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v5.4
   1/*
   2 * net/tipc/name_table.c: TIPC name table code
   3 *
   4 * Copyright (c) 2000-2006, 2014-2018, Ericsson AB
   5 * Copyright (c) 2004-2008, 2010-2014, Wind River Systems
   6 * All rights reserved.
   7 *
   8 * Redistribution and use in source and binary forms, with or without
   9 * modification, are permitted provided that the following conditions are met:
  10 *
  11 * 1. Redistributions of source code must retain the above copyright
  12 *    notice, this list of conditions and the following disclaimer.
  13 * 2. Redistributions in binary form must reproduce the above copyright
  14 *    notice, this list of conditions and the following disclaimer in the
  15 *    documentation and/or other materials provided with the distribution.
  16 * 3. Neither the names of the copyright holders nor the names of its
  17 *    contributors may be used to endorse or promote products derived from
  18 *    this software without specific prior written permission.
  19 *
  20 * Alternatively, this software may be distributed under the terms of the
  21 * GNU General Public License ("GPL") version 2 as published by the Free
  22 * Software Foundation.
  23 *
  24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34 * POSSIBILITY OF SUCH DAMAGE.
  35 */
  36
  37#include <net/sock.h>
  38#include "core.h"
  39#include "netlink.h"
  40#include "name_table.h"
  41#include "name_distr.h"
  42#include "subscr.h"
  43#include "bcast.h"
  44#include "addr.h"
  45#include "node.h"
  46#include "group.h"
  47
  48/**
  49 * struct service_range - container for all bindings of a service range
  50 * @lower: service range lower bound
  51 * @upper: service range upper bound
  52 * @tree_node: member of service range RB tree
  53 * @local_publ: list of identical publications made from this node
  54 *   Used by closest_first lookup and multicast lookup algorithm
  55 * @all_publ: all publications identical to this one, whatever node and scope
  56 *   Used by round-robin lookup algorithm
  57 */
  58struct service_range {
  59	u32 lower;
  60	u32 upper;
  61	struct rb_node tree_node;
  62	struct list_head local_publ;
  63	struct list_head all_publ;
  64};
  65
  66/**
  67 * struct tipc_service - container for all published instances of a service type
  68 * @type: 32 bit 'type' value for service
  69 * @ranges: rb tree containing all service ranges for this service
  70 * @service_list: links to adjacent name ranges in hash chain
  71 * @subscriptions: list of subscriptions for this service type
  72 * @lock: spinlock controlling access to pertaining service ranges/publications
  73 * @rcu: RCU callback head used for deferred freeing
  74 */
  75struct tipc_service {
  76	u32 type;
  77	struct rb_root ranges;
  78	struct hlist_node service_list;
  79	struct list_head subscriptions;
  80	spinlock_t lock; /* Covers service range list */
  81	struct rcu_head rcu;
  82};
  83
  84static int hash(int x)
  85{
  86	return x & (TIPC_NAMETBL_SIZE - 1);
  87}
  88
  89/**
  90 * tipc_publ_create - create a publication structure
  91 */
  92static struct publication *tipc_publ_create(u32 type, u32 lower, u32 upper,
  93					    u32 scope, u32 node, u32 port,
  94					    u32 key)
  95{
  96	struct publication *publ = kzalloc(sizeof(*publ), GFP_ATOMIC);
  97
  98	if (!publ)
  99		return NULL;
 100
 101	publ->type = type;
 102	publ->lower = lower;
 103	publ->upper = upper;
 104	publ->scope = scope;
 105	publ->node = node;
 106	publ->port = port;
 107	publ->key = key;
 108	INIT_LIST_HEAD(&publ->binding_sock);
 109	INIT_LIST_HEAD(&publ->binding_node);
 110	INIT_LIST_HEAD(&publ->local_publ);
 111	INIT_LIST_HEAD(&publ->all_publ);
 112	return publ;
 113}
 114
 115/**
 116 * tipc_service_create - create a service structure for the specified 'type'
 117 *
 118 * Allocates a single range structure and sets it to all 0's.
 119 */
 120static struct tipc_service *tipc_service_create(u32 type, struct hlist_head *hd)
 121{
 122	struct tipc_service *service = kzalloc(sizeof(*service), GFP_ATOMIC);
 123
 124	if (!service) {
 125		pr_warn("Service creation failed, no memory\n");
 126		return NULL;
 127	}
 128
 129	spin_lock_init(&service->lock);
 130	service->type = type;
 131	service->ranges = RB_ROOT;
 132	INIT_HLIST_NODE(&service->service_list);
 133	INIT_LIST_HEAD(&service->subscriptions);
 134	hlist_add_head_rcu(&service->service_list, hd);
 135	return service;
 136}
 137
 138/**
 139 * tipc_service_first_range - find first service range in tree matching instance
 140 *
 141 * Very time-critical, so binary search through range rb tree
 142 */
 143static struct service_range *tipc_service_first_range(struct tipc_service *sc,
 144						      u32 instance)
 145{
 146	struct rb_node *n = sc->ranges.rb_node;
 147	struct service_range *sr;
 148
 149	while (n) {
 150		sr = container_of(n, struct service_range, tree_node);
 151		if (sr->lower > instance)
 152			n = n->rb_left;
 153		else if (sr->upper < instance)
 154			n = n->rb_right;
 155		else
 156			return sr;
 157	}
 158	return NULL;
 159}
 160
 161/*  tipc_service_find_range - find service range matching publication parameters
 162 */
 163static struct service_range *tipc_service_find_range(struct tipc_service *sc,
 164						     u32 lower, u32 upper)
 165{
 166	struct rb_node *n = sc->ranges.rb_node;
 167	struct service_range *sr;
 168
 169	sr = tipc_service_first_range(sc, lower);
 170	if (!sr)
 171		return NULL;
 172
 173	/* Look for exact match */
 174	for (n = &sr->tree_node; n; n = rb_next(n)) {
 175		sr = container_of(n, struct service_range, tree_node);
 176		if (sr->upper == upper)
 177			break;
 178	}
 179	if (!n || sr->lower != lower || sr->upper != upper)
 180		return NULL;
 181
 182	return sr;
 183}
 184
 185static struct service_range *tipc_service_create_range(struct tipc_service *sc,
 186						       u32 lower, u32 upper)
 187{
 188	struct rb_node **n, *parent = NULL;
 189	struct service_range *sr, *tmp;
 190
 191	n = &sc->ranges.rb_node;
 192	while (*n) {
 193		tmp = container_of(*n, struct service_range, tree_node);
 194		parent = *n;
 195		tmp = container_of(parent, struct service_range, tree_node);
 196		if (lower < tmp->lower)
 197			n = &(*n)->rb_left;
 198		else if (lower > tmp->lower)
 199			n = &(*n)->rb_right;
 200		else if (upper < tmp->upper)
 201			n = &(*n)->rb_left;
 202		else if (upper > tmp->upper)
 203			n = &(*n)->rb_right;
 204		else
 205			return tmp;
 206	}
 207	sr = kzalloc(sizeof(*sr), GFP_ATOMIC);
 208	if (!sr)
 209		return NULL;
 210	sr->lower = lower;
 211	sr->upper = upper;
 212	INIT_LIST_HEAD(&sr->local_publ);
 213	INIT_LIST_HEAD(&sr->all_publ);
 214	rb_link_node(&sr->tree_node, parent, n);
 215	rb_insert_color(&sr->tree_node, &sc->ranges);
 216	return sr;
 217}
 218
 219static struct publication *tipc_service_insert_publ(struct net *net,
 220						    struct tipc_service *sc,
 221						    u32 type, u32 lower,
 222						    u32 upper, u32 scope,
 223						    u32 node, u32 port,
 224						    u32 key)
 225{
 226	struct tipc_subscription *sub, *tmp;
 227	struct service_range *sr;
 228	struct publication *p;
 229	bool first = false;
 230
 231	sr = tipc_service_create_range(sc, lower, upper);
 232	if (!sr)
 233		goto  err;
 234
 235	first = list_empty(&sr->all_publ);
 236
 237	/* Return if the publication already exists */
 238	list_for_each_entry(p, &sr->all_publ, all_publ) {
 239		if (p->key == key && (!p->node || p->node == node))
 240			return NULL;
 241	}
 242
 243	/* Create and insert publication */
 244	p = tipc_publ_create(type, lower, upper, scope, node, port, key);
 245	if (!p)
 246		goto err;
 247	if (in_own_node(net, node))
 248		list_add(&p->local_publ, &sr->local_publ);
 249	list_add(&p->all_publ, &sr->all_publ);
 250
 251	/* Any subscriptions waiting for notification?  */
 252	list_for_each_entry_safe(sub, tmp, &sc->subscriptions, service_list) {
 253		tipc_sub_report_overlap(sub, p->lower, p->upper, TIPC_PUBLISHED,
 254					p->port, p->node, p->scope, first);
 255	}
 256	return p;
 257err:
 258	pr_warn("Failed to bind to %u,%u,%u, no memory\n", type, lower, upper);
 259	return NULL;
 260}
 261
 262/**
 263 * tipc_service_remove_publ - remove a publication from a service
 264 */
 265static struct publication *tipc_service_remove_publ(struct service_range *sr,
 266						    u32 node, u32 key)
 
