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Linux/net/tipc/name_table.c

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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  * Copyright (c) 2020, Red Hat Inc
  7  * All rights reserved.
  8  *
  9  * Redistribution and use in source and binary forms, with or without
 10  * modification, are permitted provided that the following conditions are met:
 11  *
 12  * 1. Redistributions of source code must retain the above copyright
 13  *    notice, this list of conditions and the following disclaimer.
 14  * 2. Redistributions in binary form must reproduce the above copyright
 15  *    notice, this list of conditions and the following disclaimer in the
 16  *    documentation and/or other materials provided with the distribution.
 17  * 3. Neither the names of the copyright holders nor the names of its
 18  *    contributors may be used to endorse or promote products derived from
 19  *    this software without specific prior written permission.
 20  *
 21  * Alternatively, this software may be distributed under the terms of the
 22  * GNU General Public License ("GPL") version 2 as published by the Free
 23  * Software Foundation.
 24  *
 25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 26  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 28  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 29  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 35  * POSSIBILITY OF SUCH DAMAGE.
 36  */
 37 
 38 #include <net/sock.h>
 39 #include <linux/list_sort.h>
 40 #include <linux/rbtree_augmented.h>
 41 #include "core.h"
 42 #include "netlink.h"
 43 #include "name_table.h"
 44 #include "name_distr.h"
 45 #include "subscr.h"
 46 #include "bcast.h"
 47 #include "addr.h"
 48 #include "node.h"
 49 #include "group.h"
 50 
 51 /**
 52  * struct service_range - container for all bindings of a service range
 53  * @lower: service range lower bound
 54  * @upper: service range upper bound
 55  * @tree_node: member of service range RB tree
 56  * @max: largest 'upper' in this node subtree
 57  * @local_publ: list of identical publications made from this node
 58  *   Used by closest_first lookup and multicast lookup algorithm
 59  * @all_publ: all publications identical to this one, whatever node and scope
 60  *   Used by round-robin lookup algorithm
 61  */
 62 struct service_range {
 63         u32 lower;
 64         u32 upper;
 65         struct rb_node tree_node;
 66         u32 max;
 67         struct list_head local_publ;
 68         struct list_head all_publ;
 69 };
 70 
 71 /**
 72  * struct tipc_service - container for all published instances of a service type
 73  * @type: 32 bit 'type' value for service
 74  * @publ_cnt: increasing counter for publications in this service
 75  * @ranges: rb tree containing all service ranges for this service
 76  * @service_list: links to adjacent name ranges in hash chain
 77  * @subscriptions: list of subscriptions for this service type
 78  * @lock: spinlock controlling access to pertaining service ranges/publications
 79  * @rcu: RCU callback head used for deferred freeing
 80  */
 81 struct tipc_service {
 82         u32 type;
 83         u32 publ_cnt;
 84         struct rb_root ranges;
 85         struct hlist_node service_list;
 86         struct list_head subscriptions;
 87         spinlock_t lock; /* Covers service range list */
 88         struct rcu_head rcu;
 89 };
 90 
 91 #define service_range_upper(sr) ((sr)->upper)
 92 RB_DECLARE_CALLBACKS_MAX(static, sr_callbacks,
 93                          struct service_range, tree_node, u32, max,
 94                          service_range_upper)
 95 
 96 #define service_range_entry(rbtree_node)                                \
 97         (container_of(rbtree_node, struct service_range, tree_node))
 98 
 99 #define service_range_overlap(sr, start, end)                           \
100         ((sr)->lower <= (end) && (sr)->upper >= (start))
101 
102 /**
103  * service_range_foreach_match - iterate over tipc service rbtree for each
104  *                               range match
105  * @sr: the service range pointer as a loop cursor
106  * @sc: the pointer to tipc service which holds the service range rbtree
107  * @start: beginning of the search range (end >= start) for matching
108  * @end: end of the search range (end >= start) for matching
109  */
110 #define service_range_foreach_match(sr, sc, start, end)                 \
111         for (sr = service_range_match_first((sc)->ranges.rb_node,       \
112                                             start,                      \
113                                             end);                       \
114              sr;                                                        \
115              sr = service_range_match_next(&(sr)->tree_node,            \
116                                            start,                       \
117                                            end))
118 
119 /**
120  * service_range_match_first - find first service range matching a range
121  * @n: the root node of service range rbtree for searching
122  * @start: beginning of the search range (end >= start) for matching
123  * @end: end of the search range (end >= start) for matching
124  *
125  * Return: the leftmost service range node in the rbtree that overlaps the
126  * specific range if any. Otherwise, returns NULL.
127  */
128 static struct service_range *service_range_match_first(struct rb_node *n,
129                                                        u32 start, u32 end)
130 {
131         struct service_range *sr;
132         struct rb_node *l, *r;
133 
134         /* Non overlaps in tree at all? */
135         if (!n || service_range_entry(n)->max < start)
136                 return NULL;
137 
138         while (n) {
139                 l = n->rb_left;
140                 if (l && service_range_entry(l)->max >= start) {
141                         /* A leftmost overlap range node must be one in the left
142                          * subtree. If not, it has lower > end, then nodes on
143                          * the right side cannot satisfy the condition either.
144                          */
145                         n = l;
146                         continue;
147                 }
148 
149                 /* No one in the left subtree can match, return if this node is
150                  * an overlap i.e. leftmost.
