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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 <linux/list_sort.h>
39#include <linux/rbtree_augmented.h>
40#include "core.h"
41#include "netlink.h"
42#include "name_table.h"
43#include "name_distr.h"
44#include "subscr.h"
45#include "bcast.h"
46#include "addr.h"
47#include "node.h"
48#include "group.h"
49
50/**
51 * struct service_range - container for all bindings of a service range
52 * @lower: service range lower bound
53 * @upper: service range upper bound
54 * @tree_node: member of service range RB tree
55 * @max: largest 'upper' in this node subtree
56 * @local_publ: list of identical publications made from this node
57 * Used by closest_first lookup and multicast lookup algorithm
58 * @all_publ: all publications identical to this one, whatever node and scope
59 * Used by round-robin lookup algorithm
60 */
61struct service_range {
62 u32 lower;
63 u32 upper;
64 struct rb_node tree_node;
65 u32 max;
66 struct list_head local_publ;
67 struct list_head all_publ;
68};
69
70/**
71 * struct tipc_service - container for all published instances of a service type
72 * @type: 32 bit 'type' value for service
73 * @publ_cnt: increasing counter for publications in this service
74 * @ranges: rb tree containing all service ranges for this service
75 * @service_list: links to adjacent name ranges in hash chain
76 * @subscriptions: list of subscriptions for this service type
77 * @lock: spinlock controlling access to pertaining service ranges/publications
78 * @rcu: RCU callback head used for deferred freeing
79 */
80struct tipc_service {
81 u32 type;
82 u32 publ_cnt;
83 struct rb_root ranges;
84 struct hlist_node service_list;
85 struct list_head subscriptions;
86 spinlock_t lock; /* Covers service range list */
87 struct rcu_head rcu;
88};
89
90#define service_range_upper(sr) ((sr)->upper)
91RB_DECLARE_CALLBACKS_MAX(static, sr_callbacks,
92 struct service_range, tree_node, u32, max,
93 service_range_upper)
94
95#define service_range_entry(rbtree_node) \
96 (container_of(rbtree_node, struct service_range, tree_node))
97
98#define service_range_overlap(sr, start, end) \
99 ((sr)->lower <= (end) && (sr)->upper >= (start))
100
101/**
102 * service_range_foreach_match - iterate over tipc service rbtree for each
103 * range match
104 * @sr: the service range pointer as a loop cursor
105 * @sc: the pointer to tipc service which holds the service range rbtree
106 * @start, end: the range (end >= start) for matching
107 */
108#define service_range_foreach_match(sr, sc, start, end) \
109 for (sr = service_range_match_first((sc)->ranges.rb_node, \
110 start, \
111 end); \
112 sr; \
113 sr = service_range_match_next(&(sr)->tree_node, \
114 start, \
115 end))
116
117/**
118 * service_range_match_first - find first service range matching a range
119 * @n: the root node of service range rbtree for searching
120 * @start, end: the range (end >= start) for matching
121 *
122 * Return: the leftmost service range node in the rbtree that overlaps the
123 * specific range if any. Otherwise, returns NULL.
124 */
125static struct service_range *service_range_match_first(struct rb_node *n,
126 u32 start, u32 end)
127{
128 struct service_range *sr;
129 struct rb_node *l, *r;
130
131 /* Non overlaps in tree at all? */
132 if (!n || service_range_entry(n)->max < start)
133 return NULL;
134
135 while (n) {
136 l = n->rb_left;
137 if (l && service_range_entry(l)->max >= start) {
138 /* A leftmost overlap range node must be one in the left
139 * subtree. If not, it has lower > end, then nodes on
140 * the right side cannot satisfy the condition either.
141 */
142 n = l;
143 continue;
144 }
145
146 /* No one in the left subtree can match, return if this node is
147 * an overlap i.e. leftmost.
148 */
149 sr = service_range_entry(n);
150 if (service_range_overlap(sr, start, end))
151 return sr;
152
153 /* Ok, try to lookup on the right side */
154 r = n->rb_right;
155 if (sr->lower <= end &&
156 r && service_range_entry(r)->max >= start) {
157 n = r;
158 continue;
159 }
160 break;
161 }
162
163 return NULL;
164}
165
166/**
167 * service_range_match_next - find next service range matching a range
168 * @n: a node in service range rbtree from which the searching starts
169 * @start, end: the range (end >= start) for matching
170 *
171 * Return: the next service range node to the given node in the rbtree that
172 * overlaps the specific range if any. Otherwise, returns NULL.
173 */
174static struct service_range *service_range_match_next(struct rb_node *n,
175 u32 start, u32 end)
176{
177 struct service_range *sr;
178 struct rb_node *p, *r;
179
180 while (n) {
181 r = n->rb_right;
182 if (r && service_range_entry(r)->max >= start)
183 /* A next overlap range node must be one in the right
184 * subtree. If not, it has lower > end, then any next
185 * successor (- an ancestor) of this node cannot
186 * satisfy the condition either.
