATM;
 405	}
 406	return TC_LINKLAYER_ETHERNET;
 407}
 408
 409static struct qdisc_rate_table *qdisc_rtab_list;
 410
 411struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
 412					struct nlattr *tab,
 413					struct netlink_ext_ack *extack)
 414{
 415	struct qdisc_rate_table *rtab;
 416
 417	if (tab == NULL || r->rate == 0 ||
 418	    r->cell_log == 0 || r->cell_log >= 32 ||
 419	    nla_len(tab) != TC_RTAB_SIZE) {
 420		NL_SET_ERR_MSG(extack, "Invalid rate table parameters for searching");
 421		return NULL;
 422	}
 423
 424	for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) {
 425		if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) &&
 426		    !memcmp(&rtab->data, nla_data(tab), 1024)) {
 427			rtab->refcnt++;
 428			return rtab;
 429		}
 430	}
 431
 432	rtab = kmalloc(sizeof(*rtab), GFP_KERNEL);
 433	if (rtab) {
 434		rtab->rate = *r;
 435		rtab->refcnt = 1;
 436		memcpy(rtab->data, nla_data(tab), 1024);
 437		if (r->linklayer == TC_LINKLAYER_UNAWARE)
 438			r->linklayer = __detect_linklayer(r, rtab->data);
 439		rtab->next = qdisc_rtab_list;
 440		qdisc_rtab_list = rtab;
 441	} else {
 442		NL_SET_ERR_MSG(extack, "Failed to allocate new qdisc rate table");
 443	}
 444	return rtab;
 445}
 446EXPORT_SYMBOL(qdisc_get_rtab);
 447
 448void qdisc_put_rtab(struct qdisc_rate_table *tab)
 449{
 450	struct qdisc_rate_table *rtab, **rtabp;
 451
 452	if (!tab || --tab->refcnt)
 453		return;
 454
 455	for (rtabp = &qdisc_rtab_list;
 456	     (rtab = *rtabp) != NULL;
 457	     rtabp = &rtab->next) {
 458		if (rtab == tab) {
 459			*rtabp = rtab->next;
 460			kfree(rtab);
 461			return;
 462		}
 463	}
 464}
 465EXPORT_SYMBOL(qdisc_put_rtab);
 466
 467static LIST_HEAD(qdisc_stab_list);
 
 468
 469static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
 470	[TCA_STAB_BASE]	= { .len = sizeof(struct tc_sizespec) },
 471	[TCA_STAB_DATA] = { .type = NLA_BINARY },
 472};
 473
 474static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt,
 475					       struct netlink_ext_ack *extack)
 476{
 477	struct nlattr *tb[TCA_STAB_MAX + 1];
 478	struct qdisc_size_table *stab;
 479	struct tc_sizespec *s;
 480	unsigned int tsize = 0;
 481	u16 *tab = NULL;
 482	int err;
 483
 484	err = nla_parse_nested_deprecated(tb, TCA_STAB_MAX, opt, stab_policy,
 485					  extack);
 486	if (err < 0)
 487		return ERR_PTR(err);
 488	if (!tb[TCA_STAB_BASE]) {
 489		NL_SET_ERR_MSG(extack, "Size table base attribute is missing");
 490		return ERR_PTR(-EINVAL);
 491	}
 492
 493	s = nla_data(tb[TCA_STAB_BASE]);
 494
 495	if (s->tsize > 0) {
 496		if (!tb[TCA_STAB_DATA]) {
 497			NL_SET_ERR_MSG(extack, "Size table data attribute is missing");
 498			return ERR_PTR(-EINVAL);
 499		}
 500		tab = nla_data(tb[TCA_STAB_DATA]);
 501		tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
 502	}
 503
 504	if (tsize != s->tsize || (!tab && tsize > 0)) {
 505		NL_SET_ERR_MSG(extack, "Invalid size of size table");
 506		return ERR_PTR(-EINVAL);
 507	}
 
 508
 509	list_for_each_entry(stab, &qdisc_stab_list, list) {
 510		if (memcmp(&stab->szopts, s, sizeof(*s)))
 511			continue;
 512		if (tsize > 0 &&
 513		    memcmp(stab->data, tab, flex_array_size(stab, data, tsize)))
 514			continue;
 515		stab->refcnt++;
 
 516		return stab;
 517	}
 518
 519	if (s->size_log > STAB_SIZE_LOG_MAX ||
 520	    s->cell_log > STAB_SIZE_LOG_MAX) {
 521		NL_SET_ERR_MSG(extack, "Invalid logarithmic size of size table");
 522		return ERR_PTR(-EINVAL);
 523	}
 524
 525	stab = kmalloc(struct_size(stab, data, tsize), GFP_KERNEL);
 526	if (!stab)
 527		return ERR_PTR(-ENOMEM);
 528
 529	stab->refcnt = 1;
 530	stab->szopts = *s;
 531	if (tsize > 0)
 532		memcpy(stab->data, tab, flex_array_size(stab, data, tsize));
 533
 
 534	list_add_tail(&stab->list, &qdisc_stab_list);
 
 535
 536	return stab;
 537}
 538
 
 
 
 
 
 539void qdisc_put_stab(struct qdisc_size_table *tab)
 540{
 541	if (!tab)
 542		return;
 543
 
 
 544	if (--tab->refcnt == 0) {
 545		list_del(&tab->list);
 546		kfree_rcu(tab, rcu);
 547	}
 
 
 548}
 549EXPORT_SYMBOL(qdisc_put_stab);
 550
 551static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
 552{
 553	struct nlattr *nest;
 554
 555	nest = nla_nest_start_noflag(skb, TCA_STAB);
 556	if (nest == NULL)
 557		goto nla_put_failure;
 558	if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts))
 559		goto nla_put_failure;
 560	nla_nest_end(skb, nest);
 561
 562	return skb->len;
 563
 564nla_put_failure:
 565	return -1;
 566}
 567
 568void __qdisc_calculate_pkt_len(struct sk_buff *skb,
 569			       const struct qdisc_size_table *stab)
 570{
 571	int pkt_len, slot;
 572
 573	pkt_len = skb->len + stab->szopts.overhead;
 574	if (unlikely(!stab->szopts.tsize))
 575		goto out;
 576
 577	slot = pkt_len + stab->szopts.cell_align;
 578	if (unlikely(slot < 0))
 579		slot = 0;
 580
 581	slot >>= stab->szopts.cell_log;
 582	if (likely(slot < stab->szopts.tsize))
 583		pkt_len = stab->data[slot];
 584	else
 585		pkt_len = stab->data[stab->szopts.tsize - 1] *
 586				(slot / stab->szopts.tsize) +
 587				stab->data[slot % stab->szopts.tsize];
 588
 589	pkt_len <<= stab->szopts.size_log;
 590out:
 591	if (unlikely(pkt_len < 1))
 592		pkt_len = 1;
 593	qdisc_skb_cb(skb)->pkt_len = pkt_len;
 594}
 595EXPORT_SYMBOL(__qdisc_calculate_pkt_len);
 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	if (test_bit(__QDISC_STATE_DEACTIVATED,
 638		     &qdisc_root_sleeping(wd->qdisc)->state))
 639		return;
 640
 641	if (hrtimer_is_queued(&wd->timer)) {
 642		/* If timer is already set in [expires, expires + delta_ns],
 643		 * do not reprogram it.
 644		 */
 645		if (wd->last_expires - expires <= delta_ns)
 646			return;
 647	}
 648
 649	wd->last_expires = expires;
 650	hrtimer_start_range_ns(&wd->timer,
 651			       ns_to_ktime(expires),
 652			       delta_ns,
 653			       HRTIMER_MODE_ABS_PINNED);
 654}
 655EXPORT_SYMBOL(qdisc_watchdog_schedule_range_ns);
 656
 657void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
 658{
 659	hrtimer_cancel(&wd->timer);
 
