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b97bf3fd PL |
1 | /* |
2 | * net/tipc/subscr.c: TIPC subscription service | |
3 | * | |
593a5f22 | 4 | * Copyright (c) 2000-2006, Ericsson AB |
b97bf3fd | 5 | * Copyright (c) 2005, Wind River Systems |
b97bf3fd PL |
6 | * All rights reserved. |
7 | * | |
9ea1fd3c | 8 | * Redistribution and use in source and binary forms, with or without |
b97bf3fd PL |
9 | * modification, are permitted provided that the following conditions are met: |
10 | * | |
9ea1fd3c PL |
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. | |
b97bf3fd | 19 | * |
9ea1fd3c PL |
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 | |
b97bf3fd PL |
34 | * POSSIBILITY OF SUCH DAMAGE. |
35 | */ | |
36 | ||
37 | #include "core.h" | |
38 | #include "dbg.h" | |
39 | #include "subscr.h" | |
40 | #include "name_table.h" | |
41 | #include "ref.h" | |
42 | ||
43 | /** | |
44 | * struct subscriber - TIPC network topology subscriber | |
45 | * @ref: object reference to subscriber object itself | |
46 | * @lock: pointer to spinlock controlling access to subscriber object | |
47 | * @subscriber_list: adjacent subscribers in top. server's list of subscribers | |
48 | * @subscription_list: list of subscription objects for this subscriber | |
49 | * @port_ref: object reference to port used to communicate with subscriber | |
50 | * @swap: indicates if subscriber uses opposite endianness in its messages | |
51 | */ | |
52 | ||
53 | struct subscriber { | |
54 | u32 ref; | |
55 | spinlock_t *lock; | |
56 | struct list_head subscriber_list; | |
57 | struct list_head subscription_list; | |
58 | u32 port_ref; | |
59 | int swap; | |
60 | }; | |
61 | ||
62 | /** | |
63 | * struct top_srv - TIPC network topology subscription service | |
64 | * @user_ref: TIPC userid of subscription service | |
65 | * @setup_port: reference to TIPC port that handles subscription requests | |
66 | * @subscription_count: number of active subscriptions (not subscribers!) | |
67 | * @subscriber_list: list of ports subscribing to service | |
68 | * @lock: spinlock govering access to subscriber list | |
69 | */ | |
70 | ||
71 | struct top_srv { | |
72 | u32 user_ref; | |
73 | u32 setup_port; | |
74 | atomic_t subscription_count; | |
75 | struct list_head subscriber_list; | |
76 | spinlock_t lock; | |
77 | }; | |
78 | ||
79 | static struct top_srv topsrv = { 0 }; | |
80 | ||
81 | /** | |
82 | * htohl - convert value to endianness used by destination | |
83 | * @in: value to convert | |
84 | * @swap: non-zero if endianness must be reversed | |
85 | * | |
86 | * Returns converted value | |
87 | */ | |
88 | ||
89 | static inline u32 htohl(u32 in, int swap) | |
90 | { | |
91 | char *c = (char *)∈ | |
92 | ||
93 | return swap ? ((c[3] << 3) + (c[2] << 2) + (c[1] << 1) + c[0]) : in; | |
94 | } | |
95 | ||
96 | /** | |
97 | * subscr_send_event - send a message containing a tipc_event to the subscriber | |
98 | */ | |
99 | ||
100 | static void subscr_send_event(struct subscription *sub, | |
101 | u32 found_lower, | |
102 | u32 found_upper, | |
103 | u32 event, | |
104 | u32 port_ref, | |
105 | u32 node) | |
106 | { | |
107 | struct iovec msg_sect; | |
108 | ||
109 | msg_sect.iov_base = (void *)&sub->evt; | |
110 | msg_sect.iov_len = sizeof(struct tipc_event); | |
111 | ||
112 | sub->evt.event = htohl(event, sub->owner->swap); | |
113 | sub->evt.found_lower = htohl(found_lower, sub->owner->swap); | |