187 */
188 return service_range_match_first(r, start, end);
189
190 /* No one in the right subtree can match, go up to find an
191 * ancestor of this node which is parent of a left-hand child.
192 */
193 while ((p = rb_parent(n)) && n == p->rb_right)
194 n = p;
195 if (!p)
196 break;
197
198 /* Return if this ancestor is an overlap */
199 sr = service_range_entry(p);
200 if (service_range_overlap(sr, start, end))
201 return sr;
202
203 /* Ok, try to lookup more from this ancestor */
204 if (sr->lower <= end) {
205 n = p;
206 continue;
207 }
208 break;
209 }
210
211 return NULL;
212}
213
214static int hash(int x)
215{
216 return x & (TIPC_NAMETBL_SIZE - 1);
217}
218
219/**
220 * tipc_publ_create - create a publication structure
221 */
222static struct publication *tipc_publ_create(u32 type, u32 lower, u32 upper,
223 u32 scope, u32 node, u32 port,
224 u32 key)
225{
226 struct publication *publ = kzalloc(sizeof(*publ), GFP_ATOMIC);
227
228 if (!publ)
229 return NULL;
230
231 publ->type = type;
232 publ->lower = lower;
233 publ->upper = upper;
234 publ->scope = scope;
235 publ->node = node;
236 publ->port = port;
237 publ->key = key;
238 INIT_LIST_HEAD(&publ->binding_sock);
239 INIT_LIST_HEAD(&publ->binding_node);
240 INIT_LIST_HEAD(&publ->local_publ);
241 INIT_LIST_HEAD(&publ->all_publ);
242 INIT_LIST_HEAD(&publ->list);
243 return publ;
244}
245
246/**
247 * tipc_service_create - create a service structure for the specified 'type'
248 *
249 * Allocates a single range structure and sets it to all 0's.
250 */
251static struct tipc_service *tipc_service_create(u32 type, struct hlist_head *hd)
252{
253 struct tipc_service *service = kzalloc(sizeof(*service), GFP_ATOMIC);
254
255 if (!service) {
256 pr_warn("Service creation failed, no memory\n");
257 return NULL;
258 }
259
260 spin_lock_init(&service->lock);
261 service->type = type;
262 service->ranges = RB_ROOT;
263 INIT_HLIST_NODE(&service->service_list);
264 INIT_LIST_HEAD(&service->subscriptions);
265 hlist_add_head_rcu(&service->service_list, hd);
266 return service;
267}
268
269/* tipc_service_find_range - find service range matching publication parameters
270 */
271static struct service_range *tipc_service_find_range(struct tipc_service *sc,
272 u32 lower, u32 upper)
273{
274 struct service_range *sr;
275
276 service_range_foreach_match(sr, sc, lower, upper) {
277 /* Look for exact match */
278 if (sr->lower == lower && sr->upper == upper)
279 return sr;
280 }
281
282 return NULL;
283}
284
285static struct service_range *tipc_service_create_range(struct tipc_service *sc,
286 u32 lower, u32 upper)
287{
288 struct rb_node **n, *parent = NULL;
289 struct service_range *sr;
290
291 n = &sc->ranges.rb_node;
292 while (*n) {
293 parent = *n;
294 sr = service_range_entry(parent);
295 if (lower == sr->lower && upper == sr->upper)
296 return sr;
297 if (sr->max < upper)
298 sr->max = upper;
299 if (lower <= sr->lower)
300 n = &parent->rb_left;
301 else
302 n = &parent->rb_right;
303 }
304 sr = kzalloc(sizeof(*sr), GFP_ATOMIC);
305 if (!sr)
306 return NULL;
307 sr->lower = lower;
308 sr->upper = upper;
309 sr->max = upper;
310 INIT_LIST_HEAD(&sr->local_publ);
311 INIT_LIST_HEAD(&sr->all_publ);
312 rb_link_node(&sr->tree_node, parent, n);
313 rb_insert_augmented(&sr->tree_node, &sc->ranges, &sr_callbacks);
314 return sr;
315}
316
317static struct publication *tipc_service_insert_publ(struct net *net,
318 struct tipc_service *sc,
319 u32 type, u32 lower,
320 u32 upper, u32 scope,
321 u32 node, u32 port,
322 u32 key)
323{
324 struct tipc_subscription *sub, *tmp;
325 struct service_range *sr;
326 struct publication *p;
327 bool first = false;
328
329 sr = tipc_service_create_range(sc, lower, upper);
330 if (!sr)
331 goto err;
332
333 first = list_empty(&sr->all_publ);
334
335 /* Return if the publication already exists */
336 list_for_each_entry(p, &sr->all_publ, all_publ) {