 660}
 661EXPORT_SYMBOL(qdisc_watchdog_cancel);
 662
 663static struct hlist_head *qdisc_class_hash_alloc(unsigned int n)
 664{
 
 665	struct hlist_head *h;
 666	unsigned int i;
 667
 668	h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL);
 
 
 
 
 669
 670	if (h != NULL) {
 671		for (i = 0; i < n; i++)
 672			INIT_HLIST_HEAD(&h[i]);
 673	}
 674	return h;
 675}
 676
 
 
 
 
 
 
 
 
 
 
 677void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash)
 678{
 679	struct Qdisc_class_common *cl;
 680	struct hlist_node *next;
 681	struct hlist_head *nhash, *ohash;
 682	unsigned int nsize, nmask, osize;
 683	unsigned int i, h;
 684
 685	/* Rehash when load factor exceeds 0.75 */
 686	if (clhash->hashelems * 4 <= clhash->hashsize * 3)
 687		return;
 688	nsize = clhash->hashsize * 2;
 689	nmask = nsize - 1;
 690	nhash = qdisc_class_hash_alloc(nsize);
 691	if (nhash == NULL)
 692		return;
 693
 694	ohash = clhash->hash;
 695	osize = clhash->hashsize;
 696
 697	sch_tree_lock(sch);
 698	for (i = 0; i < osize; i++) {
 699		hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) {
 700			h = qdisc_class_hash(cl->classid, nmask);
 701			hlist_add_head(&cl->hnode, &nhash[h]);
 702		}
 703	}
 704	clhash->hash     = nhash;
 705	clhash->hashsize = nsize;
 706	clhash->hashmask = nmask;
 707	sch_tree_unlock(sch);
 708
 709	kvfree(ohash);
 710}
 711EXPORT_SYMBOL(qdisc_class_hash_grow);
 712
 713int qdisc_class_hash_init(struct Qdisc_class_hash *clhash)
 714{
 715	unsigned int size = 4;
 716
 717	clhash->hash = qdisc_class_hash_alloc(size);
 718	if (!clhash->hash)
 719		return -ENOMEM;
 720	clhash->hashsize  = size;
 721	clhash->hashmask  = size - 1;
 722	clhash->hashelems = 0;
 723	return 0;
 724}
 725EXPORT_SYMBOL(qdisc_class_hash_init);
 726
 727void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash)
 728{
 729	kvfree(clhash->hash);
 730}
 731EXPORT_SYMBOL(qdisc_class_hash_destroy);
 732
 733void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash,
 734			     struct Qdisc_class_common *cl)
 735{
 736	unsigned int h;
 737
 738	INIT_HLIST_NODE(&cl->hnode);
 739	h = qdisc_class_hash(cl->classid, clhash->hashmask);
 740	hlist_add_head(&cl->hnode, &clhash->hash[h]);
 741	clhash->hashelems++;
 742}
 743EXPORT_SYMBOL(qdisc_class_hash_insert);
 744
 745void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash,
 746			     struct Qdisc_class_common *cl)
 747{
 748	hlist_del(&cl->hnode);
 749	clhash->hashelems--;
 750}
 751EXPORT_SYMBOL(qdisc_class_hash_remove);
 752
 753/* Allocate an unique handle from space managed by kernel
 754 * Possible range is [8000-FFFF]:0000 (0x8000 values)
 755 */
 756static u32 qdisc_alloc_handle(struct net_device *dev)
 757{
 758	int i = 0x8000;
 759	static u32 autohandle = TC_H_MAKE(0x80000000U, 0);
 760
 761	do {
 762		autohandle += TC_H_MAKE(0x10000U, 0);
 763		if (autohandle == TC_H_MAKE(TC_H_ROOT, 0))
 764			autohandle = TC_H_MAKE(0x80000000U, 0);
 765		if (!qdisc_lookup(dev, autohandle))
 766			return autohandle;
 767		cond_resched();
 768	} while	(--i > 0);
 769
 770	return 0;
 771}
 772
 773void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len)
 774{
 775	bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED;
 776	const struct Qdisc_class_ops *cops;
 777	unsigned long cl;
 778	u32 parentid;
 779	bool notify;
 780	int drops;
 781
 782	if (n == 0 && len == 0)
 783		return;
 784	drops = max_t(int, n, 0);
 785	rcu_read_lock();
 786	while ((parentid = sch->parent)) {
 787		if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS))
 788			break;
 789
 790		if (sch->flags & TCQ_F_NOPARENT)
 791			break;
 792		/* Notify parent qdisc only if child qdisc becomes empty.
 793		 *
 794		 * If child was empty even before update then backlog
 795		 * counter is screwed and we skip notification because
 796		 * parent class is already passive.
 797		 *
 798		 * If the original child was offloaded then it is allowed
 799		 * to be seem as empty, so the parent is notified anyway.
 800		 */
 801		notify = !sch->q.qlen && !WARN_ON_ONCE(!n &&
 802						       !qdisc_is_offloaded);
 803		/* TODO: perform the search on a per txq basis */
 804		sch = qdisc_lookup(qdisc_dev(sch), TC_H_MAJ(parentid));
 805		if (sch == NULL) {
 806			WARN_ON_ONCE(parentid != TC_H_ROOT);
 807			break;
 808		}
 809		cops = sch->ops->cl_ops;
 810		if (notify && cops->qlen_notify) {
 811			cl = cops->find(sch, parentid);
 812			cops->qlen_notify(sch, cl);
 