 
 
 267{
 
 
 268	struct publication *p;
 
 
 
 
 
 
 
 269
 
 
 
 
 
 
 
 
 
 
 270	list_for_each_entry(p, &sr->all_publ, all_publ) {
 271		if (p->key != key || (node && node != p->node))
 272			continue;
 273		list_del(&p->all_publ);
 274		list_del(&p->local_publ);
 275		return p;
 276	}
 277	return NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 278}
 279
 280/**
 281 * tipc_service_subscribe - attach a subscription, and optionally
 282 * issue the prescribed number of events if there is any service
 283 * range overlapping with the requested range
 284 */
 285static void tipc_service_subscribe(struct tipc_service *service,
 286				   struct tipc_subscription *sub)
 287{
 288	struct tipc_subscr *sb = &sub->evt.s;
 289	struct service_range *sr;
 290	struct tipc_name_seq ns;
 291	struct publication *p;
 292	struct rb_node *n;
 293	bool first;
 294
 295	ns.type = tipc_sub_read(sb, seq.type);
 296	ns.lower = tipc_sub_read(sb, seq.lower);
 297	ns.upper = tipc_sub_read(sb, seq.upper);
 298
 299	tipc_sub_get(sub);
 300	list_add(&sub->service_list, &service->subscriptions);
 301
 302	if (tipc_sub_read(sb, filter) & TIPC_SUB_NO_STATUS)
 303		return;
 304
 305	for (n = rb_first(&service->ranges); n; n = rb_next(n)) {
 306		sr = container_of(n, struct service_range, tree_node);
 307		if (sr->lower > ns.upper)
 308			break;
 309		if (!tipc_sub_check_overlap(&ns, sr->lower, sr->upper))
 310			continue;
 311		first = true;
 312
 313		list_for_each_entry(p, &sr->all_publ, all_publ) {
 314			tipc_sub_report_overlap(sub, sr->lower, sr->upper,
 315						TIPC_PUBLISHED,	p->port,
 316						p->node, p->scope, first);
 317			first = false;
 318		}
 319	}
 320}
 321
 322static struct tipc_service *tipc_service_find(struct net *net, u32 type)
 323{
 324	struct name_table *nt = tipc_name_table(net);
 325	struct hlist_head *service_head;
 326	struct tipc_service *service;
 327
 328	service_head = &nt->services[hash(type)];
 329	hlist_for_each_entry_rcu(service, service_head, service_list) {
 330		if (service->type == type)
 331			return service;
 332	}
 333	return NULL;
 334};
 335
 336struct publication *tipc_nametbl_insert_publ(struct net *net, u32 type,
 337					     u32 lower, u32 upper,
 338					     u32 scope, u32 node,
 339					     u32 port, u32 key)
 340{
 341	struct name_table *nt = tipc_name_table(net);
 342	struct tipc_service *sc;
 343	struct publication *p;
 344
 345	if (scope > TIPC_NODE_SCOPE || lower > upper) {
 346		pr_debug("Failed to bind illegal {%u,%u,%u} with scope %u\n",
 347			 type, lower, upper, scope);
 348		return NULL;
 349	}
 350	sc = tipc_service_find(net, type);
 351	if (!sc)
 352		sc = tipc_service_create(type, &nt->services[hash(type)]);
 353	if (!sc)
 354		return NULL;
 355
 356	spin_lock_bh(&sc->lock);
 357	p = tipc_service_insert_publ(net, sc, type, lower, upper,
 358				     scope, node, port, key);
 359	spin_unlock_bh(&sc->lock);
 360	return p;
 361}
 362
 363struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type,
 364					     u32 lower, u32 upper,
 365					     u32 node, u32 key)
 366{
 367	struct tipc_service *sc = tipc_service_find(net, type);
 368	struct tipc_subscription *sub, *tmp;
 369	struct service_range *sr = NULL;
 370	struct publication *p = NULL;
 371	bool last;
 372
 373	if (!sc)
 374		return NULL;
 375
 376	spin_lock_bh(&sc->lock);
 377	sr = tipc_service_find_range(sc, lower, upper);
 378	if (!sr)
 379		goto exit;
 380	p = tipc_service_remove_publ(sr, node, key);
 381	if (!p)
 382		goto exit;
 383
 384	/* Notify any waiting subscriptions */
 385	last = list_empty(&sr->all_publ);
 386	list_for_each_entry_safe(sub, tmp, &sc->subscriptions, service_list) {
 387		tipc_sub_report_overlap(sub, lower, upper, TIPC_WITHDRAWN,
 388					p->port, node, p->scope, last);
 389	}
 390
 391	/* Remove service range item if this was its last publication */
 392	if (list_empty(&sr->all_publ)) {
 393		rb_erase(&sr->tree_node, &sc->ranges);
 394		kfree(sr);
 395	}
 396
 397	/* Delete service item if this no more publications and subscriptions */
 398	if (RB_EMPTY_ROOT(&sc->ranges) && list_empty(&sc->subscriptions)) {
 399		hlist_del_init_rcu(&sc->service_list);
 400		kfree_rcu(sc, rcu);
 401	}
 402exit:
 403	spin_unlock_bh(&sc->lock);
 404	return p;
 405}
 406
 407/**
 408 * tipc_nametbl_translate - perform service instance to socket translation
 409 *
 410 * On entry, 'dnode' is the search domain used during translation.
 411 *
 412 * On exit:
 413 * - if translation is deferred to another node, leave 'dnode' unchanged and
 414 *   return 0
 415 * - if translation is attempted and succeeds, set 'dnode' to the publishing
 416 *   node and return the published (non-zero) port number
 417 * - if translation is attempted and fails, set 'dnode' to 0 and return 0
 418 *
 419 * Note that for legacy users (node configured with Z.C.N address format) the
 420 * 'closest-first' lookup algorithm must be maintained, i.e., if dnode is 0
 421 * we must look in the local binding list first
 422 */
 423u32 tipc_nametbl_translate(struct net *net, u32 type, u32 instance, u32 *dnode)
 424{
 425	struct tipc_net *tn = tipc_net(net);
 426	bool legacy = tn->legacy_addr_format;
 427	u32 self = tipc_own_addr(net);
 428	struct service_range *sr;
 429	struct tipc_service *sc;
 430	struct list_head *list;
 431	struct publication *p;
 432	u32 port = 0;
 433	u32 node = 0;
 434
 435	if (!tipc_in_scope(legacy, *dnode, self))
 436		return 0;
 437
 438	rcu_read_lock();
 439	sc = tipc_service_find(net, type);
 440	if (unlikely(!sc))
 441		goto not_found;
 442
 443	spin_lock_bh(&sc->lock);
 444	sr = tipc_service_first_range(sc, instance);
 445	if (unlikely(!sr))
 446		goto no_match;
 447
 448	/* Select lookup algorithm: local, closest-first or round-robin */
 449	if (*dnode == self) {
 450		list = &sr->local_publ;
 451		if (list_empty(list))
 452			goto no_match;
 453		p = list_first_entry(list, struct publication, local_publ);
 454		list_move_tail(&p->local_publ, &sr->local_publ);
 455	} else if (legacy && !*dnode && !list_empty(&sr->local_publ)) {
 456		list = &sr->local_publ;
 457		p = list_first_entry(list, struct publication, local_publ);
 458		list_move_tail(&p->local_publ, &sr->local_publ);
 459	} else {
 460		list = &sr->all_publ;
 461		p = list_first_entry(list, struct publication, all_publ);
 462		list_move_tail(&p->all_publ, &sr->all_publ);
 463	}
 464	port = p->port;
 465	node = p->node;
 466no_match:
 467	spin_unlock_bh(&sc->lock);
 468not_found:
 469	rcu_read_unlock();
 470	*dnode = node;
 471	return port;
 472}
 473
 474bool tipc_nametbl_lookup(struct net *net, u32 type, u32 instance, u32 scope,
 475			 struct list_head *dsts, int *dstcnt, u32 exclude,
 476			 bool all)
 477{
 478	u32 self = tipc_own_addr(net);
 479	struct service_range *sr;
 480	struct tipc_service *sc;
 481	struct publication *p;
 482
 483	*dstcnt = 0;
 484	rcu_read_lock();
 485	sc = tipc_service_find(net, type);
 486	if (unlikely(!sc))
 487		goto exit;
 488
 489	spin_lock_bh(&sc->lock);
 490
 491	sr = tipc_service_first_range(sc, instance);
 492	if (!sr)
 493		goto no_match;
 494
 495	list_for_each_entry(p, &sr->all_publ, all_publ) {
 496		if (p->scope != scope)
 497			continue;
 498		if (p->port == exclude && p->node == self)
 499			continue;
 500		tipc_dest_push(dsts, p->node, p->port);
 501		(*dstcnt)++;
 502		if (all)
 503			continue;
 504		list_move_tail(&p->all_publ, &sr->all_publ);
 505		break;
 506	}