151                  */
152                 sr = service_range_entry(n);
153                 if (service_range_overlap(sr, start, end))
154                         return sr;
155 
156                 /* Ok, try to lookup on the right side */
157                 r = n->rb_right;
158                 if (sr->lower <= end &&
159                     r && service_range_entry(r)->max >= start) {
160                         n = r;
161                         continue;
162                 }
163                 break;
164         }
165 
166         return NULL;
167 }
168 
169 /**
170  * service_range_match_next - find next service range matching a range
171  * @n: a node in service range rbtree from which the searching starts
172  * @start: beginning of the search range (end >= start) for matching
173  * @end: end of the search range (end >= start) for matching
174  *
175  * Return: the next service range node to the given node in the rbtree that
176  * overlaps the specific range if any. Otherwise, returns NULL.
177  */
178 static struct service_range *service_range_match_next(struct rb_node *n,
179                                                       u32 start, u32 end)
180 {
181         struct service_range *sr;
182         struct rb_node *p, *r;
183 
184         while (n) {
185                 r = n->rb_right;
186                 if (r && service_range_entry(r)->max >= start)
187                         /* A next overlap range node must be one in the right
188                          * subtree. If not, it has lower > end, then any next
189                          * successor (- an ancestor) of this node cannot
190                          * satisfy the condition either.
191                          */
192                         return service_range_match_first(r, start, end);
193 
194                 /* No one in the right subtree can match, go up to find an
195                  * ancestor of this node which is parent of a left-hand child.
196                  */
197                 while ((p = rb_parent(n)) && n == p->rb_right)
198                         n = p;
199                 if (!p)
200                         break;
201 
202                 /* Return if this ancestor is an overlap */
203                 sr = service_range_entry(p);
204                 if (service_range_overlap(sr, start, end))
205                         return sr;
206 
207                 /* Ok, try to lookup more from this ancestor */
208                 if (sr->lower <= end) {
209                         n = p;
210                         continue;
211                 }
212                 break;
213         }
214 
215         return NULL;
216 }
217 
218 static int hash(int x)
219 {
220         return x & (TIPC_NAMETBL_SIZE - 1);
221 }
222 
223 /**
224  * tipc_publ_create - create a publication structure
225  * @type: name sequence type
226  * @lower: name sequence lower bound
227  * @upper: name sequence upper bound
228  * @scope: publication scope
229  * @node: network address of publishing socket
230  * @port: publishing port
231  * @key: publication key
232  */
233 static struct publication *tipc_publ_create(u32 type, u32 lower, u32 upper,
234                                             u32 scope, u32 node, u32 port,
235                                             u32 key)
236 {
237         struct publication *publ = kzalloc(sizeof(*publ), GFP_ATOMIC);
238 
239         if (!publ)
240                 return NULL;
241 
242         publ->type = type;
243         publ->lower = lower;
244         publ->upper = upper;
245         publ->scope = scope;
246         publ->node = node;
247         publ->port = port;
248         publ->key = key;
249         INIT_LIST_HEAD(&publ->binding_sock);
250         INIT_LIST_HEAD(&publ->binding_node);
251         INIT_LIST_HEAD(&publ->local_publ);
252         INIT_LIST_HEAD(&publ->all_publ);
253         INIT_LIST_HEAD(&publ->list);
254         return publ;
255 }
256 
257 /**
258  * tipc_service_create - create a service structure for the specified 'type'
259  * @type: service type
260  * @hd: name_table services list
261  *
262  * Allocates a single range structure and sets it to all 0's.
263  */
264 static struct tipc_service *tipc_service_create(u32 type, struct hlist_head *hd)
265 {
266         struct tipc_service *service = kzalloc(sizeof(*service), GFP_ATOMIC);
267 
268         if (!service) {
269                 pr_warn("Service creation failed, no memory\n");
270                 return NULL;
271         }
272 
273         spin_lock_init(&service->lock);
274         service->type = type;
275         service->ranges = RB_ROOT;
276         INIT_HLIST_NODE(&service->service_list);
277         INIT_LIST_HEAD(&service->subscriptions);
278         hlist_add_head_rcu(&service->service_list, hd);
279         return service;
280 }
281 
282 /*  tipc_service_find_range - find service range matching publication parameters
283  */
284 static struct service_range *tipc_service_find_range(struct tipc_service *sc,
285                                                      u32 lower, u32 upper)
286 {
287         struct service_range *sr;
288 
289         service_range_foreach_match(sr, sc, lower, upper) {
290                 /* Look for exact match */
291                 if (sr->lower == lower && sr->upper == upper)
292                         return sr;
293         }
294 
295         return NULL;
296 }
297 
298 static struct service_range *tipc_service_create_range(struct tipc_service *sc,
299                                                        u32 lower, u32 upper)
300 {
301         struct rb_node **n, *parent = NULL;
302         struct service_range *sr;
303 
304         n = &sc->ranges.rb_node;
305         while (*n) {
306                 parent = *n;
307                 sr = service_range_entry(parent);
308                 if (lower == sr->lower && upper == sr->upper)
309                         return sr;
310                 if (sr->max < upper)
311                         sr->max = upper;
312                 if (lower <= sr->lower)
313                         n = &parent->rb_left;
314                 else