 813		}
 814		sch->q.qlen -= n;
 815		sch->qstats.backlog -= len;
 816		__qdisc_qstats_drop(sch, drops);
 817	}
 818	rcu_read_unlock();
 819}
 820EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
 821
 822int qdisc_offload_dump_helper(struct Qdisc *sch, enum tc_setup_type type,
 823			      void *type_data)
 824{
 825	struct net_device *dev = qdisc_dev(sch);
 826	int err;
 827
 828	sch->flags &= ~TCQ_F_OFFLOADED;
 829	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
 830		return 0;
 831
 832	err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
 833	if (err == -EOPNOTSUPP)
 834		return 0;
 835
 836	if (!err)
 837		sch->flags |= TCQ_F_OFFLOADED;
 838
 839	return err;
 840}
 841EXPORT_SYMBOL(qdisc_offload_dump_helper);
 842
 843void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
 844				struct Qdisc *new, struct Qdisc *old,
 845				enum tc_setup_type type, void *type_data,
 846				struct netlink_ext_ack *extack)
 847{
 848	bool any_qdisc_is_offloaded;
 849	int err;
 850
 851	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
 852		return;
 853
 854	err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data);
 855
 856	/* Don't report error if the graft is part of destroy operation. */
 857	if (!err || !new || new == &noop_qdisc)
 858		return;
 859
 860	/* Don't report error if the parent, the old child and the new
 861	 * one are not offloaded.
 862	 */
 863	any_qdisc_is_offloaded = new->flags & TCQ_F_OFFLOADED;
 864	any_qdisc_is_offloaded |= sch && sch->flags & TCQ_F_OFFLOADED;
 865	any_qdisc_is_offloaded |= old && old->flags & TCQ_F_OFFLOADED;
 866
 867	if (any_qdisc_is_offloaded)
 868		NL_SET_ERR_MSG(extack, "Offloading graft operation failed.");
 869}
 870EXPORT_SYMBOL(qdisc_offload_graft_helper);
 871
 872void qdisc_offload_query_caps(struct net_device *dev,
 873			      enum tc_setup_type type,
 874			      void *caps, size_t caps_len)
 875{
 876	const struct net_device_ops *ops = dev->netdev_ops;
 877	struct tc_query_caps_base base = {
 878		.type = type,
 879		.caps = caps,
 880	};
 881
 882	memset(caps, 0, caps_len);
 883
 884	if (ops->ndo_setup_tc)
 885		ops->ndo_setup_tc(dev, TC_QUERY_CAPS, &base);
 886}
 887EXPORT_SYMBOL(qdisc_offload_query_caps);
 888
 889static void qdisc_offload_graft_root(struct net_device *dev,
 890				     struct Qdisc *new, struct Qdisc *old,
 891				     struct netlink_ext_ack *extack)
 892{
 893	struct tc_root_qopt_offload graft_offload = {
 894		.command	= TC_ROOT_GRAFT,
 895		.handle		= new ? new->handle : 0,
 896		.ingress	= (new && new->flags & TCQ_F_INGRESS) ||
 897				  (old && old->flags & TCQ_F_INGRESS),
 898	};
 899
 900	qdisc_offload_graft_helper(dev, NULL, new, old,
 901				   TC_SETUP_ROOT_QDISC, &graft_offload, extack);
 902}
 903
 904static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
 905			 u32 portid, u32 seq, u16 flags, int event)
 906{
 907	struct gnet_stats_basic_sync __percpu *cpu_bstats = NULL;
 908	struct gnet_stats_queue __percpu *cpu_qstats = NULL;
 909	struct tcmsg *tcm;
 910	struct nlmsghdr  *nlh;
 911	unsigned char *b = skb_tail_pointer(skb);
 912	struct gnet_dump d;
 913	struct qdisc_size_table *stab;
 914	u32 block_index;
 915	__u32 qlen;
 916
 917	cond_resched();
 918	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 919	if (!nlh)
 920		goto out_nlmsg_trim;
 921	tcm = nlmsg_data(nlh);
 922	tcm->tcm_family = AF_UNSPEC;
 923	tcm->tcm__pad1 = 0;
 924	tcm->tcm__pad2 = 0;
 925	tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
 926	tcm->tcm_parent = clid;
 927	tcm->tcm_handle = q->handle;
 928	tcm->tcm_info = refcount_read(&q->refcnt);
 929	if (nla_put_string(skb, TCA_KIND, q->ops->id))
 930		goto nla_put_failure;
 931	if (q->ops->ingress_block_get) {
 932		block_index = q->ops->ingress_block_get(q);
 933		if (block_index &&
 934		    nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index))
 935			goto nla_put_failure;
 936	}
 937	if (q->ops->egress_block_get) {
 938		block_index = q->ops->egress_block_get(q);
 939		if (block_index &&
 940		    nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index))
 941			goto nla_put_failure;
 942	}
 943	if (q->ops->dump && q->ops->dump(q, skb) < 0)
 944		goto nla_put_failure;
 945	if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED)))
 946		goto nla_put_failure;
 947	qlen = qdisc_qlen_sum(q);
 948
 949	stab = rtnl_dereference(q->stab);
 950	if (stab && qdisc_dump_stab(skb, stab) < 0)
 951		goto nla_put_failure;
 952
 953	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
 954					 NULL, &d, TCA_PAD) < 0)
 955		goto nla_put_failure;
 956
 957	if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
 958		goto nla_put_failure;
 959
 960	if (qdisc_is_percpu_stats(q)) {
 961		cpu_bstats = q->cpu_bstats;
 962		cpu_qstats = q->cpu_qstats;
 963	}
 964
 965	if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats, true) < 0 ||
 966	    gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
 967	    gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0)
 968		goto nla_put_failure;
 969
 970	if (gnet_stats_finish_copy(&d) < 0)
 971		goto nla_put_failure;
 972
 973	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 974	return skb->len;
 975
 976out_nlmsg_trim:
 977nla_put_failure:
 978	nlmsg_trim(skb, b);
 979	return -1;
 980}
 981
 982static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible)
 983{
 984	if (q->flags & TCQ_F_BUILTIN)
 985		return true;
 986	if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible)
 987		return true;
 988
 989	return false;
 990}
 991
 992static int qdisc_notify(struct net *net, struct sk_buff *oskb,
 993			struct nlmsghdr *n, u32 clid,
 994			struct Qdisc *old, struct Qdisc *new)
 995{
 996	struct sk_buff *skb;
 997	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 998
 999	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1000	if (!skb)
1001		return -ENOBUFS;
1002
1003	if (old && !tc_qdisc_dump_ignore(old, false)) {
1004		if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq,
1005				  0, RTM_DELQDISC) < 0)
1006			goto err_out;
1007	}
1008	if (new && !tc_qdisc_dump_ignore(new, false)) {
1009		if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq,
1010				  old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0)
1011			goto err_out;
1012	}
1013
1014	if (skb->len)
1015		return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1016				      n->nlmsg_flags & NLM_F_ECHO);
1017
1018err_out:
1019	kfree_skb(skb);
1020	return -EINVAL;
1021}
 
1022
1023static void notify_and_destroy(struct net *net, struct sk_buff *skb,
1024			       struct nlmsghdr *n, u32 clid,
1025			       struct Qdisc *old, struct Qdisc *new)
1026{
1027	if (new || old)
1028		qdisc_notify(net, skb, n, clid, old, new);
1029
1030	if (old)
1031		qdisc_put(old);
1032}
1033
1034static void qdisc_clear_nolock(struct Qdisc *sch)
1035{
1036	sch->flags &= ~TCQ_F_NOLOCK;
1037	if (!(sch->flags & TCQ_F_CPUSTATS))
1038		return;
1039
1040	free_percpu(sch->cpu_bstats);
1041	free_percpu(sch->cpu_qstats);
1042	sch->cpu_bstats = NULL;
1043	sch->cpu_qstats = NULL;
1044	sch->flags &= ~TCQ_F_CPUSTATS;
1045}
1046
1047/* Graft qdisc "new" to class "classid" of qdisc "parent" or
1048 * to device "dev".
1049 *
1050 * When appropriate send a netlink notification using 'skb'
1051 * and "n".
1052 *
1053 * On success, destroy old qdisc.
1054 */
1055
1056static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
1057		       struct sk_buff *skb, struct nlmsghdr *n, u32 classid,
1058		       struct Qdisc *new, struct Qdisc *old,
1059		       struct netlink_ext_ack *extack)
1060{
1061	struct Qdisc *q = old;
1062	struct net *net = dev_net(dev);
 
1063
1064	if (parent == NULL) {
1065		unsigned int i, num_q, ingress;
1066
1067		ingress = 0;
1068		num_q = dev->num_tx_queues;
1069		if ((q && q->flags & TCQ_F_INGRESS) ||
1070		    (new && new->flags & TCQ_F_INGRESS)) {
1071			num_q = 1;
1072			ingress = 1;
1073			if (!dev_ingress_queue(dev)) {
1074				NL_SET_ERR_MSG(extack, "Device does not have an ingress queue");
1075				return -ENOENT;
1076			}
1077		}
1078
1079		if (dev->flags & IFF_UP)
1080			dev_deactivate(dev);
1081
1082		qdisc_offload_graft_root(dev, new, old, extack);
1083
1084		if (new && new->ops->attach && !ingress)
1085			goto skip;
1086
1087		for (i = 0; i < num_q; i++) {
1088			struct netdev_queue *dev_queue = dev_ingress_queue(dev);
1089
1090			if (!ingress)
1091				dev_queue = netdev_get_tx_queue(dev, i);
1092
1093			old = dev_graft_qdisc(dev_queue, new);
1094			if (new && i > 0)
1095				qdisc_refcount_inc(new);
1096
1097			if (!ingress)
1098				qdisc_put(old);
1099		}
1100
1101skip:
1102		if (!ingress) {
1103			old = rtnl_dereference(dev->qdisc);
 