 507no_match:
 508	spin_unlock_bh(&sc->lock);
 509exit:
 510	rcu_read_unlock();
 511	return !list_empty(dsts);
 512}
 513
 514void tipc_nametbl_mc_lookup(struct net *net, u32 type, u32 lower, u32 upper,
 515			    u32 scope, bool exact, struct list_head *dports)
 516{
 517	struct service_range *sr;
 518	struct tipc_service *sc;
 519	struct publication *p;
 520	struct rb_node *n;
 521
 522	rcu_read_lock();
 523	sc = tipc_service_find(net, type);
 524	if (!sc)
 525		goto exit;
 526
 527	spin_lock_bh(&sc->lock);
 528
 529	for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
 530		sr = container_of(n, struct service_range, tree_node);
 531		if (sr->upper < lower)
 532			continue;
 533		if (sr->lower > upper)
 534			break;
 535		list_for_each_entry(p, &sr->local_publ, local_publ) {
 536			if (p->scope == scope || (!exact && p->scope < scope))
 537				tipc_dest_push(dports, 0, p->port);
 538		}
 539	}
 540	spin_unlock_bh(&sc->lock);
 541exit:
 542	rcu_read_unlock();
 543}
 544
 545/* tipc_nametbl_lookup_dst_nodes - find broadcast destination nodes
 546 * - Creates list of nodes that overlap the given multicast address
 547 * - Determines if any node local destinations overlap
 548 */
 549void tipc_nametbl_lookup_dst_nodes(struct net *net, u32 type, u32 lower,
 550				   u32 upper, struct tipc_nlist *nodes)
 551{
 552	struct service_range *sr;
 553	struct tipc_service *sc;
 554	struct publication *p;
 555	struct rb_node *n;
 556
 557	rcu_read_lock();
 558	sc = tipc_service_find(net, type);
 559	if (!sc)
 560		goto exit;
 561
 562	spin_lock_bh(&sc->lock);
 563
 564	for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
 565		sr = container_of(n, struct service_range, tree_node);
 566		if (sr->upper < lower)
 567			continue;
 568		if (sr->lower > upper)
 569			break;
 570		list_for_each_entry(p, &sr->all_publ, all_publ) {
 571			tipc_nlist_add(nodes, p->node);
 572		}
 573	}
 574	spin_unlock_bh(&sc->lock);
 575exit:
 576	rcu_read_unlock();
 577}
 578
 579/* tipc_nametbl_build_group - build list of communication group members
 580 */
 581void tipc_nametbl_build_group(struct net *net, struct tipc_group *grp,
 582			      u32 type, u32 scope)
 583{
 584	struct service_range *sr;
 585	struct tipc_service *sc;
 586	struct publication *p;
 587	struct rb_node *n;
 588
 589	rcu_read_lock();
 590	sc = tipc_service_find(net, type);
 591	if (!sc)
 592		goto exit;
 593
 594	spin_lock_bh(&sc->lock);
 595	for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
 596		sr = container_of(n, struct service_range, tree_node);
 597		list_for_each_entry(p, &sr->all_publ, all_publ) {
 598			if (p->scope != scope)
 599				continue;
 600			tipc_group_add_member(grp, p->node, p->port, p->lower);
 601		}
 602	}
 603	spin_unlock_bh(&sc->lock);
 604exit:
 605	rcu_read_unlock();
 606}
 607
 608/* tipc_nametbl_publish - add service binding to name table
 609 */
 610struct publication *tipc_nametbl_publish(struct net *net, u32 type, u32 lower,
 611					 u32 upper, u32 scope, u32 port,
 612					 u32 key)
 613{
 614	struct name_table *nt = tipc_name_table(net);
 615	struct tipc_net *tn = tipc_net(net);
 616	struct publication *p = NULL;
 617	struct sk_buff *skb = NULL;
 618
 619	spin_lock_bh(&tn->nametbl_lock);
 620
 621	if (nt->local_publ_count >= TIPC_MAX_PUBL) {
 622		pr_warn("Bind failed, max limit %u reached\n", TIPC_MAX_PUBL);
 623		goto exit;
 624	}
 625
 626	p = tipc_nametbl_insert_publ(net, type, lower, upper, scope,
 627				     tipc_own_addr(net), port, key);
 628	if (p) {
 629		nt->local_publ_count++;
 630		skb = tipc_named_publish(net, p);
 631	}
 632exit:
 633	spin_unlock_bh(&tn->nametbl_lock);
 634
 635	if (skb)
 636		tipc_node_broadcast(net, skb);
 637	return p;
 638}
 639
 640/**
 641 * tipc_nametbl_withdraw - withdraw a service binding
 642 */
 643int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower,
 644			  u32 upper, u32 key)
 645{
 646	struct name_table *nt = tipc_name_table(net);
 647	struct tipc_net *tn = tipc_net(net);
 648	u32 self = tipc_own_addr(net);
 649	struct sk_buff *skb = NULL;
 650	struct publication *p;
 651
 652	spin_lock_bh(&tn->nametbl_lock);
 653
 654	p = tipc_nametbl_remove_publ(net, type, lower, upper, self, key);
 655	if (p) {
 656		nt->local_publ_count--;
 657		skb = tipc_named_withdraw(net, p);
 658		list_del_init(&p->binding_sock);
 659		kfree_rcu(p, rcu);
 660	} else {
 661		pr_err("Failed to remove local publication {%u,%u,%u}/%u\n",
 662		       type, lower, upper, key);
 663	}
 664	spin_unlock_bh(&tn->nametbl_lock);
 665
 666	if (skb) {
 667		tipc_node_broadcast(net, skb);
 668		return 1;
 669	}
 670	return 0;
 671}
 672
 673/**
 674 * tipc_nametbl_subscribe - add a subscription object to the name table
 675 */
 676bool tipc_nametbl_subscribe(struct tipc_subscription *sub)
 677{
 678	struct name_table *nt = tipc_name_table(sub->net);
 679	struct tipc_net *tn = tipc_net(sub->net);
 680	struct tipc_subscr *s = &sub->evt.s;
 681	u32 type = tipc_sub_read(s, seq.type);
 682	struct tipc_service *sc;
 683	bool res = true;
 684
 685	spin_lock_bh(&tn->nametbl_lock);
 686	sc = tipc_service_find(sub->net, type);
 687	if (!sc)
 688		sc = tipc_service_create(type, &nt->services[hash(type)]);
 689	if (sc) {
 690		spin_lock_bh(&sc->lock);
 691		tipc_service_subscribe(sc, sub);
 692		spin_unlock_bh(&sc->lock);
 693	} else {
 694		pr_warn("Failed to subscribe for {%u,%u,%u}\n", type,
 695			tipc_sub_read(s, seq.lower),
 696			tipc_sub_read(s, seq.upper));
 697		res = false;
 698	}
 699	spin_unlock_bh(&tn->nametbl_lock);
 700	return res;
 701}
 702
 703/**
 704 * tipc_nametbl_unsubscribe - remove a subscription object from name table
 705 */
 706void tipc_nametbl_unsubscribe(struct tipc_subscription *sub)
 707{
 708	struct tipc_net *tn = tipc_net(sub->net);
 709	struct tipc_subscr *s = &sub->evt.s;
 710	u32 type = tipc_sub_read(s, seq.type);
 711	struct tipc_service *sc;
 712
 713	spin_lock_bh(&tn->nametbl_lock);
 714	sc = tipc_service_find(sub->net, type);
 715	if (!sc)
 716		goto exit;
 717
 718	spin_lock_bh(&sc->lock);
 719	list_del_init(&sub->service_list);
 720	tipc_sub_put(sub);
 721
 722	/* Delete service item if no more publications and subscriptions */
 723	if (RB_EMPTY_ROOT(&sc->ranges) && list_empty(&sc->subscriptions)) {
 724		hlist_del_init_rcu(&sc->service_list);
 725		kfree_rcu(sc, rcu);
 726	}
 727	spin_unlock_bh(&sc->lock);
 728exit:
 729	spin_unlock_bh(&tn->nametbl_lock);
 730}
 731
 732int tipc_nametbl_init(struct net *net)
 733{
 734	struct tipc_net *tn = tipc_net(net);
 735	struct name_table *nt;
 736	int i;
 737
 738	nt = kzalloc(sizeof(*nt), GFP_KERNEL);
 739	if (!nt)
 740		return -ENOMEM;
 741
 742	for (i = 0; i < TIPC_NAMETBL_SIZE; i++)
 743		INIT_HLIST_HEAD(&nt->services[i]);
 744
 745	INIT_LIST_HEAD(&nt->node_scope);
 746	INIT_LIST_HEAD(&nt->cluster_scope);
 747	rwlock_init(&nt->cluster_scope_lock);
 748	tn->nametbl = nt;
 749	spin_lock_init(&tn->nametbl_lock);
 750	return 0;
 751}
 752
 753/**
 754 *  tipc_service_delete - purge all publications for a service and delete it
 755 */
 756static void tipc_service_delete(struct net *net, struct tipc_service *sc)
 757{
 758	struct service_range *sr, *tmpr;
 759	struct publication *p, *tmp;
 760
 761	spin_lock_bh(&sc->lock);
 762	rbtree_postorder_for_each_entry_safe(sr, tmpr, &sc->ranges, tree_node) {
 763		list_for_each_entry_safe(p, tmp, &sr->all_publ, all_publ) {
 764			tipc_service_remove_publ(sr, p->node, p->key);
 