315                         n = &parent->rb_right;
316         }
317         sr = kzalloc(sizeof(*sr), GFP_ATOMIC);
318         if (!sr)
319                 return NULL;
320         sr->lower = lower;
321         sr->upper = upper;
322         sr->max = upper;
323         INIT_LIST_HEAD(&sr->local_publ);
324         INIT_LIST_HEAD(&sr->all_publ);
325         rb_link_node(&sr->tree_node, parent, n);
326         rb_insert_augmented(&sr->tree_node, &sc->ranges, &sr_callbacks);
327         return sr;
328 }
329 
330 static struct publication *tipc_service_insert_publ(struct net *net,
331                                                     struct tipc_service *sc,
332                                                     u32 type, u32 lower,
333                                                     u32 upper, u32 scope,
334                                                     u32 node, u32 port,
335                                                     u32 key)
336 {
337         struct tipc_subscription *sub, *tmp;
338         struct service_range *sr;
339         struct publication *p;
340         bool first = false;
341 
342         sr = tipc_service_create_range(sc, lower, upper);
343         if (!sr)
344                 goto  err;
345 
346         first = list_empty(&sr->all_publ);
347 
348         /* Return if the publication already exists */
349         list_for_each_entry(p, &sr->all_publ, all_publ) {
350                 if (p->key == key && (!p->node || p->node == node))
351                         return NULL;
352         }
353 
354         /* Create and insert publication */
355         p = tipc_publ_create(type, lower, upper, scope, node, port, key);
356         if (!p)
357                 goto err;
358         /* Suppose there shouldn't be a huge gap btw publs i.e. >INT_MAX */
359         p->id = sc->publ_cnt++;
360         if (in_own_node(net, node))
361                 list_add(&p->local_publ, &sr->local_publ);
362         list_add(&p->all_publ, &sr->all_publ);
363 
364         /* Any subscriptions waiting for notification?  */
365         list_for_each_entry_safe(sub, tmp, &sc->subscriptions, service_list) {
366                 tipc_sub_report_overlap(sub, p->lower, p->upper, TIPC_PUBLISHED,
367                                         p->port, p->node, p->scope, first);
368         }
369         return p;
370 err:
371         pr_warn("Failed to bind to %u,%u,%u, no memory\n", type, lower, upper);
372         return NULL;
373 }
374 
375 /**
376  * tipc_service_remove_publ - remove a publication from a service
377  * @sr: service_range to remove publication from
378  * @node: target node
379  * @key: target publication key
380  */
381 static struct publication *tipc_service_remove_publ(struct service_range *sr,
382                                                     u32 node, u32 key)
383 {
384         struct publication *p;
385 
386         list_for_each_entry(p, &sr->all_publ, all_publ) {
387                 if (p->key != key || (node && node != p->node))
388                         continue;
389                 list_del(&p->all_publ);
390                 list_del(&p->local_publ);
391                 return p;
392         }
393         return NULL;
394 }
395 
396 /*
397  * Code reused: time_after32() for the same purpose
398  */
399 #define publication_after(pa, pb) time_after32((pa)->id, (pb)->id)
400 static int tipc_publ_sort(void *priv, struct list_head *a,
401                           struct list_head *b)
402 {
403         struct publication *pa, *pb;
404 
405         pa = container_of(a, struct publication, list);
406         pb = container_of(b, struct publication, list);
407         return publication_after(pa, pb);
408 }
409 
410 /**
411  * tipc_service_subscribe - attach a subscription, and optionally
412  * issue the prescribed number of events if there is any service
413  * range overlapping with the requested range
414  * @service: the tipc_service to attach the @sub to
415  * @sub: the subscription to attach
416  */
417 static void tipc_service_subscribe(struct tipc_service *service,
418                                    struct tipc_subscription *sub)
419 {
420         struct tipc_subscr *sb = &sub->evt.s;
421         struct publication *p, *first, *tmp;
422         struct list_head publ_list;
423         struct service_range *sr;
424         struct tipc_service_range r;
425         u32 filter;
426 
427         r.type = tipc_sub_read(sb, seq.type);
428         r.lower = tipc_sub_read(sb, seq.lower);
429         r.upper = tipc_sub_read(sb, seq.upper);
430         filter = tipc_sub_read(sb, filter);
431 
432         tipc_sub_get(sub);
433         list_add(&sub->service_list, &service->subscriptions);
434 
435         if (filter & TIPC_SUB_NO_STATUS)
436                 return;
437 
438         INIT_LIST_HEAD(&publ_list);
439         service_range_foreach_match(sr, service, r.lower, r.upper) {
440                 first = NULL;
441                 list_for_each_entry(p, &sr->all_publ, all_publ) {
442                         if (filter & TIPC_SUB_PORTS)
443                                 list_add_tail(&p->list, &publ_list);
444                         else if (!first || publication_after(first, p))
445                                 /* Pick this range's *first* publication */
446                                 first = p;
447                 }
448                 if (first)
449                         list_add_tail(&first->list, &publ_list);
450         }
451 
452         /* Sort the publications before reporting */
453         list_sort(NULL, &publ_list, tipc_publ_sort);
454         list_for_each_entry_safe(p, tmp, &publ_list, list) {
455                 tipc_sub_report_overlap(sub, p->lower, p->upper,
456                                         TIPC_PUBLISHED, p->port, p->node,
457                                         p->scope, true);
458                 list_del_init(&p->list);
459         }
460 }
461 
462 static struct tipc_service *tipc_service_find(struct net *net, u32 type)
463 {
464         struct name_table *nt = tipc_name_table(net);
465         struct hlist_head *service_head;