1104			if (new && !new->ops->attach)
1105				qdisc_refcount_inc(new);
1106			rcu_assign_pointer(dev->qdisc, new ? : &noop_qdisc);
1107
1108			notify_and_destroy(net, skb, n, classid, old, new);
1109
1110			if (new && new->ops->attach)
1111				new->ops->attach(new);
1112		} else {
1113			notify_and_destroy(net, skb, n, classid, old, new);
1114		}
1115
1116		if (dev->flags & IFF_UP)
1117			dev_activate(dev);
1118	} else {
1119		const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
1120		unsigned long cl;
1121		int err;
1122
1123		/* Only support running class lockless if parent is lockless */
1124		if (new && (new->flags & TCQ_F_NOLOCK) && !(parent->flags & TCQ_F_NOLOCK))
1125			qdisc_clear_nolock(new);
1126
1127		if (!cops || !cops->graft)
1128			return -EOPNOTSUPP;
1129
1130		cl = cops->find(parent, classid);
1131		if (!cl) {
1132			NL_SET_ERR_MSG(extack, "Specified class not found");
1133			return -ENOENT;
1134		}
1135
1136		if (new && new->ops == &noqueue_qdisc_ops) {
1137			NL_SET_ERR_MSG(extack, "Cannot assign noqueue to a class");
1138			return -EINVAL;
1139		}
1140
1141		err = cops->graft(parent, cl, new, &old, extack);
1142		if (err)
1143			return err;
1144		notify_and_destroy(net, skb, n, classid, old, new);
1145	}
1146	return 0;
1147}
1148
1149static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca,
1150				   struct netlink_ext_ack *extack)
1151{
1152	u32 block_index;
1153
1154	if (tca[TCA_INGRESS_BLOCK]) {
1155		block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]);
1156
1157		if (!block_index) {
1158			NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0");
1159			return -EINVAL;
1160		}
1161		if (!sch->ops->ingress_block_set) {
1162			NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported");
1163			return -EOPNOTSUPP;
1164		}
1165		sch->ops->ingress_block_set(sch, block_index);
1166	}
1167	if (tca[TCA_EGRESS_BLOCK]) {
1168		block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]);
1169
1170		if (!block_index) {
1171			NL_SET_ERR_MSG(extack, "Egress block index cannot be 0");
1172			return -EINVAL;
1173		}
1174		if (!sch->ops->egress_block_set) {
1175			NL_SET_ERR_MSG(extack, "Egress block sharing is not supported");
1176			return -EOPNOTSUPP;
1177		}
1178		sch->ops->egress_block_set(sch, block_index);
1179	}
1180	return 0;
1181}
1182
1183/*
1184   Allocate and initialize new qdisc.
1185
1186   Parameters are passed via opt.
1187 */
1188
1189static struct Qdisc *qdisc_create(struct net_device *dev,
1190				  struct netdev_queue *dev_queue,
1191				  u32 parent, u32 handle,
1192				  struct nlattr **tca, int *errp,
1193				  struct netlink_ext_ack *extack)
1194{
1195	int err;
1196	struct nlattr *kind = tca[TCA_KIND];
1197	struct Qdisc *sch;
1198	struct Qdisc_ops *ops;
1199	struct qdisc_size_table *stab;
1200
1201	ops = qdisc_lookup_ops(kind);
1202#ifdef CONFIG_MODULES
1203	if (ops == NULL && kind != NULL) {
1204		char name[IFNAMSIZ];
1205		if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) {
1206			/* We dropped the RTNL semaphore in order to
1207			 * perform the module load.  So, even if we
1208			 * succeeded in loading the module we have to
1209			 * tell the caller to replay the request.  We
1210			 * indicate this using -EAGAIN.
1211			 * We replay the request because the device may
1212			 * go away in the mean time.
1213			 */
1214			rtnl_unlock();
1215			request_module("sch_%s", name);
1216			rtnl_lock();
1217			ops = qdisc_lookup_ops(kind);
1218			if (ops != NULL) {
1219				/* We will try again qdisc_lookup_ops,
1220				 * so don't keep a reference.
1221				 */
1222				module_put(ops->owner);
1223				err = -EAGAIN;
1224				goto err_out;
1225			}
1226		}
1227	}
1228#endif
1229
1230	err = -ENOENT;
1231	if (!ops) {
1232		NL_SET_ERR_MSG(extack, "Specified qdisc kind is unknown");
1233		goto err_out;
1234	}
1235
1236	sch = qdisc_alloc(dev_queue, ops, extack);
1237	if (IS_ERR(sch)) {
1238		err = PTR_ERR(sch);
1239		goto err_out2;
1240	}
1241
1242	sch->parent = parent;
1243
1244	if (handle == TC_H_INGRESS) {
1245		sch->flags |= TCQ_F_INGRESS;
1246		handle = TC_H_MAKE(TC_H_INGRESS, 0);
 
1247	} else {
1248		if (handle == 0) {
1249			handle = qdisc_alloc_handle(dev);
1250			if (handle == 0) {
1251				NL_SET_ERR_MSG(extack, "Maximum number of qdisc handles was exceeded");
1252				err = -ENOSPC;
1253				goto err_out3;
1254			}
1255		}
 
1256		if (!netif_is_multiqueue(dev))
1257			sch->flags |= TCQ_F_ONETXQUEUE;
1258	}
1259
1260	sch->handle = handle;
1261
1262	/* This exist to keep backward compatible with a userspace
1263	 * loophole, what allowed userspace to get IFF_NO_QUEUE
1264	 * facility on older kernels by setting tx_queue_len=0 (prior
1265	 * to qdisc init), and then forgot to reinit tx_queue_len
1266	 * before again attaching a qdisc.
1267	 */
1268	if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) {
1269		dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
1270		netdev_info(dev, "Caught tx_queue_len zero misconfig\n");
1271	}
 
1272
1273	err = qdisc_block_indexes_set(sch, tca, extack);
1274	if (err)
1275		goto err_out3;
1276
1277	if (ops->init) {
1278		err = ops->init(sch, tca[TCA_OPTIONS], extack);
1279		if (err != 0)
1280			goto err_out5;
1281	}
 
