1/*
   2 * net/tipc/name_table.c: TIPC name table code
   3 *
   4 * Copyright (c) 2000-2006, 2014-2015, 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 <net/genetlink.h>
  47
  48#define TIPC_NAMETBL_SIZE 1024		/* must be a power of 2 */
  49
  50/**
  51 * struct name_info - name sequence publication info
  52 * @node_list: circular list of publications made by own node
  53 * @cluster_list: circular list of publications made by own cluster
  54 * @zone_list: circular list of publications made by own zone
  55 * @node_list_size: number of entries in "node_list"
  56 * @cluster_list_size: number of entries in "cluster_list"
  57 * @zone_list_size: number of entries in "zone_list"
  58 *
  59 * Note: The zone list always contains at least one entry, since all
  60 *       publications of the associated name sequence belong to it.
  61 *       (The cluster and node lists may be empty.)
  62 */
  63struct name_info {
  64	struct list_head node_list;
  65	struct list_head cluster_list;
  66	struct list_head zone_list;
  67	u32 node_list_size;
  68	u32 cluster_list_size;
  69	u32 zone_list_size;
  70};
  71
  72/**
  73 * struct sub_seq - container for all published instances of a name sequence
  74 * @lower: name sequence lower bound
  75 * @upper: name sequence upper bound
  76 * @info: pointer to name sequence publication info
  77 */
  78struct sub_seq {
  79	u32 lower;
  80	u32 upper;
  81	struct name_info *info;
  82};
  83
  84/**
  85 * struct name_seq - container for all published instances of a name type
  86 * @type: 32 bit 'type' value for name sequence
  87 * @sseq: pointer to dynamically-sized array of sub-sequences of this 'type';
  88 *        sub-sequences are sorted in ascending order
  89 * @alloc: number of sub-sequences currently in array
  90 * @first_free: array index of first unused sub-sequence entry
  91 * @ns_list: links to adjacent name sequences in hash chain
  92 * @subscriptions: list of subscriptions for this 'type'
  93 * @lock: spinlock controlling access to publication lists of all sub-sequences
  94 * @rcu: RCU callback head used for deferred freeing
  95 */
  96struct name_seq {
  97	u32 type;
  98	struct sub_seq *sseqs;
  99	u32 alloc;
 100	u32 first_free;
 101	struct hlist_node ns_list;
 102	struct list_head subscriptions;
 103	spinlock_t lock;
 104	struct rcu_head rcu;
 105};
 106
 107static int hash(int x)
 108{
 109	return x & (TIPC_NAMETBL_SIZE - 1);
 110}
 111
 112/**
 113 * publ_create - create a publication structure
 114 */
 115static struct publication *publ_create(u32 type, u32 lower, u32 upper,
 116				       u32 scope, u32 node, u32 port_ref,
 117				       u32 key)
 118{
 119	struct publication *publ = kzalloc(sizeof(*publ), GFP_ATOMIC);
 120	if (publ == NULL) {
 121		pr_warn("Publication creation failure, no memory\n");
 122		return NULL;
 123	}
 124
 125	publ->type = type;
 126	publ->lower = lower;
 127	publ->upper = upper;
 128	publ->scope = scope;
 129	publ->node = node;
 130	publ->ref = port_ref;
 131	publ->key = key;
 132	INIT_LIST_HEAD(&publ->pport_list);
 133	return publ;
 134}
 135
 136/**
 137 * tipc_subseq_alloc - allocate a specified number of sub-sequence structures
 138 */
 139static struct sub_seq *tipc_subseq_alloc(u32 cnt)
 140{
 141	return kcalloc(cnt, sizeof(struct sub_seq), GFP_ATOMIC);
 142}
 143
 144/**
 145 * tipc_nameseq_create - create a name sequence structure for the specified 'type'
 146 *
 147 * Allocates a single sub-sequence structure and sets it to all 0's.
 148 */
 149static struct name_seq *tipc_nameseq_create(u32 type, struct hlist_head *seq_head)
 150{
 151	struct name_seq *nseq = kzalloc(sizeof(*nseq), GFP_ATOMIC);
 152	struct sub_seq *sseq = tipc_subseq_alloc(1);
 153
 154	if (!nseq || !sseq) {
 155		pr_warn("Name sequence creation failed, no memory\n");
 156		kfree(nseq);
 157		kfree(sseq);
 158		return NULL;
 159	}
 160
 161	spin_lock_init(&nseq->lock);
 162	nseq->type = type;
 163	nseq->sseqs = sseq;
 164	nseq->alloc = 1;
 165	INIT_HLIST_NODE(&nseq->ns_list);
 166	INIT_LIST_HEAD(&nseq->subscriptions);
 167	hlist_add_head_rcu(&nseq->ns_list, seq_head);
 168	return nseq;
 169}
 170
 171/**
 172 * nameseq_find_subseq - find sub-sequence (if any) matching a name instance
 173 *
 174 * Very time-critical, so binary searches through sub-sequence array.