466         struct tipc_service *service;
467 
468         service_head = &nt->services[hash(type)];
469         hlist_for_each_entry_rcu(service, service_head, service_list) {
470                 if (service->type == type)
471                         return service;
472         }
473         return NULL;
474 };
475 
476 struct publication *tipc_nametbl_insert_publ(struct net *net, u32 type,
477                                              u32 lower, u32 upper,
478                                              u32 scope, u32 node,
479                                              u32 port, u32 key)
480 {
481         struct name_table *nt = tipc_name_table(net);
482         struct tipc_service *sc;
483         struct publication *p;
484 
485         if (scope > TIPC_NODE_SCOPE || lower > upper) {
486                 pr_debug("Failed to bind illegal {%u,%u,%u} with scope %u\n",
487                          type, lower, upper, scope);
488                 return NULL;
489         }
490         sc = tipc_service_find(net, type);
491         if (!sc)
492                 sc = tipc_service_create(type, &nt->services[hash(type)]);
493         if (!sc)
494                 return NULL;
495 
496         spin_lock_bh(&sc->lock);
497         p = tipc_service_insert_publ(net, sc, type, lower, upper,
498                                      scope, node, port, key);
499         spin_unlock_bh(&sc->lock);
500         return p;
501 }
502 
503 struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type,
504                                              u32 lower, u32 upper,
505                                              u32 node, u32 key)
506 {
507         struct tipc_service *sc = tipc_service_find(net, type);
508         struct tipc_subscription *sub, *tmp;
509         struct service_range *sr = NULL;
510         struct publication *p = NULL;
511         bool last;
512 
513         if (!sc)
514                 return NULL;
515 
516         spin_lock_bh(&sc->lock);
517         sr = tipc_service_find_range(sc, lower, upper);
518         if (!sr)
519                 goto exit;
520         p = tipc_service_remove_publ(sr, node, key);
521         if (!p)
522                 goto exit;
523 
524         /* Notify any waiting subscriptions */
525         last = list_empty(&sr->all_publ);
526         list_for_each_entry_safe(sub, tmp, &sc->subscriptions, service_list) {
527                 tipc_sub_report_overlap(sub, lower, upper, TIPC_WITHDRAWN,
528                                         p->port, node, p->scope, last);
529         }
530 
531         /* Remove service range item if this was its last publication */
532         if (list_empty(&sr->all_publ)) {
533                 rb_erase_augmented(&sr->tree_node, &sc->ranges, &sr_callbacks);
534                 kfree(sr);
535         }
536 
537         /* Delete service item if this no more publications and subscriptions */
538         if (RB_EMPTY_ROOT(&sc->ranges) && list_empty(&sc->subscriptions)) {
539                 hlist_del_init_rcu(&sc->service_list);
540                 kfree_rcu(sc, rcu);
541         }
542 exit:
543         spin_unlock_bh(&sc->lock);
544         return p;
545 }
546 
547 /**
548  * tipc_nametbl_translate - perform service instance to socket translation
549  * @net: network namespace
550  * @type: message type
551  * @instance: message instance
552  * @dnode: the search domain used during translation
553  *
554  * On exit:
555  * - if translation is deferred to another node, leave 'dnode' unchanged and
556  * return 0
557  * - if translation is attempted and succeeds, set 'dnode' to the publishing
558  * node and return the published (non-zero) port number
559  * - if translation is attempted and fails, set 'dnode' to 0 and return 0
560  *
561  * Note that for legacy users (node configured with Z.C.N address format) the
562  * 'closest-first' lookup algorithm must be maintained, i.e., if dnode is 0
563  * we must look in the local binding list first
564  */
565 u32 tipc_nametbl_translate(struct net *net, u32 type, u32 instance, u32 *dnode)
566 {
567         struct tipc_net *tn = tipc_net(net);
568         bool legacy = tn->legacy_addr_format;
569         u32 self = tipc_own_addr(net);
570         struct service_range *sr;
571         struct tipc_service *sc;
572         struct list_head *list;
573         struct publication *p;
574         u32 port = 0;
575         u32 node = 0;
576 
577         if (!tipc_in_scope(legacy, *dnode, self))
578                 return 0;
579 
580         rcu_read_lock();
581         sc = tipc_service_find(net, type);
582         if (unlikely(!sc))
583                 goto exit;
584 
585         spin_lock_bh(&sc->lock);
586         service_range_foreach_match(sr, sc, instance, instance) {
587                 /* Select lookup algo: local, closest-first or round-robin */
588                 if (*dnode == self) {
589                         list = &sr->local_publ;
590                         if (list_empty(list))
591                                 continue;
592                         p = list_first_entry(list, struct publication,
593                                              local_publ);
594                         list_move_tail(&p->local_publ, &sr->local_publ);
595                 } else if (legacy && !*dnode && !list_empty(&sr->local_publ)) {
596                         list = &sr->local_publ;
597                         p = list_first_entry(list, struct publication,
598                                              local_publ);
599                         list_move_tail(&p->local_publ, &sr->local_publ);
600                 } else {
601                         list = &sr->all_publ;
602                         p = list_first_entry(list, struct publication,
603                                              all_publ);
604                         list_move_tail(&p->all_publ, &sr->all_publ);
605                 }
606                 port = p->port;
607                 node = p->node;
608                 /* Todo: as for legacy, pick the first matching range only, a
609                  * "true" round-robin will be performed as needed.