1282
1283	if (tca[TCA_STAB]) {
1284		stab = qdisc_get_stab(tca[TCA_STAB], extack);
1285		if (IS_ERR(stab)) {
1286			err = PTR_ERR(stab);
1287			goto err_out4;
1288		}
1289		rcu_assign_pointer(sch->stab, stab);
1290	}
1291	if (tca[TCA_RATE]) {
1292		err = -EOPNOTSUPP;
1293		if (sch->flags & TCQ_F_MQROOT) {
1294			NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc");
1295			goto err_out4;
1296		}
1297
1298		err = gen_new_estimator(&sch->bstats,
1299					sch->cpu_bstats,
1300					&sch->rate_est,
1301					NULL,
1302					true,
1303					tca[TCA_RATE]);
1304		if (err) {
1305			NL_SET_ERR_MSG(extack, "Failed to generate new estimator");
1306			goto err_out4;
1307		}
1308	}
1309
1310	qdisc_hash_add(sch, false);
1311	trace_qdisc_create(ops, dev, parent);
1312
1313	return sch;
1314
1315err_out5:
1316	/* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */
1317	if (ops->destroy)
1318		ops->destroy(sch);
1319err_out3:
1320	netdev_put(dev, &sch->dev_tracker);
1321	qdisc_free(sch);
1322err_out2:
1323	module_put(ops->owner);
1324err_out:
1325	*errp = err;
1326	return NULL;
1327
1328err_out4:
1329	/*
1330	 * Any broken qdiscs that would require a ops->reset() here?
1331	 * The qdisc was never in action so it shouldn't be necessary.
1332	 */
1333	qdisc_put_stab(rtnl_dereference(sch->stab));
1334	if (ops->destroy)
1335		ops->destroy(sch);
1336	goto err_out3;
1337}
1338
1339static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
1340			struct netlink_ext_ack *extack)
1341{
1342	struct qdisc_size_table *ostab, *stab = NULL;
1343	int err = 0;
1344
1345	if (tca[TCA_OPTIONS]) {
1346		if (!sch->ops->change) {
1347			NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc");
1348			return -EINVAL;
1349		}
1350		if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
1351			NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
1352			return -EOPNOTSUPP;
1353		}
1354		err = sch->ops->change(sch, tca[TCA_OPTIONS], extack);
1355		if (err)
1356			return err;
1357	}
1358
1359	if (tca[TCA_STAB]) {
1360		stab = qdisc_get_stab(tca[TCA_STAB], extack);
1361		if (IS_ERR(stab))
1362			return PTR_ERR(stab);
1363	}
1364
1365	ostab = rtnl_dereference(sch->stab);
1366	rcu_assign_pointer(sch->stab, stab);
1367	qdisc_put_stab(ostab);
1368
1369	if (tca[TCA_RATE]) {
1370		/* NB: ignores errors from replace_estimator
1371		   because change can't be undone. */
1372		if (sch->flags & TCQ_F_MQROOT)
1373			goto out;
1374		gen_replace_estimator(&sch->bstats,
1375				      sch->cpu_bstats,
1376				      &sch->rate_est,
1377				      NULL,
1378				      true,
1379				      tca[TCA_RATE]);
1380	}
1381out:
1382	return 0;
1383}
1384
1385struct check_loop_arg {
1386	struct qdisc_walker	w;
1387	struct Qdisc		*p;
1388	int			depth;
1389};
1390
1391static int check_loop_fn(struct Qdisc *q, unsigned long cl,
1392			 struct qdisc_walker *w);
1393
1394static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth)
1395{
1396	struct check_loop_arg	arg;
1397
1398	if (q->ops->cl_ops == NULL)
1399		return 0;
1400
1401	arg.w.stop = arg.w.skip = arg.w.count = 0;
1402	arg.w.fn = check_loop_fn;
1403	arg.depth = depth;
1404	arg.p = p;
1405	q->ops->cl_ops->walk(q, &arg.w);
1406	return arg.w.stop ? -ELOOP : 0;
1407}
1408
1409static int
1410check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
1411{
1412	struct Qdisc *leaf;
1413	const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1414	struct check_loop_arg *arg = (struct check_loop_arg *)w;
1415
1416	leaf = cops->leaf(q, cl);
1417	if (leaf) {
1418		if (leaf == arg->p || arg->depth > 7)
1419			return -ELOOP;
1420		return check_loop(leaf, arg->p, arg->depth + 1);
1421	}
1422	return 0;
1423}
1424
1425const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = {
1426	[TCA_KIND]		= { .type = NLA_STRING },
1427	[TCA_RATE]		= { .type = NLA_BINARY,
1428				    .len = sizeof(struct tc_estimator) },
1429	[TCA_STAB]		= { .type = NLA_NESTED },
1430	[TCA_DUMP_INVISIBLE]	= { .type = NLA_FLAG },
1431	[TCA_CHAIN]		= { .type = NLA_U32 },
1432	[TCA_INGRESS_BLOCK]	= { .type = NLA_U32 },
1433	[TCA_EGRESS_BLOCK]	= { .type = NLA_U32 },
1434};
1435
1436/*
1437 * Delete/get qdisc.
1438 */
1439
1440static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1441			struct netlink_ext_ack *extack)
1442{
1443	struct net *net = sock_net(skb->sk);
1444	struct tcmsg *tcm = nlmsg_data(n);
1445	struct nlattr *tca[TCA_MAX + 1];
1446	struct net_device *dev;
1447	u32 clid;
1448	struct Qdisc *q = NULL;
1449	struct Qdisc *p = NULL;
1450	int err;
1451
1452	err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1453				     rtm_tca_policy, extack);
 
 
1454	if (err < 0)
1455		return err;
1456
1457	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1458	if (!dev)
1459		return -ENODEV;
1460
1461	clid = tcm->tcm_parent;
1462	if (clid) {
1463		if (clid != TC_H_ROOT) {
1464			if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
1465				p = qdisc_lookup(dev, TC_H_MAJ(clid));
1466				if (!p) {
1467					NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid");
1468					return -ENOENT;
1469				}
1470				q = qdisc_leaf(p, clid);
1471			} else if (dev_ingress_queue(dev)) {
1472				q = dev_ingress_queue(dev)->qdisc_sleeping;
1473			}
1474		} else {
1475			q = rtnl_dereference(dev->qdisc);
1476		}
1477		if (!q) {
1478			NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device");
1479			return -ENOENT;
1480		}
1481
1482		if (tcm->tcm_handle && q->handle != tcm->tcm_handle) {
1483			NL_SET_ERR_MSG(extack, "Invalid handle");
1484			return -EINVAL;
1485		}
1486	} else {
1487		q = qdisc_lookup(dev, tcm->tcm_handle);
1488		if (!q) {
1489			NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle");
1490			return -ENOENT;
1491		}
1492	}
1493
1494	if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1495		NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1496		return -EINVAL;
1497	}
1498
1499	if (n->nlmsg_type == RTM_DELQDISC) {
1500		if (!clid) {
1501			NL_SET_ERR_MSG(extack, "Classid cannot be zero");
1502			return -EINVAL;
1503		}
1504		if (q->handle == 0) {
1505			NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero");
1506			return -ENOENT;
1507		}
1508		err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack);
1509		if (err != 0)
1510			return err;
1511	} else {
1512		qdisc_notify(net, skb, n, clid, NULL, q);
1513	}
1514	return 0;
1515}
1516
1517/*
1518 * Create/change qdisc.
1519 */
1520
1521static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n,
1522			   struct netlink_ext_ack *extack)
1523{
1524	struct net *net = sock_net(skb->sk);
1525	struct tcmsg *tcm;
1526	struct nlattr *tca[TCA_MAX + 1];
1527	struct net_device *dev;
1528	u32 clid;
1529	struct Qdisc *q, *p;
1530	int err;
1531
 
 
 