 765			kfree_rcu(p, rcu);
 766		}
 767		rb_erase(&sr->tree_node, &sc->ranges);
 768		kfree(sr);
 769	}
 770	hlist_del_init_rcu(&sc->service_list);
 771	spin_unlock_bh(&sc->lock);
 772	kfree_rcu(sc, rcu);
 773}
 774
 775void tipc_nametbl_stop(struct net *net)
 776{
 777	struct name_table *nt = tipc_name_table(net);
 778	struct tipc_net *tn = tipc_net(net);
 779	struct hlist_head *service_head;
 780	struct tipc_service *service;
 781	u32 i;
 782
 783	/* Verify name table is empty and purge any lingering
 784	 * publications, then release the name table
 785	 */
 786	spin_lock_bh(&tn->nametbl_lock);
 787	for (i = 0; i < TIPC_NAMETBL_SIZE; i++) {
 788		if (hlist_empty(&nt->services[i]))
 789			continue;
 790		service_head = &nt->services[i];
 791		hlist_for_each_entry_rcu(service, service_head, service_list) {
 792			tipc_service_delete(net, service);
 793		}
 794	}
 795	spin_unlock_bh(&tn->nametbl_lock);
 796
 797	synchronize_net();
 798	kfree(nt);
 799}
 800
 801static int __tipc_nl_add_nametable_publ(struct tipc_nl_msg *msg,
 802					struct tipc_service *service,
 803					struct service_range *sr,
 804					u32 *last_key)
 805{
 806	struct publication *p;
 807	struct nlattr *attrs;
 808	struct nlattr *b;
 809	void *hdr;
 810
 811	if (*last_key) {
 812		list_for_each_entry(p, &sr->all_publ, all_publ)
 813			if (p->key == *last_key)
 814				break;
 815		if (p->key != *last_key)
 816			return -EPIPE;
 817	} else {
 818		p = list_first_entry(&sr->all_publ,
 819				     struct publication,
 820				     all_publ);
 821	}
 822
 823	list_for_each_entry_from(p, &sr->all_publ, all_publ) {
 824		*last_key = p->key;
 825
 826		hdr = genlmsg_put(msg->skb, msg->portid, msg->seq,
 827				  &tipc_genl_family, NLM_F_MULTI,
 828				  TIPC_NL_NAME_TABLE_GET);
 829		if (!hdr)
 830			return -EMSGSIZE;
 831
 832		attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_NAME_TABLE);
 833		if (!attrs)
 834			goto msg_full;
 835
 836		b = nla_nest_start_noflag(msg->skb, TIPC_NLA_NAME_TABLE_PUBL);
 837		if (!b)
 838			goto attr_msg_full;
 839
 840		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_TYPE, service->type))
 841			goto publ_msg_full;
 842		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_LOWER, sr->lower))
 843			goto publ_msg_full;
 844		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_UPPER, sr->upper))
 845			goto publ_msg_full;
 846		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_SCOPE, p->scope))
 847			goto publ_msg_full;
 848		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_NODE, p->node))
 849			goto publ_msg_full;
 850		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_REF, p->port))
 851			goto publ_msg_full;
 852		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_KEY, p->key))
 853			goto publ_msg_full;
 854
 855		nla_nest_end(msg->skb, b);
 856		nla_nest_end(msg->skb, attrs);
 857		genlmsg_end(msg->skb, hdr);
 858	}
 859	*last_key = 0;
 860
 861	return 0;
 862
 863publ_msg_full:
 864	nla_nest_cancel(msg->skb, b);
 865attr_msg_full:
 866	nla_nest_cancel(msg->skb, attrs);
 867msg_full:
 868	genlmsg_cancel(msg->skb, hdr);
 869
 870	return -EMSGSIZE;
 871}
 872
 873static int __tipc_nl_service_range_list(struct tipc_nl_msg *msg,
 874					struct tipc_service *sc,
 875					u32 *last_lower, u32 *last_key)
 876{
 877	struct service_range *sr;
 878	struct rb_node *n;
 879	int err;
 880
 881	for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
 882		sr = container_of(n, struct service_range, tree_node);
 883		if (sr->lower < *last_lower)
 884			continue;
 885		err = __tipc_nl_add_nametable_publ(msg, sc, sr, last_key);
 886		if (err) {
 887			*last_lower = sr->lower;
 888			return err;
 889		}
 890	}
 891	*last_lower = 0;
 892	return 0;
 893}
 894
 895static int tipc_nl_service_list(struct net *net, struct tipc_nl_msg *msg,
 896				u32 *last_type, u32 *last_lower, u32 *last_key)
 897{
 898	struct tipc_net *tn = tipc_net(net);
 899	struct tipc_service *service = NULL;
 900	struct hlist_head *head;
 901	int err;
 902	int i;
 903
 904	if (*last_type)
 905		i = hash(*last_type);
 906	else
 907		i = 0;
 908
 909	for (; i < TIPC_NAMETBL_SIZE; i++) {
 910		head = &tn->nametbl->services[i];
 911
 912		if (*last_type ||
 913		    (!i && *last_key && (*last_lower == *last_key))) {
 914			service = tipc_service_find(net, *last_type);
 915			if (!service)
 916				return -EPIPE;
 917		} else {
 918			hlist_for_each_entry_rcu(service, head, service_list)
 919				break;
 920			if (!service)
 921				continue;
 922		}
 923
 924		hlist_for_each_entry_from_rcu(service, service_list) {
 925			spin_lock_bh(&service->lock);
 926			err = __tipc_nl_service_range_list(msg, service,
 927							   last_lower,
 928							   last_key);
 929
 930			if (err) {
 931				*last_type = service->type;
 932				spin_unlock_bh(&service->lock);
 933				return err;
 934			}
 935			spin_unlock_bh(&service->lock);
 936		}
 937		*last_type = 0;
 938	}
 939	return 0;
 940}
 941
 942int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb)
 943{
 944	struct net *net = sock_net(skb->sk);
 945	u32 last_type = cb->args[0];
 946	u32 last_lower = cb->args[1];
 947	u32 last_key = cb->args[2];
 948	int done = cb->args[3];
 949	struct tipc_nl_msg msg;
 950	int err;
 951
 952	if (done)
 953		return 0;
 954
 955	msg.skb = skb;
 956	msg.portid = NETLINK_CB(cb->skb).portid;
 957	msg.seq = cb->nlh->nlmsg_seq;
 958
 959	rcu_read_lock();
 960	err = tipc_nl_service_list(net, &msg, &last_type,
 961				   &last_lower, &last_key);
 962	if (!err) {
 963		done = 1;
 964	} else if (err != -EMSGSIZE) {
 965		/* We never set seq or call nl_dump_check_consistent() this
 966		 * means that setting prev_seq here will cause the consistence
 967		 * check to fail in the netlink callback handler. Resulting in
 968		 * the NLMSG_DONE message having the NLM_F_DUMP_INTR flag set if
 969		 * we got an error.
 970		 */
 971		cb->prev_seq = 1;
 972	}
 973	rcu_read_unlock();
 974
 975	cb->args[0] = last_type;
 976	cb->args[1] = last_lower;
 977	cb->args[2] = last_key;
 978	cb->args[3] = done;
 979
 980	return skb->len;
 981}
 982
 983struct tipc_dest *tipc_dest_find(struct list_head *l, u32 node, u32 port)
 984{
 
 985	struct tipc_dest *dst;
 986
 987	list_for_each_entry(dst, l, list) {
 988		if (dst->node == node && dst->port == port)
 989			return dst;
 
 990	}
 991	return NULL;
 992}
 993
 994bool tipc_dest_push(struct list_head *l, u32 node, u32 port)
 995{
 