337 if (p->key == key && (!p->node || p->node == node))
338 return NULL;
339 }
340
341 /* Create and insert publication */
342 p = tipc_publ_create(type, lower, upper, scope, node, port, key);
343 if (!p)
344 goto err;
345 /* Suppose there shouldn't be a huge gap btw publs i.e. >INT_MAX */
346 p->id = sc->publ_cnt++;
347 if (in_own_node(net, node))
348 list_add(&p->local_publ, &sr->local_publ);
349 list_add(&p->all_publ, &sr->all_publ);
350
351 /* Any subscriptions waiting for notification? */
352 list_for_each_entry_safe(sub, tmp, &sc->subscriptions, service_list) {
353 tipc_sub_report_overlap(sub, p->lower, p->upper, TIPC_PUBLISHED,
354 p->port, p->node, p->scope, first);
355 }
356 return p;
357err:
358 pr_warn("Failed to bind to %u,%u,%u, no memory\n", type, lower, upper);
359 return NULL;
360}
361
362/**
363 * tipc_service_remove_publ - remove a publication from a service
364 */
365static struct publication *tipc_service_remove_publ(struct service_range *sr,
366 u32 node, u32 key)
367{
368 struct publication *p;
369
370 list_for_each_entry(p, &sr->all_publ, all_publ) {
371 if (p->key != key || (node && node != p->node))
372 continue;
373 list_del(&p->all_publ);
374 list_del(&p->local_publ);
375 return p;
376 }
377 return NULL;
378}
379
380/**
381 * Code reused: time_after32() for the same purpose
382 */
383#define publication_after(pa, pb) time_after32((pa)->id, (pb)->id)
384static int tipc_publ_sort(void *priv, struct list_head *a,
385 struct list_head *b)
386{
387 struct publication *pa, *pb;
388
389 pa = container_of(a, struct publication, list);
390 pb = container_of(b, struct publication, list);
391 return publication_after(pa, pb);
392}
393
394/**
395 * tipc_service_subscribe - attach a subscription, and optionally
396 * issue the prescribed number of events if there is any service
397 * range overlapping with the requested range
398 */
399static void tipc_service_subscribe(struct tipc_service *service,
400 struct tipc_subscription *sub)
401{
402 struct tipc_subscr *sb = &sub->evt.s;
403 struct publication *p, *first, *tmp;
404 struct list_head publ_list;
405 struct service_range *sr;
406 struct tipc_name_seq ns;
407 u32 filter;
408
409 ns.type = tipc_sub_read(sb, seq.type);
410 ns.lower = tipc_sub_read(sb, seq.lower);
411 ns.upper = tipc_sub_read(sb, seq.upper);
412 filter = tipc_sub_read(sb, filter);
413
414 tipc_sub_get(sub);
415 list_add(&sub->service_list, &service->subscriptions);
416
417 if (filter & TIPC_SUB_NO_STATUS)
418 return;
419
420 INIT_LIST_HEAD(&publ_list);
421 service_range_foreach_match(sr, service, ns.lower, ns.upper) {
422 first = NULL;
423 list_for_each_entry(p, &sr->all_publ, all_publ) {
424 if (filter & TIPC_SUB_PORTS)
425 list_add_tail(&p->list, &publ_list);
426 else if (!first || publication_after(first, p))
427 /* Pick this range's *first* publication */
428 first = p;
429 }
430 if (first)
431 list_add_tail(&first->list, &publ_list);
432 }
433
434 /* Sort the publications before reporting */
435 list_sort(NULL, &publ_list, tipc_publ_sort);
436 list_for_each_entry_safe(p, tmp, &publ_list, list) {
437 tipc_sub_report_overlap(sub, p->lower, p->upper,
438 TIPC_PUBLISHED, p->port, p->node,
439 p->scope, true);
440 list_del_init(&p->list);
441 }
442}
443
444static struct tipc_service *tipc_service_find(struct net *net, u32 type)
445{
446 struct name_table *nt = tipc_name_table(net);
447 struct hlist_head *service_head;
448 struct tipc_service *service;
449
450 service_head = &nt->services[hash(type)];
451 hlist_for_each_entry_rcu(service, service_head, service_list) {
452 if (service->type == type)
453 return service;
454 }
455 return NULL;
456};
457
458struct publication *tipc_nametbl_insert_publ(struct net *net, u32 type,
459 u32 lower, u32 upper,
460 u32 scope, u32 node,
461 u32 port, u32 key)
462{
463 struct name_table *nt = tipc_name_table(net);
464 struct tipc_service *sc;
465 struct publication *p;
466