114 | sub->evt.found_upper = htohl(found_upper, sub->owner->swap); | |
115 | sub->evt.port.ref = htohl(port_ref, sub->owner->swap); | |
116 | sub->evt.port.node = htohl(node, sub->owner->swap); | |
117 | tipc_send(sub->owner->port_ref, 1, &msg_sect); | |
118 | } | |
119 | ||
120 | /** | |
121 | * subscr_overlap - test for subscription overlap with the given values | |
122 | * | |
123 | * Returns 1 if there is overlap, otherwise 0. | |
124 | */ | |
125 | ||
126 | int subscr_overlap(struct subscription *sub, | |
127 | u32 found_lower, | |
128 | u32 found_upper) | |
129 | ||
130 | { | |
131 | if (found_lower < sub->seq.lower) | |
132 | found_lower = sub->seq.lower; | |
133 | if (found_upper > sub->seq.upper) | |
134 | found_upper = sub->seq.upper; | |
135 | if (found_lower > found_upper) | |
136 | return 0; | |
137 | return 1; | |
138 | } | |
139 | ||
140 | /** | |
141 | * subscr_report_overlap - issue event if there is subscription overlap | |
142 | * | |
143 | * Protected by nameseq.lock in name_table.c | |
144 | */ | |
145 | ||
146 | void subscr_report_overlap(struct subscription *sub, | |
147 | u32 found_lower, | |
148 | u32 found_upper, | |
149 | u32 event, | |
150 | u32 port_ref, | |
151 | u32 node, | |
152 | int must) | |
153 | { | |
154 | dbg("Rep overlap %u:%u,%u<->%u,%u\n", sub->seq.type, sub->seq.lower, | |
155 | sub->seq.upper, found_lower, found_upper); | |
156 | if (!subscr_overlap(sub, found_lower, found_upper)) | |
157 | return; | |
158 | if (!must && (sub->filter != TIPC_SUB_PORTS)) | |
159 | return; | |
160 | subscr_send_event(sub, found_lower, found_upper, event, port_ref, node); | |
161 | } | |
162 | ||
163 | /** | |
164 | * subscr_timeout - subscription timeout has occurred | |
165 | */ | |
166 | ||
167 | static void subscr_timeout(struct subscription *sub) | |
168 | { | |
169 | struct subscriber *subscriber; | |
170 | u32 subscriber_ref; | |
171 | ||
172 | /* Validate subscriber reference (in case subscriber is terminating) */ | |
173 | ||
174 | subscriber_ref = sub->owner->ref; | |
175 | subscriber = (struct subscriber *)ref_lock(subscriber_ref); | |
176 | if (subscriber == NULL) | |
177 | return; | |
178 | ||
179 | /* Unlink subscription from name table */ | |
180 | ||
181 | nametbl_unsubscribe(sub); | |
182 | ||
183 | /* Notify subscriber of timeout, then unlink subscription */ | |
184 | ||
185 | subscr_send_event(sub, | |
186 | sub->evt.s.seq.lower, | |
187 | sub->evt.s.seq.upper, | |
188 | TIPC_SUBSCR_TIMEOUT, | |
189 | 0, | |
190 | 0); | |
191 | list_del(&sub->subscription_list); | |
192 | ||
193 | /* Now destroy subscription */ | |
194 | ||
195 | ref_unlock(subscriber_ref); | |
196 | k_term_timer(&sub->timer); | |
197 | kfree(sub); | |
198 | atomic_dec(&topsrv.subscription_count); | |
199 | } | |
200 | ||
201 | /** | |
202 | * subscr_terminate - terminate communication with a subscriber | |
203 | * | |
204 | * Called with subscriber locked. Routine must temporarily release this lock | |
205 | * to enable subscription timeout routine(s) to finish without deadlocking; | |
206 | * the lock is then reclaimed to allow caller to release it upon return. | |
207 | * (This should work even in the unlikely event some other thread creates | |
208 | * a new object reference in the interim that uses this lock; this routine will | |
209 | * simply wait for it to be released, then claim it.) | |
210 | */ | |
211 | ||
212 | static void subscr_terminate(struct subscriber *subscriber) | |
