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