1532replay:
1533	/* Reinit, just in case something touches this. */
1534	err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
1535				     rtm_tca_policy, extack);
1536	if (err < 0)
1537		return err;
1538
1539	tcm = nlmsg_data(n);
1540	clid = tcm->tcm_parent;
1541	q = p = NULL;
1542
1543	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1544	if (!dev)
1545		return -ENODEV;
1546
1547
1548	if (clid) {
1549		if (clid != TC_H_ROOT) {
1550			if (clid != TC_H_INGRESS) {
1551				p = qdisc_lookup(dev, TC_H_MAJ(clid));
1552				if (!p) {
1553					NL_SET_ERR_MSG(extack, "Failed to find specified qdisc");
1554					return -ENOENT;
1555				}
1556				q = qdisc_leaf(p, clid);
1557			} else if (dev_ingress_queue_create(dev)) {
1558				q = dev_ingress_queue(dev)->qdisc_sleeping;
1559			}
1560		} else {
1561			q = rtnl_dereference(dev->qdisc);
1562		}
1563
1564		/* It may be default qdisc, ignore it */
1565		if (q && q->handle == 0)
1566			q = NULL;
1567
1568		if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) {
1569			if (tcm->tcm_handle) {
1570				if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) {
1571					NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override");
1572					return -EEXIST;
1573				}
1574				if (TC_H_MIN(tcm->tcm_handle)) {
1575					NL_SET_ERR_MSG(extack, "Invalid minor handle");
1576					return -EINVAL;
1577				}
1578				q = qdisc_lookup(dev, tcm->tcm_handle);
1579				if (!q)
1580					goto create_n_graft;
1581				if (n->nlmsg_flags & NLM_F_EXCL) {
1582					NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override");
1583					return -EEXIST;
1584				}
1585				if (tca[TCA_KIND] &&
1586				    nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1587					NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1588					return -EINVAL;
1589				}
1590				if (q == p ||
1591				    (p && check_loop(q, p, 0))) {
1592					NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected");
1593					return -ELOOP;
1594				}
1595				qdisc_refcount_inc(q);
1596				goto graft;
1597			} else {
1598				if (!q)
1599					goto create_n_graft;
1600
1601				/* This magic test requires explanation.
1602				 *
1603				 *   We know, that some child q is already
1604				 *   attached to this parent and have choice:
1605				 *   either to change it or to create/graft new one.
1606				 *
1607				 *   1. We are allowed to create/graft only
1608				 *   if CREATE and REPLACE flags are set.
1609				 *
1610				 *   2. If EXCL is set, requestor wanted to say,
1611				 *   that qdisc tcm_handle is not expected
1612				 *   to exist, so that we choose create/graft too.
1613				 *
1614				 *   3. The last case is when no flags are set.
1615				 *   Alas, it is sort of hole in API, we
1616				 *   cannot decide what to do unambiguously.
1617				 *   For now we select create/graft, if
1618				 *   user gave KIND, which does not match existing.
1619				 */
1620				if ((n->nlmsg_flags & NLM_F_CREATE) &&
1621				    (n->nlmsg_flags & NLM_F_REPLACE) &&
1622				    ((n->nlmsg_flags & NLM_F_EXCL) ||
1623				     (tca[TCA_KIND] &&
1624				      nla_strcmp(tca[TCA_KIND], q->ops->id))))
1625					goto create_n_graft;
1626			}
1627		}
1628	} else {
1629		if (!tcm->tcm_handle) {
1630			NL_SET_ERR_MSG(extack, "Handle cannot be zero");
1631			return -EINVAL;
1632		}
1633		q = qdisc_lookup(dev, tcm->tcm_handle);
1634	}
1635
1636	/* Change qdisc parameters */
1637	if (!q) {
1638		NL_SET_ERR_MSG(extack, "Specified qdisc not found");
1639		return -ENOENT;
1640	}
1641	if (n->nlmsg_flags & NLM_F_EXCL) {
1642		NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify");
1643		return -EEXIST;
1644	}
1645	if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) {
1646		NL_SET_ERR_MSG(extack, "Invalid qdisc name");
1647		return -EINVAL;
1648	}
1649	err = qdisc_change(q, tca, extack);
1650	if (err == 0)
1651		qdisc_notify(net, skb, n, clid, NULL, q);
1652	return err;
1653
1654create_n_graft:
1655	if (!(n->nlmsg_flags & NLM_F_CREATE)) {
1656		NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag");
1657		return -ENOENT;
1658	}
1659	if (clid == TC_H_INGRESS) {
1660		if (dev_ingress_queue(dev)) {
1661			q = qdisc_create(dev, dev_ingress_queue(dev),
1662					 tcm->tcm_parent, tcm->tcm_parent,
1663					 tca, &err, extack);
1664		} else {
1665			NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device");
1666			err = -ENOENT;
1667		}
1668	} else {
1669		struct netdev_queue *dev_queue;
1670
1671		if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)
1672			dev_queue = p->ops->cl_ops->select_queue(p, tcm);
1673		else if (p)
1674			dev_queue = p->dev_queue;
1675		else
1676			dev_queue = netdev_get_tx_queue(dev, 0);
1677
1678		q = qdisc_create(dev, dev_queue,
1679				 tcm->tcm_parent, tcm->tcm_handle,
1680				 tca, &err, extack);
1681	}
1682	if (q == NULL) {
1683		if (err == -EAGAIN)
1684			goto replay;
1685		return err;
1686	}
1687
1688graft:
1689	err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack);
1690	if (err) {
1691		if (q)
1692			qdisc_put(q);
1693		return err;
1694	}
1695
1696	return 0;
1697}
1698
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1699static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb,
1700			      struct netlink_callback *cb,
1701			      int *q_idx_p, int s_q_idx, bool recur,
1702			      bool dump_invisible)
1703{
1704	int ret = 0, q_idx = *q_idx_p;
1705	struct Qdisc *q;
1706	int b;
1707
1708	if (!root)
1709		return 0;
1710
1711	q = root;
1712	if (q_idx < s_q_idx) {
1713		q_idx++;
1714	} else {
1715		if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1716		    tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1717				  cb->nlh->nlmsg_seq, NLM_F_MULTI,
1718				  RTM_NEWQDISC) <= 0)
1719			goto done;
1720		q_idx++;
1721	}
1722
1723	/* If dumping singletons, there is no qdisc_dev(root) and the singleton
1724	 * itself has already been dumped.
1725	 *
1726	 * If we've already dumped the top-level (ingress) qdisc above and the global
1727	 * qdisc hashtable, we don't want to hit it again
1728	 */
1729	if (!qdisc_dev(root) || !recur)
1730		goto out;
1731
1732	hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
1733		if (q_idx < s_q_idx) {
1734			q_idx++;
1735			continue;
1736		}
1737		if (!tc_qdisc_dump_ignore(q, dump_invisible) &&
1738		    tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid,
1739				  cb->nlh->nlmsg_seq, NLM_F_MULTI,
1740				  RTM_NEWQDISC) <= 0)
1741			goto done;
1742		q_idx++;
1743	}
1744
1745out:
1746	*q_idx_p = q_idx;
1747	return ret;
1748done:
1749	ret = -1;
1750	goto out;
1751}
1752
1753static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
1754{
1755	struct net *net = sock_net(skb->sk);
1756	int idx, q_idx;
1757	int s_idx, s_q_idx;
1758	struct net_device *dev;
1759	const struct nlmsghdr *nlh = cb->nlh;
1760	struct nlattr *tca[TCA_MAX + 1];
1761	int err;
1762
1763	s_idx = cb->args[0];
1764	s_q_idx = q_idx = cb->args[1];
1765
1766	idx = 0;
1767	ASSERT_RTNL();
1768
1769	err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX,
1770				     rtm_tca_policy, cb->extack);
1771	if (err < 0)
1772		return err;
1773
1774	for_each_netdev(net, dev) {
1775		struct netdev_queue *dev_queue;
1776
1777		if (idx < s_idx)
1778			goto cont;
1779		if (idx > s_idx)
1780			s_q_idx = 0;
1781		q_idx = 0;
1782
1783		if (tc_dump_qdisc_root(rtnl_dereference(dev->qdisc),
1784				       skb, cb, &q_idx, s_q_idx,
1785				       true, tca[TCA_DUMP_INVISIBLE]) < 0)
1786			goto done;
1787
1788		dev_queue = dev_ingress_queue(dev);
1789		if (dev_queue &&
1790		    tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb,
1791				       &q_idx, s_q_idx, false,
1792				       tca[TCA_DUMP_INVISIBLE]) < 0)
1793			goto done;
1794
1795cont:
1796		idx++;
1797	}
1798
1799done:
1800	cb->args[0] = idx;
1801	cb->args[1] = q_idx;
1802
1803	return skb->len;
1804}
1805
1806
1807
1808/************************************************
1809 *	Traffic classes manipulation.		*
1810 ************************************************/
1811
1812static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
1813			  unsigned long cl,
1814			  u32 portid, u32 seq, u16 flags, int event)
1815{
1816	struct tcmsg *tcm;
1817	struct nlmsghdr  *nlh;
1818	unsigned char *b = skb_tail_pointer(skb);
1819	struct gnet_dump d;
1820	const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
1821
1822	cond_resched();
1823	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1824	if (!nlh)
1825		goto out_nlmsg_trim;
1826	tcm = nlmsg_data(nlh);
1827	tcm->tcm_family = AF_UNSPEC;
1828	tcm->tcm__pad1 = 0;
1829	tcm->tcm__pad2 = 0;
1830	tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1831	tcm->tcm_parent = q->handle;
1832	tcm->tcm_handle = q->handle;
1833	tcm->tcm_info = 0;
1834	if (nla_put_string(skb, TCA_KIND, q->ops->id))
1835		goto nla_put_failure;
1836	if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
1837		goto nla_put_failure;
1838
1839	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
1840					 NULL, &d, TCA_PAD) < 0)
1841		goto nla_put_failure;
1842
1843	if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)
1844		goto nla_put_failure;
1845
1846	if (gnet_stats_finish_copy(&d) < 0)
1847		goto nla_put_failure;
1848
1849	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1850	return skb->len;
1851
1852out_nlmsg_trim:
1853nla_put_failure:
1854	nlmsg_trim(skb, b);
1855	return -1;
1856}
1857
1858static int tclass_notify(struct net *net, struct sk_buff *oskb,
1859			 struct nlmsghdr *n, struct Qdisc *q,
1860			 unsigned long cl, int event)
1861{
1862	struct sk_buff *skb;
1863	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1864
1865	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1866	if (!skb)
1867		return -ENOBUFS;
1868
1869	if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event) < 0) {
1870		kfree_skb(skb);
1871		return -EINVAL;
1872	}
1873
1874	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1875			      n->nlmsg_flags & NLM_F_ECHO);
1876}
1877
1878static int tclass_del_notify(struct net *net,
1879			     const struct Qdisc_class_ops *cops,
1880			     struct sk_buff *oskb, struct nlmsghdr *n,
1881			     struct Qdisc *q, unsigned long cl,
1882			     struct netlink_ext_ack *extack)
1883{
1884	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1885	struct sk_buff *skb;
1886	int err = 0;
1887
1888	if (!cops->delete)
1889		return -EOPNOTSUPP;
1890
1891	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1892	if (!skb)
1893		return -ENOBUFS;
1894
1895	if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0,
1896			   RTM_DELTCLASS) < 0) {
1897		kfree_skb(skb);
1898		return -EINVAL;
1899	}
1900
1901	err = cops->delete(q, cl, extack);
1902	if (err) {
1903		kfree_skb(skb);
1904		return err;
1905	}
1906
1907	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1908			     n->nlmsg_flags & NLM_F_ECHO);
1909	return err;
1910}
1911
1912#ifdef CONFIG_NET_CLS
1913
1914struct tcf_bind_args {
1915	struct tcf_walker w;
1916	unsigned long base;
1917	unsigned long cl;
1918	u32 classid;
1919};
1920
1921static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
1922{
1923	struct tcf_bind_args *a = (void *)arg;
1924
1925	if (n && tp->ops->bind_class) {
1926		struct Qdisc *q = tcf_block_q(tp->chain->block);
1927
1928		sch_tree_lock(q);
1929		tp->ops->bind_class(n, a->classid, a->cl, q, a->base);
1930		sch_tree_unlock(q);
1931	}
1932	return 0;
1933}
1934
1935struct tc_bind_class_args {
1936	struct qdisc_walker w;
1937	unsigned long new_cl;
1938	u32 portid;
1939	u32 clid;
1940};
1941
1942static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl,
1943				struct qdisc_walker *w)
1944{
1945	struct tc_bind_class_args *a = (struct tc_bind_class_args *)w;
1946	const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1947	struct tcf_block *block;
1948	struct tcf_chain *chain;
1949
1950	block = cops->tcf_block(q, cl, NULL);
1951	if (!block)
1952		return 0;
1953	for (chain = tcf_get_next_chain(block, NULL);
1954	     chain;
1955	     chain = tcf_get_next_chain(block, chain)) {
1956		struct tcf_proto *tp;
1957
1958		for (tp = tcf_get_next_proto(chain, NULL);
1959		     tp; tp = tcf_get_next_proto(chain, tp)) {
1960			struct tcf_bind_args arg = {};
1961
1962			arg.w.fn = tcf_node_bind;
1963			arg.classid = a->clid;
1964			arg.base = cl;
1965			arg.cl = a->new_cl;
1966			tp->ops->walk(tp, &arg.w, true);
1967		}
1968	}
1969
1970	return 0;
1971}
1972
1973static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1974			   unsigned long new_cl)
1975{
1976	const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1977	struct tc_bind_class_args args = {};
1978
1979	if (!cops->tcf_block)
1980		return;
1981	args.portid = portid;
1982	args.clid = clid;
1983	args.new_cl = new_cl;
1984	args.w.fn = tc_bind_class_walker;
1985	q->ops->cl_ops->walk(q, &args.w);
1986}
1987
1988#else
1989
1990static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
1991			   unsigned long new_cl)
1992{
1993}
1994
1995#endif
1996
1997static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
1998			 struct netlink_ext_ack *extack)
1999{
2000	struct net *net = sock_net(skb->sk);
2001	struct tcmsg *tcm = nlmsg_data(n);
2002	struct nlattr *tca[TCA_MAX + 1];
2003	struct net_device *dev;
2004	struct Qdisc *q = NULL;
2005	const struct Qdisc_class_ops *cops;
2006	unsigned long cl = 0;
2007	unsigned long new_cl;
2008	u32 portid;
2009	u32 clid;
2010	u32 qid;
2011	int err;
2012
2013	err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX,
2014				     rtm_tca_policy, extack);
 