467 if (scope > TIPC_NODE_SCOPE || lower > upper) {
468 pr_debug("Failed to bind illegal {%u,%u,%u} with scope %u\n",
469 type, lower, upper, scope);
470 return NULL;
471 }
472 sc = tipc_service_find(net, type);
473 if (!sc)
474 sc = tipc_service_create(type, &nt->services[hash(type)]);
475 if (!sc)
476 return NULL;
477
478 spin_lock_bh(&sc->lock);
479 p = tipc_service_insert_publ(net, sc, type, lower, upper,
480 scope, node, port, key);
481 spin_unlock_bh(&sc->lock);
482 return p;
483}
484
485struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type,
486 u32 lower, u32 upper,
487 u32 node, u32 key)
488{
489 struct tipc_service *sc = tipc_service_find(net, type);
490 struct tipc_subscription *sub, *tmp;
491 struct service_range *sr = NULL;
492 struct publication *p = NULL;
493 bool last;
494
495 if (!sc)
496 return NULL;
497
498 spin_lock_bh(&sc->lock);
499 sr = tipc_service_find_range(sc, lower, upper);
500 if (!sr)
501 goto exit;
502 p = tipc_service_remove_publ(sr, node, key);
503 if (!p)
504 goto exit;
505
506 /* Notify any waiting subscriptions */
507 last = list_empty(&sr->all_publ);
508 list_for_each_entry_safe(sub, tmp, &sc->subscriptions, service_list) {
509 tipc_sub_report_overlap(sub, lower, upper, TIPC_WITHDRAWN,
510 p->port, node, p->scope, last);
511 }
512
513 /* Remove service range item if this was its last publication */
514 if (list_empty(&sr->all_publ)) {
515 rb_erase_augmented(&sr->tree_node, &sc->ranges, &sr_callbacks);
516 kfree(sr);
517 }
518
519 /* Delete service item if this no more publications and subscriptions */
520 if (RB_EMPTY_ROOT(&sc->ranges) && list_empty(&sc->subscriptions)) {
521 hlist_del_init_rcu(&sc->service_list);
522 kfree_rcu(sc, rcu);
523 }
524exit:
525 spin_unlock_bh(&sc->lock);
526 return p;
527}
528
529/**
530 * tipc_nametbl_translate - perform service instance to socket translation
531 *
532 * On entry, 'dnode' is the search domain used during translation.
533 *
534 * On exit:
535 * - if translation is deferred to another node, leave 'dnode' unchanged and
536 * return 0
537 * - if translation is attempted and succeeds, set 'dnode' to the publishing
538 * node and return the published (non-zero) port number
539 * - if translation is attempted and fails, set 'dnode' to 0 and return 0
540 *
541 * Note that for legacy users (node configured with Z.C.N address format) the
542 * 'closest-first' lookup algorithm must be maintained, i.e., if dnode is 0
543 * we must look in the local binding list first
544 */
545u32 tipc_nametbl_translate(struct net *net, u32 type, u32 instance, u32 *dnode)
546{
547 struct tipc_net *tn = tipc_net(net);
548 bool legacy = tn->legacy_addr_format;
549 u32 self = tipc_own_addr(net);
550 struct service_range *sr;
551 struct tipc_service *sc;
552 struct list_head *list;
553 struct publication *p;
554 u32 port = 0;
555 u32 node = 0;
556
557 if (!tipc_in_scope(legacy, *dnode, self))
558 return 0;
559
560 rcu_read_lock();
561 sc = tipc_service_find(net, type);
562 if (unlikely(!sc))
563 goto exit;
564
565 spin_lock_bh(&sc->lock);
566 service_range_foreach_match(sr, sc, instance, instance) {
567 /* Select lookup algo: local, closest-first or round-robin */
568 if (*dnode == self) {
569 list = &sr->local_publ;
570 if (list_empty(list))
571 continue;
572 p = list_first_entry(list, struct publication,
573 local_publ);
574 list_move_tail(&p->local_publ, &sr->local_publ);
575 } else if (legacy && !*dnode && !list_empty(&sr->local_publ)) {
576 list = &sr->local_publ;
577 p = list_first_entry(list, struct publication,
578 local_publ);
579 list_move_tail(&p->local_publ, &sr->local_publ);
580 } else {
581 list = &sr->all_publ;
582 p = list_first_entry(list, struct publication,
583 all_publ);
584 list_move_tail(&p->all_publ, &sr->all_publ);
585 }
586 port = p->port;
587 node = p->node;
588 /* Todo: as for legacy, pick the first matching range only, a
589 * "true" round-robin will be performed as needed.