213 | { | |
214 | struct subscription *sub; | |
215 | struct subscription *sub_temp; | |
216 | ||
217 | /* Invalidate subscriber reference */ | |
218 | ||
219 | ref_discard(subscriber->ref); | |
220 | spin_unlock_bh(subscriber->lock); | |
221 | ||
222 | /* Destroy any existing subscriptions for subscriber */ | |
223 | ||
224 | list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list, | |
225 | subscription_list) { | |
226 | if (sub->timeout != TIPC_WAIT_FOREVER) { | |
227 | k_cancel_timer(&sub->timer); | |
228 | k_term_timer(&sub->timer); | |
229 | } | |
230 | nametbl_unsubscribe(sub); | |
231 | list_del(&sub->subscription_list); | |
232 | dbg("Term: Removed sub %u,%u,%u from subscriber %x list\n", | |
233 | sub->seq.type, sub->seq.lower, sub->seq.upper, subscriber); | |
234 | kfree(sub); | |
235 | atomic_dec(&topsrv.subscription_count); | |
236 | } | |
237 | ||
238 | /* Sever connection to subscriber */ | |
239 | ||
240 | tipc_shutdown(subscriber->port_ref); | |
241 | tipc_deleteport(subscriber->port_ref); | |
242 | ||
243 | /* Remove subscriber from topology server's subscriber list */ | |
244 | ||
245 | spin_lock_bh(&topsrv.lock); | |
246 | list_del(&subscriber->subscriber_list); | |
247 | spin_unlock_bh(&topsrv.lock); | |
248 | ||
249 | /* Now destroy subscriber */ | |
250 | ||
251 | spin_lock_bh(subscriber->lock); | |
252 | kfree(subscriber); | |
253 | } | |
254 | ||
255 | /** | |
256 | * subscr_subscribe - create subscription for subscriber | |
257 | * | |
258 | * Called with subscriber locked | |
259 | */ | |
260 | ||
261 | static void subscr_subscribe(struct tipc_subscr *s, | |
262 | struct subscriber *subscriber) | |
263 | { | |
264 | struct subscription *sub; | |
265 | ||
266 | /* Refuse subscription if global limit exceeded */ | |
267 | ||
268 | if (atomic_read(&topsrv.subscription_count) >= tipc_max_subscriptions) { | |
269 | warn("Failed: max %u subscriptions\n", tipc_max_subscriptions); | |
270 | subscr_terminate(subscriber); | |
271 | return; | |
272 | } | |
273 | ||
274 | /* Allocate subscription object */ | |
275 | ||
276 | sub = kmalloc(sizeof(*sub), GFP_ATOMIC); | |
277 | if (sub == NULL) { | |
278 | warn("Memory squeeze; ignoring subscription\n"); | |
279 | subscr_terminate(subscriber); | |
280 | return; | |
281 | } | |
282 | ||
283 | /* Determine/update subscriber's endianness */ | |
284 | ||
285 | if ((s->filter == TIPC_SUB_PORTS) || (s->filter == TIPC_SUB_SERVICE)) | |
286 | subscriber->swap = 0; | |
287 | else | |
288 | subscriber->swap = 1; | |
289 | ||
290 | /* Initialize subscription object */ | |
291 | ||
292 | memset(sub, 0, sizeof(*sub)); | |
293 | sub->seq.type = htohl(s->seq.type, subscriber->swap); | |
294 | sub->seq.lower = htohl(s->seq.lower, subscriber->swap); | |
295 | sub->seq.upper = htohl(s->seq.upper, subscriber->swap); | |
296 | sub->timeout = htohl(s->timeout, subscriber->swap); | |
297 | sub->filter = htohl(s->filter, subscriber->swap); | |
298 | if ((((sub->filter != TIPC_SUB_PORTS) | |
299 | && (sub->filter != TIPC_SUB_SERVICE))) | |
300 | || (sub->seq.lower > sub->seq.upper)) { | |
301 | warn("Rejecting illegal subscription %u,%u,%u\n", | |
302 | sub->seq.type, sub->seq.lower, sub->seq.upper); | |
303 | kfree(sub); | |
304 | subscr_terminate(subscriber); | |
305 | return; | |
306 | } | |
307 | memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr)); | |
308 | INIT_LIST_HEAD(&sub->subscription_list); | |