 
2015	if (err < 0)
2016		return err;
2017
2018	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2019	if (!dev)
2020		return -ENODEV;
2021
2022	/*
2023	   parent == TC_H_UNSPEC - unspecified parent.
2024	   parent == TC_H_ROOT   - class is root, which has no parent.
2025	   parent == X:0	 - parent is root class.
2026	   parent == X:Y	 - parent is a node in hierarchy.
2027	   parent == 0:Y	 - parent is X:Y, where X:0 is qdisc.
2028
2029	   handle == 0:0	 - generate handle from kernel pool.
2030	   handle == 0:Y	 - class is X:Y, where X:0 is qdisc.
2031	   handle == X:Y	 - clear.
2032	   handle == X:0	 - root class.
2033	 */
2034
2035	/* Step 1. Determine qdisc handle X:0 */
2036
2037	portid = tcm->tcm_parent;
2038	clid = tcm->tcm_handle;
2039	qid = TC_H_MAJ(clid);
2040
2041	if (portid != TC_H_ROOT) {
2042		u32 qid1 = TC_H_MAJ(portid);
2043
2044		if (qid && qid1) {
2045			/* If both majors are known, they must be identical. */
2046			if (qid != qid1)
2047				return -EINVAL;
2048		} else if (qid1) {
2049			qid = qid1;
2050		} else if (qid == 0)
2051			qid = rtnl_dereference(dev->qdisc)->handle;
2052
2053		/* Now qid is genuine qdisc handle consistent
2054		 * both with parent and child.
2055		 *
2056		 * TC_H_MAJ(portid) still may be unspecified, complete it now.
2057		 */
2058		if (portid)
2059			portid = TC_H_MAKE(qid, portid);
2060	} else {
2061		if (qid == 0)
2062			qid = rtnl_dereference(dev->qdisc)->handle;
2063	}
2064
2065	/* OK. Locate qdisc */
2066	q = qdisc_lookup(dev, qid);
2067	if (!q)
2068		return -ENOENT;
2069
2070	/* An check that it supports classes */
2071	cops = q->ops->cl_ops;
2072	if (cops == NULL)
2073		return -EINVAL;
2074
2075	/* Now try to get class */
2076	if (clid == 0) {
2077		if (portid == TC_H_ROOT)
2078			clid = qid;
2079	} else
2080		clid = TC_H_MAKE(qid, clid);
2081
2082	if (clid)
2083		cl = cops->find(q, clid);
2084
2085	if (cl == 0) {
2086		err = -ENOENT;
2087		if (n->nlmsg_type != RTM_NEWTCLASS ||
2088		    !(n->nlmsg_flags & NLM_F_CREATE))
2089			goto out;
2090	} else {
2091		switch (n->nlmsg_type) {
2092		case RTM_NEWTCLASS:
2093			err = -EEXIST;
2094			if (n->nlmsg_flags & NLM_F_EXCL)
2095				goto out;
2096			break;
2097		case RTM_DELTCLASS:
2098			err = tclass_del_notify(net, cops, skb, n, q, cl, extack);
2099			/* Unbind the class with flilters with 0 */
2100			tc_bind_tclass(q, portid, clid, 0);
 