 175 */
 176static struct sub_seq *nameseq_find_subseq(struct name_seq *nseq,
 177					   u32 instance)
 178{
 179	struct sub_seq *sseqs = nseq->sseqs;
 180	int low = 0;
 181	int high = nseq->first_free - 1;
 182	int mid;
 183
 184	while (low <= high) {
 185		mid = (low + high) / 2;
 186		if (instance < sseqs[mid].lower)
 187			high = mid - 1;
 188		else if (instance > sseqs[mid].upper)
 189			low = mid + 1;
 190		else
 191			return &sseqs[mid];
 192	}
 193	return NULL;
 194}
 195
 196/**
 197 * nameseq_locate_subseq - determine position of name instance in sub-sequence
 198 *
 199 * Returns index in sub-sequence array of the entry that contains the specified
 200 * instance value; if no entry contains that value, returns the position
 201 * where a new entry for it would be inserted in the array.
 202 *
 203 * Note: Similar to binary search code for locating a sub-sequence.
 204 */
 205static u32 nameseq_locate_subseq(struct name_seq *nseq, u32 instance)
 206{
 207	struct sub_seq *sseqs = nseq->sseqs;
 208	int low = 0;
 209	int high = nseq->first_free - 1;
 210	int mid;
 211
 212	while (low <= high) {
 213		mid = (low + high) / 2;
 214		if (instance < sseqs[mid].lower)
 215			high = mid - 1;
 216		else if (instance > sseqs[mid].upper)
 217			low = mid + 1;
 218		else
 219			return mid;
 220	}
 221	return low;
 222}
 223
 224/**
 225 * tipc_nameseq_insert_publ
 226 */
 227static struct publication *tipc_nameseq_insert_publ(struct net *net,
 228						    struct name_seq *nseq,
 229						    u32 type, u32 lower,
 230						    u32 upper, u32 scope,
 231						    u32 node, u32 port, u32 key)
 232{
 233	struct tipc_subscription *s;
 234	struct tipc_subscription *st;
 235	struct publication *publ;
 236	struct sub_seq *sseq;
 237	struct name_info *info;
 238	int created_subseq = 0;
 239
 240	sseq = nameseq_find_subseq(nseq, lower);
 241	if (sseq) {
 242
 243		/* Lower end overlaps existing entry => need an exact match */
 244		if ((sseq->lower != lower) || (sseq->upper != upper)) {
 245			return NULL;
 246		}
 247
 248		info = sseq->info;
 249
 250		/* Check if an identical publication already exists */
 251		list_for_each_entry(publ, &info->zone_list, zone_list) {
 252			if ((publ->ref == port) && (publ->key == key) &&
 253			    (!publ->node || (publ->node == node)))
 254				return NULL;
 255		}
 256	} else {
 257		u32 inspos;
 258		struct sub_seq *freesseq;
 259
 260		/* Find where lower end should be inserted */
 261		inspos = nameseq_locate_subseq(nseq, lower);
 262
 263		/* Fail if upper end overlaps into an existing entry */
 264		if ((inspos < nseq->first_free) &&
 265		    (upper >= nseq->sseqs[inspos].lower)) {
 266			return NULL;
 267		}
 268
 269		/* Ensure there is space for new sub-sequence */
 270		if (nseq->first_free == nseq->alloc) {
 271			struct sub_seq *sseqs = tipc_subseq_alloc(nseq->alloc * 2);
 272
 273			if (!sseqs) {
 274				pr_warn("Cannot publish {%u,%u,%u}, no memory\n",
 275					type, lower, upper);
 276				return NULL;
 277			}
 278			memcpy(sseqs, nseq->sseqs,
 279			       nseq->alloc * sizeof(struct sub_seq));
 280			kfree(nseq->sseqs);
 281			nseq->sseqs = sseqs;
 282			nseq->alloc *= 2;
 283		}
 284
 285		info = kzalloc(sizeof(*info), GFP_ATOMIC);
 286		if (!info) {
 287			pr_warn("Cannot publish {%u,%u,%u}, no memory\n",
 288				type, lower, upper);
 289			return NULL;
 290		}
 291
 292		INIT_LIST_HEAD(&info->node_list);
 293		INIT_LIST_HEAD(&info->cluster_list);
 294		INIT_LIST_HEAD(&info->zone_list);
 295
 296		/* Insert new sub-sequence */
 297		sseq = &nseq->sseqs[inspos];
 298		freesseq = &nseq->sseqs[nseq->first_free];
 299		memmove(sseq + 1, sseq, (freesseq - sseq) * sizeof(*sseq));
 300		memset(sseq, 0, sizeof(*sseq));
 301		nseq->first_free++;
 302		sseq->lower = lower;