309 | INIT_LIST_HEAD(&sub->nameseq_list); | |
310 | list_add(&sub->subscription_list, &subscriber->subscription_list); | |
311 | atomic_inc(&topsrv.subscription_count); | |
312 | if (sub->timeout != TIPC_WAIT_FOREVER) { | |
313 | k_init_timer(&sub->timer, | |
314 | (Handler)subscr_timeout, (unsigned long)sub); | |
315 | k_start_timer(&sub->timer, sub->timeout); | |
316 | } | |
317 | sub->owner = subscriber; | |
318 | nametbl_subscribe(sub); | |
319 | } | |
320 | ||
321 | /** | |
322 | * subscr_conn_shutdown_event - handle termination request from subscriber | |
323 | */ | |
324 | ||
325 | static void subscr_conn_shutdown_event(void *usr_handle, | |
326 | u32 portref, | |
327 | struct sk_buff **buf, | |
328 | unsigned char const *data, | |
329 | unsigned int size, | |
330 | int reason) | |
331 | { | |
332 | struct subscriber *subscriber = ref_lock((u32)usr_handle); | |
333 | spinlock_t *subscriber_lock; | |
334 | ||
335 | if (subscriber == NULL) | |
336 | return; | |
337 | ||
338 | subscriber_lock = subscriber->lock; | |
339 | subscr_terminate(subscriber); | |
340 | spin_unlock_bh(subscriber_lock); | |
341 | } | |
342 | ||
343 | /** | |
344 | * subscr_conn_msg_event - handle new subscription request from subscriber | |
345 | */ | |
346 | ||
347 | static void subscr_conn_msg_event(void *usr_handle, | |
348 | u32 port_ref, | |
349 | struct sk_buff **buf, | |
350 | const unchar *data, | |
351 | u32 size) | |
352 | { | |
353 | struct subscriber *subscriber = ref_lock((u32)usr_handle); | |
354 | spinlock_t *subscriber_lock; | |
355 | ||
356 | if (subscriber == NULL) | |
357 | return; | |
358 | ||
359 | subscriber_lock = subscriber->lock; | |
360 | if (size != sizeof(struct tipc_subscr)) | |
361 | subscr_terminate(subscriber); | |
362 | else | |
363 | subscr_subscribe((struct tipc_subscr *)data, subscriber); | |
364 | ||
365 | spin_unlock_bh(subscriber_lock); | |
366 | } | |
367 | ||
368 | /** | |
369 | * subscr_named_msg_event - handle request to establish a new subscriber | |
370 | */ | |
371 | ||
372 | static void subscr_named_msg_event(void *usr_handle, | |
373 | u32 port_ref, | |
374 | struct sk_buff **buf, | |
375 | const unchar *data, | |
376 | u32 size, | |
377 | u32 importance, | |
378 | struct tipc_portid const *orig, | |
379 | struct tipc_name_seq const *dest) | |
380 | { | |
381 | struct subscriber *subscriber; | |
382 | struct iovec msg_sect = {0, 0}; | |
383 | spinlock_t *subscriber_lock; | |
384 | ||
385 | dbg("subscr_named_msg_event: orig = %x own = %x,\n", | |
386 | orig->node, tipc_own_addr); | |
387 | if (size && (size != sizeof(struct tipc_subscr))) { | |
388 | warn("Received tipc_subscr of invalid size\n"); | |
389 | return; | |
390 | } | |
391 | ||
392 | /* Create subscriber object */ | |
393 | ||
394 | subscriber = kmalloc(sizeof(struct subscriber), GFP_ATOMIC); | |
395 | if (subscriber == NULL) { | |
396 | warn("Memory squeeze; ignoring subscriber setup\n"); | |
397 | return; | |
398 | } | |
399 | memset(subscriber, 0, sizeof(struct subscriber)); | |
400 | INIT_LIST_HEAD(&subscriber->subscription_list); | |
401 | INIT_LIST_HEAD(&subscriber->subscriber_list); | |
402 | subscriber->ref = ref_acquire(subscriber, &subscriber->lock); | |
403 | if (subscriber->ref == 0) { | |
404 | warn("Failed to acquire subscriber reference\n"); | |
405 | kfree(subscriber); | |
406 | return; | |
407 | } | |
408 | ||
409 | /* Establish a connection to subscriber */ | |