 996	struct tipc_dest *dst;
 997
 998	if (tipc_dest_find(l, node, port))
 999		return false;
1000
1001	dst = kmalloc(sizeof(*dst), GFP_ATOMIC);
1002	if (unlikely(!dst))
1003		return false;
1004	dst->node = node;
1005	dst->port = port;
1006	list_add(&dst->list, l);
1007	return true;
1008}
1009
1010bool tipc_dest_pop(struct list_head *l, u32 *node, u32 *port)
1011{
1012	struct tipc_dest *dst;
1013
1014	if (list_empty(l))
1015		return false;
1016	dst = list_first_entry(l, typeof(*dst), list);
1017	if (port)
1018		*port = dst->port;
1019	if (node)
1020		*node = dst->node;
1021	list_del(&dst->list);
1022	kfree(dst);
1023	return true;
1024}
1025
1026bool tipc_dest_del(struct list_head *l, u32 node, u32 port)
1027{
1028	struct tipc_dest *dst;
1029
1030	dst = tipc_dest_find(l, node, port);
1031	if (!dst)
1032		return false;
1033	list_del(&dst->list);
1034	kfree(dst);
1035	return true;
1036}
1037
1038void tipc_dest_list_purge(struct list_head *l)
1039{
1040	struct tipc_dest *dst, *tmp;
1041
1042	list_for_each_entry_safe(dst, tmp, l, list) {
1043		list_del(&dst->list);
1044		kfree(dst);
1045	}
1046}
1047
1048int tipc_dest_list_len(struct list_head *l)
1049{
1050	struct tipc_dest *dst;
1051	int i = 0;
1052
1053	list_for_each_entry(dst, l, list) {
1054		i++;
1055	}
1056	return i;
1057}
v4.17
   1/*
   2 * net/tipc/name_table.c: TIPC name table code
   3 *
   4 * Copyright (c) 2000-2006, 2014-2018, Ericsson AB
   5 * Copyright (c) 2004-2008, 2010-2014, Wind River Systems
   6 * All rights reserved.
   7 *
   8 * Redistribution and use in source and binary forms, with or without
   9 * modification, are permitted provided that the following conditions are met:
  10 *
  11 * 1. Redistributions of source code must retain the above copyright
  12 *    notice, this list of conditions and the following disclaimer.
  13 * 2. Redistributions in binary form must reproduce the above copyright
  14 *    notice, this list of conditions and the following disclaimer in the
  15 *    documentation and/or other materials provided with the distribution.
  16 * 3. Neither the names of the copyright holders nor the names of its
  17 *    contributors may be used to endorse or promote products derived from
  18 *    this software without specific prior written permission.
  19 *
  20 * Alternatively, this software may be distributed under the terms of the
  21 * GNU General Public License ("GPL") version 2 as published by the Free
  22 * Software Foundation.
  23 *
  24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34 * POSSIBILITY OF SUCH DAMAGE.
  35 */
  36
  37#include <net/sock.h>
  38#include "core.h"
  39#include "netlink.h"
  40#include "name_table.h"
  41#include "name_distr.h"
  42#include "subscr.h"
  43#include "bcast.h"
  44#include "addr.h"
  45#include "node.h"
  46#include "group.h"
  47
  48/**
  49 * struct service_range - container for all bindings of a service range
  50 * @lower: service range lower bound
  51 * @upper: service range upper bound
  52 * @tree_node: member of service range RB tree
  53 * @local_publ: list of identical publications made from this node
  54 *   Used by closest_first lookup and multicast lookup algorithm
  55 * @all_publ: all publications identical to this one, whatever node and scope
  56 *   Used by round-robin lookup algorithm
  57 */
  58struct service_range {
  59	u32 lower;
  60	u32 upper;
  61	struct rb_node tree_node;
  62	struct list_head local_publ;
  63	struct list_head all_publ;
  64};
  65
  66/**
  67 * struct tipc_service - container for all published instances of a service type
  68 * @type: 32 bit 'type' value for service
  69 * @ranges: rb tree containing all service ranges for this service
  70 * @service_list: links to adjacent name ranges in hash chain
  71 * @subscriptions: list of subscriptions for this service type
  72 * @lock: spinlock controlling access to pertaining service ranges/publications
  73 * @rcu: RCU callback head used for deferred freeing
  74 */
  75struct tipc_service {
  76	u32 type;
  77	struct rb_root ranges;
  78	struct hlist_node service_list;
  79	struct list_head subscriptions;
  80	spinlock_t lock; /* Covers service range list */
  81	struct rcu_head rcu;
  82};
  83
  84static int hash(int x)
  85{
  86	return x & (TIPC_NAMETBL_SIZE - 1);
  87}
  88
  89/**
  90 * tipc_publ_create - create a publication structure
  91 */
  92static struct publication *tipc_publ_create(u32 type, u32 lower, u32 upper,
  93					    u32 scope, u32 node, u32 port,
  94					    u32 key)
  95{
  96	struct publication *publ = kzalloc(sizeof(*publ), GFP_ATOMIC);
  97
  98	if (!publ)
  99		return NULL;
 100
 101	publ->type = type;
 102	publ->lower = lower;
 103	publ->upper = upper;
 104	publ->scope = scope;
 105	publ->node = node;
 106	publ->port = port;
 107	publ->key = key;
 108	INIT_LIST_HEAD(&publ->binding_sock);
 109	INIT_LIST_HEAD(&publ->binding_node);
 110	INIT_LIST_HEAD(&publ->local_publ);
 111	INIT_LIST_HEAD(&publ->all_publ);
 112	return publ;
 113}
 114
 115/**
 116 * tipc_service_create - create a service structure for the specified 'type'
 117 *
 118 * Allocates a single range structure and sets it to all 0's.
 119 */
 120static struct tipc_service *tipc_service_create(u32 type, struct hlist_head *hd)
 121{
 122	struct tipc_service *service = kzalloc(sizeof(*service), GFP_ATOMIC);
 123
 124	if (!service) {
 125		pr_warn("Service creation failed, no memory\n");
 126		return NULL;
 127	}
 128
 129	spin_lock_init(&service->lock);
 130	service->type = type;
 131	service->ranges = RB_ROOT;
 132	INIT_HLIST_NODE(&service->service_list);
 133	INIT_LIST_HEAD(&service->subscriptions);
 134	hlist_add_head_rcu(&service->service_list, hd);
 135	return service;
 136}
 137
 138/**
 139 * tipc_service_find_range - find service range matching a service instance
 140 *
 141 * Very time-critical, so binary search through range rb tree
 142 */
 143static struct service_range *tipc_service_find_range(struct tipc_service *sc,
 144						     u32 instance)
 145{
 146	struct rb_node *n = sc->ranges.rb_node;
 147	struct service_range *sr;
 148
 149	while (n) {
 150		sr = container_of(n, struct service_range, tree_node);
 151		if (sr->lower > instance)
 152			n = n->rb_left;
 153		else if (sr->upper < instance)
 154			n = n->rb_right;
 155		else
 156			return sr;
 157	}
 158	return NULL;
 159}
 160
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 161static struct service_range *tipc_service_create_range(struct tipc_service *sc,
 162						       u32 lower, u32 upper)
 163{
 164	struct rb_node **n, *parent = NULL;
 165	struct service_range *sr, *tmp;
 166
 167	n = &sc->ranges.rb_node;
 168	while (*n) {
 169		tmp = container_of(*n, struct service_range, tree_node);
 170		parent = *n;
 171		tmp = container_of(parent, struct service_range, tree_node);
 172		if (lower < tmp->lower)
 173			n = &(*n)->rb_left;
 174		else if (lower > tmp->lower)
 175			n = &(*n)->rb_right;
 176		else if (upper < tmp->upper)
 177			n = &(*n)->rb_left;
 178		else if (upper > tmp->upper)
 179			n = &(*n)->rb_right;
 180		else
 181			return tmp;
 182	}
 183	sr = kzalloc(sizeof(*sr), GFP_ATOMIC);
 184	if (!sr)
 185		return NULL;
 186	sr->lower = lower;
 187	sr->upper = upper;
 188	INIT_LIST_HEAD(&sr->local_publ);
 189	INIT_LIST_HEAD(&sr->all_publ);
 190	rb_link_node(&sr->tree_node, parent, n);
 191	rb_insert_color(&sr->tree_node, &sc->ranges);
 192	return sr;
 193}
 194
 195static struct publication *tipc_service_insert_publ(struct net *net,
 196						    struct tipc_service *sc,
 197						    u32 type, u32 lower,
 198						    u32 upper, u32 scope,
 199						    u32 node, u32 port,
 200						    u32 key)
 201{
 202	struct tipc_subscription *sub, *tmp;
 203	struct service_range *sr;
 204	struct publication *p;
 205	bool first = false;
 206
 207	sr = tipc_service_create_range(sc, lower, upper);
 208	if (!sr)
 209		goto  err;
 210
 211	first = list_empty(&sr->all_publ);
 212
 213	/* Return if the publication already exists */
 214	list_for_each_entry(p, &sr->all_publ, all_publ) {
 215		if (p->key == key && (!p->node || p->node == node))
 216			return NULL;
 217	}
 218
 219	/* Create and insert publication */
 220	p = tipc_publ_create(type, lower, upper, scope, node, port, key);
 221	if (!p)
 222		goto err;
 223	if (in_own_node(net, node))
 224		list_add(&p->local_publ, &sr->local_publ);
 225	list_add(&p->all_publ, &sr->all_publ);
 226
 227	/* Any subscriptions waiting for notification?  */
 228	list_for_each_entry_safe(sub, tmp, &sc->subscriptions, service_list) {
 229		tipc_sub_report_overlap(sub, p->lower, p->upper, TIPC_PUBLISHED,
 230					p->port, p->node, p->scope, first);
 231	}
 232	return p;
 233err:
 234	pr_warn("Failed to bind to %u,%u,%u, no memory\n", type, lower, upper);
 235	return NULL;
 236}
 237
 238/**
 239 * tipc_service_remove_publ - remove a publication from a service
 240 */
 241static struct publication *tipc_service_remove_publ(struct net *net,
 242						    struct tipc_service *sc,
 243						    u32 lower, u32 upper,
 244						    u32 node, u32 key,
 245						    struct service_range **rng)
 246{
 247	struct tipc_subscription *sub, *tmp;
 248	struct service_range *sr;
 249	struct publication *p;
 250	bool found = false;
 251	bool last = false;
 252	struct rb_node *n;
 253
 254	sr = tipc_service_find_range(sc, lower);
 255	if (!sr)
 256		return NULL;
 257
 258	/* Find exact matching service range */
 259	for (n = &sr->tree_node; n; n = rb_next(n)) {
 260		sr = container_of(n, struct service_range, tree_node);
 261		if (sr->upper == upper)
 262			break;
 263	}
 264	if (!n || sr->lower != lower || sr->upper != upper)
 265		return NULL;
 266
 267	/* Find publication, if it exists */
 268	list_for_each_entry(p, &sr->all_publ, all_publ) {
 269		if (p->key != key || (node && node != p->node))
 270			continue;
 271		found = true;
 272		break;
 