 303		sseq->upper = upper;
 304		sseq->info = info;
 305		created_subseq = 1;
 306	}
 307
 308	/* Insert a publication */
 309	publ = publ_create(type, lower, upper, scope, node, port, key);
 310	if (!publ)
 311		return NULL;
 312
 313	list_add(&publ->zone_list, &info->zone_list);
 314	info->zone_list_size++;
 315
 316	if (in_own_cluster(net, node)) {
 317		list_add(&publ->cluster_list, &info->cluster_list);
 318		info->cluster_list_size++;
 319	}
 320
 321	if (in_own_node(net, node)) {
 322		list_add(&publ->node_list, &info->node_list);
 323		info->node_list_size++;
 324	}
 325
 326	/* Any subscriptions waiting for notification?  */
 327	list_for_each_entry_safe(s, st, &nseq->subscriptions, nameseq_list) {
 328		tipc_subscrp_report_overlap(s, publ->lower, publ->upper,
 329					    TIPC_PUBLISHED, publ->ref,
 330					    publ->node, created_subseq);
 331	}
 332	return publ;
 333}
 334
 335/**
 336 * tipc_nameseq_remove_publ
 337 *
 338 * NOTE: There may be cases where TIPC is asked to remove a publication
 339 * that is not in the name table.  For example, if another node issues a
 340 * publication for a name sequence that overlaps an existing name sequence
 341 * the publication will not be recorded, which means the publication won't
 342 * be found when the name sequence is later withdrawn by that node.
 343 * A failed withdraw request simply returns a failure indication and lets the
 344 * caller issue any error or warning messages associated with such a problem.
 345 */
 346static struct publication *tipc_nameseq_remove_publ(struct net *net,
 347						    struct name_seq *nseq,
 348						    u32 inst, u32 node,
 349						    u32 ref, u32 key)
 350{
 351	struct publication *publ;
 352	struct sub_seq *sseq = nameseq_find_subseq(nseq, inst);
 353	struct name_info *info;
 354	struct sub_seq *free;
 355	struct tipc_subscription *s, *st;
 356	int removed_subseq = 0;
 357
 358	if (!sseq)
 359		return NULL;
 360
 361	info = sseq->info;
 362
 363	/* Locate publication, if it exists */
 364	list_for_each_entry(publ, &info->zone_list, zone_list) {
 365		if ((publ->key == key) && (publ->ref == ref) &&
 366		    (!publ->node || (publ->node == node)))
 367			goto found;
 368	}
 369	return NULL;
 370
 371found:
 372	/* Remove publication from zone scope list */
 373	list_del(&publ->zone_list);
 374	info->zone_list_size--;
 375
 376	/* Remove publication from cluster scope list, if present */
 377	if (in_own_cluster(net, node)) {
 378		list_del(&publ->cluster_list);
 379		info->cluster_list_size--;
 380	}
 381
 382	/* Remove publication from node scope list, if present */
 383	if (in_own_node(net, node)) {
 384		list_del(&publ->node_list);
 385		info->node_list_size--;
 386	}
 387
 388	/* Contract subseq list if no more publications for that subseq */
 389	if (list_empty(&info->zone_list)) {
 390		kfree(info);
 391		free = &nseq->sseqs[nseq->first_free--];
 392		memmove(sseq, sseq + 1, (free - (sseq + 1)) * sizeof(*sseq));
 393		removed_subseq = 1;
 394	}
 395
 396	/* Notify any waiting subscriptions */
 397	list_for_each_entry_safe(s, st, &nseq->subscriptions, nameseq_list) {
 398		tipc_subscrp_report_overlap(s, publ->lower, publ->upper,
 399					    TIPC_WITHDRAWN, publ->ref,
 400					    publ->node, removed_subseq);
 401	}
 402
 403	return publ;
 404}
 405
 406/**
 407 * tipc_nameseq_subscribe - attach a subscription, and issue
 408 * the prescribed number of events if there is any sub-
 409 * sequence overlapping with the requested sequence
 410 */
 411static void tipc_nameseq_subscribe(struct name_seq *nseq,
 412				   struct tipc_subscription *s)
 413{
 414	struct sub_seq *sseq = nseq->sseqs;
 415	struct tipc_name_seq ns;
 416
 417	tipc_subscrp_convert_seq(&s->evt.s.seq, s->swap, &ns);
 418