610                  */
611                 break;
612         }
613         spin_unlock_bh(&sc->lock);
614 
615 exit:
616         rcu_read_unlock();
617         *dnode = node;
618         return port;
619 }
620 
621 bool tipc_nametbl_lookup(struct net *net, u32 type, u32 instance, u32 scope,
622                          struct list_head *dsts, int *dstcnt, u32 exclude,
623                          bool all)
624 {
625         u32 self = tipc_own_addr(net);
626         struct service_range *sr;
627         struct tipc_service *sc;
628         struct publication *p;
629 
630         *dstcnt = 0;
631         rcu_read_lock();
632         sc = tipc_service_find(net, type);
633         if (unlikely(!sc))
634                 goto exit;
635 
636         spin_lock_bh(&sc->lock);
637 
638         /* Todo: a full search i.e. service_range_foreach_match() instead? */
639         sr = service_range_match_first(sc->ranges.rb_node, instance, instance);
640         if (!sr)
641                 goto no_match;
642 
643         list_for_each_entry(p, &sr->all_publ, all_publ) {
644                 if (p->scope != scope)
645                         continue;
646                 if (p->port == exclude && p->node == self)
647                         continue;
648                 tipc_dest_push(dsts, p->node, p->port);
649                 (*dstcnt)++;
650                 if (all)
651                         continue;
652                 list_move_tail(&p->all_publ, &sr->all_publ);
653                 break;
654         }
655 no_match:
656         spin_unlock_bh(&sc->lock);
657 exit:
658         rcu_read_unlock();
659         return !list_empty(dsts);
660 }
661 
662 void tipc_nametbl_mc_lookup(struct net *net, u32 type, u32 lower, u32 upper,
663                             u32 scope, bool exact, struct list_head *dports)
664 {
665         struct service_range *sr;
666         struct tipc_service *sc;
667         struct publication *p;
668 
669         rcu_read_lock();
670         sc = tipc_service_find(net, type);
671         if (!sc)
672                 goto exit;
673 
674         spin_lock_bh(&sc->lock);
675         service_range_foreach_match(sr, sc, lower, upper) {
676                 list_for_each_entry(p, &sr->local_publ, local_publ) {
677                         if (p->scope == scope || (!exact && p->scope < scope))
678                                 tipc_dest_push(dports, 0, p->port);
679                 }
680         }
681         spin_unlock_bh(&sc->lock);
682 exit:
683         rcu_read_unlock();
684 }
685 
686 /* tipc_nametbl_lookup_dst_nodes - find broadcast destination nodes
687  * - Creates list of nodes that overlap the given multicast address
688  * - Determines if any node local destinations overlap
689  */
690 void tipc_nametbl_lookup_dst_nodes(struct net *net, u32 type, u32 lower,
691                                    u32 upper, struct tipc_nlist *nodes)
692 {
693         struct service_range *sr;
694         struct tipc_service *sc;
695         struct publication *p;
696 
697         rcu_read_lock();
698         sc = tipc_service_find(net, type);
699         if (!sc)
700                 goto exit;
701 
702         spin_lock_bh(&sc->lock);
703         service_range_foreach_match(sr, sc, lower, upper) {
704                 list_for_each_entry(p, &sr->all_publ, all_publ) {
705                         tipc_nlist_add(nodes, p->node);
706                 }
707         }
708         spin_unlock_bh(&sc->lock);
709 exit:
710         rcu_read_unlock();
711 }
712 
713 /* tipc_nametbl_build_group - build list of communication group members
714  */
715 void tipc_nametbl_build_group(struct net *net, struct tipc_group *grp,
716                               u32 type, u32 scope)
717 {
718         struct service_range *sr;
719         struct tipc_service *sc;
720         struct publication *p;
721         struct rb_node *n;
722 
723         rcu_read_lock();
724         sc = tipc_service_find(net, type);
725         if (!sc)
726                 goto exit;
727 
728         spin_lock_bh(&sc->lock);
729         for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
730                 sr = container_of(n, struct service_range, tree_node);
731                 list_for_each_entry(p, &sr->all_publ, all_publ) {
732                         if (p->scope != scope)
733                                 continue;
734                         tipc_group_add_member(grp, p->node, p->port, p->lower);
735                 }
736         }
737         spin_unlock_bh(&sc->lock);
738 exit:
739         rcu_read_unlock();
740 }
741 
742 /* tipc_nametbl_publish - add service binding to name table
743  */
744 struct publication *tipc_nametbl_publish(struct net *net, u32 type, u32 lower,
745                                          u32 upper, u32 scope, u32 port,
746                                          u32 key)
747 {
748         struct name_table *nt = tipc_name_table(net);
749         struct tipc_net *tn = tipc_net(net);
750         struct publication *p = NULL;
751         struct sk_buff *skb = NULL;
752         u32 rc_dests;
753 
754         spin_lock_bh(&tn->nametbl_lock);
755 
756         if (nt->local_publ_count >= TIPC_MAX_PUBL) {
757                 pr_warn("Bind failed, max limit %u reached\n", TIPC_MAX_PUBL);
758                 goto exit;
759         }
760 
761         p = tipc_nametbl_insert_publ(net, type, lower, upper, scope,