 273	}
 274	if (!found)
 275		return NULL;
 276
 277	list_del(&p->all_publ);
 278	list_del(&p->local_publ);
 279	if (list_empty(&sr->all_publ))
 280		last = true;
 281
 282	/* Notify any waiting subscriptions */
 283	list_for_each_entry_safe(sub, tmp, &sc->subscriptions, service_list) {
 284		tipc_sub_report_overlap(sub, p->lower, p->upper, TIPC_WITHDRAWN,
 285					p->port, p->node, p->scope, last);
 286	}
 287	*rng = sr;
 288	return p;
 289}
 290
 291/**
 292 * tipc_service_subscribe - attach a subscription, and optionally
 293 * issue the prescribed number of events if there is any service
 294 * range overlapping with the requested range
 295 */
 296static void tipc_service_subscribe(struct tipc_service *service,
 297				   struct tipc_subscription *sub)
 298{
 299	struct tipc_subscr *sb = &sub->evt.s;
 300	struct service_range *sr;
 301	struct tipc_name_seq ns;
 302	struct publication *p;
 303	struct rb_node *n;
 304	bool first;
 305
 306	ns.type = tipc_sub_read(sb, seq.type);
 307	ns.lower = tipc_sub_read(sb, seq.lower);
 308	ns.upper = tipc_sub_read(sb, seq.upper);
 309
 310	tipc_sub_get(sub);
 311	list_add(&sub->service_list, &service->subscriptions);
 312
 313	if (tipc_sub_read(sb, filter) & TIPC_SUB_NO_STATUS)
 314		return;
 315
 316	for (n = rb_first(&service->ranges); n; n = rb_next(n)) {
 317		sr = container_of(n, struct service_range, tree_node);
 318		if (sr->lower > ns.upper)
 319			break;
 320		if (!tipc_sub_check_overlap(&ns, sr->lower, sr->upper))
 321			continue;
 322		first = true;
 323
 324		list_for_each_entry(p, &sr->all_publ, all_publ) {
 325			tipc_sub_report_overlap(sub, sr->lower, sr->upper,
 326						TIPC_PUBLISHED,	p->port,
 327						p->node, p->scope, first);
 328			first = false;
 329		}
 330	}
 331}
 332
 333static struct tipc_service *tipc_service_find(struct net *net, u32 type)
 334{
 335	struct name_table *nt = tipc_name_table(net);
 336	struct hlist_head *service_head;
 337	struct tipc_service *service;
 338
 339	service_head = &nt->services[hash(type)];
 340	hlist_for_each_entry_rcu(service, service_head, service_list) {
 341		if (service->type == type)
 342			return service;
 343	}
 344	return NULL;
 345};
 346
 347struct publication *tipc_nametbl_insert_publ(struct net *net, u32 type,
 348					     u32 lower, u32 upper,
 349					     u32 scope, u32 node,
 350					     u32 port, u32 key)
 351{
 352	struct name_table *nt = tipc_name_table(net);
 353	struct tipc_service *sc;
 354	struct publication *p;
 355
 356	if (scope > TIPC_NODE_SCOPE || lower > upper) {
 357		pr_debug("Failed to bind illegal {%u,%u,%u} with scope %u\n",
 358			 type, lower, upper, scope);
 359		return NULL;
 360	}
 361	sc = tipc_service_find(net, type);
 362	if (!sc)
 363		sc = tipc_service_create(type, &nt->services[hash(type)]);
 364	if (!sc)
 365		return NULL;
 366
 367	spin_lock_bh(&sc->lock);
 368	p = tipc_service_insert_publ(net, sc, type, lower, upper,
 369				     scope, node, port, key);
 370	spin_unlock_bh(&sc->lock);
 371	return p;
 372}
 373
 374struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type,
 375					     u32 lower, u32 upper,
 376					     u32 node, u32 key)
 377{
 378	struct tipc_service *sc = tipc_service_find(net, type);
 
 379	struct service_range *sr = NULL;
 380	struct publication *p = NULL;
 
 381
 382	if (!sc)
 383		return NULL;
 384
 385	spin_lock_bh(&sc->lock);
 386	p = tipc_service_remove_publ(net, sc, lower, upper, node, key, &sr);
 
 
 
 
 
 
 
 
 
 
 
 
 387
 388	/* Remove service range item if this was its last publication */
 389	if (sr && list_empty(&sr->all_publ)) {
 390		rb_erase(&sr->tree_node, &sc->ranges);
 391		kfree(sr);
 392	}
 393
 394	/* Delete service item if this no more publications and subscriptions */
 395	if (RB_EMPTY_ROOT(&sc->ranges) && list_empty(&sc->subscriptions)) {
 396		hlist_del_init_rcu(&sc->service_list);
 397		kfree_rcu(sc, rcu);
 398	}
 