 419	list_add(&s->nameseq_list, &nseq->subscriptions);
 420
 421	if (!sseq)
 422		return;
 423
 424	while (sseq != &nseq->sseqs[nseq->first_free]) {
 425		if (tipc_subscrp_check_overlap(&ns, sseq->lower, sseq->upper)) {
 426			struct publication *crs;
 427			struct name_info *info = sseq->info;
 428			int must_report = 1;
 429
 430			list_for_each_entry(crs, &info->zone_list, zone_list) {
 431				tipc_subscrp_report_overlap(s, sseq->lower,
 432							    sseq->upper,
 433							    TIPC_PUBLISHED,
 434							    crs->ref, crs->node,
 435							    must_report);
 436				must_report = 0;
 437			}
 438		}
 439		sseq++;
 440	}
 441}
 442
 443static struct name_seq *nametbl_find_seq(struct net *net, u32 type)
 444{
 445	struct tipc_net *tn = net_generic(net, tipc_net_id);
 446	struct hlist_head *seq_head;
 447	struct name_seq *ns;
 448
 449	seq_head = &tn->nametbl->seq_hlist[hash(type)];
 450	hlist_for_each_entry_rcu(ns, seq_head, ns_list) {
 451		if (ns->type == type)
 452			return ns;
 453	}
 454
 455	return NULL;
 456};
 457
 458struct publication *tipc_nametbl_insert_publ(struct net *net, u32 type,
 459					     u32 lower, u32 upper, u32 scope,
 460					     u32 node, u32 port, u32 key)
 461{
 462	struct tipc_net *tn = net_generic(net, tipc_net_id);
 463	struct publication *publ;
 464	struct name_seq *seq = nametbl_find_seq(net, type);
 465	int index = hash(type);
 466
 467	if ((scope < TIPC_ZONE_SCOPE) || (scope > TIPC_NODE_SCOPE) ||
 468	    (lower > upper)) {
 469		pr_debug("Failed to publish illegal {%u,%u,%u} with scope %u\n",
 470			 type, lower, upper, scope);
 471		return NULL;
 472	}
 473
 474	if (!seq)
 475		seq = tipc_nameseq_create(type, &tn->nametbl->seq_hlist[index]);
 476	if (!seq)
 477		return NULL;
 478
 479	spin_lock_bh(&seq->lock);
 480	publ = tipc_nameseq_insert_publ(net, seq, type, lower, upper,
 481					scope, node, port, key);
 482	spin_unlock_bh(&seq->lock);
 483	return publ;
 484}
 485
 486struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type,
 487					     u32 lower, u32 node, u32 ref,
 488					     u32 key)
 489{
 490	struct publication *publ;
 491	struct name_seq *seq = nametbl_find_seq(net, type);
 492
 493	if (!seq)
 494		return NULL;
 495
 496	spin_lock_bh(&seq->lock);
 497	publ = tipc_nameseq_remove_publ(net, seq, lower, node, ref, key);
 498	if (!seq->first_free && list_empty(&seq->subscriptions)) {
 499		hlist_del_init_rcu(&seq->ns_list);
 500		kfree(seq->sseqs);
 501		spin_unlock_bh(&seq->lock);
 502		kfree_rcu(seq, rcu);
 503		return publ;
 504	}
 505	spin_unlock_bh(&seq->lock);
 506	return publ;
 507}
 508
 509/**
 510 * tipc_nametbl_translate - perform name translation
 511 *
 512 * On entry, 'destnode' is the search domain used during translation.
 513 *
 514 * On exit:
 515 * - if name translation is deferred to another node/cluster/zone,
 516 *   leaves 'destnode' unchanged (will be non-zero) and returns 0
 517 * - if name translation is attempted and succeeds, sets 'destnode'
 518 *   to publishing node and returns port reference (will be non-zero)
 519 * - if name translation is attempted and fails, sets 'destnode' to 0
 520 *   and returns 0
 521 */
 522u32 tipc_nametbl_translate(struct net *net, u32 type, u32 instance,
 523			   u32 *destnode)
 524{
 525	struct tipc_net *tn = net_generic(net, tipc_net_id);
 526	struct sub_seq *sseq;
 527	struct name_info *info;
 528	struct publication *publ;
 529	struct name_seq *seq;
 530	u32 ref = 0;
 531	u32 node = 0;
 532
 533	if (!tipc_in_scope(*destnode, tn->own_addr))
 534		return 0;
 535
 536	rcu_read_lock();
 537	seq = nametbl_find_seq(net, type);
 538	if (unlikely(!seq))
 539		goto not_found;
 540	spin_lock_bh(&seq->lock);
 541	sseq = nameseq_find_subseq(seq, instance);
 542	if (unlikely(!sseq))
 543		goto no_match;
 544	info = sseq->info;