590 */
591 break;
592 }
593 spin_unlock_bh(&sc->lock);
594
595exit:
596 rcu_read_unlock();
597 *dnode = node;
598 return port;
599}
600
601bool tipc_nametbl_lookup(struct net *net, u32 type, u32 instance, u32 scope,
602 struct list_head *dsts, int *dstcnt, u32 exclude,
603 bool all)
604{
605 u32 self = tipc_own_addr(net);
606 struct service_range *sr;
607 struct tipc_service *sc;
608 struct publication *p;
609
610 *dstcnt = 0;
611 rcu_read_lock();
612 sc = tipc_service_find(net, type);
613 if (unlikely(!sc))
614 goto exit;
615
616 spin_lock_bh(&sc->lock);
617
618 /* Todo: a full search i.e. service_range_foreach_match() instead? */
619 sr = service_range_match_first(sc->ranges.rb_node, instance, instance);
620 if (!sr)
621 goto no_match;
622
623 list_for_each_entry(p, &sr->all_publ, all_publ) {
624 if (p->scope != scope)
625 continue;
626 if (p->port == exclude && p->node == self)
627 continue;
628 tipc_dest_push(dsts, p->node, p->port);
629 (*dstcnt)++;
630 if (all)
631 continue;
632 list_move_tail(&p->all_publ, &sr->all_publ);
633 break;
634 }
635no_match:
636 spin_unlock_bh(&sc->lock);
637exit:
638 rcu_read_unlock();
639 return !list_empty(dsts);
640}
641
642void tipc_nametbl_mc_lookup(struct net *net, u32 type, u32 lower, u32 upper,
643 u32 scope, bool exact, struct list_head *dports)
644{
645 struct service_range *sr;
646 struct tipc_service *sc;
647 struct publication *p;
648
649 rcu_read_lock();
650 sc = tipc_service_find(net, type);
651 if (!sc)
652 goto exit;
653
654 spin_lock_bh(&sc->lock);
655 service_range_foreach_match(sr, sc, lower, upper) {
656 list_for_each_entry(p, &sr->local_publ, local_publ) {
657 if (p->scope == scope || (!exact && p->scope < scope))
658 tipc_dest_push(dports, 0, p->port);
659 }
660 }
661 spin_unlock_bh(&sc->lock);
662exit:
663 rcu_read_unlock();
664}
665
666/* tipc_nametbl_lookup_dst_nodes - find broadcast destination nodes
667 * - Creates list of nodes that overlap the given multicast address
668 * - Determines if any node local destinations overlap
669 */
670void tipc_nametbl_lookup_dst_nodes(struct net *net, u32 type, u32 lower,
671 u32 upper, struct tipc_nlist *nodes)
672{
673 struct service_range *sr;
674 struct tipc_service *sc;
675 struct publication *p;
676
677 rcu_read_lock();
678 sc = tipc_service_find(net, type);
679 if (!sc)
680 goto exit;
681
682 spin_lock_bh(&sc->lock);
683 service_range_foreach_match(sr, sc, lower, upper) {
684 list_for_each_entry(p, &sr->all_publ, all_publ) {
685 tipc_nlist_add(nodes, p->node);
686 }
687 }
688 spin_unlock_bh(&sc->lock);
689exit:
690 rcu_read_unlock();
691}
692
693/* tipc_nametbl_build_group - build list of communication group members
694 */
695void tipc_nametbl_build_group(struct net *net, struct tipc_group *grp,
696 u32 type, u32 scope)
697{
698 struct service_range *sr;
699 struct tipc_service *sc;
700 struct publication *p;
701 struct rb_node *n;
702
703 rcu_read_lock();
704 sc = tipc_service_find(net, type);
705 if (!sc)
706 goto exit;
707
708 spin_lock_bh(&sc->lock);
709 for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
710 sr = container_of(n, struct service_range, tree_node);
711 list_for_each_entry(p, &sr->all_publ, all_publ) {
712 if (p->scope != scope)
713 continue;
714 tipc_group_add_member(grp, p->node, p->port, p->lower);
715 }
716 }
717 spin_unlock_bh(&sc->lock);
718exit:
719 rcu_read_unlock();
720}
721
722/* tipc_nametbl_publish - add service binding to name table
723 */
724struct publication *tipc_nametbl_publish(struct net *net, u32 type, u32 lower,
725 u32 upper, u32 scope, u32 port,
726 u32 key)
727{
728 struct name_table *nt = tipc_name_table(net);
729 struct tipc_net *tn = tipc_net(net);
730 struct publication *p = NULL;
731 struct sk_buff *skb = NULL;
732 u32 rc_dests;
733
734 spin_lock_bh(&tn->nametbl_lock);
735
736 if (nt->local_publ_count >= TIPC_MAX_PUBL) {