762                                      tipc_own_addr(net), port, key);
763         if (p) {
764                 nt->local_publ_count++;
765                 skb = tipc_named_publish(net, p);
766         }
767         rc_dests = nt->rc_dests;
768 exit:
769         spin_unlock_bh(&tn->nametbl_lock);
770 
771         if (skb)
772                 tipc_node_broadcast(net, skb, rc_dests);
773         return p;
774 
775 }
776 
777 /**
778  * tipc_nametbl_withdraw - withdraw a service binding
779  * @net: network namespace
780  * @type: service type
781  * @lower: service range lower bound
782  * @upper: service range upper bound
783  * @key: target publication key
784  */
785 int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower,
786                           u32 upper, u32 key)
787 {
788         struct name_table *nt = tipc_name_table(net);
789         struct tipc_net *tn = tipc_net(net);
790         u32 self = tipc_own_addr(net);
791         struct sk_buff *skb = NULL;
792         struct publication *p;
793         u32 rc_dests;
794 
795         spin_lock_bh(&tn->nametbl_lock);
796 
797         p = tipc_nametbl_remove_publ(net, type, lower, upper, self, key);
798         if (p) {
799                 nt->local_publ_count--;
800                 skb = tipc_named_withdraw(net, p);
801                 list_del_init(&p->binding_sock);
802                 kfree_rcu(p, rcu);
803         } else {
804                 pr_err("Failed to remove local publication {%u,%u,%u}/%u\n",
805                        type, lower, upper, key);
806         }
807         rc_dests = nt->rc_dests;
808         spin_unlock_bh(&tn->nametbl_lock);
809 
810         if (skb) {
811                 tipc_node_broadcast(net, skb, rc_dests);
812                 return 1;
813         }
814         return 0;
815 }
816 
817 /**
818  * tipc_nametbl_subscribe - add a subscription object to the name table
819  * @sub: subscription to add
820  */
821 bool tipc_nametbl_subscribe(struct tipc_subscription *sub)
822 {
823         struct name_table *nt = tipc_name_table(sub->net);
824         struct tipc_net *tn = tipc_net(sub->net);
825         struct tipc_subscr *s = &sub->evt.s;
826         u32 type = tipc_sub_read(s, seq.type);
827         struct tipc_service *sc;
828         bool res = true;
829 
830         spin_lock_bh(&tn->nametbl_lock);
831         sc = tipc_service_find(sub->net, type);
832         if (!sc)
833                 sc = tipc_service_create(type, &nt->services[hash(type)]);
834         if (sc) {
835                 spin_lock_bh(&sc->lock);
836                 tipc_service_subscribe(sc, sub);
837                 spin_unlock_bh(&sc->lock);
838         } else {
839                 pr_warn("Failed to subscribe for {%u,%u,%u}\n", type,
840                         tipc_sub_read(s, seq.lower),
841                         tipc_sub_read(s, seq.upper));
842                 res = false;
843         }
844         spin_unlock_bh(&tn->nametbl_lock);
845         return res;
846 }
847 
848 /**
849  * tipc_nametbl_unsubscribe - remove a subscription object from name table
850  * @sub: subscription to remove
851  */
852 void tipc_nametbl_unsubscribe(struct tipc_subscription *sub)
853 {
854         struct tipc_net *tn = tipc_net(sub->net);
855         struct tipc_subscr *s = &sub->evt.s;
856         u32 type = tipc_sub_read(s, seq.type);
857         struct tipc_service *sc;
858 
859         spin_lock_bh(&tn->nametbl_lock);
860         sc = tipc_service_find(sub->net, type);
861         if (!sc)
862                 goto exit;
863 
864         spin_lock_bh(&sc->lock);
865         list_del_init(&sub->service_list);
866         tipc_sub_put(sub);
867 
868         /* Delete service item if no more publications and subscriptions */
869         if (RB_EMPTY_ROOT(&sc->ranges) && list_empty(&sc->subscriptions)) {
870                 hlist_del_init_rcu(&sc->service_list);
871                 kfree_rcu(sc, rcu);
872         }
873         spin_unlock_bh(&sc->lock);
874 exit:
875         spin_unlock_bh(&tn->nametbl_lock);
876 }
877 
878 int tipc_nametbl_init(struct net *net)
879 {
880         struct tipc_net *tn = tipc_net(net);
881         struct name_table *nt;
882         int i;
883 
884         nt = kzalloc(sizeof(*nt), GFP_KERNEL);
885         if (!nt)
886                 return -ENOMEM;
887 
888         for (i = 0; i < TIPC_NAMETBL_SIZE; i++)
889                 INIT_HLIST_HEAD(&nt->services[i]);
890 
891         INIT_LIST_HEAD(&nt->node_scope);
892         INIT_LIST_HEAD(&nt->cluster_scope);
893         rwlock_init(&nt->cluster_scope_lock);
894         tn->nametbl = nt;
895         spin_lock_init(&tn->nametbl_lock);
896         return 0;
897 }
898 
899 /**
900  * tipc_service_delete - purge all publications for a service and delete it
901  * @net: the associated network namespace
902  * @sc: tipc_service to delete
903  */
904 static void tipc_service_delete(struct net *net, struct tipc_service *sc)
905 {
906         struct service_range *sr, *tmpr;
907         struct publication *p, *tmp;
908 
909         spin_lock_bh(&sc->lock);
910         rbtree_postorder_for_each_entry_safe(sr, tmpr, &sc->ranges, tree_node) {
911                 list_for_each_entry_safe(p, tmp, &sr->all_publ, all_publ) {
912                         tipc_service_remove_publ(sr, p->node, p->key);
913                         kfree_rcu(p, rcu);