 
2101			goto out;
2102		case RTM_GETTCLASS:
2103			err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS);
2104			goto out;
2105		default:
2106			err = -EINVAL;
2107			goto out;
2108		}
2109	}
2110
2111	if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
2112		NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes");
2113		return -EOPNOTSUPP;
2114	}
2115
2116	new_cl = cl;
2117	err = -EOPNOTSUPP;
2118	if (cops->change)
2119		err = cops->change(q, clid, portid, tca, &new_cl, extack);
2120	if (err == 0) {
2121		tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
2122		/* We just create a new class, need to do reverse binding. */
2123		if (cl != new_cl)
2124			tc_bind_tclass(q, portid, clid, new_cl);
2125	}
2126out:
 
 
 
2127	return err;
2128}
2129
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2130struct qdisc_dump_args {
2131	struct qdisc_walker	w;
2132	struct sk_buff		*skb;
2133	struct netlink_callback	*cb;
2134};
2135
2136static int qdisc_class_dump(struct Qdisc *q, unsigned long cl,
2137			    struct qdisc_walker *arg)
2138{
2139	struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg;
2140
2141	return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid,
2142			      a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2143			      RTM_NEWTCLASS);
2144}
2145
2146static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb,
2147				struct tcmsg *tcm, struct netlink_callback *cb,
2148				int *t_p, int s_t)
2149{
2150	struct qdisc_dump_args arg;
2151
2152	if (tc_qdisc_dump_ignore(q, false) ||
2153	    *t_p < s_t || !q->ops->cl_ops ||
2154	    (tcm->tcm_parent &&
2155	     TC_H_MAJ(tcm->tcm_parent) != q->handle)) {
2156		(*t_p)++;
2157		return 0;
2158	}
2159	if (*t_p > s_t)
2160		memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
2161	arg.w.fn = qdisc_class_dump;
2162	arg.skb = skb;
2163	arg.cb = cb;
2164	arg.w.stop  = 0;
2165	arg.w.skip = cb->args[1];
2166	arg.w.count = 0;
2167	q->ops->cl_ops->walk(q, &arg.w);
2168	cb->args[1] = arg.w.count;
2169	if (arg.w.stop)
2170		return -1;
2171	(*t_p)++;
2172	return 0;
2173}
2174
2175static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb,
2176			       struct tcmsg *tcm, struct netlink_callback *cb,
2177			       int *t_p, int s_t, bool recur)
2178{
2179	struct Qdisc *q;
2180	int b;
2181
2182	if (!root)
2183		return 0;
2184
2185	if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0)
2186		return -1;
2187
2188	if (!qdisc_dev(root) || !recur)
2189		return 0;
2190
2191	if (tcm->tcm_parent) {
2192		q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent));
2193		if (q && q != root &&
2194		    tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2195			return -1;
2196		return 0;
2197	}
2198	hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) {
2199		if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0)
2200			return -1;
2201	}
2202
2203	return 0;
2204}
2205
2206static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
2207{
2208	struct tcmsg *tcm = nlmsg_data(cb->nlh);
2209	struct net *net = sock_net(skb->sk);
2210	struct netdev_queue *dev_queue;
2211	struct net_device *dev;
2212	int t, s_t;
2213
2214	if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2215		return 0;
2216	dev = dev_get_by_index(net, tcm->tcm_ifindex);
2217	if (!dev)
2218		return 0;
2219
2220	s_t = cb->args[0];
2221	t = 0;
2222
2223	if (tc_dump_tclass_root(rtnl_dereference(dev->qdisc),
2224				skb, tcm, cb, &t, s_t, true) < 0)
2225		goto done;
2226
2227	dev_queue = dev_ingress_queue(dev);
2228	if (dev_queue &&
2229	    tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb,
2230				&t, s_t, false) < 0)
2231		goto done;
2232
2233done:
2234	cb->args[0] = t;
2235
2236	dev_put(dev);
2237	return skb->len;
2238}
2239
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2240#ifdef CONFIG_PROC_FS
2241static int psched_show(struct seq_file *seq, void *v)
2242{
 
 
 
2243	seq_printf(seq, "%08x %08x %08x %08x\n",
2244		   (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
2245		   1000000,
2246		   (u32)NSEC_PER_SEC / hrtimer_resolution);
2247
2248	return 0;
2249}
2250
 
 
 
 
 
 
 
 
 
 
 
 
 
2251static int __net_init psched_net_init(struct net *net)
2252{
2253	struct proc_dir_entry *e;
2254
2255	e = proc_create_single("psched", 0, net->proc_net, psched_show);
2256	if (e == NULL)
2257		return -ENOMEM;
2258
2259	return 0;
2260}
2261
2262static void __net_exit psched_net_exit(struct net *net)
2263{
2264	remove_proc_entry("psched", net->proc_net);
2265}
2266#else
2267static int __net_init psched_net_init(struct net *net)
2268{
2269	return 0;
2270}
2271
2272static void __net_exit psched_net_exit(struct net *net)
2273{
2274}
2275#endif
2276
2277static struct pernet_operations psched_net_ops = {
2278	.init = psched_net_init,
2279	.exit = psched_net_exit,
2280};
2281
2282DEFINE_STATIC_KEY_FALSE(tc_skip_wrapper);
2283
2284static int __init pktsched_init(void)
2285{
2286	int err;
2287
2288	err = register_pernet_subsys(&psched_net_ops);
2289	if (err) {
2290		pr_err("pktsched_init: "
2291		       "cannot initialize per netns operations\n");
2292		return err;
2293	}
2294
2295	register_qdisc(&pfifo_fast_ops);
2296	register_qdisc(&pfifo_qdisc_ops);
2297	register_qdisc(&bfifo_qdisc_ops);
2298	register_qdisc(&pfifo_head_drop_qdisc_ops);
2299	register_qdisc(&mq_qdisc_ops);
2300	register_qdisc(&noqueue_qdisc_ops);
2301
2302	rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, 0);
2303	rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, 0);
2304	rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc,
2305		      0);
2306	rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, 0);
2307	rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, 0);
2308	rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass,
2309		      0);
2310
2311	tc_wrapper_init();
 
 
 
 
 
2312
2313	return 0;
2314}
2315
2316subsys_initcall(pktsched_init);