737 pr_warn("Bind failed, max limit %u reached\n", TIPC_MAX_PUBL);
738 goto exit;
739 }
740
741 p = tipc_nametbl_insert_publ(net, type, lower, upper, scope,
742 tipc_own_addr(net), port, key);
743 if (p) {
744 nt->local_publ_count++;
745 skb = tipc_named_publish(net, p);
746 }
747 rc_dests = nt->rc_dests;
748exit:
749 spin_unlock_bh(&tn->nametbl_lock);
750
751 if (skb)
752 tipc_node_broadcast(net, skb, rc_dests);
753 return p;
754
755}
756
757/**
758 * tipc_nametbl_withdraw - withdraw a service binding
759 */
760int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower,
761 u32 upper, u32 key)
762{
763 struct name_table *nt = tipc_name_table(net);
764 struct tipc_net *tn = tipc_net(net);
765 u32 self = tipc_own_addr(net);
766 struct sk_buff *skb = NULL;
767 struct publication *p;
768 u32 rc_dests;
769
770 spin_lock_bh(&tn->nametbl_lock);
771
772 p = tipc_nametbl_remove_publ(net, type, lower, upper, self, key);
773 if (p) {
774 nt->local_publ_count--;
775 skb = tipc_named_withdraw(net, p);
776 list_del_init(&p->binding_sock);
777 kfree_rcu(p, rcu);
778 } else {
779 pr_err("Failed to remove local publication {%u,%u,%u}/%u\n",
780 type, lower, upper, key);
781 }
782 rc_dests = nt->rc_dests;
783 spin_unlock_bh(&tn->nametbl_lock);
784
785 if (skb) {
786 tipc_node_broadcast(net, skb, rc_dests);
787 return 1;
788 }
789 return 0;
790}
791
792/**
793 * tipc_nametbl_subscribe - add a subscription object to the name table
794 */
795bool tipc_nametbl_subscribe(struct tipc_subscription *sub)
796{
797 struct name_table *nt = tipc_name_table(sub->net);
798 struct tipc_net *tn = tipc_net(sub->net);
799 struct tipc_subscr *s = &sub->evt.s;
800 u32 type = tipc_sub_read(s, seq.type);
801 struct tipc_service *sc;
802 bool res = true;
803
804 spin_lock_bh(&tn->nametbl_lock);
805 sc = tipc_service_find(sub->net, type);
806 if (!sc)
807 sc = tipc_service_create(type, &nt->services[hash(type)]);
808 if (sc) {
809 spin_lock_bh(&sc->lock);
810 tipc_service_subscribe(sc, sub);
811 spin_unlock_bh(&sc->lock);
812 } else {
813 pr_warn("Failed to subscribe for {%u,%u,%u}\n", type,
814 tipc_sub_read(s, seq.lower),
815 tipc_sub_read(s, seq.upper));
816 res = false;
817 }
818 spin_unlock_bh(&tn->nametbl_lock);
819 return res;
820}
821
822/**
823 * tipc_nametbl_unsubscribe - remove a subscription object from name table
824 */
825void tipc_nametbl_unsubscribe(struct tipc_subscription *sub)
826{
827 struct tipc_net *tn = tipc_net(sub->net);
828 struct tipc_subscr *s = &sub->evt.s;
829 u32 type = tipc_sub_read(s, seq.type);
830 struct tipc_service *sc;
831
832 spin_lock_bh(&tn->nametbl_lock);
833 sc = tipc_service_find(sub->net, type);
834 if (!sc)
835 goto exit;
836
837 spin_lock_bh(&sc->lock);
838 list_del_init(&sub->service_list);
839 tipc_sub_put(sub);
840
841 /* Delete service item if no more publications and subscriptions */
842 if (RB_EMPTY_ROOT(&sc->ranges) && list_empty(&sc->subscriptions)) {
843 hlist_del_init_rcu(&sc->service_list);
844 kfree_rcu(sc, rcu);
845 }
846 spin_unlock_bh(&sc->lock);
847exit:
848 spin_unlock_bh(&tn->nametbl_lock);
849}
850
851int tipc_nametbl_init(struct net *net)
852{
853 struct tipc_net *tn = tipc_net(net);
854 struct name_table *nt;
855 int i;
856
857 nt = kzalloc(sizeof(*nt), GFP_KERNEL);
858 if (!nt)
859 return -ENOMEM;
860
861 for (i = 0; i < TIPC_NAMETBL_SIZE; i++)
862 INIT_HLIST_HEAD(&nt->services[i]);
863
864 INIT_LIST_HEAD(&nt->node_scope);
865 INIT_LIST_HEAD(&nt->cluster_scope);
866 rwlock_init(&nt->cluster_scope_lock);
867 tn->nametbl = nt;
868 spin_lock_init(&tn->nametbl_lock);
869 return 0;
870}
871
872/**
873 * tipc_service_delete - purge all publications for a service and delete it
874 */
875static void tipc_service_delete(struct net *net, struct tipc_service *sc)
876{
877 struct service_range *sr, *tmpr;
878 struct publication *p, *tmp;
879