 399	spin_unlock_bh(&sc->lock);
 400	return p;
 401}
 402
 403/**
 404 * tipc_nametbl_translate - perform service instance to socket translation
 405 *
 406 * On entry, 'dnode' is the search domain used during translation.
 407 *
 408 * On exit:
 409 * - if translation is deferred to another node, leave 'dnode' unchanged and
 410 *   return 0
 411 * - if translation is attempted and succeeds, set 'dnode' to the publishing
 412 *   node and return the published (non-zero) port number
 413 * - if translation is attempted and fails, set 'dnode' to 0 and return 0
 414 *
 415 * Note that for legacy users (node configured with Z.C.N address format) the
 416 * 'closest-first' lookup algorithm must be maintained, i.e., if dnode is 0
 417 * we must look in the local binding list first
 418 */
 419u32 tipc_nametbl_translate(struct net *net, u32 type, u32 instance, u32 *dnode)
 420{
 421	struct tipc_net *tn = tipc_net(net);
 422	bool legacy = tn->legacy_addr_format;
 423	u32 self = tipc_own_addr(net);
 424	struct service_range *sr;
 425	struct tipc_service *sc;
 426	struct list_head *list;
 427	struct publication *p;
 428	u32 port = 0;
 429	u32 node = 0;
 430
 431	if (!tipc_in_scope(legacy, *dnode, self))
 432		return 0;
 433
 434	rcu_read_lock();
 435	sc = tipc_service_find(net, type);
 436	if (unlikely(!sc))
 437		goto not_found;
 438
 439	spin_lock_bh(&sc->lock);
 440	sr = tipc_service_find_range(sc, instance);
 441	if (unlikely(!sr))
 442		goto no_match;
 443
 444	/* Select lookup algorithm: local, closest-first or round-robin */
 445	if (*dnode == self) {
 446		list = &sr->local_publ;
 447		if (list_empty(list))
 448			goto no_match;
 449		p = list_first_entry(list, struct publication, local_publ);
 450		list_move_tail(&p->local_publ, &sr->local_publ);
 451	} else if (legacy && !*dnode && !list_empty(&sr->local_publ)) {
 452		list = &sr->local_publ;
 453		p = list_first_entry(list, struct publication, local_publ);
 454		list_move_tail(&p->local_publ, &sr->local_publ);
 455	} else {
 456		list = &sr->all_publ;
 457		p = list_first_entry(list, struct publication, all_publ);
 458		list_move_tail(&p->all_publ, &sr->all_publ);
 459	}
 460	port = p->port;
 461	node = p->node;
 462no_match:
 463	spin_unlock_bh(&sc->lock);
 464not_found:
 465	rcu_read_unlock();
 466	*dnode = node;
 467	return port;
 468}
 469
 470bool tipc_nametbl_lookup(struct net *net, u32 type, u32 instance, u32 scope,
 471			 struct list_head *dsts, int *dstcnt, u32 exclude,
 472			 bool all)
 473{
 474	u32 self = tipc_own_addr(net);
 475	struct service_range *sr;
 476	struct tipc_service *sc;
 477	struct publication *p;
 478
 479	*dstcnt = 0;
 480	rcu_read_lock();
 481	sc = tipc_service_find(net, type);
 482	if (unlikely(!sc))
 483		goto exit;
 484
 485	spin_lock_bh(&sc->lock);
 486
 487	sr = tipc_service_find_range(sc, instance);
 488	if (!sr)
 489		goto no_match;
 490
 491	list_for_each_entry(p, &sr->all_publ, all_publ) {
 492		if (p->scope != scope)
 493			continue;
 494		if (p->port == exclude && p->node == self)
 495			continue;
 496		tipc_dest_push(dsts, p->node, p->port);
 497		(*dstcnt)++;
 498		if (all)
 499			continue;
 500		list_move_tail(&p->all_publ, &sr->all_publ);
 501		break;
 502	}
 503no_match:
 504	spin_unlock_bh(&sc->lock);
 505exit:
 506	rcu_read_unlock();
 507	return !list_empty(dsts);
 508}
 509
 510void tipc_nametbl_mc_lookup(struct net *net, u32 type, u32 lower, u32 upper,
 511			    u32 scope, bool exact, struct list_head *dports)
 512{
 513	struct service_range *sr;
 514	struct tipc_service *sc;
 515	struct publication *p;
 516	struct rb_node *n;
 517
 518	rcu_read_lock();
 519	sc = tipc_service_find(net, type);
 520	if (!sc)
 521		goto exit;
 522
 523	spin_lock_bh(&sc->lock);
 524
 525	for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
 526		sr = container_of(n, struct service_range, tree_node);
 527		if (sr->upper < lower)
 528			continue;
 529		if (sr->lower > upper)
 530			break;
 531		list_for_each_entry(p, &sr->local_publ, local_publ) {
 532			if (p->scope == scope || (!exact && p->scope < scope))
 533				tipc_dest_push(dports, 0, p->port);
 534		}
 535	}
 536	spin_unlock_bh(&sc->lock);
 537exit:
 538	rcu_read_unlock();
 539}
 540
 541/* tipc_nametbl_lookup_dst_nodes - find broadcast destination nodes
 542 * - Creates list of nodes that overlap the given multicast address
 543 * - Determines if any node local destinations overlap
 544 */
 545void tipc_nametbl_lookup_dst_nodes(struct net *net, u32 type, u32 lower,
 546				   u32 upper, struct tipc_nlist *nodes)
 547{
 548	struct service_range *sr;
 549	struct tipc_service *sc;
 550	struct publication *p;
 551	struct rb_node *n;
 552
 553	rcu_read_lock();
 554	sc = tipc_service_find(net, type);
 555	if (!sc)
 556		goto exit;
 557
 558	spin_lock_bh(&sc->lock);
 559
 560	for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
 561		sr = container_of(n, struct service_range, tree_node);
 562		if (sr->upper < lower)
 563			continue;
 564		if (sr->lower > upper)
 565			break;
 566		list_for_each_entry(p, &sr->all_publ, all_publ) {
 567			tipc_nlist_add(nodes, p->node);
 568		}
 569	}
 570	spin_unlock_bh(&sc->lock);
 571exit:
 572	rcu_read_unlock();
 573}
 574
 575/* tipc_nametbl_build_group - build list of communication group members
 576 */
 577void tipc_nametbl_build_group(struct net *net, struct tipc_group *grp,
 578			      u32 type, u32 scope)
 579{
 580	struct service_range *sr;
 581	struct tipc_service *sc;
 582	struct publication *p;
 583	struct rb_node *n;
 584
 585	rcu_read_lock();
 586	sc = tipc_service_find(net, type);
 587	if (!sc)
 588		goto exit;
 589
 590	spin_lock_bh(&sc->lock);
 591	for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
 592		sr = container_of(n, struct service_range, tree_node);
 593		list_for_each_entry(p, &sr->all_publ, all_publ) {
 594			if (p->scope != scope)
 595				continue;
 596			tipc_group_add_member(grp, p->node, p->port, p->lower);
 597		}
 598	}
 599	spin_unlock_bh(&sc->lock);
 600exit:
 601	rcu_read_unlock();
 602}
 603
 604/* tipc_nametbl_publish - add service binding to name table
 605 */
 606struct publication *tipc_nametbl_publish(struct net *net, u32 type, u32 lower,
 607					 u32 upper, u32 scope, u32 port,
 608					 u32 key)
 609{
 610	struct name_table *nt = tipc_name_table(net);
 611	struct tipc_net *tn = tipc_net(net);
 612	struct publication *p = NULL;
 613	struct sk_buff *skb = NULL;
 614
 615	spin_lock_bh(&tn->nametbl_lock);
 616
 617	if (nt->local_publ_count >= TIPC_MAX_PUBL) {
 618		pr_warn("Bind failed, max limit %u reached\n", TIPC_MAX_PUBL);
 619		goto exit;
 620	}
 621
 622	p = tipc_nametbl_insert_publ(net, type, lower, upper, scope,
 623				     tipc_own_addr(net), port, key);
 624	if (p) {
 625		nt->local_publ_count++;
 626		skb = tipc_named_publish(net, p);
 627	}
 628exit:
 629	spin_unlock_bh(&tn->nametbl_lock);
 630
 631	if (skb)
 632		tipc_node_broadcast(net, skb);
 633	return p;
 634}
 635
 636/**
 637 * tipc_nametbl_withdraw - withdraw a service binding
 638 */
 639int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower,
 640			  u32 upper, u32 key)
 641{
 642	struct name_table *nt = tipc_name_table(net);
 643	struct tipc_net *tn = tipc_net(net);
 644	u32 self = tipc_own_addr(net);
 645	struct sk_buff *skb = NULL;
 646	struct publication *p;
 647
 648	spin_lock_bh(&tn->nametbl_lock);
 649
 650	p = tipc_nametbl_remove_publ(net, type, lower, upper, self, key);
 651	if (p) {
 652		nt->local_publ_count--;
 653		skb = tipc_named_withdraw(net, p);
 654		list_del_init(&p->binding_sock);
 655		kfree_rcu(p, rcu);
 656	} else {
 657		pr_err("Failed to remove local publication {%u,%u,%u}/%u\n",
 658		       type, lower, upper, key);
 659	}
 660	spin_unlock_bh(&tn->nametbl_lock);
 661
 662	if (skb) {
 663		tipc_node_broadcast(net, skb);
 664		return 1;
 665	}
 666	return 0;
 667}
 668
 669/**
 670 * tipc_nametbl_subscribe - add a subscription object to the name table
 671 */
 672bool tipc_nametbl_subscribe(struct tipc_subscription *sub)
 673{
 674	struct name_table *nt = tipc_name_table(sub->net);
 675	struct tipc_net *tn = tipc_net(sub->net);
 676	struct tipc_subscr *s = &sub->evt.s;
 677	u32 type = tipc_sub_read(s, seq.type);
 678	struct tipc_service *sc;
 679	bool res = true;
 680
 681	spin_lock_bh(&tn->nametbl_lock);
 682	sc = tipc_service_find(sub->net, type);
 683	if (!sc)
 684		sc = tipc_service_create(type, &nt->services[hash(type)]);
 685	if (sc) {
 686		spin_lock_bh(&sc->lock);
 687		tipc_service_subscribe(sc, sub);
 688		spin_unlock_bh(&sc->lock);
 689	} else {
 690		pr_warn("Failed to subscribe for {%u,%u,%u}\n", type,
 691			tipc_sub_read(s, seq.lower),
 692			tipc_sub_read(s, seq.upper));
 693		res = false;
 694	}
 695	spin_unlock_bh(&tn->nametbl_lock);
 696	return res;
 697}
 698
 699/**
 700 * tipc_nametbl_unsubscribe - remove a subscription object from name table
 701 */
 702void tipc_nametbl_unsubscribe(struct tipc_subscription *sub)
 703{
 704	struct tipc_net *tn = tipc_net(sub->net);
 705	struct tipc_subscr *s = &sub->evt.s;
 706	u32 type = tipc_sub_read(s, seq.type);
 707	struct tipc_service *sc;
 708
 709	spin_lock_bh(&tn->nametbl_lock);
 710	sc = tipc_service_find(sub->net, type);
 711	if (!sc)
 712		goto exit;
 713
 714	spin_lock_bh(&sc->lock);
 715	list_del_init(&sub->service_list);
 716	tipc_sub_put(sub);
 717
 718	/* Delete service item if no more publications and subscriptions */
 719	if (RB_EMPTY_ROOT(&sc->ranges) && list_empty(&sc->subscriptions)) {
 720		hlist_del_init_rcu(&sc->service_list);
 721		kfree_rcu(sc, rcu);
 722	}
 723	spin_unlock_bh(&sc->lock);
 724exit:
 725	spin_unlock_bh(&tn->nametbl_lock);
 726}
 727
 728int tipc_nametbl_init(struct net *net)
 729{
 730	struct tipc_net *tn = tipc_net(net);
 731	struct name_table *nt;
 732	int i;
 733
 734	nt = kzalloc(sizeof(*nt), GFP_ATOMIC);
 735	if (!nt)
 736		return -ENOMEM;
 737
 738	for (i = 0; i < TIPC_NAMETBL_SIZE; i++)
 739		INIT_HLIST_HEAD(&nt->services[i]);
 740
 741	INIT_LIST_HEAD(&nt->node_scope);
 742	INIT_LIST_HEAD(&nt->cluster_scope);
 