 545
 546	/* Closest-First Algorithm */
 547	if (likely(!*destnode)) {
 548		if (!list_empty(&info->node_list)) {
 549			publ = list_first_entry(&info->node_list,
 550						struct publication,
 551						node_list);
 552			list_move_tail(&publ->node_list,
 553				       &info->node_list);
 554		} else if (!list_empty(&info->cluster_list)) {
 555			publ = list_first_entry(&info->cluster_list,
 556						struct publication,
 557						cluster_list);
 558			list_move_tail(&publ->cluster_list,
 559				       &info->cluster_list);
 560		} else {
 561			publ = list_first_entry(&info->zone_list,
 562						struct publication,
 563						zone_list);
 564			list_move_tail(&publ->zone_list,
 565				       &info->zone_list);
 566		}
 567	}
 568
 569	/* Round-Robin Algorithm */
 570	else if (*destnode == tn->own_addr) {
 571		if (list_empty(&info->node_list))
 572			goto no_match;
 573		publ = list_first_entry(&info->node_list, struct publication,
 574					node_list);
 575		list_move_tail(&publ->node_list, &info->node_list);
 576	} else if (in_own_cluster_exact(net, *destnode)) {
 577		if (list_empty(&info->cluster_list))
 578			goto no_match;
 579		publ = list_first_entry(&info->cluster_list, struct publication,
 580					cluster_list);
 581		list_move_tail(&publ->cluster_list, &info->cluster_list);
 582	} else {
 583		publ = list_first_entry(&info->zone_list, struct publication,
 584					zone_list);
 585		list_move_tail(&publ->zone_list, &info->zone_list);
 586	}
 587
 588	ref = publ->ref;
 589	node = publ->node;
 590no_match:
 591	spin_unlock_bh(&seq->lock);
 592not_found:
 593	rcu_read_unlock();
 594	*destnode = node;
 595	return ref;
 596}
 597
 598/**
 599 * tipc_nametbl_mc_translate - find multicast destinations
 600 *
 601 * Creates list of all local ports that overlap the given multicast address;
 602 * also determines if any off-node ports overlap.
 603 *
 604 * Note: Publications with a scope narrower than 'limit' are ignored.
 605 * (i.e. local node-scope publications mustn't receive messages arriving
 606 * from another node, even if the multcast link brought it here)
 607 *
 608 * Returns non-zero if any off-node ports overlap
 609 */
 610int tipc_nametbl_mc_translate(struct net *net, u32 type, u32 lower, u32 upper,
 611			      u32 limit, struct tipc_plist *dports)
 612{
 613	struct name_seq *seq;
 614	struct sub_seq *sseq;
 615	struct sub_seq *sseq_stop;
 616	struct name_info *info;
 617	int res = 0;
 618
 619	rcu_read_lock();
 620	seq = nametbl_find_seq(net, type);
 621	if (!seq)
 622		goto exit;
 623
 624	spin_lock_bh(&seq->lock);
 625	sseq = seq->sseqs + nameseq_locate_subseq(seq, lower);
 626	sseq_stop = seq->sseqs + seq->first_free;
 627	for (; sseq != sseq_stop; sseq++) {
 628		struct publication *publ;
 629
 630		if (sseq->lower > upper)
 631			break;
 632
 633		info = sseq->info;
 634		list_for_each_entry(publ, &info->node_list, node_list) {
 635			if (publ->scope <= limit)
 636				tipc_plist_push(dports, publ->ref);
 637		}
 638
 639		if (info->cluster_list_size != info->node_list_size)
 640			res = 1;
 641	}
 642	spin_unlock_bh(&seq->lock);
 643exit:
 644	rcu_read_unlock();
 645	return res;
 646}
 647
 648/*
 649 * tipc_nametbl_publish - add name publication to network name tables
 650 */
 651struct publication *tipc_nametbl_publish(struct net *net, u32 type, u32 lower,
 652					 u32 upper, u32 scope, u32 port_ref,
 653					 u32 key)
 654{
 655	struct publication *publ;
 656	struct sk_buff *buf = NULL;
 657	struct tipc_net *tn = net_generic(net, tipc_net_id);
 658
 659	spin_lock_bh(&tn->nametbl_lock);
 660	if (tn->nametbl->local_publ_count >= TIPC_MAX_PUBLICATIONS) {
 661		pr_warn("Publication failed, local publication limit reached (%u)\n",
 662			TIPC_MAX_PUBLICATIONS);