880 spin_lock_bh(&sc->lock);
881 rbtree_postorder_for_each_entry_safe(sr, tmpr, &sc->ranges, tree_node) {
882 list_for_each_entry_safe(p, tmp, &sr->all_publ, all_publ) {
883 tipc_service_remove_publ(sr, p->node, p->key);
884 kfree_rcu(p, rcu);
885 }
886 rb_erase_augmented(&sr->tree_node, &sc->ranges, &sr_callbacks);
887 kfree(sr);
888 }
889 hlist_del_init_rcu(&sc->service_list);
890 spin_unlock_bh(&sc->lock);
891 kfree_rcu(sc, rcu);
892}
893
894void tipc_nametbl_stop(struct net *net)
895{
896 struct name_table *nt = tipc_name_table(net);
897 struct tipc_net *tn = tipc_net(net);
898 struct hlist_head *service_head;
899 struct tipc_service *service;
900 u32 i;
901
902 /* Verify name table is empty and purge any lingering
903 * publications, then release the name table
904 */
905 spin_lock_bh(&tn->nametbl_lock);
906 for (i = 0; i < TIPC_NAMETBL_SIZE; i++) {
907 if (hlist_empty(&nt->services[i]))
908 continue;
909 service_head = &nt->services[i];
910 hlist_for_each_entry_rcu(service, service_head, service_list) {
911 tipc_service_delete(net, service);
912 }
913 }
914 spin_unlock_bh(&tn->nametbl_lock);
915
916 synchronize_net();
917 kfree(nt);
918}
919
920static int __tipc_nl_add_nametable_publ(struct tipc_nl_msg *msg,
921 struct tipc_service *service,
922 struct service_range *sr,
923 u32 *last_key)
924{
925 struct publication *p;
926 struct nlattr *attrs;
927 struct nlattr *b;
928 void *hdr;
929
930 if (*last_key) {
931 list_for_each_entry(p, &sr->all_publ, all_publ)
932 if (p->key == *last_key)
933 break;
934 if (p->key != *last_key)
935 return -EPIPE;
936 } else {
937 p = list_first_entry(&sr->all_publ,
938 struct publication,
939 all_publ);
940 }
941
942 list_for_each_entry_from(p, &sr->all_publ, all_publ) {
943 *last_key = p->key;
944
945 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq,
946 &tipc_genl_family, NLM_F_MULTI,
947 TIPC_NL_NAME_TABLE_GET);
948 if (!hdr)
949 return -EMSGSIZE;
950
951 attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_NAME_TABLE);
952 if (!attrs)
953 goto msg_full;
954
955 b = nla_nest_start_noflag(msg->skb, TIPC_NLA_NAME_TABLE_PUBL);
956 if (!b)
957 goto attr_msg_full;
958
959 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_TYPE, service->type))
960 goto publ_msg_full;
961 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_LOWER, sr->lower))
962 goto publ_msg_full;
963 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_UPPER, sr->upper))
964 goto publ_msg_full;
965 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_SCOPE, p->scope))
966 goto publ_msg_full;
967 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_NODE, p->node))
968 goto publ_msg_full;
969 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_REF, p->port))
970 goto publ_msg_full;
971 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_KEY, p->key))
972 goto publ_msg_full;
973
974 nla_nest_end(msg->skb, b);
975 nla_nest_end(msg->skb, attrs);
976 genlmsg_end(msg->skb, hdr);
977 }
978 *last_key = 0;
979
980 return 0;
981
982publ_msg_full:
983 nla_nest_cancel(msg->skb, b);
984attr_msg_full:
985 nla_nest_cancel(msg->skb, attrs);
986msg_full:
987 genlmsg_cancel(msg->skb, hdr);
988
989 return -EMSGSIZE;
990}
991
992static int __tipc_nl_service_range_list(struct tipc_nl_msg *msg,
993 struct tipc_service *sc,
994 u32 *last_lower, u32 *last_key)
995{
996 struct service_range *sr;
997 struct rb_node *n;
998 int err;
999
1000 for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
1001 sr = container_of(n, struct service_range, tree_node);
1002 if (sr->lower < *last_lower)
1003 continue;
1004 err = __tipc_nl_add_nametable_publ(msg, sc, sr, last_key);
1005 if (err) {
1006 *last_lower = sr->lower;
1007 return err;
1008 }
1009 }
1010 *last_lower = 0;
1011 return 0;
1012}
1013
1014static int tipc_nl_service_list(struct net *net, struct tipc_nl_msg *msg,
