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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  */
63 struct 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  */
78 struct 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  */
96 struct 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 
hash(int x)107 static int hash(int x)
108 {
109 	return x & (TIPC_NAMETBL_SIZE - 1);
110 }
111 
112 /**
113  * publ_create - create a publication structure
114  */
publ_create(u32 type,u32 lower,u32 upper,u32 scope,u32 node,u32 port_ref,u32 key)115 static 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  */
tipc_subseq_alloc(u32 cnt)139 static 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  */
tipc_nameseq_create(u32 type,struct hlist_head * seq_head)149 static 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  */
nameseq_find_subseq(struct name_seq * nseq,u32 instance)176 static 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  */
nameseq_locate_subseq(struct name_seq * nseq,u32 instance)205 static 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  */
tipc_nameseq_insert_publ(struct net * net,struct name_seq * nseq,u32 type,u32 lower,u32 upper,u32 scope,u32 node,u32 port,u32 key)227 static 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  */
tipc_nameseq_remove_publ(struct net * net,struct name_seq * nseq,u32 inst,u32 node,u32 ref,u32 key)346 static 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 
371 found:
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  */
tipc_nameseq_subscribe(struct name_seq * nseq,struct tipc_subscription * s)411 static 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 
nametbl_find_seq(struct net * net,u32 type)443 static 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 
tipc_nametbl_insert_publ(struct net * net,u32 type,u32 lower,u32 upper,u32 scope,u32 node,u32 port,u32 key)458 struct 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 
tipc_nametbl_remove_publ(struct net * net,u32 type,u32 lower,u32 node,u32 ref,u32 key)486 struct 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  */
tipc_nametbl_translate(struct net * net,u32 type,u32 instance,u32 * destnode)522 u32 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;
590 no_match:
591 	spin_unlock_bh(&seq->lock);
592 not_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  */
tipc_nametbl_mc_translate(struct net * net,u32 type,u32 lower,u32 upper,u32 limit,struct tipc_plist * dports)610 int 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);
643 exit:
644 	rcu_read_unlock();
645 	return res;
646 }
647 
648 /*
649  * tipc_nametbl_publish - add name publication to network name tables
650  */
tipc_nametbl_publish(struct net * net,u32 type,u32 lower,u32 upper,u32 scope,u32 port_ref,u32 key)651 struct 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  */
tipc_nametbl_withdraw(struct net * net,u32 type,u32 lower,u32 ref,u32 key)685 int 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  */
tipc_nametbl_subscribe(struct tipc_subscription * s)719 void 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  */
tipc_nametbl_unsubscribe(struct tipc_subscription * s)746 void 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 
tipc_nametbl_init(struct net * net)769 int 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  */
tipc_purge_publications(struct net * net,struct name_seq * seq)795 static 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 
tipc_nametbl_stop(struct net * net)816 void 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 
__tipc_nl_add_nametable_publ(struct tipc_nl_msg * msg,struct name_seq * seq,struct sub_seq * sseq,u32 * last_publ)843 static 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 
903 publ_msg_full:
904 	nla_nest_cancel(msg->skb, publ);
905 attr_msg_full:
906 	nla_nest_cancel(msg->skb, attrs);
907 msg_full:
908 	genlmsg_cancel(msg->skb, hdr);
909 
910 	return -EMSGSIZE;
911 }
912 
__tipc_nl_subseq_list(struct tipc_nl_msg * msg,struct name_seq * seq,u32 * last_lower,u32 * last_publ)913 static 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 
tipc_nl_seq_list(struct net * net,struct tipc_nl_msg * msg,u32 * last_type,u32 * last_lower,u32 * last_publ)940 static 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 
tipc_nl_name_table_dump(struct sk_buff * skb,struct netlink_callback * cb)985 int 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 
tipc_plist_push(struct tipc_plist * pl,u32 port)1025 void 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 
tipc_plist_pop(struct tipc_plist * pl)1046 u32 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 }
1062