914                 }
915                 rb_erase_augmented(&sr->tree_node, &sc->ranges, &sr_callbacks);
916                 kfree(sr);
917         }
918         hlist_del_init_rcu(&sc->service_list);
919         spin_unlock_bh(&sc->lock);
920         kfree_rcu(sc, rcu);
921 }
922 
923 void tipc_nametbl_stop(struct net *net)
924 {
925         struct name_table *nt = tipc_name_table(net);
926         struct tipc_net *tn = tipc_net(net);
927         struct hlist_head *service_head;
928         struct tipc_service *service;
929         u32 i;
930 
931         /* Verify name table is empty and purge any lingering
932          * publications, then release the name table
933          */
934         spin_lock_bh(&tn->nametbl_lock);
935         for (i = 0; i < TIPC_NAMETBL_SIZE; i++) {
936                 if (hlist_empty(&nt->services[i]))
937                         continue;
938                 service_head = &nt->services[i];
939                 hlist_for_each_entry_rcu(service, service_head, service_list) {
940                         tipc_service_delete(net, service);
941                 }
942         }
943         spin_unlock_bh(&tn->nametbl_lock);
944 
945         synchronize_net();
946         kfree(nt);
947 }
948 
949 static int __tipc_nl_add_nametable_publ(struct tipc_nl_msg *msg,
950                                         struct tipc_service *service,
951                                         struct service_range *sr,
952                                         u32 *last_key)
953 {
954         struct publication *p;
955         struct nlattr *attrs;
956         struct nlattr *b;
957         void *hdr;
958 
959         if (*last_key) {
960                 list_for_each_entry(p, &sr->all_publ, all_publ)
961                         if (p->key == *last_key)
962                                 break;
963                 if (p->key != *last_key)
964                         return -EPIPE;
965         } else {
966                 p = list_first_entry(&sr->all_publ,
967                                      struct publication,
968                                      all_publ);
969         }
970 
971         list_for_each_entry_from(p, &sr->all_publ, all_publ) {
972                 *last_key = p->key;
973 
974                 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq,
975                                   &tipc_genl_family, NLM_F_MULTI,
976                                   TIPC_NL_NAME_TABLE_GET);
977                 if (!hdr)
978                         return -EMSGSIZE;
979 
980                 attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_NAME_TABLE);
981                 if (!attrs)
982                         goto msg_full;
983 
984                 b = nla_nest_start_noflag(msg->skb, TIPC_NLA_NAME_TABLE_PUBL);
985                 if (!b)
986                         goto attr_msg_full;
987 
988                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_TYPE, service->type))
989                         goto publ_msg_full;
990                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_LOWER, sr->lower))
991                         goto publ_msg_full;
992                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_UPPER, sr->upper))
993                         goto publ_msg_full;
994                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_SCOPE, p->scope))
995                         goto publ_msg_full;
996                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_NODE, p->node))
997                         goto publ_msg_full;
998                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_REF, p->port))
999                         goto publ_msg_full;
1000                 if (nla_put_u32(msg->skb, TIPC_NLA_PUBL_KEY, p->key))
1001                         goto publ_msg_full;
1002 
1003                 nla_nest_end(msg->skb, b);
1004                 nla_nest_end(msg->skb, attrs);
1005                 genlmsg_end(msg->skb, hdr);
1006         }
1007         *last_key = 0;
1008 
1009         return 0;
1010 
1011 publ_msg_full:
1012         nla_nest_cancel(msg->skb, b);
1013 attr_msg_full:
1014         nla_nest_cancel(msg->skb, attrs);
1015 msg_full:
1016         genlmsg_cancel(msg->skb, hdr);
1017 
1018         return -EMSGSIZE;
1019 }
1020 
1021 static int __tipc_nl_service_range_list(struct tipc_nl_msg *msg,
1022                                         struct tipc_service *sc,
1023                                         u32 *last_lower, u32 *last_key)
1024 {
1025         struct service_range *sr;
1026         struct rb_node *n;
1027         int err;
1028 
1029         for (n = rb_first(&sc->ranges); n; n = rb_next(n)) {
1030                 sr = container_of(n, struct service_range, tree_node);
1031                 if (sr->lower < *last_lower)
1032                         continue;
1033                 err = __tipc_nl_add_nametable_publ(msg, sc, sr, last_key);
1034                 if (err) {
1035                         *last_lower = sr->lower;
1036                         return err;
1037                 }
1038         }
1039         *last_lower = 0;
1040         return 0;
1041 }
1042 
1043 static int tipc_nl_service_list(struct net *net, struct tipc_nl_msg *msg,
1044                                 u32 *last_type, u32 *last_lower, u32 *last_key)
1045 {
1046         struct tipc_net *tn = tipc_net(net);