 663		spin_unlock_bh(&tn->nametbl_lock);
 664		return NULL;
 665	}
 666
 667	publ = tipc_nametbl_insert_publ(net, type, lower, upper, scope,
 668					tn->own_addr, port_ref, key);
 669	if (likely(publ)) {
 670		tn->nametbl->local_publ_count++;
 671		buf = tipc_named_publish(net, publ);
 672		/* Any pending external events? */
 673		tipc_named_process_backlog(net);
 674	}
 675	spin_unlock_bh(&tn->nametbl_lock);
 676
 677	if (buf)
 678		tipc_node_broadcast(net, buf);
 679	return publ;
 680}
 681
 682/**
 683 * tipc_nametbl_withdraw - withdraw name publication from network name tables
 684 */
 685int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower, u32 ref,
 686			  u32 key)
 687{
 688	struct publication *publ;
 689	struct sk_buff *skb = NULL;
 690	struct tipc_net *tn = net_generic(net, tipc_net_id);
 691
 692	spin_lock_bh(&tn->nametbl_lock);
 693	publ = tipc_nametbl_remove_publ(net, type, lower, tn->own_addr,
 694					ref, key);
 695	if (likely(publ)) {
 696		tn->nametbl->local_publ_count--;
 697		skb = tipc_named_withdraw(net, publ);
 698		/* Any pending external events? */
 699		tipc_named_process_backlog(net);
 700		list_del_init(&publ->pport_list);
 701		kfree_rcu(publ, rcu);
 702	} else {
 703		pr_err("Unable to remove local publication\n"
 704		       "(type=%u, lower=%u, ref=%u, key=%u)\n",
 705		       type, lower, ref, key);
 706	}
 707	spin_unlock_bh(&tn->nametbl_lock);
 708
 709	if (skb) {
 710		tipc_node_broadcast(net, skb);
 711		return 1;
 712	}
 713	return 0;
 714}
 715
 716/**
 717 * tipc_nametbl_subscribe - add a subscription object to the name table
 718 */
 719void tipc_nametbl_subscribe(struct tipc_subscription *s)
 720{
 721	struct tipc_net *tn = net_generic(s->net, tipc_net_id);
 722	u32 type = tipc_subscrp_convert_seq_type(s->evt.s.seq.type, s->swap);
 723	int index = hash(type);
 724	struct name_seq *seq;
 725	struct tipc_name_seq ns;
 726
 727	spin_lock_bh(&tn->nametbl_lock);
 728	seq = nametbl_find_seq(s->net, type);
 729	if (!seq)
 730		seq = tipc_nameseq_create(type, &tn->nametbl->seq_hlist[index]);
 731	if (seq) {
 732		spin_lock_bh(&seq->lock);
 733		tipc_nameseq_subscribe(seq, s);
 734		spin_unlock_bh(&seq->lock);
 735	} else {
 736		tipc_subscrp_convert_seq(&s->evt.s.seq, s->swap, &ns);
 737		pr_warn("Failed to create subscription for {%u,%u,%u}\n",
 738			ns.type, ns.lower, ns.upper);
 739	}
 740	spin_unlock_bh(&tn->nametbl_lock);
 741}
 742
 743/**
 744 * tipc_nametbl_unsubscribe - remove a subscription object from name table
 745 */
 746void tipc_nametbl_unsubscribe(struct tipc_subscription *s)
 747{
 748	struct tipc_net *tn = net_generic(s->net, tipc_net_id);
 749	struct name_seq *seq;
 750	u32 type = tipc_subscrp_convert_seq_type(s->evt.s.seq.type, s->swap);
 751
 752	spin_lock_bh(&tn->nametbl_lock);
 753	seq = nametbl_find_seq(s->net, type);
 754	if (seq != NULL) {
 755		spin_lock_bh(&seq->lock);
 756		list_del_init(&s->nameseq_list);
 757		if (!seq->first_free && list_empty(&seq->subscriptions)) {
 758			hlist_del_init_rcu(&seq->ns_list);
 759			kfree(seq->sseqs);
 760			spin_unlock_bh(&seq->lock);
 761			kfree_rcu(seq, rcu);
 762		} else {
 763			spin_unlock_bh(&seq->lock);
 764		}
 765	}
 766	spin_unlock_bh(&tn->nametbl_lock);
 767}
 768
 769int tipc_nametbl_init(struct net *net)
 770{
 771	struct tipc_net *tn = net_generic(net, tipc_net_id);
 772	struct name_table *tipc_nametbl;
 773	int i;
 774
 775	tipc_nametbl = kzalloc(sizeof(*tipc_nametbl), GFP_ATOMIC);
 776	if (!tipc_nametbl)
 777		return -ENOMEM;
 778
 779	for (i = 0; i < TIPC_NAMETBL_SIZE; i++)
 780		INIT_HLIST_HEAD(&tipc_nametbl->seq_hlist[i]);
 781
 782	INIT_LIST_HEAD(&tipc_nametbl->publ_list[TIPC_ZONE_SCOPE]);
 783	INIT_LIST_HEAD(&tipc_nametbl->publ_list[TIPC_CLUSTER_SCOPE]);
 784	INIT_LIST_HEAD(&tipc_nametbl->publ_list[TIPC_NODE_SCOPE]);