 743	tn->nametbl = nt;
 744	spin_lock_init(&tn->nametbl_lock);
 745	return 0;
 746}
 747
 748/**
 749 *  tipc_service_delete - purge all publications for a service and delete it
 750 */
 751static void tipc_service_delete(struct net *net, struct tipc_service *sc)
 752{
 753	struct service_range *sr, *tmpr;
 754	struct publication *p, *tmp;
 755
 756	spin_lock_bh(&sc->lock);
 757	rbtree_postorder_for_each_entry_safe(sr, tmpr, &sc->ranges, tree_node) {
 758		list_for_each_entry_safe(p, tmp, &sr->all_publ, all_publ) {
 759			tipc_service_remove_publ(net, sc, p->lower, p->upper,
 760						 p->node, p->key, &sr);
 761			kfree_rcu(p, rcu);
 762		}
 763		rb_erase(&sr->tree_node, &sc->ranges);
 764		kfree(sr);
 765	}
 766	hlist_del_init_rcu(&sc->service_list);
 767	spin_unlock_bh(&sc->lock);
 768	kfree_rcu(sc, rcu);
 769}
 770
 771void tipc_nametbl_stop(struct net *net)
 772{
 773	struct name_table *nt = tipc_name_table(net);
 774	struct tipc_net *tn = tipc_net(net);
 775	struct hlist_head *service_head;
 776	struct tipc_service *service;
 777	u32 i;
 778
 779	/* Verify name table is empty and purge any lingering
 780	 * publications, then release the name table
 781	 */
 782	spin_lock_bh(&tn->nametbl_lock);
 783	for (i = 0; i < TIPC_NAMETBL_SIZE; i++) {
 784		if (hlist_empty(&nt->services[i]))
 785			continue;
 786		service_head = &nt->services[i];
 787		hlist_for_each_entry_rcu(service, service_head, service_list) {
 788			tipc_service_delete(net, service);
 789		}
 790	}
 791	spin_unlock_bh(&tn->nametbl_lock);
 792
 793	synchronize_net();
 794	kfree(nt);
 795}
 796
 797static int __tipc_nl_add_nametable_publ(struct tipc_nl_msg *msg,
 798					struct tipc_service *service,
 799					struct service_range *sr,
 800					u32 *last_key)
 801{
 802	struct publication *p;
 803	struct nlattr *attrs;
 804	struct nlattr *b;
 805	void *hdr;
 806
 807	if (*last_key) {
 808		list_for_each_entry(p, &sr->all_publ, all_publ)
 809			if (p->key == *last_key)
 810				break;
 811		if (p->key != *last_key)
 812			return -EPIPE;
 813	} else {
 814		p = list_first_entry(&sr->all_publ,
 815				     struct publication,
 816				     all_publ);
 817	}
 818
 819	list_for_each_entry_from(p, &sr->all_publ, all_publ) {
 820		*last_key = p->key;
 821
 822		hdr = genlmsg_put(msg->skb, msg->portid, msg->seq,
 823				  &tipc_genl_family, NLM_F_MULTI,
 824				  TIPC_NL_NAME_TABLE_GET);
 825		if (!hdr)
 826			return -EMSGSIZE;
 827
 828		attrs = nla_nest_start(msg->skb, TIPC_NLA_NAME_TABLE);
 829		if (!attrs)
 830			goto msg_full;
 831
 832		b = nla_nest_start(msg->skb, TIPC_NLA_NAME_TABLE_PUBL);
 833		if (!b)
 834			goto attr_msg_full;
 835
 836		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_TYPE, service->type))
 837			goto publ_msg_full;
 838		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_LOWER, sr->lower))
 839			goto publ_msg_full;
 840		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_UPPER, sr->upper))
 841			goto publ_msg_full;
 842		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_SCOPE, p->scope))
 843			goto publ_msg_full;
 844		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_NODE, p->node))
 845			goto publ_msg_full;
 846		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_REF, p->port))
 847			goto publ_msg_full;
 848		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_KEY, p->key))
 849			goto publ_msg_full;
 850
 851		nla_nest_end(msg->skb, b);
 852		nla_nest_end(msg->skb, attrs);
 853		genlmsg_end(msg->skb, hdr);
 854	}
 855	*last_key = 0;
 856
 857	return 0;
 858
 859publ_msg_full:
 860	nla_nest_cancel(msg->skb, b);
 861attr_msg_full:
 862	nla_nest_cancel(msg->skb, attrs);
 863msg_full:
 864	genlmsg_cancel(msg->skb, hdr);
 865
 866	return -EMSGSIZE;
 867}
 868
 869static int __tipc_nl_service_range_list(struct tipc_nl_msg *msg,
 870					struct tipc_service *sc,
 871					u32 *last_lower, u32 *last_key)
 872{
 873	struct service_range *sr;
 874	struct rb_node *n;
 875	int err;
 876
 877	for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
 878		sr = container_of(n, struct service_range, tree_node);
 879		if (sr->lower < *last_lower)
 880			continue;
 881		err = __tipc_nl_add_nametable_publ(msg, sc, sr, last_key);
 882		if (err) {
 883			*last_lower = sr->lower;
 884			return err;
 885		}
 886	}
 887	*last_lower = 0;
 888	return 0;
 889}
 890
 891static int tipc_nl_service_list(struct net *net, struct tipc_nl_msg *msg,
 892				u32 *last_type, u32 *last_lower, u32 *last_key)
 893{
 894	struct tipc_net *tn = tipc_net(net);
 895	struct tipc_service *service = NULL;
 896	struct hlist_head *head;
 897	int err;
 898	int i;
 899
 900	if (*last_type)
 901		i = hash(*last_type);
 902	else
 903		i = 0;
 904
 905	for (; i < TIPC_NAMETBL_SIZE; i++) {
 906		head = &tn->nametbl->services[i];
 907
 908		if (*last_type) {
 
 909			service = tipc_service_find(net, *last_type);
 910			if (!service)
 911				return -EPIPE;
 912		} else {
 913			hlist_for_each_entry_rcu(service, head, service_list)
 914				break;
 915			if (!service)
 916				continue;
 917		}
 918
 919		hlist_for_each_entry_from_rcu(service, service_list) {
 920			spin_lock_bh(&service->lock);
 921			err = __tipc_nl_service_range_list(msg, service,
 922							   last_lower,
 923							   last_key);
 924
 925			if (err) {
 926				*last_type = service->type;
 927				spin_unlock_bh(&service->lock);
 928				return err;
 929			}
 930			spin_unlock_bh(&service->lock);
 931		}
 932		*last_type = 0;
 933	}
 934	return 0;
 935}
 936
 937int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb)
 938{
 939	struct net *net = sock_net(skb->sk);
 940	u32 last_type = cb->args[0];
 941	u32 last_lower = cb->args[1];
 942	u32 last_key = cb->args[2];
 943	int done = cb->args[3];
 944	struct tipc_nl_msg msg;
 945	int err;
 946
 947	if (done)
 948		return 0;
 949
 950	msg.skb = skb;
 951	msg.portid = NETLINK_CB(cb->skb).portid;
 952	msg.seq = cb->nlh->nlmsg_seq;
 953
 954	rcu_read_lock();
 955	err = tipc_nl_service_list(net, &msg, &last_type,
 956				   &last_lower, &last_key);
 957	if (!err) {
 958		done = 1;
 959	} else if (err != -EMSGSIZE) {
 960		/* We never set seq or call nl_dump_check_consistent() this
 961		 * means that setting prev_seq here will cause the consistence
 962		 * check to fail in the netlink callback handler. Resulting in
 963		 * the NLMSG_DONE message having the NLM_F_DUMP_INTR flag set if
 964		 * we got an error.
 965		 */
 966		cb->prev_seq = 1;
 967	}
 968	rcu_read_unlock();
 969
 970	cb->args[0] = last_type;
 971	cb->args[1] = last_lower;
 972	cb->args[2] = last_key;
 973	cb->args[3] = done;
 974
 975	return skb->len;
 976}
 977
 978struct tipc_dest *tipc_dest_find(struct list_head *l, u32 node, u32 port)
 979{
 980	u64 value = (u64)node << 32 | port;
 981	struct tipc_dest *dst;
 982
 983	list_for_each_entry(dst, l, list) {
 984		if (dst->value != value)
 985			continue;
 986		return dst;
 987	}
 988	return NULL;
 989}
 990
 991bool tipc_dest_push(struct list_head *l, u32 node, u32 port)
 992{
 993	u64 value = (u64)node << 32 | port;
 994	struct tipc_dest *dst;
 995
 996	if (tipc_dest_find(l, node, port))
 997		return false;
 998
 999	dst = kmalloc(sizeof(*dst), GFP_ATOMIC);
1000	if (unlikely(!dst))
1001		return false;
1002	dst->value = value;
 
1003	list_add(&dst->list, l);
1004	return true;
1005}
1006
1007bool tipc_dest_pop(struct list_head *l, u32 *node, u32 *port)
1008{
1009	struct tipc_dest *dst;
1010
1011	if (list_empty(l))
1012		return false;
1013	dst = list_first_entry(l, typeof(*dst), list);
1014	if (port)
1015		*port = dst->port;
1016	if (node)
1017		*node = dst->node;
1018	list_del(&dst->list);
1019	kfree(dst);
1020	return true;
1021}
1022
1023bool tipc_dest_del(struct list_head *l, u32 node, u32 port)
1024{
1025	struct tipc_dest *dst;
1026
1027	dst = tipc_dest_find(l, node, port);
1028	if (!dst)
1029		return false;
1030	list_del(&dst->list);
1031	kfree(dst);
1032	return true;
1033}
1034
1035void tipc_dest_list_purge(struct list_head *l)
1036{
1037	struct tipc_dest *dst, *tmp;
1038
1039	list_for_each_entry_safe(dst, tmp, l, list) {
1040		list_del(&dst->list);
1041		kfree(dst);
1042	}
1043}
1044
1045int tipc_dest_list_len(struct list_head *l)
1046{
1047	struct tipc_dest *dst;
1048	int i = 0;
1049
1050	list_for_each_entry(dst, l, list) {
1051		i++;
1052	}
1053	return i;
1054}