1047         struct tipc_service *service = NULL;
1048         struct hlist_head *head;
1049         int err;
1050         int i;
1051 
1052         if (*last_type)
1053                 i = hash(*last_type);
1054         else
1055                 i = 0;
1056 
1057         for (; i < TIPC_NAMETBL_SIZE; i++) {
1058                 head = &tn->nametbl->services[i];
1059 
1060                 if (*last_type ||
1061                     (!i && *last_key && (*last_lower == *last_key))) {
1062                         service = tipc_service_find(net, *last_type);
1063                         if (!service)
1064                                 return -EPIPE;
1065                 } else {
1066                         hlist_for_each_entry_rcu(service, head, service_list)
1067                                 break;
1068                         if (!service)
1069                                 continue;
1070                 }
1071 
1072                 hlist_for_each_entry_from_rcu(service, service_list) {
1073                         spin_lock_bh(&service->lock);
1074                         err = __tipc_nl_service_range_list(msg, service,
1075                                                            last_lower,
1076                                                            last_key);
1077 
1078                         if (err) {
1079                                 *last_type = service->type;
1080                                 spin_unlock_bh(&service->lock);
1081                                 return err;
1082                         }
1083                         spin_unlock_bh(&service->lock);
1084                 }
1085                 *last_type = 0;
1086         }
1087         return 0;
1088 }
1089 
1090 int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb)
1091 {
1092         struct net *net = sock_net(skb->sk);
1093         u32 last_type = cb->args[0];
1094         u32 last_lower = cb->args[1];
1095         u32 last_key = cb->args[2];
1096         int done = cb->args[3];
1097         struct tipc_nl_msg msg;
1098         int err;
1099 
1100         if (done)
1101                 return 0;
1102 
1103         msg.skb = skb;
1104         msg.portid = NETLINK_CB(cb->skb).portid;
1105         msg.seq = cb->nlh->nlmsg_seq;
1106 
1107         rcu_read_lock();
1108         err = tipc_nl_service_list(net, &msg, &last_type,
1109                                    &last_lower, &last_key);
1110         if (!err) {
1111                 done = 1;
1112         } else if (err != -EMSGSIZE) {
1113                 /* We never set seq or call nl_dump_check_consistent() this
1114                  * means that setting prev_seq here will cause the consistence
1115                  * check to fail in the netlink callback handler. Resulting in
1116                  * the NLMSG_DONE message having the NLM_F_DUMP_INTR flag set if
1117                  * we got an error.
1118                  */
1119                 cb->prev_seq = 1;
1120         }
1121         rcu_read_unlock();
1122 
1123         cb->args[0] = last_type;
1124         cb->args[1] = last_lower;
1125         cb->args[2] = last_key;
1126         cb->args[3] = done;
1127 
1128         return skb->len;
1129 }
1130 
1131 struct tipc_dest *tipc_dest_find(struct list_head *l, u32 node, u32 port)
1132 {
1133         struct tipc_dest *dst;
1134 
1135         list_for_each_entry(dst, l, list) {
1136                 if (dst->node == node && dst->port == port)
1137                         return dst;
1138         }
1139         return NULL;
1140 }
1141 
1142 bool tipc_dest_push(struct list_head *l, u32 node, u32 port)
1143 {
1144         struct tipc_dest *dst;
1145 
1146         if (tipc_dest_find(l, node, port))
1147                 return false;
1148 
1149         dst = kmalloc(sizeof(*dst), GFP_ATOMIC);
1150         if (unlikely(!dst))
1151                 return false;
1152         dst->node = node;
1153         dst->port = port;
1154         list_add(&dst->list, l);
1155         return true;
1156 }
1157 
1158 bool tipc_dest_pop(struct list_head *l, u32 *node, u32 *port)
1159 {
1160         struct tipc_dest *dst;
1161 
1162         if (list_empty(l))
1163                 return false;
1164         dst = list_first_entry(l, typeof(*dst), list);
1165         if (port)
1166                 *port = dst->port;
1167         if (node)
1168                 *node = dst->node;
1169         list_del(&dst->list);
1170         kfree(dst);
1171         return true;
1172 }
1173 
1174 bool tipc_dest_del(struct list_head *l, u32 node, u32 port)
1175 {
1176         struct tipc_dest *dst;
1177 
1178         dst = tipc_dest_find(l, node, port);
1179         if (!dst)
1180                 return false;
1181         list_del(&dst->list);
1182         kfree(dst);
1183         return true;
1184 }
1185 
1186 void tipc_dest_list_purge(struct list_head *l)
1187 {
1188         struct tipc_dest *dst, *tmp;
1189 
1190         list_for_each_entry_safe(dst, tmp, l, list) {
1191                 list_del(&dst->list);
1192                 kfree(dst);
1193         }
1194 }
1195 
1196 int tipc_dest_list_len(struct list_head *l)
1197 {
1198         struct tipc_dest *dst;
1199         int i = 0;
1200 
1201         list_for_each_entry(dst, l, list) {
1202                 i++;
1203         }
1204         return i;
1205 }
1206 

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