410 | ||
411 | tipc_createport(topsrv.user_ref, | |
412 | (void *)subscriber->ref, | |
413 | importance, | |
414 | 0, | |
415 | 0, | |
416 | subscr_conn_shutdown_event, | |
417 | 0, | |
418 | 0, | |
419 | subscr_conn_msg_event, | |
420 | 0, | |
421 | &subscriber->port_ref); | |
422 | if (subscriber->port_ref == 0) { | |
423 | warn("Memory squeeze; failed to create subscription port\n"); | |
424 | ref_discard(subscriber->ref); | |
425 | kfree(subscriber); | |
426 | return; | |
427 | } | |
428 | tipc_connect2port(subscriber->port_ref, orig); | |
429 | ||
430 | ||
431 | /* Add subscriber to topology server's subscriber list */ | |
432 | ||
433 | ref_lock(subscriber->ref); | |
434 | spin_lock_bh(&topsrv.lock); | |
435 | list_add(&subscriber->subscriber_list, &topsrv.subscriber_list); | |
436 | spin_unlock_bh(&topsrv.lock); | |
437 | ||
438 | /* | |
439 | * Subscribe now if message contains a subscription, | |
440 | * otherwise send an empty response to complete connection handshaking | |
441 | */ | |
442 | ||
443 | subscriber_lock = subscriber->lock; | |
444 | if (size) | |
445 | subscr_subscribe((struct tipc_subscr *)data, subscriber); | |
446 | else | |
447 | tipc_send(subscriber->port_ref, 1, &msg_sect); | |
448 | ||
449 | spin_unlock_bh(subscriber_lock); | |
450 | } | |
451 | ||
452 | int subscr_start(void) | |
453 | { | |
454 | struct tipc_name_seq seq = {TIPC_TOP_SRV, TIPC_TOP_SRV, TIPC_TOP_SRV}; | |
455 | int res = -1; | |
456 | ||
457 | memset(&topsrv, 0, sizeof (topsrv)); | |
458 | topsrv.lock = SPIN_LOCK_UNLOCKED; | |
459 | INIT_LIST_HEAD(&topsrv.subscriber_list); | |
460 | ||
461 | spin_lock_bh(&topsrv.lock); | |
462 | res = tipc_attach(&topsrv.user_ref, 0, 0); | |
463 | if (res) { | |
464 | spin_unlock_bh(&topsrv.lock); | |
465 | return res; | |
466 | } | |
467 | ||
468 | res = tipc_createport(topsrv.user_ref, | |
469 | 0, | |
470 | TIPC_CRITICAL_IMPORTANCE, | |
471 | 0, | |
472 | 0, | |
473 | 0, | |
474 | 0, | |
475 | subscr_named_msg_event, | |
476 | 0, | |
477 | 0, | |
478 | &topsrv.setup_port); | |
479 | if (res) | |
480 | goto failed; | |
481 | ||
482 | res = nametbl_publish_rsv(topsrv.setup_port, TIPC_NODE_SCOPE, &seq); | |
483 | if (res) | |
484 | goto failed; | |
485 | ||
486 | spin_unlock_bh(&topsrv.lock); | |
487 | return 0; | |
488 | ||
489 | failed: | |
d0a14a9d | 490 | err("Failed to create subscription service\n"); |
b97bf3fd PL |
491 | tipc_detach(topsrv.user_ref); |
492 | topsrv.user_ref = 0; | |
493 | spin_unlock_bh(&topsrv.lock); | |
494 | return res; | |
495 | } | |
496 | ||
497 | void subscr_stop(void) | |
498 | { | |
499 | struct subscriber *subscriber; | |
500 | struct subscriber *subscriber_temp; | |
501 | spinlock_t *subscriber_lock; | |
502 | ||
503 | if (topsrv.user_ref) { | |
504 | tipc_deleteport(topsrv.setup_port); | |
505 | list_for_each_entry_safe(subscriber, subscriber_temp, | |
506 | &topsrv.subscriber_list, | |
507 | subscriber_list) { | |
508 | ref_lock(subscriber->ref); | |
509 | subscriber_lock = subscriber->lock; | |
510 | subscr_terminate(subscriber); | |
511 | spin_unlock_bh(subscriber_lock); | |
512 | } | |
513 | tipc_detach(topsrv.user_ref); | |
514 | topsrv.user_ref = 0; | |
515 | } | |
516 | } | |
517 | ||
518 | ||
519 | int tipc_ispublished(struct tipc_name const *name) | |
520 | { | |
521 | u32 domain = 0; | |
522 | ||
523 | return(nametbl_translate(name->type, name->instance,&domain) != 0); | |
524 | } | |
525 |