1015 u32 *last_type, u32 *last_lower, u32 *last_key)
1016{
1017 struct tipc_net *tn = tipc_net(net);
1018 struct tipc_service *service = NULL;
1019 struct hlist_head *head;
1020 int err;
1021 int i;
1022
1023 if (*last_type)
1024 i = hash(*last_type);
1025 else
1026 i = 0;
1027
1028 for (; i < TIPC_NAMETBL_SIZE; i++) {
1029 head = &tn->nametbl->services[i];
1030
1031 if (*last_type ||
1032 (!i && *last_key && (*last_lower == *last_key))) {
1033 service = tipc_service_find(net, *last_type);
1034 if (!service)
1035 return -EPIPE;
1036 } else {
1037 hlist_for_each_entry_rcu(service, head, service_list)
1038 break;
1039 if (!service)
1040 continue;
1041 }
1042
1043 hlist_for_each_entry_from_rcu(service, service_list) {
1044 spin_lock_bh(&service->lock);
1045 err = __tipc_nl_service_range_list(msg, service,
1046 last_lower,
1047 last_key);
1048
1049 if (err) {
1050 *last_type = service->type;
1051 spin_unlock_bh(&service->lock);
1052 return err;
1053 }
1054 spin_unlock_bh(&service->lock);
1055 }
1056 *last_type = 0;
1057 }
1058 return 0;
1059}
1060
1061int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb)
1062{
1063 struct net *net = sock_net(skb->sk);
1064 u32 last_type = cb->args[0];
1065 u32 last_lower = cb->args[1];
1066 u32 last_key = cb->args[2];
1067 int done = cb->args[3];
1068 struct tipc_nl_msg msg;
1069 int err;
1070
1071 if (done)
1072 return 0;
1073
1074 msg.skb = skb;
1075 msg.portid = NETLINK_CB(cb->skb).portid;
1076 msg.seq = cb->nlh->nlmsg_seq;
1077
1078 rcu_read_lock();
1079 err = tipc_nl_service_list(net, &msg, &last_type,
1080 &last_lower, &last_key);
1081 if (!err) {
1082 done = 1;
1083 } else if (err != -EMSGSIZE) {
1084 /* We never set seq or call nl_dump_check_consistent() this
1085 * means that setting prev_seq here will cause the consistence
1086 * check to fail in the netlink callback handler. Resulting in
1087 * the NLMSG_DONE message having the NLM_F_DUMP_INTR flag set if
1088 * we got an error.
1089 */
1090 cb->prev_seq = 1;
1091 }
1092 rcu_read_unlock();
1093
1094 cb->args[0] = last_type;
1095 cb->args[1] = last_lower;
1096 cb->args[2] = last_key;
1097 cb->args[3] = done;
1098
1099 return skb->len;
1100}
1101
1102struct tipc_dest *tipc_dest_find(struct list_head *l, u32 node, u32 port)
1103{
1104 struct tipc_dest *dst;
1105
1106 list_for_each_entry(dst, l, list) {
1107 if (dst->node == node && dst->port == port)
1108 return dst;
1109 }
1110 return NULL;
1111}
1112
1113bool tipc_dest_push(struct list_head *l, u32 node, u32 port)
1114{
1115 struct tipc_dest *dst;
1116
1117 if (tipc_dest_find(l, node, port))
1118 return false;
1119
1120 dst = kmalloc(sizeof(*dst), GFP_ATOMIC);
1121 if (unlikely(!dst))
1122 return false;
1123 dst->node = node;
1124 dst->port = port;
1125 list_add(&dst->list, l);
1126 return true;
1127}
1128
1129bool tipc_dest_pop(struct list_head *l, u32 *node, u32 *port)
1130{
1131 struct tipc_dest *dst;
1132
1133 if (list_empty(l))
1134 return false;
1135 dst = list_first_entry(l, typeof(*dst), list);
1136 if (port)
1137 *port = dst->port;
1138 if (node)
1139 *node = dst->node;
1140 list_del(&dst->list);
1141 kfree(dst);
1142 return true;
1143}
1144
1145bool tipc_dest_del(struct list_head *l, u32 node, u32 port)
1146{
1147 struct tipc_dest *dst;
1148
1149 dst = tipc_dest_find(l, node, port);
1150 if (!dst)
1151 return false;
1152 list_del(&dst->list);
1153 kfree(dst);
1154 return true;
1155}
1156
1157void tipc_dest_list_purge(struct list_head *l)
1158{
1159 struct tipc_dest *dst, *tmp;
1160
1161 list_for_each_entry_safe(dst, tmp, l, list) {
1162 list_del(&dst->list);
1163 kfree(dst);
1164 }
1165}
1166
1167int tipc_dest_list_len(struct list_head *l)
1168{
1169 struct tipc_dest *dst;
1170 int i = 0;
1171
1172 list_for_each_entry(dst, l, list) {
1173 i++;
1174 }
1175 return i;
1176}
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}