 785	tn->nametbl = tipc_nametbl;
 786	spin_lock_init(&tn->nametbl_lock);
 787	return 0;
 788}
 789
 790/**
 791 * tipc_purge_publications - remove all publications for a given type
 792 *
 793 * tipc_nametbl_lock must be held when calling this function
 794 */
 795static void tipc_purge_publications(struct net *net, struct name_seq *seq)
 796{
 797	struct publication *publ, *safe;
 798	struct sub_seq *sseq;
 799	struct name_info *info;
 800
 801	spin_lock_bh(&seq->lock);
 802	sseq = seq->sseqs;
 803	info = sseq->info;
 804	list_for_each_entry_safe(publ, safe, &info->zone_list, zone_list) {
 805		tipc_nameseq_remove_publ(net, seq, publ->lower, publ->node,
 806					 publ->ref, publ->key);
 807		kfree_rcu(publ, rcu);
 808	}
 809	hlist_del_init_rcu(&seq->ns_list);
 810	kfree(seq->sseqs);
 811	spin_unlock_bh(&seq->lock);
 812
 813	kfree_rcu(seq, rcu);
 814}
 815
 816void tipc_nametbl_stop(struct net *net)
 817{
 818	u32 i;
 819	struct name_seq *seq;
 820	struct hlist_head *seq_head;
 821	struct tipc_net *tn = net_generic(net, tipc_net_id);
 822	struct name_table *tipc_nametbl = tn->nametbl;
 823
 824	/* Verify name table is empty and purge any lingering
 825	 * publications, then release the name table
 826	 */
 827	spin_lock_bh(&tn->nametbl_lock);
 828	for (i = 0; i < TIPC_NAMETBL_SIZE; i++) {
 829		if (hlist_empty(&tipc_nametbl->seq_hlist[i]))
 830			continue;
 831		seq_head = &tipc_nametbl->seq_hlist[i];
 832		hlist_for_each_entry_rcu(seq, seq_head, ns_list) {
 833			tipc_purge_publications(net, seq);
 834		}
 835	}
 836	spin_unlock_bh(&tn->nametbl_lock);
 837
 838	synchronize_net();
 839	kfree(tipc_nametbl);
 840
 841}
 842
 843static int __tipc_nl_add_nametable_publ(struct tipc_nl_msg *msg,
 844					struct name_seq *seq,
 845					struct sub_seq *sseq, u32 *last_publ)
 846{
 847	void *hdr;
 848	struct nlattr *attrs;
 849	struct nlattr *publ;
 850	struct publication *p;
 851
 852	if (*last_publ) {
 853		list_for_each_entry(p, &sseq->info->zone_list, zone_list)
 854			if (p->key == *last_publ)
 855				break;
 856		if (p->key != *last_publ)
 857			return -EPIPE;
 858	} else {
 859		p = list_first_entry(&sseq->info->zone_list, struct publication,
 860				     zone_list);
 861	}
 862
 863	list_for_each_entry_from(p, &sseq->info->zone_list, zone_list) {
 864		*last_publ = p->key;
 865
 866		hdr = genlmsg_put(msg->skb, msg->portid, msg->seq,
 867				  &tipc_genl_family, NLM_F_MULTI,
 868				  TIPC_NL_NAME_TABLE_GET);
 869		if (!hdr)
 870			return -EMSGSIZE;
 871
 872		attrs = nla_nest_start(msg->skb, TIPC_NLA_NAME_TABLE);
 873		if (!attrs)
 874			goto msg_full;
 875
 876		publ = nla_nest_start(msg->skb, TIPC_NLA_NAME_TABLE_PUBL);
 877		if (!publ)
 878			goto attr_msg_full;
 879
 880		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_TYPE, seq->type))
 881			goto publ_msg_full;
 882		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_LOWER, sseq->lower))
 883			goto publ_msg_full;
 884		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_UPPER, sseq->upper))
 885			goto publ_msg_full;
 886		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_SCOPE, p->scope))
 887			goto publ_msg_full;
 888		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_NODE, p->node))
 889			goto publ_msg_full;
 890		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_REF, p->ref))
 891			goto publ_msg_full;
 892		if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_KEY, p->key))
 893			goto publ_msg_full;
 894
 895		nla_nest_end(msg->skb, publ);
 896		nla_nest_end(msg->skb, attrs);
 897		genlmsg_end(msg->skb, hdr);
 898	}
 899	*last_publ = 0;
 900
 901	return 0;
 902
 903publ_msg_full:
 904	nla_nest_cancel(msg->skb, publ);
 905attr_msg_full:
 906	nla_nest_cancel(msg->skb, attrs);
 907msg_full:
 908	genlmsg_cancel(msg->skb, hdr);
 909
 910	return -EMSGSIZE;
 911}
 912
 913static int __tipc_nl_subseq_list(struct tipc_nl_msg *msg, struct name_seq *seq,
 914				 u32 *last_lower, u32 *last_publ)
 915{
 916	struct sub_seq *sseq;
 917	struct sub_seq *sseq_start;
 918	int err;
 919
 920	if (*last_lower) {
 921		sseq_start = nameseq_find_subseq(seq, *last_lower);
 922		if (!sseq_start)
 923			return -EPIPE;
 924	} else {
 925		sseq_start = seq->sseqs;
 926	}
 927
 928	for (sseq = sseq_start; sseq != &seq->sseqs[seq->first_free]; sseq++) {
 929		err = __tipc_nl_add_nametable_publ(msg, seq, sseq, last_publ);
 930		if (err) {
 931			*last_lower = sseq->lower;
 932			return err;
 933		}
 934	}
 935	*last_lower = 0;
 936
 937	return 0;
 938}
 939
 940static int tipc_nl_seq_list(struct net *net, struct tipc_nl_msg *msg,
 941			    u32 *last_type, u32 *last_lower, u32 *last_publ)
 942{
 943	struct tipc_net *tn = net_generic(net, tipc_net_id);
 944	struct hlist_head *seq_head;
 945	struct name_seq *seq = NULL;
 946	int err;
 947	int i;
 948
 949	if (*last_type)
 950		i = hash(*last_type);
 951	else
 952		i = 0;
 953
 954	for (; i < TIPC_NAMETBL_SIZE; i++) {
 955		seq_head = &tn->nametbl->seq_hlist[i];
 956
 957		if (*last_type) {
 958			seq = nametbl_find_seq(net, *last_type);
 959			if (!seq)
 960				return -EPIPE;
 961		} else {
 962			hlist_for_each_entry_rcu(seq, seq_head, ns_list)
 963				break;
 964			if (!seq)
 965				continue;
 966		}
 967
 968		hlist_for_each_entry_from_rcu(seq, ns_list) {
 969			spin_lock_bh(&seq->lock);
 970			err = __tipc_nl_subseq_list(msg, seq, last_lower,
 971						    last_publ);
 972
 973			if (err) {
 974				*last_type = seq->type;
 975				spin_unlock_bh(&seq->lock);
 976				return err;
 977			}
 978			spin_unlock_bh(&seq->lock);
 979		}
 980		*last_type = 0;
 981	}
 982	return 0;
 983}
 984
 985int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb)
 986{
 987	int err;
 988	int done = cb->args[3];
 989	u32 last_type = cb->args[0];
 990	u32 last_lower = cb->args[1];
 991	u32 last_publ = cb->args[2];
 992	struct net *net = sock_net(skb->sk);
 993	struct tipc_nl_msg msg;
 994
 995	if (done)
 996		return 0;
 997
 998	msg.skb = skb;
 999	msg.portid = NETLINK_CB(cb->skb).portid;
1000	msg.seq = cb->nlh->nlmsg_seq;
1001
1002	rcu_read_lock();
1003	err = tipc_nl_seq_list(net, &msg, &last_type, &last_lower, &last_publ);
1004	if (!err) {
1005		done = 1;
1006	} else if (err != -EMSGSIZE) {
1007		/* We never set seq or call nl_dump_check_consistent() this
1008		 * means that setting prev_seq here will cause the consistence
1009		 * check to fail in the netlink callback handler. Resulting in
1010		 * the NLMSG_DONE message having the NLM_F_DUMP_INTR flag set if
1011		 * we got an error.
1012		 */
1013		cb->prev_seq = 1;
1014	}
1015	rcu_read_unlock();
1016
1017	cb->args[0] = last_type;
1018	cb->args[1] = last_lower;
1019	cb->args[2] = last_publ;
1020	cb->args[3] = done;
1021
1022	return skb->len;
1023}
1024
1025void tipc_plist_push(struct tipc_plist *pl, u32 port)
1026{
1027	struct tipc_plist *nl;
1028
1029	if (likely(!pl->port)) {
1030		pl->port = port;
1031		return;
1032	}
1033	if (pl->port == port)
1034		return;
1035	list_for_each_entry(nl, &pl->list, list) {
1036		if (nl->port == port)
1037			return;
1038	}
1039	nl = kmalloc(sizeof(*nl), GFP_ATOMIC);
1040	if (nl) {
1041		nl->port = port;
1042		list_add(&nl->list, &pl->list);
1043	}
1044}
1045
1046u32 tipc_plist_pop(struct tipc_plist *pl)
1047{
1048	struct tipc_plist *nl;
1049	u32 port = 0;
1050
1051	if (likely(list_empty(&pl->list))) {
1052		port = pl->port;
1053		pl->port = 0;
1054		return port;
1055	}
1056	nl = list_first_entry(&pl->list, typeof(*nl), list);
1057	port = nl->port;
1058	list_del(&nl->list);
1059	kfree(nl);
1060	return port;
1061}